id stringlengths 24 24 | title stringclasses 442
values | context stringlengths 151 3.71k | question stringlengths 12 270 | answers dict |
|---|---|---|---|---|
572ec42ecb0c0d14000f151e | Vacuum | Ion gauges are used in ultrahigh vacuum. They come in two types: hot cathode and cold cathode. In the hot cathode version an electrically heated filament produces an electron beam. The electrons travel through the gauge and ionize gas molecules around them. The resulting ions are collected at a negative electrode. The ... | Why does a mass spectrometer need to be used with gauge to be accurate at high vacuum gas measurement? | {
"answer_start": [
925
],
"text": [
"composition of gases at high vacuums will usually be unpredictable"
]
} |
572ec42ecb0c0d14000f151a | Vacuum | Ion gauges are used in ultrahigh vacuum. They come in two types: hot cathode and cold cathode. In the hot cathode version an electrically heated filament produces an electron beam. The electrons travel through the gauge and ionize gas molecules around them. The resulting ions are collected at a negative electrode. The ... | What are the two types of Ion gauges? | {
"answer_start": [
65
],
"text": [
"hot cathode and cold cathode."
]
} |
572ec82acb0c0d14000f1558 | Vacuum | Cold or oxygen-rich atmospheres can sustain life at pressures much lower than atmospheric, as long as the density of oxygen is similar to that of standard sea-level atmosphere. The colder air temperatures found at altitudes of up to 3 km generally compensate for the lower pressures there. Above this altitude, oxygen en... | density of oxygen like that of sea-level atmosphere is needed to do what? | {
"answer_start": [
36
],
"text": [
"sustain life at pressures much lower than atmospheric,"
]
} |
572ec82acb0c0d14000f1559 | Vacuum | Cold or oxygen-rich atmospheres can sustain life at pressures much lower than atmospheric, as long as the density of oxygen is similar to that of standard sea-level atmosphere. The colder air temperatures found at altitudes of up to 3 km generally compensate for the lower pressures there. Above this altitude, oxygen en... | What is the lowest altitude where acclimatization or a suit is not needed to prevent sickness in humans? | {
"answer_start": [
224
],
"text": [
"of up to 3 km"
]
} |
572ec989dfa6aa1500f8d3bd | Vacuum | Humans and animals exposed to vacuum will lose consciousness after a few seconds and die of hypoxia within minutes, but the symptoms are not nearly as graphic as commonly depicted in media and popular culture. The reduction in pressure lowers the temperature at which blood and other body fluids boil, but the elastic pr... | When will a person or animal lose consciousness when exposed to a vacuum? | {
"answer_start": [
61
],
"text": [
"after a few seconds"
]
} |
572ec989dfa6aa1500f8d3be | Vacuum | Humans and animals exposed to vacuum will lose consciousness after a few seconds and die of hypoxia within minutes, but the symptoms are not nearly as graphic as commonly depicted in media and popular culture. The reduction in pressure lowers the temperature at which blood and other body fluids boil, but the elastic pr... | A shuttle astronauts prevents ebullism at 2 kPa with what item? | {
"answer_start": [
836
],
"text": [
"the Crew Altitude Protection Suit (CAPS)"
]
} |
572ec989dfa6aa1500f8d3bf | Vacuum | Humans and animals exposed to vacuum will lose consciousness after a few seconds and die of hypoxia within minutes, but the symptoms are not nearly as graphic as commonly depicted in media and popular culture. The reduction in pressure lowers the temperature at which blood and other body fluids boil, but the elastic pr... | What is the forming of gas bubbles in body fluids at a lowered pressure called? | {
"answer_start": [
720
],
"text": [
"ebullism"
]
} |
572ec989dfa6aa1500f8d3c0 | Vacuum | Humans and animals exposed to vacuum will lose consciousness after a few seconds and die of hypoxia within minutes, but the symptoms are not nearly as graphic as commonly depicted in media and popular culture. The reduction in pressure lowers the temperature at which blood and other body fluids boil, but the elastic pr... | What prevents body rupture at low altitude when human body is bloated by gas bubbles? | {
"answer_start": [
649
],
"text": [
"tissues are elastic and porous"
]
} |
572eca8ccb0c0d14000f1576 | Vacuum | In ultra high vacuum systems, some very "odd" leakage paths and outgassing sources must be considered. The water absorption of aluminium and palladium becomes an unacceptable source of outgassing, and even the adsorptivity of hard metals such as stainless steel or titanium must be considered. Some oils and greases will... | What can boil away in extreme vaccum exposure? | {
"answer_start": [
294
],
"text": [
"Some oils and greases"
]
} |
572eca8ccb0c0d14000f1577 | Vacuum | In ultra high vacuum systems, some very "odd" leakage paths and outgassing sources must be considered. The water absorption of aluminium and palladium becomes an unacceptable source of outgassing, and even the adsorptivity of hard metals such as stainless steel or titanium must be considered. Some oils and greases will... | How should the grain direct of metallic flanges run to flange faces? | {
"answer_start": [
482
],
"text": [
"parallel"
]
} |
572eca8ccb0c0d14000f1578 | Vacuum | In ultra high vacuum systems, some very "odd" leakage paths and outgassing sources must be considered. The water absorption of aluminium and palladium becomes an unacceptable source of outgassing, and even the adsorptivity of hard metals such as stainless steel or titanium must be considered. Some oils and greases will... | What are 2 metals that can be absorbed in an ultra high vacuum system? | {
"answer_start": [
246
],
"text": [
"stainless steel or titanium"
]
} |
572eca8ccb0c0d14000f1579 | Vacuum | In ultra high vacuum systems, some very "odd" leakage paths and outgassing sources must be considered. The water absorption of aluminium and palladium becomes an unacceptable source of outgassing, and even the adsorptivity of hard metals such as stainless steel or titanium must be considered. Some oils and greases will... | What becomes a concern in an ultra high vacuum system regarding aluminum or palladium? | {
"answer_start": [
107
],
"text": [
"water absorption"
]
} |
572ecbdddfa6aa1500f8d3cb | Vacuum | In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of qua... | The state with the lowest possible energy in quantum mechanics defines what ? | {
"answer_start": [
51
],
"text": [
"vacuum"
]
} |
572ecbdddfa6aa1500f8d3cc | Vacuum | In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of qua... | A vacuum state with no matter particles or photons is called what? | {
"answer_start": [
364
],
"text": [
"QED"
]
} |
572ecbdddfa6aa1500f8d3cd | Vacuum | In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of qua... | why is a QED vacuum impossible to achieve ? | {
"answer_start": [
605
],
"text": [
"impossible to eliminate all the blackbody photons"
]
} |
572ecbdddfa6aa1500f8d3ce | Vacuum | In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of qua... | What is a QCD? | {
"answer_start": [
307
],
"text": [
"vacuum of quantum chromodynamics,"
]
} |
572ecd51c246551400ce46ae | Vacuum | QED vacuum has interesting and complex properties. In QED vacuum, the electric and magnetic fields have zero average values, but their variances are not zero. As a result, QED vacuum contains vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum flu... | When are electric and magnetic fields with zero average values, but their variances are not at zero? | {
"answer_start": [
51
],
"text": [
"In QED vacuum"
]
} |
572ecd51c246551400ce46af | Vacuum | QED vacuum has interesting and complex properties. In QED vacuum, the electric and magnetic fields have zero average values, but their variances are not zero. As a result, QED vacuum contains vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum flu... | What is a verified effect of vacuum fluctuation? | {
"answer_start": [
460
],
"text": [
"spontaneous emission"
]
} |
572ecd51c246551400ce46b0 | Vacuum | QED vacuum has interesting and complex properties. In QED vacuum, the electric and magnetic fields have zero average values, but their variances are not zero. As a result, QED vacuum contains vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum flu... | what is vacuum fluctuation? | {
"answer_start": [
213
],
"text": [
"virtual particles that hop into and out of existence"
]
} |
572ecd51c246551400ce46b1 | Vacuum | QED vacuum has interesting and complex properties. In QED vacuum, the electric and magnetic fields have zero average values, but their variances are not zero. As a result, QED vacuum contains vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum flu... | Finite energy in a QED is called what? | {
"answer_start": [
295
],
"text": [
"vacuum energy"
]
} |
572ecd51c246551400ce46b2 | Vacuum | QED vacuum has interesting and complex properties. In QED vacuum, the electric and magnetic fields have zero average values, but their variances are not zero. As a result, QED vacuum contains vacuum fluctuations (virtual particles that hop into and out of existence), and a finite energy called vacuum energy. Vacuum flu... | What modifies can Coulomb's Law in a vacuum? | {
"answer_start": [
545
],
"text": [
"vacuum near an electric charge"
]
} |
572ece9bcb0c0d14000f15ac | Vacuum | Stars, planets, and moons keep their atmospheres by gravitational attraction, and as such, atmospheres have no clearly delineated boundary: the density of atmospheric gas simply decreases with distance from the object. The Earth's atmospheric pressure drops to about 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62... | `Why does thermosphere past the Karman line vary so greatly? | {
"answer_start": [
757
],
"text": [
"due to space weather"
]
} |
572ece9bcb0c0d14000f15ad | Vacuum | Stars, planets, and moons keep their atmospheres by gravitational attraction, and as such, atmospheres have no clearly delineated boundary: the density of atmospheric gas simply decreases with distance from the object. The Earth's atmospheric pressure drops to about 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62... | What is commonly known as the boundary of outer space? | {
"answer_start": [
338
],
"text": [
"the Kármán line"
]
} |
572ece9bcb0c0d14000f15ae | Vacuum | Stars, planets, and moons keep their atmospheres by gravitational attraction, and as such, atmospheres have no clearly delineated boundary: the density of atmospheric gas simply decreases with distance from the object. The Earth's atmospheric pressure drops to about 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62... | What do Astrophysicists use to describe outer space beyond the karman line? | {
"answer_start": [
809
],
"text": [
"number density"
]
} |
572ece9bcb0c0d14000f15af | Vacuum | Stars, planets, and moons keep their atmospheres by gravitational attraction, and as such, atmospheres have no clearly delineated boundary: the density of atmospheric gas simply decreases with distance from the object. The Earth's atmospheric pressure drops to about 6998320000000000000♠3.2×10−2 Pa at 100 kilometres (62... | What is more significant than isotropic gas pressure past the Karman line? | {
"answer_start": [
506
],
"text": [
"radiation pressure from the Sun and the dynamic pressure of the solar winds"
]
} |
572ed1f3dfa6aa1500f8d411 | Vacuum | Vacuum is useful in a variety of processes and devices. Its first widespread use was in the incandescent light bulb to protect the filament from chemical degradation. The chemical inertness produced by a vacuum is also useful for electron beam welding, cold welding, vacuum packing and vacuum frying. Ultra-high vacuum i... | What was the object to use first in widespread manner process of vacuum? | {
"answer_start": [
92
],
"text": [
"incandescent light bulb"
]
} |
572ed1f3dfa6aa1500f8d412 | Vacuum | Vacuum is useful in a variety of processes and devices. Its first widespread use was in the incandescent light bulb to protect the filament from chemical degradation. The chemical inertness produced by a vacuum is also useful for electron beam welding, cold welding, vacuum packing and vacuum frying. Ultra-high vacuum i... | What is produced by a vacuum and used in electron beam welding and vacuum frying? | {
"answer_start": [
171
],
"text": [
"chemical inertness"
]
} |
572ed1f3dfa6aa1500f8d413 | Vacuum | Vacuum is useful in a variety of processes and devices. Its first widespread use was in the incandescent light bulb to protect the filament from chemical degradation. The chemical inertness produced by a vacuum is also useful for electron beam welding, cold welding, vacuum packing and vacuum frying. Ultra-high vacuum i... | Hight to ultra-high vacuums removes what obstruction? | {
"answer_start": [
537
],
"text": [
"obstruction of air,"
]
} |
572ed1f3dfa6aa1500f8d414 | Vacuum | Vacuum is useful in a variety of processes and devices. Its first widespread use was in the incandescent light bulb to protect the filament from chemical degradation. The chemical inertness produced by a vacuum is also useful for electron beam welding, cold welding, vacuum packing and vacuum frying. Ultra-high vacuum i... | How does freeze drying, distillation and metallurgy benefit from a deep vacuum? | {
"answer_start": [
917
],
"text": [
"Deep vacuum lowers the boiling point of liquids and promotes low temperature outgassing"
]
} |
572ed1f3dfa6aa1500f8d415 | Vacuum | Vacuum is useful in a variety of processes and devices. Its first widespread use was in the incandescent light bulb to protect the filament from chemical degradation. The chemical inertness produced by a vacuum is also useful for electron beam welding, cold welding, vacuum packing and vacuum frying. Ultra-high vacuum i... | What are two things made possible by the electrical properties of vacuum? | {
"answer_start": [
1147
],
"text": [
"electron microscopes and vacuum tubes"
]
} |
572ed2ee03f9891900756a5d | Vacuum | Manifold vacuum can be used to drive accessories on automobiles. The best-known application is the vacuum servo, used to provide power assistance for the brakes. Obsolete applications include vacuum-driven windscreen wipers and Autovac fuel pumps. Some aircraft instruments (Attitude Indicator (AI) and the Heading Indic... | What provides power assistance for auto brakes? | {
"answer_start": [
99
],
"text": [
"vacuum servo"
]
} |
572ed2ee03f9891900756a5e | Vacuum | Manifold vacuum can be used to drive accessories on automobiles. The best-known application is the vacuum servo, used to provide power assistance for the brakes. Obsolete applications include vacuum-driven windscreen wipers and Autovac fuel pumps. Some aircraft instruments (Attitude Indicator (AI) and the Heading Indic... | What are two available sources of vacuum on a moving airplane? | {
"answer_start": [
576
],
"text": [
"engine and an external venturi"
]
} |
572ed2ee03f9891900756a5f | Vacuum | Manifold vacuum can be used to drive accessories on automobiles. The best-known application is the vacuum servo, used to provide power assistance for the brakes. Obsolete applications include vacuum-driven windscreen wipers and Autovac fuel pumps. Some aircraft instruments (Attitude Indicator (AI) and the Heading Indic... | Why are the Attitude indicator and heading indicator vacuum-powered? | {
"answer_start": [
364
],
"text": [
"protection against loss of all (electrically powered) instruments,"
]
} |
572ed2ee03f9891900756a60 | Vacuum | Manifold vacuum can be used to drive accessories on automobiles. The best-known application is the vacuum servo, used to provide power assistance for the brakes. Obsolete applications include vacuum-driven windscreen wipers and Autovac fuel pumps. Some aircraft instruments (Attitude Indicator (AI) and the Heading Indic... | What does a manifold vacuum do on a car? | {
"answer_start": [
31
],
"text": [
"drive accessories"
]
} |
572ed2ee03f9891900756a61 | Vacuum | Manifold vacuum can be used to drive accessories on automobiles. The best-known application is the vacuum servo, used to provide power assistance for the brakes. Obsolete applications include vacuum-driven windscreen wipers and Autovac fuel pumps. Some aircraft instruments (Attitude Indicator (AI) and the Heading Indic... | What no longer used accessories were powered by vacuum? | {
"answer_start": [
192
],
"text": [
"vacuum-driven windscreen wipers and Autovac fuel pumps"
]
} |
572ed3f1cb0c0d14000f15f0 | Vacuum | Evaporation and sublimation into a vacuum is called outgassing. All materials, solid or liquid, have a small vapour pressure, and their outgassing becomes important when the vacuum pressure falls below this vapour pressure. In man-made systems, outgassing has the same effect as a leak and can limit the achievable vacuu... | what is evaporation and sublimation in a vacuum? | {
"answer_start": [
52
],
"text": [
"outgassing"
]
} |
572ed3f1cb0c0d14000f15f2 | Vacuum | Evaporation and sublimation into a vacuum is called outgassing. All materials, solid or liquid, have a small vapour pressure, and their outgassing becomes important when the vacuum pressure falls below this vapour pressure. In man-made systems, outgassing has the same effect as a leak and can limit the achievable vacuu... | Why can outgassing products ruin a space mission? | {
"answer_start": [
416
],
"text": [
"obscure optical instruments"
]
} |
572ed3f1cb0c0d14000f15f1 | Vacuum | Evaporation and sublimation into a vacuum is called outgassing. All materials, solid or liquid, have a small vapour pressure, and their outgassing becomes important when the vacuum pressure falls below this vapour pressure. In man-made systems, outgassing has the same effect as a leak and can limit the achievable vacuu... | When does outgassing become important in all solid or liquid materials? | {
"answer_start": [
174
],
"text": [
"vacuum pressure falls below this vapour pressure"
]
} |
572ed67403f9891900756a71 | Vacuum | To continue evacuating a chamber indefinitely without requiring infinite growth, a compartment of the vacuum can be repeatedly closed off, exhausted, and expanded again. This is the principle behind positive displacement pumps, like the manual water pump for example. Inside the pump, a mechanism expands a small sealed ... | Repeatedly closing off a compartment of a vacuum allows what? | {
"answer_start": [
3
],
"text": [
"continue evacuating a chamber indefinitely without requiring infinite growth"
]
} |
572ed67403f9891900756a72 | Vacuum | To continue evacuating a chamber indefinitely without requiring infinite growth, a compartment of the vacuum can be repeatedly closed off, exhausted, and expanded again. This is the principle behind positive displacement pumps, like the manual water pump for example. Inside the pump, a mechanism expands a small sealed ... | How is a vacuum created inside of a manual water pump? | {
"answer_start": [
285
],
"text": [
"a mechanism expands a small sealed cavity"
]
} |
572ed67403f9891900756a73 | Vacuum | To continue evacuating a chamber indefinitely without requiring infinite growth, a compartment of the vacuum can be repeatedly closed off, exhausted, and expanded again. This is the principle behind positive displacement pumps, like the manual water pump for example. Inside the pump, a mechanism expands a small sealed ... | Why is fluid in a manual pump pushed into the pumps cavity when a small sealed cavity is expanded? | {
"answer_start": [
347
],
"text": [
"Because of the pressure differential"
]
} |
572ed67403f9891900756a74 | Vacuum | To continue evacuating a chamber indefinitely without requiring infinite growth, a compartment of the vacuum can be repeatedly closed off, exhausted, and expanded again. This is the principle behind positive displacement pumps, like the manual water pump for example. Inside the pump, a mechanism expands a small sealed ... | What are pumps based off principle of sealed compartment pulling,pushing and expanding called? | {
"answer_start": [
208
],
"text": [
"displacement pumps"
]
} |
572ed7a0c246551400ce4716 | Vacuum | The above explanation is merely a simple introduction to vacuum pumping, and is not representative of the entire range of pumps in use. Many variations of the positive displacement pump have been developed, and many other pump designs rely on fundamentally different principles. Momentum transfer pumps, which bear some ... | What pump can capture gases in a solid or absorbed state? | {
"answer_start": [
450
],
"text": [
"Entrapment pumps"
]
} |
572ed7a0c246551400ce4717 | Vacuum | The above explanation is merely a simple introduction to vacuum pumping, and is not representative of the entire range of pumps in use. Many variations of the positive displacement pump have been developed, and many other pump designs rely on fundamentally different principles. Momentum transfer pumps, which bear some ... | Entrapment pumps often work without seals, moving parts and what else? | {
"answer_start": [
556
],
"text": [
"no vibration."
]
} |
572ed7a0c246551400ce4718 | Vacuum | The above explanation is merely a simple introduction to vacuum pumping, and is not representative of the entire range of pumps in use. Many variations of the positive displacement pump have been developed, and many other pump designs rely on fundamentally different principles. Momentum transfer pumps, which bear some ... | What pump has a higher quality vacuum than a positive displacement pump? | {
"answer_start": [
279
],
"text": [
"Momentum transfer pumps"
]
} |
572ed90fdfa6aa1500f8d44b | Vacuum | The lowest pressure that can be attained in a system is also dependent on many things other than the nature of the pumps. Multiple pumps may be connected in series, called stages, to achieve higher vacuums. The choice of seals, chamber geometry, materials, and pump-down procedures will all have an impact. Collectively,... | When multiple pumps are connected in series to produce higher vacuum it is called what? | {
"answer_start": [
172
],
"text": [
"stages"
]
} |
572ed90fdfa6aa1500f8d44c | Vacuum | The lowest pressure that can be attained in a system is also dependent on many things other than the nature of the pumps. Multiple pumps may be connected in series, called stages, to achieve higher vacuums. The choice of seals, chamber geometry, materials, and pump-down procedures will all have an impact. Collectively,... | The choice of seals, or chamber geometry ,for example impact a pump. Together these are options are called what? | {
"answer_start": [
338
],
"text": [
"vacuum technique"
]
} |
572ed90fdfa6aa1500f8d44d | Vacuum | The lowest pressure that can be attained in a system is also dependent on many things other than the nature of the pumps. Multiple pumps may be connected in series, called stages, to achieve higher vacuums. The choice of seals, chamber geometry, materials, and pump-down procedures will all have an impact. Collectively,... | What are two other relevant characteristics of a pumping system along with final pressure? | {
"answer_start": [
457
],
"text": [
"oil contamination, vibration"
]
} |
572e97d3dfa6aa1500f8d1b1 | Han_dynasty | The Han dynasty (Chinese: 漢朝; pinyin: Hàn cháo) was the second imperial dynasty of China, preceded by the Qin dynasty (221–207 BC) and succeeded by the Three Kingdoms period (220–280 AD). Spanning over four centuries, the Han period is considered a golden age in Chinese history. To this day, China's majority ethnic gro... | What period followed the Han dynasty? | {
"answer_start": [
152
],
"text": [
"Three Kingdoms"
]
} |
572e97d3dfa6aa1500f8d1b2 | Han_dynasty | The Han dynasty (Chinese: 漢朝; pinyin: Hàn cháo) was the second imperial dynasty of China, preceded by the Qin dynasty (221–207 BC) and succeeded by the Three Kingdoms period (220–280 AD). Spanning over four centuries, the Han period is considered a golden age in Chinese history. To this day, China's majority ethnic gro... | What dynasty came before the Han dynasty? | {
"answer_start": [
106
],
"text": [
"Qin"
]
} |
572e97d3dfa6aa1500f8d1b3 | Han_dynasty | The Han dynasty (Chinese: 漢朝; pinyin: Hàn cháo) was the second imperial dynasty of China, preceded by the Qin dynasty (221–207 BC) and succeeded by the Three Kingdoms period (220–280 AD). Spanning over four centuries, the Han period is considered a golden age in Chinese history. To this day, China's majority ethnic gro... | Who founded the Han dynasty? | {
"answer_start": [
454
],
"text": [
"Liu Bang"
]
} |
572e97d3dfa6aa1500f8d1b4 | Han_dynasty | The Han dynasty (Chinese: 漢朝; pinyin: Hàn cháo) was the second imperial dynasty of China, preceded by the Qin dynasty (221–207 BC) and succeeded by the Three Kingdoms period (220–280 AD). Spanning over four centuries, the Han period is considered a golden age in Chinese history. To this day, China's majority ethnic gro... | When did the Former Han period begin? | {
"answer_start": [
685
],
"text": [
"206 BC"
]
} |
572e97d3dfa6aa1500f8d1b5 | Han_dynasty | The Han dynasty (Chinese: 漢朝; pinyin: Hàn cháo) was the second imperial dynasty of China, preceded by the Qin dynasty (221–207 BC) and succeeded by the Three Kingdoms period (220–280 AD). Spanning over four centuries, the Han period is considered a golden age in Chinese history. To this day, China's majority ethnic gro... | When did the Later Han period end? | {
"answer_start": [
737
],
"text": [
"220 AD"
]
} |
572ea634cb0c0d14000f13e6 | Han_dynasty | The emperor was at the pinnacle of Han society. He presided over the Han government but shared power with both the nobility and appointed ministers who came largely from the scholarly gentry class. The Han Empire was divided into areas directly controlled by the central government using an innovation inherited from the... | When did the Qing dynasty fall? | {
"answer_start": [
766
],
"text": [
"AD 1911"
]
} |
572ea634cb0c0d14000f13e7 | Han_dynasty | The emperor was at the pinnacle of Han society. He presided over the Han government but shared power with both the nobility and appointed ministers who came largely from the scholarly gentry class. The Han Empire was divided into areas directly controlled by the central government using an innovation inherited from the... | What innovation was acquired from the Qin? | {
"answer_start": [
334
],
"text": [
"commanderies"
]
} |
572ea634cb0c0d14000f13e8 | Han_dynasty | The emperor was at the pinnacle of Han society. He presided over the Han government but shared power with both the nobility and appointed ministers who came largely from the scholarly gentry class. The Han Empire was divided into areas directly controlled by the central government using an innovation inherited from the... | What philosphy in education was sanctioned by the Chinese court? | {
"answer_start": [
590
],
"text": [
"Confucianism"
]
} |
572ea634cb0c0d14000f13e9 | Han_dynasty | The emperor was at the pinnacle of Han society. He presided over the Han government but shared power with both the nobility and appointed ministers who came largely from the scholarly gentry class. The Han Empire was divided into areas directly controlled by the central government using an innovation inherited from the... | What was an attributing factor that caused kingdoms to lose their Independence during the Han dynasty? | {
"answer_start": [
479
],
"text": [
"the Rebellion of the Seven States"
]
} |
572ea634cb0c0d14000f13ea | Han_dynasty | The emperor was at the pinnacle of Han society. He presided over the Han government but shared power with both the nobility and appointed ministers who came largely from the scholarly gentry class. The Han Empire was divided into areas directly controlled by the central government using an innovation inherited from the... | What class did a majority of appointed ministers come from during the Han dynasty? | {
"answer_start": [
174
],
"text": [
"scholarly gentry"
]
} |
572eae75c246551400ce44fa | Han_dynasty | The Han dynasty was an age of economic prosperity and saw a significant growth of the money economy first established during the Zhou dynasty (c. 1050–256 BC). The coinage issued by the central government mint in 119 BC remained the standard coinage of China until the Tang dynasty (618–907 AD). The period saw a number ... | In what year did the central government issue coins? | {
"answer_start": [
213
],
"text": [
"119 BC"
]
} |
572eae75c246551400ce44fb | Han_dynasty | The Han dynasty was an age of economic prosperity and saw a significant growth of the money economy first established during the Zhou dynasty (c. 1050–256 BC). The coinage issued by the central government mint in 119 BC remained the standard coinage of China until the Tang dynasty (618–907 AD). The period saw a number ... | What industry did the government use to help pay for its military campaigns? | {
"answer_start": [
501
],
"text": [
"iron"
]
} |
572eae75c246551400ce44fc | Han_dynasty | The Han dynasty was an age of economic prosperity and saw a significant growth of the money economy first established during the Zhou dynasty (c. 1050–256 BC). The coinage issued by the central government mint in 119 BC remained the standard coinage of China until the Tang dynasty (618–907 AD). The period saw a number ... | In what period did several government monopolies become repealed? | {
"answer_start": [
585
],
"text": [
"Eastern Han"
]
} |
572eae75c246551400ce44fd | Han_dynasty | The Han dynasty was an age of economic prosperity and saw a significant growth of the money economy first established during the Zhou dynasty (c. 1050–256 BC). The coinage issued by the central government mint in 119 BC remained the standard coinage of China until the Tang dynasty (618–907 AD). The period saw a number ... | A money based economy was first entrenched in what dynasty? | {
"answer_start": [
129
],
"text": [
"Zhou"
]
} |
572eae75c246551400ce44fe | Han_dynasty | The Han dynasty was an age of economic prosperity and saw a significant growth of the money economy first established during the Zhou dynasty (c. 1050–256 BC). The coinage issued by the central government mint in 119 BC remained the standard coinage of China until the Tang dynasty (618–907 AD). The period saw a number ... | A seismometer during the Han dynasty used what type of pendulum? | {
"answer_start": [
881
],
"text": [
"inverted"
]
} |
572eb08203f989190075694b | Han_dynasty | The Xiongnu, a nomadic steppe confederation, defeated the Han in 200 BC and forced the Han to submit as a de facto inferior partner, but continued their raids on the Han borders. Emperor Wu of Han (r. 141–87 BC) launched several military campaigns against them. The ultimate Han victory in these wars eventually forced t... | Which confederation defeated the Han in 200 BC? | {
"answer_start": [
0
],
"text": [
"The Xiongnu"
]
} |
572eb08203f989190075694c | Han_dynasty | The Xiongnu, a nomadic steppe confederation, defeated the Han in 200 BC and forced the Han to submit as a de facto inferior partner, but continued their raids on the Han borders. Emperor Wu of Han (r. 141–87 BC) launched several military campaigns against them. The ultimate Han victory in these wars eventually forced t... | What type of campaign helped establish the Silk Road? | {
"answer_start": [
229
],
"text": [
"military"
]
} |
572eb08203f989190075694d | Han_dynasty | The Xiongnu, a nomadic steppe confederation, defeated the Han in 200 BC and forced the Han to submit as a de facto inferior partner, but continued their raids on the Han borders. Emperor Wu of Han (r. 141–87 BC) launched several military campaigns against them. The ultimate Han victory in these wars eventually forced t... | In what year was Nanyue annexed? | {
"answer_start": [
813
],
"text": [
"111 BC"
]
} |
572eb08203f989190075694e | Han_dynasty | The Xiongnu, a nomadic steppe confederation, defeated the Han in 200 BC and forced the Han to submit as a de facto inferior partner, but continued their raids on the Han borders. Emperor Wu of Han (r. 141–87 BC) launched several military campaigns against them. The ultimate Han victory in these wars eventually forced t... | Which confederation conquered the territories north of the Han's border? | {
"answer_start": [
700
],
"text": [
"Xianbei"
]
} |
572eb08203f989190075694f | Han_dynasty | The Xiongnu, a nomadic steppe confederation, defeated the Han in 200 BC and forced the Han to submit as a de facto inferior partner, but continued their raids on the Han borders. Emperor Wu of Han (r. 141–87 BC) launched several military campaigns against them. The ultimate Han victory in these wars eventually forced t... | In what year did Emperor Wu of Han's reign end? | {
"answer_start": [
205
],
"text": [
"87 BC"
]
} |
572eb82403f9891900756993 | Han_dynasty | After 92 AD, the palace eunuchs increasingly involved themselves in court politics, engaging in violent power struggles between the various consort clans of the empresses and empress dowagers, causing the Han's ultimate downfall. Imperial authority was also seriously challenged by large Daoist religious societies which... | Which religious societies instigated the Yellow Turban Rebellion? | {
"answer_start": [
288
],
"text": [
"Daoist"
]
} |
572eb82403f9891900756994 | Han_dynasty | After 92 AD, the palace eunuchs increasingly involved themselves in court politics, engaging in violent power struggles between the various consort clans of the empresses and empress dowagers, causing the Han's ultimate downfall. Imperial authority was also seriously challenged by large Daoist religious societies which... | Who killed the palace eunichs after the death of Emperor Ling? | {
"answer_start": [
501
],
"text": [
"military officers"
]
} |
572eb82403f9891900756996 | Han_dynasty | After 92 AD, the palace eunuchs increasingly involved themselves in court politics, engaging in violent power struggles between the various consort clans of the empresses and empress dowagers, causing the Han's ultimate downfall. Imperial authority was also seriously challenged by large Daoist religious societies which... | Who was the last Emperor of the Han dynasty? | {
"answer_start": [
679
],
"text": [
"Xian"
]
} |
572eb82403f9891900756995 | Han_dynasty | After 92 AD, the palace eunuchs increasingly involved themselves in court politics, engaging in violent power struggles between the various consort clans of the empresses and empress dowagers, causing the Han's ultimate downfall. Imperial authority was also seriously challenged by large Daoist religious societies which... | Which King took the seat of power from Emperor Xian? | {
"answer_start": [
626
],
"text": [
"Cao Pi"
]
} |
572eb82403f9891900756997 | Han_dynasty | After 92 AD, the palace eunuchs increasingly involved themselves in court politics, engaging in violent power struggles between the various consort clans of the empresses and empress dowagers, causing the Han's ultimate downfall. Imperial authority was also seriously challenged by large Daoist religious societies which... | In what year did Emperor Ling die? | {
"answer_start": [
442
],
"text": [
"189 AD"
]
} |
572eba61c246551400ce459c | Han_dynasty | China's first imperial dynasty was the Qin dynasty (221–206 BC). The Qin unified the Chinese Warring States by conquest, but their empire became unstable after the death of the first emperor Qin Shi Huangdi. Within four years, the dynasty's authority had collapsed in the face of rebellion. Two former rebel leaders, Xia... | With what action did the Qin bring together the Chinese Warring States? | {
"answer_start": [
111
],
"text": [
"conquest"
]
} |
572eba61c246551400ce459d | Han_dynasty | China's first imperial dynasty was the Qin dynasty (221–206 BC). The Qin unified the Chinese Warring States by conquest, but their empire became unstable after the death of the first emperor Qin Shi Huangdi. Within four years, the dynasty's authority had collapsed in the face of rebellion. Two former rebel leaders, Xia... | Which commander did Liu Bang defeat in the Battle of Gaixia? | {
"answer_start": [
543
],
"text": [
"Xiang Yu"
]
} |
572eba61c246551400ce459e | Han_dynasty | China's first imperial dynasty was the Qin dynasty (221–206 BC). The Qin unified the Chinese Warring States by conquest, but their empire became unstable after the death of the first emperor Qin Shi Huangdi. Within four years, the dynasty's authority had collapsed in the face of rebellion. Two former rebel leaders, Xia... | Who was the first emperor during the Qin dynasty? | {
"answer_start": [
191
],
"text": [
"Qin Shi Huangdi"
]
} |
572eba61c246551400ce459f | Han_dynasty | China's first imperial dynasty was the Qin dynasty (221–206 BC). The Qin unified the Chinese Warring States by conquest, but their empire became unstable after the death of the first emperor Qin Shi Huangdi. Within four years, the dynasty's authority had collapsed in the face of rebellion. Two former rebel leaders, Xia... | What ultimately caused the Qin dynasty's authority to be dissolved? | {
"answer_start": [
280
],
"text": [
"rebellion"
]
} |
572eba61c246551400ce45a0 | Han_dynasty | China's first imperial dynasty was the Qin dynasty (221–206 BC). The Qin unified the Chinese Warring States by conquest, but their empire became unstable after the death of the first emperor Qin Shi Huangdi. Within four years, the dynasty's authority had collapsed in the face of rebellion. Two former rebel leaders, Xia... | Who urged Liu Bang to become emperor? | {
"answer_start": [
723
],
"text": [
"his followers"
]
} |
572ebc9303f98919007569bf | Han_dynasty | At the beginning of the Western Han dynasty, thirteen centrally controlled commanderies—including the capital region—existed in the western third of the empire, while the eastern two-thirds were divided into ten semi-autonomous kingdoms. To placate his prominent commanders from the war with Chu, Emperor Gaozu enfeoffed... | How many commanderies were in the western third of the empire? | {
"answer_start": [
45
],
"text": [
"thirteen"
]
} |
572ebc9303f98919007569c0 | Han_dynasty | At the beginning of the Western Han dynasty, thirteen centrally controlled commanderies—including the capital region—existed in the western third of the empire, while the eastern two-thirds were divided into ten semi-autonomous kingdoms. To placate his prominent commanders from the war with Chu, Emperor Gaozu enfeoffed... | Who could appoint staff to the kings? | {
"answer_start": [
878
],
"text": [
"imperial court"
]
} |
572ebc9303f98919007569c1 | Han_dynasty | At the beginning of the Western Han dynasty, thirteen centrally controlled commanderies—including the capital region—existed in the western third of the empire, while the eastern two-thirds were divided into ten semi-autonomous kingdoms. To placate his prominent commanders from the war with Chu, Emperor Gaozu enfeoffed... | When was the Rebellion of the Seven States? | {
"answer_start": [
593
],
"text": [
"154 BC"
]
} |
572ebc9303f98919007569c2 | Han_dynasty | At the beginning of the Western Han dynasty, thirteen centrally controlled commanderies—including the capital region—existed in the western third of the empire, while the eastern two-thirds were divided into ten semi-autonomous kingdoms. To placate his prominent commanders from the war with Chu, Emperor Gaozu enfeoffed... | From what source did kings derive their personal income from? | {
"answer_start": [
963
],
"text": [
"tax revenues"
]
} |
572ebc9303f98919007569c3 | Han_dynasty | At the beginning of the Western Han dynasty, thirteen centrally controlled commanderies—including the capital region—existed in the western third of the empire, while the eastern two-thirds were divided into ten semi-autonomous kingdoms. To placate his prominent commanders from the war with Chu, Emperor Gaozu enfeoffed... | The Han court replaced several kings with members of what royal family? | {
"answer_start": [
412
],
"text": [
"Liu"
]
} |
572ebdf8dfa6aa1500f8d33b | Han_dynasty | To the north of China proper, the nomadic Xiongnu chieftain Modu Chanyu (r. 209–174 BC) conquered various tribes inhabiting the eastern portion of the Eurasian Steppe. By the end of his reign, he controlled Manchuria, Mongolia, and the Tarim Basin, subjugating over twenty states east of Samarkand. Emperor Gaozu was tro... | Who was the chieftain of the Xiongnu? | {
"answer_start": [
60
],
"text": [
"Modu Chanyu"
]
} |
572ebdf8dfa6aa1500f8d33c | Han_dynasty | To the north of China proper, the nomadic Xiongnu chieftain Modu Chanyu (r. 209–174 BC) conquered various tribes inhabiting the eastern portion of the Eurasian Steppe. By the end of his reign, he controlled Manchuria, Mongolia, and the Tarim Basin, subjugating over twenty states east of Samarkand. Emperor Gaozu was tro... | What group had a trade embargo created against them? | {
"answer_start": [
514
],
"text": [
"the Xiongnu"
]
} |
572ebdf8dfa6aa1500f8d33d | Han_dynasty | To the north of China proper, the nomadic Xiongnu chieftain Modu Chanyu (r. 209–174 BC) conquered various tribes inhabiting the eastern portion of the Eurasian Steppe. By the end of his reign, he controlled Manchuria, Mongolia, and the Tarim Basin, subjugating over twenty states east of Samarkand. Emperor Gaozu was tro... | In what year were Han forces defeated in Baideng? | {
"answer_start": [
780
],
"text": [
"200 BC"
]
} |
572ebdf8dfa6aa1500f8d33e | Han_dynasty | To the north of China proper, the nomadic Xiongnu chieftain Modu Chanyu (r. 209–174 BC) conquered various tribes inhabiting the eastern portion of the Eurasian Steppe. By the end of his reign, he controlled Manchuria, Mongolia, and the Tarim Basin, subjugating over twenty states east of Samarkand. Emperor Gaozu was tro... | What agreement established equality between the Xiongnu and the Han? | {
"answer_start": [
812
],
"text": [
"heqin"
]
} |
572ebdf8dfa6aa1500f8d33f | Han_dynasty | To the north of China proper, the nomadic Xiongnu chieftain Modu Chanyu (r. 209–174 BC) conquered various tribes inhabiting the eastern portion of the Eurasian Steppe. By the end of his reign, he controlled Manchuria, Mongolia, and the Tarim Basin, subjugating over twenty states east of Samarkand. Emperor Gaozu was tro... | What type of clothing were sent as a tribute to the Xiongnu? | {
"answer_start": [
1011
],
"text": [
"silk clothes"
]
} |
572ebfc4cb0c0d14000f14f6 | Han_dynasty | Despite the tribute and a negotiation between Laoshang Chanyu (r. 174–160 BC) and Emperor Wen (r. 180–157 BC) to reopen border markets, many of the Chanyu's Xiongnu subordinates chose not to obey the treaty and periodically raided Han territories south of the Great Wall for additional goods. In a court conference assem... | The heqin agreement was reaffirmed by a court conference in what year? | {
"answer_start": [
357
],
"text": [
"135 BC"
]
} |
572ebfc4cb0c0d14000f14f7 | Han_dynasty | Despite the tribute and a negotiation between Laoshang Chanyu (r. 174–160 BC) and Emperor Wen (r. 180–157 BC) to reopen border markets, many of the Chanyu's Xiongnu subordinates chose not to obey the treaty and periodically raided Han territories south of the Great Wall for additional goods. In a court conference assem... | In what year did Emperor Wu begin a series of attacks in Xiongnu territories? | {
"answer_start": [
733
],
"text": [
"133 BC"
]
} |
572ebfc4cb0c0d14000f14f8 | Han_dynasty | Despite the tribute and a negotiation between Laoshang Chanyu (r. 174–160 BC) and Emperor Wen (r. 180–157 BC) to reopen border markets, many of the Chanyu's Xiongnu subordinates chose not to obey the treaty and periodically raided Han territories south of the Great Wall for additional goods. In a court conference assem... | What type of colony did Chinese armies use to help firm their hold on the strongholds that they had taken over? | {
"answer_start": [
893
],
"text": [
"agricultural"
]
} |
572ebfc4cb0c0d14000f14f9 | Han_dynasty | Despite the tribute and a negotiation between Laoshang Chanyu (r. 174–160 BC) and Emperor Wen (r. 180–157 BC) to reopen border markets, many of the Chanyu's Xiongnu subordinates chose not to obey the treaty and periodically raided Han territories south of the Great Wall for additional goods. In a court conference assem... | In what year did the Battle of Mobei take place? | {
"answer_start": [
967
],
"text": [
"119 BC"
]
} |
572ebfc4cb0c0d14000f14fa | Han_dynasty | Despite the tribute and a negotiation between Laoshang Chanyu (r. 174–160 BC) and Emperor Wen (r. 180–157 BC) to reopen border markets, many of the Chanyu's Xiongnu subordinates chose not to obey the treaty and periodically raided Han territories south of the Great Wall for additional goods. In a court conference assem... | Which Han commander died in the year 106 BC? | {
"answer_start": [
1050
],
"text": [
"Wei Qing"
]
} |
572ec4e8dfa6aa1500f8d373 | Han_dynasty | In 121 BC, Han forces expelled the Xiongnu from a vast territory spanning the Hexi Corridor to Lop Nur. They repelled a joint Xiongnu-Qiang invasion of this northwestern territory in 111 BC. In that year, the Han court established four new frontier commanderies in this region: Jiuquan, Zhangyi, Dunhuang, and Wuwei. The... | Who made up a majority of the people on the frontier? | {
"answer_start": [
361
],
"text": [
"soldiers"
]
} |
572ec4e8dfa6aa1500f8d374 | Han_dynasty | In 121 BC, Han forces expelled the Xiongnu from a vast territory spanning the Hexi Corridor to Lop Nur. They repelled a joint Xiongnu-Qiang invasion of this northwestern territory in 111 BC. In that year, the Han court established four new frontier commanderies in this region: Jiuquan, Zhangyi, Dunhuang, and Wuwei. The... | Who forced peasant farmers to move to new settlements? | {
"answer_start": [
384
],
"text": [
"the court"
]
} |
572ec4e8dfa6aa1500f8d375 | Han_dynasty | In 121 BC, Han forces expelled the Xiongnu from a vast territory spanning the Hexi Corridor to Lop Nur. They repelled a joint Xiongnu-Qiang invasion of this northwestern territory in 111 BC. In that year, the Han court established four new frontier commanderies in this region: Jiuquan, Zhangyi, Dunhuang, and Wuwei. The... | In what year did Han forces stop a joint Xiongnu-Qiang invasion? | {
"answer_start": [
183
],
"text": [
"111 BC"
]
} |
572ec4e8dfa6aa1500f8d376 | Han_dynasty | In 121 BC, Han forces expelled the Xiongnu from a vast territory spanning the Hexi Corridor to Lop Nur. They repelled a joint Xiongnu-Qiang invasion of this northwestern territory in 111 BC. In that year, the Han court established four new frontier commanderies in this region: Jiuquan, Zhangyi, Dunhuang, and Wuwei. The... | Where were landowners encouraged to migrate willingly to? | {
"answer_start": [
651
],
"text": [
"the frontier"
]
} |
572ec4e8dfa6aa1500f8d377 | Han_dynasty | In 121 BC, Han forces expelled the Xiongnu from a vast territory spanning the Hexi Corridor to Lop Nur. They repelled a joint Xiongnu-Qiang invasion of this northwestern territory in 111 BC. In that year, the Han court established four new frontier commanderies in this region: Jiuquan, Zhangyi, Dunhuang, and Wuwei. The... | How many commanderies in the new frontier were created by the Han court in the year 111 BC? | {
"answer_start": [
231
],
"text": [
"four"
]
} |
572ec73cc246551400ce4642 | Han_dynasty | Even before Han's expansion into Central Asia, diplomat Zhang Qian's travels from 139 to 125 BC had established Chinese contacts with many surrounding civilizations. Zhang encountered Dayuan (Fergana), Kangju (Sogdiana), and Daxia (Bactria, formerly the Greco-Bactrian Kingdom); he also gathered information on Shendu (I... | What type of Roman item was traded on the Silk Road network? | {
"answer_start": [
610
],
"text": [
"glasswares"
]
} |
572ec73cc246551400ce4643 | Han_dynasty | Even before Han's expansion into Central Asia, diplomat Zhang Qian's travels from 139 to 125 BC had established Chinese contacts with many surrounding civilizations. Zhang encountered Dayuan (Fergana), Kangju (Sogdiana), and Daxia (Bactria, formerly the Greco-Bactrian Kingdom); he also gathered information on Shendu (I... | Which diplomat helped gather information on the country of Anxi? | {
"answer_start": [
56
],
"text": [
"Zhang Qian"
]
} |
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