TIANCHI volcano,Changbaishan Mountains isthe largest modern active volcano in East Chi-na.Many times strong volcanic erupting activ-ities occurred in the Cenozoic Era.The vol-canic activities have revived again in the...TIANCHI volcano,Changbaishan Mountains isthe largest modern active volcano in East Chi-na.Many times strong volcanic erupting activ-ities occurred in the Cenozoic Era.The vol-canic activities have revived again in the Re-cent.Field investigation results show thatthere are a lot of hydrothermal anomaly out-展开更多
The mathematical model of 4He quantum interferometer gyroscope is presented. The model includes the driven equation, the current equation and the position equation. Therefore, it can sufficiently describe the gyro- sc...The mathematical model of 4He quantum interferometer gyroscope is presented. The model includes the driven equation, the current equation and the position equation. Therefore, it can sufficiently describe the gyro- scope system. The driven equation shows the thermally driven gyroscope can work for a long time but the pres- sure driven one cannot. From the current equation, the superfluid currents passing through the weak link contain the AC currents which show the rotation flux, and other currents caused by drive. As shown in the position equa- tion, the displacement of diaphragm is the only detectable parameter in the gyroscope system. The model is tested by the simulations based on experimental parameters, and can be used to research performance of the gyroscope and analyse the gyroscope error.展开更多
The isotopic compositions of helium have been investigated in hot spring gases sampled from the Liaodong Peninsula, China. The 3He/ 4He ratios range from 0.14 Ra (0.14 times the atmospheric 3He/ 4He ratio of 1.40×...The isotopic compositions of helium have been investigated in hot spring gases sampled from the Liaodong Peninsula, China. The 3He/ 4He ratios range from 0.14 Ra (0.14 times the atmospheric 3He/ 4He ratio of 1.40×10 -6) to 0.72 Ra. 3He/ 4He versus 4He/ 20Ne ratios and He contents suggest that a small amount of mantle-derived helium reaches the earth’s surface. Helium isotope ratios of the hot spring gases show a distribution pattern similar to the regional heat flow values, indicating that the positive thermal anomaly occurring in the area is closely associated with the presence of mantle-derived helium. The observations described above provide some significant evidence that the molten magma originating from partial melting of the upper mantle may have intruded into the continental crust along the activity fault. The coupling of the presence of mantle He and heat flow anomalies to seismic activity in studied region seem to imply that there is an internal relationship between mantle degassing and seismic展开更多
The^6 Li(n,t)~4 He reaction was measured as the first experiment involving neutron-induced charged particle emission reactions at the CSNS(China Spallation Neutron Source)Back-n white neutron source.The differential c...The^6 Li(n,t)~4 He reaction was measured as the first experiment involving neutron-induced charged particle emission reactions at the CSNS(China Spallation Neutron Source)Back-n white neutron source.The differential cross-sections of the^6 Li(n,t)~4 He reaction at 15 detection angles ranging from 19.2°to 160.8°are obtained from 1.0 eV to 3.0 MeV at 80 neutron energy points;for 50 energy points below 0.1 MeV they are reported for the first time.The results indicate that the anisotropy of the emitted tritium is noticeable above E_n=100 eV.The angle-integrated cross-sections are also obtained.The present differential cross-sections agree in general with the previous evaluations,but there are some differences in the details.More importantly,the present results indicate that the cross-sections of the^6 Li(n,t)~4 He reaction might be overestimated by most evaluations in the 0.5-3.0 MeV region,although they are recommended as standards below 1.0 MeV.展开更多
Almost all experimental and theoretical studies on regenerative cryocoolers at temperatures below 20 K mention the use of 4He as working fluid.A preliminary qualitative evaluation indicates that because of the superfl...Almost all experimental and theoretical studies on regenerative cryocoolers at temperatures below 20 K mention the use of 4He as working fluid.A preliminary qualitative evaluation indicates that because of the superfluid phase transition,a working fluid of 3 He would overcome the cooling temperature limitation set by 4He.Starting with a comparison of the thermophysical properties of 3He and 4He,cryogenic regenerator simulations applied to the third/last stage of a pulse tube refrigerator,with 3He and 4He separately,were implemented to quantitatively analyze performance differences of the regenerator with respect to regenerator loss, cooling power and COP.Results conclude that 3He could significantly improve the performance of a regenerative cryocooler.展开更多
According to the hydrochemical characteristics, hydrogen and oxygen isotope characteristics and the ratio of noble gas isotopes of the sandstone aquifer and basalt aquifer, this study calculated the recharge temperatu...According to the hydrochemical characteristics, hydrogen and oxygen isotope characteristics and the ratio of noble gas isotopes of the sandstone aquifer and basalt aquifer, this study calculated the recharge temperature and residence time of groundwater in the Weishan area of Wudalianchi, also calculating the contribution of noble gas components from different sources to the samples. Based on the characteristics of hydrogen and oxygen isotopes and noble gases Xe and Ne, the recharge altitude and recharge temperature of the two aquifers were estimated, and the recharge temperature fitting with the NGT model as verified, the results showing that the main recharge altitude of groundwater in the region was 500–600 m, the recharge temperature being 2–7°C. He_(eq) and He_(ea) of the samples have been simulated using the OD model, the content of radioactive ~4He in the crust being obtained, the groundwater ages under the two conditions(closed condition and open condition) both being simulated. The results show that groundwater from the sandstone layer water is older than groundwater from the basalt layer. Hydrochemical characteristics and noble gas isotope ratios indicate that in the basalt aquifer and sandstone aquifer in the Weishan area, in addition to atmospheric and crustal helium, there is also an input of mantle-derived helium. The fault constitutes the uplift channel for groundwater containings mantle components, which results in the mantle source composition in water samples near the fault being much higher than those form non-fault areas.展开更多
Experiments show that the liquid helium-4 has either superfluid phase or solid phase when tem- perature decreases or the pressure of the system changes. In this paper, we discuss the equations which govern these phase...Experiments show that the liquid helium-4 has either superfluid phase or solid phase when tem- perature decreases or the pressure of the system changes. In this paper, we discuss the equations which govern these phase transitions and derive the criterions for these phase changes. Meanwhile, we give related approxi- mate solutions and draw the phase diagram. In addition, we also prove that the liquid helium-4 bifurcates from the trivial solution to an attractor as parameters cross certain critical value. The topological structure of the bifurcated attractor is also illustrated.展开更多
In this paper, a mechanism about the variability of the L-H transition power thresh- old PL-H is proposed which is based on the ion orbit losses. Only in the edge where there are enough ion orbit losses and the negati...In this paper, a mechanism about the variability of the L-H transition power thresh- old PL-H is proposed which is based on the ion orbit losses. Only in the edge where there are enough ion orbit losses and the negative radial electric field Er is high enough can the H-mode be triggered. The ion orbit losses are determined by the ion in the loss region under certain edge conditions. For different mass A and different charge Z, the critical loss energy E Z2/A in the loss region. In H and D charges, because the D＋ loss region is larger than H＋, it can be deduced that the PL-H of H is larger than that of D. In a 4He discharge, experiment finds there exist a considerable number of 4He1＋ in the plasma edge. The actual ion orbit losses are determined by the mixing ratio of a He1＋ and 4He2＋. The 4He1＋ loss region is larger than that of 4He2＋, and the loss region of D＋ interposes between 4He1＋ and 4He2＋. Different 4He1＋ content can cause the edge ion losses in a 4He discharge to be greater than, less than or equal to that in a D discharge. So a 4He discharge can exhibit multiple experimental phenomena in the PL-H.展开更多
Residence time of deep groundwater is one of the most important parameters in safety and performance assessment for high-level radioactive waste geological disposal. In this study, we collected the deep groundwater sa...Residence time of deep groundwater is one of the most important parameters in safety and performance assessment for high-level radioactive waste geological disposal. In this study, we collected the deep groundwater samples of Jijicao in Gansu Beishan pre-selected region. The deep groundwater residence time at two depths estimated by Helium-4 accumulation method were 3.8 ka and 5.0 ka respectively upon measurement and calculation, which indicates that the deep groundwater is not derived from the deep crust circulation process. Hence, deep groundwater is featured with long residence time as well as slow circulation and update rate, and such features are conductive to the safe disposal of high-level radioactive waste.展开更多
Using two piezoelectric transducers, one measures the stress tensor response from the strain field generated by the second transducer. The ratio between the stress response and strain velocity determines the dissipati...Using two piezoelectric transducers, one measures the stress tensor response from the strain field generated by the second transducer. The ratio between the stress response and strain velocity determines the dissipative response. In the first part, we show that the dissipative stress response can be used for studying excitations in a topological superconductor. We investigate a topological superconductor for the case when an Abrikosov vortex lattice is formed. In this case, the Majorana fermions are dispersive, a fact that is used to compute the dissipative stress response. In the second part, we analyse the dissipative superfluid flow through solid 4He discoused recently. We identify low energy, an excitation which plays the role of the Majorana mode which is free to move in a direction perpendicular to the two dimensional plane spaces of the dislocations.展开更多
In this paper a comprehensive tracing study is conducted on mantle degassing and deep-seated geological structures in different types of fault zones in the continent of China based on the helium isotope data, coupled ...In this paper a comprehensive tracing study is conducted on mantle degassing and deep-seated geological structures in different types of fault zones in the continent of China based on the helium isotope data, coupled with some indices such as CO2/3He, CH4/3He and 40Ar/36Ar, and geological tectonics data. There are four representative types of fault zones: (1) Lithospheric fault zones in the extensional tectonic environment are characterized by a small Earth’s crust thickness, a lower CH4/3He-high R and lower CO2/3He-high R system, the strongest mantle de- gassing, and the dominance of mantle fluid, as is represented by the Tancheng-Lujiang fault zone. (2) The lithospheric fault zones or the subduction zone in the strongly compresso-tectonic envi- ronment, for instance, the Bangonghu-Nujiang fault zone, are characterized by a huge thick Earth’s crust, with the R/Ra values within the range of 0.43―1.13, and weak mantle degassing with mantle-source helium accounting for 5%―14% of the total. (3) The deep-seated fault zones at the basinal margins of an orogenic belt are characterized by R values being on order of mag- nitude of 10?7, and the CH4/3He values, 109―1010, CO2/3He values, 106―108; as well as much weak mantle degassing. (4) The crustal fault zones in the orogenic belt, such as the Yaojie fault zone (F19), possess a high CH4/3He-low R (10?8) and high CO2/3He-low R system, with no obvi- ous sign of mantle degassing. Studies have shown that the deep-seated huge fault zones are the major channel ways for mantle degassing, the main factors controlling the intensity of mantle degassing are fault depth, tectonic environment and crust thickness; the intensity of mantle de- gassing can reflect the depth and the status of deep-seated tectonic environment of fault, while the geochemical tracing studies of gases can open up a new research approach; upwelling ac- tivity of hydrothermal fluids from the deep interior of the Earth may be one of the driving forces for the formation and evolution of the huge deep 展开更多
Along both sides of the Tancheng-Lujiang Fracture Zone in eastern China, a series of mantle source gas pools constitute a massive-scale tectonic accumulation zone in NNE direction, with the mantle geochemical characte...Along both sides of the Tancheng-Lujiang Fracture Zone in eastern China, a series of mantle source gas pools constitute a massive-scale tectonic accumulation zone in NNE direction, with the mantle geochemical characteristics of high concentrations of CO2 and He, high 3He/4He-40Ar/36Ar ratio system and high δ13Coo2 ratios (the mainfrequency, -3.4‰-4.6‰), showing no difference from the tectonic framework of the area. In the area, thetectonic environment is a rift formed as a result of diapiric mantle injection and crust thinning to form graben-type basins and lithospheric fractures. The mantle-derived volcanic rocks and inclusions are well-developed and a high geothermal zone (mantlesource) exists in the area. The characteristics of the three components (solid, liquid and gas) of mantle, concentrated all over the same tectonic space zone, show that the rift system is of a good tectonic environment or passage for mantle degassing and gas migration. The main types of the gas pools are volcano, fault-block, anticline, buried hill and so on, but most of them are combination traps closely related with fracture. For the mantle source gas pools, rift is an optimum tectonic region, and nearby lithospheric fracture, mantle source volcanic rocks or basement uplifts are a favourable structural location when reservoir-caprock association develops.展开更多
文摘TIANCHI volcano,Changbaishan Mountains isthe largest modern active volcano in East Chi-na.Many times strong volcanic erupting activ-ities occurred in the Cenozoic Era.The vol-canic activities have revived again in the Re-cent.Field investigation results show thatthere are a lot of hydrothermal anomaly out-
基金Supported by the National Natural Science Foundation of China(61074162)the Ph.D.Program Foundation of Ministry of Education of China(200802870011)~~
文摘The mathematical model of 4He quantum interferometer gyroscope is presented. The model includes the driven equation, the current equation and the position equation. Therefore, it can sufficiently describe the gyro- scope system. The driven equation shows the thermally driven gyroscope can work for a long time but the pres- sure driven one cannot. From the current equation, the superfluid currents passing through the weak link contain the AC currents which show the rotation flux, and other currents caused by drive. As shown in the position equa- tion, the displacement of diaphragm is the only detectable parameter in the gyroscope system. The model is tested by the simulations based on experimental parameters, and can be used to research performance of the gyroscope and analyse the gyroscope error.
文摘The isotopic compositions of helium have been investigated in hot spring gases sampled from the Liaodong Peninsula, China. The 3He/ 4He ratios range from 0.14 Ra (0.14 times the atmospheric 3He/ 4He ratio of 1.40×10 -6) to 0.72 Ra. 3He/ 4He versus 4He/ 20Ne ratios and He contents suggest that a small amount of mantle-derived helium reaches the earth’s surface. Helium isotope ratios of the hot spring gases show a distribution pattern similar to the regional heat flow values, indicating that the positive thermal anomaly occurring in the area is closely associated with the presence of mantle-derived helium. The observations described above provide some significant evidence that the molten magma originating from partial melting of the upper mantle may have intruded into the continental crust along the activity fault. The coupling of the presence of mantle He and heat flow anomalies to seismic activity in studied region seem to imply that there is an internal relationship between mantle degassing and seismic
基金Supported by National Key R&D Program of China(2016YFA0401604)National Natural Science Foundation of China(11775006)Science and Technology on Nuclear Data Laboratory and China Nuclear Data Center
文摘The^6 Li(n,t)~4 He reaction was measured as the first experiment involving neutron-induced charged particle emission reactions at the CSNS(China Spallation Neutron Source)Back-n white neutron source.The differential cross-sections of the^6 Li(n,t)~4 He reaction at 15 detection angles ranging from 19.2°to 160.8°are obtained from 1.0 eV to 3.0 MeV at 80 neutron energy points;for 50 energy points below 0.1 MeV they are reported for the first time.The results indicate that the anisotropy of the emitted tritium is noticeable above E_n=100 eV.The angle-integrated cross-sections are also obtained.The present differential cross-sections agree in general with the previous evaluations,but there are some differences in the details.More importantly,the present results indicate that the cross-sections of the^6 Li(n,t)~4 He reaction might be overestimated by most evaluations in the 0.5-3.0 MeV region,although they are recommended as standards below 1.0 MeV.
基金the support from the National Natural Science Foundation of China (50806047)the Shanghai Pujiang Program
文摘Almost all experimental and theoretical studies on regenerative cryocoolers at temperatures below 20 K mention the use of 4He as working fluid.A preliminary qualitative evaluation indicates that because of the superfluid phase transition,a working fluid of 3 He would overcome the cooling temperature limitation set by 4He.Starting with a comparison of the thermophysical properties of 3He and 4He,cryogenic regenerator simulations applied to the third/last stage of a pulse tube refrigerator,with 3He and 4He separately,were implemented to quantitatively analyze performance differences of the regenerator with respect to regenerator loss, cooling power and COP.Results conclude that 3He could significantly improve the performance of a regenerative cryocooler.
基金financially supported by the China Geological Survey (No. 1212011220014)。
文摘According to the hydrochemical characteristics, hydrogen and oxygen isotope characteristics and the ratio of noble gas isotopes of the sandstone aquifer and basalt aquifer, this study calculated the recharge temperature and residence time of groundwater in the Weishan area of Wudalianchi, also calculating the contribution of noble gas components from different sources to the samples. Based on the characteristics of hydrogen and oxygen isotopes and noble gases Xe and Ne, the recharge altitude and recharge temperature of the two aquifers were estimated, and the recharge temperature fitting with the NGT model as verified, the results showing that the main recharge altitude of groundwater in the region was 500–600 m, the recharge temperature being 2–7°C. He_(eq) and He_(ea) of the samples have been simulated using the OD model, the content of radioactive ~4He in the crust being obtained, the groundwater ages under the two conditions(closed condition and open condition) both being simulated. The results show that groundwater from the sandstone layer water is older than groundwater from the basalt layer. Hydrochemical characteristics and noble gas isotope ratios indicate that in the basalt aquifer and sandstone aquifer in the Weishan area, in addition to atmospheric and crustal helium, there is also an input of mantle-derived helium. The fault constitutes the uplift channel for groundwater containings mantle components, which results in the mantle source composition in water samples near the fault being much higher than those form non-fault areas.
文摘Experiments show that the liquid helium-4 has either superfluid phase or solid phase when tem- perature decreases or the pressure of the system changes. In this paper, we discuss the equations which govern these phase transitions and derive the criterions for these phase changes. Meanwhile, we give related approxi- mate solutions and draw the phase diagram. In addition, we also prove that the liquid helium-4 bifurcates from the trivial solution to an attractor as parameters cross certain critical value. The topological structure of the bifurcated attractor is also illustrated.
基金supported by National Natural Science Foundation of China(No.11175210)
文摘In this paper, a mechanism about the variability of the L-H transition power thresh- old PL-H is proposed which is based on the ion orbit losses. Only in the edge where there are enough ion orbit losses and the negative radial electric field Er is high enough can the H-mode be triggered. The ion orbit losses are determined by the ion in the loss region under certain edge conditions. For different mass A and different charge Z, the critical loss energy E Z2/A in the loss region. In H and D charges, because the D＋ loss region is larger than H＋, it can be deduced that the PL-H of H is larger than that of D. In a 4He discharge, experiment finds there exist a considerable number of 4He1＋ in the plasma edge. The actual ion orbit losses are determined by the mixing ratio of a He1＋ and 4He2＋. The 4He1＋ loss region is larger than that of 4He2＋, and the loss region of D＋ interposes between 4He1＋ and 4He2＋. Different 4He1＋ content can cause the edge ion losses in a 4He discharge to be greater than, less than or equal to that in a D discharge. So a 4He discharge can exhibit multiple experimental phenomena in the PL-H.
基金sponsored by decommissioning of nuclear installations and radioactive waste treatment special project (K.G.E.S, No.(2014)305)
文摘Residence time of deep groundwater is one of the most important parameters in safety and performance assessment for high-level radioactive waste geological disposal. In this study, we collected the deep groundwater samples of Jijicao in Gansu Beishan pre-selected region. The deep groundwater residence time at two depths estimated by Helium-4 accumulation method were 3.8 ka and 5.0 ka respectively upon measurement and calculation, which indicates that the deep groundwater is not derived from the deep crust circulation process. Hence, deep groundwater is featured with long residence time as well as slow circulation and update rate, and such features are conductive to the safe disposal of high-level radioactive waste.
文摘Using two piezoelectric transducers, one measures the stress tensor response from the strain field generated by the second transducer. The ratio between the stress response and strain velocity determines the dissipative response. In the first part, we show that the dissipative stress response can be used for studying excitations in a topological superconductor. We investigate a topological superconductor for the case when an Abrikosov vortex lattice is formed. In this case, the Majorana fermions are dispersive, a fact that is used to compute the dissipative stress response. In the second part, we analyse the dissipative superfluid flow through solid 4He discoused recently. We identify low energy, an excitation which plays the role of the Majorana mode which is free to move in a direction perpendicular to the two dimensional plane spaces of the dislocations.
基金the State "973" Program(Grant No.G2002CB211701) the National Natural Science Foundation of China(Grant No.40372065).
文摘In this paper a comprehensive tracing study is conducted on mantle degassing and deep-seated geological structures in different types of fault zones in the continent of China based on the helium isotope data, coupled with some indices such as CO2/3He, CH4/3He and 40Ar/36Ar, and geological tectonics data. There are four representative types of fault zones: (1) Lithospheric fault zones in the extensional tectonic environment are characterized by a small Earth’s crust thickness, a lower CH4/3He-high R and lower CO2/3He-high R system, the strongest mantle de- gassing, and the dominance of mantle fluid, as is represented by the Tancheng-Lujiang fault zone. (2) The lithospheric fault zones or the subduction zone in the strongly compresso-tectonic envi- ronment, for instance, the Bangonghu-Nujiang fault zone, are characterized by a huge thick Earth’s crust, with the R/Ra values within the range of 0.43―1.13, and weak mantle degassing with mantle-source helium accounting for 5%―14% of the total. (3) The deep-seated fault zones at the basinal margins of an orogenic belt are characterized by R values being on order of mag- nitude of 10?7, and the CH4/3He values, 109―1010, CO2/3He values, 106―108; as well as much weak mantle degassing. (4) The crustal fault zones in the orogenic belt, such as the Yaojie fault zone (F19), possess a high CH4/3He-low R (10?8) and high CO2/3He-low R system, with no obvi- ous sign of mantle degassing. Studies have shown that the deep-seated huge fault zones are the major channel ways for mantle degassing, the main factors controlling the intensity of mantle degassing are fault depth, tectonic environment and crust thickness; the intensity of mantle de- gassing can reflect the depth and the status of deep-seated tectonic environment of fault, while the geochemical tracing studies of gases can open up a new research approach; upwelling ac- tivity of hydrothermal fluids from the deep interior of the Earth may be one of the driving forces for the formation and evolution of the huge deep
文摘Along both sides of the Tancheng-Lujiang Fracture Zone in eastern China, a series of mantle source gas pools constitute a massive-scale tectonic accumulation zone in NNE direction, with the mantle geochemical characteristics of high concentrations of CO2 and He, high 3He/4He-40Ar/36Ar ratio system and high δ13Coo2 ratios (the mainfrequency, -3.4‰-4.6‰), showing no difference from the tectonic framework of the area. In the area, thetectonic environment is a rift formed as a result of diapiric mantle injection and crust thinning to form graben-type basins and lithospheric fractures. The mantle-derived volcanic rocks and inclusions are well-developed and a high geothermal zone (mantlesource) exists in the area. The characteristics of the three components (solid, liquid and gas) of mantle, concentrated all over the same tectonic space zone, show that the rift system is of a good tectonic environment or passage for mantle degassing and gas migration. The main types of the gas pools are volcano, fault-block, anticline, buried hill and so on, but most of them are combination traps closely related with fracture. For the mantle source gas pools, rift is an optimum tectonic region, and nearby lithospheric fracture, mantle source volcanic rocks or basement uplifts are a favourable structural location when reservoir-caprock association develops.
