Due to its unique properties,helium is critical in scientific research and industrial innovation,particularly in cryogenics;however,its scarcity necessitates efficient resource utilization.Through a review of the hist...Due to its unique properties,helium is critical in scientific research and industrial innovation,particularly in cryogenics;however,its scarcity necessitates efficient resource utilization.Through a review of the historical development of the helium industry,this study comprehensively evaluates the value,sources,production methods,supply dynamics,and sustainability challenges of helium.The processes and mechanisms of helium enrichment,along with effective exploration methods,are systematically analyzed here.We recommend focusing on the development of technologies for helium preservation,recovery,and extraction,particularly the extraction technology for helium-poor fields.Market analysis indicates that no imminent crisis in the global helium supply is expected before 2060.Thus,enhancing helium resource protection technologies is essential to improve its economic utilization and management while providing a timely reference for the scientific community.展开更多
Helium is a valuable natural resource used widely in high-tech industries because of its unique physical and chemical properties.The study of helium in shale gas is still in its infancy,and the content,genesis,and enr...Helium is a valuable natural resource used widely in high-tech industries because of its unique physical and chemical properties.The study of helium in shale gas is still in its infancy,and the content,genesis,and enrichment patterns of helium in shale gas are not yet clear.In this paper,the concentrations and isotopic characteristics of helium were investigated in the Wufeng-Longmaxi shale gas in the Sichuan Basin and the periphery areas.The analytical results show that the concentrations of helium in the southern Sichuan shale gas fall in the range of 0.018-0.051 vol%with an average of 0.029 vol%.The helium abundance in Weiyuan shale gas are relatively low compared to those in conventional natural gas pools from the same area(generally greater than 0.20 vol%),reflecting the significance of long distance migration to the enrichment of helium in gas pools.The relatively low ratios of 3He and 4He in shale gas indicate that most of the helium are crustal derived helium.Further quantitative estimate based on helium,neon,and argon isotopic ratios suggest almost 100%crustal helium source.The helium residing in shale reservoirs can be deconvoluted into the indigenous helium generated in-situ by shale and exogenous helium generated from external helium source rocks and charged through faults and/or fractures networks.According to preliminary calculations,external helium source is required to meet the threshold of an economic helium-rich field of helium concentration of 0.1 vol%except for particular areas with extraordinarily high uranium and thorium concentration.Based on detailed study on typical helium-rich shale gas reservoirs,major advantageous features for helium's enrichment in shale gas include:(1)high-quality helium source rocks,(2)effective migration paths,and(3)diminished dilution effects of shale gas.Shale gas plays with underlying ancient cratonic basement,well developed source-connecting faults,and moderate pressure coefficient are potential targets for helium exploration.展开更多
Helium sorption cooler technology is a key means to realize highly reliable low-vibration very lowtemperature environments,which have important applications in fields such as quantum computing and space exploration.Th...Helium sorption cooler technology is a key means to realize highly reliable low-vibration very lowtemperature environments,which have important applications in fields such as quantum computing and space exploration.The laboratory designed a superfluid suppression small hole and a multi-ribbed condenser,developed a reliable-performance helium sorption cooler(HSC),and conducted experimental studies.Experimental results show that the prototype can achieve the lowest cooling temperature of 873 mK without load by filling 6MPa helium at room temperature.The low-temperature hold time is 26 h,and the temperature fluctuation is within 0.8 mK.The cooling power of the helium sorption cooler is 1 mW@0.98 K@3.5 h.Experimental results indicate that when the charging pressure is reduced to 4MPa,theminimum temperature decreases to 836mK,and the hold time shortens to 16 h.When the pre-cooling temperature increases from 3.9 to 4.9 K,the hold time is reduced to 3 h.展开更多
Research on the interstellar medium and its interaction with the solar system constitutes a significant topic in planetary physics.As the Sun traverses the local interstellar cloud,interstellar neutrals penetrate the ...Research on the interstellar medium and its interaction with the solar system constitutes a significant topic in planetary physics.As the Sun traverses the local interstellar cloud,interstellar neutrals penetrate the heliosphere,forming the interstellar wind,and scattering solar extreme ultraviolet(EUV)emission lines.The intensity of the scattered radiation provides an indicator of the characteristic parameters of the interstellar wind,crucial for characterizing the heliosphere,the interstellar medium,and the evolution of the solar system.Meanwhile,a powerful method for studying stellar evolution is investigating the EUV emissions of stars.The only ongoing mission conducting an EUV full-sky survey is the relay satellite Queqiao-2.Due to the strong absorption of the interstellar medium at EUV wavelengths,modelling is essential to any study of these influences.In this study,we reviewed classical modelling methods for the density distribution of the interstellar helium atoms in the heliosphere,and the corresponding 58.4 nm radiation intensity.We established distinct density and intensity models for different orbital positions of Earth’s revolution.We found that when the Earth enters the helium focusing cone in the downwind region,both the helium density and the 58.4 nm radiation intensity increase rapidly,with the temperature effect being particularly important.The radiation intensity in the downwind direction can be 170 times that of the upwind direction.Some negligible factors were omitted for simplicity,such as the effects of the solar line width and Doppler shift.Our research can serve as an aid to the interpretation of the EUV observations in the full-sky survey conducted by Queqiao-2.展开更多
Gifford-McMahon-type pulse-tube cryocoolers(GM-PTCs)working at liquid helium temperatures are promising in quantum technology and cryogenic physics for their high reliability and minimal vibration.These features stem ...Gifford-McMahon-type pulse-tube cryocoolers(GM-PTCs)working at liquid helium temperatures are promising in quantum technology and cryogenic physics for their high reliability and minimal vibration.These features stem from the fact that there are no extra moving parts introduced into the system.The rotary valve is a key component in GM-PTCs that transfers the output exergy from the compressor to the cold head.Because a low Carnot efficiency of 1.58%is achieved at liquid helium temperatures,optimizing the rotary valve is crucial for improving the efficiency of GM-PTCs.In this regard,an exergy-loss analysis method is proposed in this paper to quantitatively obtain the leakage loss and viscosity loss of a rotary valve by experimental measurements.The results show that viscosity loss accounts for more than 97.5%of the total exergy loss in the rotary valve,and that it is possible to improve the structure of the rotary valve by expanding the flow area by 1.5 times.To verify the method,the cooling temperature and power of a remote two-stage GM-PTC were monitored,with original or optimized rotary valves installed.The experimental results show that compared to the original rotary valve,the optimized rotary valve can improve the cooling efficiency of a GM-PTC by 16.4%,with a cooling power of 0.78 W at 4.2 K.展开更多
Y-Zr-O nano-oxide dispersion-strengthened(ODS)ferritic alloys have attracted increasing research eforts in recent years,for the enhanced nucleation and refnement of nano-oxides.Here,we report a frst-principles explora...Y-Zr-O nano-oxide dispersion-strengthened(ODS)ferritic alloys have attracted increasing research eforts in recent years,for the enhanced nucleation and refnement of nano-oxides.Here,we report a frst-principles exploration on the possible roles of Y_(2)Zr_(2)O_(7) in helium management in Y+Zr and Y+Ti+Zr co-alloyed ODS ferritic alloys.Bulk phase calculations suggested that similarly as Y_(2)Ti_(2)O_(7),Y_(2)Zr_(2)O_(7) has a comparably strong capability for trapping helium at its interstitial sites.The equilibrium Fe/Y_(2)Zr_(2)O_(7) interface structure was further predicted as the top-coordinated O-rich at the temperature range of interest.Vacancy and helium both segregate to the Y_(2)Zr_(2)O_(7) interface,in preference to the Y_(2)Ti_(2)O_(7) interface,the bulk interior of Y_(2)Zr_(2)O_(7) and the grain boundaries.In this regard,Y_(2)Zr_(2)O_(7) can be more efective than Y_(2)Ti_(2)O_(7) in preventing vacancies and helium from reaching GBs.Based on these results,the profound implications for the helium tolerance of Zralloyed ODS ferritic alloys were discussed.展开更多
Josephson junction plays a key role not only in studying the basic physics of unconventional iron-based superconductors but also in realizing practical application of thin-film based devices,therefore the preparation ...Josephson junction plays a key role not only in studying the basic physics of unconventional iron-based superconductors but also in realizing practical application of thin-film based devices,therefore the preparation of high-quality iron pnictide Josephson junctions is of great importance.In this work,we have successfully fabricated Josephson junctions from Co-doped BaFe_(2)As_(2)thin films using a direct junction fabrication technique which utilizes high energy focused helium ion beam(FHIB).The electrical transport properties were investigated for junctions fabricated with various He^(+)irradiation doses.The junctions show sharp superconducting transition around 24 K with a narrow transition width of 2.5 K,and a dose correlated foot-structure resistance which corresponds to the effective tuning of junction properties by He^(+)irradiation.Significant J_c suppression by more than two orders of magnitude can be achieved by increasing the He^(+)irradiation dose,which is advantageous for the realization of low noise ion pnictide thin film devices.Clear Shapiro steps are observed under 10 GHz microwave irradiation.The above results demonstrate the successful fabrication of high quality and controllable Co-doped BaFe_(2)As_(2)Josephson junction with high reproducibility using the FHIB technique,laying the foundation for future investigating the mechanism of iron-based superconductors,and also the further implementation in various superconducting electronic devices.展开更多
Based on the geochemical parameters and analytical data,the heat conservation equation,mass balance law,Rayleigh fractionation model and other methods were used to quantify the in-situ yield and external flux of crust...Based on the geochemical parameters and analytical data,the heat conservation equation,mass balance law,Rayleigh fractionation model and other methods were used to quantify the in-situ yield and external flux of crust-derived helium,and the initial He concentration and thermal driving mechanism of mantle-derived helium,in the Ledong Diapir area,the Yinggehai Basin,in order to understand the genetic source,migration and accumulation mechanisms of helium under deep thermal fluid activities.The average content of mantle-derived He is only 0.0014%,the ^(3)He/^(4)He value is(0.002–2.190)×10^(−6),and the R/Ra value ranges from 0.01 to 1.52,indicating the contribution of mantle-derived He is 0.09%–19.84%,while the proportion of crust-derived helium can reach over 80%.Quantitative analysis indicates that the crust-derived helium is dominated by external input,followed by in-situ production,in the Ledong diapir area.The crust-derived helium exhibits an in-situ 4 He yield rate of(7.66–7.95)×10^(−13)cm^(3)/(a·g),an in-situ 4 He yield of(4.10–4.25)×10^(−4)cm^(3)/g,and an external 4 He influx of(5.84–9.06)×10^(−2)cm^(3)/g.These results may be related to atmospheric recharge into formation fluid and deep rock-water interactions.The ratio of initial mole volume of 3 He to enthalpy(W)is(0.004–0.018)×10^(−11) cm^(3)/J,and the heat contribution from the deep mantle(X_(M))accounts for 7.63%–36.18%,indicating that deep hot fluid activities drive the migration of mantle-derived 3 He.The primary helium migration depends on advection,while the secondary migration is controlled by hydrothermal degassing and gas-liquid separation.From deep to shallow layers,the CO_(2/3) He value rises from 1.34×10^(9)to 486×10^(9),indicating large amount of CO_(2)has escaped.Under the influence of deep thermal fluid,helium migration and accumulation mechanisms include:deep heat driven diffusion,advection release,vertical hydrothermal degassing,shallow lateral migration,accumulation in traps far from faults,partial pressure balance and sealing capability.展开更多
In this study,we successfully extracted the‘knee structure’for non-sequential double ionization(NSDI)in the helium atom.To achieve this,for the first time,we solved the time-dependent Schrödinger equation in th...In this study,we successfully extracted the‘knee structure’for non-sequential double ionization(NSDI)in the helium atom.To achieve this,for the first time,we solved the time-dependent Schrödinger equation in three dimensions for the helium atom,utilizing the shielding charge approximation.Our findings corroborate prior observations by Wang et al[Wang and Eberly,Phys.Rev.Lett.105,083001(2010)],demonstrating that NSDI occurs within a narrower time window in circular polarization compared to linear polarization.As a result,the yield of linear polarization was higher than that of circular polarization,aligning with the previously reported results.Notably,in the case of circular polarization,the time window further narrows with increasing intensity,attributed to a decrease in the time-of-flight.展开更多
A series of high-entropy alloys(HEAs) containing nanoprecipitates of varying sizes is successfully prepared by a non-consuming vacuum arc melting method.In order to study the irradiation evolution of helium bubbles in...A series of high-entropy alloys(HEAs) containing nanoprecipitates of varying sizes is successfully prepared by a non-consuming vacuum arc melting method.In order to study the irradiation evolution of helium bubbles in the FeCoNiCrbased HE As with γ' precipitates,these samples are irradiated by 100-keV helium ions with a fluence of 5 × 10^(20) ions/m^(2) at 293 K and 673 K,respectively.And the samples irradiated at room temperature are annealed at different temperatures to examine the diffusion behavior of helium bubbles.Transmission electron microscope(TEM) is employed to characterize the structural morphology of precipitated nanoparticles and the evolution of helium bubbles.Experimental results reveal that nanosized,spherical,dispersed,coherent,and ordered L1_(2)-type Ni_(3)Ti γ' precipitations are introduced into FeCoNiCr(Ni_(3)Ti)_(0.1) HEAs by means of ageing treatments at temperatures between 1073 K and 1123 K.Under the ageing treatment conditions adopted in this work,γ' nanoparticles are precipitated in FeCoNiCr(Ni_(3)Ti)_(0.1) HE As,with average diameters of 15.80 nm,37.09 nm,and 62.50 nm,respectively.The average sizes of helium bubbles observed in samples after 673-K irradiation are 1.46 nm,1.65 nm,and 1.58 nm,respectively.The improvement in the irradiation resistance of FeCoNiCr(Ni_(3)Ti)_(0.1) HEAs is evidenced by the diminution in bubbles size.Furthermore,the FeCoNiCr(Ni_(3)Ti)_(0.1) HEAs containing γ' precipitates of 15.8 nm exhibits the minimum size and density of helium bubbles,which can be ascribed to the considerable helium trapping effects of heterogeneous coherent phase boundaries.Subsequently,annealing experiments conducted after 293-K irradiation indicate that HEAs containing precipitated phases exhibits smaller apparent activation energy(E_(a)) for helium bubbles,resulting in larger helium bubble size.This study provides guidance for improving the irradiation resistance of L1_(2)-strengthened high-entropy alloy.展开更多
In this paper,the dust particle surface potential for argon-helium plasma is evaluated analytically and numerically in the context of negatively charged dust particles by employing a power-law(r,q)-distribution functi...In this paper,the dust particle surface potential for argon-helium plasma is evaluated analytically and numerically in the context of negatively charged dust particles by employing a power-law(r,q)-distribution function.Recent studies have reported the argon-helium plasma and conducted a brief theoretical and experimental survey.To deepen our understanding further,this study aims to analyze the argon-helium plasma comprehensively using the same pattern but with the(r,q)-distribution function.For this purpose,the current balance equations are derived for electron,helium and argon ions,when these charge species attain the quasineutrality condition.We numerically examined the currents of plasma species for a broad range of effective distribution function parameters r and q.It is revealed that the surface potential of dust particles is significantly affected by the parameters r and q,helium ion-to-electron temperature ratio,argon ion-to-electron temperature ratio,and helium ion to argon ion number density ratio.By incorporating the multi-ion(argon-helium)species,the significance of low-temperature nonMaxwellian dusty(complex)plasma is briefly examined.展开更多
The helium bubbles induced by 14 MeV neutron irradiation can cause intergranular fractures in reduced activation ferritic martensitic steel,which is a candidate structural material for fusion reactors.In order to eluc...The helium bubbles induced by 14 MeV neutron irradiation can cause intergranular fractures in reduced activation ferritic martensitic steel,which is a candidate structural material for fusion reactors.In order to elucidate the susceptibility of different grain boundaries(GBs)to helium-induced embrittlement,the tensile fracture processes of 10 types of GBs with and without helium bubbles in body-centered cubic(bcc)iron at the relevant service temperature of 600 K were investigated via molecular dynamics methods.The results indicate that in the absence of helium bubbles,the GBs studied here can be classified into two distinct categories:brittle GBs and ductile GBs.The atomic scale analysis shows that the plastic deformation of ductile GB at high temperatures originates from complex plastic deformation mechanisms,including the Bain/Burgers path phase transition and deformation twinning,in which the Bain path phase transition is the most dominant plastic deformation mechanism.However,the presence of helium bubbles severely inhibits the plastic deformation channels of the GBs,resulting in a significant decrease in elongation at fractures.For bubble-decorated GBs,the ultimate tensile strength increases with the increase in the misorientation angle.Interestingly,the coherent twin boundary∑3{112}was found to maintain relatively high fracture strength and maximum failure strain under the influence of helium bubbles.展开更多
At present, the main controlling factors of helium accumulation is one of the key scientific problems restricting the exploration and development of helium reservoir. In this paper, based on the calculation results of...At present, the main controlling factors of helium accumulation is one of the key scientific problems restricting the exploration and development of helium reservoir. In this paper, based on the calculation results of He generation rate and the geochemical characteristics of the produced gas, both the similarities and differences between natural gas and He resources in the Bohai Bay, Ordos and the surrounding Songliao Basin are compared and analyzed, discussing the main controlling factors of helium resources in the three main petroliferous basins of the North China Craton. It is found that the three basins of Bohai Bay, Ordos and Songliao have similar characteristics of source rocks, reservoirs and cap rocks, that's why their methane resource characteristics are essentially the same. The calculated ~4He generation per cubic metamorphic crystalline basement in the three basins is roughly equivalent, which is consistent with the measured He resources, and it is believed that the ~4He of radiogenic from the crust is the main factor controlling the overall He accumulation in the three basins;there is almost no contribution of the mantle-derived CH_4, which suggests that the transport and uplift of mantle-derived ~3He carried by the present-day magmatic activities along the deep-large faults is not the main reason for the mantle-derived ~3He mixing in the basins. Combined with the results of regional volcanic and geophysical studies,it is concluded that under the background of the destruction of North China Craton, magma intrusion carried a large amount of mantle-derived material and formed basic volcanic rocks in the Bohai Bay Basin and Songliao Basin, which replenished mantle-derived ~3He for the interior of the basins, and that strong seismic activities in and around the basins also promoted the upward migration of mantle source ~3He. This study suggests that the tectonic zone with dense volcanic rocks in the Cenozoic era and a high incidence of historical strong earthquakes history may be a potential area for helium resource exploration.展开更多
Owing to the characteristics of chemical inertness,low molecular weight,low boiling point,strong permeability and high heat conductivity,helium is extensively used in the fields of aerospace,low-temperature supercondu...Owing to the characteristics of chemical inertness,low molecular weight,low boiling point,strong permeability and high heat conductivity,helium is extensively used in the fields of aerospace,low-temperature superconductivity,medicine and high tech,and it is a kind of irreplaceable strategic rare resource.So far,however,less research has been conducted on the enrichment of helium in natural gas reservoirs.To solve this problem,this paper discusses the classification standard of helium-rich gas reservoirs.Based on this,the origin,source and enrichment process of helium in typical helium-rich gas reservoirs are studied,highlighting the contribution of main helium sources to helium-rich gas reservoirs.In addition,helium enrichment models of helium-rich gas reservoir in petroliferous basins are established.And the following research results are obtained.First,6 helium enrichment models of two categories(crust-source helium enrichment and crust-mantle mixing helium enrichment)are established for different petroliferous basins in China.Second,helium-rich gas reservoirs are characterized by using the multiple helium supply and diverse helium enrichment model.And no matter what enrichment model it is,the contribution of the main helium source to gas reservoirs is indispensable.Third,the helium in the gas reservoirs of central and western basins is mainly crust-source helium,and its enrichment models include ancient formation water moving upward along the fault to dilute helium,helium enrichment in the process of natural gas migration along ancient reservoirs,and helium enrichment of shale gas.Fourth,the helium in the helium-rich gas reservoirs of eastern basins is of crust-mantle mixing origin and its enrichment models are mainly hydrocarbon gas based,carbon dioxide based and nitrogen based.In conclusion,the establishment of the helium enrichment models of helium-rich gas reservoirs in petroliferous basins provides reference and guidance for studying helium enrichment laws and main controlling factors and is of great significance to the evaluation of favorable helium exploration areas.展开更多
The helium cryogenic system supplies supercritical helium cooling capacity at 4.5 K for the superconducting magnets in the EAST superconducting tokamak.Four low-temperature helium turbines are used in the 2 kW helium ...The helium cryogenic system supplies supercritical helium cooling capacity at 4.5 K for the superconducting magnets in the EAST superconducting tokamak.Four low-temperature helium turbines are used in the 2 kW helium refrigeration system,and their performance and reliability are critical for the continuous operation of the tokamak.The turbines were made by the Helium Mechanics Company in Russia.The start-up process is very unstable,easily broken,and thus testing and improvements are needed.In this paper,we analyze the structure of the helium turbine,make improvements,and describe the testing process and results of the improved helium turbines.Some of the operational experiences during the start-up process and tests are also presented.展开更多
The reduced activation ferritic/martenstic steel CLF-1 prepared by the Southwestern Institute of Physics in China was irradiated by helium ions with an energy of 5 keV at room temperature using an electron cyclotron r...The reduced activation ferritic/martenstic steel CLF-1 prepared by the Southwestern Institute of Physics in China was irradiated by helium ions with an energy of 5 keV at room temperature using an electron cyclotron resonance （ECR） ion irradiation apparatus. After the irradiation, the helium retention and desorption were investigated using a technique of thermal desorption spectroscopy （TDS）. The experiment was conducted with both the normal and welded samples. Blisters were observed after the helium ion irradiation, and the surface density of blisters in the welded samples was lower than that in the non-welded samples. Three desorption peaks were observed in both the non-welded and welded samples. These desorption peaks corresponded to those of blister ruptures and the helium release from the inner bubbles and the defects. The amount of helium retained in the welded samples was approximately the same as that in the non- welded samples, which was much less than other reduced activation materials, such as vanadium alloy and SiC/SiC composites.展开更多
In the present paper on the one hand we apply the central limit theorem to the solution of the sign problem of a path integral of two-interacting particles in potential and give an expression for the sign solved propa...In the present paper on the one hand we apply the central limit theorem to the solution of the sign problem of a path integral of two-interacting particles in potential and give an expression for the sign solved propagator (SSP) derived from that solution and on the other hand we perform the angular decomposition of the path integrals of the 2D and 3D Helium atoms. Finally, we combine those two results and derive the SSPs of the 2D and 3D Helium atoms.展开更多
In the previous paper by one of us (hereafter paper I), the author considered Rydberg states of the muonic-electronic helium atom or helium-like ion and used the fact that the muon motion occurs much more rapidly than...In the previous paper by one of us (hereafter paper I), the author considered Rydberg states of the muonic-electronic helium atom or helium-like ion and used the fact that the muon motion occurs much more rapidly than the electron motion. Assuming that the muon and nucleus orbits are circular, he applied the analytical method based on separating rapid and slow subsystems. He showed that the electron moves in an effective potential that is mathematically equivalent to the potential of a satellite orbiting an oblate planet like the Earth. He also showed that the “unperturbed” elliptical orbit of the electron engages in two precessions simultaneously: the precession of the electron orbit in the plane of the orbit and the precession of the orbital plane of the electron around the axis perpendicular to the plane of the muon and nuclear orbits. The problem remained whether or not the allowance for the ellipticity of the orbit could significantly change the results. In the present paper, we address this problem: we study how the allowance for a relatively low eccentricity ε of the muon and nucleus orbits affects the motion of the electron. We derive an additional, ε-dependent term in the effective potential for the motion of the electron. We show analytically that in the particular case of the planar geometry (where the electron orbit is in the plane of the muon and nucleus orbits), it leads to an additional contribution to the frequency of the precession of the electron orbit. We demonstrate that this additional, ε-depen- dent contribution to the precession frequency of the electron orbit can reach the same order of magnitude as the primary, ε-independent contribution to the precession frequency. Therefore, the results of our paper seem to be important not only qualitatively, but also quantitatively.展开更多
Helium in China highly depends on import at present,so the most practical way to change the situation is searching for medium-to-large natural gasfields with high helium content.Therefore,the hydrocarbon accumulation ...Helium in China highly depends on import at present,so the most practical way to change the situation is searching for medium-to-large natural gasfields with high helium content.Therefore,the hydrocarbon accumulation mechanism and the helium origin of the Weiyuan high-helium natural gas reservoir have been analyzed tofind out the feasibility offinding natural gasfield with high helium content in the Presinian strata of the Sichuan Basin.Based on twelve outcrop sections and drilling data of four wells encountering the Presinian strata,the petrological features,sedimentary facies and source rocks of Presinian strata were systematically analyzed,which shows that the sedimentary formation developed in the Presinian is the Nanhua system,and the stratigraphic sequence revealed by outcrop section in the eastern margin includes the Nantuo,Datangpo,Gucheng and Liantuo Fms,and it is inferred that the same stratigraphic sequence may occur inside the basin.The Nantuo,Gucheng and Liantuo Fms are mainly glacial deposits of glutenite interbedded with mudstone;the Datangpo Fm is interglacial deposits of sandstone and shale,the lower part shale,rich in organic matter,is fairly good source rock.Further study showed that the Nantuo coarse-grained clastic reservoir,Datangpo source rock and the intruded granite“helium source rock”make up a good high-helium gas system.Controlled by the early rift,the thick Presinian sedimentary rocks occur primarily inside the rift.The distribution of sedimentary rocks and granite in the basin was predicted by use of the seismic data,which shows that the feasibility offinding high-helium gas reservoirs in Ziyang area of the Sichuan Basin is great.展开更多
Global helium(He) shortage is a challenging problem;however, the types of helium source rock and the mechanisms of He generation and release therein remain still poorly understood. In this study, in order to evaluate ...Global helium(He) shortage is a challenging problem;however, the types of helium source rock and the mechanisms of He generation and release therein remain still poorly understood. In this study, in order to evaluate the potential of granite as an effective helium source rock, we collected granitic samples from the North Qinling Orogen, Central China, in the south of the helium-rich Weihe Basin. The helium generation and release behaviors in granite were studied through analysis of U and Th concentrations, EMPA images, and He and Ar concentrations and isotopic ratios extracted by crushing and stepwise heating. The results indicate that Ar has a better retention and a lower mobility than He. 3 He/4 He ratios released by crushing and stepwise heating are 0.016–0.056 RA and 0.003–0.572 RA, respectively, where RA is the atmospheric 3 He/4 He of 1.4×10-6, reflecting a crustal and radiogenic source. Helium concentrations extracted by the two ways are 0.13–0.95 ucm3 STP/g and 7.82–115.62 ucm3 STP/g, respectively, suggesting that matrix-sited He accounts for more than 98% of total helium preserved in granite. In addition, the total generated He amounts in granites are calculated based on the measured U and Th concentrations in granitic samples. Dividing the preserved He quantities by the generated He amounts, it turned out that less than 10% of He produced since the formation of the granite is preserved in the rock over geological time, suggesting that more than 90% generated He can be transferred to the Weihe Basin. Temperature and fracture are the two critical factors controlling He release. Based on the relationship between He diffusivity of granites and temperature and the He closure temperatures of a variety of U-and Th-rich minerals(27–250°C), we estimate that He can be partially released out of granite at the depths <400 m and totally released at the depths >7800 m. Fractures provide effective transfer of free He from deep source rocks to shallow reservoirs. Finally, a model on granite as an effective helium source rock is established. We suggest exploring He resources in hydrocarbon basins with granitic basement(or adjacent to granite bodies), high geothermal field, and young active fractures.展开更多
基金the Strategic Pilot Science and Technology Projects of Chinese Academy of Sciences,China(No.XDC10040000).
文摘Due to its unique properties,helium is critical in scientific research and industrial innovation,particularly in cryogenics;however,its scarcity necessitates efficient resource utilization.Through a review of the historical development of the helium industry,this study comprehensively evaluates the value,sources,production methods,supply dynamics,and sustainability challenges of helium.The processes and mechanisms of helium enrichment,along with effective exploration methods,are systematically analyzed here.We recommend focusing on the development of technologies for helium preservation,recovery,and extraction,particularly the extraction technology for helium-poor fields.Market analysis indicates that no imminent crisis in the global helium supply is expected before 2060.Thus,enhancing helium resource protection technologies is essential to improve its economic utilization and management while providing a timely reference for the scientific community.
基金support from CNPC Key and Core Technology Research Project(Grant No.2021ZG13).
文摘Helium is a valuable natural resource used widely in high-tech industries because of its unique physical and chemical properties.The study of helium in shale gas is still in its infancy,and the content,genesis,and enrichment patterns of helium in shale gas are not yet clear.In this paper,the concentrations and isotopic characteristics of helium were investigated in the Wufeng-Longmaxi shale gas in the Sichuan Basin and the periphery areas.The analytical results show that the concentrations of helium in the southern Sichuan shale gas fall in the range of 0.018-0.051 vol%with an average of 0.029 vol%.The helium abundance in Weiyuan shale gas are relatively low compared to those in conventional natural gas pools from the same area(generally greater than 0.20 vol%),reflecting the significance of long distance migration to the enrichment of helium in gas pools.The relatively low ratios of 3He and 4He in shale gas indicate that most of the helium are crustal derived helium.Further quantitative estimate based on helium,neon,and argon isotopic ratios suggest almost 100%crustal helium source.The helium residing in shale reservoirs can be deconvoluted into the indigenous helium generated in-situ by shale and exogenous helium generated from external helium source rocks and charged through faults and/or fractures networks.According to preliminary calculations,external helium source is required to meet the threshold of an economic helium-rich field of helium concentration of 0.1 vol%except for particular areas with extraordinarily high uranium and thorium concentration.Based on detailed study on typical helium-rich shale gas reservoirs,major advantageous features for helium's enrichment in shale gas include:(1)high-quality helium source rocks,(2)effective migration paths,and(3)diminished dilution effects of shale gas.Shale gas plays with underlying ancient cratonic basement,well developed source-connecting faults,and moderate pressure coefficient are potential targets for helium exploration.
基金supported by the Hundred Talents Programof the Chinese Academy of Sciences,the Pre-Research Project JZX7Y20220414101801the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB35000000)the National Natural Science Foundation Projects(No.51806231).
文摘Helium sorption cooler technology is a key means to realize highly reliable low-vibration very lowtemperature environments,which have important applications in fields such as quantum computing and space exploration.The laboratory designed a superfluid suppression small hole and a multi-ribbed condenser,developed a reliable-performance helium sorption cooler(HSC),and conducted experimental studies.Experimental results show that the prototype can achieve the lowest cooling temperature of 873 mK without load by filling 6MPa helium at room temperature.The low-temperature hold time is 26 h,and the temperature fluctuation is within 0.8 mK.The cooling power of the helium sorption cooler is 1 mW@0.98 K@3.5 h.Experimental results indicate that when the charging pressure is reduced to 4MPa,theminimum temperature decreases to 836mK,and the hold time shortens to 16 h.When the pre-cooling temperature increases from 3.9 to 4.9 K,the hold time is reduced to 3 h.
基金supported by the National Key R&D Program of China(2021YFA0718600)the National Natural Science Foundation of China(42441809).
文摘Research on the interstellar medium and its interaction with the solar system constitutes a significant topic in planetary physics.As the Sun traverses the local interstellar cloud,interstellar neutrals penetrate the heliosphere,forming the interstellar wind,and scattering solar extreme ultraviolet(EUV)emission lines.The intensity of the scattered radiation provides an indicator of the characteristic parameters of the interstellar wind,crucial for characterizing the heliosphere,the interstellar medium,and the evolution of the solar system.Meanwhile,a powerful method for studying stellar evolution is investigating the EUV emissions of stars.The only ongoing mission conducting an EUV full-sky survey is the relay satellite Queqiao-2.Due to the strong absorption of the interstellar medium at EUV wavelengths,modelling is essential to any study of these influences.In this study,we reviewed classical modelling methods for the density distribution of the interstellar helium atoms in the heliosphere,and the corresponding 58.4 nm radiation intensity.We established distinct density and intensity models for different orbital positions of Earth’s revolution.We found that when the Earth enters the helium focusing cone in the downwind region,both the helium density and the 58.4 nm radiation intensity increase rapidly,with the temperature effect being particularly important.The radiation intensity in the downwind direction can be 170 times that of the upwind direction.Some negligible factors were omitted for simplicity,such as the effects of the solar line width and Doppler shift.Our research can serve as an aid to the interpretation of the EUV observations in the full-sky survey conducted by Queqiao-2.
基金supported by the National Key Research&Development Program of China(No.2023YFF0721304)the Key Research&Development Program of Jiangsu Province(No.2021015-4),China。
文摘Gifford-McMahon-type pulse-tube cryocoolers(GM-PTCs)working at liquid helium temperatures are promising in quantum technology and cryogenic physics for their high reliability and minimal vibration.These features stem from the fact that there are no extra moving parts introduced into the system.The rotary valve is a key component in GM-PTCs that transfers the output exergy from the compressor to the cold head.Because a low Carnot efficiency of 1.58%is achieved at liquid helium temperatures,optimizing the rotary valve is crucial for improving the efficiency of GM-PTCs.In this regard,an exergy-loss analysis method is proposed in this paper to quantitatively obtain the leakage loss and viscosity loss of a rotary valve by experimental measurements.The results show that viscosity loss accounts for more than 97.5%of the total exergy loss in the rotary valve,and that it is possible to improve the structure of the rotary valve by expanding the flow area by 1.5 times.To verify the method,the cooling temperature and power of a remote two-stage GM-PTC were monitored,with original or optimized rotary valves installed.The experimental results show that compared to the original rotary valve,the optimized rotary valve can improve the cooling efficiency of a GM-PTC by 16.4%,with a cooling power of 0.78 W at 4.2 K.
基金the fnancial support from the National MCF Energy R&D Program of China(No.2018YFE0306101)the Science and Technology Laboratory on Reactor Fuel and Materials of China.
文摘Y-Zr-O nano-oxide dispersion-strengthened(ODS)ferritic alloys have attracted increasing research eforts in recent years,for the enhanced nucleation and refnement of nano-oxides.Here,we report a frst-principles exploration on the possible roles of Y_(2)Zr_(2)O_(7) in helium management in Y+Zr and Y+Ti+Zr co-alloyed ODS ferritic alloys.Bulk phase calculations suggested that similarly as Y_(2)Ti_(2)O_(7),Y_(2)Zr_(2)O_(7) has a comparably strong capability for trapping helium at its interstitial sites.The equilibrium Fe/Y_(2)Zr_(2)O_(7) interface structure was further predicted as the top-coordinated O-rich at the temperature range of interest.Vacancy and helium both segregate to the Y_(2)Zr_(2)O_(7) interface,in preference to the Y_(2)Ti_(2)O_(7) interface,the bulk interior of Y_(2)Zr_(2)O_(7) and the grain boundaries.In this regard,Y_(2)Zr_(2)O_(7) can be more efective than Y_(2)Ti_(2)O_(7) in preventing vacancies and helium from reaching GBs.Based on these results,the profound implications for the helium tolerance of Zralloyed ODS ferritic alloys were discussed.
基金Project supported by the National Key Research and Development Program of China (Grant Nos.2020YFF01014706 and 2017YFC0601901)the National Natural Science Foundation of China (Grant Nos.61571019 and 52177026)。
文摘Josephson junction plays a key role not only in studying the basic physics of unconventional iron-based superconductors but also in realizing practical application of thin-film based devices,therefore the preparation of high-quality iron pnictide Josephson junctions is of great importance.In this work,we have successfully fabricated Josephson junctions from Co-doped BaFe_(2)As_(2)thin films using a direct junction fabrication technique which utilizes high energy focused helium ion beam(FHIB).The electrical transport properties were investigated for junctions fabricated with various He^(+)irradiation doses.The junctions show sharp superconducting transition around 24 K with a narrow transition width of 2.5 K,and a dose correlated foot-structure resistance which corresponds to the effective tuning of junction properties by He^(+)irradiation.Significant J_c suppression by more than two orders of magnitude can be achieved by increasing the He^(+)irradiation dose,which is advantageous for the realization of low noise ion pnictide thin film devices.Clear Shapiro steps are observed under 10 GHz microwave irradiation.The above results demonstrate the successful fabrication of high quality and controllable Co-doped BaFe_(2)As_(2)Josephson junction with high reproducibility using the FHIB technique,laying the foundation for future investigating the mechanism of iron-based superconductors,and also the further implementation in various superconducting electronic devices.
基金Supported by the National Natural Science Foundation of China(41821002,42272163,42072167)Laoshan Laboratory Science and Technology Innovation Project(LSKJ202203403)Hainan Branch Project of CNOOC(KJZH-2021-0003-00).
文摘Based on the geochemical parameters and analytical data,the heat conservation equation,mass balance law,Rayleigh fractionation model and other methods were used to quantify the in-situ yield and external flux of crust-derived helium,and the initial He concentration and thermal driving mechanism of mantle-derived helium,in the Ledong Diapir area,the Yinggehai Basin,in order to understand the genetic source,migration and accumulation mechanisms of helium under deep thermal fluid activities.The average content of mantle-derived He is only 0.0014%,the ^(3)He/^(4)He value is(0.002–2.190)×10^(−6),and the R/Ra value ranges from 0.01 to 1.52,indicating the contribution of mantle-derived He is 0.09%–19.84%,while the proportion of crust-derived helium can reach over 80%.Quantitative analysis indicates that the crust-derived helium is dominated by external input,followed by in-situ production,in the Ledong diapir area.The crust-derived helium exhibits an in-situ 4 He yield rate of(7.66–7.95)×10^(−13)cm^(3)/(a·g),an in-situ 4 He yield of(4.10–4.25)×10^(−4)cm^(3)/g,and an external 4 He influx of(5.84–9.06)×10^(−2)cm^(3)/g.These results may be related to atmospheric recharge into formation fluid and deep rock-water interactions.The ratio of initial mole volume of 3 He to enthalpy(W)is(0.004–0.018)×10^(−11) cm^(3)/J,and the heat contribution from the deep mantle(X_(M))accounts for 7.63%–36.18%,indicating that deep hot fluid activities drive the migration of mantle-derived 3 He.The primary helium migration depends on advection,while the secondary migration is controlled by hydrothermal degassing and gas-liquid separation.From deep to shallow layers,the CO_(2/3) He value rises from 1.34×10^(9)to 486×10^(9),indicating large amount of CO_(2)has escaped.Under the influence of deep thermal fluid,helium migration and accumulation mechanisms include:deep heat driven diffusion,advection release,vertical hydrothermal degassing,shallow lateral migration,accumulation in traps far from faults,partial pressure balance and sealing capability.
基金Shahid Chamran University of Ahvaz for supporting this research under the grant number SCU.SP1401.259。
文摘In this study,we successfully extracted the‘knee structure’for non-sequential double ionization(NSDI)in the helium atom.To achieve this,for the first time,we solved the time-dependent Schrödinger equation in three dimensions for the helium atom,utilizing the shielding charge approximation.Our findings corroborate prior observations by Wang et al[Wang and Eberly,Phys.Rev.Lett.105,083001(2010)],demonstrating that NSDI occurs within a narrower time window in circular polarization compared to linear polarization.As a result,the yield of linear polarization was higher than that of circular polarization,aligning with the previously reported results.Notably,in the case of circular polarization,the time window further narrows with increasing intensity,attributed to a decrease in the time-of-flight.
基金Project support provided by the National Natural Science Foundation of China(Grant No.12075200)the National Key Research and Development Program of China(Grant No.2022YFB3706004)。
文摘A series of high-entropy alloys(HEAs) containing nanoprecipitates of varying sizes is successfully prepared by a non-consuming vacuum arc melting method.In order to study the irradiation evolution of helium bubbles in the FeCoNiCrbased HE As with γ' precipitates,these samples are irradiated by 100-keV helium ions with a fluence of 5 × 10^(20) ions/m^(2) at 293 K and 673 K,respectively.And the samples irradiated at room temperature are annealed at different temperatures to examine the diffusion behavior of helium bubbles.Transmission electron microscope(TEM) is employed to characterize the structural morphology of precipitated nanoparticles and the evolution of helium bubbles.Experimental results reveal that nanosized,spherical,dispersed,coherent,and ordered L1_(2)-type Ni_(3)Ti γ' precipitations are introduced into FeCoNiCr(Ni_(3)Ti)_(0.1) HEAs by means of ageing treatments at temperatures between 1073 K and 1123 K.Under the ageing treatment conditions adopted in this work,γ' nanoparticles are precipitated in FeCoNiCr(Ni_(3)Ti)_(0.1) HE As,with average diameters of 15.80 nm,37.09 nm,and 62.50 nm,respectively.The average sizes of helium bubbles observed in samples after 673-K irradiation are 1.46 nm,1.65 nm,and 1.58 nm,respectively.The improvement in the irradiation resistance of FeCoNiCr(Ni_(3)Ti)_(0.1) HEAs is evidenced by the diminution in bubbles size.Furthermore,the FeCoNiCr(Ni_(3)Ti)_(0.1) HEAs containing γ' precipitates of 15.8 nm exhibits the minimum size and density of helium bubbles,which can be ascribed to the considerable helium trapping effects of heterogeneous coherent phase boundaries.Subsequently,annealing experiments conducted after 293-K irradiation indicate that HEAs containing precipitated phases exhibits smaller apparent activation energy(E_(a)) for helium bubbles,resulting in larger helium bubble size.This study provides guidance for improving the irradiation resistance of L1_(2)-strengthened high-entropy alloy.
文摘In this paper,the dust particle surface potential for argon-helium plasma is evaluated analytically and numerically in the context of negatively charged dust particles by employing a power-law(r,q)-distribution function.Recent studies have reported the argon-helium plasma and conducted a brief theoretical and experimental survey.To deepen our understanding further,this study aims to analyze the argon-helium plasma comprehensively using the same pattern but with the(r,q)-distribution function.For this purpose,the current balance equations are derived for electron,helium and argon ions,when these charge species attain the quasineutrality condition.We numerically examined the currents of plasma species for a broad range of effective distribution function parameters r and q.It is revealed that the surface potential of dust particles is significantly affected by the parameters r and q,helium ion-to-electron temperature ratio,argon ion-to-electron temperature ratio,and helium ion to argon ion number density ratio.By incorporating the multi-ion(argon-helium)species,the significance of low-temperature nonMaxwellian dusty(complex)plasma is briefly examined.
基金supported by the National Natural Science Foundation of China(Nos.12175231 and 11805131)Anhui Natural Science Foundation of China(No.2108085J05)+1 种基金the National Key Research and Development Plan of China(No.2018YFE0307101)the Collaborative Innovation Program of the Hefei Science Center,CAS(Nos.2021HSC-CIP020 and 2022HSC-CIP009)。
文摘The helium bubbles induced by 14 MeV neutron irradiation can cause intergranular fractures in reduced activation ferritic martensitic steel,which is a candidate structural material for fusion reactors.In order to elucidate the susceptibility of different grain boundaries(GBs)to helium-induced embrittlement,the tensile fracture processes of 10 types of GBs with and without helium bubbles in body-centered cubic(bcc)iron at the relevant service temperature of 600 K were investigated via molecular dynamics methods.The results indicate that in the absence of helium bubbles,the GBs studied here can be classified into two distinct categories:brittle GBs and ductile GBs.The atomic scale analysis shows that the plastic deformation of ductile GB at high temperatures originates from complex plastic deformation mechanisms,including the Bain/Burgers path phase transition and deformation twinning,in which the Bain path phase transition is the most dominant plastic deformation mechanism.However,the presence of helium bubbles severely inhibits the plastic deformation channels of the GBs,resulting in a significant decrease in elongation at fractures.For bubble-decorated GBs,the ultimate tensile strength increases with the increase in the misorientation angle.Interestingly,the coherent twin boundary∑3{112}was found to maintain relatively high fracture strength and maximum failure strain under the influence of helium bubbles.
基金The Natural gas formation rules and key technologies for exploration in the western exploration area KT2022A02the Science and Technology Fundamental Resources Investigation Program under contract No. 2023FY101500+2 种基金the National Key Research and Development Program of China under contract No. 2023YFC3012005the Central Public-interest Scientific Institution Basal Researchunder contract No. CEAIEF20230505。
文摘At present, the main controlling factors of helium accumulation is one of the key scientific problems restricting the exploration and development of helium reservoir. In this paper, based on the calculation results of He generation rate and the geochemical characteristics of the produced gas, both the similarities and differences between natural gas and He resources in the Bohai Bay, Ordos and the surrounding Songliao Basin are compared and analyzed, discussing the main controlling factors of helium resources in the three main petroliferous basins of the North China Craton. It is found that the three basins of Bohai Bay, Ordos and Songliao have similar characteristics of source rocks, reservoirs and cap rocks, that's why their methane resource characteristics are essentially the same. The calculated ~4He generation per cubic metamorphic crystalline basement in the three basins is roughly equivalent, which is consistent with the measured He resources, and it is believed that the ~4He of radiogenic from the crust is the main factor controlling the overall He accumulation in the three basins;there is almost no contribution of the mantle-derived CH_4, which suggests that the transport and uplift of mantle-derived ~3He carried by the present-day magmatic activities along the deep-large faults is not the main reason for the mantle-derived ~3He mixing in the basins. Combined with the results of regional volcanic and geophysical studies,it is concluded that under the background of the destruction of North China Craton, magma intrusion carried a large amount of mantle-derived material and formed basic volcanic rocks in the Bohai Bay Basin and Songliao Basin, which replenished mantle-derived ~3He for the interior of the basins, and that strong seismic activities in and around the basins also promoted the upward migration of mantle source ~3He. This study suggests that the tectonic zone with dense volcanic rocks in the Cenozoic era and a high incidence of historical strong earthquakes history may be a potential area for helium resource exploration.
基金supported by the National Natural Science Foundation of China“Water-soluble gas accumulation and its quantitative research method based on rare gas tracking”(No.41872162)the National Natural Science Foundation of China“Enrichment mechanism and resource potential of helium in superimposed basins in central-western China”(No.42141022).
文摘Owing to the characteristics of chemical inertness,low molecular weight,low boiling point,strong permeability and high heat conductivity,helium is extensively used in the fields of aerospace,low-temperature superconductivity,medicine and high tech,and it is a kind of irreplaceable strategic rare resource.So far,however,less research has been conducted on the enrichment of helium in natural gas reservoirs.To solve this problem,this paper discusses the classification standard of helium-rich gas reservoirs.Based on this,the origin,source and enrichment process of helium in typical helium-rich gas reservoirs are studied,highlighting the contribution of main helium sources to helium-rich gas reservoirs.In addition,helium enrichment models of helium-rich gas reservoir in petroliferous basins are established.And the following research results are obtained.First,6 helium enrichment models of two categories(crust-source helium enrichment and crust-mantle mixing helium enrichment)are established for different petroliferous basins in China.Second,helium-rich gas reservoirs are characterized by using the multiple helium supply and diverse helium enrichment model.And no matter what enrichment model it is,the contribution of the main helium source to gas reservoirs is indispensable.Third,the helium in the gas reservoirs of central and western basins is mainly crust-source helium,and its enrichment models include ancient formation water moving upward along the fault to dilute helium,helium enrichment in the process of natural gas migration along ancient reservoirs,and helium enrichment of shale gas.Fourth,the helium in the helium-rich gas reservoirs of eastern basins is of crust-mantle mixing origin and its enrichment models are mainly hydrocarbon gas based,carbon dioxide based and nitrogen based.In conclusion,the establishment of the helium enrichment models of helium-rich gas reservoirs in petroliferous basins provides reference and guidance for studying helium enrichment laws and main controlling factors and is of great significance to the evaluation of favorable helium exploration areas.
文摘The helium cryogenic system supplies supercritical helium cooling capacity at 4.5 K for the superconducting magnets in the EAST superconducting tokamak.Four low-temperature helium turbines are used in the 2 kW helium refrigeration system,and their performance and reliability are critical for the continuous operation of the tokamak.The turbines were made by the Helium Mechanics Company in Russia.The start-up process is very unstable,easily broken,and thus testing and improvements are needed.In this paper,we analyze the structure of the helium turbine,make improvements,and describe the testing process and results of the improved helium turbines.Some of the operational experiences during the start-up process and tests are also presented.
基金supported by National Natural Science Foundation of China (50701017)Japan-China Core University Program on Plasma and Nuclear Fusion
文摘The reduced activation ferritic/martenstic steel CLF-1 prepared by the Southwestern Institute of Physics in China was irradiated by helium ions with an energy of 5 keV at room temperature using an electron cyclotron resonance （ECR） ion irradiation apparatus. After the irradiation, the helium retention and desorption were investigated using a technique of thermal desorption spectroscopy （TDS）. The experiment was conducted with both the normal and welded samples. Blisters were observed after the helium ion irradiation, and the surface density of blisters in the welded samples was lower than that in the non-welded samples. Three desorption peaks were observed in both the non-welded and welded samples. These desorption peaks corresponded to those of blister ruptures and the helium release from the inner bubbles and the defects. The amount of helium retained in the welded samples was approximately the same as that in the non- welded samples, which was much less than other reduced activation materials, such as vanadium alloy and SiC/SiC composites.
文摘In the present paper on the one hand we apply the central limit theorem to the solution of the sign problem of a path integral of two-interacting particles in potential and give an expression for the sign solved propagator (SSP) derived from that solution and on the other hand we perform the angular decomposition of the path integrals of the 2D and 3D Helium atoms. Finally, we combine those two results and derive the SSPs of the 2D and 3D Helium atoms.
文摘In the previous paper by one of us (hereafter paper I), the author considered Rydberg states of the muonic-electronic helium atom or helium-like ion and used the fact that the muon motion occurs much more rapidly than the electron motion. Assuming that the muon and nucleus orbits are circular, he applied the analytical method based on separating rapid and slow subsystems. He showed that the electron moves in an effective potential that is mathematically equivalent to the potential of a satellite orbiting an oblate planet like the Earth. He also showed that the “unperturbed” elliptical orbit of the electron engages in two precessions simultaneously: the precession of the electron orbit in the plane of the orbit and the precession of the orbital plane of the electron around the axis perpendicular to the plane of the muon and nuclear orbits. The problem remained whether or not the allowance for the ellipticity of the orbit could significantly change the results. In the present paper, we address this problem: we study how the allowance for a relatively low eccentricity ε of the muon and nucleus orbits affects the motion of the electron. We derive an additional, ε-dependent term in the effective potential for the motion of the electron. We show analytically that in the particular case of the planar geometry (where the electron orbit is in the plane of the muon and nucleus orbits), it leads to an additional contribution to the frequency of the precession of the electron orbit. We demonstrate that this additional, ε-depen- dent contribution to the precession frequency of the electron orbit can reach the same order of magnitude as the primary, ε-independent contribution to the precession frequency. Therefore, the results of our paper seem to be important not only qualitatively, but also quantitatively.
文摘Helium in China highly depends on import at present,so the most practical way to change the situation is searching for medium-to-large natural gasfields with high helium content.Therefore,the hydrocarbon accumulation mechanism and the helium origin of the Weiyuan high-helium natural gas reservoir have been analyzed tofind out the feasibility offinding natural gasfield with high helium content in the Presinian strata of the Sichuan Basin.Based on twelve outcrop sections and drilling data of four wells encountering the Presinian strata,the petrological features,sedimentary facies and source rocks of Presinian strata were systematically analyzed,which shows that the sedimentary formation developed in the Presinian is the Nanhua system,and the stratigraphic sequence revealed by outcrop section in the eastern margin includes the Nantuo,Datangpo,Gucheng and Liantuo Fms,and it is inferred that the same stratigraphic sequence may occur inside the basin.The Nantuo,Gucheng and Liantuo Fms are mainly glacial deposits of glutenite interbedded with mudstone;the Datangpo Fm is interglacial deposits of sandstone and shale,the lower part shale,rich in organic matter,is fairly good source rock.Further study showed that the Nantuo coarse-grained clastic reservoir,Datangpo source rock and the intruded granite“helium source rock”make up a good high-helium gas system.Controlled by the early rift,the thick Presinian sedimentary rocks occur primarily inside the rift.The distribution of sedimentary rocks and granite in the basin was predicted by use of the seismic data,which shows that the feasibility offinding high-helium gas reservoirs in Ziyang area of the Sichuan Basin is great.
基金supported by the National Science Foundation of China(NSFC,No.41572131)the China Geology Survey(DD20190103).
文摘Global helium(He) shortage is a challenging problem;however, the types of helium source rock and the mechanisms of He generation and release therein remain still poorly understood. In this study, in order to evaluate the potential of granite as an effective helium source rock, we collected granitic samples from the North Qinling Orogen, Central China, in the south of the helium-rich Weihe Basin. The helium generation and release behaviors in granite were studied through analysis of U and Th concentrations, EMPA images, and He and Ar concentrations and isotopic ratios extracted by crushing and stepwise heating. The results indicate that Ar has a better retention and a lower mobility than He. 3 He/4 He ratios released by crushing and stepwise heating are 0.016–0.056 RA and 0.003–0.572 RA, respectively, where RA is the atmospheric 3 He/4 He of 1.4×10-6, reflecting a crustal and radiogenic source. Helium concentrations extracted by the two ways are 0.13–0.95 ucm3 STP/g and 7.82–115.62 ucm3 STP/g, respectively, suggesting that matrix-sited He accounts for more than 98% of total helium preserved in granite. In addition, the total generated He amounts in granites are calculated based on the measured U and Th concentrations in granitic samples. Dividing the preserved He quantities by the generated He amounts, it turned out that less than 10% of He produced since the formation of the granite is preserved in the rock over geological time, suggesting that more than 90% generated He can be transferred to the Weihe Basin. Temperature and fracture are the two critical factors controlling He release. Based on the relationship between He diffusivity of granites and temperature and the He closure temperatures of a variety of U-and Th-rich minerals(27–250°C), we estimate that He can be partially released out of granite at the depths <400 m and totally released at the depths >7800 m. Fractures provide effective transfer of free He from deep source rocks to shallow reservoirs. Finally, a model on granite as an effective helium source rock is established. We suggest exploring He resources in hydrocarbon basins with granitic basement(or adjacent to granite bodies), high geothermal field, and young active fractures.
