Liquid hydrogen(LH2)attracts widespread attention because of its highest energy storage density.However,evaporation loss is a serious problem in LH2 storage due to the low boiling point(20 K).Efficient insulation tech...Liquid hydrogen(LH2)attracts widespread attention because of its highest energy storage density.However,evaporation loss is a serious problem in LH2 storage due to the low boiling point(20 K).Efficient insulation technology is an important issue in the study of LH2 storage.Hollow glass microspheres(HGMs)is a potential promising thermal insulation material because of its low apparent thermal conductivity,fast installation(Compared with multi-layer insulation,it can be injected in a short time.),and easy maintenance.A novel cryogenic insulation system consisting of HGMs and a selfevaporating vapor-cooled shield(VCS)is proposed for storage of LH2.A thermodynamic model has been established to analyze the coupled heat transfer characteristics of HGMs and VCS in the composite insulation system.The results show that the combination of HGMs and VCS can effectively reduce heat flux into the LH2 tank.With the increase of VCS number from 1 to 3,the minimum heat flux through HGMs decreases by 57.36%,65.29%,and 68.21%,respectively.Another significant advantage of HGMs is that their thermal insulation properties are not sensitive to ambient vacuum change.When ambient vacuum rises from 10^-3 Pa to 1 Pa,the heat flux into the LH2 tank increases by approximately 20%.When the vacuum rises from 10^-3 Pa to 100 Pa,the combination of VCS and HGMs reduces the heat flux into the tank by 58.08%-69.84% compared with pure HGMs.展开更多
Mn-based zinc ion battery has the advantages of low cost and high performance,which makes it the promising energy storage system.However,the poor conductivity and the agglomeration in the synthesis process of manganes...Mn-based zinc ion battery has the advantages of low cost and high performance,which makes it the promising energy storage system.However,the poor conductivity and the agglomeration in the synthesis process of manganese-based materials restrict the performance of batteries.Herein,the Se-doped MnS/Ti_(3)C_(2)T_(x)(Se-MnS/Ti_(3)C_(2)T_(x))composite material derived from Mn-based metal-organic framework is reported.Electrochemical tests show that Se-doped could generate S defects and enhance the electrochemical activity of MnS.At the same time,the introduction of Ti_(3)C_(2)T_(x) substrate is conducive to exposing more sulfur defects and improving the utilization rate of defects.In the mechanism study,it is found that Se-MnS/Ti_(3)C_(2)T_(x) is transformed into S/Se co-doped Mn3O_(4) at the first charge,which innovatively elucidated the behavior of S/Se during activation.In the electrochemical performance test,the specific capacity can reach 74.7 mAh·g^(-1) at 5.0 A·g^(-1).In addition,the Zn-Ti_(3)C_(2)T_(x) membrane electrode is prepared by vacuum filtration as the zinc-poor anode,which is assembled into the rocking chair full battery to avoid dendrite growth and exhibit excellent rate performance.The addition of Zn2+weakens the electrostatic repulsion between the interlayers of MXene,and the formation of the folded morphology aids the penetration of the electrolyte.At 1.0 A·g^(-1),the capacity can reach 50.6 mAh·g^(-1).This work is helpful to promote the research and development of the reaction mechanism of manganese based rocking chair batteries.展开更多
In this work,a novel ultraviolet(UV)photodetector(PD)based on AlGaN/u-GaN/p-GaN/u-GaN heterojunction high electron mobility transistor(HEMT)has been developed.This HEMT epilayer is grown using the metal-organic chemic...In this work,a novel ultraviolet(UV)photodetector(PD)based on AlGaN/u-GaN/p-GaN/u-GaN heterojunction high electron mobility transistor(HEMT)has been developed.This HEMT epilayer is grown using the metal-organic chemical vapor deposition(MOCVD)technique,and the growth parameters,including the AlGaN growth temperature,preheating temperature of the p-GaN layer,and NH3/N2 flow rate,are optimized to improve the quality of the epilayer.The optimized epilayer exhibits a flat surface with a root mean square value of 0.146 nm and low dislocation density.The p-GaN thickness in epitaxial wafers has a significant influence on electrical and UV photoresponse.With a p-GaN of 1µm,the UV PD demonstrates a significant switching ratio and transconductance of 107 and 127.3 mS mm^(-1),respectively.Acting as a UV PD,it also exhibits a high light on/off ratio(I_(light)/I_(dark))of 6.35×10^(5),a high responsivity(R)of 48.11 A W^(-1),and a detectivity(D*)of 6.85×10^(12)Jones under 365-nm UV illumination with light power density of 86.972 mW cm^(-2).The high-performance HEMT and UV detectors,which incorporate p-GaN etchless technology,have been refined through advancements in epitaxial growth and structural design.These improvements solidify the groundwork for large-scale manufacturing of UV communication systems and laser diodes.展开更多
Summary What is already known about this topic?With socioeconomic development,the increase of older pregnancies and multiparas has brought risks to mothers and infants.What is added by this report?As parities increase...Summary What is already known about this topic?With socioeconomic development,the increase of older pregnancies and multiparas has brought risks to mothers and infants.What is added by this report?As parities increased,the proportion of women of advanced maternal age(AMA)and non-local domicile increased,while the proportion of women with higher education levels decreased.Women with≥3 parities are more likely to have preterm birth(PTB)and macrosomia.What are the implications for public health practice?A comprehensive analysis of pregnancy traits among women at different parities offers a robust foundation for tailored strategies against adverse pregnancy outcomes.展开更多
The issue of "missing baryons” is always an unsolved mystery in galaxy cosmology, and an important reason for the great uncertainty of the galaxies' formation and evolution. To find the "missing" b...The issue of "missing baryons” is always an unsolved mystery in galaxy cosmology, and an important reason for the great uncertainty of the galaxies' formation and evolution. To find the "missing" baryons, extra high-resolution spectral observation and imaging of the soft X-ray band (<1 kev) is required. However, the existing observation methods cannot meet this requirement. Therefore, Tsinghua University leads and proposes the Chinese "Hot Universe Baryon Surveyor (HUBS)" satellite program.展开更多
Nanosecond pulsed electric field(nsPEF)is a novel,nonthermal,and minimally invasive modality that can ablate solid tumors by inducing apoptosis.Recent animal experiments show that nsPEF can induce the immunogenic cell...Nanosecond pulsed electric field(nsPEF)is a novel,nonthermal,and minimally invasive modality that can ablate solid tumors by inducing apoptosis.Recent animal experiments show that nsPEF can induce the immunogenic cell death of hepatocellular carcinoma(HCC)and stimulate the host’s immune response to kill residual tumor cells and decrease distant metastatic tumors.nsPEF-induced immunity is of great clinical importance because the nonthermal ablation may enhance the immune memory,which can prevent HCC recurrence and metastasis.This review summarized the most advanced research on the effect of nsPEF.The possible mechanisms of how locoregional nsPEF ablation enhances the systemic anticancer immune responses were illustrated.nsPEF stimulates the host immune system to boost stimulation and prevail suppression.Also,nsPEF increases the dendritic cell loading and inhibits the regulatory responses,thereby improving immune stimulation and limiting immunosuppression in HCC-bearing hosts.Therefore,nsPEF has excellent potential for HCC treatment.展开更多
基金supported by the National Natural Science Foundation of China (62175040, 61805044, 12064027, and 62065014)the Science and Technology Program of Guangzhou(202201010242)+3 种基金Guangdong Basic and Applied Basic Research Foundation(2022A1515110981)2022 Jiangxi Province High-level and High-skilled Leading Talent Training Project Selected (No. 63)Jiangxi Provincial Department of Education Science and Technology Key Project (GJJ2204302)Jiujiang Municipal Science and Technology Program (Natural Science Foundation, Innovative Talents)(2022-2023)。
基金This research was supported by the State Key Laboratory of Technologies in Space Cryogenic Propellants,China(Grant No.SKLTSCP1903)the National Natural Science Foundation of China(Grant Nos.51706233,51427806,and U1831203)+1 种基金the Strategic Pilot Projects in Space Science of China(Grant No.XDA15010400)the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(Grant No.QYZDY-SSW-JSC028).
文摘Liquid hydrogen(LH2)attracts widespread attention because of its highest energy storage density.However,evaporation loss is a serious problem in LH2 storage due to the low boiling point(20 K).Efficient insulation technology is an important issue in the study of LH2 storage.Hollow glass microspheres(HGMs)is a potential promising thermal insulation material because of its low apparent thermal conductivity,fast installation(Compared with multi-layer insulation,it can be injected in a short time.),and easy maintenance.A novel cryogenic insulation system consisting of HGMs and a selfevaporating vapor-cooled shield(VCS)is proposed for storage of LH2.A thermodynamic model has been established to analyze the coupled heat transfer characteristics of HGMs and VCS in the composite insulation system.The results show that the combination of HGMs and VCS can effectively reduce heat flux into the LH2 tank.With the increase of VCS number from 1 to 3,the minimum heat flux through HGMs decreases by 57.36%,65.29%,and 68.21%,respectively.Another significant advantage of HGMs is that their thermal insulation properties are not sensitive to ambient vacuum change.When ambient vacuum rises from 10^-3 Pa to 1 Pa,the heat flux into the LH2 tank increases by approximately 20%.When the vacuum rises from 10^-3 Pa to 100 Pa,the combination of VCS and HGMs reduces the heat flux into the tank by 58.08%-69.84% compared with pure HGMs.
基金supported by the National Natural Science Foundation of China(No.51962032)the program for Strong Youth Technology Leading Talents in Bingtuan Technological Innovation Talents(No.2023CB00811)+2 种基金Youth Innovation Promotion Association CAS(No.2021433)the Youth Innovative Top Talents Fund,Shihezi University(No.CXBJ202203)Youth Science and Technology Innovation Leading Talent Fund,Bashi Shihezi(No.2023RC02).
文摘Mn-based zinc ion battery has the advantages of low cost and high performance,which makes it the promising energy storage system.However,the poor conductivity and the agglomeration in the synthesis process of manganese-based materials restrict the performance of batteries.Herein,the Se-doped MnS/Ti_(3)C_(2)T_(x)(Se-MnS/Ti_(3)C_(2)T_(x))composite material derived from Mn-based metal-organic framework is reported.Electrochemical tests show that Se-doped could generate S defects and enhance the electrochemical activity of MnS.At the same time,the introduction of Ti_(3)C_(2)T_(x) substrate is conducive to exposing more sulfur defects and improving the utilization rate of defects.In the mechanism study,it is found that Se-MnS/Ti_(3)C_(2)T_(x) is transformed into S/Se co-doped Mn3O_(4) at the first charge,which innovatively elucidated the behavior of S/Se during activation.In the electrochemical performance test,the specific capacity can reach 74.7 mAh·g^(-1) at 5.0 A·g^(-1).In addition,the Zn-Ti_(3)C_(2)T_(x) membrane electrode is prepared by vacuum filtration as the zinc-poor anode,which is assembled into the rocking chair full battery to avoid dendrite growth and exhibit excellent rate performance.The addition of Zn2+weakens the electrostatic repulsion between the interlayers of MXene,and the formation of the folded morphology aids the penetration of the electrolyte.At 1.0 A·g^(-1),the capacity can reach 50.6 mAh·g^(-1).This work is helpful to promote the research and development of the reaction mechanism of manganese based rocking chair batteries.
基金supported by the National Natural Science Foundation of China(11904108)Guangdong Basic and Applied Basic Research Foundation(2020B1515020032)"The pearl River Talent Recruitment Program"(2019ZT08X639)。
文摘In this work,a novel ultraviolet(UV)photodetector(PD)based on AlGaN/u-GaN/p-GaN/u-GaN heterojunction high electron mobility transistor(HEMT)has been developed.This HEMT epilayer is grown using the metal-organic chemical vapor deposition(MOCVD)technique,and the growth parameters,including the AlGaN growth temperature,preheating temperature of the p-GaN layer,and NH3/N2 flow rate,are optimized to improve the quality of the epilayer.The optimized epilayer exhibits a flat surface with a root mean square value of 0.146 nm and low dislocation density.The p-GaN thickness in epitaxial wafers has a significant influence on electrical and UV photoresponse.With a p-GaN of 1µm,the UV PD demonstrates a significant switching ratio and transconductance of 107 and 127.3 mS mm^(-1),respectively.Acting as a UV PD,it also exhibits a high light on/off ratio(I_(light)/I_(dark))of 6.35×10^(5),a high responsivity(R)of 48.11 A W^(-1),and a detectivity(D*)of 6.85×10^(12)Jones under 365-nm UV illumination with light power density of 86.972 mW cm^(-2).The high-performance HEMT and UV detectors,which incorporate p-GaN etchless technology,have been refined through advancements in epitaxial growth and structural design.These improvements solidify the groundwork for large-scale manufacturing of UV communication systems and laser diodes.
基金Supported by Capital’s Funds for Health Improvement and Research(No.2020-2-2111)Beijing Natural Science Foundation(No.9212007).
文摘Summary What is already known about this topic?With socioeconomic development,the increase of older pregnancies and multiparas has brought risks to mothers and infants.What is added by this report?As parities increased,the proportion of women of advanced maternal age(AMA)and non-local domicile increased,while the proportion of women with higher education levels decreased.Women with≥3 parities are more likely to have preterm birth(PTB)and macrosomia.What are the implications for public health practice?A comprehensive analysis of pregnancy traits among women at different parities offers a robust foundation for tailored strategies against adverse pregnancy outcomes.
基金supported by the National Natural Science Foundation of China (51706233, U1831203, 51427806)Strategic Pilot Projects in Space Science of China (XDA15010400)Key Research Program of Frontier Sciences, CAS (QYZDYSSW-JSC028)
文摘The issue of "missing baryons” is always an unsolved mystery in galaxy cosmology, and an important reason for the great uncertainty of the galaxies' formation and evolution. To find the "missing" baryons, extra high-resolution spectral observation and imaging of the soft X-ray band (<1 kev) is required. However, the existing observation methods cannot meet this requirement. Therefore, Tsinghua University leads and proposes the Chinese "Hot Universe Baryon Surveyor (HUBS)" satellite program.
基金National S&T Major Project(No.2018ZX10301201)Innovative Research Groups of National Natural Science Foundation of China(No.81721091)。
文摘Nanosecond pulsed electric field(nsPEF)is a novel,nonthermal,and minimally invasive modality that can ablate solid tumors by inducing apoptosis.Recent animal experiments show that nsPEF can induce the immunogenic cell death of hepatocellular carcinoma(HCC)and stimulate the host’s immune response to kill residual tumor cells and decrease distant metastatic tumors.nsPEF-induced immunity is of great clinical importance because the nonthermal ablation may enhance the immune memory,which can prevent HCC recurrence and metastasis.This review summarized the most advanced research on the effect of nsPEF.The possible mechanisms of how locoregional nsPEF ablation enhances the systemic anticancer immune responses were illustrated.nsPEF stimulates the host immune system to boost stimulation and prevail suppression.Also,nsPEF increases the dendritic cell loading and inhibits the regulatory responses,thereby improving immune stimulation and limiting immunosuppression in HCC-bearing hosts.Therefore,nsPEF has excellent potential for HCC treatment.
