The Floating nuclear power plant grid is composed of power generation,in-station power supply and external power delivery.To ensure the safety of the nuclear island,the in-station system adopts a special power supply ...The Floating nuclear power plant grid is composed of power generation,in-station power supply and external power delivery.To ensure the safety of the nuclear island,the in-station system adopts a special power supply mode,while the external power supply needs to be adapted to different types of external systems.Because of frequent single phase-ground faults and various fault forms,the fault line selection protection should be accurate,sensitive and adaptive.This paper presents a fault line selection method in cooperation with multi-mode grounding control.Based on the maximum united energy entropy ratio(MUEER),the optimal wavelet basis function and decomposition scale are adaptively chosen,while the fault line is selected by wavelet transform modulus maxima(WTMM).For high-impedance faults(HIFs),to enlarge the fault feature,the system grounding mode can be switched by the multi-mode grounding control.Based on the characteristic of HIFs,the fault line can be selected by comparing phase differences of zero-sequence current mutation and fault phase voltage mutation before and after the fault.Simulation results using MATLAB/Simulink show the effectiveness of the proposed method in solving the protection problems.展开更多
The nuclear pore complex(NPC),the sole exchange channel between the nucleus and cytoplasm,is composed of several subcomplexes,among which the central barrier determines the permeability/selectivity of the NPC to domin...The nuclear pore complex(NPC),the sole exchange channel between the nucleus and cytoplasm,is composed of several subcomplexes,among which the central barrier determines the permeability/selectivity of the NPC to dominate the nucleocytoplasmic trafficking essential for many important signaling events in yeast and mammals.How plant NPC central barrier controls selective transport is a crucial question remaining to be elucidated.In this study,we uncovered that phase separation of the central barrier is critical for the permeability and selectivity of plant NPC in the regulation of various biotic stresses.Phenotypic assays of nup62 mutants and complementary lines showed that NUP62 positively regulates plant defense against Botrytis cinerea,one of the world’s most disastrous plant pathogens.Furthermore,in vivo imaging and in vitro biochemical evidence revealed that plant NPC central barrier undergoes phase separation to regulate selective nucleocytoplasmic transport of immune regulators,as exemplified by MPK3,essential for plant resistance to B.cinerea.Moreover,genetic analysis demonstrated that NPC phase separation plays an important role in plant defense against fungal and bacterial infection as well as insect attack.These findings reveal that phase separation of the NPC central barrier serves as an important mechanism to mediate nucleocytoplasmic transport of immune regulators and activate plant defense against a broad range of biotic stresses.展开更多
The formation and growth of segregation ice dominate the frost heave during soil freezing,which is closely related to water migration.To analyze segregation ice during soil freezing for different soils,a freezing-thaw...The formation and growth of segregation ice dominate the frost heave during soil freezing,which is closely related to water migration.To analyze segregation ice during soil freezing for different soils,a freezing-thawing experiment was conducted with Lanzhou loess(LZL)and Qinghai-Tibet Plateau silty clay(QSC)using a novel layered nuclear magnetic resonance approach.During LZL freezing,the unfrozen water content first increased and then decreased with decreasing temperature near the freezing front,but decreased with decreasing temperature in other layers,whereas during the freezing of QSC,the unfrozen water content in different layers(including the freezing front)decreased with decreased temperature.Notably,the increased liquid water near the freezing front during LZL freezing was primarily adsorbed water.In addition to the temperature gradient,the squeezing action during soil freezing was another important factor affecting water migration,especially at the early stage of soil freezing.However,which of the two factors,squeezing action and temperature gradient,was the dominant one causing water migration depended on soil structure.At the early stage of soil freezing,the squeezing action had a significant effect on the water migration of LZL,but no significant effect on that of QSC.Furthermore,water accumulation of LZL near the freezing front due to squeezing action at the early stage of freezing limited the formation and growth of segregation ice.This study provided an improved understanding for ice segregation and water migration during soil freezing.展开更多
In this review we study the nuclear pastas as they are expected to be formed in neutron star crusts.We start with a study of the pastas formed in nuclear matter(composed of protons and neutrons),we follow with the rol...In this review we study the nuclear pastas as they are expected to be formed in neutron star crusts.We start with a study of the pastas formed in nuclear matter(composed of protons and neutrons),we follow with the role of the electron gas on the formation of pastas,and we then investigate the pastas in neutron star matter(nuclear matter embedded in an electron gas).Nuclear matter(NM)at intermediate temperatures(1 MeV≤T≤15.MeV),at saturation and and sub-saturation densities,and with proton content ranging from 30%to 50%was found to have liquid,gaseous and liquid-gas mixed phases.The isospin-dependent phase diagram was obtained along with the critical points,and the symmetry energy was calculated and compared to experimental data and other theories.At low temperatures(T≤1 MeV)NM produces crystal-like structures around satura-tion densities,and pasta-like structures at sub-saturation densities.Properties of the pasta structures were studied with cluster-recognition algorithms,caloric curve,the radial distribution function,the Lindemann coefficient,Kolmogorov statistics,Minkowski functionals;the symmetry energy of the pasta showed a connection with its morphology.Neutron star matter(NSM)is nuclear matter embedded in an electron gas.The electron gas is included in the calculation by the inclusion of an screened Coulomb potential.To connect the NM pastas with those in neutron star matter(NSM),the role the strength and screening length of the Coulomb interaction have on the formation of the pastas in NM was investigated.Pasta was found to exist even without the presence of the electron gas,but the effect of the Coulomb interaction is to form more defined pasta structures,among other effects.Likewise,it was determined that there is a minimal screening length for the developed structures to be independent of the cell size.Neutron star matter was found to have similar phases as NM,phase transitions,symmetry energy,structure function and thermal conductivity.Like in NM,pasta forms at around T≈1.5 MeV,and liquid-to-s展开更多
The natural reproduction of mammal is sexual reproduction, which needs fertilization involving sperm and oocyte. Nuclear transfer provided an asexual reproduction method for mammal. Donor cells used in previous experi...The natural reproduction of mammal is sexual reproduction, which needs fertilization involving sperm and oocyte. Nuclear transfer provided an asexual reproduction method for mammal. Donor cells used in previous experiments of nuclear transfer were mostly from undif-ferentiated or non-terminally differentiated cells, such as embryonic or fetal cells. However, since Wilmut et al. obtained a viable lamb by transfer of an adult sheep somatic cell into展开更多
针对一起110 k V变电站内不同10 k V母线上的2台Zn Yn11型曲折接地变压器核相异常事件,以电压相量图为工具,对变压器高压侧相序接反进行理论分析,给出接线正常和高压侧3种相序接反情况下的核相理论值,并通过现场试验证明理论分析的正确...针对一起110 k V变电站内不同10 k V母线上的2台Zn Yn11型曲折接地变压器核相异常事件,以电压相量图为工具,对变压器高压侧相序接反进行理论分析,给出接线正常和高压侧3种相序接反情况下的核相理论值,并通过现场试验证明理论分析的正确性。将现场核相数据与理论值作对比,判断出该变电站2号变压器高压侧U、W相接反,调整该两相接线后,核相正常。展开更多
HIV integration occurs in chromatin sites that favor the release of high levels of viral progeny;alternatively, the virus is alsoable to discreetly coexist with the host. The viral infection perturbs the cellular envi...HIV integration occurs in chromatin sites that favor the release of high levels of viral progeny;alternatively, the virus is alsoable to discreetly coexist with the host. The viral infection perturbs the cellular environment inducing the remodelling of thenuclear landscape. Indeed, HIV-1 triggers the nuclear clustering of the host factor CPSF6, but the underlying mechanism ispoorly understood. Our data indicate that HIV usurps a recently discovered biological phenomenon, called liquid–liquid phaseseparation, to hijack the host cell. We observed CPSF6 clusters as part of HIV-induced membraneless organelles (HIV-1 MLOs) inmacrophages, one of the main HIV target cell types. We describe that HIV-1 MLOs follow phase-separation rules and representfunctional biomolecular condensates. We highlight HIV-1 MLOs as hubs of nuclear reverse transcription, while the double-strandedviral DNA, once formed, rapidly migrates outside these structures. Transcription-competent proviruses localize outside but nearHIV-1 MLOs in LEDGF-abundant regions, known to be active chromatin sites. Therefore, HIV-1 MLOs orchestrate viral events priorto the integration step and create a favorable environment for the viral replication. This study uncovers single functional host–viralcomplexes in their nuclear landscape, which is markedly restructured by HIV-1.展开更多
Phase field simulations of phase separation in Fe-Cr binary alloys were performed by using the Cahn-Hilliard diffusion function. A new mobility model in relation to aging temperature and Cr content was used in the sim...Phase field simulations of phase separation in Fe-Cr binary alloys were performed by using the Cahn-Hilliard diffusion function. A new mobility model in relation to aging temperature and Cr content was used in the simulations. Two alloys of Fe-30at%Cr and Fe-35at%Cr were investigated at two different aging temperatures of 573 and 673 K. The phase separation kinetics was found to consist of three stages： wavelength modulation, amplitude increase, and coarsening of Cr-enriched regions. A higher thermal aging temperature accelerated the phase separation and increased the wavelength of concentration fluctuation. While the effect of Cr content on the phase separation kinetics was slight, Fe-Cr alloys with a higher Cr content were found to generate a larger number and a finer size of Cr-enriched regions. The simulation results provide consultation for design and safe operation of duplex stainless steel pipes in nuclear power plants.展开更多
基金Project Supported by National Natural Science Foundation of China(No.51877089).Research on the mechanism and fault ride-through integrated strategies of an active power router in hybrid AC and DC distribution grids.
文摘The Floating nuclear power plant grid is composed of power generation,in-station power supply and external power delivery.To ensure the safety of the nuclear island,the in-station system adopts a special power supply mode,while the external power supply needs to be adapted to different types of external systems.Because of frequent single phase-ground faults and various fault forms,the fault line selection protection should be accurate,sensitive and adaptive.This paper presents a fault line selection method in cooperation with multi-mode grounding control.Based on the maximum united energy entropy ratio(MUEER),the optimal wavelet basis function and decomposition scale are adaptively chosen,while the fault line is selected by wavelet transform modulus maxima(WTMM).For high-impedance faults(HIFs),to enlarge the fault feature,the system grounding mode can be switched by the multi-mode grounding control.Based on the characteristic of HIFs,the fault line can be selected by comparing phase differences of zero-sequence current mutation and fault phase voltage mutation before and after the fault.Simulation results using MATLAB/Simulink show the effectiveness of the proposed method in solving the protection problems.
基金supported by funding from the National Natural Science Foundation of China(32250001 and 31830008 to D.X.,32150023 and 32125010 to P.L.,and 31901570 to D.W.)the National Key Research and Development Program of China(2019YFA0508403 to P.L.)+1 种基金the China Postdoctoral Science Foundation(2018M631447 to J.W.)a postdoctoral fellowship of the Tsinghua-Peking Joint Center for Life Sciences.
文摘The nuclear pore complex(NPC),the sole exchange channel between the nucleus and cytoplasm,is composed of several subcomplexes,among which the central barrier determines the permeability/selectivity of the NPC to dominate the nucleocytoplasmic trafficking essential for many important signaling events in yeast and mammals.How plant NPC central barrier controls selective transport is a crucial question remaining to be elucidated.In this study,we uncovered that phase separation of the central barrier is critical for the permeability and selectivity of plant NPC in the regulation of various biotic stresses.Phenotypic assays of nup62 mutants and complementary lines showed that NUP62 positively regulates plant defense against Botrytis cinerea,one of the world’s most disastrous plant pathogens.Furthermore,in vivo imaging and in vitro biochemical evidence revealed that plant NPC central barrier undergoes phase separation to regulate selective nucleocytoplasmic transport of immune regulators,as exemplified by MPK3,essential for plant resistance to B.cinerea.Moreover,genetic analysis demonstrated that NPC phase separation plays an important role in plant defense against fungal and bacterial infection as well as insect attack.These findings reveal that phase separation of the NPC central barrier serves as an important mechanism to mediate nucleocytoplasmic transport of immune regulators and activate plant defense against a broad range of biotic stresses.
基金supported by the Key Project of the Natural Science Foundation of China(No.41630636)the National Natural Science Foundation of China(No.41501072)+1 种基金the Independent Foundation of State Key Laboratory of Frozen Soil Engineering,China(No.SKLFSE-ZT-202107)the Natural Science Foundation of Gansu,China(No.22JR5RA057).
文摘The formation and growth of segregation ice dominate the frost heave during soil freezing,which is closely related to water migration.To analyze segregation ice during soil freezing for different soils,a freezing-thawing experiment was conducted with Lanzhou loess(LZL)and Qinghai-Tibet Plateau silty clay(QSC)using a novel layered nuclear magnetic resonance approach.During LZL freezing,the unfrozen water content first increased and then decreased with decreasing temperature near the freezing front,but decreased with decreasing temperature in other layers,whereas during the freezing of QSC,the unfrozen water content in different layers(including the freezing front)decreased with decreased temperature.Notably,the increased liquid water near the freezing front during LZL freezing was primarily adsorbed water.In addition to the temperature gradient,the squeezing action during soil freezing was another important factor affecting water migration,especially at the early stage of soil freezing.However,which of the two factors,squeezing action and temperature gradient,was the dominant one causing water migration depended on soil structure.At the early stage of soil freezing,the squeezing action had a significant effect on the water migration of LZL,but no significant effect on that of QSC.Furthermore,water accumulation of LZL near the freezing front due to squeezing action at the early stage of freezing limited the formation and growth of segregation ice.This study provided an improved understanding for ice segregation and water migration during soil freezing.
基金The participation of J.A.L.was partly financed by the National Science Foundation grant NSF-PHY 1066031USA DOE's Visiting Faculty Program,and by the China-US Theory Institute for Physics with Exotic Nuclei(CUSTIPEN).C.O.D.received support from the Carrera de Investigador CON-ICET,by CONICET grants PIP0871,PIP 2015-2017 GI,founding D4247(12-22-2016)Inter-American Development Bank(IDB),Grant Number PICT 1692.
文摘In this review we study the nuclear pastas as they are expected to be formed in neutron star crusts.We start with a study of the pastas formed in nuclear matter(composed of protons and neutrons),we follow with the role of the electron gas on the formation of pastas,and we then investigate the pastas in neutron star matter(nuclear matter embedded in an electron gas).Nuclear matter(NM)at intermediate temperatures(1 MeV≤T≤15.MeV),at saturation and and sub-saturation densities,and with proton content ranging from 30%to 50%was found to have liquid,gaseous and liquid-gas mixed phases.The isospin-dependent phase diagram was obtained along with the critical points,and the symmetry energy was calculated and compared to experimental data and other theories.At low temperatures(T≤1 MeV)NM produces crystal-like structures around satura-tion densities,and pasta-like structures at sub-saturation densities.Properties of the pasta structures were studied with cluster-recognition algorithms,caloric curve,the radial distribution function,the Lindemann coefficient,Kolmogorov statistics,Minkowski functionals;the symmetry energy of the pasta showed a connection with its morphology.Neutron star matter(NSM)is nuclear matter embedded in an electron gas.The electron gas is included in the calculation by the inclusion of an screened Coulomb potential.To connect the NM pastas with those in neutron star matter(NSM),the role the strength and screening length of the Coulomb interaction have on the formation of the pastas in NM was investigated.Pasta was found to exist even without the presence of the electron gas,but the effect of the Coulomb interaction is to form more defined pasta structures,among other effects.Likewise,it was determined that there is a minimal screening length for the developed structures to be independent of the cell size.Neutron star matter was found to have similar phases as NM,phase transitions,symmetry energy,structure function and thermal conductivity.Like in NM,pasta forms at around T≈1.5 MeV,and liquid-to-s
文摘The natural reproduction of mammal is sexual reproduction, which needs fertilization involving sperm and oocyte. Nuclear transfer provided an asexual reproduction method for mammal. Donor cells used in previous experiments of nuclear transfer were mostly from undif-ferentiated or non-terminally differentiated cells, such as embryonic or fetal cells. However, since Wilmut et al. obtained a viable lamb by transfer of an adult sheep somatic cell into
文摘针对一起110 k V变电站内不同10 k V母线上的2台Zn Yn11型曲折接地变压器核相异常事件,以电压相量图为工具,对变压器高压侧相序接反进行理论分析,给出接线正常和高压侧3种相序接反情况下的核相理论值,并通过现场试验证明理论分析的正确性。将现场核相数据与理论值作对比,判断出该变电站2号变压器高压侧U、W相接反,调整该两相接线后,核相正常。
基金funded by the ANRS REACTing grant(ECTZ88162)with a nominative PhD student fellowship(ECTZ88177)for V.S.the Sidaction/Fondation pour la Recherche Médicale(FRM)grant(VIH20170718001)Institut Pasteur.
文摘HIV integration occurs in chromatin sites that favor the release of high levels of viral progeny;alternatively, the virus is alsoable to discreetly coexist with the host. The viral infection perturbs the cellular environment inducing the remodelling of thenuclear landscape. Indeed, HIV-1 triggers the nuclear clustering of the host factor CPSF6, but the underlying mechanism ispoorly understood. Our data indicate that HIV usurps a recently discovered biological phenomenon, called liquid–liquid phaseseparation, to hijack the host cell. We observed CPSF6 clusters as part of HIV-induced membraneless organelles (HIV-1 MLOs) inmacrophages, one of the main HIV target cell types. We describe that HIV-1 MLOs follow phase-separation rules and representfunctional biomolecular condensates. We highlight HIV-1 MLOs as hubs of nuclear reverse transcription, while the double-strandedviral DNA, once formed, rapidly migrates outside these structures. Transcription-competent proviruses localize outside but nearHIV-1 MLOs in LEDGF-abundant regions, known to be active chromatin sites. Therefore, HIV-1 MLOs orchestrate viral events priorto the integration step and create a favorable environment for the viral replication. This study uncovers single functional host–viralcomplexes in their nuclear landscape, which is markedly restructured by HIV-1.
基金the National High-Tech Research and Development Program of China(Nos.2012AA03A507 and 2012AA050901)the Na-tional Science and Technology Major Project of China(No.2011ZX06004)
文摘Phase field simulations of phase separation in Fe-Cr binary alloys were performed by using the Cahn-Hilliard diffusion function. A new mobility model in relation to aging temperature and Cr content was used in the simulations. Two alloys of Fe-30at%Cr and Fe-35at%Cr were investigated at two different aging temperatures of 573 and 673 K. The phase separation kinetics was found to consist of three stages： wavelength modulation, amplitude increase, and coarsening of Cr-enriched regions. A higher thermal aging temperature accelerated the phase separation and increased the wavelength of concentration fluctuation. While the effect of Cr content on the phase separation kinetics was slight, Fe-Cr alloys with a higher Cr content were found to generate a larger number and a finer size of Cr-enriched regions. The simulation results provide consultation for design and safe operation of duplex stainless steel pipes in nuclear power plants.
