期刊文献+
共找到202篇文章
< 1 2 11 >
每页显示 20 50 100
Structure,electronic,and nonlinear optical properties of superalkaline M_(3)O(M=Li,Na)doped cyclo[18]carbon
1
作者 刘晓东 卢其亮 罗其全 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期311-317,共7页
Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an ef... Cyclo[18]carbon has received considerable attention thanks to its novel geometric configuration and special electronic structure.Superalkalis have low ionization energy.Doping a superalkali in cyclo[18]carbon is an effective method to improve the optical properties of the system because considerable electron transfer occurs.In this paper,the geometry,bonding properties,electronic structure,absorption spectrum,and nonlinear optical(NLO)properties of superalkaline M_(3)O(M=Li,Na)-doped cyclo[18]carbon were studied by using density functional theory.M_(3)O and the C_(18) rings are not coplanar.The C_(18) ring still exhibits alternating long and short bonds.The charge transfer between M_(3)O and C_(18) forms stable[M_(3)O]+[C_(18)]-ionic complexes.C_(18)M_(3)O(M=Li,Na)shows striking optical nonlinearity,i.e.,their first-and second-order hyperpolarizability(βvec andγ||)increase considerably atλ=1907 nm and 1460 nm. 展开更多
关键词 superalkaline doped carbon structure and electronic properties nonlinear optical properties density functional theory(DFT)
下载PDF
Overview and progress of X-nuclei magnetic resonance imaging in biomedical studies 被引量:2
2
作者 Gengxin Wang Hongyi Yang +3 位作者 Juan Li Jie Wen Kai Zhong Changlin Tian 《Magnetic Resonance Letters》 2023年第4期327-343,共17页
Proton nuclear(^(1)H)is the observed nucleus on which most magnetic resonance imaging(MRI)applications depend.Most traditional^(1)H MRI can provide structural and functional information about organisms,while various n... Proton nuclear(^(1)H)is the observed nucleus on which most magnetic resonance imaging(MRI)applications depend.Most traditional^(1)H MRI can provide structural and functional information about organisms,while various non-proton nuclei(X-nuclei)MRI can provide more metabolic information.However,due to the relatively poor signal-to-noise ratio(SNR)of X-nuclei MRI,their applications are quite rare compared to^(1)H.Benefit from the rapid developments of MRI hardware and software technologies,X-nuclei MRI has recently attracted increasing interests in biomedical research.This review firstly introduces some current methods to improve the SNR of X-nuclei MRI.Secondly,this review describes biomedical applications of X-nuclei MRI,especially focusing on the current use of X-nuclei(^(13)C,^(17)O,^(19)F,^(23)Na and^(31)P)MRI to study related diseases in different organs,including the brain,liver,kidney,heart and bone.Finally,perspectives studies on X-nuclei imaging and its potential applications are described in biomedical research. 展开更多
关键词 Magnetic resonance imaging X-nuclei BIOMEDICAL ^(13)C ^(17)O ^(19)F ^(23)Na ^(31)P
下载PDF
Unexpected divergence in magnetoreceptor MagR from robin and pigeon linked to two sequence variations 被引量:3
3
作者 Shun Wang Peng Zhang +12 位作者 Fan Fei Tianyang Tong Xiujuan Zhou Yajie Zhou Jing Zhang Mengke Wei Yanqi Zhang Lei Zhang Yulong Huang Lin Zhang Xin Zhang Tiantian Cai Can Xie 《Zoological Research》 SCIE CSCD 2024年第1期69-78,共10页
Birds exhibit extraordinary mobility and remarkable navigational skills,obtaining guidance cues from the Earth’s magnetic field for orientation and long-distance movement.Bird species also show tremendous diversity i... Birds exhibit extraordinary mobility and remarkable navigational skills,obtaining guidance cues from the Earth’s magnetic field for orientation and long-distance movement.Bird species also show tremendous diversity in navigation strategies,with considerable differences even within the same taxa and among individuals from the same population.The highly conserved iron and iron-sulfur cluster binding magnetoreceptor(MagR)protein is suggested to enable animals,including birds,to detect the geomagnetic field and navigate accordingly.Notably,MagR is also implicated in other functions,such as electron transfer and biogenesis of iron-sulfur clusters,raising the question of whether variability exists in its biochemical and biophysical features among species,particularly birds.In the current study,we conducted a comparative analysis of MagR from two different bird species,including the migratory European robin(Erithacus rubecula)and the homing pigeon(Columba livia).Sequence alignment revealed an extremely high degree of similarity between the MagRs of these species,with only three sequence variations.Nevertheless,two of these variations underpinned significant differences in metal binding capacity,oligomeric state,and magnetic properties.These findings offer compelling evidence for the marked differences in MagR between the two avian species,potentially explaining how a highly conserved protein can mediate such diverse functions. 展开更多
关键词 Homing and migration Animal navigation Magnetoreceptor(MagR) Diverse navigation pattern Conserved protein
下载PDF
Dual-single-atoms of Pt-Co boost sulfur redox kinetics for ultrafast Li-S batteries 被引量:1
4
作者 Hanyan Wu Xuejie Gao +7 位作者 Xinyang Chen Weihan Li Junjie Li Lei Zhang Yang Zhao Ming Jiang Runcang Sun Xueliang Sun 《Carbon Energy》 SCIE EI CAS CSCD 2024年第3期53-63,共11页
Applications of lithium-sulfur(Li-S)batteries are still limited by the sluggish conversion kinetics from polysulfide to Li_(2)S.Although various single-atom catalysts are available for improving the conversion kinetic... Applications of lithium-sulfur(Li-S)batteries are still limited by the sluggish conversion kinetics from polysulfide to Li_(2)S.Although various single-atom catalysts are available for improving the conversion kinetics,the sulfur redox kinetics for Li-S batteries is still not ultrafast.Herein,in this work,a catalyst with dual-single-atom Pt-Co embedded in N-doped carbon nanotubes(Pt&Co@NCNT)was proposed by the atomic layer deposition method to suppress the shuttle effect and synergistically improve the interconversion kinetics from polysulfides to Li_(2)S.The X-ray absorption near edge curves indicated the reversible conversion of Li_(2)Sx on the S/Pt&Co@NCNT electrode.Meanwhile,density functional theory demonstrated that the Pt&Co@NCNT promoted the free energy of the phase transition of sulfur species and reduced the oxidative decomposition energy of Li_(2)S.As a result,the batteries assembled with S/Pt&Co@NCNT electrodes exhibited a high capacity retention of 80%at 100 cycles at a current density of 1.3 mA cm^(−2)(S loading:2.5 mg cm^(−2)).More importantly,an excellent rate performance was achieved with a high capacity of 822.1 mAh g^(−1) at a high current density of 12.7 mA cm^(−2).This work opens a new direction to boost the sulfur redox kinetics for ultrafast Li-S batteries. 展开更多
关键词 DFT calculation dual-single-atoms of Pt-Co fast Li-sulfur batteries sulfur redox kinetics XANES analysis
下载PDF
Mitochondrial targeting sequence of magnetoreceptor MagR:More than just targeting 被引量:2
5
作者 Yanqi Zhang Peng Zhang +10 位作者 Junjun Wang Jing Zhang Tianyang Tong Xiujuan Zhou Yajie Zhou Mengke Wei Chuanlin Feng Jinqian Li Xin Zhang Can Xie Tiantian Cai 《Zoological Research》 SCIE CSCD 2024年第3期468-477,共10页
Iron-sulfur clusters(ISC)are essential cofactors for proteins involved in various biological processes,such as electron transport,biosynthetic reactions,DNA repair,and gene expression regulation.ISC assembly protein I... Iron-sulfur clusters(ISC)are essential cofactors for proteins involved in various biological processes,such as electron transport,biosynthetic reactions,DNA repair,and gene expression regulation.ISC assembly protein IscA1(or MagR)is found within the mitochondria of most eukaryotes.Magnetoreceptor(MagR)is a highly conserved A-type iron and iron-sulfur cluster-binding protein,characterized by two distinct types of iron-sulfur clusters,[2Fe-2S]and[3Fe-4S],each conferring unique magnetic properties.MagR forms a rod-like polymer structure in complex with photoreceptive cryptochrome(Cry)and serves as a putative magnetoreceptor for retrieving geomagnetic information in animal navigation.Although the N-terminal sequences of MagR vary among species,their specific function remains unknown.In the present study,we found that the N-terminal sequences of pigeon MagR,previously thought to serve as a mitochondrial targeting signal(MTS),were not cleaved following mitochondrial entry but instead modulated the efficiency with which iron-sulfur clusters and irons are bound.Moreover,the N-terminal region of MagR was required for the formation of a stable MagR/Cry complex.Thus,the N-terminal sequences in pigeon MagR fulfil more important functional roles than just mitochondrial targeting.These results further extend our understanding of the function of MagR and provide new insights into the origin of magnetoreception from an evolutionary perspective. 展开更多
关键词 Magnetoreceptor(MagR) N-terminal sequence Mitochondrial targeting signal Iron-sulfur cluster
下载PDF
Revealing the atomic mechanism of diamond–iron interfacial reaction 被引量:1
6
作者 Yalun Ku Kun Xu +6 位作者 Longbin Yan Kuikui Zhang Dongsheng Song Xing Li Shunfang Li Shaobo Cheng Chongxin Shan 《Carbon Energy》 SCIE EI CAS CSCD 2024年第3期255-263,共9页
Diamond,with ultrahigh hardness,high wear resistance,high thermal conductivity,and so forth,has attracted worldwide attention.However,researchers found emergent reactions at the interfaces between diamond and ferrous ... Diamond,with ultrahigh hardness,high wear resistance,high thermal conductivity,and so forth,has attracted worldwide attention.However,researchers found emergent reactions at the interfaces between diamond and ferrous materials,which significantly affects the performance of diamond-based devices.Herein,combing experiments and theoretical calculations,taking diamond–iron(Fe)interface as a prototype,the counter-diffusion mechanism of Fe/carbon atoms has been established.Surprisingly,it is identified that Fe and diamond first form a coherent interface,and then Fe atoms diffuse into diamond and prefer the carbon vacancies sites.Meanwhile,the relaxed carbon atoms diffuse into the Fe lattice,forming Fe_(3)C.Moreover,graphite is observed at the Fe_(3)C surface when Fe_(3)C is over-saturated by carbon atoms.The present findings are expected to offer new insights into the atomic mechanism for diamondferrous material's interfacial reactions,benefiting diamond-based device applications. 展开更多
关键词 coherent interface counter-diffusion DIAMOND IRON phase transition
下载PDF
On the evolutionary trail of MagRs 被引量:1
7
作者 Jing Zhang Yafei Chang +7 位作者 Peng Zhang Yanqi Zhang Mengke Wei Chenyang Han Shun Wang Hui-Meng Lu Tiantian Cai Can Xie 《Zoological Research》 SCIE CSCD 2024年第4期821-830,共10页
Magnetic sense,or termed magnetoreception,has evolved in a broad range of taxa within the animal kingdom to facilitate orientation and navigation.MagRs,highly conserved A-type iron-sulfur proteins,are widely distribut... Magnetic sense,or termed magnetoreception,has evolved in a broad range of taxa within the animal kingdom to facilitate orientation and navigation.MagRs,highly conserved A-type iron-sulfur proteins,are widely distributed across all phyla and play essential roles in both magnetoreception and iron-sulfur cluster biogenesis.However,the evolutionary origins and functional diversification of MagRs from their prokaryotic ancestor remain unclear.In this study,MagR sequences from 131 species,ranging from bacteria to humans,were selected for analysis,with 23 representative sequences covering species from prokaryotes to Mollusca,Arthropoda,Osteichthyes,Reptilia,Aves,and mammals chosen for protein expression and purification.Biochemical studies revealed a gradual increase in total iron content in MagRs during evolution.Three types of MagRs were identified,each with distinct iron and/or iron-sulfur cluster binding capacity and protein stability,indicating continuous expansion of the functional roles of MagRs during speciation and evolution.This evolutionary biochemical study provides valuable insights into how evolution shapes the physical and chemical properties of biological molecules such as MagRs and how these properties influence the evolutionary trajectories of MagRs. 展开更多
关键词 MAGNETORECEPTION Magnetoreceptor(MagR) Iron-sulfur cluster STABILITY Evolutionary biochemistry
下载PDF
Band engineering of valleytronics WSe_(2)–MoS_(2)heterostructures via stacking form,magnetic moment and thickness
8
作者 吴彦玮 张宗源 +5 位作者 马亮 刘涛 郝宁 吕文刚 龙明生 单磊 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期45-49,共5页
Spin-valley polarization and bandgap regulation are critical in the developing of quantum devices.Here,by employing the density functional theory,we investigate the effects of stacking form,thickness and magnetic mome... Spin-valley polarization and bandgap regulation are critical in the developing of quantum devices.Here,by employing the density functional theory,we investigate the effects of stacking form,thickness and magnetic moment in the electronic structures of WSe_(2)–MoS_(2)heterostructures.Calculations show that spin-valley polarization maintains in all situations.Increasing thickness of 2H-MoS_(2)not only tunes the bandgap but also changes the degeneracy of the conduction band minimums(CBM)at K/K_(1) points.Gradual increase of micro magnetic moment tunes the bandgap and raises the valence band maximums(VBM)atΓpoint.In addition,the regulation of band gap by the thickness of 2H-MoS_(2)and introduced magnetic moment depends on the stacking type.Results suggest that WSe_(2)–MoS_(2)heterostructure supports an ideal platform for valleytronics applications.Our methods also give new ways of optical absorption regulation in spin-valley devices. 展开更多
关键词 valleytronics thickness STACKING magnetic moment
下载PDF
A fringe jump counting method for the phase measurement in the HCN laser interferometer on EAST and its FPGA-based implementation
9
作者 姚远 杨曜 +6 位作者 提昂 宋扬 张家敏 王琰 张耀 刘海庆 揭银先 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第4期156-161,共6页
Electron density in fusion plasma is usually diagnosed using laser-aided interferometers. The phase difference signal obtained after phase demodulation is wrapped, which is also called a fringe jump. A method has been... Electron density in fusion plasma is usually diagnosed using laser-aided interferometers. The phase difference signal obtained after phase demodulation is wrapped, which is also called a fringe jump. A method has been developed to unwrap the phase difference signal in real time using FPGA, specifically designed to handle fringe jumps in the hydrogen cyanide(HCN) laser interferometer on the EAST superconducting tokamak. This method is designed for a phase demodulator using the fast Fourier transform(FFT) method at the front end. The method is better adapted for hardware implementation compared to complex mathematical analysis algorithms, such as field programmable gate array(FPGA). It has been applied to process the phase measurement results of the HCN laser interferometer on EAST in real time. Electron density results show good confidence in the fringe jump unwrapping method. Further possible application in other laser interferometers, such as the POlarimeter-INTerferometer(POINT)system on EAST tokamak is also discussed. 展开更多
关键词 electron density laser-aided interferometer fringe jump unwrapping FPGA EAST
下载PDF
First results of CO_(2) dispersion interferometer on EAST tokamak
10
作者 刘郁阳 李维明 +7 位作者 姚远 张耀 张家敏 连辉 洪博 王守信 揭银先 刘海庆 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第3期76-82,共7页
A dispersion interferometer(DI)has been installed and operates on the Experimental Advanced Superconducting Tokamak(EAST).This DI system utilizes a continuous-wave 9.3μm CO_(2)laser source to measure line-averaged el... A dispersion interferometer(DI)has been installed and operates on the Experimental Advanced Superconducting Tokamak(EAST).This DI system utilizes a continuous-wave 9.3μm CO_(2)laser source to measure line-averaged electron densities accurately.In contrast to conventional interferometers,the DI does not require substantial vibration isolations or compensating systems to reduce the impact of vibrations in the optical path.It also employs a ratio of modulation amplitudes,ensuring it remains immune to the variations in detected intensities.Without a variation compensation system,the DI system on EAST reaches a density resolution of less than1.8×10^(-2)πrad and a temporal resolution of 20μs.The measurements made by the POlarimeterINTerferometer(POINT)system and the far-infrared hydrogen cyanide(HCN)interferometer are remarkably consistent with the DI’s results.The possibility of fringe jumps and the impact of refraction in high-density discharge can be significantly decreased using a shorter wavelength laser source.A rapid density change of 3×10^(19)m^(-3)during 0.15 s has been measured accurately in shot No.114755 of EAST.Additionally,the DI system demonstrates dependability and stability under 305 s long-pulse discharges in shot No.122054. 展开更多
关键词 dispersion interferometer(DI) electron density plasma diagnostics Experimental Advanced Superconducting Tokamak(EAST)
下载PDF
Angle-resolved photoemission study of NbGeSb with non-symmorphic symmetry
11
作者 马欢 谭宁 +5 位作者 吴徐传 李满 王义炎 路洪艳 夏天龙 王善才 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期464-470,共7页
We investigate the electronic structure of NbGeSb with non-symmorphic symmetry.We employ angle-resolved photoemission spectroscopy(ARPES)to observe and identify the bulk and surface states over the Brillouin zone.By u... We investigate the electronic structure of NbGeSb with non-symmorphic symmetry.We employ angle-resolved photoemission spectroscopy(ARPES)to observe and identify the bulk and surface states over the Brillouin zone.By utilizing high-energy photons,we identify the bulk Fermi surface and bulk nodal line along the direction X–R,while the Fermi surface of the surface state is observed by using low-energy photons.We observe the splitting of surface bands away from the high-symmetry point X.The density functional theory calculations on bulk and 1 to 5-layer slab models,as well as spin textures of NbGeSb,verify that the band splitting could be attributed to the Rashba-like spin–orbit coupling caused by space-inversion-symmetry breaking at the surface.These splitted surface bands cross with each other,forming two-dimensional Weyl-like crossings that are protected by mirror symmetry.Our findings provide insights into the two-dimensional topological and symmetry-protected band inversion of surface states. 展开更多
关键词 non-symmorphic symmetry nodal line splitting of surface bands angle-resolved photoemission spectroscopy
下载PDF
Pressure-induced magnetic phase and structural transition in SmSb_(2)
12
作者 李涛 王舒阳 +3 位作者 陈绪亮 陈春华 房勇 杨昭荣 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期473-478,共6页
Motivated by the recent discovery of unconventional superconductivity around a magnetic quantum critical point in pressurized CeSb_(2),here we present a high-pressure study of an isostructural antiferromagnetic(AFM) S... Motivated by the recent discovery of unconventional superconductivity around a magnetic quantum critical point in pressurized CeSb_(2),here we present a high-pressure study of an isostructural antiferromagnetic(AFM) SmSb_(2) through electrical transport and synchrotron x-ray diffraction measurements.At P_(C)~2.5 GPa,we found a pressure-induced magnetic phase transition accompanied by a Cmca→P4/nmm structural phase transition.In the pristine AFM phase below P_(C),the AFM transition temperature of SmSb_(2) is insensitive to pressure;in the emergent magnetic phase above P_(C),however,the magnetic critical temperature increases rapidly with increasing pressure.In addition,at ambient pressure,the magnetoresistivity(MR) of SmSb_(2) increases suddenly upon cooling below the AFM transition temperature and presents linear nonsaturating behavior under high field at 2 K.With increasing pressure above P_(C),the MR behavior remains similar to that observed at ambient pressure,both in terms of temperature-and field-dependent MR.This leads us to argue an AFM-like state for SmSb_(2) above P_(C).Within the investigated pressure of up to 45.3 GPa and the temperature of down to 1.8 K,we found no signature of superconductivity in SmSb_(2). 展开更多
关键词 high pressure ANTIFERROMAGNET MAGNETORESISTIVITY structural transition
下载PDF
Rotating magnetic field inhibits Aβ protein aggregation and alleviates cognitive impairment in Alzheimer’s disease mice
13
作者 Ruo-Wen Guo Wen-Jing Xie +5 位作者 Biao Yu Chao Song Xin-Miao Ji Xin-Yu Wang Mei Zhang Xin Zhang 《Zoological Research》 SCIE CSCD 2024年第4期924-936,共13页
Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation... Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation,leading to brain lesions and cognitive impairment,numerous studies have aimed to reduce Aβaggregation and slow AD progression.The diphenylalanine(FF)sequence is critical for amyloid aggregation,and magnetic fields can affect peptide alignment due to the diamagnetic anisotropy of aromatic rings.In this study,we examined the effects of a moderate-intensity rotating magnetic field(RMF)on Aβaggregation and AD pathogenesis.Results indicated that the RMF directly inhibited Aβamyloid fibril formation and reduced Aβ-induced cytotoxicity in neural cells in vitro.Using the AD mouse model APP/PS1,RMF restored motor abilities to healthy control levels and significantly alleviated cognitive impairments,including exploration and spatial and non-spatial memory abilities.Tissue examinations demonstrated that RMF reduced amyloid plaque accumulation,attenuated microglial activation,and reduced oxidative stress in the APP/PS1 mouse brain.These findings suggest that RMF holds considerable potential as a non-invasive,high-penetration physical approach for AD treatment. 展开更多
关键词 lzheimer’s disease Rotating magnetic field Amyloid-β Cognitive function Alzheimer’s disease animal models
下载PDF
MicroMagnetic.jl:A Julia package for micromagnetic and atomistic simulations with GPU support
14
作者 Weiwei Wang Boyao Lyu +2 位作者 Lingyao Kong Hans Fangohr Haifeng Du 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期70-79,共10页
MicroMagnetic.jl is an open-source Julia package for micromagnetic and atomistic simulations.Using the features of the Julia programming language,MicroMagnetic.jl supports CPU and various GPU platforms,including NVIDI... MicroMagnetic.jl is an open-source Julia package for micromagnetic and atomistic simulations.Using the features of the Julia programming language,MicroMagnetic.jl supports CPU and various GPU platforms,including NVIDIA,AMD,Intel,and Apple GPUs.Moreover,MicroMagnetic.jl supports Monte Carlo simulations for atomistic models and implements the nudged-elastic-band method for energy barrier computations.With built-in support for double and single precision modes and a design allowing easy extensibility to add new features,MicroMagnetic.jl provides a versatile toolset for researchers in micromagnetics and atomistic simulations. 展开更多
关键词 micromagnetic simulations atomistic simulations graphics processing units
下载PDF
Linear magnetoresistance and structural distortion in layered SrCu_(4-x)P_(2) single crystals
15
作者 聂勇 陈正 +10 位作者 韦文森 李慧杰 张勇 梅明 王园园 宋文海 宋东升 王钊胜 朱相德 宁伟 田明亮 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期591-594,共4页
We report a systematic study on layered metal SrCu_(4-x)P_(2) single crystals via transport, magnetization, thermodynamic measurements and structural characterization. We find that the crystals show large linear magne... We report a systematic study on layered metal SrCu_(4-x)P_(2) single crystals via transport, magnetization, thermodynamic measurements and structural characterization. We find that the crystals show large linear magnetoresistance without any sign of saturation with a magnetic field up to 30T. We also observe a phase transition with significant anomalies in resistivity and heat capacity at T_(p)~140 K. Thermal expansion measurement reveals a subtle lattice parameter variation near Tp, i.e.,?L_(c)/L_(c)~0.062%. The structural characterization confines that there is no structure transition below and above T_(p). All these results suggest that the nonmagnetic transition of SrCu_(4-x)P_(2) could be associated with structural distortion. 展开更多
关键词 linear magnetoresistance thermal expansion specific heat structural distortion
下载PDF
Localization effect in single crystal of RuAs_(2)
16
作者 易哲铠 刘琪 +12 位作者 光双魁 徐升 岳小宇 梁慧 李娜 周颖 吴丹丹 孙燕 李秋菊 程鹏 夏天龙 孙学峰 王义炎 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期195-200,共6页
We report the magnetotransport and thermal properties of RuAs_(2) single crystal.RuAs_(2) exhibits semiconductor behavior and localization effect.The crossover from normal state to diffusive transport in the weak loca... We report the magnetotransport and thermal properties of RuAs_(2) single crystal.RuAs_(2) exhibits semiconductor behavior and localization effect.The crossover from normal state to diffusive transport in the weak localization(WL)state and then to variable range hopping(VRH)transport in the strong localization state has been observed.The transitions can be reflected in the measurement of resistivity and Seebeck coefficient.Negative magnetoresistance(NMR)emerges with the appearance of localization effect and is gradually suppressed in high magnetic field.The temperature dependent phase coherence length extracted from the fittings of NMR also indicates the transition from WL to VRH.The measurement of Hall effect reveals an anomaly of temperature dependent carrier concentration caused by localization effect.Our findings show that RuAs_(2) is a suitable platform to study the localized state. 展开更多
关键词 weak localization variable range hopping RuAs_(2) single crystal
下载PDF
Revisit of the anisotropic vortex states of 2H-NbSe_(2) towards the zero-field limit
17
作者 张凡 侯兴元 +5 位作者 姜宇轩 张宗源 涂玉兵 朱相德 陈根富 单磊 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期80-86,共7页
We revisited the vortex states of 2H-NbSe_(2) towards zero fields by a low-temperature scanning tunneling microscope.Fine structures of the anisotropic vortex states were distinguished, one is a spatially non-splittin... We revisited the vortex states of 2H-NbSe_(2) towards zero fields by a low-temperature scanning tunneling microscope.Fine structures of the anisotropic vortex states were distinguished, one is a spatially non-splitting zero bias peak, and the other is an in-gap conductance anomaly resembling evolved crossing features around the center of the three nearest vortices.Both of them distribute solely along the next nearest neighboring direction of the vortex lattice and become unresolved in much higher magnetic fields, implying an important role played by the vortex–vortex interactions. To clarify these issues,we have studied the intrinsic vortex states of the isolated trapped vortex in zero fields at 0.45 K. It is concluded that the anisotropic zero bias peak is attributed to the superconducting gap anisotropy, and the spatially evolved crossing features are related to the vortex–vortex interaction. The vortex core size under the zero-field limit is determined. These results provide a paradigm for studying the inherent vortex states of type-II superconductors especially based on an isolated vortex. 展开更多
关键词 vortex states zero-bias conductance peak scanning tunneling microscopy
下载PDF
Synthesis,physical properties,and annealing investigation of new layered Bi-chalcogenide LaOBiHgS_3
18
作者 Yi Yu Chunchang Wang +4 位作者 Liang Li Qiuju Li Chao Cheng Shuting Wang Changjin Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第1期580-583,共4页
The transport and thermoelectric properties together with annealing of the new layered Bi-chalcogenide LaOBiHgS_3 are studied. On the transport part, the insulating behavior of the as-grown sample is evidently depress... The transport and thermoelectric properties together with annealing of the new layered Bi-chalcogenide LaOBiHgS_3 are studied. On the transport part, the insulating behavior of the as-grown sample is evidently depressed by post annealing.A hump-like abnormality appears around 170 K. The thermoelectric performance of the sample is observably improved by the annealing, mainly because of the enhanced electrical conductance. The present results suggest that the physical properties of LaOBiHgS_3 are sensitive to post annealing and the possible micro adjustments that follow, indicating the layered Bi-chalcogenide family to be an ideal platform for designing novel functional materials. 展开更多
关键词 THERMOELECTRIC material Bi-chalcogenide POST ANNEALING
下载PDF
Genome-wide identification of functional enhancers and their potential roles in pig breeding 被引量:4
19
作者 Yinqiao Wu Yuedong Zhang +8 位作者 Hang Liu Yun Gao Yuyan Liu Ling Chen Lu Liu David M.Irwin Chunhui Hou Zhongyin Zhou Yaping Zhang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2022年第6期1690-1702,共13页
Background:The pig is an economically important livestock species and is a widely applied large animal model in medical research.Enhancers are critical regulatory elements that have fundamental functions in evolution,... Background:The pig is an economically important livestock species and is a widely applied large animal model in medical research.Enhancers are critical regulatory elements that have fundamental functions in evolution,development and disease.Genome-wide quantification of functional enhancers in the pig is needed.Results:We performed self-transcribing active regulatory region sequencing(STARR-seq)in the porcine kidney epithelial PK15 and testicular ST cell lines,and reliably identified 2576 functional enhancers.Most of these enhancers were located in repetitive sequences and were enriched within silent and lowly expressed genes.Enhancers poorly overlapped with chromatin accessibility regions and were highly enriched in chromatin with the repressive histone modification H3K9me3,which is different from predicted pig enhancers detected using ChIP-seq for H3K27ac or/and H3K4me1 modified histones.This suggests that most pig enhancers identified with STARR-seq are endogenously repressed at the chromatin level and may function during cell type-specific development or at specific developmental stages.Additionally,the PPP3CA gene is associated with the loin muscle area trait and the QKI gene is associated with alkaline phosphatase activity that may be regulated by distal functional enhancers.Conclusions:In summary,we generated the first functional enhancer map in PK15 and ST cells for the pig genome and highlight its potential roles in pig breeding. 展开更多
关键词 BREEDING Functional enhancers PIG STARR-seq
下载PDF
Evaluation and Evolution of MAX-DOAS-observed Vertical NO_(2) Profiles in Urban Beijing 被引量:2
20
作者 Yanyu KANG Guiqian TANG +4 位作者 Qihua LI Baoxian LIU Jianfeng CAO Qihou HU Yuesi WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第7期1188-1196,共9页
Multiaxis differential absorption spectroscopy(MAX-DOAS)is a newly developed advanced vertical profile detection method,but the vertical nitrogen dioxide(NO_(2))profiles measured by MAX-DOAS have not yet been fully ve... Multiaxis differential absorption spectroscopy(MAX-DOAS)is a newly developed advanced vertical profile detection method,but the vertical nitrogen dioxide(NO_(2))profiles measured by MAX-DOAS have not yet been fully verified.In this study,we perform MAX-DOAS and tower gradient observations to simultaneously acquire tropospheric NO_(2)observations in the Beijing urban area from 1 April to 31 May 2019.The average values of the tropospheric NO_(2)vertical column densities measured by MAX-DOAS and the tropospheric monitoring instrument are 15.8×1015 and 12.4×1015 molecules cm−2,respectively,and the correlation coefficient R reaches 0.87.The MAX-DOAS measurements are highly consistent with the tower-based in situ measurements,and the correlation coefficients R from the ground to the upper air are 0.89(60 m),0.87(160 m),and 0.76(280 m).MAX-DOAS accurately measures the trend of NO_(2)vertical profile changes,although a large underestimation occurs by a factor of two.By analyzing the NO_(2)vertical profile,the NO_(2)concentration reveals an exponential decrease with height.The NO_(2)vertical profile also coincides with the evolution of the boundary layer height.The study shows that the NO_(2)over Beijing mainly originates from local sources and occurs in the boundary layer,and its vertical evolution pattern has an important guiding significance to better understand nitrate production and ozone pollution. 展开更多
关键词 MAX-DOAS NO_(2) tower-based in situ observation TROPOMI validation VERTICAL
下载PDF
上一页 1 2 11 下一页 到第
使用帮助 返回顶部