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Progress of hidden spin polarization in inversion-symmetric crystals

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Science China(Physics,Mechanics & Astronomy) 2022年第3期65卷 1-18页

作者： shan guan Jia-Xin Xiong Zhi Wang Jun-Wei Luo State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Academy of Quantum Information Sciences Beijing 100193China

Hidden spin polarization refers to that doubly degenerate bands protected by combined inversion and time-reversal symmetry in nonmagnetic inversion-symmetric crystals could have opposite non-zero local spin polarizations, which are spatially separated in two real-space sectors paired by the inversion symmetry. Since its first prediction from ab initio calculation, hidden spin polarization has inspired tremendous interest and has been observed experimentally due to its intriguing fundamental properties as well as the great potential for applications. Moving forward, the search for moment-dependent spin splitting has also been extended to antiferromagnets even without considering spin-orbit coupling. This paper systematically reviews recent works in this field with a focus on basic concepts and material realization. It also details several remaining bottlenecks and suggests possible avenues for future research.

关键词： spin-orbit coupling hidden spin polarization tight-binding model ab initio calculation

Characterizing and predicting smoldering temperature variations based on non-linear mixed effects models

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Journal of Forestry Research 2022年第6期33卷 1829-1839页

作者： Sainan Yin Yanlong shan Bo Gao Shuyuan Tang Xiyue Han Guojiang Zhang Bo Yu shan guan Science and Technology Innovation Center of Wildland Fire Prevention and Control Beihua University3999 Binjiang East RoadJilin City 132013JilinPeople’s Republic of China Forestry College Beihua University3999 Binjiang East RoadJilin City 132013JilinPeople’s Republic of China

Underground fires are slow spreading,long-lasting and low temperature smoldering combustion without flames,mainly occurring in peatlands and wetlands with rich organic *** spread of the smoldering is maintained by heat released during combustion and monitoring this is an important approach to detect underground *** Daxing'an Mountains region is a hotspot for underground fires in northeast *** study examined a L arix gmelinii plantation in the Tatou wetlands of the Daxing'an Mountains and determined the maximum temperature variation of humus of varying particle sizes,and the temperature rising process based on non-linear mixed effects models by an indoor combustion *** combustion temperatures up to 897.5°C,increased with humus depth;among the three models tested,Richard's equations were best for characterizing temperature variations;a non-linear equation with three parameters had the highest accuracy in fitting the combustion temperature variations with varying humus particle *** results are informative for predicting temperature variations and provide technical support for underground fire monitoring.

关键词： Underground fire NLME modeling Smoldering temperature Daxing'an mountains

Cloning and Expression of Calcium-Dependent Protein Kinase (CDPK) Gene Family in Common Tobacco (Nicotiana tabacum)

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Agricultural Sciences in China 2009年第12期8卷 1448-1457页

作者： TAI Shuai-shuai LIU guan-shan SUN Yu-he CHEN Jia Tobacco Research Institute Chinese Academy of Agricultural Sciences/Key Laboratory of Tobacco Quality Control Ministry of Agriculture Qingdao 266101 P.R. China State Key Laboratory of Plant Physiology and Biochemistry/College of Biological Sciences China Agricultural University Beijing 100193 P.R.China

To further study the function of calcium-dependent protein kinase （CDPK） gene family in common tobacco （Nicotiana tabacum）, it is necessary to isolate more CDPKs from common tobacco and describe the sequence characteristics, evolutionary relationship and gene expression. Reverse transcription-PCR （RT-PCR）, rapid amplification of cDNA （RACE） and bioinformatics methods were used to isolate CDPKs from common tobacco. A phylogenetic tree was created using the MEGA4.0 program and expression patterns of the three full-length CDPK genes were studied by RT-PCR. After all aforementioned efforts, we obtained eight additional common tobacco CDPK genes, of which three possessed complete open reading frames （ORFs）. Phylogenetic analysis divided 1 1 full-length Nicotiana CDPK genes into four subfamilies, and two putative common tobacco and Arabidopsis orthologous CDPK genes might correspond to well-conserved functions. Three full-length CDPK genes in common tobacco were detected in all tobacco organs tested, but their expression patterns were significantly different. Eight non-redundant common tobacco CDPK genes were isolated in this study. Along with the previously characterized CDPK genes, at least 15 members of the CDPK family exist in common tobacco. This work establishes a foundation for a genome-wide study of this important gene family in common tobacco.

关键词： common tobacco (Nicotiana tabacum) CDPK phylogenetic tree gene expression

Cloning of a Calcium-Dependent Protein Kinase Gene NtCDPK12, and Its Induced Expression by High-Salt and Drought in Nicotiana tabacum

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Agricultural Sciences in China 2011年第12期10卷 1851-1860页

作者： CHEN Shuai LIU guan-shan WANG Yuan-ying SUN Yu-he CHEN Jia Key Laboratory of Genetic Improvement and Biotechnology Tobacco Research Institute Chinese Academy of Agricultural Sciences Qingdao 266101 P.R.China State Key Laboratory of Plant Physiology and Biochemistry College of Biological Sciences China Agricultural University Beijing 100193 P.R. China

Calcium-dependent protein kinases （CDPKs, EC 2.***.1.37） comprise a large family of Ser/Thr kinases in plants and play an important role in plant Ca^2＋ signal transduction. A full-length CDPK gene, NtCDPK12 （GenBank accession number GQ337420）, was isolated from common tobacco （Nicotiana tabacum） leaves by rapid amplification of eDNA ends （RACE）. The NtCDPK12 eDNA is 1 816 bp length and contains an open reading frame （ORF） of 1 461 bp encoding 486 amino acids. Sequence alignments indicated that NtCDPK12 contains all conserved regions found in CDPKs and shows a high level of sequence similarity to many other plant CDPKs. The results of real-time quantitative reverse transcription-PCR （qRT- PCR） showed that NtCDPK12 was highly expressed in stems and increased in roots treated with high-salt or subjected to drought stress, which indicates that NtCDPK12 was induced by high-salt and drought stresses.

关键词： abiotic stress CDPK Nicotiana tabacum RACE real-time qRT-PCR

Generating a radioheliograph image from SDO/AIA data with the machine learning method

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Research in Astronomy and Astrophysics 2020年第12期20卷 317-322页

作者： Pei-Jin Zhang Chuan-Bing Wang guan-shan Pu CAS Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China CAS Center for the Excellence in Comparative Planetology USTCHefei 230026China Anhui Mengcheng Geophysics National Observation and Research Station USTCMengcheng 233500China

Radioheliograph images are essential for the study of solar short term activities and long term variations, while the continuity and granularity of radioheliograph data are not so ideal, due to the short visible time of the Sun and the complex electron-magnetic environment near the ground-based radio telescope. In this work, we develop a multi-channel input single-channel output neural network, which can generate radioheliograph image in microwave band from the Extreme Ultra-violet(EUV) observation of the Atmospheric Imaging Assembly(AIA) on board the Solar Dynamic Observatory(SDO). The neural network is trained with nearly 8 years of data of Nobeyama Radioheliograph(No RH) at 17 GHz and SDO/AIA from January 2011 to September 2018. The generated radioheliograph image is in good consistency with the well-calibrated No RH observation. SDO/AIA provides solar atmosphere images in multiple EUV wavelengths every 12 seconds from space, so the present model can fill the vacancy of limited observation time of microwave radioheliograph, and support further study of the relationship between the microwave and EUV emission.

关键词： Sun:radio radiation methods:observational methods:data analysis

Geranylgeranyl pyrophosphate-mediated protein geranylgeranylation regulates endothelial cell proliferation and apoptosis during vasculogenesis in mouse embryo

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Journal of Genetics and Genomics 2021年第4期48卷 300-311页

作者： Danyang Chong Zhong Chen shan guan Tongyu Zhang Na Xu Yue Zhao Chaojun Li Ministry of Education Key Laboratory of Model Animals for Disease Study Model Animal Research Center and School of MedicineNanjing UniversityNational Resource Center for Mutant MiceNanjing 210093China

Vascular development is essential for the establishment of the circulatory system during embryonic development and requires the proliferation of endothelial ***,the underpinning regulatory mechanisms are not well ***,we report that geranylgeranyl pyrophosphate(GGPP),a metabolite involved in protein geranylgeranylation,plays an indispensable role in embryonic vascular *** is synthesized by geranylgeranyl pyrophosphate synthase(GGPPS)in the mevalonate *** selective knockout of Ggpps in endothelial cells led to aberrant vascular development and embryonic lethality,resulting from the decreased proliferation and enhanced apoptosis of endothelial cells during *** defect in protein geranylgeranylation induced by GGPP depletion inhibited the membrane localization of Rho A and enhanced yes-associated protein(YAP)phosphorylation,thereby prohibiting the entry of YAP into the nucleus and the expression of YAP target genes related to cell proliferation and the antiapoptosis ***,inhibition of the mevalonate pathway by simvastatin induced endothelial cell proliferation defects and apoptosis,which were ameliorated by ***(GGOH),a precursor of GGPP,ameliorated the harmful effects of simvastatin on vascular development of developing fetuses in pregnant *** results indicate that GGPP-mediated protein geranylgeranylation is essential for endothelial cell proliferation and the antiapoptosis process during embryonic vascular development.

关键词： GGPP Protein geranylgeranylation Endothelial cell Proliferation Apoptosis

Identification of microsatellites in cattle unigenes

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Journal of Genetics and Genomics 2008年第5期35卷 261-266页

作者： Qiuliang Yan Yinghan Zhang Hongbin Li Caihong Wei Lili Niu shan guan shangang Li Lixin Du College of Animal Science and Technology NorthwestA ＆ F University Yangling 712100 China National Center for Molecular Genetics and Breeding of Animal Institute of Animal Sciences Chinese Academy of Agricultural Sciences Beijing 100094 China Institute of Crop Sciences Chinese Academy of Agricultural Sciences Beijing 100081 China

To identify EST-SSR molecular markers, 41,986 cattle UniGene sequences from NCBI were mined for analyzing SSRs. A total of 1,831 SSRs were identified from 1,666 ESTs, which represented an average density of 19.88 kb per SSR. The frequency of EST-SSRs was 4.0%. The dinucleotide repeat motif was the most abundant SSR, accounting for 54%, followed by 22%, 13%, 7% and 4%, respectively, for tri-, hexa-, penta- and tetra-nucleotide repeats. Depending upon the length of the repeat unit, the length of microsatellites varied from 14 to 86 bp. Among the di- and tri-nucleotide repeats, AC/TG （57%） and AGC （12%） were the most abundant type. Annotation of EST-SSRs was also carried out. Three hundred primer pairs were randomly designed using Prime Premier 5.0 program and Oligo 5.0 for further experimental validation.

关键词： cattle microsatellite expressed sequence tags EST-SSR

Calculation and Analysis of Near-Field Head-Related Transfer Functions from a Simplified Head-Neck-Torso Model

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Chinese Physics Letters 2012年第3期29卷 124-127页

作者： CHEN Ze-Wei YU guang-Zheng XIE Bo-Sun guan shan-Qun Laboratory of Acoustics Department of PhysicsSchool of ScienceSouth China University of TechnologyGuangzhou 510640 State Key Laboratory of Subtropical Building Science South China University of TechnologyGuangzhou 510640 Telecommunication College Beijing University of Posts and TelecommunicationsBeijing 100876

To evaluate the overall effect of the neck and torso on the head-related transfer function(HRTF),a simplified head-neck-torso(HNT)model,which consists of a spherical head,spherical torso and cylindrical neck,is proposed and the corresponding HRTFs are calculated using the boundary element method(BEM).The results indicate that the HRTF magnitudes for the HNT model are different from those of the existing spherical head-and-torso model(HAT)above 0.5 kHz,especially in the near-field and contralateral *** discrepancy in the HRTF magnitudes leads to a discrepancy in the interaural level differences(ILDs)for the HNT and HAT models,which reaches a level of-l0dB at source distance of *** the source distance increases,the discrepancy in the results of the HNT and HAT models *** on practical HNT and HAT models validates the ***,the neck influences near-field HRTFs and should be included in the near-field HRTF calculation.

关键词： calculation analysis cylindrical

Resistance modulation in Ge2Sb2Te5

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Journal of Materials Science & Technology 2020年第15期47卷 171-177页

作者： Jitendra K.Behera Wei Jie Wang Xilin Zhou shan guan Wu Weikang Yang AShengyuan Robert ESimpson ACTA Lab Singapore University of Technology and Design(SUTD)8 Somapah Road487372Singapore Jnstitute of Microelectronics A*STAR2 Fusionopolis Way138634Singapore Research Lab for Quantum Materials Singapore University of Technology and Design(SUTD)8 Somapah Road487372Singapore

Chalcogenide based phase change random access memory(PCRAM) holds great promise for high speed and large data storage *** memory is scalable,requires a low switching energy,has a high endurance,has fast switching speed,and is ***,decreasing the switching time whilst increasing the cycle endurance is a key challenge for this technology to replace dynamic random access *** we demonstrate high speed and high endurance ultrafast transient switching in the SET state of a prototypical phase change memory *** switching is modeled by electron-phonon and lattice scattering on short timescales and charge carrier excitation on long *** volatile switching in phase change materials enables the design of hybrid memory modulators and ultrafast logic circuits.

关键词： Phase change memory Transient resistance Volatile Scattering Charge carrier excitation Large endurance