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Persistent Spin Current in a Hard-Wall Confining Quantum Wire with Weak Dresselhaus Spin-Orbit Coupling

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Communications in Theoretical Physics 2009年第2期51卷 341-344页

作者： FU Xi ZHOU guang-hui Department of Physics Hunan Normal University Changsha 410081 China Department of Electronics and Physics Hunan College of Science and Technology Yongzhou 425100 China

We investigate theoretically the spin current in a quantum wire with weak Dresselhaus spin-orbit coupling connected to two normal conductors. Both the quantum wire and conductors are described by a hard-wall confining potential. Using the electron wave-functions in the quantum wire and a new definition of spin current, we have calculated the elements of linear spin current density j^Ts,xi and j^Ts,yi（i=x, y, z）. We find that the elements j^Ts,xx and j^Ts,yy have a antisymmetrical relation and the element j^Ts,yz has the same amount levelas j^Ts,xx and j^Ts,yy. We also find a net linear spin current density, which has peaks at the center of quantum wire. The net linear spin current can induce a linear electric field, which may imply a way of spin current detection.

关键词： quantum wire Dresselhaus spin-orbit coupling spin current

High-Efficiency Broadband Near-Infrared Single-Photon Frequency Upconversion and Detection

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Chinese Physics Letters 2020年第3期37卷 17-21页

作者： Jian-hui Ma hui-Qin hu Yu Chen guang-Jian Xu Hai-Feng Pan E Wu State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062 Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006

We propose and demonstrate a high efficiency broadband near infrared single-photon upconversion and detection with a broadband pump laser based on sum frequency conversion in the PPLN *** using a pump laser centered at 1040 nm with a spectral bandwidth of 10 nm,the signal single-photons centered at 1562 nm with a broadband bandwidth up to 7.2 nm are frequency-converted from the near infrared to the visible regime.A maximum conversion efficiency of 18.8%is achieved,while the background noise is measured to be only1.2×10^-3 counts/*** corresponding spectral linewidth of the upconverted photons is 0.2 *** scheme of broadband infrared single-photon upconversion and detection provides potential solutions in infrared laser ranging,broadband infrared imaging and quantum key distribution.

关键词： pump Efficiency Infrared

Edge Coloring by Total Labelings of Outerplanar Graphs

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Acta Mathematica Sinica,English Series 2013年第11期29卷 2129-2136页

作者： guang hui WANG Gui Ying YAN School of Mathematics Shandong University Academy of Mathematics and System Sciences Chinese Academy of Sciences

An edge coloring total k-labeling is a labeling of the vertices and the edges of a graph G with labels {1,2,..., k} such that the weights of the edges define a proper edge coloring of G. Here the weight of an edge is the sum of its label and the labels of its two end vertices. This concept was introduce by Brandt et al. They defined Xt＇（G） to be the smallest integer k for which G has an edge coloring total k-labeling and proposed a question： Is there a constant K with X^t（G） ≤△（G）＋1/2 K for all graphs G of maximum degree A（G）？ In this paper, we give a positive answer for outerplanar graphs ≤△（G）＋1/2 by showing that X＇t（G） ≤△（G）＋1/2 for each outerplanar graph G with maximum degree A（G）.

关键词： Edge colorings total labelings outerplanar graphs

Neighbor Sum Distinguishing Total Colorings of Graphs with Bounded Maximum Average Degree

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Acta Mathematica Sinica,English Series 2014年第4期30卷 703-709页

作者： Ai Jun DONG guang hui WANG School of Science Shandong Jiao Tong University School of Mathematics Shandong University

A proper [h]-total coloring c of a graph G is a proper total coloring c of G using colors of the set [h] ={1, 2,..., h}. Let w（u） denote the sum of the color on a vertex u and colors on all the edges incident to u. For each edge uv ∈ E（G）, if w（u） ≠ w（v）, then we say the coloring c distinguishes adjacent vertices by sum and call it a neighbor sum distinguishing [h]-total coloring of G. By tndi∑ （G）, we denote the smallest value h in such a coloring of G. In this paper, we obtain that G is a graph with at least two vertices, if mad（G）〈 3, then tndi∑ （G） ≤k ＋ 2 where k = max{△（G）, 5}. It partially confirms the conjecture proposed by Pilgniak and Wolniak.

关键词： Total coloring neighbor sum distinguishing total colorings average degree

A Middle Triassic stem-neopterygian fish from China shows remarkable secondary sexual characteristics

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Science Bulletin 2016年第4期61卷 338-344页

作者： guang-hui Xu Li-Jun Zhao Key Laboratory of Vertebrate Evolution and human Origins of Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing 100044 China Zhejiang Museum of Natural History Hangzhou 310014 China

Secondary sexual characteristics are features that appear at sexual maturity and distinguish the two sexes of a species. They are readily observed and studied in living animals, but the phenomenon is rather more difficult to identify in fossil taxa. Here we report a new sexually dimorphic stem-neopterygian fish, Venusichthys comptus gen. et sp. nov., based on 30 exceptionally well-preserved specimens from the Middle Triassic （Pelsonian, Anisian） Luoping Lagerst^itte of eastern Yunnan, China. The discovery represents the oldest known secondary sexual characteristics in Neopterygii. These characteristics, including pointed tubercles on cranial bones, scales and fins, and hook-like contact organ anterior to the anal fin, have three inferred primary functions： maintenance of body contact between the sexes during prespawning behavior or spawning; stimulation of the females during breeding; and defense of nests and territories. Lacking a specialized anal fin in the presumed males, Venusichthys would likely have a different reproductive strategy from peltopleurids and other potentially viviparous stem-neopterygians. Moreover, Venusichthys shows a unique character combination distinguished from any other stem-neopterygian families and consequently represents a new family of this clade. Assuch, the new finding provides an important addition for understanding the behavior, reproduction, and early diversification of Neopterygii.

关键词： Sexual dimorphism Breeding tuberclesVenusichthyidae Neopterygii Actinopterygii

Structure-Preserving Algorithms for a Class of Dynamical Systems

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Acta Mathematicae Applicatae Sinica 2007年第1期23卷 161-176页

作者： Ling-shu Wang guang-hui Feng School of Mathematics and Statistics Hebei University of Economics & Business Shijiazhang 050061 China Mechanical Engineering College Shijiazhuang 050003 China

In this paper, we study structure-preserving algorithms for dynamical systems defined by ordinary differential equations in R^n The equations are assumed to be of the form y^· = A（y）＋ D（y）＋ R（y）, where A（y） is the conservative part subject to （A（y）, y） = 0; D（y） is the damping part or the part describing the coexistence of damping and expanding; R（y） reflects strange phenomenon of the system. It is shown that the numerical solutions generated by the symplectic Runge-Kutta（SRK） methods with bi 〉 0 （ i = 1,..., s） have long-time approximations to the exact ones, and these methods can describe the structural properties of the quadratic energy for these systems. Some numerical experiments and backward error analysis also show that these methods are better than other methods including the general algebraically stable Runge-Kutta（RK）methods.

关键词： SRK methods numerical experiment backward error analysis

Mitochondrial sirtuins,metabolism,and aging

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Journal of Genetics and Genomics 2022年第4期49卷 287-298页

作者： Zhejun Ji guang-hui Liu Jing Qu State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Advanced Innovation Center for human Brain Protection National Clinical Research Center for Geriatric DisordersXuanwu Hospital Capital Medical UniversityBeijing 100053China

Maintaining metabolic homeostasis is essential for cellular and organismal health throughout *** signaling pathways that regulate metabolism also play critical roles in aging,such as PI3K/AKT,mTOR,AMPK,and sirtuins(SIRTs).Among them,sirtuins are known as a protein family with versatile functions,such as metabolic control,epigenetic modification and lifespan ***,by understanding how sirtuins regulate metabolic processes,we can start to understand how they slow down or accelerate biological aging from the perspectives of metabolic ***,we review the biology of SIRT3,SIRT4,and SIRT5,known as the mitochondrial sirtuins due to their localization in the mitochondrial ***,we will discuss canonical pathways that regulate metabolism more broadly and how these are integrated with aging ***,we will summarize the current knowledge about functional differences between SIRT3,SIRT4,and SIRT5 in metabolic control and integration in signaling ***,we will discuss how mitochondrial sirtuins regulate processes associated with aging and aging-related diseases.

关键词： Metabolism and aging regulation Mitochondrial sirtuins Aging-related diseases SIRT3 SIRT4 SIRT5

Distribution uniformity of added elements in twin-roll cast Al–Zn–Mg–Cu alloy by multi-electromagnetic fields

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Rare Metals 2015年第8期34卷 546-552页

作者： Xin Su guang-Ming Xu Ding-hui Jiang School of Materials and Metallurgy Northeastern University Key Laboratory of Ministry of Education for Electromagnetic Processing of Materials guangdong Donggong Information Science & Technology Company Limited

The micromorphology and the concentration o massive precipitates produced by twin-roll casting(TRC processes without and with multi-electromagnetic fields fo Al–Zn–Mg–Cu alloy at 670 °C were investigated in detai by means of optical microscopy(OM) and electron probe micro analyzer(EPMA). The results clearly show tha under a 0.2 T static magnetic field, the macro-segregation bands are remarkably alleviated according to the order o uniform static magnetic field, half-wave oscillating elec tromagnetic field as well as alternating oscillating elec tromagnetic field, as compared with the non-field TRC process(B = 0). Moreover, under the alternating oscillat ing electromagnetic TRC process, almost all segregation bands disappear. Additionally, through the observation on a smaller scale, the netlike precipitates elongated and broken by electromagnetic force, and replaced by numerous bulk depositions. EPMA analysis shows that the added atoms are diffused from deposition to a(Al) matrix, resulting in that the solute concentration in and around the precipitates is tending toward uniformity and stability.

关键词： Al–Zn–Mg–Cu alloy Electromagnetic field Twin-roll

PIM-Align: A Processing-in-Memory Architecture for FM-IndexSearch Algorithm

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Journal of Computer Science & Technology 2021年第1期36卷 56-70页

作者： Xue-Qi Li guang-Ming Tan Ning-hui Sun University of Chinese Academy of Sciences Beijing 100049China

Genomic sequence alignment is the most critical and time-consuming step in genomic *** algorithms generally follow a seed-and-extend *** of the extension phase for sequence alignment has been well explored in computing-centric architectures on field-programmable gate array(FPGA),application-specific integrated circuit(ASIC),and graphics processing unit(GPU)(e.g.,the Smith-Waterman algorithm).Compared with the extension phase,the seeding phase is more critical and ***,the seeding phase is bounded by memory,i.e.,fine-grained random memory access and limited parallelism on conventional *** this paper,we argue that the processing-in-memory(PIM)concept could be a viable solution to address these *** paper describes\PIM-Align"|an application-driven near-data processing architecture for sequence *** order to achieve memory-capacity proportional performance by taking advantage of 3D-stacked dynamic random access memory(DRAM)technology,we propose a lightweight message mechanism between different memory partitions,and a specialized hardware prefetcher for memory access patterns of sequence *** evaluation shows that the proposed architecture can achieve 20x and 1820x speedup when compared with the best available ASIC implementation and the software running on 32-thread CPU,respectively.

关键词： accelerator design genomic sequence alignment near-memory computing