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基于可视化试验的风积沙宏细观力学特性分析

西安理工大学学报 2022年第2期38卷 287-294页

作者：薛嘉麟杜强内蒙古工业大学土木工程学院内蒙古呼和浩特010051 沙旱区地质灾害与岩土工程防御自治区高等学校重点实验室内蒙古呼和浩特010051

为了研究库布齐沙漠风积沙的宏细观力学特性,采用自行设计的可视化试验仪器对风积沙进行直剪试验和压缩试验,使用数码相机对试验过程进行拍摄,利用数字图像分析软件PhotoInfor对试验照片进行分析,得到土样位移场和应变场云图,并通过数... 详细信息

为了研究库布齐沙漠风积沙的宏细观力学特性,采用自行设计的可视化试验仪器对风积沙进行直剪试验和压缩试验,使用数码相机对试验过程进行拍摄,利用数字图像分析软件PhotoInfor对试验照片进行分析,得到土样位移场和应变场云图,并通过数值模拟软件(Particle Follow Code,PFC)对风积沙直剪试验、压缩试验和三轴试验进行数值模拟,对颗粒的细观变化进行分析。通过试验发现剪切初期风积沙颗粒较为分散,随着剪切的进行,大颗粒产生位移并形成剪切带,最终剪切带贯通、稳定,在直剪过程中剪切带以上土颗粒向上竖直运动。由于压缩试验是在侧限条件下进行的,变形过程中颗粒体水平方向的速度较小,而竖直方向速度基本等同于压缩速度,越靠近荷载施加位置的颗粒体竖向位移越明显。

关键词：风积沙可视化试验位移场云图细观分析

Continuous Orbit Equivalence of Semigroup Actions

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1581-1598页

作者： Xiang Qi qiang Cheng Jun HOU School of Mathematical Science Yangzhou UniversityYangzhou 225002P.R.China

We introduce notions of continuous orbit equivalence and its one-sided version for countable left Ore semigroup actions on compact spaces by surjective local homeomorphisms,and characterize them in terms of the corresponding transformation groupoids and their operator *** particular,we show that two essentially free semigroup actions on totally disconnected compact spaces are continuously orbit equivalent if and only if there is a canonical abelian subalgebra preserving C^(∗)-isomorphism between the associated transformation groupoid C^(∗)-*** also give some examples of orbit equivalence,consider the special case of semigroup actions by homeomorphisms and relate continuous orbit equivalence of semigroup actions to that of the associated group actions.

关键词： Semigroup action continuous one-sided orbit equivalence continuous orbit equivalence groupoid C^(∗)-algebras

Preface to the Focused Issue on Fractional Derivatives and General Nonlocal Models

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Communications on Applied Mathematics and Computation 2019年第4期1卷 503-504页

作者： qiang du Jan SHesthaven Changpin Li Chi-Wang Shu Tao Tang Columbia University New YorkUSA Ecole Polytechnique Federale de Lausanne LausanneSwitzerland Shanghai University ShanghaiChina Brown University ProvidenceUSA Southern University of Science and Technology ShenzhenChina

Fractional calculus,which has two prominent characteristics-singularity and nonlocality,comprises the integration and differentiation of any positive real(and even complex)*** has a more than three-hundred-year history and can be traced back to a letter from Leib-niz to UHopital,dated 30 September 1695,in which the meaning of the one-half order derivative was first discussed and some remarks about its feasibility were *** was probably the first who rendered an application of fractional *** used the derivatives of arbitrary order to solve the tautochrone(isochrone)problem in *** calculus underwent two periods:from its beginning to the 1970s,and after *** the first period,fractional calculus was studied mainly by mathematicians as an abstract field containing only pure mathematical manipulations of little applications,except for sporadic applications in *** the second period,the paradigm shifted from pure mathematical research to applications in various realms,including anomalous diffusion,anomalous convection,power laws,allometric scaling laws,history dependence,long?range interactions,and so on.

关键词： fractional pure singularity

Efficiently simulating the work distribution of multiple identical bosons with boson sampling

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Frontiers of physics 2024年第3期19卷 197-206页

作者： Wen-qiang Liu Zhang-qi Yin Center for Quantum Technology Research and Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements(MOE) School of PhysicsBeijing Institute of TechnologyBeijing 100081China

Boson sampling has been theoretically proposed and experimentally demonstrated to show quantum computational ***,it still lacks the deep understanding of the practical applications of boson *** we propose that boson sampling can be used to efficiently simulate the work distribution of multiple identical *** link the work distribution to boson sampling and numerically calculate the transition amplitude matrix between the single-boson eigenstates in a one-dimensional quantum piston system,and then map the matrix to a linear optical network of boson *** work distribution can be efficiently simulated by the output probabilities of boson sampling using the method of the grouped probability *** scheme requires at most a polynomial number of the samples and the optical *** work opens up a new path towards the calculation of complex quantum work distribution using only photons and linear optics.

关键词： quantum simulation quantum work distribution boson sampling linear optic

Quantized bound states around a vortex in anisotropic superconductors

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 146-155页

作者： Ke Xiang Da Wang qiang-Hua Wang National Laboratory of Solid State Microstructures&School of Physics Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

The bound states around a vortex in anisotropic superconductors is a longstanding yet important *** this work,we develop a variational theory on the basis of the Andreev approximation to obtain the energy levels and wave functions of the low-energy quantized bound states in superconductors with anisotropic pairing on arbitrary Fermi *** the case of circular Fermi surface,the effective Schr¨odinger equation yielding the bound state energies gets back to the theory proposed by Volovik and Kopnin many years *** generalization here enables us to prove the equidistant energy spectrum inside a vortex in a broader class of *** importantly,we are now able to obtain the wave functions of these bound states by projecting the quasiclassical wave function on the eigenmodes of the effective Schr¨odinger equation,going beyond the quasiclassical Eilenberger results,which,as we find,are sensitive to the scattering *** the case of isotropic Fermi surface,the spatial profile of the low-energy local density of states is dominated near the vortex center and elongates along the gap antinode directions,in addition to the ubiquitous Friedel oscillation arising from the quantum inteference neglected in the Eilenberger ***,as a consequence of the pairing anisotropy,the quantized wave functions develop a peculiar distribution of winding number,which reduces stepwise towards the vortex *** work provides a flexible way to study the vortex bound states in the future.

关键词： vortex bound state anisotropic superconductor Andreev approximation

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UWLPIPE: Ultra-wide Bandwidth Low-frequency Pulsar Data Processing Pipeline

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Research in Astronomy and Astrophysics 2024年第7期24卷 148-160页

作者： Ya-Zhou Zhang Hai-Long Zhang Jie Wang Jian Li Xin-Chen Ye Shuang-qiang Wang Xu du Han Wu Ting Zhang Shao-Cong Guo Xinjiang Astronomical Observatory Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of Radio Astronomy Chinese Academy of Sciences National Astronomical Data Center Southeast University

For real-time processing of ultra-wide bandwidth low-frequency pulsar baseband data, we designed and implemented an ultra-wide bandwidth low-frequency pulsar data processing pipeline(UWLPIPE) based on the shared ringbuffer and GPU parallel technology. UWLPIPE runs on the GPU cluster and can simultaneously receive multiple 128 MHz dual-polarization VDIF data packets preprocessed by the front-end FPGA. After aligning the dual-polarization data, multiple 128M subband data are packaged into PSRDADA baseband data or multi-channel coherent dispersion filterbank data, and multiple subband filterbank data can be spliced into wideband data after time alignment. We used the Nanshan 26 m radio telescope with the L-band receiver at964 ～ 1732 MHz to observe multiple pulsars. Finally, we processed the data using DSPSR software, and the results showed that each subband could correctly fold out the pulse profile, and the wideband pulse profile accumulated by multiple subbands could be correctly aligned.

关键词： (stars:) pulsars: general methods: data analysis techniques: miscellaneous

Approximate contact solutions for non-axisymmetric homogeneous and power-law graded elastic bodies:A practical tool for design engineers and tribologists

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Friction 2024年第2期12卷 340-355页

作者： Valentin L.POPOV qiang LI Emanuel WILLERT Institute of Mechanics Technische Universität BerlinBerlin 10623Germany

In two recent papers,approximate solutions for compact non-axisymmetric contact problems of homogeneous and power-law graded elastic bodies have been suggested,which provide explicit analytical relations for the force–approach relation,the size and the shape of the contact area,as well as for the pressure distribution *** solutions were derived for profiles,which only slightly deviate from the axisymmetric *** the present paper,they undergo an extensive testing and validation by comparison of solutions with a great variety of profile shapes with numerical solutions obtained by the fast Fourier transform(FFT)-assisted boundary element method(BEM).Examples are given with quite significant deviations from axial symmetry and show surprisingly good agreement with numerical solutions.

关键词： normal contact non-axisymmetric indenter extremal principle generalized method of dimensionality reduction(MDR) functional elastic grading

Immobilization of biomacromolecules on poly-L-lactide surface via a layer-by-layer method for the improving of its cytocompatibility to bone marrow stromal cells

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Chinese Science Bulletin 2005年第24期50卷 2809-2816页

作者： LU Delong MENG Sheng ZHONG Wei du qiang-guo GONG Li LIU Jinfen dusan Bakos Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science Fudan University Shanghai 200433 China Shanghai Medical Center for Children Shanghai 200127 China Faculty of Chemical and Food Technology Slovak University of Technology in Bratislava Slovak Republic

Hyaluronic acid (HA) and chitosan (CS) were immobilized on the surface of poly-L-lactide (PLLA) by the following procedure: Firstly, PLLA was aminolyzed with 1, 6-hexanediamine, and part of the PLLA surface ester groups were converted to free amino groups. Then negatively charged hyaluronic acid and positively charged chitosan were deposited onto the surface of aminolyzed PLLA film in a layer-by-layer assembly manner. The effect of the layer-by- layer deposition was evaluated by ATR-FTIR spectroscopy, Raman spectroscopy and static contact angle measurements. The cytocompatibility of PLLA sample to bone marrow stromal cells (BMSCs) was improved after modification with chitosan and HA. The cell attachment, activity, and prolif- eration on CS/HA modified PLLA films were enhanced comparing with the control. The cells cultured on the modi- fied PLLA samples excreted abundant cytoplasm and can differentiate to vascular smooth muscle (SM)-like (SM-like) cells. A macroporous three-dimensional PLLA scaffold was prepared by integrating both the technique of freeze-drying and particle leaching. Layer-by-layer modification by HA/CS and cell culture was also applied on this scaffold. The scaf- fold cultured with BMSCs for 2 weeks has been tested suc- cessfully in vivo as a patch for repairing the artificial incision on canine pulmonary artery.

关键词：透明质酸壳聚糖生物材料表面改性细胞相容性聚-L-丙交酯骨髓间质细胞

New direction for surgery:Super minimally invasive surgery

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World Journal of Gastroenterology 2024年第12期30卷 1676-1679页

作者： En-qiang Linghu Department of Gastroenterology First Medical Center of Chinese PLA General HospitalBeijing 100853China

The top goal of modern medicine is treating disease without destroying organ structures and making patients as healthy as they were before their *** invasive surgery(MIS)has dominated the surgical realm because of its lesser ***,changes in anatomical structures of the body and reconstruction of internal organs or different organs are common after traditional surgery or MIS,decreasing the quality of life of patients ***,I propose a new treatment mode,super MIS(SMIS),which is defined as“curing a disease or lesion which used to be treated by MIS while preserving the integrity of the organs”.In this study,I describe the origin,definition,operative channels,advantages,and future perspectives of SMIS.

关键词： Super minimally invasive surgery Minimally invasive surgery Treatment mode Traditional Surgery New direction for surgery