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Split Local Artificial Boundary Conditions for the Two-Dimensional Sine-Gordon Equation on R^(2)

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Communications in Computational Physics 2011年第10期10卷 1161-1183页

作者： Houde Han zhiwen zhang Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China.

In this paper the numerical solution of the two-dimensional sine-Gordon equation is *** local artificial boundary conditions are obtained by the operator splitting *** the original problem is reduced to an initial boundary value problem on a bounded computational domain,which can be solved by the finite *** numerical examples are provided to demonstrate the effectiveness and accuracy of the proposed method,and some interesting propagation and collision behaviors of the solitary wave solutions are observed.

关键词： Sine-Gordon equation operator splitting method artificial boundary condition soliton unbounded domain

Study of lithium storage properties of the Sn-Ni alloys prepared by magnetic sputtering technology

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Acta Metallurgica Sinica(English Letters) 2010年第5期23卷 363-369页

作者： Xianhua HOU Shejun HU Wei PENG zhiwen zhang Qiang RU School of Physics and Telecommunication Engineering South China Normal University Guangzhou 510006 China

Nano-level Sn-Ni alloy thin-film electrode materials prepared by magnetic sputtering technology are characterized with X-ray diffraction （XRD）, atom force microscopy （AFM） and scanning electron microscopy （SEM）. The charge/discharge and cyclic voltammograms （CV） of the films electrodes are tested by the battery testing system of high precision. The results indicate that the materials prepared by direct current （DC） and radio frequency （RF） methods differ greatly in their performance. Ni3Sn2 alloy phase constitutes the main components prepared by DC method, the particles on the surface are tiny and show steady cycling performance, the deficiency is that they have low initial efficiency and small discharge capacity of 72% and 108 mA·h/g, respectively. Contrary to the former, Ni3Sn4 alloy phase constitutes the main com- ponents prepared by RF method, the particles on the surface appear comparatively larger, their discharge capacity did not decline in the first 15 times, keeping above 500 mA·h/g, but began to decline after 15 times.

关键词： Lithium ion battery Sn-Ni alloy Electrochemical property

A Variational Neural Network Approach for Glacier Modelling with Nonlinear Rheology

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Communications in Computational Physics 2023年第9期34卷 934-954页

作者： Tiangang Cui Zhongjian Wang zhiwen zhang School of Mathematics and Statistics University of SydneyNSW 2006Australia Division of Mathematical Sciences School of Physical and Mathematical SciencesNanyang Technological University21 Nanyang LinkSingapore 637371 Department of Mathematics The University of Hong KongPokfulam RoadHong Kong SARChina

We propose a mesh-free method to solve the full Stokes equation for modeling the glacier dynamics with nonlinear *** by the Deep-Ritz method proposed in[13],we first formulate the solution to the non-Newtonian Stokes equation as the minimizer of a variational problem with boundary ***,we approximate its solution space by a deep neural *** loss function for training the neural network is a relaxed version of the variational form,in which penalty terms are used to present soft constraints due to mixed boundary *** of introducing mesh grids or basis functions to evaluate the loss function,our method only requires uniform sampling from the physical domain and ***,we introduce a re-normalization technique in the neural network to address the significant variation in the scaling of real-world ***,we illustrate the performance of our method by several numerical experiments,including a 2D model with the analytical solution,the Arolla glacier model with realistic scaling and a 3D model with periodic boundary *** results show that our proposed method is efficient in solving the non-Newtonian mechanics arising from glacier modeling with nonlinear rheology.

关键词： Deep learning method variational problems mesh-free method non-Newtonian mechanics nonlinear rheology glacier modelling

Coordinated Active and Reactive Power Optimization Considering Load Characteristics for Active Distribution Network

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Chinese Journal of Electrical Engineering 2020年第4期6卷 97-105页

作者： Chenchen Yong Yong Li Zilong Zeng zhiwen zhang Zhenyu zhang Yanlun Liu College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Zhuhai Powint Electric Co. Ltd.Zhuhai 519085China

Voltage sensitive loads are extremely susceptible to voltage fluctuations,resulting in power system safety issues and economic *** to the load component of voltage sensitive loads being changed at different times,a voltage sensitive load model including the time characteristics is *** improve the voltage distribution in the active distribution network(ADN),the linearized active and reactive power coordinated optimization model for minimizing the operational cost(including the fluctuating cost of sensitive loads)is ***,the simulation on the IEEE 33-bus system demonstrates that the proposed control strategy can effectively stabilize the bus voltage of the sensitive load and reduce the operational costs of the ADN.

关键词： Sensitive load time-varying characteristics active distribution network

Regulation of human chorionic gonadotropin secretion and messenger ribonucleic acid levels by follistatin in the NUCC-3 choriocarcinoma cell line

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Chinese Science Bulletin 1998年第19期43卷 1635-1642页

作者： Lingyun Shi Zilong Fang Hongbo Li zhiwen zhang Beijing Med Univ Inst Physiol Beijing 100083 Peoples R China Natl Res Inst Sports Med Beijing 100029 Peoples R China

NUCC-3 choriocarcinoma cell line was used as an in vitro placental cell model to investigate the effects of follistatin on GnRH-stimulated hCG secretion and its subunit mRNA level and stability. Follistatin alone did not affect basal hCG secretion and its subunit mRNA level. GnRH increased hCG secretion and hCG β-mRNA level in a dose-dependent manner. Follistatin significantly suppressed GnRH-stimulated hCG secretion and hCG α- and β-mRNA level. It inhibited hCG secretion in response to PMA, and did not affect the stability of hCG α- and β-mRNA. The authors suggest that follistatin inhibits GnRH-stimulated hCG secretion as well as hCG α- and β-RNA level by decreasing the rate of transcription through the second messenger transduction system--protein kinase-C.

关键词： follistatin NUCC-3 choriocarcinoma cell line GnRH hCG Northern hybridization second messenger transduction system.

Autonomous navigation algorithm based on AUKF filter about fusion of geomagnetic and sunlight directions

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International Journal of Intelligent Computing and Cybernetics 2018年第4期11卷 471-485页

作者： Bing Hua zhiwen zhang Yunhua Wu Zhiming Chen College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjingChina

Purpose-The geomagnetic field vector is a function of the satellite’s *** position and speed of the satellite can be determined by comparing the geomagnetic field vector measured by on board three-axis magnetometer with the standard value of the international geomagnetic *** geomagnetic model has the disadvantages of uncertainty,low precision and long-term ***,accuracy of autonomous navigation using the magnetometer is *** purpose of this paper is to use the geomagnetic and sunlight information fusion algorithm to improve the orbit ***/methodology/approach-In this paper,an autonomous navigation method for low earth orbit satellite is studied by fusing geomagnetic and solar energy *** algorithm selects the cosine value of the angle between the solar light vector and the geomagnetic vector,and the geomagnetic field intensity as *** Adaptive Unscented Kalman Filter(AUKF)filter is used to estimate the speed and position of the satellite,and the simulation research is carried *** paper also made the same study using the UKF filter for comparison with the AUKF ***-The algorithm of adding the sun direction vector information improves the positioning accuracy compared with the simple geomagnetic navigation,and the convergence and stability of the filter are *** navigation error does not accumulate with time and has engineering application *** also can be seen that AUKF filtering accuracy is better than UKF filtering *** limitations/implications-Geomagnetic navigation is greatly affected by the accuracy of *** paper does not consider the spacecraft’s environmental interference with magnetic *** implications-Magnetometers and solar sensors are common sensors for ***-Earth satellite orbit has abundant geomagnetic field ***,the algorithm will have higher engineering significance in the practical applica

关键词： AUKF filter Geomagnetic field model Geomagnetic filtering Magnetometer Sun sensor

A Multiscale Multilevel Monte Carlo Method for Multiscale Elliptic PDEs with Random Coefficients

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Communications in Mathematical Research 2020年第2期36卷 154-192页

作者： Junlong Lyu zhiwen zhang Department of Mathematics The University of Hong KongPokfulam RoadHong Kong SARChina

We propose a multiscale multilevel Monte Carlo(MsMLMC)method to solve multiscale elliptic PDEs with random coefficients in the multi-query *** method consists of offline and online *** the offline stage,we construct a small number of reduced basis functions within each coarse grid block,which can then be used to approximate the multiscale finite element basis *** the online stage,we can obtain the multiscale finite element basis very efficiently on a coarse grid by using the pre-computed multiscale *** MsMLMC method can be applied to multiscale RPDE starting with a relatively coarse grid,without requiring the coarsest grid to resolve the smallestscale of the *** have performed complexity analysis and shown that the MsMLMC offers considerable savings in solving multiscale elliptic PDEs with random ***,we provide convergence analysis of the proposed *** results are presented to demonstrate the accuracy and efficiency of the proposed method for several multiscale stochastic problems without scale separation.

关键词： Random partial differential equations(RPDEs) uncertainty quantification(UQ) multiscale finite element method(MsFEM) multilevel Monte Carlo(MLMC) reduced basis convergence analysis

Large Active Faults and the Wharton Basin Intraplate Earthquakes in the Eastern Indian Ocean

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Journal of Ocean University of China 2023年第6期22卷 1563-1571页

作者： CHEN Jie GUO Laiyin YANG Xiaodong zhang Jinchang zhang zhiwen SUN Mengyu LIN Jingxue Fourth Institute of Oceanography Ministry of Natural ResourcesBeihai 536007China Department of Ocean Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China CAS Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyInnovation Academy of South China Sea Ecology and Environmental EngineeringChinese Academy of SciencesGuangzhou 511458China China-Pakistan Joint Research Center on Earth Science CAS-HECIslamabad 45320Pakistan University of Chinese Academy of Sciences Beijing 100049China

In recent years,great earthquakes occurred within the Wharton Basin in the eastern Indian Ocean,and they have been associa-ted with active faulting on the ancient oceanic *** seismogenic faults were thought to be the fault reactivation on the ancient oceanic crust,but these phenomena are still unclear and require *** study used high-quality multibeam bathymetry and multichannel seismic data collected over the northern Ninetyeast Ridge to investigate detailed fault geometry,structure,and *** recognized 12 large linear active faults by integrating bathymetry maps and multichannel seismic reflection *** results showed that these faults have high angles,and they all displaced the basement and propagated to the seafloor with distinct fault *** trended NWW-SEE with a spacing of 10–40km and were parallel to each other and the nearby subfault of the 2012 great intraplate earthquake,suggesting similar stress *** faults are also in agreement with the orientations of magnetic isochrons,implying their formation by seafloor ***,regarding the strike-slip focal mechanism of 2012 earthquakes,we proposed that these faults were created early by a normal spreading process and then evolved into a strike-slip pattern since the ancient oceanic crust ap-proached the subduction zones.

关键词： Ninetyeast Ridge Wharton Basin strike-slip faults great earthquakes seismogenic structure earthquake mechanism

Current approaches of nanomedicines in the market and various stage of clinical translation

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Acta Pharmaceutica Sinica B 2022年第7期12卷 3028-3048页

作者： Xiaoting Shan Xiang Gong Jie Li Jingyuan Wen Yaping Li zhiwen zhang State Key Laboratory of Drug Research&Center of Pharmaceutics Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China Yantai Key Laboratory of Nanomedicine&Advanced Preparations Yantai Institute of Materia MedicaYantai 264000China School of Pharmacy University of Chinese Academy of SciencesBeijing 100049China School of Pharmacy University of AucklandAuckland 1142New Zealand

Compared with traditional drug therapy,nanomedicines exhibit intriguing biological features to increase therapeutic efficiency,reduce toxicity and achieve targeting *** review provides a snapshot of nanomedicines that have been currently launched or in the clinical trials,which manifests a diversified trend in carrier types,applied indications and mechanisms of *** the perspective of indications,this article presents an overview of the applications of nanomedicines involving the prevention,diagnosis and treatment of various diseases,which include cancer,infections,blood disorders,cardiovascular diseases,immuno-associated diseases and nervous system diseases,***,the review provides some considerations and perspectives in the research and development of nanomedicines to facilitate their translations in clinic.

关键词： Nanomedicines Nanoparticles Liposomes Vaccines Marketed products Clinical translations Disease-driven design Quality by design