检索结果-南通市图书馆

An update on placental drug transport and its relevance to fetal drug exposure

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Medical Review 2022年第5期2卷 501-511页

作者： Qingcheng Mao Xin chen Department of Pharmaceutics School of PharmacyUniversity of WashingtonBox 357610 H272F Health Science Building 1959 NE Pacific StreetSeattleWashington 98195USA Department of Pharmaceutics School of PharmacyUniversity of WashingtonSeattleWashingtonUSA

Pregnant women are often complicated with diseases that require treatment with medication.Most drugs administered to pregnant women are off-label without the necessary dose,efficacy,and safety information.Knowledge concerning drug transfer across the placental barrier is essential for understanding fetal drug exposure and hence drug safety and efficacy to the fetus.Transporters expressed in the placenta,including adenosine triphosphate(ATP)-binding cassette efflux transporters and solute carrier uptake transporters,play important roles in determining drug transfer across the placental barrier,leading to fetal exposure to the drugs.In this review,we provide an update on placental drug transport,including in vitro cell/tissue,ex vivo human placenta perfusion,and in vivo animal studies that can be used to determine the expression and function of drug transporters in the placenta as well as placental drug transfer and fetal drug exposure.We also describe how the knowledge of placental drug transfer through passive diffusion or active transport can be combined with physiologically based pharmacokinetic modeling and simulation to predict systemic fetal drug exposure.Finally,we highlight knowledge gaps in studying placental drug transport and predicting fetal drug exposure and discuss future research directions to fill these gaps.

关键词： adenosine triphosphate-binding cassette transporters fetal drug exposure physiologically based pharmacokinetic modeling and simulation placental drug transport solute carrier transporters.

An Iterative Method for Optimal Feedback Control and Generalized HJB Equation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2018年第5期5卷 999-1006页

作者： Xuesong chen Xin chen the school of applied mathematics guangdong university of technologyGuangzhou 510006China the school of electromechanical engineering guangdong university of technologyGuangzhou 510006China

In this paper, a new iterative method is proposed to solve the generalized Hamilton-Jacobi-Bellman(GHJB) equation through successively approximate it. Firstly, the GHJB equation is converted to an algebraic equation with the vector norm,which is essentially a set of simultaneous nonlinear equations in the case of dynamic systems. Then, the proposed algorithm solves GHJB equation numerically for points near the origin by considering the linearization of the non-linear equations under a good initial control guess. Finally, the procedure is proved to converge to the optimal stabilizing solution with respect to the iteration variable. In addition, it is shown that the result is a closed-loop control based on this iterative approach. Illustrative examples show that the update control laws will converge to optimal control for nonlinear systems.

关键词：磁悬浮系统悬浮物自动控制自动化系统

An Impedance-based Parameter Design Method for Active Damping of Load Converter Station in MTDC Distribution System

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2022年第5期10卷 1423-1436页

作者： Pengwei chen Wenmeng Zhao Xin chen Wenwei Jiang IEEE Jiangsu Key Laboratory of New Energy Generation and Power Conversion College of Automation EngineeringNanjing University of Aeronautics and AstronauticsNanjingChina

To achieve the efficient application of impedance analysis in the stability assessment and enhancement of multiterminal DC distribution systems, this paper proposes the DCside reduced-order impedance models with power control and AC voltage control, respectively, by taking the load converter station as the object. By using the DC-side current as the feedforward state, the active compensator applied to the load converter station with two control modes is also derived as well as the corresponding reduced-order impedance models. Combined with the reduced-order impedance models, a method based on damping factor sensitivity is further proposed to design the parameters of the derived active compensators. The verification results in the frequency domain and time domain demonstrate the accuracy of the reduced-order impedance and the effectiveness of the proposed compensator parameter design method.

关键词： Impedance modeling order reduction active compensator damping factor sensitivity

A general two-phase mixture model for sediment-laden flow in open channel

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2022年第2期34卷 286-298页

作者： Jia-xing Li Xin chen Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System China Agricultural UniversityBeijing100083China

This work extends the sediment-laden mixture model with consideration of the turbulence damping and particle wake effects under the framework of improved efficiency and accuracy.The mixture model consists of the continuity and momentum equations for the sediment-laden mixture,and the continuity equation for the sediment.A theoretical formula is derived for the relative velocity between the water and sediment phases,with consideration of the effects of the pressure gradient,the shear stress and the lift force.A modified expression of the particle wake effect,inducing the local turbulence enhancement around the sediment particle,is employed to improve the turbulent diffusion of the coarse sediment.The k_(m)-ε_(m) model is proposed to close the mixture turbulence,with the turbulence damping effect due to the high sediment concentration expressed by the density-stratification term without an empirical parameter.The k_(m)-ε_(m) turbulence model requires smaller computational work and offers better results than an empirical density-stratification turbulence model in high sediment concentration cases.Consequently,with the proposed mixture model,the sediment transport in the open channel under a wide range of sediment sizes and concentrations can be revealed with the results in good agreement with experimental data for the velocity,the sediment concentration and the turbulent kinetic energy.

关键词： Sediment-laden flow two-phase mixture model particle wake effect turbulence damping effect density stratification

Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for Lithium-Oxygen Batteries

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第2期16卷 154-164页

作者： Xin chen Yu Zhang Chang chen Huinan Li Yuran Lin Ke Yu Caiyun Nan chen chen Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084People’s Republic of China Beijing Key Laboratory of Energy Conversion and Storage Materials Institution College of ChemistryBeijing Normal UniversityBeijing 100875People’s Republic of China

Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at present.Here,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for Lithium–oxygen battery.On one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox kinetics.On the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic molecules.Therefore,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.

关键词： Atomically dispersed Open hollow structure Discharge product Lithium Oxygen battery

iGMDR:Integrated Pharmacogenetic Resource Guide to Cancer Therapy and Research

在线全文

学校读者我要写书评

暂无评论

Genomics, Proteomics & Bioinformatics 2020年第2期18卷 150-160页

作者： Xiang chen Yi Guo Xin chen Institute of Pharmaceutical Biotechnology and the First Affiliated Hospital Department of Radiation Oncology Zhejiang University School of MedicineHangzhou 310058China Department of Polymer Science and Engineering and Key Laboratory of Adsorption and Separation Materials and Technologies of Zhejiang Province Zhejiang UniversityHangzhou 310027China Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto Zhejiang UniversityHangzhou 310058China

Current pharmacogenetic studies have obtained many genetic models that can predict the therapeutic efficacy of anticancer drugs.Although some of these models are of crucial importance and have been used in clinical practice,these very valuable models have not been well adopted into cancer research to promote the development of cancer therapies due to the lack of integration and standards for the existing data of the pharmacogenetic studies.For this purpose,we built a resource investigating genetic model of drug response(iGMDR),which integrates the models from in vitro and in vivo pharmacogenetic studies with different omics data from a variety of technical systems.In this study,we introduced a standardized process for all integrations,and described how users can utilize these models to gain insights into cancer.iGMDR is freely accessible at https://***.

关键词： Genetic model Pharmacogenetics Anticancer drug Cancer Drug response

Scalability and efficiency challenges for the exascale supercomputing system:practice of a parallel supporting environment on the Sunway exascale prototype system

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2023年第1期24卷 41-58页

作者： Xiaobin HE Xin chen Heng GUO xin LIU Dexun chen Yuling YANG Jie GAO Yunlong FENG Longde chen Xiaona DIAO Zuoning chen National Research Center of Parallel Computer Engineering and Technology Beijing 100190China

With the continuous improvement of supercomputer performance and the integration of artificial intelligence with traditional scientific computing,the scale of applications is gradually increasing,from millions to tens of millions of computing cores,which raises great challenges to achieve high scalability and efficiency of parallel applications on super-large-scale systems.Taking the Sunway exascale prototype system as an example,in this paper we first analyze the challenges of high scalability and high efficiency for parallel applications in the exascale era.To overcome these challenges,the optimization technologies used in the parallel supporting environment software on the Sunway exascale prototype system are highlighted,including the parallel operating system,input/output(I/O)optimization technology,ultra-large-scale parallel debugging technology,10-million-core parallel algorithm,and mixed-precision method.Parallel operating systems and I/O optimization technology mainly support largescale system scaling,while the ultra-large-scale parallel debugging technology,10-million-core parallel algorithm,and mixed-precision method mainly enhance the efficiency of large-scale applications.Finally,the contributions to various applications running on the Sunway exascale prototype system are introduced,verifying the effectiveness of the parallel supporting environment design.

关键词： Parallel computing Sunway Ultra-large-scale Supercomputer

General velocity formula of boundary layer above mobile sediment bed induced by asymmetric waves

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2021年第2期36卷 255-267页

作者： Xin chen Minghong chen Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System China Agricultural University

Sediment movement in the wave boundary layer above a mobile sediment bed is complex. A velocity formula for the boundary layer is proposed for sheet flow induced by asymmetric waves above a mobile sediment bed. The formula consists of a free stream velocity and a defect function which contains a phase-lead, boundary layer thickness and mobile sediment bed. Phase-lag of sediment movement is considered in the formula for the mobile sediment bed. The formula needs six dependent variables about asymmetric wave and sediment characteristics. Asymmetry effects on parameters(orbital amplitude,roughness height, bed shear stress, and boundary layer thickness) are properly considered such that the formula can yield velocity differences among onshore, offshore, acceleration, and deceleration stages.The formula estimates the net boundary layer velocity resulting from the mobile sediment bed and asymmetric boundary layer thickness. In addition, a non-constant phase-lead also contributes to the net boundary layer velocity in asymmetric oscillatory sheet flow. Results of the formula are as good as that of a two-phase numerical model. Sheet flow transport induced by asymmetric waves, and the offshore net sediment transport rate with a large phase-lag under velocity-skewed waves, can be adequately estimated by the formula with a power sediment concentration function.

关键词： Asymmetric wave Boundary layer Mobile sediment bed Sheet flow Velocity formula

Virtual Inertia Estimation Method of DFIG-based Wind Farm with Additional Frequency Control

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2021年第5期9卷 1076-1087页

作者： Pengwei chen chenchen Qi Xin chen Jiangsu Key Laboratory of New Energy Generation and Power Conversion College of Automation EngineeringNanjing University of Aeronautics and AstronauticsNanjingChina

With the increasing penetration of wind power,using wind turbines to participate in the frequency regulation to support power system has become a clear consensus.To accurately quantify the inertia provided by the doubly-fed induction generator(DFIG)based wind farm,the frequency response model of DFIG with additional frequency control is established,and then by using Routh approximation,the explicit expression of the virtual moment of inertia is derived for the DFIG gridconnected system.To further enhance the availability of the expression,an estimation method is proposed based on the matrix pencil method and the least squares algorithm for estimating the virtual moment of inertia provided by the wind farm.Finally,numerical results tested by a DFIG grid-connected system and a modified IEEE 30-bus system verify the derived expression of the virtual moment of inertia and the proposed estimation method.

关键词： Doubly-fed induction generator(DFIG) additional frequency control virtual moment of inertia matrix pencil method least squares algorithm