检索结果-南通市图书馆

Gut microbiota-mediated metabolism of Panax notoginseng saponins and its role in pharmacokinetics and pharmacodynamics

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

Traditional Medicine Research 2024年第12期9卷 41-50页

作者： Yu-Ying Zheng wei-wei Su Yu-Ling Liu wei-jian zhang Xuan Zeng Experimental Center the First Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou 510405China Guangdong Engineering&Technology Research Center for Quality and Efficacy Reevaluation of Post-Market Traditional Chinese Medicine Guangdong Provincial Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat-sen UniversityGuangzhou 510275China Department of Neurosurgery First People’s Hospital of FoshanFoshan 528010China Guangdong Hybribio Biotech Co. Ltd.Chaozhou 521011China

Panax notoginseng saponins(PNS)are a class of effective ingredients in Notoginseng Radix et Rhizoma,a well-known herbal medicine called San-Qi in *** oral administration,PNS inevitably interacts with gut microbiota,and thus affect the pharmacokinetic profiles and pharmacological *** date,studies concering gut microbiota-mediated metabolism of PNS have not been reviewed ***,we outline the metabolic profiles of Panax notoginseng saponins mediated by gut microbiota,as well as its role in the pharmacokinetics and pharmacodynamics on the basis of reported *** metabolic pathways of primary saponins are proposed,and step-by-step deglycosylation is found to be the primary degradation pathways of PNS mediated by gut *** microorganisms and enzymes involved in the metabolic processes were *** microbiota is deeply involved in the metabolism of PNS,affects the pharmacokinetic profiles,and produces a series of active *** metabolites were documented to play an essential role in the efficacy of the parent *** studies should focus on strengthening the real-world evidence,defining the interaction between gut microbiota and PNS,and developing the strategy for modulating gut microbiota to enhance the bioavailability and efficacy of *** information would be useful for further research and clinical application of PNS.

关键词： Panax notoginseng saponins gut microbiota metabolism pharmacokinetics pharmacodynamics

Research progress and development tendency on storage mechanism of multi-principal element alloys for hydrogen/tritium storage

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

Rare Metals 2024年第11期 5549-5572页

作者： Yi-Jie Chen jian-wei zhang Can-Hui Xu Mu-Hong Li Shuang-Lin Hu Yue-Xia Wang Xiao-Tao Zu Hai-Yan Xiao Xiao-Song Zhou Shu-Ming Peng Hua-Hai Shen Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Key Laboratory of Nuclear Physics and Ion-Beam Application (MOE) Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan University School of Physics University of Electronic Science and Technology of China

Sustainable clean energy is gradually replacing traditional fossil energy sources in important industrial applications and is placing higher demands on the technologies of energy storage and *** development of multi-principal element alloys(MPEAs) offers a new idea for safe solid-state hydrogen storage *** to the unique characteristics of complex components and severe lattice distortion,MPEAs are predicted to have better hydrogen storage performance and more probability for modulation and enhancement,allowing them to meet the requirements of different hydrogen storage *** unique structure characteristic potentially devotes the improvement of thermodynamic and kinetic performance,such as the hydrogen storage capacity and hydrogen adsorption/desorption ***,several important modulation factors originating from components and structures facilitate the understanding of the correlation between hydrogen storage properties and ***,we highlight the correlations of hydrogen storage mechanism,with the degree of lattice distortion,the element variation or segregation and valence electron ***,the development tendency on the hydrogen storage mechanism based on the advanced microscopy and computational approach is ***,the chemically short-range ordered structure in MPEAs is predicted as a potential modification factor of the hydrogen/tritium storage properties.

关键词：

Learning synergies based in-hand manipulation with reward shaping

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

CAAI Transactions on Intelligence Technology 2020年第3期5卷 141-149页

作者： Zhen Deng jian wei zhang TAMS Group InformaticsUniversity of HamburgHamburg D-22527Germany

In-hand manipulation is a fundamental ability for multi-fingered robotic hands that interact with their *** to the high dimensionality of robotic hands and intermittent contact dynamics,effectively programming a robotic hand for in-hand manipulations is still a challenging *** address this challenge,this work employs deep reinforcement learning(DRL)algorithm to learn in-hand manipulations for multi-fingered robotic hands.A reward-shaping method is proposed to assist the learning of in-hand *** synergy of robotic hand postures is analysed to build a low-dimensional hand posture *** additional rewards are designed based on both the analysis of hand synergies and its learning *** two additional rewards cooperating with an extrinsic reward are used to assist the in-hand manipulation *** value functions are trained jointly with respect to their reward *** they cooperate to optimise a control policy for in-hand *** reward shaping not only improves the exploration efficiency of the DRL algorithm but also provides a way to incorporate domain *** performance of the proposed learning method is evaluated with object rotation *** results demonstrated that the proposed learning method enables multi-fingered robotic hands to learn in-hand manipulation effectively.

关键词： manipulation policy jointly

An algorithm for trajectory prediction of flight plan based on relative motion between positions

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

Frontiers of Information Technology & Electronic Engineering 2018年第7期19卷 905-916页

作者： Yi LIN jian-wei zhang Hong LIU National Key Laboratory of Fundamental Science on Synthetic Vision Sichuan University National Key Laboratory of Air Traffic Control Automation System Technology Sichuan University

Traditional methods for plan path prediction have low accuracy and stability. In this paper, we propose a novel approach for plan path prediction based on relative motion between positions(RMBP) by mining historical flight trajectories. A probability statistical model is introduced to model the stochastic factors during the whole flight process. The model object is the sequence of velocity vectors in the three-dimensional Earth space. First, we model the moving trend of aircraft including the speed(constant, acceleration, or deceleration), yaw(left, right, or straight), and pitch(climb, descent, or cruise) using a hidden Markov model(HMM) under the restrictions of aircraft performance parameters. Then, several Gaussian mixture models(GMMs) are used to describe the conditional distribution of each moving trend. Once the models are built, machine learning algorithms are applied to obtain the optimal parameters of the model from the historical training data. After completing the learning process, the velocity vector sequence of the flight is predicted by the proposed model under the Bayesian framework, so that we can use kinematic equations, depending on the moving patterns, to calculate the flight position at every radar acquisition cycle. To obtain higher prediction accuracy, a uniform interpolation method is used to correct the predicted position each second. Finally, a plan trajectory is concatenated by the predicted discrete points. Results of simulations with collected data demonstrate that this approach not only fulfils the goals of traditional methods, such as the prediction of fly-over time and altitude of waypoints along the planned route, but also can be used to plan a complete path for an aircraft with high accuracy. Experiments are conducted to demonstrate the superiority of this approach to some existing methods.

关键词： Velocity vector Hidden Markov model Gaussian mixture model Machine learning Plan path prediction Relative motion between positions(RMBP)

Multiscale modeling of heterogeneous propellants from particle packing tograin failure using a surface-based cohesive approach

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2012年第3期28卷 746-759页

作者： Shi-Jun Zhi Bing Sun jian-wei zhang School of Astronautics Beihang University100191 BeijingChina

In the present work, a computational frame- work is established for multiscale modeling and analysis of solid propellants. A packing algorithm, considering the am- monium perchlorate （AP） and aluminum （A1） particles as spheres or discs is developed to match the size distribution and volume fraction of solid propellants. A homogenization theory is employed to compute the mean stress and strain of a representative volume element （RVE）. Using the mean results, a suitable size of RVE is decided. Without consider- ing the interfaces between particles and matrix, several nu- merical simulations of the relaxation of propellants are per- formed. The relaxation effect and the nonlinear mechanical behavior of propellants which are dependent on the applied loads are discussed. A new technology named surface-based cohesive behavior is proposed to describe the phenomenon of particle dewetting consisting of two ingredients： a damage initiation criterion and a damage evolution law. Several ex- amples considering contact damage behavior are computed and also nonlinear behavior caused by damaged interfaces is discussed in this paper. Furthermore the effects of the criti- cal contact stress, initial contact stiffness and contact failure distance on the damaged interface model have been studied.

关键词： Solid propellants. Nonlinear mechanical behav-ior- Cohesive. Mesomechanics

A new Bergeria(Flemingitaceae) from the Mississippian of Xinjiang,NW China and its evolutionary implications

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2019年第1期8卷 89-98页

作者： Ru Feng Ashalata D’Rozario jian-wei zhang School of Urban and Environment Science Huaiying Normal University Xinjiang Institute of Ecology and Geography Chinese Academy of Science Department of Botany Narasinha Dutt College

A new Bergeria(Lepidodendrales, Flemingitaceae), B. wenquanensis sp. nov., is described in this paper, typically characterized by the longest and elongated leaf cushions ever found. The specimen, collected from the Mississippian of Wenquan County, Xinjiang Uygur Autonomous Region, China, is represented by a fossil stem about two meters long, with distinct leaf cushions. The genus Bergeria has usually been assigned to partially decorticated Lepidodendron stems. Although Cathaysian Lepidodendron have been extensively reported in China, most of them were found in the central, eastern and southern parts of the country, rarely in northwestern China. This new species is so far the westernmost record and the most isolated representative from the Cathaysian Lepidodendron *** on the distribution of the Cathaysian Lepidodendron during the Mississippian, most of the species were in the South China Plate near the Equator, while the new species is discrete in the north, far from the Equator. According to the spatiotemporal distribution of Cathaysian Lepidodendron, this genus appeared during the Mississippian, a period which was represented by rather few species, it flourished and expanded northwards during the Pennsylvanian, taking the north block of the South China Plate as the center. Since the Cisuralian to the Guadalupian, the genus became gradually sparser in all areas of distribution, probably due to strong climate change. During the Lopingian, the genus migrated southwards to the South China block and had a broader distribution range again, and it became extinct to the end of this interval. The new species is also significant for the evolution of Lepidodendron leaf cushions. During the Mississippian, the primitive species of Lepidodendron usually had narrow, fusiform leaf cushions, while the Pennsylvanian or Permian species were more variable in shape of leaf cushions, from inverted water-drop, rhomboidal, hexagonal, trapeziform to horizontal rhomboidal.

关键词： Cathaysian flora Bergeria Lepidodendron Mississippian Xinjiang

Simulation of the orbit and spin period evolution of the double pulsars PSR J0737-3039 from their birth to coalescence induced by gravitational wave radiation

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2021年第4期21卷 319-324页

作者： Peng Liu Yi-Yan Yang jian-wei zhang Maria Rah School of Physics and Electronic Engineering Qilu Normal UniversityJinan 250200China School of Physics and Electronic Sciences Guizhou Education UniversityGuiyang 550018China Astronomy Department Beijing Normal UniversityBeijing 100875China Research Institute for Astronomy and Astrophysics of Maragha(RIAAM)-Maragha Iran

The complete orbital and spin period evolutions of the double neutron star(NS)system PSR J0737-3039 are simulated from birth to coalescence,which include the two observed radio pulsars classified as primary NS PSR J0737-3039 A and companion NS PSR J0737-3039 *** employing the characteristic age of PSR J0737-3039 B to constrain the true age of the double pulsar system,the initial orbital period and initial binary separation are obtained as 2.89 h and 1.44 x 106 km,respectively,and the coalescence age or the lifetime from the birth to merger of PSR J0737-3039 is obtained to be 1.38×10^(8)*** the last minute of coalescence,corresponding to the gravitational wave frequency changing from 20 Hz to1180 Hz,we present the binary separation of PSR J0737-3039 to be from 442 km to 30 km,while the spin periods of PSR J0737-3039 A and PSR J0737-3039 B are 27.10 ms and 4.63 s,*** the standard radio pulsar emission model,before the system merged,the primary NS could still be observed by a radio telescope,but the companion NS had crossed the death line in the pulsar magnetic-field versus period(B-P)diagram at which point it is usually considered to cease life as a *** is the first time that the whole life evolutionary simulation of the orbit and spin periods for a double NS system is presented,which provides useful information for observing a primary NS at the coalescence stage.

关键词： PSR J0737–3039 double neutron star pulsar gravitational wave simulation

Application of Fuzzy Logic for Autonomous Bay Parking of Automobiles

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2011年第4期8卷 445-451页

作者： Zhao-jian Wang jian-wei zhang Ying-Ling Huang Hui zhang Aryan Saadat Mehr State Key Laboratory of Automotive Simulation and Control Jilin University Changchun 130025 PRC Changchun Institute of Engineering and Technique Changchun 130117 PRC Department of Mechanical Engineering University of British Columbia Vancouver BC V6T lZ4 Canada Department of Mechanical Engineering University of Victoria PO Box 3055 STN CSC Victoria BC V8W 3P6 Canada Department of Electrical and Computer Engineering University of Saskatchewan 57 Campus Drive Saskatoon SK STN 5A9 Canada

In this paper, we investigate the control problem of autonomous bay parking system. We choose a referenced parking lot and define a suitable parking spot based on some measurements at various places. A kinetic model is set up for the convenience of analysis and simulation. The pose of the car during the parking procedure can be determined by the initial pose, the backward speed, and the steering angle of the wheel. Then, both a fuzzy speed controller and a fuzzy steering controller are designed for the bay parking. Finally, simulation results show the effectiveness of our designed controllers.

关键词： Fuzzy logic bay parking kinetic model simulation autonomous vehicle control.

W-Mo-Si/SiC Oxidation Protective Coating for Carbon/Carbon Composites

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2007年第4期23卷 559-562页

作者： Dangshe HOU Kezhi LI Hejun LI Qiangang FU jian wei Yulei zhang National Key Laboratory of Thermostructure Composite Materials Northwestern Polytechnical University Xi＇an 710072 China

A W-Mo-Si/SiC double-layer oxidation protective coating for carbon/carbon （C/C） composites was prepared by a two-step pack cementation technique. XRD （X-ray diffraction） and SEM （scanning electron microscopy）results show that the coating obtained by the first step pack cementation was a thin inner buffer layer of SiC with some cracks and pores, and a new phase of （WxMo1-x）Si2 appeared after the second step pack cementation. Oxidation test shows that, after oxidation in air at 1773 K for 175 h and thermal cycling between 1773 K and room temperature for 18 times, the weight loss of the W-Mo-Si/SiC coated C/C composites was only 2.06%. The oxidation protective failure of the W-Mo-Si/SiC coating was attributed to the formation of some penetrable cracks in the coating.

关键词： C/C composites Coating Microstructure Oxidation