检索结果-南通市图书馆

World Journal of Gastroenterology 2005年第30期11卷 4735-4739页

作者： Yan-Tong Guo Xi-sheng Leng tao li Ji-Run Peng sheng-Han Song liang-Fa Xiong Zhi-Zhong Qin Department of General Surgery Peking University People's Hospital Beijing 100044 China

AIM： To study the effect of rosiglitazone, which is a ligand of peroxisome proliferator-activated receptor gamma （PPARy）, on the expression of PPARy in hepatic stellate cells （HSCs） and on the biological characteristics of HSCs. METHODS： The activated HSCs were divided into three groups： control group, 3 μmol/L rosiglitazone group, and 10 μmol/L rosiglitazone group. The expression of PPARγ, α-smooth muscle actin （α-SMA）, and type Ⅰ and Ⅲ collagen was detected by RT-PCR, Western blot and immunocytochemical staining, respectively. Cell proliferation was determined with methylthiazolyltetrazolium （MTT） colodmetric assay. Cell apoptosis was demonstrated with flow cytometry. RESULTS： The expression of PPARγ at mRNA and protein level markedly increased in HSCs of 10 μmol/L rosiglitazone group （tvalue was 10.870 and 4.627 respectively, P〈0.01 in both）. The proliferation of HSCs in 10 μmol/L rosiglitazone group decreased significantly （t = 5.542, P〈0.01）, α-SMA expression level and type Ⅰ collagen synthesis ability were also reduced VS controls （tvalue = 10.256 and 14.627 respectively, P〈0.01 in both）. The apoptotic rate of HSCs significantly increased in 10 μmol/L rosiglitazone group vs control （X^2= 16.682, P〈0.01）. CONCLUSION： By increasing expression of PPARγ in activated HSCs, rosiglitazone, an agonist of PPARγ, decreases α-SNA expression and type Ⅰ collagen synthesis, inhibits cell proliferation, and induces cell apoptosis.

关键词： Peroxisome proliferator-activated receptor gamma Hepatic stellate cell Rosiglitazone

AN OPTIMAL EXPECTED TIME SEARCH ALGORITHM FOR RAY TRACING

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 1992年第3期 174-181页

作者： Wei sheng-min,li tao(Northwestern Polytechnical University)

Ray tracing can produce very high quality and extremely realistic images in ***,the computational expense of ray tracing algorithm is very *** to75% total operation in ray tracing are consumed in searching intersecting *** has the advantages of generality because it can produce accurate image regardlessof the position of the originating points of rays,and optimal expected time complexitybecause it properly divides the object space into the cubes on the path of the ray.

关键词： AN OPTIMAL EXPECTED TIME SEARCH ALGORITHM FOR RAY TRACING SEARCH

limits of Riemann Solutions for Isentropic MHD in a Variable Cross-Section Duct as Magnetic Field Vanishes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2024年第4期45卷 637-660页

作者： Wancheng sheng tao XIAO Department of Mathematics Shanghai UniversityShanghai 200444China Shanghai Aircraft Design and Research Institute Shanghai 201210China.

The stability for magnetic field to the solution of the Riemann problem for the polytropic fluid in a variable cross-section duct is *** the vanishing magnetic field method,the stable solutions are determined by comparing the limit solutions with the solutions of the Riemann problem for the polytropic fluid in a duct obtained by the entropy rate admissibility criterion.

关键词： Variable duct Magnetogasdynamics Riemann problem Stability Vanishing magnetic field method

Resolution analysis of thermal neutron radiography based on accelerator-driven compact neutron source

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2023年第5期34卷 139-151页

作者： lian-Xin Zhang Si-Ze Chen Zao-Di Zhang tao-sheng li Chuan Peng Lei Ren Rui Zhang Dan Xiao Yong Zhang Hefei Institutes of Physical Science Chinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China

Owing to the immobility of traditional reactors and spallation neutron sources,the demand for compact thermal neutron radiography(CTNR)based on accelerator neutron sources has rapidly increased in industrial ***,thermal neutron radiography experiments based on a D-T neutron generator performed by Hefei Institutes of Physical Science indicated a significant resolution deviation between the experimental results and the values calculated using the traditional resolution *** experimental result was up to 23%lower than the calculated result,which hinders the achievement of the design goal of a compact neutron radiography system.A GEANT4 Monte Carlo code was developed to simulate the CTNR process,aiming to identify the key factors leading to resolution *** effects of a low collimation ratio and high-energy neutrons were analyzed based on the neutron beam environment of the CTNR *** results showed that the deviation was primarily caused by geometric distortion at low collimation ratios and radiation noise induced by highenergy ***,the theoretical model was modified by considering the imaging position and radiation noise *** modified theoretical model was in good agreement with the experimental results,and the maximum deviation was reduced to 4.22%.This can be useful for the high-precision design of CTNR systems.

关键词： Neutron radiography Spatial resolution Accelerator-driven neutron source Geant4 MTF ESF

Advances of nanoparticles in transmucosal drug delivery

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2874-2885页

作者： li Zhang Changwei Yang Yingxiang Song tao sheng Junyan li Jicheng Yu Xiaohong Wu Xiao Ye Geriatric Medicine Center Department of EndocrinologyZhejiang Provincial People’s Hospital(Affiliated People’s HospitalHangzhou Medical College)Hangzhou 310014China Key Laboratory of Advanced Drug Delivery Systems of Zhejiang Province College of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China Jinhua Institute of Zhejiang University Jinhua 321299China liangzhu Laboratory Zhejiang University Medical CenterHangzhou 311121China Department of General Surgery Sir Run Run Shaw HospitalSchool of MedicineZhejiang UniversityHangzhou 310016China National Key Laboratory of Advanced Drug Delivery and Release Systems Zhejiang UniversityHangzhou 310058China Key Laboratory for Diagnosis and Treatment of Endocrine Gland Diseases of Zhejiang Province Hangzhou 310014China

Transmucosal drug administration represents a potential strategy for enhancing treatment efficacy and reducing side effects by avoiding the first-pass effect into the systemic circulation and delivering therapeutics directly to the target disease ***,many challenges still remain in its clinical application,including low drug availability and limited retention time in the *** burgeoning advancement of nanotechnologies offers great potential to overcome the above limitations,leveraging their distinct advantages of high drug-loading capacity and strong *** this review,the latest developments of nanoparticles(NPs)in transmucosal drug delivery as well as their clinical applications are discussed.

关键词： nanoparticles(NPs) transmucosal drug delivery mucosal barriers biomaterials

Effect of short-time low-temperature austenitizing on microstructure and mechanical properties of DT300 ultra-high strength steel fabricated by laser powder bed fusion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第7期31卷 1763-1777页

作者： Chen-yang Jiang Xiao-qiang li Jin-tao Wang Hao Luo sheng-qing Gao sheng-guan Qu Chao Yang National Engineering Research Centre of Near-Net-Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640GuangdongChina Institute of New Materials Guangdong Academy of ScienceGuangzhou 510650GuangdongChina

To address the inhomogeneous microstructure and improve the mechanical properties of DT300 ultra-high strength steel specimens fabricated by laser powder bed fusion,different post-heat treatment schedules are *** the increase in austenitizing temperature and time,the migration rate of austenite grain boundaries continuously increases with the dissolution of nano-carbides,and the formation of nano-oxides and twin martensite is also inhibited *** rapid growth in the size of prior austenite grains and martensite laths,as well as the decrease in the content of nano-oxides and twin martensite,led to a rapid decrease in the strength(yield strength and ultimate tensile strength)from HT2 to HTF *** HT1 specimens(austenitizing at 830℃for 30 min,then oil quenching and tempering at 300℃for 120 min and finally air cooling)display excellent mechanical properties of yield strength of 1572 MPa,ultimate tensile strength of 1847 MPa,elongation of 9.84%,and fracture toughness of 106 MPa m^(1/2),which are counterparts to those of conventional DT300 steel forgings after heat treatment.

关键词： DT300 ultra-high strength steel Laser powder bed fusion-Short-time low-temperature austenitizing Microstructure Mechanical property

Hierarchical Game Approach for Optimization of Regional Integrated Energy System Clusters Considering Bounded Rationality

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第1期10卷 302-313页

作者： Lei Dong Mengting li Junjie Hu sheng Chen tao Zhang Xinying Wang Tianjiao Pu school of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206China Department of Artificial Intelligence Application Research China Electric Power Research InstituteBeijing 100192China Key Laboratory of Smart Grid of Ministry of Education Key Laboratory of Smart Energy&Information Technology of Tianjin MunicipalityTianjin UniversityTianjin 300072China

Regional integrated energy system(RIES)cluster,i.e.,multi-source integration and multi-region coordination,is an effective approach for increasing energy utilization *** hierarchical architecture and limited information sharing of RIES cluster make it difficult for traditional game theory to accurately describe their game ***,a hierarchical game approach considering bounded rationality is proposed in this paper to balance the interests of optimizing RIES cluster under privacy protection.A Stackelberg game with the cluster operator(CO)as the leader and multiple RIES as followers is developed to simultaneously optimize leader benefit and RIES utilization ***,a slight altruistic function is introduced to simulate the game behavior of each RIES agent on whether to cooperate or *** introducing an evolutionary game based on bounded rationality in the lower layer,the flaw of the assumption that participants are completely rational can be ***,for autonomous optimal dispatching,each RIES is treated as a prosumer,fexibly switching its market participation role to achieve cluster coordination *** studies on a RIES cluster verify effectiveness of the proposed approach.

关键词： Bounded rationality coordinated optimization evolutionary game regionaIilntegrated energysystem stackelberg game

CO_(2)flooding in shale oil reservoir with radial borehole fracturing for CO_(2)storage and enhanced oil recovery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 519-534页

作者： Jia-Cheng Dai Tian-Yu Wang Jin-tao Weng Kang-Jian Tian li-Ying Zhu Gen-sheng li State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China China National Oil and Gas Exploration and Development Company limited Beijing100034China

This study introduces a novel method integrating CO_(2)flooding with radial borehole fracturing for enhanced oil recovery and CO_(2)underground storage,a solution to the limited vertical stimulation reservoir volume in horizontal well fracturing.A numerical model is established to investigate the production rate,reservoir pressure field,and CO_(2)saturation distribution corresponding to changing time of CO_(2)flooding with radial borehole fracturing.A sensitivity analysis on the influence of CO_(2)injection location,layer spacing,pressure difference,borehole number,and hydraulic fractures on oil production and CO_(2)storage is *** CO_(2)flooding process is divided into four *** in layer spacing will significantly improve oil production rate and gas storage ***,serious gas channeling can occur when the spacing is lower than 20 *** the pressure difference between the producer and injector,the borehole number,the hydraulic fracture height,and the fracture width can also increase the oil production rate and gas storage *** analysis shows that layer spacing and fracture height greatly influence gas storage and oil *** outcomes are expected to provide a theoretical basis for the efficient development of shale oil reservoirs in the vertical direction.

关键词： Shale oil Radial borehole fracturing Embedded discrete fracture model Enhanced oil recovery Carbon storage

Heat Transfer and Friction Characteristics of Printed Circuit Heat Exchangers with Different Channel Structures for S-CO_(2) Power System

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第3期33卷 1132-1147页

作者： JIANG tao li Mingjia Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

Printed circuit heat exchanger(PCHE)has been widely used in supercritical carbon dioxide(S-CO_(2))power systems because of its high heat transfer efficiency and good ***,due to the large variety of PCHE configurations,channel selection in practical applications lacks a ***,this paper discussed the heat transfer and friction characteristics and the synergy of three fields in the channel under the guidance of the field synergy principle for four typical PCHE ***,the comprehensive performance of four channels was ***,the heat transfer and friction factor correlations for S-CO_(2)in four channels were *** findings demonstrate that the synergy of velocity and pressure fields of the straight channel PCHE is better(β≈180°),so its resistance loss is relatively *** zigzag and sinusoidal wavy channels and the airfoil fins can reduce the angle a between the temperature gradient and velocity,thus enhancing the heat *** sinusoidal wavy channel can reduce flow resistance compared to the zigzag channel due to the rounded *** streamlined airfoil structure can guide the flow and reduce backflow,thus reducing resistance *** the range of Re studied in this paper,the maximum error of the proposed heat transfer and friction factor correlations of PCHE is 7.0%,which shows good fitting *** research in this paper can provide a reference for the selection and design of PCHE with different channel configurations.

关键词： printed circuit heat exchanger supercritical carbon dioxide typical channel structure field synergy analysis

Mechanical design and analysis of bio-inspired reentrant negative Poisson’s ratio metamaterials with rigid-flexible distinction

在线全文

学校读者我要写书评

暂无评论

International Journal of Smart and Nano Materials 2024年第1期15卷 1-20页

作者： Xinchun Zhang Junyu Wang Qidong Sun Jingyang li sheng Zhou Junfeng Qi Ran tao Hebei Key Laboratory of Electric Machinery Health Maintenance&Failure Prevention North China Electric Power UniversityBaodingChina Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijingChina Beijing Spacecrafts Manufacturing Factory BeijingChina

Aiming at achieving tunable reentrant structures with rigidity and uniformity,respectively,the C-shaped and S-shaped reentrant metamaterials were proposed by the bionic design of animal *** beam theory and energy methodology,the analytical expressions of the equivalent elastic modulus of the metamaterials were *** in deformation modes,mechanical properties,and energy absorption capacities were characterized by using experiments and the finite element analysis *** effects of ligament angle and thickness on the mechanical characteristics of two novel metamaterials were investigated by using a parametric *** results show that the stiffness,deformation mode,stress-strain curve,and energy absorption effects of three metamaterials are significantly *** design philosophy can be extended from 2D to 3D and is applicable at multiple dimensions.

关键词： Re-entrant mechanical metamaterials negative poisson’s ratio enhanced stiffness rigid-flexible distinction energy absorption