检索结果-南通市图书馆

Effect of low-energy shock waves in microfracture holes in the repair of articular cartilage defects in a rabbit model

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2011年第9期124卷 1386-1394页

作者： WANG Qi li zhong-li FU yang-mu WANG Zhi-gang WEI Min ZHAO Bin ZHANG li ZHU Juan-li Department of Orthopedics Sports Medicine Center People's Liberation Army General Hospital Beijing 100853 China

Background Microfracture is a type of bone marrow stimulation in arthroscopic cartilage repair. However, the overall concentration of the mesenchymal stem cells is quite low and declines with age, and in the end the lesion is filled by fibrocartilage. The aim of this research was to investigate a novel method of enhancing microfracture by determining whether low-energy shock waves in microfracture holes would facilitate cartilage repair in a rabbit *** Full-thickness cartilage defects were created at the medial femoral condyle of 36 mature New Zealand white rabbits without penetrating subchondral bone. The rabbits were randomly divided into three groups. In experimental group A, low-energy shock-wave therapy was performed in microfracture holes （diameter, 1 mm） at an energy flux density （EFD） of 0.095 m J/mm2 and 200 impulses by DolorClast Master （Electro Medical Systems SA, Switzerland）microprobe （diameter, 0.8 mm）. In experimental group B, microfracture was performed alone. The untreated rabbits served as a control group. At 4, 8, and 12 weeks after the operations, repair tissues at the defects were analyzed stereologically, histologically, and *** The defects were filled gradually with repair tissues in experimental groups A and B, and no repair tissues had formed in the control group at 12 weeks. Repair tissues in experimental group A contained more chondrocytes,proteoglycans, and collagen type Ⅱ than those in experimental group B. In experimental group B, fibrous tissues had formed at the defects at 8 and 12 weeks. Histological analysis of experimental group A showed a better Wakitani score （P ＜0.05） than in experimental group B at 8 and 12 weeks after the *** In the repair of full-thickness articular cartilage defects in rabbits, low-energy shock waves in microfracture holes facilitated the production of hyaline-like cartilage repair tissues more than microfracture alone. This model demonstrates a new metho

关键词： articular cartilage repair marrow stimulation shock waves

Manufacture the conducting polymer with light

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 8-9页

作者： yang li Tianyu li Yan Ji Baoguang liu College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology) Nanjing University of Posts & Telecommunications

Poly(3,4-ethylenedioxythiophene) (PEDOT), heralded as the “king” of conducting polymers, is esteemed in bioelectronics for its mixed electronic and ionic conductivity, mechanical properties compatible with biological tissues, tunable healing ability and stability in diverse environments [1]. Based on additive manufacturing of three-dimensional structures,PEDOT realizes the implementation in the efficient production of flexible bioelectronics, the construction of intricate electrode-neural implantations, and the development of smart brain-computer-interfaces [2].

关键词：

Modified Harn Authentication Key Exchange Scheme

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2000年第Z1期 75-77页

作者： li Zi-chen, li zhong-xian, yang Yi-xian (Information Security Center, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China)

Recently, Harn proposed one digital signature scheme for Diffie-Hellman key exchange system. In this paper, we point out at first that there is a weakness in Harn’s system and then we propose two modified schemes to ... 详细信息

关键词： Digital signature Key exchange Cryptography

Interpretable Machine Learning Method for Compressive Strength Prediction and Analysis of Pure Fly Ash-based Geopolymer Concrete

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 Wuhan University of Technology(Materials Science) 2025年第1期40卷 65-78页

作者： SHI Yuqiong li Jingyi ZHANG yang li li Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education Northwest A&F Uni-versityYangling 712100China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China Chongqing Key Laboratory of Public Big Data Security Technology Chongqing 401420China Chongqing College of Mobile Communication Chongqing 401520China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina National Rail Transit Electrification and Automation Engineering Technology Research Center(Hong Kong Branch) The Hong Kong Polytechnic UniversityKowloonHung HomHong KongChina

In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive *** this study,505 groups of data were collected,and a new database of compressive strength of PFGC was *** order to establish an accurate prediction model of compressive strength,five different types of machine learning networks were used for comparative *** five machine learning models all showed good compressive strength prediction performance on *** them,R2,MSE,RMSE and MAE of decision tree model(DT)are 0.99,1.58,1.25,and 0.25,*** R2,MSE,RMSE and MAE of random forest model(RF)are 0.97,5.17,2.27 and 1.38,*** two models have high prediction accuracy and outstanding generalization *** order to enhance the interpretability of model decision-making,we used importance ranking to obtain the perception of machine learning model to 13 *** 13 variables include chemical composition of fly ash(SiO_(2)/Al_(2)O_(3),Si/Al),the ratio of alkaline liquid to the binder,curing temperature,curing durations inside oven,fly ash dosage,fine aggregate dosage,coarse aggregate dosage,extra water dosage and sodium hydroxide *** temperature,specimen ages and curing durations inside oven have the greatest influence on the prediction results,indicating that curing conditions have more prominent influence on the compressive strength of PFGC than ordinary Portland cement *** importance of curing conditions of PFGC even exceeds that of the concrete mix proportion,due to the low reactivity of pure fly ash.

关键词： machine learning pure fly ash geopolymer compressive strength feature perception

在线全文

学校读者我要写书评

暂无评论

三维人体步态运动特征精密提取算法研究

微电子学与计算机 2018年第7期35卷 133-136页

作者：李扬中闽南科技学院福建泉州362332

文章提出基于超像素的三维人体步态运动特征精密提取算法.对三维人体步态运动特征点进行分割,并将分割过程能量函数最小化.利用多元统计模型对分割后的步态运动特征噪音相关信息进行准确估计,设置分形小波的无噪编码,重构三维人体步态... 详细信息

文章提出基于超像素的三维人体步态运动特征精密提取算法.对三维人体步态运动特征点进行分割,并将分割过程能量函数最小化.利用多元统计模型对分割后的步态运动特征噪音相关信息进行准确估计,设置分形小波的无噪编码,重构三维人体步态运动特征信号,完成三维人体步态运动特征噪声的高效去除.所提算法在三维人体步态运动特征增强和特征提取方面,均优于当前算法,且提取能耗低于当前方法70%左右,可为人体步态运动的进一步研究提供参考依据.

关键词：超像素步态运动特征精密提取去噪

A NOVEL SESQUITERPENE FROM CREMANTHODIUM ELliSII KITAM

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1994年第7期5卷 591-592页

作者： Hao CHEN li yang and zhong Jian JLA(Institute of Organic Chemistry, State Key Laboratory of Applied Organic Chemistry at Lanzhou University. Lanzhou 730000)

A novel sesquiterpene (1) was isolated from Cremanthodium ellisii Kitam. The structure was elucidated by spectroscopic methods and 2D-NMR techniques.

关键词：

变形及电场作用对石墨烯电学特性影响的第一性原理计算

在线全文

学校读者我要写书评

暂无评论

物理学报 2018年第7期67卷 192-198页

作者：刘贵立杨忠华沈阳工业大学力学系沈阳110870 沈阳工业大学建筑环境与能源应用工程系沈阳110870

利用基于密度泛函理论的第一性原理方法,系统研究了变形、电场及共同作用对石墨烯电学特性影响的电子机理.研究表明,本征石墨烯的能隙及态密度值在费米能级处均为0,呈现出半金属特性;在一定的变形量下对石墨烯施加剪切、拉伸、扭转及弯... 详细信息

利用基于密度泛函理论的第一性原理方法,系统研究了变形、电场及共同作用对石墨烯电学特性影响的电子机理.研究表明,本征石墨烯的能隙及态密度值在费米能级处均为0,呈现出半金属特性;在一定的变形量下对石墨烯施加剪切、拉伸、扭转及弯曲变形作用,发现剪切和扭转变形对打开石墨烯能隙的作用明显;对本征石墨烯施加不同方向的电场,可知电场方向对打开石墨烯能隙的作用效果最强.这是因为该电场方向下石墨烯C-C原子间的布居数正值较大,成键键能较高,而负值数值较小,反键键能较低;线性增加电场强度,石墨烯的能隙呈线性增长势;变形及电场共同作用下,外加电场提高了变形对打开石墨烯能隙的作用效果,但不及两种外场叠加的作用效果.

关键词：石墨烯变形作用电场作用能隙

Thickness and sp3 bond modulation of（Ti/tetrahedral amorphous carbon）_n multilayer coatings

在线全文

学校读者我要写书评

暂无评论

Tungsten 2025年第1期7卷 152-160页

作者： Zhi-Jun Xie Jia-lin li ling Gong Xiang-li zhong Hong-Jia Song Jin-Bin Wang National-Provincial Laboratory of Special Function Thin Film Materials School of Materials Science and Engineering Xiangtan University

The durability of wear-resistant tetrahedral amorphous carbon（ta-C） coatings is intimately linked to their thickness and the concentration of *** enhance the lifespan of the coatings,we have prepared a multilayer coating consisting of alternating layers of Ti and ta-C,denoted as（Ti/ta-C）_n,using arc ion plating.A multi-layer structure in conjunction with stage cooling is employed to enhance the thickness and promote *** results indicate that the ID/IGvalue,representing the ratio of the intensity of the D peak to that of the G peak in Raman spectroscopy,decreases from 0.85 when no stage cooling is applied to 0.35 when stage cooling is employed,suggesting an enhancement in the fraction of sp3bonds within the *** obtained（Ti/ta-C）_n multilayer coating without peeling off has a maximum thickness of 1.14 μm,which is almost double that of the ta-C coating single layer *** the same time,the coating has a low coefficient of friction,down to 0.069,and maintains excellent friction properties with a wear rate of 3.4×10-6mm3·N-1·*** results conclusively show that the preparation technology can enhance both thickness and sp3bonding in ta-C coatings,significantly expanding their utility across tools,molds,and precision engineering components.

关键词： Arc ion plating Multilayer structure sp3 bond Ta-C coating Wear resistance

Si-C Foam Porous-Medium Combustion Power-Generation System for Low-Calorific-Value Biomass Syngas

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 Thermal Science 2025年第1期34卷 206-222页

作者： yang Jianwen CHEN Wei CAO Bingwei liU Xinhui li Hang College of Mechanical and Aerospace Engineering Jilin University School of Mechanical and Vehicle Engineering Changchun University

Syngas produced from the gasification of organic feedstocks from biomass is one of the clean and sustainable sources of *** advantages of simple access and renewability of biomass energy can meet the energy needs of temporary power *** study presents a biomass power-generation system for vehicular *** biomass and a free-piston Stirling engine generator（FPSEG） as the primary material and prime mover,respectively,biomass energy is converted into electricity by combusting the syngas to heat the *** and key parameter design for biomass gasification and thermoelectric conversion systems within a power generation system were performed.A porous medium area was constructed using Si-C foam ceramics to obtain an energy-conversion experimental *** effects of bed height,porosity,porous-region diameter,and air-intake conditions on the power-generation performance were investigated,and optimisations were performed for the thermoelectric conversion *** rate of increase during FPSEG power generation first increased and then decreased with increasing bed height,peaking at a bed height of 40 *** increasing porous-region diameter accelerated FPSEG power generation,whereas porosity changes in the porous media did not significantly affect the rate of change during FPSEG power *** increasing air intake,the rate of increase during power generation first increased and then *** maximum change rate and the highest thermoelectric conversion efficiency of the power-generation system occurred at 9.5 m3/h and 6.5 m3/h（～45.1%）air intakes,*** the thermal inertia and combustion structure of the thermoelectric conversion system significantly increased the power-generation rate of the system,with 1.8 W/s being observed at a 9.7 m3/h air intake.

关键词： biomass combined heat and power (CHP) gasification porous media combustion power generation