SHAO Xu-dong , RONG Hui , ZHANG Yang , ZENG Tian-sheng
Abstract:Low retracting pre-stressing anchorage system(LRPAS) is a new type of post-tensioned prestressing system.An experimental study was carried out to investigate the structural behavior under the new LRPAS.A scaled test specimen using low retracting pre-stress stranded single anchorage was constructed and tested.Based on the strain measurements,the stress field under the traditional anchorage and the new LRPAS were obtained,and the test results were consistent with the theoretical calculation ones.When the same...
HOU Xiao-meng , ZHENG Wen-zhong
Abstract:An experiment was conducted on the mechanical performance of seven unbonded prestressed concrete(PC) continuous slabs after elevated temperature.The residual stress and the ultimate stress in unbonded stress wire in PC continuous slabs after elevated temperature were obtained by fitting the curve of experiment data,and the calculation method for normal section load-bearing capacity of PC slabs after elevated temperature was established.The section of the slab was divided into strips along its depth accordin...
HUANG Liang , GAO Xiang , CHEN Liang , CHEN Sheng-yun , WANG Ke , WU Hao
Abstract:30 specimens of N-type block masonries with different grouted rates were investigated for the performance of shear resistance.According to the shear-test phenomena and failure shape of specimens,the ratios of the shear-resistance crack load and the ultimate load of grouted N-type block masonry which changed with the grouted rates,were 77%~82% of half-grouted and 54%~59% of full-grouted.It has been found that the N-type block masonry shows better ductility with the increase of the grouted areas.The average v...
LIU Gui-qiu , ZHAO Yan , SHI Chu-xian , LI Zhen-mei
Abstract:The material strength match of grouted concrete block masonry must be solved in engineering design.The research results of the compressive behavior of masonry at home and abroad were summed up.The main factors influencing the compressive strength of masonry were analyzed and summarized.The relation between grouted prism strength versus grout strength was derived according to their vertical deformational coordinative principle.The optimum combination table of the material strength of grouted concrete block m...
LU Yuan-zhi , ZHONG Zhi-hua , WEN Gui-lin
Abstract:An approach to the feature identification and counting of the hole features for the Die & Mould engineering drawing was proposed to address automatic datum dimensioning.The combination notes of the functional semantic and counting results of the hole features can be given at the same time in the drawing,based on the feature identification.The proposed approach has been designed and implemented by utilizing the programming language,VisualLISP provided by AutoCAD.The practical datum dimensioning cases were gi...
HU Zhong-xun , YANG Xu-jing , JIN Xiang-zhong
Abstract:Theoretical defects of the Least Squares Method(LSM) in the evaluation of the spatial straightness error was analyzed in detail with geometry,the theory of errors,and optimization principle so as to effectively boost the precision of the assessment of the spatial straightness error.The mathematical model of improved LSM algorithm was proposed after the LSM was modified.Finally,the improved LSM algorithm was programmed,and the corresponding numerical experiments were done.The experiment results have shown th...
YANG Xiao-long , YANG Jing , LIN Tie-ping
Abstract:20% Butanol-Gasoline blend was mixed based on volume ratio with 93# unleaded gasoline.The effects of the butanol-gasoline blended fuel on the engine performance were investigated through experiments.The experiment results have shown that,without any modification of the engine,the 20% Butanol-gasoline blended fuel has little effect on the engine performance compared with the original 93# gasoline fuel.The performance at low speed is even better.And the HC and CO emissions are reduced significantly.
YAN Min , HOU Zhi-chun , LIU Yan , LI Xu
Abstract:设计了一款在0~100℃和反向电压VR为0~1 000 V条件下,能够测试二极管反向漏电流特性的测试仪.它采用桥式输入I、CL7650组成的高精度放大电路、ADC0804和AT89S51完成了高压到低压的转换、信号的放大、采样、量化及显示,通过编程软件对测试结果进行修正,提高系统的测量精确度.对二极管IN4007的测试结果表明:所得反向漏电流分辨率达0.1 nA,准确度达1.79%.
YANG Bang-yu , PENG Jian-chun , GONG Bo
Abstract:This paper presented a new algorithm for the calculation of available transfer capability(ATC) of long transmission line interconnected power system.As the loadability of long lines is constrained by static stability limits of grid,this algorithm first deduces the line transfer stability limits in order to describe the problem of static stability limits efficiently and concisely and to set up a new ATC model of long transmission line interconnected power system.Based on the algorithm of imputation of an imp...
XIA Wei-jun , JIANG Jun-feng , ZHU Su-qin , YAN Hong-ge , CHEN Zhen-hua
Abstract:AZ31 magnesium alloy sheets were prepared by multi-pass equal channel angular rolling(multi-pass ECAR).The microstructure,texture and tensile properties were investigated.The results have shown that the grains in the sheets are processed alternatively with refined and coarse multi-pass ECAR,which has a great effect on the grain size and the homogeneity in the sheets after annealing.The significant weakening of basal texture is due to the accumulative shear strain.After ECARed for 7 passes,the basal poles sp...
WU Cui-lan , CHEN Wang-lin , YUAN Min
Abstract:研究在使用过程中钻井牙轮提前断裂的原因.牙轮的材料为20Ni4Mo,热处理工艺为气体渗碳再进行780℃淬火+低温回火.利用化学分析、金相检验、硬度计及扫描电镜等方法对20Ni4Mo渗碳钢制矿用牙轮的断裂原因进行了分析.结果表明:牙轮断裂的主要原因为渗碳及热处理工艺不当,另一原因是牙轮基体存在硫化物等非金属夹杂物.为了检验牙轮的淬火工艺,将20Ni4Mo钢原材料分别在780和850℃进行淬火实验,结果证明780℃淬火工艺不合理.
XU Wei-jian , LI Hai-jun , PENG Hua , PENG Jin-yang , XIONG Yuan-qin , DENG Hong-xia
Abstract:The present study demonstrates a superhydrophobic surface prepared by using amphiphilic block copolymers and nano silica.Amphiphilic block copolymer poly(tert-butyl methacrylate-b-4-vinylpyridine) was synthesized through RAFT(reversible addition-fragmentation chain transfer) polymerization.IR,1H NMR spectrum and GPC were utilized to characterize the chemical structures of the copolymer.The "grafting" approach was used to graft the amphiphilic block copolymer brushes of Poly(tert-butyl methacrylate-block-4-v...
XIONG Yuan-qin , YANG Xiao-jing , LIU Han-mao , LU Yan-bing , XIA Xin-nian , XU Wei-jian
Abstract:通过相转移的方法制备了对熊果酸有选择性吸附的聚丙烯腈-丙烯酸分子印迹膜.通过吸附性能的检测,熊果酸在印迹和非印迹膜中的吸附量分别为0.226和0.087μmol/g.渗透实验表明:分子印迹膜对熊果酸有很好的识别特性,而非印迹膜对熊果酸的识别性低于印迹膜对熊果酸的识别性.
LI Jing-bo , ZHANG Guang-sheng , XU Zhen-yang , DOU Wen-hua
Abstract:Self-similarity is not considered in the traditional Call Admission control Algorithms,such as Admission Control based on parameters and Admission Control based on measurement.Admission Control based on parameters often provides the strictest QoS gurantee with lowest admission ratio and worst bandwidth usage.Admission Control based on measurement considers the dynamic changes of network traffic with better admission ratio and bandwidth usage.Taking advantage of the self-similarity character,and combining th...
Abstract:Digital Watermark can protect copyright effectively.Data Cube,which used for OLAP in Data Warehouse,contains not only valuable data but also design pattern and analytical pattern,which declare the owner's intellectual property rights.This article provides a common and practical scheme for watermarking Data Cube by merging digital watermark technology into Data Cube and using semantic information of Data Cube fully.
Abstract:Three new classes of orthogonal arrays that meet the equality of Rao-bound and other two bounds proposed in [9] were constructed,and these resulting orthogonal arrays can construct linear codes that reach the equality of Griesmer bound in Error-Correct Code Theory.
Abstract:The oscillation and strong oscillation of the systems of a class of impulsive delay parabolic equations with quasilinear diffusion coefficient were studied.By using the oscillatory definition,Green's formula and Newmann boundary condition,the oscillatory problem of solution to the systems of impulsive delay parabolic equations was reduced to the nonexistence of position solution of impulsive delay differential inequality,and some sufficient conditions were obtained for the oscillation and strong oscillation...
LI Jing-xia , HU Fang , LIU Zhi-hua
Abstract:The research on the performance evaluation of commercial banks is mainly embodied in the indicator system.However,the existing models do not attach importance to applicability,resulting in the lack of suitable evaluation models for the evaluation of loan projects of commercial banks.Therefore,in accordance with the characteristics of the loan projects of commercial banks,this article has combined the gray relational analysis method,fuzzy comprehensive evaluation method and stepwise discriminative analysis m...
ZENG Hui-fang , ZHU Hui-ming , LI Su-fang , YU Ke-ming
Abstract:To address the problem that the distribution feature of time series could not always be easily described due to its diversity,the likelihood function based on the asymmetric Laplace distribution was employed irrespective of the original distribution of the data.To carry out Bayesian inference on the quantile autoregression,the Metropolis-Hastings algorithm was utilized to simulate the posterior marginal distribution of quantile autoregressive parameters,which resolved the difficulties of the high dimension ...