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Numerical Simulation of Continuous Tension Leveling Process of Thin Strip Steel and Its Application 被引量:12
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作者 li sheng-zhi YIN Yuan-de +2 位作者 XU Jie HOU Jun-ming Jaehong YOON 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2007年第6期8-13,共6页
Cold-rolled thin strip steel of high flatness quality undergoes multistage deformation during tension leveling. Thus, the parameters of set-up and manipulating are more difficult. With the aid of FE code MSC. MARC, th... Cold-rolled thin strip steel of high flatness quality undergoes multistage deformation during tension leveling. Thus, the parameters of set-up and manipulating are more difficult. With the aid of FE code MSC. MARC, the tension leveling process of thin strip steel was numerically simulated. Concentrating on the influence of the roll intermeshes in 2# anti-cambering on the distribution and magnitude of residual stresses in leveled strip steel, several experiments were clone with the tension leveler based on the results from the simulation. It was found from the simulation that the magnitude of longitudinal residual stresses in the cross-section of the leveled strip steel regularly presents obvious interdependence with the roll intermeshes in 2# anti-cambering. In addition, there is a steady zone as the longitudinal residual stresses of the surface layers in leveled strip steel vary with the roll intermeshes of 2# anticambering, which is of importance in the manipulation of tension levelers. It was also found that the distribution of strains and stresses across the width of strip steel is uneven during leveling or after removing the tension loaded upon the strip, from which it was found that 3D simulation could not be replaced by 2D analysis because 2D analysis in this case cannot represent the physical behavior of strip steel deformation during tension leveling. 展开更多
关键词 cold-rolled strip steel FLATNESS tension leveling numerical simulation shell element residual stress
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堆载和固结对高饱和度废弃黏土抗剪强度影响
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作者 徐辉 王锦楠 +2 位作者 李升智 王璐楠 詹良通 《中国环境科学》 EI CAS CSCD 北大核心 2024年第8期4446-4454,共9页
以杭州某基坑开挖渣土为研究对象,开展了24组大尺寸固结-直剪试验,研究了瞬时、阶梯型和斜坡型3种加载方式下高饱和度黏土固结过程抗剪强度的变化规律.结果表明,在上覆荷载作用下,土体产生瞬时压缩,压缩量随荷载的增大而增加;在3种加载... 以杭州某基坑开挖渣土为研究对象,开展了24组大尺寸固结-直剪试验,研究了瞬时、阶梯型和斜坡型3种加载方式下高饱和度黏土固结过程抗剪强度的变化规律.结果表明,在上覆荷载作用下,土体产生瞬时压缩,压缩量随荷载的增大而增加;在3种加载方式下,当最终荷载相同时,最终沉降量较为接近;剪切曲线为应变硬化型,初始切线模量和最终剪应力均随固结度或上覆荷载的增大而提高;加载方式对初始切线模量有一定影响,对最终剪应力影响较小;抗剪强度随固结度的增长呈线性增大趋势,增大幅度随荷载的增大而显著;在3种加载方式下,当上覆荷载和固结度相同时,抗剪强度基本接近.基于试验结果,建立了高饱和度黏土固结过程抗剪强度预测模型,并利用本文试验数据和文献数据验证了其可靠性.模型分析结果表明:随着固结度的增长,抗剪强度包络线截距呈线性增大,而弯曲程度呈线性减小.在高饱和度废弃黏土堆填工程中,可采用本文建立的模型来预测不同堆填方式下土体固结过程的抗剪强度. 展开更多
关键词 高饱和度黏土 固结度 堆载方式 抗剪强度
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湖南不同二化螟种群对几种杀虫剂的抗性监测 被引量:12
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作者 叶波 李生智 +4 位作者 丁文兵 贺华良 邱林 李志文 李有志 《湖南农业科学》 2017年第9期59-62,共4页
为明确湖南二化螟对杀虫单、三唑磷、阿维菌素和氯虫苯甲酰胺的抗性程度,利用点滴法测定了阿维菌素对24县/市二化螟种群的触杀毒性,测定了三唑磷和杀虫单对22县/市二化螟种群的触杀活性;利用稻苗浸渍法测定氯虫苯甲酰胺对22县/市二化螟... 为明确湖南二化螟对杀虫单、三唑磷、阿维菌素和氯虫苯甲酰胺的抗性程度,利用点滴法测定了阿维菌素对24县/市二化螟种群的触杀毒性,测定了三唑磷和杀虫单对22县/市二化螟种群的触杀活性;利用稻苗浸渍法测定氯虫苯甲酰胺对22县/市二化螟种群的毒杀活性。结果表明:(1)24个供试种群均对三唑磷均产生抗性,其中12个种群(石门、临澧、安乡、桃江、蓝山、涟源、安仁、望城、衡南、双峰、汉寿和浏阳)对三唑磷的抗性达到极高水平抗性(抗性倍数>160);10个种群(赫山、道县、江华、湘潭、邵阳、攸县、炎陵、沅江、长沙和宁乡)对三唑磷的抗性处于高水平抗性,其抗性倍数介于40~160倍间;株洲和会同种群对三唑磷的抗性处于中等水平抗性。(2)这24个种群对杀虫单也都产生抗性,其中9个种群(涟源、石门、安乡、临澧、沅江、汉寿、双峰、衡南和桃江)对杀虫单的抗性程度处于极高水平抗性;4种群(蓝山、江华、攸县和浏阳)的抗性程度属于中等水平抗性;其余11个采集点种群的抗性倍数在40~160间,其抗性程度处于高水平抗性。(3)共测定了22个种群对阿维菌素的抗性,其中仅会同种群对阿维菌素没有产生抗性,但敏感性已降低(抗性倍数为4.1);2个种群(道县和安乡)对阿维菌素的抗性程度处于低水平抗性;8个种群(望城、株洲、醴陵、衡南、祁东、双峰、汉寿和鼎城)的抗性程度处于高水平抗性;11个种群(赫山、长沙、浏阳、宁乡、江永、湘潭、邵阳、安仁、安化、炎陵和攸县)的抗性水平为中等水平抗性。(4)这22个种群对氯虫苯甲酰胺已产生抗性,其中衡南采集点虫群的抗性处于高水平抗性,其余21个种群均为中等水平抗性。这表明,三唑磷和杀虫单不易推荐用于防治二化螟,阿维菌素和氯虫苯甲酰胺应和其他药剂交替使用,延缓其抗性的快速发展。 展开更多
关键词 二化螟 三唑磷 杀虫单 阿维菌素 氯虫苯甲酰胺 抗性监测
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一种基于用户移动行为相似性的位置预测方法 被引量:1
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作者 李昇智 乔建忠 林树宽 《计算机科学》 CSCD 北大核心 2018年第12期288-292,307,共6页
随着移动通信技术和车载定位系统的发展和广泛应用,基于位置服务越来越受到人们的关注。位置预测技术是其重要组成部分,并有着广泛的应用。在实际应用中,由于采集点丢失或新用户出现等,GPS轨迹数据往往具有稀疏特性,使得基于单个用户数... 随着移动通信技术和车载定位系统的发展和广泛应用,基于位置服务越来越受到人们的关注。位置预测技术是其重要组成部分,并有着广泛的应用。在实际应用中,由于采集点丢失或新用户出现等,GPS轨迹数据往往具有稀疏特性,使得基于单个用户数据的位置预测的准确率较低。针对这种情况,文中提出了基于移动行为相似性和用户聚类的Markov位置预测方法。首先,为使预测的位置具有物理意义,提出了基于Voronoi图的区域划分方法,并基于区域轨迹进行位置预测;其次,提出了同时考虑用户转移特性和用户区域特性的移动行为相似性计算方法;再次,根据移动行为相似性对用户进行聚类,并在聚类的用户组上采用一阶Markov模型进行位置预测,提高了位置预测的准确性。在真实GPS轨迹数据上的实验表明了所提方法的有效性。 展开更多
关键词 移动行为相似性 转移概率矩阵 区域向量 位置预测
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Expression of nucleostemin in prostate cancer and its effect on the proliferation of PC-3 cells 被引量:12
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作者 liU Ran-lu ZHANG Zhi-hong +6 位作者 ZHAO Wei-ming WANG Meng QI Shi-yong li Jing ZHANG Yue li sheng-zhi XU Yong 《Chinese Medical Journal》 SCIE CAS CSCD 2008年第4期299-304,共6页
Background Nucleostemin is essential for the proliferation and survival of stem and cancer cells, but it is unknown whether this newly identified molecule is involved in prostate cancer pathogenesis.Methods Total RNA ... Background Nucleostemin is essential for the proliferation and survival of stem and cancer cells, but it is unknown whether this newly identified molecule is involved in prostate cancer pathogenesis.Methods Total RNA and protein were extracted from prostate cancer tissues and PC-3, LNCap and DU145 cell lines. The nucleostemin mRNA and protein expression were measured by RT-PCR and Western blot. Immunohistochemistry was also used to detect the nucleostemin protein expression in prostate cancer tissues and PC-3 cells. A nucleostemin specific, short hairpin RNA, expression plasmid was used to transfect PC-3 cells. The changes of nucleostemin gene were detected and the oroliferative capacitv of the cells was determined. Results Nucleostemin was highly expressed in prostate cancer tissues and cell lines. Nucleostemin expression level in the silencer group PC-3 cells remarkably reduced. The proliferation rate of silencer group PC-3 cells decreased and the percentage of G1 stage cells increased. The neoplasm forming capacity in nude mice of the silencer group PC-3 cells decreased significantly. Conclusions Nucleostemin is highly expressed in prostate cancer tissues and cell lines. The proliferative capacity of PC-3 cells is remarkably reduced after silencing nucleostemin gene expression. 展开更多
关键词 NUCLEOSTEMIN prostatic neoplasms PC-3 RNA interference
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