期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
结构细节疲劳额定值与结构细节数之间的关系研究 被引量:8
1
作者 李宴宾 陈莉 +1 位作者 董登科 薛景川 《机械强度》 CAS CSCD 北大核心 2012年第6期934-938,共5页
针对多细节结构,介绍两种考虑结构细节数影响的概率分析模型,设计包含不同细节个数的四种试验件,并完成疲劳试验。通过试验结果(试验寿命和DFR(detail fatigue rating)值)与两种分析模型计算结果的比较,证明该分析方法是满足工程要求的。
关键词 细节疲劳额定值 可靠性寿命 疲劳额定值系 细节数效应寿命系
下载PDF
构件细节数效应系数DF及其在耐久性分析工作中的应用 被引量:2
2
作者 薛景川 杨玉恭 《结构强度研究》 2003年第4期1-12,共12页
分析了在耐久性分析时引入构件细节数效应系数DF代替构件额定值系数RC的合理性,通过耐久性分析实例说明了其可行性。
关键词 构件细节数效应系 耐久性分析 构件额定值系 可靠性寿命 飞机
原文传递
结构细节疲劳额定值和结构细节数之间的关系研究
3
作者 李宴宾 陈莉 +1 位作者 董登科 薛景川 《结构强度研究》 2010年第4期7-11,共5页
介绍了两种考虑结构细节数影响的概率分析模型,设计了包含不同细节个数的4种试验件,并完成疲劳试验。通过试验结果(试验寿命和DFR值)和两种分析模型的计算结果的比较,证明该分析方法是满足工程要求的。
关键词 结构细节疲劳额定值 可靠性寿命 疲劳额定值系 细节数效应系
原文传递
构件细节效应系数法在MED结构中的应用
4
作者 陈莉 李三元 《结构强度研究》 2018年第4期1-5,共5页
本文将构件细节效应系数法应用于广布疲劳损伤的多元件损伤(MED)结构,给出了出现首条裂纹及多条裂纹时寿命的分析方法,并与试验结果进行分析比较,用试验中出现12条裂纹的寿命反推出现第一条裂纹的寿命与物理试验结果,误差在15%以内,对... 本文将构件细节效应系数法应用于广布疲劳损伤的多元件损伤(MED)结构,给出了出现首条裂纹及多条裂纹时寿命的分析方法,并与试验结果进行分析比较,用试验中出现12条裂纹的寿命反推出现第一条裂纹的寿命与物理试验结果,误差在15%以内,对疲劳分析来说是非常接近的,工程分析结果与试验结果误差较大,基本也在工程可接受范围内。 展开更多
关键词 细节数 多元件损伤 广布疲劳损伤 寿命
原文传递
Hierarchical Detailed Description for Spatial Direction Relations 被引量:5
5
作者 WANG Jing JIANG Gangwu GUO Rui 《Geo-Spatial Information Science》 2008年第1期56-61,共6页
Direction relation is an important spatial relation. Descriptions and representations for direction relations have different levels of detail because of the varying dimensions of spatial objects and different scales o... Direction relation is an important spatial relation. Descriptions and representations for direction relations have different levels of detail because of the varying dimensions of spatial objects and different scales of the embedding spaces. Based on a direction- relation matrix, the hierarchical frame of spatial direction relations which partitions direction relations orderly and thoroughly is built. Interior direction relations are used to perfect the representation of direction relations and the binary-encoding idea is creatively applied to construct an interior detailed matrix describing multiple interior direction relations by a uniform matrix. The model integrates topological information into the description model for direction relations, which will lay the foundations of spatial compositive reasoning. 展开更多
关键词 spatial direction relations direction-relation matrix levels of detail spatial reasoning GIS
下载PDF
T-regulatory lymphocytes in peripheral blood of gastric and colorectal cancer patients 被引量:5
6
作者 Antoni M Szczepanik Maciej Siedlar +4 位作者 Marek Sierzega Dominika Goroszeniuk Karolina Bukowska-Strakova Antoni Czupryna Jan Kulig 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第3期343-348,共6页
AIM: To assess the absolute number of T-regulatory cells (Tregs; CD4+CD25+Foxp3+) in the peripheral blood of gastric and colorectal cancer patients. METHODS: We enrolled 70 cancer patients (33 gastric cancer, 37 color... AIM: To assess the absolute number of T-regulatory cells (Tregs; CD4+CD25+Foxp3+) in the peripheral blood of gastric and colorectal cancer patients. METHODS: We enrolled 70 cancer patients (33 gastric cancer, 37 colorectal cancer) and 17 healthy volunteers. The CD3+CD4+ lymphocytes and CD4+CD25+Foxp3+ Tregs in the peripheral blood were analyzed with flow cytometry. The absolute numbers of Tregs were calculated based on the CD4+CD25+Foxp3+ cells percent-age of CD3+CD4+ cells and the absolute numbers of CD3+CD4+ cells per microliter. RESULTS: The mean number of CD4+CD25+Foxp3+ cells per microliter in colorectal cancer patients was 15.7 (SD: 21.8), for gastric cancer patients 12.2 (SD: 14.3), and for controls 17.5 (SD: 11.4). The absolute number of Tregs was significantly lower in gastric cancer patients than in controls (P = 0.026). There was no statistically significant difference for gastric vs colorectal cancer or colorectal cancer vs controls. The absolute number of Tregs was also significantly depressed in N+ vs Ncancer patients [22.0 (27.7) vs 10.1 (9.0), P = 0.013], and in the subgroup of gastric cancer patients [30.3 (27.6) vs 9.6 (8.0), P = 0.003]. No statistical difference was observed in the proportion of Tregs in the CD4+ population between the groups. CONCLUSION: The absolute number of Tregs in peripheral blood of gastric cancer but not colorectal cancer patients was significantly decreased in comparison with that in healthy controls. 展开更多
关键词 CD4+CD25+Foxp3+ cells T regulatory cells Peripheral blood Gastric cancer Colorectal cancer
下载PDF
Macro and meso characteristics evolution on shear behavior of rock joints 被引量:1
7
作者 李凯辉 曹平 +1 位作者 张科 钟涌芳 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第8期3087-3096,共10页
Direct shear tests were conducted on the rock joints under constant normal load(CNL), while the acoustic emission(AE) signals generated during shear tests were monitored with PAC Micro-II system. Before and after shea... Direct shear tests were conducted on the rock joints under constant normal load(CNL), while the acoustic emission(AE) signals generated during shear tests were monitored with PAC Micro-II system. Before and after shearing, the surfaces of rock joints were measured by the Talysurf CLI 2000. By correlating the AE events with the shear stress-shear displacement curve, one can observe four periods of the whole course of shearing of rock joints. By the contrast of AE location and actual damage zone, it is elucidated that the AE event is related to the morphology of the joint. With the increase of shearing times, the shear behavior of rock joints gradually presents from the response of brittle behavior to that of ductile behavior. By combining the results of topography measurement, four morphological parameters of joint surface, S p(the maximum height of joint surface), N(number of islands), A(projection area) and V(volume of joint) were introduced, which decrease with shearing. Both the joint roughness coefficient(JRC) and joint matching coefficient(JMC) drop with shearing, and the shear strength of rock joints can be predicted by the JRC-JMC model. It establishes the relationship between micro-topography and macroscopic strength, which have the same change rule with shearing. 展开更多
关键词 rock joint shear behavior surface morphology acoustic emission joint roughness coefficient (JRC) joint matchingcoefficient (JMC)
下载PDF
结构初始广布疲劳损伤预计的概率模型研究
8
作者 李宴宾 薛景川 +1 位作者 陈莉 焦婷 《结构强度研究》 2011年第3期26-29,32,共5页
由串联系统的概率模型导出一种预计结构初始广布疲劳损伤的概率模型,此模型是由单细节结构的疲劳寿命预测多细节结构在相同应力水平下产生多裂纹时的寿命。设计两种具有不同细节数的试验件,在随机谱和常幅谱作用下完成疲劳试验(m个... 由串联系统的概率模型导出一种预计结构初始广布疲劳损伤的概率模型,此模型是由单细节结构的疲劳寿命预测多细节结构在相同应力水平下产生多裂纹时的寿命。设计两种具有不同细节数的试验件,在随机谱和常幅谱作用下完成疲劳试验(m个细节开裂时的寿命)。单细节结构的寿命分别用疲劳额定值(DFR)法和试验第一条裂纹出现的寿命计算得到,然后用预计广布疲劳损伤发生的概率模型计算m个细节产生裂纹时的寿命,与试验结果比较,验证该模型的可靠性。 展开更多
关键词 广布疲劳损伤 可靠性寿命 细节数效应系 多裂纹寿命
原文传递
Relationships between blood leukocyte mitochondrial DNA copy number and inflammatory cytokines in knee osteoarthritis 被引量:4
9
作者 Dong ZHAN Aree TANAVALEE +3 位作者 Saran TANTAVISUT Srihatach NGARMUKOS Steven WEDWARDS Sittisak HONSAWEK 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2020年第1期42-52,共11页
Osteoarthritis(OA)is a degenerative articular disorder manifested by cartilage destruction,subchondral sclerosis,osteophytes,and synovitis,resulting in chronic joint pain and physical disability in the elderly.The pur... Osteoarthritis(OA)is a degenerative articular disorder manifested by cartilage destruction,subchondral sclerosis,osteophytes,and synovitis,resulting in chronic joint pain and physical disability in the elderly.The purpose of this study was to investigate mitochondrial DNA copy number(mtDNACN)and inflammatory cytokines in primary knee OA patients and healthy volunteers.A total of 204 knee OA patients and 169 age-matched healthy volunteers were recruited.Their relative blood leukocyte mtDNACN was assessed by quantitative real-time polymerase chain reaction(qRT-PCR),and ten inflammatory cytokines in their plasma were detected by multiplex immunoassay.Blood leukocyte mtDNACN in the OA group was significantly lower than that in the control group.Leukocyte mtDNACN in the control group was negatively correlated with their age(r=−0.380,P<0.0001),whereas mtDNACN in the OA group was positively correlated with their age(r=0.198,P<0.001).Plasma interleukin-4(IL-4)and IL-6 were significantly higher in the knee OA group than in the control group.The plasma IL-6 level was positively correlated with blood leukocyte mtDNACN in the OA group(r=0.547,P=0.0014).IL-5 showed as a major factor(coefficient 0.69)in the second dimension of principle components analysis(PCA)-transformed data and was significantly higher in the OA group(P<0.001)as well as negatively correlated with mtDNACN(r=−0.577,P<0.001).These findings suggest that elevation of plasma IL-4 and IL-6 and a relative reduction in mtDNACN might be effective biomarkers for knee OA.IL-5 is a plausible factor responsible for decreasing blood leukocyte mtDNACN in knee OA patients. 展开更多
关键词 Inflammatory cytokine Blood leukocyte KNEE Mitochondrial DNA copy number OSTEOARTHRITIS
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部