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871.
872.
介绍了AASHTO 2002力学经验法设计指南中的永久变形叠加方法,在考虑应力历史、路面温度和荷载作用次数等因素的基础上,通过APA试验进行各种工况下的永久变形叠加模拟.提出以实测永久变形值与AASHTO叠加变形值之比作为AASHTO修正系数,明确了影响R主要因素包括前一个子季节的路面温度T1和永久变形D1、当前子季节的路面温度T2载作用次数N2;最终采用指数方程的形式建立了基于AASHTO 2002的永久变形叠加方程. 相似文献
873.
Miao Ge Ya-Ping Zhang Jin-Wei He Yan-Chun Yan Xin Wang Li-Xia Cao Hai-Yan Fu 《西安交通大学学报(英文版)》2010,22(1):34-38
Objective To supply a scientific basis for standardizing the normal reference value of forced vital capacity (FVC) of Chinese younger women. Methods We studied the relationship between the normal reference value of 21767 samples of FVC of younger women and eight geographical factors in 157 areas in China. Results It was found that the correlation between geographical factors and the normal reference value of FVC of younger women was quite significant (F=5.884, P=0.000). By adopting the method of mathematical regression analysis, one regression equation was inferred: =3.146+0.00006919X1+0.01315X4-0.006966X6+0.09524X8±0.254. In the above equation, is the normal reference value of younger women' FVC (L); X1 is the altitude (m); X4 is the annual mean air temperature (℃); X6 is the annual mean relative humidity (%); X8 is the annual mean wind speed (m/s); 0.254 is the value of the residual standard deviation. Conclusion If geographical values are obtained in a certain area, the normal reference value of FVC of younger women in this area can be obtained by using the regression equation. Furthermore, according to the geographical factors, China can be divided into eight regions: Northeast China Region, North China Region, Shanxi-Shaanxi-Inner Mongolia Region, middle and lower reaches of the Yangzte River Region, Southeast China Region, Northwest China Region, Southwest China Region, and Qinghai-Tibet Plateau Region. 相似文献
874.
Wei Cao Xin-Wu Niu Jie Feng Jian-Yu He Chen Huang Hui-Qun Ma Jing-Yi Yuan 《西安交通大学学报(英文版)》2010,22(3):198-202
Objective To investigate the effects of acitretin on T helper cell (Th) 1/Th2 balance and Th17 cells in psoriasis vulgaris (PV) patients. Methods A total of 13 men and 17 women with PV were investigated. 10 mg of acitretin was administered twice a day for 8 weeks for intervention therapy. Serum levels of interferon-gamma (IFN-γ), interleukin (IL)-4 and IL-17 were measured by enzyme-linked immunosorbent assay. T, Th1, Th2 and Th17 cells in skin biopsies were counted with double-labeled immunofluorescence. Psoriasis Area and Severity Index (PASI) score was calculated before and 8 weeks after treatment. Results Before treatment PV patients had higher serum levels of IFN-γ and IL-17, and increased T, Th1 and Th17 cells in skin biopsies. After treatment, both serum levels of IFN-γ and IL-17, and T, Th1 and Th17 cells infiltrating in PV skin decreased significantly. Th1/Th2 balance was restored to normal. However, their IL-4 and Th2 cells showed no significant change throughout the therapy. Conclusion Acitretin exerts influence on dermal Th1/Th2 balance and Th17 cell infiltration, so does it on production of systematic inflammatory cytokines IFN-γ and IL-17 in PV patients. However, Th2 cells and its derivative cytokine-IL-4 are not affected. 相似文献
875.
876.
以一高速公路试验路路面性能数据为基础,结合Microsoft Office Excel?表格的Solver求解器建立路面性能指标曲线的指数回归方程,并通过拟合的指数回归方程计算出状态转移概率矩阵。再根据已知的初始路面状况概率分布,得出某一时间的路面性能概率分布,最终达到预测这一时间路面性能的目的。经分析知道:运用Microsoft Office Excel?表格建立马尔可夫模型不仅方便、操作简单,且具备很高的路面性能预测能力,在实际工程中具有广阔的应用前景。 相似文献
877.
The influencing factors of the equipment support activity process have the characteristics of nonlinearity, high dimension, many constraints, random uncertainty and fuzzy uncertainty. Monte Carlo method can solve the above problems commendably. This paper analyzes the main equipment support activity process and establishes the sampling plan and simulation model of the medium maintenance process based on Monte Carlo method, and the simulation result verifies a fact that the medium maintenance time can be effectively reduced when parallel operation on some procedures is used. It has a practical value and can give good advice to achieve the capability of equipment supportability. 相似文献
878.
浅论东海大桥桥梁健康监测 总被引:1,自引:0,他引:1
结合东海大桥工程实例,论述桥梁健康检测的内容以及桥梁健康上存在的问题,最后提出东海大桥健康监测的重点。可供其他大桥制定健康监测计划时参考。 相似文献
879.
城市中的广场和道路作为城市的共同组成单元,二者之间构成的点线交融的关系对城市空间的发展起着至关重要的作用,同时,城市空间形态的演变对二者的关系又产生一定的反作用。从动态的观点出发,以发展的思维研究了基于城市空间形态的道路交通与广场的互动关系。以景德镇市人民广场及其与周边道路的关系作为一个典型案例加以具体分析,以期找到城市点、线、面三者之间的和谐共生之道。 相似文献
880.
本实验用测定培养液中葡萄糖醛酸的方法,作为培养软骨细胞生长情况的指标,以观察软骨细胞的代谢情况,了解不同种类和不同含量血清对培养软骨细胞的影响.我们用传代兔软骨细胞于不同含量小牛血清和人血清的培养液中培养,定期镜下观察并收集培养液,测定其葡萄糖醛酸含量.结果表明5%至15%牛血清或人血清培养一代兔软骨细胞均可生长;测定培养液內葡萄糖醛酸量作为反映软骨细胞生长的检测指标是可行的。 相似文献