SUV背门下垂原因分析及改进

针对国内SUV车型背门下垂的问题,运用ANSYS软件进行仿真揭示,背门下垂的主要原因是背门框整体变形及背门框承受较大偏载。为此,通过5种背门框结构改进方案的对比,确定了改进背门框受力状况的方案,设计了一种新型的导向机构。实车道路对比试验验证了改进方案的效果。     

汽车车内空气质量标准法规现状

介绍车内空气污染的主要来源和危害,以及国内外车内空气质量标准法规的状况;提出我国应尽快对车内空气质量实施国家强制性法规、政策、标准等管理制度的建议。     

大型立式轴流水泵的机电部件安装精度控制措施

立式轴流泵在防洪排水泵站中应用广泛,但安装工艺复杂、安装精度要求高。该文侧重于从安装工艺的角度分析和说明大型立式轴流泵机组各主要部件安装时为了保证精度要求而需要采取的措施,阐述了与精度有关的安装工艺方法,以及安装过程中对于高程、水平度、摆度、同心度、间隙等参数的基本控制要求。     

走"产学研"合作之路推进企业快速发展

以天津水运工程勘察设计院的发展历程为例,阐述了"产学研"合作在企业发展中的重大作用,由此证实"产学研"合作是企业做强做大的必由之路,也是企校双方的双赢发展之路.     

齿轮塑性变形失效的安定极限分析

为研究直齿圆柱齿轮优化设计中残余应力对齿轮材料塑性极限的影响,基于Hertz接触理论和齿轮局部坐标下的弹塑性接触模型,分析了直齿圆柱齿轮啮合过程中的弹性接触应力、残余应力及弹塑性接触应力.根据第三强度理论,导出齿轮材料在弹性状态下弹性极限约为简单拉压屈服极限的1.6倍;根据安定极限理论,考虑齿轮啮合过程产生的残余应力对齿轮材料的强化作用,得到弹塑性状态下齿轮接触的静力安定极限约为简单拉压屈服极限的2.3倍;与弹性极限相比,将静力安定极限作为齿面出现塑性变形的失效判据,齿轮材料的许用应力提高了约50%.     

长三角地区中小城市综合交通发展规划研究——以嘉善为例

在分析长三角地区中小城市社会经济发展情况的基础上,提出了“十二五”期间综合交通发展的趋势,研究分析了长三角地区中小城市“十二五”期间综合交通发展面临的挑战,给出了该类城市综合交通发展规划研究中的基本理论与方法,最后,结合嘉善县综合交通发展规划项目进行了案例分析,显现了本文所述方法在实际规划项目中的实用性与可操作性。     

基于AASHTO2002的沥青路面永久变形叠加方法研究

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.     

Normal reference value of forced vital capacity of Chinese younger women and geographical factors

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 21767 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.     

Effect of acitretin on the T helper cells of psoriasis vulgaris

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.     

基于智能手机的汽车故障诊断系统研究与开发

研究了一种利用OBD系统基于智能手机平台的汽车故障诊断系统,该系统由手机诊断程序和VCI系统组成。手机诊断程序通过遵循SAE J2534标准的VCI系统与车内电子控制单元进行通信,获取汽车故障代码及汽车内部实时状态数据。由智能手机对诊断数据进行处理和管理,并整合诊断辅助功能。通过实际测试验证了整个系统性能。