课程文献中心 更多>>

关键词： 铁路梁桥   转动弹性支承   变形协调条件   位移影响线   虚功原理   局部损伤  

摘要： 本文针对两端存在转动弹性支承的铁路梁桥,推导其任意测点的位移影响线解析公式,并分析转动弹性支承及局部损伤对位移影响线的影响。首先根据变形协调条件得出该类结构的力学方程,利用虚功原理求解存在局部损伤时内力和位移影响线的显式公式,这些理论公式能够描述影响线与结构刚度、局部损伤、转动刚度及测点位置等因素的关系;通过理论与数值试验结合的方法,分析转动弹性支承刚度变化及存在局部损伤时位移影响线及其曲率的变化规律。结果表明:转动支承刚度会影响不同测点位移影响线峰值及出现位置;观察位移影响线的曲率发现,局部损伤处曲率出现突变,随着转动支承刚度增大,局部损伤引起的曲率变化量减少,但相对变化比例不变。利用较易得、精确的位移信息,本文为转动弹性支承铁路梁桥的分析及检测提供一定理论依据及合理建议。

关键词： 物流企业   员工   个人服务导向   调研设计  

摘要： 在电子商务的带动下,我国的物流业进入了高速增长阶段。物流服务属于高接触服务,物流企业的一线员工在工作过程中所经历的各种心理感受会对其服务导向产生重要的影响,需要引起管理者高度重视。本研究通过变量选择、量表选择、调研方法与调研对象选择三方面对物流企业一线员工服务导向影响因素开展调研设计,对获得影响物流企业一线员工服务导向影响因素的第一手数据资料具有重要价值。

关键词： 双能X线骨密度仪   糖尿病   骨质疏松症  

摘要： 目的探讨2型糖尿病患者骨质疏松的影响因素。方法选择2011年9月至2013年3月在内分泌科住院的男性2型糖尿病患者209例为糖尿病组,选择同期体检的健康男性103例为对照组,应用双能X线骨密度仪(DXA)进行正位腰椎(L1-L4)及左侧股骨骨密度(BMD)测定,检测糖化血红蛋白(Hb A1C)、空腹血糖(FPG)及空腹C肽(CP),并进行统计学分析。结果糖尿病组骨量减少、骨质疏松发生率分别为14.35%、13.87%,明显高于对照组(P<0.05)。两组检测者随着年龄增加,骨密度均呈下降趋势,50岁以上糖尿病患者腰椎及股骨颈骨密度均明显低于同龄对照组(P<0.05)。糖尿病组骨密度多因素相关性分析显示,糖尿病患者骨密度与年龄、病程、Hb A1C呈显著负相关(P<0.05),而与体重指数(BMI)、空腹C肽(CP)呈显著正相关(P<0.05)。结论 2型糖尿病患者骨量减少及骨质疏松发生率较健康体检者明显升高;高龄、病程长及血糖控制不良是糖尿病患者BMD降低的危险因素。

关键词： 渔民收入   收入结构   灰色关联度   贡献率   拉动力  

摘要： 依据国家最新渔民收入统计制度,研究中国渔民收入结构在2008-2013年的变化趋势。利用灰色关联度量化综合模型,从变化率差异和绝对值差异两个角度,对渔民收入结构与渔民总收入的关联度进行分析,发现家庭经营收入与渔民总收入的关联度名列第一;基于强调变化率差异,财产性收入关联度名列第二;基于强调绝对差异分析,工资性收入关联度排第二位。通过进一步分析渔民收入结构对渔民总收入的贡献率和拉动力,分析发现,家庭其他经营收入对家庭经营收入提供的贡献率和拉动力高于来自渔业生产收入所提供的贡献率和拉动力,这表明渔民劳动力已产生明显分化。生产性补贴成为影响渔民收入的第二大要素,其对渔民收入的贡献率与拉动力皆名列第二。渔民工资性收入的拉动力主要来源于其他行业,说明渔业雇工水平低、渔业产业工资水平低;渔民土地和水面经营权租金对渔民财产性收入的增长产生明显的负影响,作业渔场缩减等问题制约了渔民增收。

关键词： 三相四线制   电力系统电压   谐波影响   城市供电   中性线   次谐波   电力电子设备   谐波分量   基波电流   民用住宅  

摘要： 1引言 近年来,随着三相四线制系统在工厂供电、民用住宅和城市供电等电力系统中的广泛应用,系统产生的谐波及其造成的危害日益严重,世界各国对谐波问题都给予了十分的关注和重视。电力系统的谐波是电力系统电压波形产生畸变的表征,谐波的产生来源于电力电子设备、非线性阻抗设备和其他方面的干扰。

关键词： 多西他赛   进展期肺鳞癌   瘤体反应率   生存期  

摘要： 目的分析评价多西他赛联合超低剂量放疗二线治疗进展期肺鳞癌患者对瘤体反应率和生存期的影响。方法择取2013年2月‐2015年2月入院在该院接受肺鳞癌治疗的进展期肺鳞癌患者21例,对这21例入院诊疗的进展期肺鳞癌患者进行多西他赛联合超低剂量放疗二线治疗,归为研究组;另外选取同期来该院进行治疗的21例进展期肺鳞癌患者,对其进行多西他赛治疗,归为参照组。结果研究组的瘤体缓解率较参照组高,其中,研究组原发病灶缩小大于50%以上者(PR)有6例,完全缓解(CR)患者有3例,而参照组的PR患者有2例,CR患者为0例,组间差异显著,P<0.05。另外,研究组的无进展生存期在1年以上的患者例数较参照组多,P<0.05。结论多西他赛联合超低剂量放疗二线治疗进展期肺鳞癌患者对瘤体反应率和生存期有积极的影响,能够提升瘤体缓解率以及延长患者的生存期,值得推广使用。

关键词： 兆瓦级风机   地震动力分析   多地质弹模   塔架基础  

摘要： 文章依托ANSYS软件平台,在多种地质弹性模量的作用下,模拟了兆瓦级别的风力发电机有限元三维数值模型的基础,对风机的结构进行地震动力影响分析。并探讨了多种地质弹性模量条件作用下对风机塔架基础的影响,得出了塔架与基础的应力位移特点,为以后类似研究提供参考。

关键词： Ovarian epithelial cancer   Recurrent   Benefit   Time disease control   Chemotherapy  

摘要： Objectives: The goal of this study was to determine the benefit in terms of time disease control (TDC) achieved by the succession of chemotherapy beyond the third line in patients treated for recurrent epithelial ovarian cancer. Secondary objectives were to identify patients who benefited from treatments beyond 3 lines and to estimate overall survival and disease-free progression lengths. Materials and Methods: The cohort of 122 patients was identified from a pharmacy database of patients treated with chemotherapy between 1992 and 2010. The evaluation of benefit obtained by each line was based on TDC duration, defined as the interval between the beginning of the treatment and the date of progressive disease or death. Results: Median TDC durations was 4.15 (0-54.7), 4 (0-21.7), 3.34 (0-29.6), 4.97 (0-29.2), and 3.13 months (0-15) for the fourth to eighth lines, respectively. Time to disease control was longer than 6 months in 34% to 40% of patients treated by lines 4 to 8. The most important factor influencing TDC length beyond the third line was the TDC duration observed in the 2 previous lines of therapy. Median overall survival after the third line was 15.3 months (95% confidence interval, 12-20 months). Factors associated with longer overall survival after 3 lines were performance status lower than 2 (P = 0.0058), no hepatic metastasis (P = 0.0098), no pulmonary metastasis (P = 0.0003), and platinum sensitivity (P = 0.04) Conclusions: These results may justify the administration of chemotherapy beyond the third line, in particular when the 2 previous lines are effective and resulted in disease control longer than 6 months.

关键词： CONSUMER behavior   EXPECTATION (Psychology)   BP Deepwater Horizon Explosion & Oil Spill   2010   ECONOMIC impact analysis   SOCIAL groups  

摘要： We exploit the timing of the BP Deepwater Horizon oil spill to develop a unique dataset of oyster consumer actual and anticipated behavior immediately prior to and following the event. A revealed and stated preference model allows both short- and longer-term responses to the spill to be investigated. Findings indicate that the BP spill had a negative impact on oyster demand in terms of short-run actual behavior, although spill effects show signs of dissipating several months following the spill. By accounting for unobserved heterogeneity in the sample, findings further indicate that short- and longer-term spill responses differ across consumer groups.

关键词： Bromopyruvate   Glucose   Lactate transporter   Tumor cells  

摘要： Background: Attention must be paid to chemotherapy for cancer patients in a hyperglycemia state. It is difficult for chemotherapy to cure cancer in patients in a hyperglycemia state. This study was carried out to determine the change in cell viability after treatment with bromopyruvate, which is an alkylating drug with anti-tumor activity, in a high glucose condition. Methods: The function of L-lactate and bromopyruvate transport was studied using human colon cancer cell lines (LoVo and HT-29) and radiolabeled L-lactate and bromopyruvate. Cell viability was monitored by the trypan blue exclusion assay. The expression level of human monocarboxylate transporter 1 (hMCT1) was evaluated by Western blot analysis. Results: Bromopyruvate-induced cell death was suppressed by a high glucose condition. L-Lactate and bromopyruvate uptake were suppressed by a high glucose condition. hMCT1 as a bromopyruvate carrier was functionally expressed in the cells. However, the expression of hMCT1 was suppressed by a high glucose state. Conclusions: Down-regulation of hMCT1 by a high glucose state is one of the possibilities of the bromopyruvate resistance. We should pay scrupulous attention to cancer chemotherapy for patients who have developed diabetes. Copyright (C) 2015, Published by Elsevier Ltd on behalf of The Japanese Society for the Study of Xenobiotics.