灌砂法在路基压实度检测中的应用

结合工程实践,浅谈灌砂法在路基压实度检测中的应用.     

Optimization of isolation structure under wind load excitation and experimental study of the wind resistant bearing

The method of collaborative work between steel plate anti-wind bearing (AWB) and rubber isolation bearing is proposed to study the vibration reduction effect of isolation structure under stronger wind load, and the function mechanism is explained. Based on a practical project, three kinds of schemes with different isolation layers are put forward, the finite element software ETABS is used for time history analysis, and comparison is made on the seismic response of different isolated structure and aseismic structure. Comparison result shows that the isolation layer with rubber bearing and AWB can work reasonably, but further optimization on the designed parameters is needed. Moreover, the design value of horizontal bearing capacity of lead rubber bearing (LRB) is appropriate to be close to the seismic isolation layer under wind load excitation. Finally, numerical simulation and comparative analysis of shear test of the AWB are conducted. With a very small yield displacement and yield strength over 80% of the set of horizontal bearing capacity, the AWB is validated to satisfy the working conditions which provide the horizontal bearing capacity under normal operating conditions and designed earthquake. The AWB yields and malfunctions, when the maximum displacement is less than the displacement of the isolation layer.     

Carbon dioxide emissions from diesel and compressed natural gas buses during acceleration

Motor vehicle emission factors are generally derived from driving tests mimicking steady state conditions or transient drive cycles. Neither of these test conditions, however, completely represents real world driving conditions. In particular, they fail to determine emissions generated during the accelerating phase – a condition in which urban buses spend much of their time. We analyse and compare the results of time-dependant emission measurements conducted on diesel and compressed natural gas buses during an urban driving cycle on a chassis dynamometer and we derive power-law expressions relating carbon dioxide emission factors to the instantaneous speed while accelerating from rest. Emissions during acceleration are compared with that during steady speed operation.     

全场景城轨网络化运营指挥平台探索与研究

通过阐述运营调度指挥平台的现状和发展趋势,结合新一代信息技术和运营指挥业务需求,提出一套基于全时空多数据融合、全业务场景交互的运营调度指挥平台建设思路和系统设计方案,促进实现信息"需要即可呈现,需要即可操作,需要即可分析"的线网调度指挥和设备集中管控的新型调度指挥系统建设,打造网络化运营的"最强大脑",为城市轨道交通网...     

青春期与育龄期多囊卵巢综合征患者的临床对照研究

目的 通过对青春期多囊卵巢综合征(polycystic ovarian syndrome, PCOS)与育龄期PCOS患者的临床资料的对照研究,分析两组患者的临床特点以及PCOS对女性健康和血管内皮功能的影响.方法 选择在我院妇产科门诊就诊的PCOS患者68例,其中青春期33例,育龄期35例.所有患者记录基线资料,采用ELISA法检测内皮素-1(ET-1)浓度,免疫浊度法检测C-反应蛋白(CRP)浓度,放射免疫法测定女性激素.结果 ①基线资料的比较:青春期组F-G评分及痤疮评分较育龄期组显著升高(P<0.05),而其余指标无显著性差异.②临床特点的比较:青春期患者月经失调、多毛、痤疮发生率较育龄期显著升高(P<0.05).③女性激素的比较:青春期组睾酮(T)、黄体生成素(LH)、LH/卵泡刺激素(FSH)显著高于育龄期组(P<0.05),而FSH、催乳素(PRL)、孕酮(P)和雌二醇(E2)无显著性差异(P>0.05);④ET-1浓度的测定结果:育龄期组较青春期组显著升高(P<0.05);育龄期肥胖组及胰岛素抵抗(IR)组血清ET-1浓度分别较非肥胖组及非IR组显著升高(P<0.05),而青春期组无此改变.⑤两组CRP浓度无显著性差异.结论 PCOS在女性青春期与育龄期的临床特点不同,育龄期尤其是伴有IR和(或)肥胖者血管内皮功能紊乱较明显.     

Luminol-potassium permanganate chemiluminescence system for the determination of three anthracycline antibiotics

Objective To establish a flow-injection chemiluminescence method for the determination of doxorubicin, epirubicin and mitoxantrone and study its reaction mechanism. Methods In alkaline medium, chemiluminescence of luminol-potassium permanganate system could be inhibited obviously by anthracycline antibiotics. Combined with flow-injection technique, a new chemiluminescence method for determining the anthracycline antibiotics was set up. The chemiluminescence mechanism of the luminol-potassium permanganate system was also discussed. Results Under optimal conditions, the good linear ranges of doxorubicin, epirubicin and mitoxantrone were 5.0×10-9-1.0×10-6g/mL, 1.0×10-9-1.0×10-5g/mL and 3×10-9-1.0×10-6g/mL, respectively. The detection limits of doxorubicin, epirubicin and mitoxantrone were 3.0×10-9g/mL, 5.0×10-8g/mL and 2.0×10-9g/mL, respectively. During eleven repeated inter-day and intra-day precision tests of 1.0×10-6g/mL samples, the relative standard deviations corresponded to reference values of 3.0%, 2.8% and 2.1%. Conclusion The developed method is sensitive, accurate, rapid and of low cost. It can be applied to determine doxorubicin hydrochloride, epirubicin hydrochloride and mitoxantrone hydrochloride in injection preparations.     

Increased expression of the 20S proteasome in peripheral blood mononuclear cells of type 2 diabetic patients

Objective To investigate the dynamic expression of the 20S proteasome in peripheral blood mononuclear cells (PBMCs) of type 2 diabetic patients without vascular complications. Methods PBMCs were prepared from 30 type 2 diabetic patients and 30 nondiabetic controls. The general indexes including weight, height and blood pressure were recorded. Fasting plasma glucose, fasting plasma insulin and glycosylated hemoglobin were measured. The protein level of the 20S proteasome was measured by Western blotting. The mRNA expression levels of the 20S proteasome β1, β2 and β5 subunits were detected by real-time PCR. Results Compared with that in the nondiabetic controls, the protein level of the 20S proteasome was significantly increased in the diabetic patients and was positively associated with glycosylated hemoglobin. Conclusion Type 2 diabetic patients without vascular complications have an increased 20S proteasome expression, the significance of which needs to be explored by further study.     

基于交通运输产业经济特性的交通政策分析

交通运输产业是国民经济的重要支柱,它区别于其他产业而具有独特的经济特性。交通运输政策是交通运输产业良好发展的重要保证。从交通运输产业特有的经济特性入手,分析和改善交通运输政策,以保证交通运输产业良好快速的发展,具有深远的意义。     

计算机网络安全技术在高速公路收费网络的应用探讨

介绍了高速公路收费网络的构成,分析了影响网络系统安全的因素,提出加强网络安全的具体措施。     

大鼠肝脏干细胞的胰十二指肠同源盒基因表达系的构建与初步鉴定

目的 建立大鼠肝脏干细胞的Pdx-1基因表达系.方法 逆行穿刺SD大鼠乳鼠肝脏门静脉,经胶原酶Ⅳ消化并分离肝脏干细胞;免疫组织化学鉴定大鼠肝脏干细胞标志物细胞角蛋白18/19、甲胎蛋白的表达;构建pEGFP-Pdx-1表达载体并酶切鉴定,用脂质体2000介导表达载体转染大鼠肝脏干细胞后,荧光显微镜观察GFP表达,免疫组织化学鉴定Pdx-1的表达.结果 肝脏门静脉逆行穿刺分离培养大鼠肝脏干细胞具有分裂增殖能力、角蛋白18/19、甲胎蛋白表达阳性;pEGFP-Pdx-1表达载体转染后的肝脏干细胞可表达绿色荧光蛋白报告基因和Pdx-1蛋白.结论 成功建立了大鼠肝脏干细胞Pdx-1表达系.