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关键词： 高层转运站   振动控制   动力特性   激震源  

摘要： 为改进高层转运站结构设计,提高高层转运站的抗振动能力,研究了高层转运站结构的动力特性和动力响应.通过有限元模拟,分析了高层转运站在两种振动控制方案下的结构的动力特性和动力响应.结果表明:通廊对提高高层转运站结构整体刚度效果显著;转运站结构的侧向水平振动主要受低频激振力的影响;相对于选用钢筋混凝土"门式"剪力墙加固方案,增设交叉钢支撑更适合作为一种临时加固方案.

关键词： 地铁建设   房地产价值   城市交通  

摘要： 以福州地铁1号线为例,分析地铁对沿线房地产价值的影响。首先定性分析地铁对房地产价值的影响机理,然后再运用可达性相等理论,计算地铁对沿线房地产的影响范围,最后从邻近效应和时间效应分析地铁对房地产价值的影响。结果表明:地铁站点离市中心越近,对周边楼盘价格影响的地理范围越小,地铁站点离市中心越远,对周边楼盘价格影响的地理范围越大。城市地铁的建设,提升了地铁沿线房地产的价值。

关键词： 脉冲紧线   螺线管线圈   丝线下垂   悬链线   磁轴测量  

摘要： 脉冲紧线磁轴测量方法中绷紧金属丝线在自身重力作用下产生的下垂会对测量结果产生重要影响。文中对丝线的下垂曲线进行了推导,获得了丝线下垂曲线方程,并且通过实验进行了验证。在此基础上,建立了丝线振动数值分析模型,对实际测量布局中金属丝下垂产生的信号进行了系统而详细的分析,得出丝线下垂对磁轴测量结果的影响。为减小丝线下垂引入的测量误差,可以通过对测量结果进行修正、采用新的定位方法、搭建竖直测量平台三方面着手。

关键词： 海风辐合线   强对流   多普勒雷达   卫星云图  

摘要： 青岛地区受海陆地形影响,海风辐合线是触发夏季对流性降水的重要影响因子。该文以2008年8月12-14日连续三天出现的对流性天气为例,综合运用气象观测、雷达和卫星云图等多种资料,分析不同环流形势下海风辐合线触发的对流性降水特征。研究表明:单一的海风辐合线一般不产生对流天气,但与中低空系统叠加易使局地辐合加强,触发对流天气;冷锋南压与海风辐合线交汇处易产生较强对流天气,若冷槽发展深厚则转为大尺度系统过境过程,易出现强对流天气。

关键词： 桩基础   V-T联合荷载   Gibson地基   荷载传递函数   剪切位移法  

摘要： 为探讨桩顶竖向力(V)和扭矩(T)共同作用时的桩身受力特性,于桩顶先作用V后施加T,视桩周土为Gibson地基,并考虑桩-土接触面上的位移非协调性,基于剪切位移法和桩身荷载传递函数建立出桩身位移控制方程,引入力和位移边界条件后,推导出桩周土处于不同受力阶段时的桩身内力位移解析解,由此求得不同V-T组合作用下的桩身承载力,进而获得桩身承载力包络图。进一步的参数分析表明,对于V-T联合受荷桩:保持桩身长径比m0不变,桩身承载力随桩长L的增加而变大,而L不变时,桩身承载力随m0增加而增加;随桩土刚度比λ、桩侧土体剪切模量和极限摩阻力分布常数比值n的增大,桩身承载力逐渐减小;随桩顶扭矩的增加,桩顶所能承受的竖向力不断减小,且减幅先快后慢,最终趋于零。

关键词： Semecarpus anacardium   Datura stramonium   Ethanolic and hydro-ethanolic extracts   Rhipicephalus (Boophilus) microplus   Pyrocatechol   Resistant ticks  

摘要： In an attempt to identify plants having anti-tick properties, the 95% ethanolic and 50% hydro-ethanolic extracts of the fruits of Semecarpus anacardium and leaves of Datura stramonium were evaluated against reference tick lines of Rhipicephalus (Boophilus) microplus. The 95% ethanolic extracts of S. anacardium and D. stramonium caused 50% and 20% mortality, respectively, within 72 h of treatment by adult immersion test. The LC90 value of the ethanolic fruit extract of S. anacardium was determined as 13.5% (CI 12.05-15.12). The extract was also found efficacious (73.3% +/- 3.3%) against the multi-acaricide-resistant IVRI-V line of R.(B.) microplus. The S. anacardium extract significantly affected the reproductive physiology of treated ticks by inhibiting the oviposition and was found safe. The HPTLC fingerprinting profile revealed the presence of pyrocatechol as a marker compound. The acaricidal property of S. anacardium against chemical acaricide-resistant R. (B.) microplus was discussed. (C) 2015 Elsevier B.V. All rights reserved.

关键词： Targeted ultrasound   BI-Rads   Indeterminate lesion   Mammography  

摘要： Objective: To determine the change over mammographic diagnosis, BI-RADS category and management following targeted ultrasound of an indeterminate lesion seen on mammography and associated factors, if any. Study Design: Descriptive, analytical study. Place and Duration of Study: Radiology Department, The Aga Khan University Hospital and Clifton Medical Services, Karachi, from April 2010 to May 2011. Methodology: Patients referred for targeted breast ultrasound following X-ray mammography were selected regardless of age. Targeted Ultrasound (TUS) was defined as a limited ultrasound of a specific lesion or breast part as indicated by the referring source. Comparison was made between the post mammography and post TUS lesion characterization, diagnosis and BI-RADS category (0-5) which was taken as a measure of management change. Those were evaluated to determine significance of age, marital status, parity, breast parenchymal pattern ( dense, fatty, heterogeneous), referring source for the TUS (radiology resident, radiologist or surgeon), lesion characteristics (density, echogenecity, shape, location, margins, size, depth-to-width ratio, enhancement or shadowing), presenting symptoms or signs and reason for TUS. A p-value of 0.05 or less was taken as significant. Results: There were a total of 342 patients with mean age of 49.7 +/- 13.5 years. It assigned a definite category in 232 patients with an indefinite category (0) on mammography requiring further investigation. It decreased the suspicion for malignancy in 180 (77.58%) by assigning a low BI-RADS category and increased the suspicion in 52 (22.41%). The factors significantly associated with this changes included clinical indication being diagnostic (p < 0.001), lesion characteristics on imaging (p < 0.001), heterogenous breast parenchymal pattern (p < 0.001) and presence of known risk factors (p=0.049). Conclusion: TUS served as a problem solving tool in the evaluation and management of an indeterminate breast lesion

关键词： ultrahigh field   7 T   RF antenna   radio frequency   meander  

摘要： Purpose: In this work, the transmit performance and interelement coupling characteristics of radio frequency (RF) antenna microstrip line elements are examined in simulations and measurements. Methods: The initial point of the simulations is a microstrip line element loaded with a phantom. Meander structures are then introduced at the end of the element. The size of the meanders is increased in fixed steps and the magnetic field is optimized. In continuative simulations, the coupling between identical elements is evaluated for different element spacing and loading conditions. Verification of the simulation results is accomplished in measurements of the coupling between two identical elements for four different meander sizes. Image acquisition on a 7 T magnetic resonance imaging (MRI) system provides qualitative and quantitative comparisons to confirm the simulation results. Results: Simulations point out an optimum range of meander sizes concerning coupling in all chosen geometric setups. Coupling measurement results are in good agreement with the simulations. Qualitative and quantitative comparisons of the acquired MRI images substantiate the coupling results. Conclusions: The coupling between coil elements in RF antenna arrays consisting of the investigated element types can be optimized under consideration of the central magnetic field strength or efficiency depending on the desired application. (C) 2015 American Association of Physicists in Medicine.

关键词： monochloramine   natural organic matter   partial lead service line replacement   Alkalinity   sodium silicate   galvanic corrosion   chlorine  

摘要： Water quality parameters affecting sodium silicate performance in partial lead service line replacements were examined using a fractional factorial experimental design and static pipe systems. An external copper wire was used to create a galvanic connection between a former lead service line and a new copper pipe. The pipe systems were filled with lab prepared water made to mimic real water quality. Water was changed on a three times per week basis. A 2(4-1) fractional factorial design was used to evaluate the impact of alkalinity (15mg L-1 or 250mg L-1 as CaCO3), nitrate (1mg L-1 or 7mg L-1 as N), natural organic matter (1mg L-1 or 7mg L-1 as dissolved organic carbon), and disinfectant type (1mg L-1 chlorine or 3mg L-1 monochloramine), resulting in eight treatment conditions. Fractional factorial analysis revealed that alkalinity, natural organic matter and monochloramine had a significant positive effect on galvanic current. Natural organic matter and monochloramine also had a significant positive effect with respect to both total and dissolved lead release. For the treatment conditions examined, 67-98% of the lead released through galvanic currents was stored as corrosion scales and predominantly comprised of particulate lead (96.1-99.9%) for all eight treatments. The use of monochloramine and the presence of natural organic matter (7mg L-1) were not favourable for corrosion control in sodium silicate-treated partial lead service line replacements, although further studies would be required to characterize optimal water quality parameters for specific water quality types. For utilities operating with sodium silicate as a corrosion inhibitor, this work offers further evidence regarding the consideration of chlorine as a secondary disinfectant instead of monochloramine, as well as the value of controlling natural organic matter in distributed water.

关键词： Hydrocarbons -- Biodegradation   Marine sediments   Deepwater Horizon (Drilling rig)   Microbial diversity   Polycyclic aromatic hydrocarbons -- Environmental aspects  

摘要： To study hydrocarbon biodegradation in marsh sediments impacted by Macondo oil from the Deepwater Horizon well blowout, we collected sediment cores 18-36 months after the accident at the marshes in Bay Jimmy (Upper Barataria Bay), Louisiana, United States. The highest concentrations of oil were found in the top 2 cm of sediment nearest the waterline at the shorelines known to have been heavily oiled. Although petroleum hydrocarbons were detectable, Macondo Oil Could not be identified below 8 cm in 19 of the 20 surveyed sites. At the one site where oil was detected below 8 cm, concentrations were low. Residual Macondo oil was already highly weathered at the start of the study, and the concentrations of individual saturated hydrocarbons and polycyclic aromatic hydrocarbons continued to decrease over the course of the study due to biodegradation. Desulfococcus oleovorans, Marinobacter hydrocarbonoclasticus, Mycobacterium vanbaalenii, and related mycobacteria were the most abundant oil-degrading microorganisms detected in the top 2 cm at the oiled sites. Relative populations of these taxa declined as oil concentrations declined. The diversity of the microbial community was low at heavily oiled sites compared to that of the unoiled reference sites. As oil concentrations decreased Over time, microbial diversity increased and approached the diversity levels of the reference sites. These trends show that the oil continues to be biodegraded, and microbial diversity continues to increase, indicating ongoing overall ecological recovery.