桩检反射波记录的时域和频域分析

该文简介了反射波测桩记录的时间域、频率域分析的基本原理和实质 ,并应用这一原理对几个工程的实测记录进行了时间域和频率域的分析 ,说明这两种分析是可以互相补充验证的 ,从而可以提高对桩检记录判释的可靠性。     

热电厂附近土壤中氟形态的研究

热电厂附近土壤中氟的形态特征研究结果表明:残余态氟(ResF)>水溶态氟(WsF)>有机束缚态氟(O.M.F)>铁锰结合态氟(Fe/MnF)≥可交换态氟(ExF)。全氟与残余态氟(ResF)呈非常显著正相关(r=0.7851);同时水溶态氟(WsF)与可交换态氟(ExF)(r=0.5372)呈相关,有机束缚态氟(O.M.F)与残余态氟(ResF)(r=0.5098)呈相关,可交换态氟(ExF)与总氟(r=0.5484)呈相关,说明水溶态氟(WsF)、可交换态氟(ExF)和残余态氟(ResF)在一定的条件下可以相互转化。     

钻井液流变参数计算方法的分析及流变模式的优选

钻井液流变模式的合理选择和流变参数的准确计算是钻井液优化设计的前提。针对目前比较常用的5种钻井液流变模式,分析了流变参数的常规计算方法并指出了其不足;利用回归分析的数学方法,对5种流变模式下流变参数进行了数据处理;开发了计算机软件,对流变参数的2种计算方法进行了比较和分析,充分体现线性回归的先进性和准确性。通过计算机软件计算流变参数,输出各流变模式的流变曲线,从而实现流变模式优选。     

Evaluation of contrasting techniques for X‐ray imaging of velvet worms (Onychophora)

Non‐invasive imaging techniques like X‐ray computed tomography have become very popular in zoology, as they allow for simultaneous imaging of the internal and external morphology of organisms. Nevertheless, the effect of different staining approaches required for this method on samples lacking mineralized tissues, such as soft‐bodied invertebrates, remains understudied. Herein, we used synchrotron radiation‐based X‐ray micro‐computed tomography to compare the effects of commonly used contrasting approaches on onychophorans – soft‐bodied invertebrates important for studying animal evolution. Representatives of Euperipatoides rowelli were stained with osmium tetroxide (vapour or solution), ruthenium red, phosphotungstic acid, or iodine. Unstained specimens were imaged using both standard attenuation‐based and differential phase‐contrast setups to simulate analyses with museum material. Our comparative qualitative analyses of several tissue types demonstrate that osmium tetroxide provides the best overall tissue contrast in onychophorans, whereas the remaining staining agents rather favour the visualisation of specific tissues and/or structures. Quantitative analyses using signal‐to‐noise ratio measurements show that the level of image noise may vary according to the staining agent and scanning medium selected. Furthermore, box‐and‐whisker plots revealed substantial overlap in grey values among structures in all datasets, suggesting that a combination of semiautomatic and manual segmentation of structures is required for comprehensive 3D reconstructions of Onychophora, irrespective of the approach selected. Our results show that X‐ray micro‐computed tomography is a promising technique for studying onychophorans and, despite the benefits and disadvantages of different staining agents for specific tissues/structures, this method retrieves informative data that may eventually help address evolutionary questions long associated with Onychophora.     

一种高水解稳定性有机B-N剂的摩擦学特性及机制研究

为改善有机B-N添加剂的水解稳定性,在分子结构中引入含氮官能团,设计合成一种新型含氮杂环类有机B N添加剂,利用四球式摩擦磨损试验机考察其在菜籽油中的摩擦学性能,并利用X射线吸收近边结构光谱（XANES）分析摩擦表面B元素的化学形态。研究表明：所合成的有机B N添加剂不仅具有高水解稳定性,而且在菜籽油中具有较好的抗磨性能;有机B-N添加剂在摩擦过程中发生摩擦化学反应,生成了主要由B2O3组成的边界润滑膜,从而提高菜籽油的抗磨性能。     

Performance‐based seismic design of an irregular tall building in Istanbul

Structural design of a 50‐story tall reinforced concrete residential building, which was planned to be constructed in Istanbul and given up afterwards by the investor, has been completed in accordance with the draft version of Seismic Design Code for Tall Buildings in Istanbul that adopts performance‐based seismic design as the basic approach as Tall Buildings Initiative Guidelines do. Seismic design of the building has formed the main part of the structural design process due to high seismicity of the proposed location and extremely irregular floor plan not conforming to usual tall building structures. The building consists of two individual buildings linked through sky floors at the top 12 stories whose design was one of the most challenging works. The building has been designed for design basis earthquake by elastic response spectrum analysis, and its seismic performance has been checked for maximum considered earthquake by nonlinear time‐history analyses carried out using PERFORM‐3D. Copyright © 2015 John Wiley & Sons, Ltd.     

Assessing the influence of jet-grouting underpinning on the nearby buildings

This paper focuses on the underpinning-induced ground movement due to jet-grouting. Jet-grouting technique can cause distortions as a result of an inaccurate processing sequence and/or errors made at different stages of work execution. The aim of this paper is to determine the minimum value of such movement on the basis of the findings obtained at two similar construction sites located in the Historical Center of Moscow, considering that the maximum value is usually unpredictable. Numerical simulation of the process of soil eroding agrees well with the observational data at the current stage. It was found that the minimum value of deformations （only settlement was considered in this study） due to jetgrouting is no less than 2-3 mm. By contrast, the negative scenario of deformation due to foundation underpinning is clearly demonstrated. Also, this paper provides some general solutions for excavation supporting system as well as for underpinning design.     

环境样品中~(90)Sr和~(239+240)Pu的联合分析

针对气溶胶、沉降灰、土壤、生物及淡水等环境样品中90Sr、239+240Pu的联合分析进行了流程设计,并通过实际样品的测量对流程进行了验证。结果表明:90 Sr分析流程的化学回收率为44.3%~90.2%,平均值为73.8%;239+240Pu分析流程的放化回收率为40.2%~104.3%,平均值为79.3%。在可给出单个样品化学(放化)回收率的前提下,该联合分析流程可以满足日常环境监测的要求。     

Characterisation and quality assessment of ripened sausages in relation to the origin of raw material used

An experiment was performed to characterise and to assess the quality of ripened sausages produced from different raw materials. Samples were prepared using the same production technology, starting from pork shoulders from extensively versus intensively reared animals. Chemical, sensory, and microbiological analyses were performed. The results obtained showed that the sausages made from extensively reared pigs showed a significantly higher moisture content and higher scores for red intensity and global flavour. Microbiological analyses showed no significant difference between the two kinds of sausage. Contents of lactic acid bacteria and Micrococcaceae were high in both cases.     

急冷水空冷器管束泄漏分析及预防

某炼油厂三台急冷水空冷器运行十个月后出现泄漏，通过对这三台急冷水空冷器腐蚀部位的外观、急冷水的组成的分析，阐明了介质中硫含量高是造成空冷器泄漏的主要原因，并提出了相应的预防措施，该类设备的安全稳定的运行得到了保证。