一种带构造柱混凝土砌块墙体抗震性能试验研究

提出了一种带构造柱混凝土砌块承重墙体,并已获得国家发明专利。进行了2个带构造柱混凝土砌块墙体和2个普通带芯柱混凝土砌块墙体低周反复荷载下抗震性能比较试验研究。砌块墙体高宽比为0.6和1.0,厚度均为240 mm,轴压比均为0.3。对比分析了各墙体的承载力、刚度及其退化过程、延性、耗能和破坏特征。研究表明,所提出的带构造柱混凝土砌块墙体与普通带芯柱混凝土砌块墙体相比,抗震性能显著提高。     

Numerical study of a round buoyant jet under the effect of JONSWAP random waves

This paper presents a numerical study on the hydrodynamic behaviours of a round buoyant jet under the effect of JONSWAP random waves. A three-dimensional large eddy simulation (LES) model is developed to simulate the buoyant jet in a stagnant ambient and JONSWAP random waves. By comparison of velocity and concentration fields, it is found that the buoyant jet exhibits faster decay of centerline velocity, wider lateral spreading and larger initial dilution under the wave effect, indicating that wave dynamics improves the jet entrainment and mixing in the near field, and subsequently mitigate the jet impacts in the far field. The effect of buoyancy force on the jet behaviours in the random waves is also numerically investigated. The results show that the wave effect on the jet entrainment and mixing is considerably weakened under the existence of buoyancy force, resulting in a slower decay rate of centerline velocity and a narrower jet width for the jet with initial buoyancy.     

Expressed sequence tag analysis and cloning of trehalose-6-phosphate synthase gene from marine alga Laminaria japonica (Phaeophyta)

A high quality cDNA library was constructed from the brown alga Laminaria japonica,with the titer of 1.2×10 5 pfu/ml.The average insert size of the cDNA library is about 1.6 kb.From the cDNA library,591 cDNA clones were randomly selected and sequenced.As a result,574 EST(expressed sequence tag) sequences were generated.All of the 574 ESTs were submitted to the dbEST database section of GenBank with the accession numbers from CX942625 to CX943198.The cDNA library was screened with a α-32 p labeled 453 bp T P S gene probe,which is a partial sequence yielded from Porphyra yezoensis.Four positive cDNA clones were screened and the sequencing data showed that these four cDNA clones covered majority of L.japonica TPS cDNA sequence.After PCR amplification,sequencing and assembling,the entire ORF(open reading frame) sequence of the T P S gene was obtained,which was named LjTPS.LjTPS encodes a protein containing 908 amino acids with a calculated molecular mass of 101 674 Daltons.The LjTPS gene was successfully expressed in E.coli and rice.The LjTPS gene has potential application both in plant breeding to stress tolerance and in deciphering the T P S gene function and mechanism to stress tolerance.     

The effectiveness of the ISM Code: A qualitative enquiry

Studies conducted to determine the efficacy of the ISM Code in the past include investigations of the trends of accident numbers and insurance claims and users' perceptions. None of these, however, could produce a definitive conclusion. This is because both the use of safety outcome as well as the use of perception have inherent problems and are not reliable. This paper takes a different approach. It draws on wider research on management of workplace health and safety to ascertain whether or not employment and social conditions that support effective implementation of self-regulation are present in the maritime context. The findings reveal a considerable disparity between managers' and seafarers' understanding of the use of the Code resulting in a wide gap between its intended purpose and practice. The analysis shows that the critical factor is the lack of seafarers' participation in management of workplace health and safety. The underlying causal factors for such lack of participation were located in seafarers' poor employment condition and low-trust relationship with their managers.     

厦门高集海堤开口改造工程潮流泥沙物理模型试验研究

通过潮汐水流和悬沙淤积物理模型试验,研究厦门高集海堤开口改造工程潮流泥沙问题,研究表明,高集海堤开口后,东、西海域两股水流的汇流区和分流区在高集海堤附近,东海域涨潮流速有所增大,落潮流速有所减小,西海域则相反;随着开口宽度增大,流速变幅增大,开口大于800 m后流速变幅趋缓;海堤开口后净输水方向为自东海域向西海域,有利于厦门湾内水体与外海的交换;高集海堤开口对东渡港区泥沙淤积影响不大.综合分析认为高集海堤开口宽度800～1 000 m较为合适,开口800 m时大潮条件下1d的净输水量约0.91×108m3,东渡北港区港池年平均回淤强度增大0.18 m/a左右,航道淤强增大0.05 m/a左右.     

西方经济地理学关系范式与演化范式比较研究

伴随着国际经济组织形式的多样化和社会科学理论的多元化,近20 多年来西方经济地理学出现了多种理论转向,为解释新的经济活动空间现象提供了多维视角.其中,关系转向和演化转向的研究近来显得格外活跃,都试图建立自己的理论框架,并形成了关系经济地理学和演化经济地理学两种理论范式.两种范式在一些理论假设上有很多相似之处,但对二者的比较研究却十分少见.为了更加透彻地了解两种范式的理论内涵,在对两种理论范式的产生背景、主要观点和核心概念介绍的基础上,从理论假设、核心问题、核心概念和理论构建等方面对两种范式进行了对比,进而分析了西方经济地理的走向及对中国经济地理发展的启示.     

河北省数字电磁扰动应用研究

通过数字与模拟观测对比分析,说明数模观测的一致性,结合近几年河北省及邻区中强地震,进行震例分析和研究.应用结果表明：数字与模拟观测变化一致性较好;震前数字电磁扰动出现异常变化,异常形态为：原始采集波形出现扰动变化、日均值或日总量出现高值突跳、日总量背景值上升等.     

考虑非饱和特性的黄土湿陷性与微观结构分析

利用扫描电子显微镜测试技术对3个场地16个土样的微观结构进行观测,并使用图像处理软件对微观图像进行处理、对土样孔隙的几何特征参数和分维数进行了提取,土样孔隙分布分维数为1.816~1.936。利用分形几何学原理建立非饱和土的孔隙分布函数,对天然湿度下黄土中水分分布进行分析,运用回归分析的方法对孔隙的分维数、非饱和孔隙孔隙率和湿陷性的关系进行了分析。结果表明：孔隙分维数越大,孔隙结构越复杂;天然湿度下处于非饱和状态的黄土孔隙孔径均大于40μm,黄土的湿陷系数随着孔隙分维数、非饱和孔隙孔隙率的增大而增大,非饱和孔隙是造成黄土湿陷的主要原因。     

标准升温条件下PEC柱耐火极限理论分析及简化计算

基于ABAQUS软件建立了标准升温条件下局部填充混凝土（Partially Encaed Concrete,简称PEC）柱抗火性能分析的有限元模型,计算了火灾下PEC柱的变形曲线及耐火极限,计算结果得到了已有试验数据的验证。利用上述模型分析了截面几何参数、材料物理参数、荷载比及偏心率等因素对耐火极限的影响。在参数分析的基础上,建立了标准升温条件下PEC耐火极限简化计算方法。结果表明：无耐火保护PEC柱的耐火极限一般达不到现有抗火标准的要求;荷栽比、长细比和截面周长是影响PEC柱耐火极限的主要因素;该耐火极限简化计算方法可供工程设计参考。     

基于聚类分析方法的砾岩油藏储层类型划分

砾岩油藏由于近物源、多水系和快速多变的沉积环境导致储层岩性复杂多变以及非均质性严重等特点,储层类型的精细划分成为该类油藏二次调整开发的重点和难点.本文以克拉玛依油田六中区克下组砾岩油藏为研究对象,选取密闭取心井岩心分析的物性参数、压汞驱替参数以及微观孔隙结构参数共计12项作为砾岩油藏储层类型划分的参数组合,对比研究了基于划分、基于层次、基于模型和基于密度的4种聚类算法建立的储层划分标准,结果表明基于划分的k-means算法建立的聚类标准最符合实际油藏的地质特征和储层类型的划分精度,内部度量的紧凑性、有效性和分辨性都优于其他三种算法,并且分析了Ⅴ类储层与岩性的对应关系,发现砾岩油藏储层类型受岩性控制的机制非常复杂,岩性相同的储层类型可能呈现出不同的物性和渗流性,而岩性不同的储层类型又可能表现为相同的物性和渗流性,其根本原因是储层非均质性造成的.储层类型与砾岩岩性的有效结合为该区精细开发方案的设计和水淹层的定量评价提供了技术支持.