利用二氧化碳和施加反压饱和砂样的液化试验

<正> 在评价砂土液化的动三轴试验中,采用干砂成型、二氧化碳加反压饱和是近几年发展起来的一种新方法。它是利用二氧化碳气重于空气,易溶于水这样两个特性,先将干砂按预定密度撒入试模内成型,然后自下而上通二氧化碳,将试样中的空气顶出,接着通脱气水,一是将试样中的二氧化碳挤出去,二是在反压作用下把余下的二氧化碳气泡压缩变小和溶解于水,达到增大饱和度的目的。     

基于工程项目的土建类多专业协同毕业设计模式的探索与实践

针对目前高校土建类专业毕业设计大多为各专业单独实施、缺乏多专业配合的现状,文章提出了基于工程项目的土建类多专业协同毕业设计模式,采取组建工程项目所涵盖的多专业毕业设计团队、搭建设计平台、创建协调评价考核体系等方法,培养毕业生的整体工程意识。从实施的效果来看,学生参与的积极性非常高,知识面得到进一步拓展,工程设计能力有了明显提高。     

丹江口水库变动回水区冲淤特性分析

 建库后的库区河床是水库淤积重新塑造的河床,其河势不仅与冲积河道有明显不同,而且与原来的天然河道也有很大的差别,具有水库与河道的两重性。由于各年坝前最高及最低水位运用不同,因此,各年的回水变动范围也不固定,其泥沙冲淤的范围及强度也有所不同。为了了解其冲淤特性,利用丹江口水库运用36年来实测资料,通过计算分析认为：变动回水区在年内具有汛、枯期两大造床期,泥沙冲淤具有两冲一淤的周期性冲淤特点,沿程遵循由不平衡输沙至平衡输沙的冲淤规律。变动回水区的淤积是自上而下逐段发展,动平衡库段也是自上而下逐渐发展;在动平衡库段内,消落期沿程只有顺直及弯道（狭谷）2种相间的单槽河型,最终变动回水区淤积河床向着均匀形态的方向发展。     

商丘市农村饮用水现状与分析

本文结合商丘市水文地质状况,根据水质监测成果进行分析评价,对如何改善农村饮用水水质进行分析和探讨。针对影响饮用水水质的因素从几个方面提出了改善措施。     

上海高层建筑基础设计

依据上海地基基础设计规范(DGJ08—11—1999)和《高层建筑混凝土结构技术规程》(JGJ3—2002),结合多年的工程经验,详细阐述了在上海地区进行高层建筑基础设计时结构方案的选择,筏形基础设计与计算,主楼与裙房间是否要设永久沉降缝,桩基础的设计,以及基础沉降计算等常见问题。     

湿润特性对横管降膜流动管外淡水液膜成形的影响研究

基于流体力学的运动控制方程,结合实验数据,采用流体体积函数法(VOF)处理流体与气相界面的运动,计算并分析了气-水-固接触角对管外液膜分布的影响。将数值结果与降膜实验结果进行比较,结果表明数值结果与降膜实验观测结果吻合较好。计算结果表明,膜厚的变化在不同的条件下表现出不同的特征,尤其是在形成液膜阶段,接触角直接决定着管外布液情况,是影响降膜流动性能的主要因素之一。     

绢丝复合绸针织起绒织物服用性能测试分

对7种绢丝复合绸针织起绒织物进行服用性能测试分析,采用线性回归方法分析该类织物的透湿性、抗弯刚度、抗皱性及抗起毛起球性等常用服用性能与结构参数之间的相关关系;同时采用相对性能比较法,对绢丝复合面料与纯蚕丝面料的性能进行分析比较。结果表明,绢丝复合绸针织起绒织物具有优良的服用性能,其结构参数对服用性能有重要影响。     

Preparation of Neodymium-Doped Yttrium Aluminum Garnet Transparent Ceramics by Homogeneous Precipitation Method

Neodymium-doped yttriumaluminumgarnet(Nd∶YAG)transparent polycrystalline ceramics,laser ce-ramic matrix materials,are gradually becomingsubsti-tutes for single crystals because they are provided withpredominantly chemical stability,highly doped ionconcentration,excellent optical performance and hightemperature stability[1,2].Presently,the conventionallyused methods to produce Nd∶YAG powders are solid-state processes[3],chemical precipitation methods[4,5]andlowtemperature combustiontechniqu…     

Effects of added Cd on Cd uptake by oilseed rape and pai-tsai co-cropping

The experiment was designed to study whether the decrease of Cd in the rhizosphere of Zhongyouza Ⅰ,one breed of oilseed rapes （Brassicajunica） that can hyperaccumulate cadmium from the soil, can improve the living condition of less Cd-tolerant plant pai-tsai （Brassia chinensis） with their roots permitted to intermingle and develop coincident rhizosphere. The extent of rhizosphere interactions between Zhongyouza Ⅰ and pai-tsai was controlled by different root barriers, or without barrier. The results show that in the 10 and 20 mg/kg Cd treated soils, pai-tsai gets higher shoot mass and less Cd accumulation in its shoot than in the barrier treatments or in the mono cultures, when its roots are permitted to intermingle with those of Zhongyouza Ⅰ. Meanwhile, soil decontamination rates of Zhongyouza Ⅰ are not affected much by co-cropping with pai-tsai, they are 80.0% and 91.8% of that in the mono cultures of Zhongyouza Ⅰ, respectively. However, the co-cropping method in meliorating the living condition of pai-tsai is not obvious when Cd concentration in soil reaches 40 mg/kg, and soil decontamination rate decreases to 0.14, which is 58.3% of that in the mono culture. These results indicate that the oilseed rape Zhongyouza Ⅰ may alleviate Cd toxicity of surrounding less-tolerant species, and its ability of phytoremediation is not affected much at the same time, especially in the middle polluted soil.