上排水工程在实验室中的应用

实验室作为科学研究的重要场所,其所需的配套设施也至关重要,关系到实验室的准确性及精度,对于一些特殊的实验室,对实验室内部的洁净度要求也非常严格,实验室排水作为实验室不可或缺的一部分,其安全性及重要性不容小觑。

上排水洗衣机设计探讨（上）

文章结合工作实践，就上排水洗衣机（全自动套桶和普通双桶洗衣机）的设计，做了简略分析。对排水泵、控制方式和整机结构等，通过若干设计方案的分析，提出了自己的见解。同时，对产品存在的问题提出了改进方法。

上排水洗衣机设计探讨（下）

上排水洗衣机设计探讨（下）倪子川３控制方式洗衣机的上排水系统是整机实现上排水功能的主体。由控制部件（开关电路）和执行部件（控制对象）组成。运用不同的控制部件可以实现各种控制方式。３．１全自动上排水洗衣机全自动洗衣机要实现上排水功能，排水泵必须在整机排...

烟台文化中心室内真空排水系统设计

烟台文化中心首层和地下1层内各用水点的污、废水利用重力无法自然排出,需要收集到污水泵站由污水泵提升排放。结合工程的特性,提出采用室内真空排水系统,该系统具有节水、环保、管道布置灵活,可简单实现同层排水或上排水的优点,极大提高地下各层使用空间及使用功能的任意转换。同时室内真空排水系统做为一种全密闭排水系统,有效杜绝了排水系统臭气、异味的产生,卫生条件得到质的飞跃。烟台文化中心工程经竣工验收投入使用以来,效果良好,各项指标均达到了设计要求。

洗衣机上排水的结构及电路

普通洗衣机均为下排水,人们在使用过程中总感觉有一些不方便,要求排水口必须低于内桶底的高度。

Drainage performance and capillary rise restraint effect of wicking geotextile

Wicking geotextile(WG)is considered as a possible countermeasure to reduce water content in unsaturated soil.In this research,rainfall tests were carried out to verify the drainage performance of WG.And capillary rise tests were conducted to study the effect of WG on the prevention of capillary rise.Test results indicated that WG with good drainage performance could drain gravitational and capillary water out of kaolinite soil.For kaolinite soil column with water content of 12%and compaction degree of 90%,the whole process of capillary rise in soil column with a layer of WG was a typical two-stage mode,and the maximum capillary height was about 380 mm,which provided that the WG could work as a barrier to prevent capillary rise effectively.In addition,the total vertical influential regions of WG in kaolinite soil above and below the WG layer were 400 and 100 mm,respectively.

Dynamic leakage mechanism of gas drainage borehole and engineering application

Borehole leakage not only affects the gas drainage effect but also presents considerable risk to human security. For the research on the leakage mechanism of gas drainage borehole, the rheological and visco-elastic-plastic characteristics were considered to establish the mechanical model of coal mass around borehole, which is used to analyze the leakage mechanism and deduce the dynamic leakage model. On the basis of the real coal seam conditions, the variation rules of the stress, leakage ring, and air leakage amount were analyzed through numerical simulation, and the influence factors of air leakage amount were also investigated to provide the theoretical basis for the sealing technology. Results show that the air leakage amount of borehole is inversely proportional to the increase in supporting stress and sealing length, and directly correlated with the increase in borehole radius and softening modulus. Using theoretical analysis, we design a novel active supporting sealing technology that can use grouting material to seal the fractures to reduce the leakage channels and also provide supporting stress to prevent borehole deformation. The engineering test results indicate that the average gas concentration with the novel active supporting sealing technology is increased by 162.12% than that of traditional polyurethane sealing method. Therefore, this technology not only effectively resolves borehole leakage but also significantly improves the gas drainage effect.

Low secondary compressibility and shear strength of Shanghai Clay

In order to investigate the compressibility, particularly the secondary compression behaviour, soil structure and undrained shear strength of Shanghai Clay, a series of one-dimensional consolidation tests （some up to 70 d） and undrained triaxial tests on high-quality intact and reconstituted soil specimens were carried out. Shanghai Clay is a lightly overconsolidated soil （OCR=1.2-1.3） with true cohesion or bonding. Due to the influence of soil structures, the secondary compression index Ca varies significantly with consolidation stress and the maximum value of C~ occurs in the vicinity of preconsolidation stress. Measured coefficients of secondary compression generally fall in the range of 0.2%-0.8% based on which Shanghai Clay can be classified as a soil with low to medium secondary compressibility. The effect of soil structures on the compressibility of Shanghai Clay is found to reduce with an increase in depth. Soil structure has an important influence on initial soil stiffness, but does not appear to affect undrained shear strength significantly. Undrained shear strengths of intact Shanghai Clay from compression tests are approximately 20% higher than those from extension tests.

Sensitivity of Chinese Industrial Wastewater Discharge Reduction to Direct Input Coefficients in an Input-output Context

Industrial wastewater discharge in China is increasing with the country′s economic development and it is worthy of concern. The discharge is primarily relevant to the direct discharge coefficient of each sector of the economy, its direct input coefficient and the final demand in input-output models. In this study, we calculated the sensitivity of the reduction in the Chinese industrial wastewater discharge using the direct input coefficients based on the theory of error-transmission in an input-output framework. Using input-output models, we calculated the direct and total industrial wastewater discharge coefficients. Analysis of 2007 input-output data of 30 sectors of the Chinese economy and of 30 provincial regions of China indicates that by lowering their direct input coefficients, the manufacturers of textiles, paper and paper products, chemical products, smelting and metal pressing, telecommunication equipment, computers and other electronic equipment will significantly reduce their amounts of industrial wastewater discharge. By lowering intra-provincial direct input coefficients to industrial sectors themselves of Jiangsu, Shandong and Zhejiang, there will be a significant reduction in industrial wastewater discharge for the country as a whole. Investment in production technology and improvement in organizational efficiency in these sectors and in these provinces can help lessen the direct input coefficients, thereby effectively achieving a reduction in industrial wastewater discharge in China via industrial restructuring.

Sources and Levels of Metals in the Upper Litani Basin Soils： Lebanon

There are a number of factors that contribute to heavy metal contamination in agricultural soils including deficient management of solid waste, waste water discharge, irrigation with contaminated water, and use of fertilizers and pesticides. The aim of this study is to estimate the sources and the levels of metals in soils of the ULB （Upper Litani Basin） that receive all mentioned factors. Soil samples were collected during the dry season from 24 sites along the Litani River flow, and 12 sites irrigated by Canal 900 withdrawn from the Qaraoun Dam along river. Metals in soils were analyzed using EDXRF （energy dispersive X-ray fluorescence） technique. Data revealed the following average levels of some heavy metals in soils with high percentage of samples exceeding the international guidelines： Mn （593 mg/kg）--67%, Ni （98 mg/kg）--96%, Cr （143 mg/kg）--92%, Hg （3.6 mg/kg）--38%, Cd （2.8 mg/kg）---25% and As （17.6 mg/kg）-84%. In canal soils： Mn （683 mg/kg）-86%, Ni （156 mg/kg）-100%, Cr （203 mg/kg） -100%, Hg （2.3 mg/kg）-25%, Cd （3.3 mg/kg）-25% and As （19.5 mg/kg）-92%. The prime source of toxic metals was due to the agricultural runoffs, beside sewage and domestic waste water discharge. Thus, the prominent findings of high levels of toxic metals （Cr, Cd, Hg and As） in soils and consequent probability in plants might induce a major health threat to consumers,