某工业厂房循环冷却水系统应急方案设计

结合工程实例,对循环冷却水系统应急工艺流程进行了介绍,针对应急冷却水方案设计的系统反应灵敏、自动化程度高、对工艺设备保障性高等特点,深入探讨了其方案设计的最优措施,以保证循环冷却水的可靠供应。     

石灰法投药量对循环冷却水水质的影响

介绍了将高碑店污水厂的二沉池出水经过石灰法处理后用作华能北京热电厂循环冷却水的试验情况，分析了不同石灰投量对冷却水主要水质参数的影响。试验结果表明，经过石灰法处理的二沉池出水可以满足热电厂循环冷却水的水质要求。     

电厂循环冷却水处理及其节水效果分析

随着社会的不断进步,国家对电厂循环冷却水处理以及节水的要求是越来越高,使得电厂不得不加大对循环冷却水进行处理工作的力度.于是,在这种情况之下,如何对循环冷却水进行有效的处理,如何让循环冷却水处理措施发挥出最大的节水效果,成为了我国各大电厂的首要任务.     

煤化工循环水阻垢缓蚀剂（JC-800）的制备及应用

针对西北地区煤化工企业高碱度、高硬度、高pH循环冷却水的水质特点,以锌盐、2-膦酸丁烷-1,2,4-三羧酸、苯并三氮唑、马来酸-丙烯酸共聚物等为原料,制备出适用于西北地区煤化工企业循环冷却水的阻垢缓蚀剂（JC-800）,并通过静态阻垢试验、旋转挂片腐蚀试验和现场应用试验对其进行评价。同时,在不同水质条件下,确定达到最佳缓蚀效果时的药剂投加量。测试期间系统运行情况良好,循环水管道运行正常。该阻垢缓蚀剂各项指标满足国标和行业标准,综合性能优于现有阻垢剂,具有广阔的应用前景。     

试验站工业循环冷却水系统设计方案探讨

工业循环冷却水对水温、水质的控制难度较大,以具体工程为例,指出该试验间内设计有循环冷却水系统,并对该系统进行详细的设计探讨,从而为今后开展工作提供借鉴。     

城市污水用作工业冷却水的试验

本文简述了城市污水经二、三级处理,用作工业冷却水的试验概况。 试验结果表明:从城市污水二级或三级处理出水的物理、化学指标分析,这两种水都能满足工业直流冷却或循环冷却水的水质要求,但从结垢厚度、极限污垢系数、菌类指标等分析,二级处理水不宜作为直流或循环冷却水使用。     

再生水水质对冷却水系统腐蚀的影响研究

将城市污水再生处理后回用于工业循环冷却水系统是解决我国水资源短缺的有效途径之一.通过单因素试验和正交试验考察了再生水水质对循环冷却水系统的影响.结果表明,Cl-、NH4+和SO2-4是影响腐蚀速率的三个最重要的因素,NO2-和PO3-4对腐蚀的抑制作用较为明显,而Ca2+和HCO3-在低浓度时也表现出一定的缓蚀特征.     

电厂循环水处理药剂的应用

电厂循环冷却水处理过程中主要存在着结垢与腐蚀两大问题,而这些问题在高碱、高硬、高浓缩倍数下运行时则更为突出。通过现场监测试验与三年来的现场应用实践证明,该药剂完全可以满足现场运行的要求。     

水泥厂循环冷却水回水管设计优化

在工业生产中,冷却水系统分为直流冷却水系统和循环冷却水系统。循环冷却水系统分为密闭式循环水系统和敞开式循环冷却水系统。敞开式循环冷却水系统是水泥工厂中应用最普遍的一种水冷却系统．在敞开式循环冷却水系统中．一方面循环水带走热交换设备所散发的热量：另一方面升温后的循环水通过构筑物与空气直接接触得以冷却,然后再循环使用。循环冷却水系统回流方式分为压力回流、重力回流两种类型。     

循环冷却水处理存在的问题及处理措施

循环冷却水在工业生产用水中的比重越来越大,循环冷却水系统却存在着许多问题,诸如腐蚀、结垢及微生物的滋生与粘泥等.本文通过对循环冷却水处理技术的现状分析,介绍了化学药剂处理、静电水处理、磁化处理、膜处理及臭氧处理等技术,并进一步介绍了循环冷却水水质处理的发展趋势.这对工业企业循环冷却水的处理具有一定的借鉴意义.     

不同介质中MOV小电流特性的对比研究

氧化锌电阻片(MOV)常用于过电压保护,其小电流特性决定了它的工频稳定性。随着电力技术的发展,MOV被应用于变压器绕组内部和超导电力系统中,MOV的工作介质为变压器油和液氮。将MOV在空气和变压器油、空气和液氮(77K)中分别进行对比试验,通过小波变换对原始数据进行去噪,利用各次谐波法提取阻性电流进行对比分析,结果显示:MOV在变压器油中的阻性电流峰值大于空气中的值,MOV在液氮中的晶界电容、阻性电流峰值均小于空气中的值。表明MOV的小电流特性在空气中优于变压器油中,在液氮温区优于常温下。     

中国绿道规划建设实践——从提级统筹到制度并轨

绿道在中国经过多年实践发展,在理论内涵、规划选线、综合效益等各方面都已有许多成果支撑.基于可公开获取的一系列文献资料,立足于绿道在中国各省市近20年的具体实践过程,梳理绿道在规划体系中的角色转变、在指标设置中的逐步细化和在管控上的落实方式,总结绿道实践在中国从提级统筹、常态认同到制度并轨3个阶段的发展变化,在展望绿道后...     

Alteration of arsenopyrite in soils under different vegetation covers

The weathering of arsenopyrite (FeAsS) has been monitored in soils using an in situ experimental approach. Arsenopyrite in nylon experimental bags was placed in individual horizons in soils in spruce (litter, horizons A, B, and C), beech (litter, horizons A, B, and C) and unforested (horizons A, B, and C) areas and left in contact with the soil for a period of 1 year. The individual areas on the ridge of the Krušné hory Mts., Czech Republic, had the same lithology, climatic and environmental conditions. Scorodite (FeAsO₄·2H₂O) was identified as a principal secondary mineral of arsenic (As) formed directly on the surface of the arsenopyrite. Scorodite was formed in all the areas in all soil horizons. The amount of scorodite formed decreased in the series beech, spruce and unforested areas. In forested areas, there was a larger amount of scorodite on arsenopyrites exposed in organic horizons (litter, A horizon). The greater rate of arsenopyrite alteration in organic horizons in the beech stand compared to spruce stand is probably a result of faster mineralization of organic material with resulting production of nitrate and better seepage conditions of soil in this area. Speciation of As determined using the sequential extraction technique demonstrated that As was bonded in the soils primarily in the residual fractions prior to the experiment. The As content in the mobile fractions increased in the organic horizon in the forested areas after the experiments.     

Health assessment of artisanal gold miners in Indonesia

Small scale miners use mercury to extract gold from ore in many countries. An environmental and health assessment was performed in Indonesia in two regions, Galangan in Central Kalimantan and Talawaan in Northern Sulawesi. The environmental assessment showed severe mercury contamination of the sediments, and increased mercury levels in local fish. For the health investigation 281 volunteers were recruited and examined by a standardized questionnaire, a neurological examination and neuro-psychological tests. A medical score was used consisting of significant factors of mercury intoxication. Mercury exposed workers showed typical symptoms of mercury intoxication, such as movement disorders (ataxia, tremor, dysdiadochokinesia, etc.). Blood, urine and hair samples were taken from any participant and analyzed for mercury. The mercury concentration in the biomonitors was high, partly extreme high in the working population, increased in the population living in the same habitat and low in the control group. By a standard protocol which includes a combination of threshold values of mercury in the biomonitors and a medical sum score the diagnosis of chronic mercury intoxication was made for highly burdened workers (amalgam smelters) in 55% in Sulawesi and in 62% in Kalimantan. Less exposed mineral processors and the general population in the mining areas were also intoxicated to a high percentage.     

Heterotrophic and mixotrophic growth of Micractinium pusillum Fresenius in the presence of acetate and glucose: effect of light and acetate gradient concentration

The main objective of this study was to determine the importance of secondary mechanism of organic carbon utilization (mixotrophic and heterotrophic modes) in addition to CO2 fixation (photoautotrophic mode) in the green alga, Micractinium pusillum Fresenius (chlorophyta), isolated from a waste stabilization pond. The growth was studied in the presence of acetate and glucose. The incorporation rate of 14C- acetate was measured in the light and in the dark at different concentrations. Finally, in order to underline the role of photosynthesis and respiration processes in the acetate assimilation, the effect of two specific metabolic inhibitors, a specific inhibitor of photosystem II (DCMU) and an uncoupler respiratory (DNP), has been studied. The obtained results showed that M. pusillum grows in the presence of organic substrates, i.e., glucose and acetate, in the light (mixotrophic growth) as well as in the dark (Heterotrophic growth). The growth was much more important in the light than in the dark and more in the presence of glucose than of acetate. In the light, the presence of acetate led to a variation of growth parameters mumax, iotaopt, and beta. The effect of acetate gradient on the growth of the microalga was severe as soon as its concentration in the medium was higher. The acetate uptake followed a Michaelis-Menten kinetic in the light as well as in the dark. The capacity of assimilation was slightly higher in the dark. The utilization of DNP and DCMU indicates that acetate incorporation is an active process depending on both anabolic (photosynthesis) and catabolic (respiration) metabolisms, corroborating the model of the Michaelis-Menten kinetic.     

Factors affecting bulk to total bacteria ratio in drinking water distribution systems

Bacteria in drinking water systems can grow in bulk water and as biofilms attached to pipe walls, both causing regrowth problems in the distribution system. While studies have focused on evaluating the factors influencing the bacteria in bulk water and in biofilms separately, there is a need for understanding biofilm characteristics relative to the bulk water phase. The current study evaluated the effects of chlorine and residence time on the presence of culturable bacteria in biofilms relative to that in bulk water. The results showed that when no chlorine residual was present in the system, the median ratio of bulk to total bacteria was 0.81, indicating that 81% of the bacteria were present in bulk water, whereas only 19% were present in the biofilm. As chlorine concentration increased to 0.2, 0.5, and 0.7 mg/L, the median percentage of bacteria present in bulk water decreased to 37, 28, and 31, respectively. On the other hand, as the residence times increased to 8.2, 12, 24, and 48h, the median percentage of bacteria present in bulk water increased to 7, 37, 58, and 88, respectively, in the presence of a 0.2mg/L chlorine residual. The common notion that biofilms dominate the distribution system is not true under all conditions. These findings suggest that bulk water bacteria may dominate in portions of a distribution system that have a low chlorine residual.     

Cell phones for the spirits: ancestor worship and ritual economies in vietnam and its diasporas

Religion has been thriving in the Socialist Republic of Vietnam since ??i m?i, the onset of market reforms in the late 1980s. Votive paper offerings, part of spiritual and economic well-being, play a crucial role in performing religious practices in the socialist country as well as among diasporic Vietnamese. In urban Hanoi, material objects made from paper are traded in marketplaces and later burned in the streets, in temples and pagodas, in private yards and other places on special occasions in order to be transmitted to the ancestors. In the past few years, the range of votive paper offerings produced, traded, and sent to the deceased has expanded to include new forms and references to new media. Drawing on recent debates in the role of media in religion and in particular on technologies of mediation, I focus on the use of votive paper offerings in the sociocultural context of the Vietnamese spirit world. I explore how new media and media technologies are embedded in multilayered processes of mediation in Vietnam and its diasporas. Taking religious practices of burning votive paper offerings as an ethnographic example, this essay aims to contribute to ongoing debates on popular religion and the sacred life of material goods in late socialist Vietnam, on its transnational ties, and on the entanglements between religion, media and materiality.     

Trace metal behaviour in estuarine and riverine floodplain soils and sediments: a review

This paper reviews the factors affecting trace metal behaviour in estuarine and riverine floodplain soils and sediments. Spatial occurrence of processes affecting metal mobility and availability in floodplains are largely determined by the topography. At the oxic-anoxic interface and in the anoxic layers of floodplain soils, especially redox-sensitive processes occur, which mainly result in the inclusion of metals in precipitates or the dissolution of metal-containing precipitates. Kinetics of these processes are of great importance for these soils as the location of the oxic-anoxic interface is subject to change due to fluctuating water table levels. Other important processes and factors affecting metal mobility in floodplain soils are adsorption/desorption processes, salinity, the presence of organic matter, sulphur and carbonates, pH and plant growth. Many authors report highly significant correlations between cation exchange capacity, clay or organic matter contents and metal contents in floodplain soils. Iron and manganese (hydr)oxides were found to be the main carriers for Cd, Zn and Ni under oxic conditions, whereas the organic fraction was most important for Cu. The mobility and availability of metals in a floodplain soil can be significantly reduced by the formation of metal sulphide precipitates under anoxic conditions. Ascending salinity in the flood water promotes metal desorption from the floodplain soil in the absence of sulphides, hence increases total metal concentrations in the water column. The net effect of the presence of organic matter can either be a decrease or an increase in metal mobility, whereas the presence of carbonates in calcareous floodplain soils or sediments constitutes an effective buffer against a pH decrease. Moreover, carbonates may also directly precipitate metals. Plants can affect the metal mobility in floodplain soils by oxidising their rhizosphere, taking up metals, excreting exudates and stimulating the activity of microbial symbionts in the rhizosphere.     

在革新与现代主义之间:夏昌世与德国(英文)

夏昌世,中国第一代建筑师,1920年代在德国卡尔斯鲁厄留学。1932年,他在图宾根完成了博士论文之后重返祖国。1940年代后期,他在广州成为教授,1973年与妻子一同重返德国,并在那里生活直至1996年逝世。他的设计方法不仅受到那个时代欧洲现代主义运动氛围的熏陶,还来自他对中国传统景观与建筑艺术历史的研究。他是引领岭南区域形成岭南学派建筑的主导力量之一。同时,作为一建筑学教授,他在广州培养了新一代青年建筑师。     

The study of terrestrial vertebrates of the Ob River basin

The paper describes the 300-year history of studying the terrestrial vertebrates in the Ob basin and the current state of researches into amphibians, reptiles, birds and mammals. We examine the role of the research centres in Western Siberia in studying the terrestrial vertebrates in the Ob basin, from the steppe in the south to the tundra in the north and the uplands of the Altai, Kuznetsky Alatau and Salair. We describe the degree of exploration of the terrestrial vertebrates in 11 Russian regions located in the area. The paper includes discussions of rare species, population, spatial distribution and man’s impact on the animals. We also indicate areas where there is insufficient study.