深基坑支护设计与施工应用实例

结合具体的工程实践，探讨了支护设计方案，对具体的施工组织作了分析，并阐述了相应的质量保证措施和安全保证措施，经实践证明，取得了良好的经济效益和社会效益。     

某工程的基坑支护探讨

结合具体的工程概况，对该工程的护坡方式作了探讨，对大开挖、放边坡、放坡土钉墙的施工、直立土钉墙的施工作了阐述，并对其经济作了分析，从而确保了工程的基坑支护。     

深层搅拌桩用于深基坑支护的工程实践

结合具体的工程概况，对工程地质情况作了分析，探讨了支护方案，阐述了深层搅拌桩按重力式挡土墙设计，对其支护桩设计及施工作了介绍，确保了工程质量，取得了较好的经济效益。     

拱形支护结构在深基坑开挖中的应用

结合具体的工程实践，阐述了支护方案的选择及坑底管涌的计算，介绍了拱形支护结构在深基坑开挖中的应用，并对拱形支护结构存在的问题作了分析，从而确保其整体稳定性。     

神盘隧道穿越砂层施工技术

结合具体的工程概况，对其施工原则及方案作了研究，阐述了超前支护施工技术和锚喷初期支护施工技术，并对开挖方法进行了详细介绍，以供同类工程借鉴。     

马鞍池大厦基坑支护工程的施工

以温州马鞍池大厦基坑支护工程为例，对其施工要点作了阐述，详细介绍了具体的施工流程，并提出一些加固措施，从而确保基坑支护工程的合理、安全。     

内拱梁在软土深基坑支护中的应用

结合工程实例,通过对三种深基坑支护方案的比较,选出了最优方案,并对具体设计计算作了探讨,从而证实了内拱梁在软土深基坑支护中的成功应用,为进一步推广奠定了基础。     

喷锚网支护在深基坑工程的施工实践

结合具体的工程实例，介绍了深基坑喷锚网支护的施工工艺及施工中存在的问题，并提出了相应的处理对策，对其实施效果作了分析，指出喷锚网支护安全可靠、经济节时。     

某基坑工程的失误及补救

结合具体的工程概况，从基坑支护选型问题、深层搅拌桩施工质量问题等方面，对基坑工程中失误的原因作了分析．探讨了在特定环境下进行基坑施工妥善解决止水的问题．以确保工程建设安全。     

某软土地区深基坑支护设计与施工及管理

以位于软土地区的综合枢纽地下室深基坑设计为例,就具体的基坑支护设计方案及措施作了探讨,并对基坑支护施工中出现的问题及对策进行了论述,同时对边坡稳定进行了监测,深基坑施工取得了圆满成功。     

The effects of changing water flow velocity on the formation of biofilms and water quality in pilot distribution system consisting of copper or polyethylene pipes

We studied the effects of flow velocity on the formation of biofilms and the concentration of bacteria in water in copper and plastic (polyethylene, PE) pipes. The formation of biofilms increased with the flow velocity of water. The increase in microbial numbers and contents of ATP was clearer in the PE pipes than in the copper pipes. This was also seen as increased consumption of microbial nutrients in the pipeline system. This indicates that the mass transfer of nutrients is in major role in the growth of biofilms. However, the increased biomass of biofilms did not affect microbial numbers in the water. Rapid changes in water flow rate resuspended biofilms and sediments which increased the concentrations of bacteria and copper in water. The disturbance caused by the changing water flow was also seen as an increase in the particle counts and water turbidity recorded with online instrumentation.     

Ecological succession in mountain lake ecosystems of Southern Siberia after the introduction of the peled – Coregonus peled (Gmeli, 1778)

Abstract

This article summarizes a long-standing study of the process of introduction of the peled to the Southern Siberian mountain lake ecosystems. The peled has adapted to changes in food supply. Pressure of the euryphagous peled caused the substitution of larger forms of zooplankton by smaller ones. Similar changes occurred in the content of phytoplankton. Succession of zoobenthos in the littoral part of the lakes manifested itself as the decrease in the total biomass, in its part of zoobenthos (Gammarus) and as the increase in the biomass of other groups. The opposite changes were encountered in the profundal zone of zoobenthos (the decrease in the total biomass owing to the existence of larger forms of alpha-polysaprobes). The restructuring observed in various communities signifies the substantial changes in the whole process of generation and transformation of organic substance in the mountain ecosystems with the dominance of the introduced peled.     

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.     

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.     

Polycyclic aromatic hydrocarbons (PAHs) in agricultural soil and vegetables from Tianjin

Several types of vegetables were collected from two contaminated sites in Tianjin, China. The bulk soil and the rhizosphere soil samples were also collected from the same plots. Sixteen PAHs in the samples were measured. The total concentrations of PAH16 in the bulk soil from the two sites were 1.08 and 6.25 microg/g, respectively, with similar pattern. The concentrations of PAH16 and individual compounds in the rhizosphere were significantly higher than those in the bulk soil with mean values of 2.25 and 7.82 microg/g for the two sites, respectively. The contents of both total and dissolved organic matter in the rhizosphere were also higher than those in the bulk soil. Almost all PAH compounds studied were detected in both roots and aerial parts of the vegetables studied. Abundance of higher molecular weight PAHs in vegetable, however, was lower than that in soil. Concentrations of PAH16 in vegetable were higher than those reported in the literature for other areas. It appears that agricultural soils and vegetables in Tianjin, especially those from the site located immediately next to an urban district and irrigated with wastewater for several decades, are severely contaminated by PAHs. Among the eight types of vegetable studied, the highest concentration of PAHs was found in cauliflower. By average, the concentration of PAH16 in the aerial part of vegetables was 6.5 times higher as that in vegetable root, suggesting that foliar uptake is the primary transfer pathway of PAHs from environment to vegetables.     

Biomonitoring of mercury in polluted coastal area using transplanted mussels

The Kastela Bay is heavily polluted with inorganic mercury originated from direct discharges from the chlor-alkali plant, which operated in the period from 1950 to 1990. Even though the plant was closed 15 years ago, elevated levels of total mercury are still evident in surface sediments of the bay. In order to assess the availability of remobilized mercury to marine organisms, cultured mussels (M. galloprovincialis) were transplanted from pristine area to Kastela Bay, in the period from September 2000 to March 2001. Mussel samples were collected for the analysis of THg and MeHg in whole soft tissue, gills and digestive gland. Surface sediments and suspended matter were collected for the analysis of THg. Digestive gland was the target organ for the accumulation of THg, while concentrations of MeHg were similar in all analyzed tissues. The percentage of MeHg in mussel tissues (4-27%) was characteristic for the areas contaminated with inorganic mercury. A significant negative correlation was observed between the THg concentration in the tissues and the percentage of MeHg. Concentrations of THg in mussel tissues, which were decreasing from the source of contamination in an anticlockwise direction towards the exit of the bay, were significantly positively correlated to THg content in sediment and suspended particles. Spatial distribution of mercury species (THg and MeHg) in different environmental compartments was in accordance with the prevailing circulation in the bay. Data obtained through 6 months of biomonitoring experiment indicated that digestive gland was more sensitive indicator of THg concentrations in the environment than the whole organism or gills. As for MeHg, all tissues were equally suitable as biomonitors of MeHg concentrations in the environment.     

未来高校图书馆建筑空间构成及设计特点初探

从高校图书馆发展的外部动因,使用主体的心理、行为特征和现代化设备对图书馆的影响三个方面来分析研究图书馆建筑发展的趋势和特点,归纳出未来高校图书馆建筑的功能布局及空间组织结构特点,总结出设计中要考虑的诸多因素,以期更好地指导高校图书馆的设计与建设。     

钢结构的应用前景及教学思考

本文根据钢结构的特点 ,重点介绍了钢结构在欧洲、美国和日本等广泛应用的情况。我国改革开放以来 ,钢产量持续增加 ,已经达到了约 1.6亿吨 ,钢结构产业政策 ,也从上世纪中叶的“节约用钢” ,发展到本世纪初的“推广用钢” ,这是我国钢结构政策的重大转变。结合我国部分高校中对钢结构教学认识滞后的情况 ,提出了在土木工程专业的技术基础课中设置钢结构设计原理的参考教学内容和在对应专业方向中设置相应钢结构设计的教学思路。     

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。     

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.