软弱风化复合顶板巷道锚杆支护技术研究

软弱风化复合顶板巷道是围岩变形剧烈且顶板易冒落极难维护的一类巷道,文章采用数值模拟的方法,提出了合理的锚杆支护参数,并且成功应用于工程实践。     

Evaluation of the aging behavior of ethylene copolymer films for solar applications under accelerated weathering conditions

Ethylene copolymers based on acrylic acids and acrylates are an interesting alternative to ethylene(vinylacetate) (EVA) for photovoltaic (PV) encapsulation. These materials provide similar or better mechanical and optical properties and a slightly better aging behavior, but without the formation of corrosive acetic acid during aging, which is particularly of importance in PV applications. The focus of the research work was to evaluate and screen the aging behavior of ethylene copolymers containing different types of comonomers for solar applications. To investigate the intrinsic weathering behavior of the materials, unstabilized films with comonomer contents around 10% were exposed to temperature, humidity and solar radiation. Special attention was given to the optical and mechanical properties. All investigated films showed high transparency in the solar range with hemispheric transmittance values above 91%. Regarding mechanical properties, the ethylene copolymer films exhibited a highly ductile behavior and high flexibility. Similar degradation behavior could be observed for all investigated films. Due to formation of chromophoric degradation products, yellowing could be observed and hemispheric transmittance values dropped slightly to values between 88.5 and 90.5%. The unstabilized films showed significant embrittlement due to weathering. After 750 h of weathering both strain-at-break and stress-at-break values of all ethylene copolymer films dropped significantly below 50% of the initial values.     

蒙自市蚂蚱冲水库坝基声波测试成果分析

以往中小型水库地质勘察工作主要采用钻探和人工探井,方法单一,很难对坝基岩体问题做出较为准确的判断。蒙自市蚂蚱冲水库通过声波试验配合传统勘察方法迅速而准确地对地基岩体风化界线和岩溶发育范围做出判断,提高了工程勘察的可靠度。     

有序聚类法在锦凌水库风化岩体定量分带中的应用

应用有序聚类法对辽宁省锦凌水库坝基的风化岩体进行定量分带,所得结果与地质观察方法、规范法等所得出的结果进行了分析比较.采用岩体风化差异系数法进行综合分析,最终推荐按照有序聚类方法进行风化岩体分带.     

望江矶雨花台砾石层工程地质特性及形成机理

根据野外考察与实验资料，对南京雨花区望江矶的雨花台砾石层的工程地质性质作出初步评价认为该砾石层具有一定的固结性，较好的水稳性，较强的抗剪性，中低压缩性不同于现代松散的砂砾石堆积体，作者还运用沉积原理及风化理论对影响其工程地质性质的作用因素进行了探讨。     

华南花岗岩风化壳中稀土的存在形态及迁移富集模式

本文从化学形态角度，确立了一个ＲＥ形态分析流程，得出风化壳中ＲＥ化学形态可分为活性态，Ｆｅ，Ａｌ共沉淀态及有机结合态３种，全风化层样品中ＲＥ多数以活性态为主，但平远Ｃ剖面ＲＥ却以有机结合态占大多数，活性态、有机结合态ＲＥ与粘土矿物关系密切，而Ｆｅ，Ａｌ共沉淀态的ＲＥ与粘土矿物关系不大，原岩溶出试验表明，ＲＥ在有机介质中的溶出量一般高于无机介质，ＲＥ最大可能是呈有机无机混配络离子迁移，迁移、富集过程是络合、水解、沉淀和吸附反应同时出现，反应受ｐＨ控制，本文初步建立了花岗岩风化壳中ＲＥ往下迁移、富集的模式。     

Acidification of groundwater in water-filled gravel pits -- a new environmental and geomedical threat

Swimmers and users of motor boats frequenting old, water-filled gravel pits in Kiiminki, Northern Finland, found in August 1993 that they were suffering from painful irritation of the eyes and that their boats had developed a finely polished surface on their aluminium hulls, evidently due to the corrosive action of the water. Subsequent measurements carried out by the water authority showed that the pH of the water in some of the pits was extremely low, reaching a value of 3.4 at its lowest. To find out the causes of the abnormally low pH values, the present authors began systematic measurements of the pH and determination of the chemical composition (Si, Al, Ca, Mg, K, Na, Fe, Mn, Cu, Pb, Ni, Cd, Cl^-, NO₃ ^-, SO₄ ^2-) of the water in 23 gravel pits. In addition, a series of laboratory experiments was carried out to examine the interaction of water with samples of the soil and bedrock of the area to evaluate the role of this process as a possible cause of the acidification. The results show that the reaction of water with the moderately to intensively weathered sulphide and jarosite-bearing black schists, typical of the bedrock of the area, can bring about aqueous solutions similar in pH and sulphate--nitrate ratios to those found naturally in the gravel pits. The contribution of other possible mechanisms, e.g. acidic precipitation as such or combined with enhanced evaporation, the possible use of the pits as dumping sites for acidic waste or the flow or seepage of acidic peat-bog waters into the pits from the surrounding wetlands, cannot be ruled out entirely, but their contribution seems to be of minor importance. Since the concentrations of several heavy metals (notably Pb, Cd, Ni, Fe and Mn) and of sulphate and aluminium has increased in the pit water as a result of the acidification process and exceed the norms laid down in the EU Drinking Water Directive, acidification of water in gravel pits due to the oxidation of sulphides must be regarded as a new, serious environmental and geomedical threat which has so far remained poorly known or unrecognised.