近地层相似理论适用的分析研究

利用实测的脉动场与平均场同步梯度观测资料研究近地层相似理论的适用性。结果表明：理论的核心——近地层为常数通量层的近似假设在有植被陆面上是基本不成立的。Ｗ′Ｔ′随高度明显减小；摩擦速度ｕ＊在３０ｍ高度范围内可增大２４％左右。用相似理论关系式（或称作廓线通量法）得到的通量值只代表某高度层以下的平均值     

数字化地震遥测台网不间断供电系统研制

本文介绍一种适用于数字化遥测地震台网的不间断供电系统，它具有交直流不间断切换，输出满足数据采集系统及数据传输设备所需的各种电压要求，并能对备份蓄电池自动恒流、恒压转换充电及过放电保护，冗余量大、可靠性高。解决了无人值守遥测地震台的供电问题。对其它数字设备也有广泛的应用价值。     

地下水对地电前兆影响的实验研究

以含水岩土为样本，研究了不同含水率，不同矿化度，不同压力，不同温度以及岩土层中重力水面的不等高度状态下岩土电阻率的定量变化，实验表明，岩土介质电阻率与所含水的特性有十分密切的关系，该实验首次把地下水前兆与地地前兆作为一个整体，来研究地者之间的内在联系，并分析其相关特征。     

甲醛还原Pt/TiO2催化剂用于温和条件下高效催化氧化甲醛（英文）

通过浸渍法(IM)和沉积-沉淀(DP)法制备了一系列Pt/TiO2P25)催化剂,并分别用甲醛溶液和氢气还原处理催化剂.利用原位红外监测催化剂表面吸附物种在反应过程中的变化,探究了催化剂制备和还原条件及Pt负载量对催化剂结构和催化氧化甲醛活性的影响.结果显示,用DP法制备并用甲醛还原的Pt/P25催化剂中Pt颗粒分散均匀,并具有合适的粒径和高浓度的表面活性氧,显示出良好的甲醛氧化活性.在空速30 000 ml/(g·h)、反应温度30°C和甲醛初始浓度50 mg/m的条件下,0.4%Pt/P25(DP-HCHO)上的甲醛转化率达到98%,并能稳定运行100 h以上.相比之下,Pt/P25(DP-H2)由于表面活性氧较少,不利于甲酸盐氧化,活性较低.Pt/P25(IM-H2)虽然具有高浓度的表面活性氧,却同时具有最大的Pt颗粒粒径,在甲醛转化为甲酸盐和甲酸盐氧化两步反应中的活性均较差,因而甲醛氧化活性最差.     

陕西洛川黄土-古土壤剖面中伊利石结晶度——黄土物质来源和古气候环境的指示

伊利石是我国黄土和古土壤中最主要的粘土矿物。本文选择陕西洛川黄土-古土壤国际典型剖面为研究对象,通过测定伊利石的结晶度(Kubler指数)、Srodon峰强比值(Ir)和2M_1多型含量,发现黄土物质的起源与中高温(>280℃)地质环境有关;黄土样品中伊利石结晶度值为0.25°2θ(Cu Ka),古土壤样品中伊利石结晶度值大于0.27°2θ(Cu Ka);黄土和古土壤中伊利石结晶度值的差别,是由于古土壤中伊利石含少量的膨胀层,而黄土样品中的伊利石不含有膨胀层而引起的。古土壤中伊利石的膨胀层的成因,与伊利石     

Trends In U.S. Hazardous Materials Transportation Spills

This paper examines historical and spatial trends in hazardous materials transportation spills from 1971 to 1991. While the number of spills Inc.reased steadily during the 1970s, peaking in 1978–1979, there has been a decline in frequency sInc.e then largely due to modifications in reporting. Monetary damages have the opposite temporal pattern, with major Inc.reases recorded from 1982 onward. Death and injury statistics are more variable. Spatially, accidents are more prevalent in the Rust Belt extending from the Northeast corridor westward to the Great Lakes states, as well as in the Southeast. The greatest potential risk to the public is found in smaller, more densely populated industrial states such as New Jersey, Delaware, and Maryland. The spatial distribution, however, has not changed. Potential risk sources (e.g., chemical industry, number of hazardous waste facilities, number of railroad miles) are the best predictors of hazmat Inc.ident frequency. Mitigation efforts (statewide regulatory and/or management policies) also help explain the variability in hazmat Inc.idents.     

粒度分析在塔克拉玛干沙漠研究中的应用

本文重点探讨了塔克拉玛干沙漠的风成沙粒度组成特征及其与物源的关系，同时对沙丘的下伏地层沙、现代河流沙及丘间地沙的粒度组成也进行了对比。通过对该沙漠第四纪沉积物的粒度分析，证实了风成沙的粒度分布以极细沙为主，不含粗沙，粉沙含量极小；粒度组合、分选主要受营力和源区物质制约，结果使粒度空间分布形成格局。总之，通过粒度分析得到一系列量化指征，可为研究风沙流运动，探讨沉积环境和改造沙漠、发展沙产业提供理论依据。     

湖南柿竹园钨多金属矿床成矿机理的实验研究

作者在深入柿竹园钨多金属矿床野外地质工作的基础上，采用矿区燕山期花岗岩和泥盆系灰岩作为试料，在含ｐＨ＝４．０的０．３ＭＮａＣｌ＋０．７ＭＫＦ水溶液的高压釜中持续了１２０小时的交代作用。实验的结果表明了：在４００～７００℃的温度和２５０×１０５～９００×１０５Ｐａ的压力下，形成的交代岩及其钨、锡、钼、铋矿物基本上与矿区的矽卡岩及其矿石矿物共生组合相吻合，揭示了湖南柿竹园矽卡岩型钨多金属矿床成矿的机理     

隧道开挖模拟计算中的模型识别方法初探

介绍了利用隧道施工的位移量测信息来选择计算模型的原理和方法。应用实例表明，本文所提出的方法有较好的应用前景。     

Byproduct Formation During the Reduction of TCE by Zero-Valence Iron and Palladized Iron

Trichloroethene (TCE) was reduced with zero-valence iron and palladized iron in zero-head-space extractors. Progress of the reaction in these batch studies was monitored with purge-and-trap gas chromatography and a flame ionization detector. When a 5 ppm initial concentration of TCF. reacts with zero-valence iron, approximately 140 ppb of vinyl chloride persists for as long as 73 days. The concentration of vinyl chloride (approximately If) ppb) remaining with palladized iron is approximately an order of magnitude less than when zero-valence iron is the reductant. These data suggest that volatile byproducts may be under-represented in oilier published data regarding reduction with zero-valence metals. These results also demonstrate that the reduction of TCE with palladized iron (0.05 percent palladium) is more than an order of magnitude faster than with zero-valence iron. Wilh a 5:1 solution-to-solid ratio the TCE half-life with zero-valence iron is 7.41 hours. but is only 0.59 hours with the palladized iron.