半水半陆的低桩承台基础施工

本文结合城南河大桥主墩承台的施工过程,提出了钢板桩围堰湿法施工的设计思路,介绍了钢板桩围堰配合水下吸砂施工工艺在半水半陆中基础施工的应用情况。     

Model uncertainty and aggregated default probabilities: new evidence from Austria

Understanding the determinants of aggregated corporate default probabilities (PDs) has attracted substantial research interest over the past decades. This study addresses two major difficulties in understanding the determinants of aggregate PDs: model uncertainty and multicollinearity among the regressors. We present Bayesian model averaging (BMA) as a powerful tool that overcomes model uncertainty. Furthermore, we supplement BMA with ridge regression to mitigate multicollinearity. We apply our approach to an Austrian data set. Our findings suggest that factor prices like short-term interest rates (STIs) and energy prices constitute major drivers of default rates, while firms’ profits reduce the expected number of failures. Finally, we show that the results of our model are fairly robust with respect to the choice of the BMA parameters.     

塔里木盆地南缘地区沙产业发展现状，存在问题和发展对策研究--以和田地区为例

塔里木盆地南缘的和田地区位于新疆维吾尔自治区南部,塔克拉玛干大沙漠南缘,光热资源丰富、生物资源种类多、未利用土地和沙漠面积广大,为沙产业发展提供了充足的环境条件和空间。从而充分利用沙区的有利条件,大规模发展多采光、少用水、高效益、新技术为特点的阳光农业,具有巨大的潜力。本文通过分析发展沙产业的优势,系统探讨沙产业发展的现状及存在的问题,并提出了沙产业发展的对策。     

铸造旧砂的综合利用综述

从固体废弃物资源化的角度论述铸造旧砂的综合利用情况并分析其前景。     

地震表层研究中若干试验与分析

地震表层研究主要是为地震勘探野外静校正提供低降速带厚度及速度参数。本文根据地震表层研究中所做的若干试验结果，分析了在应用地震小折射及各种测井方法确定表层参数时的内在关系；讨论了地震记录近炮点道与远炮点道波初至方向相反的原因；阐述了激发药量对压制背景噪声的重要性及偏移距与接收能量的关系，给出了包括黄土和细黄砂成份的泥浆速度的试验测定值是１４４７（ｍ／ｓ）。     

The structure of production of the Spanish telecommunications sector

The purpose of this paper is to provide empirical measures of the returns to scale coefficients, substitution elasticities between capital and labor, their marginal productivities, and the profitability of inputs in the Spanish telecommunications industry. The results of this study indicate that constant returns to scale can strongly be rejected and that the profitability indices of both factors have risen consistently since 1974. Furthermore, it concludes that the company is relatively overcapitalized, a result generally consistent with the Averch-Johnson effect for rate of return regulated monopolies.The author wishes to thank Dr. Boris Bravo-Ureta and Dr. Emilio Pagoulatos for thoughtful comments on an earlier draft. She is also indebted to an anonymous referee for valuable suggestions and to Telefónica de España for providing the data necessary for this study.     

甘肃省沙产业综合开发的现状及对策

甘肃是我国沙漠戈壁及沙漠化土地分布大省,如何坚持科学发展观,加快甘肃沙产业综合开发,实现社会经济的可持续发展,是一项重大的战略性课题。本文在充分论述大力发展沙产业重要意义的基础上,结合甘肃的实际。客观分析了甘肃发展沙产业的现状以及面临的机遇和挑战,并对如何促进甘肃沙产业的综合开发提出了建设性的对策和建议。     

新型捞油及捞砂悬绳器装置的研制

捞砂工艺是适用于低压油水井清砂的一种工艺技术,但在捞油作业过程中往往遇到需要先捞砂的特殊情况,因此研究出新型捞油及捞砂悬绳器将捞砂工艺与捞油工艺融合为一套新工艺技术,用一套工艺设备即可完成捞油、捞砂任务。该技术具有施工周期短、易于操作、节省成本、减少地层污染等诸多优点,大大的提高了作业效率。     

水平定向钻进砂层的泥浆技术

砂层为机械分散地层,颗粒间缺乏胶结,水平定向钻进时孔壁很容易坍塌。文章分析了砂层特点,阐述了泥浆功用和性能,总结了水平定向钻进砂层的泥浆体系设计方法和施工中的注意事项。     

天然气下游价格风险传导模型研究

本文通过分析天然气下游价格风险的传导途径,提出了应用沙堆模型分析了天然气下游价格风险的传导机理,并模拟了其价格雪崩过程。结合前人的研究成果,判断该风险传导网络是无标度网络。得出结论,只有提高每一位利益相关者的风险忍受阀值和控制该系统的Hub点的行为,才能有效的控制整个下游价格风险传导网络。