火山射气岩浆喷发作用研究进展

射气岩浆喷发是一种特殊类型的火山活动,水在这类火山活动中起到至关重要的作用,且其喷发产物——低平火山口和基浪堆积物在我国乃至全世界都有广泛的分布。国际上对射气岩浆喷发的研究始于1921年,迄今为止已有80余年的历史。国内外许多学者运用火山地质学、岩石学、沉积学、物理火山学及数值模拟等多学科研究手段,对射气岩浆喷发作用及其产物进行详细的野外观测描述,并探讨其成因机制。本文在前人研究基础上,以我国南方北部湾周边第四纪火山区大量存在的射气岩浆喷发成因的低平火山口和基浪堆积物为研究对象,深入讨论了基浪堆积物的地质特征、射气岩浆喷发形成的基本条件、喷发过程的动力学机制以及基浪流的搬运过程等几方面重要问题,并对已有的研究成果进行了概括和总结,提出有待解决的难点,揭示了这类火山活动特有的属性。     

Seismic shear distribution among interconnected cantilever walls of different lengths

Mid‐rise to high‐rise buildings in seismic areas are often braced by slender reinforced concrete (RC) walls, which are interconnected by RC floor diaphragms. In design, it is typically assumed that the lateral forces are distributed in proportion to the wall's elastic stiffness. Pushover analyses of systems comprising walls of different lengths have, however, shown that large compatibility forces can develop between them, which should be considered in design, but the analyses have also shown that the magnitude of the computed forces is very sensitive to the modelling assumptions. Using the results of a complex shell element model as benchmark, different simple hand‐calculation methods and inelastic beam element models are assessed and improved to yield reliable estimates of the base shear distribution among the individual walls comprising the interconnected wall system. Copyright © 2014 John Wiley & Sons, Ltd.     

自然资源资产管理的国际进展及主要建议

自然资源是经济社会发展的物质基础和空间载体,加强自然资源资产管理是适应深化自然资源管理制度改革的现实需要。本文在对比分析国内外自然资源资产管理现状的基础上,剖析了国内自然资源管理中存在的主要问题,提出了加强研究典型国家自然资源资产管理的经验、加快编制我国自然资源资产负债表、加紧落实健全国家自然资源资产管理体制等方面的建议。     

彭州市立体农业气候资源的研究(二)热量资源分析

利用彭州市境内市气象站，新兴，白果坪的日平均气温资料，进行热量资源分析。结果表明，彭州市7－8月为最热月，多年平均温度低于24．9℃，12－2月为最冷月，多年平均温度高于1．7℃。大多数年全年稳定通过0℃，可一年四季进行农业耕作，有利于作物越冬和多年生作物的种植，生长期长，积温丰富。界限温度的初，终日期及持续日数变化较大，积温际变化显著，热量资源随海拔高度增加而减少，各界限温度的初日推迟，终日提前，持续日数和积温减少，温度强度也降低，形成显著的立体农业气候。     

The deposit size frequency method for estimating undiscovered uranium deposits

The deposit size frequency (DSF) method has been developed as a generalization of the method that was used in the National Uranium Resource Evaluation (NURE) program to estimate the uranium endowment of the United States. The DSF method overcomes difficulties encountered during the NURE program when geologists were asked to provide subjective estimates of (1) the endowed fraction of an area judged favorable (factorF) for the occurrence of undiscovered uranium deposits and (2) the tons of endowed rock per unit area (factorT) within the endowed fraction of the favorable area. Because the magnitudes of factorsF andT were unfamiliar to nearly all of the geologists, most geologists responded by estimating the number of undiscovered deposits likely to occur within the favorable area and the average size of these deposits. The DSF method combines factorsF andT into a single factor (F·T) that represents the tons of endowed rock per unit area of the undiscovered deposits within the favorable area. FactorF·T, provided by the geologist, is the estimated number of undiscovered deposits per unit area in each of a number of specified deposit-size classes. The number of deposit-size classes and the size interval of each class are based on the data collected from the deposits in known (control) areas. The DSF method affords greater latitude in making subjective estimates than the NURE method and emphasizes more of the everyday experience of exploration geologists. Using the DSF method, new assessments have been made for the young, organic-rich surficial uranium deposits in Washington and idaho and for the solution-collapse breccia pipe uranium deposits in the Grand Canyon region in Arizona and adjacent Utah.     

上海沿海风能资源评估

利用上海沿海5个站点风要素资料,通过统计分析,估算上海海域可开发的风能储量。东海大桥附近海域、崇明岛以东海域、南汇和横沙东滩以东海域、远海风电场为丰富区,风能资源储量约为3 373.1×104 kW;杭州湾北岸奉贤海域为较丰富区,风能储量约为38.3×104 kW;长江口水域为可利用区。     

无验潮水深测量系统定位精度检验

利用无验潮水深测量系统定位设备,采集了静态和动态两组定位数据,从静态和动态定位两个方面分析了不同长度基线的解算结果。结果表明:基线长度在40km范围以内,定位结果完全满足无验潮水深测量系统的±10cm的测量精度要求。     

Nonlinear analysis of laterally loaded rigid piles in cohesive soil

This article presents a method for the nonlinear analysis of laterally loaded rigid piles in cohesive soil. The method considers the force and the moment equilibrium to derive the system equations for a rigid pile under a lateral eccentric load. The system equations are then solved using an iteration scheme to obtain the response of the pile. The method considers the nonlinear variation of the ultimate lateral soil resistance with depth and uses a new closed‐form expression proposed in this article to determine the lateral bearing factor. The method also considers the horizontal shear resistance at the pile base, and a bilinear relationship between the shear resistance and the displacement is used. For simplicity, the modulus of horizontal subgrade reaction is assumed to be constant with depth, which is applicable to piles in overconsolidated clay. The nonlinearity of the modulus of horizontal subgrade reaction with pile displacement at ground surface is also considered. The validity of the developed method is demonstrated by comparing its results with those of 3D finite element analysis. The applications of the developed method to analyze five field test piles also show good agreement between the predictions and the experimental results. The developed method offers an alternative approach for simple and effective analysis of laterally loaded rigid piles in cohesive soil. Copyright © 2011 John Wiley & Sons, Ltd.     

煤炭资源勘查规范的进步与发展——新型煤炭资源地质勘查法规体系的构建思维

在贯彻执行我国现行有关煤炭资源勘查规范及相关规定的基础上，对国际国内煤炭地质勘查阶段划分进行了对比，论述了建国以来中国煤炭地质勘查规范的主要技术内涵，对加强贯彻新规范，促进标准化体系建设和适应社会主义市场经济体制改革进行了探讨。     

京津冀水资源利用多效率指标的变化特征比较

提高水资源利用效率,缓解用水压力,是解决京津冀缺水问题的有效措施,对各行业用水效率历史状况的全局把握有助于未来政策的调整.论文比较了京津冀三地的万元GDP用水量、万元工业增加值用水量、管网漏损率、人均日生活用水量、污水处理率、作物水分利用效率共6项指标组成的综合用水效率,分析了 2002-2017年京津冀用水效率的Ma...