降低岩心钻探成本的途径及金刚石钻头经济效果的评价          下载免费PDF全文

白先锋 《探矿工程》1994,(6):48-51

本文分析了汽车轻量化的必要性和紧迫性；论述了汽车轻量化的要求、效果和对象；从优化设计，更换材料、革新工艺三个方面探讨了轻量化途径；并以活塞和连杆为例阐明了汽车零部件的轻量化方法。  相似文献   

钢体PDC钻头修复技术之研究          下载免费PDF全文

周龙昌  于凤兰 《探矿工程》2005,32(9):41-42,45

介绍了一种钢体PDC钻头修复技术。首先对已使用过的钢体PDC钻头的可修复性进行确认，将符合修复条件的钻头进行预处理后，以8~10 ℃/min的速度对钻头体加热，加热到620 ℃左右时，焊接切削齿的焊料开始熔化，把符合条件的复合片切削齿取下，放入600 ℃的焊剂中保温待用，最后利用堆焊技术对钻头体进行修复。现场试验证明，修复后的钻头质量与新加工钻头质量无明显差别。以修复一只12 (1/4) in钢体PDC钻头为例，至少可节约成本4.14万元人民币，经济效益明显。  相似文献   

煤炭资源开发对土壤环境影响分析--以贵州六盘水为例   总被引：3，自引：0，他引：3  

王慧 《中国地质灾害与防治学报》2004,15(3):69-72

矿山开发是造成资源匮乏和环境问题的重要原因。矿山开发建设项目实施之前，应该对矿产开发的环境影响进行评估。煤炭资源开发对土壤环境的影响很显著。文章对典型的矿业城市——贵州省六盘水市进行研究，分析煤炭资源开发对土壤环境影响的几种表现形式，提出用机会成本法和恢复费用法对不利影响的损失进行评估，指出要切实减缓不利影响必须综合采取多种有效措施。煤炭资源开发对土壤环境的影响包括直接占用土地、污染土壤环境、引发次生地质灾害等方面。在此基础上，将不利影响归为两类：①占地损失，为不可逆影响，包含引起土壤直接被占用、淹没或破坏的各种影响因素。②土壤肥力损失，为可逆影响，是由于各种污染物进入土壤所引起的。对于前者，用机会成本法进行评估，在掌握拟建工程区土壤利用现状的基础上，计算土壤利用现值；同时要将估计年限的机会成本均纳入矿山开发建设的社会成本中。对于后者，用恢复费用法进行评估，需要了解土壤受影响之前的各项指标。文章最后指出，需要从开发开采技术、工程地质、“三废”处理、土地复垦、税收管理等各方面强化对不利影响的控制。  相似文献   

How Accurate are Disaster Loss Data? The Case of U.S. Flood Damage     

MARY W. DOWNTON  ROGER A. PIELKE 《Natural Hazards》2005,35(2):211-228

Policy makers need accurate disaster loss data for decisions about disaster assistance, policy evaluation, and scientific research priorities. But loss estimation is difficult in a disaster situation, and initial loss estimates are seldom evaluated in comparison with actual costs. This paper uses the example of historical flood damage data in the U.S. to evaluate disaster loss data. It evaluates the accuracy of historical flood damage estimates from two federal agencies. The U.S. National Weather Service (NWS) has compiled annual flood loss estimates for each state since 1955. Comparison of the NWS data with similar estimates from five state emergency management agencies reveals substantial disagreement between estimates from different sources. The Federal Emergency Management Agency (FEMA) began in the 1990s to systematically collect damage estimates and cost data associated with its disaster assistance programs. Comparison of early damage estimates with actual expenditures in a California flood disaster reveals large errors in some estimates for individual counties, but no statistically significant tendency to underestimate or overestimate. Positive and negative errors tend to average out and the total damage estimate for the state approximates the final expenditures. Both comparisons indicate that damage estimates for small events or local jurisdictions often are extremely inaccurate. On the other hand, estimates aggregated over large areas or long time periods appear to be reasonably reliable; that is, this study finds that independent estimates for events with losses greater than $500 million disagree by less than 40. The paper suggests ways of interpreting and using such loss estimates to reduce the likelihood of misinterpretation.The National Center for Atmospheric Research is sponsored by the National Science Foundation.  相似文献   

婺源县森林景观游憩价值的经济评价   总被引：4，自引：0，他引：4  

欧阳勋志  廖为明  黄晓全 《地域研究与开发》2006,25(1):78-82

文章在简要分析森林游憩价值经济评价方法的基础上，采用旅行费用法（TCM）对婺源县森林景观游憩价值进行了经济评价。采用整群随机抽样的方法对研究区的游客进行半访谈式问卷调查，根据调查资料，将婺源县游客来源划分为15个出发区，建立了游林率-旅行费用回归模型。结果表明，旅行费用与游林率呈极显著的负相关，文化程度与游林率呈显著的正相关；在此基础上制定了游憩需求曲线，计算得出研究区2002年森林景观游憩经济价值为1．02亿元。  相似文献   

Assessment of seismic design procedures based on the total cost     

Nikos D. Lagaros  Andreas D. Fotis  Stilianos A. Krikos 《地震工程与结构动力学》2006,35(11):1381-1401

  相似文献   

影子价格在竞争厂商配置资源中的应用     

张延飞  徐辉 《华东地质学院学报》2006,29(4):397-400

根据线性规划对偶理论中影子价格的经济含义和竞争厂商对多生产要素(资源)的使用原则,利用资源的影子价格和市场价格的差异性,探讨在完全竞争和不完全竞争条件下竞争厂商资源配置的决策问题,对竞争厂商实现资源的最优配置具有重要的指导意义。  相似文献   

关于气象服务产品消费问题的讨论     

黄宗捷  蔡久忠 《成都信息工程学院学报》1998,(2)

在人类即将进入知识经济和信息经济的时代,在经济发展需要进入可持续性发展轨道的宏观背景下,研究气象服务产品的消费具有重大理论与实践意义。气象服务产品的消费极具特殊性,风险性等五方面的性质;其消费主体结构与消费客体结构也极为复杂;气象服务产品的消费成本在气象服务产品消费中具有十分重要的地位,决定消费成本有两个经济量,它是制约消费的基本经济变量。  相似文献   

Air quality and view degradations due to copper mining and milling: Preliminary analysis and cost estimates for Green Valley,Arizona     

Hyo-Sun Kim  Dr. DeVerle Harris 《Natural Resources Research》1996,5(2):91-102

Green Valley, Arizona is a retirement community located near major open-pit copper mines. Mining and milling activities create dust, which degrades air quality, and mine dumps and tailings banks, which degrade the viewscape. Although the tailings banks are highly visible, this study found that consumer surplus lost from dust-polluted air is more than twice that from degradation of viewscape. Consumer surplus lost from both air quality and viewscape degradation is estimated to be between $116,000,000 and $169,000,000. These preliminary estimates are based upon two studies: hedonic property values, and a contingent valuation survey of willingness to pay.  相似文献   

Optimum seismic zoning for multiple types of structures     

Jaime García‐Prez  Francisco Castellanos  Orlando Díaz 《地震工程与结构动力学》2003,32(5):711-730

We consider zoning for the design criterion that minimizes the expected present value of the total cost, including the initial cost as well as losses due to damage and failure. The problem consists of the following: given the number of zones, their boundaries and design coefficients must be such that they minimize the expected present value of all structures built in the region. We will refer to solutions in one or more dimensions, depending on the number of the types of structures built in the region to be zoned. Two methods are proposed to solve the problems. The first method is based on the different combinations performed in order to attain optimum zoning. The second method uses an analogy to the evolution of biological systems. The work ends by applying the methods developed to a region of known seismicity. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献