温度和氯离子浓度对30CrMnSiNiA腐蚀速率的影响研究

目的研究温度和氯离子浓度对金属腐蚀速率的影响。方法通过失重法研究对比30CrMnSiNiA结构钢在不同氯离子浓度和温度下的腐蚀速率。结果 30CrMnSiNiA钢的腐蚀速率都经历了一个增大-减小-趋于稳定的过程,说明腐蚀机理并未发生改变。在温度较低和氯离子浓度较低的条件下,升高温度和氯离子浓度将会提高腐蚀速率;当温度和氯离子浓度很高时,继续升高温度和氯离子浓度将会降低溶液中溶解氧的含量,使腐蚀速率降低,溶解氧的极限扩展速率将会成为限制腐蚀速率的关键因素。结论不同温度和氯离子浓度下金属腐蚀规律相同,温度和氯离子浓度在一定范围内促进了金属的腐蚀速率。当超过转化点后,提高温度和氯离子浓度会降低腐蚀速率。     

基于置信因子的交通隧道模糊综合评价

为了解决交通隧道评价中存在的大量随机性和模糊性问题,提出了一种基于置信因子的模糊评价方法,建立了带置信因子的交通隧道模糊评价模型,用于科学、定量地确认危害产生的原因;通过确定置信因子和建立模糊综合评判信度,补偿评判中主观信度,实现危险控制过程;应用实例证明该方法是有效、可行和可靠的,具有实际推广价值.     

提高煤矿无定量斗式箕斗提升系统安全性能的新途径

提出了一种基于天轮传感器的新型箕斗提升定重装载系统;探讨以该系统为基础的无定量斗式定重装载形式、数据处理以及装载控制实现方法;研究以模糊神经网络为基础的智能数据处理与控制方法,有效解决了称重系统中因交叉灵敏度而导致的稳定性差、可靠性低等生产安全问题。实现老矿井箕斗提升系统特别是无定量斗式箕斗提升系统的定重装载改造,对煤矿提升系统安全、高效运行具有重要意义。     

Null-Hypothesis Significance Testing and the Critical Weight Range for Australian Mammals

Abstract:  The critical weight range hypothesis for Australian terrestrial mammals states that species in the intermediate size range 35–5500 g are particularly susceptible to extinction. In a 2001 study Cardillo and Bromham found no statistically significant evidence for this hypothesis and suggested that research should instead focus on why small species are resistant to extinction. We used a similar data set of body sizes of Australian mammals grouped by conservation classification, but we used test statistics (mean deviation above and below the median body size) that are more statistically powerful than those of Cardillo and Bromham (quartiles, maxima, and minima of body size distributions). We found strong evidence in favor of the critical weight range hypothesis: the body size distribution of threatened species was more clustered toward the median body size from above and below. This pattern was statistically significant at the continental scale and in the arid zone, but not in the mesic zone. Confusing statistical significance with evidence of no effect, as Cardillo and Bromham did, can have negative implications for conservation biology because it can result in failure to act when action is warranted or provision of incorrect advice that affects policy and planning decisions.     

环境载荷与环境压强:环境压力指标及应用

一个国家的经济活动产生的环境压力与其具有的环境承载能力。决定了该国社会与经济发展的可持续状况。因此．测度环境压力和承载力是制定可持续发展目标和政策的必要条件之一。基于国家尺度的社会代谢物质流、地理面积和生态承载面积。可以构建出一个国家本国环境所承受的环境压力总量指标体系——环境载荷和环境压强；德国、荷兰、奥地利、日本和美国等五个工业国家的环境载荷和各环境压强总量指标若干年的实证计算和对比分析。可以发现．虽然美国的国内环境总载荷、人均物质总需求及人均生态足迹赤字等均是各国最高者．其环境压强却处于五国的最低端。与奥地利相近；以环境压强指标测度。除日本不明显外．其余四国的经济发展与本国环境压力之间在研究期（1975—1996）均显示出“脱钩”关系．即本国环境压强并没有随经济总量的增长而增加。为此．最后就环境问题的公平性和环境压力指标的优缺点进行简要讨论。     

Body Weight Dynamics in Hibernating Ground Squirrels (Citellus undulatus jacutensisBrandt, 1848)

Russian Journal of Ecology -     

PLANNING METHODOLOGY FOR ANALYSIS AND MANAGEMENT ON LAKE EUTROPHICATION1

ABSTRACT: The effects of changing nutrient inputs through land use management, waste water treatment, or effluent diversion are not clear, and managers are discovering that decisions which were effective in reversing eutrophication for one lake are often unsuccessful when applied to another. Simple empirical relationships are often used to predict the impact of management decisions. Errors in estimation could result in either substantial costs for overdesign or failure to meet desired eutrophication levels. This paper presents and illustrates a methodology to evaluate the impact of land use and water resource management decisions on lake eutrophication. The problems of worth of additional information, and uncertainty of estimates were handled within a cost-effectiveness framework. The probability of exceeding a critical level of eutrophication was considered as a measure of effectiveness. The cost criterion is the expected value of opportunity costs, costs of analysis and costs of additional information. Uncertainty analysis techniques were used to estimate the effectiveness of various management alternatives. Bayesian methods can be utilized to determine the worth of additional information. The methodology was applied to Beseck Lake, Connecticut, and the cost and effectiveness measures estimated for a number of land management alternatives. Worth of additional information was not determined in this initial effort in uncertainty analysis for lake eutrophication management.     

基于ANP方法的社区事故应急能力评估指标权重的确定

在分析社区在重大事故应急救援中特殊作用和地位的基础上,指出开展社区事故应急能力评估的目的和意义。简要分析化工型社区事故危险性和应急特点,综合考虑社区事故应急能力的各类影响因素,构建化工型社区事故应急能力评估指标体系。选择网络分析法对社区事故应急能力进行评估,建立社区事故应急能力评估指标体系的网络层次结构模型,并利用网络分析法计算各指标的权重。该方法将较好地考虑社区事故应急能力评估指标体系之间存在相互影响和反馈关系的特点,从而提高对社区事故应急能力评价的可靠性和准确性。     

综采工作面安全性评价的逼近理想解(TOPSIS)方法

基于熵权的TOPSIS(逼近理想解的排序方法)方法是一种新的安全性评价方法,该方法以灰熵理论确定评价指标的权重———熵权,从而避免低层次多因素权重确定的主观性。以评价对象与理想解和负理想解的距离确定的相对接近度作为评价准则,避免了评价方法的主观性。通过对平顶山煤业集团有限责任公司六矿综采工作面安全性进行的评价,指出综采工作面安全管理中存在的问题,并提出相应的改进措施。理论与实例表明,该方法较其他方法更加客观,更易于操作,结果也更符合生产实际。