坚硬顶板综采工作面推进速度对矿压规律影响研究

以顾桥煤矿坚硬顶板综采工作面工程地质条件为背景,运用理论分析、数值模拟和现场实测手段,分析了开采速度对工作面覆岩运动、围岩破坏、应力分布和液压支架承载特性的影响。研究结果表明:1个周期来压内工作面落煤引起的岩梁刚性回转下沉量是一定的,工作面作业循环时间引起的岩梁蠕变下沉量与岩梁刚性回转下沉量呈正比,加快工作面推进速度仅减少围岩体蠕变引起的岩梁下沉部分。工作面开采速度增加,覆岩塑性区发育范围减小,煤壁应力集中位置变浅、应力集中系数变小。工作面快速推进时,液压支架承载多为2次増阻和3次増阻,支架工作阻力较小;缓慢推进时,液压支架承载多为1次急增阻,载荷近似呈线性增长,支架工作阻力较大。     

高校宿舍楼火灾及人员疏散数值研究

为研究高校宿舍火灾烟气蔓延过程与人员疏散效果的相关联系,利用数值模拟研究了不同火灾场景下烟气流动、能见度、温度随时间变化的规律,及其对人员安全疏散的影响。研究表明:(1)火灾发生后,由于烟囱效应,烟气迅速在楼梯间蓄积,形成蓄烟池效应,堵塞疏散通道,然后逐渐发展至上部的楼层空间,对人员安全疏散极为不利;(2)高校宿舍楼人员较为集中,火灾发生时疏散人员在楼梯间易出现拥堵,人员火灾安全疏散的形势较为严峻;(3)喷淋、宿舍人数控制、建筑结构优化等安全措施能有效提高人员疏散效果,降低火灾危险性;(4)研究成果能为建筑防火设计、消防整改和宿舍管理提供科学依据。     

Job engagement,perceived organizational support,high‐performance human resource practices,and cultural value orientations: A cross‐level investigation

Drawing on social exchange theory, we developed and tested a cross‐level model of organizational‐level predictors of job engagement. Specifically, we examined the impact of high‐performance human resource (HR) practices on employee engagement and work outcomes. Based on a sample of 605 employees, their immediate supervisors, and HR managers from 130 companies, our results indicated that high‐performance HR practices were directly related to job engagement as well as indirectly related through employees' perceived organizational support. In turn, job engagement was positively related to in‐role performance and negatively related to intent to quit. Culture was found to act as a critical contextual factor, as our results also revealed that the relationship between HR practices and perceived organizational support was stronger when collectivism was high and when power distance orientation was low. Overall, the findings shed new light on the processes and conditions through which employee work‐related outcomes are enhanced owing to high‐performance HR practices. Copyright © 2015 John Wiley & Sons, Ltd.     

ZrxMg1-xO supported cobalt catalysts for methane decomposition into COx-free hydrogen and carbon nanotubes

Zirconia-magnesia supported cobalt catalysts with various Zr/Mg atomic ratios were prepared and evaluated for non-oxidative catalytic decomposition of methane to produce CO_x-free hydrogen and carbon nanotube. The catalytic performance of the catalysts was performed in a continuous fixed bed flow reactor at 700°C under atmospheric pressure. The fresh and spent catalysts were characterized by XRD, TPR, BET, TEM, and Raman spectroscopy. The results showed that the change in Zr/Mg ratio of the mixed oxide support has a significant effect on the catalytic performance of the active Co metal. The catalyst 30%Co/Zr_0.8Mg_0.2 showed the highest activity and stability within the used series of catalysts with hydrogen yield reached up to 79%. Both Co/Mg_1.0 and Co/Zr_1.0 showed poor stability due to strong Co-Mg interaction and aggregation of Co species on Zr support, respectively. All catalysts produced mainly MWCNTs with different diameters depending on the Zr/Mg ratio. The outer diameter increased with increasing Zr content in the catalyst due to the enlargement of the particle size of cobalt as a result of aggregation.     

高地应力软岩隧道初期支护优化研究*

为研究边墙曲率、支护参数等因素对高地应力软岩隧道变形控制的效果,以大瑞铁路营盘山隧道为工程背景,结合现场监测数据,建立有限元模型,分析不同边墙矢跨比及初期支护参数对隧道变形的影响,借此得到合理的初期支护参数。结果表明:原有支护结构中“直边墙”对于隧道水平方向变形与压力抵抗能力较弱,当边墙曲率调整至0.12后,支护结构的受力和变形情况得到明显改善;初期支护参数中锚杆参数对于隧道变形控制效果较小,增强衬砌的强度可以有效控制隧道的变形;通过围岩-支护特征曲线对优化后的支护方案进行安全评价,发现其安全性能较之前显著增强,现场应用结果也表明支护结构并未出现破坏失稳现象,隧道变形得到有效控制。研究结果对类似工程变形控制及支护方案优化提供一定的参考依据。     

Explosion at an aluminum factory caused by the July 2018 Japan floods: Investigation of damages and evacuation activities

An explosion at an aluminum factory occurred due to floods in Soja City, Okayama Prefecture, in July 2018. This study investigates the accident, its overall impact on local residents, and emergency management activities. The results of the study showed that several nearby structures and homes were damaged by the explosion. Concern for more explosions has led to the evacuation of residents of Shimobara area of Soja City. In Shimobara, residents had carried out voluntary disaster prevention activities before the disaster. After the explosion, Shimobara residents were able to evacuate safely in cooperation with the voluntary disaster prevention organization and the local government agency. The study revealed that there was a lack of information on chemical accident hazards shared by the factory with local government authorities and first responders, as well as with local residents. In order to be better prepared for technological accidents, and in particular accidents caused by natural disasters (known as Natechs), mechanisms for information sharing between companies and municipalities should be adopted.     

3S与在线监测技术在环境模型研究中的应用

结合环境信息系统的研究现状和研究实例，首先分析了3S和在线监测技术与环境模型研究结合的必要性，并分析指出了3S、在线监测技术在环境模型研究中潜在的应用范围，然后剖析了3S技术与环境模型研究结合的三阶水平，最后介绍了3S在环境规划模型研究中的理想结合框架。     

Ecological Modelling by ‘Ecological Modelling'

On the basis of a statistical analysis of the papers published in Ecological Modelling from 1975 to 1996, it has been attempted to examine the development of the field of ecological modelling and systems ecology. It was found that while models of aquatic ecosystems and management issues were more in focus in the 1970s, terresterial ecosystems and ecological theory have gained attention during the 1990s. Interest in ecotoxicological models seems to have increased only slightly during the entire period. It is interesting that financial support for the area of ecological modelling and systems ecology is closely related to the number of publications, which can be seen from the number of papers published by various countries in the journal. Hopefully, this clear message can be used to show to politicians that these relationships are real.     

Assessing Conservation Management's Evidence Base: a Survey of Management-Plan Compilers in the United Kingdom and Australia

Abstract:  Conservation management is becoming increasingly resource intensive as threats to biodiversity grow through habitat destruction, habitat disturbance, and overexploitation. To achieve successful conservation and sustainable use of natural resources, we need to scientifically evaluate the effectiveness of conservation interventions and provide an efficient framework through which scientific evidence can be used to support decision making in policy and practice. We conducted the first formal assessment of the extent to which scientific evidence is used in conservation management through a questionnaire survey and follow-up interviews of compilers of protected-area management plans from major conservation organizations within the United Kingdom and Australia. Our survey results show that scientific information is not being used systematically to support decision making largely because it is not easily accessible to decision makers. This, in combination with limited monitoring and evaluation of effectiveness of management interventions, results in the majority of decisions being based on experience rather than on evidence. To address this problem we propose using an evidence-based framework adapted from that used in the health services and explain how we are currently putting an equivalent framework into practice by establishing review and dissemination units to serve the conservation sector.     

A Knowledge-Based Approach to the Assessment of Watershed Condition

The Ecosystem Management Decision Support (EMDS) system is an application framework for knowledge-based decision support of ecological assessments. EMDS integrates geographic information system and knowledge base system technologies to provide an analytical tool for environmental assessment and monitoring. The basic objective of EMDS is to improve the quality and completeness of environmental assessments and the efficiency with which they are performed. The USDA Forest Service and the U.S. Environmental Protection Agency have cooperatively developed an EMDS knowledge base for watershed condition assessment. Specifically, this knowledge base evaluates watershed processes, patterns, general effects of human activity, and fisheries habitat suitability. Such assessments are based on spatially explicit input data concerning current conditions and reference conditions which are subsequently interpreted by user-defined "fuzzy" membership functions. In this paper we describe basic components of our knowledge base for assessing watershed condition and illustrate its application within northern Idaho and northwestern Montana.