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1.
    
Lower flammability limit (LFL), upper flammability limit (UFL), auto-ignition temperature (AIT) and flash point (FP) are crucial hazardous properties for fire and explosion hazards assessment and consequence analysis. In this study, a comprehensive prediction model set was constructed by using expanded chemical mixture databases of chemical mixture hazardous properties. Machine learning based gradient boosting quantitative structure-property relationship (GB-QSPR) method is implemented for the first time to improve the model performance and prediction accuracy. The result shows that all developed models have significantly higher accuracy than other regular QSPR models, with the 5-fold cross-validation RMSE of LFL, UFL, AIT, and FP models being 1.06, 1.14, 1.08, and 1.17, respectively. All developed QSPR models can be used to estimate reliable chemical mixture hazardous properties and provide useful guidance in chemical mixture hazard assessment and consequence analysis.  相似文献   
2.
The evolution of sustainability   总被引:1,自引:0,他引:1  
Six separate but related strains of thought have emerged prominently since 1950 in discussions of such phenomena as the interrelationships among rates of population growth, resource use, and pressure on the environment. They are the ecological/carrying capacity root, the resources/environment root, the biosphere root, the critique of technology root, the no growth/slow growth root, and the ecodevelopment root.Each of these strains of thought was fully developed before the word sustainable itself was used. Many of the roots are based on fundamentally opposing assessments of the future of mankind. Many of the roots, such as the ecology/carrying capacity root, are based on physical concepts, and they exclude normative values. Others, such as the ecodevelopment root, include such values as equity, broad participation in governance, and decentralized government.When the word sustainability was first used in 1972 in the context of man's future, in a British book,Blueprint for Survival, normative concepts were prominent. This continued to be the case when the word was first used in 1974 in the United States to justify a no growth economy.Sustainability was first used in a United Nations document in 1978. Normative concepts, encapsulated in the term ecodevelopment, were prominent in the United Nations publications.After about 1978, the term sustainability began to be used not only in technological articles and reports but also in policy documents culminating in the use of the term in the report of the summit meeting of the Group of Seven in 1989.The roots of the term sustainability are so deeply embedded in fundamentally different concepts, each of which has valid claims to validity, that a search for a single definition seems futile. The existence of multiple meaning is tolerable if each analyst describes clearly what he means by sustainability.  相似文献   
3.
    
The definition of corporate social responsibility (CSR) states that companies must not only pursue their main goal—to maximize profits, but also contribute to the well-being of society through voluntary efforts. The importance of CSR in today's global world is growing. It is becoming mandatory for companies to engage in socially responsible activities to support the growth of their business. It is argued that companies pursuing CSR initiatives can gain a competitive advantage over other competitors due to creation of a good public image or reputation and generate higher profits and a return on investment however some authors disagree with this. The aim of this article is to analyse the benefits and drawbacks of CSR based on systematic literature review and to develop the conceptual framework for linking CSR with the financial performance of companies. The conducted analysis revealed that in most studies the positive or neutral relationship between CSR and financial results were claimed. Though the negative and alternative connections between these issues are less frequently identified in scientific articles, they cannot be excluded from the analysis and require certain attention and further consideration.  相似文献   
4.
基于模糊聚类关联分析法的煤与瓦斯突出程度分析   总被引:7,自引:0,他引:7  
运用模糊聚类分析方法对煤与瓦斯突出的样本集合进行分类,建立了不同突出程度的模糊模式.用关联分析确定待分析样本与模式的关联程度,以此预测预报样本的煤与瓦斯突出危险程度.实例分析表明,与模糊聚类分类后、将模式与待预报样本组成新样本集合进行聚类分析并以此分类结果进行预报的方法相比,这种预报方法不仅可靠程度高,而且能定量描述待报样本与模式的亲和程度.  相似文献   
5.
随着社会经济的发展人地矛盾变得越发突出,已经成为制约城市经济进一步发展的桎梏.泉州市在社会经济快速发展的同时面临着土地资源严重紧缺的问题,亟需对其市域土地承载力进行研究,并用来指导城市的发展,从生态敏感性的视角,通过对泉州市域的生态用地和城建用地的划分,在以保护生态用地为前提的基础上,对其生态用地规模和城市用地规模进行测算,最后分别按照国际和国内两种指标来测算其土地资源承载力.  相似文献   
6.
为探究我国地质灾害多部门应急协作关系,从某地质灾害多发省搜集省-市-县3级地质灾害应急管理预案。以参与地质灾害应急职能部门为研究对象,基于社会网络分析方法构建省-市-县3级地质灾害应急合作网络模型。运用中心性与迭代相关收敛法(CONCOR)迭代相关矩阵计算得到主题词块矩阵结构,以此划分各级职能部门间子群的结构层次。通过密度矩阵,研究子群内部之间关系模式,分析各级应急部门在地质灾害应急合作网络中的中心性、网络凝聚力及互动关系。结果表明:应急职能部门在地质灾害应急合作中具有不同的互依性和小团体性,合作模式存在协同不均、信息资源堵塞等问题。整个结构中省-市级应急合作关系相对密切,但县级应急合作网络的整体结构和关系模式相对孤立,部分组织结构间联系程度较低。因此,应进一步加强各职能部门之间的相互协同能力,完善县级政府在应急管理中组织结构建设。  相似文献   
7.
To understand how trust in supervisor translates into individual job performance, we hypothesize that trust in supervisor facilitates positive psychological conditions of meaningfulness, safety, and availability, which in turn predict individual job performance. We assert that each of the three mediating paths in our model represents a distinct mechanism by which trust in supervisor contributes to individual job performance. We test our hypotheses with 206 supervisor–subordinate dyads and find that trust in supervisor contributes to job performance through psychological availability and psychological safety but not psychological meaningfulness. By examining three different psychological mechanisms within the same frame, we provide a test that compares and contrasts the uniqueness of the three pathways. Our findings suggest practical ways for managers to build trust with subordinates and guidance for the design of productive work conditions. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
8.
    
This study explored the unit‐level antecedents and outcomes of contingent workers' attitudes toward their temporary help services (THS) firm. It was proposed that (a) client‐orientation levels of the THS firm's full‐time staff would influence the level of support received by contingent workers, (b) staff supportiveness would be reciprocated by these workers in the form of favorable firm‐directed attitudes, and (c) contingent workers' attitudes toward the THS firm would influence two unit‐level outcomes—client reported service failure, and voluntary turnover rates of THS staff. Support was found for all the hypothesized relationships in a longitudinal study utilizing survey data gathered from 1324 full‐time employees, 570 contingent workers, and 1951 clients; and archival data on staff turnover from 46 strategic business units (SBUs) of a THS firm. These results are discussed within the context of employee–organization relationship (EOR), contingent workforce, and service management literatures. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
9.
根据定量构效关系( QSPR)原理,研究自燃点(AIT)与其分子结构间的内在定量关系.以265种有机化合物作为样本集,随机选择238种作为训练集,27种作为测试集,用遗传算法(GA)进行变量选择,分别建立多元线性回归( MLR)模型和支持向量机(SVM)模型研究有机物的自燃点与其分子结构间的关系.通过分析,发现造成模型预测效果不佳的原因是试验数据本身存在问题.通过对2个模型的比较,结果为GA-SVM模型明显优于GA-MLR模型,说明自燃点与其分子结构间具有很强的非线性关系.  相似文献   
10.
采用相对资源承载力的研究思路和计算方法,计算分析了1978—2004年成都市相对自然资源承载力、相对经济资源承载力和综合承载力及其动态变化过程。研究表明:①成都市的经济资源对综合承载力的贡献大于土地资源,为成都市人口的主要承载资源;②相对经济承载力富余,但相对自然资源承载力超载;③协调经济与资源的关系、控制人口增长、保持经济适度增长是实行成都市可持续发展的关键。  相似文献   
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