成都平原蔬菜生产中灌溉水对农药渗漏的影响研究

针对成都平原蔬菜生产中大量施用农药、大量灌水的特点,首次在国内应用欧洲官方成熟的农药评估模型——PEARL模型,研究评估了成都平原当前蔬菜生产中的灌溉方式对两种不同特性农药的渗漏的影响。杀毒矾(土壤吸附力(KOM)为0 L/kg,半衰期(DT50)为80 d)在没有灌溉条件下,其渗出土体时的最大质量浓度是190μg.L-1,而有灌溉条件下其渗出质量浓度则可达523μg.L-1,是没有灌溉条件下的2.75倍。三唑磷(KOM为200 L.kg-1,DT50为60 d)在没有灌溉条件下,其渗出土体时的最大质量浓度是0.025μg.L-1,而有灌溉条件下其渗出质量浓度为0.13μg.L-1,比没有灌溉时提高了4.2倍。不管有没有灌溉三唑磷在该地区对地下水的污染风险都很小,而杀毒矾的风险则很高。因此,农药的化学特性是影响农药渗漏的最重要的因子。在蔬菜生产中应尽量选用被土壤吸附力强、半衰期短的农药,例如:三唑磷;农药在土壤中的移动载体是土壤水,不合理的灌溉会大大地加大农药淋溶,应当多使用微喷、滴灌等节水灌溉措施,减少使用漫灌等耗水多的原始灌溉方式。     

谷氨酰胺转胺酶(MTG)分批发酵中温度对S.mobaraense生长及产酶影响的模型化

研究了2.5L小罐培养过程中控制温度为25℃～35℃时对细胞生长和MTG合成的影响.结果表明当控制相对较低的温度时,细胞生长的延滞期较长,当控制温度较高时,细胞生长的延滞期较短,达到最大DCW和最高MTG酶活的时间均较短;通过研究各种不同模型对细胞生长的影响得到最适合描述S.mobaraense生长与温度之间的关系方程为Schoolfield方程;通过对最大DCW和最大MTG酶活进行数学模拟,发现方程X(U)=-a     

锂离子电池安全性特点及热模型研究

锂离子电池的安全问题越来越受到重视.本文从锂离子电池热安全性特点着手,分析了锂离子电池的着火、爆炸和电解液泄漏等安全事故特点.简单介绍了锂离子电池主要材料的产热特性、相互反应产热特性.讨论了锂离子电池热模型建立的两种途径,即量热仪途径和化学反应途径,通过这些热模型的建立,来指导锂离子电池的安全设计和管理.     

The prediction of safe lifting behavior: an application of the theory of planned behavior

PROBLEM: Injuries resulting from lifting are costly, and create significant pain and discomfort. While engineering controls are the most effective means of reducing risks, most organizations continue to rely on manual lifting techniques. The problem, however, is that the use of safe-lifting techniques is inconsistent and managers have a difficult time motivating use of these techniques. Consequently, it is important to understand the factors driving safe-lifting behaviors. METHODS: This study used a survey to apply the theory of planned behavior (Ajzen., I., 1991. The theory of planned behavior. Organization Behavior and Human Processes, 50, 179-211) to safe-lifting among 136 materials management employees at a heavy manufacturing organization. Structural equation modeling and factor analysis were employed to analyze relationships among constructs. RESULTS: Results revealed that perceived behavioral control and intention were the strongest predictors of safe-lifting behavior. Subjective norms, to a lesser degree, were also important influences on intention. Attitudes did not surface as effective direct predictors of safe-lifting behavior, but did affect behavior and intent via mediating factors (subjective norms and perceived behavioral control). Finally, the theory of planned behavior was supported as an effective model explaining safe-lifting behavior, and had potential application for many other safety-related behaviors. IMPACT ON INDUSTRY: Results from this study emphasize the importance of perceived behavioral control as a factor associated with safety-related behavior.     

煤矸石山自然发火数学模型在红阳三矿新矸石山自燃防治中的应用

煤矿矸石山自燃现象普遍存在,对环境污染及危害极大,防治矸石山自燃是矿区环境修复的重点研究内容.笔者利用宏观的连续介质研究方法,以多孔介质流体动力学理论为指导,建立了煤矿矸石山自然发火数学模型,从数学上揭示了矸石山自燃的动态演变过程.通过分析矸石山内的渗流场明确了自然发火的影响因素及内在联系,针对红阳三矿新矸石山的自燃预防问题,提出了碾压、覆盖和边界注浆相结合的综合防治施工方案.该技术在红阳三矿新矸石山的现场应用表明,治理方案科学、经济、合理,实施效果良好.研究结果对预防矸石山自燃具有理论指导意义与实际应用价值.     

Oil spill cleanup cost estimation—Developing a mathematical model for marine environment

The field of oil spill cost modelling is not as well explored as desirable. Generally speaking, the existing models have either low accuracy, in that their predictions are far from the real cost, or low applicability, in that they are only valid under very specific conditions; such as in one particular country. This work strives to construct a model that is functional in a global scope and still possess a high level of accuracy. The resulting attempt is in many ways superior to the publicly available competitors, not only because of its predictive capacity but also because the model is quick to use, and its input variables should be readily available to any informed user. The model is more accurate comparing with similar available models. However, further study is needed to modify it to obtain more realistic results.     

国际比较视域下职业健康政策的量化分析及政策建议

为剖析国际职业健康政策的内容特征,推动我国职业健康事业高质量发展,以中国、美国、日本、澳大利亚、瑞典5国的职业健康政策文本为研究对象,依托政策工具理论及政策一致性(PMC)指数模型,在国际比较视域下开展5国职业健康政策的量化分析,继而提出我国职业健康政策优化建议。结果表明:5国倾向于通过环境型、供给型政策工具塑造职业健康治理的宏观发展环境与人力物力资源,较为忽视需求型政策工具的牵引作用;与其他国家相比,我国在政策性质、政策受体、政策重点与激励约束方面表现出色,在政策效力、政策视角与政策主体方面仍存在一定的发展空间;应当加强对职业健康政策工具配置不均衡问题的重视,对易遭受心理健康危害的人群给予更多的引导与帮扶,考虑劳动者在职业健康治理过程中的复杂性与动态性。     

基于无人机建模的尾矿库溃坝事故推演*

为诠释尾矿库溃坝后水砂演进过程,提升尾矿库事故灾害应急处置能力,采用无人机倾斜摄影技术获取尾矿库全息影像,建立尾矿库三维数字高程模型,导入三维流体计算软件对尾矿库进行溃坝事故推演。结果表明:尾矿库实景三维模型能高精度还原尾矿库实际情况,尾矿库溃坝将淹没库区临时厂房建筑及下游村落;其中,上游沟谷临时厂房建筑水位高程最大达8 m,尾砂淤积厚度最高达10.5 m,下游沟谷村落水位高程最大达10 m,尾砂淤积厚度最高达2.5 m;通过对库区下游布设监测点,得出各监测点处水位高程和尾砂淤积厚度变化规律,分析溃坝主要影响区域。研究结果可为尾矿库风险防控、应急响应工作提供借鉴。     

基于ISM和信息熵的铁路隧道塌方风险分析

为深入了解铁路隧道塌方风险,以铁路隧道塌方事故为研究对象,运用解释结构模型(ISM)化技术对从事故中总结的18个风险因素进行层次化分析,找出风险因素间的关系,建立铁路隧道塌方风险因素ISM;通过直接风险因素和中间风险因素求出底层风险因素的加权归一化信息熵。研究得出导致塌方事故的8个底层风险因素为安全管理不到位、地质勘测不力、选择的开挖方式不当、喷混凝土质量达不到要求、闭合成环周期过长、偏压严重、处于不良地质、地下水渗流;其中,地下水渗流、处于特殊不良地质、开挖方式的选择对隧道塌方影响较大。