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891.
蒙德安全评价法的改进及其计算机实现 总被引:5,自引:5,他引:0
蒙德安全评价法是一种广泛应用于石化领域的安全评价方法,相对于其它指数型安全评价方法具有评价全面、实施便捷的特点,在工程中被大量应用。但是蒙德法有它难以克服的缺点:定量参数查找困难、定性参数估计困难、手动计算繁琐、分析流程不确定。本文针对这些问题提出了一种自动化的蒙德评价方法,克服了上述缺点,具有分析简便、快速、准确的特点。并开发完成了基于此方法的软件,经过案例测试表明此方法具有实用性,在工程应用中具有实际价值。 相似文献
892.
Enforced institutional settings such as penitentiaries provide environments to raise awareness, carry out research, and implement
and assess practices for sustainable living. Institutions where residence is enforced due to health, recreational, military,
or legal reasons (e.g., assisted living centers, summer camps, army bases, prisons) house people who may lack scientific training
but have time and need for intellectual stimulation that can be filled by supervised research. These institutions have stable
populations, structured social organization, and measurable inputs and outputs of materials and energy to carry out sustainable
practices in tasks that affect regional resources such as groundwater quality and landfill use. We report on three examples
at a corrections center resulting from partnerships among visiting academic ecology researchers, sustainability practitioners,
corrections administrators, and prisoners: (1) research on how to sustainably “farm” moss for the horticulture trade to reduce
harvesting pressure on wild moss populations; (2) a vermiculture and thermophilic composting system to reduce the kitchen
waste; and (3) a monthly seminar series at the prison. Over 26 months: (1) participants developed methods to optimize moss
growth; (2) landfill-bound waste and particulate flow rate destined for wastewater treatment decreased by 50%, to less than
50% of permit limits; (3) resulting compost (ca. 5000 kg) fertilized institutional vegetable gardens; (4) water quality improved
so that the prison could return funds allocated to upgrade the prison’s water quality. The lectures encouraged intellectual
exchange among researchers, convicts, and guards. Researchers derived new perspectives and broader impacts for their work.
This can be a model for other correctional facilities and other enforced residential institutions (ERIs).
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
893.
The University of Tokyo started its Graduate Program in Sustainability Science (GPSS), offering a master of sustainability
science degree, in 2007. The GPSS curriculum consists of: (1) knowledge and concept oriented courses, which cover sustainability-related
subjects from a holistic viewpoint; (2) experiential learning and skills oriented practical courses, which offer practical
exercises to acquire the skills and sensibility required of future leaders; and (3) the Master’s thesis, for which students
are encouraged to address complex sustainability problems through a transdisciplinary approach. Sustainability science is
not a discipline that can be defined simply by the subjects it deals with, but is an academic field characterized by core
principles that include holistic thinking, transdisciplinarity, and respect for diversity. The GPSS has been designed so that
students may gain the capacity to understand and practice these principles. The present paper describes how the GPSS has defined
sustainability education and designed its curriculum accordingly. 相似文献
894.
Catherine Allan Allan Curtis George Stankey Bruce Shindler 《Journal of the American Water Resources Association》2008,44(1):166-174
Abstract: Adaptive management is often proposed as the most effective way to manage complex watersheds. However, our experience suggests that social and institutional factors constrain the search for, and integration of, the genuine learning that defines adaptive management. Drawing on our work as social scientists, and on a guided panel discussion at a recent AWRA conference, we suggest that watershed‐scale adaptive management must be recognized as a radical departure from established ways of managing natural resources if it is to achieve its promise. Successful implementation will require new ways of thinking about management, new organizational structures and new implementation processes and tools. Adaptive management encourages scrutiny of prevailing social and organizational norms and this is unlikely to occur without a change in the culture of natural resource management and research. Planners and managers require educational, administrative, and political support as they seek to understand and implement adaptive management. Learning and reflection must be valued and rewarded, and fora established where learning through adaptive management can be shared and explored. The creation of new institutions, including educational curricula, organizational policies and practices, and professional norms and beliefs, will require support from within bureaucracies and from politicians. For adaptive management to be effective researchers and managers alike must work together at the watershed‐scale to bridge the gaps between theory and practice, and between social and technical understandings of watersheds and the people who occupy and use them. 相似文献
895.
896.
采用共沉淀法制备了钛/钙氢氧化物新型吸附剂,并对其吸附除As的性能进行了初步研究.考察了不同制备方法、Ti/Ca比例、pH值、Ca2+、磷酸根离子对As(Ⅲ)和As(Ⅴ)去除率的影响,研究了所制备吸附剂对As(Ⅲ)和As(Ⅴ)的吸附热力学特性,并对其吸附机理进行了探讨.结果表明:所制备吸附剂对As(Ⅲ)具有优异的选择性;吸附去除率试验中,吸附剂投加量0.2 g/L、As质量浓度1 mg/L、20℃、吸附3h条件下,TC-45/5吸附剂对As(Ⅲ)的去除率达到97.3%,对As(Ⅴ)的去除率为78.2%;酸性条件和Ca2+可显著提高As(Ⅴ)去除率,但对As(Ⅲ)吸附去除的影响不大;磷酸根离子由于竞争吸附而导致As去除率下降,且对去除As(Ⅴ)的抑制作用更强烈;30℃时,As(Ⅲ)与As(Ⅴ)的Langmuir饱和吸附量分别为30.21 mg/g和16.61mg/g.研究表明,钛/钙氢氧化物对As(Ⅲ)去除效果良好. 相似文献
897.
淡水环境磷的生物有效性评估方法的发展动态 总被引:5,自引:0,他引:5
磷在水体中含量较低,但在淡水生态系统中却是十分活跃的生源要素之一,其生物有效性往往是藻类水华的驱动力.本文对水环境中磷的生物有效性评估方法的发展现状进行了综述.目前发展了很多生物有效磷估算方法,但是没有完全认同的标准方法.从实验操作角度来看,藻类培养分析法最适于水样;化学提取法适于沉积物;而氧化铁材料等磷汇方法在水样及沉积物上均比较方便.事实上,生物有效磷概念含糊,是不可准确定量的.然而,为了更有效地评估磷的生物有效性,估算生物有效磷含量又是很有必要的. 相似文献
898.
石墨粉末润湿特性及其表面自由能的研究 总被引:1,自引:0,他引:1
利用毛细上升法测定了去离子水对石墨粉末的接触角,分析温度对石墨粉末润湿性的影响,并测算了石墨粉末的表面自由能,对将石墨用作净水滤料有指导作用.在20~40℃温度范围内接触角变化不大,平均为84.11°.其主要原因是表面张力σ和黏度η随温度变化对接触角的影响相反,综合作用结果导致接触角随温度变化不大.石墨粉末表面色散自由能为21.8 mJ·m-2,极性自由能为1.8 mJ·m-2,总的表面自由能约为23.6 mJ·m-2,以色散自由能为主.这是去离子水能够湿润石墨粉末,但湿润性相对较差的一个原因.可知极性流体对石墨粉末的润湿性比较差. 相似文献
899.
为提高腐蚀管道剩余强度的预测精度,提出引入弹性梯度下降法改进BP神经网络,并融合改进海鸥优化算法(ISOA),构建腐蚀管道剩余强度预测模型。关于改进BP神经网络模型的参数寻优,首先采用Cat混沌映射初始化改进海鸥优化算法(SOA)初始种群的分布,提升寻优能力,优化SOA的搜索方向和攻击形式,增强其全局搜索能力并提高收敛速度,然后用ISOA对弹性BP神经网络(RBPNN)模型中的权值和阈值进行寻优,最后构建ISOA-RBPNN预测模型。以管道爆破数据为例,利用MATLAB进行仿真模拟,并与PSO-BPNN模型和IFA-BPNN模型预测结果进行对比分析。研究结果表明:ISOA-RBPNN模型的各项评价指标均优于其他2个模型,预测结果较实际值误差更小,在预测腐蚀管道剩余强度领域具有更好的性能,可为后续研究腐蚀管道剩余寿命和制定维修策略提供参考依据。 相似文献
900.
二元含汞重金属混合物对费氏弧菌的联合毒性研究 总被引:3,自引:0,他引:3
以费氏弧菌(Vibrio fucheri)作为毒性测试物种,测定了Hg2+、pb2+、Cu2+、Cd2+、Zn2、Cr6+对费氏弧菌的单一毒性;采用等毒性配比法研究了Hg2+/pb2+、Hg2+/Cr6+、Hg2+/Cu2+、Hg2+/Zn2+、Hs+/Cd2+5种二元混合体系的联合毒性作用.结果表明,重金属离子单独存在时均会对费氏弧菌产生毒性作用,发光菌的相对发光强度均与重金属离子质量浓度呈负相关关系,线性相关系数为0.876 4~0.973 0.Hg2+、Pb2+、Cu2+、Cd2+、Zn2+、Cr6+单独存在时对费氏弧菌的EC50分别为0.045 mg/L、0.181 mg/L、0.300mg/L、0.117 mg/L、0.614 mg/L、23.000mg/L,重金属离子毒性从大到小为Hg2+、Cd2+、pb2+、Cu2+、Zn2+、Cr6+.而与单一重金属相比,其二元混合物对费氏弧菌的生物毒性效应和强度完全不同.Hg2+/pb2+、Hg2+/Cr6+二元混合体系表现为拮抗作用,Hg2+/Cu2+、Hg2+/Zn2+均表现为协同作用,Hg2+/Cd2+表现为加和作用. 相似文献