丙烯醛与DNA碱基反应机理的AM1研究

 采用AM1方法计算了在水合质子的参与下，丙烯酸与DNA鸟嘌呤碱基发生烷化加成的可能的反应过程，从得到的能量关联图可以看出，除了其中的一个分子内质子迁移过程外，其余的每一反应过程体系的能量均是降低的,计算得到的各关键步骤的反应活化能均不大，反应易于进行,根据计算的自由能可以看出，整个反应能够自发进行，说明丙烯酸可经过2次烷化加成反应与DNA碱基发生交联作用.     

破壁化学注浆防渗理论与工程实践

破壁化学注浆防渗技术的关键是选择化学材料,确定注浆压力,估算浆液扩散半径,布置注浆孔,计算注浆量。本文结合工程实践,得出了注浆参数选择的理论计算公式和工程经验数值;为今后煤矿井壁防渗注浆提供了参考。     

Restoring habitat corridors in fragmented landscapes using optimization and percolation models

Landscape fragmentation and habitat loss are significant threats to the conservation of biological diversity. Creating and restoring corridors between isolated habitat patches can help mitigate or reverse the impacts of fragmentation. It is important that restoration and protection efforts be undertaken in the most efficient and effective way possible because conservation budgets are often severely limited. We address the question of where restoration should take place to efficiently reconnect habitat with a landscape-spanning corridor. Building upon findings in percolation theory, we develop a shortest-path optimization methodology for assessing the minimum amount of restoration needed to establish such corridors. This methodology is applied to large numbers of simulated fragmented landscapes to generate mean and variance statistics for the amount of restoration needed. The results provide new information about the expected level of resources needed to realize different corridor configurations under different degrees of fragmentation and different characterizations of habitat connectivity (“neighbor rules”). These results are expected to be of interest to conservation planners and managers in the allocation of conservation resources to restoration projects.     

On the optimal control of carbon dioxide emissions: an application of FUND

This paper presents the Climate Framework for Uncertainty, Negotiation and Distribution (FUND), an integrated assessment model of climate change, and discusses selected results. FUND is a nine‐region model of the world economy and its interactions with climate, running in time steps of one year from 1990 to 2200. The model consists of scenarios for economy and population, which are perturbed by climate change and greenhouse gas emission reduction policy. Each region optimizes its net present welfare. Policy variables are energy and carbon efficiency improvement, and sequestering carbon dioxide in forests. It is found that reducing conventional air pollution is a major reason to abate carbon dioxide emissions. Climate change is an additional reason to abate emissions. Reducing and changing energy use is preferred as an option over sequestering carbon. Under non‐cooperation, free riding as well as assurance behaviour is observed in the model. The scope for joint implementation is limited. Under cooperation, optimal emission abatement is (slightly) higher than under non‐cooperation, but the global coalition is not self‐enforcing while side payments are insufficient. Optimal emission control under non‐cooperation is less than currently discussed under the Framework Convention on Climate Change, but higher than observed in practice. This revised version was published online in July 2006 with corrections to the Cover Date.     

城市区域环境噪声监测优化布点探讨

应用数理统计中抽样理论，对瑞安市环境噪声监测点进行了优化组合，方法简单易行，兼顾了功能区特征，减少了测点数，并能达到要求的准确性。     

Efficiency,costs and trade-offs in marine reserve system design

With marine biodiversity conservation the primary goal for reserve planning initiatives, a site's conservation potential is typically evaluated on the basis of the biological and physical features it contains. By comparison, socio-economic information is seldom a formal consideration of the reserve system design problem and generally limited to an assessment of threats, vulnerability or compatibility with surrounding uses. This is perhaps surprising given broad recognition that the success of reserve establishment is highly dependent on widespread stakeholder and community support. Using information on the spatial distribution and intensity of commercial rock lobster catch in South Australia, we demonstrate the capacity of mathematical reserve selection procedures to integrate socio-economic and biophysical information for marine reserve system design. Analyses of trade-offs highlight the opportunities to design representative, efficient and practical marine reserve systems that minimise potential loss to commercial users. We found that the objective of minimising the areal extent of the reserve system was barely compromised by incorporating economic design constraints. With a small increase in area (<3%) and boundary length (<10%), the economic impact of marine reserves on the commercial rock lobster fishery was reduced by more than a third. We considered also how a reserve planner might prioritise conservation areas using information on a planning units selection frequency. We found that selection frequencies alone were not a reliable guide for the selection of marine reserve systems, but could be used with approaches such as summed irreplaceability to direct conservation effort for efficient marine reserve design.     

H2S脱除效率主控因素的广义灰色关联分析

为更好保护井下人员、设备安全,为井下H2S治理提供基础实验依据,通过脱除H2S气体实验装置,改变装置内的风速、NaHCO3溶液质量分数、H₂S气体浓度来探究影响脱除H2S效率的主控因素。选取部分数据并基于灰色关联度分析,对变量的重要度进行排序。计算结果表明:风速、NaHCO3溶液质量分数、H2S气体浓度的综合关联度分别为0.568,0.543,0.541 5,并通过这3种因素的综合分析,得出影响H2S脱除效率因素大小顺序为:风速＞溶液质量分数＞H2S气体浓度;表明一定条件下,H2S脱除效率随风速及H2S气体浓度的增大而降低、随溶液质量分数增大而增大的规律。     

公路工程施工安全事故致因模型构建

为了探究公路施工安全事故诱因及其影响关系,基于"4M"理论和事故致因"2-4"模型,识别公路工程施工安全事故致因因素并确定模型框架,运用SPSS Modeler软件对2007~2017年426起事故进行关联规则挖掘,采取路径分析与重要度分析,构建出公路工程施工安全事故致因模型。结果表明:施工单位内外部原因共同引发公路工程施工安全事故,外部原因来源于建设单位、监理单位和勘察设计单位的安全管理缺失,而施工单位内部影响因素中,人的不安全动作、物的不安全因素、不良的生产环境和自然环境是事故发生的直接原因,无效的安全监管和作业层安全素质及能力不强是间接原因,根本原因是施工程序和技术方案存在缺陷,根源原因是决策层和管理层的安全素质及能力有待提高。该模型系统展现了工程施工项目安全事故致因因素的影响关系和重要程度,为公路工程施工安全事故预防提供指导。     

基于屏障理论的安全事故原因分析方法研究

本文系统介绍了基于屏障理论的事故原因分析方法,编制事件时间链图,完整还原事故发生经过,并通过屏障辨识及分析,确定事故的直接原因、间接原因和根本原因,为事故原因分析提供参考方法和工具。最后通过实际案例进行了应用和验证。     

基于熵权物元可拓模型的地下空间火灾安全评价

为了准确评价地下空间的安全性,降低地下空间火灾事故的风险,从地下空间主动防火能力、地下空间被动防火能力、安全疏散能力以及安全管理能力4个层次构建地下空间火灾安全评价指标体系。采用熵权法和物元可拓理论建立了地下空间火灾风险的熵权可拓评价模型,并在某地下商城的火灾安全评价中进行了实际应用。结果表明,该地下商场空间的火灾安全评价等级为二级,与实际地下商场火灾安全状态相符。本文研究表明基于熵权的可拓理论可以适用于地下空间火灾的安全评价,有利于提升地下空间的火灾风险应对。