液化天然气储罐火灾爆炸事故的定量分析

介绍了某天然气站的基本情况,利用道化学指数评价法,对该站储罐区的1个3000m3球罐进行风险评价,评价结果表明：该罐火灾爆炸指数为149.1,危险等级是较大。一旦罐内天然气在储存过程中发生火灾、爆炸,将使半径38.17m内,面积4574.82m2内的设备、设施受到损害,最大可能财产损失为0.66A万元。由于罐区采取了一些安全措施对储罐安全进行补偿,有效地降低了事故损失。为操作管理者更加全面地了解整个罐区的风险状况提供参考,有利于天然气储罐区的规划、管理及事故预防等。     

生境异质性对金沙江干热河谷锥连栎天然更新幼苗早期生长的影响

锥连栎林是金沙江干热河谷仅有的几种重要天然植被之一,由于恶劣的气候环境以及长期严重的人为干扰作用,林地生境破碎化程度较高,幼苗天然更新极为困难.分析了锥连栎林更新幼苗主要生长的落叶堆积洼地、落叶堆积平地、菁沟冲积台地和缓坡草丛等4种微生境特点,并比较研究了不同微生境下天然更新幼苗生长的形态特征、生物量分配以及幼苗生存状...     

近30年我国自然灾害灾情时间分布特征分析

利用民政部统计核定的1978-2009年全国年度灾情数据,以及国家统计局发布的社会经济统计数据,从灾情指标的绝对量、相对量及其变异系数入手,分析了我国自然灾害的年际、年代际趋势变化和波动变化特征。结果表明:近30年来,我国自然灾害灾情年际和年代际变化趋势明显。总体上,死亡人口下降趋势明显,人口受灾情况、农作物受灾情况和直接经济损失上升趋势明显,但相对直接经济损失下降趋势明显,房屋倒塌比例也有所下降;1990年代,灾害造成的各项损失较之1980年代增大趋势明显。我国自然灾害的影响范围趋于相对稳定,而灾害强度波动性较大,且有增大趋势。灾情的趋势和波动变化特征,反映了全球气候变化下极端事件更加频发,强度有所增加的趋势。灾情指标的大小与年度主要灾害类型以及重灾年份有关。     

三峡库区巫山建坪地区土壤镉等重金属分布特征及来源研究

位于三峡库区的巫山建坪地区存在明显土壤高镉(Cd)异常,但对其土壤镉分布特征及来源缺乏深入认识.通过对岩石及土壤样品中镉等重金属元素的总量、土壤理化性质、典型土壤剖面Cd含量、Cd赋存形态进行分析测试,并结合相关性分析和主成分分析等统计方法,以及不同类型土壤间的对比分析,研究了巫山县建坪地区土壤中镉等重金属的含量分布特征及其来源.结果表明,岩石(包括煤及煤矸石等)中Cd含量范围为0.22～101 mg·kg-1,表层耕作土壤中Cd含量范围为0.42～42 mg·kg-1,自然土壤中Cd含量范围为0.12～8.5 mg·kg-1;除Cd外,V、Cr、Ni、Zn同样存在富集现象.土壤中弱酸提取态镉占其总量的17%～35%.研究表明,巫山建坪研究区土壤存在严重镉污染问题,土壤中高镉与研究区岩石中镉含量具有很好的地球化学继承性,且表现出表层富集的特征.研究区土壤中镉等重金属主要为自然地质源,其历史上的煤矿开采加剧了土壤镉的富集过程.土壤中镉的生物有效态高,通过食物链富集而影响人群健康的环境危害大.     

Effect of humic acids and sunlight on the cytotoxicity of engineered zinc oxide and titanium dioxide nanoparticles to a river bacterial assemblage

The effect of a terrestrial humic acid (HA) and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles (ZnONPs) and titanium dioxide nanoparticles (TiO2NPs) to natural aquatic bacterial assemblages was measured with spread plate counting. The effect of HA (10 and 40 ppm) on the cytotoxicity of ZnONPs and TiO2NPs was tested factorially in the presence and absence of natural sunlight (light irradiation (LI)). The experiment was of full factorial, completely randomized design and the results were analyzed using the General Linear Model in SAS analytical software. The method of least squares means was used to separate the means or combinations of means. We determined the mechanism of toxicity via measurements of oxidative stress and metal ions. The toxicity of ZnONPs and TiO2NPs to natural aquatic bacterial assemblages appears to be concentration dependent. Moreover, the cytotoxicity of ZnONPs and TiO2NPs appeared to be affected by HA concentration, the presence of sunlight irradiation, and the dynamic multiple interactions among these factors. With respect to light versus darkness in the control group, the data indicate that bacterial viability was inhibited more in the light exposure than in the darkness exposure. The same was true in the HA treatment groups. With respect to terrestrial versus Suwanee River HA for a given nanoparticle, in light versus darkness, bacterial viability was more inhibited in the light treatment groups containing the terrestrial HA than in those containing Suwanee River HA. Differences in the extent of reactive oxygen species formation, adsorption/binding of ZnONPs/TiO2NPs by HA, and the levels of free metal ions were speculated to account for the observed cytotoxicity. TEM images indicate the attachment and binding of the tested nanoparticles to natural bacterial assemblages. Besides the individual parameter, significant effects on bacterial viability count were also observed in the following combined treatments: HA-ZnONPs, HA-LI, ZnONPs-LI, and HA-ZnONPs-LI. The main effects of all independent variables, plus interaction effects in all cases were significant with TiO2NPs.     

祁彪佳荒政思想探析

祁彪佳的《救荒全书》是一部重要的通论式的荒政著作,这部论著包含了作者大量的荒政思想和主张,体现出了他对灾害救济的态度。他提出了荒政中用人的重要性,认为救灾＂首要得人＂;同时认为＂屯田垦荒、发展农业乃是千古救荒之祖＂;形成了＂仓储备荒＂、＂兴修水利＂、＂御灾召祥＂、＂崇尚节俭＂、＂赈灾勿缓＂等主要的荒政思想。这些思想是祁彪佳实践经验的总结,也是传统荒政思想的升华。     

Housing anxiety and multiple geographies in post-tsunami Sri Lanka

Tsunami intervention has been an extraordinary and unprecedented relief and recovery operation. This article underlines the complexities posed by shelter and housing intervention in post-tsunami Sri Lanka, revealing a pragmatic, reductionist approach to shelter and housing reconstruction in a contested and fragmented environment. Competition, housing anxiety and buffer zone implementation have resulted in compulsory villagisation inland, stirring feelings of discrimination and tension, and becoming major obstacles to equitable rebuilding of houses and livelihoods. A new tsunami geography has been imposed on an already vulnerable conflict-based geography, in which shelter has been conceived as a mono-dimensional artefact. An analysis of the process and outcomes of temporary and permanent post-tsunami housing programmes yields information about the extent to which shelter policies and programmes serve not only physical needs but 'higher order' objectives for a comprehensive and sustainable recovery plan.     

农业自然灾害与农村贫困之间的关系——基于安徽省面板数据的实证分析

自然灾害的发生对农业生产会造成巨大的负面影响。特别是经济落后的不发达地区由于本身的抗灾救灾能力弱．受到的自然灾害影响也更加严重。甚至会导致贫困的发生。目前虽然已经有学者定性地研究过农业自然灾害对农村贫困的影响．但是缺乏定量的分析。本文旨在弥补以前定量研究的空白，选择安徽省的59个县（市）面板数据为研究样本，建立模型实证分析。发现农业自然灾害受灾面积占总播种面积的比重与农村贫困发生率量负相关关系．这与已有的研究结果不同。文章的最后．依据实证结果对正确认识农业自然灾害与农村贫困之间的关系．构建农村自然灾害舫御体系．增强贫困地区农民的抗灾能力提出了政策建议。     

草原自然灾害对我国奶牛业影响分析

通过对草原自然灾害的种类和损害程度的分析，阐述了自然灾害对奶牛业影响的全过程。定量分析说明，自然灾害通过破坏草原，从而制约了奶牛业的发展。最后，针对我国奶牛业的发展现状，提出了具体的防灾措施，以减小自然灾害对奶牛业发展的影响。     

充分利用资源优势,推进涪陵开发开放

阐述了涪陵市的资源优势和开发开放的经济社会环境，提出了进一步推进开发开放的主要对策措施。