包裹碎石群桩动应力响应振动台模型试验研究∗

开展了包裹碎石群桩复合地基振动台模型试验,分析了包裹碎石桩轴向动应力及桩土之间水平剪切应力的响应特性。结果表明：地震波作用下,包裹碎石桩轴向动应力沿桩身向下迅速衰减。在地震作用过程中,包裹碎石桩上部承受的水平应力较大。某一地震作用下,取包裹碎石桩桩顶水平应力时程曲线的最大值,发现该值随输入地震加速度波峰值(0.1g~0.4g)的增大先增大,之后随输入加速度波峰值(0.6g、0.9g)的增大而减小,这表明桩顶的剪切强度降低了。     

Scenario simulation of water security in China

Umited water resources, increasing demand, low use efficiency, and serious pollution result in severe water resource difficult in China. The evaluation of addressing water problems and the search for effective countermeasures that ensure sustainable water use are key to China‘ s sustainable development. The “compound water security“ consists of food security, life security, environmental security, and economic security. By establishing a conceptual model, the water security of China has been simulated in terms of four scenarios called BAU(the business-as-usual scenario), TEC(the technology and economics scenario), IVL(the institution, values, and lifestyles scenario) and TSD(toward sustainable development) in this paper. The results indicated that water crises, especially water shortages, are being experienced now and will continue to do so for a relatively long time in China and that it is possible to reach a basic balance between supply and demand of water and grain under the TSD developing pattern by a series of approaches including technological innovation, policy adjustments, and behaviour inducement.     

重钢LF炉除尘系统工艺分析与改建

论述了关于重庆钢铁股份有限公司炼钢厂LF炉除尘工艺的现状和系统的不足,并且就相关技术问题进行了分析与研讨,提出了相应的处理方案。     

沈阳市环境铅污染对儿童健康的影响

实地调查采样、结合GIS技术进行室内综合分析,系统研究了沈阳市大气、土壤、灰尘中铅污染对儿童健康的影响.结果表明,沈阳市环境中铅暴露普遍,铅污染较严重,铅浓度空间分异大,已形成4个高浓度中心.并且大气铅浓度有明显的日、季和年变化规律沈阳市环境铅污染已经影响了儿童健康,0～10岁儿童(ZPP＞2.3μmol/L)血铅范围是10.98～511.2μg/L,平均值是135.59μg/L,40%的儿童血铅水平超标.儿童血铅与大气铅相关性最大,其次是土壤和灰尘.实行无铅汽油之后,大气铅污染有了很大改善,但是土壤和灰尘中的铅容易以扬尘的方式再次进入大气,存在潜在风险,应引起有关部门足够的重视.     

Ecological issues and risk assessment in China

As a result of economic development and population explosion, global ecological environments have been severely disturbed and markedly changed. An ecological crisis involving desertification, soil erosion, degradation of land quality, loss of biodiversity and global climate change has been brought about all over the world. In order to manage ecosystems efficiently, it is necessary to assess ecological risk at multiple scales. Ecological risk is the probability that a region and/or site will experience defined ecological or environmental problems. In this paper, the ecological risks of soil erosion, desertification, and acid deposition have been assessed on a national scale according to natural and human factors, such as topography, soil, vegetation and climate. This assessment has provided very useful information for ecological environmental management in China.     

地震应急期关键时间阶段划分研究

在研究我国地震应急救援相关法律法规、预案,以及汶川、玉树、盈江、彝良和海地、东日本等国内外地震应急救援案例的基础上,将地震应急期划分成应急启动、紧急救援、过渡性安置等3个阶段,并对各阶段的持续时间、主要工作及其先后次序进行了梳理.在实际抗震救灾工作中,这3个阶段不是互不相干、相互独立的,而是存在一定的时间相关性.这就需要指挥者对不同阶段的重点工作优先考虑,同时兼顾各项相关工作,保证抗震救灾工作的顺利进行.     

冰雪灾害中交通工程的损害类型及原因分析

通过对已建及在建的高速公路在冰灾中的损害调查,详细列出了损害的类型并进行了原因分析。并将此次灾难中暴露出的设计、施工和管理方面的问题进行了分解。     

近40年湖南冰雹时空分布和变化特征及机理分析

利用湖南省1967～2006年近四十年冰雹日数资料,分析了湖南冰雹时空分布特征,着重讨论了湖南冰雹日数年代、年、季、月、旬、日际变化、地域分布特征及湖南前后二十年冰雹的变化趋势。研究表明：湖南冰雹是典型的春雹区,春季冰雹日数占全年冰雹日数的74．9％;存在2年和4．8年的周期;日变化十分明显,多出现在午后到傍晚;地理分布呈西多东少,高山多于平原,洞庭湖北侧多于南侧的特点;近二十年冰雹呈减少趋势,多雹区更集中,主要出现在湘西北和湘东南。     

Diethylenetriaminepentaacetic Acid (DPTA)-modified Magnetic Cellulose Nanocrystals can Efficiently Remove Pb(II) from Aqueous Solution

Journal of Polymers and the Environment - Surface modification of cellulose nanocrystals (CNC) is essential for improving their reactivity and adsorption capacity. Oxidation, as a conventional...     

Water-dispersible nano-pollutions reshape microbial metabolism in type-specific manners: A metabolic and bacteriological investigation in Escherichia coli

• Water-dispersible nano-pollutions exhibit type-specific toxic effects on E. coli. • Global metabolite profiling was used to characterize metabolic disruption patterns. • Key dysregulated metabolites responsive to nano-pollution exposures were found. • Amino acid metabolism and purine metabolism are perturbed at nano-pollutions. Incomplete separation and recycling of nanoparticles are causing undesirable nanopollution and thus raising great concerns with regard to nanosafety. Since microorganisms are important regulator of physiological processes in many organisms, the interaction between nanopollution and microbial metabolomics and the resultant impact on the host’s health are important but unclear. To investigate how typical nanopollution perturbs microbial growth and metabolism, Escherichia coli (E. coli) in vitro was treated with six water-dispersible nanomaterials (nanoplastic, nanosilver, nano-TiO₂, nano-ZnO, semiconductor quantum dots (QDs), carbon dots (CDs)) at human-/environment-relevant concentration levels. The nanomaterials exhibited type-specific toxic effects on E. coli growth. Global metabolite profiling was used to characterize metabolic disruption patterns in the model microorganism exposed to different nanopollutants. The percentage of significant metabolites (p<0.05, VIP>1) accounted for 6%–38% of the total 293 identified metabolites in each of the nanomaterial-contaminated bacterial groups. Metabolic results also exhibited significant differences between different nanopollutants and dose levels, revealing type-specific and untypical concentration-dependent metabolic responses. Key metabolites responsive to nanopollution exposures were mainly involved in amino acid and purine metabolisms, where 5, 4, and 7 significant metabolic features were included in arginine and proline metabolism, phenylalanine metabolism, and purine metabolism, respectively. In conclusion, this study horizontally compared and demonstrated how typical nanopollution perturbs microbial growth and metabolomics in a type-specific manner, which broadens our understanding of the ecotoxicity of nanopollutants on microorganisms.