Modelling global-scale potential grassland changes in spatio-temporal patterns to global climate change

Grassland is one of the most widespread vegetation types worldwide and plays a significant role in global carbon cycling. Understanding the sensitivity of grassland to climate change and the effect of climate changes on the grassland ecosystems is a key issue in global carbon cycling. One of the goals of this study was to evaluate the three net primary productivity (NPP)–climate models, i.e. the Miami model, the Schuur model and the classification indices-based model. Results indicated that the classification indices-based model was the most effective model at estimating large-scale grassland NPP. In this research, changes in the spatial pattern of global potential grassland from recent past (1950–2000) to future (2001–2050) A2a scenario were analysed with the integrated orderly classification system of grassland (IOCSG) approach in a Geographic Information System (GIS) environment. NPP was evaluated with the classification indices-based model. Results indicate that under recent past climatic conditions, the main parts of global grassland are the savanna and tundra and alpine grassland and will be converted into the savanna, steppe and semi-desert grassland in A2a scenario. As a whole, areas of grassland will increase by 31.76 million hectares. The classification indices-based model estimated a 12.40% increase of total NPP in grassland from recent past to A2a scenario. It will impose a new issue for future grassland researches to support sustainable development and to provide action relevant knowledge to meet the challenge of climate change.     

Biosorption and biotransformation of crystal violet by Aeromonas hydrophila DN322p

DN322p, an offspring of Aeromonas hydrophila DN322, has the capacity to adsorb and decolorize triphenylmethane dyes in wastewater simultaneously. As a common triphenylmethane dye, crystal violet (CV) was chosen to test the decolorization characteristics of DN322p. Within 0.5 h, the strain DN322p adsorbed a large amount of CV, producing a deep-colored cell pellet and colorless supernatant. The colors of the cell pellet and supernatant lightened over time. The supernatant and dichloromethane extract of the cell pellet both showed conspicuous CV and leuco CV (LCV) characteristic absorbance peaks at 590 nm and 260 nm, respectively, in the UV-vis spectral analysis. This finding indicated that the DN322p cells can adsorb the two dyes. A 99% (w/w) decolorization rate was achieved within 2.5 h with shaking at 30°C for 50 mg CV·L^?1. High Performance Liquid Chromatography (HPLC) analysis of the dichloromethane extract of the supernatant and cell pellet confirmed that CV was mainly converted into its leuco form. Dead cells had a similar adsorption capacity with living cells. About 90% of CV in the dye solution (50 mg·L^?1) was removed by autoclaved cells with an optical delnsity at 600 nm (OD₆₀₀) above 1.0.     

云南极端气候干旱的特征分析

应用云南124个站点1961-2011年的旬、日、月降水和气温资料,采用综合气象干旱指数和逐日降水分析云南1961年以来的干旱强度。以云南的干旱过程强度指数为-50、区域代表站的干旱过程用强度指数为-100以上选取极端干旱较为合适,选取干旱强度最大1962/1963、1968/1969、1978/1979和2009/2010年为极端干旱年进行分析表明,在4次极端干旱过程中,强度最强的是2009/2010年出现的秋冬春初夏连旱,是有气象记录以来最强的,其造成的危害及经济损失也最大,其次是1978/1979年、1968/1969年和1962/1963年出现的冬春初夏连旱。云南干旱灾害出现频繁、持续时间长,其分布具有一致性的特点,干旱出现的时段大致在冬、春及初夏季,而近年来秋季干旱呈频发之势。由于云南降水分布极不均,造成各地干旱强度指数存在差异。除滇西、滇西南局部边沿地区降水偏多,出现极端干旱相对较少外,云南大部,特别是云南中部及东部地区最容易发生极端干旱。从1970年代以来,云南出现严重干旱的强度及持续时间呈加重趋势。     

全氟烷基磺酸盐(PFOS)及其替代品对两栖类胚胎的发育毒性

用非洲爪蟾胚胎致畸实验和黑斑蛙胚胎发育毒性实验,比较研究了PFOS及其4种替代品对两栖动物胚胎的发育毒性。结果发现,用调聚法合成的织物三防整理剂和50%的全氟丁基有机铵盐阳离子表面活性剂同PFOS一样对非洲爪蟾胚胎有明显毒性,且织物三防整理剂和表面活性剂的毒性强于PFOS;电解氟化法合成的C4织物及C6织物三防整理剂(以下简称C4及C6织物三防整理剂)对非洲爪蟾胚胎没有明显毒性。与非洲爪蟾不同,PFOS和4种替代品对黑斑蛙胚胎没有明显毒性。结果显示,从生物安全性的角度分析,C4和C6织物三防整理剂可作为PFOS的替代品使用,而织物三防整理剂和表面活性剂的毒性比PFOS大,作为PFOS替代品使用需要慎重考虑。     

Endosulfan in the Chinese environment: monitoring and modeling

This paper reviews the usage and emissions of endosulfan, the newest member of the persistent organic pollutants (POPs), in China, and its fate and behavior in Chinese environment. Endosulfan usage in China has been estimated to be approximately 25700 t between 1994 and 2004. Concentrations of endosulfan in different environmental compartments in China, such as air, soil, water, and biota, but focusing at air and surface soil, have been summarized. Concentrations of total endosulfan in surface soil across China were ranged from below detection limit (BDL) to 19000 pg·g^?1 dry weight (dw), with geometric mean of 120 pg·g^?1dw. The results indicated that endosulfan sulfate had highest concentration in Chinese soil, followed by ??- and ??-endosulfan. Air concentrations of endosulfan in China were ranged 0?C340 pg·m^?3 for ??-endosulfan and 0?C121 pg·m^?3 for ??-endosulfan, with high concentrations occurred in the cotton production areas. Gridded usage inventories of endosulfan on a fine gridded system with a 1/4° longitude by 1/6° latitude resolution were compiled, from which, emission to air and residues in soil of endosulfan were calculated in each grid by using a modified simplified gridded pesticide emission and residue model (SGPERM), an integrated modeling system combining mathematical model, database management system, and geographic information system. Total emissions were around 10800 t from 1994 to 2004. Based on the emission and residue inventories, concentrations of ??- and ??-endosulfan in Chinese air and agricultural surface soil were also calculated for each grid cell, which are in general consistent with the published monitoring data.     

Sediment microbial fuel cell with floating biocathode for organic removal and energy recovery

A sediment microbial fuel cell (SMFC) with three dimensional floating biocathode (FBC) was developed for the electricity generation and biodegradation of sediment organic matter in order to avoid negative effect of dissolved oxygen (DO) depletion in aqueous environments on cathode performance and search cost-effective cathode materials. The biocathode was made from graphite granules with microbial attachment to replace platinum (Pt)-coated carbon paper cathode in a laboratory-scale SMFC (3 L in volume) filled with river sediment (organic content 49±4 g·kg^-1 dry weight). After start-up of 10 days, the maximum power density of 1.00W·m^-3 (based on anode volume) was achieved. The biocathode was better than carbon paper cathode catalyzed by Pt. The attached biofilm on cathode enhanced power generation significantly. The FBC enhanced SMFC performance further in the presence aeration. The SMFC was continuously operated for an over 120-day period. Power generation peaked within 24 days, declined gradually and stabilized at a level of 1/6 peak power output. At the end, the sediment organic matter content near the anode was removed by 29% and the total electricity generated was equal to 0.251 g of chemical oxygen demand (COD) removed.     

Normative barriers improvement through the MADS/MOSAR methodology

During the past 30 years, safety and environmental topics have moved up on the list of society’s significant concerns. Administrations and regulatory bodies have to publish rules for the protection of the public, decide whether to authorize the use of a chemical product or the construction of a new plant, limit the environmental impact, regulate waste disposal, etc. All these rules i.e. the legislative, normative and procedural corpus of a country, a state, a city or a factory can be designated to a barrier function. These barriers are indispensable and play an important role in industrial safety management. In developed countries, growth during the past few years in the number of laws directed at regulating environmental and safety aspects in industry is well known to everyone. Now the definition, classification and performance of the legislative and normative barriers definitely allow the management of technological risks. So it is possible to permit the identification of the flux of hazard and to perform risk reduction in order to enhance the acceptability in a regional context. A systemic risk analysis methodology was applied to Colombian industrial sectors. The current legislation was analyzed with three scenarios. A global panorama of the different existing instruments allowing future management opportunities was suggested. The obtained analysis results propose a point of view, which could be useful for a local government or a whole national system to evaluate or improve the risk legislative and normative barriers. This modeling can be applied to other countries and to other industrial sectors.     

基于Logistic回归和DEA的水资源供需月风险评价模型及其应用

我国城市水资源供需研究多集中在供需平衡分析方面,而忽略了供需风险的研究。针对这一问题,论文从危险性、脆弱性和损失的角度构建水资源供需风险指标体系,建立了危险性和损失的函数表达式,并且考虑了随机性对损失的影响。利用Logistic回归模型模拟供水量和需水量系列的概率分布,建立了基于数据包络分析的水资源供需风险评价模型,对2020年北京市水资源供需月风险进行定量评价。结果表明：在1956—2012年的来水条件下,北京市月风险具有明显的季节变化特征,其中春季和夏季的风险系数值比较小,在0.4左右波动,秋季的风险系数值较大,基本在0.4到0.6之间波动,冬季的风险系数值最大,在0.6到1之间波动,如果不采取一些措施进行风险调控,1—10月的水资源供需风险会不断增大;利用再生水和南水北调水后,1—12月的风险均有了大幅度的降低,但是1—10月和12月的风险仍然有增大的趋势。     

乌鲁木齐市大气污染治理成效的综合评估分析

2012~2013年乌鲁木齐采用了以煤改气为主的大气环境治理措施.利用2009~2014年冬季主要污染物浓度、1993~2014年的直接辐射、能见度、霾日数据,并参考相关文献,从大气环境的化学属性、物理属性两个方面评估煤改气等工程措施对乌鲁木齐市大气环境的改善效果.结果表明, 2013~2014年两个冬季乌鲁木齐市主要污染物PM₁₀、SO₂、NO₂浓度比煤改气前期(2009~2011年冬季)各自下降了26.1%、80.2%、11.6%;细颗粒物PM_2.5中水溶性物质的总浓度比例下降了20.57%.煤改气工程前后PM_2.5中可溶性离子浓度排名前三位的均是SO₄^2-、NH₄⁺和NO₃^-,但后期SO₄^2-和NH₄⁺占据PM_2.5质量浓度比例比前期下降近一半,NO₃^-质量浓度比例变化不大.从大气物理特性来看,煤改气等工程之后乌鲁木齐冬季直接辐射量提高,且2014/2015年冬季的直接辐射量是过去23年中第二个峰值;2012/2013年冬季能见度平均增加了5.7km,是1997年以来的最大值.与上年度同期相比,增幅达35.0%;2012/2013年冬季霾日数比上年度同期减少了15d,降幅达50%.上述结果说明乌鲁木齐市的大气环境得到了一定程度的改善.     

社会-生态系统弹性概念分析及评价综述

社会-生态系统如何响应全球环境变化已经被认为是当今自然资源管理中重点关注的方面之一,弹性理论为科学分析社会-生态系统中扰动和适应性的相互作用提供重要理论基础。在人地矛盾日益突出的今天,弹性作为自然界和人类系统一个有价值的特性,对其概念内涵进行分析并总结其评价的研究进展,具有重要的意义。在介绍弹性起源基础上,对弹性定义进行了剖析,对工程弹性、生态系统弹性以及社会-生态系统弹性进行解释。在此基础上,着重分析了弹性分别与脆弱性、适应性和可持续发展之间的区别与联系,并从评价框架、评价指标和评价工具等方面对弹性的定量评价与应用进行回顾。最后,从弹性内涵、定量评价和退化的社会-生态系统弹性修复实践3个方面对未来的发展趋势进行展望。