Population Distribution and Influencing Factors Based on ESDA

Based on the exploratory spatial data analysis(ESDA) technique and geographic information system(GIS) platform,with statistic data of counties in 2005,this paper confirms that there is a large population density gap between counties in 2005 because the Gini coefficient is 0.55.Population distribution does not change a lot during the past decades,and the southeast China is still much more densely populated than the northwest China.The global spatial autocorrelation of population distribution is obvious because Moran’s I scores 0.42 and local spatial autocorrelation is partly significant.Climate and elevation are still the main natural influencing factors.Meanwhile industrial structure and transportation significantly influence population distribution.Different combinations of natural factors have different effects on population distribution.For a long term,climate and terrain factor stability affect population distribution.But its influence will be weakened by progress of technology.Economic development is the main factor that changes population distribution for a short term.     

Soil contamination with antibiotics in a typical peri-urban area in eastern China: Seasonal variation, risk assessment, and microbial responses

The prevalence and persistence of antibiotics in soils has become an emerging environmental issue and an increasing threat to soil security and global public health. The problem is more severe in areas undergoing rapid urbanization; however, the ecological risks of antibiotics, seasonal variability, and associated soil microbial responses in peri-urban soils have not been well-explored. The seasonal soil sampling campaigns were conducted in a typical peri-urban watershed in eastern China to investigate distribution of antibiotics. The results demonstrated higher mean concentrations of most antibiotic compounds in winter than in summer in peri-urban soils. The seasonal variations of norfloxacin, enrofloxacin, and ciprofloxacin were more significant than those of other antibiotics, due to their higher migration ability and bioavailability. An ecological risk assessment demonstrated that chlortetracycline, ciprofloxacin, doxycycline, and ofloxacin can pose high risks to soil microorganisms. Furthermore, the coexistence of multiple antibiotics obviously poses higher risks than individual compounds. A redundancy analysis demonstrated that tetracyclines mainly showed negative correlations with Firmicutes and Chloroflexi, and quinolones showed obviously negative correlations with Acidobacteria, Gemmatimonadetes, and Nitrospirae, suggesting potential inhibition from antibiotics on biological activities or biodegradation processes. However, the persistence of antibiotics in soil results in a significant decrease in bacterial diversity and a change in dominant species. Our results provide an overview of the seasonal variability of antibiotics and the associated effects on bacterial communities in peri-urban soils. The results can provide scientific guidance on decreasing soil contamination with antibiotics to enhance soil security in similar areas.     

单甲脒农药对鱼脑胆碱酯酶活性的影响

金鱼,鲤鱼在实验室驯化４－７ｄ,其脑胆碱酯酶活力在显著水平为Ｐ≤０．０５时,不同组的金鱼,鲤鱼无显著差异。离体实验条件下,单甲脒农药对金鱼,鲤鱼的半抑制浓度分别为１２５．９ｍｇ．ｌ＾－１和２５．７ｍｇ．ｌ＾－１。ＤＭＡ农药对鲤鱼的作用大于对金鱼的作用。     

Micro calorimeter study on the thermal stability of lithium-ion battery electrolytes

With the extensive applications of lithium-ion batteries, many batteries explosion accidents were reported. The thermal stability of lithium-ion battery electrolyte could substantially affect the safety of lithium-ion battery. The C80 micro calorimeter was used to study the thermal stability of several commonly used organic solvents and electrolytes. The samples were heated in argon atmosphere and air atmosphere, respectively. The chemical reaction kinetics was supposed to fit by an Arrhenius law, then the self-accelerating decomposition temperature was calculated. It is found that most of the samples are stable in argon atmosphere while decomposing in air atmosphere, and the single organic solvent is more stable than the electrolyte generally.     

Evaluation of rural habitat environment in under-developed areas of Western China: a case study of Northern Shaanxi

Environment, Development and Sustainability - Rural areas in Northwest China have always been the main concentration of poverty-stricken people in China. In 1986, China listed 665 poor counties...     

江湖关系演变对洞庭湖水质变化影响研究

利用长江中下游地区监测站点1950~2009年逐日水文监测数据及1995~2010年水质分析资料,结合Spearman相关分析和综合污染指数评价法,分析了长江中下游江湖关系演变对洞庭湖水质变化影响,并面向洞庭湖水环境安全提出一系列调控措施,旨在为洞庭湖地区水质改善提供理论基础与技术支持。     

人水和谐理念下城市河涌整治的环境社会学思考

导致城市河涌污染和不健康的因素众多,不仅具有生态学的根源,而且还具有社会学的根源。河涌整治已经成为许多城市环境治理的重点。文章依据环境社会学的理论和人水和谐的理念,分析当前河涌整治的模式及优缺点,重点探讨政府、企业、市民、传媒等利益相关者在城市水环境污染与治理中的角色、作用以及相互之间的互动与整合,为城市河涌综合整治建立长效社会机制提供依据。     

Preparation of Fe–Co based MOF-74 and its effective adsorption of arsenic from aqueous solution

To obtain a cost-effective adsorbent for the removal of arsenic in water,a novel nanostructured Fe–Co based metal organic framework(MOF-74)adsorbent was successfully prepared via a simple solvothermal method.The adsorption experiments showed that the optimal molar ratio of Fe/Co in the adsorbent was 2:1.The Fe_2Co_1MOF-74 was characterized by various techniques and the results showed that the nanoparticle diameter ranged from60 to 80 nm and the specific surface area was 147.82 m~2/g.The isotherm and kinetic parameters of arsenic removal on Fe_2Co_1MOF-74 were well-fitted by the Langmuir and pseudo-second-order models.The maximum adsorption capacities toward As(III)and As(V)were 266.52 and 292.29 mg/g,respectively.The presence of sulfate,carbonate and humic acid had no obvious effect on arsenic adsorption.However,coexisting phosphate significantly hindered the removal of arsenic,especially at high concentrations(10 mmol/L).Electrostatic interaction and hydroxyl and metal–oxygen groups played important roles in the adsorption of arsenic.Furthermore,the prepared adsorbent had stable adsorption ability after regeneration and when used in a real-water matrix.The excellent adsorption performance of Fe_2Co_1MOF-74 material makes it a potentially promising adsorbent for the removal of arsenic.     

Preparation of hapten-specific monoclonal antibody for cadmium and its ELISA application to aqueous samples

High-affinity and specific monoclonal antibodies against cadmium-ethylene diamine tetraacetic acid (EDTA) complex have been produced using the hybridoma technique. A hapten was synthesized and characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and UV-Vis. Competitive enzyme-linked immunosorbent assay (ELISA) for quantitative detection of cadmium in aqueous sample was developed. The monoclonal antibody with high level of binding affinity for Cd-IEDTA-BSA and high specificity for soluble Cd-EDTA complex showed less than 0.99% cross-reactivity with other 11 metals. The limit of detection was 0.10 μg·L⁻¹, and the effective linear range was 10⁻¹–10³ μg·L⁻¹. The intra- and inter-assay coefficient variations were 1.5%–6.3% and 3.2%–7.4%, respectively. The spike recovery in different water samples were between 98.5% and 110.3%. The detection limit of this assay was well below the allowable concentration of cadmium (3 μg·L⁻¹), and the working range was wider than that of other methods which showed the range of 2.19–86.38 and 0–10³ μg·L⁻¹. The competitive ELISA established in this paper was sensitive and accurate in the screening of cadmium in aqueous samples. The results will lay a solid foundation for construction of an immunoassay kit for cadmium.     

用赤泥制备复合混凝剂的研究

对用赤泥为原料制备水处理用复合混凝剂的条件进行了较详细的研究 ,包括酸浸时酸的浓度、浸出时的液固比、浸出温度及时间 ;活化时的碳酸镁用量、活化pH值、活化温度和时间 ,确定了用赤泥制备复合混凝剂的的最佳工艺条件 ,制取了有较好脱色效果的复合混凝剂