人类活动对松嫩平原生态环境的影响

探讨人类活动对松嫩平原的影响 ,有助于了解生态环境退化的过程与机制 ,对于退化生态环境的改善意义重大。本文在分析松嫩平原生态环境的脆弱性、人类活动史、人类的活动方式及人类活动对生态环境影响的基础上 ,指出人类活动干扰并破坏了生态环境的缓冲因子 ,使退化因子的作用因失去缓冲因子的制衡而加强 ,引起土地沙化和盐渍化。文章还论述了生态环境的脆弱性、外部干扰和生态环境退化之间的关系以及松嫩平原生态环境的演化机制 ,从而引导人类遵从自然规律     

金属废水溶液的中和沉淀净化理论分析

含有害金属废水溶液的中和沉淀净化过程受诸多因素的影响,其中,最重要的有溶液中金属的价态和形态,溶液的离子强度,沉淀物的组成,结构和表面效应等,本文对上述问题作了较全面的理论分析。     

灾害观测

本文应用系统科学和信息科学讨论了灾害系统的能达性、能控性与能观性。根根系统能观性原理及量测科学的基本原则,讨论了灾害观测系统应注意的一些问题。     

黄孢原毛平革菌的生长及降解石油条件的优化

在限氮振荡的条件下研究了藜芦醇、Tween-80、草酸、H2O2对黄孢原毛平革菌(P.C.菌)的生长量和石油降解性能的影响。实验结果表明:藜芦醇质量浓度低于0.05 g/L时促进P.C.菌的生长,高质量浓度时抑制P.C.菌的生长,石油降解率随藜芦醇质量浓度增加先升高后下降;Tween-80质量浓度低于7 mg/L时,P.C.菌生长量和石油降解率均随Tween-80质量浓度增大而增加,Tween-80质量浓度大于其临界胶束浓度时,P.C.菌生长量和石油降解率均低于未加Tween-80时;添加草酸抑制P.C.菌的生长,草酸质量浓度为35 mg/L时石油降解率最高,草酸质量浓度为350 mg/L时石油降解率低于未加草酸时;加入H2O2的体系中,石油降解率明显高于无H2O2体系。     

待开发区域的主导产业选择思路研究——以营口经济技术开发区为例

从区域经济发展的角度出发,系统研究待开发区域主导产业选择的基本思路.依据主导产业选择原则(发展基础原则、战略分工原则、区域适宜性原则),通过比较研究确定区域发展的产业方向,构建区域主导产业选择的指标体系,采用AHP分析方法对指标进行衡量,最终得出主导产业推荐方案.同时,对营口经济技术开发区进行实证研究,运用上述方法选择适合该区域发展的产业为:港口物流业、冶金钢材业、输变电设备制造业、重型装备制造业、电子信息业和休闲旅游业.本研究为我国待开发区域的主导产业选择提供了一种新思路,其实证分析结果也为营口经济技术开发区的主导产业选择提供了科学依据.     

Persistent organic pollutants in moss as bioindicators of atmospheric pollution in Singapore

Moss samples were collected from the island of Singapore and analysed for a range of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). Although all compounds analysed have been banned from use in Singapore, they were detected in all samples collected. Among the hexachlorocyclohexanes (HCH), beta-HCH was the most dominant isomer, while trans-chlorane was found to be the most dominant cyclodiene pesticide. High levels (79.12 ng g(-1)) of PCBs were detected in mosses collected from a nearby island due to active accumulation of pollutants associated with boat emissions. Significant spatial variations in the levels of organic pollutants in Singapore were largely absent, indicating that air masses moving over the island deposit OCPs and PCBs in a uniform pattern. A comparison of moss pollutant levels with available data from Czech Republic showed that dichlorodiphenyldichloroethylene (p,p'-DDE), dichlorodiphenyltrichloroethane (p,p'-DDT) and PCB levels in Singapore are the highest. The presence of these compounds suggests that they are still used in the region and are environmentally recalcitrant.     

Impact assessment of waste management options in Singapore

This paper describes the application of life cycle assessment for evaluating various waste management options in Singapore, a small-island city state. The impact assessment method by SimaPro is carried out for comparing the potential environmental impacts of waste treatment options including landfilling, incineration, recycling, and composting. The inventory data include gases and leachate from landfills, air emissions and energy recovery from incinerators, energy (and emission) savings from recycling, composting gases, and transport pollution. The impact assessment results for climate change, acidification, and ecotoxicity show that the incineration of materials imposes considerable harm to both human health and the environment, especially for the burning of plastics, paper/cardboard, and ferrous metals. The results also show that, although some amount of energy can be derived from the incineration of wastes, these benefits are outweighed by the air pollution (heavy metals and dioxins/furans) that incinerators produce. For Singapore, landfill gases and leachate generate minimal environmental damage because of the nation's policy to landfill only 10% of the total disposed wastes. Land transportation and separation of waste materials also pose minimal environmental damage. However, sea transportation to the landfill could contribute significantly to acidification because of the emissions of sulfur oxides and nitrogen oxides from barges. The composting of horticultural wastes hardly imposes any environmental damage. Out of all the waste strategies, the recycling of wastes offers the best solution for environmental protection and improved human health for the nation. Significant emission savings can be realized through recycling.     

Application of surface molecular imprinting adsorbent in expanded bed for the adsorption of Ni(2+) and adsorption model

A new surface molecular imprinting adsorbent (SMIA) was used in an expanded bed. The expansion ratio and adsorption performance were studied at different volumetric rates, inlet concentrations, and pH values. A model based on the Adams-Bohart adsorption model of breakthrough curves was established. The predicted curves had good agreement with the experimental curves. The breakthrough time (T(1/2)) decreased with increasing inlet concentration when the outlet concentration was half the initial concentration (C/C(0)=0.5). The inlet concentration had little effect on the adsorption rate constant (k(1)) value when the initial concentration (C(0)) was above 150 mg/L. However, T(1/2) values increased with increasing initial pH of the inlet solution, and the k(1) value decreased due to the competition between H(+) and Ni(2+).     

Empirical analysis on contribution share of safety investment to economic growth: A case study of Chinese mining industry

Insufficient investment in safety is one of the most important reasons which lead to frequent accidents in Chinese mining industry. Safety input has long been regarded as a ‘sunk cost’, lacking output, and little attention from mining companies was focused on increasing safety input according to technical codes or technical requirements due to the narrow understanding on safety input. So, the empirical analysis on the contribution share of safety investment to economic growth is very important. In this paper, a new set of production safety indexes including six 1-level indexes for describing the safety level of mining production in China was constructed on the basis of Granger causality test. Meanwhile, a mining economic growth model was constructed on the basis of the new production safety indexes with co-integration theory and dynamic modeling system. The empirical results show that the production safety factor in the short term indeed drives the GDP growth in the mining industry although labor and capital input remain the major factors impacting mining economic growth, and its long term contribution share is 7.7%. Principal Component Analysis (PCA) of production safety indexes, shows that the safety level of mining production increased more than 21-fold during 1991–2009, and the investment in mining technology development capability, mining safety production environment and mechanized level of mining should be the direction to focus for improving the safety level of mining production.     

Screening and identification of cellulose degrading bacterium Bacillus siamensis BREC-11 with tolerance to furfural北大核心CSCD

Furfural is a toxic metabolic inhibitor that is created during the conversion of lignocellulose to produce fuel, which can retard fermentation and increase production costs. thus, it is important for lignocellulosic conversion that the ability of the strain to resist furfural stress be improved. A cellulose-degrading bacterium BREC-11 with tolerance to furfural was isolated from the intestinal tract of Omphisa fuscidentalis hampson larvae via the addition of furfural in the medium. Based on analyses of morphological observations, physiological and biochemical characterizations, and 16S rDNA sequences, strain BREC-11 was shown to represent a member of the genus Bacillus and was named B. siamensis BREC-11. to study the tolerance concentration of strain BREC-11, a wide range of furfural formaldehyde concentrations were tested and strain BREC-11 was shown to grow in the mineral medium containing furfural up to 3.5 g/L. Cellulase activity of strain BREC-11 was determined at the tolerable concentration of 3.5 g/L furfural after incubation at 30 ℃ and 150 r/min for 2 days. Results indicated that filter paper enzyme, CMC-Na enzyme, and β-glucosidase activity was 0.1 U/mL, 0.21 U/mL, and 0.07 U/mL, respectively. BREC-11 is a cellulose-degrading bacterium with resistance to furfural, which has potential application in future bio-refinery processes. © 2018 Science Press. All rights reserved.