新旧版GB6566《建筑材料放射性核素限量》比较研究

为了方便检测机构、消费者和企业理解掌握新版GB6566-2010标准内容,笔者对与旧标准相比的主要变化、标准具体内容进行了归纳整理,并对实际应用中应注意的问题加以解析。     

Translating the 10 golden rules of reforestation for coral reef restoration

Efforts are accelerating to protect and restore ecosystems globally. With trillions of dollars in ecosystem services at stake, no clear framework exists for developing or prioritizing approaches to restore coral reefs even as efforts and investment opportunities to do so grow worldwide. Restoration may buy time for climate change mitigation, but it lacks rigorous guidance to meet objectives of scalability and effectiveness. Lessons from restoration of terrestrial ecosystems can and should be rapidly adopted for coral reef restoration. We propose how the 10 golden rules of effective forest restoration can be translated to accelerate efforts to restore coral reefs based on established principles of resilience, management, and local stewardship. We summarize steps to undertake reef restoration as a management strategy in the context of the diverse ecosystem service values that coral reefs provide. Outlining a clear blueprint is timely as more stakeholders seek to undertake restoration as the UN Decade on Ecosystem Restoration begins.     

低C/N比污水生物脱氮所需外加碳源量的确定

利用中试规模实验装置,探讨了现有活性污泥工艺改造成间歇曝气生物脱氮工艺的实践中,碳氮比(C/N)对废水生物脱氮效率、脱氮反应速度的影响,分析了脱氮容量,确定了所需外加碳源量.      

Inorganic nitrogen removal of toilet wastewater with an airlift external circulation membrane bioreactor

Removal of inorganic nitrogen (inorganic-N) from toilet wastewater, using a pilot-scale airlift external circulation membrane bioreactor (AEC-MBR) was studied. The results showed that the use of AEC-MBR with limited addition of alkaline reagents and volumetric loading rates of inorganic-N of 0.19-0.40 kg inorganic-N/(m3·d) helped achieve the desired nitrification and denitrification. Furthermore, the effects of pH and dissolved oxygen (DO) on inorganic-N removal were examined. Under the condition of MLSS at 1.56-2.35 g/L, BOD5/ammonia nitrogen (NH/-N) at 1.0, pH at 7.0-7.5, and DO at 1.0-2.0 mg/L, the removal efficiencies of NH4 -N and inorganic-N were 91.5% and 70.0%, respectively, in the AEC-MBR. The cost of addition of alkaline reagent was approximately 0.5-1.5 RMB yuan/m3, and the energy consumption was approximately 0.72 kWh/m3 at the flux of 8 L/(m2·h).     

Denitrification potential enhancement by addition of external carbon sources in a pre-denitrification process

The aim of this study is to investigate the denitrification potential enhancement by addition of external carbon sources and to estimate the denitrification potential for the predenitrification system using nitrate utilization rate （NUR） batch tests. It is shown that the denitrification potential can be substantially increased with the addition of three external carbon sources, i.e. methanol, ethanol, and acetate, and the denitrification rates of ethanol, acetate, and methanol reached up to 9.6, 12, and 3.2 mgN/（g VSS.h）, respectively, while that of starch wastewater was only 0.74 mgN/（g VSS,h）. By comparison, ethanol was found to be the best external carbon source. NUR batch tests with starch wastewater and waste ethanol were carried out. The denitfification potential increased from 5.6 to 16.5 mg NO3-N/L owing to waste ethanol addition. By means of NUR tests, the wastewater characteristics and kinetic parameters can be estimated, which are used to determine the denitrification potential of wastewater, to calculate the denitrification potential of the plant and to predict the nitrate effluent quality, as well as provide information for developing carbon dosage control strategy.     

负外部成本内部化约束下的煤炭开采税费水平研究

煤炭开采中面临严重的代际负外部性和生态环境负外部性问题,分别运用使用者成本法和直接市场法测算了煤炭资源开采中的代际负外部成本和生态环境负外部成本。根据两个负外部成本充分内部化的要求,提出煤炭开采中税费水平的调整目标。以2008年为例,煤炭开采中资源税的征收标准应由目前的从量0.3-5元/t(约从价1%)提至从价10%;开采吨煤应交的生态环境费用标准应由目前的24元/t提至64.23-68.47元/t,即每吨提高40.23-44.47元。综合资源税和生态环境费用的提高幅度,煤炭开采活动中的税费水平应提高约21-22个百分点;通过比较现行税费制度下煤炭开采企业实交的资源税费、生态环境税费总额与企业应交的资源、生态环境费用总额之间的差距,指出目前我国政府对开采企业隐性税费补贴的规模水平,根据价差法计算得出取消此部分税费补贴将可以削减3 653.69万tCO2排放。     

长江经济带城市对外服务能力时空演变分析

基于城市流强度模型测算2000年以来长江经济带126个地级以上城市在全国范围内的对外服务能力,进而采用改良锡尔系数、马尔可夫链和ESDA方法对城市对外服务能力的时空演变特征进行探讨。结果表明:研究时段内长江经济带各市城市流强度都有显著提升,但区域间的非均衡现象明显,城市对外服务能力呈现出由东部向西部的梯度递减;省内差异对城市对外服务能力的差异贡献率最高,是空间尺度差异的主要来源;对外服务能力存在明显的俱乐部趋同现象和空间自相关性,对外服务能力相似的区域聚集分布,东、中、西部分别形成长三角、武汉-长沙、成渝等对外服务区域中心;时空演变表现出阶段性特征,经历由极化向均衡的转变。最后指出多中心发展和寻找新增长点应成为长江经济带城市对外服务能力提升的方向。     

Identifying key needs for the integration of social–ecological outcomes in arctic wildlife monitoring

For effective monitoring in social–ecological systems to meet needs for biodiversity, science, and humans, desired outcomes must be clearly defined and routes from direct to derived outcomes understood. The Arctic is undergoing rapid climatic, ecological, social, and economic changes and requires effective wildlife monitoring to meet diverse stakeholder needs. To identify stakeholder priorities concerning desired outcomes of arctic wildlife monitoring, we conducted in-depth interviews with 29 arctic scientists, policy and decision makers, and representatives of indigenous organizations and nongovernmental organizations. Using qualitative content analysis, we identified and defined desired outcomes and documented links between outcomes. Using network analysis, we investigated the structure of perceived links between desired outcomes. We identified 18 desired outcomes from monitoring and classified them as either driven by monitoring information, monitoring process, or a combination of both. Highly cited outcomes were make decisions, conserve, detect change, disseminate, and secure food. These reflect key foci of arctic monitoring. Infrequently cited outcomes (e.g., govern) were emerging themes. Three modules comprised our outcome network. The modularity highlighted the low strength of perceived links between outcomes that were primarily information driven or more derived (e.g., detect change, make decisions, conserve, or secure food) and outcomes that were primarily process driven or more derived (e.g., cooperate, learn, educate). The outcomes expand monitoring community and disseminate created connections between these modules. Key desired outcomes are widely applicable to social–ecological systems within and outside the Arctic, particularly those with wildlife subsistence economies. Attributes and motivations associated with outcomes can guide development of integrated monitoring goals for biodiversity conservation and human needs. Our results demonstrated the disconnect between information- and process-driven goals and how expansion of the monitoring community and improved integration of monitoring stakeholders will help connect information- and process-derived outcomes for effective ecosystem stewardship.     

Study of control strategy and simulation in anoxic-oxic nitrogen removal process

The control strategy and simulation of external carbon addition were specially studied in an anoxic-oxic(A/O) process with low carbon: nitrogen(C/N) domestic wastewater. The control strategy aimed to adjust the flow rate of external carbon dosage to the anoxic zone, thus the concentration of nitrate plus nitrite(NOx^- -N) in the anoxic zone was kept closed to the set point. The relationship was studied between the NOx^- -N concentration in the anoxic zone(SNo) and the dosage of external carbon, and the results showed that the removal efficiency of the total nitrogen(TN) could not be largely improved by double dosage of carbon source when SNO reached about 2 mg/L. Through keeping SNO at the level of about 2 mg/L, the demand of effluent quality could be met and the carbon dosage could be optimized. Based on the Activated Sludge Model No. 1 (ASM No. 1), a simplified mathematical model of external carbon dosage was developed, Simulation results showed that PI controller and feed-forward PI controller both had good dynamic response and steady precision. And feed-forward PI controller had better control effects due to its consideration of influent disturbances.     

完善公司治理,强化信息披露--索克斯法案的简介与评点

2002年7月美国通过了关于会计和公司治理一系列重大改革的索克斯法案(SOX Act),该法案以加强公司治理、强化信息披露为核心,主要内容是强化对高级管理人员的监管和防止外部审计失败.本文简单系统地介绍和分析了该法案中重要措施的相关内容和出台的原因,以期对我国当前公司治理和审计业发展有所启迪和帮助.