Do lower electricity storage costs reduce greenhouse gas emissions?

In the electricity sector, innovation in large-scale storage is anticipated to reduce costs and improve performance. The effect on greenhouse gas emissions of lower storage costs depends on the interactions between storage and the entire grid. The literature has disagreed on the role of storage in reducing emissions. In this paper we present a stylized model, which suggests that the effect of storage costs on emissions depends on the supply responsiveness of both fossil and renewable generators. Under common conditions in the United States, lower storage costs are more likely to reduce emissions when wind investment responds to equilibrium electricity prices and when solar investment does not. Simulations of a computational model of grid investment and operation confirm these intuitions. Moreover, because of its effect on coal and natural gas–fired supply responsiveness, introducing a carbon dioxide emissions price may increase the likelihood that lower storage costs reduce emissions.     

The time dimension and lithium resource constraints for electric vehicles

The availability of lithium resources for a transition to electric vehicles is a vital topic for transport technology strategy. Recent debate seems to have concluded that there is ‘sufficient’ lithium available, but for the purposes of a technological transition, time matters. It is not simply the quantity of resource that is relevant—the flow rate into society may be a much more difficult constraint and transient events have disrupted heavily concentrated material supply chains in the past. Furthermore, critical assumptions such as the presence of recycling systems may not be justified without policy support. Complacency is therefore not an appropriate stance for a robust evaluation of material risks in the case of lithium.     

Value Plurality among Conservation Professionals

Abstract: Debate on the values that underpin conservation science is rarely based on empirical analysis of the values conservation professionals actually hold. We used Q methodology to investigate the values held by international conservation professionals who attended the annual Student Conference in Conservation Science at the University of Cambridge (U.K.) in 2008 and 2009. The methodology offers a quantitative means of examining human subjectivity. It differs from standard opinion surveys in that individual respondents record the way they feel about statements relative to other statements, which forces them to focus their attention on the issues they believe are most important. The analysis extracts the diverse viewpoints of the respondents, and factor analysis is used to reduce the viewpoints to a smaller set of factors that reflect shared ways of thinking. The junior conservation professionals attending the conference did not share a unifying set of core values; rather, they held a complex series of ideas and a plurality of opinions about conservation and how it should be pursued. This diversity of values empirically challenges recent proposals for conservation professionals to unite behind a single philosophy. Attempts to forge an artificial consensus may be counterproductive to the overall goals conservation professionals are pursuing.     

模拟氮沉降对北亚热带落叶阔叶林土壤呼吸的影响

于2008年4月～2009年4月在龙王山北亚热带落叶阔叶林地进行模拟氮沉降试验,利用静态箱-气相色谱法测定土壤呼吸,研究氮沉降增加对森林土壤呼吸的影响.结果表明,氮沉降没改变土壤呼吸的季节性变化规律和日变化规律.与对照(CK)相比,低氮(TL)、中氮(TM)和高氮(TH)处理使森林土壤年平均呼吸速率分别降低了8.51%、9.74%和11.24%,使日平均呼吸速率分别降低了4.42%、11.09%和12.17%.森林土壤呼吸与土壤温度存在极显著的指数关系(p0.01),CK、TL、TM和TH的土壤呼吸温度敏感系数(Q10)分别为2.53、3.22、2.64和2.92,氮沉降提高了林地土壤呼吸的温度敏感系数.本研究表明,氮沉降显著降低了森林土壤呼吸,但提高了土壤呼吸的温度敏感性.     

24孔板发酵法测定地表水和废水中粪大肠菌群的研究

对地表水和废水中粪大肠菌群的多管发酵法进行了改进。改进了初发酵方法,采用24孔板代替试管进行初发酵,复发酵方法保持不变。对环境中采集的23个污水样本采用24孔板初发酵法与多管发酵法进行比较,结果表明,两种方法相关性良好,两者在结果上无统计学意义的差别。采用改进的24孔板法进行初发酵有效节约了培养基、缩短了实验准备时间,简化了操作步骤,尤其适用于大批量的、污染严重的地表水和废水中粪大肠菌群的检测。     

The oil industry along the Atlantic coast of Cameroon: Assessing impacts and possible solutions

While the oil industry along the Atlantic coast of Cameroon has made important contributions to the national economy, this has been accompanied with adverse environmental impacts. There has been significant pollution from oil drilling, refinery waste, oil spillage, gas and flaring. After discussing these impacts, this paper argues that prevailing regulations are inadequate and need overhauling. It proposes that cleaner production requires:

(i)

specific laws to protect dwellers in the neighbourhood of oil refineries, filling stations, service stations and pipelines;     

Individual-based modelling of fishermen search behaviour with neural networks and reinforcement learning

A model to mimic the search behaviour of fishermen is built with two neural networks to cope with two separate decision-making processes in fishing activities. One neural network deals with decisions to stay or move to new fishing grounds and the other is constructed for the purpose of finding prey within the fishing areas. Some similarities with the behaviour of real fishermen are found: concentrated local search once a prey has been located to increase the probability of remaining near a prey patch and the straightforward movement to other fishing grounds. The artificial fisherman prefers areas near the port when conditions in different fishing grounds are similar or when there is high uncertainty in its world. In the latter case a reluctance to navigate to other areas is observed. The artificial fisherman selects areas with higher concentration of prey, even if they are far from the port of departure, unless a high uncertainty is related to the fishing ground. Connected areas are preferred and followed in orderly fashion if a higher catch is expected. The observed behaviour of the artificial fisherman in uncertain scenarios can be described as a risk-averse attitude. The approach seems appropriate for an individual-based modelling of fishery systems, focusing on the learning and adaptive characteristics of fishermen and on interactions that take place at a fine scale.     

Social dimensions of mining: Research,policy and practice challenges for the minerals industry in Australia

The social dimensions of the mining industry are increasingly acknowledged as critical to business success, yet remain the least understood aspect of the business concept of sustainable development—the ‘triple bottom line’ of economy, environment and society.     

江津润湿时间的温度分布研究

采用直接读取、4点统计、24点统计三种方法研究了江津试验站1998年的润湿时间的温度分布,研究表明,可以利用全年每天2、8、14、20点的4个数据统计年润湿时间的温度分布;江津地区润湿时间的温度分布特征主要为：(1)99％的年润湿时间是在5℃至30℃温度范围,每月润湿时间的温度波动一般为15℃;(2)在(0～5)℃、(5～10)℃、(10～15)℃、(15～20)℃、(20～25)℃、(25～30)℃、(30～35)℃区间内,4点统计法各区间润湿时间的百分比分别为0.34％、13．4％、24．5％、18．3％、26．0％、17．4％、0．0％。     

Q235钢在火灾条件下的力学性能研究

在试验的基础上,对建筑中常用的Q235铜在火灾条件下的力学性能进行了研究,获得了Q235钢的屈服强度、极限强度、弹性模量、极限应变等力学性能随温度变化而变化的规律,并对影响Q235钢力学性能的因素进行了分析。