Time allocation strategies in insect parasitoids: from ultimate predictions to proximate behavioral mechanisms

As most parasitoids are time limited, they usually die before they have laid all their eggs. In such cases, optimal foraging theory predicts that female parasitoids will adopt behavioral reproductive strategies enabling them to maximize progeny production per unit of time. One key situation in which parasitoid females must optimize their time budget is related to the fact that most of their hosts are distributed in discrete patches in the environment. In this review, I first present the results of basic theoretical models predicting female wasp search duration on a patch of hosts. I then compile and analyze all studies investigating the effect of different factors on parasitoid patch time allocation and patch-leaving decision rules. Different patch-leaving mechanisms that were proposed to explain the results obtained are discussed, along with statistical methods that should be used to estimate them from experimental data. Finally, ideas for future research are presented.     

多收入阶层CGE模型在能源资源税改革效应分析中的应用研究

开展能源资源税改革效应分析,是评估环境政策改革在环境效益、经济效率和公平效应上是否实现共赢目标的基础工作.通过细分社会核算矩阵中的居民收入组账户,构建面向多收入阶层的CGE模型,有利于量化环境税费领域改革产生的效应.经模拟测算得到,中国能源资源税改革将对GDP、部门总产出和社会总消费等主要宏观经济指标带来负面影响,但均在可接受范围内.微观层面上,居民收入组内的可支配收入和消费支出则受到不同程度的负面影响.     

中国生态效率的空间格局与影响机制分析

实现经济增长的生态友好模式转变是当代中国建设两型社会的必然要求,而中国地区生态效率的空间格局及影响因素分析是地理学研究的重要问题.基于此,本文利用随机前沿模型测算2004—2012年间我国地区生态效率,其次,基于探索性空间分析技术对生态效率的空间关联特征进行分析,最后,借助空间计量经济模型对区域生态效率的影响因素进行分析.结果表明:中国地区生态效率总体呈上升趋势,但效率水平偏低,东部地区生态效率高于中西部地区;生态效率空间分异格局显著,且具有正向的空间相关性,其中,低-低生态效率区域集聚分布于我国西部内陆,高-高生态效率集聚区分布于东南沿海;空间面板回归显示,城市化水平及经济发展的提高有助于区域生态效率的提高,环境法规的实施及有效的环境监管可以确保生态安全,而第二、三产业比重的增加不利于生态效率的提高.     

CO2 adsorption using TiO2 composite polymeric membranes: A kinetic study

CO₂ is the main greenhouse gas which causes global climatic changes on larger scale. Many techniques have been utilised to capture CO₂. Membrane gas separation is a fast growing CO₂ capture technique, particularly gas separation by composite membranes. The separation of CO₂ by a membrane is not just a process to physically sieve out of CO₂ through the controlled membrane pore size. It mainly depends upon diffusion and solubility of gases, particularly for composite dense membranes. The blended components in composite membranes have a high capability to adsorb CO₂. The adsorption kinetics of the gases may directly affect diffusion and solubility. In this study, we have investigated the adsorption behaviour of CO₂ in pure and composite membranes to explore the complete understanding of diffusion and solubility of CO₂ through membranes. Pure cellulose acetate (CA) and cellulose acetate-titania nanoparticle (CA-TiO₂) composite membranes were fabricated and characterised using SEM and FTIR analysis. The results indicated that the blended CA-TiO₂ membrane adsorbed more quantity of CO₂ gas as compared to pure CA membrane. The high CO₂ adsorption capacity may enhance the diffusion and solubility of CO₂ in the CA-TiO₂ composite membrane, which results in a better CO₂ separation. The experimental data was modelled by Pseudo first-order, pseudo second order and intra particle diffusion models. According to correlation factor R², the Pseudo second order model was fitted well with experimental data. The intra particle diffusion model revealed that adsorption in dense membranes was not solely consisting of intra particle diffusion.     

Thresholds of species loss in Amazonian deforestation frontier landscapes

In the Brazilian Amazon, private land accounts for the majority of remaining native vegetation. Understanding how land‐use change affects the composition and distribution of biodiversity in farmlands is critical for improving conservation strategies in the face of rapid agricultural expansion. Working across an area exceeding 3 million ha in the southwestern state of Rondônia, we assessed how the extent and configuration of remnant forest in replicate 10,000‐ha landscapes has affected the occurrence of a suite of Amazonian mammals and birds. In each of 31 landscapes, we used field sampling and semistructured interviews with landowners to determine the presence of 28 large and medium sized mammals and birds, as well as a further 7 understory birds. We then combined results of field surveys and interviews with a probabilistic model of deforestation. We found strong evidence for a threshold response of sampled biodiversity to landscape level forest cover; landscapes with <30–40% forest cover hosted markedly fewer species. Results from field surveys and interviews yielded similar thresholds. These results imply that in partially deforested landscapes many species are susceptible to extirpation following relatively small additional reductions in forest area. In the model of deforestation by 2030 the number of 10,000‐ha landscapes under a conservative threshold of 43% forest cover almost doubled, such that only 22% of landscapes would likely to be able to sustain at least 75% of the 35 focal species we sampled. Brazilian law requires rural property owners in the Amazon to retain 80% forest cover, although this is rarely achieved. Prioritizing efforts to ensure that entire landscapes, rather than individual farms, retain at least 50% forest cover may help safeguard native biodiversity in private forest reserves in the Amazon. Umbrales de Pérdida de Especies en los Paisajes Fronterizos de Deforestación en el Amazonas Ochoa‐Quintero     

A novel approach combining bootstrapped non-intrusive reduced order models and unscented transform for the robust and efficient CFD analysis of accidental gas releases in congested plants

The risk assessment for safety-critical, complex systems is a very challenging computational problem when it is performed with high-fidelity models, e.g. CFD, like in the case of accidental gas releases in congested systems. Within this framework, a novel CFD approach, named Source Box Accident Model, has been recently proposed to efficiently model such phenomena by splitting the simulation of the gas release and its subsequent dispersion in the system in two steps. In this view, the present paper proposes a non-intrusive, Proper Orthogonal Decomposition-Radial Basis Functions reduced order model that exploits the two-step nature of the SBAM approach, to mimic the behaviour of the original, long-running CFD model code at a significantly lower computational cost. Moreover, the paper presents a methodology combining the bootstrap and unscented transform approaches to efficiently assess the ROM uncertainty in the safety-critical simulation output quantities of interest, e.g. the flammable volume. The results obtained in a test case involving a high pressure, accidental gas release in an off-shore Oil & Gas plant are in very satisfactory agreement with those produced by CFD, with a relative error smaller than 10% and a reduction in the computational time of about three orders of magnitude.     

城市道路交通噪声的预测模型验证

《环境影响评价技术导则声环境》(HJ2.4-2009)对于公路道路交通噪声预测模式中的单车辐射声级没有给出固定的计算方式,本文对某两条城市道路采用实际环境影响评价中常用的各种预测模型计算并与实测值进行分析比较,结果发现,单车辐射声级采用2006版规范进行计算,同时结合2009新导则的预测模型得到的预测值与实测值较为相符。     

TiO2@酵母复合微球固定床吸附荧光增白剂-VBL的研究

研究了Ti O2@酵母复合微球在固定床中吸附阴离子型荧光增白剂-VBL(FWA-VBL)的特性,考察了溶液p H(2.0~8.0)、床层高度(1~3 cm)、进水浓度(20~80 mg·L-1)和进水流速(5~11 m L·min-1)等因素对固定床吸附特性的影响.结果表明在溶液p H为2.0,床层高度为1 cm,进水浓度为80 mg·L-1和进水流速为5 m L·min-1时,吸附剂的最大吸附量为223.80 mg·g-1.BDST、Thomas和Yoon-Nelson模型均能很好地描述不同条件下动态吸附行为,相关系数均大于0.980.同时,Ti O2@酵母复合微球具有很好的再生性能,可以重复利用4次.     

To reduce and not to reduce resource consumption? That is two questions

Recent research shows that because they rely on separate goals, cognitions about not performing a behaviour are not simple opposites of cognitions about performing the same behaviour. Using this perspective, two studies (N = 758 & N = 104) examined the psycho-social determinants of reduction in resource consumption. Results showed that goals associated with reducing versus not reducing resource consumption were not simple opposites (Study 1). Additionally, the discriminant validity of the Theory of Planned Behaviour constructs associated with reducing versus not reducing resource consumption was demonstrated (Study 1 & 2). Moreover, results revealed the incremental validity of both Intentions (to reduce and to not reduce resource consumption) for predicting a series of behaviours (Study 1 & 2). Finally, results indicated a mediation role for the importance of ecological dimensions on the effect of both Intentions on a mock TV choice and a mediation role for the importance of non ecological dimensions on the effect of Intention of not reducing on the same TV choice. Discussion is organized around the consequences, at both theoretical and applied levels, of considering separate motivational systems for reducing and not reducing resource consumption.