Optimization of pretreatment conditions for enhanced sugar release

Present investigation was done to evaluate various algal genera found in water bodies of Varanasi city. The potential of any biomass for biofuels (bioalcohols, biohydrogen, etc.) production depends on the quantity of extractable sugar present in it. Acid (H₂SO₄) and alkali (NaOH) pretreatment were performed, and H₂SO₄ was chosen due to its nearly double yield as compared with alkaline pretreatment. Response surface methodology was utilized for the optimization of operating parameters such as treatment temperature, time, and acid concentration. Sugar yield up to 0.33 g/g of dry biomass was obtained using cyanobacterial biomass of Lyngbya limnetica, at 100°C, 59.19 min, and H₂SO₄ concentration of 1.63 M.     

Starting improvement of micro-wind turbines operating in low wind speed regions

The study deals with the design and optimization of external and internal geometry of micro-wind turbines blades. A specified objective function which consists of the power coefficient and the starting time was defined and the genetic algorithm optimization technique in conjunction with the blade-element momentum theory was adopted to find the geometry of the blades including the distributions of the chord, the twist angle and also the shell thickness. Moreover, the allowable stress of the blades was considered as a constraint to the objective function. Results show that a reasonable compromise is achievable such that the starting time of the blades reduces noticeably in return for a small drop in the power coefficient. The significant improvement of the hollow blades over the solid ones indicates that the power coefficient and the starting performance could be improved through the appropriate distributions of the considered decision variables, i.e. the chord, the twist angle and also the shell thickness.     

长江流域的空间结构研究

在认识空间结构内涵与确定研究范围的基础上,运用主成分和聚类分析方法,获得了长江流域的空间分异状况。长江流域空间结构符合核心 边缘结构模式,包括3个一级核心、8个二级核心、两大跨省成长三角、1条主轴、2条辅轴、3条地方轴、1个外围区和1个边缘区。长江流域空间结构的演变,经历了低水平的离散型阶段、极化发展的非均衡阶段、扩散的多核非均衡阶段,未来将向区域一体化的高水平均衡阶段发展。从聚散原理、空间相互作用和国家宏观区域发展战略等3方面,分析了长江流域空间结构的演变机制。长江流域空间结构的优化,要从内部要素与外部力量两方面入手做3件事情。一要加快单个节点的发展和尽快形成核心区域,尤其是上游地区要构建一个以成渝为双核的兼顾南北较大范围的成长多边形;二要加快东西通道的建设和注重主轴与辅轴间的连接通道的构建或完善;三要注重基于市场一体化的区域空间治理体制的创新.     

城市景观生态网络规划的空间模式应用探讨

城市景观生态网络空间模式研究是生态城市和景观规划设计现今研究的重要领域之一,目的在于依据景观生态网络模式的应用建立起生态城市规划建设的基本框架和技术途径。在探讨城市景观生态系统特征和城市景观生态网络结构的基础上,总结景观生态网络空间模式并重点分析了水景树的空间生态模式、森林 道路 住宅复合网络模式、平原城市农田 灌木丛 河流交叉网络模式、岛屿城市的绿地 道路生态网络模式4种城市景观生态网络典型模式的图示特征及其生态意义。依此为理论指导基础,以都江堰为例,在继承都江堰大地景观格局并结合都江堰市灾后重建需求的前提下,研究都江堰市城市景观生态格局和生态过程,探讨在不同尺度和不同维度上运用4种网络图示进行都江堰城市景观生态网络优化调整的空间模式和对策。(1)依据“水景树图式”优化调整纵向维度景观生态格局;(2)依据“森林 道路 住宅”和“农田 灌木丛 河流”网络调整横向维度景观生态格局;(3)依据岛屿城市的“绿地 道路”景观生态网络调整城市组团景观生态格局.     

Legalizing markets and the consequences for poaching of wildlife species: the vicuña as a case study

Vicuña provide an excellent case study for examining the sustainable use of wildlife outside protected areas: the community-based conservation approach. Vicuña populations in the high Andes of Argentina, Bolivia, Chile, Ecuador and Perú fell to a critically low level, but a Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) ban on trade in their fiber has seen numbers recover dramatically, and now live shearing of vicuña for a high-value international market is being promoted as a mechanism to secure both sustainable vicuña populations and local livelihoods. We used a dynamic optimization model to explore the consequences of legalizing markets, including the consequences for poaching which is critical in vicuña dynamics. Using parameters obtained from the literature and expert knowledge, we explored different scenarios for the Argentine region of Cieneguillas. Our results showed that the role of the international market is ambiguous; live shearing for an international market can provide the very best of outcomes for both vicuña and local people, with large herds generating high revenues. But an international market also creates a market for poached vicuña fiber; as a result, vicuña numbers risk once again falling to critically low levels, resulting also in minimal revenues from sale of fiber. The message for the international community is that if community-based conservation is not implemented carefully then its impact can easily be perverse.     

城市绿地防灾规划建设和管理探讨——基于四川汶川大地震的思考

随着我国城市规模的急速扩张和人口密度的过度集中,健全城市防灾系统已成为刻不容缓的艰巨任务.城市绿地作为城市防灾系统的重要组成部分,不仅具有生态、景观、游憩和文化功能,还具有突出的防灾避险功能.通过分析成都、都江堰等四川汶川地震受灾城市绿地的使用情况,结合对北京市部分作为应急避难场所的公园建设和使用情况的实地调查,总结认为我国城市绿地防灾规划建设和管理现阶段存在的主要问题是:①对城市绿地的防灾避险功能认识不足;②适合用于防灾的城市绿地总量不足,分布不均;③用于防灾的城市绿地防灾配套设施及功能有待完善.最后从建立城市绿地防灾规划体系,明确城市绿地防灾建设工作重点和优化城市绿地防灾管理体制三个方面探讨如何对城市绿地防灾规划建设和管理进行优化,从而达到加强我国城市绿地防灾功能,完善城市防灾系统的目的.     

海洋石油污染处理方法优化配置及具体案例应用

海洋石油污染成为海洋污染的主要类型,对海洋水生环境造成了极大的破坏,而溢油成为石油进入海洋的主要方式,如何对溢油事故进行有效的预防和处理成为治理海洋污染的关键所在.本文对当今处理溢油使用的物理法、化学法、自然降解法、生物处理法、燃烧法等进行了介绍,详细考察了各种处理方法的适用条件,以及在限制条件下如何对各种选择方法进行优化组合.文章同时对"11.14"重大船舶溢油污染事故实际案例进行了分析,用优化组合后的方法进行处理,处理效果明显.     

固相萃取-高效液相色谱-质谱联用法测痕量双酚A的方法优化

通过优化固相萃取和液相色谱条件,建立了固相萃取-高效液相色谱-质谱法测定水中双酚A的检测方法.水样经C18固相萃取柱净化并富集双酚A后,采用C18反相色谱柱XR-ODS(2.0 mm×100 mm,2.2μm)分离,MRM负离子模式测定.结果表明:BPA浓度为5～200 ng/L范围内线性关系良好(相关系数为0.999...     

蚁群算法在生命线网络系统抗震拓扑优化中的应用

近年来,遗传算法和模拟退火算法已经应用于网络系统的抗震拓扑优化,蚁群算法也已经成功应用到多个组合优化问题中。首先论述了生命线网络系统抗震拓扑优化模型,然后介绍了网络抗震可靠度分析的最小路递推分解算法。通过对优化问题解形式的分析,采用二进制编码的蚁群算法对优化模型进行了求解。最后,结合实例分析,并与遗传算法和模拟退火算法的计算结果进行了对比。结果表明,蚁群算法可以作为一种新的工具进行网络系统的优化设计。     

基于政府间府际关系的畜禽养殖废弃物治理政策优化——以治理中小规模养殖场户畜禽粪污污染为例

本文从央地纵向关系、部门间横向关系、环保督察斜线关系等视角出发,探讨畜禽养殖废弃物治理政策背后的府际关系博弈逻辑和利益融合路径,实证探讨治理案例。结果表明,政府府际间存在利益博弈,但可以实现利益融合和治理有效。其中,经济、社会和生态利益的排序差异、治理事务权与财权不匹配、地方考核指标偏向经济等因素造成央地间利益诉求差异,可从增加融资渠道、优化考核方式、扩大监管渠道和多元共治等方面促进利益融合;双重管理体制、全局和局部利益并存等因素造成同一层级的不同政府部门间存在利益诉求差异,但环保督察等“运动式”治理、约束性生态指标被纳入官员考核体系等措施有助于其组成政绩共荣体;结合案例实证检验,提出中央政府需要通过严格制度安排和多重监管督察治理动态、整合地方政策资源帮助政府各部门间形成政绩共荣体、疏堵并举精准施策构建紧密利益联结机制、搭建“政府—市场—公众”多元共治治理格局等政策建议。