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661.
面向生态城市建设的能源结构优化研究   总被引:4,自引:0,他引:4  
基于信息熵分析了城市能源供应结构与能源消费结构的多样性,提出了生态城市能源结构优化的基础判据和约束判据.以厦门市为例,分析了城市能源结构自然演变趋势的缺陷,提出了实现生态城市建设的能源结构优化的控制方案,并判断其优化效果.结果表明,2020年前,基础情景下的厦门市能源供应结构多样性将减少,能源消费结构退化较显著,尤其是2015年前退化趋势加剧,且远远超过结构优化判据的约束条件.而通过采取提高能源生态效率,清洁燃料替代,新能源和可再生能源开发与利用,机动车用能调整强化等控制措施,2010年后厦门市未来能源结构总体上将明显优于系统自然演变结构,同时满足环境容量约束与倍数因子约束条件,从而为该市实现生态城市建设目标奠定基础.  相似文献   
662.
The optimization of a water distribution network (WDN) is a highly nonlinear, multi-modal, and constrained combinatorial problem. Particle swarm optimization (PSO) has been shown to be a fast converging algorithm for WDN optimization. An improved estimation of distribution algorithm (EDA) using historic best positions to construct a sample space is hybridized with PSO both in sequential and in parallel to improve population diversity control and avoid premature convergence. Two water distribution network benchmark examples from the literature are adopted to evaluate the performance of the proposed hybrid algorithms. The experimental results indicate that the proposed algorithms achieved the literature record minimum (6.081 M$) for the small size Hanoi network. For the large size Balerma network, the parallel hybrid achieved a slightly lower minimum (1.921M€) than the current literature reported best minimum (1.923M€). The average number of evaluations needed to achieve the minimum is one order smaller than most existing algorithms. With a fixed, small number of evaluations, the sequential hybrid outperforms the parallel hybrid showing its capability for fast convergence. The fitness and diversity of the populations were tracked for the proposed algorithms. The track record suggests that constructing an EDA sample space with historic best positions can improve diversity control significantly. Parallel hybridization also helps to improve diversity control yet its effect is relatively less significant.  相似文献   
663.
不同原料厌氧发酵及其微生物种群的研究   总被引:3,自引:0,他引:3  
使用PCR-DGGE技术,对以鸡粪、猪粪、牛粪、秸秆为发酵原料的发酵体系的微生物群落多样性进行了研究.在发酵不同时间取样,进行了日产甲烷量、日产甲烷浓度的变化分析和DGGE分析.结果表明,日产甲烷量整体趋势为猪粪>鸡粪>秸秆>牛粪,日平均产甲烷量分别为2.67、2.24、0.99、0.49L;猪粪、鸡粪、秸秆的日产甲烷浓度在整个发酵周期大多可维持在50%以上,牛粪的日产甲烷浓度大部分时间低于30%;细菌的优势菌群有拟杆菌属(Bacteroidetes)、密螺旋体属(Treponema)、厌氧绳菌科(Anaerolineaceae)等,新增优势菌群有梭菌属(Clostridium)、脱硫叶菌属(Desulfobulbus)、毛螺旋菌科(Lachnospiraceae)、醋弧菌属(Acetivibrio);古菌的优势菌群有甲烷鬃菌属(Methanosaeta)、甲烷八叠球菌属(Methanosarcina)、甲烷八叠球菌目(Methanosarcinales),新增优势菌群有斯氏甲烷球菌属(Methanosphaera stadtmanae).  相似文献   
664.
官厅水库水质特征及水体微生物多样性的响应   总被引:2,自引:0,他引:2  
针对北京市原水源地官厅水库,选择了上下游共6个采样点进行了不同季节的水质及环境因子特征分析.总体看来,4个季节水体氮磷碳营养物质浓度依次为:夏季>秋季>春季>冬季,夏秋季出现明显水华.上游妫水河水质要好于下游水库库区水质,尤其以夏秋季节最为明显.夏季上游妫水河的总碳、总氮、氨氮、总磷平均浓度为26.5, 0.95, 0.55, 0.077mg/L,而水库库区响应平均浓度分别为111.47, 4.27, 3.16, 0.25mg/L.结合PCR-DGGE对不同时期各点水体微生物进行了群落分析,发现上下游水体中细菌群落结构差异很大,水华严重区的细菌群落多样性和丰度要低于比水质较好区域.CANOCA软件分析了夏秋季水华时水体微生物群落变化与环境因子的响应关系,发现细菌群落结构与环境因子(T、pH值、DO、NFR、TP、Fe)之间存在较强的关联.水质较好的上游水体夏秋细菌群落结构主要受温度、DO影响较大;而水质较差的库区水体夏秋季细菌群落结构变化与固氮速率、pH值、总磷的相关性较好.  相似文献   
665.
In order to explore the characteristics and species diversity of the vegetation growing in the provenance slope with high-frequency debris flow, we selected the slopes on the north and south sides of the valley in the Jiangjiagou watershed as the research object. The structural characteristics and quantitative compositions of the communities of vegetation growing on different positions of the slopes were investigated. The species composition, important value, species diversity, and ground and underground biomass of the different communities on the slope were statistically analyzed, and the correlations of the ground and underground biomass with the diversity were determined. The results showed that: of the total 49 species found, the herbs were the dominant flora, of which 33 were found on the northern slope and 23 were found on the southern slope. There were significant differences in the species composition and composition of the important values along the different positions on the slope, being mainly affected by the pioneer herbaceous plants. We found that Heteropogon contortus, Eulaliopsis binata, Arthraxon hispidus, and Sesbania cannabina were highly adaptable to debris flow. These four species are common to the area and can be used as the main configuration species for future ecological restoration. There were differences in the community characteristics and species diversity at different positions on the slope. For the southern slope of the valley, the Shannon-Wiener diversity index was in the order: stable zone (2.311) > instable zone (2.161) > deposit zone (2.036), and in the order: deposit zone (2.626) > stable zone (1.338) > instable zone (1.057) for the northern slope. There were significant differences in the biomass, being in the order: stable zone > instable zone > deposit zone, with higher values in the northern slope than in the southern slope. Based on the aforementioned results, we suggest that the restoration of vegetation in the area of the provenance slope having high-frequency debris flow should focus on the prevention and protection of the instable zone of the slope by natural processes of recovery. The deposit zone needs rational remediation measures. We should introduce local shrub and arbor to increase the species composition and promote the development of plant communities with vertical structures. © 2018 Science Press. All rights reserved.  相似文献   
666.
为研究采煤沉陷对土壤-植物系统的影响,以呼伦贝尔草原煤矿为研究对象,通过在沉陷区与对照区不同坡位〔坡顶(地表沉陷边界附近)、坡中(沉陷边缘区)、坡底(沉陷中心区)〕设置样地进行土壤性质和植物群落的调查测试,对比分析沉陷干扰下土壤水分和养分、植物物种组成以及群落结构的变化,研究土壤性质与植物群落特征之间的关系,并对沉陷区和对照区土壤-植物系统进行综合评价.结果表明:①采煤沉陷后,沉陷区土壤体积含水量(简称“土壤含水量”)较对照区下降了4.8%(P < 0.05),坡中土壤水分损失最严重,比对照区同一坡位减少了8.4%(P < 0.05).沉陷区0~60 cm土壤TN(全氮)、TP(全磷)、OM(有机质)和AK(速效钾)含量平均值分别比对照区下降了17.8%、28.9%、38.0%和46.5%(P < 0.05),坡中和坡底土壤养分流失明显,TN含量在坡中比对照区相同坡位下降了29.7%(P < 0.05),OM、AK含量在坡底减少了54.1%、64.1%(P < 0.05).②沉陷区植物种类比对照区减少了28.6%~37.0%,原有优势种羊草(Leymus chinensis)、贝加尔针茅(Stipa Baicalensis)的重要值下降,而双齿葱(Allium bidentatum)、寸草苔(Carex duriuscula)等旱生植物种类和数量增多,植物群落发生退化,群落Margalef丰富度指数、Shannon-Wiener多样性指数和Simpson优势度指数明显低于对照区(P < 0.05).③通过冗余分析可知,土壤性质与群落多样性指数相关性显著(P < 0.05),其中TP、TN、OM和AK含量与多样性指数的相关系数均大于0.5(P < 0.05),TN含量是影响群落多样性的关键因子.④利用因子分析法对土壤-植物系统进行综合评价,显示沉陷区各样地土壤-植物系统与对照区相比呈退化状态,不同坡位的退化程度表现为坡中>坡顶>坡底.研究显示,受沉陷干扰影响,土壤水分和养分发生损失,群落物种多样性下降,土壤-植物系统退化趋势明显,坡中部位(沉陷边缘区)退化最严重.   相似文献   
667.
堆肥通常用于处理有机固体废弃物,可通过接种木质纤维素降解功能菌群提高堆肥进程及产品品质.然而,堆肥过程中传统的功能菌群一次性添加方式,不仅造成了堆肥过程中较低的堆肥效率,而且堆肥产品品质也并不稳定.为了探究基于不同接种方法对堆肥过程腐熟度和品质的影响,设置M0(不接菌)、M1(分阶段接菌)及M2(一次性接菌)3个好氧堆肥处理,考察各处理堆肥过程中理化性质变化、木质纤维素降解及微生物群落多样性.结果表明:M1处理下,堆肥至第20天,堆体温度达到51.2℃且拥有最高的嗜热温度(67.8℃);堆肥至第67天,发芽指数达到83.61%.此外,M1处理下腐殖质增长率、总有机碳降解率、纤维素降解率和木质素降解率均最高,分别为50.20%、53.86%、59.87%和40.61%,远高于其他2个处理.变性梯度凝胶电泳(DGGE)分析显示,在嗜热期,真菌种群对于木质纤维素生物降解的作用比细菌种群更加突出,并且受到总磷含量、pH、碱解氮含量和碳氮比的显著影响.研究显示,分阶段接菌可以显著提高堆体温度及堆体中木质纤维素降解酶活性,促进堆体腐熟进程及堆肥产品中腐殖质等养分积累.   相似文献   
668.
It is argued that the question of whether or not one is required to be or become a strict vegetarian depends, not upon a rule or ideal that endorses vegetarianism on moral grounds, but rather upon whether one's own physical, biological nature is adapted to maintaining health and well-being on a vegetarian diet. Even if we accept the view that animals have rights, we still have no duty to make ourselves substantially worse off for the sake of other rights-holders. Moreover, duties to others, such as fetuses and infants, may require one to consume meat or animal products. Seven classes of individuals who are not required to be or become vegetarians are identified and their examption is related to nutritional facts; these classes comprise most of the earth's population. The rule of vegetarianism defines a special or provisional duty rather than any general or universal rule, since its observance it based upon the biological capacities of individual humans whose genetic constitution and environment makes them suitably herbivorous. It is also argued that generalizing the vegetarian ideal as a social goal for all would be wrongful because it fails to consider the individual nutritional needs of humans at various stages of life, according to biological differences between the sexes, and because it would have the eugenic effect of limiting the adaptability of the human species. The appeal to the natural interests of omnivores will not justify any claim that humans may eat amounts of meat or animal products in excess of a reasonable safety margin since animals have rights-claims against us.  相似文献   
669.
The results of long-term studies on phytoplankton in the cooling reservoir of the Beloyarsk Nuclear Power Plant (the Middle Urals) are reviewed. Altogether, 199 taxa of the species and subspecies rank have been recorded, including 144 taxa described in this water body for the first time. The algoflora of the reservoir consists mainly of widespread and eurybiontic freshwater species.  相似文献   
670.
Environmental Education: Biodiversity   总被引:4,自引:0,他引:4  
Environmental education was a principal topic on the agenda of the Stockholm 1972 Conference. In response to its recommendation UNESCO and UNEP developed and launched the International Environmental Education Program (IEEP) in 1977. Environmental education was perceived to encompass in-school and out-of-school activities and public awareness. Later developments added training to its objectives and the concept of sustainable development to its dimensions. The international Convention on Biological Diversity (CBD) represented a phase in the world commitment to conservation of nature. It underpinned biodiversity in the fields of environmental education. Biodiversity education is based on five pivots: scale of boundaries (from local to worldwide), perspectives, goals, themes (vary according to actors), and assimilation (evaluation of programs of action). Directions relate to learners and teachers, and processes address: awareness, school education, education (and professional training) at tertiary level, roles of communication and media institutions.  相似文献   
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