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591.
592.
随着区域经济的发展,创新是时代的最显著特征,因此强化对区域创新环境的研究显得非常重要。只有建立良好的区域创新环境,才能形成更大规模的经济增长效应。对比了中部6省,分析了河南省的技术创新环境在中部6省中的地位以及其优势和劣势,指出了影响技术创新环境的主要问题,提出了培育良好的技术创新环境的基本途径。 相似文献
593.
为进一步完善我国废物焚烧标准体系,防控废物焚烧环境风险,本文对欧盟废物焚烧指令与我国焚烧标准体系进行了对比分析。欧盟废物焚烧指令分别对专用焚烧厂和协同焚烧厂从废物运输到处理处置全过程的污染物排放控制做出了相关规定,适用于危险废物和非危险废物的焚烧以及常规污染物和有毒污染物的控制。欧盟废物焚烧指令对不同规模的焚烧设施采用统一标准,以日均值和半小时均值为污染物排放限值,更客观、准确地评价了污染物排放对环境的影响。与欧盟废物焚烧指令相比,我国废物焚烧标准涉及废物联合利用处置的相关条文较少,内容不详,项目缺失。我国烟尘、HCl的排放限值均在欧盟标准限值6倍以上,SO2的排放限值是欧盟标准的4~8倍。除CO、NOx的排放限值外,其他污染物排放限值也明显高于欧盟标准限值。我国采用抽样监测方法,监测结果可能在日常排放值的95%置信区间外,不具备代表性。我国可借鉴欧盟废物焚烧指令的成果制定协同焚烧标准,并严格污染物排放限值,考虑采用日均值或半小时均值的评价方法,提高我国废物焚烧标准的精确性和可执行性。 相似文献
594.
Salthammer T 《Chemosphere》2011,82(11):1507-1517
The importance of good indoor air quality for the health of the individual was recognized as long as 150 years ago and that period also saw recommendations, which essentially related to questions of ventilation and carbon dioxide. The first evaluation standards for organic and inorganic substances were laid down in the 1970s, often on an empirical basis. It was in the mid-1980s of the 20th century that a shift occurred towards systematically evaluating the results of indoor air measurements, carrying out representative environmental surveys and deriving guideline values and reference values on the basis of toxicological, epidemiological and statistical criteria. Generally speaking the indoor environment is an area which can only be assessed with difficulty since its occupants are in most cases exposed to mixtures of substances and there can be great local and temporal variations in the substance spectrum. Data are available today for a large number of substances and this makes it possible, with the aid of statistically derived reference values and toxicologically based guideline values, to make useful recommendations regarding good indoor air quality. Nevertheless, it is still difficult to evaluate reactive compounds and reaction products. What is disadvantageous, however, is the fact that different guideline values may be published for one and the same substance, whose justification and area of application are often not transparent. A guideline or reference value can only be regarded as rational when necessary and when a strategy for its verification is available. 相似文献
595.
Hadrien P. A. Vanthomme Brave S. Nzamba Alfonso Alonso Angelique F. Todd 《Conservation biology》2019,33(2):329-338
Corridors are intended to increase species survival by abating landscape fragmentation resulting from the conversion of natural habitats into human-dominated matrices. Conservation scientists often rely on 1 type of corridor model, typically the least-cost model or current-flow model, to construct a linkage design, and their choice is not usually based on theory or empirical evidence. We developed a method to empirically confirm whether corridors produced by these 2 models are used by target species under current landscape conditions. We applied this method in the Gamba landscape between 2 national parks in southwestern Gabon. We collected signs of presence of African forest elephant (Loxodonta cyclotis), forest buffalo (Syncerus caffer nanus), and 2 apes, western lowland gorilla (Gorilla gorilla gorilla) and central chimpanzee (Pan troglodytes troglodytes), on transects. We used patch-occupancy models to identify least-cost and current-flow corridors for these 4 species. On average, 28.7% of current-flow corridors overlapped with least-cost corridors, confirming that the choice of corridor model can affect the location of the resulting linkage design. We validated these corridors by monitoring signs and examining camera detections on new transects within and outside modeled corridors. Current-flow corridors performed better than least-cost corridors for elephants, whereas the opposite was found for buffalo and apes. Locations of the highest priority corridors for the 3 taxa did not overlap, and only 18.3% of their combined surface was common among 2 species. We used centrality metrics to calculate the average contribution of corridor pixels to landscape connectivity and derived an index that can be used to prioritize corridors. As a result, we recommend protecting at least 17.4% of the land surface area around Gamba town to preserve the preferred travel routes of the target species. 相似文献
596.
Science denialism retards evidenced-based policy and practice and should be challenged. It has been a particular concern for mitigating global environmental issues, such as anthropogenic climate change. But allegations of science denialism must also be well founded and evidential or they risk eroding public trust in science and scientists. Recently, 77 published works by scholars, scientists, and science writers were identified as containing invasive species denialism (ISD; i.e., rejection of well-supported facts about invasive species, particularly the global scientific consensus about their negative impacts). We reevaluated 75 of these works but could find no examples of refutation of scientific facts and only 5 articles with text perhaps consistent with one of the 5 characteristics of science denialism. We found, therefore, that allegations of ISD were misplaced. These accusations of science denialism may have arisen because invasion biology defines its subjects—invasive species—based on multiple subjective and normative judgments. Thus, more than other applied sciences its consensus is one of shared values as much as agreed knowledge. Criticisms of invasion biology have largely targeted those subjective and normative judgments and their global imposition, not the knowledge on which the discipline is based. Regrettably, a few invasion biologists have misinterpreted the critique of their values-based consensus as a denial of their science when it is not. To make invasion biology a more robust and widely accepted science and to avoid unnecessary misunderstandings and conflicts, invasion biologists could be more accepting of perspectives originating from other disciplines and more open to values-based critique from scholars and scientists outside their field. This recommendation applies to all conservation sciences, especially those addressing global challenges, because these sciences must serve and be relevant to communities with an extraordinary diversity of cultures and values. 相似文献
597.
基于三波长透射率的水体色度检测标准 总被引:1,自引:0,他引:1
为了推动有关分光光度法测量水体色度的国家标准的建立,对美国和台湾地区的水体色度标准检测方法进行了研究,提出了新的基于三波长透射率测量水体色度的方法。根据现行国家标准中的色度学相关数据,选择在595、555和445 nm 3个波长处的光谱透射率计算水样的三刺激值,依照国标推荐的色差公式建立了测量水样色度的标准检量线。利用所提出的新的水体色度测量方法对5个水样的色度值进行了实际测量,结果表明,新的测量方法所得到的水体色度值与铂钴比色法一致。 相似文献
598.
Human urine as a source of alternative natural fertilizer in agriculture: A flight of fancy or an achievable reality 总被引:2,自引:0,他引:2
Organically agricultural products are gaining popularities through out the world as it gives the consumer satisfaction with a basket of safer and better trusted foods. It is also well established that intensive conventional agricultural practices can introduce contaminants into the food chain with adverse affect on environment. However, organic agricultural practices give an alternative environmental friendly sustainable agriculture among the farmers. Beside this fact, organic crops contain fewer nitrates, nitrites, pesticide residues and trace elements than conventional crops. Even though, in organic systems generally have 20% lower yields than conventionally produced crops. One of the major constrains of organic farming is decrease of raw organic matters to prepare compost. Therefore, scientists are looking forward for different organic sources which are plenty in nature and available at little-to-no cost. Human urine is one of them, and has been gaining popularities as a raw material for organic cultivation. However, several important merits and demerits of application of human urine are needed to be addressed in agriculture. 相似文献
599.
MIRANDA H. MOCKRIN ROBERT F. ROCKWELL KENT H. REDFORD NICHOLAS S. KEULER 《Conservation biology》2011,25(3):514-525
Abstract: Understanding the spatial dimensions of hunting and prey population dynamics is important in order to estimate the sustainability of hunting in tropical forests. We investigated how hunting offtake of vertebrates differed in mixed forest and monodominant forest (composed of Gilbertiodendron dewevrei) and over different spatial extents within the hunting catchment around the logging town of Kabo, Congo. In 9 months of recall surveys with hunters, we gathered information on over 1500 hunting trips in which ungulates were 65% of the species killed and 82% of harvested biomass. Hunters supplied information on animals killed and the hunting trip, including the area visited (i.e., hunting zone; 11 separate zones within a 506 km2 catchment or commonly hunted area). Over 65% of all animals were killed in monodominant forest, which made up 28% of the hunting catchment, and zones with small amounts of monodominant forest were used most frequently by hunters. Given the large offtakes from monodominant forests, we suggest that animal dispersal may be maintaining high, localized harvests in these areas. We believe hunters preferred to hunt in monodominant forest because the understory was accessible and that areas with small amounts of monodominant forest and large amounts of mixed forest were more productive. The variation in hunting pressure we found between and within hunting zones differs from past examinations of spatial variation in hunting offtake, where entire hunting catchments were considered population sinks and areas with low to no hunting (no‐take zones) were outside hunting catchments. Future use of no‐take zones to manage hunting should incorporate variability in offtake within hunting catchments. 相似文献
600.
中央分隔带是高速公路中对视觉景观影响最重要的一部分,在对其具体的生念、环境、景观和安全要求进行分析的基础上,提出景观设计的方法。根据笔者在焦新高速公路种植设计中的体验,从植物配置、生态要求等方面对中央分隔带的绿化景观设计进行了总结。 相似文献