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51.
模糊评价能有效的解决评价标准边界模糊和监测误差对评价结果的影响,具有一定的科学性、合理性.运用模糊数学法对天津滨海新区环境质量各因素进行定级评价,将各因素评价结果采用公式计数法进行二级赋权,较为客观评价了总体环境质量级别,为综合治理提供科学依据. 相似文献
52.
分析了三维电极法处理医院污水的影响因素,探讨了阳极材料、电流密度.水力停留时间、空气流量、极水比等因素对消毒效果的影响,确定在不加化学药剂、不影响水质和低耗能条件下电化学消毒试验的最佳使用条件。结果表明,在用涂有贵金属(钌、铂、铱)氧化物的钛板作阳极,不锈钢板作阴极,电流密度为6mA/cm^2、水力停留时间为15min、空气流量为40L/h、极水比为1.0的试验条件下,消毒后污水中总大肠菌群数〈500CFU/L。电化学法消毒处理医院污水方法简单有效、运行费用低,无二次污染.处理后的污水达到国家一级排放标准(GB8978—1996)。 相似文献
53.
The comparative research of southern Andes and Antarctic Peninsula is a key to explain the break-up of Gondwanaland. "Cuspate" , "Arcuate", "Continuing". "Overlapping" and "Modified Gulf of California" model illustrated, to some extent, southern Andes-Antarctic Peninsula relations. However, those models did not discuss the dynamic mechanism and specific evolution process of the two Plates' divergence. "Wedge" model, on the bases of eight geological evidences including tectono-stratigraphic unit, strike-slip fault system, carthquake, igneous activity and so on, not only discussed southern Andes-Antarctic Peninsula relations and its evolution process, but also presented an argument that Scotia minor-plate, which once acted as one part of Pacific Plate wedged in between the two Plates and gave rise to the break-up of Gondwanaland-The argument represents the the latest achievement made in geological research there. On the whole, all models mentioned-above are, more or less, of one-sided view. Where the dynam 相似文献
54.
55.
亭子口库区水质汞的污染特征及建库后水体中汞的预测 总被引:1,自引:1,他引:1
亭子口水利枢纽位于喜陵江平流苍溪县城以上,15km处。本文根据嘉陵江广元段水质监测资料,分析库区地面水体中汞的现状污染特征,并运用沉积物的负指数方程预测库区建坝后水体中汞的浓度。 相似文献
56.
Nada Horvatinčić José Luis Briansó Bogomil Obelić Jadranka Barešić Ines Krajcar Bronić 《Water, Air, & Soil Pollution: Focus》2006,6(5-6):475-485
The process of eutrophication in form of intense plant growth has been observed in some lakes and water streams at the Plitvice
Lakes National Park in central Croatia. Here we investigate whether this phenomenon is a consequence of anthropogenic pollution
or due to naturally produced organic matter in the lakes. We applied chemical analysis of water at two springs and four lakes
(nutrients, dissolved organic carbon (DOC), trace elements) and measurements of surface lake sediments (mineral and organic
fraction analyses, trace elements) in four different lakes/five sites. The chemical composition of water does not indicate
recent anthropogenic pollution of water because the concentrations of most trace elements are below detection limits. The
concentrations of DOC and nutrients are slightly higher in the area of increased eutrophication-plant growth. Also the content
of organic matter in the sediment is at the highest level in areas with highest C/N ratio indicating that the organic fraction of this sediment is mainly of terrestrial origin. There is no significant difference
among the trace element concentration in the upper segment of all cores, deposited approximately during last 50 years when
higher anthropogenic influence is expected due to development and touristic activity, and the lower part of the cores, corresponding
to the period approximately 100–200 years before present. The content of trace elements and organic matter in sediments decreases
from the uppermost lake downstream. According to our results there is no indication of recent anthropogenic pollution in water
and sediment. Higher concentrations of DOC in water as well as phosphorus and some other elements in the lake sediment can
be a consequence of input of natural organic matter to the lake water. 相似文献
57.
58.
钻井是石油天然气勘探开发过程中的重要环节,钻井过程中污染物的排放管理也受到各国普遍的重视。对钻井污染物的特点进行了分析,在此基础上概括地介绍了美国的相关环境管理法规体系。重点论述了与钻井排污有关的资源保护与补偿法、安全饮用水法、清洁水法等,总结了可供我国借鉴的若干法规、标准制定的理念和方法。 相似文献
59.
Germano L. D. Leite Paula D. de Paulo José C. Zanuncio Anarelly C. Alvarenga Luan R. Dourado 《Journal of environmental science and health. Part. B》2017,52(1):70-76
Selective agrochemicals including herbicides that do not affect non-target organisms such as natural enemies are important in the integrated pest management (IPM) programs. The aim of this study was to evaluate the herbicide toxicity, selectivity and hormesis of nicosulfuron, recommended for the corn Zea mays L. (Poaceae) crop, on 10 Trichogrammatidae (Hymenoptera) species. A female of each Trichogramma spp. or Trichogrammatoidea annulata De Santis, 1972 was individually placed in plastic test tubes (no choice) with a cardboard containing 45 flour moth Anagasta ( = Ephestia) kuehniella Zeller, 1879 (Lepidoptera: Pyralidae) eggs. Parasitism by these natural enemies was allowed for 48 h and the cardboards were sprayed with the herbicide nicosulfuron at 1.50 L.ha?1, along with the control (only distilled water). Nicosulfuron reduced the emergence rate of Trichogramma bruni Nagaraja, 1983 females, but increased that of Trichogramma pretiosum Riley, 1879, Trichogramma acacioi Brun, Moraes and Smith, 1984 and T. annulata females. Conversely, this herbicide increased the emergence rate of Trichogramma brasiliensis Ashmead, 1904, T. bruni, Trichogramma galloi Zucchi, 1988 and Trichogramma soaresi Nagaraja, 1983 males and decreased those of T. acacioi, Trichogramma atopovilia Oatman and Platner, 1983 and T. pretiosum males. In addition, nicosulfuron reduced the sex ratio of T. galloi, Trichogramma bennetti Nagaraja and Nagarkatti, 1973 and T. pretiosum and increased that of T. acacioi, T. bruni, T. annulata, Trichogramma demoraesi Nagaraja, 1983, T. soaresi and T. brasiliensis. The herbicide nicosulfuron was “harmless” (class 1, <30% reduction) for females and the sex ratio of all Trichogrammatidae species based on the International Organization for Biological Control (IOBC) classification. The possible hormesis effect of nicosulfuron on Trichogrammatidae species and on the bacterium Wolbachia sp. (Rickettsiales: Rickettsiaceae) was also discussed. 相似文献
60.
Rose Emília Queiroz José Guerreiro Maria Anunciação Ventura 《Environment, Development and Sustainability》2014,16(5):1119-1135
In general, tourism plays a significant role in the economy of archipelagos and islands. The Autonomous Region of the Azores has a great potential for tourism, offering multiple attractions, both natural and cultural, creating a big challenge for a sustainable tourism policy since little attention has been paid to the archipelagos and their special needs. This work aims to understand the profile and type of ecotourist that visits the Azores. This knowledge is of great importance for a better management and development of nature-based tourism, and products tailored to the needs and expectations of visitors. The data were collected by means of exit surveys conducted at the Airport of São Miguel Island, the larger and most populated island of the archipelago, during the high tourist season—July–September 2009. The analysis of the visitor’s profile and preferences is crucial to draw adequate strategies of management for tourism, while it helps to adequate the offer to the demand. Results showed that 41.1 % of the tourists claimed to be attracted to the islands due to their “natural values” (e.g., landscape, biodiversity, and geodiversity). The most practiced activities were whale-watching (32.4 %) and mountaineering/hiking (31.6 %), followed by diving (7 %) and other sports (5.1 %). The tourists’ profile points to a mainstream, soft, and incidental type of ecotourist. This information helps to develop and support a strategic planning and management, both at local and regional levels, for sustainable tourism policies. 相似文献