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121.
球形红杆菌废水除磷作用的研究 总被引:3,自引:0,他引:3
文章考察了磷源、碳源、硫源对废水生物除磷优势菌球形红杆菌磷代谢的影响,结果表明:在微好氧条件下,缺磷环境会使球形红杆菌产生过量摄磷现象;经无碳和无硫培养后,转移到富磷培养基内,也会产生过量摄磷现象,但随着培养时间的延长,菌体摄磷量下降;该菌体经预培养转入富磷培养基后,碳源不同其摄磷能力有所差异;以苹果酸为碳源时的摄磷量略大于以乙酸源时的摄磷量。 相似文献
122.
利用模糊集理论与分形理论相结合的模糊分维方法 ,处理了山东聊古 1井水氡 1 0多年来的观测资料 ,找出了水氡模糊分维值的 3次较大变化与相应 3次地震的关系。在这 3次地震前水氡模糊分维值都出现明显地小于 0 5 7的低值异常变化。这可能反映了系统在较大地震前的明显降维特征 相似文献
123.
Per StÅlnacke Anders Grimvall Karin Sundblad Andrzej Tonderski 《Environmental monitoring and assessment》1999,58(2):173-200
This article presents the results of the first critical examination of time series of riverine nutrient-load data for the entire Baltic Sea drainage area. Water quality data collected by or for the different national environmental agencies were compiled and analysed statistically to identify and remove inconsistent or obviously incorrect observations. Moreover, sampling tours were undertaken to acquire additional information about the present nutrient concentrations in the largest rivers in the study area. Gaps in the time series of approved data were then filled in by employing statistical interpolation and extrapolation methods. Thereafter, the concentration and runoff data were combined to obtain estimates of monthly nutrient loads for the time period 1970–93. The results of the calculations showed that although there had been substantial changes in land use, atmospheric deposition and wastewater treatment in many parts of the study area, the total riverine loads of nitrogen (N) and phosphorus (P) to the Baltic Sea have been fairly constant since 1980, and most likely also since 1970. Moreover, the interannual variation was clearly correlated to the runoff. The mean annual loads for the time period 1980–93 were found to be about 825 000 tonnes N and 41 000 tonnes P, respectively. This implies that (i) several other investigators have strongly underestimated the riverine loads of nutrients, especially the nitrogen, and that (ii) the riverine loads by far exceed the input to the Baltic Sea from other sources, {i.e.} atmospheric deposition, direct emissions from cities and industries along the Baltic Sea coast and nitrogen fixation by marine algae. 相似文献
124.
Characterizing fish responses to a river restoration over 21 years based on species’ traits
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Stefanie Höckendorff Jonathan D. Tonkin Peter Haase Margret Bunzel‐Drüke Olaf Zimball Matthias Scharf Stefan Stoll 《Conservation biology》2017,31(5):1098-1108
Understanding restoration effectiveness is often impaired by a lack of high‐quality, long‐term monitoring data and, to date, few researchers have used species’ trait information to gain insight into the processes that drive the reaction of fish communities to restoration. We examined fish‐community responses with a highly resolved data set from 21 consecutive years of electrofishing (4 years prerestoration and 17 years postrestoration) at multiple restored and unrestored reaches from a river restoration project on the Lippe River, Germany. Fish abundance peaked in the third year after the restoration; abundance was 6 times higher than before the restoration. After 5–7 years, species richness and abundance stabilized at 2 and 3.5 times higher levels relative to the prerestoration level, respectively. However, interannual variability of species richness and abundance remained considerable, illustrating the challenge of reliably assessing restoration outcomes based on data from individual samplings, especially in the first years following restoration. Life‐history and reproduction‐related traits best explained differences in species’ responses to restoration. Opportunistic short‐lived species with early female maturity and multiple spawning runs per year exhibited the strongest increase in abundance, which reflected their ability to rapidly colonize new habitats. These often small‐bodied and fusiform fishes typically live in dynamic and ephemeral instream and floodplain areas that river‐habitat restorations often aim to create, and in this case their increases in abundance indicated successful restoration. Our results suggest that a greater consideration of species’ traits may enhance the causal understanding of community processes and the coupling of restoration to functional ecology. Trait‐based assessments of restoration outcomes would furthermore allow for easier transfer of knowledge across biogeographic borders than studies based on taxonomy. 相似文献
125.
Jagers Sverker C. Harring Niklas Löfgren Åsa Sjöstedt Martin Alpizar Francisco Brülde Bengt Langlet David Nilsson Andreas Almroth Bethanie Carney Dupont Sam Steffen Will 《Ambio》2020,49(7):1282-1296
Ambio - The phenomenon of collective action and the origin of collective action problems have been extensively and systematically studied in the social sciences. Yet, while we have substantial... 相似文献
126.
Mikael Larsson Carl-Erik Grip Hans Ohlsson Staffan Rutqvist Jan-Olov Wikström Sten Ångström 《International Journal of Green Energy》2013,10(2):171-183
During the years 2001–2002, a comprehensive study regarding CO2 emissions related to the steel production for the integrated steel making production route, was carried out. The study was financed by SSAB and carried out by a research group with members from SSAB, MEFOS and LTU. The aim was to study the emissions from the existing system and how these could be influenced by process changes and by process modifications. The calculations were made using a global spreadsheet model for calculating the CO2 emissions, developed from an existing Energy and Process Integration model of the same system. The calculated cases included the existing BF/BOF route as well as integration of other processes, e.g., an electric arc furnace, DR processes, COREX and a new future smelting reduction process concept (Sidcomet). All new existing alternative ore based process technologies would increase the specific CO2 emission from the system. A technology transfer to scrap based metallurgy would significantly decrease the emission level, but is not feasible for SSAB, due to the future product mix and the structure of scrap availability. In a 5–20 year perspective, the existing steel making process route with the use of magnetite ore for pellet production has the lowest specific CO2 emission. In a long-term perspective, 20–50 years, alternative process routes, e.g., based on H2 and DRI, could be of interest. Studies on such changes are, however, big projects and should be carried out as joint European and/or international efforts. 相似文献
127.
Taru Peltola Maria Åkerman Jarkko Bamberg Pauliina Lehtonen Outi Ratamäki 《Journal of Environmental Policy & Planning》2018,20(2):157-169
Drawing on the wide social scientific literature on emotions and affects, we highlight the value and potential contribution of the affect theory for understanding public engagement in environmental policy and planning. We suggest that such theorization complements political ontologies that envision concerned publics to arise as citizens are attached to objects and other beings in their everyday life. Focus on emotions and affects enables in-depth exploration of the corporeality of these attachments, increasing understanding about how affected publics get driven for action and how new sensibilities and horizons for action are created. Based on the discussion of affect theory and case examples, we argue that emotions and affects should be treated as crucial carriers of knowledge about transformation of political subjects and their concerns. They also direct analytic gaze beyond public participation procedures and encourage the development of novel, more inclusive settings for public engagement. 相似文献
128.
Common mussels (Mytilus edulis L.) were exposed over a 5-month period to low-level concentrations (0.5 to 1.5 ppm) of a nonionic surfactant. Upon maturation at the end of this period, spawning ability was examined. Fertilization occurred at low-level concentrations (0.1 to 2.0 ppm) of the surfactant, and was most successful for gametes from the long-term controls and the highest long-term concentration (1.5 ppm). Inhibited or delayed larval development was observed, related to the concentration gradient of the short-term exposures. Gametes from mussels long-term exposed to the surfactant were more sensitive than those from the long-term control. 相似文献
129.
Water, Air, &; Soil Pollution: Focus - 相似文献
130.