排序方式: 共有22条查询结果,搜索用时 15 毫秒
11.
Justus von Geibler 《生态毒理学报》2003,25(3):63-66
要维持其市场地位,中小企业就必须提高他们的效率.然而,他们往往因为缺少时间、金钱和信息而难以对他们自己的活动、制定目标以及因此不断提高产品和服务(经济上、社会上和环境上)做出正确估价.现有的复杂的国际环境管理方案,对于中小企业常常不适用.不同级别信息"门童"间的合作,对于提高中小企业的环境与社会健康生产方式意识、教给他们日常业务中一体化关注环境与社会的方法、确立经济地位以及奖励这些努力,都是十分必要的. 相似文献
12.
13.
14.
Landscape multifunctionality: a powerful concept to identify effects of environmental change 总被引:2,自引:0,他引:2
Janine Bolliger Michèle Bättig Justus Gallati Andreas Kläy Michael Stauffacher Felix Kienast 《Regional Environmental Change》2011,11(1):203-206
The interdisciplinary concept of landscape multifunctionality provides a suitable platform to combine or disentangle effects
of multiple environmental stressors acting on the landscape. The concept allows mapping of trade-offs, synergies, and priority
conflicts between individual landscape functions, thus providing easily accessible, hands-on means to communicate findings
of environmental research to decision makers and society. This rapid communication provides an overview of current developments
and potential future research avenues in landscape multifunctionality. 相似文献
15.
Billy Justus 《Environmental monitoring and assessment》2010,168(1-4):363-383
A three-phased study identified one least-impaired (reference) lake for each of four Arkansas lake classifications: three classifications in the Mississippi Alluvial Plain (MAP) ecoregion and a fourth classification in the South Central Plains (SCP) ecoregion. Water quality at three of the least-impaired lakes generally was comparable and also was comparable to water quality from Kansas and Missouri reference lakes and Texas least-impaired lakes. Water quality of one least-impaired lake in the MAP ecoregion was not as good as water quality in other least-impaired lakes in Arkansas or in the three other states: a probable consequence of all lakes in that classification having a designated use as a source of irrigation water. Chemical and physical conditions for all four lake classifications were at times naturally harsh as limnological characteristics changed temporally. As a consequence of allochthonous organic material, oxbow lakes isolated within watersheds comprised of swamps were susceptible to low dissolved oxygen concentrations to the extent that conditions would be limiting to some aquatic biota. Also, pH in lakes in the SCP ecoregion was <6.0, a level exceeding current Arkansas water-quality standards but typical of black water systems. Water quality of the deepest lakes exceeded that of shallow lakes. N/P ratios and trophic state indices may be less effective for assessing water quality for shallow lakes (<2 m) than for deep lakes because there is an increased exposure of sediment (and associated phosphorus) to disturbance and light in the former. 相似文献
16.
Degradation of macrolide antibiotics by ozone: a mechanistic case study with clarithromycin 总被引:6,自引:0,他引:6
Lange F Cornelissen S Kubac D Sein MM von Sonntag J Hannich CB Golloch A Heipieper HJ Möder M von Sonntag C 《Chemosphere》2006,65(1):17-23
Macrolide antibiotics are widely used (in the order of 1g per person per year). They pass the body largely unchanged and are also not degraded in wastewater treatment plants. With not too much effort, they may be eliminated from their effluents by ozonation. The macrolide antibiotics have all a dimethylamino group at one of the carbohydrate residues in common. This functional group is the target of the ozone reaction, and clarithromycin has been selected here for a more detailed study. Since only the free amine reacts with ozone, the rate of reaction is pH dependent (at pH 7: k = 4 x 10(4) M(-1) s(-1)). In analogy to the ozonolysis of trimethylamine, the main reaction is a transfer of an O-atom yielding the N-oxide (identified by HPLC/MS-MS). A minor product (10%, based on formaldehyde yields) is demethylated clarithromycin (identified by HPLC/MS-MS). The dimethylamino group is thought to be essential for the binding of the macrolide antibiotics to their target. As a consequence, chemical changes of this functional group, notably the formation of the N-oxide that is no longer a proton acceptor, inactivates these drugs as assayed by the suppression of the growth of Pseudomonas putida. This is most important for wastewater treatment, as mineralization of clarithromycin by ozone would require 100 times as much ozone. 相似文献
17.
中小企业越来越期望对他们自己环境和社会影响负起责任来(正如跨国公司所做的那样),理解不同利益相关者的兴趣和要求,并且通过更大的透明度证明自己的行为是负责任的.许多要素既可以阻碍也可以驱动较小企业推动法人环境与社会责任战略的实施.为了克服实施这类战略的障碍,适合小型或中等企业需要的方法才可用.在某些领域.会同跨国公司这个关键的利益相关者团体一起,这方面的促进努力已经行动起来了. 相似文献
18.
Justus Kristine A. Murlis John Jones Chris Cardé Ring T. 《Environmental Fluid Mechanics》2002,2(1-2):115-142
The patterns of stimulus available to moths flying along pheromone plumes in a 3-m-long wind tunnel were characterized using a high frequency photoionization detector in conjunction with an inert tracer gas. Four contrasting flow regimes and source conditions were produced: odor released in pulses from a vertical and horizontal array of four sources, odor released continuously from a point source, and odor released continuously from a point source into an oscillatory wake. Although the four flow regimes produced plumes of intermittent and fluctuating concentration, there were considerable differences in the structure of the signal presented to the sensor. Pulses of tracer gas released at 10 Hz retained most of their longitudinal and lateral separation. The plume growing in the disturbed flow (`oscillatory'), was broader in its lateral extent than the plume growing in an undisturbed flow (`continuous'), and the concentrations in the former were lower at each downstream position. The signal recorded in the disturbed flow had higher intermittency, but the ratio between the peak concentration and the signal mean was lower than in the continuous plume. Time scales were typically longer in the tunnel than in a field setting, but length scales and the main features of intermittency and fluctuation were similar. Moths flying along plumes of pheromone in this and similar wind tunnels typically slow their velocity and narrow the lateral excursions of their flight track as they approach a pheromone source. Which features of the plumes measured in this study account for these behavioral reactions remains to be determined. 相似文献
19.
Article impact statement: Normative scientists must be trained in current thinking of the philosophy that underlies their fields, an issue not fully realized in conservation. 相似文献
20.
This report describes a study to identify reference lakes in two lake classifications common to parts of two level III ecoregions in western Arkansas—the Arkansas Valley and Ouachita Mountains. Fifty-two lakes were considered. A screening process that relied on land-use data was followed by reconnaissance water-quality sampling, and two lakes from each ecoregion were selected for intensive water-quality sampling. Our data suggest that Spring Lake is a suitable reference lake for the Arkansas Valley and that Hot Springs Lake is a suitable reference lake for the Ouachita Mountains. Concentrations for five nutrient constituents—orthophosphorus, total phosphorus, total kjeldahl nitrogen, total nitrogen, and total organic carbon—were lower at Spring Lake on all nine sampling occasions and transparency measurements at Spring Lake were significantly deeper than measurements at Cove Lake. For the Ouachita Mountains ecoregion, water quality at Hot Springs Lake slightly exceeded that of Lake Winona. The most apparent water-quality differences for the two lakes were related to transparency and total organic carbon concentrations, which were deeper and lower at Hot Springs Lake, respectively. Our results indicate that when nutrient concentrations are low, transparency may be more valuable for differentiating between lake water quality than chemical constituents that have been useful for distinguishing between water-quality conditions in mesotrophic and eutrophic settings. For example, in this oligotrophic setting, concentrations for chlorophyll a can be less than 5 μg/L and diurnal variability that is typically associated with dissolved oxygen in more productive settings was not evident. 相似文献