首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   19篇
  免费   0篇
  国内免费   1篇
综合类   7篇
基础理论   7篇
污染及防治   4篇
评价与监测   1篇
社会与环境   1篇
  2021年   2篇
  2018年   1篇
  2016年   1篇
  2014年   2篇
  2013年   2篇
  2012年   1篇
  2011年   1篇
  2009年   1篇
  2007年   1篇
  2006年   1篇
  2001年   2篇
  2000年   1篇
  1997年   1篇
  1995年   1篇
  1981年   1篇
  1975年   1篇
排序方式: 共有20条查询结果,搜索用时 15 毫秒
11.
Recently, local governments have an increasing need to take extensive and effective local measures to adapt to regional climate change, but have difficulty knowing how and when to adapt to such change. This study aims: 1) to characterize an efficient and cost-effective database management tool (DMT) for developing a Geographic Information System (GIS) based approach to using observed and projected data, for decision-making by non-expert government authorities, and 2) to document how DMT can be used to provide specialized yet understandable climate change information to assist local decision-makers in clarifying regional priorities within a wide array of adaptation options. The DMT combines climate change mapping, statistical GIS, and a vulnerability assessment. Okutama-machi, a 225.63 km2 sparsely populated mountainous region (2012 population 5,856) northwest of Tokyo, Japan, was chosen for this pilot study. In this paper, the most recent regional climate projections (5 km resolution) are transcribed into an understandable form for use by non-expert citizens who use the GIS-based DMT. Results illustrate qualitative agreement in projection of summer daily mean temperatures; the mean temperature increase at Okutama-machi is the greatest of any area in Tokyo. In comparing near future and future conditions, August monthly mean temperature will increase more than 0.7–0.9 °C and 2.8–2.9 °C, and monthly precipitation by 50 % and 25–41 %, respectively. However, the root mean square (RMS) errors and bias of percentage change for monthly precipitation in summertime are 26.8 % and 4.3 %, respectively. These data provide an early warning and have implications for local climate policy response.  相似文献   
12.
This paper describes the analyses of polychlorinated dibenzodioxins, dibenzofurans, and related compounds in diphenyl ether herbicides, CNP, NIP, and X-52. The levels of tetra-, penta-CDDs, and tetra-CDFs were about 150, 30, and 15 ppm, respectively in CNP formulations. NIP and X-52 contained lower chlorine alalogs. Isomer distribution of PCDDs in CNP agreed with an estimate from the reaction of chlorophenols. Freshwater fish samples heavily contaminated with CNP in the application season also contained 0.2 ppb of 1,3,6,8-tetra-CDD.  相似文献   
13.
This paper analyzes whether the reduction of pollution emissions improves a firm’s economic performance through the increase in sales to environmentally conscious customers and the cost reductions associated with the improvement in productivity. Because the selection of the control (end-of-pipe) or prevention (cleaner production) approach differently influences the effect through the improvement in productivity, this is also considered. Using panel data for Japanese manufacturing firms over the period 2002–2008, the findings indicate that firms that have reduced their pollution emissions can increase their economic performance through the increase in demand for their products and an improvement in productivity. However, the latter is conditional, and so the prevention approach is preferred.  相似文献   
14.
Sneaking tactic, a male alternative reproductive tactic involving sperm competition, is generally adopted by small individuals because of its inconspicuousness. However, large size has an advantage when competition occurs between sneakers for fertilization of eggs. Here, we suggest that both large- and small-size advantages of sneaker males are present within the same species. Large sneaker males of the dusky frillgoby Bathygobius fuscus showed a high success rate in intruding into spawning nests because of their advantage in competition among sneaker males in keeping a suitable position to sneak, whereas small sneakers had few chances to sneak. However, small sneaker males were able to stay in the nests longer than large sneaker males when they succeeded in sneak intrusion. This suggests the possibility of an increase in their paternity. The findings of these size-specific behavioural advantages may be important in considering the evolution of size-related reproductive traits.  相似文献   
15.
Several ice nucleating substances have been identified, which exist in vivo or can be extracted from biological materials. Spider silk, which has a strong ability for water condensation, has also been found to possess an ice nucleation activity. The freezing temperature of water droplets was higher in the presence than in the absence of spider silk. Moreover, by means of environmental scanning electron microscopy, it was observed that the activity is not due to foreign matter attached to the silk but to the silk fibroin itself.  相似文献   
16.
The development of gill chloride cells was examined in premetamorphic larvae (leptocephali) and juveniles (glass eels) of the Japanese eel, Anguilla japonica. Branchial chloride cells were detected by immunocytochemistry using an antiserum specific for Na+,K+-ATPase. The specificity and availability of the antiserum for the detection of Japanese eel chloride cells were confirmed by Western blot analysis. The chloride cells first appeared on the developing gill filaments in a mid larval stage of leptocephalus (32.2 mm). Both immunoreactivity and the number of chloride cells gradually increased as the fish grew to a late stage of leptocephalus over 54 mm. In glass eels just after metamorphosis, gill lamellae developed from the gill filaments, and a rich population of chloride cells was observed in the gill filaments. In glass eels collected at a coastal area, chloride cells were extensively distributed in the gill filaments. The chloride cell size decreased progressively in glass eels transferred from seawater (SW) to freshwater (FW), whereas there was no difference in cell number. In contrast, some Na+,K+-ATPase immunoreaction distinct from typical chloride cells was observed in the gill lamellae throughout FW-transferred fish, but disappeared in control fish maintained in SW for 14 days. These findings indicate that the gill and gill chloride cells developed slowly during the extremely long larval stage, followed by rapid differentiation during a short period of metamorphosis. The excellent euryhalinity of glass eels may be due to the presence of the filament chloride cells and lamellar Na+,K+-ATPase-immunoreaction, presumably being responsible for SW and FW adaptation, respectively.  相似文献   
17.
To evaluate the osmoregulatory ability of eyedstage embryos of laboratory-reared chum salmon, Oncorhynchus keta, we examined changes in osmolality of the perivitelline fluid and blood following transfer to 50 and 100% seawater (SW), together with morphological changes in chloride cells present in the yolk sac membrane. Transfer to SW did not cause any significant change in the whole egg weight. However, the embryos shrank when the eggs were transferred to SW, whereas the perivitelline space increased at the expense of the embryo. Osmolality of the perivitelline fluid increased rapidly to reach environmental levels 3 h after transfer, indicating that the egg shell is permeable to ions and water. Blood osmolality increased after transfer to SW, reached a peak level at 3 h, and then decreased gradually. The chloride cells in the yolk sac membrane became activated following transfer, as shown by increased cell size and frequent appearance of apical openings. These results indicate that the eyed-stage embryos of chum salmon possess hypoosmoregulatory ability and that chloride cells in the yolk sac membrane may be involved in salt extrusion, in place of gill chloride cells, during the late embryonic stage.  相似文献   
18.
We examined the degradation of dibromophenols (DBPs), i.e. 2,4-DBP, 2,6-DBP and 3,5-DBP by ultraviolet (UV) irradiation and estimated the relationship between degradability and molecular orbital properties of each dibromopbenol. The removal of DBPs under a UV lamp system was successfully performed in an aqueous solution. After 5 min of irradiation, the initial DBPs concentration of 20 mg/L was decreased to below 1 mg/L, and about 60% of bromide ion was released. A decrease in the concentration of dissolved organic carbon (DOC) suggested the mineralization of DBPs, The mineralization may occur after release of bromide ions because the decrease of DOC was slower than the release of bromide ions. The degradability of 3,5-DBP was slightly lower than 2,6-DBP and 2,4-DBE Molecular orbital calculation suggested that the electrophilic frontier density and the highest occupied molecular orbital (HOMO) energy may be related to the degradability of DBPs.  相似文献   
19.
The future of the environment in China until the year 2050 has been forecasted through a heuristic approach. A questionnaire survey was given to a group of Japanese experts concerning 47 selected indices, including past data and reference data about other countries. The indices were related to aspects of the economy, population, food, energy, transportation, and the environment. The experts were requested to plot a graph for each index up to 2050 based on their intuition. The lines drawn by 60 experts were compiled along with their comments, and the characteristics of each index were analyzed. Different values for the indices regarding transportation and per capita GDP were forecasted by the experts, while rather similar values were obtained for those referencing population and food consumption. The respective fields of the experts were found to affect their perspectives on the future. Economists tended to show rather optimistic views, expressing a business-as-usual scenario, while engineers predicted limited growth but technological innovation.  相似文献   
20.
Academics, policymakers, and practitioners have long considered peace and sustainability to be fundamentally linked. However, despite the increased attention paid toward the intersection of peace and sustainability, there is still limited knowledge on the nature of their linkages. To advance the current understanding on the peace–sustainability nexus and inform an integrated research agenda, this paper employs a scientometric analysis of literature to identify publication trends, thematic clusters, and knowledge gaps. Analyzing the publications according to the types of peace, the pillars of positive peace, the dimensions of sustainability, and the SDGs further reveals weak engagement among academic disciplines and across the SDGs. The results of this analysis emphasize the need for future research to focus on underexamined subjects, geographic regions, and sectors to bolster the linkages between peace and sustainability.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01388-8) contains supplementary material, which is available to authorized users.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号