全文获取类型
收费全文 | 40篇 |
免费 | 1篇 |
国内免费 | 7篇 |
专业分类
废物处理 | 6篇 |
综合类 | 14篇 |
基础理论 | 9篇 |
污染及防治 | 13篇 |
评价与监测 | 3篇 |
社会与环境 | 2篇 |
灾害及防治 | 1篇 |
出版年
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 7篇 |
2012年 | 6篇 |
2011年 | 5篇 |
2010年 | 1篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1993年 | 1篇 |
1989年 | 1篇 |
1982年 | 1篇 |
1976年 | 2篇 |
排序方式: 共有48条查询结果,搜索用时 31 毫秒
1.
This is the first report of gynandromorphy in Isoptera. An Asian dry-wood termite, Neotermes koshunensis (Shiraki) [Kalotermitidae], possessing both male and female phenotypic characteristics, was found on Okinawa Island, Japan. This deformed individual showed morphological and anatomical hermaphroditism in the abdomen. The right side of the seventh sternite was the female form and contained an ovary, while the left side was the male form and contained a testis. Genotypic analysis revealed that this individual was a genotypic bilateral chimera. These results suggested that the termite was a bilateral gynandromorph with a male left side and a female right side. As reported previously in other insects, double fertilization (by two sperms, one with an X and one with a Y chromosome) of a binucleate egg is the most likely mechanism that generated this genotypic bilateral chimera. N. koshunensis has the ability to reproduce through parthenogenesis, in which the secondary polar body is likely to be used for nuclear phase recovery. If the second polar body in this mechanism has high fertility and healthy embryogenic potential, like an egg nucleus, some of gynandromorphs might be produced by a side effect of parthenogenetic ability. 相似文献
2.
3.
4.
Although recent studies have demonstrated that calcification in a wide range of marine organisms is profoundly affected by CO2-induced ocean acidification, the mechanism of this phenomenon is still unclear. To clarify the effects of ocean acidification on the calcification process at the molecular level, we evaluated the expression of three biomineralization-related genes in the sea urchin Hemicentrotus pulcherrimus exposed under control, 1,000, and 2,000?ppm CO2 from egg to pluteus larval stage. We found that the expression of the gene msp130, which is proposed to transport Ca2+ to the calcification site, is suppressed by increased CO2 at pluteus larval stage. Meanwhile, expression of the spicule protein matrix genes SM30 and SM50 was apparently not affected. The results suggest that the combined effects of ocean acidification on the expression of skeletogenesis-related genes as well as the change in seawater carbonate chemistry affect the biomineralization ability of sea urchins. 相似文献
5.
6.
The emission of waste in an economy, including landfill, is to a large extent determined by its patterns of technology, institutions,
and lifestyle. A mathematical model (the waste input–output model) is presented that gives a simple analytical representation
of this interdependence. The model was used to evaluate the effects of alternative waste disposal and recycling options on
the levels of industrial production, landfill consumption, and the emission of carbon dioxide, and also to analyze the overall
dependence on landfill of individual industries. It was found that a systematic combination of the options could be effective
in reducing the overall landfill consumption and carbon dioxide emission.
Received: November 4, 2000 / Accepted: August 2, 2001 相似文献
7.
Yasushi?InoueEmail author Arata?Katayama 《Journal of Material Cycles and Waste Management》2004,6(1):48-57
An improved rescue number, RNSOIL, which is an indicator for evaluating remediation technologies for contaminated ground that is based on both the risk and the remediation cost, is proposed as a tool of risk communication. The risk posed by contaminated ground is indicated by the figure of treatment priority at time t, FTP(t), which represents the human health risk as the number of people affected by the contaminated ground at time t during the remediation process. The calculation of the value of FTP(t) is based on exposure to contaminants that have migrated through environmental media from the contaminated ground, and is estimated by using a CalTOX model and the Monte Carlo method. The integration of FTP(t) with time, which represents the cumulative number of people affected by the contaminated ground, is used to estimate the performance of individual remediation technologies in risk reduction. The figure of unprocessibility for waste (FUW), which represents difficulties in remediation, is expressed as the remediation cost. FUW is estimated by using actual costs per unit volume of remediated soil. As an overall performance value, the rescue number for each remediation technology for contaminated ground (RNSOIL) is calculated by multiplication of the integral FTP(t) by FUW. Smaller values of RNSOIL are judged to indicate a better technology. The rescue index (RI), calculated as the ratio of the reduction of the integral FTP(t) to FUW, indicates the cost-effectiveness of the remediation technologies. Successful estimation of the indices (FTP(t), integral FTP(t), FUW, RNSOIL and RI) demonstrate the usefulness of these indices in risk communication.Part of this paper was presented at 13th meeting of Japan Society of Waste Management Experts (2002) 相似文献
8.
Takeo Kurihara Hideki Takami Takeharu Kosuge Susumu Chiba Masatsugu Iseda Takenori Sasaki 《Marine Biology》2011,158(9):2095-2107
Increases of low-latitude species in various sea areas and poleward shifts of ranges of many species have been reported and
linked to warming environments. To examine the generality of these trends for mollusks, we conducted 7 quadrat surveys during
1978–2006 on Pacific rocky shores in Japan (26.6–45.0°N). Results showed that the dominance of southern species increased
on 11 of the 15 shores in a southern, warming sea area but on only 1 of the 6 shores in a northern area with no warming trend.
The latitudes of species ranges increased on average but showed large interspecific variations which showed a weak, positive
correlation with interspecific taxonomic distance. The differences of these results from the previously reported trends are
discussed in relation to the unique current patterns in our study area and the phylogenetic constraints of species-specific
responses to a warming environment. 相似文献
9.
Yuichi Yamaura David Lindenmayer Yusuke Yamada Hao Gong Toshiya Matsuura Yasushi Mitsuda Takashi Masaki 《Conservation biology》2020,34(1):194-206
Stand structure develops with stand age. Old-growth forests with well-developed stand structure support many species. However, development rates of stand structure likely vary with climate and topography. We modeled structural development of 4 key stand variables and a composite old-growth index as functions of climatic and topographic covariates. We used a hierarchical Bayesian method for analysis of extensive snap-shot National Forest Inventory (NFI) data in Japan (n = 9244) to account for differences in stand age. Development rates of structural variables and the old-growth index exhibited curvilinear responses to environmental covariates. Flat sites were characterized by high rates of structural development. Approximately 150 years were generally required to attain high values (approximately 0.8) of the old-growth index. However, the predicted age to achieve specific values varied depending on environmental conditions. Spatial predictions highlighted regional variation in potential structural development rates. For example, sometimes there were differences of >100 years among sites, even in the same catchment, in attainment of a medium index value (0.5) after timber harvesting. The NFI data suggested that natural forests, especially old natural forests (>150 years), remain generally on unproductive ridges, steep slopes, or areas with low temperature and deep snow, where many structural variables show slow development rates. We suggest that maintenance and restoration of old natural forests on flat sites should be prioritized for conservation due to the likely rapid development of stand structure, although remaining natural forests on low-productivity sites are still important and should be protected. 相似文献
10.
Mahbubul Alam Yasushi Furukawa Kazuhiro Harada 《Environment, Development and Sustainability》2010,12(2):147-158
The tropical deciduous forest in Bangladesh provides a substantial part of country’s forest and where the government has introduced
participatory agroforestry landuse. This study examined management issues, financial viability, and environmental as well
as social sustainability of this landuse system. The forest department allocated a plot of size 1.0 ha among the selected
participants where they were allowed to practice agriculture as well as to plant tree species for 10 years. The financial
indicators indicated that the landuse system was profitable and attractive [net present value (NPV) = US$ 17,710 and benefit-cost
ratio (BCR) = 4.12]. It was also viable and suitable from the social and environmental stand points. The study concluded that
under the present environmental and socio-economic scenario, this production system could be the best management tool that
would earn money, stop forest degradation, and finally be a model of sustainable land management in an overpopulated country. 相似文献