全文获取类型
收费全文 | 73篇 |
免费 | 0篇 |
国内免费 | 5篇 |
专业分类
废物处理 | 15篇 |
环保管理 | 4篇 |
综合类 | 29篇 |
基础理论 | 8篇 |
环境理论 | 1篇 |
污染及防治 | 19篇 |
社会与环境 | 2篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 1篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 8篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有78条查询结果,搜索用时 125 毫秒
61.
It is generally recognized that the sonographic findings of infantile polycystic kidney disease (IPKD) are bilaterally enlarged kidneys, oligohydramnios, an absent fetal bladder, and the typical kidney texture. Since there is a broad spectrum of renal compromise with IPKD, in utero diagnosis is thought to be limited to the severe forms. This paper reports a mild case of IPKD, where the in utero diagnosis was established by measuring fetal urine production and amniotic fluid volume serially during pregnancy, and by ultrasonographic examination of fetal kidneys. 相似文献
62.
Takeshi?TakegakiEmail author Takashi?Kaneko Yukio?Matsumoto 《Die Naturwissenschaften》2012,99(4):285-289
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
63.
Ryoko Matsumoto Shigeru Suzuki Khisigjav Tsogtbaatar Susan E. Evans 《Die Naturwissenschaften》2009,96(2):233-242
New material of the enigmatic diapsid Khurendukhosaurus is described from the Mongolian type locality, Khuren Dukh, providing additional data on the vertebral column, pelvis, and
hind limb. It confirms the choristoderan status of the genus and permits a more detailed phylogenetic analysis that supports
a relationship between Khurendukhosaurus and the long-necked Asian Hyphalosauridae. The existence of tall caudal neural spines implies that Khurendukhosaurus was a deep-tailed swimmer. This and the open sacral costocentral sutures suggest a primarily aquatic lifestyle.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Institutional abbreviations MNHN BL, Museum National d’Histoire Naturelle, Paris, France; MPC, Mongolian Paleontological Center; PIN, Paleontologicheski
Institut, Akademii Nauk, Moscow; HMNS, Hayashibara Museum of Natural Sciences, Okayama, Japan. 相似文献
64.
Myxomycetes are organisms characterized by a life cycle that includes a fruiting body stage. Myxomycete fruiting bodies contain spores, and wind dispersal of the spores is considered important for this organism to colonize new areas. In this study, the presence of airborne myxomycetes and the temporal changes in the myxomycete composition of atmospheric particles (aerosols) were investigated with a polymerase chain reaction (PCR)-based method for Didymiaceae and Physaraceae. Twenty-one aerosol samples were collected on the roof of a three-story building located in Sapporo, Hokkaido Island, northern Japan. PCR analysis of DNA extracts from the aerosol samples indicated the presence of airborne myxomycetes in all the samples, except for the one collected during the snowfall season. Denaturing gradient gel electrophoresis (DGGE) analysis of the PCR products showed seasonally varying banding patterns. The detected DGGE bands were subjected to sequence analyses, and four out of nine obtained sequences were identical to those of fruiting body samples collected in Hokkaido Island. It appears that the difference in the fruiting period of each species was correlated with the seasonal changes in the myxomycete composition of the aerosols. Molecular evidence shows that newly formed spores are released and dispersed in the air, suggesting that wind-driven dispersal of spores is an important process in the life history of myxomycetes. This study is the first to detect airborne myxomycetes with the use of molecular ecological analyses and to characterize their seasonal distribution. 相似文献
65.
Z. J. U. Malley M. Taeb T. Matsumoto 《Environment, Development and Sustainability》2009,11(1):175-195
Sustainable agricultural development is a necessity for sustainable economic growth and social development in Africa. Sustainable
agriculture largely depends on how effective natural and environmental resources are managed and utilized; it also depends
on the security of continuous access to such resources. This research was aimed to look into trends in agricultural productivity,
examine the persistence of the environmental insecurity, analyze the relationship between the two, and explore their links
to the national development policies. The results are discussed in the context of relevance to national development policies
and their implications on the sustainability of agriculture and rural livelihoods security. Literature survey, records collection
from the stakeholders, village level participatory assessments (PAs), observations and questionnaire survey were tools used
for data collection. The study shows significant (P < 0.01) declines in cereal crop yields, cattle milk yield and cattle calving rate, and increasing cattle mortality rate.
Elements of environmental insecurity were found to account for decline in agricultural productivity; significant (P < 0.01) proportion (68%), of 266 households interviewed, reported land resources deterioration, declining soil fertility,
and increasing drought frequencies as the causes of their low productivity. Declined fertilizer consumption and increasing
variability in rainfall amount significantly (P < 0.01) accounted for 59% and 39%, respectively, of the variations observed in total annual production of rice and maize,
which are major cereals in the study area. This study recommends measures to improve soil productivity such as improved fertilizer
application and use of organic manures along with mineral fertilizers for maintaining soil productivity; education of farmers
on sustainable use and management of land resources; and pro-poor rural policies in agricultural development and environmental
governance.
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
66.
Rebecca M. Niemiec Greg P. Asner Julie A. Gaertner Philip G. Brodrick Nick Vaughn Joseph Heckler Flint Hughes Lisa Keith Tracie Matsumoto 《Conservation biology》2020,34(2):505-514
Conservation across human-dominated landscapes requires an understanding of the social and ecological factors driving outcomes. Studies that link conservation outcomes to social and ecological factors have examined temporally static patterns. However, there may be different social and ecological processes driving increases and decreases in conservation outcomes that can only be revealed through temporal analyses. Through a case study of the invasion of Falcataria moluccana in Hawaii, we examined the association of social factors with increases and decreases in invader distributions over time and space. Over 7 years, rates of invader decrease varied substantially (66–100%) relative to social factors, such as building value, whether land was privately or publically owned, and primary residence by a homeowner, whereas rates of increase varied only slightly (<0.1–3.6%) relative to such factors. These findings suggest that links between social factors and invasion in the study system may be driven more by landowners controlling existing invasive species, rather than by landowners preventing the spread of invasive species. We suggest that spatially explicit, time-dependent analyses provide a more nuanced understanding of the way social factors influence conservation outcomes. Such an understanding can help managers develop outreach programs and policies targeted at different types of landowners in human-dominated landscapes. 相似文献
67.
68.
Barbara F. Crandall Mitchell S. Golbus James D. Goldberg Myles Matsumoto 《黑龙江环境通报》1991,11(6):377-380
Maternal sera (MS) taken from 1396 women prior to chorionic villus sampling at 9–12 menstrual weeks were assayed for unconjugated oestriol (uE3) and alpha-fetoprotein (AFP). Median levels increased by 41 and 26 per cent per week respectively in normal pregnancies. There were 32 pregnancies with a chromosome abnormality. The median MS uE3 and AFP were 0.73 and 0.75 multiples of the median (MoM) respectively in the ten cases of Down's syndrome (DS) but not decreased in the other abnormalities. These results suggest that both uE3 and AFP may be useful in identifying DS in the first trimester. Additional prospective studies are needed to confirm these findings. 相似文献
69.
70.
We assayed maternal serum samples from 134 black and 268 white women from 16 to 18 weeks of gestation for intact human chorionic gonadotropin (hCG), and unconjugated oestriol (uE3). Serum from women with high ( ⩾ 2·5 MOMs) or low (risk for Down syndrome ⩾ 1/365) maternal serum alpha-fetoprotein (MSAFP) levels were excluded. After correcting for maternal weight, we found that median hCG levels were 16 per cent higher in black women but uE3 levels were not significantly different. These results confirm three other studies for hCG and one study for uE3. Corrections are recommended for both maternal serum hCG and AFP before calculating the risk for Down syndrome in black women. 相似文献