全文获取类型
收费全文 | 95057篇 |
免费 | 435篇 |
国内免费 | 880篇 |
专业分类
96372篇 |
出版年
2023年 | 19篇 |
2022年 | 43篇 |
2021年 | 68篇 |
2020年 | 64篇 |
2019年 | 71篇 |
2018年 | 11892篇 |
2017年 | 10717篇 |
2016年 | 7540篇 |
2015年 | 713篇 |
2014年 | 399篇 |
2013年 | 464篇 |
2012年 | 4364篇 |
2011年 | 12937篇 |
2010年 | 12064篇 |
2009年 | 8299篇 |
2008年 | 9872篇 |
2007年 | 11441篇 |
2006年 | 348篇 |
2005年 | 597篇 |
2004年 | 1027篇 |
2003年 | 1063篇 |
2002年 | 847篇 |
2001年 | 298篇 |
2000年 | 180篇 |
1999年 | 49篇 |
1998年 | 18篇 |
1997年 | 30篇 |
1996年 | 23篇 |
1994年 | 11篇 |
1993年 | 38篇 |
1992年 | 30篇 |
1991年 | 45篇 |
1990年 | 14篇 |
1989年 | 13篇 |
1988年 | 28篇 |
1987年 | 21篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 18篇 |
1983年 | 18篇 |
1978年 | 7篇 |
1975年 | 8篇 |
1972年 | 251篇 |
1971年 | 276篇 |
1970年 | 7篇 |
1968年 | 6篇 |
1965年 | 15篇 |
1962年 | 24篇 |
1944年 | 12篇 |
1940年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
THE interaction between the cell surface and the substratum is very important in determining several characteristics of cells growing in tissue culture. Transformed cells are less adherent to the substratum than untransformed cells1 and this reduced interaction with the substratum may be responsible for abnormal properties such as the loss of contact or density dependent inhibition of growth2 and the ability to form colonies in agar and to grow in suspension culture. 相似文献
962.
Anthony Marcus 《Dialectical Anthropology》2008,32(1-2):59-86
For most of the twentieth century the state was not a major part of the anthropological toolkit. Despite significant archaeologically driven work on evolution and state formation, most socio-cultural anthropologists have viewed the state with empiricist scepticism, populist hostility, or ethnographic indifference. Typically, state-theory has been left to other disciplines, such as political science and sociology. Since the end of the cold war there has been a greatly increased interest in the state among anthropologists. Philip Abrams, Michael Herzfeld, and Akhil Gupta, who coined the phrase “ethnography of the state”, have been particularly important to this development. However, there remains no serious engagement with the body of state-theory generated, over the last century, by political activists, scientists, sociologists, and anthropologists. It will be argued that this has allowed for the growth of an unproblematised orthodoxy around an ethnographically informed variant of classic American pluralist state-theory. This orthodoxy has hobbled the understanding and explanation of complex political phenomena, led to confusion between hypotheses and conclusions, and tied parts of the discipline to a partisan political project that remains largely un-interrogated. This essay seeks to provide context and clarification on state-theory as a step towards discussion of anthropology’s contemporary engagement with the state and broader questions of political action and social change. 相似文献
963.
964.
Sanjay G. Revankar 《Current fungal infection reports》2010,4(1):46-51
Brown–black (or dematiaceous) fungi are responsible for a wide variety of infectious syndromes in both immunocompetent and
immunocompromised patients, including local infections, allergic disease, pneumonia, brain abscess, and disseminated infection.
They are distinct from the more common hyaline molds, Aspergillus and Fusarium, that cause human disease. They are often found in soil and generally distributed worldwide. In recent years, these fungi
have been increasingly recognized as important pathogens. Dematiaceous fungi may have unique pathogenic mechanisms owing to
the presence of melanin in their cell walls, which imparts the characteristic dark color to their spores and hyphae. Diagnosis
rests on careful microscopic and pathologic examination, as there are no specific laboratory tests to reliably identify these
fungi. Therapy depends upon the clinical syndrome, although disseminated infection often has high mortality. Triazoles such
as voriconazole, posaconazole, and itraconazole are the most active antifungal agents available. Further studies are needed
to better understand the pathogenesis and optimal treatment of these uncommon infections. 相似文献
965.
Winfried Häuser Petra Klose Jost Langhorst Babak Moradi Mario Steinbach Marcus Schiltenwolf Angela Busch 《Arthritis research & therapy》2010,12(3):R79
Introduction
The efficacy and the optimal type and volume of aerobic exercise (AE) in fibromyalgia syndrome (FMS) are not established. We therefore assessed the efficacy of different types and volumes of AE in FMS. 相似文献966.
967.
Atanu Sarkar 《EcoHealth》2010,7(1):114-126
Millions of people living in India are at risk by consuming arsenic contaminated groundwater. Several technological solutions
have failed to address the problem due to segmental approaches, resulting in human suffering for a period of three decades.
The article is based on an analysis of arsenic-related health problems from an ecosystem perspective through a primary survey
conducted in five arsenic affected villages in the state of West Bengal and review of existing research and policy documents.
Although modern agricultural practices and drinking water policies have resulted in arsenic contamination of groundwater,
current mitigation policy is essentially confined to biomedical approaches, which includes potable water supply and medical
care. The study also shows that existing disparity, difficulty in coping, inaccessibility to health service and potable water
supply and lack of participation in decision making have resulted in more suffering among the poor. On the other hand, spreading
of arsenic contamination in the ecosystem remains unabated. Foods grown in the affected area have emerged as additional sources
of exposure to humans. There is lack of evidence of any perceivable benefits due to sustainable agriculture, as present nature
of agriculture practice is essentially driven by crop yield only. Further research is needed to generate credible evidence
of alternative agriculture paradigms that may eventually reduce body burden of arsenic through reduced dependency on groundwater. 相似文献
968.
969.
Norihide Hinomoto Tomomi Higaki Junichiro Abe Masafumi Yamane Eizi Yano 《Applied Entomology and Zoology》2012,47(2):165-171
We have developed and characterized 21 microsatellite markers in the aphidophagous gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). All 21 loci tested were polymorphic: the number of alleles ranged from 2 to 17. Allelic
richness and observed heterozygosities were higher in females than in males. Several loci had no heterozygosity in males,
suggesting that the loci were located on sex chromosomes or E-chromosomes, common to cecidomyiids. The high polymorphism detected
in this study suggests the markers will be of value in analyzing genetic structure of field populations. 相似文献
970.