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   5128篇
  免费   390篇
  国内免费   11篇
  2024年   12篇
  2023年   66篇
  2022年   168篇
  2021年   333篇
  2020年   194篇
  2019年   208篇
  2018年   263篇
  2017年   221篇
  2016年   298篇
  2015年   365篇
  2014年   396篇
  2013年   428篇
  2012年   397篇
  2011年   349篇
  2010年   253篇
  2009年   186篇
  2008年   212篇
  2007年   182篇
  2006年   143篇
  2005年   147篇
  2004年   131篇
  2003年   89篇
  2002年   94篇
  2001年   26篇
  2000年   26篇
  1999年   25篇
  1998年   7篇
  1997年   20篇
  1996年   13篇
  1995年   19篇
  1994年   11篇
  1993年   7篇
  1992年   12篇
  1991年   17篇
  1990年   8篇
  1989年   13篇
  1988年   15篇
  1987年   9篇
  1986年   7篇
  1985年   14篇
  1984年   16篇
  1983年   17篇
  1982年   12篇
  1981年   11篇
  1980年   9篇
  1979年   5篇
  1975年   5篇
  1971年   5篇
  1964年   4篇
  1857年   4篇
排序方式: 共有5529条查询结果,搜索用时 718 毫秒
61.
International Journal of Peptide Research and Therapeutics - Lassa virus (LASV) is responsible for a type of acute viral haemorrhagic fever referred to as Lassa fever. Lack of adequate treatment...  相似文献   
62.
Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer‐related deaths in women worldwide. In this study, a large Chinese pedigree with breast cancer including a proband and two female patients was recruited and a familial history of breast cancer was collected by questionnaire. Clinicopathological assessments and neoadjuvant therapy‐related information were obtained for the proband. Blood samples were taken, and gDNA was extracted. The BRCA1/2 and PALB2 genes were screened using next‐generation sequencing by a targeted gene panel. We have successfully identified a novel, germline heterozygous, missense mutation of the gene BRCA2: c.7007G>T, p.R2336L, which is likely to be pathogenic in the proband and her elder sister who both had breast cancer. Furthermore, the risk factors for developing breast cancer in this family are discussed. Thus, genetic counselling and long‐term follow‐up should be provided for this family of breast cancer patients as well as carriers carrying a germline variant of BRCA2: c.7007G>T (p.R2336L).  相似文献   
63.
64.
Perovskite solar cells (PSC) have shown that under laboratory conditions they can compete with established photovoltaic technologies. However, controlled laboratory measurements usually performed do not fully resemble operational conditions and field testing outdoors, with day‐night cycles, changing irradiance and temperature. In this contribution, the performance of PSCs in the rooftop field test, exposed to real weather conditions is evaluated. The 1 cm2 single‐junction devices, with an initial average power conversion efficiency of 18.5% are tracked outdoors in maximum power point over several weeks. In parallel, irradiance and air temperature are recorded, allowing us to correlate outside factors with generated power. To get more insight into outdoor device performance, a comprehensive set of laboratory measurements under different light intensities (10% to 120% of AM1.5) and temperatures is performed. From these results, a low power temperature coefficient of ?0.17% K?1 is extracted in the temperature range between 25 and 85 °C. By incorporating these temperature‐ and light‐dependent PV parameters into the energy yield model, it is possible to correctly predict the generated energy of the devices, thus validating the energy yield model. In addition, degradation of the tested devices can be tracked precisely from the difference between measured and modelled power.  相似文献   
65.
66.
Bioprocess and Biosystems Engineering - The β-glucanase produced from Bacillus sp. CSB55 not only depicts the potent industrial characteristics but also relates as bio-industrial catalyst...  相似文献   
67.
Bioprocess and Biosystems Engineering - Despite the green energy generation with low cost compared to conventional fuel cells, microbial fuel cells (MFCs) still suffer with anode related...  相似文献   
68.
The population abundance, infestation, and harmful effects of the aphid Aphis craccivora Koch (Hemiptera: Aphididae) were studied on four bean plant species, namely the country bean (Lablab purpureus var. BARI Seem 1), the yard‐long bean (Vigna sesquipedalis var. BARI Borboti 1), the hyacinth bean (Dolichos lablab var. BARI Seem 6), and the bush bean (Phaseolus vulgaris var. BARI Jar Seem 3). Aphid abundance and infestation on the leaves, inflorescences, flowers, and pods differed significantly among the bean plant species, with P. vulgaris and V. sesquipedalis having the lowest and highest results, respectively. Aphid severity grade and the number of trichomes of the bean plant species were negatively correlated. The duration of the growth stages among the bean plant species were significantly different, with V. sesquipedalis having the shortest durations. Aphid abundance and infestation significantly affected the physical and phytochemical characteristics of the bean plant species. The highest reduction of number of leaves, flower inflorescences, and pod inflorescences per plant, and moisture and chlorophyll content in the leaves was found in L. purpureus. The results for V. sesquipedalis revealed the highest reduction in plant height, seed weight, and pH, while those of D. lablab showed the highest reduction in leaf area.  相似文献   
69.
70.
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