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   1277篇
  免费   68篇
电工技术   15篇
综合类   1篇
化学工业   384篇
金属工艺   27篇
机械仪表   27篇
建筑科学   130篇
矿业工程   6篇
能源动力   46篇
轻工业   167篇
水利工程   20篇
石油天然气   3篇
无线电   79篇
一般工业技术   150篇
冶金工业   73篇
原子能技术   15篇
自动化技术   202篇
  2023年   14篇
  2022年   42篇
  2021年   52篇
  2020年   38篇
  2019年   43篇
  2018年   58篇
  2017年   50篇
  2016年   54篇
  2015年   37篇
  2014年   63篇
  2013年   87篇
  2012年   69篇
  2011年   83篇
  2010年   66篇
  2009年   63篇
  2008年   48篇
  2007年   61篇
  2006年   42篇
  2005年   29篇
  2004年   30篇
  2003年   14篇
  2002年   17篇
  2001年   18篇
  2000年   20篇
  1999年   27篇
  1998年   20篇
  1997年   11篇
  1996年   12篇
  1995年   12篇
  1994年   15篇
  1993年   10篇
  1992年   9篇
  1991年   7篇
  1990年   9篇
  1989年   5篇
  1988年   8篇
  1987年   9篇
  1985年   6篇
  1983年   7篇
  1982年   5篇
  1981年   5篇
  1979年   5篇
  1978年   6篇
  1977年   4篇
  1975年   4篇
  1974年   3篇
  1966年   3篇
  1954年   3篇
  1940年   4篇
  1934年   3篇
排序方式: 共有1345条查询结果,搜索用时 0 毫秒
111.
There is currently an international drive to build new nuclear power plants, bringing about what is being termed a “nuclear renaissance”. However, the public perception of nuclear energy has historically been, and continues to be, a key issue, particularly in light of the Fukushima nuclear incident. This paper discusses the disparity between perceived and calculated risks based on the last four decades of research into risk perception. The leading psychological and sociological theories, Psychometric Paradigm and Cultural Theory, respectively, are critically reviewed. The authors then argue that a new nuclear-build policy that promotes a broader approach to design incorporating a wider range of stakeholder inputs, including that of the lay public, may provide a means for reducing the perceived risk of a nuclear plant. Further research towards such a new approach to design is proposed, based on integrating expert and lay stakeholder inputs and taking into account broader socio-cultural factors whilst maintaining the necessary emphasis on safety, technological development, economics and environmental sustainability.  相似文献   
112.
113.
Quadruplex nucleic acids are promising targets for cancer therapy. In this study we used a fragment-based approach to create new flexible G-quadruplex (G4) DNA-interactive small molecules with good calculated oral drug-like properties, based on quinoline and triazole heterocycles. G4 melting temperature and polymerase chain reaction (PCR)-stop assays showed that two of these compounds are selective G4 ligands, as they were able to induce and stabilize G4s in a dose- and DNA sequence-dependent manner. Molecular docking studies have suggested plausible quadruplex binding to both the G-quartet and groove, with the quinoline module playing the major role. Compounds were screened for cytotoxicity against four cancer cell lines, where 4,4′-(4,4′-(1,3-phenylene)bis(1H-1,2,3-triazole-4,1-diyl))bis(1-methylquinolin-1-ium) ( 1 d ) showed the greater activity. Importantly, dose–response curves show that 1 d is cytotoxic in the human colon cancer HT-29 cell line enriched in cancer stem-like cells, a subpopulation of cells implicated in chemoresistance. Overall, this study identified a new small molecule as a promising lead for the development of drugs targeting G4 in cancer stem cells.  相似文献   
114.
Brito  Claúdia  Esteves  Marisa  Peixoto  Hugo  Abelha  António  Machado  José 《Wireless Networks》2022,28(3):1269-1277
Wireless Networks - Continuous ambulatory peritoneal dialysis (CAPD) is a treatment used by patients in the end-stage of chronic kidney diseases. Those patients need to be monitored using blood...  相似文献   
115.
Xanthophyllomyces dendrorhous is one of the most attractive natural sources of astaxanthin. The yeast produces the compound intracellularly, therefore, it is necessary to evaluate cell rupture methods using clean and efficient technologies for its extraction and it subsequent use in industries. At present work, two non-conventional high-pressure extraction methods were evaluated for astaxanthin recovery: Supercritical fluid extraction and microfluidisation. Results: Effect of pressure (15, 30, and 45 Megapascals; MPa), Temperature (313 and 343 °K) and usage of co-solvent were studied in supercritical extraction process, meanwhile the effect of microfluidisation process (five stages and 160 MPa) for cell rupture and its combination with conventional technics (lithic enzymes, glass beads and ultrasonication) for the recovery of astaxanthin were evaluated. Supercritical fluid extraction presented a higher astaxanthin recovery, 54% yield extraction, at 32.5 MPa and 313 °K, and using ethanol as co-solvent, compared to a 31% yield extraction by mean microfluidisation process at 160 MPa combined with 15 min of sonication (amplitude of 80%).  相似文献   
116.

Colorectal cancer (CRC) is the second most diagnosed cancer in the United States. It is identified by histopathological evaluations of microscopic images of the cancerous region, relying on a subjective interpretation. The Colorectal Histology dataset used in this study contains 5000 images, made available by the University Medical Center Mannheim. This approach proposes the automatic identification of eight types of tissues found in CRC histopathological evaluation. We apply Transfer Learning from architectures of Convolutional Neural Networks (CNNs). We modify the structures of CNNs to extract features from the images and input them to well-known machine learning methods: Naive Bayes, Multilayer Perceptron, k-Nearest Neighbors, Random Forest, and Support Vector Machine (SVM). We evaluated 108 extractor–classifier combinations. The one that achieved the best results is DenseNet169 with SVM (RBF), reaching an Accuracy of 92.083% and F1-Score of 92.117%. Therefore, our approach is capable of distinguishing tissues found in CRC histopathological evaluation.

  相似文献   
117.
Multimedia Tools and Applications - Microsoft has recently released a mixed reality headset called HoloLens. This semi-transparent visor headset allows the user who wears it to view the projection...  相似文献   
118.
119.
The influence of high-pressure homogenisation (HPH) at 100 MPa on Lacticaseibacillus paracasei 90 (L90) was studied in vitro and in situ (fermented milk and cheese). Lysis and injury signs were observed in cells treated with HPH, which were linked to the release of intracellular enzymes and changes in the metabolic activity of L90. HPH treatment led to a higher lactic acid content and lower pH and pyruvic acid levels in fermented milk. The microbiological and peptide profiles of cheeses were modified by using cells or cell-free extracts of L90. Finally, this study suggests that L90 could release bioactive peptides.  相似文献   
120.
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