全文获取类型
收费全文 | 999篇 |
免费 | 51篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 6篇 |
综合类 | 8篇 |
化学工业 | 406篇 |
金属工艺 | 25篇 |
机械仪表 | 8篇 |
建筑科学 | 50篇 |
矿业工程 | 2篇 |
能源动力 | 12篇 |
轻工业 | 134篇 |
水利工程 | 11篇 |
石油天然气 | 4篇 |
无线电 | 30篇 |
一般工业技术 | 151篇 |
冶金工业 | 31篇 |
原子能技术 | 2篇 |
自动化技术 | 171篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 46篇 |
2021年 | 65篇 |
2020年 | 25篇 |
2019年 | 28篇 |
2018年 | 27篇 |
2017年 | 33篇 |
2016年 | 41篇 |
2015年 | 36篇 |
2014年 | 55篇 |
2013年 | 73篇 |
2012年 | 77篇 |
2011年 | 68篇 |
2010年 | 49篇 |
2009年 | 43篇 |
2008年 | 63篇 |
2007年 | 40篇 |
2006年 | 46篇 |
2005年 | 34篇 |
2004年 | 23篇 |
2003年 | 19篇 |
2002年 | 21篇 |
2001年 | 15篇 |
2000年 | 7篇 |
1999年 | 15篇 |
1998年 | 15篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1977年 | 1篇 |
排序方式: 共有1051条查询结果,搜索用时 15 毫秒
11.
12.
Petra Pavel Stefan Blunder Verena Moosbrugger-Martinz Peter M. Elias Sandrine Dubrac 《International journal of molecular sciences》2022,23(4)
Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease in which dry and itchy skin may develop into skin lesions. AD has a strong genetic component, as children from parents with AD have a two-fold increased chance of developing the disease. Genetic risk loci and epigenetic modifications reported in AD mainly locate to genes involved in the immune response and epidermal barrier function. However, AD pathogenesis cannot be fully explained by (epi)genetic factors since environmental triggers such as stress, pollution, microbiota, climate, and allergens also play a crucial role. Alterations of the epidermal barrier in AD, observed at all stages of the disease and which precede the development of overt skin inflammation, manifest as: dry skin; epidermal ultrastructural abnormalities, notably anomalies of the lamellar body cargo system; and abnormal epidermal lipid composition, including shorter fatty acid moieties in several lipid classes, such as ceramides and free fatty acids. Thus, a compelling question is whether AD is primarily a lipid disorder evolving into a chronic inflammatory disease due to genetic susceptibility loci in immunogenic genes. In this review, we focus on lipid abnormalities observed in the epidermis and blood of AD patients and evaluate their primary role in eliciting an inflammatory response. 相似文献
13.
Daniela Grimm Herbert Schulz Marcus Krüger Jos Luis Corts-Snchez Marcel Egli Armin Kraus Jayashree Sahana Thomas J. Corydon Ruth Hemmersbach Petra M. Wise Manfred Infanger Markus Wehland 《International journal of molecular sciences》2022,23(6)
Cancer is a disease exhibiting uncontrollable cell growth and spreading to other parts of the organism. It is a heavy, worldwide burden for mankind with high morbidity and mortality. Therefore, groundbreaking research and innovations are necessary. Research in space under microgravity (µg) conditions is a novel approach with the potential to fight cancer and develop future cancer therapies. Space travel is accompanied by adverse effects on our health, and there is a need to counteract these health problems. On the cellular level, studies have shown that real (r-) and simulated (s-) µg impact survival, apoptosis, proliferation, migration, and adhesion as well as the cytoskeleton, the extracellular matrix, focal adhesion, and growth factors in cancer cells. Moreover, the µg-environment induces in vitro 3D tumor models (multicellular spheroids and organoids) with a high potential for preclinical drug targeting, cancer drug development, and studying the processes of cancer progression and metastasis on a molecular level. This review focuses on the effects of r- and s-µg on different types of cells deriving from thyroid, breast, lung, skin, and prostate cancer, as well as tumors of the gastrointestinal tract. In addition, we summarize the current knowledge of the impact of µg on cancerous stem cells. The information demonstrates that µg has become an important new technology for increasing current knowledge of cancer biology. 相似文献
14.
Harri Tuomisto Petra Lundstrm Ritva Korhonen Jzsef Elter Milan Hladký Jozef Tomek Ludovít Fagula 《Nuclear Engineering and Design》2003,221(1-3):181
There are twelve operating VVER-440/213 reactors in the Czech Republic, Hungary and Slovakia. The plant owners have carried out extensive safety enhancement programmes, which have included measures to improve prevention, mitigation and control of design basis accidents. Recently, there have been a number of projects to study the Severe Accident Management aspects of these plants. The plant owners have also initiated Plant Life Management programmes. The objective of the VERSAFE Concerted Action is to create a network of the VVER-440/213 plant owners and operators, which aims at definition of the further research needs of severe accidents and plant ageing from the utilities’ viewpoint. The starting point is to formulate a general approach to severe accident management and plant life management and then proceed to define the needs for the additional information expected from the safety research. The role of national research institutes and organisations of the partner countries is of crucial importance in performing such research and, thus, creating and maintaining the expertise on the national level. The successful completion of the project will assist in establishing well-defined research projects that are oriented to the needs of the end-users and provide information that can be used to facilitate and support the negotiations of the EU applicant countries operating VVER-440 reactors. 相似文献
15.
Besides serving as a structural membrane component and intermediate of the glycerolipid metabolism, lysophosphatidic acid (LPA) has a prominent role as a signaling molecule through its binding to LPA receptors at the cell surface. Extracellular LPA is primarily produced from lysophosphatidylcholine (LPC) through the activity of secreted lysophospholipase D, autotaxin (ATX). The degradation of extracellular LPA to monoacylglycerol is mediated by lipid phosphate phosphatases (LPPs) at the cell membrane. This review summarizes and interprets current literature on the role of the ATX-LPA-LPP3 axis in the regulation of energy homeostasis, insulin function, and adiposity at baseline and under conditions of obesity. We also discuss how the ATX-LPA-LPP3 axis influences obesity-related metabolic complications, including insulin resistance, fatty liver disease, and cardiomyopathy. 相似文献
16.
Inside Back Cover: Ancestral Haloalkane Dehalogenases Show Robustness and Unique Substrate Specificity (ChemBioChem 14/2017) 下载免费PDF全文
17.
The cathodic reduction of dibenzofuran ( 2 ), 2-chlorodibenzofuran ( 4 ), and 3-chlorodibenzofuran ( 1 ) in deuterated methanol is investigated. The Birch-type reduction product 1,4-dibenzofuran ( 3 ) is formed from 1 via 2 , whereas 2-chloro-1,4-dihydrodibenzofuran ( 5 ) is obtained as by-product besides 3 from 4 as starting compound. Deuterium is only incorporated into the reduction products if CH3OD or CD3OD but not if CD3OH are used. This observation is strongly indicative of a polar mechanism involving protonation rather than a radical mechanism with hydrogen atom abstraction to be operative. 相似文献
18.
Dr. Tom Robinson Prof. Dr. Petra S. Dittrich 《Chembiochem : a European journal of chemical biology》2019,20(20):2666-2673
Giant unilamellar vesicles (GUVs) are considered to be the gold standard for assembling artificial cells from the bottom up. In this study, we investigated the behavior of such biomimetic vesicles as they were subjected to mechanical compression. A microfluidic device is presented that comprises a trap to capture GUVs and a microstamp that is deflected downwards to mechanically compress the trapped vesicle. After characterization of the device, we show that single-phase GUVs can be controllably compressed to a high degree of deformation (D=0.40) depending on the pressure applied to the microstamp. A permeation assay was implemented to show that vesicle bursting is prevented by water efflux. Next, we mechanically compressed GUVs with co-existing liquid-ordered and liquid-disordered membrane phases. Upon compression, we observed that the normally stable lipid domains reorganized themselves across the surface and fused into larger domains. This phenomenon, observed here in a model membrane system, not only gives us insights into how the multicomponent membranes of artificial cells behave, but might also have interesting consequences for the role of lipid rafts in biological cells that are subjected to compressive forces in a natural environment. 相似文献
19.
Peter M. Bandelt Riess Jörg Engstle Michael Kuhn Heiko Briesen Petra Först 《化学工程与技术》2018,41(10):1956-1964
Packed beds used in absorption columns are evaluated to determine whether they can also be beneficial for cake‐forming filtrations. To assess this, model systems are characterized and separated by using a dead‐end filter cell. Filtrations are conducted with different packings; the filtrate amount over time and resulting turbidity are evaluated. Packings increase the filter cake resistance and the separation time of the cakes formed with approximately incompressible solids. However, they exhibit a positive effect on the filtration of a more complex, compressible substance; the process is not only accelerated, but also the quality of the obtained filtrate is not compromised. These results demonstrate potential in the use of packed beds for the filtration of complex biogenic suspensions. 相似文献
20.
Anna M. Schoepf Dr. Stefan Salcher Verena Hohn Florina Veider Prof. Dr. Petra Obexer Prof. Dr. Ronald Gust 《ChemMedChem》2020,15(12):1067-1077
New strategies to eradicate cancer stem cells in chronic myeloid leukemia (CML) include a combination of imatinib with peroxisome proliferator-activated receptor gamma (PPARγ) ligands. Recently, we identified the partial PPARγ agonist telmisartan as effective sensitizer of resistant K562 CML cells to imatinib treatment. Here, the importance of the heterocyclic core on the cell death-modulating effects of the telmisartan-derived lead 4′-((2-propyl-1H-benzo[d]imidazol-1-yl)methyl)-[1,1′-biphenyl]-2-carboxylic acid ( 3 b ) was investigated. Inspired by the pharmacodynamics of HYL-6d and the selective PPARγ ligand VSP-51, the benzimidazole was replaced by a carbazole or an indole core. The results indicate no correlation between PPARγ activation and sensitization of resistant CML cells to imatinib. The 2-COOH derivatives of the carbazoles or indoles achieved low activity at PPARγ, while the benzimidazoles showed 60-100 % activation. Among the 2-CO2CH3 derivatives, only the ester of the lead ( 2 b ) slightly activated PPARγ. Sensitizing effects were further observed for this non-cytotoxic 2 b (80 % cell death), and to a lesser extent for the lead 3 b or the 5-Br-substituted ester of the benzimidazoles ( 5 b ). 相似文献