全文获取类型
收费全文 | 748篇 |
免费 | 76篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 361篇 |
金属工艺 | 8篇 |
机械仪表 | 15篇 |
建筑科学 | 27篇 |
能源动力 | 20篇 |
轻工业 | 169篇 |
水利工程 | 4篇 |
石油天然气 | 2篇 |
无线电 | 33篇 |
一般工业技术 | 97篇 |
冶金工业 | 9篇 |
自动化技术 | 77篇 |
出版年
2024年 | 3篇 |
2023年 | 28篇 |
2022年 | 89篇 |
2021年 | 99篇 |
2020年 | 37篇 |
2019年 | 28篇 |
2018年 | 42篇 |
2017年 | 27篇 |
2016年 | 44篇 |
2015年 | 30篇 |
2014年 | 34篇 |
2013年 | 57篇 |
2012年 | 36篇 |
2011年 | 58篇 |
2010年 | 34篇 |
2009年 | 34篇 |
2008年 | 30篇 |
2007年 | 18篇 |
2006年 | 21篇 |
2005年 | 9篇 |
2004年 | 11篇 |
2003年 | 13篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1985年 | 2篇 |
1980年 | 1篇 |
排序方式: 共有824条查询结果,搜索用时 63 毫秒
51.
Thioether Analogues of Disulfide‐Bridged Cyclic Peptides Targeting Death Receptor 5: Conformational Analysis,Dimerisation and Consequences for Receptor Activation
下载免费PDF全文
![点击此处可从《Chembiochem : a European journal of chemical biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Karolina Pulka‐Ziach Dr. Valeria Pavet Neila Chekkat Dr. Karine Estieu‐Gionnet Roman Rohac Dr. Marie‐Charlotte Lechner Dr. Cristian R. Smulski Dr. Gabrielle Zeder‐Lutz Dr. Danièle Altschuh Dr. Hinrich Gronemeyer Prof. Dr. Sylvie Fournel Dr. Benoit Odaert Dr. Gilles Guichard 《Chembiochem : a European journal of chemical biology》2015,16(2):293-301
Cyclic peptides containing redox‐stable thioether bridges might provide a useful alternative to disulfide‐bridged bioactive peptides. We report the effect of replacing the disulfide bridge with a lanthionine linkage in a 16‐mer cyclic peptide that binds to death receptor 5 (DR5, TRAIL‐R2). Upon covalent oligomerisation, the disulfide‐bridged peptide has previously shown similar behaviour to that of TNF‐related apoptosis inducing ligand (TRAIL), by selectively triggering the DR5 cell death pathway. The structural and biological properties of the DR5‐binding peptide and its desulfurised analogue were compared. Surface plasmon resonance (SPR) data suggest that these peptides bind DR5 with comparable affinities. The same holds true for dimeric versions of these peptides: the thioether is able to induce DR5‐mediated apoptosis of BJAB lymphoma and tumorigenic BJELR cells, albeit to a slightly lower extent compared to its disulfide homologue. NMR analysis revealed subtle variation in the conformations of the two peptides and suggests that the thioether peptide is slightly less folded than its disulfide homologue. These observations could account for the different capability of the two dimers to cluster DR5 receptors on the cell surface and to trigger apoptosis. Nevertheless, our results suggest that the thioether peptide is a potential candidate for evaluation in animal models. 相似文献
52.
Cesira Pasquarella Licia Veronesi Giorgio Liguori Christian Napoli Ida Torre Valeria Di Onofrio Carola Tinteri SItI working group "Hygiene in Dentistry 《The Science of the total environment》2010,408(19):4045-4051
The dental practice is associated with a high risk of infections, both for patients and healthcare operators, and the environment may play an important role in the transmission of infectious diseases. A microbiological environmental investigation was carried out in six dental clinics as a pilot study for a larger multicentre study that will be performed by the Italian SItI (Society of Hygiene, Preventive Medicine and Public Health) working group "Hygiene in Dentistry". Microbial contamination of water, air and surfaces was assessed in each clinic during the five working days of the week, before and during treatments. Air and surfaces were also examined at the end of the daily activity. A wide variation was found in microbial environmental contamination, both within the participating clinics and relative to the different sampling times. Microbial water contamination in Dental Unit Water Systems (DUWS) reached values of up to 26 × 104 cfu/mL (colony forming units per millilitre). P. aeruginosa was found in 33% of the sampled DUWS and Legionella spp. in 50%. A significant decrease in the Total Viable Count (TVC) was recorded during the activity. Microbial air contamination showed the highest levels during dental treatments and tended to decrease at the end of the working activity (p < 0.05). Microbial buildup on surfaces increased significantly during the working hours. As these findings point out, research on microbial environmental contamination and the related risk factors in dental clinics should be expanded and should also be based on larger collections of data, in order to provide the essential knowledge aimed at targeted preventive interventions. 相似文献
53.
Valeria A Tironi Mabel C Tomás María C Añón 《Journal of the science of food and agriculture》2007,87(12):2239-2246
Sea salmon is a very appreciated seafood. The aim of this work was to analyze changes in lipid and protein fractions of minced muscle during chilled storage (1 ± 1 °C). Lipid oxidation was important during the first 6 days of storage according to 2‐thiobarbituric acid (TBA) values determined, decreasing mainly ω3 22:6 fatty acid content. Lipid hydrolysis was evident after 9 days of storage. Interaction compounds between oxidation products and other cellular components were analyzed by fluorescence measurements. The results obtained showed evidence of the formation of interaction products involved, mainly polar components such as proteins. Decreases in myosin and actin thermal stability and myosin denaturation were recorded by differential scanning calorimetry. Solubility of total and myofibrillar proteins decreased after 6 days of storage. The electrophoretic profile of soluble fractions showed an increase in the intensity of bands corresponding to low‐molecular‐weight polypeptides and a decrease in high‐molecular‐weight species. Available lysine content did not change during chilled storage. Copyright © 2007 Society of Chemical Industry 相似文献
54.
55.
SCIDDICA-SS3: a new version of cellular automata model for simulating fast moving landslides 总被引:1,自引:0,他引:1
Maria Vittoria Avolio Salvatore Di Gregorio Valeria Lupiano Paolo Mazzanti 《The Journal of supercomputing》2013,65(2):682-696
Cellular Automata (CA) are discrete and parallel computational models useful for simulating dynamic systems that evolve on the basis on local interactions. Some natural events, such as some types of landslides, fall into this type of phenomena and lend themselves well to be simulated with this approach. This paper describes the latest version of the SCIDDICA CA family models, specifically developed to simulate debris-flows type landslides. The latest model of the family, named SCIDDICA-SS3, inherits all the features of its predecessor, SCIDDICA-SS2, with the addition of a particular strategy to manage momentum. The introduction of the latter permits a better approximation of inertial effects that characterize some rapid debris flows. First simulations attempts of real landslides with SCIDDICA-SS3 have produced quite satisfactory results, comparable with the previous model. 相似文献
56.
Liviu Sacarescu Mihaela Simionescu Gabriela Sacarescu Valeria Harabagiu 《Journal of Inorganic and Organometallic Polymers and Materials》2013,23(3):621-628
This work presents a solution-phase approach for the “one pot” synthesis of polysilane-gold nanorods. The process starts by the reduction of HAuCl4 to Auo with a solution of poly[diphenylsilane-co-methyl(H)silane] cooled to 4 °C. The formed small Au nanoparticles (5–15 nm diameter) serve further as seeds for the heterogeneous nucleation and anisotropic growth that takes place at 25 °C and yields crystalline needle-like polymer–gold nanostructures. The evolution of the small spherical nanoparticles to nanorods with length/width aspect ratios up to 103 has been proved by UV–Vis spectroscopy, polarized light microscopy and AFM. Further insights on the growth mechanism were obtained by SEM, DLS and TEM. 相似文献
57.
58.
Daniela de Oliveira Ribeiro Bianca Waruar Lobo Nádia Maria Volpato Venício Féo da Veiga Mendes Lúcio Cabral Valeria Pereira de Sousa 《Nutrition journal》2009,8(1):51-13
Background
Preterm infants need high amounts of calcium and phosphorus for bone mineralization, which is difficult to obtain with parenteral feeding due to the low solubility of these salts. The objective of this study was to evaluate the physicochemical compatibility of high concentrations of calcium associated with organic phosphate and its influence on the stability of AIO admixtures for neonatal use. 相似文献59.
Claudia M. Asensio Valeria Nepote Nelson R. Grosso 《International Journal of Food Science & Technology》2013,48(11):2417-2428
The objective of this study was to evaluate chemical and physical stability and consumers' acceptance of olive oil flavoured with oregano essential oils (EOs; Compacto, Cordobes, Criollo and Mendocino). Samples of olive oil were added with 0.05% EO and stored in dark (D) and light (L) conditions for 126 days. Samples with oregano EO had lower lipid oxidation indicator values [K232, K269, peroxide value (PV) and anisidine value], especially in darkness. Olive oil with Cordobes EO in D had the lowest PV (18.71 meqO2 kg?1). Using prediction equations, 20 meqO2 kg?1 PV in olive oil should be reached in 34 days in L control sample and in 126 days in the Cordobes EO sample in darkness. Samples with Cordobes and Criollo EOs in darkness had the highest chlorophyll content after 126 days (2.91 and 2.88 mg kg?1, respectively). Sensory analysis showed that oregano EO addition in olive oil was detected by panellists in discriminative test and affected consumer acceptance. 相似文献
60.
Maria De Marsico Stephen Kimani Valeria Mirabella Kent L. Norman Tiziana Catarci 《Universal Access in the Information Society》2006,5(2):150-169
Most of the existing efforts for supporting the design, preparation, and deployment of accessible e-learning applications propose guidelines that primarily address technical accessibility issues. Little, if any, consideration is given to the real actors involved in the learning experience, such as didactical experts and disabled learners. Moreover, implementing artifacts addressed to the e-learning world requires a wide range of particular skills which are related not only to technical but also to didactical, pedagogical, usability, and accessibility aspects of the produced material. This paper argues that the know-how of a number of stakeholders should be blended into a joint design activity, and that it should be possible to determine the role of each participant in the successive phases of the development lifecycle of e-learning applications. The paper sketches the methodological guidelines of a design framework based on involving the users with disabilities, as well as pedagogical experts, in the development process. The novelty of this proposal mainly stems from being built up around the core of strategies and choices specifically bound to accessibility requirements. Characteristic elements of learner-centered design are then further integrated into processes and methodologies which are typical of participatory and contextual design approaches. Following such guidelines, it will be possible to gain a deeper understanding of the requirements and of the operational context of people needing accessible material, either as learners or educators. The underlying objective is to increase the potential to realize learning systems that better meet different user needs and that provide a more satisfying learning experience. Moreover, when people get involved in the development process, they gain a sense of ownership of the system and are therefore more likely to accept and “promote” it. 相似文献