全文获取类型
收费全文 | 736篇 |
免费 | 30篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 14篇 |
化学工业 | 89篇 |
金属工艺 | 12篇 |
机械仪表 | 24篇 |
建筑科学 | 31篇 |
矿业工程 | 1篇 |
能源动力 | 10篇 |
轻工业 | 83篇 |
水利工程 | 4篇 |
石油天然气 | 1篇 |
无线电 | 56篇 |
一般工业技术 | 189篇 |
冶金工业 | 142篇 |
原子能技术 | 11篇 |
自动化技术 | 100篇 |
出版年
2023年 | 2篇 |
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 9篇 |
2019年 | 9篇 |
2018年 | 11篇 |
2017年 | 19篇 |
2016年 | 35篇 |
2015年 | 10篇 |
2014年 | 28篇 |
2013年 | 44篇 |
2012年 | 36篇 |
2011年 | 31篇 |
2010年 | 30篇 |
2009年 | 32篇 |
2008年 | 35篇 |
2007年 | 22篇 |
2006年 | 30篇 |
2005年 | 28篇 |
2004年 | 16篇 |
2003年 | 13篇 |
2002年 | 8篇 |
2001年 | 13篇 |
2000年 | 17篇 |
1999年 | 13篇 |
1998年 | 41篇 |
1997年 | 34篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 13篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 8篇 |
1988年 | 2篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 9篇 |
1975年 | 4篇 |
1973年 | 6篇 |
1967年 | 3篇 |
1930年 | 1篇 |
排序方式: 共有767条查询结果,搜索用时 15 毫秒
101.
Ariana de Souza Soares Afonso Mota Ramos Érica Nascif Rufino Vieira Ellen Silva Lago Vanzela Patrícia Martins de Oliveira Daniele de Almeida Paula 《International Journal of Food Science & Technology》2018,53(9):2229-2238
The goal of this research was to evaluate the use of vacuum impregnation (VI) and soaking techniques (ST) in the application of edible coatings of chitosan and chitosan + lauric acid to minimally processed pumpkins (MPP). The vacuum impregnation method led to greater component incorporation (5.9% and 1.75%, respectively) in the pumpkins when compared to soaking and consequently the formation of more uniform, thicker coatings (25.6 and 22.3 μm, respectively). However, VI caused greater changes in pH, acidity, colour and firmness. Relating to water content and carotenoid content, noncoated pumpkins presented greater losses during the storage period, regardless of impregnation method. The pumpkins with edible coatings, regardless of method, presented lower numbers of psychrotrophic micro‐organisms and coliforms during the storage period. Therefore, soaking was considered the best method for the application of chitosan‐based edible coatings to minimally processed pumpkins, as it led to smaller changes in the properties of the product. 相似文献
102.
Daniele de Almeida Paula Eduardo Basílio de Oliveira Alvaro Vianna Novaes de Carvalho Teixeira Ariana de Souza Soares Afonso Mota Ramos 《International Journal of Food Science & Technology》2018,53(2):475-483
This study addressed the correlation between physical characteristics of double emulsions and sensory perception, as the microstructure of these systems may provide the mechanism to understanding the initial cause of the altered salty taste. Thus, double emulsions (W/O/W) were prepared using different volumes of the internal aqueous phase while maintaining the same fat and sodium contents in the evaluated systems. Polyglycerol polyricinoleate (PGPR) and tween 80 were used as hydrophobic and hydrophilic emulsifiers, respectively. After preparation, the samples were stored at 25 °C for 4 days and submitted to analysis of optical microscopy, distribution and polydispersity of the oil droplets size, electrical conductivity, rheological behaviour and sensorial analysis. It was found that the use of different emulsifier concentrations (PGPR) did not influence the physical characteristics of the emulsions with the same formulation, but emulsions with different internal aqueous phase concentrations presented different results. These distinct characteristics may have influenced sensorial perception, as the emulsion with higher internal phase concentration was considered saltier. Thus, it can be concluded that structural differences of the double emulsions can be used to decrease the sodium contents without perceivable changes in salty taste. 相似文献
103.
104.
Naves LZ Santana FR Castro CG Valdivia AD Da Mota AS Estrela C Correr-Sobrinho L Soares CJ 《Microscopy research and technique》2011,74(12):1088-1092
Morphology, etching patterns, surface modification, and characterization of 2 different fiber posts: Gfp, Glass fiber post; and Cfp, carbon fiber were investigated by SEM analysis, after different surface treatments. Thirty fiber posts, being 15 Gfp and 15 Cfp were divided into a 5 surface treatments (n = 3): C-alcohol 70% (control); HF 4%-immersion in 4% hydrofluoric acid for 1min; H(3) PO(4) 37%-immersion in 37% phosphoric acid for 30s; H(2) O(2) 10%-immersion in 10% hydrogen peroxide for 20 min; H(2) O(2) 24%-immersion in 24% hydrogen peroxide for 10 min. Morphology, etching patterns, surface modification and surface characterization were acessed by SEM analysis. SEM evaluation revealed that the post surface morphology was modified following all treatment when compared with a control group, for both type of reinforced posts. HF seems to penetrate around the fibers of Gfp and promoted surface alterations. The Cfp surface seems to be inert to treatment with HF 4%. Dissolution of epoxy resin and exposure of the superficial fiber was observed in both post groups, regardless the type of reinforcing fiber, H(2) O(2) in both concentrations. Relative smooth surface area was produced by H(3) PO(4) 37% treatment, but with similar features to untreated group. Surface treatment of fiber post is a determinant factor on micromechanical entanglement to resin composite core. Post treatment with hydrogen peroxide resulted strength of carbon and glass/epoxy resin fiber posts to resin composite core. 相似文献
105.
Gilbert Andrew Trumble Matthew Malleson Charles Hilton Adrian Collomosse John 《International Journal of Computer Vision》2019,127(4):381-397
International Journal of Computer Vision - We propose an approach to accurately estimate 3D human pose by fusing multi-viewpoint video (MVV) with inertial measurement unit (IMU) sensor data,... 相似文献
106.
107.
Marcelo de Paiva Guimarães Diego Roberto Colombo Dias José Hamilton Mota Bruno Barberi Gnecco Vinícius Humberto Serapilha Durelli Luis Carlos Trevelin 《Multimedia Tools and Applications》2018,77(1):347-361
This study explores the possibility of effectively using web-standard technologies (i.e., HTML5, JavaScript, WebGL, and WebRTC) to deploy full immersive and interactive virtual reality applications. These applications are based on computer clusters and run in multi-projection environments, such as CAVEs, Panoramas and Power Walls. Until recently, these applications were build using tailored solutions, such low-level libraries to distribute data. We discuss the modern-day web technology which allows these applications meet a multi-platform requirement. This paper also evaluates the communication and synchronization requirements of these applications that are traditionally the main bottleneck. As a proof-of-concept to show the feasibility of our study, we devised and implemented an immersive and interactive virtual reality application employing only web technologies. Our proof-of-concept runs on a miniCAVE environment with three displays and a 6-node cluster. 相似文献
108.
Tribology Letters - Three commercially available carbon-graphite cryogenic materials(EC-5, M234 and P5N) that are used as seals in rocket turbopumpassemblies have been characterized as part of a... 相似文献
109.
We investigate the impact of hydroxyl groups on the properties of C(60)(OH)(n) systems, with n = 1, 2, 3, 4, 8, 10, 16, 18, 24, 32 and 36 by means of first-principles density functional theory calculations. A detailed analysis from the local density of states has shown that adsorbed OH groups can induce dangling bonds in specific carbon atoms around the adsorption site. This increases the tendency to form polyhydroxylated fullerenes (fullerenols). The structural stability is analyzed in terms of the calculated formation enthalpy of each species. Also, a careful examination of the electron density of states for different fullerenols shows the possibility of synthesizing single molecules with tunable optical properties. 相似文献
110.
Nicholas R. Glavin Christopher Muratore Michael L. Jespersen Jianjun Hu Phillip T. Hagerty Al M. Hilton Austin T. Blake Christopher A. Grabowski Michael F. Durstock Michael E. McConney Drew M. Hilgefort Timothy S. Fisher Andrey A. Voevodin 《Advanced functional materials》2016,26(16):2640-2647
Next‐generation nanoelectronics based on 2D materials ideally will require reliable, flexible, transparent, and versatile dielectrics for transistor gate barriers, environmental passivation layers, capacitor spacers, and other device elements. Ultrathin amorphous boron nitride of thicknesses from 2 to 17 nm, described in this work, may offer these attributes, as the material is demonstrated to be universal in structure and stoichiometric chemistry on numerous substrates including flexible polydimethylsiloxane, amorphous silicon dioxide, crystalline Al2O3, other 2D materials including graphene, 2D MoS2, and conducting metals and metal foils. The versatile, large area pulsed laser deposition growth technique is performed at temperatures less than 200 °C and without modifying processing conditions, allowing for seamless integration into 2D device architectures. A device‐scale dielectric constant of 5.9 ± 0.65 at 1 kHz, breakdown voltage of 9.8 ± 1.0 MV cm?1, and bandgap of 4.5 eV were measured for various thicknesses of the ultrathin a‐BN material, representing values higher than previously reported chemical vapor deposited h‐BN and nearing single crystal h‐BN. 相似文献