全文获取类型
收费全文 | 2057篇 |
免费 | 67篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 38篇 |
综合类 | 3篇 |
化学工业 | 396篇 |
金属工艺 | 49篇 |
机械仪表 | 52篇 |
建筑科学 | 35篇 |
矿业工程 | 3篇 |
能源动力 | 98篇 |
轻工业 | 91篇 |
水利工程 | 6篇 |
石油天然气 | 16篇 |
无线电 | 336篇 |
一般工业技术 | 467篇 |
冶金工业 | 292篇 |
原子能技术 | 21篇 |
自动化技术 | 231篇 |
出版年
2023年 | 18篇 |
2022年 | 38篇 |
2021年 | 56篇 |
2020年 | 43篇 |
2019年 | 41篇 |
2018年 | 70篇 |
2017年 | 60篇 |
2016年 | 53篇 |
2015年 | 36篇 |
2014年 | 71篇 |
2013年 | 145篇 |
2012年 | 97篇 |
2011年 | 93篇 |
2010年 | 64篇 |
2009年 | 77篇 |
2008年 | 75篇 |
2007年 | 83篇 |
2006年 | 63篇 |
2005年 | 43篇 |
2004年 | 47篇 |
2003年 | 45篇 |
2002年 | 53篇 |
2001年 | 33篇 |
2000年 | 31篇 |
1999年 | 40篇 |
1998年 | 96篇 |
1997年 | 63篇 |
1996年 | 53篇 |
1995年 | 54篇 |
1994年 | 40篇 |
1993年 | 31篇 |
1992年 | 32篇 |
1991年 | 27篇 |
1990年 | 28篇 |
1989年 | 18篇 |
1988年 | 26篇 |
1987年 | 10篇 |
1986年 | 14篇 |
1985年 | 14篇 |
1984年 | 14篇 |
1983年 | 15篇 |
1982年 | 12篇 |
1981年 | 12篇 |
1980年 | 5篇 |
1979年 | 16篇 |
1978年 | 14篇 |
1977年 | 8篇 |
1976年 | 20篇 |
1975年 | 6篇 |
1973年 | 11篇 |
排序方式: 共有2134条查询结果,搜索用时 15 毫秒
991.
Rupesh D. Shah Hanumanthappa Patil Jyotirmay Banerjee 《Journal of Mechanical Science and Technology》2012,26(6):1753-1763
Large eddy simulation (LES) of a co-axial combustor is reported. Accuracy of LES depends on the ability of the sub-grid scale (SGS) models to predict the turbulent viscosity. The sensitivity of LES results for different SGS models is established for a coaxial annular combustor. The radial, axial and tangential velocity distribution predicted by four sub-grid scale models is compared with the experimental results of Sommerfeld and Qiu. It is observed that the flow physics is captured more accurately by WALE model as compared to other SGS models. The predictions of WALE model are closer to the experimental results for all stations in the flow domain. 相似文献
992.
993.
994.
Dhirendra Mohan Ram Prasad Srikumar Banerjee 《Journal of the American Ceramic Society》2001,84(9):2126-2128
Lead magnesium niobate (PMN) and lead iron niobate (PFN) were prepared by the semiwet hydroxide route, and their dielectric properties were measured in temperature ranges around their peak dielectric constants. The dielectric constant of PFN was much larger as compared with that of PMN sintered at the same temperature. The dielectric properties of PMN and PFN are compared and explained on the basis of their structure development. 相似文献
995.
Rituparna Banerjee Naveena Basappa Maheswarappa 《Critical reviews in food science and nutrition》2019,59(8):1256-1263
Superchilling is an attractive technique for preservation of muscle foods which freezes part of the water and insulate the food products from temperature fluctuations thereby enhancing the shelf-life during storage, transportation and retailing. Superchilling process synergistically improves the product shelf-life when used in combination with vacuum or modified atmospheric packaging. The shelf-life of muscle foods was reported to be increased by 1.5 to 4.0 times relative to traditional chilling technique. Advantages of superchilling and its ability to maintain the freshness of muscle foods over freezing has been discussed and its potential for Industrial application is highlighted. Present review also unravel the mechanistic bases for ice-crystal formation during superchilling and measures to ameliorate the drip loss. The future challenges especially automation in superchilling process for large scale Industrial application is presented. 相似文献
996.
Priyanka Saha Pritha Banerjee Dinesh Kumar Dash Subir Kumar Sarkar 《Journal of Materials Engineering and Performance》2018,27(6):2708-2712
This paper presents an analytical model of an asymmetric junctionless double-gate (asymmetric DGJL) silicon-on-nothing metal-oxide-semiconductor field-effect transistor (MOSFET). Solving the 2-D Poisson’s equation, the expressions for center potential and threshold voltage are calculated. In addition, the response of the device toward the various short-channel effects like hot carrier effect, drain-induced barrier lowering and threshold voltage roll-off has also been examined along with subthreshold swing and drain current characteristics. Performance analysis of the present model is also demonstrated by comparing its short-channel behavior with conventional DGJL MOSFET. The effect of variation of the device features due to the variation of device parameters is also studied. The simulated results obtained using 2D device simulator, namely ATLAS, are in good agreement with the analytical results, hence validating our derived model. 相似文献
997.
The expeditious development of novel cobalt-base γ–γ′ alloys as possible next generation superalloys critically depends on achieving a comprehensive understanding of the coarsening kinetics of ordered γ′ precipitates. This paper discusses the coarsening of L12 ordered Co3(W, Al) precipitates in a model ternary Co–10Al–10W (at.%) alloy during isothermal annealing at 800 and 900 °C. The experimentally determined temporal evolution of average size of the γ′ precipitates suggests classical matrix diffusion limited Lifshitz–Slyozov–Wagner coarsening at both temperatures. The γ′ coarsening rate constants have been determined using a modified coarsening rate equation for non-dilute solutions. Furthermore, using the Cahn–Hilliard formulation for interfacial energy, the γ/γ′ interfacial energies at the respective annealing temperatures have been correlated to the concentration profile across the interface that has been experimentally determined using atom probe tomography. The calculated interfacial energies are in comparable range with those observed in nickel-base superalloys. Additionally, this analysis has permitted, for the first time, the determination of the gradient energy coefficient for γ/γ′ interfaces in Co-base alloys, a critical input for phase-field and other simulation models for microstructural evolution. 相似文献
998.
The changes of structure and properties of nanofibers were studied as a function of solubility parameters of the organic solvents that are used in interfacial polymerization of polyaniline (PAni) nanofibers. The presence of UV–visible absorbance at 340, 440, and 800 nm confirmed the formation of emeraldine salt structure of the prepared PAni nanofibers. Fourier transform infrared spectral results indicate an increasing trend of benzenoid to quinoid ratio with the decrease of interaction of the solvents with aniline. This can be correlated to the increase in the degree of conjugation of the polymer chain. Photoluminescence study revealed an increase in the density of defect state with the decrease of interaction. Single‐line approximation technique was used to analyze the broadening of the most intense X‐ray reflection peak corresponding to (110) plane of the nanofibers. The greater the solvent–monomer interaction, the lesser was the domain length and π‐stacking of the PAni chains. The study of this interaction is instrumental to precisely control the internal conformation of the PAni nanofibers. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
999.
R.K. Singh Raman P. Chakraborty Banerjee Derrek E. Lobo Hemtej Gullapalli Madusha Sumandasa Ashwin Kumar Lokesh Choudhary Rachel Tkacz Pulickel M. Ajayan Mainak Majumder 《Carbon》2012,50(11):4040-4045
Graphene coating on copper (Cu) is shown to increase the resistance of the metal to electrochemical degradation by one and half orders of magnitude. Detailed electrochemical characterization in aggressive chloride environment shows the impedance of Cu increasing dramatically and the anodic and cathodic current densities of the coated Cu becoming nearly 1–2 orders of magnitude smaller when coated with graphene. The observations are counterintuitive as graphite in contact with metals increases metallic corrosion. The results can bring paradigm changes in the development of anti-corrosion coatings using conformal, ultrathin graphene films. 相似文献
1000.
Residual lignocellulosics left to decay in fields and forest has a huge potential to serve as a low cost feedstock for production of bioethanol. In Indian subcontinent Ricinus communis is a major lignocellulosics growing in arid conditions containing 42% cellulose and 19.8% lignin. In the present study, Response Surface Methodology (RSM) based on Central Composite Design (CCD) has been used to explore the effects of pH, temperature, solid to liquid ratio (w/v), enzyme concentration and incubation time on enzymatic depolymerization of R. communis. The maximum delignification obtained was 85.69%. In case of lignified R. communis the optimum reducing sugar produced was about 288.83 mg/g dry substrate, whereas, in case of delignified R. communis the optimum reducing sugar produced was about 775.17 mg/g dry delignified substrate. After delignification reducing sugar yield was increased to about 2.68 fold. 相似文献