全文获取类型
收费全文 | 19133篇 |
免费 | 970篇 |
国内免费 | 136篇 |
专业分类
电工技术 | 325篇 |
综合类 | 32篇 |
化学工业 | 4197篇 |
金属工艺 | 597篇 |
机械仪表 | 643篇 |
建筑科学 | 370篇 |
矿业工程 | 47篇 |
能源动力 | 1374篇 |
轻工业 | 1187篇 |
水利工程 | 149篇 |
石油天然气 | 84篇 |
武器工业 | 1篇 |
无线电 | 2390篇 |
一般工业技术 | 4386篇 |
冶金工业 | 1455篇 |
原子能技术 | 175篇 |
自动化技术 | 2827篇 |
出版年
2024年 | 78篇 |
2023年 | 418篇 |
2022年 | 963篇 |
2021年 | 1162篇 |
2020年 | 917篇 |
2019年 | 950篇 |
2018年 | 1241篇 |
2017年 | 971篇 |
2016年 | 945篇 |
2015年 | 608篇 |
2014年 | 852篇 |
2013年 | 1531篇 |
2012年 | 899篇 |
2011年 | 1081篇 |
2010年 | 864篇 |
2009年 | 822篇 |
2008年 | 726篇 |
2007年 | 582篇 |
2006年 | 478篇 |
2005年 | 372篇 |
2004年 | 277篇 |
2003年 | 248篇 |
2002年 | 194篇 |
2001年 | 179篇 |
2000年 | 173篇 |
1999年 | 170篇 |
1998年 | 292篇 |
1997年 | 244篇 |
1996年 | 221篇 |
1995年 | 172篇 |
1994年 | 158篇 |
1993年 | 153篇 |
1992年 | 103篇 |
1991年 | 130篇 |
1990年 | 101篇 |
1989年 | 96篇 |
1988年 | 79篇 |
1987年 | 90篇 |
1986年 | 76篇 |
1985年 | 88篇 |
1984年 | 75篇 |
1983年 | 72篇 |
1982年 | 61篇 |
1981年 | 70篇 |
1980年 | 48篇 |
1979年 | 32篇 |
1978年 | 27篇 |
1977年 | 26篇 |
1976年 | 35篇 |
1971年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
861.
It is widely accepted that understanding the kinetics of steelmaking is a complex task, and reliable and validated kinetics models are required for developing successful steelmaking process models. Therefore, as an initial attempt, this paper analyses the applicability of first order kinetics to explain the steelmaking reaction kinetics using the published data in the IMproving Phosphorus Refining research report. The process data for 20 heats in a 6?tonne pilot plant were analysed for the removal of carbon, silicon, manganese and phosphorus using first order kinetics with static and dynamic equilibrium conditions. It was observed that the removal behaviour of silicon closely followed a first order kinetics relationship, while that of carbon only approximately followed a first order kinetics relationship. The removal of manganese did not show a good degree of fit with first order kinetics using static equilibrium condition, but a clear improvement was observed when calculated using dynamic equilibrium condition. In contrast, the kinetics of phosphorus oxidation did not follow any first order relationship. 相似文献
862.
Debasis Das Adhikary Goutam Kumar Bose Dipak Kumar Jana Dipankar Bose Souren Mitra 《Quality Engineering》2016,28(3):352-357
This article presents a multi-objective (maximization of availability and minimization of maintenance cost) preventive maintenance (PM) scheduling model for a continuous operating series system (COSS) which do not provide an off-working period for PM. The objective functions are optimized by using a Multi-Objective Genetic Algorithm (MOGA). The effectiveness of the model is demonstrated through a coal-fired boiler-tube. The case study shows that the model can improve the availability along with profound reduction of the maintenance cost, i.e., increases the profit of the plant. 相似文献
863.
864.
865.
Physico chemical,microstructural and sensory characteristics of low‐fat meat emulsion containing aloe gel as potential fat replacer
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yogesh Kumar Narsaiah Kairam Tanbir Ahmad Deep N. Yadav 《International Journal of Food Science & Technology》2016,51(2):309-316
In this study, a possible use of aloe gel (AG) as a potential fat replacer in the manufacture of low‐fat meat emulsion was investigated. The low‐fat meat emulsions with added AG and vegetable oil (VO) in different proportions [AG7.5 (7.5% AG + 7.5% VO); AG5 (5% AG + 10% VO); AG2.5 (2.5% AG + 12.5% VO)] were compared with full‐fat meat emulsion [Control (15% VO only)]. A substantial fat reduction (P < 0.05) up to 50% as compared to full‐fat control meat emulsion was recorded without compromising other sensory attributes of meat emulsion. Microstructural properties as studied by scanning electron microscopy indicated more homogenous regular emulsion matrix with fewer cracks and more regular shaped oil droplets in AG‐added samples than the control samples. 相似文献
866.
Wireless Personal Communications - Privacy and security concerns are significant barrier for RFID deployment in many applications in modern day world. The implementation of authentication schemes... 相似文献
867.
Pankaj Kumar Nilesh P. Gurao Arunansu Haldar Satyam Suwas 《Metallurgical and Materials Transactions A》2012,43(6):2043-2055
This article presents the deformation behavior of high-strength pearlitic steel deformed by triaxial compression to achieve
ultra-fine ferrite grain size with fragmented cementite. The consequent evolution of microstructure and texture has been studied
using scanning electron microscopy, electron back-scatter diffraction, and X-ray diffraction. The synergistic effect of diffusion
and deformation leads to the uniform dissolution of cementite at higher temperature. At lower temperature, significant grain
refinement of ferrite phase occurs by deformation and exhibits a characteristic deformation texture. In contrast, the high-temperature
deformed sample shows a weaker texture with cube component for the ferrite phase, indicating the occurrence of recrystallization.
The different mechanisms responsible for the refinement of ferrite as well as the fragmentation of cementite and their interaction
with each other have been analyzed. Viscoplastic self-consistent simulation was employed to understand deformation texture
in the ferrite phase during triaxial compression. 相似文献
868.
S.L. Ashok Kumar M. Saravana Kumar R.P. John P. Thomas Muthiah A. Sreekanth 《Materials science & engineering. C, Materials for biological applications》2013,33(5):2519-2525
1,5-Bis (2-hydroxyacetophenone)thiocarbohydrazone (H4L) has been synthesized and characterized by means of spectroscopic and single crystal X-ray diffraction methods. Interactions of the H4L with a variety of anions were investigated using a combination of UV–visible and fluorescence spectroscopic methods in a biological competing solvent DMSO. The H4L has a high degree of selectivity for fluoride over other anions. 1H NMR titration experiments indicate that a deprotonation process is involved in the chemo sensing process. 相似文献
869.
Kausik Kumar Majumdar D. Dutta Majumder 《International journal of systems science》2013,44(15):889-901
Uncertain information processing by fuzzy if–then rules has received much attention. Here we have taken a different path to model a system, about which we do not have precise information, namely modelling the system by fuzzy-valued functions without resorting to fuzzy if–then rules. As a result, the phase (state) space of the system becomes a fuzzy set and the underlying fuzzy mapping becomes a fuzzy attainability set mapping. Uncertain or fuzzy dynamical systems have been defined in terms of fuzzy attainability set mappings. Fuzzy differentiable dynamical systems have been discussed with a particular emphasis on fuzzy differential inclusion (FDI) relations. An evolutionary algorithm for solving one-dimensional FDIs has been developed. A model of the creation of a tropical cyclone in the form of a vortex, created by winds coming from different directions and colliding under certain conditions, has been proposed in terms of FDIs. A model has been considered for the highly uncertain system of evolution of a tumour in a human body and an FDI relation model of the whole system has been proposed and simulated. The model of an evolution of turbulence, as a random occurrence of vortices in a three-dimensional dynamic fluid, has been proposed and simulated, where each vortex is modelled by a fuzzy-valued function, where uncertain parameter and variable values are fuzzy numbers. All the systems represented by FDI relations have been simulated with the help of the evolutionary algorithm mentioned above. 相似文献
870.