全文获取类型
收费全文 | 691篇 |
免费 | 30篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 11篇 |
综合类 | 1篇 |
化学工业 | 194篇 |
金属工艺 | 20篇 |
机械仪表 | 34篇 |
建筑科学 | 11篇 |
能源动力 | 47篇 |
轻工业 | 34篇 |
水利工程 | 4篇 |
无线电 | 69篇 |
一般工业技术 | 162篇 |
冶金工业 | 38篇 |
原子能技术 | 7篇 |
自动化技术 | 91篇 |
出版年
2024年 | 3篇 |
2023年 | 11篇 |
2022年 | 24篇 |
2021年 | 38篇 |
2020年 | 32篇 |
2019年 | 27篇 |
2018年 | 46篇 |
2017年 | 33篇 |
2016年 | 36篇 |
2015年 | 21篇 |
2014年 | 27篇 |
2013年 | 65篇 |
2012年 | 35篇 |
2011年 | 38篇 |
2010年 | 40篇 |
2009年 | 39篇 |
2008年 | 35篇 |
2007年 | 36篇 |
2006年 | 16篇 |
2005年 | 13篇 |
2004年 | 11篇 |
2003年 | 16篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1984年 | 4篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有723条查询结果,搜索用时 10 毫秒
711.
Kondlalli Ganesh Kumar Sarpabhushana Manjunatha Bijjanal Jayappa Gireesha Fahad Munir Abbasi Sabir Ali Shehzad 《亚洲传热研究》2019,48(5):1899-1912
Convective heat transfer plays a central role in the numerous industrial devices because it perturbs the mechanical behavior of a system along with its thermodynamics. Keeping such applications in mind, analysis of heat transportation in three‐dimensional tangent hyperbolic fluid flow is investigated here. Convective heat transportation at the boundaries is considered. Rosseland's approximation has been used for the radiation effects. Closed form analytical solutions for the governing equations are difficult to obtain even after the use of similarity transformations. Therefore, the numerical solutions are presented through the Runge‐Kutta‐Fehlberg forth‐fifth method. Graphical analysis of the numerical results has been carried out. Roles of sundry constraints on flow are studied. It is also noted that the rates of heat transportation and skin‐friction are higher in the presence of convective heat transfer near the boundary. 相似文献
712.
Gopalakrishnan Kumar Periyasamy Sivagurunathan Parthiban Anburajan Arivalagan Pugazhendhi Ganesh D. Saratale Chang-Su Choi Sang-Hyoun Kim 《International Journal of Hydrogen Energy》2018,43(25):11452-11459
This study investigated the bioconversion of dilute acid (2% H2SO4) pretreated red algae (Gelidium amansii) hydrolysate into H2 by anaerobic fermentation in a continuous stirred tank reactor under mesophilic conditions using hybrid immobilized cells as microbial catalyst. Two different hydraulic retention times (HRT) of 24 h and 16 h with a feed concentration of 15 g/L hexose equivalent have been investigated over 85 days of operation to evaluate H2 production performance and stability of the continuous system. The highest hydrogen production rate (HPR) and hydrogen yield (HY) of 2.7 L/L/d and 1.3 mol/mol substrate hexoseadded was achieved at 24 h HRT, while further operation at 16 h HRT led to a significant drop in the hydrogen production with a HPR and HY values of 1.8 L/L/d and 0.7 mol/mol substrate hexoseadded, respectively. The bacterial community analysis characterized by 454 pyrosequencing revealed that the changes in HRT significantly influence the composition of the dominant microflora. At longer HRT (24 h), the phyla Firmicutes was abundant over 98%, whereas at shorter HRT (16 h), Proteobacteria being the dominant populations with 84%. These outcomes suggested that controlling appropriate HRT is prerequisite for efficient hydrogen production. 相似文献
713.
The article explores the thermodynamics of an alternate hydrogen generation process - dry autothermal reforming and its comparison to autothermal reforming process of isooctane for use in gasoline fuel processors for SOFC. A thermodynamic analysis of isooctane as feed hydrocarbon for autothermal reforming and dry autothermal reforming processes for feed OCIR (oxygen to carbon in isooctane ratio) from 0.5 to 0.7 at 1 bar pressure under analogous thermoneutral operating conditions was done using Gibbs free energy minimization algorithm in HSC Chemistry. The trends in thermoneutral points (TNP), important product gas compositions at TNPs and fuel processor energy requirements were compared and analyzed. Dry autothermal reforming was identified as a less energy consuming alternative to autothermal reforming as the syngas can be produced with lower energy requirements at thermoneutral temperatures, making it a promising candidate for use in gasoline fuel processors to power the solid oxide fuel cells. The dry autothermal reforming process for syngas production can also be used for different fuels. 相似文献
714.
Manjappa Archana Mundalamane Manjappa Praveena Kondlahalli Ganesh Kumar Sabir Ali Shehzad Manzoor Ahmad 《亚洲传热研究》2020,49(8):4907-4922
The present flow problem investigates the incompressible and squeezed flow between two parallel plates. The mathematical formulation includes the constitutive equations of Casson nanofluid, which is treated as a lubricant. Brownian movement, slip condition, and thermophoretic mechanisms are also considered. The formulated model is tackled by Runge-Kutta-Fehlberg fourth- and fifth-order numerical scheme joint with shooting criteria. Momentum, thermal, and mass species behavior is executed by plots of distinct physical constraints values. It is found that the velocity component is boosted for the larger squeezed parameter whereas the temperature component shows the same behavior for Brownian motion and thermophoresis parameter. Near the lower half of the plate, velocity increases for the slip parameter whereas it decreases for magnetic and Casson parameters. 相似文献
715.
M. D. Mathew J. Ganesh Kumar V. Ganesan K. Laha 《Metallurgical and Materials Transactions A》2014,45(2):731-737
Small punch creep (SPC) studies have been carried out to evaluate the creep properties of 316LN stainless steel (SS) at 923 K (650 °C) at various stress levels. The results have been compared with uniaxial creep rupture data obtained from conventional creep tests. The minimum deflection rate was found to obey Norton power law. SPC rupture life was correlated with uniaxial creep rupture life. The influence of nitrogen content on the creep rupture properties of 316LN SS was investigated in the range of 0.07 to 0.14 wt pct. SPC rupture life increased and the minimum deflection rate decreased with the increase in nitrogen content. The trends were found to be in agreement with the results obtained from uniaxial creep rupture tests. These studies have established that SPC is a fast and reliable technique to screen creep properties of different experimental heats of materials for optimizing the chemical composition for developing creep-resistant materials. 相似文献
716.
Sanjay Darvekar A. B. Koteswara Rao S. Shankar Ganesh K. Ramji 《The International Journal of Advanced Manufacturing Technology》2013,67(5-8):1609-1621
This paper presents multiobjective optimization of a typical 2-degree-of-freedom (DOF) parallel kinematic machine (PKM) tool that has only single DOF joints. Nondimensional indices, namely global stiffness index (GSI), global conditioning index (GCI), and workspace index, are considered as the objectives for optimization. The indices GSI and GCI depict the variation of stiffness and dexterity of PKM within the workspace. The leg length and distance between two rails on which actuators slide are treated as design variables as these greatly influence the characteristics of PKM. A multiobjective genetic algorithm (MOGA) approach is implemented in MATLAB to find an efficient solution to this complex optimization problem. Fitness function includes inverse kinematics equations, Jacobian and stiffness matrices to compute and optimize the nondimensional indices. First, the optimal value of each index is obtained by single-objective GA. To further improve the results, a hybrid function PATTERNSEARCH is used. This helps to select appropriate boundary conditions for MOGA. To obtain the optimal values of all the three indices, a multiobjective GA is carried out. The results are compared with a conventional exhaustive search method of optimization. The obtained results show that the use of MOGA enhances the quality of the optimization outcome. Secondly, a prototype has been designed and developed with the optimal dimensions. The actual workspace of the PKM and influence of leg collision on the workspace are studied. Finally, a preliminary experimentation was carried out. A comparison between PKM and the three-axis serial kinematic machine tool is presented. 相似文献
717.
Prachi Agrawal Khalid Alnowibet Talari Ganesh Adel F. Alrasheedi Hijaz Ahmad Ali Wagdy Mohamed 《计算机、材料和连续体(英文)》2022,70(1):817-829
Recent years witness a great deal of interest in artificial intelligence (AI) tools in the area of optimization. AI has developed a large number of tools to solve the most difficult search-and-optimization problems in computer science and operations research. Indeed, metaheuristic-based algorithms are a sub-field of AI. This study presents the use of the metaheuristic algorithm, that is, water cycle algorithm (WCA), in the transportation problem. A stochastic transportation problem is considered in which the parameters supply and demand are considered as random variables that follow the Weibull distribution. Since the parameters are stochastic, the corresponding constraints are probabilistic. They are converted into deterministic constraints using the stochastic programming approach. In this study, we propose evolutionary algorithms to handle the difficulties of the complex high-dimensional optimization problems. WCA is influenced by the water cycle process of how streams and rivers flow toward the sea (optimal solution). WCA is applied to the stochastic transportation problem, and obtained results are compared with that of the new metaheuristic optimization algorithm, namely the neural network algorithm which is inspired by the biological nervous system. It is concluded that WCA presents better results when compared with the neural network algorithm. 相似文献
718.
A study into the impact of cell size parameter on the performance of a CDMA network is presented. The findings suggest optimum cell sizes for maximum CDMA capacity and reduced handoff overhead 相似文献
719.
King-Jien Chui Kah-Wee Ang Narayanan Balasubramanian Ming-Fu Li Ganesh S. Samudra Yee-Chia Yeo 《Electron Devices, IEEE Transactions on》2007,54(2):249-256
A novel strained-silicon (Si) n-MOSFET with 50-nm gate length is reported. The strained n-MOSFET features silicon-carbon (Si1-yCy) source and drain (S/D) regions formed by a Si recess etch and a selective epitaxy of Si1-yCy in the S/D regions. The carbon mole fraction incorporated is 0.013. Lattice mismatch of ~0.56% between Si 0.987C0.013 and Si results in lateral tensile strain and vertical compressive strain in the Si channel region, both contributing to substantial electron-mobility enhancement. The conduction-band offset DeltaEc between the Si0.987 C0.013 source and the strained Si channel could also contribute to an increased electron injection velocity nuinj from the source. Implementation of the Si0.987 C0.013 S/D regions for n-MOSFET provides significant drive current IDsat enhancement of up to 50% at a gate length of 50 nm 相似文献
720.
S. Raju B. Jeya Ganesh Arun Kumar Rai R. Mythili S. Saroja E. Mohandas M. Vijayalakshmi K.B.S. Rao Baldev Raj 《Journal of Nuclear Materials》2009,389(3):385-393
The on-heating phase transformation temperatures up to the melting regime and the specific heat capacity of a reduced activation ferritic-martensitic steel (RAFM) with a nominal composition (wt%): 9Cr-0.09C-0.56Mn-0.23V-1W-0.063Ta-0.02N, have been measured using high temperature differential scanning calorimetry. The α-ferrite + carbides → γ-austenite transformation start and finish temperatures, namely Ac1, and Ac3, are found to be 1104 and 1144 K, respectively for a typical normalized and tempered microstructure. It is also observed that the martensite start (MS) and finish (Mf) temperatures are sensitive to the austenitising conditions. Typical MS and Mf values for the 1273 K normalized and 1033 K tempered samples are of the order 714 and 614 K, respectively. The heat capacity CP of the RAFM steel has been measured in the temperature range 473-1273 K, for different normalized and tempered samples. In essence, it is found that the CP of the fully martensitic microstructure is found to be lower than that of its tempered counterpart, and this difference begins to increase in an appreciable manner from about 800 K. The heat capacity of the normalized microstructure is found to vary from 480 to 500 J kg−1 K−1 at 500 K, where as that of the tempered steel is found to be higher by about, 150 J kg−1 K−1. 相似文献