全文获取类型
收费全文 | 420篇 |
免费 | 37篇 |
专业分类
电工技术 | 18篇 |
综合类 | 1篇 |
化学工业 | 93篇 |
金属工艺 | 11篇 |
机械仪表 | 19篇 |
建筑科学 | 14篇 |
矿业工程 | 3篇 |
能源动力 | 40篇 |
轻工业 | 42篇 |
水利工程 | 4篇 |
石油天然气 | 12篇 |
无线电 | 48篇 |
一般工业技术 | 72篇 |
冶金工业 | 18篇 |
原子能技术 | 3篇 |
自动化技术 | 59篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 2篇 |
2021年 | 21篇 |
2020年 | 19篇 |
2019年 | 36篇 |
2018年 | 34篇 |
2017年 | 25篇 |
2016年 | 31篇 |
2015年 | 23篇 |
2014年 | 27篇 |
2013年 | 61篇 |
2012年 | 25篇 |
2011年 | 25篇 |
2010年 | 25篇 |
2009年 | 25篇 |
2008年 | 16篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有457条查询结果,搜索用时 34 毫秒
1.
Rauf Tavakoli Bakhshi Puyan Mirarab Meysam Shahbazi Khalil 《Theoretical Foundations of Chemical Engineering》2020,54(5):995-1004
Theoretical Foundations of Chemical Engineering - In this work, with the aim of accurate prediction of water content, H2S and CO2 absorption capacity of diethanolamine (DEA) solvent in Khangiran... 相似文献
2.
3.
Tavakoli Rouhollah Mohseni Seyyed Mohammad 《Structural and Multidisciplinary Optimization》2014,49(4):621-642
Structural and Multidisciplinary Optimization - A new algorithm for the solution of multimaterial topology optimization problems is introduced in the present study. The presented method is based on... 相似文献
4.
Liquid phase volumetric mass transfer coefficients for oxygen are determined in a three-phase fluidized bed and in a bubble column. The concept of exponential decreasing axial variation of volumetric mass transfer coefficient leads to a better representation of oxygen concentration profiles inside the column. Compared to the bubble column, kla axial variations are more important in the lower part of the fluidized bed column, where solid particles increase the coalescence phenomenum, particularly with viscous liquids. 相似文献
5.
Reserve estimation is a key to find the correct NPV in a mining project. The most important factor in reserve estimation is the metal price. Metal price fluctuations in recent years were exaggerated, and imposed a high degree of uncertainty to the re-serve estimation, and in consequence to the whole mine planning procedure. Real option approach is an efficient method of deci-sion making in the uncertain conditions. This approach has been used for evaluation of defined natural resources projects until now. This study considering the metal price uncertainty used real option approach to prepare a methodology for reserve estimation in open pit mines. This study was done on a copper cylindrical deposit, but the achieved methodology can be adjusted for all kinds of deposits. This methodology was comprehensively described through the examples in such a manner that can be used by the mine planners. 相似文献
6.
Mansoor Kazemimoghadam Afshin Pak Toraj Mohammadi 《Microporous and mesoporous materials》2004,70(1-3):127-134
In this research, dehydration of water/1-1-dimethylhydrazine (UDMH) mixtures by zeolite NaA and hydroxy sodalite membranes has been investigated. Support of these membranes has been tubular mullites that have been made by extruding a mixture of about 67–75% kaolin clay and 33–25% distilled water using an extruder. Zeolite NaA and hydroxy sodalite membranes have been coated on the external surface of the porous supports by the hydrothermal synthesis.
UDMH/water mixtures have been separated at ambient temperature and pressure by pervaporation (PV) using these zeolite membranes. These membranes showed very high selectivity of water for all UDMH mixtures. For the UDMH/water mixtures, separation factor as high as 10 000 has been obtained for UDMH feed concentration of 2%. Total mass fluxes of 1.05–0.2 kg/(m2 h) have been also obtained. 相似文献
7.
Fatemeh Ghods Hamed Yousefi Ali Mohammad Afshin Hemmatyar Ali Movaghar 《Computer Networks》2013,57(18):3812-3825
Data aggregation is a key, yet time-consuming functionality in wireless sensor networks (WSNs). Multi-channel design is a promising technique to alleviate interference as a primary reason for long latency of TDMA aggregation scheduling. Indeed, it provides more potential of parallel transmissions over different frequency channels, thus minimizing time latency. In this paper, we focus on designing a multi-channel minimum latency aggregation scheduling protocol, named MC-MLAS, using a new joint approach for tree construction, channel assignment, and transmission scheduling. To our best knowledge, this is the first work in the literature which combines orthogonal channels and partially overlapping channels to consider the total latency involved in data aggregation. Extensive simulations verify the superiority of MC-MLAS in WSNs. 相似文献
8.
Seong-Hwan Cho Afshin Karshenas Akhtarhusein A. Tayebali Murthy N. Guddati 《International Journal of Pavement Engineering》2017,18(12):1098-1110
The debonding distress in asphalt pavement structures is a critical problem that affects the performance of asphalt concrete pavements. It occurs at the layer interface due to the poor bond quality between adjacent asphalt concrete layers and/or when stresses at the layer interface exceed the strengths of the material at the interface. The debonding of the adjacent layers, especially the top surface layer of an asphalt pavement, is a contributing factor to the premature cracking of pavements. Hence, the debonding distress can lead to a reduction in the life of the pavement. This paper presents an analytical and experimental framework to evaluate the potential for debonding at the layer interface of asphalt concrete pavements. Computational analysis was performed to determine the critical stress and strain states in layered asphalt pavements under moving vehicle loads using the Layered ViscoElastic pavement analysis for Critical Distresses (LVECD) computer program developed at North Carolina State University. This computational analysis enables a greater understanding of the critical stress that is involved in debonding and the ways that such stress is affected by pavement design parameters and environmental conditions. In addition, a prediction model was developed that can determine the shear bond strength at the interface of asphalt concrete layers with different tack coat materials at various temperatures, loading rates and normal confining stresses. The systematic and mechanistic framework developed in this study employs the maximum shear ratio concept as a shear failure criterion and provides a tool to evaluate the effects of various loading, environmental and pavement factors on the debonding potential of asphalt pavements. The overall advantages of the mechanistic framework and approach using the LVECD analysis tool will help lead to better understanding of the debonding mechanism, proper selection of the tack coats, and economic benefit in highway pavement maintenance and rehabilitation costs. 相似文献
9.
Akram Tavakoli Ali Akbar Babaluo Khadijeh Safaee 《Fullerenes, Nanotubes and Carbon Nanostructures》2017,25(5):312-317
In this work, multi-wall carbon nanotube (MWCNT) was successfully modified using aqueous solution of Oxone as a new oxidant. The effect of oxidation temperature on various characteristics of the treated MWCNTs was also investigated. FTIR and titration analysis proved the formation of carboxyl, carbonyl and epoxide groups at the surface of MWCNTs. The concentration of the functional groups increased as the modification temperature increased. The presence of such oxygen containing groups at the surface of MWCNTs justified the long time stability of the treated MWCNTs suspensions in water and methanol. The modified MWCNTs showed higher entanglement compared to row MWCNT due to the cross-links adjacent effect of pendant functional groups. Finally, it was concluded that Oxone oxidation process destroys the structure of the MWCNTs, but not severe enough to unzip the MWCNTs. 相似文献
10.
Spillways are hydraulic structures which transfer water to the downstream. Stepped spillways areseriously attended to, since they are highly efficient regarding energy dissipation. In this study, the flow pattern over stepped spillways was simulated with five different pool configurations. The VOF method was used to simulate the flow free surface, and K??(RNG) was employed to model turbulence. The results obtained fromthe numerical model were fairly consistent with the experimental results. The results demonstrated that theflow velocity and the residual head showed significant differences in the spillway width with regard to different pool configurations. The pool configuration in which the pools were installed as staggered configuration of flat and pooled steps showed the least residual head at the downstream and as a result the greatest energy dissipation. 相似文献