全文获取类型
收费全文 | 449篇 |
免费 | 29篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 8篇 |
综合类 | 1篇 |
化学工业 | 150篇 |
金属工艺 | 7篇 |
机械仪表 | 13篇 |
建筑科学 | 17篇 |
矿业工程 | 6篇 |
能源动力 | 18篇 |
轻工业 | 96篇 |
水利工程 | 5篇 |
石油天然气 | 3篇 |
无线电 | 19篇 |
一般工业技术 | 57篇 |
冶金工业 | 18篇 |
原子能技术 | 1篇 |
自动化技术 | 60篇 |
出版年
2023年 | 10篇 |
2022年 | 17篇 |
2021年 | 37篇 |
2020年 | 21篇 |
2019年 | 22篇 |
2018年 | 28篇 |
2017年 | 13篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 25篇 |
2013年 | 25篇 |
2012年 | 21篇 |
2011年 | 25篇 |
2010年 | 22篇 |
2009年 | 14篇 |
2008年 | 25篇 |
2007年 | 10篇 |
2006年 | 13篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 1篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有479条查询结果,搜索用时 15 毫秒
41.
Steel dome structures, with their striking structural forms, take a place among the impressive and aesthetic load bearing systems featuring large internal spaces without internal columns. In this paper, the seismic design optimization of spatial steel dome structures is achieved through three recent metaheuristic algorithms that are water strider (WS), grey wolf (GW), and brain storm optimization (BSO). The structural elements of the domes are treated as design variables collected in member groups. The structural stress and stability limitations are enforced by ASD-AISC provisions. Also, the displacement restrictions are considered in design procedure. The metaheuristic algorithms are encoded in MATLAB interacting with SAP2000 for gathering structural reactions through open application programming interface (OAPI). The optimum spatial steel dome designs achieved by proposed WS, GW, and BSO algorithms are compared with respect to solution accuracy, convergence rates, and reliability, utilizing three real-size design examples for considering both the previously reported optimum design results obtained by classical metaheuristic algorithms and a gradient descent-based hyperband optimization (HBO) algorithm. 相似文献
42.
In this study, we proposed to investigate how the effect of electron-donating methyl ( CH3) group at p-position of amin ( NH2) group in aminophenol (AP) compound affected thermal stability, optical, electrochemical properties, and conductivity measurement. For this reason, we choice 2-AP and 2-amino-4-methylphenol compounds and synthesized phenolic monomers by condensation reactions 4-fluorobenzaldehyde with aromatic amino phenols. Then, these monomers were converted to their polyphenol derivatives by oxidative polycondensation reactions in an aqueous alkaline medium. Structural characterizations were carried out by FTIR, NMR, and size exclusion chromatography. Cyclic voltammetry was used to determine the electrochemical oxidation-reduction characteristics. Optical properties were investigated by UV–vis and fluorescence analyses. Solid state electrical conductivities were measured on polymer films by four-point probe technique using an electrometer. Thermal data of monomer/polymer and polymers were obtained by TG-DTA and DSC techniques, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
43.
Ahmed Y. Musa Abu Bakar Mohamad Abdul Amir H. Kadhum Mohd Sobri Takriff Waleed Ahmoda 《Journal of Industrial and Engineering Chemistry》2012,18(1):551-555
Quantum chemical calculations were performed on ten thio compounds using semi-empirical method PM3 within program package of Material Studio 5.5. The effect of molecular structure on the corrosion inhibition efficiency was investigated using the quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, (LUMO–HOMO) energy gap, dipole moment (λ) and fraction of electron transfer (ΔN) were calculated and discussed. A relationship between the corrosion inhibition efficiency and several quantum parameters was established with coefficient correlation (R2) of 0.8894. 相似文献
44.
M. D. Martynenko Garib Musa Garib 《Journal of Engineering Physics and Thermophysics》1990,59(2):1069-1070
We have derived a nonlinear integrodifferential equation to find the unbent shape of the middle surface of a sloping shell of constant thickness, subjected to a given temperature and force field.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 59, No. 2, pp. 314–316, August, 1990. 相似文献
45.
Ahmed Y. Musa Abu Bakar Mohamad Abdul Amir H. Kadhum Yousef Bashir A. Tabal 《Journal of Materials Engineering and Performance》2011,20(3):394-398
The corrosion inhibition of Al-Alloy (Al2024) in 0.5 M nitric acid solution at 30 °C was achieved using 4-4-dimethyloxazolidine-2-thione
(DMT) as a corrosion inhibitor. The electrochemical performance of the DMT was studied by electrochemical impedance spectroscopy
(EIS), potentiodynamic polarization measurements, and scanning electron microscopic study (SEM). The results indicated that
DMT acts as an inhibitor for Al2024 in 0.5 M nitric acid. Polarization curves indicated that DMT was a mixed-type inhibitor.
Inhibition efficiencies were observed to be increased with an increase in DMT concentration and attains approximately to 93.4%
at 2 mM of DMT in 0.5 M nitric acid. The adsorption of DMT model on Al2024 surface obeyed in accordance with Langmuir adsorption
isotherm model. The value of the free energy of adsorption ΔG
ads indicated that the adsorption of DMT molecule was a spontaneous process and was typical of physical and chemical adsorption. 相似文献
46.
Musa Y.I. Keri A.J.F. Halladay J.A. Jagtiani A.S. Mandeville J.D. Johnnerfelt B. Stenstrom L. Khan A.H. Freeman W.B. 《Power Delivery, IEEE Transactions on》2002,17(4):957-962
An 800-kV metal oxide transmission line surge arrester (TLA) has been developed, installed and tested on the AEP 765-kV Marysville-Kammer transmission line. The purpose of this TLA is to pave the way for the development, construction and application of an 800-kV SF/sub 6/ dead tank circuit breaker without closing resistors and free standing current transformers at American Electric Power's (AEP) 800-kV Orange station. Eight hundred kilovolts is the maximum design operating voltage, and 765 kV is the nominal operating voltage. Successful field test results of the TLAs ability to limit switching overvoltages emanating from circuit breaker operation to below the transmission line switching withstand are given. In addition, successful test results of the 800-kV dead tank circuit breaker design dielectric test are given in this paper. 相似文献
47.
MusaKarakus RobertMoore 《中国耐火材料》2003,12(3):3-6
1 Introduction Kyanite is an important naturally occurring in-dustrial mineral and is used in the manufacture of avariety of industrial ceramic products; notable exam-ples include refractories and porcelains. It is a high-pressure polymorph of the aluminosilicates of the ne-sosilicate group, which includes kyanite, sillimanite,and andalusite. These three aluminous or alumina-rich minerals are chemically identical with the compo-sition, Al_2SiO_5, but have different crystal structuresand physical properties. It is, however, their alumina 相似文献
48.
Operational profiles in software-reliability engineering 总被引:1,自引:0,他引:1
A systematic approach to organizing the process of determining the operational profile for guiding software development is presented. The operational profile is a quantitative characterization of how a system will be used that shows how to increase productivity and reliability and speed development by allocating development resources to function on the basis of use. Using an operational profile to guide testing ensures that if testing is terminated and the software is shipped because of schedule constraints, the most-used operations will have received the most testing and the reliability level will be the maximum that is practically achievable for the given test time. For guiding regression testing, it efficiently allocates test cases in accordance with use, so the faults most likely to be found, of those introduced by changes, are the ones that have the most effect on reliability 相似文献
49.
The engineering process that underlies software development is examined. A brief summary of how information technology has affected both institutions and individuals in the past few decades is given. Engineering with models and metrics is then discussed. Improving software quality, making software engineering technology more transferable, and transferring software technology into an organization are addressed 相似文献
50.