全文获取类型
收费全文 | 562篇 |
免费 | 34篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 7篇 |
综合类 | 1篇 |
化学工业 | 120篇 |
金属工艺 | 11篇 |
机械仪表 | 52篇 |
建筑科学 | 25篇 |
能源动力 | 40篇 |
轻工业 | 49篇 |
水利工程 | 9篇 |
石油天然气 | 8篇 |
无线电 | 46篇 |
一般工业技术 | 109篇 |
冶金工业 | 9篇 |
原子能技术 | 1篇 |
自动化技术 | 112篇 |
出版年
2023年 | 3篇 |
2022年 | 19篇 |
2021年 | 35篇 |
2020年 | 39篇 |
2019年 | 39篇 |
2018年 | 40篇 |
2017年 | 36篇 |
2016年 | 31篇 |
2015年 | 22篇 |
2014年 | 42篇 |
2013年 | 92篇 |
2012年 | 40篇 |
2011年 | 32篇 |
2010年 | 32篇 |
2009年 | 23篇 |
2008年 | 16篇 |
2007年 | 9篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 7篇 |
2001年 | 1篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有599条查询结果,搜索用时 15 毫秒
81.
Amira Ben Rabeh Faouzi Benzarti Hamid Amiri 《International journal of imaging systems and technology》2017,27(1):3-11
Alzheimer disease is a neurodegenerative disorder that impairs memory, cognitive function, and gradually leads to dementia, physical deterioration, loss of independence, and death of the affected individual. In this context, segmentation of medical images is a very important technique in the field of image analysis and Computer‐Assisted Diagnosis. In this article, we introduce a new automatic method of brain images’ segmentation based on the Active Contour (AC) model to extract the Hippocampus and the Corpus Callosum (CC). Our contribution is to combine the geometric method with the statistical method of the AC. We used the Caselle Level Set and added a learning phase to build an average shape and to make the initialization task automatic. For the step of contour evolution, we used the principle of Level set and we added to it the a priori knowledge. Experimental results are very promising. © 2017 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 27, 3–11, 2017 相似文献
82.
A miniaturized inset‐fed on‐body meandered bowtie antenna designed for brain microwave imaging systems is presented in this article. The proposed on‐body antenna can contribute to the realization of a wearable and portable brain microwave imaging system. The size of 18 × 18 mm2 is achieved at a frequency range of 0.75 to 4 GHz by the simultaneous use of self‐complementary structures and meandered lines. The frequency band is a trade‐off between penetration depth and spatial resolution. The proposed antenna performance was studied at different positions on the human head voxel model in terms of several parameters such as reflection coefficient, near‐field directivity, and fidelity factor. In addition, the antenna bandwidth was surveyed on several volunteers using a wearable measurement setup. It has been found that the averages of measured reflection coefficients in different scenarios are in good agreement with the corresponding simulation results, and the antenna shows stable performance under different practical situations. The proposed antenna takes advantage of a small footprint and body matching, which make it an eligible choice for compact, portable, and wearable head microwave imaging systems. 相似文献
83.
Khraief Chadia Benzarti Faouzi Amiri Hamid 《Multimedia Tools and Applications》2020,79(27-28):19537-19560
Multimedia Tools and Applications - Fall is the biggest threat to seniors, with significant emotional, physical and financial implications. It is the major cause of serious injuries, disabilities,... 相似文献
84.
R. Udaiyakumar Senoj Joseph T. V. P. Sundararajan D. Vigneswaran R. Maheswar Iraj S. Amiri 《Wireless Personal Communications》2018,103(1):99-115
The aggressive scaling of CMOS technology has inevitably led to vastly increased power dissipation, process variability and reliability degradation, posing tremendous challenges to robust circuit design. To continue the success of integrated circuits, advanced design research must start in parallel with or even ahead of technology development. In this paper, an attempt is made to analyze various circuits’ delay and power performance by introducing certain level of variation to important process parameters like threshold voltage (Vth), mobility of carriers (μ0), oxide thickness (tox) and doping concentration (nsd). Basic Monte Carlo simulation is carried out on these circuits to ascertain the stability in performances. A 16 × 1 multiplexer is considered for detailed analysis. SPICE characterization is done for three different input slew rates (0.1, 0.5 and 1 ns) against four different output load drive strengths (1×, 2×, 3× and 4× output capacitive load). From the obtained results, output slew rates and average power results are observed and discussed. 相似文献
85.
Seyed Armin Zare Estekhraji Sahar Amiri 《Journal of Inorganic and Organometallic Polymers and Materials》2017,27(4):883-891
Anti-corrosion, anti-fungus, and self-cleaning properties of coatings containing ZnO–TiO2, SiO2–TiO2 and SiO2/TiO2/ZnO nanoparticles synthesized based on sol–gel precursors using tetra methoxysilane, 3-glycidoxypropyl trimethoxysilane, tetra (n-butyl orthotitanate) and zinc acetate dihydrate were investigated by FESEM, EDAX and TEM analyses. Results indicated uniform dispersion of inorganic nanoparticles in the range of 20–40 nm in size. Anti-corrosion property of the hybrid coating was characterized by EIS measurements and parametrically analyzed in an equivalent circuit when the coating was exposed to salt solution. Results showed that, ZnO and TiO2 nanoparticles enhance anti-corrosion property of the hybrid coatings. Anti-fungus and anti-bacterial properties of the coatings were determined by diameter of inhibition zone and inhabitation of bacterial growth, respectively. The coating containing ZnO and TiO2 nanoparticles showed anti-fungus and anti-bacterial properties which were related to their photocatalytic properties. Degradation of methylene blue in aqueous solution was determined by UV–Visible tests which indicated self-cleaning property of the coatings containing ZnO and TiO2 nanoparticles. 相似文献
86.
87.
Recent studies have shown that surface and gaseous contaminant interactions may play an important role in indoor air quality. Modeling is an important tool to improve our knowledge about the phenomena involved and define appropriate ventilation strategies. However, data for sorption isotherms and diffusion in building materials remain woefully lacking. This paper deals with the latter point. It aims at investigating a methodology based on an analysis of the material porosity first and then the application of Carniglia's mathematical model to determine the effective diffusivity of gaseous species in building materials. This methodology, whose main principles are presented in the first part of the paper, was applied to seven commonly found materials. Mercury intrusion porosimetry (MIP) tests, and the calculations using Carniglia's model, reveal typical total porosities and tortuosity factors for these materials. The analysis of pore size distributions (PSDs) also draws one's attention to the possible differences in the pore structures that may exist between two samples of the same type of material and the differences in the effective diffusivities of contaminants that may result from them. The computed effective diffusivities were subsequently compared to data from experiments carried out in the frame of the EC project MATHIS. An agreement was obtained, thus validating Carniglia's methodology - a methodology that offers many practical advantages compared to diffusion-cell methods. 相似文献
88.
Simulating urban expansion and scenario prediction using a cellular automata urban growth model,SLEUTH, through a case study of Karaj City,Iran 总被引:1,自引:0,他引:1
89.
Mojtaba Kaveh Vahid Majazi Dalfard Sajjad Amiri 《Neural computing & applications》2014,24(5):1179-1190
In the present paper, the dynamic facilities layout problem is studied in presence of ambiguity of information flow. Product demand (and consequently material flow) is defined as fuzzy numbers with different membership functions. The problem is modeled in fuzzy programming. Three models of expected value, chance-constrained programming and dependent-chance programming and two hybrid intelligent algorithms are then presented. At the end, efficiency of algorithms for solving fuzzy models of dynamic facilities layout is shown through some numerical examples. 相似文献
90.
Shima Eshaghi Hamed Kharrati Mohammad Ali Badamchizadeh Iraj Hasanzadeh 《International Journal of Control, Automation and Systems》2012,10(3):574-581
In this paper a hybrid control strategy is presented based on Dynamic Matrix Control (DMC) and feedback linearization methods for designing a predictive controller of five bar linkage manipulator as a MIMO system (two inputs and two outputs). Analyzing the internal dynamic of robot shows the open loop system is unstable and non-minimum phase, so in order to apply the predictive controller, special modifications are needed. These modifications on non-minimum phase behavior are performed using feedback linearization procedure based on state space realization. The design objective is to track a desirable set point as well as time varying trajectories as a command references with globally asymptotical stabilization. The proposed controller is applied to nonlinear fully coupled model of the typical five bar linkage manipulator with non-minimum phase behavior. Simulation results show that the proposed controller has good efficiency. The step responses of system with and without feedback linearization process illustrated that the mentioned modification for stabilizing is performed properly. After applying the proposed predictive controller, the joint angle of robot tracks the reference input while another input acts as the disturbance and vice versa. 相似文献