全文获取类型
收费全文 | 330篇 |
免费 | 16篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 20篇 |
化学工业 | 58篇 |
金属工艺 | 4篇 |
机械仪表 | 4篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 16篇 |
轻工业 | 24篇 |
水利工程 | 2篇 |
无线电 | 30篇 |
一般工业技术 | 71篇 |
冶金工业 | 24篇 |
自动化技术 | 89篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 8篇 |
2021年 | 17篇 |
2020年 | 19篇 |
2019年 | 15篇 |
2018年 | 12篇 |
2017年 | 4篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 17篇 |
2013年 | 31篇 |
2012年 | 12篇 |
2011年 | 22篇 |
2010年 | 11篇 |
2009年 | 13篇 |
2008年 | 20篇 |
2007年 | 16篇 |
2006年 | 4篇 |
2005年 | 6篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 10篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 7篇 |
1976年 | 2篇 |
1971年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有347条查询结果,搜索用时 359 毫秒
31.
Anjan Sarkar Anjan Banerjee Nilanjan Banerjee Siddhartha Brahma B Kartikeyan Manab Chakraborty K L Majumder 《IEEE transactions on image processing》2005,14(5):634-645
This work deals with multisensor data fusion to obtain landcover classification. The role of feature-level fusion using the Dempster-Shafer rule and that of data-level fusion in the MRF context is studied in this paper to obtain an optimally segmented image. Subsequently, segments are validated and classification accuracy for the test data is evaluated. Two examples of data fusion of optical images and a synthetic aperture radar image are presented, each set having been acquired on different dates. Classification accuracies of the technique proposed are compared with those of some recent techniques in literature for the same image data. 相似文献
32.
Koel Das Aditi Majumder Monica Siegenthaler Hans Keirstead M. Gopi 《The Visual computer》2011,27(12):1055-1069
Remyelination therapy is a state-of-the-art technique for treating spinal cord injury (SCI). Demyelination—the loss of myelin
sheath that insulates axons, is a prominent feature in many neurological disorders resulting in SCI. This lost myelin sheath
can be replaced by remyelination. In this paper, we propose an algorithm for efficient automated cell classification and visualization
to analyze the progress of remyelination therapy in SCI. Our method takes as input the images of the cells and outputs a density
map of the therapeutically important oligodendrocyte-remyelinated axons (OR-axons) which is used for efficacy analysis of
the therapy. Our method starts with detecting cell boundaries using a robust, shape-independent algorithm based on iso-contour
analysis of the image at progressively increasing intensity levels. The detected boundaries of spatially clustered cells are
then separated using the Delaunay triangulation based contour separation method. Finally, the OR-axons are identified and
a density map is generated for efficacy analysis of the therapy. Our efficient automated cell classification and visualization
of remyelination analysis significantly reduces error due to human subjectivity. We validate the accuracy of our results by
extensive cross-verification by the domain experts. 相似文献
33.
S. B. Majumder P. S. Dobal B. Roy S. Bhaskar R. S. Katiyar Amar Bhalla 《Ferroelectrics Letters Section》2001,28(3):85-92
We have studied the effect of rare earth dopants (Nd, Gd and Ce) on the phase formation behavior and electrical properties of sol-gel derived Pb1.05(Zr0.53Ti0.47)O3 thin films. In all these films the perovskite phase is obtained up to 5 at% doping and beyond that pyrochlore phase was found to coexist with the perovskite phase. Ce and Gd doping(1-2 at%) exhibited improved ferroelectric and dielectric properties as compared to the undoped PZT films. Nd doping (2 at%) was found to be effective to increase the retained switchable polarization of undoped PZT from 63% to 84%. The transition temperature of undoped PZT film was found to be reduced with Nd doping. The Nd doped films also exhibited typical relaxor behavior and a diffuse phase transition, characteristic of the relaxor material. Introduction of Nd into the PZT lattice probably introduces disorder in the B site of ABO3 lattice which causes the observed relaxor behavior 相似文献
34.
Haiderali M. Bhavnagary Tirunillai S. Krishnamurthy Suvendu K. Majumder 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1979,29(7):433-436
Optimum conditions have been presented for the production of methyl bromide by employing the reactants, sulphur, methyl alcohol, liquid bromine and water. For the maximum recovery of methyl bromide from liquid bromine used in the reaction, a 5% excess of sulphur and 30% excess of water than the stoichiometric quantities were found necessary. The addition of liquid bromine to the reaction mixture at slower rates of 0.5 to 2.5 cm3 min?1, reduced the loss of bromine as sulphur bromide and increased the yield of methyl bromide from 42 to 94.3%. With these standardised conditions, the product had a methyl bromide content of 98.2% with an overall yield of 94.42% based on liquid bromine. 相似文献
35.
36.
The paper describes the implementation of a centralised control-design scheme in a real-time laboratory-based dynamic simulator. A centralised multivariable-control algorithm is designed employing remote feedback signals considering delay in signal transmission. The transmitted signals can be used for multiple-swing-mode damping using a single controller. Such an algorithm is numerically intensive owing to the high controller size and the predictor that takes care of the delay in signal transmission. The performance of the proposed controller is demonstrated by practical implementation using a rapid-prototyping controller mounted on a PC-ATX. Results of the experimental tests are shown for a detailed model of the power system implemented using Linux PC-based multiprocessor technology. 相似文献
37.
AbstractSteganography is a data-concealing technique that provides a covert communication. This paper proposes a spatial domain color steganography method that uses a neighboring pixel-pair differencing concept to enhance the embedding capacity. The proposed method considers the distortion tolerance capacity of each color plane and the difference value between two neighboring pixels while deciding the number of bits that can be concealed in that pixel-pair. Each plane is divided into some disjoint blocks of size 3?×?3 pixels. The method forms eight pairs of pixels in one block using the eight-neighboring pixel concept, which enables the method to utilize all the edge pixels in all probable directions. It also uses the XOR encoding technique before the embedding process. This step provides an additional layer of security to the secret information. The simulation results show that the proposed method is able to achieve a high embedding capacity with good visual quality as per the calculation of imperceptibility metrics. The robustness of the method is tested by RS steganalysis and pixel difference histogram analysis. Further, a comparison between the proposed method and the existing methods on the basis of embedding capacity and stego image quality is shown. 相似文献
38.
Subhashis Roy Anup Dey Bikram Biswas Subir Kumar Sarkar 《Journal of Materials Engineering and Performance》2018,27(6):2635-2642
Ethanol sensors based on different WO3 and ZnO structures are studied in the present work. The XRD and SEM processes are used to characterize the sensing layer’s surface morphology which reveals the presence of nanoparticle in sensing layer. Further reducing the nanoparticle diameter by the addition of palladium (Pd) and platinum (Pt) for both the sensors (ZnO and WO3) gives good results on sensitivity, operating temperature, response time and recovery time. Nanoparticle diameter for undoped WO3, Pd-modified WO3 and Pt-modified WO3 based sensors is 11.8, 6 and 5.4 nm, whereas nanoparticle diameter for undoped, Pd-modified and Pt-modified ZnO based sensors is 20, 14 and 11 nm, respectively. Analysis of dynamic response of the sensors when exposed to different concentrations of ethanol vapour (from 500 to 10,000 ppm) and various temperatures indicate the improvement in sensitivity up to 77.2% for WO3 and 74.6% for ZnO based sensors. 相似文献
39.
Mainak Majumder Clint Rendall Michelle Li Natnael Behabtu J. Alexander Eukel Robert H. Hauge Howard K. Schmidt Matteo Pasquali 《Chemical engineering science》2010,65(6):2000-2008
Spray coating is a scalable and high-throughput process for fabrication of transparent and conducting coatings (TCCs) composed of single-walled carbon nanotubes (SWNTs). Presently the fundamentals of this process are not well understood. We show that suppression of coalescence of spray droplets by sufficiently rapid heat- and mass-transfer yields homogeneous SWNT films by preventing the formation of ‘coffee stains’ of larger length scale. Such heat and mass transfer is driven by differential evaporation between the top and edges of the drops, whereas thermal and compositional effects on surface tension and buoyancy are weak. Ultrasonic spraying ensures that the droplets are deposited without significant splashing, and delayed splashing at higher Weber number is evidenced. We find that the performance of spray-coated TCCs made from HiPCO SWNTs is limited by bundle diameter rather than length of the constituent SWNTs and bundes. Vapor acid doping with concentrated sulfuric acid roughly doubles the conductivity of the TCCs. 相似文献
40.
In this article we have reviewed our recent research efforts on the synthesis and characterization of a wide spectrum of ferroelectric thin films for a variety of electronic and electro-optic devices including computer memories, tunable microwave devices, infra-red detectors, and electro-optic modulators. The review is separated into three sections; first we have described the process induced modifications of the properties of perovskite films prepared by sol-gel technique. The next section reviews the effect of certain impurity elements (e.g. La, Nd, Ce etc) in modifying the electrical characteristics of perovskite thin films followed by our experimental observations on the synthesis of epitaxially grown perovskite thin films by sol-gel technique. The epitaxial quality of BST thin films has been evaluated by fabricating eight element coupled microstrip phase shifters at NASA Glenn Research Center. Finally, future directions of sol-gel thin film research have been highlighted in view of these experimental observations. 相似文献