全文获取类型
收费全文 | 249篇 |
免费 | 12篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 3篇 |
综合类 | 1篇 |
化学工业 | 75篇 |
金属工艺 | 8篇 |
机械仪表 | 5篇 |
建筑科学 | 16篇 |
能源动力 | 16篇 |
轻工业 | 19篇 |
石油天然气 | 4篇 |
无线电 | 17篇 |
一般工业技术 | 34篇 |
冶金工业 | 22篇 |
原子能技术 | 8篇 |
自动化技术 | 35篇 |
出版年
2024年 | 2篇 |
2023年 | 11篇 |
2022年 | 8篇 |
2021年 | 16篇 |
2020年 | 15篇 |
2019年 | 11篇 |
2018年 | 14篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 24篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 10篇 |
2009年 | 26篇 |
2008年 | 22篇 |
2007年 | 10篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 5篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
排序方式: 共有263条查询结果,搜索用时 31 毫秒
91.
M. Abdulkadir D. Zhao S. Sharaf L. Abdulkareem I.S. Lowndes B.J. Azzopardi 《Chemical engineering science》2011,(11):2453
When gas/liquid mixtures flow around a bend they are subjected to forces additional to those encountered in a straight pipe. The behaviour of the flows at the inlet and outlet of the bend depends on the orientation of the pipes. Air/silicone oil flows around a 90° bend have been investigated using advanced instrumentation: Electrical Capacitance Tomography (ECT), Wire Mesh Sensor Tomography (WMS) and high-speed video. The first two provide time and cross-sectionally resolved data on void fraction. ECT probes were mounted 10 diameters upstream of the bend whilst WMS was positioned either immediately upstream or immediately downstream of the bend. The downstream pipe was maintained horizontal whilst the upstream pipe was mounted either vertically or horizontally. The bend (R/D=2.3) was made of transparent acrylic resin. From an analysis of the output from the tomography equipment, flow patterns were identified using both the reconstructed images as well as the characteristic signatures of Probability Density Function (PDF) plots of the time series of cross-sectionally averaged void fraction as suggested by Costigan and Whalley (1996). The superficial velocities of the air ranged from 0.05 to 4.73 m/s and for the silicone oil from 0.05 to 0.38 m/s. Bubble/spherical cap, slug, unstable slug and churn flows were observed before the bend for the vertical pipe and plug, slug, stratified wavy and annular flows when the pipe was horizontal. Bubble, stratified wavy, slug, semi-annular and annular flows are seen after the bend for the vertical 90° bend whilst for the horizontal 90° bend, the flow patterns remained the same as before the bend. Flow patterns for the vertical and horizontal 90° bends are shown on the diagram of the gas superficial velocity versus liquid superficial velocity. These results are confirmed by the high-speed videos taken around the bend. A previously proposed criterion, to determine stratification after the bend, based on a modified Froude number have been shown to be valid for a liquid different from that tested in the original paper. 相似文献
92.
Siavash Ghavami Olaf Wolkenhauer Farshad Lahouti Mukhtar Ullah Michael Linnebacher 《IET systems biology》2014,8(5):230
Knowing the expected temporal evolution of the proportion of different cell types in sample tissues gives an indication about the progression of the disease and its possible response to drugs. Such systems have been modelled using Markov processes. We here consider an experimentally realistic scenario in which transition probabilities are estimated from noisy cell population size measurements. Using aggregated data of FACS measurements, we develop MMSE and ML estimators and formulate two problems to find the minimum number of required samples and measurements to guarantee the accuracy of predicted population sizes. Our numerical results show that the convergence mechanism of transition probabilities and steady states differ widely from the real values if one uses the standard deterministic approach for noisy measurements. This provides support for our argument that for the analysis of FACS data one should consider the observed state as a random variable. The second problem we address is about the consequences of estimating the probability of a cell being in a particular state from measurements of small population of cells. We show how the uncertainty arising from small sample sizes can be captured by a distribution for the state probability.Inspec keywords: cancer, tumours, cellular biophysics, biomedical measurement, Gaussian distribution, maximum likelihood estimation, mean square error methods, hidden Markov models, fluorescence, random processes, convergence of numerical methodsOther keywords: cancer cell population dynamics, malignant tumours, tissue samples, normal tissue cells, disease, drugs, Markov process, cell population size measurement, hidden Markov model, noisy measurement, state transition probability, fluorescence‐activated cell sorting measurement, minimum mean square error estimator, maximum likelihood estimator, transition probability matrix, noise distributions, Gaussian distributions, MMSE, convergence mechanism, standard deterministic approach, stochastic phenomena, random variable 相似文献
93.
Abdulkadir Akin Ipek BazAuthor VitaeAlexandre SchmidAuthor Vitae Yusuf LeblebiciAuthor Vitae 《Integration, the VLSI Journal》2014
The computational complexity of disparity estimation algorithms and the need of large size and bandwidth for the external and internal memory make the real-time processing of disparity estimation challenging, especially for High Resolution (HR) images. This paper proposes a hardware-oriented adaptive window size disparity estimation (AWDE) algorithm and its real-time reconfigurable hardware implementation that targets HR video with high quality disparity results. Moreover, an enhanced version of the AWDE implementation that uses iterative refinement (AWDE-IR) is presented. The AWDE and AWDE-IR algorithms dynamically adapt the window size considering the local texture of the image to increase the disparity estimation quality. The proposed reconfigurable hardware architectures of the AWDE and AWDE-IR algorithms enable handling 60 frames per second on a Virtex-5 FPGA at a 1024×768 XGA video resolution for a 128 pixel disparity range. 相似文献
94.
Vladan Popovic Kerem Seyid Abdulkadir Akin Ömer Cogal Hossein Afshari Alexandre Schmid Yusuf Leblebici 《Journal of Signal Processing Systems》2014,76(2):169-184
Panoptic is a custom spherical light field camera used as a polydioptric system where imagers are distributed over a hemispherical surface, each having its own vision of the surroundings and a distinct focal plane. The spherical light field camera records light information from any direction around its center. This paper revises previously developed Nearest Neighbor and Linear blending techniques. Novel Gaussian blending and Restricted Gaussian blending techniques for vision reconstruction of a virtual observer located inside the spherical geometry are presented. These new blending techniques improve the output quality of the reconstructed image with respect to the ordinary stitching techniques and simpler image blending algorithms. A comparison of the developed blending algorithms is also given in this paper. A hardware architecture based on Field Programmable Gate Arrays (FPGA) enabling the real-time implementation of the blending algorithms is presented, along with the imaging results and resource utilization comparison. A recorded omnidirectional video is attached as a supplementary material. 相似文献
95.
96.
Mukhtar M. Ali 《时间序列分析杂志》1983,4(4):217-220
Abstract. This note considers approximating the distribution of the d statistic proposed by Durbin and Watson (1950,1951) by four-parameter Pearson distribution. It is shown that the approximations are remarkably close to the exact distributions for four sets of published data considered by Durbin and Watson (1971). 相似文献
97.
The goal of this work is to predict the daily performance (COP) of a ground-source heat pump (GSHP) system with the minimum data set based on an adaptive neuro-fuzzy inference system (ANFIS) with a fuzzy weighted pre-processing (FWP) method. To evaluate the effectiveness of our proposal (FWP–ANFIS), a computer simulation is developed on MATLAB environment. The comparison of the proposed hybridized system's results with the standard ANFIS results is carried out and the results are given in the tables. The efficiency of the proposed method was demonstrated by using the 3-fold cross-validation test. The statistical methods, such as the root-mean squared (RMS), the coefficient of multiple determinations (R2) and the coefficient of variation (cov), are given to compare the predicted and actual values for model validation. The average R2 values is 0.9998, the average RMS value is 0.0272 and the average cov value is 0.7733, which can be considered as very promising. The data set for the COP of GSHP system available included 38 data patterns. The simulation results show that the FWP-based ANFIS can be used in an alternative way in these systems. The prediction results of the proposed structure were much better than the standard ANFIS results. Therefore, instead of limited experimental data found in the literature, faster and simpler solutions are obtained using hybridized structures such as FWP-based ANFIS. 相似文献
98.
Synthesis of yttrium and cerium doped ZnO nanoparticles as highly inexpensive and stable photocatalysts for hydrogen evolution 总被引:1,自引:0,他引:1
Irshad Ahmad Muhammad Shoaib Akhtar Mian Faisal Manzoor Muhammad Wajid Muhammad Noman Ejaz Ahmed Mukhtar Ahmad Waheed Qamar Khan Anwar M.Rana 《中国稀土学报(英文版)》2021,39(4):440-445
Yttrium and cerium co-doped ZnO nanoparticles were synthesized by combustion route and characterized using X-ray diffraction(XRD),scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET),energy dispersive spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),UV-visible diffuse reflectance spectroscopy(UV-vis DRS),photoluminescence(PL)and electrochemical impedance spectroscopy(EIS)techniques.The introduction of yttrium ions has efficiently increased the relative percentage of Ce3+ions in ZnO.Yttrium and cerium co-doped ZnO shows efficient photo activity for hydrogen evolution(10.61 mmol/((g·h))higher than previously reported optimal value for rare earth codoped ZnO photocatalysts.This remarkably increased hydrogen evolution can be ascribed to the synergy between electronic anchoring effect of Y3+/Y2+and Ce4+/Ce3+redox couples.This report presents new idea for the synthesis of efficient photocatalyst using economical route and ion anchoring effect.The hydrogen evolution was also tested using Na2S and Na2SO3as electron donors under visible light illumination.The synthesized photocatalysts also exhibit high stability. 相似文献
99.
Pandian Bothi Raja Ahmad Kaleem Qureshi Afidah Abdul Rahim Khalijah Awang Mat Ropi Mukhtar Hasnah Osman 《Journal of Materials Engineering and Performance》2013,22(4):1072-1078
The inhibition effect of mild steel (MS) corrosion in 1 M HCl was studied by the addition of indole alkaloids (crude) isolated from Alstonia angustifolia var. latifolia (A. latifolia) leaves at 303 K. Potentiodynamic polarization, impedance spectroscopy, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) analyses were used for this study. Results show that the isolated alkaloid extract of A. latifolia is a good inhibitor and exhibited maximum inhibition efficiency (above 80%) at concentrations between 3 and 5 mg/L. Polarization measurements indicated that the inhibitor does not alter the mechanism of either anodic or cathodic reactions and acted as mixed-type inhibitor. The inhibition efficiencies of both electrochemical techniques are found to be in good agreement and adsorption of inhibitor follows Langmuir isotherm. Adsorption of inhibitor over metal surface was well supported by the SEM studies, while FTIR studies evidenced the presence of indole alkaloids as green inhibitor that reduces the rate of corrosion. 相似文献
100.
Magosso Enrico Ansari Mukhtar Alam Gopalan Yogheswaran Shuaib Ibrahim Lutfi Wong Jia-Woei Khan Nurzalina Abdul Karim Abu Bakar Mohamed Rizal Ng Bee-Hong Yuen Kah-Hay 《Nutrition journal》2013,12(1):1-8