全文获取类型
收费全文 | 87篇 |
免费 | 0篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 16篇 |
金属工艺 | 3篇 |
机械仪表 | 3篇 |
建筑科学 | 2篇 |
能源动力 | 8篇 |
轻工业 | 1篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 10篇 |
一般工业技术 | 32篇 |
冶金工业 | 7篇 |
自动化技术 | 8篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 1篇 |
2007年 | 4篇 |
2006年 | 7篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有94条查询结果,搜索用时 171 毫秒
1.
E. E. Shalsha A. A. Bahgat M. H. El-Kottamy N. A. Elssa 《Journal of Materials Science》1987,22(11):3931-3938
The galssy ferromagnets Fe81.5B14.5Si4 and Fe40Ni40B20 have been studied by Mössbauer spectroucopy from 77.5 up to 650 and 680K, respectively, In the glassy state, the average magnetic hyperfine field decreases with increasing temperature due to a distribution of exchange inter-actions. At low temperatureH(T)/H(0) has a temperature dependence (1 -BT
/32 -CT
/52) whereB andC are constants, indicative of spin-wave excitations in glassy ferromagnets. The value of B/32) = 0.40 = 0.05 is almost four times larger than those of crystalline iron and nickel. On the other hand, fluctuations of the exchange interaction constant are found to decrease with increasing temperature. The Curie temperaturesT
c - 608 K for the glassy Fe81.5B14.5Si4 andT
c = 583K for the glassy Fe40Ni40B20 are found to be well defined. AtT close toT
c
H(T) behaves as a power law with critical exponent = 0.3. The crystallizationT
cr glassy Fe81.5B14.5Si4 was found to be 645K. The crystalline material obtained contains three different phases, namely -Fe, Fe2B and Fe-8% Si. 相似文献
2.
T. Hussein M.S. Saad A.L. Elshafei A. Bahgat 《Expert systems with applications》2009,36(10):12104-12112
This paper introduces a robust adaptive fuzzy controller as a power system stabilizer (RFPSS) used to damp inter-area modes of oscillation following disturbances in power systems. In contrast to the IEEE standard multi-band power system stabilizer (MB-PSS), robust adaptive fuzzy-based stabilizers are more efficient because they cope with oscillations at different operating points. The proposed controller adopts a dynamic inversion approach. Since feedback linearization is practically imperfect, components that ensure robust and adaptive performance are included in the control law to compensate for modelling errors and achieve acceptable tracking errors. Two fuzzy systems are implemented. The first system models the nominal values of the system’s nonlinearities. The second system is an adaptive one that compensates for modelling errors. A feedback linearization-based control law is implemented using the identified model. The gains of the controller are tuned via a particle swarm optimization routine to ensure system stability and minimum sum of the squares of the speed deviations. A bench-mark problem of a 4-machine 2-area power system is used to demonstrate the performance of the proposed controller and to show its superiority over other conventional stabilizers used in the literature. 相似文献
3.
The foundations of information theory as a whole, and the rate distortion theory in particular, were ably laid by Shannon in 1948. The rate distortion function R(D) is defined as the effective rate (R) at which the source produces information subject to the constraint that the user can tolerate an average distortion of D. The rate distortion functions for Gaussian Markov Processes were studied by Berger [1] and Bunin [2] for small distortion values. This paper presents the generalization of this study fornth-order Gaussian Markov processes for all distortion levels from 0 to
2. The function is first derived, computer simulated, and then calculated for first and second order cases, and the corresponding results are commented. 相似文献
4.
Muhammad G. Abd El-Moghny Hafsa H. Alalawy Ahmad M. Mohammad Amina A. Mazhar Mohamed S. El-Deab Bahgat E. El-Anadouli 《International Journal of Hydrogen Energy》2017,42(16):11166-11176
Research is moving rapidly to sustain convenient energy resources fulfilling the global climate legislations. Herein, a novel catalyst of platinum nanoparticles (PtNPs) dispersed onto polyaniline (PANi) is recommended for formic acid electro-oxidation (FAO); the fundamental anodic reaction in direct formic acid fuel cells (DFAFCs). The catalyst's preparation scheme allows a sequential electrodeposition of fibril PANi and spherical PtNPs (ca. 65 nm in size) on a glassy carbon (GC) substrate and permits a precise control over the deposition sequence and loading. Interestingly, incorporation of PANi into the catalyst's ingredients can significantly (ca. 16 times) improve the catalytic activity of the catalyst towards FAO by shifting the mechanism towards the desirable dehydrogenation pathway and mitigating the undesirable poisoning dehydration pathway. The catalytic efficiency is tuned by manipulating the deposition order and loading of different catalyst's ingredients. Several techniques are employed to confirm the successful deposition of the catalyst and to evaluate its morphology, composition and crystal structure. While PtNPs are essential for FA adsorption, PANi improves the dispersion of PtNPs and mediates FAO to facilitate the charge transfer and mitigate CO poisoning. A promising catalytic stability is achieved in a long continuous (150 CVs) electrolysis experiment. 相似文献
5.
A High Speed, Low Voltage CMOS Offset Comparator 总被引:3,自引:0,他引:3
A high speed, low voltage offset comparator is presented. No common mode tracking circuit is used and the offset is added without compromising the high input impedance nature of the circuit. The circuit operates at 480 Mbps with 3.0–3.6 V and 1.6–2.0 V supplies and –40 to 125°C temperature range on a typical 0.5 m technology. 相似文献
6.
A.?S.?FoudaEmail author M.?A.?Elmorsi T.?Fayed Samy?M.?Shaban O.?Azazy 《Surface Engineering and Applied Electrochemistry》2018,54(2):180-193
The objective of this study is to investigate the corrosion inhibition of API N80 steel pipelines in 1M HCl solution by a synthesized compound (N-(3-(dimethyl octyl ammonio) propyl) palmitamide bromide, subjected to four different modes of measurements. Weight loss (WL) was investigated at five different temperatures: 25–60°C, while potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) were tested at 25°C. The result showed that the synthesized inhibitor was good and its protection efficiency (%η) significantly increased by increasing both the dose and the temperature. The polarization curve revealed that the studied inhibitor acts as mixed-type of inhibitor. Adsorption of the investigated inhibitor led to a reduction in the double layer capacitance and an increase in the charge transfer resistance. The adsorption of this inhibitor was found to obey the Langmuir adsorption model. The thermodynamic parameters were calculated and discussed. A clear correlation was found between corrosion protection efficiency and theoretical parameters obtained using density functional theory. 相似文献
7.
We introduce a design of an associative memory array processor (AMAP) to be used in character recognition. The design example is based upon the bit-parallel organization. The AMAP consists of identical processing elements that can store information about a specific position into the pattern and also contain some logic gates to carry out logical operations. No effort has been made to perform either processing or feature extraction of any kind 相似文献
8.
Five different compositions of K x V 2 O 5 ·nH 2 O(where x=0.00,0.0017,0.0049,0.0064 and 0.0091 mol) were prepared by the sol-gel process.Electrical conductivity and thermoelectric power were measured parallel to the substrate surface in the temperature range of 300-480 K.The electrical conductivity showed that all samples were semiconductors and that conductivity increased with increasing K content.The conductivity of the present system was primarily determined by hopping carrier mobility.The carrier density was evaluated as well.The conduction was confirmed to obey non-adiabatic small polaron hopping.The thermoelectric power or Seebeck effect,increased with increasing K ions content.The results obtained indicated that an n-type semiconducting behavior within the temperature range was investigated. 相似文献
9.
A method is presented for designing a constant-gain state feedback controller for assigning the closed-loop poles of a linear time-invariant multivariable system to desired locations which at the same time minimizes the sensitivity of these poles to variation in the parameters of the plant. The design procedure is illustrated by examples. 相似文献
10.
ELSayed Ahmed S. Ebeid Hala M. Roushdy Mohamed Fayed Zaki T. 《Pattern Analysis & Applications》2019,22(4):1537-1559
Pattern Analysis and Applications - Palm and knuckle prints can be extracted from a hand using a low-cost camera in a contactless manner. This makes the process of palm and knuckle recognition fast... 相似文献