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11.
ABSTRACTThis research work was carried out to examine the performance of different polyethylene/cellulose composites. The effect of three different factors was examined. First factor was the effect of clay type as filler, in which diatomite and bentonite were used. Second factor was the effect of cellulose grafting with cyclic oxymethylene. Third factor was the presence of polyethylene grafted with maleic anhydride (PE-g-MA) in the polymer matrix of polyethylene/cellulose as a compatibilizer. The polymer matrix was characterized by scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Tensile test and permeability were also examined. 相似文献
12.
Elyas Sadeq Alaghbari Zulkarnain Zainal Imad Hamadneh Mohd Zobir Bin Hussein Mohd Haniff Bin Wahid 《Journal of Superconductivity and Novel Magnetism》2012,25(2):255-260
Zn- and Ca-doped ErBa2Cu3O7−δ
were successfully prepared via coprecipitation method using metal acetates as the starting salts. The precipitated samples
were calcined for 20 h at 900 °C and sintered at 920 °C for 24 h. All heat treatments were carried out under oxygen environment.
Results show that there is a selectivity of the doping site depending on the ionic radius of the dopant. Furthermore, increase
in the critical temperature, T
c
, was observed in 0.05 mole of calcium and zinc doped samples. The difference in ionic radius of the dopant led to the increase
in porosity as the ionic radius decreases. On the other hand, structural distortion increased as the difference of ionic radius
became larger. 相似文献
13.
Sawsan Abdul-Majid Imad Hasan Qi Zheng Ramón Maldonado-Basilio Serge Bidnyk Trevor Hall 《电信纪事》2013,68(1-2):49-55
Radio-over- fibre (RoF) technology is receiving large attention due to its ability to provide simple antenna front ends, increased capacity and increased wireless access coverage. Coherently detected RoF systems would enable the information to be carried in both the amplitude and phase or in different states of the polarisation of the optical field. Additionally, the selectivity of coherent receiver is very well suited for access networks. We present a 90° optical hybrid built on a silicon-on-insulator planar light-wave circuit, which can be used as the optical front end of the digital coherent receiver in a digitised RoF link and will lead to reduced receiver footprint and cost. The optical hybrid circuit includes 2?×?2 and 4?×?4 multimode interference (MMI) splitters, in a polarisation diversity configuration. The simulation results at vacuum wavelength 1,550 nm show polarisation independence and phase errors between the ports of less than 0.03°. The properties of the prototyped 4?×?4 MMI were measured over a wide range of wavelengths. The 2?×?2 and 4?×?4 MMI showed nearly equal splitting ratios. Measurements of the relative phase relationship between the ports for Transverse Electric mode polarisation are shown to match the simulation results. 相似文献
14.
There are increasing demands on portable communication devices to run multimedia applications. ISO (an International Organization
for Standardization) standard MPEG-4 is an important and demanding multimedia application. To satisfy the growing consumer
demands, more functions are added to support MPEG-4 video applications. With improved CPU speed, memory sub-system deficiency
is the major barrier to improving the system performance. Studies show that there is sufficient reuse of values for caching
that significantly reduce the memory bandwidth requirement for video data. Software decoding of MPEG-4 video data generates
much more cache-memory traffic than required. Proper understanding of the decoding algorithm and the composition of its data
set is obvious to improve the performance of such a system. The focus of this paper is cache modeling and optimization for
portable communication devices running MPEG-4 video decoding algorithm. The architecture we simulate includes a digital signal
processor (DSP) for running the MPEG-4 decoding algorithm and a memory system with two levels of caches. We use VisualSim
and Cachegrind simulation tools to optimize cache sizes, levels of associativity, and cache levels for a portable device decoding
MPEG-4 video.
Abu Asaduzzaman is, currently, a PhD candidate in the department of Computer Science and Engineering (CSE), Florida Atlantic University (FAU),
Boca Raton, Florida. He received his MS degree in computer engineering from FAU in 1997.
Mr. Asaduzzaman worked for ECI Telecom as a software engineer from 1998 to 2001. From 2001 to 2003, he worked for BlueCross
and BlueShield of Florida and SunPass (FDoT) as an IT Consultant. Currently, he is working as a research assistant at CSE
Dept, FAU. His research interests include cache optimization, architecture exploration, embedded system evaluation, and networks-on-a-chip
(NoC). He has published several research papers in these areas. Abu is a member of the honor society of Phi Kappa Phi, Tau
Beta Pi, Upsilon Phi Epsilon, and the Association for Computing Machinery (ACM) FAU Chapter.
Imad Mahgoub received the MS degree in applied mathematics and MS degree in electrical and computer engineering, both from North Carolina
State University, Raleigh in 1983 and 1986 respectively and the PhD degree in computer engineering from the Pennsylvania State
University, University Park, PA in 1989.
Dr. Mahgoub joined Florida Atlantic University (FAU), Boca Raton, Florida in 1989. Currently he is a full professor of Computer
Science and Engineering department and the director of the Mobile Computing Laboratory. His research interests include performance
evaluation, mobile computing, sensor networks, and parallel and distributed processing. He has published over 80 research
papers in these areas. He is the co-editor of the Mobile Computing Handbook and the Handbook of Sensor Networks. Dr. Mahgoub
has served on the program committees of numerous conferences. He has been the vice-chair for the Symposium on Performance
Evaluation of Computer and Telecommunication Systems (SPECTS) since 2003. He is a senior member of the IEEE. He is also a
member of Tau Beta Pi, Upsilon Pi Epsilon, the IEEE Computer Society, and the ACM. 相似文献
15.
Under cyclic loading, the plasticized zone becomes complicated; it contains in particular a second plasticized zone, resulting from the local compression which occurs at the time of the closing of the crack to each cycle. The two plastic zones, monotonous (rm) and cyclic (rc), are proportional to (Kmax/Re)2 et (ΔK/Re)2, respectively. The objective of this work is to study the evolution of the fatigue crack grown rate (FCGR) and the influence of the plastic zone size (rc), which represents the seat of the residual stresses, on this evolution in the case of 12NC6 steel. Generally, the plastic zone size increases with the crack advance. The FCGR can be correlated with the energy absorptive in these plastic zones. 相似文献
16.
In this note a Lyapunov function for a 2-D time invariant discrete linear system is introduced, using the 2-D system model given by Roesser [1]. The Lyapunov function may be used to investigate the asymptotic stability of the 2-D system. Previous work dealing with asymptotic stability of 2-D systems [3]-[5] is based upon the location of roots of the characteristic polynomial in the closed polydiskoverline{U}^{2} . 相似文献
17.
Imad A Ahmed Abdul Wahab K Ahmed Richard K Robinson 《Journal of the science of food and agriculture》1997,74(1):64-68
Segments of fruits from 12 varieties of date (Phoenix dactylifera) and three stages of maturation were inoculated with a toxigenic strain of Aspergillus parasiticus. During growth at 28°C for 10 days, 8 varieties supported appreciable aflatoxin production at the Khalal stage—the most popular stage for direct human consumption, with a maximum value in excess of 300 μg g-1 of fruit. Marked differences in susceptibility to infection and/or aflatoxin production were observed between varieties and/or stage of maturation. It was concluded that toxigenic aspergilli could proliferate on any date fruits that suffered mechanical damage in the field or during harvesting, and hence that such fruits should be considered as likely to be unfit for human or animal consumption. © 1997 SCI. 相似文献
18.
Ghada Ziadeh Sossy Shadarevian Amal Malek Joanna Khalil Tharwat Haddad John Haddad Imad Toufeili 《Journal of food science》2005,70(8):s548-s552
Pita bread loaves were prepared from flours fortified with calcium carbonate, calcium sulfate, and tricalcium dicitrate at 8 ascending levels to provide ranges of 800 to 2500, 700 to 1500, and 400 to 2000 mg of added Ca/100 g flour, respectively. The detection thresholds of calcium salts in pita bread were determined by the 3‐alter‐native forced choice (3‐AFC) test and construction of dose‐response curves. Detection thresholds determined by calculating geometric mean of individual best estimate thresholds, using criterion of 50%‐above‐chance and probit analysis of 3‐AFC data, were in the middle region of calcium concentrations. Analysis of dose‐response curves yielded values for thresholds outside the range of surveyed calcium concentrations. The detection threshold of CaSO4 (2724 mg/100 g) in pita bread was significantly higher (P < 0.01) than those of calcium carbonate (1984 mg/100 g) and tricalcium dicitrate (2132 mg/100 g). Calcium‐fortified pita bread was similar (P < 0.01) to its regular counterpart when formulated to contain 1254.6, 1772.5, or 1155 mg/100 g of CaCO3, CaSO4, or tricalcium dicitrate, respectively. At the indicated levels of fortification, calcium‐fortified pita bread is expected to provide between 61% and 126.5% of the recommended daily intake for calcium for Middle Eastern populations. 相似文献
19.
Mostafa El Mallahi Amal Zouhri Abderrahim Mesbah Aissam Berrahou Imad El Affar Hassan Qjidaa 《Multimedia Tools and Applications》2018,77(6):6583-6604
In this paper, we introduce new sets of 2D and 3D rotation, scaling and translation invariants based on orthogonal radial Racah moments. We also provide theoretical mathematics to derive them. Thus, this work proposes in the first case a new 2D radial Racah moments based on polar representation of an object by one-dimensional orthogonal discrete Racah polynomials on non-uniform lattice, and a circular function. In the second case, we present new 3D radial Racah moments using a spherical representation of volumetric image by one-dimensional orthogonal discrete Racah polynomials and a spherical function. Further 2D and 3D invariants are extracted from the proposed 2D and 3D radial Racah moments respectively will appear in the third case. To validate the proposed approach, we have resolved three problems. The 2D/ 3D image reconstruction, the invariance of 2D/3D rotation, scaling and translation, and the pattern recognition. The result of experiments show that the Racah moments have done better than the Krawtchouk moments, with and without noise. Simultaneously, the mentioned reconstruction converges rapidly to the original image using 2D and 3D radial Racah moments, and the test 2D/3D images are clearly recognized from a set of images that are available in COIL-20 database for 2D image, and PSB database for 3D image. 相似文献
20.
Imad Ibrahim Alicja Bachmatiuk Felix Börrnert Jan Blüher Ulrike Wolff Jamie H. Warner Bernd Büchner Gianaurelio Cuniberti Mark H. Rümmeli 《Carbon》2011,49(15):5029-5037
Single-crystal stable-temperature (ST)-cut quartz substrates, which have a (0 1 1 1) crystallographic plane with their surface normal lying close to 38° from the y axis ([0 1 0]), were annealed in air prior to use as a support for aligned carbon nanotube growth by chemical vapor deposition. Very smooth substrate surfaces were obtained with annealing times in the vicinity of 15 h at a temperature of 750 °C. These smooth surfaces are ideal for the growth of horizontally aligned SWCNTs with high spatial density, while less dense SWCNTs were obtained with less smooth surfaces. Under optimized growth conditions, only SWCNT are observed and they can grow to lengths in excess of 100 μm. Our findings suggest structural defects interfere with the growth process. A binary Fe/Co catalyst was employed to grow the nanotubes. No obvious dependence on the Fe:Co ratio is observed. 相似文献