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排序方式: 共有497条查询结果,搜索用时 15 毫秒
1.
Samani Saeideh Vadiati Meysam Azizi Farahnaz Zamani Efat Kisi Ozgur 《Water Resources Management》2022,36(10):3627-3647
Water Resources Management - Precise estimation of groundwater level (GWL) might be of great importance for attaining sustainable development goals and integrated water resources management.... 相似文献
2.
Crystallization of calcium carbonate (CC) in aqueous solutions by gas‐liquid diffusion procedure was investigated systematically in the presence of poly(4‐sulfonic acid diphenylamine)‐block‐poly(ethylene glycol) (PSDA‐b‐PEG), wherein the PSDA block is a polymeric zwitterion. PSDA‐b‐PEG was synthesized with the reaction of tosylated PEG and amine‐functionalized PSDA and was characterized by nuclear magnetic resonance. The parameters such as, block copolymer concentration, crystallization time and initial pH were considered as indicators of block copolymer's capability in controlling the morphology of CC particles. The particles were characterized by Fourier transform infrared, scanning electron microscopy, and X‐ray diffraction. The results suggest that PSDA‐b‐PEG is a suitable template to control the growth mechanism of CC to produce meso‐sized particles with different morphologies. POLYM. ENG. SCI., 59:96–102, 2019. © 2018 Society of Plastics Engineers 相似文献
3.
4.
Orhan Gazi A. Ozgur Yilmaz 《Communications Letters, IEEE》2007,11(2):173-175
Decoding delay is an important consideration for the use of turbo codes in practical applications. We propose a new structure for turbo codes which is very suitable for parallel decoding. It is shown by union bound analysis and simulation results that the proposed system performance is comparable to that of the classical turbo codes 相似文献
5.
Ozgur Sinanoglu Ismet Bayraktaroglu Alex Orailoglu 《Journal of Electronic Testing》2003,19(4):457-467
Parallel test application helps reduce the otherwise considerable test times in SOCs; yet its applicability is limited by average and peak power considerations. The typical test vector loading techniques result in frequent transitions in the scan chain, which in turn reflect into significant levels of circuit switching unnecessarily. Judicious utilization of logic in the scan chain can help reduce transitions while loading the test vector needed. The transitions embedded in both test stimuli and the responses are handled through scan chain modifications consisting of logic gate insertion between scan cells as well as inversion of capture paths. No performance degradation ensues as these modifications have no impact on functional execution. To reduce average and peak power, we herein propose computationally efficient schemes that identify the location and the type of logic to be inserted. The experimental results confirm the significant reductions in test power possible under the proposed scheme. 相似文献
6.
A transport equation for the mean flux in spatially random media is derived, and is referred to as Modified-Levermore–Pomraning equation (M-L–P). It differs from the conventional L–P equations in that |μ| in the latter is replaced by μ in M-L–P. It is shown that when scattering is present the L–P equations are always incorrect in the sense there is not any special situation in which they can lead to an exact result. In particular they always predict the relaxation lengths of the spatial modes incorrectly. On the other hand, the M-L–P equations are exact when the flux at the origin is deterministic, as in some special cases such as half-infinite medium, and infinite medium with a localized source at the origin, when the density of the medium is spatially random. However, the M-L–P equations become approximate when the medium is a finite slab because of the right boundary condition. But the relaxation rates of the spatial modes are always calculated exactly even in finite slab. The nature of approximation inherent in the M-L–P is elucidated by comparison with the exact “stochastic transition matrix formalism” developed earlier in two-stream transport. 相似文献
7.
Scaling Laws for One- and Two-Dimensional Random Wireless Networks in the Low-Attenuation Regime 总被引:1,自引:0,他引:1
Ozgur A.. Leveque O.. Preissmann E.. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2007,53(10):3573-3585
The capacity scaling of extended two-dimensional wireless networks is known in the high-attenuation regime, i.e., when the power path loss exponent alpha is greater than 4. This has been accomplished by deriving information-theoretic upper bounds for this regime that match the corresponding lower bounds. On the contrary, not much is known in the so-called low-attenuation regime when 2lesalphales4. (For one-dimensional networks, the uncharacterized regime is 1lesalphales2.5.) The dichotomy is due to the fact that while communication is highly power-limited in the first case and power-based arguments suffice to get tight upper bounds, the study of the low-attenuation regime requires a more precise analysis of the degrees of freedom involved. In this paper, we study the capacity scaling of extended wireless networks with an emphasis on the low-attenuation regime and show that in the absence of small scale fading, the low attenuation regime does not behave significantly different from the high attenuation regime. 相似文献
8.
Viscosity measurements under Newtonian flow conditions had been performed on cetyltrimethylammonium bromide (CTAB) aqueous
solutions in the combined presence of sodium salts of aromatic acids (sodium salicylate, NaSal; sodium benzoate, NaBen; sodium
anthranilate, NaAn) and organic additives (1-hexanol, C6OH; n-hexylamine, C6NH2) at 30°C. On addition of C6OH or C6NH2, the viscosity of 25 mM CTAB solution remained nearly constant without salt as well as with a lower salt concentration. This
is due to low CTAB concentration which is not sufficient to produce structural changes in this concentration range of salts.
However, as the salt concentration was increased further, the effect of C6OH/C6NH2 addition was different with different salts: The viscosity first increased; then a decrease was observed with the former
while with C6NH2 a decrease followed by constancy appeared in plots of relative viscosities (η
r
) vs. organic additive concentrations. At further higher salt concentration, the magnitude of η
r
was much higher. The viscosity increase is explained in terms of micellar growth and the decrease in terms of swollen micelle
formation (due to interior solubilization of organic additive) or micellar disintegration (due to formation of water + additive
pseudophase). 相似文献
9.
10.
The use of graphite modified polymer films has been investigated, on stainless steel. Polythiophene and polypyrrole films have been synthesized electrochemically on stainless steel, and then very thin graphite layers were realized on polymer films. Since the graphite layer is not applicable as a top coat, polymeric top films were also electrosynthesized on graphite layers. Following this procedure, polypyrrole-graphite-polypyrrole and polythiophene-graphite-polythiophene coatings have been obtained on stainless steel. The corrosion behaviours of coated samples have been investigated in 0.1 M H2SO4 solution, by means of electrochemical impedance spectroscopy (EIS) and anodic polarization curves. The intercalation of graphite layer altered the performance and properties of coatings significantly. Especially, polypyrrole coating system was found to exhibit almost an excellent coating behaviour that hindered the attack of corrosive environment within 96 h exposure time. The EIS results of polypyrrole coating system were indicating to almost a perfect capacitive behaviour that the response was reflecting capacitive behaviour in a wide frequency region. This property was also examined with successive cyclic voltammograms in a potential range between 0.10 and 0.40 V (vs. Ag/AgCl). The charge densities involved in oxidation and reduction regions were determined for successive cycles and it was shown that coated sample was able to exhibit charge-discharge (i.e. oxidation and reduction) behaviour successfully, without any degradation. 相似文献