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991.
Bon Ki Koo Young Kyu Choi Chang Woo Chu Jae Chul Kim Byoung Tae Choi 《ETRI Journal》2005,27(2):235-238
A new mesh reconstruction scheme for approximating a surface from a set of unorganized 3D points is proposed. The proposed method, called a shrink‐wrapped boundary face (SWBF) algorithm, produces the final surface by iteratively shrinking the initial mesh generated from the definition of the boundary faces. SWBF surmounts the genus‐0 spherical topology restriction of previous shrink‐wrapping‐based mesh generation techniques and can be applied to any type of surface topology. Furthermore, SWBF is significantly faster than a related algorithm of Jeong and others, as SWBF requires only a local nearest‐point‐search in the shrinking process. Our experiments show that SWBF is very robust and efficient for surface reconstruction from an unorganized point cloud. 相似文献
992.
Such devices would be useful for monitoring line voltages in, for example, SF6 gas-insulated bus ducts. The theory of the devices is described and the results of tests on a laboratory prototype are presented. Furthermore, the design of a device monolithically integrating a capacitive divider and an integrated-optics Mach-Zehnder interferometer is proposed 相似文献
993.
Hyunjin Lim Sooyoun Park Hyeonsik Cheong Hyun-Min Choi Young Chool Kim 《Diamond and Related Materials》2010,19(10):1254-1258
We have performed low-temperature (8 K) photoluminescence (PL) measurements on 71 natural and 12 high-pressure-and-high-temperature (HPHT)-treated type IIa diamonds. The GR1, NV0, NV?, H4, and H3 defect center PL signals are compared. Some distinct differences in the PL lineshape, intensity, and appearance of side-band PL signals are observed. Furthermore, we processed 6 of the natural diamond samples with the HPHT treatment to investigate the effect of the treatment on the PL spectrum. By systematically analyzing the differences in the PL spectra, we developed a scheme to discriminate natural and HPHT-treated diamonds with 99% validity. 相似文献
994.
Young Wook Jung Dong-Shig Oh Meejeong Kim Jae-Woo Park 《Nutrient Cycling in Agroecosystems》2010,87(2):261-275
LEACHN model is useful to describe the nitrogen transport and transformation in soil but requires many input parameters. A
sensitivity analysis can help to sort out the sensitive ones among many input parameters. A global sensitivity analysis technique,
Latin Hypercube One factor At a Time (LH-OAT) method, was applied to LEACHN model in this study. Only a few parameters were
found to be sensitive compared to many input parameters of the model from the sensitivity analysis. Using the results from
the sensitivity analysis, calibration and validation of LEACHN model for nitrate leaching was performed for the experimental
results from pot experiments that consisted of six types with different soil depth in mini-lysimeters and different fertilizer
additions. The results indicated that the use of LH-OAT method could help the facile field application of LEACHN model. Model
fitting could be improved by adopting current values in yearly crop parameters in validation. 相似文献
995.
Mari K. N?ss David J. Young Jianqiang Zhang Jan Erik Olsen Gabriella Tranell 《Oxidation of Metals》2012,78(5-6):363-376
Small scale laboratory experiments on the oxidation of liquid silicon have reproduced important features of the industrial refining of liquid silicon: active oxidation led to the formation of amorphous silica spheres as a reaction product. The boundary condition for active oxidation in terms of maximum oxygen partial pressure in the bulk gas was found to lie between 2·10?3 and 5·10?3?atm at T?=?1,500?°C. The active oxidation of liquid silicon had linear kinetics, and the rate was proportional to bulk oxygen partial pressure and the square root of the linear gas flow rate, consistent with viscous flow mass transfer theory. Classical theory for unconstrained flow over a flat plate led to mass transfer rates for SiO(g) which were 2–3 times slower than observed. However, computational fluid dynamic modeling to take into account the effects of reactor tube walls on flow patterns yielded satisfactory agreement with measured volatilization rates. 相似文献
996.
Study of dynamic effects by convective velocity in the membrane process: Operator theoretic approach
Young G. Park 《Korean Journal of Chemical Engineering》1998,15(4):381-389
This paper studies the dynamic mass transfer effects of solute through fluid-solid interactions in a heterogeneous system.
It is found that the convective velocity in internal pores of the membrane can be used to accelerate the speed of the solute
by convective velocity at the fluid phase. The theoretical model for the membrane transport is studied in this paper by using
the operator theoretic method. A typical example of this dynamic interaction problem is applied in a multi-layered composite
membrane. Danckwerts Boundary conditions are analyzed in the inner and outer regions of membrane process. A spectral evaluation
of the transport operator is performed by the operator properties in the system. The findings of this paper are useful in
guiding the design of membrane separation devices as well as in proving useful to the synthetic performance of composite membrane. 相似文献
997.
The oxidation and reduction behavior of Sr and Zr substituted BaTiO3 has been studied by measuring equilibrium electrical conductivities as a function of oxygen activity. The substitution of Sr+2 and Zr+4 for Ba2+ and Ti4+ in BaTiO3 shifted the conductivity profiles to lower oxygen partial pressures. The replacement of Ba with smaller Sr ions suppresses the oxygen dissociation from the lattice, consequently increasing the enthalpy for reduction (ΔH n ), whereas the Sr substitution requires less energy for oxidation (ΔH p ). The increase in reduction enthalpy at lower oxygen activities suppresses the formation of oxygen vacancies, the materials becoming resistant to reduction process. Such a reduction resistant behavior gave rise to greater electrical resistivities for (Ba0.9Sr0.1)(Ti0.9Zr0.1)O3 than for Ba(Ti0.9Zr0.1)O3 when the samples were sintered at lower P(O2). 相似文献
998.
H Kook JH Rhee SE Lee SY Kang SS Chung KW Cho YH Baik 《Canadian Metallurgical Quarterly》1999,365(2-3):267-272
Recently we reported that Vibrio vulnificus hemolysin, an exotoxin produced by V. vulnificus, dilates rat thoracic aorta via elevated cGMP levels without affecting nitric oxide synthase. We investigated the mechanism further by observing the guanylyl cyclase activities in cytosolic, membrane, unfractionated, or reconstituted preparations. Hemolysin did not activate guanylyl cyclase in the membrane or cytosolic fraction, while it activated guanylyl cyclase in unfractionated or reconstituted preparation. The increased activity was not inhibited by the HS-142-1, a microbial polysaccharide which antagonizes atrial natriuretic peptide receptor, or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a soluble guanylyl cyclase inhibitor. However, it was attenuated by 6-(phenylamino)-5,8-quinolinedione (LY 83.583), which inhibits the catalytic domain of both guanylyl cyclases, and by cholesterol, which blocks hemolysin-incorporation into the membrane. Removing ATP, a cofactor of particulate guanylyl cyclase, attenuated the activation and ATPgammaS, a non-phosphorylating analog, restored it. These results suggest that V. vulnificus hemolysin activates particulate guanylyl cyclase via hemolysin incorporation into the vascular smooth muscle cell membrane in cooperation with certain unidentified cytosolic component(s). 相似文献
999.
R. L. Kodell J. F. Young R. R. Delongchamp A. Turturro J. J. Chen D. W. Gaylor P. C. Howard Q. Zheng 《Food Additives & Contaminants》2001,18(3):237-253
Data from the National Toxicology Program's carcinogenesis study of fumonisin B1 in B6C3F1 mice, conducted at the National Center for Toxicological Research, were used to fit the Moolgavkar-Venzon-Knudson (MVK) two-stage, clonal-expansion model of carcinogenesis. In addition to tumour data from the conventional 2-year bioassay, the study included data on tissue weights, cell proliferation, cell death, and sphingolipid metabolism in primary target organs. The model was used to predict 2-year liver tumour rates in female and male mice based on differences among dose groups in the effect of fumonisin B1 on the growth of normal tissue and on the proliferation of preneoplastic cells as a compensatory response to sphinganine-induced cell death. Fumonisin B1 was assumed to be non-genotoxic, i.e. the model did not include any effect of fumonisin B1 on either of the two mutation rates of the MVK model. The model was able to reproduce reasonably well the observed tumour rates in both female and male mice, predicting substantially increased rates above background only at the highest doses of fumonisin B1 in females. 相似文献