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41.
Temperature sensitive and electric field sensitive hydrogels were prepared for use in modulated drug release systems. Crosslinked poly(N-isopropyl-acrylamide) and its networks, modified with hydrophobic components by copolymerization or by interpenetrating polymer networks (IPNs) formation, were utilized as temperature sensitive hydrogels. Indomethacin (a model solute)-release from polymer matrix and permeation through polymer membrane demonstrated “on-off” regulation with temperature fluctuation. This was the result of polymer surface properties rather than bulk swelling, as temperature was changed past the swelling transition temperature range of the polymer. The on-off regulation in an electric field was also obtained with a positively charged solute (Edrophonium chloride) release in distilled-deionized water from a matrix of crosslinked poly(2-acrylamido-2-methylpropanesulfonic acid-co-butyl methacrylate). This was attributed to the ion exchange between Edrophonium ion and protons produced at the anode. The swelling changes produced by local pH or ionic strength changes affected non-charged solute release. 相似文献
42.
Gitae Moon Intae Son Chunho Kim Chi Hyeong Cho Eunbi Lee Eun Hyoung Bae 《Molecular Crystals and Liquid Crystals》2019,687(1):60-67
AbstractTo enable recent 3D and moving picture applications, liquid crystal displays (LCD) must exhibit fast response and wide viewing angle characteristics. Pre-tilted vertical alignment layers for high-speed LCD were fabricated using bi-functional photoreactive monomers. The monomers can be confined to the polyimide layer and photo-polymerized by UV exposure under voltage. Response characteristics of photo-controlled alignment films according to the structure were investigated. Vertical alignment properties were evaluated using a polarizing optical microscope, and electro-optical characteristics were compared through the voltage-transmittance curve and response time measurement. Faster response speed could be obtained by using photoreactive monomers having a long alkyl chain. 相似文献
43.
44.
The charge structure and interaction mechanism on In-doped sulphur spinel FeInxCr2−xS4 are studied. The temperature dependence of magnetization μB, measured from 60 K to room temperature, suggests that FeInxCr2−xS4 (x=0.1, 0.3) are ferrimagnetic. The Néel temperature is decreased with increasing non-magnetic In substitution as consequence of reduction of superexchange interaction for increased lattice parameter. FeInxCr2−xS4 is investigated by Mössbauer spectra from 4.2 K to room temperature. The asymmetric line broadening is observed for the sample FeInxCr2−xS4 and considered to be dynamic Jahn–Teller relaxation. The charge state of Fe ions is ferrous in character. 相似文献
45.
Kihong Son Haijo Jung Sang Hun Shin Hyun-Ho Lee Mi-Sook Kim Young Hoon Ji Kum Bae Kim 《Radiation measurements》2011,46(10):1117-1122
We aimed to evaluate the suitability of a glass dosimeter (GD) for high-energy photon and electron beams in experimental and clinical use, especially for radiation therapy. We examined the expanded dosimetric characteristics of GDs including dose linearity up to 500 Gy, uniformity among GD lots and for individual GDs, the angular dependence, and energy dependence of 4 therapeutic x-ray qualities. In addition, we measured the dosimetric features (dose linearity, uniformity, angular dependence, and energy dependence) of the GD for electron beams of 10 different electron energy qualities. All measurements with the exception of dose linearity for photon beam were performed in a water phantom. For high-energy photon beams, dose linearity has a linear relationship for a dose ranging from 1 to 500 Gy with the coefficient of determination; R2 of 0.998. The uniformity of each GD of dose measurements was within ±0.5% for four GD lots and within ±1.2% for 80 GDs. In terms of the effects of photon beam angle, lower absorbed doses of within 1.0% were observed between 60° and 105° than at 90°. The GD energy dependence of 4 photon beam energy qualities was within ±2.0%. On the other hand, the result of the dose linearity for high-energy electron beams showed well fitted regression line with the coefficient of determination; R2 of 0.999 between 6 and 20 MeV. The uniformity of GDs exposed to the nominal electron energies 6, 9, 12, 16, and 20 MeV was ±1.2%. In terms of the angular dependence to electron beams, absorbed doses were within 2.0% between 60° and 105° than at 90°. In evaluation of the energy dependence of the GD at nominal electron energies between 5 and 20 MeV, we obtained responses between 1.1% and 3.5% lower than that for a cobalt-60 beam. Our results show that GDs can be used as a detector for determining doses when a high-energy photon beam is used, and that it also has considerable potential for dose measurement of high-energy electron beam. 相似文献
46.
An adjustable approach to fuzzy soft set based decision making 总被引:2,自引:0,他引:2
Molodtsov’s soft set theory was originally proposed as a general mathematical tool for dealing with uncertainty. Recently, decision making based on (fuzzy) soft sets has found paramount importance. This paper aims to give deeper insights into decision making based on fuzzy soft sets. We discuss the validity of the Roy-Maji method and show its true limitations. We point out that the choice value designed for the crisp case is no longer fit to solve decision making problems involving fuzzy soft sets. By means of level soft sets, we present an adjustable approach to fuzzy soft set based decision making and give some illustrative examples. Moreover, the weighted fuzzy soft set is introduced and its application to decision making is also investigated. 相似文献
47.
J.S. Bae S.S. Yi J.H. Kim K.S. Shim B.K. Moon J.H. Jeong Y.S. Kim 《Applied Physics A: Materials Science & Processing》2006,82(2):369-372
Gd2O3:Eu3+ luminescent thin films have been grown on Al2O3(0001) substrates using pulsed-laser deposition. The films grown at different deposition conditions showed different crystalline
phases, surface morphologies and luminescent characteristics. Both cubic and monoclinic crystalline phases were observed for
the Gd2O3:Eu3+ films, and the crystalline structure and the surface morphology of the films were highly dependent on the oxygen pressure
and substrate temperature. The cubic system showed a higher luminescence than the monoclinic system. The luminescence characteristics
were strongly influenced by not only the crystalline structure but also the surface morphology of the films. The photoluminescencebrightness
data obtained from Gd2O3:Eu3+ films indicate that Al2O3(0001) is a promising substrate for growth of high-quality Gd2O3:Eu3+ thin-film red phosphor. In particular, the Gd2O3:Eu3+ films showed a much better photoluminescence behavior than a Y2O3:Eu3+ films with the same thickness.
PACS 78.20.-e; 78.55.-m; 78.66.-w 相似文献
48.
Jong Seong Bae Kyoo Sung Shim Soung-soo Yi Young Soo Kim 《Applied Surface Science》2006,252(13):4564-4568
The influence of lithium doping on the crystallization, the surface morphology, and the luminescent properties of pulsed laser deposited Y2−xGdxO3:Eu3+ thin film phosphors was investigated. The crystallinity, the surface morphology, and the photoluminescence (PL) of films depended highly on the Li-doping and the Gd content. The relationship between the crystalline and morphological structures and the luminescent properties was studied, and Li+ doping was found to effectively enhance not only the crystallinity but also the luminescent brightness of Y2−xGdxO3:Eu3+ thin films. In particular, the incorporation of Li and Gd into the Y2O3 lattice could induce remarkable increase in the PL. The highest emission intensity was observed Li-doped Y1.35Gd0.6O3:Eu3+ thin films whose brightness was increased by a factor of 4.6 in comparison with that of Li-doped Y2O3:Eu3+ thin films. 相似文献
49.
This paper presents a new method of forming a Si/SiGe dual channel on a Si0.8Ge0.2 virtual substrate. Generally, in a CMOS process using a Si/SiGe dual channel, due to several processes involving ion-implantation, annealing and dry-etching after the deposition of the Si/SiGe dual channel, the surface can be damaged, leading to reduced electrical properties. However, if the dual channel is formed during a specific stage of the CMOS process, the defects of the dual channel can be reduced and the thermal stability will be excellent. Therefore, in this paper, a method for minimizing the defects of the dual channel is presented. This method uses the segregation of the Ge in the oxidation process of a SiGe. A Si/SiGe dual channel formed using this method achieved results that were identical to a dual channel deposited using the chemical vapor deposition (CVD) method. 相似文献
50.