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111.
112.
Abstract SERS has been used as a state-resolving probe to study the adsorption states. in the case of pyridine (Py) adsorbed on the Ag electrode surface, the equilibrium and transition between two adsorbed states, i.e., the perpendicular mode adsorbed through the nitrogen lone-pair electrons and the flat mode through the π electrons of the aromatic ring, were studied. It was found that in the low pyridine concentration or the initial stage of adsorption, the flat mode was favored. While the concentration became higher and the adsorption tended to equilibrium, the adsorbed molecules would transit to the perpendicular mode. The similar phenomenon was also observed when changing the applied electric potential and the pH value of the solution. In the case of the adsorption of Methylene Blue (MB) on the HNO3-etched silver surface, the influence of Cl? ions on the adsorption states of MB was investigated. It showed that MB molecules adsorbed on the silver surface tended to transform from the “lying-down” state to the “end-on” state while adding Cl? ions. 相似文献
113.
Mark A. Blitz Namil Choi Tams Kovcs Paul W. Seakins Michael J. Pilling 《Proceedings of the Combustion Institute》2005,30(1):927-933
Laser flash photolysis of ketene at 308 nm, coupled with H atom vacuum ultraviolet laser induced fluorescence, was used to determine the branching ratio for the CH3 + H channel (1a) in the reaction of CH21A1 (1CH2) with H2, over the temperature range 300–500 K. This reaction channel competes with collision induced intersystem crossing (CIISC) to form triplet methylene, CH23B1 (3CH2) (channel 1b). The branching ratio for H formation, k1a/k1, was determined by measuring the relative H atom yield in three time resolved measurements of H: (i) in ketene, H2 mixtures, where H is exclusively formed by reaction 1a, (ii) in ketene, H2, NO mixtures ([NO] [H2]), where H is formed at short times by 1a and at longer times by 3CH2 + NO, following 1b, and (iii) in ketene, He, NO mixtures ([NO] [He]), where H is exclusively formed from 3CH2 + NO, following deactivation of singlet to triplet methylene by He. k1a/k1 was found to increase from 0.85 at 300 K to unity at 500 K, with the yield of CIISC decreasing from 0.15 to zero. This is the first measurement of the temperature dependence of the rate coefficient for CIISC in a reactive system. The rate coefficient for CIISC with an inert gas increases with T. It has been suggested that the fractional yield of CIISC will increase with temperature in reactive systems, thus reducing the rate coefficient for reaction at high temperature, with significant consequences for combustion systems. The present experiments demonstrate that this is not the case for reaction with H2 and implies a different CIISC mechanism for reactive vs inert collision partners. 相似文献
114.
溴酚蓝和亚甲蓝双显色体系萃取光度法测定铜 总被引:4,自引:0,他引:4
向三元络合物[Cu(phen)_3)BPB的二氯乙烷萃取液中,加入KCN水溶液,形成的[Cu(CN)_2)~-和溴酚蓝离子(BPB)进入水相,向其中加入与BPB颜色相近的亚甲蓝(MB)再进行萃取光度测定。因萃取液中[MB_2BPB)和[Cu(CN)_2)MB两者的吸光作用,使本方法具有很高的灵敏度,ε=1.77×10~5L·mol~(-1)·cm~(-1)。铜含量在0~5μg/25ml遵从比耳定律,对含铜量为10~(-8)g/ml的水样测定5次,相对标准偏差为2%。 相似文献
115.
116.
Hermann Schägger 《Applied biochemistry and biotechnology》1994,48(3):185-203
Protocols for the optimal resolution of membrane and watersoluble proteins in SDS-denatured state (Tricine SDS-PAGE and Blue
Tricine SDS-PAGE; Laemmli SDS-PAGE and Blue Laemmli SDSPAGE) and in the native state (Blue Native PAGE) are presented. The
protocols for protein recovery from these gels include techniques of electroelution and electroblotting optimized to the type
of the preceding electrophoresis system. Native and denatured proteins thus are obtainable in near quantitative yield in soluble
and in immobilized form. These techniques can optionally be performed in the milligram range, e.g., for the use of immunization
and N-terminal protein sequencing, or in the analytical range. 相似文献
117.
Summary The HPLC method developed for the analysis of the dye Patent Blue V in extracts from cheese is sufficiently sensitive to detect
and measure concentrations above 0.1 ppm with a standard deviation of 3%. The extraction procedure described gives a recovery
from cheese of about 80%. The method has been applied to commercial samples of cheese and a concentration of the dye of about
0.12 ppm was measured in one case. 相似文献
118.
Ultrafine particles of BaMgAl10O17:Eu2+ (BAM) phosphor were synthesized by a solid-state combustion reaction in a powder bed of 0.9BaCO3+MgO+5Al2O3+0.05Eu2O3+k(KClO3+1.5C) composition. A large exothermic reaction of the mixture (KClO3+1.5C) leads to a self-sustaining combustion mode. Under optimized combustion conditions, the product consisted of BAM powder and KCl was obtained. BAM ultrafine particles resulting from the combustion process were easily obtained by simply washing the salt by-product with water. Combustion-processed BAM phosphor shows a homogeneous grain size of 100-500 nm, good dispersity, regular morphology, and improved luminescence properties. 相似文献
119.
Min Wu Yan Lv Zhengping Fu Jiao Xu Ting Guo Yongxun Zhao 《Applied Surface Science》2010,256(23):7125-9486
The simultaneous Ag loaded and N-doped TiO2 hollow nanorod arrays with various contents of silver (Ag/N-THNAs) were successfully synthesized on glass substrates by one-pot liquid phase deposition (LPD) method using ZnO nanorod arrays as template. The catalysts were characterized by Raman spectrum, field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscope (HRTEM), ultraviolet-vis (UV-vis) absorption spectrum and X-ray photoelectron spectroscopy (XPS). The results suggest that AgNO3 additive in the precursor solutions not only can promote the anatase-to-rutile phase transition, but also influence the amount of N doping in the samples. The photocatalytic activity of all the samples was evaluated by photodegradation of methylene blue (MB) in aqueous solution. The sample exhibited the highest photocatalytic activity under UV light illumination when the AgNO3 concentration in the precursor solution was 0.03 M, due to Ag nanoparticles acting as electron sinks; When the AgNO3 concentration was 0.07 M, the sample performed best under visible light illumination, attributed to the synergetic effects of Ag loading, N doping, and the multiphase structure (anatase/rutile). 相似文献
120.
Dong LiuPeng Yuan Daoyong Tan Hongmei Liu Tong WangMingde Fan Jianxi ZhuHongping He 《Journal of colloid and interface science》2012,388(1):176-184
Hierarchically porous carbons were prepared using a facile preparation method in which diatomite was utilized as both template and catalyst. The porous structures of the carbon products and their formation mechanisms were investigated. The macroporosity and microporosity of the diatomite-templated carbons were derived from replication of diatom shell and structure-reconfiguration of the carbon film, respectively. The macroporosity of carbons was strongly dependent on the original morphology of the diatomite template. The macroporous structure composed of carbon plates connected by the pillar- and tube-like macropores resulted from the replication of the central and edge pores of the diatom shells with disk-shaped morphology, respectively. And another macroporous carbon tubes were also replicated from canoe-shaped diatom shells. The acidity of diatomite dramatically affected the porosity of the carbons, more acid sites of diatomite template resulted in higher surface area and pore volume of the carbon products. The diatomite-templated carbons exhibited higher adsorption capacity for methylene blue than the commercial activated carbon (CAC), although the specific surface area was much smaller than that of CAC, due to the hierarchical porosity of diatomite-templated carbons. And the carbons were readily reclaimed and regenerated. 相似文献