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排序方式: 共有1332条查询结果,搜索用时 31 毫秒
31.
As a new concept for the design of effective photocatalysts, an ion beam technology using accelerated metal ions, a metal ion implantation and an ionized cluster beam (ICB) method, have been applied to design unique photocatalysts. The metal ion implantation of TiO2 and Ti-containing zeolites with highly accelerated metal ions (V+, Cr+, etc.) is useful in designing photocatalysts that can operate efficiently under visible light irradiation. Also, an ICB method with a low acceleration energy is useful in preparing transparent TiO2 thin films on various types of substrates for the efficient photocatalytic degradation of pollutants diluted in water and air. The combination of the ICB method and metal ion implantation can develop the TiO2 thin films that are able to operate not only under UV light but also under visible light irradiation. 相似文献
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33.
V. Bruder-Hubscher F. LagardeM.J.F. Leroy C. CoughanowrF. Enguehard 《Analytica chimica acta》2002,451(2):285-295
The release of five elements (Cr, Cu, Mn, Pb and Zn) from a municipal solid waste incineration bottom ash (BA) under different extraction conditions has been investigated by performing the three-step sequential extraction procedure proposed by the Standards, Measurements and Testing Program of the European Union. A fourth step (strong acid attack) has been added in order to calculate the mass balance. The results of this study provide information on the potential mobility of the studied elements. Almost all of the Cr and part of the Mn are extracted with strong acid which indicates low potential mobility in the environment. Most of the Cu is extracted under oxidizing conditions. Pb and Zn are released under acidic condition, indicating the possibility of their mobilization by changes in pH. The reproducibility of the sequential extraction procedure is also discussed. 相似文献
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35.
F. Langmaier P. Mokrejs K. Kolomazník M. Mládek R. Karnas 《Journal of Thermal Analysis and Calorimetry》2007,88(3):857-862
Differential scanning calorimetry was employed to investigate the reaction of diglycidyl ethers of bisphenol A (DGEBA) of
mean molecular mass 348–480 Da, with collagen hydrolysate of chrome-tanned leather waste in a solvent-free environment. The
reaction leads to biodegradable polymers that might facilitate recycling of plastic parts in products of the automotive and/or
aeronautics industry provided with protective films on this basis. The reaction proceeds in a temperature interval of 205–220°C,
at temperatures approx. 30–40°C below temperature of thermal degradation of collagen hydrolysate. The found value of reaction
enthalpy, 519.19 J g−1 (= 101.24 kJ mol−1 of epoxide groups) corresponds with currently found enthalpy values of the reaction of oxirane ring with amino groups. Reaction
heat depends on the composition of reaction mixture (or on mass fraction of diglycidyl ethers in the reaction mixture); proving
the dependence of kinetic parameters of the reaction (Arrhenius pre-exponential factor A (min−1) and activation energy E
a (kJ mol−1)) did not succeed. Obtained values of kinetic parameters are on a level corresponding to the assumption that reaction kinetics
is determined by diffusion. 相似文献
36.
Highly sensitive catalytic determination of molybdenum 总被引:1,自引:0,他引:1
A novel, highly sensitive, selective, and simple kinetic method was developed for the determination of Mo(VI) based on its catalytic effect on the oxidation of 1-amino-2-naphthol-4-sulfonic acid (ANSA) with H2O2. The reaction was followed spectrophotometrically by tracing the oxidized product at 465 nm after 30 min of mixing the reagents. The optimum reaction conditions were: 10 mmol l−1 ANSA, 50 mmol l−1 H2O2, 100 mmol l−1 acetate buffer of pH 5.0 ± 0.05 and at 40 °C. Addition of 200 μg ml−1 diethylenetriaminepentaacetic acid (DTPA) conferred high selectivity for the proposed method. Following the recommended procedure, Mo(VI) could be determined with a linear calibration graph up to 2.5 ng ml−1 and a detection limit, based on the 3Sb-criterion, of 0.027 ng ml−1. The unique sensitivity and selectivity of the implemented method allowed its direct application to the determination of Mo(VI) in natural and industrial waste water. The method was validated by comparison with the standard ETAAS method. Moreover, published catalytic-spectrophotometric methods for the determination of molybdenum were reviewed. 相似文献
37.
A new fertilizer of cocrystal type,known as durably efficacious ammonium bicarbonate (DEAB),has been developed by adding a certain amount of dicyandiamide (DCD) as an ammonia-stabilizing agent to ammonium bearbenate(AB)during the process of its production.As compared with AB,DEAB was found to have a reduction of direct volatilization loss by 53%,a fertilizer availability period prolonged from 35-45 to 90-110 d,and an increase in the rate of nitrogen in fertilizer being utilized by 5.9%-10.2%,and a saving of the amount of fertilizer to be ap-phed by 20%-30% for the same level of yield,or an increase of the crop yield by over 10% for the same level of ni-tregen fertilization;in addition,it was found to show usually a function of promoting the crop to early mature.It can be apptied as basal dressing all in one time to soil and thus also used as a labour-saving and crop yield-increasing fertil-izer for is non-mtertillage,plastics film covering and water-saving agriculture 相似文献
38.
《Arabian Journal of Chemistry》2022,15(12):104329
To reduce the amount of hazardous chemical bottle waste in the environment, we report the optimization research of silica extraction in chemical bottle waste into silica gel. Alkali fusion and sol–gel process were utilised to prepare silica gel effectively. The alkali fusion process was carried out by adding sodium hydroxide to produce sodium silicate. Afterwards, silica gel was prepared by the sol–gel method using hydrochloric acid. Box-Behnken Design (BBD) was applied to Optimisation factors the poptimiseactors affecting the silica recovery. The factors that optimised mass ratio, particle size, and temperature. The optimum recovery of silica gel was obtained by SiO2: NaOH mass ratio of 1:3, the particle size of 63–74 µm, and a temperature of 800 °C. The purity of silica gel optimum is 63.74% characterised using X-ray fluorescence. The structure of silica gel is the appearance of amorphous peaks at 2θ 20-30° characterised using an x-ray diffractogram. The silica gel surface was characterises using scanning electron microscopy-energy dispersive x-ray. It showed an irregular surface and characteristic showed that silica gel had a radius of 15.74 nm and a specific surface area of 297.08 m2. 相似文献
39.
Physicochemical and biologic analysis of dairy wastewater showed that the effluent had a high organic load (chemical oxygen
demand [COD]: 5095 mg/L), an acidic pH (6.4), and a high probability of coliforms (most probable number [MPN]>1100). The various
bacterial strains isolated and purified were identified as Sporolactobacillus sp., Citrobacter sp., Pseudomonas sp., Alcaligenes sp., Bacillus sp., Staphylococcus sp., and Proteus sp., as per the Bergey’s manual of systematic bacteriology. Among the five selected bacterial strains, the strain designated
as MMRR7 and identified as Alcaligenes sp. was found to give a maximum reduction in COD (62%) in 5 d of incubation. Chemical coagulation using alum at a concentration
of 0.5 g/100 mL was found to be effective in the primary treatment of the effluent. Studies on free-cell treatment of the
coagulated effluent with the selected bacterial strain Alcaligenes sp. MMRR7 gave a maximum COD reduction of 91% in 120 h. This study clearly indicates the possibility of using Alcaligenes sp. MMRR7 for the effective treatment of dairy wastewater. 相似文献
40.