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71.
The effect of calcination temperature on the activity and some properties of low temperature water gas shift reaction catalysts
has been investigated. The activities of catalysts have been determined using a fixed bed catalytic reactor. The following
results may be deduced from the present study. 1. The catalysts' total surface area decreased with increasing calcination
temperature, presumably due to the partial sintering of the catalysts particles. 2. The presence of an amorphous CuO phase
within the structure of some catalysts may be related to the desirable conditions prevailing during synthesis of the latter.
3. Observation of a similar trend between the increase in copper crystallite particle size and enhancement of catalyst activities
with increasing calcination temperature demonstrates the important contribution made by the copper crystallite phase to the
overall activities of water gas shift reaction catalysts.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
72.
Intraelemental relative photoelectron line intensities for 20 pure elements obtained under ultrahigh vacuum (5·10?9 torr) and high resolution with cleaned surfaces are presented. Theoretical and experimental aspects of relative photoelectron line intensities as well as other characteristics of significance to quantitative analysis are discussed. Experimental data are related to theoretical results and compared with other recent work. 相似文献
73.
Oxidative electrochemical detection is used for liquid chromatographic separation of polynuclear aromatic hydrocarbons (PAH's). The amperometric response is shown to be dependent on the working potential, ionic strength, flow rate, pH, temperature and pretreatment of the glassy carbon electrode surface. These experimental factors were optimized by choosing the maximum signal-to-noise ratio for anthracene and benz(a)-anthracene. The figures of merit (sensitivity, limit of detection and linear dynamic range) of six PAH's are reported and compared with ultraviolet absorption detection. Varying the applied potential gives the capability for selective detection. 相似文献
74.
Tungstate sulfuric acid (TSA)/KMnO4 as a novel heterogeneous system for rapid deoximation 总被引:1,自引:0,他引:1
Neat chlorosulfonic acid reacts with anhydrous sodium tungstate to give tungstate sulfuric acid (TSA), a new dibasic inorganic solid acid in which two sulfuric acid molecules connect to a tungstate moiety via a covalent bond. A variety of oximes were oxidized to their parent carbonyl compounds under mild conditions with excellent yields in short times by a heterogeneous wet TSA/KMnO4 in dichloromethane system. 相似文献
75.
Morteza Moniri 《Archive for Mathematical Logic》2010,49(3):291-300
In this paper we prove conservation theorems for theories of classical first-order arithmetic over their intuitionistic version.
We also prove generalized conservation results for intuitionistic theories when certain weak forms of the principle of excluded
middle are added to them. Members of two families of subsystems of Heyting arithmetic and Buss-Harnik’s theories of intuitionistic
bounded arithmetic are the intuitionistic theories we consider. For the first group, we use a method described by Leivant
based on the negative translation combined with a variant of Friedman’s translation. For the second group, we use Avigad’s
forcing method. 相似文献
76.
Morteza Sadeghi Homayoon Moadel Somaieh Khatti Behnam Ghalei 《Journal of Macromolecular Science: Physics》2013,52(6):1128-1135
The sorption behaviors of sulfuric, perchloric, and phosphoric acids in polybenzimidazole membranes have been investigated. The results of sorption isotherms are consistent with the general form of a dual-mode sorption isotherm. The dual-mode sorption parameters were found using a least-squares program by fitting experimental data to a dual-mode equation. Results indicate a correlation between permeant properties like acidity, size, and the affinity constant in Langmuir-mode sorption species. Moreover, the results show that the size of the permeants has the dominant effect on Henry's constant. The obtained results for , site saturation constant, in Langmuir-mode sorption in the case of perchloric and phosphoric acids, reveals that the two acid molecules interact with two N?H basic groups in the polybenzimidazole repeat units. But in the case of sulfuric acid, it is shown that sulfuric acid neutralizes some of the basic groups in the polymer by its strong second hydrogen and the obtained value for was 1.25. 相似文献
77.
78.
Saeed Balalaie Morteza Ashouriha Frank Rominger Hamid Reza Bijanzadeh 《Molecular diversity》2013,17(1):55-61
A three-component reaction of 3-formyl chromones, dialkyl acetylenedicarboxylate, and isocyanides in the presence of $\text{ POCl}_{3}$ was used as a highly efficient and practical approach for the synthesis of 3-amino-5-chromenyl-butenolides. High yields and high bond forming efficiency, and simple operations are the advantages of this method. Graphical abstract 相似文献
79.
Qamar Salamat Yadollah Yamini Morteza Moradi Abolfazl Farahani Neda Feizi 《Journal of separation science》2019,42(8):1620-1628
In the present study, a supramolecular solvent was formed from reverse micelle aggregates of octanol. The proposed supramolecular solvent was used for rapid extraction of some antidepressants drugs including amitriptyline, imipramine, desipramine, maprotiline, sertraline, and doxepin from biological samples. Alkanol‐based supramolecular solvents have a unique array of physicochemical properties, making them a very attractive alternative to replace organic solvents in analytical extractions. The parameters affecting the extraction of target analytes (i.e., the volume of tetrahydrofuran and octanol as the major components comprising the supramolecular solvent, chain length of alkanols, sample solution pH, salt addition, and ultrasonic time) were investigated and optimized by factor by factor optimization method. Under the optimum conditions, preconcentration factors of 470, 490, 460, 385, 370, and 430 were obtained for amitriptyline, doxepin, imipramine, desipramine, maprotiline, and sertraline, respectively. The linear ranges and coefficients of determination (R2) were obtained in the range of 0.01–100 μg/L and 0.9974–0.9991, respectively. Also the limits of detection (S/N = 3) of 0.003–0.03 μg/L, and precisions (n = 5) of 4.9–8.9% were calculated. Finally, the method was successfully applied for the extraction of antidepressant drugs in biological samples, and relative recoveries in the range of 91–102% were obtained. 相似文献
80.
Morteza Mohseni 《International Journal of Theoretical Physics》2008,47(4):1079-1082
We introduce a Lagrangian which can be varied to give both the equation of motion and world-line deviations of spinning particles
simultaneously. 相似文献