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1.
Modern trends in designing mechatronic systems call for a synergic design of the separated subsystems (mechanic, electronic parts, control modules, etc.) concurring to the overall performance. Following this point of view, this paper presents a control oriented model and a nonlinear control design for a Common Rail injection system. First a model is developed, which is tuned in a virtual simulation environment, representing the injection system in details in a reliable replication of reality. Then a sliding mode control is developed. Both the model of the injection process and of the control law are validated by a virtual detailed simulation environment. The prediction capability of the model and the control efficiency are clearly shown. 相似文献
2.
A multiresidue method for isolation and liquid chromatographic determination of oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) in milk is presented. The sensitivity of the method is adequate to meet the needs of regulatory agencies. The European Community established 100 micrograms/kg as the maximum residue limit (MRL) in milk for TC, CTC, and OTC. Recoveries exceeded 80% for all tetracyclines at all levels, with good precision. Correlation coefficients of standards curves for individual tetracyclines isolated from fortified samples ranged from 0.991 for CTC to 0.998 for OTC. Other antibiotics that might interfere with analysis did not interfere with elution times of OTC, TC, and CTC. The procedure is rapid, precise, and quantitative and requires minimal preparation and minimal use of organic solvents. It can be applied to routine surveillance programs. We can prepare 10 samples for analysis in about 1.45 h. 相似文献
3.
Pure manganese dioxide, prepared synthetically, has been used for the oxidative decomposition of chrome ores. The usual constituents of the ores, viz. Cr(2)O(3) FeO, Al(2)O(3), MgO, CaO and SiO(2) have been estimated and the results compare favourably with those obtained by standard methods. 相似文献
4.
A 'bottom-up' approach for the expression of results obtained from analytical methods that include analytical steps with recovery inherently different from 100% [mass transfer steps (MTS): extraction, evaporation, clean-up procedures, digestion, etc.] is presented. The estimation of the combination of all MTS uncertainty involves the comparison of the experimental dispersion of replicated analyses of spiked samples with the estimation of the uncertainty obtained for the combination of all uncertainty sources except MTS ones ('incomplete' estimation). The estimation of MTS uncertainty by difference is performed after evaluating the statistical difference between the 'incomplete' estimation and the experimental dispersion (F-test). When the two estimations are statistically equivalent, the MTS uncertainty is considered to be negligible in relation to the other sources budget. The assumption of constancy of MTS performance within the analytical range is tested through single analyses at several concentration levels and is evaluated by the inclusion of the expected values at the intervals resulting from the combination of the MTS uncertainty estimation performed at one concentration level and the 'incomplete' estimation. The developed methodology can also be useful for method optimisation and validation and for the detection of small trends in results. The determination of pesticides in sweet peppers by GC-NPD was used to explore the above concepts. 相似文献
5.
Soluble complex-formation of mercury(II) thiocyanate has been studied oscillometrically. The titration of mercury(II) nitrate with thiocyanate gives one inflection corresponding to the formation of Hg(SCN)2, while in the reverse titration the formation of Hg(SCN)+ is also indecated. The method is useful for a rapid determination of very small quantities of mercury or thiocyanate in highly dilute solutions. The titrations can be effected in presence of nitric acid provided its total acidity in the system does not exceed about N. Further Work on the mercury(II) -halide and mercury(II)-cyanide reactions is in progress. 相似文献
6.
Feng K De Boni L Misoguti L Mendonca CR Meador M Hsu FL Bu XR 《Chemical communications (Cambridge, England)》2004,(10):1178-1180
Two new classes of two-photon absorbing Y-shaped molecules have been developed to possess an imidazole-thiazole core and a stilbene-type conjugation pathway with either nitro or sulfonyl as terminal electron-accepting group. 相似文献
7.
Given aself similar fractal K ? ? n of Hausdorff dimension α>n?2, andc 1>0, we give an easy and explicit construction, using the self similarity properties ofK, of a sequence of closed sets? h such that for every bounded open setΩ?? n and for everyf ∈ L2(Ω) the solutions to $$\left\{ \begin{gathered} - \Delta u_h = f in \Omega \backslash \varepsilon _h \hfill \\ u_h = 0 on \partial (\Omega \backslash \varepsilon _h ) \hfill \\ \end{gathered} \right.$$ converge to the solution of the relaxed Dirichlet boundary value problem $$\left\{ \begin{gathered} - \Delta u + uc_1 \mathcal{H}_{\left| K \right.}^\alpha = f in \Omega \hfill \\ u = 0 on \partial \Omega \hfill \\ \end{gathered} \right.$$ (H ∣ α denotes the restriction of the α-dimensional Hausdorff measure toK). The condition α>n?2 is strict. 相似文献
8.
B. R. Sant 《Fresenius' Journal of Analytical Chemistry》1955,145(4):257-260
Summary The oxidation of hydroxylamine by alkaline ferricyanide has been studied. It is observed that in presence of sodium hydroxide the molar ratio of NH2OH to K3Fe(CN)6 varies between 11.3 to 11.6. Quantitative oxidation to N2 is therefore carried out in weakly alkaline medium using borax-boric acid buffer. Hydroxylamine is estimated by titrating the ferrocyanide formed with standard ceric sulphate. Accurate and reproducible results are obtained if too large an excess of ferricyanide is avoided. Application of the present procedure to the determination of oximes and their metal complexes is suggested.Grateful thanks of the author are due to Prof. S. S. Joshi for facilities and encouragement and to Dr. G. S. Deshmukh for kind interest in the work. 相似文献
9.
Suseela B. Sant 《Fresenius' Journal of Analytical Chemistry》1959,168(2):112-115
Summary Potentiometric titrations of potassium ferricyanide with hydrazine sulfate and arsenic(III) are shown to be feasible at room temperature (25–30° C) and in an optimum alkali concentration of about 2 N when carried out in the initial presence of a few drops of osmic acid as catalyst. The method which is simple, rapid and accurate can be used in the estimation of hydrazine, arsenic(III) or ferricyanide.This work constituted, in part, the author's Ph. D. thesis (1956) at the Banaras Hindu University (India). 相似文献
10.
The capacity for anaerobic decolorization of a sulfonated azo dye, Congo Red, by a strain of a sulfate-reducing bacterium
was evaluated. After optimizing the growth rate of the bacteria on a simple carbon source and terminal electron acceptor pair,
lactate and sulfate, respectively, the effect of the dye concentration on their growth rate was analyzed. The decolorization
rate was affected by the dye concentration in the growth medium. The azo-bond cleavage mechanism of reductive decolorization
with the formation of benzidine was consistent with the results, as this metabolite was identified by high-performance liquid
chromatography. Several fractions of the culture medium, including lysed cell extracts, were examined for the capacity to
reduce the azo dye. This reduction capacity was found in the culture medium in which the cells had previously grown. The results
showed that the mechanism of reductive decolorization of this sulfonated azo dye was extracellular and nonenzymatic, consistent
with the production of sulfide anion by the microorganisms while growing on lactate and sulfate. The sulfide anions were the
cause of the reduction leading to the disappearance of color in the medium. To increase the rate of decolorization, the presence
of ferrous ion was also necessary together with the lactate and sulfate substrates. 相似文献