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951.
Abdullah Aydın Mehmet Akkurt Leyla Uzun Leyla Yıldırım Tijen Önkol 《Journal of chemical crystallography》2010,40(10):816-820
Abstract
The title compound {6-[2-(2-chlorophenyl)-1,3-thiazol-4-yl]-2-oxo-1,3-benzothiazol-3(2H)-yl}acetic acid was prepared and characterized by elemental analyses, FT-IR, 1H NMR spectroscopy, X-ray diffraction. A quantum-chemical calculation was performed using the CNDO method. In the title compound, C18H11ClN2O3S2, the crystal structure is stabilized by intermolecular hydrogen bonds (C–H···O=C) to form centrosymmetric R22 R_{2}^{2} (16) dimers and the C–H···O, O–H···N, and C–H···N interactions generating the graph set motifs R22 R_{2}^{2} (9) and R22 R_{2}^{2} (22). 相似文献952.
Abdullah A. Al-badr 《光谱学快报》2013,46(9):673-682
An analytical method is described for the assay of two important oral hypoglycemic agents, namely, glibenclamide (glyburide); and tolazamide; using PMR technique. The method is rapid, accurate, specific and precise. The principle of the method involves comparing the integral of a chosen signal in the PMR spectrum of the drug under investigation with that of the methylene group signal of the internal standard, benzyl benzoate. 相似文献
953.
F. I. SHARRAD Hewa Y. Abdullah N. AL-DAHAN N. M. Umran A. A. OKHUNOV H. Abu KASSIM 《中国物理 C》2013,37(3):41-44
The energy levels, transition energy, B (E2) values,intrinsic quadrupole moment Q0 and potential energy surface for even-even 184W and 184Os nuclei were calculated using IBM-1. The predicted energy levels, transition energy, B(E2) values and intrinsic quadrupole moment Q0 results are reasonably consistent with the experimental data. A contour plot of the potential energy surfaces shows that two interesting nuclei are deformed and have rotational characters. 相似文献
954.
Suppose that a homogeneous linear differential equation has entire coefficients of finite order and a fundamental set of solutions each having zeros with finite exponent of convergence. Upper bounds are given for the number of zeros of these solutions in small discs in a neighbourhood of infinity. 相似文献
955.
Abdullah J Ahmad M Heng LY Karuppiah N Sidek H 《Analytical and bioanalytical chemistry》2006,386(5):1285-1292
The stacked-film immobilization of 3-methyl-2-benzothiazolinone hydrazone (MBTH) in hybrid nafion/sol-gel silicate film and
horseradish peroxidase (HRP) in chitosan, performed in order to allow the determination of phenolic compounds, was investigated
via an optical method. The stacked films were deposited onto a microscope glass slide by a spin-coating technique. The quinone
or free radical product formed by the enzymatic reactions of phenolic compounds interacts with MBTH to form azo-dye products,
which can be measured spectrophotometrically at a wavelength of 500 nm. The color intensity of the product was found to increase
in proportion to the phenolic concentration after 5 min of exposure. The response of the biosensor was linear over concentration
ranges of 0.025–0.500, 0.010–0.070 and 0.050–0.300 mM for guaiacol, resorcinol and o-cresol, respectively, and gave detection limits of 0.010, 0.005 and 0.012 mM. The sensor exhibited good sensitivity and stability
for at least two months. 相似文献
956.
It has been shown that for each Killing–Yano (KY)-form accepted by an n-dimensional (pseudo)Riemannian manifold of arbitrary signature, two different gravitational currents can be defined. Conservation
of the currents are explicitly proved by showing co-exactness of the one and co-closedness of the other. Some general geometrical
facts implied by these conservation laws are also elucidated. In particular, the conservation of the one-form currents implies
that the scalar curvature of the manifold is a flow invariant for all of its Killing vector fields. It also directly follows
that, while all KY-forms and their Hodge duals on a constant curvature manifold are the eigenforms of the Laplace–Beltrami
operator, for an Einstein manifold this is certain only for KY 1-forms, (n − 1)-forms and their Hodge duals. 相似文献
957.
We investigated the antibacterial activity of some new macromolecules such as bis‐pyrazoline, bis‐pyrazole, bis‐pyrimidines prepared from the reaction of bis‐chalcone with thiosemicarbazide/phenyl hydrazine/guanidine hydrochloride/thiourea. All the macromolecules have been characterized by IR, 1H NMR, 13C NMR, mass and elemental analyses. The antibacterial activity of these compounds was first tested in vitro by the disc diffusion assay against two Gram‐positive and two Gram‐negative bacteria, and then the minimum inhibitory concentration was determined with the reference to standard drug chloramphenicol. The results showed that pyrazoline derivative showed better antibacterial activity on S. typhimurium and E. coli than the reference drug chloramphenicol. 相似文献
958.
959.
The present paper reports on the first preparation of 2,4,6-tris(2-pyridyl)-1,3,5-triazine nanobelts (TPTNBs) by adjusting the pH value of the solution and the subsequent synthesis of Ag nanoparticle (AgNP)-decorated TPTNBs (AgNP-TPTNBs) by mixing an aqueous AgNO(3) solution with preformed TPTNBs without use of any external reducing agent. It is found that the resultant AgNP-TPTNBs exhibit notable catalytic performance for H(2)O(2) reduction. A glucose biosensor was fabricated by immobilizing glucose oxidase (GOD) onto a AgNP-TPTNBs-modified glassy carbon electrode (GCE) for glucose detection. The constructed glucose sensor has a wide linear response range from 3 mM to 20 mM (r: 0.999) with a detection limit of 190 μM. It is further shown that this glucose biosensor can be used for glucose detection in human blood serum. 相似文献
960.
Samy A. El-Daly Khalid A. Alamry Abdullah M. Asiri Mahmoud A. Hussein 《Journal of luminescence》2012,132(10):2747-2752
The photophysical properties such as electronic absorption, molar absorptivity, emission spectra, fluorescence quantum yield and fluorescence lifetime of N,N′-bis(4-pyridyl)-3,4:9,10-perylene bis(dicarboximide) (BPPD) have been measured in different solvents. Both electronic absorption and fluorescence spectra are not sensitive to medium polarity, while the fluorescence quantum yield (?f) is solvent dependent. The ground state geometry has been computed by using density functional theory (DFT), the transition from HOMO to LUMO from perylene core with maximum absorption at 512 nm and HOMO–LUMO energy difference equal 2.53 eV. BPPD dye undergoes molecular aggregation to dimmer or higher aggregates in dimethyl sulfoxide (DMSO). Crystalline solids of BPPD gives excimer-like emission at 676 nm. The fluorescence quenching of BPPD is also studied using hydrated ferric oxide nanoparticle (FeOOH), and the Stern–Volmer rate constants (Ksv) were calculated as 8×106 and 9.2×106 M?1 in ethanol and ethylene glycol, respectively. 相似文献