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101.
Electron paramagnetic resonance spectra of Cu2+ impurities in cytosine hydrochloride single crystals are observed at liquid nitrogen temperature. Two magnetically equivalent sites for Cu2+ have been observed. The parameters of 63Cu obtained with the fitting of spectra to rhombic symmetry spin Hamiltonian are: g x = 2.047 ± 0.002, g y = 2.187 ± 0.002, g z = 2.390 ± 0.002, A x = (86 ± 3) × 10?4 cm?1, A y = (87 ± 3) × 10?4 cm?1, and A z = (138 ± 3) × 10?4 cm?1. The observed bands in optical spectra of the single crystal recorded at room temperature are assigned to various d–d and charge-transfer transitions. Using both EPR and optical data, the nature of bonding of metal ion with different ligands is discussed. 相似文献
102.
In this paper, a new class of intuitionistic fuzzy closed sets called intuitionistic fuzzy generalized preregular closed sets (briefly intuitionistic fuzzy gpr-closed sets) and intuitionistic fuzzy generalized preregular open sets (briefly intuitionistic fuzzy gpr-open sets) are introduced and their properties are studied. Further the notion of intuitionistic fuzzy preregular T 1/2-spaces and intuitionistic fuzzy generalized preregular continuity (briefly intuitionistic fuzzy gpr-continuity) are introduced and studied. 相似文献
103.
We construct a free-probability quantum Yang-Mills theory on the two dimensional plane, determine the Wilson loop expectation values, and show that this theory is the N=∞ limit of U(N) quantum Yang-Mills theory on the plane. Our model provides an example of a stochastic geometry, motivated by quantum field theory, based on free probability theory. 相似文献
104.
This study was carried out to produce bioconverted products by microbial fermentation of tomato using a plant pathogenic bacterium Pectobacterium atrosepticum and to evaluate their in vitro antimycotic effect against pathogenic Candida species. The bioconverted products (500 microg/disc) provoked promising antimycotic effects against pathogenic isolates of Candida species as shown by the diameters of zones of inhibition (9 +/- 0.6 to 14 +/- 0.4 mm), along with their respective minimum inhibitory and minimum fungicidal concentration values, which increased from 250 to 1000 and 250 to 2000 microg/mL, respectively. With the viable counts of the tested fungal pathogens, exposure of the bioconverted products revealed a remarkable antimycotic effect. In addition, the morphology of a clinical isolate of C. glabrata KBN06P00368, visualized by scanning electron microscopy, showed a severe detrimental effect produced by the bioconverted products at the minimum inhibitory concentration (250 microg/mL). The bioconverted products significantly inhibited the in vitro growth of all the tested clinical and pathogenic laboratory isolates of Candida species. This study confirmed the potent antimycotic efficacy of the bioconverted products of tomato, hence justifying the therapeutic uses of bioconverted products in pharmaceutical preparations as an alternative approach to support the antifungal activity of conventional antimycotics. 相似文献
105.
Nilanjan Dey Dipen Biswakarma Alankriti Bajpai Prof. Jarugu Narasimha Moorthy Prof. Santanu Bhattacharya 《Chemphyschem》2019,20(6):881-889
The excited-state proton-transfer efficiency of a tetraarylpyrene derivative, 1,3,6,8-tetrakis(4-hydroxy-2,6-dimethylphenyl)pyrene (TDMPP), was investigated thoroughly in the presence of various surfactant assemblies, such as micelles and vesicles. The confined microheterogeneous environments can significantly retard the extent of the excited-state proton-transfer process, resulting in a distinguishable optical signal compared to that in the bulk medium. Physical characteristics of the surfactant assemblies, such as order, interfacial hydration, and surface charge, influence the proton transfer process and allow multiparametric sensing. A higher degree of interfacial hydration facilitates the proton-transfer process, while the positively charged head groups of the surfactants specifically stabilize the anionic form of the probe (TDMPP−O*). Furthermore, Forster energy transfer from the probe to riboflavin was studied in a phospholipid membrane, wherein the relative ratio of the neutral versus anionic forms (TDMPP-OH/TDMPP−O*) was found to influence the extent of energy transfer. Overall, we demonstrate how an ultrafast photophysical process, that is, the excited-state proton transfer, can be influenced by the microenvironment. 相似文献
106.
Malachite green adsorption characteristics of magnetic beads have been investigated by batch and column methods. The maximum removal percentage of malachite green (93.9 %) was obtained at pH 7–8. The Langmuir and Freundlich isotherms were used to investigate the adsorption equilibrium. It was found that the Freundlich model provides the best correlation with the equilibrium. In the column method, the BDST model was used to obtain an empirical relationship for the design of the adsorption column. The characterization of the prepared magnetic beads has been accomplished by FTIR, SEM, and XRD measurements. 相似文献
107.
The real (χ′
n) and imaginary (χ″
n) parts of even harmonic susceptibility (n⩽6) are measured as a function of external DC field (H
dc) in the field increasing (H↑) and decreasing (H↑) cycle. Hysteresis is observed betweenH↑ andH↓ cycles. In theH↓ cycle, at a field,H
comp=4·2G, bothχ′ andχ″ of all the even harmonics vanish indicating a true cancellation of fields in the intergrain region (H
eff≈0) caused by the balance betweenH
dc and the remanent magnetization of the grains. The position of the extrema and the zero of the various harmonics undergo a
shift proportional to the remanent magnetization of the grains at that particular field. 相似文献
108.
Application of energy dispersive X-ray fluorescence (EDXRF) and proton induced X-ray emission (PIXE) methods has been demonstrated
for determining the elemental composition of thin film superconducting materials. The results of analysis carried out by EDXRF
method have been compared with those obtained by PIXE method. Thin films of YBa2Cu3O7 superconducting material were deposited on various substrates such as thin mylar sheet and thick substrates of SrTiO3, MgO and Al2O3. In thin backing the minimum detection limits obtained for Cu, Y, Ba by the PIXE method are 20 ng, 70 ng and 800 ng respectively
and the corresponding values by the EDXRF method are 3000 ng, 600 ng and 1000 ng. Detection limits for samples on thick backings
deteriorated to a large extent by both methods. 相似文献
109.
The Vickers microhardness test is found to be a suitable analytical method for studying thermal change in thin films of polymers. It is utilised to analyse the effect of thermal pretreatment (annealing and quenching) on the surface microhardness of guargum (GG); a natural polymer), polyacrylonitrile (PAN; a synthetic polymer) and their cast blends, guargum-grafted-polyacrylonitrile (GG-g-PAN) and polyacrylonitrile-guargum (PAN-GG). Annealing at various temperatures reveals the change in configuration and crystallinity of thin films of polymers. Peak values of hardness are found to occur in GG, PAN and PAN-GG but not in GG-g-PAN. The quenched hardness for GG is found to be nonlinear with temperature. However, for other polymers quenched hardness decreases, initially, up to a certain temperature and then starts increasing; such temperatures for PAN, PAN-GG and GG-g-PAN are 86, 66 and 86°C, respectively. The behaviour of polymer blends on quenching can be represented by a calculated value of the exponent which is 0·62 and 0·75 for GG-g-PAN and PAN-GG, respectively. 相似文献
110.
Applied Biochemistry and Biotechnology - 相似文献