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111.
H. Ünver M. Yıldız D. Mehmet Zengin S. Özbey E. Kendi 《Journal of chemical crystallography》2001,31(4):211-216
N-(3-pyridil)-2-oxo-1-naphthylidenemethylamine (C16H12N2O) was studied by elemental analysis, IR, 1H NMR, and UV–visible techniques and X-ray diffraction methods. The UV–visible spectrum of the compound was investigated in solutions effect polarity. The polarity of the some solvents was modifierly the additional (CF3COOH) and [(C2H5)3N]. The compound is in tautomeric equilibrium (phenol-imine O–H···N and keto-amine O···H–N forms) in polar and nonpolar solvents. The keto-amine form is observed in basic solutions of DMSO, ethanol, chloroform, benzene, cyclohexane, and in acidic solutions of chloroform and benzene, but not in acidic solutions of DMSO and ethanol. The compound crystallizes in the monoclinic, space group P21/a with a = 7.010(5) Å, b = 13.669(4) Å, c = 12.764(4) Å, = 101.23(4)°, V = 1199.6(10) Å3, Z = 4, D
c = 1.375 g/cm3, (Mo K) = 0.088 mm–1, R = 0.045 for 1658 reflections [I > 2(I)]. The title compound is not planar two Schiff base moieties A [C1–C11, O1] and B [N1, C12, C13, N2, C14, C15, C16] are inclined at an angle of 27.4(1)° reflecting mainly the twist about C12–N1 [C11–C12–N1–C13, 29.7(2)°]. There is a strong intramolecular hydrogen bond (O–H···N) of 2.529(2) Å. 相似文献
112.
H. Ünver M. Kabak D. Mehmet Zengin T. Nuri Durlu 《Journal of chemical crystallography》2001,31(4):203-209
1-[N-(4-chlorophenyl)]aminomethylidene-2(1H)naphthalenone (C17H12NOCl) (1) was synthesized and the crystal structure was determined. Compound 1 crystallizes in the monoclinic space group P21/n with a = 4.761(3) Å, b = 20.347(1) Å, c = 13.773(2) Å, = 92.89(3)°, V = 1332.4(3) Å3, Z = 4, D
c = 1.404 g cm–3, (Mo K) = 0.28 mm–1, and R = 0.036 for 2680 reflections [I > 2(I)]. Molecule 1 is not planar, and the dihedral angle between the naphthaldeyde plane A [C1–C11, 01] and the 4-chloroaniline plane B [C12–C17, C11, N1] is 20.1(3)°. An intramolecular hydrogen bond occurs between the hydroxyl oxygen and imine nitrogen atoms [2.528(3) Å]. IR, 1H NMR, and UV measurements and AM1 semiempirical quantum mechanical calculations support the keto form found in the X-ray structure. 相似文献
113.
A model was proposed to calculate some thermodynamic parameters for the acid dissolution process of a bentonite containing
a calcium-rich smectite as clay mineral along with quartz, opal and feldspar as impurities. The bentonite sample was treated
with H2SO4 by applying dry method in the temperature range 50–150°C for 24 h. The acid content in the dry bentonite-sulphuric acid mixture
was 45 mass%. The total content (x) of Al2O3, Fe2O3 and MgO remained in the undissolved sample after treatment was taken as an equilibrium parameter. An apparent equilibrium
constant, K
a, was calculated for each temperature by assuming K
a=(x
m−x)/x where x
m is the total oxide content of the natural bentonite. Also, an apparent change in Gibbs free energy, ΔG
ao, was calculated for each temperature by using the K
a value. The graphs of lnK
a
vs. 1/T and ΔG
ao
vs. T were drawn and then the real change in both the enthalpy, ΔH
o and the entropy, ΔS
o, values were calculated from the slopes of the straight lines, respectively. Inversely, real ΔG
o and K values were calculated from the real ΔH
o and ΔS
o values through ΔG
o = −RT ln K = ΔH
o − TΔS
o equation. The best ΔH
o and ΔS
o fittings to this relation were found to be 65687 J mol−1 and 164 J mol−1K−1, respectively. 相似文献
114.
杯[4]芳烃的上端和下端通过金属复分解闭环反应以较高产率合成一系列新型杯[4]冠醚衍生物(8a-c),目标产物结构经元素分析、IR、MS、1H NMR及13C NMR证实。 相似文献
115.
The preparation and H2S sensing potential of thick‐films of a mixed oxide, Fe2O3? Fe2(MoO4)3, were investigated. A Fourier‐transform infrared (FTIR) study confirmed the existence of sulfur species at the surface after the interaction of H2S gas with the mixed oxide. The starting material, β‐FeMoO4, was synthesized by a solvothermal method, followed by supercritical drying. Heat treatment of this material (oxidation) above 500 °C resulted in the formation of Fe2O3? Fe2(MoO4)3 mixed oxide, where Fe2O3 was a by‐product. An increase in the conductivity of the films in the presence of H2S gas (concentration range 1–20 ppm in air) was observed with the simultaneous formation of water and sulfide ions at 225 °C. An improvement of the H2S sensing potential is obtained, using an intermediate short heat treatment at higher temperature (500 °C) in the beginning of recovery (desorption) phase. This intermediate high temperature, used before every expected exposure to H2S gas, may contribute the formation of an initial surface coverage of O2?. 相似文献
116.
Seda Ünlü Göknur Yaşa Atmaca Fikriye Tuncel Elmalı Ali Erdoğmuş 《Photochemistry and photobiology》2023,99(5):1233-1239
Although the sonophotodynamic method has an effective therapeutic outcome for anticancer treatment compared with the photodynamic method, there are not enough related studies in the literature and this study aims to contribute to the development of sonophotodynamic studies. For this purpose, the Schiff base substituted silicon phthalocyanines were designed and synthesized as effective sensitizer candidates and the photophysicochemical and sonophotochemical features of the phthalocyanines were examined to increase singlet oxygen efficiency. The calculated ΦΔ values indicate that the contribution of substituent groups improved the production of singlet oxygen compared with silicon (IV) phthalocyanine dichloride (SiPcCI2) and also the sonophotochemical applications increased the singlet oxygen yields. The ΦΔ values (ΦΔ = 0.76 for axially bis-{4-[(E)-(pyridin-3-ylimino)methyl]phenol} substituted silicon (IV) phthalocyanine ( 2a ), 0.68 for axially bis-4-[(E)-{[(pyridin-3-yl)methyl]imino}methyl]phenol substituted silicon (IV) phthalocyanine ( 2b ) in photochemical study) reached to ΦΔ = 0.98 for 2a , 0.94 for 2b in sonophotochemical study. This article will enrich the literature on increasing singlet oxygen yield. 相似文献
117.
Using integer and noninteger n-Slater type orbitals in single- and double-zeta approximations, the Hartree-Fock-Roothaan calculations were performed for the ground states of first ten cationic members of the isoelectronic series of He atom. All the noninteger parameters and orbital exponents were fully optimized. In the case of noninteger n-Slater type orbitals in double zeta basis sets, the results of calculations obtained are more close to the numerical Hatree-Fock values and the average deviations of our ground state energies do not exceed 2×10-6 hartrees of their numerical results. 相似文献
118.
We report how the control of a single parameter, the co-surfactant, determines the phase transitions of oil-in-water swollen liquid crystals (SLCs) prepared with cetyltrimethylammonium bromide (CTAB), from cubic to hexagonal, lamellar, and finally sponge-like structures. SLCs are complex mixtures (surfactant + co-surfactant + water + salt + oil) usually prepared to form hexagonal mesophases, with cell parameters tunable between 3 and 30 nm. These hexagonal mesophases were successfully used as nanoreactors to prepare a broad range of nanostructured materials. Because the potential of these mesophases as adaptive nanoreactors has not been extended to other liquid crystal geometries than the hexagonal, we studied in a first step the structure evolution of SLCs made with CTAB, cyclohexane, pentanol-1, water and different stabilising salts. We used small-angle X-ray scattering (SAXS), polarised light microscopy and Freeze-Fracture TEM to provide a partial phase diagram and list the different mesophases obtained as a function of composition. We report that the adjustment of a single parameter, the co-surfactant (pentanol-1), determines the phase transition between cubic, hexagonal, lamellar, and sponge-like structures, all other parameters such as the nature and concentration of salt, or amount of oil being constant. 相似文献
119.
Increased consumption of fossil fuels in industrial production has led to a significant elevation in the emission of greenhouse gases and to global warming. The most effective international action against global warming is the Kyoto Protocol, which aims to reduce carbon emissions to desired levels in a certain time span. Carbon trading is one of the mechanisms used to achieve the desired reductions. One of the most important implications of carbon trading for industrial systems is the risk of uncertainty about the prices of carbon allowance permits traded in the carbon markets. In this paper, we consider stochastic and time series modeling of carbon market prices and provide estimates of the model parameters involved, based on the European Union emissions trading scheme carbon allowances data obtained for 2008–2012 period. In particular, we consider fractional Brownian motion and autoregressive moving average–generalized autoregressive conditional heteroskedastic modeling of the European Union emissions trading scheme data and provide comparisons with benchmark models. Our analysis reveals evidence for structural changes in the underlying models in the span of the years 2008–2012. Data‐driven methods for identifying possible change‐points in the underlying models are employed, and a detailed analysis is provided. Our analysis indicated change‐points in the European Union Allowance (EUA) prices in the first half of 2009 and in the second half of 2011, whereas in the Certified Emissions Reduction (CER) prices three change‐points have appeared, in the first half of 2009, the middle of 2011, and in the second half of 2012. These change‐points seem to parallel the global economic indicators as well. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
120.
Cover Picture: On The Potential of Dynamic Nuclear Polarization Enhanced Diamonds in Solid‐State and Dissolution 13C NMR Spectroscopy (ChemPhysChem 17/2016)
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