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151.
Summary Two -cyclodextrin (-CD)-containing polymers have been prepared either by condensation of -CD molecules with a bifunctional reagent or by grafting a -CD derivative on to a linear polymer (polyvinylimidazole). HPLC stationary phases were obtained by adsorption of the -CD polymers on to silica. The ability of these chromatographic supports to resolve racemic mixtures of organic compounds such as amino acid derivatives, phenylhydantoins, barbiturates, and hydroxycoumarin derivatives has been investigated. Results were found to depend on the chemical structure of the -CD polymers 相似文献
152.
绿色合成氧化剂高铁酸盐 总被引:13,自引:0,他引:13
高铁酸盐是绿色、无污染、高选择性和高活性的强氧化剂,其氧化性能比KMn04、O3和Cl还强,可以氧化醇类、含氮化合物、甚至烃类等有机化合物,高铁酸盐在有机物氧化合成中的应用具有很好的发展前景。本文介绍了有关高铁酸盐的制备方法、性质及有机物氧化合成方面的研究进展。 相似文献
153.
Liquid and solid cyclic peroxides derived from aliphatic ketones are explosive materials so their enthalpies of vaporization
and other thermodynamic or condensed-phase properties cannot be measured directly. In this work the enthalpies of vaporization
of peroxides at 298.15 K were estimated simply from gas chromatographic retention times measured at different temperatures.
The technique correlates changes in the retention times of compounds whose enthalpies of vaporization are known (called the
reference series), with those of the compounds of interest. If t
R′ is the adjusted retention time (retention time of each compound minus the retention time of unretained diethyl ether, used
as solvent) a plot of ln t
R′ against 1/T for each compound (reference compounds and cyclic peroxides) results in a straight line (r
2 > 0.99 for all compounds). The enthalpy of transfer from solution to the vapor state (Δsolg
H
m) can be obtained by multiplying the slope by the gas constant (R). A second plot correlates the enthalpies of transfer from
solution to the vapor state (Δsolg
H
m), as measured by gas–liquid chromatography (GLC), with enthalpies of vaporization of reference materials (Δvap
H
m at 298.15 K) available in the literature. C9–C15 fatty acid methyl esters and hydrocarbons were used as reference compounds. The enthalpies of vaporization of the cyclic
organic peroxides were calculated from the equation of the line obtained in this second correlation, the slope of which was
Δvap
H
m (at 298.15 K)/Δg
sol
H
m. The experiments were performed under isothermal conditions with a DB-5 capillary column, flame-ionization detection (FID),
and nitrogen as carrier gas. The column temperature was varied over a range of at least 30–70 K between 403 and 473 K, with
chromatograms being acquired at 10 K intervals. Enthalpies of vaporization of cyclic organic peroxides are not available in
the literature, and the values given in this paper, obtained by gas chromatography, are the first to be reported. 相似文献
154.
Bikshandarkoil R. Srinivasan Christian Näther Sunder N. Dhuri Wolfgang Bensch 《Monatshefte für Chemie / Chemical Monthly》2006,137(4):397-411
Summary. Four new organic ammonium tetrathiotungstates (N–Me–enH2)[WS4] (1), (N,N′-dm-1,3-pnH2)[WS4] (2), (1,4-bnH2)[WS4] (3), and (mipaH)2[WS4] (4), (N–Me–enH2 = N-methylethylenediammonium, N,N′-dm-1,3-pnH2 = N,N′-dimethyl-1,3-propanediammonium, 1,4-bnH2 = 1,4-butanediammonium, and mipaH = monoisopropylammonium) were synthesized by the base promoted cation exchange reaction and characterized by elemental analysis,
infrared, Raman, UV-Vis and 1H NMR spectroscopy as well as single crystal X-ray crystallography. The structures of 1–4 consist of [WS4]2− tetrahedra which are linked to the organic ammonium cations via N–H⋯S hydrogen bonding. The strength and number of the S⋯H
interactions affect the W–S bond lengths as evidenced by distinct short and long W–S bonds. The IR spectra exhibit splitting
of the W–S vibrations, which can be attributed to the distortion of the [WS4]2− tetrahedron. From a comparative study of several known tetrathiotungstates it is observed that a difference of more than
0.033 ? between the longest and shortest W–S bonds in a tetrathiotungstate will result in the splitting of the asymmetric
stretching vibration of the W–S bond. 相似文献
155.
The photochemistry of some members of the two series of γ-phenyl substituted acyclic β, γ-unsaturated ketones 1 and 2 upon direct irradiation with γ 310nm has been investigated, viz 1c–1h and 2b+2c.The alkyl substituted (E)-5-phenyl-4-penten-2-ones 1c–1h yield the corresponding 1,3-acyl shift products and (Z)-isomers, and 1g and 1h in addition two decarbonylated products. 2b only yields the (Z)-isomer and some benzaldehyde, but 2c yields the 1,3-acyl shift product, the ODPM product, three hydrocarbons formed by disproportionation of the allyl radical, and some benzaldehyde. The β-phenyl β, γ-UK 3a proved to be photostable. The 1,3-acyl shift products of 1c–1h result mainly from the singlet excited state in a cage radical process. The exclusive formation of the (E)-configuration of the 1,3-acyl shift product is explained in terms of conformational preference of the intermediate allyl radical. It is proposed that the formation of the (Z)-isomer proceeds from 1T(π -π*) which is populated according to . Evidence is presented which supports the proposed mechanism.The β,γ-UK 2b containing a benzoyl moiety leads to a higher degree of (E)-(Z) isomerization than the corresponding 1d which has an acetyl moiety.The triplet energies of (E)- and (Z)-1h are 56 and ca 70 kcal/mol respectively. 相似文献
156.
157.
A solvent-free lift-off method has been introduced to fabricate the aluminum nano-hole array with diameter down to 80 nm as the base electrode for a vertical organic transistor. The imprinted vertical organic transistor exhibited base leakage current density as low as 5 × 10−5 mA/cm2 and high ON/OFF current ratio as high as 105. 相似文献
158.
Two new oligothiophene-based small molecules, namely DRCN6T-F and DRCN8T-F, with 3,3′-difluoro-2,2′-bithiophene as the central building block and 2-(1,1-dicyanomethylene)-rhodanine as end groups, were designed and synthesized. Compared to their non-fluorinated counterparts DRCN6T and DRCN8T, DRCN6T-F and DRCN8T-F exhibit enhanced intermolecular interactions and lower HOMO energy levels. However, PCEs of 2.26% and 5.07% were obtained for DRCN6T-F and DRCN8T-F based optimized devices, respectively, lower than those of non-fluorinated molecules DRCN6T and DRCN8T. The relatively poor performance for the DRCN6T-F and DRCN8T-F were mainly caused by their low short-circuit current densities, due to their unfavorable morphologies and low charge carrier mobilities. 相似文献
159.
160.
Recently, stamping transfer process using by soft mold or film has been considered by promising technology to solve the drawbacks of spin coating such as deposition of large area and specific region, reducing the material loss, and multi-staking device structures. For the previous researches, polyurethane acrylate (PUA) stamp was essentially treated the 1H, 1H, 2H, 2H-Perfluorooctyltrichlorosilane (FOTS) for self-assembled monolayer (SAM) onto the Si wafer to modify surface energy. Because the FOTS is known as corrosive material, it is necessary to develop the intrinsic property of PUA with environment friendly. In this research, we investigates non-FOTS based PUA stamping transfer and the different surface energy properties that result in various physical phenomena when used for organic photovoltaics. To transfer the material, the energy release rate (G) between the PUA and the coated material should be smaller than the G between the coated material and the substrate. As a result, hydrophilic PUA was used to reduce the interaction between the PUA and the organic bulk heterojunction (BHJ) layer to transfer the BHJ layer from the PUA stamp to a PEDOT:PSS-coated ITO-substrate. 2-Hydroxyethyl methacrylate (HEMA) is included as the reactive diluent to reduce the PUA viscosity, and the contact angle was measured to compare the surface property between the reference PUA and the HEMA-PUA. The stamping-transferred BHJ device exhibits a 95% relative efficiency (2.9%) when compared to that obtained when using a spin-coating process, which is considered as a good alternative to fabricate optoelectronic devices. More importantly, we have found a decrease in the fill factor (64%–58%) and a comparable performance (3.0%–2.9%) derived from the increase in the charge recombination and resistance during the stamping transfer. 相似文献