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971.
Four symmetrical α,α′,δ,δ′-tetramethyl-cucurbit[6]uril-based compounds have been prepared and characterised by X-ray crystallography. Their crystal structures displayed the acetate anion-selective encapsulating capability of symmetrical α,α′,δ,δ′-tetramethyl-cucurbit[6]uril. The host–guest interaction between the symmetrical α,α′,δ,δ′-tetramethyl-cucurbit[6]uril and the acetate anion in aqueous solution has also been observed by variable temperature 1H NMR spectroscopy. 相似文献
972.
In this work, a series of novel shape memory liquid crystalline (LC) epoxides with lateral substituent were prepared and characterized. Dynamic mechanical analysis (DMA) and shape memory testing were used to investigate on the thermo-mechanical properties and shape memory effects of prepared samples. The results showed that the modulus in the rubbery region (ER ) decreased as the length of lateral alkyl group increases. And more than 95% of the deformation can be fixed as the sample was cooled down below the glass transition temperature (Tg), which was determined by differential scanning calorimetry (DSC) measurement, and can be recovered completely as heating. Effects of the curing agent and substituent on the shape memory behavior were also studied. We found that LC epoxides cured by aromatic diamine have a higher recovery speed. The recovering speeds of the shape memory decreased as the length of lateral alkyl group inscreased. The local ordered structures and the lateral substituent played an important role in shape memory effects. 相似文献
973.
974.
975.
In this work, a projection algorithm is considered for treating strongly continuous semigroups of demicontinuous pseudocontractions. Theorems of strong convergence of fixed points are established in the framework of real Hilbert spaces. 相似文献
976.
In this paper, the Taguchi method combined with fuzzy approach was applied to find the extended optimization for a multi-objective design of a miniature 2.5× zoom fold optics with liquid elements. Relative illuminance (RI) and modulation transfer function (MTF) were considered to be optimized. The experiments were simulated and the results were evaluated by the optical software tool CODE V. It was concluded that the method used in this research was successful in optimizing the values. In our proposed method, the appropriate weight of MTF and RI for the inputs of fuzzy controllers increased the MTF by 9.92%, but the RI only reduced by 0.19% in systematic wide-angle end, respectively. 相似文献
977.
978.
Two-dimensional covalent organic framework(COF) has distinctive properties that offer potential opportunities for developing advanced electrode materials.In this work,a core-shell material composed of TAPB-DMTP-COF(TAPB,1,3,5-tris(4-aminophenyl)benzene;DMTP,2,5-dimethoxyterephaldehyde)core and conducting polymer shell,TAPB-DMTP-COF@PANI,was synthesized solvothermally using a polymerization method.The structural cha racteristics of the prepared composite were revealed by X-ray diffraction patterns(XRD),fourier transform infrared spectra(FTIR),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM).The electrochemical analyses were verified by subsequent monitoring of trace levels of acetaminophen.This resultant composite not only facilitated acetaminophen to interact with absorption sites by π-π stacking effect and hydrogen bonding but also overcame the poor conductivity of COF.Under the optimal conditions,a low limit of detection of0.032 μmol/L and wide linear range of 0.10-500 μmol/L were obtained.The electrochemical platform was almost unaffected by other interfering substances,and successfully applied for the practical detection of acetaminophen in commercial tablet,human blood serum and urine.The enhanced performance makes this COF based core-shell composite a promising material in electrochemical senso r. 相似文献
979.
980.
Lingjie Sun Dr. Weigang Zhu Wei Wang Dr. Fangxu Yang Congcong Zhang Prof. Shufeng Wang Dr. Xiaotao Zhang Prof. Rongjin Li Prof. Huanli Dong Prof. Wenping Hu 《Angewandte Chemie (International ed. in English)》2017,56(27):7831-7835
Cocrystals of 4-styrylpyridine and 1,2,4,5-tetracyanobenzene were successfully prepared by supramolecular self-assembly. Donor–acceptor interactions between the molecular components are the main driving force for self-assembly and contribute to intermolecular charge transfer. The cocrystals possess two-photon absorption properties that are not observed in the individual components; suggesting that two-photon absorption originates from intermolecular charge-transfer interactions in the donor–acceptor system. The origin of two-photon absorption in multichromophore systems remains under-researched; thus, the system offers a rare demonstration of two-photon absorption by cocrystallization. Cocrystal engineering may facilitate further design and development of novel materials for nonlinear optical and optoelectronic applications. 相似文献