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981.
α-和β-四烷氧取代酞菁的合成及性能研究 总被引:4,自引:0,他引:4
利用 3 烷氧取代邻苯二腈和 4 烷氧取代邻苯二腈与相应的金属盐反应制备了两大系列 (α 和 β )四烷氧取代酞菁 .讨论了温度对中间体烷氧取代邻苯二腈合成的影响 ,探讨了酞菁的两种环合方法 ,并对 β 烷氧酞菁的环合历程进行了初步的考察 .研究了不同取代位置和酞菁的最大吸收波长之间的关系 ,结果表明 ,α 取代烷氧取代酞菁导致λmax红移值较大 ,而相应 β位取代情况下红移值较小 ,说明给电子基团在α位对酞菁骨架的π共轭结构微扰作用比 β位大 .同时研究了溶解度及热失重与酞菁结构的关系 相似文献
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984.
Zibao Gan Yuejian Lin Lun Luo Guangmei Han Wei Liu Zhengjie Liu Chuanhao Yao Linhong Weng Lingwen Liao Jishi Chen Xu Liu Yi Luo Chengming Wang Shiqiang Wei Prof. Zhikun Wu 《Angewandte Chemie (International ed. in English)》2016,55(38):11567-11571
The structural features that render gold nanoclusters intrinsically fluorescent are currently not well understood. To address this issue, highly fluorescent gold nanoclusters have to be synthesized, and their structures must be determined. We herein report the synthesis of three fluorescent Au24(SR)20 nanoclusters (R=C2H4Ph, CH2Ph, or CH2C6H4tBu). According to UV/Vis/NIR, differential pulse voltammetry (DPV), and X‐ray absorption fine structure (XAFS) analysis, these three nanoclusters adopt similar structures that feature a bi‐tetrahedral Au8 kernel protected by four tetrameric Au4(SR)5 motifs. At least two structural features are responsible for the unusual fluorescence of the Au24(SR)20 nanoclusters: Two pairs of interlocked Au4(SR)5 staples reduce the vibration loss, and the interactions between the kernel and the thiolate motifs enhance electron transfer from the ligand to the kernel moiety through the Au?S bonds, thereby enhancing the fluorescence. This work provides some clarification of the structure–fluorescence relationship of such clusters. 相似文献
985.
Xin Shang Zhiqiang Guo Wei Gan Ru Zhou Cheng Ma Ke Hu Haihong Niu Jinzhang Xu 《Ionics》2016,22(3):435-443
For the first time, we report a one-step fabrication of an environment-friendly approach to synthesize flower-like α-Fe2O3 hierarchical nanoparticles (NPs)/reduced graphene oxide (RGO) hybrids by combining the graphene oxide (GO) with the growth of α-Fe2O3 NPs. The GO sheet which possesses the functional group, such as hydroxyl (–OH) and carbonyl groups (–OOH), can be easily incorporated with the petal of the flower-like α-Fe2O3 in ethanol and water solution through a solvothermal process, during which GO is reduced to RGO without the addition of any strong reducing agent or requiring any post-high-temperature annealing process. The as-prepared samples are loose and porous with flower-like structure, and the RGO hybrids were wrapped up uniformly on the sheet of α-Fe2O3 NPs. To demonstrate the potential applications, we have fabricated dye-sensitized solar cells (DSSCs) from the as-synthesized hierarchical flower-like α-Fe2O3/RGO and investigated it for the photoanode of DSSCs. Results show that the hierarchical α-Fe2O3/RGO solar cell exhibits improved performances in comparison with the free α-Fe2O3 NPs. The enhancement of photovoltaic properties is attributed to the unique porous nature and good conductivity which allow more efficient diffusion of I? ions and facilitate the transfer of electron in the network. 相似文献
986.
A stereospecific gas chromatography-mass spectrometry analysis method for amphetamine-type stimulants in human urine was recently developed. For maximum efficiency, liquid-liquid extraction and chiral derivatization of the analytes using (R)-(-)-alpha-methoxy-alpha-(trifluoromethyl)phenylacetyl chloride were performed simultaneously. The effects of (1) use of saturated sodium chloride in 2.0 m sodium hydroxide, (2) extraction solvent volume, (3) percentage of triethylamine, (4) derivatization reagent volume, (5) sample mixing time, (6) incubation temperature and (7) incubation time on method sensitivity and variability were assessed using a two-level, eight-run Plackett-Burman design followed by a fold-over design. The use of saturated sodium chloride solution and the derivatization reagent volume were significant factors (ANOVA, p < 0.01). The saturated sodium chloride solution decreased sensitivity whereas an increased volume of derivatization reagent increased sensitivity. Calibration curves for all analytes were linear between 5 and 500 microg/L, with correlation coefficients of >0.99. Detection limits were =2.3 microg/L and quantitation limits =7.7 microg/L. Reproducibility was good, with relative standard deviation values at <20%. Recovery exceeded 100% for most analytes. The experimental design enabled easy and rapid identification of significant factors using a minimal number of samples. This method has good potential for studies requiring rapid and sensitive stereospecific quantification of amphetamine-type stimulants. Copyright (c) 2008 John Wiley & Sons, Ltd. 相似文献
987.
Various reactions of fullerene-mixed peroxides were investigated in an effort to explore the chemistry of functional groups on the fullerene surface. Amines convert fullerene peroxides into fullerene epoxides through SN2′ type reaction. Lewis acid catalyzed hydrolysis of fullerene epoxides led to vicinal fullerendiols, which may be oxidized into fullerendiones by diacetoxyiodobenzene (DIB). Alcohols and amines react with the adjacent dione to form acetal or hemiacetal groups through different mechanisms. 相似文献
988.
The activation of C-O bonds in allylic acetates in water as a suspension medium has been accelerated by carrying out the reactions in the presence of platinum complexes associated with ligands. The platinum-catalyzed allylation of aminonaphthalenes using allylic acetates gave the corresponding N-allylic aminonaphthalenes in good yields. 相似文献
989.
Aqueous solution of anionic surfactant,sodium oleate(NaOA),was studied by means of steady-state shear rheology and dynamic oscillatory technique.The system of NaOA/Na3PO4 showed high viscosity,strong viscoelasticity and good ability of countering Ca^2+,Mg^2+.The Maxwell model and Cole-Cole plot were applied to study the dynamic viscoelasticity of wormlike micelles.The microstructures of the wormlike micelles were characterized by FF-TEM. 相似文献
990.