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81.
8-羟基喹啉衍生物及其金属配合物的合成与光致发光特性 总被引:6,自引:0,他引:6
设计合成了三种新型的8-羟基喹啉衍生物配体: 5-[(4-E-苯乙烯基)-苯甲亚胺基]-8-羟基喹啉(1), 5-[(4-溴-2-氟)-苯甲亚胺基]-8-羟基喹啉(2)和N-乙基-3-[2-(8-羟基喹啉基)-乙烯基]咔唑(3), 以及它们相应的金属配合物, 产物经质谱(MS)、元素分析(EA)、红外光谱(IR)、紫外光谱(UV)、核磁共振氢谱(1H NMR)进行表征, 并测定了它们的荧光性质. 结果与8-羟基喹啉比较表明, 5位和2位取代8-羟基喹啉衍生物的荧光发生了明显的红移. 同时测定了配合物(3)2Zn的荧光寿命, 结果表明, N-乙基-3-[2-(8-羟基喹啉基)-乙烯基]咔唑锌配合物表现出较长的荧光寿命. 相似文献
82.
Chen P Nie S Mi W Wang XC Liang SP 《Rapid communications in mass spectrometry : RCM》2004,18(2):191-198
A simple method of solid-phase derivatization and sequencing of tryptic peptides has been developed for rapid and unambiguous identification of spots on two-dimensional gels using post-source decay (PSD) matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The proteolytic digests of proteins are chemically modified by 4-sulfophenyl isothiocyanate. The derivatization reaction introduces a negative sulfonic acid group at the N-terminus of a peptide, which can increase the efficiency of PSD fragmentation and enable the selective detection of only a single series of fragment ions (y-ions). This chemically assisted method avoids the limitation of high background normally observed in MALDI-PSD spectra, and makes the spectra easier to interpret and facilitates de novo sequencing of internal fragment. The modification reaction is conducted in C(18) microZipTips to decrease the background and to enhance the signal/noise. Derivatization procedures were optimized for MALDI-PSD to increase the structural information and to obtain a complete peptide sequence even in critical cases. The MALDI-PSD mass spectra of two model peptides and their sulfonated derivatives are compared. For some proteins unambiguous identification could be achieved by MALDI-PSD sequencing of derivatized peptides obtained from in-gel digests of phosphorylase B and proteins of hepatic satellite cells (HSC). 相似文献
83.
Effects of organic solvents on the structure stability of TS-1 for the ammoximation of cyclohexanone 总被引:6,自引:0,他引:6
Chengtian Wu Yaquan Wang Zhentao Mi Li Xue Wei Wu Enze Min Sen Han Fei He Songbao Fu 《Reaction Kinetics and Catalysis Letters》2002,77(1):73-81
The effects of organic solvents on the ammoximation of cyclohexanone to cyclohexanone oxime with H2O2and NH3 over TS-1 were studied. To investigate the effects of ammonia and organic solvents on the structure stability of the catalyst, TS-1 samples were pretreated under severe conditions in ammonia solution or ammonia solution plus methanol, toluene or t-butanol, respectively, and then characterized bySEM, XRD, FTIR, etc. The results revealed that t-butanol is the best solvent for the ammoximation reaction; ammonia tends to destroy the active sites, -Ti-O-Si- structure in TS-1, but the presence of organic solvents remarkably limits this damaging effect of ammonia. 相似文献
84.
Hu Chuanjiang Duan Chunying Meng Qingjin Liu Yongjiang Lu Changsheng Reng Xiaoming Chen Yijun Cao Mi 《Transition Metal Chemistry》2000,25(2):141-144
The mixed-valence molybdovanadate compound Na2(NH4)4[VIVVV
8Mo)O28] · 10H2O [Vanadata(6-)tetradeca--oxotetra-3-oxodi-6-oxoheptaoxo(oxomolybdate) nonatetrammonium disodium, decahydrate] has been synthesized from sodium molybdate(VI) dihydrate and sodium metavanadate dihydrate in aqueous solution by adding NH2OH · HCl. The molecular structure has been determined by X-ray diffraction and is based on the isopolydecavanadate structure. The molybdate atom is crystallographically disordered over 6MO6 octahedral sites. The e.s.r. spectrum clearly indicates that one vanadium atom has the oxidation number +4. 相似文献
85.
In this work, an integral equation approach to investigate the atactic polystyrene (aPS) melt based on polymer reference interaction site model (PRISM) theory is proposed. The intramolecular structure factors, required as input to PRISM theory, are obtained from the semiflexible chain model. With a novel coarse-graining procedure and the explicit-atom molecular-dynamics (MD) simulations for aPS, the parameters needed for the coarse-grained model are obtained by using an automatic simplex optimization. These parameters can be used to describe the structure and thermodynamic properties of the complex aPS melt and good agreement is obtained between the theory and MD simulations. The proposed integral equation approach provides a basis for describing the structure and properties of PS nanocomposites where the application of molecular simulation is difficult. 相似文献
86.
87.
Jang‐Hee Yoon G. Muthuraman JeeEun Yang Yoon‐Bo Shim Mi‐Sook Won 《Electroanalysis》2007,19(11):1160-1166
Pt‐nanoparticles were synthesized and introduced into a carbon paste electrode (CPE), and the resulting modified electrode was applied to the anodic stripping voltammetry of copper(II) ions. The synthesized Pt‐nanoparticles were characterized by cyclic voltammetry, scanning electron microscopy and X‐ray photoelectron spectroscopy techniques to confirm the purity and the size of the prepared Pt‐nanoparticles (ca. 20 nm). This incorporated material seems to act as catalysts with preconcentration sites for copper(II) species that enhances the sensitivity of Cu(II) ions to Cu(I) species at a deposition potential of ?0.6 V in an aqueous solution. The experimental conditions, such as, the electrode composition, pH of the solution, pre‐concentration time, were optimized for the determination of Cu(II) ion using as‐prepared electrode. The sensitivity changes on the different binder materials and the presence of surfactants in the test solution. The interference effect of the coexisted metals were also investigated. In the presence of surfactants, especially TritonX‐100, the Cu(II) detection limit was lowered to 3.9×10?9 M. However, the Pt‐nanoparticle modified CPE begins to degrade when the period of deposition exceeds to 10 min. Linear response for copper(II) was found in the concentration range between 3.9×10?8 M and 1.6×10?6 M, with an estimated detection limit of 1.6×10?8 M (1.0 ppb) and relative standard deviation was 4.2% (n=5). 相似文献
88.
89.
The indications of a Clark-type electrochemical sensor with a polyethylene foil used as a membrane are noticeably changed if vapours of chlorine derivatives of methane (CCl4, CHCl3, CH2Cl2) are present in the atmosphere examined and the sensor has been calibrated in an atmosphere from which those vapours were absent. The sensitivity of the sensor increases and tends to deviate from linearity. The increase is more profound, when the number of chlorine atoms within a molecule of the vapour increases, the partial pressure of the vapour increases and the temperature of the atmosphere examined decreases. If the vapours affect the membrane for a long time, the response time decreases. If the membrane is freshly subjected to the influence of the vapours, a longer period of time is needed to reach a stable indication corresponding to the partial pressure of oxygen actually observed. 相似文献
90.