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991.
992.
993.
Controlling the BET Surface Area of Porous Carbon by Using the Cd/C Ratio of a Cd–MOF Precursor and Enhancing the Capacitance by Activation with KOH 下载免费PDF全文
Dr. Zuo‐Xi Li Xue Zhang Yi‐Chen Liu Kang‐Yu Zou Man‐Li Yue 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17734-17747
Herein, four new cadmium metal–organic frameworks (Cd–MOFs), [Cd(bib)(bdc)]∞ ( 1 ), [Cd(bbib)(bdc)(H2O)]∞ ( 2 ), [Cd(bibp)(bdc)]∞ ( 3 ), and [Cd2(bbibp)2(bdc)2(H2O)]∞ ( 4 ), have been constructed from the reaction of Cd(NO3)2 ? 4 H2O with 1,4‐benzenedicarboxylate (H2bdc) and structure‐related bis(imidazole) ligands (1,4‐bis(imidazol‐1‐yl)benzene (bib), 1,4‐bis(benzoimidazol‐1‐yl)benzene (bbib), 4,4′‐bis(imidazol‐1‐yl)biphenyl (bibp), and 4,4′‐bis(benzoimidazol‐1‐yl)biphenyl (bbibp)) under solvothermal conditions. Cd–MOF 1 shows a 2D (4,4) lattice with parallel interpenetration, whereas 2 displays an interesting 3D interpenetrating dia network, 3 exhibits an unusual 3D interpenetrating dmp network, and 4 presents a 3D self‐catenated pillar‐layered framework with a Schäfli symbol of [43 ? 63]2 ? [46 ? 616 ? 86]. The structural diversity indicates that the backbone of the bis(imidazole) ligand (including the terminal group and spacer) plays a crucial role in the assembly of mixed‐ligand frameworks. By using the pore‐forming effect of cadmium vapor, for the first time we have utilized these Cd–MOFs as precursors to further prepare porous carbon materials (PCs) in a calcination–thermolysis procedure. These PCs show different porous features that correspond to the topological structures of Cd–MOFs. Significantly, it was found that the specific surface area and capacitance of PCs are tuned by the Cd/C ratio of the MOF. Furthermore, the as‐synthesized PCs were processed with KOH to obtain activated porous carbon materials (APCs) with higher specific surface area and porosity, which greatly promoted the energy‐storage capacity. After full characterization, we found that APC‐bib displays the largest specific surface area (1290 m2 g?1) and total pore volume (1.37 cm3 g?1) of this series of carbon materials. Consequently, APC‐bib demonstrates the highest specific capacitance of 164 F g?1 at a current density of 0.5 A g?1, and also excellent retention of capacitance (≈89.4 % after 5000 cycles at 1 A g?1). Therefore, APC‐bib has great potential as the electrode material in a supercapacitor. 相似文献
994.
Controlled metal‐free polymerization toward well‐defined thermoresponsive polypeptides by polymerization at low temperature 下载免费PDF全文
Yuanzhang Jiang Shixue Wang Xiaojie Zhang Youhua Tao Xianhong Wang 《Journal of polymer science. Part A, Polymer chemistry》2016,54(16):2618-2624
A controlled metal‐free synthetic methodology toward well‐defined thermoresponsive polypeptides by decreasing the reaction temperature to 0 °C has been developed. Good control over the molecular weight in the polymerization of a trithiocarbonate‐functionalized N‐carboxyanhydride (MES‐l ‐Glu‐NCA) monomer was obtained using n‐hexylamine as the initiator at 0 °C. It yielded homopolypeptide macro‐transfer agent (PMESLG) with narrow molecular weight distribution (PDI < 1.3) and controllable chain length. Detailed 1H NMR and MALDI‐TOF‐MS analysis clearly confirmed that frequently occurring side‐reactions was absent at 0 °C, and the polymerization was controlled. The resultant PMESLG was applied to mediate the reversible addition‐fragmentation chain transfer (RAFT) polymerization of oligo‐ethylene‐glycol acrylate (OEGA) for the metal‐free synthesis of thermoresponsive polypeptides. These thermoresponsive polypeptides have well‐controlled molecular weight, adopted regular α‐helical conformation, and exhibited a lower critical solution temperature between 23 °C and 55 °C. To the best of our knowledge, there are very few reports about the synthesis of well‐defined thermoresponsive graft polypeptides via NCA polymerization and RAFT. Consequently, this provides a new strategy for the synthesis of promising intelligent material for future biomedical applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2618–2624 相似文献
995.
Zuo Rui Wang Lina Shi Rongtao Yang Jie Wang Jinsheng Teng Yanguo 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(2):887-896
Journal of Radioanalytical and Nuclear Chemistry - The sorption of U(VI) on shale has been experimentally investigated as a function of pH, initial uranium concentration, rock particle size and... 相似文献
996.
997.
Rui Zuo Xiaoping Liang Zhifeng Liu Jian Liu Dajun Luo Dongmei Li Kai Liu Xinyu Mao 《Journal of Sol-Gel Science and Technology》2014,69(2):303-310
Nanocrystalline LiNi1/3Co1/3Mn1/3O2 cathode materials are synthesized by sol–gel method using polyacrylic acid as a chelating agent. The effects of the calcination temperature and calcination time on the structure, morphology, and electrochemical performances of the LiNi1/3Co1/3Mn1/3O2 electrode materials are investigated by X-ray diffraction, scanning electron microscopy and charge–discharge cycling test, respectively. All experiments show that the microscopic structural features and the morphology properties are deeply related with the electrochemical performance. The results show that the nanocrystalline LiNi1/3Co1/3Mn1/3O2 with a particle size of 80 nm sintered at 700 °C for 2 h presents good α-NaFeO2 layer structure and the best electrochemical performance. When it is discharged between 4.4 and 2.8 V at 20 mAg?1, the initial specific capacity of the LiNi1/3Co1/3Mn1/3O2 obtained at 700 °C for 2 h is 169.2 mAhg?1. The investigated electrode materials retain 151 mAhg?1 after 30 cycles when cycled at 20 mAg?1. 相似文献
998.
An efficient and environmentally benign synthesis of 3-substituted or 3,4-disubstituted coumarins was accomplished via iron(III) chloride–catalyzed cascade reactions of salicylaldehydes and activated methylene compounds. The reaction preceded cleanly under mild reaction conditions to provide the desired coumarin derivatives in good to excellent yields. 相似文献
999.
1000.
Trace quantification of 1‐triacontanol in beagle plasma by GC‐MS/MS and its application to a pharmacokinetic study 下载免费PDF全文
Chunfeng Wang Ali Fan Xiaojie Zhu Yang Lu Shuhua Deng Wenchao Gao Wei Zhang Qi Liu Xijing Chen 《Biomedical chromatography : BMC》2015,29(5):749-755
1‐Triacontanol (TA), a member of long chain fatty alcohol, has recently been received great attention owing to its antitumor activity. In this study, an accurate, sensitive and selective gas chromatography–tandem mass spectrometry method was developed and validated for the quantification of TA in beagle plasma using 1‐octacosanal as the internal standard (IS) for the first time. With temperature programming, chromatographic separation was carried out on an HP‐5MS column, using helium as carrier gas and argon as collision gas, both at a flow rate of 1 mL/min. TA was analyzed using positive ion electrospray ionization in multiple‐reaction monitoring mode, with the precursor to product ion transitions of m/z 495.6 → 97.0 and m/z 467.5 → 97.0 for TA and the IS, respectively. The lower limit of quantitation, linearity, intra‐ and interday precision, accuracy, stability, extraction recovery and matrix effect of TA were within the acceptable limits. The validated method was successfully applied to a pharmacokinetic study of TA in beagles. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献