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951.
952.
953.
Abstract
Three copper(II), one zinc(II), and one ferrous(II) complexes having 3-bromo or 3,8-dibromo-1,10-phenanthroline ligand with different metal/ligand molar ratios, formulated as [Cu(3-bromo-phen)(ClO4)(C3H7NO)2(H2O)](ClO4) (1), [Cu(3,8-dibromo-phen)(ClO4)(C3H7NO)2(H2O)](ClO4) (2), [Cu(3,8-dibromo-phen)(ClO4)(H2O)3](ClO4)(H2O)3 (3), [Zn(3,8-dibromo-phen)2(H2O)2](ClO4)2(H2O)2 (4), and [Fe(3,8-dibromo-phen)3](ClO4)2(H2O)(CH4O)(C3H6O)2 (5) (phen = 1,10-phenanthroline), have been synthesized and characterized in this paper. X-ray single-crystal diffraction studies reveal the different crystallographic symmetry and packing fashions between neighboring phen rings in 1:1 Cu(II) complexes 1–3 due to the alteration of bromo substituent 1,10-phenanthroline ligands and coordinated or free solvent molecules. Additionally, in 1:2 Zn(II) and 1:3 Fe(II) complexes 4 and 5, continuous π–π stacking and alternating π–π and dimeric p–π stacking are found. 相似文献954.
Qingyong Meng Hai-Bo Chang Ming-Bao Huang Hua Dong 《Theoretical chemistry accounts》2011,128(3):359-365
The N-loss predissociation mechanisms of the A 2Σ+ (2 2
A′) state of N2O+ to the first and second dissociation limits were studied in the C
s symmetry. The potential energy curves (PECs) and minimum energy crossing points (MECPs) for the C
s states of N2O+ were calculated at the CAS levels. On the basis of our CAS calculation results (CASPT2 energetic results and CASSCF spin
orbit couplings), we suggest two processes for N-loss predissociation mechanisms of A 2Σ+ (2 2
A′) to the first and second limits. The first two steps in the two processes are the same: A 2Σ+ passes through the 2 2
A′/1 4
A″ MECP and then reaches the 1 4
A″ (1 4Σ−) PEC. The 2 2
A′/1 4
A″ MECP has a bent geometry and is slightly higher in energy than the transition state along the 1 4
A″ PEC. Our mechanisms are different from the previously suggested mechanisms (via 1 4Π). 相似文献
955.
956.
运用TPO,XRD,BET,O2-TPD,H2-TPR,XPS等技术,研究了在CeO2中引入不同Mn含量对催化剂表面氧性质的影响,并重点探讨了吸附于氧空位上的原子吸附氧O-与催化碳烟燃烧活性的关联。结果表明:将Mn中引入CeO2后,MnOx-CeO2晶格中可形成较CeO2更多的氧空位,并有利于氧的活化和迁移,生成了较多原子吸附氧O-;MnOx(0.4)-CeO2在碳烟起燃温度区间有最多的原子吸附氧O-,其碳烟起燃活性最高,对应的起燃温度是346℃,比无催化剂时降低了111℃,比CeO2降低了35℃。 相似文献
957.
Yuying Huang Fengqiang Sun Tianxing Wu Zhong Huang Zihe Zhang 《Journal of solid state chemistry》2011,184(3):644-58
CdS hollow microspheres have been successfully prepared by a photochemical preparation technology at room temperature, using polystyrene latex particles as templates, CdSO4 as cadmium source and Na2S2O3 as both sulphur source and photo-initiator. The process involved the deposition of CdS nanoparticles on the surface of polystyrene latex particles under the irradiation of an 8 W UV lamp and the subsequent removal of the latex particles by dispersing in dichloromethane. Photochemical reactions at the sphere/solution interface should be responsible for the formation of hollow spheres. The as-prepared products were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Such hollow spheres could be used in photocatalysis and showed high photocatalytic activities in photodegradation of methyl blue (MB) in the presence of H2O2. The method is green, simple, universal and can be extended to prepare other sulphide and oxide hollow spheres. 相似文献
958.
Three novel conjugated polymers bearing 3,4-bis(4-hexylthiophen-2-yl)-3-cyclobutene-1,2-dione unit in their main chain have been synthesized successfully in good yields through Suzuki or Stille coupling reaction.Their molecular structures have been confirmed by FT-IR,1H NMR and 13C NMR.All these copolymers exhibit broad and strong absorption bands in UV-vis region,and their optical band gaps are calculated to be 1.6-2.0 eV.suggesting that they have good coverage with the solar spectrum.These polymers have good thermostability and solubility in common organic solvents.Moreover,all these objective macromolecules possess high electron affinity of~3.8 eV determined from cyclic voltammetry measurement,implying that they are potential n-type polymeric photovoltaic materials. 相似文献
959.
Yanming Wang Meng Li Jianhua Rong Guangting Nie Jing Qiao Haiyan Wang Dayong Wu Zhaohui Su Zhongwei Niu Yong Huang 《Colloid and polymer science》2013,291(6):1541-1546
Polymer fibers composed of poly(ethylene oxide) (PEO) and nanoclay were fabricated by electrospinning. The morphology of the composite nanofibers was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), which showed aligned nanoclays in the fibers. Polarized Fourier transform infrared (FT-IR) spectroscopy revealed that the PEO chains in the composite fibers exhibit a higher degree of orientation than that in PEO nanofibers containing no nanoclay. It is believed that spatial confinement is present in the electrospun nanofibers, which results in the enforcement of the mutual restriction. The anisotropic hierarchical nanostructure may have potential applications in optics, mechanical materials, and biomedical materials for cell culture. 相似文献
960.
A novel simple but effective initiating system of H2O/AlCl3 /veratrole (VE) has been developed to synthesize high molecular weight polyisobutylene (PIB) at elevated temperatures via cationic polymerization of isobutylene (IB) in solvent mixture of hexane/methylene dichloride (n-Hex/CH2Cl2 = 2/1, V/V). VE played very important roles in decreasing cationicity of the growing chain ends, suppressing side reactions of chain transfer and termination during polymerization, leading to production of high molecular weight PIBs. PIBs with high yields, having very high weight-average molecular weight (Mw ) of 1117000 and 370000 g/mol could be synthesized with H2O/AlCl3 /VE initiating system at VE concentration of 5.4 mmol/L at 80 and 60℃ respectively. Molecular weight of PIB increased remarkably with increasing VE concentration. The reaction order with respect to VE concentration was determined to be 3.52 via FTIR spectroscopy in combination with a diamond tipped attenuated total reflectance (ATR) immersion probe. The negative reaction order of VE was consistent with its retarding effect on IB polymerization by interacting with the propagating species. Molecular weight of PIB decreased with increasing polymerization temperature. The activation energy for polymerization degree (EDP ) could be determined to be around 23 kJ/mol when VE concentration was 5.4 mmol/L or 6.4 mmol/L. 相似文献