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171.
Kiyoshi Endo Yosiyuki Kondo 《Journal of polymer science. Part A, Polymer chemistry》2008,46(8):2858-2863
Polymerization of 2‐pentene with [ArN?C(An)C(An)·NAr)NiBr2 (Ar?2,6‐iPr2C6H3)] ( 1‐Ni) /M‐MAO catalyst was investigated. A reactivity between trans‐2‐pentene and cis‐2‐pentene on the polymerization was quite different, and trans‐2‐pentene polymerized with 1‐Ni /M‐MAO catalyst to give a high molecular weight polymer. On the other hand, the polymerization of cis‐2‐butene with 1‐Ni /M‐MAO catalyst did not give any polymeric products. In the polymerization of mixture of trans‐ and cis‐2‐pentene with 1‐Ni /M‐MAO catalyst, the Mn of the polymer increased with an increase of the polymer yields. However, the relationship between polymer yield and the Mn of the polymer did not give a strict straight line, and the Mw/Mn also increased with increasing polymer yield. This suggests that side reactions were induced during the polymerization. The structures of the polymer obtained from the polymerization of 2‐ pentene with 1‐Ni /M‐MAO catalyst consists of ? CH2? CH2? CH(CH2CH3)? , ? CH2? CH2? CH2? CH(CH3)? , ? CH2? CH(CH2CH2CH3)? , and methylene sequence ? (CH2)n? (n ≥ 5) units, which is related to the chain walking mechanism. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2858–2863, 2008 相似文献
172.
通过水热法合成了[N i(C5H4NCOO)2.(H2O)4]晶体。对其进行了元素分析、红外光谱以及热重分析,并通过单晶X-射线衍射确定了其晶体结构。该晶体属于三斜晶系,空间群为P1,晶胞参数为a=0.62878(7)nm,b=0.69008(8)nm,c=0.92440(10)nm,α=96.500(10),°β=105.130(10)°,γ=113.320(10)°。通过UV-VIS-NIR反射光谱研究了其光学性质,表明其在近红外区有强吸收,而在可见区域基本为透明,对太阳辐射的吸光系数(ε)为0.014μm-1。 相似文献
173.
Some binary and ternary complexes of Ni(II) with arylideneanthranilic acids and Lewis bases have been prepared and characterized by elemental analyses, IR spectra and X-ray powder diffraction. On the basis of the IR spectra it was found that the Schiff bases used act as monobasic bidentate ligands except for the ortho-hydroxy derivative which acts as a dibasic tridentate ligand. From X-ray analysis it is concluded that the binary Ni(II) chelates are isostructural, and the ternary Ni(II) complexes are also isostructural. 相似文献
174.
In this study, molecular dynamics (MD) was used to simulate the rapid solidification process of Ni47Co53 and Ni48Co52 alloys at a cooling rate of 1012 K/s. The effects of HCP on the formation of twin boundaries and dislocations in two Ni–Co alloys are studied. It is found that the difference of HCP clusters is the main effect that producing discrepancies on microstructure of two alloys. The number of HCP clusters accounted for 9.23% in Ni47Co53 alloy. They are regularly arranged to form the number of single-layer twin boundaries, and each twin boundary ends in a dislocation. The FCC and HCP structures coexist in the same atomic layers, which is easy to create dislocations. The relatively standard FCC crystal and only 0.32% HCP clusters are formed in Ni48Co52 alloy at 300 K. That small amount of HCP clusters are dispersed on the surface, and cause the formation of dislocation in the border with FCC clusters. 相似文献
175.
Molecular dynamics simulations of dopant effectson lattice trapping of cracks in Ni matrix 下载免费PDF全文
Shulan Liu 《中国物理 B》2021,30(11):116107-116107
Molecular dynamic analysis was performed on pure and doped (by Re, Ru, Co or W) Ni at 300 K using the embedded-atom-method (EAM) potentials to understand the crack formation of the doped Ni matrix in the (010)[001] orientation. When Ni was doped with Re, Ru, and W, the matrix demonstrated increased lattice trapping limits and, as a result, improved the mechanical properties. Consequently, this prevented the bond breakage at the crack tips and promoted crack healing. The average atomic and surface energy values increased when Re, Ru, and W were added. Analysis of these energy increase helped us to understand the influence these elements had on the lattice trapping limits. The fracture strength of the Ni matrix at 300 K increased because of the formation of the stronger Ni-Re, Ni-Ru, and Ni-W bonds. At the same time, doping the Ni matrix with Co did not demonstrate any strengthening effects because of the formation of Co-Ni bonds, which are weaker than the Ni-Ni bonds. Out of all dopants tested in this work, Ni doping with W showed the best results. 相似文献
176.
Takashi Tsuno Yu Sugiyama Henri Brunner Michael Bodensteiner Kosei Lee 《Journal of Coordination Chemistry》2017,70(20):3459-3470
Treatment of NiCl2 with the tripod ligand (LMent,SC)-1H led to (LMent,SC)-[Cp(PNMent)NiCl] in which the potentially tridentate ligand coordinated to the metal center in a bidentate way via the cyclopentadienyl system and the phosphorus atom. In the presence of NH4PF6 [(LMent,SC)-[Cp(PNMent)NiCl] readily underwent Cl/PPh3 exchange to give (LMent,SC)-[Cp(PNMent)NiPPh3]PF6. Reaction of (LMent,SC)-[Cp(PNMent)NiCl] with 0.5 eq. of dppe afforded [{(LMent,SC)-[Cp(PNMent)Ni]}2dppe](PF6)2. (LMent,SC)-[Cp(PNMent)NiPPh3]PF6 and [{(LMent,SC)-[Cp(PNMent)Ni]}2dppe](PF6)2 were characterized by NMR and MS spectroscopy, and also by single crystal X-ray diffraction. The cyclopentadienyl ligand of (LMent,SC)-[Cp(PNMent)NiPPh3]PF6 shows a distortion intermediate between the ene-allyl and diene types, while the two cyclopentadienyl ligands of [{(LMent,SC)-[Cp(PNMent)Ni]}2dppe](PF6)2 have intermediate and diene distortions, respectively. According to the temperature dependent NMR spectra of (LMent,SC)-[Cp(PNMent)NiPPh3]PF6 and [{(LMent,SC)-[Cp(PNMent)Ni]}2dppe](PF6)2 two different conformations of the tether in the Cp(PNMent)Ni system could be frozen out at low temperatures. 相似文献
177.
Jamshid Rakhtshah Mohammad Ali Zolfigol Saeed Baghery 《Journal of Coordination Chemistry》2017,70(2):340-360
A nickel(II) Schiff base complex immobilized on multi-wall carbon nanotubes (MWCNTs) surface as a highly efficient heterogeneous catalyst was synthesized and characterized by IR, X-ray diffraction patterns, scanning electron microscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma, elemental analysis, and thermal gravimetric analysis. Then a facile and environmentally benign procedure was developed for synthesis of polyhydroquinoline derivatives via Hantzsch one-pot condensation reaction of aromatic aldehydes, 1,3-diones, ethyl acetoacetate, and ammonium acetate in the presence of above synthesized catalyst under solvent-free conditions. This protocol has the advantages of stability, easy availability, recyclability and eco-friendly nature of catalyst, simple experimental and work-up procedure, and also high to excellent yields. Considering the solvent-free condition and also temperature, time, and yield of the model reaction, the nanocatalyst reported here is among the best catalysts reported so far for synthesis of polyhydroquinolines. 相似文献
178.
《中国化学会会志》2017,64(9):1104-1110
A new unsymmetrical tridentate NNS Schiff base ligand, 2‐(2‐nitrophenylthio)‐N‐((pyridine‐2‐yl)methylene)benzenamine (L), and its Mn(II ), Ni(II ), Cu(II ), and Zn(II ) complexes were synthesized. These compounds were characterized by different physicochemical and spectroscopic techniques. The molecular structure of [NiL2 ](ClO4 )2 was determined by single‐crystal X‐ray diffraction. In this complex, two ligands coordinate through azomethine‐N, pyridine‐N, and thioether‐S, forming a mononuclear 6‐coordinate distorted octahedral geometry about a nickel. 相似文献
179.
Platinum–nickel nanoparticles were synthesized by a reduction procedure. The Pt–Ni/C composite was characterized by X-ray diffraction, infrared spectroscopy, transmission electron microscopy, and electrochemical analysis. The measurements show that the Pt–Ni/multiwalled carbon nanotubes provided higher electrocatalytic activity for the oxidation of uric acid than Pt–Ni/carbon black. The sensor prepared from the characterized material provided a long linear dynamic range from 0.1 to 240.4?µM with a detection limit of 0.03?µM and a sensitivity of 41.21?µA?mM?1?cm?2. The reported modified electrode also provided excellent selectivity, good stability, and satisfactory reproducibility for the determination of uric acid. 相似文献
180.
Microstructure of nickel nanoparticles embedded in carbon films: case study on annealing effect by micromorphology analysis 下载免费PDF全文
Ştefan Ţălu Miroslaw Bramowicz Slawomir Kulesza Azizollah Shafiekhani Maryam Rahmati Atefeh Ghaderi Mohammad Ahmadirad Shahram Solaymani 《Surface and interface analysis : SIA》2017,49(3):153-160
The presented study is aimed at analyzing the surface texture of amorphous hydrogenated carbon layers containing nickel nanoparticles (Ni‐NPs@a‐C:H) within their structure, which were deposited by Radio Frequency (RF) sputtering and RF‐Plasma Enhanced Chemical Vapor Deposition (RF‐PECVD) methods on glass substrates. Prepared films were then used as research material following their annealing at two different temperatures of 250 °C and 350 °C in an inert argon atmosphere. Series of height samples were taken with the help of atomic force microscopy (AFM) operating in a non‐contact mode and examined in order to determine their fractal characteristics. Raw AFM data were first plane‐fitted to remove the surface bow exhibiting the so‐called residual surface, and then numerically processed to calculate the Areal Autocorrelation Function (AACF), which was later used to compute the Structure Function (SF). The log–log plots of the latter served for calculation of fractal properties of surfaces under investigation, including fractal dimension D, and pseudo‐topothesy K. The analysis of 3‐D surface texture helps to understand their essential characteristics and their implications as well as graphical models and their implementation in computer simulation. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献