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971.
Synthesis, spectroscopic and electrochemical property of an unsymmetrical porphyrin and its Zn compound 总被引:1,自引:0,他引:1
Chang Fu Zhuang Yu Jing Zhang Ai Qing Xia Wen Hui Lian Yun Fang Wang Ping Zhang Tong Shun Shi 《中国化学快报》2010,21(7):769-773
<正>In this article,a new 5-(p-maleicaminophenyl)-10,15,20-triphenylporphyrin(H_2P) and relative zinc compound(ZnP) were synthesized and characterized by means of elemental analyses,UV-vis,IR,MS and ~1H NMR spectroscopies.Furthermore,we have investigated the fluorescence spectroscopy of these compounds.The oxidation and reduction properties of the compounds were studied by the cyclic voltarnmetry,the oxidation-reduction potentials were obtained. 相似文献
972.
Martin M.F.Choi 《中国化学快报》2010,21(3):346-348
<正>The determination method of catechol by fluorescence quenching was developed.The assay was based on the combination of the unique property of gold nanoparticles with tyrosinase enzymatic reaction.In the presence of tyrosinase,the fluorescence of gold nanoparticles was quenched by catechol which can be employed to detect catechol.Under the optimal conditions,a linear range 5.0×10~(-7)-1.0×10~(-3) mol L~(-1) and a detection limit 1.0×10~(-7) mol L~(-1) of catechol were obtained.o-Quinone intermediate produced from the enzymatic catalyzed oxidation of catechol was considered to play the main role in the fluorescence quenching. 相似文献
973.
<正>Gibberellin A4 is effectively separated from mixture of gibberellin A4 and its analogue gibberellin A7,in the form of its crystalline complex with N,N,N',N'-tetramethylethylenediamine.After removing the tetramethylethylenediamine from the crystal by dilute HCl,gibberellin A4 is obtained a purity of 98.1%and a yield of 72.7%. 相似文献
974.
Nan Hu Wen‐Xi Ji Yin‐Yin Tong Zi‐Chen Li Er‐Qiang Chen 《Journal of polymer science. Part A, Polymer chemistry》2010,48(20):4621-4626
The reversible addition‐fragmentation chain transfer (RAFT) polymerization of N‐vinylcarbazole (NVK) mediated by macromolecular xanthates was used to prepare three types of block copolymers containing poly(N‐vinylcarbazole) (PVK). Using a poly(ethylene glycol) monomethyl ether based xanthate ( PEG‐X ), the RAFT polymerization of NVK proceeded in a controlled way to afford a series of PEG‐b‐PVK with different PVK chain lengths. Successive RAFT polymerization of NVK and vinyl acetate (VAc) with a small molecule xanthate ( X1 ) as the chain transfer agent was tested to prepare PVK‐b‐PVAc. Though both monomers can be homopolymerized in a controlled manner with this xanthate, only by polymerizing NVK first could give well‐defined block copolymers. The xanthate groups in the end of PVK could be removed by radical‐induced reduction using tributylstannane, and PVK‐b‐PVA was obtained by further hydrolysis of PVK‐b‐PVAc under basic conditions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
975.
Wen Wang Jian-Cun Rao Hua Ke Ming Feng Rui-Lin Xia Qing-Chang Meng De-Chang Jia Yu Zhou 《Journal of Sol-Gel Science and Technology》2010,56(1):87-92
We report the independent invention of perovskite ferroelectric nanowires strontium bismuth tantalate (SrBi2Ta2O9, SBT). Electrophoretic sol–gel techniques have been used successfully. The morphology and structures are analyzed via SEM,
TEM and XRD. SBT nanowires and nanoparticles filled template revealed 30 and 40 μm long, respectively. SBT are proved to be
a single phase of orthorhombic perovskite structure. As it indicated, SBT nanowires has been crystallized at 700 °C. To minimize
surface polarity, SBT nanowires oriented preferentially along the growing axis (c axis) by translation and rotation of atomic clusters of SBT. 相似文献
976.
TiO2/organically modified silane organic–inorganic hybrid films doped with different disperse red 1 contents are prepared by combining
a low-temperature sol–gel method and a spin-coating process. Effects of the disperse red 1 content on the third-order nonlinear
and the planar waveguide properties of the hybrid films are also studied by a z-scan technique and a prism coupling technique.
Results indicate that the nonlinear refractive index of the hybrid films is negative, whose magnitude is of the order of 10−8 esu for the measured samples. It is suggested that both the thermal effect and the photoisomerization process contribute
to the third-order nonlinear optical properties of the hybrid films jointly. It is also found that the refractive index and
the thickness of the hybrid films decrease with an increase of the temperature as the independent variable. In addition to,
optical absorption properties of the hybrid films are characterized by UV–Visible spectroscopy. These results indicate that
the as-prepared hybrid films are promising candidates for photonic applications. 相似文献
977.
Xiao‐Dong Wen Dr. Thomas J. Cahill Roald Hoffmann Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(22):6555-6566
Various one‐, two‐ and three‐dimensional Group 14 (C, Si, Ge, Sn, and Pb) element structures at P=1 atm are studied in this work. As expected, coordination number (CN)—not an unambiguous concept for extended structures—plays an important part in the stability of structures. Carbon not only favors four‐coordination, but also is quite happy with π‐bonding, allowing three‐ and even two‐coordination to compete. Highly coordinated (CN>4) discrete carbon molecules are rare; that “saturation of valence” is reflected in the instability of C extended structures with CN>4. Si and Ge are quite similar to each other in their preferences. They are less biased in their coordination than C, allowing (as their molecular structures do) CN=5 and 6, but tending towards four‐coordination. Sn and Pb 3D structures are very flexible in their bonding, so that in these elements four‐ to twelve‐coordinate structures are close in energy. This lack of discrimination among ordered structures also points to an approach to the liquid state, consistent with the low melting point of Sn and Pb. The Group 14 liquid structures we simulate in molecular dynamics calculations show the expected, effective, first coordination number increase from 5.1 for Si to 10.4 for Pb. A special point of interest emerging from our study is the instability of potential multilayer graphene structures down Group 14. Only for C will these be stable; for all the other Group 14 elements pristine, unprotected, bi‐ and multilayer graphenes should collapse, forming “vertical” bonds as short as the in‐plane ones. 相似文献
978.
Hui Ming Ge Dr. Wen Hao Yang Yan Shen Dr. Nan Jiang Dr. Zhi Kai Guo Qiong Luo Qiang Xu Prof. Jing Ma Prof. Ren Xiang Tan Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(21):6338-6345
Two novel resveratrol aneuploids, hopeachinols A ( 1 ) and B ( 2 ), as well as a potent immunosuppressive polyphenol diptoindonesin G ( 3 ) were characterized from the ethanol extract of Hopea chinensis stem barks. The structure of the polyphenols was accommodated by comprehensive spectroscopic analysis with the absolute stereochemistry determined by the CD approach coupled with theoretical ECD spectra computer‐generated through the Gaussian 03 program. The distinct structure and biological profile of 3 recommended it as a starting molecule for the relevant drug discovery. 相似文献
979.
Elisa Barea Dr. Giulia Tagliabue Wen‐Guo Wang Dr. Manuel Pérez‐Mendoza Dr. Laura Mendez‐Liñan Francisco J. López‐Garzon Prof. Simona Galli Dr. Norberto Masciocchi Prof. Jorge A. R. Navarro Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(3):931-937
The novel coordination polymers [Cu(Hoxonic)(H2O)]n ( 1 ) and [Cu(Hoxonic)(bpy)0.5]n ? 1.5 n H2O ( 2?H2O ) (H3oxonic: 4,6‐dihydroxy‐1,3,5‐triazine‐2‐carboxylic acid; bpy: 4,4′‐bipyridine) have been isolated and structurally characterised by ab initio X‐ray powder diffraction. The dense phase 1 contains 1D zig‐zag chains in which Hoxonic dianions bridge square‐pyramidal copper(II) ions, apically coordinated by water molecules. On the contrary, 2?H2O , prepared by solution and solventless methods, is based on 2D layers of octahedral copper(II) ions bridged by Hoxonic ligands, further pillared by bpy spacers. The resulting pro‐porous 3D network possesses small hydrated cavities. The reactivity, thermal, magnetic and adsorptive properties of these materials have been investigated. Notably, the adsorption studies on 2 show that this material possesses unusual adsorption behaviour. Indeed, guest uptake is facilitated by increasing the thermal energy of both the guest and the framework. Thus, neither N2 at 77 K nor CO2 at 195 K are incorporated, and CH4 is only minimally adsorbed at 273 K and high pressures (0.5 mmol g?1 at 2500 kPa). By contrast, CO2 is readily incorporated at 273 K (up to 2.5 mmol g?1 at 2500 kPa). The selectivity of 2 towards CO2 over CH4 has been investigated by means of variable‐temperature zero coverage adsorption experiments and measurement of breakthrough curves of CO2/CH4 mixtures. The results show the highly selective incorporation of CO2 in 2 , which can be rationalised on the basis of the framework flexibility and polar nature of its voids. 相似文献
980.
Wen‐Zuo Li Jian‐Bo Cheng Qing‐ Zhong Li Bao‐An Gong Jia‐Zhong Sun 《International journal of quantum chemistry》2010,110(10):1857-1862
The HBeN? and HNBe? anions have been investigated for the first time using the CASSCF, CASPT2, and DFT/B3LYP methods with the contracted atomic natural orbital (ANO) and cc‐pVTZ basis sets. The geometries of all stationary points along the potential energy surfaces were optimized at the CASSCF/ANO and B3LYP/cc‐pVTZ levels. The ground and the first excited states of HBeN? are predicted to be X2Π and A2Σ+ states, respectively. It was predicted that the ground state of HNBe? is X2Σ+ state. The A2Π state of HNBe? has unique imaginary frequency. A bend local minimum M1 was found along the 12A″ potential energy surface and the A2Π state of HNBe? should be the transition state of the isomerization reactions for M1 ? M1. The CASPT2/ANO potential energy curves of isomerization reactions were calculated as a function of HBeN bond angle. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献