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901.
In this study, the organosilane‐functionalized graphene oxide as a stabilizer was prepared by a facile one‐step silylation approach. [Cu(PPh3)3Cl] complex was successfully immobilized onto the graphene oxide surface through coordination interaction with organosilane ligand spacers. The supported catalyst showed enhanced catalytic performance toward Sonogashira reaction of aryl halides with phenylacetylene in water solvent compared with the homogeneous analogues, and it could be readily recycled and reused several times without discernible loss of its activity. 相似文献
902.
Hamed Nosrati Marziyeh Salehiabar Elahe Attari Soodabeh Davaran Hossein Danafar Hamidreza Kheiri Manjili 《应用有机金属化学》2018,32(2)
We report the synthesis of iron oxide magnetic nanoparticles (IONPs) coated with various natural amino acids (AAs) using a one‐pot reaction in an aqueous medium. Several AAs, which contained hydrophilic and hydrophobic groups, were selected to study their effects on size, morphology and toxicity of IONPs. Functionalized IONPs were characterized using X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and scanning and transmission electron microscopies. Furthermore, vibrating sample magnetometry analysis shows these nanoparticles have excellent magnetic properties. Cellular toxicity of IONPs was also investigated on HFF2 cell lines. The AA‐coated IONPs are non‐toxic and biocompatible. Natural AA‐coated IONPs show a potential for their development in in vitro and in vivo biomedical fields due to their non‐toxicity, good ζ‐potential and related small size and narrow size distribution. 相似文献
903.
Electrochemical Reduction of Carbon Dioxide to Methanol on Hierarchical Pd/SnO2 Nanosheets with Abundant Pd–O–Sn Interfaces 下载免费PDF全文
Wuyong Zhang Qing Qin Dr. Lei Dai Ruixuan Qin Dr. Xiaojing Zhao Xumao Chen Daohui Ou Dr. Jie Chen Dr. Tracy T Chuong Prof. Binghui Wu Prof. Nanfeng Zheng 《Angewandte Chemie (International ed. in English)》2018,57(30):9475-9479
Electrochemical conversion of CO2 into fuels using electricity generated from renewable sources helps to create an artificial carbon cycle. However, the low efficiency and poor stability hinder the practical use of most conventional electrocatalysts. In this work, a 2D hierarchical Pd/SnO2 structure, ultrathin Pd nanosheets partially capped by SnO2 nanoparticles, is designed to enable multi‐electron transfer for selective electroreduction of CO2 into CH3OH. Such a structure design not only enhances the adsorption of CO2 on SnO2, but also weakens the binding strength of CO on Pd due to the as‐built Pd–O–Sn interfaces, which is demonstrated to be critical to improve the electrocatalytic selectivity and stability of Pd catalysts. This work provides a new strategy to improve electrochemical performance of metal‐based catalysts by creating metal oxide interfaces for selective electroreduction of CO2. 相似文献
904.
《Surface and interface analysis : SIA》2018,50(8):795-801
In this paper, we have analyzed the effect of the rhodium surface modification on the surface state of SnO2 films. SnO2 films, subjected for the surface modification, were deposited by spray pyrolysis, while Rh was deposited by using a microelectron beam evaporation. The thickness of the Rh coating varied in the range 0 to 0.1 monolayer. An explanation of the observed effects was proposed. Basing on the results of X‐ray photoelectron spectroscopy, it was assumed that at a small thickness of the rhodium covering, Rh was in a the well‐dispersed state, close to atomically dispersed state. The growth in the size of the nanoparticles began mainly when the thickness of the Rh covering exceeeded 0.01 monolayer. The size of clusters did not exceed 0.5 to 1.0 nm. 相似文献
905.
《无机化学与普通化学杂志》2018,644(4):215-220
Two nickel(II) coordination polymers, namely, {[Ni1/2(TPO)1/3(bib)1/2(H2O)] · H2O}n ( 1 ), and [Ni(HTPO)(bpy)(H2O)2]n ( 2 ), were assembled from tripodal ligand of tripodal tri(p‐carboxyphenyl) phosphane oxide (H3TPO) and two N‐donors [bib = 1,4‐bis(imidazolyl)benzene, and bpy = 4,4′‐bipyridine]. Their structures were determined by single‐crystal X‐ray diffraction analysis and further characterized by elemental analysis, IR spectra, powder X‐ray diffraction (PXRD), and thermogravimetric analysis (TGA). Structural analysis reveals that complex 1 is an interestingly 3D (3,4)‐connected {103}2{106}3 net, whereas complex 2 is a 1D polymeric chain, which was further expanded into a 3D supramolecular structure through hydrogen bonds. Luminescent sensing measurements show two nickel CPs can selectively and sensitively detect for acetone from normal solvents (DMF, DMA, DMSO, MeOH, EtOH, CH3CN, H2O, and N‐butanol). 相似文献
906.
《无机化学与普通化学杂志》2018,644(11):525-533
A series of mer‐[Ln(NO3)3(Ph3PO)3] complexes were prepared from Ln(NO3)3 · xH2O and Ph3PO in chloroform (Ln = La, Nd, Sm, Eu, Gd, Tb, Dy, and Er). The La and Nd complexes were 0.25 CHCl3 solvates, whereas the others were solvent‐free. The identical reaction using Yb(NO3)3 · xH2O produced the unique salt trans‐[Yb(NO3)2(Ph3PO)4][Yb(NO3)4(Ph3PO)] · Et2O. All nitrate ions in all complexes are η2‐chelating. A comparison of the various [Ln(NO3)3(Ph3PO)3] structures, including those in the literature, reveals at least four common polymorphs, each of which is represented by isomorphic structures of multiple Ln ions. Luminescence of mer‐[Ln(NO3)3(Ph3PO)3] (Ln = Y, La, Nd, Sm, Eu, Gd, Tb, and Dy), trans‐[Yb(NO3)2(Ph3PO)4][Yb(NO3)4(Ph3PO)] and Ph3PO assignments are reported. Latva's empirical rule allows for the antenna effect, in which energy is transferred from the triplet state of the Ph3PO ligand, to occur only for Tb3+. Excitation via Ph3PO results in strong green luminescence for Tb3+ having twice the intensity as that which results from direct excitation of the f‐f transitions. 相似文献
907.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(2):236-239
The crystal structure of Ce0.8Gd0.1Ho0.1O1.9 (cerium gadolinium holmium oxide) has been determined from powder X‐ray diffraction data. This is a promising material for application as a solid electrolyte for intermediate‐temperature solid oxide fuel cells (IT‐SOFCs). Nanoparticles were prepared using a novel sodium alginate sol‐gel method, where the sodium ion was exchanged with ions of interest and, after washing, the gel was calcined at 723 K in air. The crystallographic features of Gd and Ho co‐doped cerium oxide were investigated around the desired operating temperatures of IT‐SOFCs, i.e. 573 ≤ T ≤ 1023 K. We find that the crystal structure is a stable fluorite structure with the space group Fmm in the entire temperature range. In addition, the trend in lattice parameters shows that there is a monotonic increase with increasing temperature. 相似文献
908.
Core-shell type nanoparticles with a ceria core and polymer shell have good dispersibility. Some applications, such as fillers for increasing the refractive index and/or protecting resin films from ultraviolet (UV) light, i.e., UV cutting, require a smaller shell. Previous studies have decreased the shell weight by heat treatment in gas; however, the dispersibility of the treated nanoparticles was poor in water or alcohol. In this study, we investigated the efficacy of acid treatment for decreasing the shell weight and also evaluated the dispersibility of acid-treated nanoparticles. The thus-formed nanoparticles treated by acetic acid and formic acid show not only good dispersibility but also a well decreased shell thickness. The structure of the shell after acetic acid treatment was found to be the same as that of the untreated core-shell nanoparticles; moreover, acetic acid was present in the shell. Furthermore, by using the acetic-acid-treated nanoparticles, a transparent resin film without nanoparticle aggregation could be obtained. 相似文献
909.
β‐Cyclodextrin Functionalized Nanoporous Graphene Oxides for Efficient Resolution of Asparagine Enantiomers 下载免费PDF全文
《化学:亚洲杂志》2018,13(19):2812-2817
Efficient resolution of racemic mixture has long been an attractive but challenging subject since Pasteur separated tartrate enantiomers in 19th century. Graphene oxide (GO) could be flexibly functionalized by using a variety of chiral host molecules and therefore, was expected to show excellent enantioselective resolution performance. However, this combination with efficient enantioselective resolution capability has been scarcely demonstrated. Here, nanoporous graphene oxides were produced and then covalently functionalized by using a chiral host material‐β‐cyclodextrin (β‐CD). This chiral GO displayed enantioselective affinity toward the l ‐enantiomers of amino acids. In particular, >99 % of l ‐asparagine (Asn) was captured in a racemic solution of Asn while the adsorption of d ‐enantiomer was not observed. This remarkable resolution performance was subsequently modelled by using an attach‐pull‐release dynamic method. We expect this preliminary concept could be expanded to other chiral host molecules and be employed to current membrane separation technologies and finally show practical use for many other racemates. 相似文献
910.
《中国化学》2018,36(4):299-305
The selective synthesis of polypropylene carbonate (PPC) and cyclic propylene carbonate (CPC) from coupling reaction of CO2 and propylene oxide (PO) is a long term pursuing target. Here we report that a temperature controllable porphyrin aluminum catalyst using 5,10,15,20‐tetra(1,2,3,4,5,6, 7,8‐octahydro‐1,4:5,8‐dimethanoanthracen‐9‐yl)porphyrin as ligand, once in conjunction with suitable onium salt, achieved single cycloaddition or copolymerization reaction. Only cycloaddition reaction happened at temperature above 75 °C to produce 100% CPC, whereas copolymerization became dominant to afford PPC with selectivity over 99% at 25 °C, and the obtained PPC showed over 99% carbonate linkage and 92% head‐to‐tail structure. Based on systematic analysis of the electronic and steric feature in the porphyrin ligand, it was found that the electronic feature of the substituent in porphyrin ligand was decisive for PPC selectivity, porphyrin ligand bearing strong electron‐donating substituents displayed a significantly reduced tolerance towards increased temperature with respect to PPC formation. Therefore, temperature‐responsive catalyst could be designed by suitable modification in porphyrin ligand, and such accurate synthesis of target product by one catalyst may create a useful and facile platform for selective PPC or CPC production. 相似文献