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961.
Synthesis of Bi2WO6/Bi2O3 Composite with Enhanced Photocatalytic Activity by a Facile One‐step Hydrothermal Synthesis Route 下载免费PDF全文
Tianye Wang Fengjun Zhang Guosheng Xiao Shuang Zhong Cong Lu 《Photochemistry and photobiology》2015,91(2):291-297
In this study, the characterization and photocatalytic activity of Bi2WO6/Bi2O3 under visible‐light irradiation was investigated in detail. The results suggested that Bi2WO6/Bi2O3 can be synthesized by a facile one‐pot hydrothermal route using a super big 200 mL Teflon‐lined autoclave with optimal sodium oleate/Bi molar ratio of 1.25. Through the characterization of Bi2WO6/Bi2O3 by X‐ray diffraction, scanning electron microscopy, X‐ray photoelectron spectroscopy, Fourier transform infrared, UV‐vis diffuse reflectance spectra and Photoluminescence spectra, it was found that the as‐prepared composite possessed smaller crystallite size and higher visible‐light responsive than the pure Bi2WO6. Moreover, it was expected that the as‐prepared composites exhibited enhanced photocatalytic activity for the degradation of Rhodamine B under visible‐light irradiation, which could be ascribed to their improved light absorption property and the reduced recombination of the photogenerated electrons and holes during the photocatalytic reaction. In general, this study could provide a principle method to synthesize Bi2WO6/Bi2O3 with enhanced photocatalytic activity by one‐step hydrothermal synthesis route for environmental purification. 相似文献
962.
UVR8 is the only known plant photoreceptor that mediates light responses to UV‐B (280–315 nm) of the solar spectrum. UVR8 perceives a UV‐B signal via light‐induced dimer dissociation, which triggers a wide range of cellular responses involved in photomorphogenesis and photoprotection. Two recent crystal structures of Arabidopsis thaliana UVR8 (AtUVR8) have revealed unusual clustering of UV‐B‐absorbing Trp pigments at the dimer interface and provided a structural framework for further mechanistic investigation. This review summarizes recent advances in spectroscopic, computational and crystallographic studies on UVR8 that are directed toward full understanding of UV‐B perception at the molecular level. 相似文献
963.
Susceptibility of Ureaplasma urealyticum to Methylene Blue‐Mediated Photodynamic Antimicrobial Chemotherapy: An in vitro Study 下载免费PDF全文
Tinglu Ye Bancheng Chen Bo Yu Qili Zhong Guoxin Huang Xiaoping Hu Wei Zhang 《Photochemistry and photobiology》2015,91(4):917-922
The aim of this study was to detect the susceptibility of Ureaplasma urealyticum to methylene blue‐mediated photodynamic antimicrobial chemotherapy (PACT). Three U. urealyticum strains including the standard serotype 1 and 5, and a clinically collected strain were used in this study. Strains were first incubated in 96‐well culture plates in the presence of methylene blue with decreasing concentrations (from 1 to 0.015625 mg mL?1) for 20 or 60 min, and then submitted to irradiation with a light‐emitting diode laser with a power density of 100 mW cm?2 for 8, 17, 34 or 68 min. Regrowth of the strains was performed soon after irradiation. A significant inactivation effect was observed after PACT. Longer incubation time induced more extensive inactivation of U. urealyticum. No difference in response to PACT was observed between the two biovars of U. urealyticum. It was concluded that PACT had a significant inactivation effect on U. urealyticum, and it might be a promising alternative treatment for resistant U. urealyticum infections. 相似文献
964.
The Convenient Synthesis of 11‐Methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione Derivatives 下载免费PDF全文
Guang‐Fan Han Li‐Jun Zhao Li‐Zhuang Chen Jia‐Wei Du Zhong‐Xia Wang 《Journal of heterocyclic chemistry》2015,52(4):1219-1225
The 2‐arylidene‐3‐oxobutanenitrile derivatives 2 were prepared by the Knoevenagel condensation between aldehydes and 3‐oxobutanenitrile 1 , which was obtained by acid hydrolysis of β‐aminocrotononitrile. 3‐Acetyl‐2‐amino‐4H‐chromen‐5(6H)‐one derivatives 3 were synthesized by reaction of 2‐arylidene‐3‐oxobutanenitrile 2 and 5‐substituted‐1,3‐cyclohexanedione in ethylene glycol. The 11‐methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione derivatives 4 were obtained by Friedländer reaction of compounds 3 with 5‐substituted‐1,3‐cyclohexanedione, using p‐toluenesulfonic acid monohydrate as catalyst. The structures of all novel compounds were characterized by elemental analysis, IR, MS, and 1H NMR spectra. The crystal and molecular structure of compound 4f has been determined by single crystal XRD analysis. 相似文献
965.
Zhixiong Zhong Gongke Li Zhibin Luo Zhe Liu Yijuan Shao Wanwen He Jianchao Deng Xingling Luo 《Analytica chimica acta》2015
A carboxylated graphene oxide/polyvinyl chloride (CGO/PVC) material was prepared as a sorbent for the selective extraction of sulphonamides from complex sample. After being dispersed in buffer solution, sample was transferred into the prefabricated solid-phase extraction (SPE) column, which integrated extraction and cleanup into one single-step. A multi-response optimization based on the Box-Behnken design was used to optimize factors affecting extraction efficiency. Compared with the commonly commercial sorbents including MCX, WCX and C18, CGO/PVC hybrid material had higher extraction selectivity and capacity to sulphonamides. The limits of detection and quantification for seven target compounds were in the range of 3.4–7.1 μg/L and 11.4–23.7 μg/L, respectively. The self-assembly SPE cartridge was successfully used to enrich seven analytes in anti-acne cosmetics prior to ion chromatography detection with good recoveries of 87.8–102.0% and relative standard deviations of 1.2–6.4%, implying that this method was suitable for routine analysis of cosmetics. 相似文献
966.
Jun Ren Jinzhou Yang Wei Wang Hailong Guo Zhijun Zuo Jianying Lin Zhong Li 《International journal of quantum chemistry》2015,115(13):853-858
The activity and selectivity of heterogeneous catalysts can be significantly improved by dispersion of another active component in the metal substrate. The impact of Rh promoter on the formation of dimethyl carbonate (DMC) via oxidative carbonylation of methanol on Cu–Rh/AC (activated carbon) catalyst was investigated by density functional theory calculations. The most stable configurations of reacting species (CO, OH, CH3O, monomethyl carbonate, and DMC) adsorbed on the Cu0(zero‐valent copper)/AC and Cu–Rh/AC surfaces were determined on the basis of the calculated results. The reaction energy and activation energy of the rate‐limiting steps on the Cu–Rh/AC and Cu0/AC surfaces were compared. The activation energies of the rate‐limiting step of CO insertion into dimethoxide are 206.3 and 304.8 kJ mol?1 on the Cu–Rh/AC and Cu0/AC surfaces, respectively. The activation energies of the rate‐limiting step of CO insertion into methoxide are 78.5 and 92.7 kJ/mol on the Cu–Rh/AC and Cu0/AC surfaces, respectively. The calculated results indicate that the addition of Rh atom has a significant effect on decreasing the active energy the main pathway for DMC formation. © 2015 Wiley Periodicals, Inc. 相似文献
967.
Paecilomycines A and B,Novel Diterpenoids,Isolated from Insect‐Pathogenic Fungi Paecilomyces sp. ACCC 37762 下载免费PDF全文
Kun Zhou Xiao‐Ling Zhao Li‐Ping Han Meng‐Meng Cao Chuan Chen Bao‐Zhong Shi Du‐Qiang Luo 《Helvetica chimica acta》2015,98(5):642-649
Two new diterpenoids, named paecilomycine A ( 1 ) and paecilomycine B ( 2 ), including a novel skeleton with a five‐membered lactone ring, together with three known labdane diterpenoids, rel‐(1R,3S,4aS,5R,8aS)‐5‐[(3E)‐4‐carboxy‐3‐methylbut‐3‐en‐1‐yl]decahydro‐3‐hydroxy‐1,4a‐dimethyl‐6‐methylidenenaphthalene‐1‐carboxylic acid ( 3 ), botryosphaerin E ( 4 ), and agathic acid ( 5 ), were isolated from solid culture of the insect pathogenic fungi strain Paecilomyces sp. The structures of all compounds were established on the basis of comprehensive spectroscopic studies. The relative configurations of 1 and 2 were determined by single‐crystal X‐ray diffraction analyses. 相似文献
968.
Facile Interchange of 3d and 4f Ions in Single‐Molecule Magnets: Stepwise Assembly of [Mn4], [Mn3Ln] and [Mn2Ln2] Cages within Calix[4]arene Scaffolds 下载免费PDF全文
Dr. Maria A. Palacios Dr. Ross McLellan Dr. Christine M. Beavers Dr. Simon J. Teat Dr. Høgni Weihe Dr. Stergios Piligkos Dr. Scott J. Dalgarno Prof. Euan K. Brechin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(31):11212-11218
The central MnII ions in a series of calix[4]arene‐stabilised butterflies can be sequentially replaced with LnIII ions, maintaining the structural integrity of the molecule but transforming its magnetic properties. The replacement of MnII for GdIII allows for the examination of the transferability of spin‐Hamiltonian parameters within the family as well as permitting their reliable determination. The introduction of the 4f ions results in weaker intramolecular magnetic exchange, an increase in the number of low‐lying excited states, and an increase in magnetisation relaxation, highlighting the importance of exchange over single‐ion anisotropy for the observation of SMM behaviour in this family of complexes. The presence of the [TMII/III(TBC[4])(OH)(solvent)] metalloligand (TM=transition metal, TBC=p‐tBu‐calix[4]arene) suggests that magnetic calix[n]arene building blocks can be employed to encapsulate a range of different “guests” within structurally robust “hosts”. 相似文献
969.
970.
采用共沉淀法制备了不同Co2AlMgx(x=0.5、1、1.5和2)原子比的类水滑石,用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)、表面孔吸附(BET)及电感耦合等离子光谱(ICP)等技术手段表征了催化剂的结构、组成和比表面积,并考察了其催化苯甲醇选择氧化制苯甲醛的性能。 结果表明,随着Mg含量的增加,催化剂的碱性增强,苯甲醛的选择性提高。 在优化条件:苯甲醇0.02 mol,催化剂Co2AlMg1类水滑石100 mg,过氧化氢叔丁醇0.04 mol,溶剂乙腈8 mL,反应温度60 ℃,反应时间9 h下,苯甲醇的转化率为39.5%,苯甲醛的选择性达到89.2%。 催化剂重复使用5次后其活性与选择性未见明显降低,表明催化剂具有较好的稳定性。 相似文献