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81.
Elaissi A Rouis Z Mabrouk S Salah KB Aouni M Khouja ML Farhat F Chemli R Harzallah-Skhiri F 《Molecules (Basel, Switzerland)》2012,17(3):3044-3057
The essential oils of fifteen Eucalyptus species harvested from the Jbel Abderrahman and Korbous arboreta (North East Tunisia) were screened for their antibacterial activities by the agar disc diffusion method. Eighteen major components as identified by GC/FID and GC/MS were selected for a study of the chemical and biological activity variability. The main one was 1,8-cineole, followed by spathulenol, trans-pinocarveol, α-pinene, p-cymene, globulol, cryptone, β-phellandrene, viridiflorol, borneol, limonene and isospathulenol. The chemical principal component analysis identified five species groups and subgroups, where each group constituted a chemotype, however that of the values of zone diameter of the inhibition (zdi) identified six groups of Eucalyptus oils, characterized by their antibacterial inhibition ability. The strongest activity was shown by E. platypus oil against Enterococcus faecalis and by E. lamannii oil against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. A correlation between the levels of some major components and the antibacterial activities was observed. 相似文献
82.
Stereoselective functionalization of pyrrolidinone moiety towards the synthesis of salinosporamide A
Julien Barbion Geoffroy Sorin Mohamed Selkti Esther Kellenberger Rachid Baati Stefano Santoro Fahmi Himo Ange Pancrazi Marie-Isabelle Lannou Janick Ardisson 《Tetrahedron》2012,68(32):6504-6512
An important feature of the synthesis of salinosporamide A, a potent proteasome inhibitor, is the establishment of the quaternary stereocenter at C3. A new route has been developed based on the methylation of a functionalized pyrrolidinone. Direct methylation reaction led to the unwanted diastereomer; however, by means of a Corey–Chaykovsky reaction followed by LiAlH4 epoxide opening, the desired alcohol was obtained. The pyrrolidinone was elaborated through a key allylation reaction between a tertiary allyltitanium reagent and an aldehyde bearing a spiroketal moiety in α-position. 相似文献
83.
Khalil Al Mamari Hamid Ennajih Hafid Zouihri Rachid Bouhfid Seik Weng Ng El Mokhtar Essassi 《Tetrahedron letters》2012,53(18):2328-2331
The 1,3-dipolar cycloaddition of 1-allyl-5-haloisatin derivatives as dipolarophiles with the azomethine ylides generated in situ from N-allylisatin and l-proline to furnish novel dispiro-oxindoles has been investigated. The structures and relative stereochemistry of both types of cycloadducts were confirmed by single crystal X-ray diffraction, 1H and 13C NMR spectroscopy and mass spectrometry. 相似文献
84.
Houcine Ammar Fatma Abdelkafi Souhir Abid Bouchra Benjelloum-Mlayah Rachid El Gharbi Michel Delmas 《Chemistry of Natural Compounds》2012,48(1):99-102
Alfa grass pulping was successfully performed in hydro-organic acid medium under mild conditions (107°C, atmospheric pressure, cooking
time: 3 h). Use of an acetic acid/formic acid/water mixture as pulping liquor was perfectly suitable for selective isolation
of pulp, lignin, and hemicelluloses. The unbleached pulp obtained in good yield was first delignified by peroxyacids in organic
acid medium and then bleached with hydrogen peroxide in a basic medium to give pulp offering good physico-chemical and mechanical
characteristics. 相似文献
85.
86.
87.
El Antri A Messouri I Bouktaib M El Alami R Bolte M El Bali B Lachkar M 《Molecules (Basel, Switzerland)》2004,9(8):650-657
Two tetrahydroisoquinoline alkaloids were extracted from the alkaloid fraction of a methanol extract of the seeds of Calycotome Villosa Subsp. intermedia. Their structures were established as (R)-1-hydroxymethyl-7-8-dimethoxy-1,2,3,4-tetrahydro- isoquinoline (1) and (S)-7-hydroxymethyl-2-3-dimethoxy-7,8,9,10-tetrahydroisoquinoline chloride (2) by spectroscopic techniques and X-ray diffraction analysis. 相似文献
88.
Benzocycloheptapyrimidines are an important class of compounds because of their pharmacological properties. We report here two new synthetic procedures for the preparation of 2,4-dialkylamino substituted benzocycloheptapyrimidines. One of these methods is based on the reaction of substituted cyanamides with the vinyl triflate of the 1-benzosuberone while the other preparation relies on the nucleophilic displacement of methylsulfonyl groups by secondary amines at the 2 and 4 positions of benzocycloheptapyrimidine intermediates. 相似文献
89.
Pasquale Curcio Christelle Zandanel Alain Wagner Charles Mioskowski Rachid Baati 《Macromolecular bioscience》2009,9(6):596-604
This paper describes a new type of surface imprinting technique that combines the advantages of both the semi‐covalent approach and one‐stage miniemulsion polymerization. This process has been successfully applied for the preparation of glucose surface‐imprinted nanoparticles. The selective artificial receptors for glucopyranoside were fully characterized by IR, TEM and BET analyses, and their molecular recognition abilities by binding experiments carried out in batch processes. The molecular affinity and selectivity of the glucose molecularly imprinted polymers were accurately quantified. These characteristics are essential for verification of the efficiency of the developed surface imprinting process. The imprinting effect was clearly demonstrated using the batch rebinding method. We have found that the glucose imprinted polymers produced using the optimized one‐stage mini‐emulsion exhibited quite fast kinetics of binding and equilibration with glucopyranoside templates, compared to polymers prepared by bulk polymerization technique, as well as extremely low levels of unspecific bindings. We also demonstrated that glucose molecular imprinted polymer (MIP) exhibited very good selectivity for its original template compared to other glycopyranoside derivatives, such as galactose. Finally, the extraction of the binding properties from isotherms of binding by fitting to the bi‐Langmuir and Freundlich models allowed the determination of the affinity constant distribution of the binding sites. This imprinting protocol allowed the determination of an affinity constant (KD), involving exclusively H‐bonding interactions, for the glucose MIP ( P2C ) with the best template 1 , in CH3CN as the solvent system.
90.
The Relationship between the Relative Solvating Power of Electrolytes and Shuttling Effect of Lithium Polysulfides in Lithium–Sulfur Batteries 下载免费PDF全文
Dr. Chi‐Cheung Su Meinan He Rachid Amine Zonghai Chen Dr. Khalil Amine 《Angewandte Chemie (International ed. in English)》2018,57(37):12033-12036
Relative solvating power, that is, the ratio of the coordination ratios between a solvent and the reference solvent, was used to probe the quantitative structure–activity relationship of electrolyte solvents and the lithium polysulfide (LiPS) dissolution in lithium–sulfur batteries. Internally referenced diffusion‐ordered nuclear magnetic resonance spectroscopy (IR‐DOSY) was used to determine the diffusion coefficient and coordination ratio, from which the relative solvating power can be easily measured. The higher the relative solvating power of an ethereal solvent, the more severe will be the LiPS dissolution and the lower the coulombic efficiency of the lithium–sulfur battery. A linear relationship was established between the logarithm of relative solvating power of a solvent and the degree of LiPS dissolution, rendering relative solvating power an important parameter in choosing the electrolyte solvent for lithium–sulfur batteries. 相似文献