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101.
Novel (N‐heterocyclic carbene)Pd(pyridine)Br2 complexes for carbonylative Sonogashira coupling reactions: Catalytic efficiency and scope for arylalkynes,alkylalkynes and dialkynes 下载免费PDF全文
Mansur Ibrahim Imran Malik Waseem Mansour Muhammad Sharif Mohammed Fettouhi Bassam El Ali 《应用有机金属化学》2018,32(4)
New N,N′‐substituted imidazolium salts and their corresponding dibromidopyridine–palladium(II) complexes were successfully synthesized and characterized. Reactions of palladium bromide with the newly synthesized N,N′‐substituted imidazolium bromides ( 2a and 2b ) in pyridine afforded the corresponding new N‐heterocyclic carbene pyridine palladium(II) complexes ( 3a and 3b ) in high yields. Their single‐crystal X‐ray structures show a distorted square planar geometry with the carbene and pyridine ligands in trans position. Both complexes show a high catalytic activity in carbonylative Sonogashira coupling reactions of aryl iodides and aryl diiodides with arylalkynes, alkylalkynes and dialkynes. 相似文献
102.
Bassam El Ali Jimoh Tijani Mohammed Fettouhi 《Journal of molecular catalysis. A, Chemical》2005,230(1-2):9-16
Acetals were formed under hydroformylation conditions of alkenes in alcohols as solvents. The hydroformylation process is combined with acetalization in a one-pot reaction leading to acetals as final products. These reactions sequences were catalyzed by the simple rhodium catalyst RhCl3·3H2O. The effects of the addition of different types and amounts of phosphine and phosphite ligands were carefully studied in order to improve the regioselectivity of the reaction. 相似文献
103.
Till?R?hrich Bassam Abu?Thaher Hans-Hartwig?OttoEmail author 《Monatshefte für Chemie / Chemical Monthly》2004,135(1):55-68
Summary. 1,2-Thiazetidine-3-acetic acid 1,1-dioxide was N-alkylated using bromoacetates, and N-acylated using either acyl chlorides, protected amino acid fluorides, or N-protected amino acid NCA, which seemed to be the most universal method. Most of the obtained -sultam peptides were sensitive against humidity, they hydrolyzed forming sulfonic acids, and reactions with amines resulted in sulfonamides. Reactions of N-acylated products showed that the sulfonyl group was faster attacked than the imide structure. 相似文献
104.
Mark R. Mason Doug Ogrin Bassam Fneich Thomas S. Barnard Kristin Kirschbaum 《Journal of organometallic chemistry》2005,690(1):157-162
Deprotonation of di(3-methylindol-2-yl)phenylmethane (L2H2) or with two equivalents of nBuLi, followed by reactions with Cp2TiCl2 or Cp2ZrCl2 yielded complexes . Compounds 1-4 were characterized by NMR spectroscopy, and compounds 1, 3, and 4 were further analyzed by X-ray crystallography and elemental analysis. The molecular structures of 1, 3, and 4 illustrate that chelating di(3-methylindol-2-yl)methanes have a structural relationship to coordinated bis(pyrazolyl)borates. 相似文献
105.
Bassam El Ali 《Reaction Kinetics and Catalysis Letters》2002,77(2):227-236
The hydrocarboxylation and the hydroesterification of styrene was studied in the presence of PdCl2(PPh3)2 as a catalyst. The effect of the addition of the heteropolyacids of a general formula H3+nPMo12-nVnO40 (HPA-n, n=1-4) on the hydrocarboxylation and the hydroesterification of styrene was considered. 相似文献
106.
Moataz S. Hendy Shereen Mowaka Ehab F. Elkady Asmaa El-Zaher Bassam M. Ayoub 《Journal of separation science》2023,46(6):2200921
Gliflozins are successfully marketed antidiabetic agents with a reported neuroprotective effect, and this study tests their blood–brain barrier crossing ability. Henceforward, a computational hypothesis interpreting their effects was reasonable after failure to cross into the brain. A chromatographic bioassay for canagliflozin, dapagliflozin, and empagliflozin was developed, validated, and applied to the rat's and rat's plasma and brain. HPLC method robustness was tested over two levels using Design of Experiment on MINITAB. It is the first method for gliflozins’ detection in rats’ brain tissue. The method was applied on 18 rats and six for each drug. Concentrations in plasma were determined but neither of them was detected in brain at the described chromatographic conditions. A computational study for the three drugs was endorsing two techniques. First, ligand-based target fishing reveals possible targets for gliflozins. They showed an ability to bind with human equilibrative nucleoside transporter 1, a regulator of adenosine extracellularly. Second, a docking study was carried out on this protein receptor. Results showed perfect alignment with a minimum of one hydrogen bond. Dapagliflozin achieved the lowest energy score with two hocking hydrogen bonds. This is proposing gliflozins ability to regulate equilibrative nucleoside transporter 1 receptors in peripheries, elevating the centrally acting neuroprotective adenosine. 相似文献
107.
Bassam M. Tashtoush Amjad M. Qandil Elaine L. Jacobson Myron K. Jacobson 《Chromatographia》2008,68(1-2):135-138
Octyl nicotinate is an ester prodrug which is under development for delivery of nicotinic acid to skin for treatment and prevention of dermatological conditions that involve skin barrier impairment such as chronic photodamage and atopic dermatitis or for mitigating skin barrier impairment that results from therapy such as retinoids or steroids. We report here an isocratic RF-LC method with water/acetonitrile (10:90, v/v) as a mobile phase, for the rapid analysis of octyl nicotinate in aqueous solutions. The method was validated in terms of linearity, precision, accuracy and mean recovery of octyl nicotinate from skin homogenate ranging from 98.8 to 102.6%. Separation and quantification of amounts as low as 0.25 μg mL?1 octyl nicotinate was accomplished. The kinetic of degradation of octyl nicotinate in aqueous solution at 310, 333, 343, and 353 K was studied. The hydrolysis rate constants for degradation of octyl nicotinate in phosphate buffer and skin homogenate were reported. This method will be effective for routine analysis of octyl nicotinate stability in different formulations in future studies. 相似文献
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