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71.
72.
Anti‐neurotoxic evaluation of synthetic and characterized metal complexes of thiosemicarbazone derivatives
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Quinoline‐2‐caboxyaldehyde thiosemicarbazone (HL1) and quinoline ‐2‐caboxyaldehyde N‐dimethyl thiosemicarbazone (HL2) metal complexes were prepared and characterized using analytical and spectroscopic techniques. The measurements showed that ligands behave as monovalent or neutral tridentate ligands bonding via azomethine, quinoline ring nitrogen atoms and sulfur atoms in thiol or thion forms. The anti‐neurotoxic effect of ligands and their complexes showed that, exposure to aluminum increase oxidative stress in the brain, an effect that could be offset by concomitant thiosemicarbazone complexes. Complexes could be having an effect on absorption or excretion of aluminum, due to their chelating activity. These findings may shed light on the potential clinical importance of thiosemicarbazone complexes in Alzheimer's disease. 相似文献
73.
S. M. Hadji Saied 《Journal of Radioanalytical and Nuclear Chemistry》2001,249(3):665-667
The Bio-Rex 5 resin was used for the recovery of 123I, producedin a cyclotron by irradiation of a 124 Xe target. Initially fouranion exchange resins AG1-X8, AG2-X8, Amberlite IRA-93 and Bio-Rex 5 wereused, but none of them gave good separations. Bio-Rex 5, consisting of a largeportion of tertiary and a smaller portion of quaternary amino groups, wasthen modified so that the resin contained only tertiary amine functional groupsand this modified resin was used for the separation. The concentrations ofiodide solutions were ca 5 ppb and the volumes about 120 ml. For measurementof iodide, 131I was added as tracer. In this study 6 columns ofvarious sizes were used and the best of them, in terms of maximum recoveryand minimum volume of NaOH for elution, was selected for routine production. 相似文献
74.
Abdollah Salimi Loghman Mohamadi Rahman Hallaj Saied Soltanian 《Electrochemistry communications》2009,11(6):1116-1119
For the first time silicon carbide nanoparticles (SiC) was used for electrode modification and electrocatalytic oxidation of insulin. In comparison to bare glassy carbon (GC) electrode, the oxidation of insulin at GC electrode modified with SiC nanoparticles occurred at reduced overpotentials. The modified electrode was applied for insulin detection using cyclic voltammetry, differential pulse voltammetry (DPV) and flow injection analysis (FIA). Flow injection amperometric determination of insulin at this modified electrode yielded a calibration curve with the following characteristics; linear dynamic range up to 600 pM, sensitivity of 710 pA pM?1 cm?2 and detection limit of 3.3 pM. In addition interference effect of the electroactive existing species (uric acid, glucose, lactic acid, l-cysteine and cholesterol) was diminished and for ascorbic acid eliminated by covering the surface of modified electrode with nafion film. This electrode shows many advantages as an insulin sensor such as simple preparation method without using any specific electron transfer mediator or specific reagent, high sensitivity, excellent catalytic activity, short response time, long term stability and remarkable antifouling property toward insulin and its oxidation product. Sensitivity, detection limit and antifouling properties of this insulin sensor are better than all of the reports in the literature for insulin detection at physiological pH solutions. 相似文献
75.
Abdel Fattah M. El Walily Azza Abdel Kader Gazy Saied F. Belal Essam F. Khamis 《光谱学快报》2013,46(6):931-948
Spectrophotometric and spectrofluorimetric procedures for the quantitative determination of four penicillins [Amoxycillin (AMX), Bacampicillin (BAC), Piperacillin (PPN) and Sultamcillin (SULT)] and ten cephalosporins [Cefadroxil (CDL), Cefamandole nafate (MAN), Cefuroxime axetil or sodium (CFX), Cefaclor (CFCR), Ceftazidime (CZD), Ceftizoxime (CTIZ), Ceftriaxone (CTRX), Cefoperazone (CPZ), Cefixime (CXIM) and Cefpodoxime proxetil (CFPD)] are described. Both methods are based on the acidic oxidation of the antibiotics with cerium (IV) at elevated temperature. The effect of the reagent concentration, volume of the acid,and the heating temperature were studied to optimize the reaction conditions. Each antibiotic was determined by either measuring the absorbance difference at 317 nm or the cerous inherent fluorescence at 256 and 356 nm for excitation and emission wavelengths, respectively. The two procedures have been successfully applied to the assay of these antibiotics in their pharmaceutical dosage forms. The obtained results have been statistically compared with those obtained by the official methods. 相似文献
76.
Saied Saeed Hosseiny Davarani Ahmad PourahadiSaeed Nojavan Mohammad Hossein BanitabaMahnaz Nasiri-Aghdam 《Analytica chimica acta》2012
Electro membrane extraction (EME) as a new microextraction method was applied for extraction of sodium diclofenac (SDF) as an acidic compound from wastewater, urine, bovine milk and plasma samples. Under applied potential of 20 V during the extraction, SDF migrated from a 2.1 mL of sample solution (1 mM NaOH), through a supported liquid membrane (SLM), into a 30 μL acceptor solution (10 mM NaOH), exist inside the lumen of the hollow fiber. The negative electrode was placed in the donor solution, and the positive electrode was placed in the acceptor solution. 1-octanol was immobilized in the pores of a porous hollow fiber of polypropylene as SLM. Then the extract was analyzed by means of high-performance liquid chromatography (HPLC) with UV-detection for quantification of SDF. Best results were obtained using a phosphate running electrolyte (10 mM, pH 2.5). The ranges of quantitation for different samples were 8–500 ng mL−1. Intra- and inter-day RSDs were less than 14.5%. Under the optimized conditions, the preconcentration factors were between 31 and 66 and also the limit of detections (LODs) ranged from 2.7 ng mL−1 to 5 ng mL−1 in different samples. This procedure was applied to determine SDF in wastewater, bovine milk, urine and plasma samples (spiked and real samples). Extraction recoveries for different samples were between 44–95% after 5 min of extraction. 相似文献
77.
Abu-Youssef MA Soliman SM Langer V Gohar YM Hasanen AA Makhyoun MA Zaky AH Öhrström LR 《Inorganic chemistry》2010,49(21):9788-9797
[Ag(2-amino-3-methylpyridine)(2)]NO(3) (1) and [Ag(pyridine-2-carboxaldoxime)NO(3)] (2) were prepared from corresponding ligands and AgNO(3) in water/ethanol solutions, and the products were characterized by IR, elemental analysis, NMR, and TGA. The X-ray crystal structures of the two compounds show that the geometry around the silver(I) ion is bent for complex 1 with nitrate as an anion and trigonal planar for complex 2 with nitrate coordinated. ESI-MS results of solutions of 2 indicate the independent existence in solution of the [Ag(pyridine-2-carboxaldoxime)](+) ion. The geometries of the complexes are well described by DFT calculations using the ZORA relativistic approach. The compounds were tested against 14 different clinically isolated and four ATCC standard bacteria and yeasts and also compared with 17 commonly used antibiotics. Both 1 and 2 exhibited considerable activity against S. lutea , M. lutea , and S. aureus and against the yeast Candida albicans , while 2-amino-3-methylpyridine is slightly active and pyridine-2-carboxaldoxime shows no antimicrobial activity. In addition, the interaction of these metal complexes with DNA was investigated. Both 1 and 2 bind to DNA and reduce its electrophoretic mobility with different patterns of migration, while the ligands themselves induce no change. 相似文献
78.
This study presents a phytochemical investigation of the fruits of Berberis vulgaris Linn. The isolation and structure elucidation of four compounds are discussed. The terpenoids lupeol (1) and oleanolic acid (2) and the steroids stigmasterol (3) and stigmasterol glucoside (4) are isolated for the first time from this plant. The structure and stereochemistry at various asymmetric centers were established by different spectroscopic techniques. 相似文献
79.
Imen Essouissi Nadia Malek Saied Najoua Mejri Sihem Guizani Hadeer Lazim Mouldi Saidi 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(3):987-996
In this work we propose a technetium-99m-labeled derivative from Ethionamide (ETH), further referred to as 99mTc-ECF for tuberculosis diagnosis. The biological features of this radioactive agent have been studied. The 2-ethylpyridine-4-carbothioamide-ferrocène (ECF) was chemically synthesized and then labeled with technetium-99m. It has been confirmed through this work that 99mTc-ECF is obtained with high radiolabelling yield (>90 %). Radiochemical analysis of 99mTc-ECF revealed that the molecule was efficiently labeled with a little free remaining pertechnetate. Only 1–2 % of the tracer was leached out from the complex at 24 h when incubated in serum at 37 °C which confirmed its high stability. The sensitivity test of ECF showed that the group of grafted ferrocenyl does not seem to have largely altered the active site of the molecule. In-vitro investigations were conducted using BCG (Bacille Calmette-Guérin) as analogue of Mycobacterium Tuberculosis and Listeria Monocytogenes as negative control. It was proved that for BCG, ECF has kept the bacteriostatic properties of the parent compound (ETH). In physiological conditions, the measured up-take of the tracer with live bacteria was about 24.1 and 7.1 % for BCG and Listeria Monocytogenese, respectively. The comparison of the 99mTc-ECF accumulation at sites of BCG infected animals, which is expressed as target-to-non-target ratio (found to be equal to 2.15) with other radiotracers was discussed. This allowed us to consider that 99mTc-ECF could be a reasonable radiotracer for mycobacterial infections. Obtained results were good and encourage to undergo a similar labeling for the Mycobacterium tuberculosis as perspective of this work. 相似文献
80.
Khaled F. Saied Salwa S. Abdelwahab Heba E. Hashem Kamal A. Kandeel 《Journal of heterocyclic chemistry》2020,57(3):1344-1360
1-Aryl, 1,3-diaryl- and 5-(2-oxo-2-arylethyl)-2-thioxo-imidazolidin-4-ones 2 were prepared as before, nevertheless, equivalent amounts of potassium hydroxide were added to the reaction conditions. This change, dramatically, reduced the reaction time and highly increased the yield of some derivatives. Treatment of 2 with sulfuric acid converted them into their analogous (E)/(E,Z)-5-(2-oxo-2-arylethylidene) derivatives 3 . Reactions of 2 and/or 3 with chromium trioxide affected their conversion into the corresponding 2,4-diones 4 and 5 , respectively. Treatment of 2 and/or 3 with ethyl bromoacetate affected conversion of the former into their respective 2,4-diones 4 , whereas it gave the respective 2-alkylthio derivatives of the latter. Reactions of 2b with aromatic aldehydes gave mixtures of spiro-1H- and 2H-pyrrole diastereomers. Structures of the new products were evidenced by infrared, EI-MS, 1H- and 13C-NMR spectroscopic measurements. Many of the selected compounds showed good antimicrobial activity. 相似文献