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11.
Brouwers EE Tibben MM Joerger M van Tellingen O Rosing H Schellens JH Beijnen JH 《Analytical and bioanalytical chemistry》2005,382(7):1484-1490
A method for sensitive determination of the anti-cancer agent oxaliplatin in human plasma and human plasma ultrafiltrate (pUF) is presented. The method is based on the quantification of platinum by graphite-furnace atomic-absorption spectrometry, with Zeeman correction and an atomisation temperature of 2,700°C. Sample pretreatment involves dilution of the samples with a solution containing 0.15 mol L–1 NaCl and 0.20 mol L–1 HCl in water. Validation was performed in accordance with the most recent FDA guidelines for bioanalytical method validation. All results were within requirements. The validated ranges of quantification were 0.10–400 mol L–1 for human pUF and 0.50–400 mol L–1 for plasma. The assay is now successfully used to support pharmacokinetic studies of cancer patients treated with oxaliplatin. 相似文献
12.
The review considers problems related to the formation, in the living organism, of nitric oxide, a versatile and vitally important regulator of cell metabolism. The pathways of formation of endogenous nitric oxide from L-arginine are discussed and the main approaches to increasing the NO concentration by introducing various types of exogenous nitric oxide donors into the organism and chemical and biological characteristics of these donors are considered. Primary attention is devoted to the known drugs that were shown to release NO under hydrolytic, oxidative, or reductive conditions. The solution of problems related to the elucidation of the mechanisms of drug action requires that the formation of nitric oxide be taken into account. 相似文献
13.
Summary Nickel dithiocarbamate complexes derived from some sympathomimetic drugs are examined on silica Radial-Pak columns using binary solvents containing a small percentage of an organic polar modifier. Both the type and concentration of this modifier was found to influence the separation of the ternary from the parent binary complexes. When the two ligands in a ternary complex are racemic to each other, separation of the ternary complex is only possible when certain structural requirements of the molecule are fulfilled. Ternary complexes which contain structurally similar, but nonracemic ligands, are shown to be readily separated from binary complexes. When two such complexes differ only in that one of the ligands in one is enantiomeric to a ligand in the second complex, then it can be shown that the ternary complex with the (+) enantiomer ligand elutes faster from the silica column than the one with the (–) enantiomer ligand. An example of the use of ternary complexes for the identification of optical and structurally related impurities in pharmaceutical products is also given. 相似文献
14.
A new procedure for determining nitrogenated bases by forming ion pairs with Fe(SCN)63– is studied. The method consists of extracting the ion pair formed by a nitrogenated base and the inorganic complex Fe(SCN)63– into an organic phase, and measuring the iron in the organic phase by AAS at 248.3 nm. The optimal experimental conditions for determining amylocaine, avacan, bromhexine, diphenhydramine and papaverine are studied. The organic phase used is 1,2-dichloroethane. The standard deviation of the method varies between 10–1 and 10–2. The interferences produced by various substances are studied. 相似文献
15.
This paper reports the development of a method based on capillary electrophoresis with laser-induced fluorescence detection for the simultaneous determination of thiouracil (TU) and phenylthiouracil (PhTU) with high sensitivity (nanomolar range, i.e., attomoles detected). After derivatization with 5-iodoacetamidofluorescein, the analytes were separated by capillary zone electrophoresis using 20 mM phosphate buffer (pH 10.0) and quantified by fluorescence detection. The linearity range, precision, recovery, and detection limits were determined, and the method was shown to be applicable for the determination of TU and PhTU in spiked feed samples and urine. 相似文献
16.
17.
An automated sample pretreatment of human blood plasma for liquid chromatographic determination of three antidepressant drugs, dibenzepine; a tricyclic antidepressant (TCA), reboxetine; a selective noradrenaline reuptake inhibitor (SNRI) and fluvoxamine; a selective serotonin reuptake inhibitor (SSRI), based on supported liquid membrane (SLM) for unsurpassed sample clean-up and analyte enrichment, has been developed. The chromatograms after enrichment of plasma blank and aqueous blank are virtually indistinguishable. The entire analytical procedure revealed good linearity and low detection limits of 5, 15 and 20 ng mL–1 for dibenzepine, reboxetine and fluvoxamine, respectively. No carry-over effects were noted. The repeatability of extraction at three concentrations in the range 40–150 ng mL–1 for the three drugs was between ca. 3% and 7% as relative standard deviation. The reproducibility relative standard deviation during three different days (replacing the membrane each day) was not significantly higher. 相似文献
18.
Desai S. R. Shaikh M. M. Dharwadkar S. R. 《Journal of Thermal Analysis and Calorimetry》2003,71(2):651-658
Chemical compatibility of two drugs, namely, etamsylate and fluconazole was studied with lactose as excipient, employing differential
scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques. The DSC patterns recorded for the mixtures of both the
drugs with the common excipient (lactose) indicated that fluconazole as well as etamsylate were incompatible with lactose
at high temperatures. X-ray diffraction patterns recorded for pure drugs and lactose and the mixtures of individual drugs
with lactose prepared at room temperature by intimate grinding of the components revealed incompatibility of both the drugs
with lactose also at room temperature.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
We have reported recently that high-speed normal-phase (NP) HPLC separations of a broad range of organic compounds can be performed on cyano columns using gradients of methanol in hexane-like solvent-ethoxynonafluorobutane (ENFB), available commercially. In this communication, we demonstrate that atmospheric pressure chemical ionization (APCI) in combination with mass spectrometry (MS) can be effectively used for detection in such separations. The efficiency of APCI under conditions studied has also been compared to the efficiency of traditional electrospray ionization (ESI) in combination with MS for reversed-phase (RP) HPLC of the same compounds. The compounds included in this study were steroids, benzodiazepines, and other central nervous system-active substances, nonsteroidal anti-inflammatory drugs, tricyclic antidepressants, and beta-adrenergic blocking agents. Non-polar compounds were found to respond stronger when APCI-MS technique was used, whereas APCI and ESI ionization efficiencies were comparable when polar substances were studied. The combination of normal-phase HPLC separation conditions with mass spectral detection may expand the range of LC-MS applications traditionally associated with reversed-phase HPLC and ESI-MS detection. 相似文献
20.
Rudnev AV Aleksenko SS Semenova O Hartinger CG Timerbaev AR Keppler BK 《Journal of separation science》2005,28(2):121-127
A CE method has been developed to evidence and quantitatively characterize the interaction between platinum-based antitumor drugs and human serum proteins. This method is a variant of affinity CE modified regarding both experimental setup and data treatment so as to measure the peaks (or vacancies) that correspond to the bound drug when it slowly binds to the protein. Using the formalism of the Hummel-Dreyer method and cisplatin and oxaliplatin as test compounds, a protocol for determining albumin and transferrin binding constants and stoichiometries, including (and distinguished by) 48 hours of incubation of the reaction mixture, was elaborated. Relative affinities of drugs toward different proteins in aqueous solution at physiological pH, chloride concentration, and temperature were compared in terms of overall binding constants and numbers of drug molecules attached to the protein. The results indicate that both platinum drugs bind to albumin more strongly than to transferrin, supporting the concept that the albumin fraction is a major drug supply route for chemotherapeutical needs. From a comparison with the binding parameters measured previously for cisplatin by other methods, conclusions were drawn about the validity of CE as a simple and convenient method for assaying protein-drug reactions with slow kinetics. 相似文献