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101.
The anodic behavior and determination of pefloxacin on boron-doped diamond and glassy carbon electrodes were investigated using cyclic, linear sweep, differential pulse and square wave voltammetric techniques. In cyclic voltammetry, pefloxacin shows one main irreversible oxidation peak and additional one irreversible ill-defined wave depending on pH values for both electrodes. The results indicate that the process of pefloxacin is irreversible and diffusion controlled on boron-doped diamond electrode and irreversible but adsorption controlled on glassy carbon electrode. The peak current is found to be linear over the range of concentration 2 × 10−6 to 2 × 10−4 M in 0.5 M H2SO4 at about +1.20 V (versus Ag/AgCl) for differential pulse and square wave voltammetric technique using boron-doped diamond electrode. The repeatability, reproducibility, precision and accuracy of the methods in all media were investigated. Selectivity, precision and accuracy of the developed methods were also checked by recovery studies. The procedures were successfully applied to the determination of the drug in pharmaceutical dosage forms and humans serum samples with good recovery results. No electroactive interferences from the excipients and endogenous substances were found in the pharmaceutical dosage forms and biological samples, respectively. 相似文献
102.
This paper provides analytical chemical information on selected new molecular entities (NMEs) which are drugs that have recently been approved by the FDA. These are the antiretroviral drugs, atazanavir, indinavir and emtricitabine, the antibacterial gemifloxacin, rosuvastatine which is a cholesterol-lowing drug, the anti-cancer drug gefitinib and aprepitant for neurological disorders. Electrospray ionisation-quadrupole ion trap mass spectrometry (ESI-MSn) was employed to generate tandem mass spectrometric (MS2) data of the drugs studied and structural assignments of product ions were supported by quadrupole time-of-flight mass spectrometry (QToF-MS/MS). These fragmentation studies were then utilised in the development and validation of a specific and sensitive liquid chromatographic method (LC–ESI-MS2) to identify and determine these drugs at therapeutic concentration levels in serum after a single protein precipitation procedure with acetonitrile. In addition, this method was compared to the application of gas liquid chromatography-flame ionisation detection (GLC-FID) and differential pulse polarography (DPP) for the analysis of these NMEs in serum. 相似文献
103.
A reverse-phase high-performance liquid chromatographic method has been developed for the separation and simultaneous determination
of two COX-2 inhibitors, celecoxib and rofecoxib, in addition to two well-known non-steroidal anti-inflammatory drugs (NSAIDs),
sodium diclofenac and niflumic acid in human serum samples. Good chromatographic separation was achieved using a C18 bonded
silica column applying a gradient with acetronitrile and water, from 15 to 60% acetonitrile. The mobile phase contained 0.1%
trifluoroacetic acid as an organic modifier. Detection was made using a diode array detector (DAD) and the analytical parameters
were established at the wavelength maximum in the UV spectrum of each drug. Linearity was studied up to 100.0 mg L−1. Calibration functions, quantification and detection limits, intra- and inter-day reproducibility and accuracy were estimated
for each drug. Solid phase extraction was needed to separate and concentrate the drugs from human serum samples. The method
was successfully applied to determine the drugs in human serum samples at levels of 1.0 mg L−1. 相似文献
104.
《Arabian Journal of Chemistry》2023,16(1):104395
Nanoscience research aims to produce nanoparticles without adverse effects for medical applications. The pulsed laser ablation (PLA) technique was utilized in this study to synthesize gold nanoparticles (AuNPs) using bovine serum albumin (BSA) in simulated body fluid (SBF) at the fundamental wavelength of the Nd: YAG laser (1064 nm). BSA acted as a stabilizer, reducing and capping agent to produce spherically shaped AuNPs (diameter 3–10 nm). The successful synthesis of AuNPs was confirmed through color changes and UV–vis spectroscopy. The agglomeration and precipitation of AuNPs are attributed to the presence of BSA in the solution, and electrostatic repulsion interactions between BSA and Au nanoclusters. The effect of salt concentration of SBF on BSA stability as well as the interaction of BSA conjugated AuNPs to form complexes was studied using molecular dynamic simulations. Our results show that the stability of AuNPs-BSA conjugates increase with the salt concentration of BSA. Moreover, the synthesized AuNPs exhibit low toxicity and high biocompatibility, supporting their application in drug delivery. Investigation of the cytotoxic effect of the synthesized AuNPs show that normal fibroblast cells (L929) remain intact after treatment whereas a dose-dependent inhibition effect on the growth of cervix cancer cells (HeLa) is observed. In general, this study presents an effective, environmentally-friendly, and facile approach to the synthesis of multifunctional AuNPs using the PLA technique, as a promising efficacious therapeutic treatment of cervical cancer. 相似文献
105.
The quantitative structure-activity relationship (QSAR) for neutral carriers used to prepare hydrogen ion sensors has been studied. A series of synthesized carrier compounds were taken as the training set. Five molecular structure parameters of the compounds were calculated by using CNDO/2 algorithm and used as feature variables in constructing QSAR model. The lower and upper limits of the linear pH response range were taken as the activity measure. The corresponding model equations were derived from the stepwise regression procedure. With the established QSAR model, a new pH carrier, (4-hydroxybenzyl) didodecylamine (XIII) was proposed and synthesized. The PVC membrane pH electrode based on carrier XIII with a wide pH linear response range of 2.0-12.5 was prepared. Having a theoretical Nernstian response slope of 57.2 ± 0.3 mV/pH (n = 5 at 25 °C) without a super-Nernstian phenomenon, the sensor had low resistance, short response time, high selectivity and good reproducibility. Moreover, the sensor was successfully applied to detecting the pH value of serum samples. 相似文献
106.
Identification of human hepatocellular carcinoma-related proteins by proteomic approaches 总被引:14,自引:0,他引:14
Yang MH Tyan YC Jong SB Huang YF Liao PC Wang MC 《Analytical and bioanalytical chemistry》2007,388(3):637-643
Hepatocellular carcinoma (HCC) is the most common malignant liver tumor. Analysis of human serum from HCC patients using two-dimensional
gel electrophoresis (2DE) combined with nano-high-performance liquid chromatography electrospray ionization tandem mass spectrometry
(nano-HPLC–ESI-MS/MS) identified fourteen different proteins differentially expressed between HCC patients and the control
group. Twelve proteins were up-regulated and two down-regulated. By using nano-HPLC–MS/MS system to analyze proteome in human
serum, 317 proteins were identified, twenty-nine of which to high confidence levels (protein matched at last two unique peptide
sequences). Of these twenty-nine proteins, six were present only in HCC patients and may serve as biomarkers for HCC.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
107.
Poulsen ME Christensen HB Sørensen MT Leffers H Andersen JH 《Analytical and bioanalytical chemistry》2007,389(6):1799-1804
Chlormequat is a plant growth regulator widely used on cereals, and there is general concern that it may impair human fertility.
A LC–MS/MS method for the analysis of chlormequat in milk and serum was developed and validated in connection with an investigation
on the effect of chlormequat on pig reproduction. Validation of the method was based on recovery tests at three spiking levels,
determined as double determinations and repeated at least four times. Samples were extracted with methanol–water–acetic acid,
centrifuged, filtrated and determined by LC–MS/MS. The mean recoveries were in the range 80–110%, and the LOD was 0.2 ng/g
for serum and 0.3 ng/g for milk. The values for repeatability and reproducibility were within 2/3 of the limits given by the
Horwitz equation. Samples of pig serum (59) and sow milk (27) were analyzed using the method. Chlormequat was determined in
four milk samples in the range of 0.4 ng/g to 1.2 ng/g and in all serum samples in the range of 0.2 ng/g−4.0 ng/g. 相似文献
108.
人工神经网络方法用于肺癌的辅助诊断 总被引:8,自引:0,他引:8
根据人发和血清中微量元素的含量,将人工神经网络(ANN)用于正常人与癌症患者的分类预测.用独立预测样本作了检验,表明该方法可作为肺癌诊断的一种辅助手段.讨论了当预测样本中有元素缺损时ANN的分类预测情况,并研究了人发和血清样品中的元素对分类预测的影响. 相似文献
109.
塞曼效应石墨炉原子吸收法测定骨肿瘤患者血清中铬 总被引:1,自引:0,他引:1
用镧盐涂覆石墨管,大幅度提高测定血清铬灵敏度,选用硝酸铵基体改进剂,消除干扰,方法简便快速,灵敏度和精密度高。 相似文献
110.