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111.
建立了气相色谱-串联质谱一次进样同时检测重叠峰偶氮染料的分析方法.皮革和纺织品中的偶氮染料用柠檬酸盐缓冲液提取,再用连二亚硫酸钠将其还原裂解为胺类物质,经液-液萃取、浓缩处理,所得残渣用甲醇溶解,通过VF-5ms色谱柱分离,采用串联质谱的多反应监测模式开设多通道存储子离子信息,进行定性、定量分析.实验结果表明:优化质谱分析条件后,气相色谱一串联质谱可进一步消除杂质干扰,分离共流出组分.大部分芳香胺3种浓度水平的加标回收率(n=6)保持在71%~94%之间,检测限为0.008~0.672μg/mL(S/N=3),相对标准偏差(n=6)小于11%,2~50μg/mL浓度范围内线性相关系数大于0.9917,满足禁用偶氮染料的分析要求. 相似文献
112.
A method using an automated on-line purge and trap gas chromatograph with a dry electrolytic conductivity detector (DELCD) has been developed for monitoring four regulated trihalomethanes in drinking water distribution systems. This analyzer samples trihalomethanes from drinking water by pervaporation through a silicone capillary membrane contained within a gas extraction cell (GEC) followed by preconcentration using an adsorbent trap. Trihalomethanes are subsequently desorbed from the trap onto a capillary column, separated and detected. The analyzer operates in real-time, samples directly from the drinking water distribution system and is fully automated. The optimization, operation, and evaluation of the analyzer and method are discussed. Method detection limits (MDL) are less than 1.0 μg L−1 with acceptable estimates for accuracy, and precision. The results from two on-line monitoring studies in chlorinated and chloraminated distribution systems are presented. The performance of the method is compared directly to United Stated Environmental Protection Agency Method 502.2 and shows a very slight, but acceptable bias. 相似文献
113.
Coleman MD Brewer PJ Smith IM Harris PM Clift MG Milton MJ 《Analytica chimica acta》2007,601(2):189-195
We report the use of a calibration transfer strategy to correct for drift in the quantitative sensitivity of a portable quadrupole mass spectrometer (QMS) aimed at process monitoring applications. Gas mixtures of CH4/Ar/C2H6/CO2 were studied with calibration phase measurements made of the pure gases for a univariate analysis and of 40 multi-component mixtures for a multivariate approach. To evaluate calibrations, test set spectra of a CH4/Ar/C2H6/CO2 gas mixture were recorded bi-weekly over a period of 12 months. As part of the strategy a standard of pure argon was measured during both calibration and test phases so that correction factors could be calculated for each measurement day. It was shown that in the absence of a calibration transfer strategy quantifications of test set spectra could be inaccurate by more than an order of magnitude over 12 months. Furthermore, due to the effects of drift in the sensitivity over the 6 days required to record the training set in the calibration phase it was found that the multivariate analysis quantified test spectra less accurately than the univariate analysis. However, by applying the calibration transfer strategy across all measurements (both calibration and test phases) it was shown that the errors in prediction using the multivariate analysis previously seen after 2 weeks were not observed until approximately 12 months later. 相似文献
114.
A p‐Hydroxyphenacyl–Benzothiazole–Chlorambucil Conjugate as a Real‐Time‐Monitoring Drug‐Delivery System Assisted by Excited‐State Intramolecular Proton Transfer 下载免费PDF全文
Shrabani Barman Sourav K. Mukhopadhyay Sandipan Biswas Surajit Nandi Moumita Gangopadhyay Satyahari Dey Anakuthil Anoop N. D. Pradeep Singh 《Angewandte Chemie (International ed. in English)》2016,55(13):4194-4198
Among the well‐known phototriggers, the p‐hydroxyphenacyl (pHP) group has consistently enabled the very fast, efficient, and high‐conversion release of active molecules. Despite this unique behavior, the pHP group has been ignored as a delivery agent, particularly in the area of theranostics, because of two major limitations: Its excitation wavelength is below 400 nm, and it is nonfluorescent. We have overcome these limitations by incorporating a 2‐(2′‐hydroxyphenyl)benzothiazole (HBT) appendage capable of rapid excited‐state intramolecular proton transfer (ESIPT). The ESIPT effect also provided two unique advantages: It assisted the deprotonation of the pHP group for faster release, and it was accompanied by a distinct fluorescence color change upon photorelease. In vitro studies showed that the p‐hydroxyphenacyl–benzothiazole–chlorambucil conjugate presents excellent properties, such as real‐time monitoring, photoregulated drug delivery, and biocompatibility. 相似文献
115.
Pavel Sistik Romana Urinovska Hana Brozmanova Ivana Kacirova Petr Silhan Karel Lemr 《Biomedical chromatography : BMC》2016,30(2):217-224
A UPLC/MS/MS method with simple protein precipitation has been validated for the fast simultaneous analysis of agomelatine, asenapine, amisulpride, iloperidone, zotepine, melperone, ziprasidone, vilazodone, aripiprazole and its metabolite dehydro‐aripiprazole in human serum. Alprenolol was applied as an internal standard. A BEH C18 (2.1 × 50 mm, 1.7 µm) column provided chromatographic separation of analytes using a binary mobile phase gradient (A, 2 mmol/L ammonium acetate, 0.1% formic acid in 5% acetonitrile, v/v/v; B, 2 mmol/L ammonium acetate, 0.1% formic acid in 95% acetonitrile, v/v/v). Mass spectrometric detection was performed in the positive electrospray ionization mode and ion suppression owing to matrix effects was evaluated. The validation criteria were determined: linearity, precision, accuracy, recovery, limit of detection, limit of quantification, reproducibility and matrix effect. The concentration range was as follows: 0.25–1000 ng/mL for agomelatine; 0.25–100 ng/mL for asenapine and iloperidone; 2.5–1000 ng/mL for amisulpride, aripiprazole, vilazodone and zotepine; 2.3–924.6 ng/mL for dehydroaripiprazole; 2.2–878.4 ng/mL for melperone; and 2.2–883.5 ng/mL for ziprasidone. Limits of quantitation below a therapeutic reference range were achieved for all analytes. Intra‐run precision of 0.4–5.5 %, inter‐run precision of 0.6–8.2% and overall recovery of 87.9–114.1% were obtained. The validated method was successfully implemented into routine practice for therapeutic drug monitoring in our hospital. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
116.
Rixt A. Wijma Bart C. H. van der Nagel Bram Dierckx Gwen C. Dieleman Daan J. Touw Teun van Gelder Birgit C. P. Koch 《Biomedical chromatography : BMC》2016,30(6):794-801
The antipsychotics risperidone, aripiprazole and pipamperone are frequently prescribed for the treatment in children with autism. The aim of this study was to validate an ultra‐high performance liquid chromatography–mass spectrometry method for the quantification of these antipsychotics in plasma. An ultra‐high performance liquid chromatography–mass spectrometry assay was developed for the determination of the drugs and metabolites. Gradient elution was performed on a reversed‐phase column with a mobile phase consisting of ammonium acetate, formic acid in methanol or in Milli‐Q ultrapure water at a flow rate of 0.5 mL/min. The method was validated according to the US Food and Drug Administration guidelines. The analytes were found to be stable enough after reconstitution and injection of only 5 μL improved the accuracy and precision in combination with the internal standard. Calibration curves of all five analytes were linear. All analytes were stable for at least 72 h in the autosampler and the high quality control of 9‐OH‐risperidone was stable for 48 h. The method allows quantification of all analytes. The advantage of this method is the combination of a minimal injection volume, a short run‐time, an easy sample preparation method and the ability to quantify all analytes in one run. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
117.
118.
Quality assurance and process understanding are assuming increasing importance in the production of Active Pharmaceutical Ingredients (APIs). NMR has the potential to report on physical processes, quantities, structures, and speciation as chemical reactions progress. Following the progression of chemical reactions by placing the sample in an NMR tube, one can perform a large number of useful studies that provide chemical and mechanistic insight. But this simple approach can have limitations, and we have therefore constructed an apparatus comprising a laboratory reactor coupled with an NMR flow cell. The reactor duplicates the exact reaction conditions that will apply with large-scale production. This reaction mixture is sampled and pumped to a high-resolution NMR flow cell where the spectrum is recorded through the course of the reaction. We demonstrate the utility of reaction monitoring using NMR both for simple cases where tubes can be used, and describe the design of the on-flow apparatus and highlight its utility with an example. 相似文献
119.
Mauriz E Calle A Manclús JJ Montoya A Lechuga LM 《Analytical and bioanalytical chemistry》2007,387(4):1449-1458
Multi-analyte detection of environmentally relevant pesticides is performed by using a two-channelled surface plasmon resonance
(SPR) biosensor. The special design of the SPR instrument allows the determination of several analytes (DDT, chlorpyrifos
and carbaryl) via different immobilization formats. First, simultaneous pesticide monitoring is possible by flowing chlorpyrifos,
carbaryl or DDT samples separately over each channel of the SPR system, wherein their corresponding recognition element was
previously immobilized. The second approach is based on the multiple and combined immobilization of several analyte recognition
elements on the sensing surface of one individual flow cell. In this format, the analysis time for all three pesticides varied
from 40 to 60 min depending on the number of regeneration cycles. In most cases, similar detection limits were attained for
the target analyte irrespective of the assay format, with sensitivity values at the nanogram per litre level (18–50 ng L−1). The assay reproducibility was proved through the repeated use of the same sensor surface for over more than 200 assay cycles,
whereas the absence of biosensor response to non-related analytes showed the specificity and reliability of the analysis.
The SPR instrument, including optics, electronics and microfluidics, is already commercialised by the company SENSIA, SL. 相似文献
120.
利用商品化ITO玻璃导电层的温阻效应, 无需任何微加工手段, 实现了自加热和传感的芯片温度自动程序控制, 最大程度地减小了传感滞后对温度控制稳定性的影响, 温度控制的稳定性达到了0.2 ℃, 升温速度最快可达20 ℃/s以上, 在冷却风扇辅助下降温速度最快达到了8 ℃/s. 芯片温控单元的引线从传统的两对(一对用于传感, 一对用于加热)减少为一对. 通过在该芯片上直接构建多个开放微池反应器的方法成功地实现了λDNA 157 bp片段的并行扩增. 将该芯片置于倒置荧光显微镜样品台上, 以蓝色(575 nm)发光二极管为光源, 以光电倍增管为检测手段检测了dsDNA和SYBR Green Ⅰ嵌合物的荧光强度随温度的实时变化曲线. 相似文献