首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1151篇
  免费   9篇
  国内免费   55篇
化学   1086篇
力学   1篇
物理学   128篇
  2024年   1篇
  2023年   4篇
  2022年   2篇
  2021年   3篇
  2020年   3篇
  2019年   8篇
  2018年   2篇
  2017年   14篇
  2016年   13篇
  2015年   13篇
  2014年   14篇
  2013年   37篇
  2012年   111篇
  2011年   56篇
  2010年   62篇
  2009年   79篇
  2008年   75篇
  2007年   98篇
  2006年   99篇
  2005年   81篇
  2004年   109篇
  2003年   61篇
  2002年   40篇
  2001年   35篇
  2000年   29篇
  1999年   21篇
  1998年   10篇
  1997年   17篇
  1996年   10篇
  1995年   12篇
  1994年   24篇
  1993年   16篇
  1992年   16篇
  1991年   19篇
  1990年   4篇
  1989年   5篇
  1988年   4篇
  1987年   2篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1977年   1篇
排序方式: 共有1215条查询结果,搜索用时 15 毫秒
21.
An overview of liquid phase chemiluminescence (CL) processes is presented and the potential for CL detection in liquid chromatography (LC) is discussed, with particular reference to the luminol and peroxyoxalate reactions. Post column ion displacement from a solid phase reagent [a cation exchange resin in the copper(II) form] followed by catalysis of the luminol reaction is used for the quantification of mixtures of weak acids after separation by ion-exclusion chromatography. Polyaromatic hydrocarbons (PAHs) released during the combustion of biomass fuels are separated by reversed-phase chromatography and quantified by their sensitizing effect on the peroxyoxalate reaction. This procedure is also used for the determination of carboxylic acids in non-aqueous media after selective pre-column derivatization with a fluorescent label (9-anthracenemethanol).  相似文献   
22.
Song Z  Lü J  Zhao T 《Talanta》2001,53(6):2510-1177
A novel chemiluminescence (CL) sensor for isoniazid combined with flow-injection technology is presented in this paper. The analytical reagents, luminol and ferricyanide, were both immobilized on an anion-exchange column. The CL signal produced by the reaction between luminol and ferricyanide, which were eluted from the column through sodium phosphate injection, was decreased in the presence of isoniazid. The decreased CL intensity was linear with isoniazid concentration in the range 0.001–1.0 μg·ml−1; and the detection limit was 0.35 ng·ml−1 (3s). The whole process, including sampling and washing, could be completed in 2 min with a relative standard deviation of less than 4.1%. The sensor could be reused more than 400 times and has been applied for the determination of isoniazid in pharmaceutical preparations.  相似文献   
23.
本文在调查和了解天津市独立科技信息服务机构现状的基础上,研究和探讨了其调整原则和调整目标,确立了调整的步骤和要点。最后提出天津市独立科技信息服务机构的七点调整对策。  相似文献   
24.
黎朝 《分析化学》1998,26(5):556-560
在碱性介质中,铜氨络离子去催化过氧化氢与金霉素的化学发光反应,表面活性剂 溴化十六烷基三甲基铵(CTMAB)对该反应具有增敏作用.化学发光强度与金霉素的含量在 4.0×10-8~4.0×10-6mol/L范围内呈线性关系;7次平行测定的相对标准偏差为1.7%~ 4.1%;标准加入回收率为98.8%~101.l%.应用于尿液中金霉素的测定,结果满意.  相似文献   
25.
藉高锰酸钾氧化双乙酰的化学发光反应测定微量锰   总被引:10,自引:0,他引:10  
朱昌青  王伦 《分析化学》1997,25(4):387-390
研究了高锰酸钾氧化双乙酰的化学发光反应。根据微量Mn62+对上述体系化学发光山峰时间的影响,建立了测定Mn62+的分析方法。该法线性范围为1.0×10^-4-8.0×10^-67mol/L,相对标准偏差为3.5%,检出限为6.0×10^-8mol/L。应用于合金中锰的测定,结果良好。  相似文献   
26.
Clinical applications of chemiluminescence   总被引:8,自引:0,他引:8  
L. J. Kricka   《Analytica chimica acta》2003,500(1-2):279-286
This article reviews the clinical applications of chemiluminescence in routine testing and surveys the diverse applications of chemiluminescence in clinical research. In routine clinical testing, chemiluminescent labels (acridinium ester, acridinium sulfonamide) and detection reactions for peroxidase and alkaline phosphatase enzyme labels (luminol and adamantyl 1,2-dioxetane-based reactions, respectively) are widely used in immunoassay and nucleic acid probe assays (e.g. hybridization protection assay, Hybrid Capture® assay). In clinical research the sensitivity, dynamic range and diversity of chemiluminescent assays has led to a vast range of applications, notably in protein and nucleic acid blotting, microarray-based assays, monitoring reactive oxygen species, and as detection reactions for substances separated by HPLC, capillary electrophoresis (CE), and flow-injection analysis.  相似文献   
27.
在微流控芯片上实现了鲁米诺-过氧化氢-Co2+化学发光反应及分析应用研究。探讨了分离电压对电泳图谱的影响,发现在选定实验条件下,Co2+检出限可达到2.0×10-6mol/L;并且在微流控芯片上实现了Co2+与Cu2+的快速分离及检测。  相似文献   
28.
A new detection system based on microdialysis sampling and chemiluminescence (CL) reaction was developed for in vivo monitoring of uric acid (UA) with high sensitivity, selectivity and accuracy. The uric acid is indirectly monitored by CL detection of enzymatic reaction product formation (H2O2), catalyzed by Uricase. A microprobe was modified and coated with immobilized enzyme through a Streptavidin-biotin mediated linker by using a chitosan support membrane, polyurethane trapped ferrocene film is employed to protect the probe surface and diminish the interference from reductant molecules, which often are present in the blood (e.g. ascorbic acid). The earlier mentioned probe and the constructed sensor can detect uric acid in the range of 0.01-1 mM with detection limit (3σ) of 5 μM. Finally, the system is used to monitor uric acid (UA) variation through an acute myocardial infarction (AMI) model. Following AMI-induced oxidative stress, the UA level decreases continuously, thus suggesting that UA plays a protective role as a substitute antioxidant. Furthermore, the in vivo monitoring results show good agreement with those obtained by a standard method, and the procedure is recommended for in vivo and real time monitoring of UA. In addition, the proposed method can be more accurate since the UA may be potentially oxidized by in vitro exposure to oxygen in the presence of a catalyst.  相似文献   
29.
This study describes the employment of a novel imidazole-substituted phenol [4-(1-imidazolyl)phenol] as a highly potent signal enhancer in a horseradish peroxidase (HRP)-luminol chemiluminescence (CL) immunoassay. This competitive-type immunoassay for the model antigen fentanyl is based on the use of fentanyl polyclonal antibody immobilized on white microtiter plates and a biotinylated bovine serum albumin (BSA)-fentanyl derivative as a tracer. The latter was detected by means of streptavidin labeled with HRP, resulting in the generation of a high-intensity and relatively stable chemiluminescent signal, immediately after the addition of the substrate solution (NOAS). The developed method fulfilled the requirements of accuracy (percentage recovery ranged from 93.8 to 107%) and precision (intra- and inter-assay CVs were 2.5-5.2 and 4.5-11.9%, respectively). Its plasma detection limit (1.05 pg ml−1) was lower than those of previous immunoassays. The novel assay was compared in terms of sensitivity and concentration range with other common HRP substrate systems: luminol-p-iodophenol-H2O2 and TMB-H2O2. Finally, the described method was compared with an HRP-fentanyl conjugate-based assay, similar to commercially available kits (SKIT), employing the novel substrate solution for both assays and the differences observed were explained by applying previously described models. The detection limit was 4.82 pg ml−1 for SKIT, recovery values were 94.2-105% and intra- and inter-assay CVs were 2.5-5.2 and 4.5-11.9%, respectively. In conclusion, the proposed assay could be utilized for a wide range of molecules and replace the existing enzyme-labeled antigen-based kits.  相似文献   
30.
IntroductionDuring recent years,organophosphorus pesticides(OPPs)have been widely used in agriculture becauseof their low environmental persistence and high effec-tiveness.However,they have a high acute toxicity.Trace amounts of OPPs may remain in foodstu…  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号