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1.
卤族元素氟、氯、溴、碘广泛分布在地圈、水圈和生物圈,它们是矿产资源,也是许多地学研究的信息载体,更与人类生活紧密相关。卤族元素分析是地质分析的重要组成部分,而X射线荧光光谱分析方法在当今的卤族元素分析中占有重要地位。本文收集我国1988年—2020年间X射线荧光光谱分析地质材料氟、氯、溴、碘的文献126篇,在简述卤族元素的天然存在、分析技术、X射线谱学特点及现代X射线荧光光谱仪器条件的基础上,分类评介了X射线荧光光谱在氟、氯、溴、碘分析中的应用。样品类型包括:作为主组分的卤化物矿石矿物,作为次量和痕量组分的岩石、矿石、海洋样品、煤及石油、天然卤水、生物样品和以土壤、沉积物为主的地球化学调查样品。对作为主元素存在的矿石矿物中的F和Cl,测定精度(RSD)可达到<0.5%的水平;对于以痕量元素存在的F,Cl,Br和I,多数文献的检出限水平(粉末压片制样)分别为:<50,<20,<1.0和<10 μg·g-1。至今已经有两篇文献报道了经一次压片制样依次测定了样品中的F,Cl,Br和I四元素,这无论是对地质分析,还是X射线荧光光谱分析都是一明显进展。文章最后指出,X射线荧光光谱已经成为地质材料卤族元素分析的重要方法,而由于其制样简单、快速、经济、无污染和多元素同时测定的独特优势在未来的卤族元素分析中将发挥更大作用;同时也提醒关注Cl在测定中的不稳定问题和卤族元素分析在XRF分析中的典型意义。引文134篇。  相似文献   
2.
综述了国内外采用X射线荧光光谱法的各类标准,其中包括美国材料与试验协会(ASTM)标准、国际标准化组织(ISO)标准和我国国家标准,主要应用在石油及产品、合金和矿石中元素的含量测定(引用文献31篇)。  相似文献   
3.
本文介绍了气体元素分析样品表面处理的最新研究成果,综述了热导法、红外吸收法、库仑滴定法、飞行时间质谱法和火花源原子发射光谱法等分析方法在无机固态材料气体分析中的应用现状,分析了各自的特点及存在的问题,并展望了气体分析的发展方向(引用文献85篇)。  相似文献   
4.
Chemical analysis based on colour changes recorded with imaging devices is gaining increasing interest. This is due to its several significant advantages, such as simplicity of use, and the fact that it is easily combinable with portable and widely distributed imaging devices, resulting in friendly analytical procedures in many areas that demand out-of-lab applications for in situ and real-time monitoring. This tutorial review covers computer vision-based analytical (CVAC) procedures and systems from 2005 to 2015, a period of time when 87.5% of the papers on this topic were published. The background regarding colour spaces and recent analytical system architectures of interest in analytical chemistry is presented in the form of a tutorial. Moreover, issues regarding images, such as the influence of illuminants, and the most relevant techniques for processing and analysing digital images are addressed. Some of the most relevant applications are then detailed, highlighting their main characteristics. Finally, our opinion about future perspectives is discussed.  相似文献   
5.
Cytokines are bioactive proteins produced by many different cells of the immune system. Due to their role in different inflammatory disease states and maintaining homeostasis, there is enormous clinical interest in the quantitation of cytokines. The typical standard methods for quantitation of cytokines are immunoassay-based techniques including enzyme-linked immusorbent assays (ELISA) and bead-based immunoassays read by either standard or modified flow cytometers. A review of recent developments in analytical methods for measurements of cytokine proteins is provided. This review briefly covers cytokine biology and the analysis challenges associated with measurement of these biomarker proteins for understanding both health and disease. New techniques applied to immunoassay-based assays are presented along with the uses of aptamers, electrochemistry, mass spectrometry, optical resonator-based methods. Methods used for elucidating the release of cytokines from single cells as well as in vivo collection methods are described.  相似文献   
6.
人造麝香的危害性及其残留检测方法研究进展   总被引:1,自引:0,他引:1  
综述了近年来人造麝香的危害性及其残留检测方法的研究进展。对化妆品、水、大气、土壤和药物中人造麝香的前处理方法和检测方法进行了比较,同时对此领域的发展方向进行了展望(引用文献31篇)。  相似文献   
7.
This paper is intended to review advances in the botanical, traditional uses, phytochemical and pharmacological studies of the Pulsatilla chinensis. Up to date, 68 kinds of chemical constituents have been isolated and identified from P. chinensis. Among these compounds, triterpenoids, flavonoids, lignans and coumarins are the major constituents. Researches about the pharmacological properties of P. chinensis revealed that this plant exhibited therapeutic potential both in vivo and in vitro, including antitumor, anti-inflammatory, anti-microbial and antiviral activities. Further attention should be paid to gathering information about their toxicology data, quality-control measures, and the clinical value of the active compounds from P. chinensis.  相似文献   
8.
The National Natural Science Foundation of China (NSFC) is a vital government agency supporting basic research and people to create knowledge and meet major national needs, where a rigorous and objective merit-based peer review mechanism is the key to funding the most promising research proposals. This invited comment overviews some recent attempts aimed at bettering the academic evaluation environment at the Department of Chemical Science in 2019, through measures such as grouped panel committee meetings, standardized panel committee meeting procedures, and review process refinement to improve the project review at panel committee meeting levels.  相似文献   
9.
Ion funnel is a new-style ion guider which can reduce spatial divergence and energy dispersity of the transmission ions by using radio frequency (RF) electric field to confine the ions radially and the direct current (DC) axial electric field to move the ions toward the exit, and thus it can greatly increase the ion transmission efficiency and improve the sensitivity of the mass spectrometry. Since ion funnel was invented in 1997, it has attracted a close attention of mass spectrometry scientists all over the world. Ion funnel has been used in various kinds of mass spectrometry, and built a bridge with high efficiency ion transmission between low vacuum ionization source and high vacuum mass analyzer. In this paper, the principle, technology development, and application progress of ion funnel are reviewed, and the future prospects are prospected.  相似文献   
10.
This article summarizes the known methods for calculating the internal resistance of tracked undercarriages. The values of the coefficient of internal resistance for sample tracked vehicles are available in the literature and presented in this paper. Although they are suitable for simple computations, they cannot be used to optimize the energy efficiency of new generation tracked undercarriages. This problem might be solved by the models where every phenomenon leading to energy dissipation during vehicle motion is described by a separate submodel as a function of vehicle speed, track tension, undercarriage layout, design features of the undercarriage components, etc. This kind of model is still missing for vehicles with conventional rubber tracks. The article presents multiple state-of-the-art models describing rolling resistance of road wheels, bending resistance of rubber belts, etc., including the models of belt conveyors resistance. A vast majority of the phenomena discussed herein are described by several incompatible models whose parameters have not yet been determined for conventional rubber tracks. Consequently, in the second and the third part of the article, the authors have undertaken a theoretical and experimental studies on the methods for calculating and optimizing the internal motion resistance of vehicles with conventional rubber tracks.  相似文献   
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