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1.
土壤腐殖质的分析化学研究进展   总被引:7,自引:1,他引:7  
吴景贵  姜岩 《分析化学》1997,25(10):1221-1227
对土壤腐殖质的分析化学研究进展作了综述。具体包含如下几个方面的内容;土壤腐殖质的组成和结构的研究,土壤腐殖质的起源和形成的研究,土壤腐殖质与土壤中有机,无机物质的相互作用的研究以及有机物料的分解,转化及其对腐殖质影响的研究,同时,对土壤腐殖质的研究中有待进一步用分析化学方法解决的几个问题进行了探讨。  相似文献   

2.
高速分析四十年   总被引:1,自引:0,他引:1  
1 高速分析的产生从总体上看,分析化学是帮助我们获得物质的化学组成和结构信息的科学.服务于不同领域的分析化学,由于分析对象的不同,带来了具体分析要求的差异.于是产生了具有各自特征的工业分析化学、农业分析化学、临床分析化学等许多分支.而在生产技术发展的进程中对分析化学的要求也不断地变化和提高.作为服务于工业生产的分析化学一工业分析化学的重要性主要表现在对产品的质量控制.50年代初,我国大力发展钢铁工业,为了配合冶炼工艺和保证钢铁产品的质量,要求解决炉前快速分析问题.上海材料研究所早在1954年就确定以解决这一问题作为研究工作的主要方向,并取得积极成果.  相似文献   

3.
黎朝 《大学化学》2016,31(1):48-53
介绍了Origin软件中用户自定义非线性拟合功能的使用方法,并结合实例讨论如何应用非线性拟合对分析化学实验数据进行处理。结果表明,该方法能准确计算实验结果、对实验数据进行评价,同时还可方便得到绘制的图表,应在分析化学实验教学中推广应用。  相似文献   

4.
针对分析化学教学存在的问题,对教学观念、内容、方法等进行了改革。从而使学生掌握分析化学的基本理论,培养其严谨的科学态度和解决实际问题的能力。  相似文献   

5.
本文介绍了线性拟合和多项式拟合的方法及其在分析化学中的应用示例。文中给出了分析化学中拟合标准曲线方程、由光度法测量数据计算一元酸离解常数、用多项式拟合法进行转子流量计的校准等的方法、程序及应用实例。  相似文献   

6.
分析化学中非线性多元函数拟合的遗传算法   总被引:6,自引:2,他引:4  
蔡煜东 《分析化学》1995,23(7):790-792
本文提出分析化学中非线性多元函数拟合的遗传算法,并以一组试验数据为对象,尝试了遗传算法的效果。结果表明,遗传算法性能良好,可望成为分析化学中各类非线性函数拟合,曲线校正的有效方法。  相似文献   

7.
李娜 《大学化学》2023,(6):69-74
介绍了北京大学化学分析教材《定量化学分析简明教程》的内容特色以及各版次的内容演进。从分析化学工作者解决问题思路的角度出发实现各版次内容的演进。在此过程中,强调解决分析化学问题的基础与基本工具,如系统深入介绍化学平衡以及增加对数据处理的内容,以应用实例为载体,阐释解决分析化学问题的思维方式。  相似文献   

8.
化学计量学在电分析化学中的应用   总被引:10,自引:2,他引:8  
倪永年  白洁玲 《分析化学》1996,24(5):606-612
本文对化学计量学各种方法,诸如多元校正,因子分析,信号处理,参数估计,模式识别等电分析化学中的应用作了回顾及评述,指出了化学计量学电分析化学中应用的良好前景。  相似文献   

9.
主成分—人工神经网络在近红外光谱定量分析中的应用   总被引:5,自引:0,他引:5  
近红外光谱的主成分由非线性迭代偏最小二乘法(NIPALS)求出,主成分作标准化处理后,作为B-P神经网络的输入结点进行非线性迭代。该法的优点是,充分利用了全光谱的数据,得到消除噪声后的最佳主成分,能建立非线性模型,B-P神经网络迭代时间显著缩短,用该法对大麦中的淀粉含量进行了定量分析研究。结果为:校准和预测的相关系数分别为0.981和0.953,校准和预测的相对标准偏差分别为1.70%和2.48%  相似文献   

10.
主成分-人工神经网络在近红外光谱定量分析中的应用   总被引:13,自引:0,他引:13  
近红外光谱的主成分由非线性迭代偏最小二乘法(NIPALS)求出。主成分作标准化处理后,作为B-P神经网络的输入结点进行非线性迭代。该法的优点是,充分利用了全光谱的数据,得到消除噪声后的最佳主成分,能建立非线性模型,B-P神经网络迭代时间显著缩短。用该法对大麦中的淀粉含量进行了定量分析研究。结果为:校准和预测的相关系数分别为0.981和0.953,校准和预测的相对标准偏差分别为1.70%和2.48%。  相似文献   

11.
Artificial neural networks are a family of non-linear computational methods, loosely inspired by the human brain, that have found application in an increasing number of fields of analytical chemistry and specifically of food control. In this review, the main neural network architectures are described and examples of their application to solve food analytical problems are presented, together with some considerations about their uses and misuses.  相似文献   

12.
Flow analysis has achieved its majority as a well-established tool to solve analytical problems. Evolution of flow-based approaches has been analyzed by diverse points of view, including historical aspects, the commutation concept and the impact on analytical methodologies. In this overview, the evolution of flow analysis towards green analytical chemistry is demonstrated by comparing classical procedures implemented with different flow approaches. The potential to minimize reagent consumption and waste generation and the ability to implement processes unreliable in batch to replace toxic chemicals are also emphasized. Successful applications of greener approaches in flow analysis are also discussed, focusing on the last 10 years.  相似文献   

13.
Tauler R 《Analytica chimica acta》2007,595(1-2):289-298
Although alternating least squares algorithms have revealed extremely useful and flexible to solve multivariate curve resolution problems, other approaches based on non-linear optimization algorithms using non-linear constraints are possible. Once the subspaces defined by PCA solutions are identified, appropriate rotation and perturbation of these solutions can produce solutions fulfilling the constraints obeyed by the physical nature of the investigated systems. In order to perform such a rotation, an optimization algorithm based in the fulfillment of constraints and some examples of application in chemistry and environmental chemistry are given. It is shown that the solutions obtained either by alternating least squares or by the new proposed algorithm are rather similar and that they are both within the boundaries of the band of feasible solutions obtained by an algorithm previously developed to estimate them.  相似文献   

14.
Some problems in teaching chemistry students metrology (mainly chemical) were considered briefly. Special attention was given to teaching students of analytical chemistry. Ways to solve the problems were proposed.  相似文献   

15.
王敬尊 《大学化学》2018,33(8):47-51
简述了分析化学的发展历史。分析化学的"昨天",从基于物理化学的溶液理论,以目视可见为工具的"化学分析",进入以物理方法为基础的仪器分析,因此有人提出"化学正在走出分析化学";分析化学的"今天",因为它的主体任务是解决物质的分子原子结构和成分,所以又回归化学领域;对分析化学的"明天"寄厚望,分析化学走出历来仅仅以"为他人报告提供数据"的技术支持者的角色,成为"实际问题解决者",利用分析化学中综合分析的"剖析技术",为新产品开发创制的"反工艺研究"做出独特的贡献。  相似文献   

16.
This overview covers current chemometric methodologies using second-order advantage to solve problems of analyzing highly complex matrices. Among the existing algorithms, it focuses on those most frequently used (e.g., the standard for second-order approaches to data analysis, PARAFAC (parallel factor analysis), and MCR-ALS (multivariate curve resolution alternating least squares), as well as the most recently implemented BLLS (bilinear least-squares), and U-PLS/RBL (unfolded partial least squares/residual bilinearization)). All of these are based on linear models. The overview also covers ANN/RBL (artificial neural networks followed by residual bilinearization), which achieves the second-order advantage in systems involving non-linear behavior. In addition, the overview deals with the drawbacks of these approaches, as well as other drawbacks that are inherent in the analytical techniques to question.  相似文献   

17.
王芳  王松  丛海林  于冰 《色谱》2020,38(9):1013-1021
毛细管电泳-质谱(CE-MS)联用技术具有高灵敏度、高分析效率、低样品损耗等优点,在强极性和带电荷的物质分析中具有明显优势,已广泛应用于生命科学、医学、药学等多个领域。在过去的十几年,影响其应用的主要因素包括系统的稳定性、实验的可重复性、数据的准确性等。为解决现有问题,进一步拓展其应用,研究人员在技术设计和改进等方面做了大量工作。医学和分析化学领域的相关研究证明了CE-MS在代谢组学和蛋白质组学中的实用性。这篇文章综述了2015年以来,CE-MS在技术和应用方面的最新进展,为未来的技术发展及应用提供借鉴。为提高CE-MS的分析效率和数据可比性,该文对多个方面的研究进行了讨论,包括涂层与样品的相互作用、接口技术、运行参数和数据处理方法。文中关于复杂样品(组织、细胞、体液等)代谢组学/蛋白质组学的综述研究,使癌症病理分析、药物开发和疾病监测等分析数据更加可视化,为CE-MS临床分析应用提供借鉴。除了对CE-MS的最新发展进行综合评述外,还提出未来应加强3个方面的研究:(i)从样品前处理和分离技术方面优化分析方法;(ii)从毛细管涂层和接口技术方面调整分析技术;(iii)从临床研究和数据分析方面开发新思路。  相似文献   

18.
During the past ten years, the means by which more information can be extracted from experimental data have become an important area of research in analytical chemistry. Digital filters have been demonstrated to have a number of applications to analytical problems. These techniques typically involve a least-squares fit of experimental data to some model of the process being filtered. One method for filtering experimental data is based on the Kalman filter, a recursive, linear digital filter first developed for use in navigation, but now used in many fields. This paper discusses the implementation of Kalman filters in analytical chemistry. The principles of state-space digital filtering are reviewed, and the development of state/space models is discussed. Discussion is focused on the discrete Kalman algorithms. Two examples are provided to demonstrate the operation of the discrete Kalman filtering algorithm. Similarities between Kalman filtering and weighted least-squares methods are considered, and the specific advantages and disadvantages of linear and nonlinear Kalman filtering approaches are evaluated. To illustrate the range of problems which benefit from use of the filter, a comprehensive literature survey of the application of Kalman filtering to chemical problems is provided.  相似文献   

19.
Analytical Chemistry in Modern Society: What we can Expect   总被引:1,自引:0,他引:1  
Analytical chemistry today contributes many analytical techniques which are required in industry, environmental control, medical laboratories and other areas of society. However, increased portability and miniaturization has the potential to enable us to solve new problems such as the analysis of new matrices including the possibility to analyse even cellular compartments. In this development process it is also being attempted to produce instruments and techniques which can be used by non-specialists. The integration, in a recent future, of microanalytical systems into our water taps permitting to control the presence of contaminants or microanalytical systems to control our health profile are some examples of the future contribution of analytical chemistry to society which probably will change our life.  相似文献   

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