关于PW—1480X44软件中的数学通式问题

本文讨论ＰＷ－１４８０Ｘ４４软件中的数学通式问题。作者指出，软件中所提供的数学通式不妥，应该改正，软件应作适当修改。     

也谈有机化合物的同系列

关于同系列通式的推导贵刊有2次报道,现介绍一种利用数学等差公式的简单方法。等差公式为：an=a1 (n-1)a其中a．为第n项,d为公差,a1为首项,将之用于有机化学同系列通式的推导如下：     

酸碱体系pH统一公式及Mathematica精确求算

酸碱体系pH计算是大学分析化学理论课程学习的重点难点,教材涉及繁多的计算公式和近似条件,局限于常见的简单体系。采用酸离解常数（Ka）对酸、碱、两性物质的酸碱反应平衡进行统一描述,建立质子平衡方程,推导得到适用于所有酸碱体系的pH计算统一公式,并使用Mathematica数学软件,便捷地解决精确求解的问题。学习通法通式,并采用计算机精确计算pH,有助于学生整体掌握分析化学理论课程中pH计算的理论基础及解决复杂体系精确计算问题。     

氧化还原滴定的理论公式

本文提出了氧化还原滴定理论处理的一般模型，导出了化学计量点电位计算通式和终点误差的计算通式，给出了滴定突跃范围及指定误差要求时终点电位允许变动范围的一般计算方法。本处理方法推导过程严谨、系统而简明，优于现有文献及专著的报道。     

烃类通式的推导

通式是指表示某个同系列中各同系物的组成的共同式子,它常用于书写同系物的分子式、化学计算和推导化合物的结构。每个同系列都有一个相应的通式。在基础有机化学教学中,以烃类的通式较为重要,掌握烃类通式的推导方法,可以给学习带来方便。然而,在有机化学教科书中,除了烷烃外,其他烃类一般只给出通式而不     

判断氧化还原滴定可行性的通式

本文从反应不完全度出发,提出了判断氧化还原滴定可行性的通式.在能选择到好的指示剂的前题下,该通式适用于所有的氧化还原滴定可行性的判断.从通式中可以清楚看出氧化还原滴定可行性的判断比较复杂,所以教学中若能从通式逐步简化讨论,就可既全面又清楚,并澄清一些错误认识.     

基于安德雷德通式的旋转黏度计校准方法研究与应用

基于安德雷德通式提出两种旋转黏度计校准方法:安德雷德通式运用法和标准黏度液定值数据拟合法。经过实验验证,安德雷德通式运用法得到旋转黏度计计算黏度示值同实测黏度示值的相对误差在±1%之内;标准黏度液定值数据拟合法得到的旋转黏度计计算修正系数同实测修正系数的相对误差为0.2%~0.4%。安德雷德通式运用法和标准黏度液定值数据拟合法在实际旋转黏度计校准工作中可行,可以提高校准效率。     

一个大统一的有机新通式的应用

现行中学有机教材中各类烃及一些衍生物均有各自独立的通式。诸多通式互无联系,难以记忆,功能单一。     

有机化合物通式推导补遗

有关同系物通式的推导贵刊已有3次报道[1-3],给有机物通式的推断指明了方向,其中魏荣宝同志介绍的利用数列等差公式法,令人耳目一新.根据高教出版社的<实用有机化学辞典>[4]可知,同系物不仅局限于相差一个或几个"CH2"的物质,而是分子结构相近,化学性质相似,具有一个通式,组成彼此一个或若干个原子团的一系列化合物.贵刊报道所述的都仅限于A W nB形式(W代表系差),由于所列出的物质的系差都比较直观,理所当然通式也易求得.当实际上组成系差的原子数目可能与"n"相关,则通式就不易求出,这时要善于挖掘题意隐含,充分运用等差、等比数列等数学知识,方可使通式水落石出.     

谈谈酸碱滴定教学中新知识的引进

对分析化学酸碱滴定教学中引进酸碱滴定通式的问题进行了讨论。通过实例表明,将酸碱滴定通式引入到教学中,有助于学生更完整正确地把握酸碱滴定的理论。     

Design and use of reference data sets for testing scientific software

A general methodology for evaluating the accuracy of the results produced by scientific software has been developed at the National Physical Laboratory. The basis of the approach is the design and use of reference data sets and corresponding reference results to undertake black-box testing.

The approach enables reference data sets and results to be generated in a manner consistent with the functional specification of the problem addressed by the software. The results returned by the software for the reference data are compared objectively with the reference results. Quality metrics are used for this purpose that account for the key aspects of the problem.

In this paper it is shown how reference data sets can be designed for testing software implementations of solutions to a broad class of problems arising throughout science. It is shown how these data sets can be used in practice and how the results provided by software under test can properly be compared with reference results. The approach is illustrated with three examples: (i) mean and standard deviation, (ii) straight-line fitting, and (iii) principal components analysis. Software for such problems is used routinely in many fields, including optical spectrometry.     

The development of a new LDF mass transfer correlation for adsorption in fixed beds

In this study, a general LDF model has been introduced to predict mass transfer rate through adsorbents with the macropore diffusion as the controlling step. Using this relation eliminates the need for solving the time-consuming diffusion equation to find mass transfer rate through the porous adsorbent. The proposed relation was successfully applied in the general mathematical model for an adsorption fixed bed. This correlation was adjusted to be capable of predicting the mass transfer rate in a wide range of gas adsorption systems reported in the literature. This correlation was used in 21 different adsorbent and adsorbate systems. The results demonstrated an excellent agreement between the correlation results and those obtained using Fickian diffusion equation. By applying the developed LDF model instead of diffusion model, a great deal of CPU time can be saved. The latter characteristic will be very important when this model is employed in commercial software such as Aspen Adsorption or Prosim Dynamic Adsorption Column.     

Designing Interactive Instructional Software: Students as Educators

This paper reviews a project conducted as part of a general chemistry course. The primary goal of the assignment was to involve our students in the process of teaching chemistry. Our work is part of STEMTEC, the Science, Technology, Engineering, and Mathematics Teacher Education Collaborative, which has been developed to improve the preparation of preservice teachers, stimulate the interest of undergraduate science and mathematics majors in the teaching profession, and increase the educational effectiveness of science and mathematics courses. The assigned project required students to create an interactive computer module that could be used to educate other students about concepts taught in general chemistry. The paper includes examples of these modules and evaluates this method of instruction. The software programs designed by the students are available for download from the Internet ().     

Introduction of measurement uncertainty estimation into analytical instrument software: mission impossible?

In this paper we argue that introduction of ISO GUM based uncertainty estimation into analytical equipment software is a “mission possible” and is wholly realistic at this stage of development of the art. A possible general scheme of implementation of uncertainty estimation into analytical instrument software is presented based on the example of high-performance liquid chromatography (HPLC) but is also applicable to most other analytical instruments. This implementation would be very beneficial for the analysts/practitioners as the uncertainty would be handled within their everyday software environment.     

DynamO: a free O(N) general event-driven molecular dynamics simulator

Molecular dynamics algorithms for systems of particles interacting through discrete or "hard" potentials are fundamentally different to the methods for continuous or "soft" potential systems. Although many software packages have been developed for continuous potential systems, software for discrete potential systems based on event-driven algorithms are relatively scarce and specialized. We present DynamO, a general event-driven simulation package, which displays the optimal O(N) asymptotic scaling of the computational cost with the number of particles N, rather than the O(N) scaling found in most standard algorithms. DynamO provides reference implementations of the best available event-driven algorithms. These techniques allow the rapid simulation of both complex and large (>10(6) particles) systems for long times. The performance of the program is benchmarked for elastic hard sphere systems, homogeneous cooling and sheared inelastic hard spheres, and equilibrium Lennard-Jones fluids. This software and its documentation are distributed under the GNU General Public license and can be freely downloaded from http://marcusbannerman.co.uk/dynamo.     

Introduction of measurement uncertainty estimation into analytical instrument software: mission impossible?

In this paper we argue that introduction of ISO GUM based uncertainty estimation into analytical equipment software is a “mission possible” and is wholly realistic at this stage of development of the art. A possible general scheme of implementation of uncertainty estimation into analytical instrument software is presented based on the example of high-performance liquid chromatography (HPLC) but is also applicable to most other analytical instruments. This implementation would be very beneficial for the analysts/practitioners as the uncertainty would be handled within their everyday software environment.

     

New applications of electron diffraction in the pharmaceutical industry: polymorph determination by using a combination of electron diffraction and synchrotron X-ray powder diffraction techniques.

Electron diffraction has been recently used in the pharmaceutical industry to study the polymorphism in crystalline drug substances. While conventional X-ray diffraction patterns could not be used to determine the cell parameters of two forms of the microcrystalline GP IIb/IIIa receptor antagonist roxifiban, a combination of electron single-crystal and synchrotron powder diffraction techniques were able to clearly distinguish the two polymorphs. The unit-cell parameters of the two polymorphs were ultimately determined using new software routines designed to take advantage of each technique's unique capabilities. The combined use of transmission electron microscopy (TEM) and synchrotron patterns appears to be a good general approach for characterizing complex (low-symmetry, large-unit-cell, micron-sized) polymorphic pharmaceutical compounds.     

A Computer-based, Interactive, Multimedia Software System for Teaching and Independent Student Learning of Liquid Chromatography

This paper describes the design and development of an interactive, simulation-based education software system for the exploration of key concepts in liquid chromatography. Evaluation results of student use of the software will be presented.Software modules have been designed to supplement, but not replace, classroom and laboratory learning about liquid chromatography, providing students with theory, visual aids, and interactive simulations. Combined with animations and narration, the modules complement the foundation on which chromatography is taught in a general, analytical, or organic chemistry setting. Furthermore, this software allows the student to interact with the illustrated chemistry lessons, which is especially important in instances where the concepts taught transcend typical classroom material.This work serves to connect what one observes experimentally in a chromatography experiment to changing parameters such as capacity factor, number of theoretical plates, height equivalent of a theoretical plate, column length, resolution, retention time, and selectivity factor. Simulated separations are portrayed in an animated fashion as a chromatogram developing over time as a function of one or more of these variables. Finally, the software has real sample, mobile phase, column type, flow rate, and detection type options allowing the selection and simulation of solving a realistic chromatography problem. Hypothetical unknown mixtures can be separated and the sample components identified after simulating the separation of known samples.     

Design and synthesis of a diverse morpholine template library

Efficient and general procedures have been developed for the solution-phase preparation of substituted morpholine derivatives, and a library has been produced around generic structure 1. This library was designed with proprietary modeling software for use as a general screening library. The 30 R1 reagents were phenols, and the 275 R2 reagents were taken from five different reagent classes, giving a variety of product classes in the final library of 8250 potential products. All of the library members were generated from a common intermediate, mesylate (5), which was synthesized efficiently, in bulk, in three steps from N-benzylethanolamine (2). High-throughput chemistry using robotics was carried out to produce the 7907 library members, which were individually characterized by reversed-phase LC/MS analysis.     

Multicomponent salt systems: Methodology, studies, achievements, and promises. Proceedings of the 68th Kurnakov readings, Moscow, 2009

AvtoKMIMS, an automated integrated methodology for studying multicomponent systems, has been developed. It includes a general study algorithm using software for modeling phase complexes and newgeneration differential thermal analysis equipment for performing single confirming experiments. AvtoK-MIMS rapidly and rationally obtains accurate information from the phase diagrams of multicomponent systems, thus giving impetus to create innovative materials and technologies.