取代苯化合物生物可降解性的定量预测

应用分子电性距离矢量(MEDV)结构表征取代苯化合物和预测相对生物可降解性(relative biodegradability),通过多元线性回归方法建立MEDV与相对生物可降解性之间的定量模型,结果良好,其模型相关系数为P=0.953;继以留一法(leave-one-out,LOO)交叉检验,相关系数为R=0.912,说明定量相关模型的稳定性和预测能力良好.     

Teaching aerodynamics using a microcomputer

An interactive and wholly automatized computer code has been developed on a microcomputer for the aerodynamic analysis of airfoils in incompressible now fields. It is intended to serve as a useful support in teaching aerodynamics. The code contains a number of modules (or blocks) for: (1) drawing the shape with the help of an interactive graphic device interfaced with the microcomputer; (2) computing the aerodynamic inviscid and viscous flow field and the aerodynamic coefficients; (3) modifying and/or correcting the body shape and then computing the new aerodynamic coefficients. In this way the student can evaluate, operating directly and interactively, the influence of the changes in shape on the aerodynamics of the airfoil under study.     

Visual interactive simulation using a microcomputer

The paper describes an approach to discrete event simulation in which the status of a model is dynamically displayed on a graphics screen. The end user may watch and interact with the model in order to try alternative strategies. The paper reports that the visual interactive technique, if used on a time sharing computer suffers due to variable response times and that the implementation using a microcomputer gives a feasible alternative.     

Analysis of mixed lipid extracts using 1H NMR spectra

A method has been developed for rapid analysis of lipid proton NMR spectra. Identification of lipid content is possible because of the presence of unique peaks or ratios of peaks for individual lipids. Spectra can be subdivided into regions where peaks represent certain chemical groups held in common, or uniquely by the various lipids. Vectors (B) are made up of the areas of these subdivisions of peaks from spectra of unknown components. A new FORTRAN algorithm, LIPICK, tests for the presence of unique peaks or combinations of peaks to determine which lipids may be present. The spectra vectors of known identified lipids are then placed in the (A) matrix of possible solution candidates. Quantitation of lipids in an 1H NMR spectrum (B) of an unknown mixture then proceeds by solving the equation AX = B for X (the concentrations of the individual lipids present) by singular value analysis. At this time, it is possible to test 1 mg of total lipid for the presence and relative concentration of 15 common lipids: cholesterol and its esters; phosphatidyl-ethanolamine, -choline, -serine, -inositol, -glycerol; tri- or di-glycerides; fatty acid; lysophosphatidylcholine; sphingomyelin; cerebrosides and sulfatides; dolichol and dolichol P; and phosphatidic acid. This procedure is suitable for membrane lipid analysis and has been evaluated using known mixtures of purified standard lipids.     

Analysis of plane frames using a microcomputer

It is now mandatory to perform several iterations on a structure to get an optimum design. This requires the use of a digital computer. A major difficulty encountered by users of microcomputers is the non-availability of software. In this paper, a program developed by the authors for the analysis of plane frames is described. The output for an example problem is also given. This program is a powerful tool for the analysis and design of these frames which are frequently encountered in practice.     

Landmarking of cephalograms using a microcomputer system

Landmarks, or certain characteristic reference points, on cephalograms are used as a diagnostic aid employed in treatment planning by orthodontists. This work presents an algorithm for recognizing some anatomical features and locating landmarks on lateral skull X rays (cephalograms) using digital image processing and feature recognition techniques. A cephalogram is digitized and stored in a computer memory. Prefiltering is applied to remove image noise. The bony and flesh profiles of jaw and front face are traced. Using these profiles the algorithm locates 17 points on the image, some on bony features and others on soft tissue. To locate these points, edge-enhancement, thresholding, and edge-detection techniques are applied. The algorithm can be run on an IBM compatible microcomputer.     

Analyzing the oxidation of graphite using a microcomputer

A graphics program, written in BASIC and designed for use on a microcomputer, has been created which analyzes the oxidation of a single layer of a graphite crystallite. With this program, one can see how differences in relative activities of reactive sites can produce differently shaped holes and edges in graphite crystallites. The results then can be compared with experimental observations to test proposed burning mechanisms. Using the program has shown that proposed relative activities of active sites does produce equilateral hexagonal etch pits, as observed experimentally.     

A microcomputer program for second-order simulation of EPR spectra

A program for second-order simulation of isotropic EPR spectra has been developed for a microcomputer Apple II Plus. The programming is done in UCSD Pascal language. A recursion algorithm is developed for nuclear spin I < 0.5. Some applications of second-order simulations are calculated and discussed.     

A C-language program for the computation of power spectra on a laboratory microcomputer

A computer program is described which performs power-spectral analyses on time-domain data. The program is written in the C language and incorporates an algorithm for the fast Fourier transform translated from BASIC into C. Sequential segments of time-domain data are accessed by the program, transformed to the frequency domain, and ensemble-averaged to generate smoothed spectra. Specific application of the program to the detection of high-frequency oscillations in the phrenic neurogram of the cat is addressed. Thus, 100 successive 512-point fast Fourier transforms were found to accurately reveal the relative strength (power) and frequency position (spectrum) of multiple peaks in this respiratory motor pathway. Because C language programs are very transportable, this program should run on machines other than our LSI 11/23, provided a C-compiler is available.     

Surgical audit using patient records on a microcomputer

The collection and manipulation of patient data from the earliest stage by microcomputer is a desirable goal as in this way valuable information is captured which can be used for the administration of hospital admissions and subsequent analysis of the data will provide the information required for surgical audit. We have implemented a system using a pair of Apple II microcomputers with specifically written software in UCSD PASCAL that has been used in the clinical environment with proven success.     

Interactive postprocessor and animation system using a microcomputer

This paper is concerned with the development of a microcomputer-aided graphic system. In this system the difficult task of computation for graphical representation is carried out on a large computer, whereas a microcomputer is used as the graphic terminal. Interface programs are newly developed for this purpose. A technique is proposed here to minimize the transfer time of graphic data from the large computer to the microcomputer. Finally, the animation and the interactive tomography systems are developed as extensions of the graphic system.     

Plastic design of steel portal frames using a microcomputer

The greatest benefit to structural designers from the use of microcomputers will probably come from the time savings which can be obtained in the design processes which would previously have been performed manually. One example of this is industrial portal frame design using plastic theory. A program has been developed which aids the designer in this task. All of the fairly simple but very time-consuming calculations involved are done rapidly by the machine, while leaving complete control with the designer. The design process is similar in sequence and appearance to its manual equivalent and can therefore be performed with the minimum of learning by the engineer. The time savings are, nevertheless, very considerable. Whilst greater speed can be achieved in some cases by allowing automatic optimisation, the combination of computer and experienced designer working together is extremely efficient, and is the quicker when factors not easily incorporated into the optimisation process become important.     

Life-cycle studies of a concrete structure using simulation on a microcomputer

This paper describes a means of exploiting the combination of microcomputers and Monte Carlo simulation to perform a systematic life-expectancy and financial analysis. The use of the program Venturer, is illustrated using an example of a footbridge. The service life of the structure is modelled using the times taken for carbonation and visible corrosion. The possible prolongation of the life expectancy due to the application of a coating is considered. The results of sensitivity analyses which indicate the relative importance of the factors considered are also shown.     

A unified approach to shaft calculations using a microcomputer

This paper describes a program written for a microcomputer which allows shaft (or beam) calculations to be made for a wide range of geometrical, loading and support conditions. Expressions for generalized support conditions are developed including support flexibility and unloaded support misalignment. The program, occupying 6100 bytes of memory without problem data statements, is shown applied to a simple flexible support problem and to a complex paper-making machine shaft mounted on 21 supports.     

ANTHEPROT: a package for protein sequence analysis using a microcomputer

A simple microcomputer package is described to make the theoretical analysis of protein sequences. Several methods designed to compare two sequences, to model proteolytic reactions and to predict the secondary structure, the hydrophobic/hydrophilic regions and the potential antigenic sites of proteins have been included in an Apple II microcomputer software. The package comprises 21 programs as well as the secondary structure database of Kabsch and Sander (1983).     

Calculation of charges from photoelectron spectra

A computer program to calculate charges on the various atoms in a molecule using experimentally determined binding energies from X-ray photoelectron spectra is described. The method is based on the charge potential model with the incorporation of electronegativities. A program written in BASIC suitable for execution on IBM PC compatible computers is presented, along with two auxiliary programs for the projection of a molecule and for the calculation of interatomic distances within two given moieties.