计算机多元分析在饲料研究中的应用     

李华祥  刘庆颖 《广东海洋大学学报》1991,(1)

本文用多元分析方法运用电子计算机依10种动物必需氨基酸构成比例对58种饲料进行数值分类。分类是用欧氏距离作为相似性测度,聚类算法采用类平均距离法,得到一系统聚类图。  相似文献   

EPR study of coordination of Ag and Pb cations in BaB<Subscript>2</Subscript>O<Subscript>4</Subscript> crystals and barium borate glasses     

V. P. Solntsev  R. I. Mashkovtsev  A. V. Davydov  E. G. Tsvetkov 《Physics and Chemistry of Minerals》2008,35(6):311-320

It is shown the possibility to determine the coordination of paramagnetic ions in disordered solid structures, e.g., in barium borate glasses. For this purpose the electron paramagnetic resonance (EPR) method was used to study α-and β-BaB₂O₄ crystals and glasses of 45·BaO × 55·B₂O₃ and 40·BaO × 60·B₂O₃ (mol%) composition activated by Ag⁺ and Pb²⁺ ions. After the samples were exposed to X-rays at 77 K, different EPR centers were observed in them. In α-and β-BaB₂O₄ crystals and glasses the EPR centers Ag²⁺, Ag⁰, Pb⁺, Pb³⁺, and hole centers of O⁻ type were studied. The EPR parameters of these centers and their arrangement in crystal structure were determined. It is shown that Pb³⁺ ions in β-BaB₂O₄ crystals occupy Ba²⁺ position in an irregular polyhedron from the eight oxygen, whereas in α-BaB₂O₄ crystals they occupy Bа₂ position in a sixfold coordination. Pb⁺ ions in α-BaB₂O₄ crystals occupy Bа₁ position in a ninefold coordination from oxygen. In barium borate glasses, Pb³⁺ ions were studied in coordination polyhedron from six oxygen atoms and in a polyhedron from nine to ten oxygen atoms. It is assumed that the established difference in the structural position of Pb³⁺ ions in glasses is due to their previous incorporation in associative cation–anion complexes (AC) and “free” structure-forming cations (FC). Computer simulations have been performed to analyze the stability of specific associative complexes and to compare their bond lengths with experimental data.  相似文献   

计算机真实感图形技术在数码城市可视化中的应用   总被引：2，自引：0，他引：2  

刘强 《四川测绘》2001,24(4):156-158

目前，数码城市的建设正逐渐成为我国信息产业的热点，如何真实，生动，实时地表现城市面貌，是数码城市建设要达到的关键目标之一。本文对计算机真实感图形技术在数码城市可视化建设中的应用进行了初步探讨。  相似文献   

《数字地图制图学》课件的设计   总被引：2，自引：0，他引：2  

王泽根  郭健  郑海鹰 《测绘工程》2001,10(1):60-62

计算机辅助教学对提高学生的学习效率和教学质量具有传统教育不可比拟的优越性。本文介绍了《数字地图制图学》课件的设计思想、特点、原则、环境和制作流程，并总结了对CAI设计与制作的经验与体会。  相似文献   

计算机辅助岩土工程(CAGE)概论     

黄运飞  赵术强 《工程地质学报》1997,5(4):357-361

本文简要论述了计算机辅助岩土工程(CAGE)的提出、发展、方法及主要内容, 最后给出了计算机辅助核电工程勘察实例。  相似文献   

A numerical model for shore-normal sediment size variation on a macrotidal beach     

Diane P. Horn 《地球表面变化过程与地形》1992,17(8):755-773

This paper describes a computer simulation model which is designed to predict the selective shore-normal sorting of grain sizes in the nearshore environment. The model simulates wave shoaling, wave height attenuation due to frictional losses and breaking, using linear theory up to the break point and a breaker decay model in the surf zone. Peak horizontal orbital velocities at the bed are calculated from Stokes second-order wave theory. The peak onshore and offshore velocities are used with the threshold expression of Komar and Miller (1975) to generate a spatial pattern of size variation of threshold grain diameter along a profile normal to the shore from deep water to the swash zone. The predicted grain size is used in an hydraulic interpretation of grain size distribution on the intertidal profile, based on the hydrodynamic variations over a tidal cycle on a macrotidal beach. The model is successful in predicting the broad pattern of increasing grain size in the onshore direction which has been observed in nature. Comparisons between measured and predicted grain size distributions indicate that the predictions of the model are better than those of previous models, but the model is more successful at predicting sediment size distributions than at predicting mean sizes on a beach profile.  相似文献   

Computer estimation of intensities: The 1985 Berhida,Hungary, earthquake     

Tibor Zsíros  Péter Mónus  László Tóth 《Pure and Applied Geophysics》1990,132(3):533-543

In this paper a computerized method for the intensity estimation from macroseismic observations is presented. The successive steps of the MSK intensity scale (2° to 10°) receives weights according to the observations marked on the earthquake questionnaires. These weights are summed for the individual scale steps. The distribution of these summed weights and their relation to an experimentally chosen function of the criterion make it possible to estimate the appropriate intensity value and its reliability. By computer evaluation of earthquake reports an objective comparison of estimated intensities given by different seismologists can be made, provided that uniform earthquake questionnaires are used. The application of this method will result in more homogeneous intensity data.  相似文献   

Segmentation of contacting soil particles in images by modified watershed analysis     

《Computers and Geotechnics》2016

Image-based soil particle size and shape characterization relies on computer methods to process and analyze the images. For contacting particles spread on a flat surface this requires delineation of particle boundaries through shape-based image segmentation. The traditional method using watershed analysis fails for particles that have constrictions (are peanut-shaped). The oversegmentation interprets such particles as being two, thereby underestimating the long particle dimension by about 50% and overestimating particle sphericity by about a factor of two. This paper presents a solution to the problem of oversegmentation through morphologic reconstruction. The key to this improvement is distinguishing the necks in peanut shaped particles from actual contacts between particles. A parameter α is defined to quantify the necks and contacts. Approximately 220,000 particles in a range of 2.0–35.0 mm having various shapes and angularities were studied to find typical α values for necks and contacts. An algorithm is proposed to correct the oversegmentation based on α. The results show that this improved watershed analysis accurately segments sand particles at contacts while preserving the continuity of peanut shaped particles. Example lab tests demonstrate the significance of the problem and its solution.  相似文献   

一种工业计算机局部网络通信协议     

游华 《中国海洋大学学报(自然科学版)》1994,(Z2)

介绍了一种用于工业现场的计算机局部网络通信协议．详细介绍了网络的硬件结构和与之相配合的软件设计．同时，对其中关键技术如介质存取控制方式，数据的ＤＭＡ存取，缓冲区的分配与管理等作了重点说明．  相似文献   

The EPIC atmospheric model with an isentropic/terrain-following hybrid vertical coordinate     

Timothy E. Dowling  Mary E. Bradley  John Kramer  Grace C.H. Lee  Raul Morales-Juberías  Vimal K. Parimi 《Icarus》2006,182(1):259-273

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