酶法水解动物蛋白工艺研究

用三种不同蛋白酶(胰蛋白酶和酸性蛋白酶)对猪肉在不同条件下进行酶解，利用甲醛滴定法对水解效果进行了对比。采用L18(37)确定两种蛋白酶水解猪肉的最佳工艺参数。     

电视发射机非线性指标的分析与测试

讨论了部分电视发射机的非线性指标及其测试方法，如互调、微分增益、微分相位、亮度非线性等，指出了实践中存在的问题和应当注意的方面。     

高速铣削的技术特点及在模具加工的应用

分析了高速铣削加工的技术特点及对加工设备、数控系统、刀柄和刀具、加工工艺的技术要求,并指出高速铣削技术在模具加工应用的优越性。     

遗传模拟退火算法在非线性最小二乘中的应用

对于非线性最小二乘问题,传统的算法往往是从一个初始值开始,经过迭代来逼近问题的最优解,其结果必会受到初始值的影响,而遗传模拟退火算法求解则具有很好的全局搜索能力,不受初始值的影响.研究表明,采用遗传模拟退火算法来求解非线性最小二乘问题,可取得较好的效果.     

广义洛特卡分布特征参数解区间的确定*

广义洛特卡分布特征参数解区间的确定对于研究两组科学生产数据的相容性非常关键。采取记录通过K-S检验的特征参数的最小值和最大值的方法,探讨了广义洛特卡分布特征参数解区间的确定,编制了确定解区间的Matlab计算程序。实例验证表明计算程序简单方便、吻合度较好。     

Prolonged static stretching does not influence running economy despite changes in neuromuscular function

Abstract

The aim of this study was to examine the acute effects of prolonged static stretching (SS) on running economy. Ten male runners ([Vdot]O_2peak 60.1 ± 7.3 ml · kg^?1 · min^?1) performed 10 min of treadmill running at 70%[Vdot]O_2peak before and after SS and no stretching interventions. For the stretching intervention, each leg was stretched unilaterally for 40 s with each of eight different exercises and this was repeated three times. Respiratory gas exchange was measured throughout the running exercise with an automated gas analysis system. On a separate day, participants were tested for sit and reach range of motion, isometric strength and countermovement jump height before and after SS. The oxygen uptake, minute ventilation, energy expenditure, respiratory exchange ratio and heart rate responses to running were unaffected by the stretching intervention. This was despite a significant effect of SS on neuromuscular function (sit and reach range of motion, +2.7 ± 0.6 cm; isometric strength, ?5.6% ± 3.4%; countermovement jump height ?5.5% ± 3.4%; all P < 0.05). The results suggest that prolonged SS does not influence running economy despite changes in neuromuscular function.     

Prediction equation for head volume of Japanese young adults

Accurate measurement of head volume is indispensable for precise assessments of body composition determined by hydrostatic weighing without head submersion. The purpose of this study was to establish a prediction equation for head volume measured by the immersion method from multiple regression analysis using head parameters (head circumference, head length, head breadth, neck girth and head thickness) as independent variables. The participants were 106 Japanese young adults (55 males and 51 females) aged 17?–?27 years. Intra-class correlation coefficients (ICCs) for each head parameter and head volume in males and females were very high (ICC = 0.993?–?0.999, 0.992?–?0.998). Head circumference was closely related to head volume measured by the immersion method (r = 0.719, 0.861, P <?0.05), and was the most important parameter for the prediction equation in both sexes. Head breadth was related poorly (r = 0.475, 0.500, P <?0.05) and showed a small individual difference. It was, therefore, excluded from the independent variables. The prediction equation for males was predicted head volume = 122.10X ₁ + 106.19X ₃ + 37.16X ₄ - 89.46X ₅ - 4754.93, R = 0.909, SEE = 121.75?ml, and that for females was predicted head volume = 213.83X ₁ + 45.24X ₃ + 36.85X ₄ - 74.34X ₅ - 8912.43, R = 0.913, SEE = 136.26?ml (where X ₁ = head circumference, X ₃ = head length, X ₄ = neck girth, X ₅ = head thickness, and SEE = standard error of the estimate). The limits of agreement for predicted and measured head volume were –?234.5 to 234.1?ml for males, and ??261.0 to 261.0?ml for females. In cross-validation groups of both sexes, there were no significant differences between measured head volume and predicted head volume. The correlation coefficients between measured head volume and predicted head volume in males and females were 0.894 and 0.908, respectively. The predicted head volume from prediction equations was considered to have high reliability and validity.     

Sport and Mathematics: A Definition and Delineation

Abstract

Charles O. Dotson begins this section by discussing the concept of research reflecting high density logic, indicating that the most desirable research papers are those sharply reasoned contributions with maximal application of inductive syllogisms. This is followed by a critical review of the quality of research published in the Research Quarterly over the past 50 years. Dotson suggests that much of this research reflects low logical density, and concludes his paper with several recommendations for upgrading the logical density of research in physical education. The second paper in this section was prepared by Robert W. Schutz, who discusses the role of mathematical analysis in the study of sport strategy and structure and in the development and verification of theories of motor behavior. Schutz delineates a field of sports studies labelled sport mathematics and classifies topics of investigation amenable to mathematical analysis. He presents arguments supporting the identification of mathematics and sport as a subdiscipline within sports studies. Mathematical analysis in the study of motor behavior, on the other hand, is viewed as a methodology.     

五角形状的典型零件PowerMILL五轴模拟加工实践

以五角形状典型零件为例,采用powermill软件模拟五轴加工,并对模型中负角、斜面钻孔、球面刻字等难加工区域进行分析,提出解决的方法,确保加工安全可靠。     

数控车（铣）床试切法对刀探究

在数控加工中,工件坐标系确定后,还要确定刀具的刀位点在工件坐标系中的位置,即常说的对刀问题。数控机床上,目前,常用的对刀方法为手动试切对刀。而对刀是数控加工中最主要的操作以及最重要的技能,在可稳定的条件中,提高加工中的对刀精度是零件生产加工中的重要环节。本次研究中从数控车（铣）床的对刀原理相关技术以及对刀方法来阐述与探究,对刀选择中使用广州数控980T系统来举例提出相关论述。