目的:探讨中等强度有氧体育锻炼对大学生工作记忆的影响,确定有氧体育锻炼对记忆的改善效果.方法:利用Grant和Degenback的计算广度任务测试中等强度有氧体育锻炼前后大学生工作记忆的变化情况.结果:实验组与对照组的计算能力没有显著性的差异,说明中等强度有氧体育锻炼并不能够直接提高大学生的数学计算能力;实验组在实验后数字错误数、反应时方面要明显的优于对照组,并且与对照组具有显著性的差异.意义:中等强度有氧体育锻炼可以有效地改善大学生的工作记忆能力,可以在大学的体育课堂增加中等强度有氧体育锻炼方式,以此来增强大学生的工作记忆水平.

本文以沈阳大学的2个排球普修班为实验对象,以软式排球和硬式排球教学为教学方法,对排球的技术测试进行了相关的分析,通过实验,对排球技术测试的比较结果分析:经过组间对比发现,在实验前,实验组与对照组的传球、垫球和发球没有显著性的差异,但是在实验后,实验组与对照组的传球、垫球和发球具有显著性的差异;进行组内对比,对照组和实验组实验前后传球、垫球和发球均存在显著性差异,而实验组的传球、垫球和发球成绩要明显好于对照组.

介绍了FEM地层元素测井仪的研制与设计.采用BGO晶体探测器,相较于传统的NaI(T1)探测器,较大地提高了对伽马射线的探测效率.为了消除仪器自身材料产生的俘获伽马本底,在仪器外表面加了一定厚度的硼套;重点分析了采集控制电路的设计及流程,以及元素标准谱的制作方法、解谱方法和氧化物闭合模型.对FEM地层元素测井仪进行了模型井和现场测井试验,试验结果证实了在不同岩性地区FEM测井曲线均能较好地反映地层岩性特征.

Based on years of teaching experience and a great number of calculation exercises,the knowledge is summarized and the conclusion is got that solving the problem of sequence of number with the knowledge of function,not only can deepen students' understanding of the concepts of sequence of number and function,but also enhance students' knowledge of the cognitive law that getting the general idea from specialty,and apply the general idea to specialty.

The definition and the theoretical foundation of the comprehensive teaching method are fully illustrated.Based on many years of teaching experience,good teaching effect has been achieved.It is pointed out that teachers should utilize more appropriate teaching methods to make students participate in learning more consciously,and accept knowledge more actively.This method placed students in a multiple environment,which provided a broader learning space for students,and helped students to acquire a new learning method by self-study and self-research.

In this paper,we formulate a predator-prey Gompertz model in a polluted environment with pulse toxicant input and the predator is stage structured.We obtain sufficient conditions for global attractability of the predator-extinction periodic solution and permanence of the system.

MSA6240 mechanical sidewall contact device mainly consists of microelectrode arm linkage and caliper arm linkage.It can perform the function of minilog,caliper log and microspherically focused log in one run.This paper theoretically analyses its working principle and finally verifies the rationality of the device.

In this paper,considering biological control and chemical control strategy and the effects of chemical pesticides on natural enemy,we propose a predator-prey model with Ivlev's functional response by using impulsive differential equation.It is proved that there exists an asymptotically stable pest-eradication periodic solution when the impulsive period is less than some critical value.Otherwise,the system can be permanent.We obtain that our impulsive control strategy is more effective than the classical one if we take chemical control efficiently.

The exact divided of polynomial in the rational number is discussed when investigate the problem of polynomial in the rational number.The other form of the discriminance of Eisenstein is given.