数列极限ε-N定义的注记

从数列极限概念的定性描述出发，通过对“无限增大”、“无限接近”的精确数学表述，引出了数列极限的定义，并对数列极限的定义作了几何上的分析。     

数列极限定义"ε-N"语言阐释

数列极限定义“ε-N”语言是经典的分析定义，它把极限认识过程的定性描述转化为定量描述。更加准确地把握极限过程的合理性与精确性。     

二个新的极限定义—空心极发与实心极限

本文对极限的传统定义作了一些补充，给出了二个新的极限定义－空心极限和实心极限，并在此基础上改进了一些相关的定理。     

关于数列极限定义认知过程的教学

从数列极限的描述性定义出发,采用逐步精确化的方法,引出数列极限精确的数学语言定义,以便于学生深刻理解数列极限的定义的本质。同时通过实例用极限的精确定义证明数列的极限,并指出了证明时的要点。     

谈数列极限定义教学

数列极限定义是学习极限理论的基础和难点之一，在教学中，宜采取由具体到抽象、由浅入深的方法，先通过数列极限实例引入数列极限的严格定义，再拓展联系进一步分析定义，最后由定义的定量描述返回到定性描述。     

数列极限概念教学的探讨和实践

数列极限的“ε-N”定义是数学分析中非常重要的一个概念,也是初学数学分析的学生不容易掌握的概念.本文通过6个问题,论述数列极限定义的教学方法与实践.     

数列极限“ε-N”定义的教学组织

数列极限对建立函数的各种极限形式有重要的引领作用．本文用形式逻辑思维和辩证逻辑思维,从四个有机关联的层面对数列极限“ε-N”定义的教学进行组织．     

从极限的概念谈定性向定量描述的数学转化思想

极限是微积分中重要概念,也是研究函数各种性质的重要工具。本文从最简单的数列极限的定性定义入手,分析了此定义的缺点,进行分析,最终导出了极限的定量定义,解决了这一教学难点,进而将这种分析方法推广到函数的极限。     

极限定义教学探讨

从极限定义的引出以及定义的正反两方面分析，结合计算机辅助教学讨论极限定义教学的方法和过程。     

关于数列极限定义教学中的几点注记

本文就数列的极限的“ε -N”定义的教学从对ε、N的理解与具体证明谈了五点注记     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.