有限可解群的一些充分条件

利用子群的弱c-正规性得到了有限可解群的一些条件.首先,得到了有限可解群的一个充要条件,即有限群G是可解群当且仅当G的任二相邻子群A,B有A在B中弱c-正规.其次,得到了有限可解群的一些充分条件,若有限群G满足下列条件之一,则G是可解群;G的任一极大子群M的Sylow子群均在G中弱c-正规;G的任一极大子群M的极大子群均在G中弱c-正规;假设H是G的Hallπ-子群且2∈π,如果N_G(H)是可解群且在G中弱c-正规.     

有限群的弱c—正规子群与可解性

群G的一个子群H称为在G中弱c-正规,如果存在G的一个次正规子群K,使得G=HK且H∩K≤HG,其中HG是包含在H中的最大的正规子群,利用子群的弱c-正规性给出了一个群为可解群的若干充分条件.     

有限群的s-正规子群与可解性

群G的一个子群H称为在G中s-正规，如果存在G的一个次正规子群尼使得G=HK且H∩K≤HSG，其中SG=〈Hi／Hi在G中次正规且Hi包含于H〉．利用子群的s-正规性对有限群结构的影响，给出了有限群可解的若干充分条件．     

弱C-正规子群与有限群的可解性

首先利用H a ll子群的弱c-正规性,得到了有限群π-可解得一个充分条件,并推广了S chur-Z assenhaus定理;其次利用子群的弱c-正规性得到了有限群G可解的一些充分条件和非单位正规子群可解的一个充要条件.     

共轭置换子群对群p-幂零性的影响

群G的一个子群H称为自共轭置换子群,如果对于g∈G,由HHg=HgH可推出H=Hg.本文利用P阶及4阶循环子群的自共轭置换性讨论有限群的结构,给出了此类群的结构描述．     

子群的局部M-正规性

子群H称为在群G中M-正规的,若存在正规子群B,使得G=HB,且对于H的任意极大子群H1,都有H1B为的G真子群.将子群的性质局部化,即在群G的Sylow子群的正规化子中来考察这一性质,对有限群构造作进一步探索,得到P-幂零群、超可解群的一些新结果.     

有限群的弱拟正规子群及其性质

称群G的子群H为G的弱拟正规子群，如果G中存在一个p-sylow子群与H可换，其中p为|G|的任意素数因子。本文讨论了弱拟正规子群的性质并给出一个群为可解群的一些条件。     

CC-子群与有限群结构

该文主要利用CC-子群的存在性来刻画有限群。首先,从CC-子群的存在性推导了一部分已知阶群的结构;其次,推导了当次正规子群和正规子群为CC-子群时的有限群的简单结构,得到了以下主要结论：定理1（1）若｜G｜=pq,p,q为素数,若G无CC-子群,则G为交换群。（2）若｜G｜=p2qn,p,q为奇素数,若G的CC-子群个数为1,则G为q幂零群.定理2设G为有限可解群,若G的每个次正规子群均为CC-子群,则｜G｜=pq。定理3设G为有限可解群,若G的每个正规子群为CC-子群,那么｜G｜=pqn,G=〈a〉G＇,其中,〈a〉为p阶子群。     

某些s-拟正规子群对有限群结构的影响

利用某些子群的s-拟正规性,得到了有限p-幂零群和超可解群的充分条件,即：（1）p是IGI的最小素因子且PESyl一（G）．若P的每个极大子群在G中s-拟正规,则G是户一幂零群;（2）N是有限群G的一个正规子群且使得G／N为超可解群．如果F＊（N）的任意奇阶Sylow子群Q的所有极大子群均在NG（Q）中s-拟正规,F＊（N）的Sylow2-子群的极大子群在G中s-拟正规,则G是超可解群,并推广了一些已知结果．     

Huppert定理的推广

将有限群理论中的著名的Huppert定理推广至群系中．具体地,设F为一个包含超可解群类μ的饱和群系,G为一个有限群,N为G的一个使得G／N∈F成立的正规子群．若对G的任一个不包含N的极大子群M,均有[G：M]是一个素数,则G∈F．     

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,     

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.     

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?     

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.