又一个特征为素数的无限域

构造出一个特征为素数的无限域借以避免人们误认无限域以素数为特征的仅只（K,,⊙）一个,其中K={f（x）/g（x）｜f（x）,g（x）∈Zp[x],g（x）≠0,p为素数},,⊙分别是有理函数域中的加及乘运算.     

对一道高等代数题的推广

张禾瑞在《高等代数》（第五版）习题中给出了多项式的一个结论：＂设f（x）,g（x）和h（x）是实数域上的多项式,证明若f（x）2=xg（x）2＋xh（x）2,那么f（x）=g（x）=h（x）=0＂。本文借助一般化方法将该结论推广为更一般的定理,并给出了证明。     

三角形三边不等式的代数变换f(a,b,c)=f(y+z,z+x,x+y)

关于△ABC三边a、b、c的不等式证明，文已给出了若干证明方法．其中，文建立了代数变换：f（s-a，s-b，s-c）=f（x，y，z）；文建立了代数变换：f（ra，rb，rc）=f（x，y，z）（其中半周长s=a＋b＋c/2；ra，rb，rc分别为△ABC的旁切圆半径）．但是，对于一类“轮换对称不等式”，以上方法显得力不从心．本文将文的代数变换：f（s-a，s-b，s-c）=f（x，y，z），改造为代数变换：f（a，b，c）=f（y＋z，z＋x，x＋y），导出了两个漂亮的定理，找到了△ABC三边a、b、c的不等式（包括非完全对称的“轮换对称不等式”）的证明妙法．     

有限仿射空间中面偏序集合上的Msbius函数

设ae（n,F_q）是有限域Fq上的n-维仿射空间,而P（n）是AG（n,F_q）中的所有面构成的集合。按照包含或反包含关系规定P（n）的偏序,得到两个偏序集合,并主要计算了这些偏序集合上的Mōebius函数和秩生成函数。     

有限域上一类方程在(F*)n中的解数公式

设F=Fq是一个q元有限域,F^＊=F^＊q为其乘法群,q=p^f,f≥1,p是一个奇素数。该文利用组合的方法给出了有限域上F=Fq上一类三次方程x1x2＋x1x2x3＋x2x3x4＋…xn-4xn-2＋xn-1xn=b在（F^＊）^n上解数的一个直接公式,这里b∈F=Fq     

有限域上一类方程在（F^＊）^n中的解数公式

设F=Fq是一个q元有限域,F^＊=F^＊q为其乘法群,q=p^f,f≥1,p是一个奇素数。该文利用组合的方法给出了有限域上F=Fq上一类三次方程x1x2＋x1x2x3＋x2x3x4＋…xn-4xn-2＋xn-1xn=b在（F^＊）^n上解数的一个直接公式,这里b∈F=Fq     

求两个二次曲线交点个数的解决策略

学习平面解析几何最重要的是树立解析思想,抓住几何问题如何适当地用代数方法解决,以及代数运算的过程中表达了怎样的几何现象。例如曲线C1：f1（x,y）=0与曲线C2：f2（x,y）=0有交点的充要条件是方程组{f（x,y）=0（1） f2（x,y）=0（2）有实数解,     

不同的代数变换导致不同的数形结合

解析几何中，常将方程解的个数问题分解为两个函数的交点问题，即方程人工）一y（x）的解的个数可用C；：x一f（x）与C。：x一g（X）的交点个数来判别．前者属代数范畴，而后者属几何范畴．在解决交点个数时，对特殊情况的值（临界值）又需经过计算，故两曲线交点问题的解决方法常被称为数形结合法．由于方程可变形，如将f（X）一S（X）变为人（X）二目（X），故不同的代数变换可导致不同的数形结合法．因此，对方程的合理变形，是决定数形结合难易程度的一个重要因素．以下通过举例加以说明．例已知抛物线y—－x‘＋mx－l，点A（3，0）…     

关于一类拟线性椭圆方程正解的存在性问题

讨论了拟线性椭圆方程-u″＋u-k（u^2）″u=f（x,u）,x∈R（＊）,其中k〉0是常数,f（x,u）是一个关于“的超线性和次临界函数,且f（x,0）=0．在函数f（x,u）满足某些条件下,通过变分法证明了方程（＊）至少存在一个正解．     

周期函数的四种特殊类型及其应用

类型一若y＝f（x）是定义在R上的函数，且f（x＋k）＝－f（x），则函数y＝f（x）的周期为２k（k为非零常数）．证明∵f（x＋２k）＝f犤（x＋k）＋k犦＝－f（x＋k）＝f（x），∴函数y＝f（x）的周期为２k．例１定义在R上的偶函数y＝f（x）满足f（x＋１）＝－f（x），且在区间犤－１，０犦上单调递增．比较f（２√）、f（２）、f（３）的大小．解析∵f（x＋１）＝－f（x），∴由类型一知f（x）的周期为２．又因为f（２√）＝f（－２＋２√），f（２）＝f（－２＋２）＝f（０），f（３）＝f（－４＋３）＝f（－１），且－１＜－２＋２√＜０，…     

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.     

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.     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.     

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.