双向亚铁磁棱型自旋链的热力学性质研究

基于近些年来试验上有机和无机磁性高分子化合物的合成,文章利用双时格林函数方法, 对AB2型双向聚合物棱型自旋链的磁学和热力学性质进行了研究．在半满强耦合极限条件下,该系统可转化为量子铁磁-反铁磁自旋为1／2的AB2型海森堡模型,该模型将由零温量子相转变到亚铁磁基态．在Tyablikov耦合近似条件下,基态的自旋波、以及亚晶格的磁化强度和系统的磁化率在不同的序参量和不同外场的条件下进行了研究．结果显示该模型低温下的性质和自旋为1／2的铁磁相互作用的海森堡链相同．     

一维反铁磁链中非线性自旋波激发的A—B效应

采用Ｍａｔｉｓ［１］转动，研究在Ａ—Ｂ磁通作用下的一维闭合反铁磁链中的非线性自旋波激发。计算结果表明，一维闭合反铁磁链中的非线性自旋波激发可以形成一种沿链传播的孤立波，而Ａ—Ｂ效应的存在对非线性自旋波谱、能隙、以及孤立波的稳定性都有影响     

交错相互作用反铁磁链的临界区域

本文应用玻色化方法,研究了电子间具有交错相互作用和晶格格具有弹性作用的反铁磁链能谱。在一定的晶格畸变范围内,该模型同样会出现自旋Ｐｅｉｅｒｌｓ相变,最终给出了模型基态能量密度与晶格畸变的函数关系和模型出现自旋Ｐｅｉｅｒｌｓ相变的晶格畸变区域。     

交错相互作用反铁磁链的临界区域

本文应用玻色化方法,研究了电子间具有交错相互作用和晶格间具有弹性作用的反铁磁链能谱．在一定的晶格畸变范围内,该模型同样会出现自旋Peierls相变．最终给出了模型基态能量密度与晶格畸变的函数关系和模型出现自旋Peierls相变的晶格畸变区域．     

存在DM相互作用的海森堡链中的贝尔不等式违背

研究了存在DM相互作用的两比特和三比特海森堡链中热态的贝尔不等式违背.结果表明:两比特海森链情况下贝尔不等式可以被破坏;三比特情况下贝尔不等式不能被破坏.     

一维更键海森堡铁磁链间隙非线性元激发

研究结果表明:对于一维更键（alternatingbond）铁磁链海森堡摸型，在一级近似下：（1）存在磁间隙孤子（振动频率位于磁频谱间隙内）和响应纽结（振动频率位于磁频谱内）．（2）内禀局域模（振动频率位于所有磁频谱带上方）是不可能存在的．     

二次三项式因式分解的一种简易方法

二次三项式因式分解的一种简易方法兰州铁道学院附中郝亚平设二次三项式Ａｘ２＋Ｂｘ＋Ｃ可分解为（８Ｘ＋ｂ）（Ｃｘ＋ｄ），亦即ａｃｘ２＋（ａｄ＋ｂｃ）ｘ＋ｂｄ。比较系数得Ａ＝ａｃ，Ｂ＝ａｄ＋ｂｃ，Ｃ＝ｂｄ。设ａｄ＝Ｆ１，ｂｃ＝Ｆ２，则有ＡＣ＝Ｆ１·Ｆ２，Ｂ...     

一个三元不等式链的进一步探究

刘永春老师提出了一个有趣的三元不等式链[1 ] :9 ａ ａ2 ≤ ａ≤ ｂ2 +ｂｃ+ｃ23≤ ｂ2 +ｃ22 ≤3 ａ2 ≤ ｂｃａ ≤ 2ａ2ｂ+ｃ≤ ｂ2 +ｃ22ａ ≤ ａ3ｂｃ.(其中ａ ,ｂ ,ｃ∈Ｒ+ , 、 分别表示循环和、循环积 ;下同 )随后 ,陈永毅、张云华两位老师均对此作了有益的探索[2 ] [3] .在此基础上 ,本文将作进一步探究 ,推证出下列不等式链 ,并探寻其解题功能 .定理　设ａ、ｂ、ｃ∈Ｒ+ ,则 ａ3ｂｃ ≥ ｂ2 +ｃ22ａ ≥ (ｂ +ｃ) 24ａ ≥ ｂｃａ ≥3 ａ2 ≥ ｂ2 +ｃ22 ≥ ｂ2 +ｂｃ +ｃ23≥ ａ≥ 3 ｂｃ≥ ｂｃ≥ 33 ａ≥ 9 ａ ａ≥…     

一道条件不等式的证法综述

引导学生开展“一题多解，一题多证”的训练和探究，必将有助于激发学生学习数学的兴趣和热情，启迪他们的创新思维，培养数学综合能力，进而提高他们的数学素质． 本文以一道脍炙人口的条件不等式赛题为例，从九个方面研究其证明的策略和技巧． 题（前苏联奥尔德荣尼基市第三届数学竞赛题）设 ａ，ｂ，ｃ∈Ｒ＋，且 ａ＋ｂ＋ｃ＝１，求证；ａ２＋ｂ２＋ｃ２≥１／３１ 代入法 证１ 注意恒等式 ３（ａ２十ｂ２十ｃ２）＝（ａ＋ｂ＋ｃ）２＋（ａ－ｂ）２十（ｂ ｃ）’＋（ｃ ａ）’将已知ａ＋ｂ＋ｃ二ｌ代人得 ３（ａ’＋ｂ‘＋ｃ’）二１：…     

一维反铁磁链中的孤波研究

本文从双子格模型出发，利用霍斯坦因一普里马克夫变换，计算一维反铁磁链中的孤波，并得到相应孤子解。     

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.     

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.     

汉字倒说

汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。     

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?     

Social and Cultural Influence on Word Meaning

Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language.     

钱生钱!

我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了     

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.