共查询到20条相似文献，搜索用时 111 毫秒
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在能量表象和坐标表象中，分别计算了一维谐振子综的密度矩阵，并得到了在温度T时的平均密度分布，最后讨论了高温极限(T→∞)和低温极限（T→∞)． 相似文献
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极限是正确理解微积分和发展数学思维的最基本数学概念,在概念定义和概念表象理论框架下研究理工科大一新生对数列极限概念的理解情况,发现:学生拥有数列极限不同类型的概念表象,这些概念表象将对极限严格定义的理解产生影响.因此,教学中要给学生机会发展与极限定义相协调的概念表象,建立起更为广泛的概念表象,从而帮助学生能更好地运用数列极限定义解决数学任务,这是学生转向高等数学思维的关键. 相似文献
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相互作用表象综合了薛定谔表象和海森堡表象的优点。在处理光场和原子作用时，有着重要的应用。本文较详细地阐述了在相互作用表象中态矢量、力学量算符、演化算符的运动方程以及密度算符的基本性质，最后完成了对密度矩阵和力学量算符平均值所满足的运动方程的推导。 相似文献
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极限的“ε-N”定义对大学生高层次数学思维的发展起着重要的作甩。在APOS理论框架下探究学生对数列极限的理解,结果表明学生对极限的理解大都局限在操作和过程阶段,学生所拥有的概念表象影响了极限的严格化定义。教师的教学法则要基于APOS理论设计高水平数学活动,从根本上帮助学生建立数列极限的“深刻直觉”,这是理解“ε-N”定义的核心。 相似文献
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考虑捕食者无密度制约,食饵具有非线性密度制约的第３类Ｈｏｌｉｎｇ功能性反应捕食者－食饵系统,对该系统给出了完整的定性分析,证明了该系统至多有一个极限环,存在极限环的充要条件是正平衡点不稳定 相似文献
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本文从密度矩阵的微扰展式出发,在能量表象中,求出非线性谐振子H=((1/2m)P~2 (1/2)mω~2x~2) αx~2的配分函数Z。进而,由热力学公式可得出其它热力学量。 相似文献
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许清海 《泉州师范学院学报》2001,19(4):9-12,23
相对熵密度的极限性质是信息率的一个重要问题。当任意信息源是可列实数集时，探讨相对于独立型几何分布的熵密度偏差的极限性质，获得三个相对熵密度的强偏差定理。在n→ ∞时，给出相对熵密度偏差大小的强大数估计。 相似文献
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王学武 《南阳师范学院学报》2007,6(3):14-17
利用分析法研究了马氏链相对熵密度的若干极限性质,推广了Shannon-M cM illan的极限定理,改进并推广了文[1]~[3]的主要结果,建立了新的有限非齐次马尔可夫链的强极限定理. 相似文献
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隐喻的表象表征及其加工效应研究 总被引：1，自引：0，他引：1
用时间隐喻为研究材料,考查了隐喻表象性与多个心理维度(理解度、熟悉度、喜好度、适当性、重要性)的相关性,并通过比较被试对表象程度不同的时间隐喻在表象加工和语义加工后的语义确认成绩,考查表象加工对时间隐喻表征所产生的加工效应。结果表明时间隐喻表象性与这些心理维度有密切联系;虽然语义表征是时间隐喻表征的基础和起点,但表象表征并不完全是一种附带产物,而是句子表象性程度的函数,在隐喻理解过程中有介入作用。高表象性的隐喻存在双重编码。 相似文献
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《海外英语》2007,(5):10-11
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? 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
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. 相似文献
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《海外英语》2007,(4):36
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. 相似文献
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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. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
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. 相似文献
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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. 相似文献
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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. 相似文献