矢引力子场度规场引力理论

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绞股蓝对明矾诱发遗传物质损伤的抑制作用

本次遗传毒理实验以绞股蓝为材料,以明矾为诱变剂,以小白鼠骨髓嗜多染红细胞的微核率和染色体畸变率作为DNA损伤的指标。结果含10%的绞股蓝饲料使明矾诱变的微核率从8.83±1.7‰降到3.67±0.52‰(P＜0.001),染色体畸变率从14.17±0.98%降至5.67±1.37%(P＜0.001)。表明绞股蓝对明矾诱发的DNA损伤具有明显的抑制作用,提示绞股蓝具有抗癌作用。     

图论初步

先看一个著名的数学问题—哥尼斯堡七桥问的点和代表终点外,每点相连的线均应有偶数条.这是题. 例i如图l,帕瑞格尔河从哥尼斯堡城市穿过,河中有两个岛A与D,河上有七座桥架在河上连结两个岛及河的两岸B、C.问:一个旅行者能否经过每座桥恰好一次,既无重复也无遗漏?因为在旅行路线中有进入该点的一条线,必相应的有一条引出的线.现与点A、B、C、D相连的线都是奇数条.这一事实说明一个旅行者无重复无遗漏地走过七座桥是不可能的. 图论研究的对象是图.什图2图l 伟大的数学家欧拉采用了这样的解决方法:将两个岛和两岸用点表示,再在相应的两个点…     

一元多项式的根

对于1’>O,如果了(劣)~‘扩+‘一:扩一’十…十al劣+a0是复系数一元:次多项式,那么方程f(:)二。,即 a·‘,+‘一、‘,一‘+…+a,:+a。=0②①叫做复系数一元二次方程.方程②的根,也称多项式① 的根. 一27一中学数学(湖北)1992.12 类似地,如果j(,)是实系数(或有理系数、整系数等)一元:(、>0)次多项式,那么方程j(幻二O叫做实系数(或有理系数、整系数等)一元:次方程. 关于多项式的根的个数有以下重要定理: l代数墓本定理一元:次多项式在复数集中至少有一个根. :799年伟大的数学家高斯证明了这一重要定理· 2根的个数定理一元二次多项式有且仅有…     

Hopfield型模型的收敛性

本文考虑Ｈｏｐｆｉｅｌｄ型模型的收敛性问题和吸引子的吸引域的刻画。证明了Ｎ＜＋∞与Ｎ＝＋∞时Ｈｏｐｆｉｅｌｄ模型在几乎处处的意义下收敛于吸引集。当Ｎ＜＋∞时，模型将在有限时间内稳定于某一吸引子上．对于Ｎ＜＋∞与Ｎ＝＋ ∞的情形，分别得到了吸引域的一个集的刻画。     

On the correspondence between three nodes W states in quantum network theory and the oriented links in knot theory

The GHZ states and W states are two fundamental types of three qubits quantum entangled states. For finding the knotted pictures of three nodes W states, on the one side, we empty any one node, thus obtaining three degenerated twonode W states, then we find the nonzero submatrix of the corresponding covariance correlation tensor in quantum network theory. On the other side, excepting the linkage 41 corresponding to Bell bases, we conjecture that the another one possible oriented link(which is composed of two-component knots entangled with each other and has four crossings) would be the required knotted pictures of the two nodes W states, thence obtain the nonzero submatrix of the Alexander relation matrix in the theory of knot crystals for these knotted pictures. The equality of the two nonzero submatrices of different kinds thus verify the exactness of our conjecture. The superposition of three knotted pictures of two-node W states from different choices of the emptied node gives the knotted pictures of three-node W states, thus shows the correspondence between three-node W states in quantum network theory and the oriented links in knot theory. Finally we point out that there is an intimate and simple relationship between the knotted pictures of GHZ states and W states.     

结构视域下高三数学一轮复习课的设计与实施——以“导数的几何意义”为例

为了积极应对素养导向的高考评价改革,需要教师系统设计和稳健开展高三数学一轮复习工作.本文以“导数的几何意义”为例,从结构视域视角出发,通过“五环节”设计和“三举措”实施一轮复习课教学,夯实“四基”,提升“四能”,让关键能力在复习中得以巩固和提升.     

思维导图在物理教学中的应用

思维导图作为一种新型的可视化工具,其最大特点即是发散性.将思维导图应用于物理教学中,有助于教师理清教学内容的知识点及其主次关系,可以有效防止由于课堂生成而造成的知识点遗漏的现象发生.     

一种隔热弹衣对弹体装药反应的影响

采用烤燃试验研究了一种隔热弹衣对弹体装药反应的影响。通过对比包覆隔热弹衣试验件和无隔热弹衣试验件火烧后的反应状态,发现隔热弹衣对弹体装药反应等级没有明显影响,但可有效延迟装药热点火反应时间达32min,为火灾环境下弹药救援处置赢得时间。进一步分析发现,隔热弹衣的热防护效果不仅与其自身的低导热性有关,也与隔热弹衣和弹体之间的空气间隙有关。     

Magnetic transition and large reversible magnetocaloric effect in EuCu1.75P2 compound

The magnetocaloric effect(MCE) in EuCu1.75P2 compound is studied by the magnetization and heat capacity measurements.Magnetization and modified Arrott plots indicate that the compound undergoes a second-order phase transition at TC ～ 51 K.A large reversible MCE is observed around TC.The values of maximum magnetic entropy change(-△SxMma) reach 5.6 J·kg-1·K-1 and 13.3 J·kg-1·K-1 for the field change of 2 T and 7 T,respectively,with no obvious hysteresis loss in the vicinity of Curie temperature.The corresponding maximum adiabatic temperature changes(△Tadmax) are evaluated to be 2.1 K and 5.0 K.The magnetic transition and the origin of large MCE in EuCu1.75P2 are also discussed.