首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
本文对Mandelbrot分形渗流发生中的临界概率数P_c进行了微小的修正,并对[5]中求带多数P的不动点给出一种精确的解法.  相似文献   

2.
研究了三维MANDELBROT过程的SHEET-渗流问题,证明了当P>PS时,三维MANDELBROT过程的SHEET-渗流条数是几乎处处有限的,并且给出了其上界估计.参5.  相似文献   

3.
引入双参数随机置换,考虑了具有参数p,q的随机Sierpinski垫的各种形态的相位,讨论了p,q跨跃某些相位曲线时,其构成形态的变化情形,它包括了q=0的Sierpinski垫和q=p的Mandelbrot渗流模型。  相似文献   

4.
本文采用位置空间重整化群和蒙特-卡罗模拟方法,研究了三维各向异性渗流模型。分别计算出其临界值Pc和临界指数α,β,γ,δ,νηΔ等值。结果表明:1.三维次近临各向异性渗流问题与最近邻各向同性的渗流问题属于不同的普适类。2.临界指数仅与格点内部的联接方式有关。  相似文献   

5.
首次制得二乙基胺甲基膦酸锆-亚磷酸锆Zr(HPO_3)_(2-x)·(O_3PCH_2NEt_2)_x·H_2O(ZDEAMP-ZP,x=0.75,0.60,0.50).将ZDEAMP-ZP用溴化苄季铵化,得到部分季铵化的产物:溴化苄基二乙基铵甲基膦酸锆-二乙基胺甲基膦酸锆-业磷酸锆Zr(HPO_3)_(2-x)·(O_3PCH_2NEt_2)_(x-y)·(O_3PCH_2N ̄+Et_2·CH_2Ph·Br ̄-)_y·H_2O(Y<X,ZBDEAMPB-ZDEAMP-ZP).ZBDEAMPB-ZDEAMP-ZP用于进行液/固/液或固固/液三相催化的亲核取代成醚、卤代烃和羧酸盐合成酯及二氯卡宾加成反应,均得到良好的结果。催化剂易于分离和回收,通常回收70%~100%,催化剂重复使用10次以上无明显失活。  相似文献   

6.
本文用平阳霉素(BLMA_5)和吡柔比星(THP)对裸鼠移植的人体食管癌进行化疗,实验重复两次,结果:在棵鼠可耐受的剂量下,BLMA_5、THP、BLMA_5+THP等各组肿瘤抑制率分别为56%-61%(P<0.01)、34%-39%(P<0.05)、71%-75%(P<0.01),说明BLMA_5和THP对裸鼠移植的人体食管癌均有一定的抑制作用,两药合用可明显提高疗效。研究结果提示BLMA_5和THP合用有可能用于食管癌的临床化疗。  相似文献   

7.
Windows操作系统是一个基于消息的操作系统 ,其程序总要同消息打交道 ,这正是Windows程序同Dos程序不同的地方。实际上 ,Windows系统通过Windows消息告诉所有应用程序发生了什么事件 ,例如用户点击了鼠标、用户点击了键盘的哪个键等 ,每个应用程序都有消息处理函数或一组消息响应函数 ,用于对消息进行响应。使用WindowsAPI函数编程时 ,你将不得不使用许多复杂的代码去处理Windows消息。MFC合理的封装了WIN3 2API函数 ,并设计了一套方便的消息映射机制。但这套机制本身比较庞大和复杂 ,对它的分析和了解无疑有助于我们写出更为合理的高效的程序。1 消息映射的声明 :DECLARE_MESSAGE_MAP宏在MFC的框架结构下 ,进行消息处理的类的头文件里一般都含有这样的结构 :classCDerivedClass :PublicCBaseClass{  ... DECLARE_MESSAGE_MPA()};在这里DECLARE_MESSAGE_MAP宏相当于为类声明了如下的一种数据类型 :#defineDECLARE_MESSAGE_MAP()private : staticc...  相似文献   

8.
矩阵的一个定理和线性方程组解的结构   总被引:1,自引:0,他引:1  
设A∈M_(m×n)(F),则存在m阶可逆矩阵P和n阶可逆矩阵Q,使其中r=R(A);本文还讨论了一般线性方程组A_(mn)X_(n1)=b_(m1)的可解性及解的结构与矩阵P,Q之间的关系。  相似文献   

9.
Ru(OAc)_2(Ph_3P_2)和等摩尔的N,N-双-[邻-(二苯基膦苯甲基)]乙二胺(简称P_2N_2H_4)在四氢峡哺中回流反应,高产率地合成了新型四齿胺膦配位的Ru(OAc)_2P_2N_2H_4.红外光谱、核磁共振和结构测定表明该配合物具有反式的构型。P_2N_2H_4作为四齿的配体与中心钉原子配位。在温度30~70℃、氢压1.0~4.0MPa内。发现了Ru(OAc)_2p_2N_2H_4是比具有类似组成和结构的Ru(OAc)_2P_2N_2更有效的氢化催化剂。  相似文献   

10.
Pb(Ⅱ)、Zn(Ⅱ)与5-Br-PADAP络合平衡的研究   总被引:2,自引:0,他引:2  
本文研究了Pb(Ⅱ)-5-Br-PADAP及Zn(Ⅱ)-5-Br-PADAP络合反应体系的吸收光谱,用基于Rosenbrock算法的最优化程序处理了光度测量数据,发现Pb(Ⅱ)与5-Br-PADAP形成1:1络合物,稳定常数lgβ_1=11.21,摩尔吸光系数ε_1=6.2×10 ̄4L·mol ̄(-1)·cm ̄(-1);Zn(Ⅱ)在c_L>c_M的条件下主要形成1:2络合物,lgβ_2=22.36,ε_2=1.28×10 ̄5L·mol ̄(-1)·cm ̄(-1)。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号