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1.
本文讨论二阶复合型方程组(CE2):10012t2+100λ/R22x21+0(λ-k2)/k2(λ-1)/k02x1x2+λ0012x22u1u2=0(0<k<1,λ<0)得到了该方程组有解的必要条件,并由此知道该方程组的Cauchy问题是不适定的,转而讨论问题(D2),证明了问题(D2)是可解的,并给出了解的表达式  相似文献   

2.
本文讨论了Cn空间中有界区域D上的2n维正则向量函数(满足方程LF=0,L=∑nk=1|′×…×|′×0/zk/zk0×|×…×|)的Dirichlet边值问题,获得了边界值为C1类的2n维复值向量函数的Dirichlet边值问题的可解条件,同时还获得了D上的n元解析函数的Dirichlet问题的可解条件,并将以上结果应用到Cn空间中的超球与多圆柱区域上,获得了相应的结果  相似文献   

3.
对于如下奇异动力系统:D是含原点的R2中的区域,u=(u1,u2),V=V(t,u)∈C1(R1×(D-{0},R1),且V(t+T,u)=V(t),Vu=graduV(t,u)=(V/u1,V/u2),本文讨论了具有奇异位势(即limV(t,V)=-∞)的二阶动力系统的小周期解的存在性问题:u¨+Vu(t,u)=0。  相似文献   

4.
讨论由向量场的平方和构成的某些二阶偏微分算子的非解析亚椭圆性.所用方法是构造这些算子的奇异解后,将这些偏微分算子的解析亚椭圆性的讨论转化成某些特殊的常微分方程的研究.该构造过程是非常清晰和直接的.而且它涉及到那些带有依赖大参数位势的广义调和振子的第一特征值和第一特征函数的研究,最终获得了如下两个结果:1)令非负整数l,k满足l>k且l=2k+1,则算子P=(x)2+(xky)2+(xlt)2在原点o∈R3不是解析亚椭圆的.2)对非负整数ki≥1,i=1,2,3,…,n,算子Q=(x)2+(y)2+x2k1(t1)2+…+x2kn(tn)2其中(x,y,t1,…,tn)∈Rn+2,则Q在原点o∈Rn+2不是解析亚椭圆的.  相似文献   

5.
由Fick定理导出球形对称扩散方程ct=2Drcr+rDcr探讨了扩散系数为准常量时,浓度随时间发生不同变化状况下,球形对称扩散及球状体扩散源周围浓度分布的方程及应用。  相似文献   

6.
一、相变与化学变化的热力学性质的异同相变是物理变化,化学反应是化学变化。物理化学中热力学的研究对象是发生物理和(或)化学变化的体系,因此从热力学的角度考虑,相变和化学变化有许多相同之处,如两者在热效应(△H)与温度的关系、吉布斯自由能变(△G)与温度的关系等方面可以用完全相同的方法进行处理。1.热效应与温度的关系若化学反应表示为:   0=νBB根据基尔霍夫定律,△H与温度的关系为:   (△H)TP=νBCp.m.в对于相变体系,如H2O(1)H2O(g)   △H=H(g)-H(1)…  相似文献   

7.
渗碳不锈钢的开发Oarpenter工艺技术公司为轴承和齿轮应用,开发了一种新的渗碳不锈钢,具有良好的抗腐蚀、耐热和抗疲劳性能。Pyrowear675不锈钢的组成为:Fe-13Cr-5.4Co-2.6Ni-0.8Mo-1.6V-0.4Si-0.07C-...  相似文献   

8.
讨论下面方程的Cauchy问题:utt-Δu=|ut(x,t)|p,t≥0,x∈R3,u(x,0)=εf(x),ut(x,0)=εg(x),x∈R3,这里Δ=∑3i=12x2i,常数p>1,ε是正参数,H.Takamura(ComminPDE,1992,17(1&2):189)猜侧上面的Cauchy问题在p>2时是否对充分小的初值存在整体C2解.本文将在f(x),g(x)满足一定条件下在p>3时部分回答这个问题  相似文献   

9.
从紧算子的谱理论出发,给出了高阶方程∑mi=12x2i2u-∑mj=12y2i2u=f(x,y),x=(x1,x2,…,xm),y=(y1,y2,…,ym),在有界区域(闭)G(x)×G(y)/上的一类边界问题解的存在性和唯一性定理。  相似文献   

10.
本文给出RN上拟线性临界增长椭圆型方程-∑Ni=1|u|p-2uxi=|u|q-2u+f(x,u)(q=NpN-p,N>p≥2)的一个紧结果。  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
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   

20.
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   

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