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1.
单生反应扩散过程的最优耦合及其应用   总被引:2,自引:0,他引:2  
论述了单生反应摭用过程最优耦合的存在性,并应用最优耦合对一类单生反应扩散过程的国性进行了研究,给出了一个遍历准则。  相似文献   

2.
研究了一类具强耦合源的退化抛物方程组的Cauchy问题,其中初值为Radon测度。当指标满足一定范围时,克服了方程退化性与强耦合源同时存在带来的困难, 从而得到了解的存在性。还进一步证明了指标的限制范围对解的存在性来说是最优的。  相似文献   

3.
针对热耦合的斯托克斯流方程组的解析解给出了其存在性以及正则性的分析. 给出此方程组多解情形下的有限元格式,并且证明了此非线性问题数值解的存在性.研究方程的非奇异解的逼近性质的同时,证明了有限元解的收敛性.在Lp理论下给出了其最优的误差估计.  相似文献   

4.
采用最优控制的方法解决区域分解算法中内交界面上方程解的值的确定问题。将确定内交界面值的问题转化为边界控制问题,为克服控制问题的不适定性引入了正则化方法,证明了正则最优边界的存在性和收敛性,给出了表征最优边界的耦合方程组。  相似文献   

5.
一类距离下的最优耦合   总被引:1,自引:0,他引:1  
研究了跳过程在一类距离ρ下的最优耦合,证明在相当弱的条件下,如果存在的保序耦合Ω,则Ω是ρ最优的,并且给了Ωρ的明确表达式,还讨论了离散时间马氏链在该类距离下的最优耦合,结论与连续时间的情形是平等的。  相似文献   

6.
解决了在给定的一些距离这下二维生灭过程的最优耦合问题,给出了这些最优耦合的结构,并对所得结果做了一些比较。  相似文献   

7.
串调动力制动闭环系统,是一个多变量互有耦合的非线性系统,其调节器的参数难以用一般工程方法加以确定。利用计算机仿真和寻优可以很方便地获得闭环最优控制系统参数。文中采用的变步长公式、单纯体相对边长算法以及收敛速度缓慢和发散的处理程序,为保证仿真寻优过程的迅速性和准确性提供了有效的方法。  相似文献   

8.
光面爆破径向不耦合系数优化研究   总被引:4,自引:0,他引:4  
隧道爆破施工时,径向不耦合系数是一个重要的参数,它直接影响爆破质量的好坏。为获得最优径向不耦合系数,基于武汉地铁二号线工程实例,运用ANSYS数值分析软件,建立了径向不耦合系数K为1.0、1.4、2.1时的三维模型。通过比较分析关键部位的应力值大小及分布规律,验证了经典爆破理论,得出了最优径向不耦合系数为1.4~2.1。  相似文献   

9.
研究了两个复杂网络指数同步的最优牵制控制问题.基于线性反馈策略, 给出了两个网络达到指数同步 的牵制准则.通过具体例子展示了牵制节点数目和反馈增益的可行组合的计算方法以及最优组合的确定方法, 同 时也分析了耦合强度和网络的稠密程度对最优牵制比的影响. 最后, 给出两个例子验证了该最优控制方法的有 效性.  相似文献   

10.
为了解决双转子电动机动力耦合系统内发动机的控制问题,基于双转子电动机动力耦合系统的结构与原理,分析了双转子电动机动力耦合系统的工作模式以及各工作模式之间相互切换的条件,并据此提出了发动机最优工作点控制的思路和方法.借助高次幂数据拟合方法与最速下降算法,确定了某型发动机的最优工作点,采用模糊控制方法在Simulink环境内建立了发动机最优工作点控制器的仿真模型.仿真结果表明:发动机最优工作点控制方法能够对发动机转矩、转速进行有效调节,能最大限度降低发动机燃油消耗率;在混合动力驱动低速状态下发动机最优工作点控制方法的寻优时间对系统稳定性有明显影响.  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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