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1.
研究一类非均匀介质,各向异性的板几何迁移系统的临界解。籍助泛函分析方法,特别是Lp空间(1≤p<+∞)上的线性算子理论,证明了积分算子的主本征值(即临界参数)的性质,并获得了系统处于次临界状态的条件以及使系统处于临界状态的平板厚度的存在性。  相似文献   

2.
研究板几何具广义周期边界条件的迁移系统的临界解,使用泛涵分析方法,特别是L ̄p空间上的线性算子理论,1≤p<+∞,证明了相在的Boltzmann积分算子主本征值(临界参数)的性质。获得了迁移系统处于次临界和超临界状态的条件,并证明了临界解的存在性。  相似文献   

3.
研究一类非均匀介质,具部分反射边界条件的板几何迁移系统临界解的离散纵标逼近理论。以泛函分析为工具,应用Banach空间上的总体列紧算子理论,证明了近似计算临界板厚度及相应的非负本征函数的离散纵标方法的收敛性。  相似文献   

4.
研究一类非均匀介质、具反射边界条件的平板几何迁移系统临界解的离散纵标逼近理论。以泛函分析为工具,使用Banach空间上的总体列紧算子理论,证明了近似计算临界板厚度以及相应的非负临界解的离散纵标方法的收敛性。  相似文献   

5.
相互作用的系统自然地朝着一种临界状态演化。该文运用自组织临界状态理论,建立了楔状体临界锥顶角数学模型。文章还对楔状体的变形方式进行了初步探讨。  相似文献   

6.
已有研究发现人静息态时大脑皮层活动处于近临界状态,且具有优化的信息传输效率.然而大脑在感觉刺激状态下脑电临界动力学特征少有研究.此外,轻音乐被报道对于抑郁症、精神分裂症及术后损伤均具有较好的辅助治疗作用.本文应用临界动力学理论,研究了轻音乐刺激状态时大脑皮层脑电临界动力学特性.我们记录了26名被试在闭眼、睁眼及闭眼听音乐状态的脑电信号,对3种状态进行了频率特性和临界动力学特征分析.结果显示人在睁眼状态,全脑脑电信号活动率显著高于闭眼和听音乐状态.相对于闭眼的临界状态,音乐状态和睁眼状态分别趋向于次临界和超临界的状态,即趋向于系统的低耗能态和高耗能态.说明轻优美的音乐可以帮助大脑进入更好的休息状态,没有大尺度的活动发生,这为音乐治疗提供了有价值的实验依据.  相似文献   

7.
王强 《科技咨询导报》2007,(36):209-210
本文研究非均匀介质、单速、各向同性、具部分反射边界条件的几何迁移系统的临界解的离散纵标逼近理论。运用泛函分析方法,特别是Lp空间上的线性算子理论,证明了近似计算临界板厚度及相应的负本征函数的离散纵标方法的收敛性。  相似文献   

8.
菅永明  屈晓英  袁维  赵刚 《科学技术与工程》2022,22(26):11585-11591
采用强度折减法寻找三维边坡临界滑动面是边坡稳定性分析工作中的重要问题。基于对边坡临界状态位移场的分析,提出一种三维边坡临界滑动面的确定方法,即认为当边坡处于临界状态时,滑动面上的点是空间倾斜角度最大的位置点。通过强度折减计算使边坡达到临界状态,沿边坡表面及坡体内部等距布置测线和离散点,并计算各离散点的空间倾斜角度,提取每条测线上离散点空间倾斜角度最大值的坐标点;然后利用局部加权回归散点平滑方法做平滑处理,并将曲面在边坡范围外的多余部分进行裁剪即可得到三维边坡的临界滑动面。最后,探讨了倾斜变形计算长度大小和离散点布置的疏密程度对滑动面的影响,结果表明,倾斜变形计算长度对滑动面形状影响较小,离散点间距对滑动面形状存在一定的影响。  相似文献   

9.
 相变和临界现象在自然界普遍存在,研究的主要手段是重整化群理论。随着计算机技术的发展,基于重整化群思想的数值模拟也得到了广泛的应用,它能够精确地计算系统处于临界状态时的物理参数。该文采用角转移矩阵重化群方法计算了无外场二维伊辛模型的临界耦合常数,得到了准确度为10-5的数值计算结果。  相似文献   

10.
制冷系统的蒸发温度、制冷量、输入功率、性能系数随毛细管的改变而变化,其工作特性对整个系统而言显得十分重要的。因此对毛细管的流动过程建立了质量、能量和动量守恒特性方程,以熵最大原则建立了临界流状态下毛细管出口临界状态的参数关联式,分析计算了进口压力和毛细管内径对出口临界参数的影响,并与标准试验毛细管曲线进行了对比,结果表明,该模型在一定参数范围内与实际状况吻合。  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.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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   

19.
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   

20.
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   

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