一个类似于多元许定理的结果

本文考虑了如下的一般多元线性模型■中未知参数阵B与∑的线性函数tr(D＇B)+tr(C∑)的联立估计问题,给出了tr(D＇B~*)+tr(C∑~*)是其期望值的一致最小方差不变二次加线性无偏估计(UM-VIQLUE)的充要条件,这是一个类似于多元许定理的结果,其中B~*与∑~*分别是B与∑的在一定意义下的最小二乘估计.     

多元正态线性模型中一个估计是最优非负二次估计的条件

考虑多元线性模型_nY_p=X_1BX_2~′+■ε～N_(np)(0,I■∑).∑~*是∑的一定意义下的最小二乘估计.对指定的非负定阵C,本文给出了tr(C∑~*)是tr(C∑)的一致最小方差非负二次无偏估计的充要条件.     

一个估计的非负最优性

考虑多元线性模型Y=X_1BX'_I+Uε,Eε=0.假设ε=ε,Eεε’=I∑,Covεε’=2(I∑)(I∑).∑~*是∑的一定意义下的最小二乘估计,C≠0是非负定阵,本文给出了tr(C∑~*)是tr(C∑)的一致最小方差非负二次无偏估计的充要条件。     

多元正态总体协差阵∑的一类新的Bayes估计

本文讨论了在一类新的损失函数 L(∑,)=tr(∑~(-1)-I_m)D(∑~(-1)-I_m)＇之下,多元正态总体协差阵∑的Bayes估计。     

有约束的生长曲线模型中协差阵的最小二乘估计

利用投影理论及矩阵的谱分解方法，给出了有约束的生长曲线模型中协方差阵∑及tr（C∑）在一定条件下的最小二乘估计。     

有协变量的推广增长曲线模型中协差阵的估计

考虑协变量存在情形下推广的增长曲线模型中的参数估计问题，本文利用矩阵的谱分解和一般投影理论，在不变估计类中得到了该模型中未知协方差矩阵∑及其线性组合tr(C∑)的最小二乘估计。     

一个推广生长曲线模型协差阵的最小模估计

给出了一个推广生长曲线模型中tr(C∑）中的无偏不变最小模二次估计（MINQE（U,I））,并到得了MINQE（U,I）成为一致最小方差不变二次无偏估计（UMVIAUE）的充要条件。     

Mlinex损失函数下指数分布尺度参数的Bayes估计

在Mlinex损失函数下,求出了指数分布的尺度参数的唯一Bayes估计量,并对Bayes估计δB的容许性和形如d[c＋T（x）]的估计量的容许性进行讨论。其主要结果是：在Mlinex损失函数下,指数分布的尺度参数的唯一Bayes估计是δB=[Г（α＋β）/Г（α＋β-c）]^1/c（λ＋∑i=1^mxi,而且可容许的;形如dEc＋T（z）]的估计量当C〉0,d’〈d〈∞以及当c〉0,d。一d时是可容许的。     

关于参数矩阵的线性经验Bayes估计

设X为p×q随机矩阵,θ为p×q参数矩阵,且θ有先验分布G(Vec(θ)),给定θ,X有条件密度f(Vec(X)｜Vec(θ)).选取矩阵损失L(D(X),θ)=(D(X)-θ)′(D(X)-θ),并在风险矩阵的迹的大小比较标准下讨论θ的线性经验tr Bayes估计及其渐近性质.获得经验tr Bayes估计D tr(X)= X+U(X- X),及具有o(N-1δ-2N)的渐近收敛速度.     

关于Dirichlet L-函数的倒数的加权均值

利用特征和估计、三角和估计与解析方法，研究了Dirichlet L-函数的倒数的偶次幂的加权均值，得到一个较强的均值分布公式：∑／q≤QD^k(q)/ψ^2(q)∑/xmodq|G(m,x)|^2/|L(1,x)|^2k=(15/π^2)^kQ O(Q^1/2 ε）。     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

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