Covariant form

The Covariant form of four-dimensional torque is studied, the expression of three-dimensional torque that meets relativistic demand is given, with the use of it, Some paradoxs of the torque are explained more satisfactorily.

研究四维力矩的协变式，给出满足相对论要求的三维力矩的表达式，并运用这一表达式对几个力矩佯谬进行了较满意的解释。

Cointegration or Co-breaking:Empirical Eevidence from China s Imports and Exports Time Series(1950—2004);

协整还是协变:来自中国进出口时间序列的经验证据(1950—2004)

co-breaking model.

文章根据1952~2005年的样本数据,利用带有结构突变的单位根检验方法和协变模型判定了我国国内生产总值和资本形成总额时间序列均是带有一次均值突变的趋势平稳过程,证实了我国经济增长与资本形成之间存在着同期协变关系;并利用脉冲响应函数、方差分解以及动态相关系数研究了中国经济增长和资本形成间的动态相关性。

Although the viewpoints of Einstein have occupied a dominant position after this debate,but,for lack of covariance,the gravitational energy momentum tensor remains one old,great and difficult problem which has not been solved satisfactorily till now.

后来虽然爱因斯坦的观点占了上风 ,但其定义的引力场能动张量 ,由于缺乏协变性 ,成了至今尚未完满解决的“老大难”问题 。

According to the contravariance and covariance characteristics of physical tensors, the author has made a uniform regulation on the physical meaning of subscript and superscript in the expression of a tensor.

根据物理张量逆变和协变的性质，对张量角标位置的物理意义作了统一规定，给出了分量矩阵的具体形式，从而使得矩阵的运算性质能完全适用于张量运算，为定量讨论物理张量提供了可靠的数学依据。

conservation condition and covariance;3.

守恒条件与协变性问题；３、分析力学中的能量问题。

Effect of Covariate Imbalance on the Power of ANCOVA;

协变量的不均衡对协方差分析的影响

Statistical adjustment of treatment effect for covariates in clinical trials;

临床试验中评价处理效应的协变量调整问题

The ROC Analysis for Diagnostic Test Data with Covariates;

具有协变量或干扰因素的诊断试验数据的ROC分析