王昌龄为七绝创作发展作出的重要贡献

初唐时,七言绝句不仅数量较少,题材狭窄,而且在诗坛上的影响也很小。至盛唐时,年岁较长、诗名早著的王昌龄,不仅率先并大力创作七绝,而且在他的笔下七绝的题材也得到了大大拓展,举凡从军、出塞、怀古、赠别、狩猎、宴饮以及奉佛、崇道、闺思、宫怨等等,无不可用七绝来表现,扩大了七绝在诗坛的影响。不仅如此,王昌龄的七绝还具有示范效应和标杆作用,受到当世特别是后世作者的追模和学习,从而进一步扩大了七绝的影响。因此“七绝圣手”王昌龄,从题材的拓展、数量的增加、影响的扩大等诸方面,为七绝的创作发展作出了重要贡献。     

垄断产品的价格歧视分析

从垄断者角度出发，讨论了垄断者产品的价格歧视问题。就质量歧视与数量歧视对消费者边际效用和社会福利的影响进行了分析。     

企业空间增长模式分析

本文通过对企业扩张过程、规律、模式的分析 ,旨在为我国大型国有企业的发展壮大提供理论指导     

On a statistic useful in dimensionality reduction in multivariable linear stochastic system

In this paper we study the sampling properties of a test statistic which has important applications in the area of linear stochastic control systems with multi-inputs and multi-outputs. The statistic is the ratio of a partial sum of the eigenvalues of a sample covariance matrix and its trace. It turns out that using a method due to Sugiura we may derive a useful approximation for its distribution up to and including terms of order l/n, where n denotes the appropriate size. Numerical illustrations using real data are given.     

Simultaneous bootstrap confidence bands in regression

We suggest pivotal methods for constructing simultaneous bootstrap confidence bands in regression. Most attention is given to the problem of simple linear regression, but our techniques admit trivial extension to other cases, including polynomial regression. The advantages of our bootstrap approach are twofold. Firstly, the bootstrap allows a very general distribution for the errors, and secondly, it admits a wide variety of shapes for the confidence band. In our technique the shape of each envelope of the band is determined by a general template, chosen by the experimenter, and bootstrap methods are used to select the scale of the template.     

The effects on the distributions of sample canonical correlations under nonnormality

In this paper, we study the effects of nonnormality on the distributions of sample canonical correlations when the population canonical correlations are simple. In order to achieve the purpose, we derive asymptotic expansion formulas for the distributions of a function of the canonical correlations as well as the individual canonical correlations under nonnormal populations. We particularly discuss the distribution of sample canonical correlations under the class of elliptical population. These expansions are given by using a perturbation method. Simulation results are also given.     

Ridge regression estimators in the linear regression models with non-spherical errors

The present paper considers a family of ordinary ridge regression estimators in the linear regression model when the disturbances covariance matrix depends upon a few unknown parameters. An asymptotic expansion for the distribution of the ridge regression estimator is developed and under the quadratic loss function its asymptotic risk is compared with that of the feasible GLS estimator.     

A test for bivariate symmetry based on the empirical distribution function

Hollander (1970) proposed a conditionally distribution-free test of bivariate symmetry based on the empirical distribution function. In this paper Hollander’s test statistic is examined In greater detail: in particular; its conditional asymptotic distribution is derived under the null hypothesis as well as under a sequence of local alternatives. Percentage points of the asymptotic distribution are presented; a power comparison between Hollander’s statistic and the likelihood ratio criterion in testing a variant of the sphericity hypothesis in multivariate analysis is made.     

A new special class of peb designs

A new class of partially efficiency-balanced designs is introduced from a practical point of view. This new design includes all equireplicated incomplete block designs available in literature as special cases. The fundamental properties of the design are clarified with relation to other block designs.     

高等农业院校“非农”专业扩展趋势分析

我国高等农业院校专业设置已经从原来的单科型转变为多科型,人文社科专业的扩展使这种趋势更加明显,但在专业扩展中也面临着一些不容忽视的问题。在多数农业院校中,人文社科专业基础依然薄弱,尚未构成完整的学科体系;另一方面,“多科性”并不代表“全科型”,要防止把农业院校办成全科型高校的倾向。正确认识并着力解决这些问题,是农业院校在市场经济条件下持续发展的重要保证。