条纹动感投影片的剪贴法设计原则及技巧

从设计系列条纹投影片的实践中,总结出设计条纹投影片所要遵循的原则,找出了解决实际问题的一些技巧和规律,有利于教师和技术人员更多、更好地设计高质量的条纹动感投影片。     

汉字OCR的原理、方法与应用

介绍了汉字OCR的原理、方法与应用。     

On geometric objects,the non-existence of a gravitational stress-energy tensor,and the uniqueness of the Einstein field equation

The question of the existence of gravitational stress-energy in general relativity has exercised investigators in the field since the inception of the theory. Folklore has it that no adequate definition of a localized gravitational stress-energetic quantity can be given. Most arguments to that effect invoke one version or another of the Principle of Equivalence. I argue that not only are such arguments of necessity vague and hand-waving but, worse, are beside the point and do not address the heart of the issue. Based on a novel analysis of what it may mean for one tensor to depend in the proper way on another, which, en passant, provides a precise characterization of the idea of a “geometric object”, I prove that, under certain natural conditions, there can be no tensor whose interpretation could be that it represents gravitational stress-energy in general relativity. It follows that gravitational energy, such as it is in general relativity, is necessarily non-local. Along the way, I prove a result of some interest in own right about the structure of the associated jet bundles of the bundle of Lorentz metrics over spacetime. I conclude by showing that my results also imply that, under a few natural conditions, the Einstein field equation is the unique equation relating gravitational phenomena to spatiotemporal structure, and discuss how this relates to the non-localizability of gravitational stress-energy. The main theorem proven underlying all the arguments is considerably stronger than the standard result in the literature used for the same purposes (Lovelock's theorem of 1972): it holds in all dimensions (not only in four); it does not require an assumption about the differential order of the desired concomitant of the metric; and it has a more natural physical interpretation.     

Chance,determinism and the classical theory of probability

This paper situates the metaphysical antinomy between chance and determinism in the historical context of some of the earliest developments in the mathematical theory of probability. Since Hacking's seminal work on the subject, it has been a widely held view that the classical theorists of probability were guilty of an unwitting equivocation between a subjective, or epistemic, interpretation of probability, on the one hand, and an objective, or statistical, interpretation, on the other. While there is some truth to this account, I argue that the tension at the heart of the classical theory of probability is not best understood in terms of the duality between subjective and objective interpretations of probability. Rather, the apparent paradox of chance and determinism, when viewed through the lens of the classical theory of probability, manifests itself in a much deeper ambivalence on the part of the classical probabilists as to the rational commensurability of causal and probabilistic reasoning.     

从Simpson悖论看群体生物学中统计解释和因果解释之争

在理论的群体生物学中,有三种模型都是通过性状适合度(trait fitness)的分布来解释和预见种群结构变化的量和方向。双因子和单因子模型都将性状适合度看成是一种因果属性,而丹尼斯.沃尔什(Denis Walsh)等则指出它们仅仅是一种统计学的属性。笔者通过分析沃尔什的有力论证,尝试表明如果将性状适合度看成是一种因果属性的话,将导致Simpson悖论,因而是不融贯的。所以,关于种群结构变化的统计学解释要优于因果解释。     

工程风险治理的预防原则:困境与消解

在工程风险治理中,预防原则要求:积极预防,工程开发主体承担举证责任。它存在逻辑困惑以及与成本—效益分析冲突等理论困境,也存在可能鼓励无知、可能限制创新以及难以操作等实践困境。要消解这些困境,需要明确预防原则的根本目的和适用范围。预防原则要求对公众的健康和安全的考量优先于对经济利益和其他权利的追求,它适用于那些概率不能确定的灾难性的、不可逆转的工程风险。     

高等代数中抽屉原理的应用

抽屉原理是数学中的重要原理,在初等数学中有广泛的应用,本文探讨此原理在解决高等代数问题中的应用。     

Mechanisms, principles, and Lorentz's cautious realism

I show that Albert Einstein's distinction between principle and constructive theories was predated by Hendrik A. Lorentz's equivalent distinction between mechanism- and principle-theories. I further argue that Lorentz's views toward realism similarly prefigure what Arthur Fine identified as Einstein's “motivational realism.”     

援形写神穷理味道--论两宋写实画风

两宋时形成的以刻画精微、形神兼备为尚的鲜明画风,把中国美术史上的写实性绘画推向极致,耸立起以写实为追求的时代丰碑。它的形成是前代写实性理论和艺术实践的厚积,同时也与特定历史境遇中时人对万物之理的孜孜追求无不关联。这种写实性画风形成与嬗变的过程,也正是画者打通物我之分,对自然规律和外物精神的感悟和表述。     

市场能量释放机理与影响场的影响模式

市场变化经常出人意料，已有的分析市场、激励市场和预测市场的方法和手段，常常对此还无能为力。本文在定义市场能量和市场能量释放概念的基础上，构建了由影响场系统、心理介质系统和市场能量系统组成的市场能量释放系统，并引入“场”的概念描述影响因素对市场能量系统的作用机理，根据系统理论分析了影响场系统的结构关系，研究各影响场相互关系的影响模式，从而为把握市场变化规律提供理论和方法支持。