fluctuation of river discharge

The emphasis is placed on the exact definition of momentum variables and the general expression of momentum operators, and the importance of the additional divergence term in this expression to ensuring their hermiticity is demonstrated.

用几何语言扼要阐述了有限自由度无约束经典系统量子化的普遍理论，着重介绍动量变量的准确定义及动量算符的一般表式，证明了动量算符表式中附加散度项对保证厄米性的重要作用；并以此为指导对量子力学教学界长期存在的“正则动量算符之争”给出明确结论，同时也澄清了与量子化有关的若干重要认识问题。

From the point of spatial information expression and communication, this paper discusses visualization mechanism of 3D model in the field of 3D GIS such as 3D spatial data model, visual variable and dynamic variable.

本文从空间信息表达与传输的角度,阐述了3D GIS中3维模型的可视化机理,包括3维空间数据模型、视觉变量和动态变量等内容;并借助图形实现语言Java 3D,实现了3维模型在城市道路横断面设计中的具体应用。

A foundation method of GBOM product family based on variable driving

基于变量驱动的GBOM产品族模型建立方法

Based on the modeling and dimension variable driving of the main parts as well as the modification of dimension variable, the preliminary design and modification of reactor core is carried out with high design efficiency and quality as well as short periods.

研究使用MechanicalDesktop(MDT)软件对中国先进研究堆 (CARR)堆本体主要部件进行三维参数化建模 ,并通过尺寸及相关位置数值的变量驱动进行CARR堆本体初步设计及修改。