Direct volume rendering of multiple scalar fields

Rendering of volume data without forming geometric objects is often termed direct volume rendering. Most of the previously developed methods for this purpose are restricted to display of one scalar variable. This paper presents methods for direct volume rendering of several scalar variables defined at discrete points in three-dimensional space. Typical requirements for the rendering of such data are proposed and then used as a basis for the derivation of a computational model. The proposed model uses a classification technique to composite specific types of information from different scalar fields. The visual display of the composite information is controlled through a set of rendering parameters.     

Orientation of Organic Nanocrystals Grown in Sol–Gel Matrices under a High Magnetic Field

In order to obtain new optical properties, such as quadratic nonlinear optical or electro‐optical properties, we have undertaken the orientation control of organic nanocrystals during their growth in the pore of sol–gel matrices by applying a high magnetic field, H , of 16 T. H favors the dye aggregation and improves the crystalline quality of nanocrystals by reducing the orientation freedom of molecules and clusters through their diamagnetic susceptibility. When H is not applied, the NPP (N‐(4‐nitrophenyl)‐(L )‐prolinol) nanocrystals generate a weak second harmonic generation (SHG) intensity due to self‐oriented domains of nanocrystals induced by dipole–dipole interactions. In the case of 3‐methyl‐4‐nitropyridine‐1‐oxide (POM), which exhibits a very weak dipolar moment, no SHG signal can be detected. When H is applied, the SHG intensity of NPP nanocrystals increases significantly due to the reduction of their orientational freedom and the increase of dipole–dipole interactions, thus improving the formation of oriented domains of nanocrystals.     

A T-shaped specimen for the direct characterization of orthotropic materials

This paper deals with the definition of a new test specimen geometry for the direct measurement of the four in-plane stiffness components of orthotropic materials. The technique is based on a suitable use of the principle of virtual work. The choice and application of four different types of virtual kinematic fields leads to a system of equations that links the our stiffness components to the global force applied and geometry parameters. A numerical simulation based on finite lement modelling is used to validate the approach. The stability of the process is also demonstrated. © 1998 John Wiley & Sons, Ltd.     

VARIABLE KINEMATIC MODELLING OF LAMINATED COMPOSITE PLATES

A displacement-based variable kinematic global–local finite element model is developed using hierarchical, multiple assumed displacement fields at two different levels: (1) at the element level, and (2) at the mesh level. The displacement field hierarchy contains both a conventional plate expansion (2-D) and a full layerwise (3-D) expansion. Depending on the accuracy desired, the variable kinematic element can use various terms from the composite displacement field, thus creating a hierarchy of different elements having a wide range of kinematic complexity and representing a number of different mathematical models. The VKFE is then combined with the mesh superposition technique to further increase the computational efficiency and robustness of the computational algorithm. These models are used to analyse a number of laminated composite plate problems that contain localized subregions where significant 3-D stress fields exist (e.g. free-edge effects).     

可拓工程在印染企业应用浅谈

受国际金融危机的冲击,2009年以来中国印染行业历经了艰难的搏杀,尽管产销有所增速加快,而产品利润却大大下降,印染企业的出路在哪里,现在应该以什么样的理念,什么样的态势,去面对现实,走出困境,这是摆在众多企业家面前的问题,本文就此应用可拓工程作一初步讨论。     

无砾石管式地下渗滤系统的改进研究

针对传统无砾石管式地下渗滤系统存在的处理性能差,渗滤通量低两个问题,通过去掉包裹织物,提高渗滤管开孔率、改变开孔方式,设计了无砾石微孔管地下渗滤系统。通过实验研究表明,无砾石微孔管地下渗滤系统对COD、氨氮的去除率比传统管式系统分别提高了10.8%、12.7%,总磷去除率并无显著差异,ORP值提高约85mV,渗滤通量提高26.8%。无砾石微孔管地下渗滤系统和传统管式地下渗滤系统对COD、氨氮在土壤中的降解趋势线存在明显的差异,而对磷的去除过程几乎完全相同。     

糖液物理场在制糖工业结晶中作用的研究

基于工业结晶过程的粒数衡算原理,本文作者首先提出,糖液物理场在蔗糖工业结晶中将明显地影响着产品的粒度分布。然后,通过对实际结晶体系的实验,作者进一步验证了运一观点,从而使人们可以从一含新的角度探讨工业结晶过程的粒度分布控制问题。     

Building Curves with Arbitrary Small MOV Degree over Finite Prime Fields

We present a fast algorithm for building ordinary elliptic curves over finite prime fields having arbitrary small MOV degree. The elliptic curves are obtained using complex multiplication by any desired discriminant.     

GPS在油气田的应用

全球卫星定位系统(GPS)技术作为先进的测量手段,已经应用于国民经济、国防建设和社会发展的相关领域,但在油气田的应用则刚刚起步。文章介绍了GPS系统在油气田车辆运行管理、安全管理方面应用的情况,以及GPS在油气田的物探、管道、海洋油气开发等领域的应用概况,指出应逐步深入地研究GPS技术及其应用领域,充分利用高新技术为油气田建设服务。