激光测烟雷达探测烟气抬升的初步研究

本文分析了在山西某电厂进行的大气环境测试中用两部激光测烟雷达同时分段对210米烟囱排放的烟羽探测的资料,并对几个常用的、有代表性的烟气抬升高度计算式进行了比较分析。实测数据表明:在近中性类稳定度条件下的烟流抬升路径与“2/3次律”相近。在此基础上经验拟合出了适用于该测试地区C、D和E—F类大气稳定度条件下的烟气抬升高度计算式。     

A STUDY ON CELLULAR AUTOMATA BASED ON RELATIONAL DATABASES AND SPATIO-TEMPORAL SIMULATIONS OF CULTURE DIFFUSION

This paper presents a development of the extended Cellular Automata (CA), based on relational databases(RDB), to model dynamic interactions among spatial objects. The integration of Geographical Information System (GIS)and CA has the great advantage of simulating geographical processes. But standard CA has some restrictions in cellularshape and neighbourheod and neighbour rules, which restrict the CA‘s ability to simulate complex, real world environ-ments. This paper discusses a cell‘‘s spatial relation based on the spatial object‘s geometrical and non-geometrical characteris-tics, and extends the cell‘‘ s neighbour definition, and considers that the cell‘ s neighbour lies in the forms of not only spa-tial adjacency but also attribute correlation. This paper then puts forward that spatial relations between two different ceilscan be divided into three types, including spatial adjacency, neighbourheod and complicated separation. Based on tradition-al ideas, it is impossible to settle CA‘‘s restrictions completely. RDB-based CA is an academic experiment, in whichsome fields are designed to describe the essential information needed to define and select a cell‘‘s neighbour. The cultureinnovation diffusion system has multiple forms of space diffusion and inherited characteristics that the RDB-based CA iscapable of simulating more effectively. Finally this paper details a successful case study on the diffusion of fashion weartrends. Compared to the original CA, the RDB-based CA is a more natural and efficient representation of human knowl-edge over space, and is an effective tool in simulating complex systems that have multiple forms of spatial diffusion.     

Spurious contribution to cosmic ray scattering calculations

The quasi-linear theory for cosmic ray propagation is a well-known and widely accepted theory. In this paper, we discuss the different contributions to the pitch-angle Fokker–Planck coefficient from large and small scales for slab geometry using the damping model of dynamical turbulence. These examinations will give us a hint on the limitation range where the quasi-linear approximation is a good approximation.     

Search for rapid spectral feature variations in chemically peculiar star HR 4330

The chemically peculiar star HR 4330 (=HD 96707, EP-UMa) was observed using the 2-m Himalayan Chandra Telescope at the Indian Astronomical Observatory, Hanle, India, for studying the variations in its spectral features. It was found that the spectral features of Ca  ii 3933 Å and Sr  ii 4077 Å were showing rapid variations in their equivalent widths with a periodicity of  0.28 ± 0.02 d  . Such short-term variations suggest that there could be a dynamically active surface with rapid variation in the conditions of the stellar atmosphere.     

Cultural Patterns and Processes in Advanced Placement Human Geography

Abstract

In this article I outline some of the key concepts and approaches that form the cultural patterns and processes section of the Advanced Placement human geography course. In addition, I provide examples to illuminate and help explain those concepts and suggest strategies for pursuing educational discussions concerning the range of cultural geographies.     

POLAR COORDINATE MEAN INFORMATION FIELDS

Polar Coordinate Mean Information Fields have several advantages over the traditional square grid method of Hagerstrand. These include consistency with theory, more explicit and accurate incorporation of directions, ease of rotation, and easy conversion to 3-dimensional diffusion.