计算机配色技术应用于木材染色初探

介绍了计算机测色配色系统的原理,研究了建立木材染色基础数据库的方法,提出了注意事项,并分析了自动配色过程中产生色差的原因及解决方法。     

空气钻井条件下录井工艺方法与技术配套探讨

针对玉门青西油田深部高陡易斜地层存在可钻性差、自然造斜能力强，致使钻井周期长、成本高等特点，中油集团公司在吐哈油田设立钻探“工程探索井（L14井）”重大科研项目，试验研究空气钻井技术。根据L14井录井的实际情况，首先分析了空气钻井条件对录井带来的影响和常规的录井工艺方法和技术设备存在的不足；从5个方面介绍了录井工艺、技术方法的改进，探讨了空气钻井下的岩屑上返理论；介绍了配置装备的改进，分析了该井录井配套技术的应用效果。从该试验井的录井效果看，经改进的录井工艺、方法及装备基本上能满足空气钻井的需要，取全取准了地质及工程资料，为地质解释和评价提供了可靠依据；在工程监测、保障施工安全方面，工程录井也发挥了作用。但综合录井仪软件及后台评价程序还不适应空气钻井的需要，相关的理论研究及工艺完善还有许多课题尚需深入。     

交错群A_5的4度连通对称图的分类

一个图Г称为G-对称的(symmetric).如果其同构群Aut(r)的一个子群G在图r的有向孤集(set of ordered pairs of adjacent vertices)上的作用是传递的(transitive).本文主要结果是:设图Г是4度对称图.全自同构群Aut(r)=A_5,则图r是且仅是如下图之一:(1)Г是15个点的完全图K_5的三维覆盖(3-fold cover)图.(2)Г是完全图K_5.     

紧凑式换热面瞬态实验中的全程直接配比法

在紧凑式换热面的瞬态实验中，为获得准确的实验结果，不仅要建立符合试验工况的理 论解，而且还要选择合适的配比方法，以便尽可能减小测量误差对配比结果的影响．本文就瞬态实 验的配比，提出了一种新的基于计算机的全程直接配比法，由于它采用了所有可用测试点进行配 比并且其理论解与实测值的配比误差是通过最小搜索步长来控制的，因此，实验结果的准确性和 可靠性优于通常应用的间接配比法和选点配比法．     

R－X图解法计算多级串联理想混合反应器

论述Ｒ－Ｘ图解法计算多级串联理想混合反应器的基本原理，并结合实例，对Ｒ－Ｘ法的计算步骤予以详细介绍，为多级串联反应器的设计与计算，提供一种新颖适用的图解计算方法。     

Lubricating behavior of iron rhenate and its relation to matching pairs

The iron rhenate was compounded by chemical method, which may be generated during wear process of Fe-Re alloys at elevated temperature. The friction coefficient of iron rhenate has been determined by a pin-on-disc device. The results show that iron rhenate plays role of lubricating at RT-600 °C. The lubricating behavior is related to the matching pairs. The hardness of the materials of matching pairs, compatibility of iron rhenate with materials of matching pairs and surface roughness of disc affect the lubricating behavior of iron rhenate mostly. The principle of matching pairs is proposed. Project supported by the National Natural Science Foundation of China Synopsis of the first author Xiong Dangsheng. associated professor, born in 1960. Current research fields include high-temperature self-lubricating alloys and tribological properties of material.     

A region-based selective optical flow back-projection for genuine motion vector estimation

Motion vector plays one significant feature in moving object segmentation. However, the motion vector in this application is required to represent the actual motion displacement, rather than regions of visually significant similarity. In this paper, region-based selective optical flow back-projection (RSOFB) which back-projects optical flows in a region to restore the region's motion vector from gradient-based optical flows, is proposed to obtain genuine motion displacement. The back-projection is performed based on minimizing the projection mean square errors of the motion vector on gradient directions. As optical flows of various magnitudes and directions provide various degrees of reliability in the genuine motion restoration, the optical flows to be used in the RSOFB are optimally selected based on their sensitivity to noises and their tendency in causing motion estimation errors. In this paper a deterministic solution is also derived for performing the minimization and obtaining the genuine motion magnitude and motion direction.     

Volumetric three‐dimensional up‐conversion display medium

Abstract— Several rare‐earth‐doped fluoride crystals that are excited to emit visible light by sequential two‐photon absorption have been investigated as display‐medium candidates for static volumetric three‐dimensional displays. Dispersion of powders of these materials in a refractive‐index‐matched polymer is reported because such a medium may result in a scalable display. The scattering problem in such a medium is greatly reduced by index‐matching the polymer to the crystalline particles. An index‐matching condition that optimizes the performance is identified.     

High‐error approximate dictionary search using estimate hash comparisons

A method for finding all matches in a pre‐processed dictionary for a query string q and with at most k differences is presented. A very fast constant‐time estimate using hashes is presented. A tree structure is used to minimize the number of estimates made. Practical tests are performed, showing that the estimate can filter out 99% of the full comparisons for 40% error rates and dictionaries of up to four million words. The tree is found to be efficient up to a 50% error rate. Copyright © 2006 John Wiley & Sons, Ltd.