基于多色系统参数的CT硬化校正算法

为提高工业CT中的图像质量,提出了一种校正X射线多色性产生的硬化现象的方法。该方法利用多色系统参数,将多色投影数据通过多项式运算转化为单色投影数据。定义了多色系统参数,证明了该参数在中能量段(0.3～5.0MeV),中低原子序数物质条件下,近似与被扫描物体无关的性质,并给出了获得该参数的方法。用该方法对模拟截面进行了硬化校正数字模拟实验。校正结果和真实值符合的很好。与现有的硬化校正方法相比,该方法不需进行迭代,不需要准确的先验知识,校正速度快和应用灵活是其主要优势。

勒·柯布西耶现代建筑(五点)之第六点:颜色

勒·柯布西耶,20世纪最重要的建筑师之一,其作品常与混凝土材料相联系.也因此常与灰色相关联。文章旨在阐释一个相反的事实,即,颜色是柯布工作的一个不可或缺的要素。作者根据柯布使用颜色方式的不同,以及对空间进行着色处理的方式的不同.分三个阶段阐释:纯净主义时期(1920-1935年),粗野主义时期(1935-1955年),以及抒情时期(1955-1965年)。在前两个阶段中,柯布对颜色的使用方式更像是一位画家;而在第三个阶段,柯布则开始了色彩的光影游戏。

NOVEL GREY DECISION MAKING MODEL AND ITS NUMERICAL SIMULATION

A grey multi-stage decision making method is proposed for a type of grey multi-index decision problems with weighted values completely unknown and attributes as interval grey numbers. Firstly, a method for compar- ing two grey numbers based on probability is developed to calculate weighted values of the attributes. Secondly, the experts＇ evaluation scores for attribute values are presented in terms of internal grey numbers. Finally, a weight solving method for multiple-stages evaluation is proposed. An example analysis verifies the availability of the proposed method. The method provides a new way of thinking for solving grey decision problem.

Diversity of parasitic cuckoos and their hosts in China

In this exposé we provide the first review of host use by brood parasitic cuckoos in a multiple-cuckoo system in China, based on our own long-term field data and a compilation of observations obtained from the literature. In total, we found that 11 species of cuckoos utilized altogether 55 host species. These hosts belong to 15 families, in which Sylviidae, Turdidae and Timaliidae account for 22.6%, 20.8% and 17.0% of parasitism records, respectively. The Common Cuckoo (Cuculus canorus) had the widest range of host species, accounting for 45.5% of the total number of parasitized species (25 in 10 families) of all parasitism records and is the most frequent brood parasite in the country. Cuckoo species differed in their egg coloration and the extent of egg polymorphism with most of them, e.g. the Common Cuckoo, the Lesser Cuckoo (C. poliocephalus) and the Plaintive Cuckoo (Cacomantis merulinus) laying well mimetic eggs with respect to their hosts based on human being’s visual observations, while others such as the Large Hawk-cuckoo (C. sparverioides), the Himalayan Cuckoo (C. saturatus) and the Asian Emerald Cuckoo (Chrysococcyx maculatus) usually laid non-mimetic eggs. The use of cuckoo hosts and egg color variation in China are compared with those in other parts of their ranges in Asia.

Risk Assessment of Diary Cattle Brucellosis Based on Systematic Multilevel Grey Relation Entropy Method

[Objective] The study was to explore the major factors affecting diary cattle brucellosis risk assessment,as well as their strong-to-weak sequence,so as to provide theoretical basis for assessing diary cattle brucellosis risk level in different regions.[Method] From 4 dimensions of feeding and importing,breeding,housing and polyculture situation,an evaluation index system was set up,and diary cattle brucellosis risk survey was conducted in 3 typical regions.Finally,systematic multilevel grey relation entropy method was applied to perform data analysis.[Result] The strong-to-weak sequence of Level 1 impact factor of diary cattle brucellosis was as follows：feeding and importinghousingpolyculture situationbreeding;the sequence of Level 2 impact factor was U32〉U12〉U11〉U31〉U21〉U42〉U43〉U23〉U22〉U41;the risk level sequence of 3 typical regions was Province A（County A1,A2,A3）Province B（County B1,B2,B3）Province C（County C1,C2,C3）.[Conclusion] According to the weight of Level 1 index strata,administrative departments at all levels and dairy cattle farmers should lay emphasis on the aspects of feeding,importing and housing;viewed from the perspective of Level 2 index strata,dairy cattle farmers should value the siting of cattle field,the brucellosis surveillance before importing and milking modes most.According to the diary cattle brucellosis risk level of 3 typical regions,if administrative departments at all levels strengthen peoples＇ awareness of their personal health and increase investment in this area,with new healthy cultured atmosphere built,the risk level of diary cattle brucellosis will surly decline.

实现高效率移印的解决方案

本文主要介绍了目前市场上常见的几种移印解决方案,并对它们的优缺点进行了比较。

Consistency maintenance for constraint in role-based access control model

Constraint is an important aspect of role based access control and is sometimes argued to be the principal motivation for role based access control (RBAC). But so far few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces corresponding formal rules, rule based reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally, the paper introduces briefly the application of consistency maintenance in ZD PDM, an enterprise oriented product data management (PDM) system.

数字印刷机全面接触

数字印刷机全面接触 由于市场对于彩色短版活及可变数据印刷品的需求不断增长,传统印刷机已完全不能满足这种需求。各家印刷设备供应厂家,纷纷推出“数字印刷机”,令持币观望的印刷厂家眼花缭乱,不知何种数字印刷机才是最佳选择。下面就介绍一下目前市场上主要的数字印刷机。

Selecting Suitable Heat Source in Refinery for Multi-effect Distillation Based on Grey System Theory

For dealing with high-salinity wastewater in the refinery, the high cost of driving heat source is the disadvantage of multi-effect distillation (MED) so it is of great importance to evaluate the performance of low-temperature heat source for conducting MED and select the optimal temperature for it. Both the MED and the low-temperature heat sources studied in this paper were from a typical refinery located in northwestern China. Besides, a new methodology to evaluate heat sources as the optimal candidate was proposed for MED based on the grey system theory. Five process units, which included 18 fluids of the refinery, were named as the evaluation projects. Three factors, which included safety effects, total costs and characteristics of low-temperature heat sources were determined as the evaluation indexes, the values of which were established through the analyses. The results obtained through the grey correlation analyses have revealed that the grey correlation degrees of these units were 0.661(AVDU), 0.732 (#1 FCCU), 0.618 (#2 FCCU), 0.535 (#1 DCU), and 0.572 (#2 DCU), respectively. Thus, the optimal heat source was provided from #1 FCCU. Through further analyses of the fluids from #1 FCCU, the grey correlation degrees of the fluids were 0.597 (oil and gas at top of tower), 0.714 (recycle oil and gas), and 0.512 (diesel), respectively. Thus, the optimal heat source was the oil and gas recycle stream.

The Development and Application of Color Doppler Ultrasound Image-text Management System

In this paper, the advantages and disadvantages of the existing ultrasonic image management system are analyzed, and also a multi-functional color Doppler ultrasound image-text management system is researched and developed in combination with the experience of color Doppler ultrasound doctors. With this system, the related operations such as color Doppler ultrasound images acquisition, processing, preservation, and medical records are implemented. In the design of the system, a professional acquisition card is used for implementing the acquisition of ordinary video signals. In the meantime, DICOM interface is designed using DICOM3.0 protocol for implementing multi-mode acquisition.

流溢与回归——乔托绘画中的两种光色结构

新柏拉图思想中的“光照”经过中世纪的教义转化后变成基督教艺术特有的“神圣光色”结构,艺术家通过光与色的视觉再现来隐喻世俗与神圣、生命与永恒。乔托延续拜占庭艺术遗风的同时探索出光源象征的金色系统和色相象征的多色系统,表现为金色向外流动和多色向内回归的色彩结构。一方面,金色表征的“光”作为图像向观者传递“神圣光辉”的中介作用,观者也通过金色感知图像的精神性;另一方面,多色作为比文字更具感染力的视觉载体,启示了神圣形象的在场和激发虔诚的宗教情感。文章讨论新柏拉图思想中光色象征体系与乔托绘画的关联,概括其作品中运用的两种色彩系统,认为乔托的色彩实践观念是基于“神圣光色”追求的艺术语言探索。

光纤记录系统在神经科学研究中的应用

近年来,光纤记录系统作为一种记录自由活动动物大脑特定核团神经元活动的技术,在神经科学领域研究中广受欢迎,是研究动物神经元活动与行为关系的重要技术手段。本文综述了单通道光纤记录系统、多通道光纤记录系统及多色光纤记录系统在认知、行为学、心理学等神经科学基础及神经疾病中的应用,并简述了光纤记录系统与功能磁共振成像技术结合、光纤记录系统与递质探针结合在神经科学领域中的应用。

A new proof for the correctness of the F5 algorithm

In 2002, Faugere presented the famous F5 algorithm for computing GrSbner basis where two cri- teria, syzygy criterion and rewritten criterion, were proposed to avoid redundant computations. He proved the correctness of the syzygy criterion, but the proof for the correctness of the rewritten criterion was left. Since then, F5 has been studied extensively. Some proofs for the correctness of F5 were proposed, but these proofs are valid only under some extra assumptions. In this paper, we give a proof for the correctness of F5B, an equivalent version of F5 in Buchberger＇s style. The proof is valid for both homogeneous and non-homogeneous polynomial systems. Since this proof does not depend on the computing order of the S-pairs, any strategy of selecting S-pairs could be used in F5B or F5. Furthermore, we propose a natural and non-incremental variant of F5 where two revised criteria can be used to remove almost all redundant S-pairs.

环氧树脂地面涂料在工程中的应用

介绍环氧树脂地面涂料的优点以及在工程中的具体应用。

Quantum Fisher Information of Driven Multi-particle Systems in Structured Bosonic Reservoirs

We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single driven atom is described by the time local quantum master equation. The dynamics of the quantum Fisher information for many entangled atoms is obtained by means of the supreoperator mapping. The estimation limit is superior to the standard quantum limit during a characteristic interval. At a given time, the precision of parameter estimation can be improved to a maximal value if the number of entangled atoms is chosen to be an optimal value. The optimal number of entangled atoms is determined by the dynamical property. The decay of quantum Fisher information is accelerated with the increase of the number of entangled atoms.

Genetic diversity and offspring fitness in the red and white fruit color morphs of the wild strawberry Fragaria pentaphylla

Aims Fruit color polymorphisms are widespread in plants,but what maintains them is largely unclear.One hypothesis is that some morphs are preferred by dispersers while others have higher pre-or postdispersal fitness.This leads to the prediction that fruit color morphs will differ in pre-or postdispersal fitness.Methods We compared genetic and clonal diversity,mating system,morphological traits that might be associated with resistance to freezing,and germination,survival and seed production of progeny of the red and white fruit morphs in a population of a diploid,wild strawberry,Fragaria pentaphylla,from south-central China.Important Findings The red morph was much more abundant than the white but did not show higher genetic diversity as measured by observed and effective numbers of alleles,Shannon information index,or expected or observed heterozygosities.AMOVA showed that most of the genetic variation in the population was within rather than between morphs.Morphs did not differ in mating system parameters,and no significant biparental inbreeding was found in either morph.Gene flow between two morphs was high(N_(m)=6.89).Seeds of the red morph germinated about 2 days earlier and had a 40%higher rate of germination than those of the white morph,but survival of seedlings and seed production by surviving offspring did not differ between morphs.The whole postdispersal fitness of the red morph was about two times higher than that of the white morph.Red morphs had hairier petioles but not more surface wax on leaves.Overall,results showed partial evidence for difference in pre-and postdispersal fitness between fruit color morphs in F.pentaphylla.Differences in fitness independent of dispersal may thus partially account for fruit color polymorphism in all cases.

Quantifying Spontaneously Symmetry Breaking of Quantum Many-Body Systems

Spontaneous symmetry breaking is related to the appearance of emergent phenomena, while a non-vanishing order parameter has been viewed as the sign of turning into such symmetry-breaking phase. We study the spontaneous symmetry breaking in the conventional superconductor and Bose–Einstein condensation with a continuous measure of symmetry by showing that both the many-body systems can be mapped into the many spin model. We also formulate the underlying relation between the spontaneous symmetry breaking and the order parameter quantitatively. The degree of symmetry stays unity in the absence of the two emergent phenomena, while decreases exponentially at the appearance of the order parameter which indicates the inextricable relation between the spontaneous symmetry and the order parameter.

Novel metal-dielectric metameric optical filters for optical security devices

Optical security devices play an essential role in the fight against counterfeiting. In this paper, we study and design a pair of metal-dielectric optical filters based on metameric effect, which offer a hidden image effect by the color shift at a specific angle of observation. Compared with all-dielectric multilayer system, the metal-dielectric multilayer structure has larger color shift with varying incident angle, higher color saturation and fewer layers. Finally, the stacks with 5 layers and 7 layers are achieved, and the color difference index is only 0.71, which shows good metameric matching effect. Simultaneously, the sensitivity of filters to deposition errors is analyzed when the thickness deviation is ±2%, and the results show that the two filters have good manufacturability.