A general form of color difference formula based on color discrimination ellipsoid parameters

A general color difference formula has been derived based on the parameters of color discrimination ellipsoids in the CIE 1976 L*a*b* color space. By using different orders of approximation, the general formula resembles the basic forms of the current formulae. The method described in this article suggests a framework for modifying the CIE 1976 L*a*b* color difference formula.     

A new color image space HRU related to the CIEL*a*b* color space

The color image space with one kind of merit color image scales (WIP) is derived using the psychophysical method of magnitude estimation method, usually used in visual assessment of color appearance, which can be used to describe the color image meanings of colors of works of art in parallel with those of people. The results show that a new color image space HRU is developed, and the relativity between this space and the CIEL*a*b* color space is also discussed. And, a good relationship between the HRU color image space and the CIEL*a*b* color space can be found. This may be of great advantage to the new color image space HRU in predicting the color image for single color based on the color space CIEL*a*b*. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 452–457, 2009     

基于COMSOL Multiphysics的PEMFC的数值模拟

由于燃料电池内的环境是高度反应性的,因此,很难在电池运行时进行许多详细的在线测量工作。为了更好地了解电池内复杂的流动结构、化学组分的传递过程、优化水、热管理以及缩短电池的设计和优化周期,这些信息常需要通过建立数学模型和数值模拟工作来寻求。在建立了二维全电池模型的基础上,在COMSOL Multiphysics 3.3a环境下对全电池的内部电流密度、气体流速、气体压力和含水量等进行了数值模拟,并得出在模拟条件下,最大电流密度为9 027 A/m^2、最大气体流速为0.7 m/s。     

纳米Bi2O3·SnO2的制备及对RDX热分解特性的影响

为了研究纳米Bi2O3*SnO2对推进剂燃烧的催化作用,以BiCl3和SnCl4*5H2O为原料,采用共沉淀法制备出纳米Bi2O3*SnO2粉体,产物的粒径约为5 nm.用DSC测试了纳米Bi2O3*SnO2对RDX热分解特性的影响.结果表明,纳米Bi2O3*SnO2对RDX热分解有明显的催化效果,使RDX的分解峰温前移了13.7 ℃,放热量增加665 J/g,活化能降低49.42 kJ/mol.     

A novel method for color determination of edible oils in L*a*b* format

A simple method that uses visible spectrophotometer data and an artificial neural network (ANN) was developed to determine edible oil color based on the L*a*b* format. The 100 oil samples consisted of nine pure oils, a sesame oil blend and three heated oils. Binary, ternary and quaternary mixtures of these 13 oils in different ratios were prepared, and absorbance values of the samples were measured in the visible region (380–700 nm). The absorbance values at wavelengths of 416, 456, 483, 537, 611 and 672 nm were used to train, validate and test the network. Strong correlations between the instrumental L*a*b*ΔE and the estimated L*a*b*ΔE were found for the test samples, with correlation coefficients (R²) of 0.989, 0.984, 0.996 and 0.992 for L*, a*, b*, and ΔE, respectively. The effects of number and combination of the wavelengths used for training of the ANN on the estimation capability of the network for the test samples were also investigated. Although a good agreement, average R² of 0.991– 0 993 for L*a*b*, was obtained for combinations composed of three to six wavelengths with 483 and 537 nm in common, the best R² value was obtained when all six wavelengths were used to train the ANN. The developed method is objective, cost effective and simple, and allows the color measurement with a basic visible spectrophotometer and disposable cuvettes.     

Low‐temperature UV irradiation induced the color change kinetics and the corresponding structure development of PVC film

The low‐temperature ultraviolet (UV) irradiation equipment, developed in our Lab, was used to study the photo‐aging of poly (vinyl chloride) (PVC) films at low temperature. The color change kinetics and corresponding structure development of PVC film during low‐temperature UV aging were studied through L*a*b* coordinates Commission International d' Eclau‐age (CIE 1976 color space) and Ultraviolet spectrophotometer (UV–vis) and Fourier transform infrared spectroscopy (FTIR). It was found that the yellowness difference (?b*) and color difference (?E*) of the PVC film increased almost linearly with the aging time. Their values had a slower change at lower temperature. The kinetic study showed that the relationship between the velocity of coloration of the PVC film and the temperature agreed well with Arrhenius equation at low temperature. The activation energy of coloration of the PVC film was calculated. The FTIR spectra indicated that photo‐dehydrochloration, resulting in the generation of conjugated carbon–carbon double bonds, was the main reaction for PVC during photo‐aging at low temperature. Meanwhile, the photo‐oxidation was also obvious and could not be neglected. It clearly confirmed that the absorption peaks of conjugated carbon–carbon double bond increased and shifted to longer wavelength during photo‐aging in the UV‐abs analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

超临界流体萃取塔的流体力学和传质性能

New models for describing hydrodynamics and mass transfer performance in supercritical fluid extraction columns were proposed.Those models were proved by experimental data,which were obtained in supercritical fluid extraction packed column,spray column and sieve tray column respectively.The inner diameter of those columns areΦ25mm，These experimental systems include supercritical carbon dioxideisopropanol-water and supercritical carbon dioxide-ethanol-water,in which supercritical carbon dioxide was dispersed phase,and another was continuous phase.The extraction processes were operated with continuous countercurrent flow.The predicted values are agreed well with experimental data.     

An adaptive color similarity function suitable for image segmentation and its numerical evaluation

In this article, we present an adaptive color similarity function defined in a modified hue‐saturation‐intensity color space, which can be used directly as a metric to obtain pixel‐wise segmentation of color images among other applications. The color information of every pixel is integrated as a unit by an adaptive similarity function thus avoiding color information scattering. As a direct application we present an efficient interactive, supervised color segmentation method with linear complexity respect to the number of pixels of the input image. The process has three steps: (1) Manual selection of few pixels in a sample of the color to be segmented. (2) Automatic generation of the so called color similarity image (CSI), which is a gray level image with all the gray level tonalities associated with the selected color. (3) Automatic threshold of the CSI to obtain the final segmentation. The proposed technique is direct, simple and computationally inexpensive. The evaluation of the efficiency of the color segmentation method is presented showing good performance in all cases of study. A comparative study is made between the behavior of the proposed method and two comparable segmentation techniques in color images using (1) the Euclidean metric of the a* and b* color channels rejecting L* and (2) a probabilistic approach on a* and b* in the CIE L*a*b* color space. Our testing system can be used either to explore the behavior of a similarity function (or metric) in different color spaces or to explore different metrics (or similarity functions) in the same color space. It was obtained from the results that the color parameters a* and b* are not independent of the luminance parameter L* as one might initially assume in the CIE L*a*b* color space. We show that our solution improves the quality of the proposed color segmentation technique and its quick result is significant with respect to other solutions found in the literature. The method also gives a good performance in low chromaticity, gray level and low contrast images. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 156–172, 2017     

Review and evaluation of color spaces for image/video compression

A color space plays an important role in color image processing and color vision applications. While compressing images/videos, properties of the human visual system are used to remove image details unperceivable by the human eye, appropriately called psychovisual redundancies. This is where the effect of the color spaces' properties on compression efficiency is introduced. In this work, we study the suitability of various color spaces for compression of images and videos. This review work is undertaken in two stages. Initially, a comprehensive review of the published color spaces is done. These color spaces are classified and their advantages, limitations, and applications are also highlighted. Next, the color spaces are quantitatively analyzed and benchmarked in the perspective of image and video compression algorithms, to identify and evaluate crucial color space parameters for image and video compression algorithms.     

复混(合)肥配方软件设计原理和方法

介绍研制各种复混(合)肥配方软件的参数设计和软件运行流程及应用方法。以上软件适合复混(合)肥厂和BB肥配肥站使用。     

Experimental study on CH* chemiluminescence characteristics of impinging flames in an opposed multi‐burner gasifier

The bandpass filtered images of impinging flames in an opposed multi‐burner (OMB) gasifier was visualized by a CCD camera combined with a high temperature endoscope. A filtering and image processing method by use of three bandpass filters was applied to subtract soot and CO₂* contributions in the CH* band and obtain the CH* chemiluminescence of impinging flames. The results show that a clear reaction core is generated in the impinging zone of four‐burner impinging flames. The size of the reaction core is affected by the O/C equivalence ratio ([O/C]_e) and the impingement effect is relatively stronger at lower [O/C]_e. The flame lift‐off length in the gasifier is jointly controlled by the syngas concentration and the diesel atomization effect. The impingement effect shortens the flame lift‐off length. The relationship between the syngas concentration and the maximum CH* intensity makes it possible to evaluate the syngas concentration from CH* intensity. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2007–2018, 2017     

中国聚烯烃塑料制品的现状与展望

本文介绍了国内聚烯烃塑料制品的产量与分布、产品分类和应用领域，并叙述了发展前景。     

110*树脂对镝的吸附及机理研究

用树脂吸附的方法研究了稀土金属的富集及回收。测定了在不同介质pH、温度、吸附时间、树脂量等因素对吸附的影响。结果表明:110*树脂在pH=5.13的HAc-NaAc体系中吸附最佳,静态饱和吸附容量为316.67 mg/g;用0.5 mol/L的HC l可定量洗脱;等温吸附服从Freund lich经验式;表观速率常数k298=1.49×10-5s-1;用化学和红外光谱等方法讨论了吸附机理。     

固体酸SnCl_4·5H_2O/C催化合成乳酸正丁酯的研究

以固体酸SnCl4·5H2O/C为催化剂,合成了乳酸正丁酯,最佳合成条件为:酸醇摩尔比1∶3,催化剂用量10%(质量分数),反应时间为2 5h,产率92 4%,该催化剂具有制备简单,可循环使用等优点。     

用Cp*TiCl3/MAO催化体系合成间规聚苯乙烯

介绍了以Cp TiCl3 为主催化剂、MAO为助催化剂组成催化体系制备间规聚苯乙烯的实验室方法 ,研究了试验条件变化对聚合反应的影响。合适的聚合反应条件是 :反应温度 5 0℃ ,Al/Ti摩尔比在 5 0 0～ 30 0 0之间 ,催化剂浓度 0 .5× 1 0 - 4 ～ 1 .5× 1 0 - 4 mol·L- 1 ,反应时间 1～2h,催化剂有较高的活性 ,聚合反应能平稳进行。得到间规度大于 97%以上的聚苯乙烯 ,并有很高收率     

大肠杆菌中同时表达的可溶性和不溶性人α-干扰素-2b的初步分离研究

1 INTRODUCTION Interferons are proteins naturally occurring in the hu-man body with antiviral, antiproliferative and immu-noregulatory activity[1]. The commercial production of interferons as important clinic medicines was carried out by using recombinant E. coli system[2]. Despite the ease of cloning and genetic manipulation in E. coli, heterogeneous protein was almost expressed as inclusion body form since the outer membrane appears to be a very effective barrier to the release of pro…     

用FA和ECM方法测定吸附等温线的比较

Adsorption isotherm is the most fundamental information related to chromatography.To calculate the parameters of Langmuir adsorption isotherm of thymidine,fronal analysis(FA)and lution-curve method(ECM)were adopted in reversed-phase high performance liguid chromatography(RP-HPLC).In FA,tha concentration of stationary phase was measured from the elution curves and the isotherm was determined by regression analysis,while the parameters by ECM were obtained by parameter optimization.The adsorption isotherms of thymidine from the two methods were very similar.The superiority of ECM over FA was that the consumption of sample was less and only one or two in jections of sample were required.     

Dietary sphingolipids lower plasma cholesterol and triacylglycerol and prevent liver steatosis

The prevalence of dyslipidemia and obesity resulting from excess energy intake and physical inactivity is increasing. The liver plays a pivotal role in the systemic lipid homeostasis. Effective, natural dietary interventions that lower plasma lipids and promote liver health are needed. APOE*3Leiden mice were fed a Western‐type diet, supplemented with different sphingolipids, to determine their effect on plasma lipids and liver steatosis. Hepatic lipid levels and lipid‐related gene expression were also determined. Dietary sphingolipids dose‐dependently lowered both plasma cholesterol (C) and triglycerides (TG) in APOE*3Leiden mice. 1% Phytosphingosine (PS) reduced C and TG by 57 and 58%, respectively. PS (a) decreased the absorption of dietary C and free fatty acid but did not affect the intestinal TG lipolysis, (b) increased hepatic VLDL‐TG production whereas plasma lipolysis was not affected; and (c) increased the hepatic uptake of VLDL remnants. Hepatic mRNA levels indicated enhanced hepatic lipid synthesis and VLDL and LDL uptake. Livers of PS (1%) fed mice were lighter (?22%), less pale, and contained less cholesteryl ester (?61%) and TG (?56%). Furthermore, markers for liver inflammation (SAA) and liver damage (ALAT) were decreased by 74% and 79%, respectively in PS‐fed mice. Sphingolipids lower plasma C and TG and protect the liver from fat‐ and cholesterol‐induced steatosis. In a preliminary small double‐blind cross‐over study with six middle‐aged slightly overweight male volunteers the daily supplementation of one gram of PS to the diet resulted in a ?9.8% (p = 0.0074) and – 13.2% (p = 0.0002) reduction of total C and LDL‐C, respectively. The C/HDL‐C ratio was not significantly affected (p = 0.0571). Due to the relatively low pre‐study levels of TG in the human volunteers, and the individual variability of TG levels, the TG lowering in humans was not significant in this first small study, but per individual there was a clear trend in TG lowering.     

光致聚合物的全息存储机理与特性

阐述了光致聚合物的存储机理、全患图类型及形成的机理,介绍了用于光致聚合物材料的基本组成,详细分析了光致聚合物材料的性能指标。用于全息存储的光致聚合物,由于其高分辨率、高衍射效率、高感光灵敏度以及较宽的光谱范围等优点,可望在未来的数字数据存储领域发挥巨大的作用。