测试PVC塑料黄色指数的影响因素

介绍了Hunterlab Agera台式分光色差仪的操作步骤及注意事项,并利用该设备研究了测试标准、白色背景板及样品形式、制备方法、装填方式、厚度等因素对PVC塑料黄色指数测试结果的影响。指出在比较PVC塑料样品黄色指数时,应在相同的条件下进行,否则测试结果不具有可比性。

一种直观判别两个表面色相对偏色的方法

本文介绍了一种利用分色差概念，精确计算出两个表面色的相对偏色（解析方法），并在ＣＩＥＬＡＢ色差分析图上直观显示出来（图解法）。亦可根据孟塞尔颜色系统的计算机模型，实现ＣＩＥＬＡＢ色空间到孟塞尔颜色系统的转换，计算出两个表面色的孟塞尔色相角，从而判断出两个表面色的相对偏色。为生产厂家提供了一种简便、快捷、准确、直观的判别色样偏色的检验手段。

红枣发酵饮料的研制及电子感官技术在其货架期评定中的应用

以清涧红枣为主要原料,制备红枣清汁。通过单因素及正交实验优化干酪乳酸菌、植物乳杆菌、鼠李糖乳杆菌的添加量、复配比例及发酵时间、初始可溶性固形物含量;考察其货架期的pH值、可溶性固形物含量、总酸、还原糖和乳酸菌活菌数的变化,并利用电子感官技术快速准确评价货架期品质。结果表明,红枣发酵饮料以干酪乳杆菌∶植物乳杆菌∶鼠李糖乳杆菌=6∶1∶1复配,接菌量0.01%(m/m),初始可溶性固形物含量13.5%,37℃发酵48 h后,环磷酸腺苷含量21.4μg/mL,活菌数可达到1×10^8 CFU/mL以上;在4℃条件下贮藏21 d时,总酸5.52 g/kg,还原糖11.7 g/100 g,活菌数5.63×10^6 CFU/mL,符合果蔬发酵汁标准QB/T5356—2018;货架期电子感官分析结果与感官评定、微生物及理化指标的测定结果有很好的一致性,确定红枣发酵饮料货架期为21 d,证实电子感官评价技术可应用于红枣发酵饮料货架期的质量评定。

Prediction method of highway pavement rutting based on the grey theory

In order to make a scientific pavement maintenance decision, a grey-theory-based prediction methodological framework is proposed to predict pavement performance. Based on the field pavement rutting data,analysis of variance （ANOVA）was first used to study the influence of different factors on pavement rutting. Cluster analysis was then employed to investigate the rutting development trend.Based on the clustering results,the grey theory was applied to build pavement rutting models for each cluster, which can effectively reduce the complexity of the predictive model.The results show that axial load and asphalt binder type play important roles in rutting development.The prediction model is capable of capturing the uncertainty in the pavement performance prediction process and can meet the requirements of highway pavement maintenance,and,therefore,has a wide application prospects.

DEVELOPMENT AND PRELIMINARY APPLICATION OF OBJECTIFYING SYSTEM FOR TCM COLOR INSPECTION

An objectifying system for color inspections of traditional Chinese medicine （CITCM） is developed. The entire system includes two parts ： The hardware and the software. The hardware is an image acquiring device under a standard lighting condition, and it mainly includes a xenon lamp with color temperature of 5 500 K as light source, an integrating sphere used for diffusing light and a high resolution CCD camera. The software is used for digital image processing, and the procedure is divided into three steps. Firstly the skin/non-skin classifi- cation is performed by utilizing the threshold in chrominance channels of the RGB color space. Secondly, the fa- cial features are localized by using the image segmentation and coordinates sorting. Finally, the facial special re- gion（SR） corresponding to five internal organs is achieved by utilizing masks designed to take advantage of mor- phology. Subsequently, the chromaticity is calculated. The system is tested by taking 83 samples of 30 young and 53 elderly people. The experiment shows that there is significant difference of all SRs between the young and the elderly, and the system has better performance for objectifying research of CITCM.

Full-Wave Analysis of Slotline Using Time-Domain Finite-Difference Method

The transmission and dispersive characteristics of slotline are calculated in this paper. The tail of Gaussion pulse is improved because a modified dispersive boundary condition (DBC) is adopted. It leads to a reduction in computer memory requirements and computational time. The computational domain is greatly reduced to enable performance in personal computer. At the same time because edges of a boundary and summits are treated well, the computational results is more accurate and more collector.

Effect of Varieties on Tea Pigment and Chromatic Aberration of Black Tea Infusion

Effects of varieties on the content of tea pigment, L＊, a＊ and b＊ value of chromatic aberration of black tea infusion was studied. The correlation relationship between content of TF, TR, TB and L＊, a＊, b＊ value was extremely significant at P＆lt;0.05. Fresh tea leaves with plucking standard of 1 bud and 2 leaves could man-ufacture black tea with higher content of tea pigment, higher a＊ and b＊ value but lower L＊ value, than those of plucking standard of 1 bud and 3 leaves. But the discrepancy of certain parameter of the two plucking standards changed with vari-eties. Varieties’ quality potential could be concealed by improper plucking standards. Six varieties were divided into four groups on the basis of gross tea polyphenols in fresh tea leaves （GTP）, consumption of tea polyphenols to gross tea polyphenols ratio （CTP/GTP） and gross tea pigment to consumption of tea polyphenols ratio （GP/CTP）. Hybrid performed the very suitability of black tea manufacturing. To en-sure high quality of made black tea, suitable variety should be chosen and reason-able plucking standard also should be taken into consideration.

An improved Vibe algorithm for illumination mutations

The visual background extractor(Vibe)algorithm can lead to a large area of false detection in the extracted foreground target when the illumination is mutated.An improved Vibe method based on the YCbCr color space and improved three-frame difference is proposed in this paper.The algorithm detects the illumination mutation frames accurately based on the difference between the luminance components of two frames adjacent to a video frame.If there exists a foreground moving target in the previous frame of the mutated frame,three-frame difference method is utilized;otherwise,Vibe method using current frame is used to initialize background.Improved three-frame differential method based on the difference in brightness between two frames of the video changes the size of the threshold adaptively to reduce the interference of noise on the foreground extraction.Experiment results show that the improved Vibe algorithm can not only suppress the“ghost”phenomenon effectively but also improve the accuracy and completeness of target detection,as well as reduce error rate of detection when the illumination is mutated.

Techniques of Image Processing Based on Artificial Neural Networks

This paper presented an online quality inspection system based on artificial neural networks. Chromatism classification and edge detection are two difficult problems in glass steel surface quality inspection. Two artificial neural networks were made and the two problems were solved. The one solved chromatism classification. Hue, saturation and their probability of three colors, whose appearing probabilities were maximum in color histogram, were selected as input parameters, and the number of output node could be adjusted with the change of requirement. The other solved edge detection. In this neutral network, edge detection of gray scale image was able to be tested with trained neural networks for a binary image. It prevent the difficulty that the number of needed training samples was too large if gray scale images were directly regarded as training samples. This system is able to be applied to not only glass steel fault inspection but also other product online quality inspection and classification.

Submarine Pipeline Routing Risk Quantitative Analysis

A new method for submarine pipeline routing risk quantitative analysis was provided, and the study was developed from qualitative analysis to quantitative analysis.The characteristics of the potential risk of the submarine pipeline system were considered, and grey-mode identification theory was used. The study process was composed of three parts: establishing the indexes system of routing risk quantitative analysis, establishing the model of grey-mode identification for routing risk quantitative analysis, and establishing the standard of mode identification result. It is shown that this model can directly and concisely reflect the hazard degree of the routing through computing example, and prepares the routing selection for the future.

Building a Comprehensive Well-off Society in Yunnan＇s Minority Areas A Study of the Prediction on the Differences in Economic Development Indexes

Based on the gray theory and GM （1, 1） model, the various indexes in 2013-2020 are predicted using the data of all indexes of the economic development of Yunnan＇ s 8 minority areas in 2013-2020 and also compared with the standard values of all indexes of building a well-off society in 2020, and the differences between them are analyzed. The purpose of this study is to provide a reference basis for Yunnan province＇ s government to analyze the economic development of the minority areas.

Optimization of tribological parameters over WC-12%Co laser alloyedpearlitic ductile iron using Taguchi based Grey relational analysis

Pearlitic ductile irons(PDIs)are used in transportation and nuclear energy industries.In heavy loading situation,the service life of PDI is affected by numerous tribo aspects.In this study,surface of the PDI is alloyed with WC-12%Co powder using a high power fibre laser.The wear properties of the base material and laser alloying samples were investigated by tribometer with various parameters,i.e.,temperature,load and sliding speed.Based on experimental test,the load has maximum percentage of contribution and followed by sliding speed and working temperature.The optimized tribological parameters by Grey relational analysis(GRA)were established and those values are closely matched with predicted values.Besides,base material and laser alloying surfaces were examined through Vickers hardness machine,scanning electron microscopy(SEM)and roughness tester.The laser altered specimen shows no defects and improves the wear properties than substrates.The identified optimal tribological parameters are load of 30 N,speed of 0.5 m/s and working temperature of 300℃,and load of 30 N,speed of 0.5 m/s and working temperature of 200℃ for base metal and laser alloying samples,respectively.

The Gray-Markov GM （1, 1） prediction model Optimal Allocation of Equipment Maintenance Personnel Research based on Difference Method

Based on the situation that the statistic of the missile facilities＇ stability was small, and the conventional big example preview method was no longer of use. So, this article used the gray GM （1, 1） model to preview a facility＇ s stability .The gray GM （1, 1） model doesn＇ t need a large number of example statistics, and it is also accurate, so this model solved the problem in the analyze and preview of the stability of the missile＇ s electronic facility system, and it has possibility to imply to engineering use.

Efficient Approach for Face Detection in Video Surveillance

Security access control systems and automatic video surveillance systems are becoming increasingly important recently,and detecting human faces is one of the indispensable processes.In this paper,an approach is presented to detect faces in video surveillance.Firstly,both the skin-color and motion components are applied to extract skin-like regions.The skin-color segmentation algorithm is based on the BPNN (back-error-propagation neural network) and the motion component is obtained with frame difference algorithm.Secondly,the image is clustered into separated face candidates by using the region growing technique.Finally,the face candidates are further verified by the rule-based algorithm.Experiment results demonstrate that both the accuracy and processing speed are very promising and the approach can be applied for the practical use.

Principal Component Analysis （PCA） on Multivariate Data of Lard Analysis in Cooking Oil

Discrimination of fatty acids （FAs） of lard in used cooking oil is important in halal determination. The aim of this study was to find the information related to the changes FAs of lard when frying in cooking oil. Quantitative analysis of FAs composition extracted from a series of experiments which involving frying cooking oil spiked with lard at three different parameters; concentration of spiked lard, heating temperatures and period of frying. The samples were analyzed using Gas Chromatography （GC） and Principal Components Analysis （PCA） technique. Multivariate data from chromatograms of FAs were standardized and computed using Unscrambler X10 into covariance matrix and eigenvectors correspond to Principal Components （PCs）. Results have shown that the first and second PCs contribute to the FAs mapping which can be visualized by scores and loading plots to discriminate FAs of lard in used cooking oil

On the use of the discontinuous Galerkin method for numerical simulation of two-dimensional compressible turbulence with shocks

In this paper,the discontinuous Galerkin(DG)method combined with localized artificial diffusivity is investigated in the context of numerical simulation of broadband compressible turbulent flows with shocks for under-resolved cases.Firstly,the spectral property of the DG method is analyzed using the approximate dispersion relation(ADR)method and compared with typical finite difference methods,which reveals quantitatively that significantly less grid points can be used with DG for comparable numerical error.Then several typical test cases relevant to problems of compressible turbulence are simulated,including one-dimensional shock/entropy wave interaction,two-dimensional decaying isotropic turbulence,and two-dimensional temporal mixing layers.Numerical results indicate that higher numerical accuracy can be achieved on the same number of degrees of freedom with DG than high order finite difference schemes.Furthermore,shocks are also well captured using the localized artificial diffusivity method.The results in this work can provide useful guidance for further applications of DG to direct and large eddy simulation of compressible turbulent flows.

Rayleigh backscattering minimization in single fiber colorless WDM-PON using intensity remodulation technique

The performance of colorless wavelength-division multiplexed passive optical network(WDM-PON) systems suffers from the transmission impairments mainly due to Rayleigh backscattering(RB).In this paper,we propose and demonstrate a single fiber colorless WDM-PON which enhances the tolerance to RB induced noise.The high extinction ratio in both return-to-zero(RZ)-shaped differential phase shift keying(DPSK) downstream(DS) data signal and intensity-remodulated upstream(US) data signal helps to improve the tolerance to RB induced noise.Simulation results show that downstream and upstream signals can achieve error-free performance at 10 Gbit/s with negligible penalty and improve the tolerance to RB induced noise over 25 km standard single-mode fiber.