硬岩深孔大口径取芯钻进的钻头研究

介绍了硬岩深孔钻进中热压金刚石钻头的设计方法与研制技术,重点就钻头胎体的设计研究方法进行了较全面的分析与阐述,对钻头的结构设计作了深入的研究与探讨,为读者研究金刚石钻头提供了思路与方法。论文以科钻一井为例,在分析岩石性质与钻进条件的前提下,对硬岩、深孔、大口径取芯金刚石钻头的设计作了具体的论述,钻头的保径措施和工作层结构采用了全新的设计方案;热压工艺完全不同于普通钻头的传统烧结规程,钻头质量在科钻一井使用的各类钻头中取得了平均时效（1．12m／h）和平均寿命（28．85m／个）最好的效果。钻进事实表明,胎体的设计研究方法是一种先进的具有普遍意义的方法;钻头的结构设计和保径措施．同样具有创新性和实用价值．     

Physico-chemical Properties, Vitamin C Content, and Antimicrobial Properties of Pomegranate Fruit (Punica granatum L.)

Pomegranate (Punica granatum L.) fruit is widely used in the food and process industries due to its excellent nutritional and health value and as a raw material for the manufacture of secondary products such as jellies, dyes, and cosmetics. The objectives of this research were to determine the vitamin C content and antimicrobial properties of fresh and dried fractions of fruit peel and arils of locally grown and imported pomegranate in Oman. A significant variation in vitamin C content was found among the five varieties of pomegranate studied, ranging from 52.8 to 72.0 mg/100 g fresh weight (fw) for arils and 76.8 to 118.4 mg/100 g fw for peels. Irrespective of the variety of pomegranate, vitamin C content in the peel was significantly higher than the aril, with differences ranging from 24.4% to 97.0% depending on variety. Fruit fractions showed antimicrobial effects (inhibition zone) on Staphylococcus aureus and Pseudomonas aeruginosa but not Escherichia coli. Sun drying of fruit peel significantly (p ≤ 0.05) enhanced vitamin C retention and antimicrobial effects in comparison with oven drying presumably due to lower rate of moisture removal associated with low temperature drying over longer duration in comparison with short-time high-temperature oven drying.     

Significant physical attributes affecting quality of Indian black (CTC) tea

In this research work, an attempt was made to discriminate different grades of black crush-tear-curl (CTC) tea based upon their physical attributes such as color of brewed liquor, texture, size and shape of the tea granules obtained by machine vision technique. The principal component analysis (PCA) was applied over two types of data. First, tea samples with seven different quality grades but same mechanical grading and second, samples with same quality grade but nine different mechanical grades (Brokens, Fannings and Dust) were considered for analysis, respectively. The results of PCA showed that best discrimination (100%) in both types of data was given by color attributes only. Correlations among tea samples and physical attributes were determined. Based upon these results it may be concluded that color only attributes are the most significant and sufficient for quantification of tea quality whereas other physical attributes contribute so little to quality estimation that they may be ignored.     

Grading and color evolution of apples using RGB and hyperspectral imaging vision cameras

The potential of RGB digital imaging and hyperspectral imaging (900–1700 nm) was evaluated for discriminating maturity level in apples under different storage conditions along the shelf-life. Segmentation, preprocessing and partial least squares-discriminant analysis (PLS-DA) were used for hyperspectral data analysis, while illumination correction, dimensionality reduction and linear discriminant analysis (LDA) were used for RGB data analysis. The results showed that hyperspectral discrimination classified different storage regimes better than RGB, with an overall success rate of 95.83%. In addition, color evolution of apples during shelf-life under different storage regimes was modeled using RGB zero and first order regression models, fitting better to a first order kinetic model.     

普梳色纺纱的生产工艺优化

探讨了普梳色纺纱生产工艺的优化。针对色纺纱生产特点,从原料及生产全流程采取一系列工艺技术和管理措施,并运用正交试验优化了细纱工艺,最终较好地改善了14.6tex普梳色纺纱质量。认为:合理选用染色原棉,正确选择原料混和及混色方式,优选各工序工艺配置,严格控制色差,能够收到改善色纺成纱质量的良好效果,纺制出质量符合国家标准、满足用户要求的普梳色纺纱。     

Meat quality and cooking attributes of thawed pork with different low field NMR T(21)

A relationship of low field NMR T(2) components to meat quality and cooking attributes of pork was investigated. Longissimus muscle was removed from 23 pig carcasses at 24h postmortem for meat quality measurements and cooking test. Frozen samples were classified into three groups by LF-NMR T(21) of thawed samples: A (<40ms), B (40-44ms) and C (>44ms). There were significant differences (P<0.05) in pH, lightness (L* value) and pressing loss among the three groups. Cooking time to attain 70°C was slightly lower in group C than the other groups. Shear force value of cooked samples was not affected by T(21). The component T(21) correlated (P<0.05) with L* value, muscle pH and pressing loss, while L* value correlated (P<0.05) with thawing loss and muscle pH. Therefore, combined LF-NMR and color measurements could be a good way to differentiate water holding capacity of pork.     

Predicting beef tenderness using color and multispectral image texture features

The objective of this study was to investigate the usefulness of raw meat surface characteristics (texture) in predicting cooked beef tenderness. Color and multispectral texture features, including 4 different wavelengths and 217 image texture features, were extracted from 2 laboratory-based multispectral camera imaging systems. Steaks were segregated into tough and tender classification groups based on Warner-Bratzler shear force. The texture features were submitted to STEPWISE multiple regression and support vector machine (SVM) analyses to establish prediction models for beef tenderness. A subsample (80%) of tender or tough classified steaks were used to train models which were then validated on the remaining (20%) test steaks. For color images, the SVM model correctly identified tender steaks with 100% accurately while the STEPWISE equation identified 94.9% of the tender steaks correctly. For multispectral images, the SVM model predicted 91% and STEPWISE predicted 87% average accuracy of beef tender.     

动态设备关联特性文件颜色模式转换精度评价

为评估和比较最新的基于动态设备关联特性文件的“动态黑成分最大化” (Dynamic K)与基于设备关联特性文件的“最大灰成分替代”(Max GCR)、基于ICC设备特性文件的“参考颜色空间(PCS)转换”在颜色模式转换中的效果,通过实验模拟的方法来测试这3种转换方法的颜色模式转换精度、印刷墨量以及印刷的稳定性.结果表明基于动态设备关联特性文件的“动态黑成分最大化”在颜色模式转换方面,不仅能与其他两种方法达到相同的转换精度,节省更多彩色油墨,且提高了印刷稳定性,是值得推广的在两种CMYK模式设备间进行颜色模式转换的好方法.     

Application of hybrid image features for fast and non-invasive classification of raisin

A new approach for the non-invasive classification of raisins is presented based on the hybrid image features, namely morphological, color and texture features. A total of 74 features (8 morphological, 30 color, and 36 textural) were extracted from RBG images. Seven kinds of models were established based on different feature sets. They were three kinds of models established based on single feature set, three kinds of models established based on the combination of two feature sets, and one kind of model established based on the combination of all feature sets. Five kinds of classifiers, namely partial least squares (PLS), linear discriminant analysis (LDA), soft independent modeling of class analogy (SIMCA), and least squares support vector machine (LS-SVM) with linear and radial basis function (RBF) kernels were used for the model establishment based on different feature sets. The best correct answer rates (CAR) of 99% was obtained when LDA was used to establish the classification model based on the combination of all feature sets, which was higher than those of the models established based on single feature set or the combination of two feature sets. The results show that the feature combination is helpful to improve the accuracy of raisin classification. It was concluded that the varieties of raisin could be accurately classified based on RGB image features and the combination of morphological, color and texture features was an accurate way to improve the accuracy of classification.     

The effects of modified atmosphere gas composition on microbiological criteria, color and oxidation values of minced beef meat

This paper reports the effects of modified atmosphere gas compositions with different concentrations of CO(2)/O(2)/N(2) on color properties (L*, a* and b* values), oxidation stability (TBARS value) and microbiological properties of minced beef meat stored at +4 °C. Sampling was carried out on the 1st, 3rd, 5th, 7th, 9th, 11th and 14th day of storage. The gas mixtures used were as follows: (i) %30O(2) + %70CO(2) (MAP1), (ii) %50O(2) + %50CO(2) (MAP2), (iii) %70O(2) + %30CO(2) (MAP3), (iv) %50O(2) + %30CO(2) + %20N(2) (MAP4), and (v) %30O(2) + %30CO(2) + %40N(2) (MAP5). Control samples (AP) were packaged under atmospheric air. Pseudomonas, lactic acid bacteria, Brochothrix thermosphacta, and Enterobacteriaceae members were monitored. Among these five modified atmosphere gas compositions, the best preservation for minced beef meat was in MAP4 gas combination maintaining acceptable color together with oxidation stability and acceptable microbial loads until the end of storage period of fourteen days.