纹理合成的自相关性判别法及其应用

从加快纹理相似性的判别速度出发,提出了一种纹理合成的自相关性判别法.传统的纹理合成算法随着邻域和样本的增大,计算量将成倍增加,纹理合成速度减慢的劣势逐渐体现出来.因此,算法对样本纹理建立简单的自相关性距离查找表,利用L邻域内像素的自相关性距离作为像素匹配的判别依据,以查找取代传统匹配过程中的繁琐计算,极大地加快了合成速度,可实现动态的、多精度的合成效果调控,以及避免块匹配中易出现纹理接缝的问题.经验证,该算法可在纹理合成、图像修补及纹理检索中应用,并可很好地达到实时的应用要求.     

Study of MoO3 (0 1 0) surface clusters by ab initio HF approaches

The clusters Mo₂O₁₁H₁₀, Mo₃O₁₆H₁₄ and Mo₇O₃₂H₂₂ of MoO₃ (0 1 0) surface were studied by using ab initio HF approaches. The geometry of each cluster was fully optimized at RHF or UHF/MINI/ECP-SBK level of theory. The bonding properties, electronic structures and orbital populations of structurally different oxygens were obtained. It was shown that there exist some differences in the bonding properties between Mo atoms and the different oxygens. The symmetrically bridging oxygens exhibit more ionic feature while the terminal oxygens are more covalent. Moreover, information on explaining the active sites for the insertion of oxygen into allylic species in the second step of the oxidation processes of propylene to acrolein could be inferred from the frontier orbital populations of MoO₃ surface cluster.     

黄磷尾气蒸汽锅炉新技术

介绍了一种黄磷尾气蒸汽锅炉新技术。黄磷尾气含有高浓度的一氧化碳,具有很高的热值,但是由于含有难以净化去除的磷、硫等杂质,大多被用来烧制热水和烘干原料等,利用率和价值很低。该技术通过采用一种将燃烧和换热蒸发分开进行的低压蒸汽锅炉结构,解决了杂质对设备的腐蚀问题,可以稳定生产出蒸汽供厂内其他工序使用。通过运行,各项技术指标均达到设计能力。该技术的成功运用实现了节能减排,提高了黄磷尾气的利用价值,为黄磷尾气利用提供了一条可行的新途径。     

大电流发电机断路器动特性优化

以EVH4-15/T6300-80F高压交流发电机断路器为例,介绍了大电流发电机断路器动特性,同时应用CAE软件对断路器在不同的结构配置下的动特性进行了分析研究,并介绍了在实物样机上的验证结果。     

轻质GRC屋面建筑结构体系

ＧＲＣ制品在工业与民用建筑中已得到广泛应用,但大跨度房屋一直受到屋面支撑的制约,导致造价过高。本文介绍了新型轻质ＧＲＣ拱形统波屋面的研制开发及应用推广情况,结果表明：它具有性能可靠、节少投资、施工简便等优点,具有较高的推广价值。     

基于约束的形状自动求解新算法

基于约束的产品形状描述及求解是目前计算机辅助设计研究的一个热点。本文在研究国内外现有技术的基础上，提出了一个基于约束的形状自动求解算法，该算法与国内外现有相关算法相比具有高效、实用、易于扩充，支持约束有效性检测，支持局部优化生成等显著优点，该算法已被实用系统所采用，成为我们最新研制的参数化二维草图系统的核心算法。     

泡沫塑料连续挤出成型中的进气系统

通过实验研究,详细分析了进气流量进气压力、进气益、喷嘴结构对气泡形态的影响,指出了在泡沫塑料连续挤出成型过程中的最佳进气效果和合理的进气条件。     

Identification of key enzymes involved in the accumulation of carotenoids during fruit ripening of Lycium barbarum L. by a proteomic approach

The isobaric tag for relative and absolute quantification (iTRAQ)-based proteomic approach was used to identify the key enzymes involved in the carotenoids accumulation from flowering to maturity stage of Lycium barbarum L. A total of 1,799 differentially expressed proteins were identified, and 190 were related to carotenoids metabolism. Six enzymes, including phytoene synthase, phytoene desaturase, zeta-carotene desaturase, P450 carotenoid beta-ring hydroxylase (LUT5), neoflavin synthase and nine-cis-epoxycarotenoid dioxygenase were found to be associated with the carotenoid accumulation during L. barbarum ripening by the proteomic analysis and qRT-PCR. The changes in the chromaticity and carotenoid contents during fruit ripening were also studied. The contents of carotenoid, except violaxanthin were strongly correlated with the expression levels of the key enzymes, and the colours were strongly correlated with the contents of carotenoid. This study may contribute to further investigations of the accumulation mechanism of carotenoids in L. barbarum.     

Electret characteristics of melt-blown polylactic acid fabrics for air filtration application

Polylactic acid (PLA) is a biodegradable and biocompatible polymer. Melt-blown PLA electret fabrics have become attractive materials for air filter applications. Its filtration performance mainly depends on the electrostatic effect originating from electrets. How to improve their electret behavior and then to enhance their filtration efficiency has always been challenging. In this article, three melt-blown PLA fabrics with different morphological or crystal structure are made from different process conditions or ingredient. The electrets are formed by means of corona charging technology. Their crystalline and morphological structure was analyzed, and filtration performance was measured. Their charge-trapping feature was studied by thermal stimulating discharge technology. The results proved that the air filtration efficiency of three melt-blown samples improved a lot when electrets were formed. Different crystalline structures of PLA fabrics will result in differences in their electret charge-trapping feature. The PLA fabrics with semi-crystalline characteristics display a regular charge-trapped level distribution and amorphous structure hints the diversity of charge-trapped levels. The deference in filtration resistance is mainly ascribed to the different fiber diameters and their distributions. More narrow distribution of fiber diameter leads to more compact fabrics and to higher filtration resistance. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48309.     

纤维增强对镁基复合板物理力学性能的影响

以玻璃纤维为增强材料,以镁基无机矿物质为基体材料,制备了新型纤维增强镁基无机复合板.研究了短切纤维、纤维网格布以及短切纤维结合纤维网格布3种增强方式对镁基复合板的物理力学性能和耐湿热性能的影响.结果表明,纤维增强方式对镁基无机复合板的密度、含水率、吸水率等性能影响较小,对复合板的力学性能和耐湿热尺寸稳定性影响较大,采用...