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Xu Zhi-Zheng Jiang Feng Zhong Chong-Quan Gou Yong-Jie Teng Hong-Fei 《Structural and Multidisciplinary Optimization》2020,61(1):207-223
Structural and Multidisciplinary Optimization - The overall layout optimization design of an orbital propellant depot involves the optimization of shape, size, and positions of propellant tanks in... 相似文献
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目前国内外核设施实物保护系统大多采用路径分析法进行有效性评价,通过计算截住概率来衡量系统的优劣,评估指标单一,未能精确反映系统可靠性、指挥策略、信息安全设计等因素对系统性能的影响。为全面分析实物保护系统综合效能,从影响系统效能因素集出发,采用层次分析法(Analytic Hierarchy Process,AHP)建立实物保护系统综合效能评估指标体系,同时借助BP(Back Propagation)神经网络的非线性复合能力,建立核设施实物保护系统综合效能评估模型,完成了海洋核动力平台实物保护系统综合效能评估。评估结果表明:该BP神经网络评估模型收敛迅速,避免了AHP评估过程中不能满足多数样本集中效应的缺点,且具有较好的自适应性、稳定性,为实物保护效能评估领域提供了一种全新思路。 相似文献
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White-light-emitting phosphors based on phosphate host matrix, KSrPO_4 doped with Dy~(3+), were prepared by solid state reaction and their VUV luminescent properties were firstly investigated. The excitation band peaking at 125-153 nm corresponding to the absorption of PO_4~(3-) group exhibits very strong absorption. The phosphors emit warm-white luminescence under vacuum ultraviolet excitation of 147 nm, which consists of three main emission peaks located at 475, 570 and 662 nm, respectively.According to the luminescence and color chromaticity of the optimal sample KSrPO_4:1 mol%Dy~(3+),1.3 mol%Li~+, it can be a potential candidate for mercury-free fluorescent lamps. 相似文献
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Hongyan Liu Yuchang Qin Qing Ma Qingyu Zhao Xiaoqing Guo Lina Ma Chunlin Gou Yu Xia Ren-You Gan Junmin Zhang 《International Journal of Food Science & Technology》2021,56(6):2604-2611
In the study, lamb, feed and soil samples were collected from three regions of China in the year 2017 and 2018. The δ13C and δ15N values in lamb (defatted dry mass and lipids) and grass and the contents of nine elements in lamb, grass and soil were determined. The results indicated that except for Fe, Zn and Rb, most variables of lamb showed significant differences among two or three regions, and the contents of Fe, Sr and Cs showed significant differences between two years, and the contents of Cu and Zn showed significant differences among different muscle sections. Besides, significant correlations were found for δ13C between defatted lamb and lipid (r2 = 0.973, P < 0.05) and for the element contents between lamb and soil. Finally, four key variables δ13C, δ15N, Sr and Mo were selected through stepwise canonical discriminant analysis with the cross-validation correct classification rate of 99.1%. 相似文献
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Hao Jiang Yuxiang Gu Min Gou Tianyu Xia 《Critical reviews in food science and nutrition》2020,60(9):1417-1430
AbstractThe shelf life of foods is usually limited due to the frequent contamination by pests and microorganisms. Although low risk of pathogen contamination and no growth potential compared to those in high water activity animal- or vegetal-derived products, the low-moisture food has still significantly contributed to the total number of foodborne infections and outbreaks. Radio frequency (RF) treatments can be classified as a dielectric heating, which is a promising technology for achieving effective food pasteurization and disinfestations because of the associated rapid and volumetric heating with large penetration depth. The RF technique could be applied at low-moisture food as both the dipole dispersion and ionic conductivity may play effective roles. It can selectively heat and kill the microorganisms/pests without damaging the agricultural product because of the large difference of dielectric loss factors between target microorganisms/pests and host foods. In this article, the low-moisture foods sterilized and disinfested by RF energy are reviewed through basic theories, dielectric properties, heating effect, and uniformity. The potential research directions for further RF heating applications are finally recommended in low-moisture foods. 相似文献
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AbstractThe impacts of using radio frequency (RF) energy to dry purple-fleshed potatoes were investigated and compared to infrared radiation (IR) and microwave (MW) drying techniques. The gelatinization rate, color, flavor, morphological, and structural characteristics, thermodynamic properties, as well as antioxidant capacity were examined. The results indicated that the drying time of RF (70?min) and MW (21?min) were shorter than IR (105?min). The gelatinization ratio of MW, RF, and IR were 94.4?±?2.0, 88.3?±?1.4, and 64.5?±?1.1%, respectively. The degree of crystallization of purple-fleshed potato powder decreased with all three drying methods. RF-dried potatoes were able to retain higher polyphenols (loss rate: 4.3%), total anthocyanin (3.7%), and total flavonoid content (35.1%), whereas IR showed the lowest retention. The content of polyphenols also decreased significantly. Furthermore, after RF heating, the scavenging of free radicals was higher compared to MW and IR. 相似文献
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以OMS-2粉体催化剂为基础,对催化剂进行挤出成型,考察粘结剂种类、粘结剂用量、润滑剂和孔结构改进剂用量、焙烧温度对成型催化剂机械强度的影响。得到最佳成型工艺条件为,粘结剂硅溶胶用量为OMS-2粉体催化剂质量的105%~110%、辅助粘结剂纳米ZrO_2用量为OMS-2粉体催化剂质量的30%~35%、润滑剂田菁粉用量为OMS-2粉体催化剂质量的2. 5%~3. 0%、孔结构改进剂柠檬酸用量为OMS-2粉体催化剂质量的5%~6%,焙烧温度450℃。成型后催化剂机械强度可达150 N·cm~(-1),满足工业化应用对催化剂强度的要求。将成型催化剂应用于催化湿式氧化印染废水处理,经过432 h活性评价时间,COD平均去除率约91. 6%,反应结束后催化剂结构完整,平均机械强度约144 N·cm~(-1),表现出良好的水热稳定性。 相似文献