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基于灰色关联度和层次分析法的油桃果汁品质评价

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中国食品学报 2014年第12期14卷 154-163页

作者：焦艺刘璇毕金峰陈芹芹吴昕烨阮卫红中国农业科学院农产品加工研究所农业部农产品加工综合性重点实验室北京100193

为了研究不同品种油桃的制汁特性,对北京平谷地区10个品种油桃果汁的理化与营养指标(p H、总糖、总酚、抗坏血酸、可溶性固形物、可滴定酸、糖酸比、蛋白质)和加工指标(果汁色泽、粘度、褐变度、出汁率)进行测定。首先利用相关性分析、... 详细信息

为了研究不同品种油桃的制汁特性,对北京平谷地区10个品种油桃果汁的理化与营养指标(p H、总糖、总酚、抗坏血酸、可溶性固形物、可滴定酸、糖酸比、蛋白质)和加工指标(果汁色泽、粘度、褐变度、出汁率)进行测定。首先利用相关性分析、主成分分析和聚类分析法筛选核心指标,然后运用层次分析法确定指标的权重,最后采用灰色关联度分析法建立油桃品种制汁适宜性综合评价模型。结果表明:糖酸比、出汁率、L*值、黏度和总酚是油桃果汁品质评价的核心指标。通过灰色关联度分析,综合制汁品质较好的品种有瑞光51号、瑞光29号、瑞光18号等,而意大利5号的制汁品质最差,此结果可为油桃的育种和生产加工提供科学的依据。

关键词：油桃果汁品质评价评价因子层次分析灰色关联度分析

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浸胀与干燥过程对桃胶色泽及总酚含量的影响

中国食品学报 2021年第11期21卷 105-111页

作者：刘梦毕金峰刘璇刘嘉宁吕健陈佳歆周沫中国农业科学院农产品加工研究所/农业农村部农产品加工重点实验室北京100193

通过测定不同干燥方式、料液比条件下样品中吸水率、色泽及总酚含量,探究桃胶商品化处理过程中浸泡溶胀(浸胀)与干燥过程对桃胶色泽及总酚含量的影响。结果表明:桃胶浸胀过程中吸水量最多达自身质量的26倍。未浸胀桃胶中总酚的平均含量... 详细信息

通过测定不同干燥方式、料液比条件下样品中吸水率、色泽及总酚含量,探究桃胶商品化处理过程中浸泡溶胀(浸胀)与干燥过程对桃胶色泽及总酚含量的影响。结果表明:桃胶浸胀过程中吸水量最多达自身质量的26倍。未浸胀桃胶中总酚的平均含量是浸胀后样品的2.49倍(以干基计),不同料液比下真空冷冻干燥后样品中的总酚平均含量是热泵干燥后样品的1.14倍(以干基计);浸胀后的样品与未浸胀样品有显著色差(P<0.05),色彩饱和度与鲜艳度均显著提高(P<0.05),其中b*值显著增加,且真空冷冻干燥后样品色差低于热泵干燥后的样品。相关性分析结果表明:总酚含量与L*值呈极显著正相关(P<0.01),与△E值呈显著负相关(P<0.05)。本研究明确了浸胀过程使桃胶色彩饱和度与鲜艳度得到明显改善,而亮度受到一定影响。真空冷冻干燥在减小样品色差的同时,较高地保留了桃胶中的酚类物质。

关键词：桃胶浸胀色泽总酚含量相关性

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汤汁特性对罐藏黄桃贮藏期质构品质的影响

食品科学 2021年第13期42卷 208-214页

作者：吕健于笑颜毕金峰王凤昭谢晋张嗣伟郭崇婷中国农业科学院农产品加工研究所农业农村部农产品加工重点实验室北京100193

为探究汤汁特性对罐藏黄桃质构品质的影响,本实验以‘金童5号’黄桃为材料制成黄桃罐头,研究贮藏期间汤汁特性,如pH值、可溶性固形物(total soluble solid,TSS)含量、浊度、色泽、表观黏度、渗透压及汤汁水溶性果胶(water soluble pecti... 详细信息

为探究汤汁特性对罐藏黄桃质构品质的影响,本实验以‘金童5号’黄桃为材料制成黄桃罐头,研究贮藏期间汤汁特性,如pH值、可溶性固形物(total soluble solid,TSS)含量、浊度、色泽、表观黏度、渗透压及汤汁水溶性果胶(water soluble pectin in syrup,SWSP)含量的变化,并采用扫描电子显微镜和光学显微镜观察贮藏期间罐藏黄桃果肉微观结构。结果表明:同一贮藏时间、不同取样位置(上、中、下层)汤汁pH值、TSS含量无显著差异,可以认为贮藏期间汤汁与黄桃细胞组分之间的传质是均匀的;随着贮藏时间的延长,汤汁pH值未呈现显著变化,TSS含量、亮度(L值)和红绿度(a值)均先总体呈现下降趋势,浊度、黄蓝度(b值)、渗透压、SWSP含量总体先呈现上升趋势,并均在贮藏后期变化趋于平缓;贮藏过程中,罐藏黄桃果肉细胞发生形变或坍塌、细胞间隙增加,宏观表现为果肉质构软化,即硬度、咀嚼性显著降低(P<0.05);罐藏黄桃果肉质构与汤汁特性相关性分析发现,果肉质构特性(硬度、回复性、凝聚性、咀嚼性)与b值、浊度、渗透压、SWSP含量呈显著负相关(P<0.05),果肉硬度、咀嚼性与L、a值呈显著正相关(P<0.05),可以推断汤汁特性显著影响罐藏黄桃质构,可以通过调控汤汁特性改善罐藏黄桃的质构品质。

关键词：罐藏黄桃贮藏汤汁特性质构渗透压

预干燥过程水分分布对热风-真空冷冻干燥桃脆片微观结构与质构的影响

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食品科学 2023年第15期44卷 69-79页

作者：于宛加金鑫胡丽娜鲜美林刘萍毕金峰青岛农业大学食品科学与工程学院山东青岛266109 青岛海军食品与营养创新研究院(青岛特种食品研究院) 山东青岛266109 中国农业科学院农产品加工研究所农业农村部农产品加工重点实验室北京100193

为探究预干燥过程水分分布对热风-真空冷冻干燥桃片微观结构与质构品质的影响,以提升桃脆片综合食用品质,本研究对3个温度(40、60、80℃)热风预干燥过程中桃片的水分分布和升温过程中的温度进行监测,3个温度下各选取干基水分含量分别为7... 详细信息

为探究预干燥过程水分分布对热风-真空冷冻干燥桃片微观结构与质构品质的影响,以提升桃脆片综合食用品质,本研究对3个温度(40、60、80℃)热风预干燥过程中桃片的水分分布和升温过程中的温度进行监测,3个温度下各选取干基水分含量分别为7、6 g/g和5 g/g作为水分转换点,进行热风-真空冷冻干燥(联合干燥),对桃脆片色泽、皱缩率、微观结构、孔隙分布、质构特性和吸湿性进行测定和分析。结果表明,温度对干燥过程样品的水分分布有明显影响,但3个温度下水分迁移的总体趋势一致。热风预干燥样品的水分含量越低,联合干燥后样品的色泽越接近鲜样,其中,40℃、转换点水分含量5 g/g的样品色泽最接近鲜样。干燥时间较温度对皱缩率的影响更大,干燥时间较温度对皱缩率的影响更大,干燥至相同水分转换点,40℃较60℃和80℃需要更长时间,样品在预干燥阶段和联合干燥阶段均有明显收缩。真空冷冻干燥样品与联合干燥样品的孔隙结构有明显差异,其中,水分转换点为5 g/g时,孔隙结构最不均匀;联合干燥样品较冷冻干燥样品的平均硬度提高了52.11%,样品预干燥水分含量越低,联合干燥后的硬度越大,通过热风预干燥处理可以有效调控桃脆片的硬度和脆度。与真空冷冻干燥样品相比,联合干燥后样品吸湿率更低,这与预干燥过程形成的结构差异有关。综上,相比于单一的真空冷冻干燥,热风-真空冷冻干燥更有利于改善桃脆片的质构品质和提升贮藏稳定性。

关键词：桃脆片联合干燥水分迁移微观结构质构特性

Numerical simulation of aircraft arresting process with an efficient full-scale rigid-flexible coupling dynamic model

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Chinese Journal of Aeronautics 2024年第5期37卷 586-602页

作者： Haoyuan SHAO Daochun LI Zi KAN Lanxi bi Zhuoer YAO Jinwu XIANG School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Tianmushan Laboratory Hangzhou 310023China

The arresting process of carrier-based aircraft is widely recognized as a challenging task,characterized by the highest accident rate among all carrier-based aircraft *** simulation plays a crucial role in assessing the intricate responses of the arresting process,favoring the design of carrier-based *** efficient and accurate rigid-flexible coupling model for analyzing the dynamic response of the arresting process is *** combining the dynamic characteristics of airframe,landing gear,arresting hook and arresting gear system,the rigid-flexible coupling dynamic model is established to reflect the relative motion of the coupling parts and arresting *** dynamic model is verified through simulations of landing gear landing drops and by comparing the arresting simulation results with corresponding data in the US military ***,simulations of the arresting process under different off-center distance and aircraft yaw angle are conducted to obtain the dynamic response of the aircraft during the arresting *** result indicates that the rigid-flexible coupling dynamic model proposed is effective for analyzing the arresting dynamics response of carrier-based *** axial force of the arresting cable on both sides of the hook engagement point,pitch and yaw angle of aircraft are inconsistent under yaw and off-center *** analysis method and obtained results provide valuable references for assessing the dynamic responses of carrier-based aircraft during arresting process and offer valuable in-sights in the design of carrier-based aircraft.

关键词： Carrier-based aircraft Deck landing Rigid-flexible coupling dynamic model Finite element method Dynamic analysis

Responses of soil stoichiometry and soil enzyme activities in the different distance around opencast coal mine of the Hulun Buir Grassland of China

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International Journal of Coal Science & Technology 2024年第1期11卷 221-231页

作者： Yinli bi Nan Guo Yanxu Zhang Xianglei Li Ziheng Song State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources China University of Mining and Technology(Beijing)Beijing100083China Institute of Ecological Environment Restoration in Mine Areas of West China Xi’an University of Science and TechnologyXi’an710054China

The objectives of this study were to explore the changes in soil stoichiometry and enzyme activities at different distances from an opencast coal mine in the Hulun Buir Grassland of China. Four transects were established on north and east sides of the opencast coal mining area, and samples were collected at 50 m, 550 m, and 1550 m from the pit on each transect. Control samples were collected from a grassland station 8 km from the opencast coal mining area that was not disturbed by mining. Four replicate soil samples were collected at each point on the four transects. Soil physicochemical properties and enzyme activities were determined, and correlations between soil properties and stoichiometric ratios and enzyme activities were explored using redundancy analysis. The increase in distance from mining did not significantly affect soil properties, although soil urease activity was significantly lower than that of the control area. Soil properties 1550 m from the mine pit were similar to those at the grassland control. In addition, soil total nitrogen had the greatest effect on soil stoichiometry, and soil total potassium had the greatest effect on soil enzyme activities. Coal dust from opencast mining might be the main factor affecting soil stoichiometry and enzyme activities. The results of this study provide direction for the next step in studying the influence of mining areas on soil properties and processes.

关键词： Opencast coal mine Soil stoichiometry Soil enzyme activities Distance Grassland

Influence of rare earth oxides on microstructure and mechanical properties of nickel-based superalloys fabricated by high energy beam processing:A review

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Journal of Rare Earths 2024年第9期42卷 1629-1645,I0001页

作者： Lianjie bi Hua Yan Peilei Zhang Haichuan Shi Zhiyuan Li Ruidi Li School of Materials Science and Engineering Shanghai University of Engineering ScienceShanghai201620China College of Agricultural Science and Engineering Hohai UniversityNanjing211100China Department of Mechanics and Maritime Science Chalmers University of TechnologyGothenburSE41296Sweden State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China

In this paper,the effects of rare earth oxides on the micro structure and mechanical properties of nickelbased superalloys prepared by high-energy beam processing technology were critically *** focus is on the optimal amount of rare earth oxides that can produce ideal *** attention was paid to their main strengthening mechanisms,including solid solution strengthening mainly in the form of solid solution dissolved in the nickel-based alloy and improving the microstructure of the alloy by grain refinement or fine grain strengthening produced by homogenizing the distribution phase.Y_(2)O_(3),La_(2)O_(3) and CeO_(2) rare earth oxides can also improve the fluidity of the alloy molten pool and reduce the segregation of alloying *** advantages can significantly improve the mechanical properties of the ***,this paper outlines the future research directions of rare earth oxides,aiming to expand their application potential.

关键词： Rare earths High energy beam Nickel-based superalloys Microstructure Mechanical properties

气质联用结合电子鼻表征不同温度热风干燥苹果脆片关键香气化合物

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食品工业科技 2022年第18期43卷 272-282页

作者：李嘉欣吴昕烨毕金峰苟敏大连工业大学食品学院辽宁大连116034 中国农业科学院农产品加工研究所农业农村部农产品加工综合性重点实验室北京100193

为明确富士苹果的关键香气化合物以及干燥温度对富士苹果关键香气化合物的影响,采用顶空固相微萃取气质联用(headspace solid-phase micro-extraction gas chromatography-mass spectrometer,HS-SPME-GC-MS)技术结合电子鼻对富士苹果鲜... 详细信息

为明确富士苹果的关键香气化合物以及干燥温度对富士苹果关键香气化合物的影响,采用顶空固相微萃取气质联用(headspace solid-phase micro-extraction gas chromatography-mass spectrometer,HS-SPME-GC-MS)技术结合电子鼻对富士苹果鲜样、50、60、70和80℃热风干燥苹果脆片的挥发性化合物进行表征。结果表明,苹果鲜样和4种干燥样品共鉴定出64种挥发性化合物,包括酯类23种、醇类18种、醛类8种、烯烃类2种、酮类2种、内酯类3种、酸类1种、含硫化合物3种和杂环化合物4种。不同样品各类挥发性化合物的种类及含量均存在较大差异,鲜样香气化合物含量为397.059 mg/kg,不同温度热风干燥样品挥发性化合物含量由高到低分别为64.189 mg/kg(50℃处理)、57.703 mg/kg(80℃处理)、32.124 mg/kg(70℃处理)、32.020 mg/kg(60℃处理)。气味活性值(odor-active value,OAV)分析表明,苹果鲜样与热风干燥样品共有关键香气化合物8种,分别为α-法尼烯(12746.11~1597.75)、2-甲基丁酸己酯(755.62~6.90)、己醇(2988.00~168.54)、1-辛烯-3-醇(53.12~12.08)、壬醛(1534.99~47.36)、反式-2-壬烯醛(1202.98~189.38)、芳樟醇(1264.30~212.75)和6-甲基-5-庚烯-2-酮(11.27~3.90)。除此以外,热风干燥样品独有的关键香气化合物包括2-甲基-1-丁醇(32.26~7.16)、3-甲基-4-庚醇(14.39~6.90)、苯乙醇(11.11~4.67)、辛醛(211.25~84.36)、3-羟基-2-丁酮(64.57~21.86)、3-甲硫基丙醇(13.52~5.88)和2-戊基呋喃(26.44~14.88)。电子鼻分析表明鲜样与热风处理苹果脆片香气轮廓存在差异,通过主成分分析(principle component analysis,PCA)可以对鲜样和脱水苹果脆片进行有效区分。综合考虑香气、能耗,相比于50℃热风处理,80℃可以在短时间内使苹果片呈现热风脱水制品的特征性风味。因此,80℃热风干燥条件最佳。

关键词：苹果脆片热风干燥关键香气化合物气相色谱-质谱法(GC-MS) 电子鼻香气活性值(OAV) 主成分分析(PCA)

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Structural Characteristics and Influencing Factors of Carbon Emission Spatial Association Network:A Case Study of Yangtze River Delta City Cluster,China

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Chinese Geographical Science 2024年第4期34卷 689-705页

作者： bi Xi SUN Renjin HU Dongou SHI Hongling ZHANG Han School of Economics and Management China University of Petroleum(Beijing)Beijing 102249China China Petroleum Planning&Engineering Institute Beijing 100083China

City cluster is an effective platform for encouraging regionally coordinated *** reduction of carbon emissions within city cluster via the spatial association network between cities can help coordinate the regional carbon emission management,realize sustainable development,and assist China in achieving the carbon peaking and carbon neutrality *** paper applies the improved gravity model and social network analysis(SNA)to the study of spatial correlation of carbon emissions in city clusters and analyzes the structural characteristics of the spatial correlation network of carbon emissions in the Yangtze River Delta(YRD)city cluster in China and its influencing *** results demonstrate that:1)the spatial association of carbon emissions in the YRD city cluster exhibits a typical and complex multi-threaded network *** network association number and density show an upward trend,indicating closer spatial association between cities,but their values remain generally ***,the network hierarchy and network efficiency show a downward trend but remain high.2)The spatial association network of carbon emissions in the YRD city cluster shows an obvious‘core-edge’distribution *** network is centered around Shanghai,Suzhou and Wuxi,all of which play the role of‘bridges’,while cities such as Zhoushan,Ma'anshan,Tongling and other cities characterized by the remote location,single transportation mode or lower economic level are positioned at the edge of the network.3)Geographic proximity,varying levels of economic development,different industrial structures,degrees of urbanization,levels of technological innovation,energy intensities and environmental regulation are important influencing factors on the spatial association of within the YRD city ***,policy implications are provided from four aspects:government macro-control and market mechanism guidance,structural characteristics of the‘core-edge’network,reconfigura

关键词： carbon emission spatial association network social network analysis(SNA) quadratic assignment procedure(QAP)model Yangtze River Delta city cluster China