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功能性香精添加前后烟丝挥发性成分变化及对感官品质的影响

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郑州轻工业学院学报（自然科学版） 2012年第2期27卷 31-36页

作者：马骥常宇付磊冯洪涛梅涌毛多斌郑州轻工业学院烟草科学与工程学院河南郑州450002 红云红河烟草(集团)有限责任公司技术中心红河分中心云南弥勒652300 红塔烟草(集团)有限责任公司技术中心云南玉溪653100

采用气相色谱-质谱联用法对2类功能性香精的挥发性成分进行分析,探讨了香精在烟叶中添加前后的香味成分变化及对感官品质的影响.结果表明:香精加入烟叶后,其主要的香气化学成分总体上叠加入烟叶中;香精加入后烟叶内在感官品质明显提升,... 详细信息

采用气相色谱-质谱联用法对2类功能性香精的挥发性成分进行分析,探讨了香精在烟叶中添加前后的香味成分变化及对感官品质的影响.结果表明:香精加入烟叶后,其主要的香气化学成分总体上叠加入烟叶中;香精加入后烟叶内在感官品质明显提升,总体变化方向与香精功效相吻合.研究结果对卷烟的加料设计具有一定的指导意义.

关键词：烟丝功能性香精挥发性成分感官品质

Constitutive Model of Warm Deformation Behavior of Medium Carbon Steel

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Journal of Iron and Steel Research International 2016年第9期23卷 940-948页

作者： hong-bin LI Yun-li feng tao YAN En-lin YU National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan University College of Metallurgy and Energy North China University of Science and Technology Equipment Manufacturing College Hebei University of Engineering

The compressive behaviors of medium carbon steel specimens were investigated over a wide range of tem- peratures and strain rates using a Gleeble-3500 thermo-simulation machine. The results show that the flow stress in- creased with strain at first, and then gradually decreased after reaching a peak value. The flow stress softening rate at a high strain rate was larger than that at a low strain rate. The effects of deformation heating and friction on flow stress were analyzed. A new friction correction method, wherein the effect of strain on frictional coefficient was con- sidered, was established here. The stresses revised by the new method deviated from the measured stresses with in- creasing strain. Meanwhile, the apparent frictional coefficient variation law with strain was obtained. The frictional coefficient increased as the strain increased and then slightly decreased after maintaining a constant value. The stress was corrected by considering deformation heating. The accuracy of the temperature correction method was verified using a special experiment. The results of the verification experiment show that the temperature correction method exhibited a good accuracy in calculating the variation of stress caused by deformation heating. A constitutive model considering strain was proposed here to describe the deformation behaviors. Compared with experimental data, the modified constitutive model exhibited a good accuracy as to constitutive correlation.

关键词： friction correction temperature correction deformation heating flow stress constitutive model

Preparation and tensile properties of DD5 single crystal castings

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International Journal of Minerals,Metallurgy and Materials 2016年第6期23卷 683-690页

作者： Xiang-feng Liang Yu-tao Zhao Zhi-hong Jia Chi Zhang School of Material Science and Engineering Jiangsu University

The preparation procedure of DD5 single crystal castings was optimized. The microstructure characteristics of DD5 single crystal superalloy were investigated by microstructure observation and segregation behavior examination. The results show that the grain orientation is optimized by constraining the spiral crystallizer in [001] orientation and spatial scale. Also, the γ＇ phase of inter-dendrites is larger and more irregular than that in dendrite arms. High temperature tensile tests of DD5 single crystal castings exhibit that the peak stress increases with increasing temperature, while the area reduction shows an opposite trend, when the temperature is below 800℃; meanwhile, when the temperature is between 800℃ and 1000℃, the fracture stress of the alloy is the same as the peak stress. The fracture mode changes from shear to ductile with increasing temperature from 600℃ and 1000℃.

关键词： superalloys single crystals segregation tensile properties alloy preparation castings

Equivalent combined cycle modelling for three-heat-reservoir thermal Brownian heat pump with heat-transfer effect and its optimal performance

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Science China Technological Sciences 2025年

作者： Lingen CHEN Congzheng QI Yanlin GE Huijun feng Hubei Provincial Key Laboratory of Chemical Equipment Intensification and Intrinsic Safety Wuhan Institute of Technology Hubei Provincial Engineering Technology Research Center of Green Chemical Equipment Wuhan Institute of Technology Institute of Thermal Science and Power Engineering Wuhan Institute of Technology School of Mechanical & Electrical Engineering Wuhan Institute of Technology

Because of the important role of the absorption heat pump in low-grade thermal energy utilization, this paper extends it to micro domain and performs a finite-time thermodynamic modelling for a three-heat-reservoir (THR) thermal Brownian heat pump with heat transfer effect by using an equivalent combined cycle method, which was applied for macro endoreversible THR heat pumps. The working principle and energy transformation rule are studied, and the coefficient of performance (COP) and heating load are derived. With a fixed overall thermal conductance of three heat exchangers, the maximal heating load is determined by optimizing thermal conductance distributions among three heat exchangers and barrier height, and the optimal working temperatures are also obtained. The impact of external heat transfer is elucidated to show the difference between this model and a non-equilibrium thermodynamic one. Results indicate that external heat transfer determines the energy transformation directly, and performance characteristics are closer to reality when external heat transfer is considered. The heating load has a maximal value about thermal conductance allocation ratios. About half the overall heat exchanger inventory needs to be assigned to the heat exchanger of the heating space for maximal heating load. When the cycle is with only heat transfer effect, the net particle numbers are zero, and the cycle fails to pump heat. The research results are expected to offer an idea for thermodynamic optimization and design of micro THR thermal Brownian heat pump devices.

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Spatiotemporal characteristics and influencing factors of vegetation water use efficiency on the Tibetan Plateau in 2001–2020

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Journal of Geographical Sciences 2025年第1期35卷 39-64页

作者： HE Chenyang WANG Yanjiao YAN feng LU Qi School of Ecological and Environmental Science East China Normal University Institute of Ecological Conservation and Restoration Chinese Academy of Forestry National Climate Center China Meteorological Administration

Water use efficiency （WUE）,as a pivotal indicator of the coupling degree within the carbon–water cycle of ecosystems,holds considerable importance in assessment of the carbon–water balance within terrestrial ***,in the context of global warming,WUE evolution and its primary drivers on the Tibetan Plateau remain *** study employed the ensemble empirical mode decomposition method and the random forest algorithm to decipher the nonlinear trends and drivers of WUE on the Tibetan Plateau in 2001–*** indicated an annual mean WUE of 0.8088 gC/mm·m2across the plateau,with a spatial gradient reflecting decrease from the southeast toward the *** manifesting monotonous trends of increase or decrease in WUE accounted for 23.64%and 9.69%of the total,***,66.67%of the region exhibited trend reversals,i.e.,39.94%of the area of the Tibetan Plateau showed transition from a trend of increase to a trend of decrease,and 26.73%of the area demonstrated a shift from a trend of decrease to a trend of *** factors accounted for 70.79%of the variability in *** leaf area index and temperature served as the major driving forces of WUE variation.

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A Bayesian expectation maximization algorithm for state estimation of intelligent vehicles considering data loss and noise uncertainty

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Science China Technological Sciences 2025年

作者： Yan WANG feng TIAN Jianqiang WANG Keqiang LI Department of Industrial and Systems Engineering The Hong Kong Polytechnic University School of Vehicle and Mobility Tsinghua University

Sideslip angle, yaw rate, and vehicle velocity are essential for intelligent vehicle control. Since these vehicle states are not measured directly, some Kalman-based approaches have been developed to estimate these states using in-vehicle sensors. However, the existing studies seldom account for the influence of sensor data loss on estimation accuracy. In addition,the process and measurement noise change during the estimation process because of the various driving conditions. To address these problems, an expectation-maximization robust extended Kalman filter (EMREKF) is proposed. Firstly, a robust extended Kalman filter (REKF) is developed to deal with the impact of missing measurements. Then, an improved expectation maximization (EM) algorithm that considers data loss is presented to update the noise parameter of the REKF dynamically. Finally,the improved EM is fused with the REKF to form the EMREKF to estimate vehicle state. The experimental results demonstrate that the EMREKF outperforms EKF, REKF, and maximum correntropy criterion EKF for various degrees of data loss and the proposed algorithm has a strong adaptive ability to different driving conditions.

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Genes and proteins expressed at different life cycle stages in the model protist Euplotes vannus revealed by both transcriptomic and proteomic approaches

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Science China Life Sciences 2025年第1期68卷 232-248页

作者： Yaohan Jiang Xiao Chen Chundi Wang Liping Lyu Saleh A.Al-Farraj Naomi A.Stover feng Gao Key Laboratory of Evolution & Marine Biodiversity (Ministry of Education) and Institute of Evolution & Marine Biodiversity Ocean University of China Marine College Shandong University Zoology Department College of ScienceKing Saud University Department of Biology Bradley University Laboratory for Marine Biology and Biotechnology Qingdao Marine Science and Technology Center

Sexual reproduction first appeared in unicellular protists and has continued to be an essential biological process in almost all *** protists, which contain both germline and somatic genomes within a single cell, have evolved a special form of sexual reproduction called conjugation that involves mitosis, meiosis, fertilization, nuclear differentiation, genome rearrangement, and the development of unique cellular structures. The molecular basis and mechanisms of conjugation vary dramatically among ciliates, and many details of the process and its regulation are still largely unknown. In order to better comprehend these processes and mechanisms from an evolutionary perspective, this study provides the first comprehensive overview of the transcriptome and proteome profiles during the entire life cycle of the newly-established marine model ciliate Euplotes vannus. Transcriptome analyses from 14 life cycle stages(three vegetative stages and 11 sexual stages) revealed over 26,000 genes that are specifically expressed at different stages, many of which are related to DNA replication,transcription, translation, mitosis, meiosis, nuclear differentiation, and/or genome rearrangement. Quantitative proteomic analyses identified 338 proteins with homologs associated with conjugation and/or somatic nuclear development in other ciliates, including dicer-like proteins, Hsp90 proteins, RNA polymerase Ⅱ and transcription elongation factors, ribosomal-associated proteins, and ubiquitin-related proteins. Four of these homologs belong to the PIWI family, each with different expression patterns identified and confirmed by RT-qPCR,which may function in small RNA-mediated genome rearrangement. Proteins involved in the nonhomologous end-joining pathway are induced early during meiosis and accumulate in the developing new somatic nucleus, where more than 80% of the germline sequences are eliminated from the somatic genome. A number of new candidate genes and proteins likely t

关键词： sexual reproduction transcriptomic proteomic genome rearrangement PIWI NHEJ

Advances in the Development of Gradient Scaffolds Made of Nano‑Micromaterials for Musculoskeletal Tissue Regeneration

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Nano-Micro Letters 2025年第3期17卷 455-500页

作者： Lei Fang Xiaoqi Lin Ruian Xu Lu Liu Yu Zhang feng Tian Jiao Jiao Li Jiajia Xue Beijing Laboratory of Biomedical Materials Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China State Key Laboratory of Organic‑Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China School of Biomedical Engineering Faculty of Engineering and ITUniversity of Technology SydneySydneyNSW 2007Australia

The intricate hierarchical structure of musculoskeletal tissues,including bone and interface tissues,necessitates the use of complex scaffold designs and material structures to serve as tissue-engineered *** has led to growing interest in the development of gradient bone scaffolds with hierarchical structures mimicking the extracellular matrix of native tissues to achieve improved therapeutic *** on the anatomical characteristics of bone and interfacial tissues,this review provides a summary of current strategies used to design and fabricate biomimetic gradient scaffolds for repairing musculoskeletal tissues,specifically focusing on methods used to construct compositional and structural gradients within the *** latest applications of gradient scaffolds for the regeneration of bone,osteochondral,and tendon-to-bone interfaces are ***,the current progress of testing gradient scaffolds in physiologically relevant animal models of skeletal repair is discussed,as well as the challenges and prospects of moving these scaffolds into clinical application for treating musculoskeletal injuries.

关键词： Gradient scaffolds Musculoskeletal tissues Advanced manufacturing Biomaterials Tissue regeneration

Integrated Towing Transportation Technique for Offshore Wind Turbine with Composite Bucket Foundation

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China Ocean Engineering 2022年第1期36卷 133-143页

作者： DING hong-yan feng Zun-tao ZHANG Pu-yang LE Cong-huan State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China Key Laboratory of Coast Civil Structure Safety Ministry of EducationTianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China

Composite bucket foundation and one-step installation technology for offshore wind turbine are the integration of foundation construction,transportation and whole installation at *** cost of offshore wind turbine construction and installation has been largely *** stability is the key technology in the process of towing *** observation data can reflect the real state of the *** this paper,the influence of water depth and towing speed on liquid level,the compartment pressure,and the pitch angles during towing of composite bucket foundation are *** data are analyzed based on the field measurements data from a 3.3 MW offshore wind power project in *** results show that with varied water depths and towing speeds,the compartment pressure changes are small during the bucket foundation towing *** offshore wind turbine composite bucket foundation is stable while being towed in the ocean.

关键词： composite bucket foundation towing transportation field measurements stability