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以提升空间热度为导向的上海花木-龙阳路绿道选线及优化研究 被引量:14
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作者 姜佳怡 戴菲 章俊华 《中国园林》 北大核心 2020年第1期70-74,共5页
通过对2018年一周内(3月2631日)上海市中心城区百度热力图进行分时段统计分析发现:同一规划级别的城市中心在城市空间热度上存在着巨大差异,这与上海市现行城市规划中强化城市中央活动区、城市副中心以及地区中心的建设目标存在一定差... 通过对2018年一周内(3月2631日)上海市中心城区百度热力图进行分时段统计分析发现:同一规划级别的城市中心在城市空间热度上存在着巨大差异,这与上海市现行城市规划中强化城市中央活动区、城市副中心以及地区中心的建设目标存在一定差距。为缩小同级别城市中心的空间热度差异,以提升空间热度为导向,选取空间热度较低的代表性地区上海市浦东新区花木-龙阳路副中心,以公共设施类POI(Point of Interest)核密度分布为基础、道路与交通设施类POI核密度分布为补充,进行绿道选线与优化结果分析。同时,根据人群空间热度,从绿地类型、使用时间2个维度,以及主轴线规划、副轴线规划、绿地斑块规划和夜间灯光设计4个方面提出花木-龙阳路副中心区绿道优化策略,在实现区域绿道覆盖率目标的基础上,通过绿道构建提升区域内部的连通性,进而提升空间热度。 展开更多
关键词 风景园林 空间分布热度 绿道 花木-龙阳路 POI数据 百度热力图
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海上主副油管注过热蒸汽热损失等效算法探讨 被引量:5
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作者 孙逢瑞 姚约东 李相方 《北京石油化工学院学报》 2017年第2期15-18,24,共5页
减小井筒热损失是稠油油藏高效开发的基础。通过引入过热蒸汽状态数据,利用质量守恒、动量守恒和能量守恒方程,结合考虑海水扰流的井筒外热损失计算模型,建立了完整的海上平行双管注过热蒸汽井筒热物性参数分布模型。对目标井注汽参数... 减小井筒热损失是稠油油藏高效开发的基础。通过引入过热蒸汽状态数据,利用质量守恒、动量守恒和能量守恒方程,结合考虑海水扰流的井筒外热损失计算模型,建立了完整的海上平行双管注过热蒸汽井筒热物性参数分布模型。对目标井注汽参数进行优化,研究表明:随着海上平台日注汽量的增加,井筒中同一深度处过热度先增加后减小,目标井最优日注汽量为120t/d;随着注汽温度增加,井筒中相同深度处过热度增加,但井筒热损失增加,井筒热效率下降。 展开更多
关键词 平行双管 过热蒸汽 等效算法 热度分布 海水扰流 稠油开发
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Experimental study on thermal characteristics of a double skin faade building 被引量:2
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作者 王芳 张小松 +1 位作者 谭俊杰 李秀伟 《Journal of Southeast University(English Edition)》 EI CAS 2014年第4期462-466,共5页
An experimental study of the thermal characteristics of an existing office building with double skin facade DSF were conducted in hot summer daytime in Nanjing China. The temperature distributions of the DSF and indoo... An experimental study of the thermal characteristics of an existing office building with double skin facade DSF were conducted in hot summer daytime in Nanjing China. The temperature distributions of the DSF and indoor environment were measured at different control modes of DSF.The results show that the energy consumption of the air conditioning system in room B with opened exterior vents a closed interior facade and an air cavity with shading was 21.0% less than that in room A with closed exterior vents a closed interior facade and air cavity without shading in 9.5 h. The temperature distributions of the DSF and indoor environment in both horizontal and vertical directions were decisively influenced by shading conditions. The usage of shading devices strengthens the stack effect on the air cavity. Compared to room A the temperature distribution in room B is more uniform with smaller fluctuations.Meanwhile the problem of overheating in the air cavity of the DSF is still present in all tested conditions. 展开更多
关键词 double skin facade THERMAL characteristics temperature distribution energy consumption
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Structural design and experimental research of microwave radiation heater for asphalt pavements 被引量:2
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作者 朱松青 史金飞 《Journal of Southeast University(English Edition)》 EI CAS 2009年第1期68-73,共6页
In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and a... In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and antenna length are established according to the law of energy conservation and microwave antenna radiation theory. Modeling and simulation are carried out using IE3D software. The simulation results demonstrate that, with a fixed horn surface size, the shortened electric antenna length is the main factor leading to the improved heating uniformity. On the other hand, with a fixed antenna length and diminished surface size, the standing wave ratio decreases with the improved radiation efficiency. Furthermore, the efficiency of radiation drops with increased distance between the horn surface and the asphalt pavement. Microwave heating experiments are carried out using this type of heater. The temperature distribution of asphalt samples is obtained by the grid temperature measurement method, and Matlab simulation is performed. The experimental results are in good agreement with the simulation. 展开更多
关键词 asphalt mixtures microwave heating temperature distribution microwave radiation heater structural design
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CUTTING TEMPERATURE MEASUREMENT IN HIGH-SPEED END MILLING 被引量:8
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作者 全燕鸣 林金萍 王成勇 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第1期47-51,共5页
A computer aided measurement system is used to measure the cutting temperature directly in high-speed machining by natural thermocouples and standard thermocouples. In this system the tool/workpiece interface temperat... A computer aided measurement system is used to measure the cutting temperature directly in high-speed machining by natural thermocouples and standard thermocouples. In this system the tool/workpiece interface temperature is measured by the tool/workpiece natural thermocouple, while the temperature distribution on the workpiece surface and that of interior are measured by some standard thermocouples prearranged at proper positions. The system can be used to measure cutting temperature in the machining with the rotary cutting tools, such as vertical drill and end milling cutter. It is practically used for the research on high-speed milling with hardened steel. 展开更多
关键词 high-speed milling end milling cutter cutting temperature THERMOCOUPLE
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基于红外热成像技术的舞台灯具散热数据研究
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作者 乌日乐 李国棋 《演艺科技》 2018年第7期9-14,共6页
利用红外热成像技术对舞台灯具温度进行实时测量,得到红外热像图,可直观、全面、完整地了解灯具表面热分布的情况;并通过分析比对数据,寻找灯体表面温度变化的规律。
关键词 红外热成像技术 红外热像图 热度分布 灯具散热
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Application of Thermal Science to Tongue Inspection in Traditional Chinese Medicine 被引量:2
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作者 诸凯 魏珺 +4 位作者 马一太 何坚 张伯礼 高秀梅 王怡 《Transactions of Tianjin University》 EI CAS 2004年第1期5-8,共4页
The study on Traditional Chinese Medicine (TCM)by the technology and method of thermal science is a new cut in point in interdisciplinary science, and its purpose is to study the tongue inspection in TCM from the view... The study on Traditional Chinese Medicine (TCM)by the technology and method of thermal science is a new cut in point in interdisciplinary science, and its purpose is to study the tongue inspection in TCM from the view of the bio heat transfer theory. In this paper human tongues were studied with the infrared thermal imaging technology. And the characteristic relationship between temperature distribution and age, tongue color as well as infrared thermal tongue image concerning the characteristic of viscera was analyzed by the experimental data,which confirms that the change in temperature distribution in different positions of the tongue is related to the diseases of different internal organs of the body. From a series of invasive experiments in animals, the blood perfusion rate was measured with the equipment of CBI 8000 Doppler Blood Flow Meter and MP 100 Physiologic Research System for the first time and the characteristic relationship curve between the temperature on the surface of the tongue and the blood perfusion rate was obtained. From the experiments the temperature on the surface of the tongue reflects objectively the tongue color which is influenced by the blood perfusion rate. This will help to develop some new cognition in the theory of TCM. 展开更多
关键词 Traditional Chinese Medicine (TCM) tongue inspection bio heat transfer temperature on the surface of tongue blood perfusion rate
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Theoretical and Experimental Study on Ground Coupled Heat Pump with Vertical Spiral Coil 被引量:4
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作者 李新国 周倩 +2 位作者 赵军 朱强 胡璟 《Transactions of Tianjin University》 EI CAS 2003年第2期123-126,共4页
The numeric al simulation study on the temperature distribution of underground field for the ground coupled heat pump (GCHP) with vertical spira l coil was carried out by using finite element. The distribution and rec... The numeric al simulation study on the temperature distribution of underground field for the ground coupled heat pump (GCHP) with vertical spira l coil was carried out by using finite element. The distribution and recovery of undergroun d field temperature under different operation ratio and the optimal operation ratio were simulated.The performance parameters, i.e. inlet and outlet temperature of the ground spiral coil in heating and cooling modes were tested, the heat extracted or emitted by the heat pump to the ground was calculated, and the coefficients of performance (COP) of GCHP at heat ing and cooling modes were analyzed. 展开更多
关键词 ground coupled heat pump (GCHP) vert ic al spiral coil underground temperature distribution optimal operation ratio
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Numerical simulation of temperature distribution and heat transfer during solidification of titanium alloy ingots in vacuum arc remelting process 被引量:10
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作者 杨治军 赵小花 +3 位作者 寇宏超 李金山 胡锐 周廉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第10期1957-1962,共6页
In order to get a better understanding of the vacuum consumable arc remelting(VAR) processes and thus to optimize them,a 3D finite element model was developed for the temperature fields and heat transfer of titanium a... In order to get a better understanding of the vacuum consumable arc remelting(VAR) processes and thus to optimize them,a 3D finite element model was developed for the temperature fields and heat transfer of titanium alloy ingots during VAR process.The results show that the temperature fields obtained by the simulation are well validated through the experiment results.The temperature distribution is different during the whole VAR process and the steady-state molten pool forms at 329 s for d100 mm × 180 mm ingots.At the initial stage of remelting,the heat dissipation of crucible bottom plays an important role in the whole heat dissipation system.At the middle of remelting,the crucible wall becomes a major heat dissipation way.The effect of cooling velocity on the solidification structure of ingots was investigated based on the temperature fields and the results can well explain the macrostructure of titanium alloy ingots. 展开更多
关键词 vacuum arc remelting(VAR) process titanium alloy ingot MACROSTRUCTURE temperature field heat transfer
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Simulation of alumina dissolution and temperature response under different feeding quantities in aluminum reduction cell 被引量:2
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作者 LI Si-yun LI Mao +2 位作者 HOU Wen-yuan LI He-song CHENG Ben-jun 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第8期2119-2128,共10页
In the feeding process of aluminum electrolytic, feeding quantity of alumina affects eventually dissolved quantity at the end of a feeding cycle. Based on the OpenFOAM platform, dissolution model coupled with heat and... In the feeding process of aluminum electrolytic, feeding quantity of alumina affects eventually dissolved quantity at the end of a feeding cycle. Based on the OpenFOAM platform, dissolution model coupled with heat and mass transfer was established. Applying the Rosin-Rammler function, alumina particle size distribution under different feeding quantities was obtained. The temperature response of electrolyte after feeding was included and calculated, and the dissolution processes of alumina with different feeding quantities (0.6, 0.8, 1.0, 1.2, 1.4, 1.6 kg) after feeding were simulated in 300 kA aluminum reduction cell. The results show that with the increase of feeding quantity, accumulated mass fraction of dissolved alumina decreases, and the time required for the rapid dissolution stage extends. When the feeding quantity is 0.6 kg and 1.2 kg, it takes the shortest time for the electrolyte temperature dropping before rebounding back. With the increase of feeding quantity, the dissolution rate in the rapid dissolution stage increases at first and then decreases gradually. The most suitable feeding quantity is 1.2 kg. The fitting equation of alumina dissolution curve under different feeding quantities is obtained, which can be used to evaluate the alumina dissolution and guide the feeding quantity and feeding cycle. 展开更多
关键词 alumina dissolution heat and mass transfer particle size distribution temperature response NUMERICAL
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Investigation on the temperature distribution and strength of flat steel ribbon wound cryogenic high-pressure vessel 被引量:1
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作者 CUI Xiao-long CHEN Guang-ming 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第2期210-215,共6页
By analyzing heat transfer on the wall of fiat steel ribbon wound vessel (FSRWV), a numerical model of temperature distribution on the entire wall (including inner core wall, flat steel ribbons, outside cylinder of... By analyzing heat transfer on the wall of fiat steel ribbon wound vessel (FSRWV), a numerical model of temperature distribution on the entire wall (including inner core wall, flat steel ribbons, outside cylinder of jacket and insulating layer) was established by the authors. With the model, the temperature distribution and the length change in the vessel walls and flat steel ribbons in low temperature are calculated and analyzed. The results show that the flat steel ribbon wound cryogenic high-pressure vessel is simpler in structure, safer and easier to manufacture than those of conventional ones. 展开更多
关键词 Cryogenic high-pressure vessel Flat steel ribbon wound vessel (FSRWV) Temperature distribution Numerical simulation
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Heat transfer study on solid and porous convective fins with temperature-dependent heat generation using efficient analytical method 被引量:10
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作者 S.E.Ghasemi P.Valipour +1 位作者 M.Hatami D.D.Ganji 《Journal of Central South University》 SCIE EI CAS 2014年第12期4592-4598,共7页
A simple and highly accurate semi-analytical method, called the differential transformation method(DTM), was used for solving the nonlinear temperature distribution equation in solid and porous longitudinal fin with t... A simple and highly accurate semi-analytical method, called the differential transformation method(DTM), was used for solving the nonlinear temperature distribution equation in solid and porous longitudinal fin with temperature dependent internal heat generation. The problem was solved for two main cases. In the first case, heat generation was assumed variable by fin temperature for a solid fin and in second heat generation varied with temperature for a porous fin. Results are presented for the temperature distribution for a range of values of parameters appearing in the mathematical formulation(e.g. N, εG, and G). Results reveal that DTM is very effective and convenient. Also, it is found that this method can achieve more suitable results in comparison to numerical methods. 展开更多
关键词 heat transfer convective fin solid and porous fin heat generation analytical method thermal analysis
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Thermal analysis of an innovative flat heat pipe radiator 被引量:1
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作者 寇志海 白敏丽 杨洪武 《Journal of Central South University》 SCIE EI CAS 2011年第2期568-572,共5页
An innovative flat heat pipe radiator was put forward, and it has the features of high efficiency of heat dissipation, compact construction, low thermal resistance, light weight, low cost, and anti-dust-deposition. Th... An innovative flat heat pipe radiator was put forward, and it has the features of high efficiency of heat dissipation, compact construction, low thermal resistance, light weight, low cost, and anti-dust-deposition. The thermal analysis of the flat heat pipe radiator for cooling high-power light emitting diode (LED) array was conducted. The thermal characteristics of the flat heat pipe radiator under the different heat loads and incline angles were investigated experimentally in natural convection. An electro-thermal conversion method was used to measure the junction temperature of the LED chips. It is found that the integral temperature distribution of the flat heat pipe radiator is reasonable and uniform. The total thermal resistance of the flat heat pipe radiator varies in the range of 0.38-0.45 K/W. The junction temperatures of LED chips with the flat heat pipe radiator and with the aluminum board at the same forward current of 0.35 A are 52.5 and 75.2 ℃, respectively. 展开更多
关键词 energy technology thermal analysis flat heat pipe radiator thermal characteristics
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Temperature Distribution in Ethylene Pyrolyzer 被引量:3
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作者 蓝兴英 高金森 徐春明 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第6期622-625,共4页
A good understanding of the detailed temperature distribution in the furnace plays an important role in the implementation of operation optimization and design improvement of ethylene pyrolyzer. Numerical simulation o... A good understanding of the detailed temperature distribution in the furnace plays an important role in the implementation of operation optimization and design improvement of ethylene pyrolyzer. Numerical simulation of the turbulent flow, combustion and heat transfer was carried out to investigate the temperature distribution in industrial furnace. Inhomogeneities of the flue-gas temperature distribution were observed in X, Y, and Z direction of the furnace from the simulated results. Along the height of the furnace, the average flue-gas temperature increased initially and decreased afterward, and reached its peak at the height of 5 m. The reactor tube skin temperature varied not only along the height of the furnace, but also around the circumference of the tube. The heat flux profiles from the furnace towards the reactor tubes followed the shape of the average flue-gas temperature profile. The heat flux of the inlet tubes was constantly higher than that of the outlet tubes at the same height in the furnace. 展开更多
关键词 ETHYLENE pyrolyzer FURNACE reactor tube FLUE-GAS TEMPERATURE heat flux
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THERMAL EFFECTS OF BUILDING′S EXTERNAL SURFACES IN CITY——Characteristics of Heat Flux into and out of External Wall Surfaces 被引量:2
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作者 ZHANGYi-ping HEYun-ling +3 位作者 LIUYu-hong MAYou-xin LIYou-rong DOUJun-xia 《Chinese Geographical Science》 SCIE CSCD 2004年第4期343-349,共7页
This study examined the thermal effects of building′s external wall surfaces, using observational data of spatial-temporal distribution of surface temperature, air temperature, and heat flux into and out of external ... This study examined the thermal effects of building′s external wall surfaces, using observational data of spatial-temporal distribution of surface temperature, air temperature, and heat flux into and out of external surface. Results indicate that external wall surface temperature and nearby air temperature vary with the change of orientation, height and season. In general, the external wall surface temperature is lower near the ground, and is higher near the roof, than nearby air temperature. But north wall surface temperature is mostly lower than nearby air temperature at the same height; south wall surface temperature during the daytime in December, and west wall surface temperature all day in August, is respectively higher than nearby air temperature. The heat fluxes into and out of external wall surfaces show the differences that exist in the various orientations, heights and seasons. In December, south wall surface at the lower sites emits heat and north wall surface at the higher sites absorbs heat. In April, all external wall surfaces, emit heat near the ground and absorb heat near the roof. In August, west wall surface all day emits heat, and other wall surfaces just show the commensurate behavior with that in April. 展开更多
关键词 external wall surface thermal effect heat flux intensity spatial-temporal distribution
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Characterization of A390 aluminum alloy produced at different slow shot speeds using vacuum assisted high pressure die casting 被引量:11
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作者 Wen-bo YU Zi-hao YUAN +1 位作者 Zhi-peng GUO Shou-mei XIONG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第12期2529-2538,共10页
The effects of vacuum assistance on the microstructure and mechanical properties of high pressure die cast A390alloy at different slow shot speeds were evaluated.Plate-shaped specimens of hypereutectic A390aluminum al... The effects of vacuum assistance on the microstructure and mechanical properties of high pressure die cast A390alloy at different slow shot speeds were evaluated.Plate-shaped specimens of hypereutectic A390aluminum alloy were produced on a TOYO BD?350V5cold chamber die casting machine incorporated with a self-improved TOYO vacuum system.According to the results,the vacuum pressure inside the die cavity increased linearly with the increasing slow shot speed at the beginning of mold filling.Meanwhile,tensile properties of vacuum die castings were deteriorated by the porosity content.In addition,the average primary silicon size decreased from23to14μm when the slow shot speed increased from0.05to0.2m/s,which has a binary functional relationship with the slow shot speed.After heat treatment,microstructural morphologies revealed that needle-shaped and thin-flaked eutectic silicon particles became rounded while Al2Cu dissolved intoα(Al)matrix.Furthermore,the fractography revealed that the fracture mechanism has evolved from brittle transgranular fracture to a fracture mode with many dimples after heat treatment. 展开更多
关键词 A390 aluminum shot speed vacuum assisted high pressure die casting (VHPDC) Si distribution tensile strength heat treatment
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Age, Growth and Distribution of the Antarctic Fish Chaenocephalus Aceratus Based on Otoliths 被引量:2
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作者 Ryszard Jacek Traczyk 《Journal of Environmental Science and Engineering(A)》 2015年第8期401-419,共19页
The Chaenocephalus aceratus were sampled in summers between 1979 and 1990. Their otoliths show pattern of daily microincrements as otoliths of similar species--Pseudochaenichthys georgianus and fishes both temperate a... The Chaenocephalus aceratus were sampled in summers between 1979 and 1990. Their otoliths show pattern of daily microincrements as otoliths of similar species--Pseudochaenichthys georgianus and fishes both temperate and tropical waters. Changes of the microincrements growth pattern and otolith shape are described in relation to larval, hatching and metamorphosis stages have similar patterns for Ps. georgianus and Charnpsocephalus gunnari, reflecting similar habitats in their early life. Width of larvae-postlarvae daily increments are: (1.0-1.6)×10-3 SSI, (1.8-2.8)×10-3 SG1 and (1.5-2.4)×10-3 ANI. They were search and chosen automatically from density profiles of otolith tissues. Tissues were prepared by new saving time and materials way--one time up to 40 ones per microscopic glass. Age of fish estimated from microincrements was alike to that inferred from the body length distribution, otoliths mass (age (years) = 140.82 OM (g) + 0.8546) and otolith shape changes--large in length and surface on medial plane. Those parameters create age groups of close neighbours. They have different environments. C. aceratus due to its adaptation to cold water, attain rapidly large body according to a growth equation: Lt= 75.1 ×10-3 (1-e-0.26(t-0.51). Among large fishes there were only females. 展开更多
关键词 Chaenocephalus aceratus otolith shape age of icefish Antarctic fish.
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Heat Transfer Analysis of Sterilization of Canned Milk Using Computational Fluid Dynamics Simulations 被引量:1
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作者 Prateek Dhayal Narayansing Chhanwal Chinnaswamy Anandharamakrishnan 《Journal of Food Science and Engineering》 2013年第11期571-583,共13页
A uniform and effective heat distribution inside the canned milk is very crucial for achieving effective sterilization. It is extremely difficult to establish the temperature profile inside the canned milk during cont... A uniform and effective heat distribution inside the canned milk is very crucial for achieving effective sterilization. It is extremely difficult to establish the temperature profile inside the canned milk during continuous industrial scale operation. Computational fluid dynamics (CFD) simulation can be a useful tool to determine the temperature distribution of the fluid inside the can during the sterilization process. A CFD model was developed for the sterilization of canned milk at 121 ~C. The simulation results were validated with the experimental measurements of temperatures. The formation and movement of slowest heating zone (SHZ) during the sterilization process was tracked. Moreover, effect of can position (vertical and horizontal) during processing on milk temperature distribution inside the can was also investigated. Higher Grashof and Rayleigh numbers were obtained for vertical positioning of can compared to horizontal can processing. Further, effectiveness of the process was calculated based on F-value and these results reinforced the positive effect of horizontal position of can during the sterilization process. 展开更多
关键词 CFD HORIZONTAL STERILIZATION canned milk.
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Analysis of atmospheric turbulence in the upper layers of sea fog 被引量:5
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作者 李永平 郑运霞 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第3期809-818,共10页
Atmospheric turbulence plays a vital role in the formation and dissipation of fog. However,studies of such turbulence are typically limited to observations with ultrasonic anemometers less than 100 m above ground. Thu... Atmospheric turbulence plays a vital role in the formation and dissipation of fog. However,studies of such turbulence are typically limited to observations with ultrasonic anemometers less than 100 m above ground. Thus,the turbulence characteristics of upper fog layers are poorly known. In this paper,we present 4-layers of data,measured by ultrasonic anemometers on a wind tower about 400 m above the sea surface; we use these data to characterize atmospheric turbulence atop a heavy sea fog. Large differences in turbulence during the sea fog episode were recorded. Results showed that the kinetic energy,momentum flux,and sensible heat flux of turbulence increased rapidly during the onset of fog. After onset,high turbulence was observed within the uppermost fog layer. As long as this turbulence did not exceed a critical threshold,it was crucial to enhancing the cooling rate,and maintaining the fog. Vertical momentum flux and sensible heat flux generated by this turbulence weakened wind speed and decreased air temperature during the fog. Towards the end of the fog episode,the vertical distribution of sensible heat flux reversed,contributing to a downward momentum flux in all upper layers. Spatial and temporal scales of the turbulence eddy were greater before and after the fog,than during the fog episode. Turbulence energy was greatest in upper levels,around 430 m and 450 m above mean sea level(AMSL),than in lower levels of the fog(390 m and 410 m AMSL); turbulence energy peaked along the mean wind direction. Our results show that the status of turbulence was complicated within the fog; turbulence caused fluxes of momentum and sensible heat atop the fog layer,affecting the underlying fog by decreasing or increasing average wind speed,as well as promoting or demoting air temperature stratification. 展开更多
关键词 ultrasonic anemometers turbulence characteristics momentum flux sensible heat flux variation in sea fog
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Effects of pin angle and preheating on temperature distribution during friction stir welding operation 被引量:2
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作者 R. KEIVANI B. BAGHERI +2 位作者 F. SHARIFI M. KETABCHI M. ABBASI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第9期2708-2713,共6页
Friction stir welding (FSW) is applied extensively in industry for joining of nonferrous metals especially aluminum. A three-dimensional model based on finite element analysis was used to study the thermal character... Friction stir welding (FSW) is applied extensively in industry for joining of nonferrous metals especially aluminum. A three-dimensional model based on finite element analysis was used to study the thermal characteristic of copper C I 1000 during the FSW process. The model incorporates the mechanical reaction of the tool and thermo-mechanieal characteristics of the weld material, while the friction between the material and the probe and the shoulder serves as the heat source. It was observed that the predicted results about the temperature were in good compatibility with the experimental results. Additionally, it was concluded that the numerical method can be simply applied to measuring the temperature of workpiece just beneath the tool. The effects of preheating temperature and pin angle on temperature distribution were also studied numerically. The increase of pin angle enhances the temperature around the weld line, but preheating does not affect temperature distribution along the weld line considerably. 展开更多
关键词 friction stir welding SIMULATION temperature distribution pin angle PREHEATING
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