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The Impact of Seasonal Variation on Clinical Pregnancy and Live Birth Rates in Assisted Reproductive Technology: A Retrospective Cohort Study in Hainan
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作者 Jingjing Zhong Zhiyong Lu +10 位作者 Ning Ma Zhi Zhou Hui Lu Yejuan Li Jiajia Hu Bangbei Wan Jin Huang Anguo Wang Hailing Ruan Liqiang Zhaol Weiying Lu 《Journal of Clinical and Nursing Research》 2024年第8期243-250,共8页
Objective:To investigate the influence of season on live birth and clinical pregnancy rates,as well as assisted reproductive technology(ART)outcomes,in the Hainan region.Methods:Patients were categorized into four gro... Objective:To investigate the influence of season on live birth and clinical pregnancy rates,as well as assisted reproductive technology(ART)outcomes,in the Hainan region.Methods:Patients were categorized into four groups based on the dates of artificial insemination and transplantation:spring,summer,autumn,or winter.The main outcome measures were clinical pregnancy rates and live birth rates.Secondary outcomes included body mass index(BMI),oocyte number,two pronuclei(2PN)cleavage rate,total gonadotropin(Gn)dosage and days,age,2PN fertilization rate,sperm concentration,sperm PR rate,anti-Müllerian hormone(AMH),and endometrial thickness.Outpatient semen quality indicators included sperm PR rate,total sperm count,sperm concentration,and total sperm motility.Results:This retrospective cohort study analyzed 2,016 artificial insemination cycles and 1,783 ovarian retrieval cycles from January 2017 to October 2022,and assessed the semen quality of 6,651 outpatients from May 2017 to October 2022.In artificial insemination cycles,sperm PR rate and clinical pregnancy rate were highest in winter,with a statistically significant difference between groups(P<0.05).Clinical pregnancy rate was influenced by both age and sperm PR rate(P<0.05).In ovarian retrieval cycles,the winter group had significantly higher clinical pregnancy,2PN fertilization,and 2PN cleavage rates than the other groups.The autumn group had higher live birth rates,though not significantly different.Additionally,winter months showed higher total sperm concentration and total sperm number compared to other seasons.Conclusion:Seasonality affected clinical pregnancy and live birth rates in artificial insemination cycles but not in ovarian retrieval cycles in the Hainan region.These findings suggest that while there is no need to choose a specific season for ovarian retrieval cycles,artificial insemination in winter may be preferable for patients. 展开更多
关键词 ENDOCRINOLOGY Assisted reproductive technology SEASONALITY pregnancy rate Artificial insemination
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Physics-informed neural network approach for heat generation rate estimation of lithium-ion battery under various driving conditions 被引量:3
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作者 Hui Pang Longxing Wu +2 位作者 Jiahao Liu Xiaofei Liu Kai Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第3期1-12,I0001,共13页
Accurate insight into the heat generation rate(HGR) of lithium-ion batteries(LIBs) is one of key issues for battery management systems to formulate thermal safety warning strategies in advance.For this reason,this pap... Accurate insight into the heat generation rate(HGR) of lithium-ion batteries(LIBs) is one of key issues for battery management systems to formulate thermal safety warning strategies in advance.For this reason,this paper proposes a novel physics-informed neural network(PINN) approach for HGR estimation of LIBs under various driving conditions.Specifically,a single particle model with thermodynamics(SPMT) is first constructed for extracting the critical physical knowledge related with battery HGR.Subsequently,the surface concentrations of positive and negative electrodes in battery SPMT model are integrated into the bidirectional long short-term memory(BiLSTM) networks as physical information.And combined with other feature variables,a novel PINN approach to achieve HGR estimation of LIBs with higher accuracy is constituted.Additionally,some critical hyperparameters of BiLSTM used in PINN approach are determined through Bayesian optimization algorithm(BOA) and the results of BOA-based BiLSTM are compared with other traditional BiLSTM/LSTM networks.Eventually,combined with the HGR data generated from the validated virtual battery,it is proved that the proposed approach can well predict the battery HGR under the dynamic stress test(DST) and worldwide light vehicles test procedure(WLTP),the mean absolute error under DST is 0.542 kW/m^(3),and the root mean square error under WLTP is1.428 kW/m^(3)at 25℃.Lastly,the investigation results of this paper also show a new perspective in the application of the PINN approach in battery HGR estimation. 展开更多
关键词 Lithium-ion batteries Physics-informed neural network Bidirectional long-term memory heat generation rate estimation Electrochemical model
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Effects of cooling rate on solution heat treatment of as-cast A356 alloy 被引量:13
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作者 杨长林 李远兵 +2 位作者 党波 吕贺宾 刘峰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第10期3189-3196,共8页
The effect of cooling rate of the solidification process on the following solution heat treatment of A356 alloy was investigated,where the cooling rates of 96 K/s and 3 K/s were obtained by the step-like metal mold.Th... The effect of cooling rate of the solidification process on the following solution heat treatment of A356 alloy was investigated,where the cooling rates of 96 K/s and 3 K/s were obtained by the step-like metal mold.Then the eutectic silicon morphology evolution and tensile properties of the alloy samples were observed and analyzed after solution heat treatment at 540 °C for different time.The results show that the high cooling rate of the solidification process can not only reduce the solid solution heat treatment time to rapidly modify the eutectic silicon morphology,but also improve the alloy tensile properties.Specially,it is found that the disintegration,the spheroidization and coarsening of eutectic silicon of A356 alloy are completed during solution heat treatment through two stages,i.e.,at first,the disintegration and spheroidization of the eutectic silicon mainly takes place,then the eutectic silicon will coarsen. 展开更多
关键词 A356 aluminum alloy solution heat treatment eutectic silicon cooling rate
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Decay rates and time lags of heat conduction in building construction under field conditions
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作者 彭昌海 吴智深 +1 位作者 陈振乾 李敏 《Journal of Southeast University(English Edition)》 EI CAS 2010年第2期249-253,共5页
The field measurements of decay rates and time lags of heat conduction in a building construction taken in Nanjing during the summer of 2001 are presented.The decay rates and time lags are calculated according to the ... The field measurements of decay rates and time lags of heat conduction in a building construction taken in Nanjing during the summer of 2001 are presented.The decay rates and time lags are calculated according to the frequency responses of the heat absorbed by the room's internal surfaces,inside surface temperature,indoor air temperature and outdoor synthetic temperature.The measured results match very well with the theoretical results of the zeroth and the first order values of the decay rates and time lags of heat conduction in the building construction,but the difference between the measured values and the theoretical values for the second order is too great to be accepted.It is therefore difficult to accurately test the second order value.However,it is still advisable to complete the analysis using the zeroth-and the first-orders values of the decay rates and time lags of heat conduction in building construction under field conditions,because in these cases the decay rates of heat conduction reach twenty which meets the requirements of engineering plans. 展开更多
关键词 decay rates time lags heat conduction building construction FIELD
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Application of moderate nitrogen levels alleviates yield loss and grain quality deterioration caused by post-silking heat stress in fresh waxy maize 被引量:7
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作者 Jue Wang Pengxiao Fu +1 位作者 Weiping Lu Dalei Lu 《The Crop Journal》 SCIE CSCD 2020年第6期1081-1092,共12页
High temperature(HT)during grain filling is one of the most important environmental factors limiting maize yield and grain quality.Nitrogen(N)fertilizer is essential for maintaining normal plant growth and defense aga... High temperature(HT)during grain filling is one of the most important environmental factors limiting maize yield and grain quality.Nitrogen(N)fertilizer is essential for maintaining normal plant growth and defense against environmental stresses.The effects of three N rates and two temperature regimes on the grain yield and quality of fresh waxy maize were studied using the hybrids Suyunuo 5(SYN5)and Yunuo 7(YN7)as materials.N application rates were 1.5,4.5,and 7.5 g plant-1,representing low,moderate,and high N levels(LN,MN,and HN,respectively).Mean day/night temperatures during the grain filling of spring-and summer-sown plants were 27.6/21.0°C and 28.6/20.0°C for ambient temperature(AT)and 35/21.0°C and 35/20.0°C for HT,respectively.On average,HT reduced kernel number,weight,yield,and moisture content by 29.8%,17.9%,38.7%,and 3.3%,respectively.Kernel number,weight,yield,moisture,and starch contents were highest under MN among the three N rates under both temperature regimes.HT reduced grain starch content at all N levels.HT increased grain protein content,which gradually increased with N rate.Mean starch granule size under MN was larger(10.9μm)than that under LN and HN(both 10.4μm)at AT.However,the mean size of starch granules was higher under LN(11.7μm)and lower under MN(11.2μm)at HT.Iodine binding capacity(IBC)was lowest under MN and highest under HN among the three N levels under both temperature regimes.In general,IBC at all N rates was increased by HT.Peak viscosity(PV)was gradually reduced with increasing N rate at AT.In comparison with LN,PV was increased by MN and decreased by HN at HT.Retrogradation percentage gradually increased with N rate at AT,but was lowest under MN among the three N rates at HT.LN+AT and MN+HT produced grain with high pasting viscosity and low retrogradation tendency.MN application could alleviate the negative effects of HT on the grain yield and quality of fresh waxy maize. 展开更多
关键词 Fresh waxy maize Grain quality heat stress Nitrogen rate Starch granule size
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Relationship among solution heating rate,mechanical properties,microstructure and texture of Al−Mg−Si−Cu alloy 被引量:6
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作者 Xiao-feng WANG Ming-xing GUO +2 位作者 Wen-fei PENG Yong-gang WANG Lin-zhong ZHUANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第1期36-52,共17页
The relationship among heating rate, mechanical properties, microstructure and texture of Al-Mg-Si-Cu alloy during solution treatment was investigated through tensile test, scanning electron microscope, X-ray diffract... The relationship among heating rate, mechanical properties, microstructure and texture of Al-Mg-Si-Cu alloy during solution treatment was investigated through tensile test, scanning electron microscope, X-ray diffractometer and EBSD technology. The experimental results reveal that there is a non-monotonic relationship among solution heating rate, mechanical properties, microstructure and texture. As the solution heating rate increases, the strength variations are dependent on the tensile direction;work hardening exponent n decreases first, and then increases;plastic strain ratio r increases first, and then decreases, and finally increases. The final microstructure and texture are also affected by heating rate. As heating rate increases, the microstructure transforms from elongated grain structure to equiaxed grain structure, and the average grain size decreases first, and then increases, and decreases finally. Although the texture components including CubeND{001}<310> and P{011}<122> orientations almost have no change with the increase of heating rate, the texture intensity and volume fraction decrease first, and then increase, and finally decrease. Both microstructure and texture evolutions are weakly affected by heating rate. Improving heating rate is not always favorable for the development of fine equiaxed grain structure, weak texture and high average r value, which may be related to the recrystallization behavior. 展开更多
关键词 Al−Mg−Si−Cu alloy solution heating rate mechanical properties microstructure TEXTURE
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Effect of heating rate on the densification of NdFeB alloys sintered by an electric field 被引量:1
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作者 Gang Yang, Yi Yang Dong Lu Kun-lan Huang Jun Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第11期1023-1028,共6页
This study introduces a novel method of electric field sintering for preparing NdFeB magnets. NdFeB alloy compacts were all sintered by electric fields for 8 min at 1000~C with different preset heating rates. The char... This study introduces a novel method of electric field sintering for preparing NdFeB magnets. NdFeB alloy compacts were all sintered by electric fields for 8 min at 1000~C with different preset heating rates. The characteristics of electric field sintering and the effects of heating rate on the sintering densification of NdFeB alloys were also studied. It is found that electric field sintering is a new non-pressure rapid sintering method for preparing NdFeB magnets with fine grains at a relatively lower sintering temperature and in a shorter sintering time. Using this method, the sintering temperature and process of the compacts can be controlled accurately. When the preset heating rate in- creasing from 5 to 2000~C/s the densification of NdFeB sintered compacts gradHally improves. As the preset heating rate is 2000C/s, Nd-rich phases are small, dispersed and uniformly distributed in the sintered compact, and the magnet has a better microstructure than that made by conventional vacuum sintering. Also, the maximum energy product of the sintered magnet reaches 95% of conventionally vacuum sintered magnets. 展开更多
关键词 permanent magnets electric fields SINTERING heating rate DENSIFICATION
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Effect of Heating Rates on the Formable Oxide Scale on a C-Steel Surface 被引量:1
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作者 A.A.El-Meligi 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第5期591-594,共4页
Oxide scale formation on a C-steel surface has been investigated using linear heating rates ranging from 0.1℃/min to 10℃/min at high temperatures. The studies on the oxide scale formation at high temperature (650℃)... Oxide scale formation on a C-steel surface has been investigated using linear heating rates ranging from 0.1℃/min to 10℃/min at high temperatures. The studies on the oxide scale formation at high temperature (650℃) at slower heating rate (0.1℃/min) shows that the kinetic regime is linear. X-ray diffraction measurements revealed that the scale constituents are significantly influenced by the heating rate. The adherence of the scale was improved by using slower heating rate (0.1℃/min-≤650℃), while above such degree the scale was susceptible to cracking and flaking out of the alloy surface. In fact, the development of oxide growth stresses can cause considerable scale cracking. As well, variation of the crystallite sizes under the aforementioned conditions might affect the scale stacking to the alloy surface. The secondary electron detector images of the oxide scale shows that the scale was imperfectly smooth and there were a number of voids and defects in the scale skin, especially at fast heating rate. This observation could be attributed to defects of the as-received alloy. In general, slower heating rate reduced the defects of the scale and improved its adherence. 展开更多
关键词 C-steel Oxide scale heating rate Weight gain XRD
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Properties of Reactive Magnetron Sputtered ITO Films without in-situ Substrate Heating and Post-deposition Annealing 被引量:4
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作者 Meng CHEN, Xuedong BAI, Jun GONG, Chao SUN, Rongfang HUANG and Lishi WEN (Institute of Metal Research, the Chinese Academy of Sciences, Shenyang 110015, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第3期281-285,共5页
Indium tin oxide (ITO) films were prepared on polyester, Si and glass substrate with relatively high deposition rate of above 0.9 nm/s by DC reactive magnetron sputtering technique at the sputtering pressure of 0.06 P... Indium tin oxide (ITO) films were prepared on polyester, Si and glass substrate with relatively high deposition rate of above 0.9 nm/s by DC reactive magnetron sputtering technique at the sputtering pressure of 0.06 Pa system, respectively. The dependence of resistivity on deposition parameters, such as deposition rate, target-to-substrate distance (TSD), oxygen flow rate and sputtering time (thickness), has been investigated, together with the structural and the optical properties. It was revealed that all ITO films exhibited lattice expansion. The resistivity of ITO thin films shows significant substrate effect: much lower resistivity and broader process window have been reproducibly achieved for the deposition of ITO films onto polyester rather than those prepared on both Si and glass substrates. The films with resistivity of as low as 4.23 x 10^-4 Ω.cm and average transmittance of ~78% at wavelength of 400~700 nm have been achieved for the films on polyester at room temperature. 展开更多
关键词 ITO Properties of Reactive Magnetron Sputtered ITO Films without in-situ Substrate heating and Post-deposition Annealing TSD rate than
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Influence of Heating Rate on Double Reversible Transformation in CuZnAlMnNi Shape Memory Alloy 被引量:1
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作者 Yujun Bai, Chengwei Lu, Xiangang Xu, Guili Geng, Longwei Yin (Mechanical Department, Shandong University of Science and Technology, Jinan 250031, China Institute of Materials Science and Engineering, Shandong University, Jinan 250061, China) 《Rare Metals》 SCIE EI CAS CSCD 2001年第2期117-120,共4页
The influence of heating rate on double reversible transformation in CuZnAlMnNi shape memory alloy was investigated by differential scanning calorimetry. It was found that rapid heating inhibits X -->M transformati... The influence of heating rate on double reversible transformation in CuZnAlMnNi shape memory alloy was investigated by differential scanning calorimetry. It was found that rapid heating inhibits X -->M transformation but is favorable to the reverse martensite transformation, giving rise to the approach of the two transformation peaks. With the decrease of heating rate, the two transformation peaks separate gradually. 展开更多
关键词 double reversible transformations heating rate CuZnAlMnNi shape memory alloy differential scanning calorimetry
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Effect of temperature and heating rate on mechanical properties of magnesium alloy AZ31 被引量:1
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作者 袁权 陈斌 +2 位作者 罗吉 张丁非 权国政 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第B07期426-429,共4页
Effects of temperature and heating rate on the mechanical properties of the tensile specimens of magnesium alloy AZ31 were experimentally investigated using a Gleeble-1500 thermo-mechanical material testing system.The... Effects of temperature and heating rate on the mechanical properties of the tensile specimens of magnesium alloy AZ31 were experimentally investigated using a Gleeble-1500 thermo-mechanical material testing system.The metallurgraphs of the fracture section of the specimens were also experimentally observed and analyzed for exploring their failure mechanism under different temperatures and heating rates.The results show that the higher the temperature,the lower the ultimate strength of the specimens.And the higher the heating rate,the higher the ultimate strength of the specimens.The high temperatures and high heating rates will induce microvoids in the specimens which make the specimens failure under relatively low loads. 展开更多
关键词 AZ31 magnesium alloy TEMPERATURE heating rate STRENGTH PLASTICITY
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Effects of Heating Rate on the Process Parameters of Superplastic Forming for Zr_(55)Cu_(30)Al_(10)Ni_5 被引量:1
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作者 杨璠 SHI Tielin 廖广兰 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第6期1136-1140,共5页
We investigated the effects of heating rate on the process parameters of superplastic forming for Zr55Cu30Al10Ni5 by differential scanning calorimetry. The continuous heating and isothermal annealing analyses suggeste... We investigated the effects of heating rate on the process parameters of superplastic forming for Zr55Cu30Al10Ni5 by differential scanning calorimetry. The continuous heating and isothermal annealing analyses suggested that the temperatures of glass transition and onset crystallization are heating rate-dependent in the supercooled liquid region. Then, the time-temperature-transformation diagram under different heating rates indicates that increasing the heating rate can lead to an increase of the incubation time at the same anneal temperature in the supercooled liquid region. Based on the Arrhenius relationship, we discovered that the incubation time increases by 1.08-1.11 times with double increase of the heating rate at the same anneal temperature, and then verified it by the data of literatures and the experimental results. The obtained curve of the max available incubation time reveals that the incubation time at a certain anneal temperature in the supercooled liquid region is not infinite, and will increase with increasing heating rate until this temperature shifts out of the supercooled liquid region because of exceeding critical heating rate. It is concluded that heating rate must be an important processing parameter of superplastic forming for Zr55Cu30Al10Ni5. 展开更多
关键词 bulk metallic glass annealing superplastic forming heating rate incubation time
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Physiological Performances of Temperate Vegetables with Response to Chronic and Acute Heat Stress 被引量:1
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作者 Cheng-Hsiang Lai Jie He 《American Journal of Plant Sciences》 2016年第14期2055-2071,共18页
In face of climate change catastrophes, understanding the thermal limits and optimal physiological thermal window food crop is of particular urgency. This research aims to evaluate: 1) how physiological performances o... In face of climate change catastrophes, understanding the thermal limits and optimal physiological thermal window food crop is of particular urgency. This research aims to evaluate: 1) how physiological performances of plant will change with increasing chronic and acute heat stress;2) if the examined parameters form a hierarchy in terms of thermal tolerance;and 3) the optimal thermal window and critical temperatures of the examined plants with response to chronic and acute heat stress. Six temperate vegetables were subjected to chronic and acute heat stress and a suite of physiological parameters were evaluated. Dose responses were observed in shoot fresh weight, photosynthetic gas exchange, photosynthetic oxygen evolution, electron transfer rate, photo- and non-photochemical quenching with significant drop in performance as early as 28&deg;C for selected species. Conversely, ratio of variable to maximum fluorescence (F<sub>v</sub>/F<sub>m</sub>) was not affected by heat stress until 46&deg;C in chronic heat stress. Examining the temperature at which a measured parameter’s performance dropped by 50% compared to control (LT<sub>50</sub>), a distinct hierarchy of the indices was observed for Canasta, recombinant inbred line 141, Lactuca serriola and Lactuca sativa (L. “Salinas”): shoot fresh weight, representing the highest integrated level of photosynthesis was the most sensitive to thermal stress (28&deg;C - 30&deg;C), followed by oxygen evolution (35&deg;C - 45&deg;C) while non-photochemical and photochemical quenching which is subcellular function of stress alleviation had a much higher capacity failure temperature (47&deg;C - 60&deg;C). It is expected that F<sub>v</sub>/F<sub>m</sub> ratio, a measurement of sub-cellular structural integrity, will approach that of non-photochemical and photochemical quenching, if not exceeding it. By examining the photosynthetic parameters via their hierarchy of biological organization, it can be inferred that plants like Arugula and recombinant inbred line 192 are already operating near their thermal limit and have less energetic investment into heat stress mediation whereas L. serriola prioritizes thermal tolerance at the expense of photosynthesis efficiency. 展开更多
关键词 Chlorophyll Fluorescence heat Stress O2 Evolution Photosynthetic CO2 Assimilation rate Stomatal Conductance THERMOTOLERANCE
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Spatial Distributions of Atmospheric Radiative Fluxes and Heating Rates over China during Summer 被引量:1
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作者 YANG Da-Sheng WANG Pu-Cai 《Atmospheric and Oceanic Science Letters》 2010年第5期248-251,共4页
The latitude-altitude distributions of radiative fluxes and heating rates are investigated by utilizing CloudSat satellite data over China during summer. The Tibetan Plateau causes the downward shortwave fluxes of the... The latitude-altitude distributions of radiative fluxes and heating rates are investigated by utilizing CloudSat satellite data over China during summer. The Tibetan Plateau causes the downward shortwave fluxes of the lower atmosphere over central China to be smaller than the fluxes over southern and northern China by generating more clouds. The existence of a larger quantity of clouds over central China reflects a greater amount of solar radiation back into space. The vertical gradients of upward shortwave radiative fluxes in the atmosphere below 8 km are greater than those above 8 km. The latitudinal-altitude distributions of downward longwave radiative fluxes show a slantwise decreasing trend from low latitudes to high latitudes that gradually weaken in the downward direction. The upward longwave radiative fluxes also weaken in the upward direction but with larger gradients. The maximum heating rates by solar radiation and cooling rates by longwave infrared radiation are located over 28 40°N at 7 8 km mean sea level (MSL), and they are larger than the rates in the northern and southern regions. The heating and cooling rates match well both vertically and geographically. 展开更多
关键词 radiative flux shortwave heating rate long- wave cooling rate vertical distribution temporal and spatial distribution. CloudSat. Cloud Profilin Radar
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Heat Production Rate Calculation of Thermal Manikin with a Compensation Method
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作者 朱利军 张渭源 +1 位作者 陈文飞 陈景山 《Journal of China Textile University(English Edition)》 EI CAS 2000年第1期79-81,共3页
Thermal manikin plays important roles in simulating thethermal state of human bodies to facilitate the evaluationof thermal comfort properties of various clothing assem-blies.Based on the heat balance principle and an... Thermal manikin plays important roles in simulating thethermal state of human bodies to facilitate the evaluationof thermal comfort properties of various clothing assem-blies.Based on the heat balance principle and analysis ofrelated factors,the heat production rate of manikin isrecommended as an efficient evaluation index.Whereas,its inside heat production which occurs as a result of theexistence of temperature difference between its insidepart and outside surface,should not be ignored.Through a series of theoretical analysis and calculations,a compensative equation is deduced in this paper. 展开更多
关键词 thermal MANIKIN heat balance non - evapora-tive heat loss heat PRODUCTION rate INNER heat PRODUCTION rate CALCULATION compensation.
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Decline of nucleation in the heating process with a high heating rate
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作者 杨高林 林鑫 +3 位作者 宋梦华 胡桥 汪志太 黄卫东 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第8期426-429,共4页
The effect of the heating rate on the nucleation of metallic glass in a rapid heating process starting from the glass transition temperature is investigated. The critical nucleus radius increases with the increase of ... The effect of the heating rate on the nucleation of metallic glass in a rapid heating process starting from the glass transition temperature is investigated. The critical nucleus radius increases with the increase of the temperature of the undercooling liquid. If the increment rate of the critical nucleus radius, owing to the heating process, is higher than the growth rate of the nuclei, the nuclei generated at the low temperature will become the embryos at the high temperature. This means that the high heating rate can make no nucleation happen in the heating process. In consideration of the interfacial energy, the growth rate of the nuclei increases with the increase of their size and the growth rate of the critical nucleus is zero. Thus, the lower heating rate can also make the nuclei decline partially. Finally, this theory is used to analyze the nucleation process during laser remelting metallic glass. 展开更多
关键词 NUCLEATION growth rate heating rate bulk metallic glass
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EFFECT OF HEATING RATE ON THERMO-INDUCED AGGREGATION OF POLY(ETHYLENE OXIDE)-b-POLY(N-ISOPROPYLACRYLAMIDE) IN AQUEOUS SOLUTIONS
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作者 梁德海 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2010年第3期437-447,共11页
The effects of heating rate on the aggregate behavior of poly(ethylene oxide)-b-poly(N-isopropylacrylamide) in aqueous solutions were investigated in detail by laser light scattering and TEM. By employing two sepa... The effects of heating rate on the aggregate behavior of poly(ethylene oxide)-b-poly(N-isopropylacrylamide) in aqueous solutions were investigated in detail by laser light scattering and TEM. By employing two separate heating protocols, step-by-step heating at 〈 5 K/step and one-step jump, to heat the sample from 15℃ to the selected temperature, we found that the heating rate only showed significant effect on the aggregates above the cloud point. The aggregate formed by step-by-step heating exhibited a much larger size and a broader size distribution than those formed by one-step jump heating. Moreover, neither of the aggregates were ideal micellar structures as indicated by the size and the Rg/Rh values. On the contrary, at temperatures below the cloud point where the block copolymer formed core-shelled micelles, the heating rate showed negligible effect on the size and size distribution of the micelles. Since the system underwent a phase separation above the cloud point, the heating rate effect could be reasonably explained by the phase separation mechanisms: the nucleation-and-growth mechanism in the metastable region and the spinodal decomposition mechanism in the unstable region. 展开更多
关键词 heating rate Cloud point Nucleation-and-growth Spinodal decomposition PEO-b-PNIPAm.
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A FINITE-ELEMENT FORMULATION OF HEATING RATE AND SKIN FRICTION ON THE BASIS OF CONSERVAION LAWS
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作者 段占元 童秉纲 姜贵庆 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2000年第2期128-132,共5页
In the framework of the finite element method (FEM), a prediction method for the heating rate and the skin friction on a body surface is presented by using the energy and momentum conservation equations respectively. ... In the framework of the finite element method (FEM), a prediction method for the heating rate and the skin friction on a body surface is presented by using the energy and momentum conservation equations respectively. Meanwhile, a brief analysis is made of the role the weighted functions play in the present work. 展开更多
关键词 conservation equations heating rate skin friction weighted functions
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Effects of the Annealing Heating Rate on Sputtered Aluminum Oxide Films
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作者 唐秀凤 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第1期94-99,共6页
AlxOy films by DC reactive magnetron sputtering were annealed in air ambient at 500 ℃for 1 h with different heating rates of 5,15,and 25 ℃/min.Then heat treatments at 900 ℃ were carried out on these 500 ℃-annealed... AlxOy films by DC reactive magnetron sputtering were annealed in air ambient at 500 ℃for 1 h with different heating rates of 5,15,and 25 ℃/min.Then heat treatments at 900 ℃ were carried out on these 500 ℃-annealed films to simulate the high-temperature application environment.Effects of the annealing heating rate on structure and properties of both 500 ℃-annealed and 900 ℃-heated films were investigated systematically.It was found that distinct γ-Al2O3 crystallization was observed in the 900 ℃-heated films only when the annealing heating rates are 15 and 25 ℃/min.The 500 ℃-annealed film possessed the most compact surface morphology in the case of 25 ℃/min.The highest microhardness of both 500 ℃-annealed and 900℃-heated films were obtained when the annealing heating rate was 15 ℃/min. 展开更多
关键词 aluminum oxide film SPUTTERING annealing heating rate MICROSTRUCTURE
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EXPERIMENTAL STUDY OF MEASUREMENT FOR DISSIPATION RATE SCALING EXPONENT IN HEATED WALL TURBULENCE
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作者 姜楠 王玉春 +1 位作者 舒玮 王振东 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第9期1035-1044,共10页
Experimental investigations have been devoted to the study of scaling law of coarse-grained dissipation rate structure function for velocity and temperature fluctuation of non-isotropic and inhomogeneous turbulent flo... Experimental investigations have been devoted to the study of scaling law of coarse-grained dissipation rate structure function for velocity and temperature fluctuation of non-isotropic and inhomogeneous turbulent flows at moderate Reynolds number. Much attention has been paid to the case of turbulent boundary layer, which is typically the non-istropic and inhomogeneous trubulence because of the dynamically important existence of organized coherent structure burst process in the near wall region . Longitudinal velocity and temperature have been measured at different vertical positions in turbulent boundary layer over a heated and unheated flat plate in a wind tunnel using hot wire anemometer. The influence of non-isotropy and inhomogeneity and heating the wall on the scaling law of the dissipation rate structure function is studied because of the existence of organized coherent structure burst process in the near wall region . The scaling law of coarse-grained dissipation rate structure function is foun 展开更多
关键词 heatING wall turbulence dissipation rate scaling law hierarchical structure model
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