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气象观测场在汽车试验场中的应用研究
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作者 陈海建 《时代汽车》 2024年第14期172-174,178,共4页
汽车试验场作为汽车开展道路测试的重要场所,用于验证汽车产品的品质以及可靠性。除了场地道路外,气象条件作为汽车道路测试的重要一环,在《GB/T12534-1990汽车道路试验方法通则》中也有明确要求,如:试验时应是无雨无雾天气,相对湿度小... 汽车试验场作为汽车开展道路测试的重要场所,用于验证汽车产品的品质以及可靠性。除了场地道路外,气象条件作为汽车道路测试的重要一环,在《GB/T12534-1990汽车道路试验方法通则》中也有明确要求,如:试验时应是无雨无雾天气,相对湿度小于95%,气温0-40℃,风速不大于3m/s。同时气象条件也作为试验场道路管控的重要依据,实时风速、雨量、能见度等信息为场地管理者发布限速、限行、封场等通知提供必要参考依据,直接影响道路测试安全管控的及时性。因此,文章从气象观测场的建设、气象服务、异常天气道路管控等方面开展气象观测场在汽车试验场中的应用研究。 展开更多
关键词 products. In addition to the SITE roads METEOROLOGICAL conditions are an important part of AUTOMOTIVE ROAD testing and there are also clear requirements in the GB/T12534-1990 General Rules for AUTOMOTIVE ROAD Test Methods. For example the test should be conducted in rain and fog free weather with a relative humidity of less than 95% a temperature of 0-40 and a wind SPEED of no more than 3m/s. At the same time METEOROLOGICAL conditions also serve as an important basis for ROAD control in the test site. Real time information such as wind SPEED rainfall and visibility provides necessary reference for SITE managers to issue notices on SPEED limits SITE closures and trac restrictions directly aecting the timeliness of ROAD testing safety control. Therefore this article conducts research on the application of METEOROLOGICAL observation SITES in AUTOMOTIVE testing SITES from the construction of METEOROLOGICAL observation SITES METEOROLOGICAL services and abnormal weather ROAD control.
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Pt-Al<sub>2</sub>OM<sub>3</sub>Composite Material Designed for Cyclic Production of Optical Glasses under High Temperature Conditions
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作者 Aleksandr Bochegov Aleksandr Ermakov Irina Vandysheva 《Journal of Materials Science and Chemical Engineering》 2014年第3期30-36,共7页
The article considers one of the possible approaches to the solution of an urgent issue of metal consumption reduction, increase of operating life and maximum operating temperature as well as reduction of irrecoverabl... The article considers one of the possible approaches to the solution of an urgent issue of metal consumption reduction, increase of operating life and maximum operating temperature as well as reduction of irrecoverable losses of platinum products and alloys when operating under high temperature conditions, particularly for glassblowing and single crystal growing crucibles. A two-layered composite material based on platinum-group metals and corundum plasma ceramics is thoroughly investigated. A successful experience of crucibles exploitation, designed for production of high temperature optical glasses from the composite and results of the research on composite material specimens are described. 展开更多
关键词 Sandwich-Structured Composite Material Plasmaceramics Platinum-Group Metals Reduction of Metal Consumption Crucibles for Glassblowing and Single Crystal Growing HIGH temperature Creep HIGH temperature Strength and Heat Resistance Irrecoverable Losses
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Oxidation Kinetics of Aluminum Powders in a Gas Fluidized Bed Reactor in the Potential Application of Surge Arresting Materials
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作者 Hong Shih 《Materials Sciences and Applications》 2019年第3期253-292,共40页
In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arre... In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arresting materials are discussed. Theoretical calculations of oxidation of spherical aluminum powders in a typical gas fluidization bed are demonstrated. Computer software written by the author is used to carry out the basic calculations of important parameters of a gas fluidization bed at different temperatures. A mathematical model of the dynamic system in a gas fluidization bed is developed and the analytical solution is obtained. The mathematical model can be used to estimate aluminum oxide thickness at a defined temperature. The mathematical model created in this study is evaluated and confirmed consistently with the experimental results on a gas fluidization bed. Detail technical discussion of the oxidation mechanism of aluminum is carried out. The mathematical deviations of the mathematical modeling have demonstrated in great details. This mathematical model developed in this study and validated with experimental results can bring a great value for the quantitative analysis of a gas fluidization bed in general from a theoretical point of view. It can be applied for the oxidation not only for aluminum spherical powders, but also for other spherical metal powders. The mathematical model developed can further enhance the applications of gas fluidization technology. In addition to the development of mathematical modeling of a gas fluidization bed reactor, the formation of oxide film through diffusion on both planar and spherical aluminum surfaces is analyzed through a thorough mathematical deviation using diffusion theory and Laplace transformation. The dominant defects and their impact to oxidation of aluminum are also discussed in detail. The well-controlled oxidation film on spherical metal powders such as aluminum and other metal spherical powders can potentially become an important part of switch devices of surge arresting materials, in general. 展开更多
关键词 Aluminum Spherical Power GAS FLUIDIZATION Bed Oxidation Mechanism Oxide Growth Rate Gibbs Free Energy Ellingham Diagram Mathematical Modeling Dynamic System Plasma DIFFUSION DIFFUSION Coefficient Crystallographic Defect Vacancy Pressure temperature Flow Laplace Transform Equation Boundary Condition Ficks Second Law Software Experimental Theoretical SURGE ARRESTING MATERIALS Analytical Solution
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The assessment of time dependent flow of Williamson fluid with radiative blood flow against a wedge
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作者 K.Subbarayudu S.Suneetha P.Bala Anki Reddy 《Propulsion and Power Research》 SCIE 2020年第1期87-99,共13页
The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic Williamson fluid model.Assuming the flow is unsteady and blood is treated as Williamson fluid over a we... The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic Williamson fluid model.Assuming the flow is unsteady and blood is treated as Williamson fluid over a wedge with radiation.The governing equations are transformed into ordinary differential equations by using similarity variables.The analytical solutions of the transformed governing equations are obtained by using the RK 4th order method along with shooting technique solver.The effects of various physical parameters such as Hartmann number,local Weissenberg number,radiation parameter,unsteadiness parameter,Prandtl number,Lewis number,Brownian diffusion,thermophoresis,wedge angle parameter,moving wedge parameter,on velocity,temperature,concentration,skin friction,heat transfer rate and mass transfer rate have been discussed in detail.The velocity and temperature profile deprives for larger We and an opposite trend is observed for concentration.The radiation parameter is propositional to temperature and a counter behaviour is observed for Pr. 展开更多
关键词 The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic WILLIAMSON fluid model. Assuming the flow IS unsteady and blood IS treated as WILLIAMSON fluid over a WEDGE with radiation. The governing EQUATIONS are transformed into ordinary differential EQUATIONS by using similarity variables. The analytical solutions of the transformed governing EQUATIONS are obtained by using the RK 4th order method along with shooting technique solver. The effects of various physical parameters such as Hartmann NUMBER local Weissenberg NUMBER radiation PARAMETER unsteadiness PARAMETER Prandtl NUMBER Lewis NUMBER Brownian diffusion thermophoresis WEDGE angle PARAMETER moving WEDGE PARAMETER on velocity temperature concentration skin friction heat transfer rate and mass transfer rate have been discussed in detail. The velocity and temperature profile deprives for larger We and an opposite trend IS observed for concentration. The radiation PARAMETER IS propositional to temperature and a counter behaviour IS observed for Pr.
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温度和热驯化对胡氏大生熊虫运动行为的影响 被引量:4
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作者 李晓晨 王立志 《动物学报》 SCIE CAS CSCD 北大核心 2005年第3期516-520,共5页
The beneficial acclimation hypothesis (BAH) predicts that animals acclimated to a particular temperature have enhanced performance or fitness at that temperature in comparison with animals acclimated to other temperat... The beneficial acclimation hypothesis (BAH) predicts that animals acclimated to a particular temperature have enhanced performance or fitness at that temperature in comparison with animals acclimated to other temperatures. The BAH has been tested by a variety of empirical examinations, and was rejected by some of them. In order to provide new evidences for the BAH, the effects of acute and acclimation temperature (AT) on locomotor performance of Macrobiotus hufelandi (Tardigrada: Macrobiotidae) were investigated. The tardigrades were collected from Nanwutai, Qinling Mountains which traverse from west to east in central China. The subjects were acclimated to either 2℃ or 22℃ for 2 weeks. The animal was transferred onto a frosted slide and allowed to walk freely at the performance temperature (PT) 2℃ or 22℃. Only one individual was tested per test bout, which lasted from three to five minutes. To avoid occurrence of thermal acclimation effect, the standard adaptation time was limited to 1.5 min. Each subject was tested for once at the same PT, and was tested only at one PT. A total of 25 individuals were tested and measured at the same PT. The locomotor performance of the animals was recorded with a digital video camera mounted on a microscope at 4×10 amplification and replayed on a PC. Every subject was identified. Walking speed (WS) and percentage of time moving (PTM) at both PTs (2℃ or 22℃) were selected as the rate parameters of locomotor performance. The two-way repeated measures ANOVA with a significance level of α= 0.05 and Duncan multiple range test were used to analyze the data. WS of the animals acclimated to and tested at the same temperatures was significantly faster than that for animals acclimated to and tested at the different temperatures, similarly, PTM of the animals acclimated to 22℃ and tested at 22℃ was significantly greater than PTM of animals acclimated to 22℃ and tested at 2℃, which indicated that the animals acclimated to a particular temperature have enhanced locomotor performance in that temperature relative to the animals acclimated to that temperature in other thermal environment. WS of the animals acclimated to 22℃ and tested at 22℃ was significantly faster than WS of animals acclimated to 2℃ and tested at 22℃, PTM of the animals acclimated to 22℃ and tested at 22℃ was significantly greater than PTM of animals acclimated to 2℃ and tested at 22℃. These results supported the BAH. It could be concluded that the PT and thermal acclimation as well as the interaction between the PT and AT significantly influence the locomotor performance of M.hufelandi, and that, despite the existence of a few results of this study that don’t support the BAH, some results of this study support for this hypothesis, and that the animals acclimated to a particular temperature have enhanced locomotor performance in that temperature relative to the animals acclimated to that temperature in other thermal environment, implying that any performance temperature that deviates from the acclimation temperature could cause the reduction of the walking speed which is closely related to the fitness of the M.hufelandi. 展开更多
关键词 standard performa multiple effects central digital speed with camera the was test time The slide total video level range PTM east WALK one at in new PTS be
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Augmenting the Heat Sink for Better Heat Dissipation
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作者 Mohammed H. S. Al Ashry 《Circuits and Systems》 2015年第2期21-29,共9页
Heat sinks were invented to absorb heat from an electronic circuit conduct, and then to dissipate or radiate this heat to the surrounding supposedly, ventilated space, at a rate equal to or faster than that of its bui... Heat sinks were invented to absorb heat from an electronic circuit conduct, and then to dissipate or radiate this heat to the surrounding supposedly, ventilated space, at a rate equal to or faster than that of its buildup. Ventilation was not initially recognized as an essential factor to thermal dispersion. However, as electronic circuit-boards continued to heat up, circuit failure became a problem, forcing the inclusion of miniaturized high speed fans. Later, heat sinks with fins and quiet fans were incorporated in most manufactured circuits. Now heat sinks come in the form of a fan with fans made to function as fins to disperse heat. Heat sinks absorb and radiate excess heat from circuit-boards in order to prolong the circuit’s life span. The higher the thermal conductivity of the material used the more efficient and effective the heat sink is. This paper is an attempt to theoretically design a heat sink with a temperature gradient lower than that of the circuit board’s excess heat. 展开更多
关键词 CONVECTIVE HEAT Transfer: HEAT Absorbed by the Natural AIR Flow Surrounding Hot Objects FORCED CONVECTIVE HEAT Transfer: Absorption of HEAT Using FORCED AIR Flow Conductivity: Is the Ability of a System to Exchange or TRANSFER temperature within a Body or MATERIAL through the Movement of Electrons MATERIAL That Does Not Conduct HEAT Is Considered a Nonconductor
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Co-variation of the surface wind speed and the sea surface temperature over mesoscale eddies in the Gulf Stream region:momentum vertical mixing aspect
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作者 HE Jingjing LIN Xiaopei 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第4期1154-1164,共11页
The co-variation of surface wind speed and sea surface temperature (SST) over the Gulf Stream frontal region is investigated using high-resolution satellite measurements and atmospheric reanalysis data. Results show t... The co-variation of surface wind speed and sea surface temperature (SST) over the Gulf Stream frontal region is investigated using high-resolution satellite measurements and atmospheric reanalysis data. Results show that the pattern of positive SST-surface wind speed correlations is anchored by strong SST gradient and marine atmospheric boundary layer (MABL) height front, with active warm and cold-ocean eddies around. The MABL has an obvious transitional structure along the strong SST front, with greater (lesser) heights over the north (south) side. The significant positive SST-surface wind-speed perturbation correlations are mostly found over both strong warm and cold eddies. The surface wind speed increases (decreases) about 0.32 (0.41) m/s and the MABL elevates (drops) approximate 55 (54) m per 1℃ of SST perturbation induced by warm (cold) eddies. The response of the surface wind speed to SST perturbations over the mesoscale eddies is mainly attributed to the momentum vertical mixing in the MABL, which is confirmed by the linear relationships between the downwind (crosswind) SST gradient and wind divergence (curl). 展开更多
关键词 GULF Stream positive sea SURFACE temperature (SST)-surface wind speed correlation marine atmospheric boundary layer (MABL) height MESOSCALE EDDY MOMENTUM vertical mixing
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Theory and Application of Numerical Simulation of Chemical Flooding in High Temperature and High Salt Reservoirs
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作者 Yirang Yuan Aijie Cheng +1 位作者 Danping Yang Changfeng Li 《International Journal of Geosciences》 2014年第9期956-970,共15页
Applications, theoretical analysis and numerical methods are introduced for the simulation of mechanical models and principles of the porous flow in high temperature, high salt, complicated geology and large-scale res... Applications, theoretical analysis and numerical methods are introduced for the simulation of mechanical models and principles of the porous flow in high temperature, high salt, complicated geology and large-scale reservoirs in this paper. Considering petroleum geology, geochemistry, computational permeation fluid mechanics and computer technology, we state the models of permeation fluid mechanics and put forward a sequence of implicit upwind difference iteration schemes based on refined fractional steps of the upstream, which can compute the pressures, the saturation and the concentrations of different chemistry components. A type of software applicable in major industries has been completed and carried out in numerical analysis and simulations of oil extraction in Shengli Oil-field, which brings huge economic benefits and social benefits. This software gives many characters: spatial steps are taken as ten meters, the number of nodes is up to hundreds of thousands and simulation time period can be tens of years and the high-order accuracy can be promised in numerical data. Precise analysis is present for simplified models of this type and that provides a tool to solve the international famous problem. 展开更多
关键词 HIGH temperature and HIGH SALT COMPLICATED Chemical FLOODING Computational PERMEATION Fluid Mechanics Numerical Method and Engineering Software Actual Application of Oil-Fields Theoretical Analysis
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耐高温起泡剂膦甲基酚醛树脂PMP的合成及性能 被引量:1
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作者 何耀春 黄步耕 侯士法 《油田化学》 CAS CSCD 北大核心 2004年第4期301-303,306,共4页
由苯酚、甲醛、PCl3合成了水溶性固体膦甲基酚醛树脂(PMP),其HLB值为20 7。简介了合成方法,考察了PMP作为起泡剂的配方性能。PMP溶液室温发泡体积Vf随浓度增大(5~20g/L)而略有增大,泡沫半衰期t1/2在浓度12 5g/L时最长,为20 2min,此时Vf... 由苯酚、甲醛、PCl3合成了水溶性固体膦甲基酚醛树脂(PMP),其HLB值为20 7。简介了合成方法,考察了PMP作为起泡剂的配方性能。PMP溶液室温发泡体积Vf随浓度增大(5~20g/L)而略有增大,泡沫半衰期t1/2在浓度12 5g/L时最长,为20 2min,此时Vf=520mL(/100mL溶液)。在该浓度PMP溶液中分别加入CMC、硅酸钠、三乙醇胺、膨润土使Vf值略降,t1/2值在适宜加量范围大幅延长,加量分别为1 0、2 0、12 5、40g/L时有最大值370 0、85 2、180 2、174 2min;这4个复配PMP/添加剂溶液在温度升高时(30~90℃)Vf值增大但t1/2值大幅缩短。12 5g/LPMP溶液在150~200℃滚动16h后室温下Vf值不变,t1/2值随滚动温度升高而降低,200℃时为11 3min;12 5/2 0/10/40g/LPMP/硅酸钠/三乙醇胺/膨润土溶液在200℃滚动16h后,室温下Vf值为470mL,t1/2值高达50h。PMP为耐高温性能良好的起泡剂,可与硅酸钠、三乙醇胺、膨润土复配使用。图2表4参10。 展开更多
关键词 PMP 2.5g PCl3 HLB 40g f 20g CMC
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Bose–Einstein distribution temperature features of quasiparticles around magnetopolaron in Gaussian quantum wells of alkali halogen ions
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作者 Xin Zhang Sarengaowa +7 位作者 Shuang Han Ran An Xin-Xue Zhang Xin-Ying Ji Hong-Xu Jiang Xin-Jun Ma Pei-Fang Li Yong Sun 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期521-526,共6页
We have applied strong coupling unitary transformation method combined with Bose–Einstein statistical law to investigate magnetopolaron energy level temperature effects in halogen ion crystal quantum wells.The obtain... We have applied strong coupling unitary transformation method combined with Bose–Einstein statistical law to investigate magnetopolaron energy level temperature effects in halogen ion crystal quantum wells.The obtained results showed that under magnetic field effect,magnetopolaron quasiparticle was formed through the interaction of electrons and surrounding phonons.At the same time,magnetopolaron was influenced by phonon temperature statistical law and important energy level shifts down and binding energy increases.This revealed that lattice temperature and magnetic field could easily affect magnetopolaron and the above results could play key roles in exploring thermoelectric conversion and conductivity of crystal materials. 展开更多
关键词 temperature effect quantum well asymmetric GAUSSIAN potential MAGNETOPOLARON
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New Insight to the Surface Temperature of the Sun
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作者 Ryszard Petela 《Energy and Power Engineering》 2024年第8期285-292,共8页
Information is given on thermal radiation from the Sun, considered in practical engineering calculations of heat exchange. It was found that although the surface temperature of the Sun is assumed to be about 5800 K, t... Information is given on thermal radiation from the Sun, considered in practical engineering calculations of heat exchange. It was found that although the surface temperature of the Sun is assumed to be about 5800 K, the solar spectrum data measured by Kondratyev lead to a value of at least 7134 K. Such a higher value can be obtained by interpreting the Planck formula for the black radiation spectrum for the Kondratyev data. In addition, using the Stefan-Boltzmann law, the energetic emissivity of the Sun’s surface was determined to be 0.431. Furthermore, based on Petela’s formulae for exergy of thermal radiation, the exergetic emissivity of the Sun’s surface was also calculated at the level of 0.426. 展开更多
关键词 Thermal Radiation Radiation temperature Surface temperature Surface Emissivity Sun Radiation Spectrum Plank Law Exergy of Radiation Photosphere
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Temperature Effects on the Electrical Performance of Large Area Multicrystalline Silicon Solar Cells Using the Current Shunt Measuring Technique 被引量:1
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作者 Hala Mohamed Abdel Mageed Ahmed Faheem Zobaa +2 位作者 Mohamed Helmy Abdel Raouf Abla Hosni Abd El-Rahman Mohamed Mamdouh Abdel Aziz 《Engineering(科研)》 2010年第11期888-894,共7页
The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shun... The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shunt measuring technique. Therefore, most of the problems encountered with traditional measuring techniques are avoided. The temperature dependency of the current shunt from 5oC up to 50oC has been investigated. Its temperature coefficient proves to be negligible which means that the temperature dependency of the solar cell is completely independent of the current shunt. The solar module installed in a tilted position at the optimum angle of the location, has been tested in two different seasons (winter and summer). The obtained solar cell short circuit current, open circuit voltage and output power are correlated with the measured incident radiation in both seasons and all results are discussed. 展开更多
关键词 Large Area MULTICRYSTALLINE Silicon Solar Cell CURRENT SHUNT Measuring Technique temperature Effects SHORT CIRCUIT CURRENT Open CIRCUIT Voltage Accumulated Power INCIDENT Radiation
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Seasonal influence of freshwater discharge on spatio-temporal variations in primary productivity, sea surface temperature, and euphotic zone depth in the northern Bay of Bengal
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作者 Hafez Ahmad Felix Jose +2 位作者 Md.Simul Bhuyan Md.Nazrul Islam Padmanava Dash 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第6期1-14,共14页
Ocean productivity is the foundation of marine food web,which continuously removes atmospheric carbon dioxide and supports life at sea and on land.Spatio-temporal variability of net primary productivity(NPP),sea surfa... Ocean productivity is the foundation of marine food web,which continuously removes atmospheric carbon dioxide and supports life at sea and on land.Spatio-temporal variability of net primary productivity(NPP),sea surface temperature(SST),sea surface salinity(SSS),mixed layer depth(MLD),and euphotic zone depth(EZD) in the northern B ay of Bengal(BoB) during three monsoon seasons were examined in this study based on remote sensing data for the period 2005 to 2020.To compare the NPP distribution between the coastal zones and open BoB,the study area was divided into five zones(Z1-Z5).Results suggest that most productive zones Z2 and Zl are located at the head bay area and are directly influenced by freshwater discharge together with riverine sediment and nutrient loads.Across Z1-Z5,the NPP ranges from 5 315.38 mg/(m^(2)·d) to 346.7 mg/(m^(2)·d)(carbon,since then the same).The highest monthly average NPP of 5 315.38 mg/(m^(2)·d) in February and 5 039.36 mg/(m^(2)·d) in June were observed from Z2,while the lowest monthly average of 346.72 mg/(m^(2)·d) was observed in March from Z4,which is an oceanic zone.EZD values vary from 6-154 m for the study area,and it has an inverse correlation with NPP concentration.EZD is deeper during the summer season and shallower during the wintertime,with a corresponding increase in productivity.Throughout the year,monthly SST shows slight fluctuation for the entire study area,and statistical analysis shows a significant correlation among NPP,and EZD,overall positive between NPP and MLD,whereas no significant correlation among SSS,and SST for the northern BoB.Long-term trends in SST and productivity were significantly po sitive in head bay zones but negatively productive in the open ocean.The findings in this study on the distribution of NPP,SST,SSS,MLD,and EZD and their seasonal variability in five different zones of BoB can be used to further improve the management of marine resources and overall environmental condition in response to climate changes in BoB as they are of utmost relevance to the fisheries for the three bordering countries. 展开更多
关键词 chlorophyll a sea surface temperature euphotic zone depth primary productivity Ganges-Brahmaputra ocean color Bay of Bengal MONSOON
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Circulation Pattern Controls of Summer Temperature Anomalies in Southern Africa
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作者 Chibuike Chiedozie IBEBUCHI Cameron C.LEE 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第2期341-354,共14页
This study investigates the relationship between circulation patterns and austral summer temperature anomalies in southern Africa. The results show that the formation of continental lows tends to increase the thicknes... This study investigates the relationship between circulation patterns and austral summer temperature anomalies in southern Africa. The results show that the formation of continental lows tends to increase the thickness of the lower atmosphere. Further, the distinct variabilities of high and low pressure under the circulation types, influence air mass advection from the adjacent oceans, as well as atmospheric stability over land. Stronger anticyclonic circulation at the western branch of the Mascarene high-pressure system enhances the low-level cold air advection by southeast winds,decreases the thickness, and lowers the temperature over a majority of the land in southern Africa. Conversely, a weaker Mascarene High, coupled with enhanced cyclonic activity in the southwest Indian Ocean increases low-level warm air advection and increases temperature anomalies over vast regions in southern Africa. The ridging of a closed South Atlantic anticyclone at the southern coast of southern Africa results in colder temperatures near the tip of southern Africa due to enhanced low-level cold air advection by southeast winds. However, when the ridge is weak and westerly winds dominate the southern coast of southern Africa, these areas experience temperature increases. The northward track of the Southern Hemisphere mid-latitude cyclone, which can be linked to the negative Southern Annular Mode, reduces the temperature in the southwestern part of southern Africa. Also, during the analysis period, El Ni?o was associated with temperature increases over the central parts of southern Africa;while the positive Indian Ocean dipole was linked to a temperature increase over the northeastern, northwestern, and southwestern parts of southern Africa. 展开更多
关键词 temperature circulation types Subtropical Indian Ocean dipole Southern Annular Mode El Ni?o Indian Ocean dipole Mascarene High South Atlantic anticyclone
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Spatiotemporal dynamics of land use/land cover(LULC)changes and its impact on land surface temperature:A case study in New Town Kolkata,eastern India
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作者 Bubun MAHATA Siba Sankar SAHU +2 位作者 Archishman SARDAR Laxmikanta RANA Mukul MAITY 《Regional Sustainability》 2024年第2期26-48,共23页
Rapid urbanization creates complexity,results in dynamic changes in land and environment,and influences the land surface temperature(LST)in fast-developing cities.In this study,we examined the impact of land use/land ... Rapid urbanization creates complexity,results in dynamic changes in land and environment,and influences the land surface temperature(LST)in fast-developing cities.In this study,we examined the impact of land use/land cover(LULC)changes on LST and determined the intensity of urban heat island(UHI)in New Town Kolkata(a smart city),eastern India,from 1991 to 2021 at 10-a intervals using various series of Landsat multi-spectral and thermal bands.This study used the maximum likelihood algorithm for image classification and other methods like the correlation analysis and hotspot analysis(Getis–Ord Gi^(*) method)to examine the impact of LULC changes on urban thermal environment.This study noticed that the area percentage of built-up land increased rapidly from 21.91%to 45.63%during 1991–2021,with a maximum positive change in built-up land and a maximum negative change in sparse vegetation.The mean temperature significantly increased during the study period(1991–2021),from 16.31℃to 22.48℃in winter,29.18℃to 34.61℃in summer,and 19.18℃to 27.11℃in autumn.The result showed that impervious surfaces contribute to higher LST,whereas vegetation helps decrease it.Poor ecological status has been found in built-up land,and excellent ecological status has been found in vegetation and water body.The hot spot and cold spot areas shifted their locations every decade due to random LULC changes.Even after New Town Kolkata became a smart city,high LST has been observed.Overall,this study indicated that urbanization and changes in LULC patterns can influence the urban thermal environment,and appropriate planning is needed to reduce LST.This study can help policy-makers create sustainable smart cities. 展开更多
关键词 Urbanization Land use/land cover (LULC)changes Land surface temperature Urban heat island Hotspot analysis Smart city
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Self-Absorption Effects on Electron Temperature-Measurements Utilizing Laser Induced Breakdown Spectroscopy (LIBS)-Techniques 被引量:1
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作者 Shawqi A. M. Mansour 《Optics and Photonics Journal》 2015年第3期79-90,共12页
In the present work, we have studied the temporal evolution of aluminum alloy plasma produced by the fundamental (1064 nm) of a Q-switched Nd:YAG laser by placing the target material in air at atmospheric pressure. Th... In the present work, we have studied the temporal evolution of aluminum alloy plasma produced by the fundamental (1064 nm) of a Q-switched Nd:YAG laser by placing the target material in air at atmospheric pressure. The four Al I-neutral lines at 308.21, 309.27, 394.40 and 369.15 nm as well as Al II-ionic lines at 281.61, 385.64 and 466.30 nm are used for the determination of the electron temperature Te using Saha-Boltzmann plot method. The neutral aluminum lines were found to suffer from optical thickness which manifested itself on the form of scattered points around the Saha-Boltzmann line. The isolated optically thin hydrogen Hα-line at 656.27 nm appeared in the spectra under the same experimental conditions was used to correct the Al I-lines which contained some optical thickness. The measurements were repeated at different delay times ranging from 1 to 5 μs. The comparison between the deduced electron temperatures from aluminum neutral lines before correction against the effect self-absorption to that after correction revealed a precise value in temperature. The results sure that, in case of the presence of self-absorption effect the temperature varies from (1.4067 - 1.2548 eV) as the delay time is varied from 0 to 5 μs. Whereas, in the case of repairing against the effect, it varies from (1.2826 - 0.8961 eV) for the same delay time variation. 展开更多
关键词 Laser Induces Breakdown Spectroscopy (LIBS) SELF-ABSORPTION (SA) Saha-Boltzmann PLOT Delay Time (Td) Electron Number Density (Ne) Plasma temperature (Te)
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沂水杂岩中变泥砂质岩石的岩石化学特征及年代 被引量:10
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作者 赵子然 宋会侠 +1 位作者 沈其韩 宋彪 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第8期1863-1871,共9页
含夕线石十字石榴二云斜长片麻岩是沂水杂岩中首次发现的一种少见的变泥砂质岩石,包裹于沂水牛心官庄岩浆杂岩体中,为残留的变质表壳岩透镜体,它经历了两期变质作用的改造。早期高角闪岩相变质与区域麻粒岩相变质有关,峰期矿物共生组合... 含夕线石十字石榴二云斜长片麻岩是沂水杂岩中首次发现的一种少见的变泥砂质岩石,包裹于沂水牛心官庄岩浆杂岩体中,为残留的变质表壳岩透镜体,它经历了两期变质作用的改造。早期高角闪岩相变质与区域麻粒岩相变质有关,峰期矿物共生组合主要为:石榴子石(中心域)+黑云母±白云母+斜长石+石英,M_1峰期变质温压条件为:T=660±10℃,P=5.7±0.3kb;晚期角闪岩相变质矿物共生组合为:十字石+石榴子石(边部域)+黑云母±白云母+斜长石±夕线石+石英,以形成大量自形-半自形十字石和具有明显的成分环带的石榴子石为特征,晚期石榴子石的形成由核部→边部经历了一降温降压过程,石榴子石核部:T=650±10℃,P=7.7±0.5Kb,石榴子石边部:T=578±10℃,P=4.7±0.1kb;晚期变质作用早期(石榴子石成核)阶段与埋深导致的部分熔融有关,晚期石榴子石生长阶段与岩浆热事件有关。锆石SHRIMP U-Pb定年结果表明:碎屑锆石不一致线上交点年龄为2695±32Ma,代表变泥砂质岩石源区岩浆岩的结晶年龄,变泥砂质岩石的早期变质变质作用年龄小于此值;晚期变质作用年龄为2537±5Ma。 展开更多
关键词 complex supracrustal rock age temperature and pressure related crystallization time GRANULITE FACIES the upper crust partial melting SHRIMP dating
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Resilience of a high latitude Red Sea corals to extreme temperature
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作者 Mohamed Zaki Moustafa Zaki Daniel Moustafa Mary Sue Moustafa 《Open Journal of Ecology》 2013年第3期242-253,共12页
Our research objective was to expand the very limited knowledgebase pertaining to the ecology of fringing coral reefs in the Gulf of Suez, Egypt. Specifically, determine dominant coral species and investigate why this... Our research objective was to expand the very limited knowledgebase pertaining to the ecology of fringing coral reefs in the Gulf of Suez, Egypt. Specifically, determine dominant coral species and investigate why this reef is capable of surviving at such a high-latitude and extreme harsh environment. Data collection included annual reef surveys, randomized quadrat sampling, five permanent video transects and in situ seawater temperature. Of the known Gulf of Suez 35 taxa, only six (Acropora humilis, A. microclados, A. hemprichii, Litophyton arboretum, Stylophora pistillata, Porites columna, and P. plantulata), compose 94% of the reef's coral cover. Coral dominance across species shifted drastically during the study period. However, the six coral dominance remained unchanged, while some decreased others increased. These six coral taxa regularly experience daily changes in seawater temperature and seasonal variations that exceed These extreme temperatures variation and the fact that only six coral taxa dominance remained unchanged, suggest that these corals may have developed a mechanism to cope with extreme seawater temperatures as evidenced by their continued growth and survival over the study period. We speculate that species dominance shift occurred largely as a result of a local oil spill rather than exposure to extreme temperatures. Further scrutiny of these species and the mechanisms by which they are able to thrive is recommended, as they hold the potential to benefit other coral communities as a resilient transplant species and model for understanding coral survivability in extreme environmental conditions. 展开更多
关键词 Red Sea Fringing REEF GULF of Suez CORAL BLEACHING temperature Tolerance MARGINAL REEF Thermal Limits Omponent Formatting Style STYLING Insert
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Anomalously High Conductivity of Deformed Metals at the Positive Temperatures
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作者 Gennady A. Markov Vladimir N. Malyshev 《World Journal of Condensed Matter Physics》 2012年第2期85-90,共6页
The description of experimentally observed phenomenon of abnormally high electrical conductivity—'superconductivity' (SC) at the room and higher temperatures is represented. The effect was observed in metalli... The description of experimentally observed phenomenon of abnormally high electrical conductivity—'superconductivity' (SC) at the room and higher temperatures is represented. The effect was observed in metallic monospirals of small radius curvature with high density and regular distribution of dislocations. Transition into state of SC has been observed experimentally in the range from –50 up to 3000°C at the density of transmitting current up to 2·109 A/cm2. The experimental data confirming the watched phenomenon are represented. The explanations of this phenomenon are being proposed in the framework of the dislocation model. 展开更多
关键词 Metallic Monospirals DISLOCATION DENSITY The Anomalously High Conductivity in Metals-Superconductivity Room and other POSITIVE temperatureS The Velocity of Current DENSITY Growth
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Effect of Lithium Chloride on the Fibre Length Distribution, Processing Temperature and the Rheological Properties of High-Yield-Pulp-Fibre-Reinforced Modified Bio-Based Polyamide 11 Composite
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作者 Robenson Cherizol Mohini Sain Jimi Tjong 《Advances in Nanoparticles》 2017年第2期48-61,共14页
The aim of this work was to investigate the effect of lithium chloride (LiCl) on the fibre length distribution, melting temperature and the rheological characteristics of high yield pulp fibre reinforced polyamide bio... The aim of this work was to investigate the effect of lithium chloride (LiCl) on the fibre length distribution, melting temperature and the rheological characteristics of high yield pulp fibre reinforced polyamide biocomposite. The inorganic salt lithium chloride (LiCl) was used to decrease the melting and processing temperature of bio-based polyamide 11. The extrusion method and Brabender mixer approaches were used to carry out the compounding process. The densities and fibre content were found to be increased after processing using both compounding methods. The HYP fibre length distribution analysis realized using the FQA equipment showed an important fibre-length reduction after processing by both techniques. The rheological properties of HYP-reinforced net and modified bio-based polyamide 11 “PA11” (HYP/PA11) composite were investigated using a capillary rheometer. The rheological tests were performed in function of the shear rate for different temperature conditions. The low-temperature process compounding had higher shear viscosity;this was because during the process the temperature was low and the mixing and melting were induced by the high shear rate created during compounding process. Experimental test results using the extrusion process showed a steep decrease in shear viscosity with increasing shear rate, and this melt-flow characteristic corresponds to shear-thinning behavior in HYP/PA11, and this steep decrease in the melt viscosity can be associated to the hydrolyse reaction of nylon for high pulp fibre moisture content at high temperature. In addition to the low processing temperature, the melt viscosity of the biocomposite using the Brabender mixer approach increases with increasing shear rate, and this stability in the increase even at high shear rate for high pulp moisture content is associated to the presence of inorganic salt lithium chloride which creates the hydrogen bonds with pulp during the compounding process. 展开更多
关键词 HYP/PA11 Melting temperature of NYLON 11 Inorganic Salt Chloride Lithium (Licl) Fibre Aspect Ratio and Length DISTRIBUTION RHEOLOGICAL Characteristic
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