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A Number Theoretic Analysis of the Enthalpy, Enthalpy Energy Density, Thermodynamic Volume, and the Equation of State of a Modified White Hole, and the Implications to the Quantum Vacuum Spacetime, Matter Creation and the Planck Frequency
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作者 Michele Nardelli Amos S. Kubeka Alizera Amani 《Journal of Modern Physics》 2024年第1期1-50,共50页
In this paper, we analyze the enthalpy, enthalpy energy density, thermodynamic volume, and the equation of state of a modified white hole. We obtain new possible mathematical connections with some sectors of Number Th... In this paper, we analyze the enthalpy, enthalpy energy density, thermodynamic volume, and the equation of state of a modified white hole. We obtain new possible mathematical connections with some sectors of Number Theory, Ramanujan Recurring Numbers, DN Constant and String Theory, that enable us to extract the quantum geometrical properties of these thermodynamic equations and the implication to the quantum vacuum spacetime geometry of our early universe as they act as the constraints to the nature of quantum gravity of the universe. 展开更多
关键词 Number Theory Ramanujan Recurring Numbers DN Constant String Theory Loop Quantum Gravity Matter Creation Enthalpy Energy Density Thermodynamic Volume ENTHALPY
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Atmospheric and oceanic responses to Super Typhoon Mangkhut in the South China Sea:a coupled CROCO-WRF simulation 被引量:1
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作者 Mingyu LI Yijun HE Guoqiang LIU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第4期1369-1388,共20页
The South China Sea(SCS)is the largest marginal sea in the Northwest Pacific Ocean,and it encounters frequent typhoons.The atmosphere and ocean will create significant thermal and dynamic responses during the intense ... The South China Sea(SCS)is the largest marginal sea in the Northwest Pacific Ocean,and it encounters frequent typhoons.The atmosphere and ocean will create significant thermal and dynamic responses during the intense disturbance caused by typhoons.However,these responses have not been thoroughly investigated owing to the complicated marine environment.According to the satellite data,the SCS Basin was observed to have a strong sea surface temperature(SST)response to Typhoon Mangkhut,resulting in widespread SST cooling.A coupled model was used to investigate the atmospheric and oceanic responses to Typhoon Mangkhut.Best-track data,satellite SST,and ARGO measurements show that the coupled WRF-CROCO simulation displays better track,intensity,SST,temperature,and salinity profiles than those of the WRF-only simulation.Results show that the typhoon induced rightward intensifications in wind speed,ocean current,and SST.The following are some remarkable atmosphere and ocean responses:(1)the SST below the inner-core region is cooled by 1℃,resulting in a 37%-44%decrease in wet enthalpy,and the central pressure is increased by~9 hPa.Therefore,the changes in SST below the innercore region of the SCS Basin have a significant impact on air-sea fluxes under high-wind conditions;(2)the ocean boundary layer analysis shows that near-inertial oscillations on the right side of the typhoon track and a strong inertial current up to~2.28 m/s in the upper ocean were observed,which resonated with the local wind and flow field on the right side and induced strong SST cooling;(3)a decrease in SST decreased the moist static energy of the typhoon boundary layer,thereby weakening the typhoon’s intensity.The difference in equivalent potential temperature and sea surface pressure have a good correlation,indicating that the influence of moist static energy on typhoon intensity cannot be overlooked. 展开更多
关键词 Super Typhoon Mangkhut coupled ocean-atmosphere model wet enthalpy inertial current
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Design of a graphene oxide@melamine foam/polyaniline@erythritol composite phase change material for thermal energy storage
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作者 Jianhui Zhou Xin Lai +3 位作者 Jianfeng Hu Haijie Qi Shan Liu Zhengguo Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第6期282-290,共9页
At present,only a single modification method is adopted to improve the shortcomings of erythritol(ET)as a phase change material(PCM).Compared with a single modification method,the synergistic effect of multiple modifi... At present,only a single modification method is adopted to improve the shortcomings of erythritol(ET)as a phase change material(PCM).Compared with a single modification method,the synergistic effect of multiple modification methods can endow ET with comprehensive performance to meet the purpose of package,supercooling reduction,and enhancement of thermal conductivity.In this work,we innovatively combine graphene oxide(GO)nanosheet modified melamine foam(MF)and polyaniline(PANI)to construct a novel ET-based PCM by blending and porous material adsorption modification.PANI as the nucleation center can enhance the crystallization rate,thereby reducing the supercooling of ET.Meanwhile,GO@MF foam can not only be used as a porous support material to encapsulate ET but also as a heat conduction reinforcement to improve heat storage and release rate.As a result,the supercooling of GO@MF/PANI@ET(GMPET)composite PCM decreases from 91.2℃ of pure ET to 57.9℃ and its thermal conductivity(1.58 W·m^(-1)·K^(-1))is about three times higher than that of pure ET(0.57 W·m^(-1)·K^(-1)).Moreover,after being placed at 140℃ for 2 h,there is almost no ET leakage in the GMPET composite PCM,and the mass loss ratio is less than 0.75%.In addition,the GMPET composite PCM displays a high melting enthalpy of about 259 J·g^(-1) and a high initial mass loss temperature of about 198℃.Even after the 200th cycling test,the phase transition temperature and the latent heat storage capacity of the GMPET PCM all remain stable.This work offers an effective and promising strategy to design ET-based composite PCM for the field of energy storage. 展开更多
关键词 Composites ENTHALPY Heat conduction NUCLEATION Phase change
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Efficient SO_(2)removal using aqueous ionic liquid at low partial pressure
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作者 Yutong Jiang Yifeng Chen +4 位作者 Fuliu Yang Jixue Fan Jun Li Zhuhong Yang Xiaoyan Ji 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第6期355-363,共9页
The development of novel absorbents is essential for SO_(2)removal.In this study,a novel ionic liquid(IL,[BHEP][HSO_(4)])was prepared,and water was selected as the co-solvent.The density and viscosity of aqueous[BHEP]... The development of novel absorbents is essential for SO_(2)removal.In this study,a novel ionic liquid(IL,[BHEP][HSO_(4)])was prepared,and water was selected as the co-solvent.The density and viscosity of aqueous[BHEP][HSO_(4)]were measured and the SO_(2)absorption performance was systematically investigated.Furthermore,the thermodynamic properties of SO_(2)in aqueous[BHEP][HSO_(4)]were calculated.Additionally,the mechanism of SO_(2)absorption in aqueous[BHEP][HSO_(4)]was confirmed using Fouriertransform infrared and nuclear magnetic resonance spectroscopy.It showed that[BHEP][HSO_(4)]absorbed0.302 g·g^(-1)(g SO_(2)/g IL)at an SO_(2)partial pressure of 2000μl·L^(-1)at 303.2 K,and the SO_(2)desorption enthalpy was-39.63 k J·mol^(-1).The mechanistic study confirmed the chemical absorption of SO_(2)in aqueous[BHEP][HSO_(4)]. 展开更多
关键词 Ionic liquids Sulfur dioxide Absorption capacity Desorption enthalpy
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Impacts of Surface Exchange Coefficients on Simulations of Super Typhoon Megi(2010)Using a Coupled Ocean-Atmosphere-Wave Model
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作者 ZHANG Wenqing ZHANG Jialin +1 位作者 GUAN Changlong SUN Jian 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第3期587-600,共14页
In this study,the effects of surface exchange coefficients on simulations of Super Typhoon Megi(2010)are investigated using a fully coupled ocean-atmosphere-wave model.Several experiments are conducted using different... In this study,the effects of surface exchange coefficients on simulations of Super Typhoon Megi(2010)are investigated using a fully coupled ocean-atmosphere-wave model.Several experiments are conducted using different parameterization schemes for the drag(C_(D))and enthalpy exchange(C_(K))coefficients.For the selected case,considering only the leveling-off of C_(D)at high wind speeds does not effectively improve the simulated typhoon track,intensity,or size.We found that increasing C_(K)monotonically with wind speed(Komori et al.,2018)yields stronger winds and deeper pressures by enhancing latent and sensible heat fluxes,but typhoon intensity remains underestimated.We propose a new higher C_(K)than that from Komori et al.(2018)based on the theory of Emanuel(1995).This approach produces a greater modeled typhoon intensity that is in good agreement with the best track data and effectively improves the track error for the simulation.Improved accuracy for modeled typhoon intensity is achieved with the new coefficient because C_(K)/C_(D)reaches the threshold of about 0.75 predicted by Emanuel(1995).The new proposed C_(K)also results in a reasonably accurate modeled sea surface temperature.However,typhoon size and surface wave height are overestimated.This finding implies that more numerical tests for tropical cyclones of different nature(such as strong,weak,dissipating,rapidly intensifying,or weakening tropical cyclones)should be studied,and more physical processes should be explored in future coupled models. 展开更多
关键词 TYPHOON drag coefficient enthalpy exchange coefficient coupled ocean-atmosphere-wave model
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A group of ductile metallic glasses prepared by modifying local structure of icosahedral quasicrystals
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作者 乔琪 王吉 +5 位作者 蔡正清 冯士东 宋贞强 霍本科 李子敬 王利民 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期550-554,共5页
Inspired by research into the association between icosahedral local orders and the plasticity of metallic glasses(MGs),beryllium(Be) is added to the icosahedral quasi-crystal forming alloy Zr40Ti40Ni20. In this way, b... Inspired by research into the association between icosahedral local orders and the plasticity of metallic glasses(MGs),beryllium(Be) is added to the icosahedral quasi-crystal forming alloy Zr40Ti40Ni20. In this way, bulk metallic glasses(BMGs) with favorable compressive plasticity are fabricated. Therein, the icosahedral quasi-crystalline phase is the main competing phase of amorphous phases and icosahedral local orders are the main local atomic motifs in amorphous phases.The alloys of(Zr40Ti40Ni20)76Be24and (Zr40Ti40Ni20)72Be28with their greater plastic strain capacity show similar characteristics to highly plastic amorphous systems: The serrated flow of compression curves always follows a near-exponential distribution. The primary and secondary shear bands intersect each other, bifurcate, and bend. Typical vein patterns are densely distributed on the fracture surfaces. The relaxation enthalpy of four MGs is linearly correlated with the plastic strain, that is, the greater the relaxation enthalpy, the larger the plastic strain. 展开更多
关键词 metallic glass glass formation compressive plasticity relaxation enthalpy
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Early Detection of Heartbeat from Multimodal Data Using RPA Learning with KDNN-SAE
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作者 A.K.S.Saranya T.Jaya 《Computer Systems Science & Engineering》 SCIE EI 2023年第4期545-562,共18页
Heartbeat detection stays central to cardiovascular an electrocardiogram(ECG)is used to help with disease diagnosis and management.Existing Convolutional Neural Network(CNN)-based methods suffer from the less generali... Heartbeat detection stays central to cardiovascular an electrocardiogram(ECG)is used to help with disease diagnosis and management.Existing Convolutional Neural Network(CNN)-based methods suffer from the less generalization problem thus;the effectiveness and robustness of the traditional heartbeat detector methods cannot be guaranteed.In contrast,this work proposes a heartbeat detector Krill based Deep Neural Network Stacked Auto Encoders(KDNN-SAE)that computes the disease before the exact heart rate by combining features from multiple ECG Signals.Heartbeats are classified independently and multiple signals are fused to estimate life threatening conditions earlier without any error in classification of heart beat.This work contained Training and testing stages,in the preparation part at first the Adaptive Filter Enthalpy-based Empirical Mode Decomposition(EMD)is utilized to eliminate the motion artifact in the signal.At that point,the robotic process automation(RPA)learning part extracts the effective features are extracted,and normalized the value of the feature then estimated utilizing the RPA loss function.At last KDNN-SAE prepared training for the data stored in the dataset.In the subsequent stage,input signal compute motion artifact and RPA Learning the evaluation part determines the detection of Heartbeat.So early diagnosis of heart failures is an essential factor.The results of the experiments show that our proposed method has a high score outcome of 0.9997.Comparable to the CIF,which reaches 0.9990.The CNN and Artificial Neural Network(ANN)had less score 0.95115 and 0.90147. 展开更多
关键词 Deep neural network krill herd optimization stack auto-encoder adaptive filter enthalpy based empirical mode decomposition robotic process automation
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Modified White Hole Enthalpy Coupled to Quantum Bose-Einstein Condensate at Extremely Low Entropy
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作者 Amos S. Kubeka Alireza Amani Mantile Lekala 《Journal of Modern Physics》 2023年第12期1587-1599,共13页
We model the universe as a white hole, and in the process we perform detailed analysis of the enthalpy equation of the modified white hole, and we get a much detailed picture of when and how did;quantum gravity (cosmo... We model the universe as a white hole, and in the process we perform detailed analysis of the enthalpy equation of the modified white hole, and we get a much detailed picture of when and how did;quantum gravity (cosmology) phase, inflationary phase, and the acceleration phase of the universe happened. We determine the field equations of the modified white hole and evolve the scale factor and compare the evolution to the thermodynamic properties of the universe. We also illustrate that the strong energy condition is violated, but both the null energy condition and the strong cosmic censorship are not violated. Lastly, we couple the enthalpy to the Bose-Einstein condensate at extremely low entropy at the quantum gravity (cosmology) regime. Thereafter, we determine the unstable condition of the Bose-Einstein quantum equation which we interpret as the moment when the big bang occurred. 展开更多
关键词 Modified White Hole Quantum Bose-Einstein Condensate Enthalpy Energy Density Stability Analysis Strong Cosmic Censorship
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Formation condition of solid solution type high-entropy alloy 被引量:22
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作者 任明星 李邦盛 傅恒志 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第4期991-995,共5页
Formation condition of high-entropy alloys with solid solution structure was investigated. Seventeen kinds of the high-entropy alloys with different components were prepared, the influencing factors (the comprehensiv... Formation condition of high-entropy alloys with solid solution structure was investigated. Seventeen kinds of the high-entropy alloys with different components were prepared, the influencing factors (the comprehensive atomic radius difference δ, the mixing enthalpy AH and the mixing entropy AS) of phase composition of the alloys were calculated, and the microstructure and phase compositions of alloys were analyzed by using SEM and XRD. The result shows that only the systems with δ≤2.77 and △H≥-8.8 kJ/mol will form high entropy alloy with simple solid solution. Otherwise, intermetallic compounds will exist in the alloys. So, selection of the type of element has important effects on microstructure and properties of high entropy alloys. 展开更多
关键词 high entropy alloy solid solution comprehensive atomic radius difference mixing enthalpy formation condition
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Theoretical Study of the C-CI Bond Dissociation Enthalpy and Electronic Structure of Substituted Chlorobenzene Compounds 被引量:1
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作者 张瑞州 李小红 张现周 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第3期235-240,339,共7页
Quantum chemical calculations were used to estimate the bond dissociation energies (BDEs) for 13 substituted chlorobenzene compounds. These compounds were studied by the hybrid density functional theory (B3LYP, B3P... Quantum chemical calculations were used to estimate the bond dissociation energies (BDEs) for 13 substituted chlorobenzene compounds. These compounds were studied by the hybrid density functional theory (B3LYP, B3PW91, B3P86) methods together with 6-31G^** and 6-311G^** basis sets. The results show that B3P86/6-311G^** method is the best method to compute the reliable BDEs for substituted chlorobenzene compounds which contain the C-C1 bond. It is found that the C-C1 BDE depends strongly on the computational method and the basis sets used. Substituent effect on the C-C1 BDE of substituted chlorobenzene compounds is further discussed. It is noted that the effects of substitution on the C-C1 BDE of substituted chlorobenzene compounds are very insignificant. The energy gaps between the HOMO and LUMO of studied compounds estimate the relative thermal stability ordering are also investigated and from this data we of substituted chlorobenzene compounds. 展开更多
关键词 Density functional theory Bond dissociation enthalpy Substituent effect Substituted chlorobenzene compound
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探讨用差示扫描量热法(DSC)测量相变材料相变温度和相变焓 被引量:17
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作者 张玉辉 刘海波 赵丰东 《中国建材科技》 2006年第4期35-37,共3页
在规定的气体环境及程序温度的控制下,测量输入到试样和参比样的热流速率差随温度和/或时间变化的关系,得到DSC特征曲线,分析得出相变材料的熔融、结晶温度,通过热流速率对时间的积分,测得相变材料的熔融焓变和结晶焓变。
关键词 相变材料(Phase CHANGE Material) 差示扫描量热法(Differential Scanning Calorimeter) 熔融温度(fusion temperature) 结晶温度(crystaUization temperature) 相变焓(enthalpy of PHASE change)
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Application of Microcalorimetric Technique for the Screening and Examination of Medicines
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作者 张有民 王保怀 《Journal of Chinese Pharmaceutical Sciences》 CAS 1993年第1期24-32,共9页
According to the heating effect caused by interaction between matters,a series of experiments on the interaction between drugs and cells from human bodies,DNA and physiological saline have been carried out with a MS-8... According to the heating effect caused by interaction between matters,a series of experiments on the interaction between drugs and cells from human bodies,DNA and physiological saline have been carried out with a MS-80 standard Calvet microcalorimeter.The experiments include: (1) Thermokinetic studies of the effect of anticancer drugs [sodium norcantharidate (ASN),the bioac- tire materials (Sp.P and Sp.S) from algae etc.]on the cancer cells [Hela,human breast carcinoma (Bcap-37),human adenocarcinoma gastric cells (SGc-7901 and MCF-7) etc.] and the normal cells from human bodies [diploid fibroblasts from human fetal lung (2BS) etc.] at 310.15 K:(2) Studies of the in- tercalation binding of some alkaloidal drugs with the bioactivity to inhibit monoamine oxidase (harmalinc and harmine etc.) to call thymus DNA in neutral aqueous solution at 298.15 K:(3) Studies of the interaction between long acting drugs (long acting oral contraceptive-norgestrel etc.) and slow- releasing drug (Contac) and aqueous solution of 0.9% NaCI at 310.15 K.All the experimental results have given their characteristic thermograms and the interaction enthalpy changes.On the analysis of all the results,the authors put forward a method on application of microcalorimetric technique for screen- ing and examination of medicines.The principle of application and the experimental operation of this method have been expounded,and some results of the above experiments have been discussed.As one of the methods for screening and examining medicines,the microcalorimctric method has some distin- guished features and advantages over other methods. 展开更多
关键词 Anticancer drug CELL DNA Thermogram Enthalpy change
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Linear correlations of formation enthalpies/bulk modules and atomic volumes observed in Pt-Zr compounds by ab initio calculation 被引量:2
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作者 白雪 李家好 +1 位作者 戴叶 柳百新 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第12期3704-3713,共10页
118 kinds of Pt-Zr phases were established and investigated by considering various structures. Then the related physical properties, such as structural stability, lattice constants, formation enthalpies, elastic const... 118 kinds of Pt-Zr phases were established and investigated by considering various structures. Then the related physical properties, such as structural stability, lattice constants, formation enthalpies, elastic constants and bulk moduli, are obtained by ab initio calculations. Based on the calculated results of formation enthalpies, the ground-state convex hull is derived for the Pt-Zr system. The calculated physical data would provide a basis for further thermodynamic calculations and atomistic simulations. For these Pt-Zr compounds, it is found there are a positive linear correlation between the formation enthalpies and atomic volumes, and a negative linear correlation between the bulk modules and atomic volumes. 展开更多
关键词 Pt-Zr system thermal properties elastic property ab initio calculations formation enthalpy bulk module atomic volume
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Density Functional Theory Calculations on Ni-Ligand Bond Dissociation Enthalpies
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作者 王冰 傅尧 +1 位作者 于海珠 石景 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第6期640-646,I0003,共8页
The formation and breaking of Ni-L (L=N-heterocyclic carbene, tertiary phosphine etc.) bond is involved in many Ni-catalyzed/mediated reactions. The accurate prediction of Ni-L bond dissociation enthalpies (BDEs) ... The formation and breaking of Ni-L (L=N-heterocyclic carbene, tertiary phosphine etc.) bond is involved in many Ni-catalyzed/mediated reactions. The accurate prediction of Ni-L bond dissociation enthalpies (BDEs) is potentially important to understand these Ni-complex involving reactions. We assess the accuracy of diffierent DFT functionals (such as B3LYP, M06, MPWB1K, etc.) and diffierent basis sets, including both effective core potentials for Ni and the all electron basis sets for all other atoms in predicting the Ni-L BDE values reported recently by Nolan et al. [J. Am. Chem. Soc. 125, 10490 (2003) and Organometallics 27, 3181 (2008)]. It is found that the MPWB1K/LanL2DZ:6-31+G(d,p)//MPWB1K/LanL2DZ:6-31G(d) method gives the best correlations with the experimental results. Meanwhile, the solvent effect calculations (with CPCM, PCM, and SMD models) indicate that both CPCM and PCM perform well. 展开更多
关键词 Density functional theory Ni complex Bond dissociation enthalpy
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Kinetics of forward extraction of Ti(IV) from H_2SO_4 medium by P_(507) in kerosene using the single drop technique 被引量:8
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作者 ZHU Ping HONG Dai WU Jinhua QIAN Guangren 《Rare Metals》 SCIE EI CAS CSCD 2011年第1期1-7,共7页
The kinetics of forward extraction of Ti(IV) from H2SO4 medium by P507 in kerosene has been investigated using the single drop technique.In the low concentration region of Ti(IV),the rate of forward extraction at ... The kinetics of forward extraction of Ti(IV) from H2SO4 medium by P507 in kerosene has been investigated using the single drop technique.In the low concentration region of Ti(IV),the rate of forward extraction at 298 K can be represented by F(kmol·m-2·s-1)=10-5.07 [TiO 2 + ][H+]-1 [NaHA 2 ](o)·Analysis of the rate expression reveals that the rate determining step is(TiO)(i)2+ +(HA 2)(i)-[TiO(HA2)](i)+.The values of Ea,H±,S±,and G±298 are calculated to be 22 kJ·mol-1,25 kJ·mol-1,-218 J·mol-1·K-1,and 25 kJ·mol-1,respectively.The experimental negative S± values indicate that the reaction step occurs via SN2 mechanism. 展开更多
关键词 TITANIUM solvent extraction reaction kinetics activation energy ENTHALPY ENTROPY
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A Rapid Analysis Tool for Aerodynamics/Aerothermodynamics of Hypersonic Vehicles 被引量:8
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作者 Li Zhengzhou Xiao Tianhang +3 位作者 Lü Fanxi Yu Xiongqing Zhang Zhenming Du Sha 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2017年第4期398-404,共7页
A rapid engineering surface panel method to analyze aerodynamics and aerothermodynamics of hypersonic vehicles is developed.To obtain the surface pressure distribution of a hypersonic vehicle,the local surface inclina... A rapid engineering surface panel method to analyze aerodynamics and aerothermodynamics of hypersonic vehicles is developed.To obtain the surface pressure distribution of a hypersonic vehicle,the local surface inclination method is applied to calculate the pressure coefficient for each surface panel element,of which the normal vector is corrected first by using an efficient data structure and Rey-casting algorithm,local Reynolds numbers are calculated according to the geometric streamline method,then the aerodynamic heating flux is computed by both reference enthalpy relations and Reynolds analogy method.Several typical test cases are performed and the results indicate that,the developed tool is effective in predicting the aerodynamics/aerothermodynamics for complex geometry of hypersonic vehicle in a wide range of Mach numbers with a sufficient accuracy. 展开更多
关键词 HYPERSONIC AERODYNAMICS AEROTHERMODYNAMICS engineering prediction reference enthalpy relation Reynolds analogy
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Heat stress management in underground mines 被引量:6
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作者 Ryan Anderson Euler De Souza 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第4期651-655,共5页
Heat management must be maintained within the mine working environment to minimize stress on equipment and personnel. The issue is a growing concern as mines continue to expand in size, depth and infrastructure. Heat ... Heat management must be maintained within the mine working environment to minimize stress on equipment and personnel. The issue is a growing concern as mines continue to expand in size, depth and infrastructure. Heat management is a concern as it relates to both heat sensitive equipment and more importantly the health and safety of the workers found within the mine. Proper application of engineering protocols and work practice controls will have a direct impact on the health and safety of workers and increased productivity. Using continuous monitoring stations placed in strategic locations throughout the mine to capture the environmental conditions, various strategies can be used in the planning and prevention of potential hazard exposure. Economic analysis is used to select the most feasible strategy for heat stress control. This paper presents a step by step methodology that may be considered by ventilation specialists to effectively implement a heat management control system. A case study based on a detailed heat management assessment conducted for a potash mine in Saskatchewan, Canada is presented. 展开更多
关键词 HEAT MANAGEMENT ENTHALPY MINE Environment monitoring
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Batch studies of adsorption of copper and lead on activated carbon from Eucalyptus camaldulensis Dehn. bark 被引量:6
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作者 Phussadee Patnukao Apipreeya Kongsuwan Prasert Pavasant 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第9期1028-1034,共7页
Powdered activated carbon (PAC) prepared from Eucalyptus camaldulensis Dehn. bark was tested for its adsorption capacity for Cu(Ⅱ) and Pb(Ⅱ). The experiment was conducted to investigate the effects of pH, contact ti... Powdered activated carbon (PAC) prepared from Eucalyptus camaldulensis Dehn. bark was tested for its adsorption capacity for Cu(Ⅱ) and Pb(Ⅱ). The experiment was conducted to investigate the effects of pH, contact time, initial metal concentration, and temperature. The best adsorption of both Cu(Ⅱ) and Pb(Ⅱ) occurred at pH 5, where the adsorption reached equilibrium within 45 min for the whole range of initial heavy metal concentrations (0.1-10 mmol/L). The adsorption kinetics was found to follow the pseudo-... 展开更多
关键词 heavy metal removal ISOTHERM kinetics enthalpy of adsorption SORPTION
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Theoretical Calculation Model of Heat Transfer for Deep-derived Supercritical Fluids with a Case Study 被引量:6
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作者 HUWenxuan JINZhijun +2 位作者 SONGYucai SUNRui DUANZhenhao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第1期221-229,共9页
Based on a set of equations established by Duan et al. (1992, 1996) for a geofluid system H2O-CO2-CH4(-N2), a formula is obtained to calculate the heat changes. Combining the geological T-P conditions (geothermal grad... Based on a set of equations established by Duan et al. (1992, 1996) for a geofluid system H2O-CO2-CH4(-N2), a formula is obtained to calculate the heat changes. Combining the geological T-P conditions (geothermal gradients and lithostatic and hydrostatic pressures), the enthalpy of some typical geofluids is figured out. Then the principles of heat transfer of deep-derived supercritical fluids are discussed. The result shows that deep-derived geofluids can bring a large amount of thermal heat and release most heat to the shallow surroundings as they move up, because the molar enthalpies vary very greatly from the deep to shallow, increasing with the increases of T and P. Generally, more than tens of kilojoules heat per molar can be released. Furthermore, the molar enthalpy is affected by the compositions of the geofluids, and the molar enthalpy of CO2, CH4, or N2 is greater than that of H2O, being twice, more than twice, and about 140% of H2O, respectively. Finally, a case study is conducted by investigating a source rock sequence affected hydrothermally by magmatic fluids in the Huimin depression of Shengli Oilfield. The thermal heat calculated theoretically of the fluids related to a diabase intrusion is quite large, which can increase the temperature near the diabase to about 300℃, and that can, to some extent, account for the abnormal rise of the vitrinite reflectance, with the highest of about 3.8% (Ro). 展开更多
关键词 heat transfer ENTHALPY theoretical calculation deep-derived fluids a case study
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A general thermodynamic model for the long-period stacking ordered phases in magnesium alloys 被引量:5
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作者 Kai Xu Shuhong Liu +3 位作者 Keke Chang Yongpeng Liang Yong Du Zhanpeng Jin 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2021年第1期144-155,共12页
A thermodynamic model Mg x(Xs,Mg)6(Xl,Mg)8(Xs and Xl are elements smaller and larger than Mg)for long-period stacking ordered phases(LPSOs)was proposed based on two key factors:the Xs 6 Xl 8-type L12 clusters and the ... A thermodynamic model Mg x(Xs,Mg)6(Xl,Mg)8(Xs and Xl are elements smaller and larger than Mg)for long-period stacking ordered phases(LPSOs)was proposed based on two key factors:the Xs 6 Xl 8-type L12 clusters and the variation of chemical compositions.In general,all available LPSOs can be described with this model.As a representative system,Mg-Y-Zn with three LPSOs was investigated using the CALPHAD(calculation of phase diagram)approach aided with first-principles calculations.Two new three-phase equilibria were predicted and were validated by key experiments.The model-based descriptions will be the basis for the research and development of magnesium alloys. 展开更多
关键词 LPSOs Thermodynamic model Formation enthalpy CALPHAD SOLIDIFICATION
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