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Energetics of lateral eddy diffusion/advection: Part IV. Energetics of diffusion/advection in sigma coordinates and other coordinates 被引量:1
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作者 HUANG Rui Xin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第3期58-78,共21页
Gravitational potential energy (GPE) source and sink due to stirring and cabbeling associated with sigma dif fusion/ advection is analyzed. It is shown that GPE source and sink is too big, and they are not closely l... Gravitational potential energy (GPE) source and sink due to stirring and cabbeling associated with sigma dif fusion/ advection is analyzed. It is shown that GPE source and sink is too big, and they are not closely linked to physical property distribution, such as temperature, salinity and velocity. Although the most frequently quoted advantage of sigma coordinate models are their capability of dealing with topography; the exces sive amount of GPE source and sink due to stirring and cabbeling associated with sigma diffusion/advec tion diagnosed from our analysis raises a very serious question whether the way lateral diffusion/advection simulated in the sigma coordinates model is physically acceptable. GPE source and sink in three coordinates is dramatically different in their magnitude and patterns. Overall, in terms of simulating lateral eddy diffu sion and advection isopycnal coordinates is the best choice and sigma coordinates is the worst. The physical reason of the excessive GPE source and sink in sigma coordinates is further explored in details. However, even in the isopycnal coordinates, simulation based on the Eulerian coordinates can be contaminated by the numerical errors associated with the advection terms. 展开更多
关键词 energetics of horizontal advection energetics of horizontal eddy diffusion energetics ofisopycnal advection energetics of isopycnal eddy diffusion energetics of sigma advectiondiffusion energetics of sigma eddy diffusion
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Energetics of lateral eddy diffusion/advection: Part III. Energetics of horizontal and isopycnal diffusion/ advection 被引量:2
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作者 HUANG Rui Xin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第3期40-57,共18页
Gravitational Potential Energy (GPE) change due to horizontal/isopycnal eddy diffusion and advection is examined. Horizontal/isopycnal eddy diffusion is conceptually separated into two steps: stirring and sub scale... Gravitational Potential Energy (GPE) change due to horizontal/isopycnal eddy diffusion and advection is examined. Horizontal/isopycnal eddy diffusion is conceptually separated into two steps: stirring and sub scale diffusion. GPE changes associated with these two steps are analyzed. In addition, GPE changes due to stirring and subscale diffusion associated with horizontal/isopycnal advection in the Eulerian coordinates are analyzed. These formulae are applied to the SODA data for the world oceans. Our analysis indicates that horizontal/isopycnal advection in Eulerian coordinates can introduce large artificial diffusion in the model. It is shown that GPE source/sink in isopycnal coordinates is closely linked to physical property distribution, such as temperature, salinity and velocity. In comparison with z-coordinates, GPE source/sink due to stir ring/cabbeling associated with isopycnal diffusion/advection is much smaller. Although isopycnal coordi nates may be a better choice in terms of handling lateral diffusion, advection terms in the traditional Eule rian coordinates can produce artificial source of GPE due to cabbeling associated with advection. Reducing such numerical errors remains a grand challenge. 展开更多
关键词 energetics of horizontal eddy diffusion energetics of horizontal advection energetics ofisopycnal eddy diffusion energetics of isopycnal advection
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The Sigma-1 Receptor as a Pharmacologic Chaperone: Energetics
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作者 Robert B. Raffa Joseph V. Pergolizzi Jr. 《Journal of Biosciences and Medicines》 2024年第8期347-356,共10页
Initially thought to be an opioid receptor subtype, Sigma-1 receptors (S1R) are now known to be unique proteins that have chaperone-like properties. As such, they play critical roles in cellular signaling, homeostasis... Initially thought to be an opioid receptor subtype, Sigma-1 receptors (S1R) are now known to be unique proteins that have chaperone-like properties. As such, they play critical roles in cellular signaling, homeostasis, and cell survival. These roles offer significant insight for understanding homeostasis of normal physiologic processes, and the pathophysiologic consequences of disruption of normal function. Because of the broad nature of chaperone action, S1R agonists and antagonists represent potential drug discovery goals for the pharmacotherapeutic treatment of a variety of disorders that result from dysfunctional proteins. The present study summarizes the S1R as a pharmacologic chaperone crucial for protein folding and cellular homeostasis. Through literature review and thermodynamic analysis, it explores how S1R stabilizes target proteins, influencing neuroprotection and potential drug therapies. The binding of chaperones to target proteins is thermodynamically favorable, offering insights into treating diseases linked to protein misfolding. 展开更多
关键词 CHAPERONE Sigma-1 Receptor energetics THERMODYNAMICS Isothermal Titration Microcalorimetry
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Adsorption/reaction energetics measured by microcalorimetry and correlated with reactivity on supported catalysts: A review 被引量:1
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作者 李林 林坚 +3 位作者 李筱玉 王爱琴 王晓东 张涛 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第12期2039-2052,共14页
The formations and transformations of the chemical bonds of reactants and intermediates on cata- lyst surfaces occur in conjunction with the evolution of heat during catalytic reactions. Measure- ment of this evolved ... The formations and transformations of the chemical bonds of reactants and intermediates on cata- lyst surfaces occur in conjunction with the evolution of heat during catalytic reactions. Measure- ment of this evolved heat is helpful in terms of understanding the nature of the interactions be- tween the catalyst and the adsorbed species, and provides insights into the reactivity of the catalyst. Although various techniques have previously been applied to assessments of evolved heat, direct measurements using a Tian-Calvet microcalorimeter are currently the most reliable method for this purpose. In this review, we summarize the relationship between the adsorption/reaction energetics determined by microcalorimetry and the reactivities of supported catalysts, and examine the im- portant role of microcalorimetry in understanding catalytic performance from the energetic point of view. 展开更多
关键词 Catalysis Microcalorimetry Reactivity energetics Binding strength Catalyst characterization
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Energetics of lateral eddy diffusion/advection: Part I. Thermodynamics and energetics of vertical eddy diffusion 被引量:5
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作者 HUANG Rui Xin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第3期1-18,共18页
Two important nonlinear properties of seawater thermodynamics linked to changes of water density, cab beling and elasticity (compressibility), are discussed. Eddy diffusion and advection lead to changes in den sity;... Two important nonlinear properties of seawater thermodynamics linked to changes of water density, cab beling and elasticity (compressibility), are discussed. Eddy diffusion and advection lead to changes in den sity; as a result, gravitational potential energy of the system is changed. Therefore, cabbeling and elasticity play key roles in the energetics of lateral eddy diffusion and advection. Vertical eddy diffusion is one of the key elements in the mechanical energy balance of the global oceans. Vertical eddy diffusion can be con ceptually separated into two steps: stirring and subscale diffusion. Vertical eddy stirring pushes cold/dense water upward and warm/light water downward; thus, gravitational potential energy is increased. During the second steps, water masses from different places mix through subscale diffusion, and water density is increased due to cabbeling. UsingWOA01 climatology and assuming the vertical eddy diffusivity is equal to a constant value of 2x103 pa2/s, the total amount of gravitational potential energy increase due to vertical stirring in the world oceans is estimated at 263 GW. Cabbeling associated with vertical subscale diffusion is a sink of gravitational potential energy, and the total value of energy lost is estimated at 73 GW. Therefore, the net source of gravitational potential energy due to vertical eddy diffusion for the world oceans is estimated at 189 GW. 展开更多
关键词 cabbeling COMPRESSIBILITY elasticity energetics of vertical eddy diffusion gravitationalpotential energy parameterization of eddy diffusion
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GLOBAL VIEW OF MICROSTRUCTURAL EVOLUTION:ENERGETICS,KINETICS AND DYNAMICAL SYSTEMS 被引量:4
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作者 杨卫 锁志钢 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1996年第2期144-157,共14页
An evolving material structure is in a non-equilibrium state, with free energy expressed by the generalized coordinates. A global approach leads to robust computations for the generalized thermodynamic forces. Those f... An evolving material structure is in a non-equilibrium state, with free energy expressed by the generalized coordinates. A global approach leads to robust computations for the generalized thermodynamic forces. Those forces drive various kinetic processes, causing dissipation at spots, along curves, surfaces and interfaces, and within volumetric regions. The actual evolution path, and therefore the final equilibrium state, is determined by the energetics and kinetics. A virtual work principle Links the free energy landscape and the kinetic processes, and assigns a viscous environment to every point on the landscape. The approach leads to a dynamical system that governs the evolution of generalized coordinates. The microstructural evolution is globally characterized by a basin map in the coordinate space; and by a diversity map and a variety map in the parameter space. The control of basin boundaries raises the issue of energetic and kinetic bifurcations. The variation of basin boundaries under different sets of controlling parameters provides an analytical way to plot the diversity maps of structural evolution. 展开更多
关键词 microstructural evolution energetics KINETICS dynamic system
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Energetics of lateral eddy diffusion/advection: Part II. Numerical diffusion/diffusivity and gravitational potential energy change due to isopycnal diffusion 被引量:4
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作者 HUANG Rui Xin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第3期19-39,共21页
Study of oceanic circulation and climate requires models which can simulate tracer eddy diffusion and ad vection accurately. It is shown that the traditional Eulerian coordinates can introduce large artificial hori zo... Study of oceanic circulation and climate requires models which can simulate tracer eddy diffusion and ad vection accurately. It is shown that the traditional Eulerian coordinates can introduce large artificial hori zontal diffusivity/viscosity due to the incorrect alignment of the axis. Therefore, such models can smear sharp fronts and introduce other numerical artifacts. For simulation with relatively low resolution, large lateral diffusion was explicitly used in models; therefore, such numerical diffusion may not be a problem. However, with the increase of horizontal resolution, the artificial diffusivity/viscosity associated with hori zontal advection in the commonly used Eulerian coordinates may become one of the most challenging ob stacles for modeling the ocean circulation accurately. Isopycnal eddy diffusion (mixing) has been widely used in numerical models. The common wisdom is that mixing along isopycnal is energy free. However, a careful examination reveals that this is not the case. In fact, eddy diffusion can be conceptually separated into two steps: stirring and subscale diffusion. Due to the thermobaric effect, stirring, or exchanging water masses, along isopycnal surface is associated with the change of GPE in the mean state. This is a new type of instability, called the thermobaric instability. In addition, due to cabbeling subscale diffusion of water parcels always leads to the release of GPE. The release of GPE due to isopycnal stirring and subscale diffusion may lead to the thermobaric instability. 展开更多
关键词 Eulerian coordinates numerical diffusivity numerical dissipation energetics of isopycnal eddydiffusion
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Energetics and conserved quantity of an axially moving string undergoing three-dimensional nonlinear vibration 被引量:3
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作者 Liqun Chen C. W. Lim Hu Ding 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2008年第2期215-221,共7页
Nonlinear three-dimensional vibration of axially moving strings is investigated in the view of energetics. The governing equation is derived from the Eulerian equation of motion of a continuum for axially accelerating... Nonlinear three-dimensional vibration of axially moving strings is investigated in the view of energetics. The governing equation is derived from the Eulerian equation of motion of a continuum for axially accelerating strings. The time-rate of the total mechanical energy associated with the vibration is calculated for the string with its ends moving in a prescribed way. For a string moving in a constant axial speed and constrained by two fixed ends, a conserved quantity is proved to remain unchanged during three-dimensional vibration, while the string energy is not conserved. An approximate conserved quantity is derived from the conserved quantity in the neighborhood of the straight equilibrium configuration. The approximate conserved quantity is applied to verify the Lyapunov stability of the straight equilibrium configuration. Numerical simulations are performed for a rubber string and a steel string. The results demonstrate the variation of the total mechanical energy and the invariance of the conserved quantity. 展开更多
关键词 Nonlinear free vibration Axial movingstring energetics Conserved quantity STABILITY
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Energetics and temporal variability of internal tides in Luzon Strait:a nonhydrostatic numerical simulation 被引量:2
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作者 李明杰 侯一筠 +1 位作者 李元龙 胡珀 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第5期852-867,共16页
A fully nonlinear,three-dimensional nonhydrostatic model driven by four principal tidal constituents(M2,S2,K1,and O1) is used to investigate the spatial-temporal characteristics and energetics of internal tides in Luz... A fully nonlinear,three-dimensional nonhydrostatic model driven by four principal tidal constituents(M2,S2,K1,and O1) is used to investigate the spatial-temporal characteristics and energetics of internal tides in Luzon Strait(LS).The model results show that,during spring(neap) tides,about 64(47) GW(1 GW=109 W) of barotropic tidal energy is consumed in LS,of which 59.0%(50.5%) is converted to baroclinic tides.About 22(11) GW of the derived baroclinic energy flux subsequently passes from LS,among which 50.9%(54.3%) flows westward into the South China Sea(SCS) and 45.0%(39.7%) eastward into the Pacific Ocean,and the remaining 16(13) GW is lost locally owing to dissipation and convection.It is revealed that generation areas of internal tides vary with the spring and neap tide,indicating different source areas for internal solitary waves in the northern SCS.The region around the Batan Islands is the most important generation region of internal tides during both spring and neap tides.In addition,the baroclinic tidal energy has pronounced seasonal variability.Both the total energy transferred from barotropic tides to baroclinic tides and the baroclinic energy flux flowing out of LS are the highest in summer and lowest in winter. 展开更多
关键词 internal tide energetics temporal variability Luzon Strait (LS) MITgcm
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Analysis of hohlraum energetics of the SG series and the NIF experiments with energy balance model 被引量:2
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作者 Guoli Ren Jie Liu +1 位作者 Wenyi Huo Ke Lan 《Matter and Radiation at Extremes》 SCIE EI CAS 2017年第1期22-27,共6页
The basic energy balance model is applied to analyze the hohlraum energetics data from the Shenguang(SG)series laser facilities and the National Ignition Facility(NIF)experiments published in the past few years.The an... The basic energy balance model is applied to analyze the hohlraum energetics data from the Shenguang(SG)series laser facilities and the National Ignition Facility(NIF)experiments published in the past few years.The analysis shows that the overall hohlraum energetics data are in agreement with the energy balance model within 20%deviation.The 20%deviation might be caused by the diversity in hohlraum parameters,such as material,laser pulse,gas filling density,etc.In addition,the NIF's ignition target designs and our ignition target designs given by simulations are also in accordance with the energy balance model.This work confirms the value of the energy balance model for ignition target design and experimental data assessment,and demonstrates that the NIF energy is enough to achieve ignition if a 1D spherical radiation drive could be created,meanwhile both the laser plasma instabilities and hydrodynamic instabilities could be suppressed. 展开更多
关键词 Energy balance model Hohlraum energetics National Ignition Facility(NIF) Shenguang(SG)series
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A High-resolution Simulation of Supertyphoon Rammasun(2014)--Part Ⅰ:Model Verification and Surface Energetics Analysis 被引量:1
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作者 Xinghai ZHANG Yihong DUAN +2 位作者 Yuqing WANG Na WEI Hao HU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第6期757-770,共14页
A 72-h high-resolution simulation of Supertyphoon Rammasun (2014) is performed using the Advanced Research Weather Research and Forecasting model. The model covers an initial 18-h spin-up, the 36-h rapid intensifica... A 72-h high-resolution simulation of Supertyphoon Rammasun (2014) is performed using the Advanced Research Weather Research and Forecasting model. The model covers an initial 18-h spin-up, the 36-h rapid intensification (RI) period in the northern South China Sea, and the 18-h period of weakening after landfall. The results show that the model reproduces the track, intensity, structure of the storm, and environmental circulations reasonably well. Analysis of the surface energetics under the storm indicates that the storm's intensification is closely related to the net energy gain rate (eg), defined as the difference between the energy production (PD) due to surface entropy flux and the energy dissipation (Ds) due to surface friction near the radius of maximum wind (RMW). Before and during the RI stage, the ~:g is high, indicating sufficient energy supply for the storm to intensify. However, the Sg decreases rapidly as the storm quickly intensifies, because the Ds increases more rapidly than the PD near the RMW. By the time the storm reaches its peak intensity, the Ds is about 20% larger than the PD near the RMW, leading to a local energetics deficit under the eyewall. During the mature stage, the PD and Ds can reach a balance within a radius of 86 km from the storm center (about 2.3 times the RMW). This implies that the local PD under the eyewall is not large enough to balance the Ds, and the radially inward energy transport from outside the eyewall must play an important role in maintaining the storm's intensity, as well as its intensification. 展开更多
关键词 Rammasun (2014) high-resolution simulation energetics analysis rapid intensification
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STUDIES ON THE BIOCHEMICAL COMPOSITION,ENERGETICS AND ESSENTIAL AMINO ACIDS OF THREE MUDSKIPPERS IN XIAMEN HARBOUR
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作者 王军 苏永全 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1995年第4期374-379,共6页
Measurements were made on the contents of protein, lipid, glycogen (PLG) and water, and on caloric values and amino acids, in muscle of three mudskippers Periophthalmis cantonensis, Scarteiaos viridis and Boleophthalm... Measurements were made on the contents of protein, lipid, glycogen (PLG) and water, and on caloric values and amino acids, in muscle of three mudskippers Periophthalmis cantonensis, Scarteiaos viridis and Boleophthalmus pectinirostris collected from Haicang, Xiamen. The essential amino acids (EAA) for these fishes were also studied with radioisotopic trace method. The results showed: (1) The content of each component in tested fish muscles differed slightly, and protein was the most important component making up from 6.685% to 9.891% of the wet weight (about 44.21%-50.45% of dry weight); (2) Energy calculated from the sum of protein, lipid and glycogen in wet muscle was low (<4.3kJ/g) in these fishes, especially in B. pectinirostris (<3.1 kJ/g); the ratios of energy to protein content (E/P) also were low (<39.873 -45.535kJ/g); (3) Seventeen amino acids were determined in these three fishes. The content of the same amino acid (among the seventeen) tested in different species and sexes varied slightly. The amounts of methionine, phenylalanine lysine, arginme, histidine, threonine isoleucine and leucine which are indispensable for the needs of human beings and animals were relative-ly high, accounting for 47.35%-48.06% of the total amino acid content. (4) Leucine, isoleucine, arginme, lysine, phenylalanine, tryptophan, methionine, histidine, threonine, and valine, are essential in the diet of the three mudskippers as the radioisotopic trace method using D-[U-^(14) C]-glucose showed little or no radioactivity was incorporated into these ten amino acids. 展开更多
关键词 biochemical composition energetics amino acids mudskippers
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Structures,Energetics,and Infrared Spectra of the Cationic Monomethylamine-Water Clusters
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作者 Shu-kang Jiang Dong Yang +8 位作者 Xiang-tao Kong Chong Wang Xiang-yu Zang Hui-jun Zheng Gang Li Hua Xie Wei-qing Zhang Xue-ming Yang Ling Jiang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第1期31-36,共6页
The structures,energetics,and infrared(IR)spectra of the cationic monomethylamine-water clusters,[(CH3NH2)(H2O)n]^+(n=1-5),have been studied using quantum chemical calculations at the MP2/6-311+G(2d,p)level.The result... The structures,energetics,and infrared(IR)spectra of the cationic monomethylamine-water clusters,[(CH3NH2)(H2O)n]^+(n=1-5),have been studied using quantum chemical calculations at the MP2/6-311+G(2d,p)level.The results reveal that the formation of protontransferred CH2NH3+ ion core structure is preferred via the intramolecular proton transfer from the methyl group to the nitrogen atom and the water molecules act as the acceptor for the O…HN hydrogen bonds with the positively charged NH3^+ moiety of CH2NH3^+,whose motif is retained in the larger clusters.The CH3NH2^+ ion core structure is predicted to be less energetically favorable.Vibrational frequencies of CH stretches,hydrogen-bonded and free NH stretches,and hydrogen-bonded OH stretches in the calculated IR spectra of the CH2NH3^+ and CH3NH2^+ type structures are di erent from each other,which would a ord the sensitive probes for fundamental understanding of hydrogen bonding networks generated from the radiation-induced chemical processes in the[(CH3NH2)(H2O)n]+complexes. 展开更多
关键词 Monomethylamine WATER STRUCTURE energetics Infrared spectroscopy
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Energetics Constraint for Linear Disturbances Development
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作者 Y.L.McHall 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1993年第3期273-286,共14页
In development of baroclinic disturbances, baroclinity of basic temperature field varies with conversion of available potential energy. The growth rate which depends on the baroclinity varies as well. However, in prev... In development of baroclinic disturbances, baroclinity of basic temperature field varies with conversion of available potential energy. The growth rate which depends on the baroclinity varies as well. However, in previous linear theories, the growth rate was considered constant, so development of disturbances was not constrained by energy sources in the linear theories. In terms of energy conservation and conversion in an isolated atmosphere, we may study the variations in the baroclinity and growth rate and draw the corresponding pictures of perturbation developments in the varying environments. The amplification for the most unstable Eady wave is discussed as an example. It will be found that growth of baroclinic perturbations constrained by energy conservation is significantly different from the growth at the initial constant rate after mature stage. 展开更多
关键词 Linear disturbance development Eddy mean-field interaction APE conversion energetics constraint Eady waves
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Mitochondrial bioenergetics and neurodegeneration:a paso doble
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作者 Alice Rossi Paola Pizzo 《Neural Regeneration Research》 SCIE CAS CSCD 2021年第4期686-687,共2页
Mitochondria and neuronal activity:The brain is one of the highest energy demanding organs,consuming~20%of the total ATP produced by the whole body.Importantly,neurons mainly rely on ATP synthesized by mitochondrial b... Mitochondria and neuronal activity:The brain is one of the highest energy demanding organs,consuming~20%of the total ATP produced by the whole body.Importantly,neurons mainly rely on ATP synthesized by mitochondrial bioenergetics and neuronal activity is strictly dependent on specific mitochondrial localization at synapses,sites consuming a high amount of energy requested for both pre-and post-synaptic processes.Here,mitochondria produce ATP and buffer Ca^2+rises,two essential processes for neurotransmission and generation of membrane potential along the axon(Magistretti and Allaman,2015). 展开更多
关键词 ORGANS consuming energetics
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Studies of Catalysis in Partial Oxidation of Methane to Syngas(Ⅱ)──Chemisorbed Species,Energetics and Mechanism
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作者 CHEN Ping ZHANG Hong-bin LIN Guo-dong andTSAI Khi-rui(Department of Chemistry &State Key Laboratory for Physical Chemistyry of the Solid Surface ,Xiamen University ,Xiamen 361005) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1995年第4期323-335,共13页
he characteristic study,by means of in-situ IR spectroscopy, of chemisorbed species on the Ni-catalysts for the partial oxidation of methane(POM)to syngas demonstrated the existence of CH_x(a)and H_xCO(a)adspecies on... he characteristic study,by means of in-situ IR spectroscopy, of chemisorbed species on the Ni-catalysts for the partial oxidation of methane(POM)to syngas demonstrated the existence of CH_x(a)and H_xCO(a)adspecies on the functioning Ni-catalysts, Several designed experimental investigations on the reactivities of methane with CO_2 and with O_2,respectively,over the Ni-catalysts, and of CO_2 with the prereduced Ni-catalyst,ats well as of the deposited carbon with CO_2 and with O_2,respectlvely,liave been carried out and the reLqults were unfavorable to the two-step mechanistic interpretation proposed for the POM reaction. By means of tlie BOC-MP Approach,energetics of a set of elementary reactions,which may be involved in the POM process,on the clean(111)surface of Ni,Fe,Cu and Pd, re- spectively,has been studied.The result;of the experiments and the calculation of the present work favor the direct catalytic dissociation-plus-surface oxidation-plus-further debdrogenation mechanism as the dominant pathway making major contribution to the POM reaction. 展开更多
关键词 Partial oxidation of methane SYNGAS Chemisorbed species energetics. Mechanism
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Energetics of He and H Atoms in W–Ta Alloys: First-Principle Calculations
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作者 Chu-Bin Wan Su-Ye Yu Xin Ju 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第4期95-97,共3页
Properties of various defects of He and H atoms in W-Ta alloys are investigated based on density functional theory. The tetrahedral interstitial site is the most configured site for self-interstitial He and H in W and... Properties of various defects of He and H atoms in W-Ta alloys are investigated based on density functional theory. The tetrahedral interstitial site is the most configured site for self-interstitial He and H in W and W-Ta alloys. Only a single He atom favors a substitutional site in the presence of a nearby vacancy. However, in the coexistence of He and H atoms in the presence of the vacancy, the single H atom favors the tetrahedral interstitial site(TIS) closest to the vacancy, and the He atom takes the vacancy center. The addition of Ta can reduce the formation energy of TIS He or H defects. The substituted Ta affects the charge density distribution in the vicinity of the He atom and decreases the valence electron density of the H atoms. A strong hybridization of the H s states and the nearest W d state s exists in W(53)He1 H1 structure. The sequence of the He p projected DOS at the Fermi energy level is in agreement with the order of the formation energy of the He-H pair in the systems. 展开更多
关键词 Ta Alloys energetics of He and H Atoms in W First-Principle Calculations
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Surface Energetics Study and Determination of the Combined Negative Hamaker Coefficient for Hepatitis C Virus Infected Human Blood Cells
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作者 C. H. Achebe S. Iweriolor J. L. Chukwuneke 《Journal of Biomedical Science and Engineering》 2018年第11期307-319,共13页
This study investigated the interactive effects of Hepatitis C virus on human cells using the contact angle approach. The methodology involves the use of sessile drop approach to determine the contact angle formed on ... This study investigated the interactive effects of Hepatitis C virus on human cells using the contact angle approach. The methodology involves the use of sessile drop approach to determine the contact angle formed on the infected and uninfected blood cells in the presences of glycerin as the probe liquid. It was observed that the presence of the virus in the human blood cells depleted the immune system of infected cells giving rise to a decreased CD4 count on the average of 514.5 ± 243.10 when compared with the uninfected cells CD4 count of 1267.2 ± 368.27. The measurement of contact angle also unveils that among the blood components separated in the course of the experiment, the white blood cell is the principal target of the virus with the highest average contact angle of 63.4 ± 3.20 while the uninfected white blood cells have a lower contact angle of 48.5 ± 2.75. The result of the measured contact angle was used for MATLAB computation to determine the surface energy, force of adhesion and the Hamaker coefficient. Response surface methodology was also employed in this study to visualize the viral impact on the blood cells as well as generating model equations for prediction of the interaction between the virus and the blood cells. Infected surfaces on the average have higher values of Hamaker coefficient than uninfected surfaces. It was discovered that an increase in the contact angles causes a significant increase in Hamaker coefficient with a corresponding decrease in the CD4 counts on the infected surfaces. This increase is attributed to the presence of the HCV virus in the infected samples and the highest value was observed in the white blood cell component. Computation of the combined negative Hamaker coefficient revealed that there exists a possibility of separating the virus from the human lymphocyte, hence a negative value of the A132 of the infected sample was seen to be &minus;0.150 × 10&minus;18 mJ/m2 (&minus;0.150 × 10&minus;25 J). This is in agreement with the value reported in literature when an alternative method to contact angle was used (ultraviolent spectrophotometer approach) to investigate HIV infected human cells. The combined negative Hamaker coefficient of &minus;0.281 × 10&minus;25 J was obtained in that study. Both results have unveiled the possibility of applying the concept of combined negative Hamaker coefficient as a means of separating the virus from the lymphocytes. It therefore implies that additives in the form of drug(s) to the serum (as an intervening medium) which could alter the surface energy of the serum to a value of ≥&minus;0.150 × 10&minus;25 J can have the capability of totally isolating the virus from the lymphocytes. 展开更多
关键词 Absolute Hamaker COEFFICIENT Blood Components Contact Angle Hepatitis C LYMPHOCYTES SURFACE energetics
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An Analysis of the Spectral Energetics for a Planet Experiencing Rapid Greenhouse Gas Emissions
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作者 André Ferreira Aranha José Augusto P. Veiga 《Atmospheric and Climate Sciences》 2017年第1期117-126,共10页
So far, energetics studies related to climate change have focused on the disturbed and undisturbed kinetic and potential energies, as well as their transformations, without dealing with the energetics involved in the ... So far, energetics studies related to climate change have focused on the disturbed and undisturbed kinetic and potential energies, as well as their transformations, without dealing with the energetics involved in the phenomena of different spatial scales. Thus, the present work reports the first analysis of the spectral energetics for a condition of climate change, followed by the high-range emission scenario, RCP8.5, which originated from the new Max Planck Institute Earth System Model (MPI-ESM). The results showed that both types of generation (Go and Gn), baroclinic processes (Co and Cn), kinetic energies (Ko and Kn) and the barotropic process, Mn, significantly increase in the condition of a warming climate. Moreover, the results still reveal that in the most components of the energetics, is the planetary scale waves that are the most impacted under a climate change scenario. These results highlight that global warming can have different impacts on particular types of motions. 展开更多
关键词 energetics Global energetics SPECTRAL energetics Climate Change MPI-ESM Model
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Environmental Energetics aspects of anomalous Cyclogenesis over indian Ocean during 2013
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作者 Somenath Dutta Narkhedkar S. G. +1 位作者 Sunitha Devi Sudheesh TM 《Journal of Atmospheric Science Research》 2018年第1期27-35,共9页
An attempt has been made to understand the dynamics behind anomalous cyclogenesis over North Indian Ocean during 2013 cyclone seasons, from an atmospheric energetics point of view. For that various energy terms, their... An attempt has been made to understand the dynamics behind anomalous cyclogenesis over North Indian Ocean during 2013 cyclone seasons, from an atmospheric energetics point of view. For that various energy terms, their generation and conversion terms have been computed using NCEP/NCAR reanalysis data during different phases of the intense cyclonic vortices formed in 2013 over North Indian Seas. It is observed that maximum intensification of all the intense cyclonic vortices was associated with an enhancement in both conversions viz., from eddy available potential energy (AE) to eddy kinetic energy (KE) and zonal kinetic energy (KZ) to eddy kinetic energy (KE). Energetics analysis suggested that during intensification of the storms, dissipation of both eddy available potential energy ( AE )and zonal available potential energy (AZ) have taken place, suggesting the intensification of storms at the cost of AE and AZ. For all of these systems baroclinic eddy kinetic energy conversions i.e. from AE to KE dominates over barotropic eddy kinetic energy conversions i.e. from KZ to KE.Anomalous cyclogenesis in 2013, was partly attributed to a positive anomaly in moist static energy of the environment along with positive anomaly in baroclinic and barotropic eddy kinetic energy conversions during cyclone seasons over the region under study. Release of convective instability in the atmosphere can be partly attributed for anomalous cyclogenesis in 2013. 展开更多
关键词 energetics ANOMALOUS CYCLOGENESIS Cyclonic VORTICES CONVECTIVE instability
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