期刊文献+
共找到72篇文章
< 1 2 4 >
每页显示 20 50 100
Radiation and energy balance on a hillslope forest: horizontal versus slope-parallel installation of radiometer 被引量:1
1
作者 WANG Xing-chang LIU Fan WANG Chuan-kuan 《Journal of Mountain Science》 SCIE CSCD 2022年第11期3076-3087,共12页
Radiation is a major driver to the carbon,water, and energy exchanges of an ecosystem. For local radiation balance measurements, one essential question is whether the measurement systems should be installed horizontal... Radiation is a major driver to the carbon,water, and energy exchanges of an ecosystem. For local radiation balance measurements, one essential question is whether the measurement systems should be installed horizontally or parallel to inclined slope surface. With a case study over a temperate deciduous forest on a moderate inclined(9°) northwest-facing slope, we quantified the slope effect on net radiation(Rn) and its components and the energy balance closure measured by an eddy covariance(EC) system.Compared with the slope-parallel radiometer, the horizontal sensor overestimated the incident solar radiation(SR) by 7%, the incoming photosynthetically active radiation(PAR) by 1.5%, and the incoming near-infrared radiation(NIR) by 10%;while underestimated the reflected shortwave radiation(SR)by 4% and NIR by 5%. The influence of radiometerorientation on incoming longwave radiation(LR) was about 3%, while that on outgoing LR was negligible.Summing all these components, horizontal sensor overestimated the Rn by 9%. Converting the horizontally-measured incident radiation to slopesurface reduced a half of the biases on incoming SR and Rn. Measuring the Rn with slope-parallel radiometer and correcting the slope-effect on horizontally-measured incident SR improved the energy balance ratio(EBR) by 8% and 5%,respectively. A mini-review indicated that, the horizontal sensor underestimated(overestimated) the EBR on north-facing(south-facing) slopes in temperate zone in the Northern Hemisphere, with an inclination angular sensitivity of EBR as high as 1.17%per degree of inclination angle. We recommend measuring radiations on inclined terrains with slopeparallel radiometers, or correcting at least for the incident SR in energy balance studies. 展开更多
关键词 RADIATION Sloping terrain energy balance closure Eddy covariance
下载PDF
Analysis of hohlraum energetics of the SG series and the NIF experiments with energy balance model 被引量:1
2
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
下载PDF
A Diagnostic Approach towards the Causes of Energy Balance Closure Problem 被引量:1
3
作者 Ali Varmaghani William E. Eichinger John H. Prueger 《Open Journal of Modern Hydrology》 2016年第2期101-114,共14页
Hydrometeorological models are often evaluated and optimized on the basis of micrometeorological measurements. However, it has been known for more than three decades that surface measurements of sensible and latent he... Hydrometeorological models are often evaluated and optimized on the basis of micrometeorological measurements. However, it has been known for more than three decades that surface measurements of sensible and latent heat energy (LE) are systematically underestimated. We studied this problem using six years of eddy-correlation measurements for four fields (corn, soybean, and prairie) in central Iowa, USA. We recorded major components of the energy equation (i.e. net radiation, sensible heat flux, LE, and soil heat flux, photosynthesis), and indirectly estimated most of the minor components of energy balance (namely storage in the soil, canopy and air). Storage in the canopy was related to leaf area index (LAI) acquired from Moderate Resolution Imaging Spectrometer (MODIS). In this paper, a diagnostic approach is investigated where systematic error is identified first. Three dimensional (3D) plots of the residual of energy equation vs. potential variables indicated the imbalance was largest mainly during the cold non-growing season when the soil was dry. Correlations between energy balance residual (EBR) and energy components showed that soil storage was not precisely estimated. Finally, an a-posteriori analysis (constrained linear multiple regression (CMLR)) was conducted to quantify the contribution of major/minor components of the energy equation towards EBR. The result highlights that the contribution of pertinent components of energy to EBR is mainly controlled by prevailing monthly hydrometeorological conditions;however, precise quantification of causes of imbalance is site-specific. A comparison between the a-posteriori analysis technique and the Bowen-ratio method demonstrates that the Bowen-ratio basically presumes a higher level of underestimation in LE. The results obtained in this study suggest that a-posteriori analysis may offer a superior methodology to correct measured eddy-correlation measurements. Furthermore, the overall trends in the correction of LE measurements suggest that there is a potential for rough monthly corrections of LE, irrespective of the type of crop. 展开更多
关键词 energy balance Closure CORN SOYBEANS PRAIRIE A-Posteriori Analysis
下载PDF
An analysis approach of mass and energy balance in a dual-reactor circulating fluidized bed system
4
作者 Yangjun Wei Leming Cheng Liyao Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第12期18-26,共9页
An analysis approach considering gas-solids hydrodynamics,reaction kinetics and reacting species nonuniformity together in a dual-reactor system is presented for better understanding its mass and energy balance.It was... An analysis approach considering gas-solids hydrodynamics,reaction kinetics and reacting species nonuniformity together in a dual-reactor system is presented for better understanding its mass and energy balance.It was achieved by a 3-dimensional comprehensive hydrodynamics and reaction model for the dual-reactor system,which was developed from the successfully verified 3-dimensional comprehensive combustion model for one circulating fluidized bed(CFB)system(Xu and Cheng,2019).The developed model and analysis approach was successfully used on a 1 MW circulating fluidized bed–bubbling fluidized bed(CFB-BFB)dual-reactor system.Results showed the sensible and chemical energy between two reactors as well as the energy distributions in each reactor were balanced and they agreed well with the experimental measurements.The analysis approach indicated energy balance had a close relationship with the mass transfer in the CFB-BFB dual-reactor system.It may be applied in a design and operation optimization for a dual-reactor system. 展开更多
关键词 Mass and energy balance circulating fluidized bed–bubbling fluidized bed Dual-reactor Comprehensive model
下载PDF
A two-dimensional energy balance climate model on Mars
5
作者 YaoKun Li JiPing Chao 《Earth and Planetary Physics》 EI CSCD 2022年第3期284-293,共10页
A two-dimensional energy balance climate model has been built to investigate the climate on Mars.The model takes into account the balance among solar radiation,longwave radiation,and energy transmission and can be sol... A two-dimensional energy balance climate model has been built to investigate the climate on Mars.The model takes into account the balance among solar radiation,longwave radiation,and energy transmission and can be solved analytically by Legendre polynomials.With the parameters for thermal diffusion and radiation processes being properly specified,the model can simulate a reasonable surface atmospheric temperature distribution but not a very perfect vertical atmospheric temperature distribution compared with numerical results,such as those from the Mars Climate Database.With varying solar radiation in a Martian year,the model can simulate the seasonal variation of the air temperature on Mars.With increasing dust content,the Martian atmosphere gradually warms.However,the warming is insignificant in the cold and warm scenarios,in which the dust mixing ratio varies moderately,whereas the warming is significant in the storm scenario,in which the dust mixing ratio increases dramatically.With an increasing albedo value of either the polar cap or the non-ice region,Mars gradually cools.The mean surface atmospheric temperature decreases moderately with an increasing polar ice albedo,whereas it increases dramatically with an increasing non-ice albedo.This increase occurs because the planetary albedo of the ice regions is smaller than that of the non-ice region. 展开更多
关键词 MARS energy balance climate model solar radiation DUST surface albedo
下载PDF
Absence of the Impact of the Flux of Cosmic Rays and the Cloud Cover on the Energy Balance of the Earth
6
作者 H.I.Abdussamatov 《Journal of Atmospheric Science Research》 2020年第3期1-7,共7页
The energy of solar radiation absorbed by the Earth,as well as the thermal radiation of the Earth’s surface,which is released to the space through the atmospheric transparency window,depends on variations of the area... The energy of solar radiation absorbed by the Earth,as well as the thermal radiation of the Earth’s surface,which is released to the space through the atmospheric transparency window,depends on variations of the area of the cloud cover.Svensmark et al.suggest that the increase in the area of the cloud cover in the lower atmosphere,presumably caused by an increase in the flux of galactic cosmic rays during the quasi-bicentennial minimum of solar activity,results only in an increase in the fraction of the solar radiation reflected back to the space and weakens the flux of the solar radiation that reached the Earth surface.It is suggested,without any corresponding calculations of the variations of the average annual energy balance of the EarthЕ,that the consequences will include only a deficit of the solar energy absorbed by the Earth and a cooling of the climate up to the onset of the Little Ice Age.These suggestions ignore simultaneous impact of the opposite aspects of the increase in the area of the cloud cover on the climate warming.The latter will result from a decrease in the power of thermal radiation of the Earth’s surface released to the space,and also in the power of the solar radiation reflected from the Earth’s surface,due to the increase in their absorption and reflection back to the surface.A substantial strengthening in the greenhouse effect and the narrowing of the atmospheric transparency window will also occur.Here,we estimate the impact of all aspects of possible long-term 2%growth of the cloud cover area in the lower atmosphere byЕ.We found that an increase in the cloud cover area in the lower atmosphere will result simultaneously both in the decrease and in the increase in the temperature,which will virtually compensate each other,while the energy balance of the Earth E before and after the increase in the cloud cover area by 2%will stay essentially the same:E1-E0≈0. 展开更多
关键词 CLIMATE Cosmic rays Cloud Cover energy balance Little Ice Age Solar Irradiance Greenhouse Effect Atmospheric Transparency Window
下载PDF
An Energy Balance Simulation of the Universe
7
作者 Peter Y.P.Chen 《Applied Mathematics》 2019年第11期956-966,共11页
We have developed an energy balance equation for the universe. The two system parameters involved in the equation could be “fine-tuned” so that the predicted temperature histories all lead to what is observed in the... We have developed an energy balance equation for the universe. The two system parameters involved in the equation could be “fine-tuned” so that the predicted temperature histories all lead to what is observed in the present cosmic microwave background. We have shown that various combinations of these two parameters are possible;in particular, the present background temperature needs not be the remnant of a very hot temperature in the far distance past. We also solved for the propagation of vortex solitons in optical fibres as contrasting examples to show how electromagnetic wave could be transmitted in a particular waveform under strictly controlled conditions. To avoid singularity, all vortexes have a black centre. We conclude that while numerical techniques can be used to account for an infinite quantity, it is unlikely that such a quantity could exist in reality. 展开更多
关键词 Transient Simulation energy balance Modelling Cosmic Microwave Background Temperature Histories of the Universe Vortex Solitons
下载PDF
Comparison of mesophilic and thermophilic anaerobic digestions of thermal hydrolysis pretreated swine manure: Process performance,microbial communities and energy balance 被引量:1
8
作者 Xiaohui Liu Changmin Lee Jae Young Kim 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2023年第4期222-233,共12页
Anaerobic digestion (AD) of swine manure (SM) commonly shows low biogas output and unsatisfactory economic performance. In this study, thermophilic AD (TAD, 50±1℃) was combined with thermal hydrolysis pretreatme... Anaerobic digestion (AD) of swine manure (SM) commonly shows low biogas output and unsatisfactory economic performance. In this study, thermophilic AD (TAD, 50±1℃) was combined with thermal hydrolysis pretreatment (THP, 170℃/10 bar), to investigate its potential for maximizing biogas yield, securing successful digestion and microbial diversity, as well as improving energy balance. Four lab-scale continuously stirred tank reactors were operated for 300 days and compared with each other, i.e., reactor 1 (raw SM fed in mesophilic AD:RSM-MAD), reactor 2 (THP-treated SM fed in MAD:TSM-MAD), reactor 3 (RSM-TAD),and reactor 4 (TSM-TAD). The results showed that THP was efficient to increase methane production of SM, TSM-TAD mode led to the highest methane yield (129.8±40.5 mL-CH_(4)/gVS/day) among the tests (p <0.05). Although TAD was more likely to induce free ammonia (> 700 mg/L) or volatile fatty acids (> 6000 mg/L) accumulation compared with MAD in start-up phase, TSM-TAD treatment mode behaved a sustainable digestion process in a long-term operation. For TSM-TAD scenario, higher Shannon–Weaver (3.873) and lower Simpson index (0.061) indicated this mode ensured and enlarged the diversity of bacteria communities. Phylum Bathyarchaeota was dominant (59.3%-90.0%) in archaea community,followed by Euryarchaeota in the four reactors. RSM-MAD treatment mode achieved the highest energy output (4.65 GJ/day), TSM-TAD was less effective (-17.38 GJ/day) due to increased energy demands. Thus improving the energetic efficiency of THP units is recommended for the development of TSM-TAD treatment mode. 展开更多
关键词 Thermal hydrolysis pretreatment Digestion temperature Process performances Microbial communities energy balance
原文传递
Stability Analysis of DC-DC Converters with Energy Balance Control
9
作者 Lei Wang Yang Liu +2 位作者 Yongliang Guo Qing-Hua Wu Guangfu Tang 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2023年第5期1765-1773,共9页
With variation of parameters,DC-DC converters may change from a stable state to an unstable state,which severely degrades the performances of the converter system.In this article,by establishing the state-space averag... With variation of parameters,DC-DC converters may change from a stable state to an unstable state,which severely degrades the performances of the converter system.In this article,by establishing the state-space average model,the stability and bifurcation of a boost and a buck-boost converter with energy balance control(EBC)is studied,respectively.Then the stability boundary and stable parameter domains are accurately predicted.The obtained stability region provides a parameter regulating range for converter design.Furthermore,compared with the one-cycle control(OCC)method,the EBC possesses an extended stable parameter domain,while avoiding unstable behaviors such as Hopf bifurcation,Quasi-periodic Oscillation even chaos,etc.The theoretic analysis is well validated through simulation and experiment. 展开更多
关键词 DC-DC converter energy balance control average model slow-scale stability
原文传递
Spatial variation of net radiation and its contribution to energy balance closures in grassland ecosystems 被引量:3
10
作者 Changliang Shao Linghao Li +1 位作者 Gang Dong Jiquan Chen 《Ecological Processes》 SCIE EI 2014年第1期190-200,共11页
Introduction:Low energy balance closure(EBC)at a particular eddy-covariance flux site has increased the uncertainties of carbon,water,and energy measurements and has thus hampered the urgent research of scaling up and... Introduction:Low energy balance closure(EBC)at a particular eddy-covariance flux site has increased the uncertainties of carbon,water,and energy measurements and has thus hampered the urgent research of scaling up and modeling analyses through site combinations in regional or global flux networks.Methods:A series of manipulative experiments were conducted in this study to explore the role of net radiation(Rn)in the EBC in relation to spatial variability of vegetation characteristics,source area,and sensor type in three sites of the Inner Mongolian grassland of northern China.Results:At all three sites,the residual fluxes of EBC peaked consistently at 110 W m^(-2).The spatial variability in net radiation was 19 W m^(-2)(5%of R_(n))during the day and 7 W m^(-2)(16%)at night,with an average of 13 W m^(-2)(11%)from eight plot measurements across the three sites.Large area measurements of Rn significantly increased by 9 W m^(-2)during the day and decreased by 4 W m^(-2)at night in the unclipped treatments.Net radiation decreased by 25 W m^(-2)(6%of Rn)at midday and 81 MJ m^(-2)(6%)during a growing season with heavier regular clipping than that in unclipped treatments.The Rn was lower by 11–21 W m^(-2)(~20–40%of Rn)measured by CNR1 than by Q7.1 at night,while there was only 6 W m^(-2)(~1–2%of Rn)difference during the daytime between these two types of commonly used net radiometers.Conclusions:Overall,the inclusion of the uncertainty in available energy accounted for 65%of the~110 W m^(-2)shortfalls in the lack of closure.Clearly,the unclosed energy balance at these three grassland sites remains significant,with unexplored mechanisms for future research. 展开更多
关键词 Inner Mongolia EDDY-COVARIANCE energy balance closure Net radiation Spatial variability Typical steppe
原文传递
Lycium barbarum Polysaccharides Promotes Mitochondrial Biogenesis and Energy Balance in NAFLD Cell Model 被引量:2
11
作者 ZHANG Yan-nan GUO Yi-qiong +3 位作者 FAN Yan-na TAO Xiu-juan GAO Qing-han YANG Jian-jun 《Chinese Journal of Integrative Medicine》 SCIE CAS CSCD 2022年第11期975-982,共8页
Objective:To explore the protective effect and underlying mechanism of Lycium barbarum polysaccharides(LBP)in a non-alcoholic fatty liver disease(NAFLD)cell model.Methods:Normal human hepatocyte LO2 cells were treated... Objective:To explore the protective effect and underlying mechanism of Lycium barbarum polysaccharides(LBP)in a non-alcoholic fatty liver disease(NAFLD)cell model.Methods:Normal human hepatocyte LO2 cells were treated with 1 mmol/L free fatty acids(FFA)mixture for 24 h to induce NAFLD cell model.Cells were divided into 5 groups,including control,model,low-,medium-and high dose LBP(30,100and 300μg/mL)groups.The monosaccharide components of LBP were analyzed with high performance liquid chromatography.Effects of LBP on cell viability and intracellular lipid accumulation were assessed by cell counting Kit-8 assay and oil red O staining,respectively.Triglyceride(TG),alanine aminotransferase(ALT),aspartate aminotransferase(AST),adenosine triphosphate(ATP)and oxidative stress indicators were evaluated.Energy balance and mitochondrial biogenesis related mRNA and proteins were determined by quantitative real-time polymerase chain reaction and Western blot,respectively.Results:Heteropolysaccharides with mannose and glucose are the main components of LBP.LBP treatment significantly decreased intracellular lipid accumulation as well as TG,ALT,AST and malondialdehyde levels(P<0.05 or P<0.01),increased the levels of superoxide dismutase,phospholipid hydroperoxide glutathione peroxidase,catalase,and ATP in NAFLD cell model(P<0.05).Meanwhile,the expression of uncoupling protein 2 was down-regulated and peroxisome proliferator-activated receptor gamma coactivator-1α/nuclear respiratory factor 1/mitochondrial transcription factor A pathway was up-regulated(P<0.05).Conclusion:LBP promotes mitochondrial biogenesis and improves energy balance in NAFLD cell model. 展开更多
关键词 Lycium barbarum polysaccharides non-alcoholic fatty liver disease mitochondrial biogenesis energy balance Chinese medicine
原文传递
Assessment of the Energy Conversion on the Thermal Balance and Atmospheric Emissions in Ceramic Tile Product Industry in Tunisia: A Case Study 被引量:1
12
作者 Imed Ben Salah Moufida Ben M’barek Jemaï +1 位作者 Aycer Ben Saad Safa Mezza 《Atmospheric and Climate Sciences》 2020年第4期421-442,共22页
This work aims to assess the effect of energy conversion (Thermal oil, Natural gas and cogeneration system) on atmospheric emission and energy consumption in ceramic tile product sector in Tunisia. Two tile manufactur... This work aims to assess the effect of energy conversion (Thermal oil, Natural gas and cogeneration system) on atmospheric emission and energy consumption in ceramic tile product sector in Tunisia. Two tile manufactures were selected. The first plant has two production lines: The first line (FF1) operates with thermal oil with a lower calorific value (LHV) of 9811 cal/g and the second line (FG1) operating with natural gas has a lower calorific value (HHV) of 10,520 cal/g, ensuring a daily output of 300 tons each one. The second manufacture (SC2) operates with natural gas with the same LHV value. The thermal oil energy balance showed a specific consumption of 0.0481 toe/ton tile product for the FF1 manufacture line, 0.0198 toe/ton of tile product for the FG1 manufacture line and 0.0143 toe/ton of tile product for the SC2 manufactory. The electrical energy consumption was 0.0121 toe/ton of tile product for the FF1 line, 0.0108 toe/ton of tile product for the FG1 line and a production of energy (exergy) of 0.014 toe/ton for the SC2 production line. The specific consumption was split into 40% for dryer and 60% for tunnel kilns. The conversion allow to record a dryer reduction rate of 80% for nitrogen oxides (NOx), 56% for sulfur oxides (SOx), 56% for fluorinated compounds, 52% for chlorinated compounds and 52% for volatile organic compound. Whereas, the kiln reduction rate was 36% for nitrogen oxides, 51% for sulfur oxides, 36% for chlorinated compounds and 55% for fluorinated and 50% for volatile organic compounds (VCOs). Compared to natural gas line, the use of cogeneration system in kiln process shows a decrease of 67% for NOx emissions, 80% for SOx emissions, 89% for fluorinated compounds, 58% for chlorinated emissions and 64% for volatiles organic compounds. Compared to thermal oil, the use of cogeneration system reduces the thermal energy consumption by 70% and allowed to save 30% of electric energy by generate 20% of needed electric energy. The specific atmospheric gaseous emission level decrease from 2.066 g/kg of tile product for the thermal oil process to reach 0.43 g/kg of tile product for cogeneration process. 展开更多
关键词 CERAMIC energy Conversion COGENERATION energy balance Atmospheric Emissions
下载PDF
Natural Environment and Landscape Energy of Western Georgia
13
作者 Zurab Seperteladze Eter Davitaia +3 位作者 Tariel Kikvadze George Gaprindashvili Tamar Aleksidze Nino Rukhadze 《Natural Resources》 CAS 2023年第1期1-12,共12页
The particularly great practical importance of modern physical geography and, in particular, landscape science, is first of all manifested in the detection and study of the resource potential of landscapes, as well as... The particularly great practical importance of modern physical geography and, in particular, landscape science, is first of all manifested in the detection and study of the resource potential of landscapes, as well as in the optimization of the environment. The resource potential, on the other hand, greatly depends on the balance of substance and energy exchange in the natural resources, i.e. the energy of the landscape. In this case, one of the important things is to study the functioning of natural-territorial complexes (NTC). Through it, it is possible and relatively easy to explain, model and, most importantly, predict many complex processes taking place in NTC, including the role of landscape energy balance in increasing the productivity and yield of agro-landscapes, which was the first attempt to research this problem in Georgia. 展开更多
关键词 Landscape energy Agro-Landscape OPTIMIZATION Solar Radiation energy balance
下载PDF
High Elevation Energy and Water Balance:the Roles of Surface Albedo and Temperature 被引量:3
14
作者 Massimo MENENTI Li JIA +13 位作者 Marco MANCINI Xin LI Francesca PELLICCIOTTI Kun YANG Jiancheng SHI Maria Jose ESCORIHUELA Chiara CORBARI Shaoting REN Chunfeng MA Chaolei ZHENG Lian LIU Thomas SHAW Baohong DING Wei YANG 《Journal of Geodesy and Geoinformation Science》 2020年第4期70-78,共9页
Observation and modeling of the coupled energy and water balance is the key to understand hydrospheric and cryospheric processes at high elevation.The paper summarizes the progress to address this aspect in relation w... Observation and modeling of the coupled energy and water balance is the key to understand hydrospheric and cryospheric processes at high elevation.The paper summarizes the progress to address this aspect in relation with different earth system elements,from glaciers to wetlands.The energy budget of two glaciers,i.e.Xiao Dongkemadi and Parlung No.4,was studied by means of extended field measurements and a distributed model of the coupled energy and mass balance was developed and evaluated.The need for accurate characterization of surface albedo was further documented for the entire Qinghai Tibet Plateau by numerical experiments with Weather Research and Forecast(WRF)on the sensitivity of the atmospheric boundary layer to the parameterization of land surface processes.A new approach to the calibration of a coupled distributed watershed model of the energy and water balance was demonstrated by a case study on the Heihe River Basin in northwestern China.The assimilation of land surface temperature did lead to the retrieval of critical soil and vegetation properties as the soil permeability and the canopy resistance to the exchange of vapour and carbon dioxide.The retrievals of actual Evapo-Transpiration(ET)were generated by the ETMonitor system and evaluated against eddy covariance measurements at sites spread throughout Asia.As regards glacier response to climate variability,the combined findings based on satellite data and model experiments showed that the spatial variability of surface albedo and temperature is significant and controls both glacier mass balance and flow.Experiments with both atmospheric and hydrosphere-cryosphere models documented the need and advantages of using accurate retrievals of land surface albedo to capture lan-atmosphere interactions at high elevation. 展开更多
关键词 ICE SNOW ALBEDO energy water balance
下载PDF
Digital simulation studies on long transmission line protection based on balance of energy
15
作者 文明浩 陈德树 尹项根 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2001年第4期409-411,共3页
The protection based balance of energy is a new technique specially proposed for long transmission lines. This technique depends upon the calculation of net energy into the transmission line by two independent methods... The protection based balance of energy is a new technique specially proposed for long transmission lines. This technique depends upon the calculation of net energy into the transmission line by two independent methods and comparing them to indicate healthy and faulty conditions. In order to study the performance and feasibility of the protection based on balance of energy, the new protection has been extensively tested by using EMTP on a long transmission line with various configurations and operating conditions (including single pole line, double circuit lines and two phase operation). The results calculated by EMTP show that under any condition of a power system, the proposed technique has excellent performance,the viability even for high resistance ground faults and a short operation time. 展开更多
关键词 balance of energy long UHV transmission line transmission line protection digital simulation
下载PDF
Attribution of Biases of Interhemispheric Temperature Contrast in CMIP6 Models
16
作者 Shiyan ZHANG Yongyun HU +1 位作者 Jiankai ZHANG Yan XIA 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第2期325-340,共16页
One of the basic characteristics of Earth's modern climate is that the Northern Hemisphere(NH) is climatologically warmer than the Southern Hemisphere(SH). Here, model performances of this basic state are examined... One of the basic characteristics of Earth's modern climate is that the Northern Hemisphere(NH) is climatologically warmer than the Southern Hemisphere(SH). Here, model performances of this basic state are examined using simulation results from 26 CMIP6 models. Results show that the CMIP6 models underestimate the contrast in interhemispheric surface temperatures on average(0.8 K for CMIP6 mean versus 1.4 K for reanalysis data mean), and that there is a large intermodel spread, ranging from -0.7 K to 2.3 K. A box model energy budget analysis shows that the contrast in interhemispheric shortwave absorption at the top of the atmosphere, the contrast in interhemispheric greenhouse trapping, and the crossequatorial northward ocean heat transport, are all underestimated in the multimodel mean. By examining the intermodel spread, we find intermodel biases can be tracked back to biases in midlatitude shortwave cloud forcing in AGCMs. Models with a weaker interhemispheric temperature contrast underestimate the shortwave cloud reflection in the SH but overestimate the shortwave cloud reflection in the NH, which are respectively due to underestimation of the cloud fraction over the SH extratropical ocean and overestimation of the cloud liquid water content over the NH extratropical continents.Models that underestimate the interhemispheric temperature contrast exhibit larger double ITCZ biases, characterized by excessive precipitation in the SH tropics. Although this intermodel spread does not account for the multimodel ensemble mean biases, it highlights that improving cloud simulation in AGCMs is essential for simulating the climate realistically in coupled models. 展开更多
关键词 interhemispheric temperature contrast energy balance shortwave cloud forcing ITCZ CMIP6 AGCM
下载PDF
Reduced protein diet with near ideal amino acid profile improves energy efficiency and mitigate heat production associated with lactation in sows 被引量:3
17
作者 Sai Zhang Jay S.Johnson +1 位作者 Mu Qiao Nathalie L.Trottier 《Journal of Animal Science and Biotechnology》 CAS CSCD 2020年第2期587-601,共15页
Background:The study objective was to test the hypothesis that 1)lowering dietary crude protein(CP)increases dietary energetic efficiency and reduces metabolic heat associated with lactation,and 2)excessive dietary le... Background:The study objective was to test the hypothesis that 1)lowering dietary crude protein(CP)increases dietary energetic efficiency and reduces metabolic heat associated with lactation,and 2)excessive dietary leucine(Leu)supplementation in a low CP diet decreases dietary energetic efficiency and increases metabolic heat associated with lactation.Methods:Fifty-four lactating multiparous Yorkshire sows were allotted to 1 of 3 isocaloric diets(10.80 MJ/kg net energy):1)control(CON;18.75%CP),2)reduced CP with a near ideal or optimal AA profile(OPT;13.75%CP)and 3)diet OPT with excessive Leu(OPTLEU;14.25%CP).Sow body weight and backfat were recorded on day 1 and 21 of lactation and piglets were weighed on day 1,4,8,14,18,and 21 of lactation.Energy balance was measured on sows during early(day 4 to 8)and peak(day 14 to18)lactation,and milk was sampled on day 8 and 18.Results:Over 21-day lactation,sows fed OPT lost body weight and body lipid(P<0.05).In peak lactation,sows fed OPT had higher milk energy output(P<0.05)than CON.Sows fed OPTLEU tended(P=0.07)to have less milk energy output than OPT and did not differ from CON.Maternal energy retention was lower(P<0.05)in OPT and OPTLEU compared to CON sows,and did not differ between OPTLEU and OPT sows.Sows fed OPT had higher(P<0.05)apparent energy efficiency for milk production compared to CON.Heat production associated with lactation was lower(P<0.05)or tended to be lower(P=0.082),respectively,in OPT and OPTLEU compared to CON sows.Conclusion:The OPT diet,in peak lactation,improved dietary energy utilization for lactation due to less urinary energy and metabolic heat loss,and triggered dietary energy deposition into milk at the expense of maternal lipid mobilization.Leucine supplementation above requirement may reduce dietary energy utilization for lactation by decreasing the energy partitioning towards milk,partially explaining the effectiveness of OPT diet over CON diets. 展开更多
关键词 Amino acid energy balance Heat production Lactating sows LEUCINE Reduced protein diet
下载PDF
A numerical study of coupled maps representing energy exchange processes between two environmental interfaces regarded as biophysical complex systems 被引量:1
18
作者 Dragutin Mihailovic Mirko Budincevic +2 位作者 Darko Kapor Igor Balaz Dusanka Perisic 《Natural Science》 2011年第1期75-84,共10页
The field of environmental sciences is abundant with various interfaces and is the right place for the application of new fundamental approaches leading towards a better understanding of environmental phenomena. Follo... The field of environmental sciences is abundant with various interfaces and is the right place for the application of new fundamental approaches leading towards a better understanding of environmental phenomena. Following the definition of environmental interface by Mihailovic and Bala? [1], such interface can be, for example, placed between: human or animal bodies and surrounding air, aquatic species and water and air around them, and natural or artificially built surfaces (vegetation, ice, snow, barren soil, water, urban communities) and the atmosphere, cells and surrounding environment, etc. Complex environmental interface systems are (i) open and hierarchically organised (ii) interactions between their constituent parts are nonlinear, and (iii) their interaction with the surrounding environment is noisy. These systems are therefore very sensitive to initial conditions, deterministic external perturbations and random fluctuations always present in nature. The study of noisy non-equilibrium processes is fundamental for modelling the dynamics of environmental interface regarded as biophysical complex system and for understanding the mechanisms of spatio-temporal pattern formation in contemporary environmental sciences. In this paper we will investigate an aspect of dynamics of energy flow based on the energy balance equation. The energy exchange between interacting environmen- tal interfaces regarded as biophysical complex systems can be represented by coupled maps. Therefore, we will numerically investigate coupled maps representing that exchange. In ana- lysis of behaviour of these maps we applied Lyapunov exponent and cross sample entropy. 展开更多
关键词 Environmental Interface NONLINEARITY CHAOS Logistic Equation energy balance Equation Coupled Maps HIERARCHY Biophysical Complex Systems
下载PDF
Prospect of energy management system for large steel enterprise
19
作者 ZHANG Qin Baosteel Engineering & Technology Group Co.,Ltd.,Shanghai 201900,China 《Baosteel Technical Research》 CAS 2010年第S1期97-,共1页
The energy management system(EMS),which acts as the heart of the energy management center of a steel enterprise,is a large computer system focused on the concentrative monitor and control of the production and utiliza... The energy management system(EMS),which acts as the heart of the energy management center of a steel enterprise,is a large computer system focused on the concentrative monitor and control of the production and utilization of energy.Although Chinese steel industry was well developed in the latest decade, so far the levels of the comprehensive energy consumption per ton steel among Chinese steel enterprises are remarkably distinct,and the average value of the comprehensive energy consumption per ton steel of them has still been much higher than the value of those in developed countries.This bad situation,in the opinion of the author,partially results from the poor ability for most Chinese steel enterprises to manage the production and utilization of energy.National policies associated to energy-saving and ejection-decreasing call for steel enterprises to build the EMS;and more and more steel enterprises themselves also desire to achieve EMS projects so that they can optimize their energy production and utilization.Baosteel,the largest and most advanced steel enterprise in China,has got plenty of experience in the EMS due to its incessant practice for more than 30 years in the design,construction,application,and revampment of its EMS.In the present article,the features of an advanced EMS is described and discussed based on the design practice of the EMS of Baosteel Zhanjiang Project.An advanced EMS should be an optimized and integrated system,which possesses of the characteristic of high managing efficiency,enough openness in expansion,friendly interfaces, and simple structure.Furthermore,it could support many-sided applications,e.g.,energy related data mineing,energy network combination and co-supply,application of geographic information technology,and other technical researched on energy-saving aspects.It is known that some energy-related indexes of Baosteel have stood on a high level better than those of some worldwide famous steel enterprises.Moreover,it goes without saying that the indexes of Baosteel Zhanjiang will be better than those of present Baosteel.Therefore, one can easily expect that the new EMS of Baosteel Zhanjiang will be much more advanced,which will be more helpful to fulfil systematiclly saving of energy,to elevate the efficiency of energy utilization,to lower the comprehensive energy consumption per ton steel. 展开更多
关键词 energy management system energy energy balance energy consumption real-time monitoring and controlling
下载PDF
Energy and Material Flow Evaluation with CO2 Emissions in the Glass Production Process
20
作者 Gregor Berger Zlatko Raonic +2 位作者 Daniel Forthuber Harald Raupenstrauch Robert Hermann 《Advances in Materials Physics and Chemistry》 2022年第5期82-105,共24页
Glass manufacturing is an energy-intensive process with high demands on product quality. The wide usage of glass products results in a high end-product diversity. In the past, many models have been developed... Glass manufacturing is an energy-intensive process with high demands on product quality. The wide usage of glass products results in a high end-product diversity. In the past, many models have been developed to optimize specific process steps, such as glass melting or glass forming. This approach presents a tool for the modeling of the entire glass manufacturing process for container glass, flat glass, and glass fibers. The tool considers detailed bottom-up energy and material balance in each step of the processing route with the corresponding costs and CO<sub>2</sub> emissions. Subsequently, it provides the possibility to quantify optimization scenarios in the entire glass manufacturing process in terms of energy, material and cost flow efficiency. 展开更多
关键词 energy Efficiency Glass Industry energy balance Container Glass Flat Glass Glass Fiber
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部