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Effects of Different Protein Energy Ratios on Fattening Performance,Slaughter Performance and Meat Quality of Pigs
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作者 Cui YANG Rongsheng JIANG +8 位作者 Yongshao WU Xiying YANG Haihong LIAO Qian QIN Shishan QIN Ying ZHANG Jiahuang YANG Limei QIN Fulin WANG 《Agricultural Biotechnology》 CAS 2023年第2期59-62,75,共5页
[Objectives]Protein energy ratio refers to the proportional relationship between protein and energy levels in animal diets,i.e.,the grams of crude protein corresponding to every megacalorie of energy,which is generall... [Objectives]Protein energy ratio refers to the proportional relationship between protein and energy levels in animal diets,i.e.,the grams of crude protein corresponding to every megacalorie of energy,which is generally expressed as CP:ME or CP:DE.This study was conducted to investigate the effects of different diets on fattening and slaughter performance and meat quality traits for"L(Large Yorkshire)×L(Landrace)"crossbred pigs.[Methods]Eighteen piglets of L×L crossbred with similar body weights about 51 kg were selected.The piglets were divided into 3 groups randomly and each group was assigned to 3 replicates with 2 piglets in a replicate.Group A was fed diet Ⅰ (control diet),group B was fed the same diet of group A in the first month of the trial but fed diet Ⅱ in second month,and group C consumed diet Ⅲ.All the pigs were fed in the same feeding condition for two months except the different diets during the trial.One pig in similar body weight from each replicate was slaughtered for the determination of slaughter performance and meat quality traits in the end of the trial.[Results]The average daily feed intake(ADFI)of pigs from group B was only(2.32±0.52)kg and significantly lower than those from group A and group C(P<0.05),but no difference was found in average daily gain(ADG) and feed/gain(P>0.05).Also,no differences occurred in the carcass length,back fat thickness,longissimus muscle (LM) area and dressing percentage(P>0.05).In addition,no differences were found in the meat quality traits of shear force,meat color,pH_(45 min),pH_(24 h) and cooking loss(P>0.05).However,the water-holding capacity of meat from group C was(2.58±0.02)ms and significantly lower than that of(2.80±0.20)ms from group A(P<0.05).Although the contents of glutamic acid and cystine in LM from group B was significantly lower than those from group A and group C(P<0.05),no differences occurred in the contents of other amino acids,the total amino acid and total flavor amino acid among the three groups(P>0.05).However,the inosine monophosphate content of LM from group C was only(331.80±11.53)mg/100 g and significantly lower than those of(361.00±6.36)and(366.37±4.80)mg/100 g from group A and B(P<0.05).Even though no differences were found in the contents of DM and CP in LM among the three groups of pigs,the content of intramuscular fat(IMF)in LM from group B and group C was increased by 45.6%and 46.58%respectively from that of group A(P<0.05),but no difference occurred between group B and C(P>0.05).[Conclusions]DietsⅡ and Ⅲ in this study caused no differences in fattening and slaughter performance of L×L crossbred pigs,but the effects on some meat traits were still significant,especially on the improvement of intramuscular fat in experimental pigs.Therefore,they could improve the meat quality of crossbred pigs to a certain extent. 展开更多
关键词 Protein energy ratio L×L crossbred FATTENING Slaughter performance Meat quality IMF
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Effects of pulse energy ratios on plasma characteristics of dual-pulse fiber-optic laser-induced breakdown spectroscopy
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作者 Yu-Hua Hang Yan Qiu +5 位作者 Ying Zhou Tao Liu Bin Zhu Kaixing Liao Ming-Xin Shi Fei Xue 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第2期387-397,共11页
Laser-induced plasmas of dual-pulse fiber-optic laser-induced breakdown spectroscopy with different pulse energy ratios are studied by using the optical emission spectroscopy(OES)and fast imaging.The energy of the two... Laser-induced plasmas of dual-pulse fiber-optic laser-induced breakdown spectroscopy with different pulse energy ratios are studied by using the optical emission spectroscopy(OES)and fast imaging.The energy of the two laser pulses is independently adjusted within 0–30 m J with the total energy fixed at 30 m J.The inter-pulse delay remains 450 ns constantly.As the energy share of the first pulse increases,a similar bimodal variation trend of line intensities is observed.The two peaks are obtained at the point where the first pulse is half or twice of the second one,and the maximum spectral enhancement is at the first peak.The bimodal variation trend is induced by the change in the dominated mechanism of dual-pulse excitation with the trough between the two peaks caused by the weak coupling between the two mechanisms.By increasing the first pulse energy,there is a transition from the ablation enhancement dominance near the first peak to the plasma reheating dominance near the second peak.The calculations of plasma temperature and electron number density are consistent with the bimodal trend,which have the values of 17024.47 K,2.75×10^(17)cm;and 12215.93 K,1.17×10^(17)cm;at a time delay of 550 ns.In addition,the difference between the two peaks decreases with time delay.With the increase in the first pulse energy share,the plasma morphology undergoes a transformation from hemispherical to shiny-dot and to oblate-cylinder structure during the second laser irradiation from the recorded images by using an intensified charge-coupled device(ICCD)camera.Correspondingly,the peak expansion distance of the plasma front first decreases significantly from 1.99 mm in the single-pulse case to 1.34 mm at 12/18(dominated by ablation enhancement)and then increases slightly with increasing the plasma reheating effect.The variations in plasma dynamics verify that the change of pulse energy ratios leads to a transformation in the dual-pulse excitation mechanism. 展开更多
关键词 fiber-optic laser-induced breakdown spectroscopy(FO-LIBS) dual-pulse excitation pulse energy ratio spectral enhancement
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Load-bearing characteristics and energy evolution of fractured rock masses after granite and sandstone grouting
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作者 WU Xu-kun ZHAO Guang-ming +4 位作者 MENG Xiang-rui LIU Chong-yan LIU Zhi-xi HUANG Shun-jie ZHANG Qi-hang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2810-2825,共16页
Experiments on grouting-reinforced rock mass specimens with different particle sizes and features were carried out in this study to examine the effects of grouting reinforcement on the load-bearing characteristics of ... Experiments on grouting-reinforced rock mass specimens with different particle sizes and features were carried out in this study to examine the effects of grouting reinforcement on the load-bearing characteristics of fractured rock mass.The strength and deformation features of grouting-reinforced rock mass were analyzed under different loading manners;the energy evolution mechanism of grouting-reinforced rock mass specimens with different particle sizes and features was investigated;the energy dissipation ratio and post-peak stress decreasing rate were employed to evaluate the bearing stability of grouting-reinforced rock mass.The results show that the strength and ductility of granite-reinforced rock mass(GRM)under biaxial loading are higher than that of sandstone-reinforced rock mass(SRM)under uniaxial loading.Besides,the energy evolution characteristics of grouting-reinforced rock mass under uniaxial and biaxial loading mainly could be divided into early,middle,and late stages.In the early stage,total,elastic,and dissipation energies were quite small with flatter curves;in the middle stage,elastic energy increased rapidly,whereas dissipation energy increased slowly;in the late stage,dissipation energy increased sharply.The energy dissipation ratio was used to represent the pre-peak plastic deformation.Under uniaxial loading,this ratio increased as the particle size increased and the pre-peak plastic deformation of grouting-reinforced rock mass became larger;under biaxial loading,it dropped as the particle size increased,and the pre-peak plastic deformation of grouting-reinforced rock mass became smaller.The post-peak stress decline rate A_(v) was used to assess the post-peak bearing performance of grouting-reinforced rock mass.Under uniaxial loading,parameter A_(v) exhibited reduction as the particle size kept increasing,and the ability of post-peak of grouting-reinforced rock mass to allow deformation development was greater,and the bearing capacity was greater;under biaxial loading,A_(v) increased with the particle size,and the ability of post-peak of grouting-reinforced rock mass to allow deformation development was low and the bearing capacity was reduced.The findings are considered instrumental in improving the stability of the roadway-surrounding rock by granite and sandstone grouting. 展开更多
关键词 grouting-reinforced rock mass particle size energy dissipation ratio post-peak stress decreasing rate load-bearing characteristics
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Simulation Study of Diesel Spray Tilt Angle and Ammonia Energy Ratio Effect on Ammonia-Diesel Dual-Fuel Engine Performance
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作者 Zhifeng Zhao Xuelong Miao +4 位作者 Xu Chen Jinbao Zheng Yage Di Zhenjie Bao Zhuo Yang 《Energy Engineering》 EI 2024年第9期2603-2620,共18页
Ammonia-diesel dual fuel(ADDF)engines for transportation applications are an important way to reduce carbon emissions.In order to achieve better combustion of ammonia in diesel engines.A small-bore single-cylinder eng... Ammonia-diesel dual fuel(ADDF)engines for transportation applications are an important way to reduce carbon emissions.In order to achieve better combustion of ammonia in diesel engines.A small-bore single-cylinder engine was converted into an ADDF engine with the help of mature computational fluid dynamics(CFD)simulation software to investigate the performance of an engine with a high ammonia energy ratio(AER),and to study the effect of spray tilt angle on ADDF engine.The results showed that the increase in AER reduced nitric oxide(NO)and nitrogen dioxide(NO2)emissions but increased nitrous oxide(N2O)and unburned ammonia emissions.AER in the range of 50%-70%achieved lower greenhouse gases(GHG)emissions than the pure diesel mode.Relative to the pure diesel mode,when the AER was 60%,the indicated thermal efficiency(ITE)was increased by 0.2%and the GHG emissions were decreased by 22.3%,but carbon monoxide(CO)and Hydrocarbon(HC)emissions were increased.Increasing the in-cylinder combustion temperature or high-temperature region range of the ADDF engine could reduce GHG emissions.At an AER of 60%,an increase in the spray tilt angle helped the ammonia combustion in the residual gap to reduce the unburned ammonia emissions.Compared to the pure diesel mode with a spray tilt angle of 75°,an AER of 60%with a spray tilt angle of 77.5°improved the ITE by 1.5%,and reduced theGHGemissions by 25.7%.Adjusting the spray tilt angle of theADDFengine also reducedCOandHCemissions.This is an effective way to improve ADDF engine performance by adjusting the spray tilt angle. 展开更多
关键词 Ammonia-diesel engine ammonia energy ratio greenhouse gases carbon-free fuel
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Economic feasibility and efficiency enhancement approaches for in situ upgrading of low-maturity organic-rich shale from an energy consumption ratio perspective
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作者 LU Shuangfang WANG Jun +5 位作者 LI Wenbiao CAO Yixin CHEN Fangwen LI Jijun XUE Haitao WANG Min 《地学前缘》 EI CAS CSCD 北大核心 2023年第1期281-295,共15页
The technical feasibility of in situ upgrading technology to develop the enormous oil and gas resource potential in low-maturity shale is widely acknowledged.However,because of the large quantities of energy required ... The technical feasibility of in situ upgrading technology to develop the enormous oil and gas resource potential in low-maturity shale is widely acknowledged.However,because of the large quantities of energy required to heat shale,its economic feasibility is still a matter of debate and has yet to be convincingly demonstrated quantitatively.Based on the energy conservation law,the energy acquisition of oil and gas generation and the energy consumption of organic matter cracking,shale heat-absorption,and surrounding rock heat dissipation during in situ heating were evaluated in this study.The energy consumption ratios for different conditions were determined,and the factors that influence them were analyzed.The results show that the energy consumption ratio increases rapidly with increasing total organic carbon(TOC)content.For oil-prone shales,the TOC content corresponding to an energy consumption ratio of 3 is approximately 4.2%.This indicates that shale with a high TOC content can be expected to reduce the project cost through large-scale operation,making the energy consumption ratio after consideration of the project cost greater than 1.In situ heating and upgrading technology can achieve economic benefits.The main methods for improving the economic feasibility by analyzing factors that influence the energy consumption ratio include the following:(1)exploring technologies that efficiently heat shale but reduce the heat dissipation of surrounding rocks,(2)exploring technologies for efficient transformation of organic matter into oil and gas,i.e.,exploring technologies with catalytic effects,or the capability to reduce in situ heating time,and(3)establishing a horizontal well deployment technology that comprehensively considers the energy consumption ratio,time cost,and engineering cost. 展开更多
关键词 shale gas content in situ upgrading energy consumption ratio high-efficiency heating efficient organic matter transformation
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Research on Energy-Saving Performance of Intermittent Heating for Rooms in Hot Summer&ColdWinter Zone
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作者 Guoqing Yu Nan Fang +1 位作者 Dingke Hu Wei Zhao 《Energy Engineering》 EI 2023年第7期1563-1582,共20页
In the hot summer&cold winter zone in China,intermittent heating space for rooms is widely used.However,in comparison with continuous space heating,the energy-saving performance of intermittent space heating has n... In the hot summer&cold winter zone in China,intermittent heating space for rooms is widely used.However,in comparison with continuous space heating,the energy-saving performance of intermittent space heating has not been sufficiently investigated.This paper studied the factors influencing the energy performance of intermittent heating for the representativeoffice inhot summer&coldwinter zone.Basedon theheatbalancemethod,adynamic thermalmodel of the intermittent heating roomwas built and tested by experiments.And then,it analyzed the total space heating load,the amount of energy saving and energy saving ratio of the intermittent heating under different preheating hours,occupation hours,required roomtemperatures,air change rates,overall heat transfer coefficients(U-value)of windows and wall materials.If the adjacent rooms were not heated,for a typical room occupied about 10 h a day,the energy-saving ratio of intermittent heating was about 30%compared with continuous heating.But the preheating power was higher than two times of continuous heating.The results also indicated that the occupation hours had a significant effect on energy saving amount and ratio,it should be noted that the energy saving ratio by intermittent heating was much lower than the unoccupied period ratio.Relative to other factors,the heating temperatures,room air change rates and U-value of windows,and room envelope materials had little effect on energy efficiency.If the adjacent rooms were heated in the same manner as the roomin question,the energy-saving ratio of the total load of intermittent heating was heavily reduced to 8.46%. 展开更多
关键词 Intermittent heating space heat load continuous heating hot summer&cold winter zone energy saving ratio
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On the Ratios Dark Matter (Energy)/Ordinary Matter ≈5.4(13.6) in the Universe
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作者 F. C. Hoh 《Journal of Modern Physics》 2020年第7期967-975,共9页
An upper limit of the average ratio dark matter/ordinary matter in galaxies is estimated to be 8.4, in agreement with the observed ratio 5.4. Upper limit of the average ratio dark energy/ordinary matter for slowly mov... An upper limit of the average ratio dark matter/ordinary matter in galaxies is estimated to be 8.4, in agreement with the observed ratio 5.4. Upper limit of the average ratio dark energy/ordinary matter for slowly moving protons in the outer parts of the universe is estimated to be 8.4, much less than the observed ratio 13.6. The discrepancy is tentatively attributed to that the bulk of the protons in these outer parts of the universe moves fastly and their contribution to dark energy has not been estimated. The positive and negative relative energies between the diquark and quark in the proton play the roles of dark energy and dark matter, respectively. 展开更多
关键词 Relative energy Between Quarks Scalar Strong Interaction Hadron Theory Ratio of Dark Matter to Ordinary Matter Ratio of Dark energy to Ordinary Matter Gravitational Pull of Diquark and Quark Proton Orbit Diquark Equations
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Estimation of quality factors by energy ratio method 被引量:1
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作者 王宗俊 曹思远 +5 位作者 张浩然 曲英铭 袁殿 杨金浩 张德龙 邵冠铭 《Applied Geophysics》 SCIE CSCD 2015年第1期86-92,122,123,共9页
The quality factor Q, which reflects the energy attenuation of seismic waves in subsurface media, is a diagnostic tool for hydrocarbon detection and reservoir characterization. In this paper, we propose a new Q extrac... The quality factor Q, which reflects the energy attenuation of seismic waves in subsurface media, is a diagnostic tool for hydrocarbon detection and reservoir characterization. In this paper, we propose a new Q extraction method based on the energy ratio before and after the wavelet attenuation, named the energy-ratio method(ERM). The proposed method uses multipoint signal data in the time domain to estimate the wavelet energy without invoking the source wavelet spectrum, which is necessary in conventional Q extraction methods, and is applicable to any source wavelet spectrum; however, it requires high-precision seismic data. Forward zero-offset VSP modeling suggests that the ERM can be used for reliable Q inversion after nonintrinsic attenuation(geometric dispersion, refl ection, and transmission loss) compensation. The application to real zero-offset VSP data shows that the Q values extracted by the ERM and spectral ratio methods are identical, which proves the reliability of the new method. 展开更多
关键词 Quality factor Q energy ratio time domain seismic wavelet spectral ratio method
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Effects of dietary protein/energy ratio on growth performance,carcass trait,meat quality,and plasma metabolites in pigs of different genotypes 被引量:39
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作者 Yingying Liu Xiangfeng Kong +6 位作者 Guoli Jiang Bi'e Tan Jinping Deng Xiaojian Yang Fengna Li Xia Xiong Yulong Yin 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2015年第4期435-444,共10页
Background: The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and incre... Background: The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment. This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance, carcass traits, meat quality, and plasma metabolites of pigs of different genotypes. Methods: Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups (Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio; n = 24 per treatment) in a 2 x 2 factorial arrangement. Blood and muscle samples were collected at the end of the nursery, growing, and finishing phases. Results: We observed significant interactions (P 〈 0.05) between breed and diet for total fat percentage, intramuscular fat (IMF) content, protein content in biceps femoris (BF) muscle, and plasma urea nitrogen (UN) concentration in the nursery phase; for average daily gain (ADG), average daily feed intake (ADFI), dry matter, IMF content in psoas major (PM) muscle, and plasma total protein and albumin concentrations in the growing phase; and for drip loss and plasma UN concentration in the finishing phase. Breed influenced (P 〈 0.05) growth performance, carcass traits, and meat quality, but not plasma metabolites. Throughout the trial, Landrace pigs showed significantly higher (P 〈 0.0_5) ADG, ADFI, dressing percentage, lean mass rate, and loin-eye area than did Bama mini-pigs, but significantly lower (P 〈 0.0.5) feed/gain ratio, fat percentage, backfat thickness, and IMF content. Dietary protein/energy ratio influenced the pH value, chemical composition of BF and PM muscles, and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase, and plasma concentration of UN. Conclusions: Compared with Landrace pigs, Bama mini-pigs showed slower growth and lower carcass performance, but had better meat quality. Moreover, unlike Landrace pigs, the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs. These results suggest that, in swine production, low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment. 展开更多
关键词 Dietary protein/energy ratio Growth performance Meat quality MINI-PIG Plasma metabolites
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Net energy yield and carbon footprint of summer corn under different N fertilizer rates in the North China Plain 被引量:4
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作者 WANG Zhan-biao WEN Xin-ya +2 位作者 ZHANG Hai-lin LU Xiao-hong CHEN Fu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2015年第8期1534-1541,共8页
Excessive use of N fertilizer in intensive agriculture can increase crop yield and at the same time cause high carbon(C) emissions.This study was conducted to determine optimized N fertilizer application for high gr... Excessive use of N fertilizer in intensive agriculture can increase crop yield and at the same time cause high carbon(C) emissions.This study was conducted to determine optimized N fertilizer application for high grain yield and lower C emissions in summer corn(Zea mays L.).A field experiment, including 0(N0), 75(N75), 150(N150), 225(N225), and 300(N300) kg N ha–1 treatments, was carried out during 2010–2012 in the North China Plain(NCP).The results showed that grain yield, input energy, greenhouse gas(GHG) emissions, and carbon footprint(CF) were all increased with the increase of N rate, except net energy yield(NEY).The treatment of N225 had the highest grain yield(10 364.7 kg ha–1) and NEY(6.8%), but the CF(0.25) was lower than that of N300, which indicates that a rate of 225 kg N ha–1 can be optimal for summer corn in NCP.Comparing GHG emision compontents, N fertilizer(0–51.1%) was the highest and followed by electricity for irrigation(19.73–49.35%).We conclude that optimazing N fertilizer application rate and reducing electricity for irrigation are the two key measures to increase crop yield, improve energy efficiency and decrease GHG emissions in corn production. 展开更多
关键词 MAIZE nitrogen fertilizer rate grain yield net energy ratio greenhouse gas emissions
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Application of empirical mode decomposition based energy ratio to vortex flowmeter state diagnosis 被引量:4
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作者 孙志强 张宏建 《Journal of Central South University》 SCIE EI CAS 2009年第1期154-159,共6页
To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into i... To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into intrinsic mode functions using the empirical mode decomposition approach. Based on the empirical mode decomposition results, the energy of each intrinsic mode function was extracted, and the vortex energy ratio was proposed to analyze how the perturbation in the flow affected the measurement performance of the vortex flowmeter. The relationship between the vortex energy ratio of the signal and the flow condition was established. The results show that the vortex energy ratio is sensitive to the flow condition and ideal for the characterization of the vortex flowmeter signal. Moreover, the vortex energy ratio under normal flow condition is greater than 80%, which can be adopted as an indicator to diagnose the state of a vortex flowmeter. 展开更多
关键词 flow state diagnosis energy ratio vortex flowmeter empirical mode decomposition
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Dietary lipid and gross energy affect protein utilization in the rare minnow Gobiocypris rarus 被引量:2
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作者 吴本丽 熊小琴 +1 位作者 解绶启 王剑伟 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第4期740-748,共9页
An 8-week feeding trial was conducted to detect the optimal dietary protein and energy, as well as the ef fects of protein to energy ratio on growth, for the rare minnow( Gobiocypris rarus), which are critical to nutr... An 8-week feeding trial was conducted to detect the optimal dietary protein and energy, as well as the ef fects of protein to energy ratio on growth, for the rare minnow( Gobiocypris rarus), which are critical to nutrition standardization for model fi sh. Twenty-four diets were formulated to contain three gross energy(10, 12.5, 15 kJ/g), four protein(20%, 25%, 30%, 35%), and two lipid levels(3%, 6%). The results showed that optimal dietary E/P was 41.7–50 kJ/g for maximum growth in juvenile rare minnows at 6% dietary crude lipid. At 3% dietary lipid, specifi c growth rate(SGR) increased markedly when E/P decreased from 62.5 kJ/g to 35.7 kJ/g and gross energy was 12.5 kJ/g, and from 75 kJ/g to 42.9 kJ/g when gross energy was 15.0 kJ/g. The optimal gross energy was estimated at 12.5 kJ /g and excess energy decreased food intake and growth. Dietary lipid exhibited an apparent protein-sparing eff ect. Optimal protein decreased from 35% to 25%–30% with an increase in dietary lipid from 3% to 6% without adversely ef fecting growth. Dietary lipid level af fects the optimal dietary E/P ratio. In conclusion, recommended dietary protein and energy for rare minnow are 20%–35% and 10–12.5 k J/g, respectively. 展开更多
关键词 rare minnow Gobiocypris rarus protein to energy ratio(E/P) crude lipid GROWTH
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Relative energy zero ratio-based approach for identifying pulse-like ground motions 被引量:2
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作者 Liu Ping Li Ning +2 位作者 Ma Hua Xie Lili Zhou Baofeng 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2020年第1期1-16,共16页
Pulse-like ground motions are capable of inflicting significant damage to structures. Efficient classification of pulse-like ground motion is of great importance when performing the seismic assessment in near-fault re... Pulse-like ground motions are capable of inflicting significant damage to structures. Efficient classification of pulse-like ground motion is of great importance when performing the seismic assessment in near-fault regions. In this study, a new method for identifying the velocity pulses is proposed, based on different trends of two parameters: the short-time energy and the short-time zero crossing rate of a ground motion record. A new pulse indicator, the relative energy zero ratio(REZR), is defined to qualitatively identify pulse-like features. The threshold for pulse-like ground motions is derived and compared with two other identification methods through statistical analysis. The proposed procedure not only shows good accuracy and efficiency when identifying pulse-like ground motions but also exhibits good performance for classifying records with high-frequency noise and discontinuous pulses. The REZR method does not require a waveform formula to express and fit the potential velocity pulses;it is a purely signal-based classification method. Finally, the proposed procedure is used to evaluate the contribution of pulse-like motions to the total input energy of a seismic record, which dramatically increases the seismic damage potential. 展开更多
关键词 pulse-like ground motion velocity pulse relative energy zero-crossing ratio short-time input energy shorttime zero crossing rate
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Effect of specimen size on energy dissipation characteristics of red sandstone under high strain rate 被引量:26
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作者 Li Ming Mao Xianbiao +4 位作者 Lu Aihong Tao Jing Zhang Guanghui Zhang Lianying Li Chong 《International Journal of Mining Science and Technology》 SCIE EI 2014年第2期151-156,共6页
In this experiment, red sandstone specimens, having slenderness ratios of 0.5, 0.7, 0.9 and 1.1 respectively, were subjected to blow tests using a Split Hopkinson Pressure Bar(SHPB) system at a pressure of 0.4 atmosph... In this experiment, red sandstone specimens, having slenderness ratios of 0.5, 0.7, 0.9 and 1.1 respectively, were subjected to blow tests using a Split Hopkinson Pressure Bar(SHPB) system at a pressure of 0.4 atmospheres. In this paper, we have analyzed the effect of slenderness ratio on the mechanical properties and energy dissipation characteristics of red sandstone under high strain rates. The processes of compaction, elastic deformation and stress softening deformation of specimens contract with an increase in slenderness ratio, whilst the nonlinear deformation process extends correspondingly. In addition, degrees of damage of specimens reduced gradually and the type of destruction showed a transformation trend from stretching failure towards shear failure when the slenderness ratio increased. A model of dynamic damage evolution in red sandstone was established and the parameters of the constitutive model at different ratios of length to diameter were determined. By comparison with the experimental curve, the accuracy of the model, which could reflect the stress–strain dynamic characteristics of red sandstone, was verified. From the view of energy dissipation, an increase in slenderness ratio of a specimen decreased the proportion of energy dissipation and caused a gradual fall in the capability of energy dissipation during the specimen failure process. To some extent, the study indicated the effects of slenderness ratios on the mechanical properties and energy dissipation characteristics of red sandstone under the high strain rate, which provides valuable references to related engineering designs and academic researches. 展开更多
关键词 Red sandstone Slenderness ratio SHP BImpact failure energy dissipation
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ADAPTIVE EIGENFREQUENCY ANALYSIS BY IMPROVED r-AND h-ADAPTIVE FINITE ELEMENT METHOD BASED ON PERTURBATION AND ELEMENT ENERGY RATIO
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作者 Liu Hanbing Gong Guoqing Wei Yuan 《Acta Mechanica Solida Sinica》 SCIE EI 2001年第4期349-356,共8页
A new adaptive technique of r-and h-version for vibration problemsutilizing the matrix per- turbation theory and element energy ratiois proposed. In structural vibration analysis, through the r-conver-gence adaptvie f... A new adaptive technique of r-and h-version for vibration problemsutilizing the matrix per- turbation theory and element energy ratiois proposed. In structural vibration analysis, through the r-conver-gence adaptvie finite element process, mesh optimization can berealized. In the light of the judgement on the changes in themagnitude of the element energy ratio, local refinement can beachieved in the process of h- convergence adaptive finite element sothat more accurate finite element solutions can be obtained with asfew meshes as possible. Many numerical examples are given and theproposed approach is shown to be feasible and effective. 展开更多
关键词 r-and h-adaptive FEM iterative perturbation element energy ratio eigenvalue problems
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Zonal flow energy ratio evolution during L-H and H-L transitions in EAST plasmas
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作者 Hailin ZHAO Tao LAN +8 位作者 Adi LIU Defeng KONG Huagang SHEN Jie WU Wandong LIU Changxuan YU Wei ZHANG Guosheng XU Baonian WAN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2017年第3期54-61,共8页
The essential role of zonal flow in the L-H transition and the suppression of turbulence have been studied with a long range correlation technique using Langmuir probe arrays in EAST tokamak.Two toroidally localized p... The essential role of zonal flow in the L-H transition and the suppression of turbulence have been studied with a long range correlation technique using Langmuir probe arrays in EAST tokamak.Two toroidally localized probe arrays are used to measure the zonal flow during L-H transition and H-L back transition.The energy ratio of the low frequency zonal flow to the total drift wave turbulence is calculated.During ELM-free H mode,the energy ratio is higher than that in L mode,which reveals the important role of zonal flows in regulating turbulence amplitude in L-H transition. 展开更多
关键词 zonal flow L-H transition energy ratio
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Net Energy Ratio and Greenhouse Gas Analysis of a Biogas Power Plant
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作者 Wolfgang Bauer 《Journal of Energy and Power Engineering》 2013年第9期1656-1661,共6页
The results of a net energy life cycle analysis and greenhouse gas analysis for a 1.45 MW (0.71 MW electrical) biogas power plant operating with a 70% corn silage and 30% cow dung feedstock mixture are presented aft... The results of a net energy life cycle analysis and greenhouse gas analysis for a 1.45 MW (0.71 MW electrical) biogas power plant operating with a 70% corn silage and 30% cow dung feedstock mixture are presented after its initial five years of operation. A ratio of 8.0 for the total output electrical energy divided by the total input energy from fossil fuels is found. A net efficiency of 1.2% of converting solar energy into electricity and usable heat (0.6% electricity) is achieved. Only 16 g CO2 per kWh are generated in the process. If all greenhouse gases are considered, this process even actively reduces the total greenhouse gas load on the atmosphere. In terms of producing transportation biofuels, this process provides 3.8 times more yield per hectare than bioethanol generation. 展开更多
关键词 BIOGAS renewable energy POWER greenhouse gas net energy ratio.
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Channel Slope Effect on Energy Dissipation of Flow over Broad Crested Weirs
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作者 Shaymaa A. M. Al-Hashimi Huda M. Madhloom +1 位作者 Thameen N. Nahi Nadhir Al-Ansari 《Engineering(科研)》 2016年第12期837-851,共15页
The main purpose of broad crested weir used in open channels is to raise and control upstream (U/S) water level. In this study, a new performance was added to this weir, by making a step at downstream (D/S) of weir. T... The main purpose of broad crested weir used in open channels is to raise and control upstream (U/S) water level. In this study, a new performance was added to this weir, by making a step at downstream (D/S) of weir. The energy dissipation, the height of the weir/the upstream water height ratio and Froude number relationships (E% – P/h – Fr) for three range of flume slop S = 0.0, 0.002 and 0.004 were simulated. The experiments were performed in a laboratory horizontal channel of 4.6 m length, 0.3 m width and 0.3 m depth for a wide range of discharge. The D/S step height of the weir was 7.5 cm. FLUENT software was used as numerical model which represent a type of Computational Fluid Dynamics (CFD) model in order to simulate flow over weirs. The Volume of Fluid (VOF) method with the Standard k – ε turbulence model was used to estimate the free surface profile and the structured mesh with high concentration near the wall regions. The experimental results of the water surface profile gave a high agreement with the results of the numerical models. The maximum value 28.78 of E% was obtained in single step broad crested weir in the experimental result and 27.35 in numerical result at S = 0.004. Finally, the range of the relative error of the energy dissipation between experimental and numerical results was achieved and the maximum was 6.76 in all runs. 展开更多
关键词 Broad Crested Weir Numerical CFD Model Standard k ε Turbulence Model energy Dissipation Ratio (E%) Sloping Flume
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Analysis of a Water-Cooled Unit under Different Loads
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作者 Daoming Shen Jinhong Xia +1 位作者 Chao Gui Songtao Xue 《Fluid Dynamics & Materials Processing》 EI 2023年第7期1863-1873,共11页
In order to ensure the safe operation of the compressors used in water chillers,in the present study some interlock protections have been added to the related design.These include a low pressure protection,a high pres... In order to ensure the safe operation of the compressors used in water chillers,in the present study some interlock protections have been added to the related design.These include a low pressure protection,a high pressure protection,an exhaust temperature protection and a differential pressure protection.Some tests have been conducted by tuning the saturation suction and exhaust temperatures of the compressor through adjustment of the cold source outlet temperature and the ambient temperature.The results show that the ambient temperature increases with decreasing device load and increasing fan speed under the same saturated suction temperature;the device refrigerating capacity steps up with augmenting load and dropping saturation exhaust temperature,while it is not greatly affected by the fan speed.Moreover,the Energy efficiency ratio(COP)decreases with the rise of the saturation exhaust temperature.This parameter is not affected much by the device load and fan speed at high saturation exhaust temperature,while it improves on increasing the device load and decreasing the fan speed at low saturation exhaust temperature. 展开更多
关键词 Ambient temperature cold source temperature refrigerating capacity energy efficiency ratio(COP) fan speed LOAD
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Broadband and wide-angle plane focal surface Luneburg lens
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作者 李珏 周杨阳 陈焕阳 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期16-20,共5页
The energy crisis has aroused widespread concern, and the reform of energy structure is imminent. In the future,the energy structure will be dominated by the solar energy and other renewable energy sources. The solar ... The energy crisis has aroused widespread concern, and the reform of energy structure is imminent. In the future,the energy structure will be dominated by the solar energy and other renewable energy sources. The solar concentrating technology as a promising method has been widely studied for collecting solar energy. However, the previous solar concentrating technologies suffer from some drawbacks, such as low focusing efficiency and large concentrating size. The Luneburg lens with highly efficient aberration-free focusing provides a new route for solar/energy concentrator. In this work, we designed a plane focal surface Luneburg lens(PFSLL) by transformation optics(TO). The PFSLL provides a relatively high focusing efficiency and concentration ratio of collection of energy. At the same time, it circumvents the disadvantage of curve surface of the classical Luneburg lens in device integration. Based on the reciprocity of electromagnetic waves, the PFSLL can also be applied to the antenna field to achieve broadband wide-angle scanning and highly directional radiation. 展开更多
关键词 plane focal surface Luneburg lens(PFSLL) focusing efficiency concentration ratio of collection of energy
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