This work concerns an experimental and numerical study of energy losses in a typical oven usually used in the agro-food craft sector in Burkina Faso. The experimental results were obtained by infrared thermography of ...This work concerns an experimental and numerical study of energy losses in a typical oven usually used in the agro-food craft sector in Burkina Faso. The experimental results were obtained by infrared thermography of the oven and by monitoring the evolution of the wall temperatures using thermocouples connected to a data acquisition system. These results indicate that the energy losses are mainly through the walls of the oven. The numerical study based on the energy balance and corroborated by the experimental study made it possible to quantify these losses of energy which represents almost half of the fuel used. These results will allow us to work on a new, more efficient oven model for the grilling sector in Burkina Faso.展开更多
Collisions between multibody systems are irreversible processes which cause loss of internal energy by a stress wave that propagates in the impacting bodies away from the region of impact. A coefficient of restitution...Collisions between multibody systems are irreversible processes which cause loss of internal energy by a stress wave that propagates in the impacting bodies away from the region of impact. A coefficient of restitution relating to approach velocity is introduced to denote the losses of translational kinetic energy. A parameter β involved in internal energy losses has been obtained to calculate the coefficient of restitution. As a result, the internal energy losses caused by elastic stress waves and the contact duration in metals can be calculated numerically for the collision between circular cylinder and half plane. The metals include aluminum alloys, steel-mild 1020, steel-stainless austenitic 304, tungsten alloys, copper alloys, nickel alloys and titanium alloys. By introducing a coefficient of velocity-frequency, an exponential aggression equation related the normalized oscillating frequency and normalized approach velocity has been obtained by the numerical method.展开更多
This study proposes a new method which aims to optimally install tie-lines and distributed generations simultaneously.This is done to optimize the post-outage reconfiguration and minimize energy losses and energy not ...This study proposes a new method which aims to optimally install tie-lines and distributed generations simultaneously.This is done to optimize the post-outage reconfiguration and minimize energy losses and energy not supplied of distribution systems.The number and location of tie-lines,as well as the number,size,and location of DGs,are pinpointed through teaching the learning-based optimization(TLBO)method.The objective function in the current research is to minimize the costs pertaining to the investment,operation,energy losses,and energies not supplied.In addition to the normal operational condition,fault operational condition is also evaluated.Therefore,the optimal post-fault reconfigurations for fault occurrences in all lines are established.Moreover,the operational constraints such as the voltage and line current limits are taken into account in both normal and post-fault operational modes.Finally,the modified IEEE 33-bus and 69-bus distribution test systems are selected and tested to demonstrate the effectiveness of the simultaneous placement of DGs and tie-line technique proposed in this paper.展开更多
Due to the influence of magnetic hysteresis and energy loss inherent in giant magnetostrictive materials (GMM), output displacement accuracy of giant magnetostrictive actuator (GMA) can not meet the precision and ...Due to the influence of magnetic hysteresis and energy loss inherent in giant magnetostrictive materials (GMM), output displacement accuracy of giant magnetostrictive actuator (GMA) can not meet the precision and ultra precision machining. Using a GMM rod as the core driving element, a GMA which may be used in the field of precision and ultra precision drive engineering is designed through modular design method. Based on the Armstrong theory and elastic Gibbs free energy theory, a nonlinear magnetostriction model which considers magnetic hysteresis and energy loss characteristics is established. Moreover, the mechanical system differential equation model for GMA is established by utilizing D'Alembert's principle. Experimental results show that the model can preferably predict magnetization property, magnetic potential orientation, energy loss for GMM. It is also able to describe magnetostrictive elongation and output displacement of GMA. Research results will provide a theoretical basis for solving the dynamic magnetic hysteresis, energy loss and working precision for GMA fundamentally.展开更多
In an Underwater Wireless Sensor Network(UWSN),extreme energy loss is carried out by the early expiration of sensor nodes and causes a reduction in efficiency in the submerged acoustic sensor system.Systems based on c...In an Underwater Wireless Sensor Network(UWSN),extreme energy loss is carried out by the early expiration of sensor nodes and causes a reduction in efficiency in the submerged acoustic sensor system.Systems based on clustering strategies,instead of each node sending information by itself,utilize cluster heads to collect information inside the clusters for forwarding collective information to sink.This can effectively minimize the total energy loss during transmission.The environment of UWSN is 3D architecture-based and follows a complex hierarchical clustering strategy involving its most effecting unique parameters such as propagation delay and limited transmission bandwidth.Round base clustering strategy works in rounds,where each round comprises three fundamental stages:cluster head selection,grouping or node association,and data aggregation followed by forwarding data to the sink.In UWSN,the energy consumed during the formation of clusters has been considered casually or completely evaded in the previous works.In this paper,the cluster head setup period has been considered the main contributor to extra energy utilizer.A numerical channel model is proposed to compute extra energy.It is performed by using a UWSN broad model.The results have shown that extra maximum energy consumption is approximately 12.9 percent of the system total energy consumed in information transmissions.展开更多
An ultra-high vacuum (UHV) compatible electron spectrometer employing a double toroidal analyzer has been de- veloped. It is designed to be combined with a custom-made scanning tunneling microscope (STM) to study ...An ultra-high vacuum (UHV) compatible electron spectrometer employing a double toroidal analyzer has been de- veloped. It is designed to be combined with a custom-made scanning tunneling microscope (STM) to study the spatially localized electron energy spectrum on a surface. A tip-sample system composed of a piezo-driven field-emission tungsten tip and a sample of highly ordered pyrolytic graphite (HOPG) is employed to test the performance of the spectrometer. Two-dimensional images of the energy-resolved and angle-dispersed electrons backscattered from the surface of HOPG are obtained, the performance is optimized and the spectrometer is calibrated. A complete electron energy loss spectrum covering the elastic peak to the secondary electron peaks for the HOPG surface, acquired at a tip voltage of -140 V and a sample current of 0.5 pA, is presented, demonstrating the viability of the spectrometer.展开更多
The oxidation microstructure and maximum energy product (BH)max loss of a 8m(Co0.76, Fe0.1, Cu0.1, Zr0.04)7 magnet oxidized at 500 ℃ were systematically investigated. Three different oxidation regions were formed...The oxidation microstructure and maximum energy product (BH)max loss of a 8m(Co0.76, Fe0.1, Cu0.1, Zr0.04)7 magnet oxidized at 500 ℃ were systematically investigated. Three different oxidation regions were formed in the oxidized magnet: a continuous externM oxide scale, an internal reaction layer, and a diffusion zone. Both room-temperature and high-temperature (BH)max losses exhibited the same parabolic increase with oxidation time. An oxygen diffusion model was proposed to simulate the dependence of (BH)max loss on oxidation time. It is found that the external oxide scale has little effect on the (BH)max loss, and both the internal reaction layer and diffusion zone result in the (BH)max loss. Moreover, the diffusion zone leads to more (BH)max loss than the internal reaction layer. The values of the oxidation rate constant k for internal reaction layer and oxygen diffusion coefficient D for diffusion zone were obtained, which are about 1.91×10^-10 cm^2/s and 6.54×10^-11 cm^2/s, respectively.展开更多
Self-consistent calculations of energy loss for a Ga ion moving in hot Au plasmas are made under the assumption of wide ranges of the projectile energy and the plasma temperature with all important mechanisms consider...Self-consistent calculations of energy loss for a Ga ion moving in hot Au plasmas are made under the assumption of wide ranges of the projectile energy and the plasma temperature with all important mechanisms considered in detail.The relevant results are found to be quite different from those of an a particle or a proton.One important reason for this is the rapid increasing of the charge state of a Ga ion at plasma temperature.This reason also leads to the inelastic stopping which does not always decrease with the increase of plasma temperature,unlike the case of an a particle.The nuclear stopping becomes very important at high enough plasma temperature due to the heavy reduced mass of a Ga and an Au ion and the above-mentioned reason.The well-known binary collision model[Phys.Rev.126(1962)1]and its revised one[Phys.Rev.A 29(1984)2145]are not working or unsatisfactory in this case.展开更多
<span style="font-family:Verdana;">The main reason for the early failure of radio-cephalic arteriovenous fistula (RCAVF) is non-maturity, which means that the blood flow rate in the fistula cannot incr...<span style="font-family:Verdana;">The main reason for the early failure of radio-cephalic arteriovenous fistula (RCAVF) is non-maturity, which means that the blood flow rate in the fistula cannot increase to the expected value for dialysis. From a mechanical perspective, the vascular resistance at the artificially designed anastomosis causes an energy loss that affects blood flow rate growth and leads to early failure. This research studied how to maximize the RCAVF maturity and primary patency by controlling the energy loss rate. We theoretically analyzed and derived a model that evaluates the energy loss rate <em>E</em><sub><em>avf</em></sub> in RCAVF as a function of its blood vessel geometric parameters (GPs) for given flow rates. There was an aggregate of five controllable GPs in RCAVF: radial artery diameter (<em>D</em><sub><em>ra</em></sub>), cephalic vein diameter (<em>D</em><sub><em>cv</em></sub>), blood vessel distance between artery and vein (<em>h</em>), anastomotic diameter (<em>D</em><sub><em>a</em></sub>), and anastomotic angle (<em>θ</em>). Through this analysis, it was found that <em>E</em><sub><em>avf</em></sub> was inversely proportional to <em>D</em><sub><em>ra</em></sub>, <em>D</em><sub><em>cv</em></sub>, <em>D</em><sub><em>a</em></sub>, and <em>θ</em>, whereas proportional to <em>h</em>. Therefore, we recommended surgeons choose the vessels with large diameters, close distance, and increase the diameter and angle of the anastomosis to decrease the early failure of RCAVF. Simultaneously, we could explain the results of many clinical empiricisms with our formula. We found that increasing <em>D</em><sub><em>cv</em></sub> and <em>θ</em> was more significant in reducing <em>E</em><sub><em>avf</em></sub> than increasing <em>D</em><sub><em>ra</em></sub> and <em>D</em><sub><em>a</em></sub>. Based on our model, we could define two critical energy loss rates (<em>CEL</em><sub><em>a</em></sub>, <em>CEL</em><sub><em>b</em></sub>) to help surgeons evaluate the blood vessels and choose the ideal range of <em>θ</em>, and help them design the preoperative RCAVF plan for each patient to increase the maturity and the primary patency of RCAVF.</span>展开更多
The effective energy loss functions for Al have been derived from differential i nverse inelastic mean free path based on the extended Landau approach. It has be en revealed that the effective energy loss function is ...The effective energy loss functions for Al have been derived from differential i nverse inelastic mean free path based on the extended Landau approach. It has be en revealed that the effective energy loss function is very close in value to th e theoretical surface energy loss function in the lower energy loss region but g radually approaches the theoretical bulk energy loss function in the higher ener gy loss region. Moreover, the intensity corresponding to surface excitation in e ffective energy loss functions decreases with the increase of primary electron e nergy. These facts show that the present effective energy loss function describe s not only surface excitation but also bulk excitation. At last, REELS spectra s imulated by Monte Carlo method based on use of the effective energy loss functio ns has reproduced the experimental REELS spectra with considerable success.展开更多
Ternary strategy is a convenient and effective method to boost the performance of polymer solar cells(PSCs).Utilizing a ternary strategy to trade-off between the energy loss and the efficiency of devices however requi...Ternary strategy is a convenient and effective method to boost the performance of polymer solar cells(PSCs).Utilizing a ternary strategy to trade-off between the energy loss and the efficiency of devices however requires further exploration.Here,through the hydroxyl(-OH)and acetoxy(-OCOMe)substitution atβ-position of the IC terminal group,we developed two new synthetic acceptors,BTIC-OH-βand BTICOCOMe-β,which were designed to confine the morphology aggregation.Introduction of an analogue as the third component provides a simple but efficient way to further balance the short current density(Jsc)and open-circuit voltage(Voc),leading to a champion efficiency based on PBDB-T:PBDB-TF:BTIC-OCOMe-β,effectively as high as 12.45%.The results were examined mainly in terms of the morphology characterization,electroluminescence external quantum efficiency(EQEEL),steady-state photoluminescence(PL)and transient technology.It suggested fine-tuning of the morphology by ratio modulation,reduction of the energy loss,construction of a promising pathway for charge transfer in the ternary system and enhancing the carrier extraction.In this way,a ternary strategy with an analogue donor could provide more routes to higher-quality solar cells.展开更多
Based on our previous work(Phys.Plasmas 25 012704(2018)),a fitting formula is given for electron-ion energy partition fraction of 3.54-MeV fusion alpha particles in deuterium-tritium(DT) plasmas as a function of plasm...Based on our previous work(Phys.Plasmas 25 012704(2018)),a fitting formula is given for electron-ion energy partition fraction of 3.54-MeV fusion alpha particles in deuterium-tritium(DT) plasmas as a function of plasma mass density ρ,electron temperature T_(e),and ion temperature T_(i).The formula can be used in a huge range of the plasma state,where ρ varies between 1.0 g/cc~10.0^(3) g/cc and both T_(e) and T_(i) change from 0.1 keV to 100.0 keV.Relativistic effect for electrons is investigated including the effect of the projectile recoil in the plasmas at T_(e)≥ 50.0 keV.The partition fraction for T_(e)>T_(i) is found to be close to that for T_(e)=T_(i). The comparisons with other fitting results are made at some plasma densities when T_(e)=T_(i),and the difference is explained.The fitting result is very close to the calculated one in most cases,which is convenient for the simulation of alpha heating in hot dense DT plasmas for inertial confined fusion.展开更多
Background Vector flow mapping is a novel echocardiographic technique that enables the visualization of the intraventricular flow. We aimed to evaluate and compare the index of hemodynamic dissipative energy loss in p...Background Vector flow mapping is a novel echocardiographic technique that enables the visualization of the intraventricular flow. We aimed to evaluate and compare the index of hemodynamic dissipative energy loss in patients with hypertension and the ones with normotensive, unaffected control subjects. Methods & Results Transthoracic echocardiography was performed in eighty-nine hypertensive patients with preserved left ventricular ejection fraction, fifty-one hypertensive patients with left ventricular hypertrophy(LVH group) and thirty-eight hypertensive patients without LVH(non-LVH group). Forty-two healthy volunteers were enrolled as the control group. The stored images were analyzed to calculate the energy loss. The average energy loss of diastole in the LVH group was significantly increased(controls vs. non-LVH vs. LVH: 7.07 ± 0.91 vs. 12.44 ± 3.14 vs. 16.29 ± 3.17 J/s per m^3). Compared with the control group, the energy loss was significantly increased in the LVH group during the different periods in diastole. The energy loss in the non-LVH group was the greatest among the three groups during the atrial contraction period. Conclusions Energy loss provides a promising method for evaluating the energy efficiency in the left ventricle and may be a new indicator of left ventricular cardiac dysfunction.展开更多
The total energy loss of N^+q ions (for v 〈 Bohr velocity) grazing on the Al(111) has been simulated without any 'fit' parameter and compared with the experimental data. The energy loss due to the charge excha...The total energy loss of N^+q ions (for v 〈 Bohr velocity) grazing on the Al(111) has been simulated without any 'fit' parameter and compared with the experimental data. The energy loss due to the charge exchange, happening before the N^+q hits the Al(111) surface, is studied. The present simulation shows that the energy loss strongly depends on the charge state of the projectile and the lattice orientation of Al(111) surface. The calculated total energy loss agrees with experimental data very well.展开更多
The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that a...The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that at a temperature of 15 × 10^9 K, the neutrino energy loss rates which come from the electron capture process for most iron group nuclei decrease no more than 2 orders of magnitude but for the others (such as ^53,55,56,57,58,59,6o Co, ^56,59Ni) they can decrease about 3 orders of magnitude due to strong electron screening (SES), whereas, at a temperature of 10^9K the neutrino energy loss rates of the most iron group nuclei can be diminished greatly due to the SES. For example, ^61Fe, ^60Fe, and ^62Ni the neutrino energy loss rates decrease about 4, 15 and 16 orders of magnitude and for ^57Cr, ^58Cr, and ^60Cr decrease about 18, 12, and 10 orders of magnitude respectively. According to our calculations the neutrino energy loss rates of nuclei ^58Mn, ^59Mn, ^60Mn, and ^62Mn may decrease about 13 orders of magnitude at a temperature of 10^9 K due to the SES.展开更多
The strong force effect on gluon distribution of quark-gluon plasma and its influence on jet energy loss with detailed balance are studied. We solve the possibility equation and obtain the value of non-extensive param...The strong force effect on gluon distribution of quark-gluon plasma and its influence on jet energy loss with detailed balance are studied. We solve the possibility equation and obtain the value of non-extensive parameter q. In the presence of strong interaction, more gluons stay at low-energy state than the free gluon case. The strong interaction effect is found to be important for jet energy loss with detailed balance at intermediate jet energy. The energy gain via absorption increases with the strong interaction. This will affect the nuclear modification factor RAA and the parameter of q at intermediate jet energy.展开更多
The lowest energies which make Cu,In,Ga,and Se atoms composing Cu(In,Ga)Se_2(CIGS) material displaced from their lattice sites are evaluated,respectively.The non-ionizing energy loss(NIEL) for electron in CIGS m...The lowest energies which make Cu,In,Ga,and Se atoms composing Cu(In,Ga)Se_2(CIGS) material displaced from their lattice sites are evaluated,respectively.The non-ionizing energy loss(NIEL) for electron in CIGS material is calculated analytically using the Mott differential cross section.The relation of the introduction rate(k) of the recombination centers to NIEL is modified,then the values of k at different electron energies are calculated.Degradation modeling of CIGS thin-film solar cells irradiated with various-energy electrons is performed according to the characterization of solar cells and the recombination centers.The validity of the modeling approach is verified by comparison with the experimental data.展开更多
In India most part receives 4 - 7 kWh of solar radiation per square meter per day with 200 - 250 sunny days in a year. Tamilnadu state also receives the highest annual radiation in India. In this paper, the grid conne...In India most part receives 4 - 7 kWh of solar radiation per square meter per day with 200 - 250 sunny days in a year. Tamilnadu state also receives the highest annual radiation in India. In this paper, the grid connected photovoltaic plant has a peak power of 80 KWp supplies electricity requirement of GRT IET campus during day time (7 hrs) and reduces load demand and generates useful data for future implementation of such PV plant projects in the Tamilnadu region. Photovoltaic plant was installed in April 2015, monitored during 6 months, and the performance ratio and the various power losses (power electronics, temperature, soiling, internal, network, grid availability and interconnection) were calculated. The PV plant supplied 64,182.86 KWh to the grid from April to September 2015, ranging from 11,510.900 to 10,200.9 kWh. The final yield ranged from 143.886 (h/d) to 127.51 (y/d), reference yield ranged from 201.6 (h/d) to 155.31 (h/d) and performance ratio ranged from 71.3% to 82.1%, for a duration of six months, it had given a performance ratio of 83.82%, system efficiency was 4.16% and the capacity factor of GRT IET Campus for six months was 18.26%. Payback period in years = 9 years 4 months, energy saving per year = 204,400 KWh, cost reduction per year = 1,737,400, Indian rupee = 26,197.30 USD and total CO<sub>2</sub> reductions per year = 102,200 tons CO<sub>2</sub>/year.展开更多
At present,the leakage rate of the water distribution network in China is still high,and the waste of water resources caused by water distribution network leakage is quite serious every year.Therefore,the location of ...At present,the leakage rate of the water distribution network in China is still high,and the waste of water resources caused by water distribution network leakage is quite serious every year.Therefore,the location of pipeline leakage is of great significance for saving water resources and reducing economic losses.Acoustic emission technology is the most widely used pipeline leak location technology.The traditional non-stationary random signal de-noising method mainly relies on the estimation of noise parameters,ignoring periodic noise and components unrelated to pipeline leakage.Aiming at the above problems,this paper proposes a leak location method for water supply pipelines based on a multivariate variational mode decomposition algorithm.This method combines the two parameters of the energy loss coefficient and the correlation coefficient between adjacent modes,and adaptively determines the decomposition mode number K according to the characteristics of the signal itself.According to the correlation coefficient,the effective component is selected to reconstruct the signal and the cross-correlation time delay is estimated to determine the location of the pipeline leakage point.The experimental results show that this method has higher accuracy than the cross-correlation method based on VMD and the cross-correlation method based on EMD,and the average relative positioning error is less than 2.2%.展开更多
A novel 4H-Si C trench insulated gate bipolar transistor(IGBT)with a controllable hole-extracting(CHE)path is proposed and investigated in this paper.The CHE path is controlled by metal semiconductor gate(MES gate)and...A novel 4H-Si C trench insulated gate bipolar transistor(IGBT)with a controllable hole-extracting(CHE)path is proposed and investigated in this paper.The CHE path is controlled by metal semiconductor gate(MES gate)and metal oxide semiconductor gate(MOS gate)in the p-shield region.The grounded p-shield region can significantly suppress the high electric field around gate oxide in Si C devices,but it weakens the conductivity modulation in the Si C trench IGBT by rapidly sweeping out holes.This effect can be eliminated by introducing the CHE path.The CHE path is pinched off by the high gate bias voltage at on-state to maintain high conductivity modulation and obtain a comparatively low on-state voltage(VON).During the turn-off transient,the CHE path is formed,which contributes to a decreased turn-off loss(EOFF).Based on numerical simulation,the EOFFof the proposed IGBT is reduced by 89%compared with the conventional IGBT at the same VONand the VONof the proposed IGBT is reduced by 50%compared to the grounded p-shield IGBT at the same EOFF.In addition,the average power reduction for the proposed device can be 51.0%to 81.7%and 58.2%to 72.1%with its counterparts at a wide frequency range of 500 Hz to 10 k Hz,revealing a great improvement of frequency characteristics.展开更多
文摘This work concerns an experimental and numerical study of energy losses in a typical oven usually used in the agro-food craft sector in Burkina Faso. The experimental results were obtained by infrared thermography of the oven and by monitoring the evolution of the wall temperatures using thermocouples connected to a data acquisition system. These results indicate that the energy losses are mainly through the walls of the oven. The numerical study based on the energy balance and corroborated by the experimental study made it possible to quantify these losses of energy which represents almost half of the fuel used. These results will allow us to work on a new, more efficient oven model for the grilling sector in Burkina Faso.
文摘Collisions between multibody systems are irreversible processes which cause loss of internal energy by a stress wave that propagates in the impacting bodies away from the region of impact. A coefficient of restitution relating to approach velocity is introduced to denote the losses of translational kinetic energy. A parameter β involved in internal energy losses has been obtained to calculate the coefficient of restitution. As a result, the internal energy losses caused by elastic stress waves and the contact duration in metals can be calculated numerically for the collision between circular cylinder and half plane. The metals include aluminum alloys, steel-mild 1020, steel-stainless austenitic 304, tungsten alloys, copper alloys, nickel alloys and titanium alloys. By introducing a coefficient of velocity-frequency, an exponential aggression equation related the normalized oscillating frequency and normalized approach velocity has been obtained by the numerical method.
文摘This study proposes a new method which aims to optimally install tie-lines and distributed generations simultaneously.This is done to optimize the post-outage reconfiguration and minimize energy losses and energy not supplied of distribution systems.The number and location of tie-lines,as well as the number,size,and location of DGs,are pinpointed through teaching the learning-based optimization(TLBO)method.The objective function in the current research is to minimize the costs pertaining to the investment,operation,energy losses,and energies not supplied.In addition to the normal operational condition,fault operational condition is also evaluated.Therefore,the optimal post-fault reconfigurations for fault occurrences in all lines are established.Moreover,the operational constraints such as the voltage and line current limits are taken into account in both normal and post-fault operational modes.Finally,the modified IEEE 33-bus and 69-bus distribution test systems are selected and tested to demonstrate the effectiveness of the simultaneous placement of DGs and tie-line technique proposed in this paper.
基金Supported by National Natural Science Foundation of China(Grant No.51305277)Doctoral Program of Higher Education China(Grant No.20132102120007)+1 种基金Shenyang Science and Technology Plan Project(Grant No.F15-199-1-14)China Postdoctoral Science Foundation(Grant No.2014T70261)
文摘Due to the influence of magnetic hysteresis and energy loss inherent in giant magnetostrictive materials (GMM), output displacement accuracy of giant magnetostrictive actuator (GMA) can not meet the precision and ultra precision machining. Using a GMM rod as the core driving element, a GMA which may be used in the field of precision and ultra precision drive engineering is designed through modular design method. Based on the Armstrong theory and elastic Gibbs free energy theory, a nonlinear magnetostriction model which considers magnetic hysteresis and energy loss characteristics is established. Moreover, the mechanical system differential equation model for GMA is established by utilizing D'Alembert's principle. Experimental results show that the model can preferably predict magnetization property, magnetic potential orientation, energy loss for GMM. It is also able to describe magnetostrictive elongation and output displacement of GMA. Research results will provide a theoretical basis for solving the dynamic magnetic hysteresis, energy loss and working precision for GMA fundamentally.
文摘In an Underwater Wireless Sensor Network(UWSN),extreme energy loss is carried out by the early expiration of sensor nodes and causes a reduction in efficiency in the submerged acoustic sensor system.Systems based on clustering strategies,instead of each node sending information by itself,utilize cluster heads to collect information inside the clusters for forwarding collective information to sink.This can effectively minimize the total energy loss during transmission.The environment of UWSN is 3D architecture-based and follows a complex hierarchical clustering strategy involving its most effecting unique parameters such as propagation delay and limited transmission bandwidth.Round base clustering strategy works in rounds,where each round comprises three fundamental stages:cluster head selection,grouping or node association,and data aggregation followed by forwarding data to the sink.In UWSN,the energy consumed during the formation of clusters has been considered casually or completely evaded in the previous works.In this paper,the cluster head setup period has been considered the main contributor to extra energy utilizer.A numerical channel model is proposed to compute extra energy.It is performed by using a UWSN broad model.The results have shown that extra maximum energy consumption is approximately 12.9 percent of the system total energy consumed in information transmissions.
基金supported by the National Basic Research Program of China (Grant No. 2010CB923301)the National Natural Science Foundation of China (GrantNos. 11327404 and 11174268)
文摘An ultra-high vacuum (UHV) compatible electron spectrometer employing a double toroidal analyzer has been de- veloped. It is designed to be combined with a custom-made scanning tunneling microscope (STM) to study the spatially localized electron energy spectrum on a surface. A tip-sample system composed of a piezo-driven field-emission tungsten tip and a sample of highly ordered pyrolytic graphite (HOPG) is employed to test the performance of the spectrometer. Two-dimensional images of the energy-resolved and angle-dispersed electrons backscattered from the surface of HOPG are obtained, the performance is optimized and the spectrometer is calibrated. A complete electron energy loss spectrum covering the elastic peak to the secondary electron peaks for the HOPG surface, acquired at a tip voltage of -140 V and a sample current of 0.5 pA, is presented, demonstrating the viability of the spectrometer.
基金Project supported by the National High Technology Research and Development Program of China (Grant No. 2010AA03A401)the National Natural Science Foundation of China (Grant No. 51071010)+1 种基金the Aviation Foundation of China (AFC) (Grant No. 2009ZF51063)the Fundamental Research Funds for the Central Universities
文摘The oxidation microstructure and maximum energy product (BH)max loss of a 8m(Co0.76, Fe0.1, Cu0.1, Zr0.04)7 magnet oxidized at 500 ℃ were systematically investigated. Three different oxidation regions were formed in the oxidized magnet: a continuous externM oxide scale, an internal reaction layer, and a diffusion zone. Both room-temperature and high-temperature (BH)max losses exhibited the same parabolic increase with oxidation time. An oxygen diffusion model was proposed to simulate the dependence of (BH)max loss on oxidation time. It is found that the external oxide scale has little effect on the (BH)max loss, and both the internal reaction layer and diffusion zone result in the (BH)max loss. Moreover, the diffusion zone leads to more (BH)max loss than the internal reaction layer. The values of the oxidation rate constant k for internal reaction layer and oxygen diffusion coefficient D for diffusion zone were obtained, which are about 1.91×10^-10 cm^2/s and 6.54×10^-11 cm^2/s, respectively.
基金This work was supported by the Foundation for the Development of Science and Technology of the Chinese Academy of Engeering Physics under grant No.2014B09036,National Natural Science Foundation of China(Grants Nos.11574034,U1530142,11104017,11371218,11474031,and 11474033)the National Basic Research Program of China under grant No.2013CB922200.
文摘Self-consistent calculations of energy loss for a Ga ion moving in hot Au plasmas are made under the assumption of wide ranges of the projectile energy and the plasma temperature with all important mechanisms considered in detail.The relevant results are found to be quite different from those of an a particle or a proton.One important reason for this is the rapid increasing of the charge state of a Ga ion at plasma temperature.This reason also leads to the inelastic stopping which does not always decrease with the increase of plasma temperature,unlike the case of an a particle.The nuclear stopping becomes very important at high enough plasma temperature due to the heavy reduced mass of a Ga and an Au ion and the above-mentioned reason.The well-known binary collision model[Phys.Rev.126(1962)1]and its revised one[Phys.Rev.A 29(1984)2145]are not working or unsatisfactory in this case.
文摘<span style="font-family:Verdana;">The main reason for the early failure of radio-cephalic arteriovenous fistula (RCAVF) is non-maturity, which means that the blood flow rate in the fistula cannot increase to the expected value for dialysis. From a mechanical perspective, the vascular resistance at the artificially designed anastomosis causes an energy loss that affects blood flow rate growth and leads to early failure. This research studied how to maximize the RCAVF maturity and primary patency by controlling the energy loss rate. We theoretically analyzed and derived a model that evaluates the energy loss rate <em>E</em><sub><em>avf</em></sub> in RCAVF as a function of its blood vessel geometric parameters (GPs) for given flow rates. There was an aggregate of five controllable GPs in RCAVF: radial artery diameter (<em>D</em><sub><em>ra</em></sub>), cephalic vein diameter (<em>D</em><sub><em>cv</em></sub>), blood vessel distance between artery and vein (<em>h</em>), anastomotic diameter (<em>D</em><sub><em>a</em></sub>), and anastomotic angle (<em>θ</em>). Through this analysis, it was found that <em>E</em><sub><em>avf</em></sub> was inversely proportional to <em>D</em><sub><em>ra</em></sub>, <em>D</em><sub><em>cv</em></sub>, <em>D</em><sub><em>a</em></sub>, and <em>θ</em>, whereas proportional to <em>h</em>. Therefore, we recommended surgeons choose the vessels with large diameters, close distance, and increase the diameter and angle of the anastomosis to decrease the early failure of RCAVF. Simultaneously, we could explain the results of many clinical empiricisms with our formula. We found that increasing <em>D</em><sub><em>cv</em></sub> and <em>θ</em> was more significant in reducing <em>E</em><sub><em>avf</em></sub> than increasing <em>D</em><sub><em>ra</em></sub> and <em>D</em><sub><em>a</em></sub>. Based on our model, we could define two critical energy loss rates (<em>CEL</em><sub><em>a</em></sub>, <em>CEL</em><sub><em>b</em></sub>) to help surgeons evaluate the blood vessels and choose the ideal range of <em>θ</em>, and help them design the preoperative RCAVF plan for each patient to increase the maturity and the primary patency of RCAVF.</span>
基金This work was supported by the National Natural Science Foundation of China(No.10025420,No.20075026,No.60306006 and No.90206009)the post-doctoral fellowship provided by a Grant-in-Aid for Creative Scientific Research of Japanese govermment(No.13GS0022).The authors would also like to thank Dr.H.Yoshikawa,National Institute for Materials Science of Japan,and Dr.T.Nagatomi,Osaka University,for their helpful comments.
文摘The effective energy loss functions for Al have been derived from differential i nverse inelastic mean free path based on the extended Landau approach. It has be en revealed that the effective energy loss function is very close in value to th e theoretical surface energy loss function in the lower energy loss region but g radually approaches the theoretical bulk energy loss function in the higher ener gy loss region. Moreover, the intensity corresponding to surface excitation in e ffective energy loss functions decreases with the increase of primary electron e nergy. These facts show that the present effective energy loss function describe s not only surface excitation but also bulk excitation. At last, REELS spectra s imulated by Monte Carlo method based on use of the effective energy loss functio ns has reproduced the experimental REELS spectra with considerable success.
基金the financial support from the National Natural Science Foundation of China(21975115,21733005)the Shenzhen Fundamental Research Program(JCYJ20190809163011543,JCYJ20200109140801751)+2 种基金the Guangdong Provincial Key Laboratory of Catalysis(2020B121201002)the Guangdong Innovative and Entrepreneurial Research Team Program(2016ZT06G587)the Shenzhen Sci-Tech Fund(KYTDPT20181011104007)。
文摘Ternary strategy is a convenient and effective method to boost the performance of polymer solar cells(PSCs).Utilizing a ternary strategy to trade-off between the energy loss and the efficiency of devices however requires further exploration.Here,through the hydroxyl(-OH)and acetoxy(-OCOMe)substitution atβ-position of the IC terminal group,we developed two new synthetic acceptors,BTIC-OH-βand BTICOCOMe-β,which were designed to confine the morphology aggregation.Introduction of an analogue as the third component provides a simple but efficient way to further balance the short current density(Jsc)and open-circuit voltage(Voc),leading to a champion efficiency based on PBDB-T:PBDB-TF:BTIC-OCOMe-β,effectively as high as 12.45%.The results were examined mainly in terms of the morphology characterization,electroluminescence external quantum efficiency(EQEEL),steady-state photoluminescence(PL)and transient technology.It suggested fine-tuning of the morphology by ratio modulation,reduction of the energy loss,construction of a promising pathway for charge transfer in the ternary system and enhancing the carrier extraction.In this way,a ternary strategy with an analogue donor could provide more routes to higher-quality solar cells.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0402300 and 2017YFA0403200)the National Natural Science Foundation of China(Grant No.11574034)+1 种基金the Innovation Development Foundation of China Academy of Engineering Physics(CAEP)(Grant No.CX20200029)the Science Challenge Project(Grant Nos.JCKY201612A501)。
文摘Based on our previous work(Phys.Plasmas 25 012704(2018)),a fitting formula is given for electron-ion energy partition fraction of 3.54-MeV fusion alpha particles in deuterium-tritium(DT) plasmas as a function of plasma mass density ρ,electron temperature T_(e),and ion temperature T_(i).The formula can be used in a huge range of the plasma state,where ρ varies between 1.0 g/cc~10.0^(3) g/cc and both T_(e) and T_(i) change from 0.1 keV to 100.0 keV.Relativistic effect for electrons is investigated including the effect of the projectile recoil in the plasmas at T_(e)≥ 50.0 keV.The partition fraction for T_(e)>T_(i) is found to be close to that for T_(e)=T_(i). The comparisons with other fitting results are made at some plasma densities when T_(e)=T_(i),and the difference is explained.The fitting result is very close to the calculated one in most cases,which is convenient for the simulation of alpha heating in hot dense DT plasmas for inertial confined fusion.
基金the Capital Characteristic Clinic Project (No. Z181100001718015)。
文摘Background Vector flow mapping is a novel echocardiographic technique that enables the visualization of the intraventricular flow. We aimed to evaluate and compare the index of hemodynamic dissipative energy loss in patients with hypertension and the ones with normotensive, unaffected control subjects. Methods & Results Transthoracic echocardiography was performed in eighty-nine hypertensive patients with preserved left ventricular ejection fraction, fifty-one hypertensive patients with left ventricular hypertrophy(LVH group) and thirty-eight hypertensive patients without LVH(non-LVH group). Forty-two healthy volunteers were enrolled as the control group. The stored images were analyzed to calculate the energy loss. The average energy loss of diastole in the LVH group was significantly increased(controls vs. non-LVH vs. LVH: 7.07 ± 0.91 vs. 12.44 ± 3.14 vs. 16.29 ± 3.17 J/s per m^3). Compared with the control group, the energy loss was significantly increased in the LVH group during the different periods in diastole. The energy loss in the non-LVH group was the greatest among the three groups during the atrial contraction period. Conclusions Energy loss provides a promising method for evaluating the energy efficiency in the left ventricle and may be a new indicator of left ventricular cardiac dysfunction.
基金Project supported by the Research Fund for the Doctoral Program of Higher Education, China (Grant No 20030730004), the National Natural Science Foundation of China (Grant No 10374039) and the Natural Science Foundation of Gansu Province, , China .(G_ra_nt N oZS031-A25-001-Z).
文摘The total energy loss of N^+q ions (for v 〈 Bohr velocity) grazing on the Al(111) has been simulated without any 'fit' parameter and compared with the experimental data. The energy loss due to the charge exchange, happening before the N^+q hits the Al(111) surface, is studied. The present simulation shows that the energy loss strongly depends on the charge state of the projectile and the lattice orientation of Al(111) surface. The calculated total energy loss agrees with experimental data very well.
基金Project supported by the National Natural Science Foundation of China (Grant No 10347008).
文摘The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that at a temperature of 15 × 10^9 K, the neutrino energy loss rates which come from the electron capture process for most iron group nuclei decrease no more than 2 orders of magnitude but for the others (such as ^53,55,56,57,58,59,6o Co, ^56,59Ni) they can decrease about 3 orders of magnitude due to strong electron screening (SES), whereas, at a temperature of 10^9K the neutrino energy loss rates of the most iron group nuclei can be diminished greatly due to the SES. For example, ^61Fe, ^60Fe, and ^62Ni the neutrino energy loss rates decrease about 4, 15 and 16 orders of magnitude and for ^57Cr, ^58Cr, and ^60Cr decrease about 18, 12, and 10 orders of magnitude respectively. According to our calculations the neutrino energy loss rates of nuclei ^58Mn, ^59Mn, ^60Mn, and ^62Mn may decrease about 13 orders of magnitude at a temperature of 10^9 K due to the SES.
基金Supported by the National Natural Science Foundation of China under Grant No 11205024the Doctoral Scientific Fund Project of the Ministry of Education of China under Grant No 2012004112004
文摘The strong force effect on gluon distribution of quark-gluon plasma and its influence on jet energy loss with detailed balance are studied. We solve the possibility equation and obtain the value of non-extensive parameter q. In the presence of strong interaction, more gluons stay at low-energy state than the free gluon case. The strong interaction effect is found to be important for jet energy loss with detailed balance at intermediate jet energy. The energy gain via absorption increases with the strong interaction. This will affect the nuclear modification factor RAA and the parameter of q at intermediate jet energy.
基金Project supported by the National Natural Science Foundation of China(Grant No.11547151)
文摘The lowest energies which make Cu,In,Ga,and Se atoms composing Cu(In,Ga)Se_2(CIGS) material displaced from their lattice sites are evaluated,respectively.The non-ionizing energy loss(NIEL) for electron in CIGS material is calculated analytically using the Mott differential cross section.The relation of the introduction rate(k) of the recombination centers to NIEL is modified,then the values of k at different electron energies are calculated.Degradation modeling of CIGS thin-film solar cells irradiated with various-energy electrons is performed according to the characterization of solar cells and the recombination centers.The validity of the modeling approach is verified by comparison with the experimental data.
文摘In India most part receives 4 - 7 kWh of solar radiation per square meter per day with 200 - 250 sunny days in a year. Tamilnadu state also receives the highest annual radiation in India. In this paper, the grid connected photovoltaic plant has a peak power of 80 KWp supplies electricity requirement of GRT IET campus during day time (7 hrs) and reduces load demand and generates useful data for future implementation of such PV plant projects in the Tamilnadu region. Photovoltaic plant was installed in April 2015, monitored during 6 months, and the performance ratio and the various power losses (power electronics, temperature, soiling, internal, network, grid availability and interconnection) were calculated. The PV plant supplied 64,182.86 KWh to the grid from April to September 2015, ranging from 11,510.900 to 10,200.9 kWh. The final yield ranged from 143.886 (h/d) to 127.51 (y/d), reference yield ranged from 201.6 (h/d) to 155.31 (h/d) and performance ratio ranged from 71.3% to 82.1%, for a duration of six months, it had given a performance ratio of 83.82%, system efficiency was 4.16% and the capacity factor of GRT IET Campus for six months was 18.26%. Payback period in years = 9 years 4 months, energy saving per year = 204,400 KWh, cost reduction per year = 1,737,400, Indian rupee = 26,197.30 USD and total CO<sub>2</sub> reductions per year = 102,200 tons CO<sub>2</sub>/year.
基金supported by the three funds:Industry-University-research Project of Anhui Jianzhu University HYB20210116National Key Research and Development Project of China No.2017YFC0704100(entitled New Generation Intelligent Building Platform Techniques)Research Project of Anhui Jianzhu University jy2021-c-017(Project Name:Research and Application ofWater Distribution Network Leakage Detection System Based on DMA Partition).
文摘At present,the leakage rate of the water distribution network in China is still high,and the waste of water resources caused by water distribution network leakage is quite serious every year.Therefore,the location of pipeline leakage is of great significance for saving water resources and reducing economic losses.Acoustic emission technology is the most widely used pipeline leak location technology.The traditional non-stationary random signal de-noising method mainly relies on the estimation of noise parameters,ignoring periodic noise and components unrelated to pipeline leakage.Aiming at the above problems,this paper proposes a leak location method for water supply pipelines based on a multivariate variational mode decomposition algorithm.This method combines the two parameters of the energy loss coefficient and the correlation coefficient between adjacent modes,and adaptively determines the decomposition mode number K according to the characteristics of the signal itself.According to the correlation coefficient,the effective component is selected to reconstruct the signal and the cross-correlation time delay is estimated to determine the location of the pipeline leakage point.The experimental results show that this method has higher accuracy than the cross-correlation method based on VMD and the cross-correlation method based on EMD,and the average relative positioning error is less than 2.2%.
基金Project supported by the Hunan Provincial Natural Science Foundation of China(Grant No.2021JJ30738)Scientific Research Fund of Hunan Provincial Education Department(Grant No.19K001)Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering’s Open Fund Project-2020(Grant No.202016)。
文摘A novel 4H-Si C trench insulated gate bipolar transistor(IGBT)with a controllable hole-extracting(CHE)path is proposed and investigated in this paper.The CHE path is controlled by metal semiconductor gate(MES gate)and metal oxide semiconductor gate(MOS gate)in the p-shield region.The grounded p-shield region can significantly suppress the high electric field around gate oxide in Si C devices,but it weakens the conductivity modulation in the Si C trench IGBT by rapidly sweeping out holes.This effect can be eliminated by introducing the CHE path.The CHE path is pinched off by the high gate bias voltage at on-state to maintain high conductivity modulation and obtain a comparatively low on-state voltage(VON).During the turn-off transient,the CHE path is formed,which contributes to a decreased turn-off loss(EOFF).Based on numerical simulation,the EOFFof the proposed IGBT is reduced by 89%compared with the conventional IGBT at the same VONand the VONof the proposed IGBT is reduced by 50%compared to the grounded p-shield IGBT at the same EOFF.In addition,the average power reduction for the proposed device can be 51.0%to 81.7%and 58.2%to 72.1%with its counterparts at a wide frequency range of 500 Hz to 10 k Hz,revealing a great improvement of frequency characteristics.