期刊文献+
共找到4,232篇文章
< 1 2 212 >
每页显示 20 50 100
Optimal scheduling of a township integrated-energy system using the adjustable heat-electricity ratio model
1
作者 Quan Chen Jingyi Wang +4 位作者 Min Cang Xiaomeng Zhai Xi Cheng Shuang Wu Dongwei Li 《Global Energy Interconnection》 EI CSCD 2024年第1期48-60,共13页
With the expansion and implementation of rural revitalization strategies,there is a constant need for new energy sources for the construction of new townships.Consequently,integrated energy systems with the interconne... With the expansion and implementation of rural revitalization strategies,there is a constant need for new energy sources for the construction of new townships.Consequently,integrated energy systems with the interconnection and interaction of multiple energy sources are developing rapidly.Biomass energy,a renewable green energy source with low pollution and wide distribution,has significant application potential in integrated energy systems.Considering the application of biomass energy in townships,this study established an integrated biomass energy system and proposed a model to optimize its operation.Lowest economic cost and highest clean energy utilization rate were considered as the objective functions.In addition,a plan was suggested to adjust the heat-electricity ratio based on the characteristics of the combined heat and power of the biomass.Finally,a simulation analysis conducted for a town in China was discussed,demonstrating that the construction of a township integrated-energy system and the use of biomass can significantly reduce operating costs and improve the energy utilization rate.Moreover,by adjusting the heat-electricity ratio,the economic cost was further reduced by 6.70%,whereas the clean energy utilization rate was increased by 5.14%. 展开更多
关键词 Biomass energy Integrated-energy system Afterburning device Heat-electricity ratio Operation optimization
下载PDF
Simulation Study of Diesel Spray Tilt Angle and Ammonia Energy Ratio Effect on Ammonia-Diesel Dual-Fuel Engine Performance
2
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
下载PDF
Short-term prediction of photovoltaic power generation based on LMD-EE-ESN with error correction
3
作者 YU Xiangqian LI Zheng 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2024年第3期360-368,共9页
Considering the instability of the output power of photovoltaic(PV)generation system,to improve the power regulation ability of PV power during grid-connected operation,based on the quantitative analysis of meteorolog... Considering the instability of the output power of photovoltaic(PV)generation system,to improve the power regulation ability of PV power during grid-connected operation,based on the quantitative analysis of meteorological conditions,a short-term prediction method of PV power based on LMD-EE-ESN with iterative error correction was proposed.Firstly,through the fuzzy clustering processing of meteorological conditions,taking the power curves of PV power generation in sunny,rainy or snowy,cloudy,and changeable weather as the reference,the local mean decomposition(LMD)was carried out respectively,and their energy entropy(EE)was taken as the meteorological characteristics.Then,the historical generation power series was decomposed by LMD algorithm,and the hierarchical prediction of the power curve was realized by echo state network(ESN)prediction algorithm combined with meteorological characteristics.Finally,the iterative error theory was applied to the correction of power prediction results.The analysis of the historical data in the PV power generation system shows that this method avoids the influence of meteorological conditions in the short-term prediction of PV output power,and improves the accuracy of power prediction on the condition of hierarchical prediction and iterative error correction. 展开更多
关键词 photovoltaic(PV)power generation system short-term forecast local mean decomposition(LMD) energy entropy(EE) echo state network(ESN)
下载PDF
Integrating Virtual Reality and Energy Analysis with BIM to Optimize Window-to-Wall Ratio and Building’s Orientation for Age-in-Place Design at the Conceptual Stage
4
作者 Vafa Rostamiasl Ahmad Jrade 《Open Journal of Civil Engineering》 2024年第3期305-333,共29页
This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approxi... This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approximately 30% of total energy consumed worldwide. The greatest contributors to energy expenditure in buildings are internal artificial lighting and heating and cooling systems. The WWR, determined by the proportion of the building’s glazed area to its wall area, is a significant factor influencing energy efficiency and minimizing energy load. This study introduces the development of a semi-automated computer model designed to offer a real-time, interactive simulation environment, fostering improving communication and engagement between designers and owners. The said model serves to optimize both the WWR and building orientation to align with occupants’ needs and expectations, subsequently reducing annual energy consumption and enhancing the overall building energy performance. The integrated model incorporates Building Information Modeling (BIM), Virtual Reality (VR), and Energy Analysis tools deployed at the conceptual design stage, allowing for the amalgamation of owners’ inputs in the design process and facilitating the creation of more realistic and effective design strategies. 展开更多
关键词 Building Information Modeling (BIM) Virtual Reality (VR) Game Engine energy Analysis Window-to-Wall ratio Building Orientation Computer Integration and Automation
下载PDF
Impact of material and energy flow variation-based iron /steel ratio on production cost
5
作者 陆彪 陈光 +2 位作者 陈德敏 虞维平 丁毅 《Journal of Southeast University(English Edition)》 EI CAS 2015年第3期375-379,共5页
This paper establishes a model for the production cost of iron and steel enterprise.The variation rule of the production cost versus the iron/steel ratio for two cases, namely,fixed steel production and a fixed amount... This paper establishes a model for the production cost of iron and steel enterprise.The variation rule of the production cost versus the iron/steel ratio for two cases, namely,fixed steel production and a fixed amount of molten iron,is analyzed,and the concept of a steel scrap threshold price is proposed.According to the analysis results,when the steel scrap unit price exceeds the steel scrap threshold price, an increase in the iron/steel ratio can reduce the production cost,and vice versa.When the gap between the steel scrap unit price and the steel scrap threshold price is relatively large, the impact of the iron/steel ratio on the production cost is more prominent.According to the calculation example,when steel production is fixed (284 358 t/month)and the steel scrap unit price is 263.2 yuan/t more than the steel scrap threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 750 000 yuan (2.63 yuan/t).When the amount of molten iron is fixed (270 425 t/month)and the steel scrap unit price is 140.7 yuan/t more than the threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 430 000 yuan (1.5 yuan/t).The results indicate that iron and steel enterprise should adjust the production strategy in time when the scrap price fluctuates, and then the production cost will be reduced. 展开更多
关键词 iron/steel ratio material flow energy flow model of production cost steel scrap threshold price
下载PDF
Estimation of quality factors by energy ratio method 被引量:1
6
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
下载PDF
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
7
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
下载PDF
Photodissociation of HOD via the C1B1 State: OD/OH Branching Ratio and OD Bond Dissociation Energy
8
作者 程丽娜 程元 +4 位作者 袁开军 郭庆 汪涛 戴东旭 杨学明 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第2期129-133,I0003,共6页
Photodissociation of jet-cooled HOD via the C state around 124 nm has been studied using the H(D)-atom Rydberg tagging time-of-flight technique. Rotational state resolved action spectrum and the product translationa... Photodissociation of jet-cooled HOD via the C state around 124 nm has been studied using the H(D)-atom Rydberg tagging time-of-flight technique. Rotational state resolved action spectrum and the product translational energy distribution spectra have been recorded for both D+OH and H+OD dissociation channels. Product channel OH/OD branching ratios for the individual C-X rotational transition have been determined. A comparison is also given with the B-X and A-X transitions. In addition, the dissociation energy of the OD bond in HOD has been determined accurately to be 41751.3±5 cm-1. 展开更多
关键词 PHOTODISSOCIATION Rydberg tagging Branching ratio Dissociation energy
下载PDF
Relative energy zero ratio-based approach for identifying pulse-like ground motions 被引量:2
9
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
下载PDF
Application of empirical mode decomposition based energy ratio to vortex flowmeter state diagnosis 被引量:4
10
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
下载PDF
Prognostic significance of the preoperative hemoglobin to albumin ratio for the short-term survival of gastric cancer patients 被引量:2
11
作者 Ce-Gui Hu Bai-E Hu +2 位作者 Jin-Feng Zhu Zheng-Ming Zhu Chao Huang 《World Journal of Gastrointestinal Surgery》 SCIE 2022年第6期580-593,共14页
BACKGROUND Hemoglobin and albumin are associated with the prognosis of gastric cancer(GC)patients. However, the prognostic value of the hemoglobin to albumin ratio(HAR) for the short-term survival of GC patients with ... BACKGROUND Hemoglobin and albumin are associated with the prognosis of gastric cancer(GC)patients. However, the prognostic value of the hemoglobin to albumin ratio(HAR) for the short-term survival of GC patients with D2 radical resection has not been studied.AIM To investigate the significance of the HAR in evaluating the short-term survival of GC patients after D2 radical resection and to construct a nomogram to predict the prognosis in GC patients after surgery, thus providing a reference for the development of postoperative individualized treatment and follow-up plans.METHODS Cox regression and Kaplan-Meier analysis was used for prognostic analysis.Logistic regression was used to analyze the relationships between HAR and the clinicopathological characteristics of the GC patients. A prognostic nomogram model for the short-term survival of GC patients was constructed by R software.RESULTS HAR was an independent risk factor for the short-term survival of GC patients.GC patients with a low HAR had a poor prognosis(P < 0.001). Low HAR was markedly related to high stage [odds ratio(OR) = 0.45 for Ⅱ vs Ⅰ;OR = 0.48 for Ⅲ vs Ⅰ], T classification(OR = 0.52 for T4 vs T1) and large tumor size(OR = 0.51 for ≥4 cm vs < 4 cm)(all P < 0.05). The nomogram model was based on HAR, age,CA19-9, CA125 and stage, and the C-index was 0.820.CONCLUSION Preoperative low HAR was associated with short-term survival in GC patients.The prognostic nomogram model can accurately predict the short-term survival of GC patients with D2 radical resection. 展开更多
关键词 Gastric cancer Hemoglobin to albumin ratio short-term survival Prognosis Nomogram
下载PDF
Performance improvement of the stochastic-resonance-based tri-stableenergy harvester under random rotational vibration 被引量:2
12
作者 Tingting Zhang Yanfei Jin Yanxia Zhang 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2022年第5期326-331,共6页
In this paper,the stochastic-resonance-based tri-stable energy harvester(TEH)is proposed to enhance harvesting performance under random rotational vibration.An electromechanical coupled system interfaced with a standa... In this paper,the stochastic-resonance-based tri-stable energy harvester(TEH)is proposed to enhance harvesting performance under random rotational vibration.An electromechanical coupled system interfaced with a standard rectifier circuit driven by colored noise is considered.The stationary probability density function(SPDF)of the harvester is obtained by the improved stochastic averaging.Then,with the adiabatic approximation theory,the analytical expression of signal-to-noise ratio(SNR)for the TEH is deduced to characterize stochastic resonance(SR).To enhance direct current(DC)power delivery from a rotational TEH,the influences of system parameters on SR is discussed.The obtained results suggest that there are damping-induced resonance and noise-intensity-induced SR in the tri-stable system.The TEH has higher harvesting performance under the optimal SR.That is,the optimal parameter combinations can induce optimal SR and maximize harvesting performance.Thus,the stochastic-resonance-based TEH can be optimized to enhance energy harvesting through choosing the optimal parameter. 展开更多
关键词 Tri-stable energy harvesting Stochastic resonance Random rotational vibration Signal-to-noise ratio
下载PDF
Case Study of a Short-Term Wave Energy Forecasting Scheme:North Indian Ocean 被引量:1
13
作者 ZHENG Chongwei SONG Hui 《Journal of Ocean University of China》 SCIE CAS CSCD 2021年第3期463-477,共15页
Short-term forecasts of wave energy play a key role in the daily operation,maintenance planning,and electrical grid operation of power farms.In this study,we propose a short-term wave energy forecast scheme and use th... Short-term forecasts of wave energy play a key role in the daily operation,maintenance planning,and electrical grid operation of power farms.In this study,we propose a short-term wave energy forecast scheme and use the North Indian Ocean(NIO)as a case study.Compared with the traditional forecast scheme,our proposed scheme considers more forecast elements.In addition to the traditional short-term forecast factors related to wave energy(wave power,significant wave height(SWH),wave period),our scheme emphasizes the forecast of a series of key factors that are closely related to the effectiveness of the energy output,capture efficiency,and conversion efficiency.These factors include the available rate,total storage,effective storage,co-occurrence of wave power-wave direction,co-occurrence of the SWH-wave period,and the wave energy at key points.In the regional nesting of nu-merical simulations of wave energy in the NIO,the selection of the southern boundary is found to have a significant impact on the simulation precision,especially during periods of strong swell processes of the South Indian Ocean(SIO)westerly.During tropical cyclone‘VARDAH’in the NIO,as compared with the simulation precision obtained with no expansion of the southern boundary(scheme-1),when the southern boundary is extended to the tropical SIO(scheme-2),the improvement in simulation precision is significant,with an obvious increase in the correlation coefficient and decrease in error.In addition,the improvement is much more significant when the southern boundary extends to the SIO westerly(scheme-3).In the case of strong swell processes generated by the SIO westerly,the improvement obtained by scheme-3 is even more significant. 展开更多
关键词 wave energy short-term forecast regional nesting boundary condition
下载PDF
Variation in energy metabolism structure of microbial community during bioleaching chalcopyrites with different iron-sulfur ratios 被引量:1
14
作者 YANG Yu ZHU Zhen-yu +2 位作者 HU Ting-ting ZHANG Meng-jun QIU Guan-zhou 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第7期2022-2036,共15页
The energy metabolism structure of microbial community plays an important role in the process of biohydrometallurgy.In this article,an artificial microbial community composed of three strains(Acidithiobacillus ferroox... The energy metabolism structure of microbial community plays an important role in the process of biohydrometallurgy.In this article,an artificial microbial community composed of three strains(Acidithiobacillus ferrooxidans,Leptospirillum ferriphilum and Acidithiobacillus thiooxidans)was used to leach three kinds of chalcopyrites with different iron-sulfur ratios.After 36 d of leaching,the chalcopyrite with iron-sulfur ratio of about 1:1 achieved the highest copper extraction(69.62%).In the early stage,iron oxidizing bacteria predominated,and the expression of rus and rio was 8 times higher than that in the late stage.In the late stage,sulfur oxidizing bacteria predominated,and the expression of tetH and HdrAB was 4 times higher than that in the early stage.Furthermore,the three bioleaching systems above were added with elemental sulfur(3 g/L);the chalcopyrite with iron-sulfur ratio of about 2:1 achieved the highest copper extraction(80.63%).The results suggest that the energy metabolism structure of the microbial community could be changed by changing the iron-sulfur ratio during the leaching process for improving the leaching efficiency of chalcopyrite. 展开更多
关键词 energy metabolism structure microbial community BIOLEACHING chalcopyrite iron-sulfur ratio
下载PDF
Influence of Chemical Effect on the Kβ/Kα Intensity Ratios and Kβ Energy Shift of Co, Ni, Cu, and Zn Complexes 被引量:1
15
作者 G. Apaydin V. Aylikci +2 位作者 Z. Biyiklioglu E. Tirasoglu H. Kantekin 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2008年第6期591-595,共5页
Chemical effects on the Kβ/Kα intensity ratios and △E energy differences for Co, Ni, Cu, and Zn complexes were investigated. The samples were excited by 59.5 keV γ-rays from a ^241Am annular radioactive source. K ... Chemical effects on the Kβ/Kα intensity ratios and △E energy differences for Co, Ni, Cu, and Zn complexes were investigated. The samples were excited by 59.5 keV γ-rays from a ^241Am annular radioactive source. K X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. We observed the effects of different ligands on the Kβ/Kα intensity ratios and △E energy differences for Co, Ni, Cu, and Zn complexes. We tried to investigate chemical effects on central atoms using the behaviors of different ligands in these complexes. The experimental values of Kβ/Kα were compared with the theoretical and other experimental values of pure Co, Ni, Cu, and Zn. 展开更多
关键词 Chemical effect K intensity ratio △E energy difference Ultra-LEGe detector 241Am annular radioactive source
下载PDF
ANALYSES OF THE DIFFERENCE BETWEEN IRRIGATED AND NONIRRIGATED AREA FOR LUMINOUS ENERGY UTILIZATION RATIO AND PRODUCTIVE POTENTIALITIES IN NINGXIA
16
作者 Sun Fulu Ningxia Center of Climatological Date 《干旱区资源与环境》 CSCD 1993年第Z1期391-396,共6页
Situated in arid and semi-arid lands, the Ningxia Hui Autonomous Region is locatedat the middle reaches of the Yellow River. An adequate system of gravity irrigation was es-tablished in the north of Ningxia. Adding to... Situated in arid and semi-arid lands, the Ningxia Hui Autonomous Region is locatedat the middle reaches of the Yellow River. An adequate system of gravity irrigation was es-tablished in the north of Ningxia. Adding to abundant sunshine, strong solar radiation andmoderate heat, the agriculture is very developed. The south mountainous area of Ningxia, including both Yanchi and Tongxin counties,is short of rain, The vast lands cannot be irrigated. Nonirrigated agriculture and 展开更多
关键词 IRRIGATED AGRICULTURE RAINFED AGRICULTURE LUMINOUS energy Utilization ratio Productive POTENTIALS
下载PDF
Control of Beam Energy and Flux Ratio in an Ion-Beam-Background Plasma System Produced in a Double Plasma Device
17
作者 WEI Zian MAJinxiu +2 位作者 LI Yuanrui SUN Yan JIANG Zhengqi 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第11期1076-1080,共5页
Plasmas containing ion beams have various applications both in plasma technology and in fundamental research. The ion beam energy and flux are the two factors characterizing the beam properties. Previous studies have ... Plasmas containing ion beams have various applications both in plasma technology and in fundamental research. The ion beam energy and flux are the two factors characterizing the beam properties. Previous studies have not achieved the independent adjustment of these two parameters. In this paper, an ion-beam-background-plasma system was produced with hotcathode discharge in a double plasma device separated by two adjacent grids, with which the beam energy and flux ratio (the ratio between the beam flux and total ion flux) can be controlled independently. It is shown that the discharge voltage (i.e., voltage across the hot-cathode and anode) and the voltage drop between the two separation grids can be used to effectively control the beam energy while the flux ratio is not affected by these voltages. The flux ratio depends sensitively on hot-filaments heating current whose influence on the beam energy is relatively weak, and thus enabling approximate control of the flux ratio 展开更多
关键词 ion beam background plasma beam energy flux ratio
下载PDF
Zonal flow energy ratio evolution during L-H and H-L transitions in EAST plasmas
18
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
下载PDF
ADAPTIVE EIGENFREQUENCY ANALYSIS BY IMPROVED r-AND h-ADAPTIVE FINITE ELEMENT METHOD BASED ON PERTURBATION AND ELEMENT ENERGY RATIO
19
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
下载PDF
Effects of pulse energy ratios on plasma characteristics of dual-pulse fiber-optic laser-induced breakdown spectroscopy
20
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
下载PDF
上一页 1 2 212 下一页 到第
使用帮助 返回顶部