期刊文献+
共找到24篇文章
< 1 2 >
每页显示 20 50 100
System-L evel Efficiency Optimization of a Linear Induction Motor Drive System 被引量:6
1
作者 Wei Xu Dong Hu +1 位作者 Gang Lei Jianguo Zhu 《CES Transactions on Electrical Machines and Systems》 CSCD 2019年第3期285-291,共7页
Linear induction motors are superior to rotary induction motors in direct drive systems because they can generate direct forward thrust force independent of mechanical transmission.However,due to the large air gap and... Linear induction motors are superior to rotary induction motors in direct drive systems because they can generate direct forward thrust force independent of mechanical transmission.However,due to the large air gap and cut-open magnetic circuit,their efficiency and power factor are quite low,which limit their application in high power drive systems.To attempt this challenge,this work presents a system-level optimization method for a single-sided linear induction motor drive system.Not only the motor but also the control system is included in the analysis.A system-level optimization method is employed to gain optimal steady-state and dynamic performances.To validate the effectiveness of the proposed optimization method,experimental results on a linear induction motor drive are presented and discussed. 展开更多
关键词 efficiency optimization control linear inductor motor system loss model system-level optimization.
下载PDF
Improved Efficiency Test Method for the Motor Controller with SiC MOSFETs
2
作者 Wei Wang Qiang Song +1 位作者 Yiting Li Mukhtiar Ahmad 《Journal of Beijing Institute of Technology》 EI CAS 2020年第3期294-302,共9页
The traditional measurement method was inaccurate to evaluate the motor controller efficiency,which the measurement efficiency value could be more than 100%in practical testing experiments.To deal with this issue,an i... The traditional measurement method was inaccurate to evaluate the motor controller efficiency,which the measurement efficiency value could be more than 100%in practical testing experiments.To deal with this issue,an improved electrical measurement method for the motor controller efficiency is proposed in this paper,which is established by analyzing the power loss distribution and phase currents of the motor controller.It is demonstrated that the SiC MOSFET chips are the main power loss devices in the motor controller,accounting for more than 93.1%of the total power loss.The accuracy of the proposed method is compared with the traditional method in simulation.It shows that the test error of the efficiency obtained by the traditional method fluctuates on a large scale,which varied from 0.094%to 1.911%.Compared with the traditional method,the test error of the proposed method appears to be less than 0.083%,which provides significant guidance for the motor controller efficiency test and design. 展开更多
关键词 electrical measurement method motor controller efficiency power loss distribution SiC MOSFET
下载PDF
Field Efficiency Trial of Microbial Fertilizer against Eggplant Verticillium Wilt
3
作者 Zhang Dongmei Gao Zhenjiang +3 位作者 Gao Wa Wang Qi Zhang Dongxu Liu Mingxing 《Plant Diseases and Pests》 CAS 2016年第1期19-21,共3页
The control effect of microbial fertilizer on eggplant verticillium wilt was studied through investigation of disease index and diseased plant rate. The reiults showed that the disease index and diseased plant rate of... The control effect of microbial fertilizer on eggplant verticillium wilt was studied through investigation of disease index and diseased plant rate. The reiults showed that the disease index and diseased plant rate of eggplant verticillium wilt were the lowest in the plots with substrate treatment and root-irrigation treatnent. The control effects in the plots with substrate treatment were higher than those in the plots with only root irrigation treatment. Moreover, higher concentration of microbial fertilizer resulted in better control effect and higher yield. Thus, the microbial fertilizer had a broad application prospect. 展开更多
关键词 Microbial fertilizer EGGPLANT Verticillium wilt Disease index Control efficiency
下载PDF
Control Efficiency of 36% Carbendazim Triadimefon SC on Wheat Powdery Mildew and Pink Mold
4
作者 Lu Jie Shao Mei 《Plant Diseases and Pests》 CAS 2015年第1期28-30,共3页
This paper explored the control efficiency of 36% Carbendazim triadimefon SC on wheat powdery mildew, wheat pink mold and rope sclerotinia, and the impact on rape yield through field experiment. The results showed tha... This paper explored the control efficiency of 36% Carbendazim triadimefon SC on wheat powdery mildew, wheat pink mold and rope sclerotinia, and the impact on rape yield through field experiment. The results showed that the control efficiency was the best on the 7th and 14th day after the application of 36% Car- bendazim triadimefon SC in the dosage of 2 250 mL/hm2, and rope yield was improved by 32%. 展开更多
关键词 Carbendazim triadimefon Wheat powdery mildew Wheat pink mold Rape sclerotinia Control efficiency
下载PDF
Effect Trials on Abamectin + Chlorpyrifos 8% GR for Controlling Turf Grubs
5
作者 Sun Shujun You Xiufeng Shao Mei 《Plant Diseases and Pests》 CAS 2015年第1期13-14,共2页
To screen high-efficiency, low-toxicity, and safe pesticides for controlling soil pests, experimental investigations of Abamectin + Chlorpyrifos 8 % GR for controlling tuff grubs were implemented according to Field P... To screen high-efficiency, low-toxicity, and safe pesticides for controlling soil pests, experimental investigations of Abamectin + Chlorpyrifos 8 % GR for controlling tuff grubs were implemented according to Field Pharrnacodynamic Test Standards of the Ministry of Agricuhure. The results showed that as the active in- gredient of Abamectin + Chlorpyrifos 8% GR is 1 625 - 1 950 g/hm2, the control efficiency of tuff grubs is 81.43% -90.46% 3 - 10 days after pesticide applica- tion, the readily availability and persistent effect achieve the ideal level, and it is safe for turf. 展开更多
关键词 TUFF GRUB Abamectin Chlorpyrifos 8% GR Control efficiency
下载PDF
Agronomic Efficiency of Herbicide Tolerant Crops in Peninsular India——A Review
6
作者 Chinnusamy Chinnagounder Bharathi Chandrasekaran +2 位作者 Ravishankar Duraisamy Nithya Chinnasamy Sivakamy Kannan 《Journal of Agricultural Science and Technology(B)》 2020年第6期317-326,共10页
Crops made resistant to herbicides by biotechnology are being widely adopted in various parts of the world and several herbicide resistant crops have become available in many countries for commercial cultivation.But i... Crops made resistant to herbicides by biotechnology are being widely adopted in various parts of the world and several herbicide resistant crops have become available in many countries for commercial cultivation.But in India,the technology of herbicide tolerant crops is in initial stage of field evaluation.Hence,field trials have been carried out to evaluate and consolidate the agronomic advantages of herbicide tolerant transgenic cotton and maize.Herbicide tolerant stacked traits of maize and cotton have been evaluated under Bio-safety Research Level(BRL I)as confined field trials for its agronomic efficiency on weed control and enhanced crop productivity at Tamil Nadu Agricultural University(TNAU),Coimbatore and Punjab Agricultural University(PAU),Ldhiana for many years.In both crops,potassium salt formulation of glyphosate was sprayed at different doses(900,1,350,1,800,2,700,3,600 and 5,400 g a.e./ha twice at 25 days after sowing(DAS)and 60 DAS in cotton and 900,1,800 and 3,600 g a.e./ha at 25 DAS in maize).Evaluation was made on weed control efficiency,phyto-toxicity on crops,yield and economics and carry over effects on the succeeding crops.Application of glyphosate at 2,700 g a.e./ha recorded lower weed density,dry weight and higher weed control efficiency(WCE)in cotton.Post-emergence(POE)glyphosate at 900,1,800 and 3,600 g a.e./ha registered lower weed density,dry weight and higher WCE in transgenic Hishell and 900 M Gold and in 30V92 and 30B11 corn hybrids.Post-emergence application of glyphosate in transgenic maize hybrids did not affect the germination percent,vigour and yield of succeeding green gram in the transgenic maize trials and sunflower,soybean and pearl millet in cotton trials.Phytotoxicity symptoms were not observed in cotton with glyphosate at lower doses viz.,900,1,350,1,800 and 2,700 g a.e./ha.Higher doses viz.3,600 g a.e./ha and 5,400 g a.e./ha were noticed with phytotoxicity symptoms at early stages of herbicide application.Glyphosate applied at 900,1,350,1,800 and 2,700 g a.e./ha recorded more number of bacteria,fungi and actinomycetes compared to atrazine treatments.Higher grain yield was recorded with POE application of glyphosate at 900,1,800 and 3,600 g a.e./ha in Hishell and 900 M Gold transgenic hybrids and higher net return and benefit cost ratio were recorded in glyphosate at 1,800 g a.e./ha in transgenic 900 M Gold in all the four seasons.Post-emergence application of glyphosate at 900 g a.e./ha and 1,800 g a.e./ha registered higher grain yield in transgenic 30V92 and 30B11 corn hybrids.In maize and cotton transgenic crops,post-emergence weed management with glyphosate proved to be the better management option for the control of weeds. 展开更多
关键词 Herbicide tolerant crops weed control efficiency PHYTOTOXICITY carry over effect corn and cotton productivity and profitability
下载PDF
Empirical Analysis of Forest Pest Control Efficiency from 2003 to 2014 in China
7
作者 Cai Qi Cai Yushi +3 位作者 Sun Shibo Ding Huimin Ren jie Wen Yali 《Plant Diseases and Pests》 CAS 2017年第5期20-22,共3页
Three indexes including forest pest occurrence area,control area and input fund of 31 provinces from 2003 to 2014 were selected from Forestry Statistical Yearbook,to establish dynamic interaction index evaluation syst... Three indexes including forest pest occurrence area,control area and input fund of 31 provinces from 2003 to 2014 were selected from Forestry Statistical Yearbook,to establish dynamic interaction index evaluation system with clustering robust regression model and Stata 13. 0 software. Total forest pest control efficiency in China was determined according to the computing result of entropy method. Suggestions such as improving forest pest control efficiency,increasing service efficiency and input amount of forest pest control input funds were put forward. It will provide empirical basis for target management evaluation of forest pest control work and accountability system. 展开更多
关键词 Forest pest Control efficiency Cluster robust regression model Entropy method
下载PDF
白花蛇舌草提取液对感染TMV烟株的生理效应及品质的影响(英文)
8
作者 白海群 刘子仪 崔德强 《Plant Diseases and Pests》 CAS 2010年第4期12-15,共4页
The extract from Hedyotis diffusae was used to treat tobacco plants infected by TMV before and after incidence. The effect of the changes of some physiological and biochemical indices related with the virus-resistance... The extract from Hedyotis diffusae was used to treat tobacco plants infected by TMV before and after incidence. The effect of the changes of some physiological and biochemical indices related with the virus-resistance in tobacco leaves on tobacco quality ware determined. The resuits showed that H. diffusae extract could remarkably increase the total phenol content in tobacco leaves ,strength the activity of phenylalanine ammonialyase ( PAL) , improve the membrane permeability and tobacco quality. Prevention treatment was better than therapy treatment. In conclusion, H. diffusae extract could induce plants to produce disease resistance and strength tha antiviral capability of tobacco against TMV. 展开更多
关键词 Hedyotis diffusae Willd. EXTRACT TMV Control efficiency Physiologic~ effect China
下载PDF
Impact of environmental regulations on the efficient control of industrial pollution in China 被引量:1
9
作者 Mian Yang Xinghong Yan Qiangyi Li 《Chinese Journal of Population,Resources and Environment》 2021年第3期230-236,共7页
The continuous progress of industrialization is a fundamental cause of China’s increasingly severe environmental pollution problem.Improving the efficiency of industrial pollution control is an inevitable choice to e... The continuous progress of industrialization is a fundamental cause of China’s increasingly severe environmental pollution problem.Improving the efficiency of industrial pollution control is an inevitable choice to effectively decrease pollution emissions,thus winning the battle of pollution prevention and control.In this paper,we used the stochastic frontier analysis(SFA)model to measure the provincial efficiency of industrial pollution control based on the input and output data of industrial pollution control of 29 administrative provinces in China from 2000 to 2017.On this basis,a spatial econometric model was used to explore the influence of environmental regulation intensity on the efficiency of industrial pollution control.In addition,the spatial spillover effect of pollution reduction was thoroughly examined.The results show that:(1)The efficiency of industrial pollution control in China has improved year by year,but the overall efficiency is still low,with the average value increasing from 0.165 in 2000 to 0.309 in 2017.Furthermore,there is significant regional heterogeneity with the highest efficiency level in the east and lowest efficiency level in the west.(2)By increasing the financial and material input,the efficiency of industrial pollution control has increased.However,the increase of human input has not been so helpful.(3)The global Moran’s I index is significantly greater than zero,indicating a strong spatial correlation and agglomeration in the efficiency of industrial pollution control,which is reflected in high-high agglomeration in the eastern region and low-low agglomeration in the western region.(4)Stringent environmental regulation has a positive effect on improving the efficiency of industrial pollution control.It also imposes a positive spatial spillover effect,indicating a strategic interaction and coordination of regional pollution control.In line with this,related proposals have been made to optimize the investment structure for environmental pollution control,establish a flow mechanism for the factor market,and strengthen the environmental responsibility awareness of state-owned enterprises.On this basis,we expect to provide a policy for improving the efficiency of industrial pollution control and promoting regional joint pollution control in China. 展开更多
关键词 Industrial pollution control efficiency Environmental regulation Stochastic frontier analysis Spatial spillover effect
下载PDF
Chemical Application for Prevention and Control of Post-harvest Citrus Diseases 被引量:1
10
作者 Xu Weisong Tan Yaohua +1 位作者 Zhou Zhenbiao Shao Mei 《Plant Diseases and Pests》 CAS 2015年第1期25-27,共3页
[ Objective] To study the control efficiency of 45% Prochloraz amines ME and 500 g/L Triabendazole SC for the post-harvest diseases of citrus fruits, and the economic and efficient dosage and application techniques. [... [ Objective] To study the control efficiency of 45% Prochloraz amines ME and 500 g/L Triabendazole SC for the post-harvest diseases of citrus fruits, and the economic and efficient dosage and application techniques. [ Method] Carry out prevention and control test of common post-harvest diseases of tangerines, such as anthracnose, green mold and penicillium disease. [ Result] The experiment agent 45% Prochloraz amines ME showed excellent effect in controlling post- harvest anthracnose of citrus fruits, the 45t^-day control efficiency was above 73% ; the 45ts-day control efficiency of 45% Prochloras amines ME and 500 g/L Tri- abendazole SC for green mold and penicillium disease was above 72%. [ Conclusion] 45% Prochloraz amines ME and 500 g/L Triabendazole SC are two ideal agents for preventing and controlling post-harvest diseases and safeguarding quality of citrus fruits. 展开更多
关键词 Triabendazole Prochloraz amines CITRUS Fruit disease Control efficiency
下载PDF
Control method on serial type pump-valve coordinated electro-hydraulic servo system 被引量:1
11
作者 谢文 汪首坤 +1 位作者 王军政 吴建 《Journal of Beijing Institute of Technology》 EI CAS 2016年第1期100-107,共8页
In order to compromise the conflicts between control accuracy and system efficiency of conventional electro-hydraulic servo systems,a novel pump-valve coordinated electro-hydraulic servo system was designed and a corr... In order to compromise the conflicts between control accuracy and system efficiency of conventional electro-hydraulic servo systems,a novel pump-valve coordinated electro-hydraulic servo system was designed and a corresponding control strategy was proposed.The system was constituted of a pumpcontrolled part and a valve-controlled part,the pump controlled part is used to adjust the flow rate of oil source and the valve controlled part is used to complete the position tracking control of the hydraulic cylinder.Based on the system characteristics,a load flow grey prediction method was adopted in the pump controlled part to reduce the system overflow losses,and an adaptive robust control method was adopted in the valve controlled part to eliminate the effect of system nonlinearity and parametric uncertainties due to variable hydraulic parameters and system loads on the control precision.The experimental results validated that the adopted control strategy increased the system efficiency obviously with guaranteed high control accuracy. 展开更多
关键词 pump-valve coordinated grey prediction adaptive robust control efficiency
下载PDF
Experimental study on water-saving and emission-reduction effects of controlled drainage technology 被引量:4
12
作者 Meng-hua Xiao Xiu-jun Hu Lin-lin Chu 《Water Science and Engineering》 EI CAS CSCD 2015年第2期114-120,共7页
Field experiments and laboratory analysis were carried out to determine the effects of controlled drainage(CTD) and conventional drainage(CVD) technologies on drainage volume, concentrations of NH4^+ -N, NO3^-N, ... Field experiments and laboratory analysis were carried out to determine the effects of controlled drainage(CTD) and conventional drainage(CVD) technologies on drainage volume, concentrations of NH4^+ -N, NO3^-N, and total phosphorus(TP), nitrogen and phosphorus losses, rice yield,and water utilization efficiency. Results show that CTD technology can effectively reduce drainage times and volume; NH4^+ -N, NO3^-N, and TP concentrations, from the first to the fourth day after four rainstorms decreased by 28.7%e46.7%, 37.5%e47.5%, and 22.7e31.2%, respectively,with CTD. These are significantly higher rates of decrease than those observed with CVD. CTD can significantly reduce nitrogen and phosphorus losses in field drainage, compared with CVD; the reduction rates observed in this study were, respectively, 66.72%, 55.56%, and 42.81% for NH4^+ -N, NO3^-N, and TP. Furthermore, in the CTD mode, the rice yield was cut slightly. In the CVD mode, the water production efficiencies in unit irrigation water quantity, unit field water consumption, and unit evapotranspiration were, respectively, 0.85, 0.48, and 1.22 kg/m^3, while in the CTD mode they were 2.91, 0.84, and 1.61 kg/m^3 din other words, 3.42, 1.75, and 1.32 times those of CVD. Furthermore, the results of analysis of variance(ANOVA) show that the indicators in both the CVD and CTD modes, including the concentrations of NH4^+ -N, NO3^-N, and TP, the losses of NH4^+ -N, NO3^-N, and TP, irrigation water quantity, and water consumption, showed extremely significant differences between the modes, but the rice yield showed no significant difference. 展开更多
关键词 Controlled drainage Nitrogen Phosphorus Rice yield Drainage volume Water utilization efficiency
下载PDF
Regulation characteristics of oxide generation and formaldehyde removal by using volume DBD reactor 被引量:3
13
作者 陈秉岩 高香香 +7 位作者 陈可 刘昌裕 李沁书 苏巍 蒋永锋 何湘 朱昌平 费峻涛 《Plasma Science and Technology》 SCIE EI CAS CSCD 2018年第2期56-66,共11页
Discharge plasmas in air can be accompanied by ultraviolet(UV) radiation and electron impact,which can produce large numbers of reactive species such as hydroxyl radical(OH·),oxygen radical(O·),ozone... Discharge plasmas in air can be accompanied by ultraviolet(UV) radiation and electron impact,which can produce large numbers of reactive species such as hydroxyl radical(OH·),oxygen radical(O·),ozone(O3),and nitrogen oxides(NOx),etc.The composition and dosage of reactive species usually play an important role in the case of volatile organic compounds(VOCs) treatment with the discharge plasmas.In this paper,we propose a volume discharge setup used to purify formaldehyde in air,which is configured by a plate-to-plate dielectric barrier discharge(DBD) channel and excited by an AC high voltage source.The results show that the relative spectral-intensity from DBD cell without formaldehyde is stronger than the case with formaldehyde.The energy efficiency ratios(EERs) of both oxides yield and formaldehyde removal can be regulated by the gas flow velocity in DBD channel,and the most desirable processing effect is the gas flow velocity within the range from2.50 to 3.33 m s^-1.Moreover,the EERs of both the generated dosages of oxides(O3 and NO2) and the amount of removed formaldehyde can also be regulated by both of the applied voltage and power density loaded on the DBD cell.Additionally,the EERs of both oxides generation and formaldehyde removal present as a function of normal distribution with increasing the applied power density,and the peak of the function is appeared in the range from 273.5 to 400.0 W l-1.This work clearly demonstrates the regulation characteristic of both the formaldehyde removal and oxides yield by using volume DBD,and it is helpful in the applications of VOCs removal by using discharge plasma. 展开更多
关键词 reactive species volume DBD energy efficiency ratio(EER) regulation and control
下载PDF
Evaluation of Control Effects against Sugarcane Pests:A New Sustained-release and Long-lasting Pesticide and Convenient and Efficient Pesticide Application Technology 被引量:1
14
作者 Li Wenfeng Pu Chunhua +5 位作者 Zhang Rongyue Yin Jiong Luo Zhiming Shan Hongli Wang Xiaoyan Huang Yingkun 《Plant Diseases and Pests》 CAS 2017年第5期11-14,共4页
[Objective]The paper was to screen a new ideal sustained-release,long-lasting and low-toxic pesticide and convenient and efficient pesticide application technology for controlling Ceratovacuna lanigera and Baliathrips... [Objective]The paper was to screen a new ideal sustained-release,long-lasting and low-toxic pesticide and convenient and efficient pesticide application technology for controlling Ceratovacuna lanigera and Baliathrips serratus. [Method]2% Imidacloprid GR were selected and applied in the soil for field efficacy trial. [Result] The optimum dosage of 2% imidacloprid GR was 30 kg/hm^2( active ingredient 600 g),which can be mixed with fertilizer( 30 kg pesticide and 40-80 kg fertilizer per hm^2) once combined with sugarcane planting management or big ridging during February and June. The control effects against C. lanigera and B. serratus could be more than 98. 2% and 81. 1%,respectively. The actual yield and sugar content in various pesticide treatments were increased by 33 390 kg/hm^2 and 6. 6% respectively compared to blank control. [Conclusion]2% imidacloprid GR has good control effects on C. lanigera and B. serratus. It is a new pesticide with ideal sustained-release,long-lasting and low-toxin effects against C. lanigera and B. serratus. Therefore,it could be used alternatively with other pesticides,to delay production and development of drug resistance. 展开更多
关键词 Sustained-release and long-lasting pesticide Convenient and efficient pesticide application Sugarcane pests Control effect evaluation
下载PDF
Screening of Chemical Control for Potato Blight
15
作者 Chen Chunyan Wang Chaohai +3 位作者 Chen Yuzhang Liang Zhengjuan Wang Shengnan Wang Song 《Plant Diseases and Pests》 CAS 2015年第2期16-18,共3页
To screen chemicals for controlling potato blight effectively, randomized block experiment was adopted, the control efficiency of five chemicals for Carbendazim, Metalaxyl, Dithane mancozeb, Curzate, Cymoxanil mancoze... To screen chemicals for controlling potato blight effectively, randomized block experiment was adopted, the control efficiency of five chemicals for Carbendazim, Metalaxyl, Dithane mancozeb, Curzate, Cymoxanil mancozeb was explored. The results showed that the efficiency of Metalaxyl was much better than that of other conventional chemicals in controlling potato blight, up to 70.59% ; the mean control efficiency of Curzate and Cymoxanil mancozeb was 68.76% and 67.05% ; the control efficiency of Carbendazim was lower, 55.76%. Big and middle tuber rate, tuber weight per hole, plot yield, unit area yield of potatoes in Metalaxyl treatment were the highest, 78.05%, 437.24 g/hole, 34.0 kg/21.6 m2 and 15 748.61 kg/hm2, 49.12% higher than the control yield. The indexes of potatoes in Cymoxanil mancozeb treatment were the second highest, 73.33%, 385.31 g/hole, 32.8 kg/21.6 m2 and 15 192.78 kg/hm2, 43.86% higher than the control yield. 展开更多
关键词 Potato blight CHEMICAL Control efficiency Yield increase rate
下载PDF
Rotor cross-tilt optimization for yaw control improvement of multi-rotor eVTOL aircraft
16
作者 Xufei YAN Ye YUAN +1 位作者 Yanqin ZHAO Renliang CHEN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第3期153-167,共15页
Manned multi-rotor electric Vertical Takeoff and Landing(eVTOL)aircraft is prone to actuator saturation due to its weak yaw control efficiency.To address this inherent problem,a rotor cross-tilt configuration is appli... Manned multi-rotor electric Vertical Takeoff and Landing(eVTOL)aircraft is prone to actuator saturation due to its weak yaw control efficiency.To address this inherent problem,a rotor cross-tilt configuration is applied in this paper,with an optimization method proposed to improve the overall control efficiency of the vehicle.First,a flight dynamics model of a 500-kg manned multi-rotor eVTOL aircraft is established.The accuracy of the co-axial rotor model is verified using a single arm test bench,and the accuracy of the flight dynamics model is verified by the flight test data.Then,an optimization method is designed based on the flight dynamics model to calculate an optimal rotor cross-tilt mounting angle,which not only improves the yaw control efficiency,but also basically maintains the efficiency of other control channels.The ideal rotor cross-tilt mounting angle for the prototype is determined by comprehensively considering the optimal results with different payloads,forward flight speeds,and rotor mounting angle errors.Finally,the feasibility of the rotor cross-tilt mounting angle is proved by analyzing the control derivatives of the flight dynamics model,the test data of a ground three Degree-of-Freedom(3DOF)platform,and the actual flight data of the prototype.The results show that a fixed rotor cross-tilt mounting angle can achieve ideal yaw control effectiveness,improving yaw angle tracking and hold ability,increasing endurance time,and achieving good yaw control performance with different payloads and forward speeds. 展开更多
关键词 Multi-rotor eVTOL Control efficiency Flight dynamics model Cross-tilt optimization Endurance time
原文传递
Effect of aerial spray adjuvant applying on the efficiency of small unmanned aerial vehicle for wheat aphids control 被引量:15
17
作者 Yanhua Meng Yubin Lan +3 位作者 Guiying Mei Yongwang Guo Jianli Song Zhiguo Wang 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2018年第5期46-53,共8页
Small unmanned aerial vehicles(UAVs)have been widely used in different aspects of modern farming management,including pest and disease control in China in recent years.In this study,the spray performance of a small pl... Small unmanned aerial vehicles(UAVs)have been widely used in different aspects of modern farming management,including pest and disease control in China in recent years.In this study,the spray performance of a small plant protection UAV at low volume spray was evaluated by adjusting the pesticide dosage and adding aerial spraying adjuvants.Droplet deposition,droplet density,coverage,control effect and pesticide residue from field trials were assessed.In addition,the residue and control effect of UAV spray were compared to manual knapsack at high volume spray.The results showed that,the adjuvant applying improved the efficiency of UAV spray.Also,the adjuvant applying reduced the dosage of imidacloprid by 20%.However,there was no significant difference on initial residue between UAV spray and knapsack spray.Thus,plant protection UAV spraying pesticide by adding appropriate adjuvant showed the ability of improving the pesticide effectiveness by improving the control efficiency,reducing the pesticide dosage and residue. 展开更多
关键词 unmanned aerial vehicle(UAV) aerial spraying adjuvant deposition control efficiency pesticide residue wheat aphid
原文传递
Ligand density control boosts the efficiency of all-inorganic CsPbBr3 perovskite nanocrystal based light emitting diodes
18
作者 Andrey L. Rogach 《Science Bulletin》 SCIE EI CAS CSCD 2017年第5期314-315,共2页
Lead halide perovskites attracted a lot of attention in the last several years,with a focus gradually shifting from the record power conversion efficiencies reported for photovoltaic devices based on thin perovskite f... Lead halide perovskites attracted a lot of attention in the last several years,with a focus gradually shifting from the record power conversion efficiencies reported for photovoltaic devices based on thin perovskite films[1]towards superior 展开更多
关键词 LEDs Ligand density control boosts the efficiency of all-inorganic Cs Pb Br3 perovskite nanocrystal based light emitting diodes Cs PB Br
原文传递
Protective effect of multi-row HDPE board sand fences:A wind tunnel study 被引量:6
19
作者 Kai Zhang Peiwen Zhao +1 位作者 Jianchang Zhao Xingxin Zhang 《International Soil and Water Conservation Research》 SCIE CSCD 2021年第1期103-115,共13页
Recently,sand fences,made of high density polyethylene(HDPE)board,which is resistant against harsh plateau environmental conditions,could possibly be used to control the wind-blown sand along the Qinghai section of th... Recently,sand fences,made of high density polyethylene(HDPE)board,which is resistant against harsh plateau environmental conditions,could possibly be used to control the wind-blown sand along the Qinghai section of the Golmud-Korla Railway.In this paper,wind tunnel simulation was performed on the protective effect of multiple rows of HDPE board sand fences on wind-blown sand.Two parameters have been used to reflect the protective effect of sand fences,that is,windproof efficiency and sand control efficiency,referring to the reduction rates of wind speed at a height of 0.04 m and sand flux in a run of test with the fence compared those in the control run of test without it,respectively.The test results showed that when the porosity was 30%,the single-row sand fence had the best wind proof and sand control efficiency with respective values of 46%and 65.3%.The windproof efficiencies of double-row and triple-row sand fences at 20H were 59%and 62%,respectively.Compared with the windproof effi-ciency of the single-row sand fence,those of the two-row and three-row fences increased by 13%and 16%,respectively:The maximum sand control efficiency of the double-row and triple-row sand fences were 92.1%and 96.5%,increased by 26.8%and 31.2%,respectively,compared with that of the single-row sand fence.This study indicates that the sand control efficiency after adding one or two rows was not double or triple that of the single-row fence,while the first-row sand fence played a major protective role.Compared with the double-row sand fences,the effect of the third row sand fence in triple-row sand fences is limited,and thus double-row HDPE board sand fences with the porosity of 30%are rec-ommended to control wind-blown sand along the Qinghai section of the Golmud-Korla Railway. 展开更多
关键词 HDPE board sand fences Windproof efficiency Sand control efficiency Reasonable spacing Porosity
原文传递
Removing ammonia from air with a constant pH, slightly acidic water spray wet scrubber using recycled scrubbing solution 被引量:5
20
作者 Ahmad Kalbasi Ashtari Amir M. Samani Majd +2 位作者 Gerald L. Riskowski Saqib Mukhtar Lingying Zhao 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2016年第6期159-168,共10页
Previous research on wet scrubbers has only studied highly acidic scrubbing solutions because of their high ammonia capture efficiencies; however, the high acidity created practical problems. Lower acidity solutions w... Previous research on wet scrubbers has only studied highly acidic scrubbing solutions because of their high ammonia capture efficiencies; however, the high acidity created practical problems. Lower acidity solutions would reduce corrosion, maintenance, and cost; however, designers may need to use strategies for increasing scrubber effectiveness, such as using lower air velocities. The objective of this studywas to determine if a spray scrubber with slightly acidic and higher p H scrubbing solution (pH from 2 to 8) could effectively remove NH3 from NH3 laden air (such as animal building exhaust air), and also collect this valuable resource for rater use as a fertilizer. A bench-scale spray wet scrubber treated 20 ppmv NH3/air mixture in a countercurrent contact chamber. First, the solution pH was varied from 2 to 8while maintaining constant air velocity at 1.3 m. s-1. Next, air velocity was increased (2and 3 m.s-1) while solution pH remained constant at pH6. At 1.3 m.s -1, NH3 removal efficiencies ranged between 49.0% (pH8) and 84.3% (pH2). This study has shown that slightly acidic scrubbing solutions are a practical means of removing ammonia from air especially if the scrubber is designed to increase collisions between solution droplets and NH3 molecules. The NH3 removed from the air was held in solution as NH4+ and accumulates over time so the solution should be an excellent fertilizer. 展开更多
关键词 Ammonia Spray wet scrubber Slightly acidic scrubbing solution Controlled pH Removal efficiency
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部