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Effects of the Mn/Co ratio on the magnetic transition and magnetocaloric properties of Mn_(1+x)Co_(1-x)Ge alloys 被引量:5
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作者 马胜灿 王敦辉 +3 位作者 轩海成 沈凌佳 曹庆琪 都有为 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第8期411-414,共4页
We have investigated the magnetic transition and magnetocaloric effects of Mn1+xCo1-xGe alloys by tuning the ratio of Mn/Co. With increasing Mn content, a series of first-order magnetostructural transitions from ferr... We have investigated the magnetic transition and magnetocaloric effects of Mn1+xCo1-xGe alloys by tuning the ratio of Mn/Co. With increasing Mn content, a series of first-order magnetostructural transitions from ferromagnetic to paramagnetic states with large changes of magnetization are observed at room temperature. Further increasing the content of Mn (x = 0.11) gives rise to a single second-order magnetic transition. Interestingly, large low-field magnetic entropy changes with almost zero magnetic hysteresis are observed in these alloys. The effects of Mn/Co ratio on magnetic transition and magnetocaloric effects are discussed in this paper. 展开更多
关键词 Mn/Co ratio magnetic transition magnetocaloric properties magnetic hysteresis losses
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Efficient Method to Extract Coupling Ratio and Round-trip Loss Parameters of Optical Waveguide Ring Resonator
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作者 HAN Xiu-you PANG Fu-fei +1 位作者 FANG Zu-jie ZHAO Ming-shan 《Semiconductor Photonics and Technology》 CAS 2008年第3期158-161,173,共5页
Based on the measurement of the contrast ratios of the transmission spectra from the throughput and drop ports of ring resonator, an efficient method is proposed to extract the coupling ratio and round-trip loss of th... Based on the measurement of the contrast ratios of the transmission spectra from the throughput and drop ports of ring resonator, an efficient method is proposed to extract the coupling ratio and round-trip loss of the integrated optical waveguide ring resonator. The parameters of a racetrack resonator prepared by ion-exchange technique in K9 optical glass substrate are examined, which demonstrates the validity of this method. The accuracy and applicable range of this method are also discussed. 展开更多
关键词 integrated optics waveguide ring resonator coupling ratio round-trip loss
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The Analysis of Effectiveness of Cost Control Strategy on the Profitability of Coca-Cola Company From Year 2015 to 2017
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作者 Zhiqi Xiao Jingxian Zhang 《Management Studies》 2020年第3期232-239,共8页
This paper is aiming to evaluate the effect of cost control strategy on the profitability of Coca-Cola Company from year 2015 to 2017 by using the ratio analysis and offer essential recommendations for the company.Thi... This paper is aiming to evaluate the effect of cost control strategy on the profitability of Coca-Cola Company from year 2015 to 2017 by using the ratio analysis and offer essential recommendations for the company.This paper is divided into three parts.First part is to introduce the current business operation activities and basic background information.This paper adopts desk research as data collection method.The major sources of information are the annual report of Coca-Cola Company,the database of World Health Organisation and other scholastic websites such as Wan Fang Database.Second,financial statements analysis and profitability analysis.This part contains three data analysis methods that are horizontal analysis and ratio analysis.Third part is the conclusion which is from year 2015 to 2017,that Coca-Cola Company has strengthened its profitability through cost control strategy but there are fatal hazards in the profitability of Coca-Cola Company that is the worse utilization of its assets to generate profit and dispute with IRS.The recommendations are also provided based on the conclusion which could be referenced by other companies to some extent. 展开更多
关键词 horizontal analysis ratio analysis profitability ratio financial statement analysis Coca-Cola Company
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A STUDY ON ECONOMY EVALUATION ON THE PROFIT AND LOSS OF GEOLOGIC ENVIRONMENTAL QUALITY ABOUT GEOLOGIC ENVIRONMENTAL EXPLOITATION PROJECT
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《石家庄经济学院学报》 1995年第S1期106-109,共4页
The problems of environmental geology refer to the geologic phenomena, incidents or accidents arising from action of environmental geology. The action is mainly the mutual influence between human activity and geologic... The problems of environmental geology refer to the geologic phenomena, incidents or accidents arising from action of environmental geology. The action is mainly the mutual influence between human activity and geologic environment. When human activity is uncoordinated with objective laws of the geologic environment, the problems of environmental geology or economic loss would occur.Therefore,the level and the changing orientation of geologic environmental quality are relative to the types of human activity,particularly relative to human intentional-activities of geologic environmental exploitation project. The geologic environment fitting to mining may not fit to urban construction,and fitting to water conservancy and hydroelectric projects may not fit to communication,and so on.Economy evaluation on the profit and loss of geologic environmental quality is exactly to depict the level of the profit and loss of geologic environmental quality about geologic environmental exploitation projects and the 展开更多
关键词 TH A STUDY ON ECONOMY EVALUATION ON the profit AND loss of GEOLOGIC ENVIRONMENTAL QUALITY ABOUT GEOLOGIC ENVIRONMENTAL EXPLOITATION PROJECT
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Mechanical Harvesting Effects on Seed Yield Loss,Quality Traits and Profitability of Winter Oilseed Rape (Brassica napus L.) 被引量:13
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作者 MA Ni ZHANG Chun-lei +4 位作者 LI Jun ZHANG Ming-hai CHENG Yu-gui LI Guang-ming ZHANG Shu-jie 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第8期1297-1304,共8页
China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cu... China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cultivar Zhongshuang 11 (Brassica napus L.) was employed in two rounds of field experiments from 2009 to 2011. Seeds were sown with machine, three combine harvesting times namely combine harvesting A, B, and C (CHA, CHB, and CHC) were designed and manual harvesting (MH) as control was performed at maturity. The harvesting treatments were determined according to color of pod and seed in the field. Seed yield loss and quality in different treatments were evaluated. Results showed that both seed yields and harvesting losses in 2009-2010 were higher than that in 2010-2011, whereas seed oil contents in 2010-2011 were higher than that in 2009-2010. The highest yield appeared in CHB, which was significantly higher than that in MH. Furthermore, harvesting loss in CHB were 50% that in MH. Seed oil content and chlorophyll exhibited no obvious difference between CHB and MH. Economic profit analysis demonstrated that mechanical sowing/combine harvesting (MS/CH) showed an input/output ratio of 1:1.6, and it was 1:1.2 in mechanical sowing/manual harvesting (MS/MH). Labor-cost accounted for more than 70% of the total cost in MS/MH, which led to low profitability to a great extent. Our results suggested that CHB was the optimum harvesting time for winter oilseed rape along the Yangtze River. 展开更多
关键词 winter oilseed rape (Brassica napus L.) combine harvesting harvesting loss seed quality economic profit
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Effect of the Inclination Angle on Slippage Loss in Gas-Liquid Two-Phase Flow 被引量:4
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作者 Yushan Liu Yubin Su +2 位作者 Zhenhua Wu Wei Luo Ruiquan Liao 《Fluid Dynamics & Materials Processing》 EI 2020年第3期475-488,共14页
The lifting efficiency and stability of gas lift well are affected by the socalled slippage-loss effect in gas-liquid two-phase flow.The existing studies on this subject have generally been based on vertical and horiz... The lifting efficiency and stability of gas lift well are affected by the socalled slippage-loss effect in gas-liquid two-phase flow.The existing studies on this subject have generally been based on vertical and horizontal wells.Only a few of them have considered inclined pipes.In the present work a new focused study is presented along these lines.More specifically,we use the non-slip pressure drop model with Flanigan’s fluctuation correction coefficient formula(together with the parameters of slippage density,slippage pressure drop and slippage ratio)to analyze the influence of the inclination angle on slippage loss for different conditions(different gas-liquid superficial velocity and pipe diameters).Moreover,the“standard regression coefficient method”is used for multi-factor sensitivity analysis.The experimental results indicate that slippage loss is affected by multiple factors,and the influence of the inclination angle on slippage loss is less significant than other factors.The change of the slippage pressure drop with the superficial velocity of gas-liquid is similar to that of the total pressure drop.The inclination angles of 45°and 60°have the greatest influence on slippage loss.The correlation between slippage density and slippage ratio is not obvious.Using the so-called slippage ratio seems to be a more accurate option to evaluate the degree of slippage loss. 展开更多
关键词 Inclined pipes gas-liquid flow slippage loss pressure drop gas-liquid ratio
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Highly sensitive detection of Rydberg atoms with fluorescence loss spectrum in cold atoms 被引量:1
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作者 Xuerong Shi Hao Zhang +3 位作者 Mingyong Jing Linjie Zhang Liantuan Xiao Suotang Jia 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第1期218-222,共5页
Fluorescence loss spectrum for detecting cold Rydberg atoms with high sensitivity has been obtained based on lock-in detection of fluorescence of 6 P3/2 state when cooling lasers of the magneto-optical trap are modula... Fluorescence loss spectrum for detecting cold Rydberg atoms with high sensitivity has been obtained based on lock-in detection of fluorescence of 6 P3/2 state when cooling lasers of the magneto-optical trap are modulated.The experiment results show that the signal to noise ratio has been improved by 32.64 dB when the modulation depth(converted to laser frequency)and frequency are optimized to 4 MHz and 6 kHz,respectively.This technique enables us to perform a highly sensitive non-destructive detection of Rydberg atoms. 展开更多
关键词 fluorescence loss spectrum Rydberg atoms signal to noise ratio
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Economic Evaluation Method of Photovoltaic Power Generation Installed in Ordinary Homes 被引量:1
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作者 Yasushi Iwasaki Kayoko Yamamoto 《Smart Grid and Renewable Energy》 2014年第6期137-151,共15页
This study aims to develop an economic evaluation method for installing photovoltaic power generation in ordinary homes using GIS (Geographic Information Systems). The conclusions can be summarized in the following th... This study aims to develop an economic evaluation method for installing photovoltaic power generation in ordinary homes using GIS (Geographic Information Systems). The conclusions can be summarized in the following three points: 1) This method determines the profit and loss and payback period in order to evaluate the installation of photovoltaic power generation, taking into account the price of equipment, solar battery module conversion efficiency, subsidy, electricity purchase price, service life and rate for selling electricity. 2) The proposed evaluation method was applied to Kanagawa Prefecture in Japan, providing plural scenarios. Using a solar battery module conversion efficiency of more than 15%, it is possible to make the payback period shorter than the 20-year service life and anticipate a profit in almost the whole area. 3) The areas suitable for photovoltaic power generation are Kawasaki City and Ninomiya-machi. It is necessary to adopt measures to increase the subsidy and install photovoltaic power generating systems in specific places in areas where subsidies are not provided in enough amounts. 展开更多
关键词 Photovoltaic Power Generation ECONOMIC Evaluation SUBSIDY profit and loss and Payback PERIOD GIS (Geographic Information Systems)
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Key sources of SOE profitability and their implications for social welfare
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作者 韩朝华 周晓艳 《China Economist》 2009年第6期120-128,共9页
An analysis of the sources of profit growth for China's state-owned industry since 1999 indicates that the key source of profit growth is not the high productivity of state-owned enterprises (SOEs) but rather thei... An analysis of the sources of profit growth for China's state-owned industry since 1999 indicates that the key source of profit growth is not the high productivity of state-owned enterprises (SOEs) but rather their monopoly position and pricing power in some basic industries. From an overall social perspective, such high profitability means an inefficient allocation of industrial resources and a potential loss of social welfare. Therefore, further expanding and deepening the reform of SOE property rights, encouraging the development of non-SOEs and boosting the competitiveness of basic industries will significantly improve the resource allocation efficiency of the Chinese industry and enhance overall social welfare. 展开更多
关键词 source of profit growth low COMPETITIVENESS PRICING power potential WELFARE lossES
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Spatial and seasonal dynamics of soil loss ratio in mountain rangelands of south-western Kyrgyzstan
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作者 Maksim KULIKOV Udo SCHICKI-IOFF Peter BORCHARDT 《Journal of Mountain Science》 SCIE CSCD 2016年第2期316-329,共14页
Vegetation cover is the main factor of soil loss prevention.The C-factor of the RUSLE(Revised Universal Soil Loss Equation) was predicted with NDVI,ground data and exponential regression equation for mountain rangelan... Vegetation cover is the main factor of soil loss prevention.The C-factor of the RUSLE(Revised Universal Soil Loss Equation) was predicted with NDVI,ground data and exponential regression equation for mountain rangelands of Kyrgyzstan.Time series of C-factor,precipitation and temperature were decomposed into seasonal and trend components with STL(seasonal decomposition by loess) to assess their interrelations.C-factor,precipitation and temperature trend components indicated significant lagged correlation,whereas seasonal components indicated more complex relations with climate factors which can be promoting as well as limiting factors for vegetation development,depending on the season.Rainy springs and hot summers may increase soil loss dramatically,whereas warm and dry springs with rainy summers can decrease it.Steep slopes indicated higher soil loss ratio,whereas flat areas were better protected by vegetation. 展开更多
关键词 Soil loss ratio C-FACtoR RUSLE NDVI Time series Remote sensing
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Balance Analysis of Profit and Loss on Exploiting Coal-Bed Gas in China
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作者 肖建洪 苗建国 陈晓慧 《Journal of China University of Mining and Technology》 2001年第2期196-198,共3页
Models about four aspects according to the balance principle and practice in China were established, which involve the minimum production scale, alert production scale, safe running scale, and the goal production scal... Models about four aspects according to the balance principle and practice in China were established, which involve the minimum production scale, alert production scale, safe running scale, and the goal production scale for specified profit level. It provides an effective quantitative analyzing method for the investors of coal bed gas exploitation project. 展开更多
关键词 coal bed gas production scale balance of profit and loss INVESTMENT model
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Effects of Soil C/N Ratio on Apple Growth and Nitrogen Utilization,Residue and Loss
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作者 Shunfeng GE Yihua REN +4 位作者 Ling PENG Haigang XU Mengmeng JI Shaochong WEI Yuanmao JIANG 《Asian Agricultural Research》 2014年第2期69-72,76,共5页
Soil C /N ratio is an important influencing factor in soil nitrogen cycling. Two-year old apple trees( Borkh. cv. ‘Fuji'/Malus hupehensis) were used to understand the effect of soil C/N ratio [6. 52( CK),10,15,20... Soil C /N ratio is an important influencing factor in soil nitrogen cycling. Two-year old apple trees( Borkh. cv. ‘Fuji'/Malus hupehensis) were used to understand the effect of soil C/N ratio [6. 52( CK),10,15,20,25,30,35 and 40]on apple growth and nitrogen utilization and loss by using15N trace technique. The results showed that,with the increasing of soil C/N ratio,apple shoot length and fresh weight increased at first,and then decreased; the higher apple shoot length and fresh weight appeared in C/N = 15,20 and 25 treatments,and there were no significant differences among these three treatments,but significantly higher than the other treatments. Statistical analysis revealed that there was significant difference in nitrogen utilization rate between the different treatments,the highest N utilization rate was occurred in soil C/N = 25 treatment which value was 22. 87%,and there was no significant difference between soil C/N = 25 and C/N = 20 treatments,but both the two treatments were significantly higher than the other treatments; Soil C/N = 40 had the lowest N utilization rate which value was 15. 43%,and this value was less than CK( 16. 65%). The proportion of plant absorption nitrogen from fertilizer was much higher when the value of soil C/N ratio in the range of 15- 25,but the percentage of plant absorption nitrogen from soil was much higher when the soil C/N ratio was too low( < 15) or high( < 25). Amount of residual nitrogen in soil increased gradually with the soil C/N ratio increasing,the amount of residual nitrogen in C/N = 40 treatment was 1. 32 times than that in CK. With the increasing of soil C/N ratio,fertilizer nitrogen loss decreased at first,and then increased,fertilizer nitrogen loss was the minimum in C/N = 25 treatments( 49. 87%) and the maximum were occurred in CK( 61. 54%). Therefore,regarding the apple growth and nitrogen balance situation,the value of soil C/N ratio in the range of 15- 25 would be favorable for apple growth and could increase effectively nitrogen fixed by soil,reduce nitrogen loss,and improve the nitrogen utilization ratio. 展开更多
关键词 SOIL C/N ratio APPLE 15N Nitrogen UTILIZATION Nitr
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Estimation of USLE crop and management factor values for crop rotation systems in China 被引量:6
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作者 GUO Qian-kun LIU Bao-yuan +2 位作者 XIE Yun LIU Ying-na YIN Shui-qing 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2015年第9期1877-1888,共12页
Soil erosion on cropland is a major source of environmental problems in China ranging from the losses of a non-renewable resource and of nutrients at the source to contamination of downstream areas. Regional soil loss... Soil erosion on cropland is a major source of environmental problems in China ranging from the losses of a non-renewable resource and of nutrients at the source to contamination of downstream areas. Regional soil loss assessments using the Universal Soil Loss Equation (USLE) would supply a scientiifc basis for soil conservation planning. However, a lack of in-formation on the cover and management (C) factor for cropland, one of the most important factors in the USLE, has limited accurate regional assessments in China due to the large number of crops grown and their complicated rotation systems. In this study, single crop soil loss ratios (SLRs) were col ected and quantiifed for 10 primary crops from past studies or re-ports. The mean annual C values for 88 crop rotation systems in 12 cropping system regions were estimated based on the combined effects of single crop SLRs and the percentage of annual rainfal erosivity (R) during the corresponding periods for each system. The C values in different cropping system regions were compared and discussed. The results indicated that the SLRs of the 10 primary crops ranged from 0.15 to 0.74. The mean annual C value for al 88 crop rotation systems was 0.34, with a standard deviation of 0.12. The mean C values in the single, double and triple cropping zones were 0.37, 0.36 and 0.28, respectively, and the C value in the triple zone was signiifcantly different from those in single and double zones. The C values of dryland crop systems exhibited signiifcant differences in the single and triple cropping system regions but the differences in the double regions were not signiifcant. This study is the ifrst report of the C values of crop rotation systems in China at the national scale. It wil provide necessary and practical parameters for accurately assessing regional soil losses from cropland to guide soil conservation plans and to optimize crop rotation systems. 展开更多
关键词 cover and management factor crop rotation system soil loss ratio rainfall erosivity cropping system region
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Association between routine hematological parameters and sudden sensorineural hearing loss:A meta-analysis 被引量:2
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作者 Wei Ni Shao-Peng Song Yi-Dao Jiang 《Journal of Otology》 CSCD 2021年第1期47-54,共8页
Objective:Recent studies have shown that chronic inflammation contributes to the development of sudden sensorineural hearing loss(SSNHL).Some hematologic parameters have also been linked to the prognosis of SSNHL.Howe... Objective:Recent studies have shown that chronic inflammation contributes to the development of sudden sensorineural hearing loss(SSNHL).Some hematologic parameters have also been linked to the prognosis of SSNHL.However,the prognostic value of such hematological factors is not conclusive.This study explored the association of routine hematological parameters with SSNHL.Methods:A systematic literature search was conducted in PubMed,Cochrane Library,Web of Science and Embase to identify eligible studies.Standardized mean deviation(SMD)and the 95%confidence interval(CI)were retried from relevant studies for analysis.Heterogeneity,subgroup,and publication bias analyses were performed.Results:A total of 18 studies involving 1505 SSNHL patients and 1466 healthy persons were enrolled in the final analysis.The study population included 699 responders and 458 non-responders to treatment.Pooled results revealed that the neutrophil/lymphocyte ratio(NLR)and platelet/lymphocyte ratio(PLR)value in the SSNHL patient group were higher than in the healthy group(SMD=1.05,95%CI:0.86,1.24,p<0.001,SMD=0.52,95%CI:0.26,0.78,p<0.001,respectively).However,there was no significant difference in the mean platelet volumes(MPV)between the groups(SMD=0.03,95%CI:0.44,0.49,p=0.91).Notably,NLR and PLR values were evidently higher in the unrecovered group than in the recovered group(SMD=0.63,95%CI:1.02,0.23,p=0.002,SMD=0.4,95%CI:0.76,0.03,p=0.03,respectively).However,the MPV value was similar in both groups(SMD=0.35,95%CI:1.14,0.44,p=0.38).Conclusions:Our results show that NLR and PLR values can predict the onset and prognosis of SSNHL. 展开更多
关键词 Sudden sensorineural hearing loss Prognosis Neutrophil/lymphocyte ratio Platelet/lymphocyte ratio META-ANALYSIS
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Estimation of soil erosion and sediment yield in Wadi El Hachem watershed(Algeria)using the RUSLE-SDR approach 被引量:2
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作者 SAOUD Mohammed MEDDI Mohamed 《Journal of Mountain Science》 SCIE CSCD 2023年第2期367-380,共14页
One of the most common types of soil degradation is water erosion.It reduces soil quality at the erosion site and may cause sedimentation issues at the deposition site.This phenomenon is estimated using a variety of m... One of the most common types of soil degradation is water erosion.It reduces soil quality at the erosion site and may cause sedimentation issues at the deposition site.This phenomenon is estimated using a variety of models.The Revised Universal Soil Loss Equation(RUSLE)model is the most often used,due to its consistence and low data requirement.It is useful for estimating annual soil loss at the watershed scale.To investigate the relationship between soil erosion and sediment deposition,the combined RUSLE and Sediment Delivery Ratio(SDR)models are used.The Wadi El Hachem watershed is a coastal and mountainous Mediterranean basin with rugged topography and high degree of climatic aggressiveness.Both of these characteristics can have an immediate effect on soil erosion and sediment yield.This research includes estimating the Average Annual Soil Loss(A)and Sediment Yield(SY)in the Wadi El Hachem watershed,mapping different RUSLE factors as well as A and SY,and studying the influence of rainfall erosivity(R)on A and SY in dry and rainy years.The A results vary from 0 to 410 t·ha^(-1)·yr^(-1)with an annual average of 52 t·ha^(-1)·yr^(-1).The Renfro's SDR model was selected as the best model for estimating SY,with standard error,standard deviation,coefficient of variation,and Nash–Sutcliffe efficiency(NSE)values of 0.38%,0.02,0.07%,and 1.00,respectively.The average SY throughout the whole watershed is around 27 t·ha^(-1)·yr^(-1).The SY map for the entire Wadi El Hachem watershed revealed that sediment production zones are mainly concentrated in the Northeast of the basin,at the basin’s outlet,and in the tributaries of the dam.The simulation results of soil loss and sediment yield in dry and rainy years revealed that R is one of the main factors affecting soil erosion and sediment deposition in the Wadi El Hachem watershed.The mean difference in R factor between dry year and rainy year is 671 MJ·mm·ha^(-1)·h^(-1)·yr^(-1).As a result of this fluctuation,the soil loss and sediment yield have increased by 15 and 8 t·ha^(-1)·yr^(-1),respectively.The results of this research can be used to provide scientific and technical support for conservation and management strategies of the Wadi El Hachem watershed. 展开更多
关键词 RUSLE Sediment delivery ratio Soil loss Sediment yield Wadi El Hachem Algeria
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Computational Study on Effect of Variation of Pitch-Chord on Secondary Losses in Rectilinear Turbine Cascade 被引量:1
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作者 Pulijala Shravya 《Engineering(科研)》 2015年第11期733-741,共9页
Losses in turbine cascade are categorized as profile loss, secondary loss, tip clearance loss and annulus loss. Profile loss occurs due to development of boundary layer on surface of blade [1]. Increase in thickness o... Losses in turbine cascade are categorized as profile loss, secondary loss, tip clearance loss and annulus loss. Profile loss occurs due to development of boundary layer on surface of blade [1]. Increase in thickness of boundary layer and adverse pressure gradient increases profile loss. Secondary loss occurs due to turning of flow through flow passage which results in blowing of energy from pressure side to suction side. In turbine rotor blade suction surface leads and tip clearance loss occurs due to leakage of air from pressure side to suction side of the blade through tip clearance. Annulus loss occurs due to development of boundary layer on stationary row of blade. It also occurs in moving row of blade but in moving row of blades boundary layer is scraped by flow over the blades. This paper presents effects of variation of pitch-chord ratio on secondary loss. 展开更多
关键词 TURBINE CASCADE Pitch-Chord ratio SECONDARY lossES
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Study of High Capacitance Ratios CPW MEMS Shunt Switches
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作者 Jianhai Sun Dafu Cui 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2006年第A03期548-549,共2页
This paper describes a fixed-fixed beam ohmic switch in series with a fixed capacitor as a replacement for a capacitive switch.In this switch,a metal plate deposited on the dielectric ensures perfectly contact with th... This paper describes a fixed-fixed beam ohmic switch in series with a fixed capacitor as a replacement for a capacitive switch.In this switch,a metal plate deposited on the dielectric ensures perfectly contact with the dielectric layer in the down state.The area size of the metal plate directly influences the capacitance ratio of the switch,as the area size of the metal cap decreases,the capacitance ratio dramatically rises up.The down/up capacitance ratio can exceed 800 times over the conventional designs using the same materials and the equal size.Measurement results show that high capacitance ratio of the switches has a large effect on the isolation,and can actually improve the performance of the switches. 展开更多
关键词 capacitive shunt switch capacitance ratio ISOLATION insertion loss
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Assessment of Sedimentation Impacts on Small Dams—A Case of Small Reservoirs in the Lotsane Catchment
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作者 Berhanu F. Alemaw Malebogo Majauale Timoty Simalenga 《Journal of Water Resource and Protection》 2013年第12期1127-1131,共5页
Sedimentation is a major problem for agricultural dams in Botswana, as it reduces the storage capacity and life span of the reservoirs. The process of sedimentation starts from day one of the impounding of water in an... Sedimentation is a major problem for agricultural dams in Botswana, as it reduces the storage capacity and life span of the reservoirs. The process of sedimentation starts from day one of the impounding of water in any given reservoir. Even though a provision is made for every reservoir during planning for a certain storage capacity, specifically for sediment deposition, called dead storage, a major portion of the sediment gets deposited for many years of the reservoir’s life in areas other than the dead storage, and this trend cannot be reversed at easy cost. This study is aimed at the analysis of prevailing sedimentation processes in the nearby dozens of dams found in the Lotsane catchment located within the Limpopo Basin of Botswana, and focuses on assessment of annual sedimentation rate. A spatial analysis and modelling study was conducted based on the Revised Universal Soil Loss Equation and GIS to determine sediment yield and degree of impact of each reservoir for a given landscape, rainfall and catchment heterogeneity. Field observations and soil sampling were carried out in order to determine the factors that lead to reservoir sedimentation. Spatial data on the dams in Lotsane catchment were also collected from Ministry of Agriculture, which were used for ground-truthing, GIS-based calculations and model validation. The average sediment rate and sediment delivery ratio were found to be 1.74 t/ha/year and 81%, respectively. These are useful parameters to estimate service life of the dams and plan remedial measures related to sedimentation problems. 展开更多
关键词 SEDIMENTATION Erosion Revised Universal Soil loss Equation SEDIMENT Yield SEDIMENT Delivery ratio SMALL RESERVOIRS Botswana
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Syngas Production and Losses Encountered in Gasification of Rice Husks
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作者 Ethel D. Kasembe Zacharia M. Mganilwa +2 位作者 Zacharia M. Mganilwa Geoffrey R. John Cuthbert F. Mhilu 《Journal of Power and Energy Engineering》 2015年第4期423-430,共8页
This paper addresses the syngas production and evaluation losses in high temperature gasification process using coffee husks. A fast and inexpensive way to evaluate the losses in gasification processes is by the appli... This paper addresses the syngas production and evaluation losses in high temperature gasification process using coffee husks. A fast and inexpensive way to evaluate the losses in gasification processes is by the application mathematical models which allow to predict the values needed in full scale. Hence, the quantification of gasifier’s losses at temperatures ranges of 800 K - 1400 K at an equivalence ratios of 0.3, 0.35 and 0.4 at 1 bar are revealed by using exergy model incorporating a chemical equilibrium model. The model evaluated the product syngas compositions, syngas heating values and degree of irreversibility values (losses). The results from the model showed that the production of H2 increased from 9.9% to 18.9% and the formation of CO2 ranges from 7.2% to 12.3%. CO production is from 21.8% to 17.2%. The irreversibility values obtained were less than 27%. Hence, reduction of losses protracts biomass resources to be used in energy generation. 展开更多
关键词 CofFEE HUSKS Equivalence ratio EXERGY GASIFICATION IRREVERSIBILITY (losses)
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Assessment of Quality of Experience (QoE) of Web and Video Services over a Mobile Network Using a Network Emulator
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作者 Akpovi Ominike Jonah Joshua +1 位作者 Oludele Awodele Achimba Ogbonna 《Journal of Computer and Communications》 2020年第5期89-95,共7页
This paper investigates the subjective assessment of QoE of web and video services over a mobile network. To achieve this, the authors used the network emulator (NetEm) traffic control functionality to simulate the dy... This paper investigates the subjective assessment of QoE of web and video services over a mobile network. To achieve this, the authors used the network emulator (NetEm) traffic control functionality to simulate the dynamic behaviour of a mobile network. Experiments were conducted in a laboratory setting and test conditions were varied to ascertain the QoE, with a focus on QoE metrics such as delay and packet loss ratio. From the experiments conducted, it was observed that there was a negative correlation between delay and average mean opinion score (MOS), and between packet loss ratio and average MOS. The results obtained can be adopted by network operators to provide better services which would lead to improved subscriber base and profitability for the operators and better QoE for the end users. 展开更多
关键词 NETWORK EMULAtoR DELAY PACKET loss ratio (PLR) Quality of Experience (QoE)
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