The promotion of energy efficiency(EE)helps address energy constraints and promote environmental sustainability.This study comprehensively explores the spatiotemporal variations,influencing factors,and configuration p...The promotion of energy efficiency(EE)helps address energy constraints and promote environmental sustainability.This study comprehensively explores the spatiotemporal variations,influencing factors,and configuration promotion paths of EE in 284 Chinese cities during 2003‒2019 using the global super-efficiency minimum distance to strong efficient frontier(G-S-MinDS),exploratory spatial data analysis(ESDA),multiscale geographically weighted regression(MGWR),and fuzzy set qualitative comparative analysis(fsQCA)methods.The findings are:①China’s cities have an annual average EE of 0.658 with a growth rate of 0.53%,showing considerable promotion potential.②Industrial structure optimization,population agglomeration,economic development,and increased green coverage contribute positively,while government intervention and openness hinder China’s urban EE.③Four configurational promotion paths for enhancing China’s urban EE are identified,where among those paths population density is a core condition,while government intervention is not.This study provides valuable insights into substantially improving urban EE,emphasizing the need for targeted policies to address energy and environmental crises in China.展开更多
Electrical discharge milling(ED-milling) can be a good choice for titanium alloys machining and it was proven that its machining efficiency can be improved to compete with mechanical cutting. In order to improve energ...Electrical discharge milling(ED-milling) can be a good choice for titanium alloys machining and it was proven that its machining efficiency can be improved to compete with mechanical cutting. In order to improve energy utilization efficiency of ED-milling process, unstable arc discharge and stable arc discharge combined with normal discharge were implemented for material removal by adjusting servo control strategy. The influence of electrode rotating speed and dielectric flushing pressure on machining performance was investigated by experiments. It was found that the rotating of electrode could move the position of discharge plasma channel, and high pressure flushing could wash melted debris out the discharge gap effectively. Both electrode rotating motion and high pressure flushing are contributed to the improvement of machining efficiency.展开更多
The relationship between infrared light (IR) and vacuum ultraviolet (VUV) emission in shadow mask plasma display panels (SMPDP) at high xenon content and high voltage is investigated. The respective ratios of VI...The relationship between infrared light (IR) and vacuum ultraviolet (VUV) emission in shadow mask plasma display panels (SMPDP) at high xenon content and high voltage is investigated. The respective ratios of VIS/IR-823 am, VIS/IR-828 nm and of efficacy/VIS/IR-823 nm, efficacy/VIS/IR-823 nm are calculated to determine the behavior of the xenon excitation efficiency and the electron excitation efficiency as a function of the driving voltage and xenon content. It is found that the xenon excitation efficiency is almost independent of the driving voltage, and increases approximately linearly with the xenon content. The values for efficacy/VIS/IR-828 nm increase rapidly with the xenon content, but saturate at a xenon ratio of about 30% while, on the other hand, the efficacy/VIS/IR-823 nm values decrease continuously with the xenon content.展开更多
[Objective] This study aimed to provide basis for rational fertilizer application of wheat in fluvo-aquic soil in the northwest of Shandong Province.[Method] In this paper,the treatments of reduced N,P and K were set ...[Objective] This study aimed to provide basis for rational fertilizer application of wheat in fluvo-aquic soil in the northwest of Shandong Province.[Method] In this paper,the treatments of reduced N,P and K were set in order to explore the effects of fertilizer recommendation based on ASI systematic approach on wheat yield,agronomic efficiency and recovery rate of nutrients.[Result] Nitrogen was the main limiting factor for wheat production in that area,followed by phosphorus,and the third was potassium.Compared with the optimum treatment (OPT),the reduction of N,P and K reduced the grain yield obviously,which came up to 22.4%,14.4% and 13.4% respectively.There were no obvious differences in grain yield among Farmer's Fertilization Practice (FP),60% OPT-N and OPT treatment.[Conclusion] Agronomic efficiency of N,P and K was 6.3,12.9 and 10 kg/kg respectively.The recovery rates of N,P and K in wheat season were 16.41%,17.27% and 27.27% respectively.展开更多
The research advance on the influencing factors of crop water use effi-ciency (WUE) was reviewed in this paper. Based on the discussion on the conno-tation of crop WUE, the influencing factors of crop WUE, such as c...The research advance on the influencing factors of crop water use effi-ciency (WUE) was reviewed in this paper. Based on the discussion on the conno-tation of crop WUE, the influencing factors of crop WUE, such as crop, environ-ment, chemicals, cultivation measures, cropping systems, etc, were elaborated. A-mong them, the species and varieties of crop, soil and chemicals were discussed in detail.展开更多
The Linxing area within the Ordos Basin exhibits pronounced reservoir heterogeneity and intricate micro-pore structures,rendering it susceptible to water-blocking damage during imbibition extraction.This study delved ...The Linxing area within the Ordos Basin exhibits pronounced reservoir heterogeneity and intricate micro-pore structures,rendering it susceptible to water-blocking damage during imbibition extraction.This study delved into the traits of tight sandstone reservoirs in the 8th member of the Shihezi Formation(also referred to as the He 8 Member)in the study area,as well as their effects on fracturing fluid imbibition.Utilizing experimental techniques such as nuclear magnetic resonance(NMR),high-pressure mercury intrusion(HPMI),and gas adsorption,this study elucidated the reservoir characteristics and examined the factors affecting the imbibition through imbibition experiments.The findings reveal that:①The reservoir,with average porosity of 8.40%and average permeability of 0.642×10^(-3)μm^(2),consists principally of quartz,feldspar,and lithic fragments,with feldspathic litharenite serving as the primary rock type and illite as the chief clay mineral;②Nano-scale micro-pores and throats dominate the reservoir,with dissolution pores and intercrystalline pores serving as predominant pore types,exhibiting relatively high pore connectivity;③Imbibition efficiency is influenced by petrophysical properties,clay mineral content,and microscopic pore structure.Due to the heterogeneity of the tight sandstone reservoir,microscopic factors have a more significant impact on the imbibition efficiency of fracturing fluids;④A comparative analysis shows that average pore size correlates most strongly with imbibition efficiency,followed by petrophysical properties and clay mineral content.In contrast,the pore type has minimal impact.Micropores are vital in the imbibition process,while meso-pores and macro-pores offer primary spaces for imbibition.This study offers theoretical insights and guidance for enhancing the post-fracturing production of tight sandstone reservoirs by examining the effects of these factors on the imbibition efficiency of fracturing fluids in tight sandstones.展开更多
Due to a wide range of field vibration problems caused by flood discharge at the Xiangjiaba Hydropower Station, vibration characteristics and influencing factors were investigated based on prototype observation. The r...Due to a wide range of field vibration problems caused by flood discharge at the Xiangjiaba Hydropower Station, vibration characteristics and influencing factors were investigated based on prototype observation. The results indicate that field vibrations caused by flood discharge have distinctive characteristics of constancy, low frequency, small amplitude, and randomness with impact, which significantly differ from the common high-frequency vibration characteristics. Field vibrations have a main frequency of about 0.5-3.0 Hz and the characteristics of long propagation distance and large-scale impact. The vibration of a stilling basin slab runs mainly in the vertical direction. The vibration response of the guide wall perpendicular to the flow is significantly stronger than it is in other directions and decreases linearly downstream along the guide wall. The vibration response of the underground turbine floor is mainly caused by the load of unit operation. Urban environmental vibration has particular distribution characteristics and change patterns, and is greatly affected by discharge, scheduling modes, and geological conditions. Along with the increase of the height of residential buildings, vibration responses show a significant amplification effect. The horizontal and vertical vibrations of the 7th floor are, respectively, about 6 times and 1.5 times stronger than the corresponding vibrations of the 1st floor. The vibration of a large-scale chemical plant presents the combined action of flood discharge and working machines. Meanwhile, it is very difficult to reduce the low-frequency environmental vibrations. Optimization of the discharge scheduling mode is one of the effective measures of reducing the flow impact loads at present. Choosing reasonable dam sites is crucial.展开更多
This study analyzed the spatial-temporal heterogeneity of green development efficiency and its influencing factors in the growing Xuzhou Metropolitan Area for the period 2000–2015.The slacks-based measure(SBM)model,s...This study analyzed the spatial-temporal heterogeneity of green development efficiency and its influencing factors in the growing Xuzhou Metropolitan Area for the period 2000–2015.The slacks-based measure(SBM)model,spatial autocorrelation,and the geographically weighted regression(GWR)model were used to conduct the analysis.The conclusions were as follows:first,the overall efficiency of green development of the Xuzhou Metropolitan Area decreased,the regional differences and spatial agglomeration shrunk and differences within the region were the main contributors to the regional differences of green development efficiency.Second,the counties with high-efficiency green development were distributed along the coast,and along the routes of the Beijing-Shanghai and the Eastern Longhai railways.A developing axis of the high-efficiency counties was the main feature of the spatial pattern for green development efficiency.Third,regarding spatial correlation and green development efficiency,the High-High type counties in the Xuzhou Metropolitan Area formed a centralized distribution corridor along the inter-provincial border areas of Henan and Jiangsu,whereas the Low-Low type counties were concentrated in the external,marginal parts of the metropolitan area.Fourth,the major factors(ranked in decreasing order of impact)influencing green development efficiency were innovation,government regulations,the economic development level,energy consumption,and industrial structure.These factors exerted their influence to varying extents;the influence of the same factor had different effects in different regions and obvious spatial differences were observed for the different regions.展开更多
In this paper,an improved discharging circuit was proposed to quicken the decay of the current in the drive coil in a reluctance accelerator when the armature reaches the center of the coil.The aim of this is to preve...In this paper,an improved discharging circuit was proposed to quicken the decay of the current in the drive coil in a reluctance accelerator when the armature reaches the center of the coil.The aim of this is to prevent the suck-back effect caused by the residual current in drive coil.The method is adding a reverse charging branch with a small capacitor in the traditional pulsed discharging circuit.The results under the traditional circuit and the improved circuit were compared in a simulation.The experiment then verified the simulations and they had good agreement.Simulation and experiment both demonstrated the improved circuit can effectively prevent the suck-back effect and increase the efficiency.At the voltage of 800 V,an efficiency increase of 36.34% was obtained.展开更多
Using a heterogeneity stochastic frontier model(HSFM),we empirically investigated the economic efficiency of Beijing-Tianjin-Hebei from 2003 to 2016 and its influencing factors.The key findings of the paper lie in:1)i...Using a heterogeneity stochastic frontier model(HSFM),we empirically investigated the economic efficiency of Beijing-Tianjin-Hebei from 2003 to 2016 and its influencing factors.The key findings of the paper lie in:1)in Beijing-Tianjin-Hebei,the overall economic and technological efficiency tended to increase in a wavelike manner,economic growth slowed down,and there was an obvious imbalance in economic efficiency between the different districts,counties and cities;2)the heterogeneity stochastic frontier production functions(SFPFs)of Beijing,Tianjin and Hebei were different from each other,and investment was still an important impetus of economic growth in Beijing-Tianjin-Hebei;3)economic efficiency was positively correlated with economic agglomeration,human capital,industrial structure,infrastructure,the informatization level,and institutional factors,but negatively correlated with the government role and economic opening.The following policy suggestions are offered:1)to improve regional economic efficiency and reduce the economic gap in Beijing-Tianjin-Hebei,governments must reduce their intervention in economic activities,stimulate the potentials of labor and capital,optimize the structure of human resources,and foster new demographic incentives;2)governments must guide economic factors that are reasonable throughout Beijing-Tianjin-Hebei and strengthen infrastructure construction in underdeveloped regions,thus attaining sustainable economic development;3)governments must plan overall economic growth factors of Beijing-Tianjin-Hebei and promote reasonable economic factors(e.g.,labor,resources,and innovations)across different regions,thus attaining complementary advantages between Beijing,Tianjin,and Hebei.展开更多
The homogeneous dielectric barrier discharge (DBD) in atmospheric air between two symmetric-columnar copper electrodes with epoxy plates as the dielectric barriers is generated using a us pulse high voltage power su...The homogeneous dielectric barrier discharge (DBD) in atmospheric air between two symmetric-columnar copper electrodes with epoxy plates as the dielectric barriers is generated using a us pulse high voltage power supply. The discharge characteristics are studied by measurement of its electrical discharge parameters and observation of its light emission phenom- ena, and the main discharge parameters of the homogenous DBD, such as discharge current and average discharge power, are calculated. Results show that the discharge generated is a homogeneous one with one larger single current pulse of about 2 #s duration appearing in each voltage pulse, and its light emission is radially homogeneous and covers the entire surface of the two elec- trodes. The influences of applied voltage amplitude, air gap distance and barrier thickness on the transition of discharge modes are studied. With the increase of air gap distance, the discharge will transit from homogeneous mode to filamentary mode. The higher the thickness of dielectric barriers, the larger the air gap distance for generating the homogeneous discharge mode. The average discharge power increases non-linearly with increasing applied voltage amplitude, and decreases non-linearly with the increase of air gap distance and barrier thickness. In order to generate stable and homogeneous DBD with high discharge power, thin barriers distance should be used, and higher applied voltage amplitude should be applied to small air gap.展开更多
Energy efficiency evaluation plays an important role in energy efficiency improvement of the ethylene production. It is observed from the actual production data that the ethylene production energy efficiency often var...Energy efficiency evaluation plays an important role in energy efficiency improvement of the ethylene production. It is observed from the actual production data that the ethylene production energy efficiency often varies with the complex production working conditions. In the favored methods for energy efficiency evaluation,DEA models may show poor resolution when directly used to evaluate the efficiency values. Therefore, a new energy efficiency evaluation method for ethylene production is proposed based on DEA integrated factor analysis with respect to operation classification. Three key factors, including raw material composition, cracking depth and load rate, are taken into account in determining the production working conditions by means of k-means algorithm. Based on the multi-working conditions mode the energy efficiency evaluation of the ethylene production is made by using DEA model, where the most related energy data are screened by factor analysis.Furthermore, the supporting decision of energy efficiency improvement is provided to the operators. The accuracy and effectiveness of the proposed method are illustrated by applying in a practical ethylene production,which gives more effective energy efficiency evaluation in the complicated working conditions of ethylene production with declined dimension of input indicators.展开更多
Based on the DEA-based Malmquist index method,the total factor productivity was calculated for 5 major banana production areas in 2003-2004,and it was further divided into technological progress and technical efficien...Based on the DEA-based Malmquist index method,the total factor productivity was calculated for 5 major banana production areas in 2003-2004,and it was further divided into technological progress and technical efficiency.The results show that the total factor productivity of banana industry in China was 1.3% in the sample period,mainly due to technological progress,the average growth rate was 2.6%,while the pure technical efficiency and scale efficiency was -0.1% and -1.2% respectively.The improvement of total factor productivity in banana industry in China relied mainly on technological progress,cultivation of new banana varieties,management of high quality cultivation,popularization and application of water conservation and fertilizer saving technology,and injury-free picking technologies.The pure technical efficiency and scale efficiency of banana production were negative,indicating that the management level of banana was not high.The effect of scale economy of this industry through agglomeration and consolidation is still to be practiced.Banana growers should promote the improvement of large scale and management level of the banana industry at the same time of promoting the technological progress.展开更多
Listed companies of the swine industry,as an important form of agricultural industrialized operation,are typical representatives of large-scale production and the level of their operation efficiency exerts a direct in...Listed companies of the swine industry,as an important form of agricultural industrialized operation,are typical representatives of large-scale production and the level of their operation efficiency exerts a direct influence on the healthy development of the swine industry.Using the DEA-based Malmquist method,this paper made a static and dynamic evaluation of the operation efficiency of 16 listed companies in China's swine industry in 2010-2014. It obtained following results:( i) The overall efficiency of listed companies of China's swine industry remained at high level and the development trend was excellent.( ii) Different types of enterprises had difference in the overall efficiency,pure technical efficiency and scale efficiency. In general,pig feed processing companies had the best performance,followed by slaughtering and deep processing companies,and swine breeding companies were the worst.( iii) The total factor productivity characterized by the Malmquist index declined year by year in 2010-2013 and was improved in 2014,mainly due to technological progress.( iv) The total asset turnover ratio,equity concentration,and R & D management level had a significantly positive impact on the operation efficiency of listed companies in the swine industry,while the human capital had a significantly negative impact.展开更多
Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable output variable,...Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable output variable, this paper conducts SBM model to evaluate the aquaculture efficiency based on the data of 16 aquaculture-developed provinces in China from 2004 to 2011. The results show the efficiency in China has not changed much in recent years with the efficiency values mainly between 0.39 and 0.53, and the efficiency of marine-aquaculture-dominated provinces is generally higher than that of freshwater-aquaculture-dominated ones. To analyze the difference under the efficiency, the panel Tobit model is used with education level factor, training factor, technology extension factor, technical level factor, scale factor and species factor as the efficiency influencing factors. The results show that technology extension factor and technical level factor have significant positive influence.展开更多
<strong>Objective</strong> To investigate the level of readiness for discharge of patients after prostate cancer surgery based on the concept of Enhanced Recovery After Surgery (ERAS), and to explore its i...<strong>Objective</strong> To investigate the level of readiness for discharge of patients after prostate cancer surgery based on the concept of Enhanced Recovery After Surgery (ERAS), and to explore its influencing factors, so as to provide references for improving the readiness for discharge of patients after prostate cancer surgery. <strong>Methods </strong>The general information questionnaire, the discharge preparation scale, and the discharge guidance quality scale were used to investigate 119 patients discharged from the urological surgery department of a tertiary A-level hospital in Guangzhou after radical prostatectomy. <strong>Results </strong>The total score of discharge readiness of patients after radical prostatectomy was 147.74 ± 35.71 points, which was at a lower middle level and the total score of discharge guidance quality was 180.68 ± 38.91 points, which was at a medium level. Multiple linear regression analysis showed that education level, family monthly income, Gleason score, whether to perform lymphatic dissection, whether to discharge with a urinary catheter, and the quality of discharge guidance were the main factors influencing the readiness for discharge of patients after prostate cancer surgery. <strong>Conclusion </strong>In clinical nursing work, it is necessary to implement individualized health education according to the characteristics and needs of different patients to improve the level of preparation for discharge of patients after prostate cancer surgery.展开更多
<strong>Objective:</strong> To evaluate the status quo and influencing factors of readiness for hospital discharge of patients undergoing hysteromyomectomy. <strong>Methods:</strong> A total of...<strong>Objective:</strong> To evaluate the status quo and influencing factors of readiness for hospital discharge of patients undergoing hysteromyomectomy. <strong>Methods:</strong> A total of 240 patients with uterine fibroid undergoing hysteromyomectomy from 2 hospitals in Jingzhou were investigated using a self-designed general information questionnaire, the Readiness for Hospital Discharge Scale and the Quality of Discharge Teaching Scale. <strong>Results:</strong> The total score of readiness for hospital discharge was (91.36 ± 18.46), the multiple linear regression analysis showed that the quality of discharge guidance, the scope of myomectomy, pain degree of incision and the average monthly income per family were the main influencing factors of readiness for hospital discharge. <strong>Conclusion:</strong> The readiness for hospital discharge was at a medium level in patients with uterine fibroid undergoing hysteromyomectomy, medical personnel should give specific discharge guidance according to the specific conditions of patients to ensure the safety of patients after discharge.展开更多
To address air pollution and offer a convenient and comfortable living environment,the Chinese government launched a smart city pilot(SCP)project in 2012,accompanied by a comprehensive set of environmental and energy-...To address air pollution and offer a convenient and comfortable living environment,the Chinese government launched a smart city pilot(SCP)project in 2012,accompanied by a comprehensive set of environmental and energy-related laws and regulations.Although academic interest in smart cities has surged,there remains a notable gap in empirical research exploring the economic,environmental,and energy effects of such initiatives.Taking 232 prefecture-level cities from 2003 to 2017 as research subjects,this study measures energy effi‐ciency by using energy consumption per unit of GDP and adopts a difference-in-differences(DID)analysis to investigate the impact of SCPs on energy efficiency.The empirical results indicate that SCPs improved energy efficiency by promoting urban technological innovation capabilities and green total factor productivity,and this effect was more pronounced in cities that were more dependent on traditional fossil fuel energy sources and had more developed fiscal and financial levels.Studying the impact of smart city construction on energy utilization efficiency in developing countries,such as China,is not only significantly enlightening for China’s green and low-carbon transition but also provides reference opinions for constructing smart cities and the path to enhancing energy efficiency in other developing countries.The findings provide valuable insights into the global development of smart cities,urban sustainability,and high-quality economic growth.展开更多
The electroless plating of palladium and palladium alloy membranes is fast becoming an important and enabling technology. This is more so when juxtaposed with the rising demand for high purity hydrogen for application...The electroless plating of palladium and palladium alloy membranes is fast becoming an important and enabling technology. This is more so when juxtaposed with the rising demand for high purity hydrogen for applications particularly in proton exchange membrane fuel cells (PEMFC). The effect of process factors such as sensitization and activation during surface modification, concentration of the reducing agent, plating temperature, time, pH, additives, air aeration on plating efficiency, quality of the palladium film and deposit morphology is reviewed with the aim of identifying areas requiring further investigation. The paper also reviews how these process factors could be optimised for better plating efficiency and overall membrane quality. The concentration of the reducing agent has been identified as the limiting factor on plating efficiency albeit other process factors separately impact on the plating efficiency. Furthermore, bulk precipitation caused by concentration of the reducing agent has been identified as a major problem during electroless plating with hydrazine based plating baths. To ameliorate this problem, a multi step addition of the hydrazine reducer in separate portions has been recommended.展开更多
Green development is an important issue of sustainable development in China.Due to the relatively backward economy and the fragile ecological environment,restricted development zones need to embrace green development....Green development is an important issue of sustainable development in China.Due to the relatively backward economy and the fragile ecological environment,restricted development zones need to embrace green development.Taking 38 counties in Jilin Province as the empirical research objects,and based on cross-sectional data for each county in 2005,2010,and 2015,we accurately depicted the spatiotemporal evolutionary characteristics of green development efficiency(GDE)in restricted development zones of Jilin Province using the slacks-based measure-data envelope analysis(SBM-DEA)model.Moreover,the factors that influence GDE were further analyzed using the Tobit model.We found that:first,GDE showed a V-shaped trend in restricted development zones of Jilin Province.The differences in GDE in the eastern,central,and western Jilin Province increased gradually.Second,76%of counties in the restricted development zones had high or higher efficiencies.The resource-based cities were the main areas with low or lower GDE.Third,the economic development level was the core factor affecting GDE.Urbanization level had a significant negative effect on GDE in the restricted development zones.The effect of technological innovation level on GDE fluctuated,and we found that a‘backward mechanism’of technological innovation was beginning to form.Industrial structure and environmental governance had no significant effects on GDE.展开更多
基金the financial support provided by the National Natural Science Foundation of China[Grant No.72373138 and 71973131]Major Project of National Social Science Foundation of China[Grant No.19VHQ002].
文摘The promotion of energy efficiency(EE)helps address energy constraints and promote environmental sustainability.This study comprehensively explores the spatiotemporal variations,influencing factors,and configuration promotion paths of EE in 284 Chinese cities during 2003‒2019 using the global super-efficiency minimum distance to strong efficient frontier(G-S-MinDS),exploratory spatial data analysis(ESDA),multiscale geographically weighted regression(MGWR),and fuzzy set qualitative comparative analysis(fsQCA)methods.The findings are:①China’s cities have an annual average EE of 0.658 with a growth rate of 0.53%,showing considerable promotion potential.②Industrial structure optimization,population agglomeration,economic development,and increased green coverage contribute positively,while government intervention and openness hinder China’s urban EE.③Four configurational promotion paths for enhancing China’s urban EE are identified,where among those paths population density is a core condition,while government intervention is not.This study provides valuable insights into substantially improving urban EE,emphasizing the need for targeted policies to address energy and environmental crises in China.
基金Project(MSV-2013-09)supported by State Key Laboratory of Mechanical System and Vibration,China
文摘Electrical discharge milling(ED-milling) can be a good choice for titanium alloys machining and it was proven that its machining efficiency can be improved to compete with mechanical cutting. In order to improve energy utilization efficiency of ED-milling process, unstable arc discharge and stable arc discharge combined with normal discharge were implemented for material removal by adjusting servo control strategy. The influence of electrode rotating speed and dielectric flushing pressure on machining performance was investigated by experiments. It was found that the rotating of electrode could move the position of discharge plasma channel, and high pressure flushing could wash melted debris out the discharge gap effectively. Both electrode rotating motion and high pressure flushing are contributed to the improvement of machining efficiency.
基金supported by National Natural Science Foundation of China (No. 60571033)the National Hi'Tech projects of China (No. 2008AA03A308)Programme of Introducing Talents of Discipline to Universities of China (B07027)
文摘The relationship between infrared light (IR) and vacuum ultraviolet (VUV) emission in shadow mask plasma display panels (SMPDP) at high xenon content and high voltage is investigated. The respective ratios of VIS/IR-823 am, VIS/IR-828 nm and of efficacy/VIS/IR-823 nm, efficacy/VIS/IR-823 nm are calculated to determine the behavior of the xenon excitation efficiency and the electron excitation efficiency as a function of the driving voltage and xenon content. It is found that the xenon excitation efficiency is almost independent of the driving voltage, and increases approximately linearly with the xenon content. The values for efficacy/VIS/IR-828 nm increase rapidly with the xenon content, but saturate at a xenon ratio of about 30% while, on the other hand, the efficacy/VIS/IR-823 nm values decrease continuously with the xenon content.
文摘[Objective] This study aimed to provide basis for rational fertilizer application of wheat in fluvo-aquic soil in the northwest of Shandong Province.[Method] In this paper,the treatments of reduced N,P and K were set in order to explore the effects of fertilizer recommendation based on ASI systematic approach on wheat yield,agronomic efficiency and recovery rate of nutrients.[Result] Nitrogen was the main limiting factor for wheat production in that area,followed by phosphorus,and the third was potassium.Compared with the optimum treatment (OPT),the reduction of N,P and K reduced the grain yield obviously,which came up to 22.4%,14.4% and 13.4% respectively.There were no obvious differences in grain yield among Farmer's Fertilization Practice (FP),60% OPT-N and OPT treatment.[Conclusion] Agronomic efficiency of N,P and K was 6.3,12.9 and 10 kg/kg respectively.The recovery rates of N,P and K in wheat season were 16.41%,17.27% and 27.27% respectively.
基金Supported by National Science-Technology Support Plan Project(2012BAD40B02)~~
文摘The research advance on the influencing factors of crop water use effi-ciency (WUE) was reviewed in this paper. Based on the discussion on the conno-tation of crop WUE, the influencing factors of crop WUE, such as crop, environ-ment, chemicals, cultivation measures, cropping systems, etc, were elaborated. A-mong them, the species and varieties of crop, soil and chemicals were discussed in detail.
基金funded by the National key R&D Program of China(No.2023YFE0120700)the National Natural Science Foundation of China(No.51934005)+2 种基金the Shaanxi Province 2023 Innovation Capability Support Plan(No.2023KJXX-122)the Technology Innovation Leading Program of Shaanxi(No.2022 PT-08)the Project of Youth Innovation Team of Shaanxi Universities(No.22JP063).
文摘The Linxing area within the Ordos Basin exhibits pronounced reservoir heterogeneity and intricate micro-pore structures,rendering it susceptible to water-blocking damage during imbibition extraction.This study delved into the traits of tight sandstone reservoirs in the 8th member of the Shihezi Formation(also referred to as the He 8 Member)in the study area,as well as their effects on fracturing fluid imbibition.Utilizing experimental techniques such as nuclear magnetic resonance(NMR),high-pressure mercury intrusion(HPMI),and gas adsorption,this study elucidated the reservoir characteristics and examined the factors affecting the imbibition through imbibition experiments.The findings reveal that:①The reservoir,with average porosity of 8.40%and average permeability of 0.642×10^(-3)μm^(2),consists principally of quartz,feldspar,and lithic fragments,with feldspathic litharenite serving as the primary rock type and illite as the chief clay mineral;②Nano-scale micro-pores and throats dominate the reservoir,with dissolution pores and intercrystalline pores serving as predominant pore types,exhibiting relatively high pore connectivity;③Imbibition efficiency is influenced by petrophysical properties,clay mineral content,and microscopic pore structure.Due to the heterogeneity of the tight sandstone reservoir,microscopic factors have a more significant impact on the imbibition efficiency of fracturing fluids;④A comparative analysis shows that average pore size correlates most strongly with imbibition efficiency,followed by petrophysical properties and clay mineral content.In contrast,the pore type has minimal impact.Micropores are vital in the imbibition process,while meso-pores and macro-pores offer primary spaces for imbibition.This study offers theoretical insights and guidance for enhancing the post-fracturing production of tight sandstone reservoirs by examining the effects of these factors on the imbibition efficiency of fracturing fluids in tight sandstones.
基金supported by the National Natural Science Foundation of China(Grants No.51479124 and 51109143)the Open Cooperation Fund of State Key Laboratory of Hydraulics and Mountain River Engineering(Grant No.SKHL1422)the Nanjing Hydraulic Research Institute Foundation(Grant No.Y115006)
文摘Due to a wide range of field vibration problems caused by flood discharge at the Xiangjiaba Hydropower Station, vibration characteristics and influencing factors were investigated based on prototype observation. The results indicate that field vibrations caused by flood discharge have distinctive characteristics of constancy, low frequency, small amplitude, and randomness with impact, which significantly differ from the common high-frequency vibration characteristics. Field vibrations have a main frequency of about 0.5-3.0 Hz and the characteristics of long propagation distance and large-scale impact. The vibration of a stilling basin slab runs mainly in the vertical direction. The vibration response of the guide wall perpendicular to the flow is significantly stronger than it is in other directions and decreases linearly downstream along the guide wall. The vibration response of the underground turbine floor is mainly caused by the load of unit operation. Urban environmental vibration has particular distribution characteristics and change patterns, and is greatly affected by discharge, scheduling modes, and geological conditions. Along with the increase of the height of residential buildings, vibration responses show a significant amplification effect. The horizontal and vertical vibrations of the 7th floor are, respectively, about 6 times and 1.5 times stronger than the corresponding vibrations of the 1st floor. The vibration of a large-scale chemical plant presents the combined action of flood discharge and working machines. Meanwhile, it is very difficult to reduce the low-frequency environmental vibrations. Optimization of the discharge scheduling mode is one of the effective measures of reducing the flow impact loads at present. Choosing reasonable dam sites is crucial.
基金Under the auspices of the National Natural Science Foundation of China(No.41671123,41971158,41671122)Major Project of Philosophy and Social Science Research of Jiangsu Universities(No.2018SJZDA010).
文摘This study analyzed the spatial-temporal heterogeneity of green development efficiency and its influencing factors in the growing Xuzhou Metropolitan Area for the period 2000–2015.The slacks-based measure(SBM)model,spatial autocorrelation,and the geographically weighted regression(GWR)model were used to conduct the analysis.The conclusions were as follows:first,the overall efficiency of green development of the Xuzhou Metropolitan Area decreased,the regional differences and spatial agglomeration shrunk and differences within the region were the main contributors to the regional differences of green development efficiency.Second,the counties with high-efficiency green development were distributed along the coast,and along the routes of the Beijing-Shanghai and the Eastern Longhai railways.A developing axis of the high-efficiency counties was the main feature of the spatial pattern for green development efficiency.Third,regarding spatial correlation and green development efficiency,the High-High type counties in the Xuzhou Metropolitan Area formed a centralized distribution corridor along the inter-provincial border areas of Henan and Jiangsu,whereas the Low-Low type counties were concentrated in the external,marginal parts of the metropolitan area.Fourth,the major factors(ranked in decreasing order of impact)influencing green development efficiency were innovation,government regulations,the economic development level,energy consumption,and industrial structure.These factors exerted their influence to varying extents;the influence of the same factor had different effects in different regions and obvious spatial differences were observed for the different regions.
基金This work was supported by the Fundamental Research Funds for the Central Universities[Grant number 2019XJ01].
文摘In this paper,an improved discharging circuit was proposed to quicken the decay of the current in the drive coil in a reluctance accelerator when the armature reaches the center of the coil.The aim of this is to prevent the suck-back effect caused by the residual current in drive coil.The method is adding a reverse charging branch with a small capacitor in the traditional pulsed discharging circuit.The results under the traditional circuit and the improved circuit were compared in a simulation.The experiment then verified the simulations and they had good agreement.Simulation and experiment both demonstrated the improved circuit can effectively prevent the suck-back effect and increase the efficiency.At the voltage of 800 V,an efficiency increase of 36.34% was obtained.
基金Under the auspices of National Natural Science Foundation of China(No.41771131,41301116,41877523)Premium Funding Project for Academic Human Resources Development in Beijing Union University(No.BPHR2017CS13)
文摘Using a heterogeneity stochastic frontier model(HSFM),we empirically investigated the economic efficiency of Beijing-Tianjin-Hebei from 2003 to 2016 and its influencing factors.The key findings of the paper lie in:1)in Beijing-Tianjin-Hebei,the overall economic and technological efficiency tended to increase in a wavelike manner,economic growth slowed down,and there was an obvious imbalance in economic efficiency between the different districts,counties and cities;2)the heterogeneity stochastic frontier production functions(SFPFs)of Beijing,Tianjin and Hebei were different from each other,and investment was still an important impetus of economic growth in Beijing-Tianjin-Hebei;3)economic efficiency was positively correlated with economic agglomeration,human capital,industrial structure,infrastructure,the informatization level,and institutional factors,but negatively correlated with the government role and economic opening.The following policy suggestions are offered:1)to improve regional economic efficiency and reduce the economic gap in Beijing-Tianjin-Hebei,governments must reduce their intervention in economic activities,stimulate the potentials of labor and capital,optimize the structure of human resources,and foster new demographic incentives;2)governments must guide economic factors that are reasonable throughout Beijing-Tianjin-Hebei and strengthen infrastructure construction in underdeveloped regions,thus attaining sustainable economic development;3)governments must plan overall economic growth factors of Beijing-Tianjin-Hebei and promote reasonable economic factors(e.g.,labor,resources,and innovations)across different regions,thus attaining complementary advantages between Beijing,Tianjin,and Hebei.
基金supported by National Natural Science Foundation of China(No.50707012)Opening Project of State Key Laboratory of Electrical Insulation and Power Equipment in Xi'an Jiaotong University of China(No.EIPE11205)"Qing Lan Project" of Jiangsu Province,China
文摘The homogeneous dielectric barrier discharge (DBD) in atmospheric air between two symmetric-columnar copper electrodes with epoxy plates as the dielectric barriers is generated using a us pulse high voltage power supply. The discharge characteristics are studied by measurement of its electrical discharge parameters and observation of its light emission phenom- ena, and the main discharge parameters of the homogenous DBD, such as discharge current and average discharge power, are calculated. Results show that the discharge generated is a homogeneous one with one larger single current pulse of about 2 #s duration appearing in each voltage pulse, and its light emission is radially homogeneous and covers the entire surface of the two elec- trodes. The influences of applied voltage amplitude, air gap distance and barrier thickness on the transition of discharge modes are studied. With the increase of air gap distance, the discharge will transit from homogeneous mode to filamentary mode. The higher the thickness of dielectric barriers, the larger the air gap distance for generating the homogeneous discharge mode. The average discharge power increases non-linearly with increasing applied voltage amplitude, and decreases non-linearly with the increase of air gap distance and barrier thickness. In order to generate stable and homogeneous DBD with high discharge power, thin barriers distance should be used, and higher applied voltage amplitude should be applied to small air gap.
基金Supported by the High-tech Research and Development Program of China(2014AA041802)Fundamental Research Funds for the Central Universities(DUT15RC(3)007)
文摘Energy efficiency evaluation plays an important role in energy efficiency improvement of the ethylene production. It is observed from the actual production data that the ethylene production energy efficiency often varies with the complex production working conditions. In the favored methods for energy efficiency evaluation,DEA models may show poor resolution when directly used to evaluate the efficiency values. Therefore, a new energy efficiency evaluation method for ethylene production is proposed based on DEA integrated factor analysis with respect to operation classification. Three key factors, including raw material composition, cracking depth and load rate, are taken into account in determining the production working conditions by means of k-means algorithm. Based on the multi-working conditions mode the energy efficiency evaluation of the ethylene production is made by using DEA model, where the most related energy data are screened by factor analysis.Furthermore, the supporting decision of energy efficiency improvement is provided to the operators. The accuracy and effectiveness of the proposed method are illustrated by applying in a practical ethylene production,which gives more effective energy efficiency evaluation in the complicated working conditions of ethylene production with declined dimension of input indicators.
基金Supported by Industrial Economic Post of National Banana Industrial Technological System of the Ministry of Agriculture(CARS-32-10)
文摘Based on the DEA-based Malmquist index method,the total factor productivity was calculated for 5 major banana production areas in 2003-2004,and it was further divided into technological progress and technical efficiency.The results show that the total factor productivity of banana industry in China was 1.3% in the sample period,mainly due to technological progress,the average growth rate was 2.6%,while the pure technical efficiency and scale efficiency was -0.1% and -1.2% respectively.The improvement of total factor productivity in banana industry in China relied mainly on technological progress,cultivation of new banana varieties,management of high quality cultivation,popularization and application of water conservation and fertilizer saving technology,and injury-free picking technologies.The pure technical efficiency and scale efficiency of banana production were negative,indicating that the management level of banana was not high.The effect of scale economy of this industry through agglomeration and consolidation is still to be practiced.Banana growers should promote the improvement of large scale and management level of the banana industry at the same time of promoting the technological progress.
基金Supported by Young Scholar Project of Humanities and Social Science Foundation of Ministry of Education"Study on Stability Mechanism of Symbiosis Network of the Swine Industry"(15YJC630118)
文摘Listed companies of the swine industry,as an important form of agricultural industrialized operation,are typical representatives of large-scale production and the level of their operation efficiency exerts a direct influence on the healthy development of the swine industry.Using the DEA-based Malmquist method,this paper made a static and dynamic evaluation of the operation efficiency of 16 listed companies in China's swine industry in 2010-2014. It obtained following results:( i) The overall efficiency of listed companies of China's swine industry remained at high level and the development trend was excellent.( ii) Different types of enterprises had difference in the overall efficiency,pure technical efficiency and scale efficiency. In general,pig feed processing companies had the best performance,followed by slaughtering and deep processing companies,and swine breeding companies were the worst.( iii) The total factor productivity characterized by the Malmquist index declined year by year in 2010-2013 and was improved in 2014,mainly due to technological progress.( iv) The total asset turnover ratio,equity concentration,and R & D management level had a significantly positive impact on the operation efficiency of listed companies in the swine industry,while the human capital had a significantly negative impact.
基金supported by the Major State Basic Research Development Program of China: the Research on the Key Technology of Clean and High Efficient Mariculture Pond (Grant Nos. 2011BAD 13B03)Promotive Research Fund for Excellent Young and Middle-Aged Scientists of Shandong Province: High Efficiency and Low Carbon Development Research of Shandong Mariculture Industry (Grant Nos. BS2012HZ 024)the Research of Chinese Mariculture Industry High Efficiency and Low Carbon Development Model Implementation Mechanism Funded by the Marine Development Institute of Ocean University of China Humanities and Social Science Key Research Base of Ministry of Education (Grant Nos. 2012JDZS02)
文摘Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable output variable, this paper conducts SBM model to evaluate the aquaculture efficiency based on the data of 16 aquaculture-developed provinces in China from 2004 to 2011. The results show the efficiency in China has not changed much in recent years with the efficiency values mainly between 0.39 and 0.53, and the efficiency of marine-aquaculture-dominated provinces is generally higher than that of freshwater-aquaculture-dominated ones. To analyze the difference under the efficiency, the panel Tobit model is used with education level factor, training factor, technology extension factor, technical level factor, scale factor and species factor as the efficiency influencing factors. The results show that technology extension factor and technical level factor have significant positive influence.
文摘<strong>Objective</strong> To investigate the level of readiness for discharge of patients after prostate cancer surgery based on the concept of Enhanced Recovery After Surgery (ERAS), and to explore its influencing factors, so as to provide references for improving the readiness for discharge of patients after prostate cancer surgery. <strong>Methods </strong>The general information questionnaire, the discharge preparation scale, and the discharge guidance quality scale were used to investigate 119 patients discharged from the urological surgery department of a tertiary A-level hospital in Guangzhou after radical prostatectomy. <strong>Results </strong>The total score of discharge readiness of patients after radical prostatectomy was 147.74 ± 35.71 points, which was at a lower middle level and the total score of discharge guidance quality was 180.68 ± 38.91 points, which was at a medium level. Multiple linear regression analysis showed that education level, family monthly income, Gleason score, whether to perform lymphatic dissection, whether to discharge with a urinary catheter, and the quality of discharge guidance were the main factors influencing the readiness for discharge of patients after prostate cancer surgery. <strong>Conclusion </strong>In clinical nursing work, it is necessary to implement individualized health education according to the characteristics and needs of different patients to improve the level of preparation for discharge of patients after prostate cancer surgery.
文摘<strong>Objective:</strong> To evaluate the status quo and influencing factors of readiness for hospital discharge of patients undergoing hysteromyomectomy. <strong>Methods:</strong> A total of 240 patients with uterine fibroid undergoing hysteromyomectomy from 2 hospitals in Jingzhou were investigated using a self-designed general information questionnaire, the Readiness for Hospital Discharge Scale and the Quality of Discharge Teaching Scale. <strong>Results:</strong> The total score of readiness for hospital discharge was (91.36 ± 18.46), the multiple linear regression analysis showed that the quality of discharge guidance, the scope of myomectomy, pain degree of incision and the average monthly income per family were the main influencing factors of readiness for hospital discharge. <strong>Conclusion:</strong> The readiness for hospital discharge was at a medium level in patients with uterine fibroid undergoing hysteromyomectomy, medical personnel should give specific discharge guidance according to the specific conditions of patients to ensure the safety of patients after discharge.
文摘To address air pollution and offer a convenient and comfortable living environment,the Chinese government launched a smart city pilot(SCP)project in 2012,accompanied by a comprehensive set of environmental and energy-related laws and regulations.Although academic interest in smart cities has surged,there remains a notable gap in empirical research exploring the economic,environmental,and energy effects of such initiatives.Taking 232 prefecture-level cities from 2003 to 2017 as research subjects,this study measures energy effi‐ciency by using energy consumption per unit of GDP and adopts a difference-in-differences(DID)analysis to investigate the impact of SCPs on energy efficiency.The empirical results indicate that SCPs improved energy efficiency by promoting urban technological innovation capabilities and green total factor productivity,and this effect was more pronounced in cities that were more dependent on traditional fossil fuel energy sources and had more developed fiscal and financial levels.Studying the impact of smart city construction on energy utilization efficiency in developing countries,such as China,is not only significantly enlightening for China’s green and low-carbon transition but also provides reference opinions for constructing smart cities and the path to enhancing energy efficiency in other developing countries.The findings provide valuable insights into the global development of smart cities,urban sustainability,and high-quality economic growth.
文摘The electroless plating of palladium and palladium alloy membranes is fast becoming an important and enabling technology. This is more so when juxtaposed with the rising demand for high purity hydrogen for applications particularly in proton exchange membrane fuel cells (PEMFC). The effect of process factors such as sensitization and activation during surface modification, concentration of the reducing agent, plating temperature, time, pH, additives, air aeration on plating efficiency, quality of the palladium film and deposit morphology is reviewed with the aim of identifying areas requiring further investigation. The paper also reviews how these process factors could be optimised for better plating efficiency and overall membrane quality. The concentration of the reducing agent has been identified as the limiting factor on plating efficiency albeit other process factors separately impact on the plating efficiency. Furthermore, bulk precipitation caused by concentration of the reducing agent has been identified as a major problem during electroless plating with hydrazine based plating baths. To ameliorate this problem, a multi step addition of the hydrazine reducer in separate portions has been recommended.
基金Under the auspices of National Natural Science Foundation of China(No.41771138,41801105)。
文摘Green development is an important issue of sustainable development in China.Due to the relatively backward economy and the fragile ecological environment,restricted development zones need to embrace green development.Taking 38 counties in Jilin Province as the empirical research objects,and based on cross-sectional data for each county in 2005,2010,and 2015,we accurately depicted the spatiotemporal evolutionary characteristics of green development efficiency(GDE)in restricted development zones of Jilin Province using the slacks-based measure-data envelope analysis(SBM-DEA)model.Moreover,the factors that influence GDE were further analyzed using the Tobit model.We found that:first,GDE showed a V-shaped trend in restricted development zones of Jilin Province.The differences in GDE in the eastern,central,and western Jilin Province increased gradually.Second,76%of counties in the restricted development zones had high or higher efficiencies.The resource-based cities were the main areas with low or lower GDE.Third,the economic development level was the core factor affecting GDE.Urbanization level had a significant negative effect on GDE in the restricted development zones.The effect of technological innovation level on GDE fluctuated,and we found that a‘backward mechanism’of technological innovation was beginning to form.Industrial structure and environmental governance had no significant effects on GDE.