The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering (EPS) system. Bad tracking performance will cause assistant torque delay, and make road ...The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering (EPS) system. Bad tracking performance will cause assistant torque delay, and make road feeling bad, and is influenced by the input steering torque and system measuring noise. However the existing methods have some shortages on system's robust dynamic performance and robust stability. The mixed H2/H∞ strategy for recirculating ball-type EPS system in a pure electric bus is proposed, and vehicle dynamic model of the system is established. Due to the existence of system model uncertainty, disturbance signals, sensor noises and the demand of system dynamic performance, the indexes of robust performance and road feeling for drivers are defined as the appraisal control objectives. The H∞ method is introduced to design the H∞ controller, and the H2 method is applied to optimize the H∞ controller, thus the mixed H2/H∞ controller is designed. The response of EPS system to the motor current command with amplitude of 20 A, the road disturbance with amplitude of 500 N and the sensor random noise with the amplitude of 1 A is simulated. The simulation results show that the recirculating ball-type EPS system with the mixed H2/H∞ controller can attenuate the random noises and disturbances and track the boost curve well, so the mixed H2/H∞ controller can improve the system's robust performance and dynamic performance. For the purpose of verifying the performance of the designed control strategy, the motor current tracking performance ground tests are conducted with step response input of the steering wheel, double-lane steering test and lemniscate steering test, respectively. The tests show that the mixed H2/H∞ controller for the recirculating ball-type EPS system of pure electric bus is feasible. The designed controller can solve the robust performance and robust stability of the system, thus improve the tracking performance of the EPS system and provide satisfied road feeling for the drivers.展开更多
To solve the problems of rural revitalization performance research,a quantitative model of non-oriented range-wide EBM(Epsilon-Based Measure)-GML(Global-Malmquist)based on VRS(Variable Returns to Scale)conditions incl...To solve the problems of rural revitalization performance research,a quantitative model of non-oriented range-wide EBM(Epsilon-Based Measure)-GML(Global-Malmquist)based on VRS(Variable Returns to Scale)conditions including non-desired outputs is constructed.A comprehensive spatio-temporal heterogeneity research index system of rural revitalization performance is also constructed.Taking the typical rural in Chifeng City as an example,the panel data from 2016-2020 are selected for empirical analysis,the conclusions and countermeasures are suggested as follows:1)In general,the rural revitalization performance of Chifeng City increases significantly during the five-year period,with significant spatio-temporal heterogeneity.The overall analysis shows that the overall performance value of rural revitalization in Chifeng City is 0.683 from 2016 to 2020.The highest performance value is 1 and the lowest performance value is 0.389.The performance growth rate increases year by year,with an average annual growth rate of 4.46%.2)From 2016 to 2020,the GML index of rural revitalization performance in Chifeng City is 1.174,showing an increasing trend.Based on the range of change of GML index,Chifeng City can be classified into three types:Continuous improvement,fluctuating improvement and fluctuating decline.3)Niujiayingzi,Guandongche,Zhaidamu,and Qiangangtai rural have the highest degree of technological progress.展开更多
[Objective] The study was carried out to investigate the effects of dietary crude fiber on growth performance and serum biochemical in-dex of Dingan geese aged from 35 to 70 days.[Method] A total of 120 Dingan geese o...[Objective] The study was carried out to investigate the effects of dietary crude fiber on growth performance and serum biochemical in-dex of Dingan geese aged from 35 to 70 days.[Method] A total of 120 Dingan geese on day 28 with the same genetic background and similar initial weight(1 384.83.73±0.76 g) were randomly assigned into 3 groups, with 4 replicates per group and 10 geese per replicate. Geese were fed the diets containing 4.29%, 5.29% and 6.29 % crude fiber, respectively. The experiment lasted 35 d.[Result] Final weight and daily gain of 5.29 %CF group were significantly higher than those of 6.29 % CF group(P<0.05);Feed intake was markedly higher than those of 4.29% and 6.29 % CF groups(P<0.05);Feed gain ratio was significantly lower than that of 6.29 % CF group(P<0.05). Compared with 4.29% and 6.29 % CF groups, serum albumin concentrations of 5.29 % CF group increased significantly(P<0.05), while serum total protein and globin contents were higher(P>0.05), but serum uric acid level was lower(P>0.05).[Conclusion] 5.29 % crude fiber could lead to higher growth performance of Dingan geese.展开更多
In order to improve the lightning protection performance of transmission lines, lightning protection management has been divided into every tower that lightning protection performance has been evaluated respectively. ...In order to improve the lightning protection performance of transmission lines, lightning protection management has been divided into every tower that lightning protection performance has been evaluated respectively. According to factors such as landform, span, tower type, grounding resistance, isolator type, and so on, relative ratio of tripping operation of every tower in the line has been calculated to evaluate its lightning protection safety performance, it is beneficial to operation maintenance and lightning reconstruction of transmission lines.展开更多
[Objective]The paper was to investigate the effects of dietary crude fiber level on production performance,organ index and serum biochemical parameters of Dingan geese aged from 1 to 28 days.[Method]A total of 144 1-d...[Objective]The paper was to investigate the effects of dietary crude fiber level on production performance,organ index and serum biochemical parameters of Dingan geese aged from 1 to 28 days.[Method]A total of 144 1-day-old Dingan geese with the same genetic background and similar initial weight(88.75±0.21g)were randomly assigned into 3 groups with 4 replicates per group and 12 geese per replicate,and fed with the diets containing 2.56%,3.52% and 4.48% crude fiber,respectively.The trial lasted 28 d.[Result]1)The final weight and daily gain of 3.52% CF group were significantly higher than those of 2.56% CF group(P<0.05);the feed/gain ratio was markedly lower than that of 2.56% CF group(P<0.05).2)The slaughter rate,semi-eviscerated rate and leg muscle rate of 3.52% CF group were higher than those of 2.56% and 4.48% CF groups(P>0.05).3)As the dietary crude fiber levels rose,the abdominal fat rate showed a downward trend(P>0.05).4)The liver index of 3.52% CF group was significantly higher than that of 2.56% CF group(P<0.05).4)Compared with 2.5%and 4.48% CF groups,the serum albumin concentrations of 3.52% CF group markedly increased(P<0.05),the serum total protein and globin contents were higher(P>0.05),but the serum uric acid level was lower(P>0.05).[Conclusion]When the crude fiber level was 3.52%,the production performances of Dingan geese aged from 1 to 28 days were better,and the liver index and serum albumin level could be obviously improved.展开更多
Objective Assessment of right ventricular function in patients with atrial septal defect(ASD)is difficult.The Doppler myocardial performance index(MPI)may provide a method of assessing function in these patients.The p...Objective Assessment of right ventricular function in patients with atrial septal defect(ASD)is difficult.The Doppler myocardial performance index(MPI)may provide a method of assessing function in these patients.The purposes of this study were to evaluate the right ventricular function and its changes in patients with ASD after transcatheter closure of ASD.Methods MPI,defined as the sum of isovolumic relaxation time and isovolumic contraction time derived by ejection time,was measured from tricuspid inflow and right ventricular outflow;Doppler velocity profiles recorded during routine echocardiography.Twenty nine patients(13 men,16 women;mean age 25.28±12.69,range 6 to 57 years)were diagnosed to secundum ASD[the stretched diameters of ASD were from 9 To 36(24.91±7.98)mm],and had a successfully placed Amplatzer septal occluder(ASO)(the sizes of ASO were from 11 to 40 mm);there were 81 sex-matched,age-matched healthy people(control group 41men,40 women;mean age 29.02±14.22,range 4 to 45 years).MPI was measured again on 3 days and 1 month after closure of ASD.Change in the study group was assessed and compared to the control subjects with structurally normal hearts.A complete 2-dimensional and Doppler echocardiographic examination was performed in all study groups.Results 1)The isovolumic relaxation and isovolumic contraction times[respectively(77.59±14.39)ms vs(60.93±12.94)ms,P<0.0001;(28.28±10.88)ms vs(23.64±9.01)ms,P=0.027]were prolonged,and ejection time[(260.65±21.86)ms vs(271.85±21.92)ms,P=0.033]was shortened in patients with ASD compared with that in control subjects,resulting in a marked increase in the MPI(0.40±0.07 vs 0.31±0.05,P<0.0001)from normal values;2)by Pearson's correlations,the MPI had no correlation with heart rate and blood pressure in control subjects and patients with ASD,but it correlated positively with age in patients with ASD;3)by Pearson's correlations,the MPI correlated positively with the diameter of ASD and pulmonary artery pressure;4)after transcatheter closure of ASD,the MPI decreased markedly.Conclusions 1)MPI is a conceptually new,simple,and reproducible Doppler index in patients with ASD;2)MPI is free from the effect of age,heart rate and blood pressure;(3)MPI appears to be relatively dependent on changes in the diameter of ASD and pulmonary artery pressure;4)the right ventricular function was improved after transcatheter closure of ASD.展开更多
As a highly sensitive and stable detector,refractive index detector is usually used for quantitative detection of substances such as polymer,sugar and organic acid. The research reviewed the application of HPLC-RID in...As a highly sensitive and stable detector,refractive index detector is usually used for quantitative detection of substances such as polymer,sugar and organic acid. The research reviewed the application of HPLC-RID in the fields of quantitative determination of medicine and food,in order to lay a foundation for wider use of RID.展开更多
The deformation performance index limits of high reinforced concrete (RC) shear wall components based on Chinese codes were discussed by the nonlinear finite element method. Two typical RC shear wall specimens in th...The deformation performance index limits of high reinforced concrete (RC) shear wall components based on Chinese codes were discussed by the nonlinear finite element method. Two typical RC shear wall specimens in the previous work were first used to verify the correctness of the nonlinear finite element method. Then, the nonlinear finite element method was applied to study the deformability of a set of high RC shear wall components designed according to current Chinese codes and with shear span ratio λ≥2.0. Parametric studies were made on the influence of shear span ratio, axial compression ratio, ratio of flexural capacity to shear capacity and main flexural reinforcement ratio of confined botmdary members. Finally, the deformation performance index and its limits of high RC shear wall components under severe earthquakes were proposed by the finite element model results, which offers a reference in determining the performance status of RC shear wall components designed based on Chinese codes.展开更多
The Code for Seismic Design of Buildings(GB50011-2010)in 2016 and the method of seismic performance-based design for high-rise buildings in the Guide for Performance-based Design of High-Rise Buildings(TBI2017)are com...The Code for Seismic Design of Buildings(GB50011-2010)in 2016 and the method of seismic performance-based design for high-rise buildings in the Guide for Performance-based Design of High-Rise Buildings(TBI2017)are compared.In view of the characteristics and limitations of the seismic performance index set by the Sino-US seismic code,a“three-index”performance index system and evaluation process considering the displacement angle of the structural interlayer,the plastic damage degree of components and the plastic strain of material is put forward;combining the example of time-history analysis of a out-of-code high-rise building under the rare earthquakes is verified.The results show that the method of seismic performance evaluation by using deformation control index in Sino-US seismic code is relatively simple;however,both are lacking in the setting of specific components and the whole structure level respectively.The"three-index"system can comprehensively and quantitatively evaluate the seismic performance of out-of-code high-rise buildings.展开更多
[Objective] The study was aimed to investigate the effects of NS series composite lactobacillus preparation on production performance and some immune indexes of sows. [Method] The sows were fed on the diets supplement...[Objective] The study was aimed to investigate the effects of NS series composite lactobacillus preparation on production performance and some immune indexes of sows. [Method] The sows were fed on the diets supplemented with the NS series composite lactobacillus prepara- tion, and the changes of production performance, plasma biochemical indexes, levels of IgG, IgA and IgM in serum and colostrum, and T lympho- cyte subpopulations were detected. [ Result] When the NS series composite lactobacillus preparation was supplemented to the sow diet at a propor- tion of 0.2%, the average weaning litter weight at 21 days old was significantly increased. The serum contents of total protein and glucose as well as the serum activities of aspartate aminotransferase (AST), alkaline phosphatase (ALP) and superoxide dismutase (SOD) were significantly in- creased after 30 d post delivery. Moreover, the levels of IgG, IgA and IgM in serum and colostrum of sows were significantly increased at the time of delivery and after 30 d post delivery. The antibodies in colostrum could be maintained at high levels. The percentage of CD3 * and CD4~ |ympho- cyte subpopulations was also increased after supplementation with the NS series composite lactobacillus preparation at a proportion of 0.2%. [ (Con- des'ion] The NS series composite lactobacillus preparation can improve performance, promote growth and metabolism, and enhance humoral and cellular immunity in sows.展开更多
Data Envelopment Analysis (DEA) is becoming an increasingly popular tool for assessing the relative performance of industries and companies. By applying DEA theory to the non-financial sector, the relative efficiency ...Data Envelopment Analysis (DEA) is becoming an increasingly popular tool for assessing the relative performance of industries and companies. By applying DEA theory to the non-financial sector, the relative efficiency of 27 listed corporations in the United Arab Emirates (UAE) has been analyzed in this paper. The focus of the study has been on the impact of the financial crisis and the recovery thereafter. Further, the productivity change was decomposed into technical efficiency change and technological change by using the non-parametric Malmquist Productivity Index (MPI) over the period from 2007 to 2014. Based on Malmquist analysis, we find that the most efficient industries during the post-crisis period were food and beverages, telecommunication and pharmaceuticals. In contrast, the sectors that were adversely affected by the crisis were services, real estate, construction and cements. The break-up of the TFP indicated that the efficiency indices in the top performing industries were driven by technological improvements or frontier effects. The top-performing companies in the UAE during the 2007-14 period demonstrated innovation-led growth, aided by the use of better technology, investments in capital equipment, and adoption of new production processes.展开更多
Hamiltonian function is firstly constituted for solving optimal control. When character of controlled object is known,Hamiltonian function is determined by performance index. In this paper,by constituting Hamiltonian ...Hamiltonian function is firstly constituted for solving optimal control. When character of controlled object is known,Hamiltonian function is determined by performance index. In this paper,by constituting Hamiltonian function and solving optimal control of a sort of performance index,we can understand optimal control theory and apply optimal control method better.展开更多
Forty years of reform and opening up,China has become to the world’s second-largest economy with great success.However,it is an undoubted actuality that the economic mode of Chinese development is still at the extens...Forty years of reform and opening up,China has become to the world’s second-largest economy with great success.However,it is an undoubted actuality that the economic mode of Chinese development is still at the extensive stage.China’s economy has shifted from a high-speed growth phase to a high-quality development phase.In this study,we analyzed three major urban agglomerations’total factor productivity index dynamically by means of Malmquist productivity i?ndex method.The results showed that MPI of Beijing-Tianjin-Hebei urban agglomeration was the highest,as the reasons of the effectiveness of dual-wheel driving both the technology progress and the cluster scale.The mean of MPI of Yangtze River Delta urban agglomeration was fallen into decline by an average of 1.3%annually due to the rate of increase of the size of the cluster towards to optimal frontier was inferior to the relative risk reduction of technology progress.Pearl River Delta urban agglomeration MPI declined by an average of 2.2%annually as a result of the contribution of technology progress reducing.The study of the economic performance of three major urban agglomerations provides a theoretical basis and important practical value for urban development of high quality optimization.展开更多
[Objectives]The purpose of this experiment was to study the effects of dietary supplementation of Herba Picriae extract on the growth performance and immune organ index of Guangxi partridge chickens.[Methods]A total o...[Objectives]The purpose of this experiment was to study the effects of dietary supplementation of Herba Picriae extract on the growth performance and immune organ index of Guangxi partridge chickens.[Methods]A total of 500 one-day-old Guangxi partridge chickens were selected and randomly divided into five groups,five replicates for each group and 20 chickens for each replicate.Groups A,B and C were treatment groups,in which 0.70%,0.35%and 0.175%of Herba Picriae extract was added to the basal diet,respectively.Group D was a positive drug control group,in which 0.01%colistin sulfate premix was supplemented.Group E was a blank control group,in which the chickens were fed the basal diet.The experimental period was 105 d.During the experiment,five chickens were randomly selected from each group on days 21,35 and 49,respectively for the measurement of immune organ index.[Results]When the chickens were fed basal diet supplemented with 0.175%of Herba Picriae extract,their daily body weight gain increased significantly from day 22 to day 35 and from day 71 to day 105 and tended to increase from day 1 to day 21,from day 36 to day 49,and from day 50 to day 70,with a range of 7.37%-8.72%.Dietary supplementation of 0.70%and 0.175%of Herba Picriae extract significantly promoted the growth and development of Fabricius bursae in the experimental chickens.[Conclusions]Dietary supplementation of 0.175%of Herba Picriae extract improved the growth performance and feed intake,as well as 21-d-old bursal index of the experimental chickens.展开更多
At present, the overall economic and social development of our country is fast, but the rate of development of the remote land and territories in the land is still far behind the speed of the inland and the east. This...At present, the overall economic and social development of our country is fast, but the rate of development of the remote land and territories in the land is still far behind the speed of the inland and the east. This has also triggered a series of frontier issues. This requires our frontier government to strengthen border governance, seize the opportunity to meet challenges, and at the same time we must also strengthen the assessment of the governance capacity of the frontier government. This article hopes that through the actual investigation and study of frontier counties and the consideration of border issues according to local conditions, a set of performance evaluation index system for frontier county-level governments will be proposed, which will help the frontier government in border control.展开更多
Background: Reduced kidney function in blacks is associated with an increased frequency of left ventricular hypertrophy. Given the unavailability of echocardiography in most developing countries, the diagnostic perfor...Background: Reduced kidney function in blacks is associated with an increased frequency of left ventricular hypertrophy. Given the unavailability of echocardiography in most developing countries, the diagnostic performance of current ECG indexes needs to be evaluated. Objective: To compare the diagnostic performance of 3 commonly used ECG indexes (Sokolow-Lyon, Cornell voltage and Cornell product) in black hypertensive patients. Methods: Electrocardiography and echocardiography estimated left ventricular mass of 155 consecutive hypertensive patients who participated from January 2012 to January 2013 to an echocardiographic cross-sectional study of left ventricular structure was analyzed to compare Cornell voltage and Cornell product indexes with Sokolow-Lyon voltage index as a reference. Reduced kidney function was defined as eGFR 2. ROC curves in relation to LVH diagnosis were used to estimate the sensitivities and specificities of each index. P Results: The sensitivity and specificity were 43% and 85%, 23% and 77% and 26% and 77% for Sokolow-Lyon, Cornell voltage and Cornell product indexes, respectively. However, Sokolow-Lyon index (AUC;95% CI: 0.64;0.50 - 0.78) showed better performance than Cornell voltage (0.42;0.25 - 0.59) and Cornell product (0.43;0.28 - 0.59). Sokolow-Lyon index cut-point ≥ 37 mm corresponded to the highest Youden index (39.4% of sensitivity and 92.3% of specificity). Conclusion: Although the overall performance of the 3 ECG indexes versus echocardiography was low, Sokolow-Lyon index performed better than the two other indexes in diagnosing LVH.展开更多
Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis (e...Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis (e. g. the pushover analysis), and the structural damage is considered via plastic hinges. Simultaneously, a practical approach is developed to obtain the relationships between the proposed index and earthquake intensities based on the capacity spectrum method. The proposed index is then illustrated through two low-rise reinforced concrete frames, and it is also compared with some other indices. The results indicate that the proposed index is on the safe side and not sensitive to the lateral load pattern. The storey index is helpful to reflect the storey damage and to uncover the position of the weak storey. Finally, the relationship between performance levels and damage index values is also proposed through statistical analysis for the performance-based seismic evaluation.展开更多
The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytica...The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytical expressions of the temperature dependent performance,such as breakdown characteristics and on resistance of 6H SiC unipolar power devices are derived in a closed form.The analytical results are compared with the experimental results,with good accordance found in the breakdown characteristics.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 51005115, No. 51005248)Science Fund of State Key Laboratory of Automotive Safety and Energy of China (Grant No. KF11201)
文摘The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering (EPS) system. Bad tracking performance will cause assistant torque delay, and make road feeling bad, and is influenced by the input steering torque and system measuring noise. However the existing methods have some shortages on system's robust dynamic performance and robust stability. The mixed H2/H∞ strategy for recirculating ball-type EPS system in a pure electric bus is proposed, and vehicle dynamic model of the system is established. Due to the existence of system model uncertainty, disturbance signals, sensor noises and the demand of system dynamic performance, the indexes of robust performance and road feeling for drivers are defined as the appraisal control objectives. The H∞ method is introduced to design the H∞ controller, and the H2 method is applied to optimize the H∞ controller, thus the mixed H2/H∞ controller is designed. The response of EPS system to the motor current command with amplitude of 20 A, the road disturbance with amplitude of 500 N and the sensor random noise with the amplitude of 1 A is simulated. The simulation results show that the recirculating ball-type EPS system with the mixed H2/H∞ controller can attenuate the random noises and disturbances and track the boost curve well, so the mixed H2/H∞ controller can improve the system's robust performance and dynamic performance. For the purpose of verifying the performance of the designed control strategy, the motor current tracking performance ground tests are conducted with step response input of the steering wheel, double-lane steering test and lemniscate steering test, respectively. The tests show that the mixed H2/H∞ controller for the recirculating ball-type EPS system of pure electric bus is feasible. The designed controller can solve the robust performance and robust stability of the system, thus improve the tracking performance of the EPS system and provide satisfied road feeling for the drivers.
基金Research on Local Knowledge Mapping and Planning Application Strategies of Traditional Rural in Qinba Mountains(No.19YJAZH107)Humanities and Social Sciences Research Planning Fund,Ministry of Education,China.
文摘To solve the problems of rural revitalization performance research,a quantitative model of non-oriented range-wide EBM(Epsilon-Based Measure)-GML(Global-Malmquist)based on VRS(Variable Returns to Scale)conditions including non-desired outputs is constructed.A comprehensive spatio-temporal heterogeneity research index system of rural revitalization performance is also constructed.Taking the typical rural in Chifeng City as an example,the panel data from 2016-2020 are selected for empirical analysis,the conclusions and countermeasures are suggested as follows:1)In general,the rural revitalization performance of Chifeng City increases significantly during the five-year period,with significant spatio-temporal heterogeneity.The overall analysis shows that the overall performance value of rural revitalization in Chifeng City is 0.683 from 2016 to 2020.The highest performance value is 1 and the lowest performance value is 0.389.The performance growth rate increases year by year,with an average annual growth rate of 4.46%.2)From 2016 to 2020,the GML index of rural revitalization performance in Chifeng City is 1.174,showing an increasing trend.Based on the range of change of GML index,Chifeng City can be classified into three types:Continuous improvement,fluctuating improvement and fluctuating decline.3)Niujiayingzi,Guandongche,Zhaidamu,and Qiangangtai rural have the highest degree of technological progress.
基金Special Project for Technical Development of Hainan Scientific Research Institutions(SQ2017JSKF0008)China Agricultural Industry Research System(CARS-43-42)
文摘[Objective] The study was carried out to investigate the effects of dietary crude fiber on growth performance and serum biochemical in-dex of Dingan geese aged from 35 to 70 days.[Method] A total of 120 Dingan geese on day 28 with the same genetic background and similar initial weight(1 384.83.73±0.76 g) were randomly assigned into 3 groups, with 4 replicates per group and 10 geese per replicate. Geese were fed the diets containing 4.29%, 5.29% and 6.29 % crude fiber, respectively. The experiment lasted 35 d.[Result] Final weight and daily gain of 5.29 %CF group were significantly higher than those of 6.29 % CF group(P<0.05);Feed intake was markedly higher than those of 4.29% and 6.29 % CF groups(P<0.05);Feed gain ratio was significantly lower than that of 6.29 % CF group(P<0.05). Compared with 4.29% and 6.29 % CF groups, serum albumin concentrations of 5.29 % CF group increased significantly(P<0.05), while serum total protein and globin contents were higher(P>0.05), but serum uric acid level was lower(P>0.05).[Conclusion] 5.29 % crude fiber could lead to higher growth performance of Dingan geese.
文摘In order to improve the lightning protection performance of transmission lines, lightning protection management has been divided into every tower that lightning protection performance has been evaluated respectively. According to factors such as landform, span, tower type, grounding resistance, isolator type, and so on, relative ratio of tripping operation of every tower in the line has been calculated to evaluate its lightning protection safety performance, it is beneficial to operation maintenance and lightning reconstruction of transmission lines.
基金Supported by Special Fund for Technology Development of Hainan Scientific Research Institute(KYYS-2019-04)Natural Science Foundation of Hainan Province(318MS109)+1 种基金Special Fund for Construction of China Agricultural Industry Research System(CARS-43-42)Special Funds for Local Science and Technology Development Guided by the Central Committee(ZY2019HN01)
文摘[Objective]The paper was to investigate the effects of dietary crude fiber level on production performance,organ index and serum biochemical parameters of Dingan geese aged from 1 to 28 days.[Method]A total of 144 1-day-old Dingan geese with the same genetic background and similar initial weight(88.75±0.21g)were randomly assigned into 3 groups with 4 replicates per group and 12 geese per replicate,and fed with the diets containing 2.56%,3.52% and 4.48% crude fiber,respectively.The trial lasted 28 d.[Result]1)The final weight and daily gain of 3.52% CF group were significantly higher than those of 2.56% CF group(P<0.05);the feed/gain ratio was markedly lower than that of 2.56% CF group(P<0.05).2)The slaughter rate,semi-eviscerated rate and leg muscle rate of 3.52% CF group were higher than those of 2.56% and 4.48% CF groups(P>0.05).3)As the dietary crude fiber levels rose,the abdominal fat rate showed a downward trend(P>0.05).4)The liver index of 3.52% CF group was significantly higher than that of 2.56% CF group(P<0.05).4)Compared with 2.5%and 4.48% CF groups,the serum albumin concentrations of 3.52% CF group markedly increased(P<0.05),the serum total protein and globin contents were higher(P>0.05),but the serum uric acid level was lower(P>0.05).[Conclusion]When the crude fiber level was 3.52%,the production performances of Dingan geese aged from 1 to 28 days were better,and the liver index and serum albumin level could be obviously improved.
文摘Objective Assessment of right ventricular function in patients with atrial septal defect(ASD)is difficult.The Doppler myocardial performance index(MPI)may provide a method of assessing function in these patients.The purposes of this study were to evaluate the right ventricular function and its changes in patients with ASD after transcatheter closure of ASD.Methods MPI,defined as the sum of isovolumic relaxation time and isovolumic contraction time derived by ejection time,was measured from tricuspid inflow and right ventricular outflow;Doppler velocity profiles recorded during routine echocardiography.Twenty nine patients(13 men,16 women;mean age 25.28±12.69,range 6 to 57 years)were diagnosed to secundum ASD[the stretched diameters of ASD were from 9 To 36(24.91±7.98)mm],and had a successfully placed Amplatzer septal occluder(ASO)(the sizes of ASO were from 11 to 40 mm);there were 81 sex-matched,age-matched healthy people(control group 41men,40 women;mean age 29.02±14.22,range 4 to 45 years).MPI was measured again on 3 days and 1 month after closure of ASD.Change in the study group was assessed and compared to the control subjects with structurally normal hearts.A complete 2-dimensional and Doppler echocardiographic examination was performed in all study groups.Results 1)The isovolumic relaxation and isovolumic contraction times[respectively(77.59±14.39)ms vs(60.93±12.94)ms,P<0.0001;(28.28±10.88)ms vs(23.64±9.01)ms,P=0.027]were prolonged,and ejection time[(260.65±21.86)ms vs(271.85±21.92)ms,P=0.033]was shortened in patients with ASD compared with that in control subjects,resulting in a marked increase in the MPI(0.40±0.07 vs 0.31±0.05,P<0.0001)from normal values;2)by Pearson's correlations,the MPI had no correlation with heart rate and blood pressure in control subjects and patients with ASD,but it correlated positively with age in patients with ASD;3)by Pearson's correlations,the MPI correlated positively with the diameter of ASD and pulmonary artery pressure;4)after transcatheter closure of ASD,the MPI decreased markedly.Conclusions 1)MPI is a conceptually new,simple,and reproducible Doppler index in patients with ASD;2)MPI is free from the effect of age,heart rate and blood pressure;(3)MPI appears to be relatively dependent on changes in the diameter of ASD and pulmonary artery pressure;4)the right ventricular function was improved after transcatheter closure of ASD.
文摘As a highly sensitive and stable detector,refractive index detector is usually used for quantitative detection of substances such as polymer,sugar and organic acid. The research reviewed the application of HPLC-RID in the fields of quantitative determination of medicine and food,in order to lay a foundation for wider use of RID.
基金Project(2009ZA04) supported by the Independent Research Foundation of State Key Laboratory of Subtropical Architecture Science,China
文摘The deformation performance index limits of high reinforced concrete (RC) shear wall components based on Chinese codes were discussed by the nonlinear finite element method. Two typical RC shear wall specimens in the previous work were first used to verify the correctness of the nonlinear finite element method. Then, the nonlinear finite element method was applied to study the deformability of a set of high RC shear wall components designed according to current Chinese codes and with shear span ratio λ≥2.0. Parametric studies were made on the influence of shear span ratio, axial compression ratio, ratio of flexural capacity to shear capacity and main flexural reinforcement ratio of confined botmdary members. Finally, the deformation performance index and its limits of high RC shear wall components under severe earthquakes were proposed by the finite element model results, which offers a reference in determining the performance status of RC shear wall components designed based on Chinese codes.
文摘The Code for Seismic Design of Buildings(GB50011-2010)in 2016 and the method of seismic performance-based design for high-rise buildings in the Guide for Performance-based Design of High-Rise Buildings(TBI2017)are compared.In view of the characteristics and limitations of the seismic performance index set by the Sino-US seismic code,a“three-index”performance index system and evaluation process considering the displacement angle of the structural interlayer,the plastic damage degree of components and the plastic strain of material is put forward;combining the example of time-history analysis of a out-of-code high-rise building under the rare earthquakes is verified.The results show that the method of seismic performance evaluation by using deformation control index in Sino-US seismic code is relatively simple;however,both are lacking in the setting of specific components and the whole structure level respectively.The"three-index"system can comprehensively and quantitatively evaluate the seismic performance of out-of-code high-rise buildings.
基金funded by the Key Technologies R&D Program of Guangxi of China (0992014-5)
文摘[Objective] The study was aimed to investigate the effects of NS series composite lactobacillus preparation on production performance and some immune indexes of sows. [Method] The sows were fed on the diets supplemented with the NS series composite lactobacillus prepara- tion, and the changes of production performance, plasma biochemical indexes, levels of IgG, IgA and IgM in serum and colostrum, and T lympho- cyte subpopulations were detected. [ Result] When the NS series composite lactobacillus preparation was supplemented to the sow diet at a propor- tion of 0.2%, the average weaning litter weight at 21 days old was significantly increased. The serum contents of total protein and glucose as well as the serum activities of aspartate aminotransferase (AST), alkaline phosphatase (ALP) and superoxide dismutase (SOD) were significantly in- creased after 30 d post delivery. Moreover, the levels of IgG, IgA and IgM in serum and colostrum of sows were significantly increased at the time of delivery and after 30 d post delivery. The antibodies in colostrum could be maintained at high levels. The percentage of CD3 * and CD4~ |ympho- cyte subpopulations was also increased after supplementation with the NS series composite lactobacillus preparation at a proportion of 0.2%. [ (Con- des'ion] The NS series composite lactobacillus preparation can improve performance, promote growth and metabolism, and enhance humoral and cellular immunity in sows.
文摘Data Envelopment Analysis (DEA) is becoming an increasingly popular tool for assessing the relative performance of industries and companies. By applying DEA theory to the non-financial sector, the relative efficiency of 27 listed corporations in the United Arab Emirates (UAE) has been analyzed in this paper. The focus of the study has been on the impact of the financial crisis and the recovery thereafter. Further, the productivity change was decomposed into technical efficiency change and technological change by using the non-parametric Malmquist Productivity Index (MPI) over the period from 2007 to 2014. Based on Malmquist analysis, we find that the most efficient industries during the post-crisis period were food and beverages, telecommunication and pharmaceuticals. In contrast, the sectors that were adversely affected by the crisis were services, real estate, construction and cements. The break-up of the TFP indicated that the efficiency indices in the top performing industries were driven by technological improvements or frontier effects. The top-performing companies in the UAE during the 2007-14 period demonstrated innovation-led growth, aided by the use of better technology, investments in capital equipment, and adoption of new production processes.
文摘Hamiltonian function is firstly constituted for solving optimal control. When character of controlled object is known,Hamiltonian function is determined by performance index. In this paper,by constituting Hamiltonian function and solving optimal control of a sort of performance index,we can understand optimal control theory and apply optimal control method better.
文摘Forty years of reform and opening up,China has become to the world’s second-largest economy with great success.However,it is an undoubted actuality that the economic mode of Chinese development is still at the extensive stage.China’s economy has shifted from a high-speed growth phase to a high-quality development phase.In this study,we analyzed three major urban agglomerations’total factor productivity index dynamically by means of Malmquist productivity i?ndex method.The results showed that MPI of Beijing-Tianjin-Hebei urban agglomeration was the highest,as the reasons of the effectiveness of dual-wheel driving both the technology progress and the cluster scale.The mean of MPI of Yangtze River Delta urban agglomeration was fallen into decline by an average of 1.3%annually due to the rate of increase of the size of the cluster towards to optimal frontier was inferior to the relative risk reduction of technology progress.Pearl River Delta urban agglomeration MPI declined by an average of 2.2%annually as a result of the contribution of technology progress reducing.The study of the economic performance of three major urban agglomerations provides a theoretical basis and important practical value for urban development of high quality optimization.
基金Science and Technology Major Project of Guangxi Zhuang Autonomous Region(Gui Ke AA17204052)Fundamental Research Fund for Public-welfare Scientific Research Institutions Directly under Guangxi Zhuang Autonomous Region(Gui Mu Yan Ke 2019-9)+1 种基金Guangxi Innovation Team Construction Project of National Modern Agricultural Industry Technology System(nycytxgxcxtd-19)Guangxi Science and Technology Base Special Project(20182023-1).
文摘[Objectives]The purpose of this experiment was to study the effects of dietary supplementation of Herba Picriae extract on the growth performance and immune organ index of Guangxi partridge chickens.[Methods]A total of 500 one-day-old Guangxi partridge chickens were selected and randomly divided into five groups,five replicates for each group and 20 chickens for each replicate.Groups A,B and C were treatment groups,in which 0.70%,0.35%and 0.175%of Herba Picriae extract was added to the basal diet,respectively.Group D was a positive drug control group,in which 0.01%colistin sulfate premix was supplemented.Group E was a blank control group,in which the chickens were fed the basal diet.The experimental period was 105 d.During the experiment,five chickens were randomly selected from each group on days 21,35 and 49,respectively for the measurement of immune organ index.[Results]When the chickens were fed basal diet supplemented with 0.175%of Herba Picriae extract,their daily body weight gain increased significantly from day 22 to day 35 and from day 71 to day 105 and tended to increase from day 1 to day 21,from day 36 to day 49,and from day 50 to day 70,with a range of 7.37%-8.72%.Dietary supplementation of 0.70%and 0.175%of Herba Picriae extract significantly promoted the growth and development of Fabricius bursae in the experimental chickens.[Conclusions]Dietary supplementation of 0.175%of Herba Picriae extract improved the growth performance and feed intake,as well as 21-d-old bursal index of the experimental chickens.
文摘At present, the overall economic and social development of our country is fast, but the rate of development of the remote land and territories in the land is still far behind the speed of the inland and the east. This has also triggered a series of frontier issues. This requires our frontier government to strengthen border governance, seize the opportunity to meet challenges, and at the same time we must also strengthen the assessment of the governance capacity of the frontier government. This article hopes that through the actual investigation and study of frontier counties and the consideration of border issues according to local conditions, a set of performance evaluation index system for frontier county-level governments will be proposed, which will help the frontier government in border control.
文摘Background: Reduced kidney function in blacks is associated with an increased frequency of left ventricular hypertrophy. Given the unavailability of echocardiography in most developing countries, the diagnostic performance of current ECG indexes needs to be evaluated. Objective: To compare the diagnostic performance of 3 commonly used ECG indexes (Sokolow-Lyon, Cornell voltage and Cornell product) in black hypertensive patients. Methods: Electrocardiography and echocardiography estimated left ventricular mass of 155 consecutive hypertensive patients who participated from January 2012 to January 2013 to an echocardiographic cross-sectional study of left ventricular structure was analyzed to compare Cornell voltage and Cornell product indexes with Sokolow-Lyon voltage index as a reference. Reduced kidney function was defined as eGFR 2. ROC curves in relation to LVH diagnosis were used to estimate the sensitivities and specificities of each index. P Results: The sensitivity and specificity were 43% and 85%, 23% and 77% and 26% and 77% for Sokolow-Lyon, Cornell voltage and Cornell product indexes, respectively. However, Sokolow-Lyon index (AUC;95% CI: 0.64;0.50 - 0.78) showed better performance than Cornell voltage (0.42;0.25 - 0.59) and Cornell product (0.43;0.28 - 0.59). Sokolow-Lyon index cut-point ≥ 37 mm corresponded to the highest Youden index (39.4% of sensitivity and 92.3% of specificity). Conclusion: Although the overall performance of the 3 ECG indexes versus echocardiography was low, Sokolow-Lyon index performed better than the two other indexes in diagnosing LVH.
基金The National Basic Research Program of China(973 Program)(No.2007CB714200)
文摘Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis (e. g. the pushover analysis), and the structural damage is considered via plastic hinges. Simultaneously, a practical approach is developed to obtain the relationships between the proposed index and earthquake intensities based on the capacity spectrum method. The proposed index is then illustrated through two low-rise reinforced concrete frames, and it is also compared with some other indices. The results indicate that the proposed index is on the safe side and not sensitive to the lateral load pattern. The storey index is helpful to reflect the storey damage and to uncover the position of the weak storey. Finally, the relationship between performance levels and damage index values is also proposed through statistical analysis for the performance-based seismic evaluation.
文摘The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytical expressions of the temperature dependent performance,such as breakdown characteristics and on resistance of 6H SiC unipolar power devices are derived in a closed form.The analytical results are compared with the experimental results,with good accordance found in the breakdown characteristics.