Background:Vestibular assessments,such as the video ocular counter roll(vOCR)test,offer valuable insights into the interactions between age,otolith function,and vestibular performance.Objective:To analyze the relation...Background:Vestibular assessments,such as the video ocular counter roll(vOCR)test,offer valuable insights into the interactions between age,otolith function,and vestibular performance.Objective:To analyze the relation between age and vOCR gains as a potential marker of age-related otolith degeneration.Methods:A total of 107 participants underwent vOCR testing.Descriptive statistics and simple linear regression analyses were conducted to explore the association between age and vOCR gains.Results were presented using regression coefficients,95%confidence intervals,p-values,and R-squared values.Results:In the overall sample,statistically significant associations were observed between age and vOCR gains in both ears.For the right ear,vOCR gains decreased with increasing age(coefficient:-0.03;95%CI:-0.05 to-0.01;p<0.001;R^(2)=0.08),while the left ear showed a slightly stronger association(coefficient:-0.04;95%CI:-0.07 to-0.02;p<0.001;R²=0.12).These findings indicate a moderate age-related decline in otolith-mediated vestibular responses.Conclusion:vOCR gains appear to decline with age,reflecting potential age-related otolith degeneration.These results support the clinical value of vOCR as a non-invasive method to assess vestibular function and its changes across the lifespan.展开更多
Supersonic Tailless Aerial Vehicles(STAVs)will become an essential force in Penetrating Counter Air(PCA),but STAVs do not have the traditional horizontal and vertical tails,making pitch and yaw control difficult.The a...Supersonic Tailless Aerial Vehicles(STAVs)will become an essential force in Penetrating Counter Air(PCA),but STAVs do not have the traditional horizontal and vertical tails,making pitch and yaw control difficult.The attack angle and the sideslip angle need to be limited to ensure that the engine inlet and the aerodynamic rudder at the rear of the vehicle can work properly,which is the so-called security constraints.In addition,the tracking error of the aerodynamic angle needs to be limited to achieve effective attitude control or high-accuracy tracking of trajectories,which is the so-called performance constraints.To this end,an attitude control method that meets the needs of PCA has been devised,based on constraint definition,coupled constraints handling,and control law design.Firstly,mathematical descriptions of the security constraints,performance constraints,and control constraints are given.Secondly,two treatment methods,coupled command filter and coupled funnel control are proposed for the aerodynamic angle coupled constraint problem.Finally,based on Nonlinear Dynamic Inverse(NDI)design,the coupled funnel controller is designed and validated by simulation for two typical mission scenarios,high-altitude penetration and low-altitude surprise defence.The proposed control method not only satisfies the security and performance constraints of STAV attitude control but also is highly robust.展开更多
ZIF-67 containing cobalt cation was selected as the research object,and the carbon-containing cobalt matrix nanocomposite(C&Co)was obtained after heat treatment in a nitrogen atmosphere at the appropriate temperat...ZIF-67 containing cobalt cation was selected as the research object,and the carbon-containing cobalt matrix nanocomposite(C&Co)was obtained after heat treatment in a nitrogen atmosphere at the appropriate temperature.The nanostructures and morphologies of the nanocomposite were analyzed by X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,and X-ray photoelectron spectroscopy.The electrochemical response was comprehensively characterized by cyclic voltammetry,electrochemical impedance spectroscopy,and Tafel polarization.The electrochemical analysis of the C&Co nanocomposite electrode shows that the electrode has an obvious electrocatalytic activity for the reduction of the triiodide compound.The conversion efficiency of dye-sensitized solar cells prepared with C&Co nanocomposite electrode shows 5.3%under the condition of AM1.5G simulated sunlight irradiation,which shows great application potential in Pt-free electrode materials.展开更多
Developing a novel drop counter by introducing the Internet of Things concept has been vigorously conducted in recent years. Understanding the newly introduced drop counter’s flow rate control accuracy and flow rate ...Developing a novel drop counter by introducing the Internet of Things concept has been vigorously conducted in recent years. Understanding the newly introduced drop counter’s flow rate control accuracy and flow rate count feature is essential for improving safety in infusion management. This study aimed to verify if the new drop counters could secure accurate flow rate and drip count by conducting actual flow rate measurements using gravimetry and functional evaluation. A drop counter was attached to each drip chamber of the infusion set, and an IV drip was conducted at the 100 ml/h flow rate. The weight of discharged physiological saline was measured to plot trumpet curves. Next, three different types of drop counters were evaluated to determine if they maintained drip count accuracy according to the changes in their position angles. The flow rate errors in all conditions indicated trumpet-like curves, exhibiting an overall error range within ±10% in all observation windows. Although every drop counter successfully detected and measured dripping, it was challenging in some counters to detect dripping when the drip chamber was tilted. In comparing adult and pediatric IV sets, the adult IV set was found to be less likely to detect dripping in the angled position. No significant differences in results were confirmed between high and low flow rates, suggesting that the drop count function would not be affected by the flow rate in the ranges of typical infusion practices. Doppler sensors have a wide range of measurements and high sensitivity;the dripping was detected successfully even when the drip chamber was tilted, probably due to the advantages of these sensors. In contrast, miscounts occurred in those equipped with infrared sensors, which could not detect light intensity changes in tilted positions. Understanding the tendencies in flow rate errors in infusion can be valuable information for infusion management.展开更多
The influence of filling parameters including pouring temperature, filling speed, boost pressure and synchronous pressure on the fatigue of A357 alloy produced by counter pressure plaster casting was studied. The Tagu...The influence of filling parameters including pouring temperature, filling speed, boost pressure and synchronous pressure on the fatigue of A357 alloy produced by counter pressure plaster casting was studied. The Taguchi method was used to investigate the relationship between the fatigue performance and filling parameters. The results show that filling speed is the most significant factor among the four parameters. Synchronous pressures is less influential on the fatigue life when the value of synchronous pressure is from 400 kPa to 600 kPa.展开更多
Significant progress has been made in the development of non-precious metal electrocatalysts （NPMEs） during the past decade. Correspondingly, there is an urgent demand for an appropriate measurement method to be est...Significant progress has been made in the development of non-precious metal electrocatalysts （NPMEs） during the past decade. Correspondingly, there is an urgent demand for an appropriate measurement method to be established for the reliable evaluation of NPMEs. In this study, platinum and graphite counter electrodes were used to investigate the impact of counter electrode material on the accelerated durability testing （ADT） of NPMEs in acidic medium. Platinum used as the coun- ter electrode in a traditional three-electrode electrochemical cell was found to dissolve in acidic medium and re-deposit on NPME coated on the working electrode during ADT. Such re-deposition causes the oxygen reduction reaction （ORR） performance of NPMEs to remarkably improve, and thus will seriously mislead our judgment of NPMEs if we are unaware of it. The phenomenon can be avoided using a graphite counter electrode.展开更多
文章通过对Counting Online Usage of Networked Electronic Resources Codes of Practice(COUNTER)项目的成立背景、组织成员、日常管理、业务的介绍以及其成功因素的分析,认为我国也亟需加强对数字期刊及其他资源利用情况的统计,并提...文章通过对Counting Online Usage of Networked Electronic Resources Codes of Practice(COUNTER)项目的成立背景、组织成员、日常管理、业务的介绍以及其成功因素的分析,认为我国也亟需加强对数字期刊及其他资源利用情况的统计,并提出了相关建议。展开更多
文摘Background:Vestibular assessments,such as the video ocular counter roll(vOCR)test,offer valuable insights into the interactions between age,otolith function,and vestibular performance.Objective:To analyze the relation between age and vOCR gains as a potential marker of age-related otolith degeneration.Methods:A total of 107 participants underwent vOCR testing.Descriptive statistics and simple linear regression analyses were conducted to explore the association between age and vOCR gains.Results were presented using regression coefficients,95%confidence intervals,p-values,and R-squared values.Results:In the overall sample,statistically significant associations were observed between age and vOCR gains in both ears.For the right ear,vOCR gains decreased with increasing age(coefficient:-0.03;95%CI:-0.05 to-0.01;p<0.001;R^(2)=0.08),while the left ear showed a slightly stronger association(coefficient:-0.04;95%CI:-0.07 to-0.02;p<0.001;R²=0.12).These findings indicate a moderate age-related decline in otolith-mediated vestibular responses.Conclusion:vOCR gains appear to decline with age,reflecting potential age-related otolith degeneration.These results support the clinical value of vOCR as a non-invasive method to assess vestibular function and its changes across the lifespan.
基金supported by the National Natural Science Foundation of China(No.62103439)the China Postdoctoral Science Foundation(No.2020M683716)+1 种基金the National Key Laboratory of Unmanned Aerial Vehicle Technology,Chinathe Youth Innovation Team of Shaanxi University,China.
文摘Supersonic Tailless Aerial Vehicles(STAVs)will become an essential force in Penetrating Counter Air(PCA),but STAVs do not have the traditional horizontal and vertical tails,making pitch and yaw control difficult.The attack angle and the sideslip angle need to be limited to ensure that the engine inlet and the aerodynamic rudder at the rear of the vehicle can work properly,which is the so-called security constraints.In addition,the tracking error of the aerodynamic angle needs to be limited to achieve effective attitude control or high-accuracy tracking of trajectories,which is the so-called performance constraints.To this end,an attitude control method that meets the needs of PCA has been devised,based on constraint definition,coupled constraints handling,and control law design.Firstly,mathematical descriptions of the security constraints,performance constraints,and control constraints are given.Secondly,two treatment methods,coupled command filter and coupled funnel control are proposed for the aerodynamic angle coupled constraint problem.Finally,based on Nonlinear Dynamic Inverse(NDI)design,the coupled funnel controller is designed and validated by simulation for two typical mission scenarios,high-altitude penetration and low-altitude surprise defence.The proposed control method not only satisfies the security and performance constraints of STAV attitude control but also is highly robust.
基金supported by the National Natural Science Foundation of China(21965013)Hainan Provincial Natural Science Foundation(521CXTD438)Hainan Province Postdoctoral Research Funding Project(RZ2300005520)
文摘ZIF-67 containing cobalt cation was selected as the research object,and the carbon-containing cobalt matrix nanocomposite(C&Co)was obtained after heat treatment in a nitrogen atmosphere at the appropriate temperature.The nanostructures and morphologies of the nanocomposite were analyzed by X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,and X-ray photoelectron spectroscopy.The electrochemical response was comprehensively characterized by cyclic voltammetry,electrochemical impedance spectroscopy,and Tafel polarization.The electrochemical analysis of the C&Co nanocomposite electrode shows that the electrode has an obvious electrocatalytic activity for the reduction of the triiodide compound.The conversion efficiency of dye-sensitized solar cells prepared with C&Co nanocomposite electrode shows 5.3%under the condition of AM1.5G simulated sunlight irradiation,which shows great application potential in Pt-free electrode materials.
文摘Developing a novel drop counter by introducing the Internet of Things concept has been vigorously conducted in recent years. Understanding the newly introduced drop counter’s flow rate control accuracy and flow rate count feature is essential for improving safety in infusion management. This study aimed to verify if the new drop counters could secure accurate flow rate and drip count by conducting actual flow rate measurements using gravimetry and functional evaluation. A drop counter was attached to each drip chamber of the infusion set, and an IV drip was conducted at the 100 ml/h flow rate. The weight of discharged physiological saline was measured to plot trumpet curves. Next, three different types of drop counters were evaluated to determine if they maintained drip count accuracy according to the changes in their position angles. The flow rate errors in all conditions indicated trumpet-like curves, exhibiting an overall error range within ±10% in all observation windows. Although every drop counter successfully detected and measured dripping, it was challenging in some counters to detect dripping when the drip chamber was tilted. In comparing adult and pediatric IV sets, the adult IV set was found to be less likely to detect dripping in the angled position. No significant differences in results were confirmed between high and low flow rates, suggesting that the drop count function would not be affected by the flow rate in the ranges of typical infusion practices. Doppler sensors have a wide range of measurements and high sensitivity;the dripping was detected successfully even when the drip chamber was tilted, probably due to the advantages of these sensors. In contrast, miscounts occurred in those equipped with infrared sensors, which could not detect light intensity changes in tilted positions. Understanding the tendencies in flow rate errors in infusion can be valuable information for infusion management.
文摘The influence of filling parameters including pouring temperature, filling speed, boost pressure and synchronous pressure on the fatigue of A357 alloy produced by counter pressure plaster casting was studied. The Taguchi method was used to investigate the relationship between the fatigue performance and filling parameters. The results show that filling speed is the most significant factor among the four parameters. Synchronous pressures is less influential on the fatigue life when the value of synchronous pressure is from 400 kPa to 600 kPa.
基金supported by the Fundamental Research Funds for the Central Universities(DUT15RC(3)001,DUT15ZD225)the Program for Liao-ning Excellent Talents in University(LR2015014)+1 种基金the Liaoning BaiQianWan Talents Program(201519)Dalian Excellent Young Scientific and Technological Talents(2015R006)
文摘Significant progress has been made in the development of non-precious metal electrocatalysts （NPMEs） during the past decade. Correspondingly, there is an urgent demand for an appropriate measurement method to be established for the reliable evaluation of NPMEs. In this study, platinum and graphite counter electrodes were used to investigate the impact of counter electrode material on the accelerated durability testing （ADT） of NPMEs in acidic medium. Platinum used as the coun- ter electrode in a traditional three-electrode electrochemical cell was found to dissolve in acidic medium and re-deposit on NPME coated on the working electrode during ADT. Such re-deposition causes the oxygen reduction reaction （ORR） performance of NPMEs to remarkably improve, and thus will seriously mislead our judgment of NPMEs if we are unaware of it. The phenomenon can be avoided using a graphite counter electrode.
文摘文章通过对Counting Online Usage of Networked Electronic Resources Codes of Practice(COUNTER)项目的成立背景、组织成员、日常管理、业务的介绍以及其成功因素的分析,认为我国也亟需加强对数字期刊及其他资源利用情况的统计,并提出了相关建议。
