A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete...A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete components.Each channel consists of an integrator,a pole-zero cancellation net,and a linear amplification stage,which can be adapted to accommodate either positive or negative input signals.The RMS equivalent input noise charges are 3.3 fC,the conversion gains are approximately±2 mV∕fC,and the intrinsic time resolution reaches 32 ps.In the prototype PPAC application,the CSA performs as well as the commercial FTA820A amplifier,providing a position resolution as good as 0.17 mm,and exhibiting reliable stability during several hours of continuous data acquisition.展开更多
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
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
基金supported by the National Natural Science Foundation of China(Nos.U2167202,12225504,12005276)the Natural Science Foundation of Shandong Province(No.ZR2024QA172)the Fundamental Research Funds of Shandong University.
文摘A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete components.Each channel consists of an integrator,a pole-zero cancellation net,and a linear amplification stage,which can be adapted to accommodate either positive or negative input signals.The RMS equivalent input noise charges are 3.3 fC,the conversion gains are approximately±2 mV∕fC,and the intrinsic time resolution reaches 32 ps.In the prototype PPAC application,the CSA performs as well as the commercial FTA820A amplifier,providing a position resolution as good as 0.17 mm,and exhibiting reliable stability during several hours of continuous data acquisition.
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.
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。
