Many studies have revealed that anchovy has exhibited large variability in population size on decadal tim-escales. However, such works concerning anchovy population are mainly based on short historical catch records. ...Many studies have revealed that anchovy has exhibited large variability in population size on decadal tim-escales. However, such works concerning anchovy population are mainly based on short historical catch records. In order to understand the causes of variability in fish stocks （natural and/or anthropogenic） and calibrate the error between catches and standing stocks, it is essential to develop long-term time series of fish stocks from the time when human impacts are minimal or negligible. Well preserved fish scales from sediment record are regarded as useful indicators revealing the history of fish population dynamics over the last centuries. Anchovy scales was first analyzed over the Yellow Sea and East China Sea and the largest abundance was found in the central South Yellow Sea where is regarded as the largest overwintering ground for Japanese anchovy （Engraulis japonicas）. Thus in the central South Yellow Sea, two cores covering the last 150 years were collected for estimating fish scale flux. The scale deposition rate （SDR） records show that the decadal scale SDRs were obviously coherent between cores with independent chronologies. Thecalibration of downcore SDRs to the standing stocks of anchovy further validated that SDR is a reliable proxy to recon-struct the long-term anchovy population dynamic in the central South Yellow Sea where anoxic conditions prevail in the sediment. When assembled with other productivity proxies, it would be expected that SDR could be associated with changes in oceanic productivity and may make a contribution to determine the forcing factors and elucidate the mechanism of the process in future.展开更多
In this paper, the properties of dark energy are investigated according to the parameterized deceleration parameter q（z）, which is used to describe the extent of the accelerating expansion of the universe. The poten...In this paper, the properties of dark energy are investigated according to the parameterized deceleration parameter q（z）, which is used to describe the extent of the accelerating expansion of the universe. The potential of dark energy V（φ） and the cosmological parameters, such as the dimensionless energy density Ωφ, Ωm, and the state parameter wφ, are connected to it. Concretely, by giving two kinds of parameterized deceleration parameters q（z） = a ＋ bz/（1 ＋ z） and q（z） = 1/2 ＋ （az ＋ b）/（1 ＋ z）^2, the evolution of these parameters and the reconstructed potentials V（φ） are plotted and analysed. It is found that the potentials run away with the evolution of universe.展开更多
The degradation process of organosol coated tinplate in beverage was investigated by electrochemical noise (EN) technique combined with morphology characterization.EN data were analyzed using phase space reconstructio...The degradation process of organosol coated tinplate in beverage was investigated by electrochemical noise (EN) technique combined with morphology characterization.EN data were analyzed using phase space reconstruction theory.With the correlation dimensions obtained from the phase space reconstruction,the chaotic behavior of EN was quantitatively evaluated.The results show that both electrochemical potential noise (EPN) and electrochemical current noise (ECN) have chaotic properties.The correlation dimensions of EPN increase with corrosion extent,while those of ECN seem nearly unchanged.The increased correlation dimensions of EPN during the degradation process are associated with the increased susceptibility to local corrosion.展开更多
The low anodic oxidation potential severely suppresses the output voltage(≤0.6 V)of MXene-based symmetrical aqueous microsupercapacitors(MSA-MSCs)employing acidic electrolytes.Herein,a surface terminals reconstructio...The low anodic oxidation potential severely suppresses the output voltage(≤0.6 V)of MXene-based symmetrical aqueous microsupercapacitors(MSA-MSCs)employing acidic electrolytes.Herein,a surface terminals reconstruction mechanism on cathode of MSA-MSCs adopting aqueous neutral electrolyte(1 M Na_(2)SO_(4))is first revealed by systematical electrochemical experiments and in/ex-situ spectral analysis,which indicates that:the-O terminals on Ti3C2Tx flakes of cathode can combine with intercalated Na+cations during charging process to reconstruct into-ONa units to(i)inhibit the splitting reaction of adjacent water molecules,decreasing cathodic hydrogen evolution potential,more significantly,(ii)lower the potential of zero voltage(P0V)between the symmetrical electrodes to avoid anode oxidation,enabling full use of the unexploited potential range of cathode.Thus,the output voltage of the MSA-MSCs tremendously expanded from 0.6 V in acidic polyacrylamide(PAM)/1 M H_(2)SO_(4)hydrogel electrolyte to 1.5 V in neutral polyacrylamide/1 M Na2SO4 hydrogel electrolyte,boosting the corresponding areal energy density from 9.9 to 34.6μW·h·cm^(-2).The demonstrated deep insight on the surface terminals reconstruction mechanism for synchronously modulating the P0V between symmetrical electrodes and hydrogen evolution potential on cathode provides critical guidance for widening the cell voltage of MSA-MSCs with safer and more inexpensive neutral electrolytes.展开更多
农村居民点整治潜力测算及模式确定是土地整治规划的重要组成部分。该文针对灾后重建区农村居民点整治的复杂状况,采用实地调查数据与户均建设用地标准法,以行政村为单元,介绍了一种灾后重建区农村居民点整治潜力的测算方法;在此基础上...农村居民点整治潜力测算及模式确定是土地整治规划的重要组成部分。该文针对灾后重建区农村居民点整治的复杂状况,采用实地调查数据与户均建设用地标准法,以行政村为单元,介绍了一种灾后重建区农村居民点整治潜力的测算方法;在此基础上,选取了包括整治潜力在内的影响重建区整治模式的15个典型指标,通过分析处理土地利用、数字高程模型及社会经济与人口等数据,运用地理信息系统软件ArcGIS对各指标进行定量描述,并结合多元统计分析软件SPSS(statistical productand service solutions)提取6个主成份指标,通过层次聚类法将155个行政村进行量化分析,最终确定了5种农村居民点整治模式。研究表明,绵竹市农村居民点整治潜力为1763.23hm2;适宜改造提升模式的村有81个、适宜特色整治模式的村15个、适宜迁村并点模式的村16个、适宜集聚扩展模式的村28个、适宜生态搬迁模式的村15个。该研究成果可为灾后重建地区农村居民点整治规划及整治模式的选择提供理论支撑和实践指导。展开更多
目的比较Prolift盆底重建术与传统手术(阴式子宫全切加阴道前后壁修补手术)的临床疗效,比较术后盆底功能恢复情况。方法回顾性分析2010年12月—2012年1月北京大学人民医院34例行Prolift盆底重建术的重度盆腔器官脱垂(POP-QⅢ和Ⅵ度)患者...目的比较Prolift盆底重建术与传统手术(阴式子宫全切加阴道前后壁修补手术)的临床疗效,比较术后盆底功能恢复情况。方法回顾性分析2010年12月—2012年1月北京大学人民医院34例行Prolift盆底重建术的重度盆腔器官脱垂(POP-QⅢ和Ⅵ度)患者(研究组),与同期19例传统手术的重度盆腔脏器脱垂患者(对照组)的临床资料,包括一般情况、围手术期情况、POP-Q指示点分值等,利用法国杉山公司的PHNIX USB 8盆底功能诊断治疗仪对2组患者盆底功能进行生物电生理评估。结果研究组手术时间、手术出血量明显少于对照组,但术后保留导尿时间、住院天数2组相比未见统计学差异(P>0.05)。2组自身POP-Q指示点术前、术后测量值变化有统计学意义(P<0.05);2组间术后各指示点数值相比较,仅TVL差异有统计学意义(P>0.05);2组患者盆底肌肌电位无统计学差异(P>0.05),研究组盆底肌力、肌张力明显高于对照组(P<0.05)。结论 Prolift盆底重建术纠正子宫脱垂解剖恢复率高,更好地恢复盆底肌肉功能,优于传统手术。展开更多
研究局部场电位信号(Local Field Potential,LFP)的重构问题。依据传统的采样定理对LFP信号进行采样,将会产生庞大的数据量,为LFP信号的传输、存储及处理带来巨大压力。为降低LFP信号的采样速率,减少有效的采样样本,提出压缩感知的局部...研究局部场电位信号(Local Field Potential,LFP)的重构问题。依据传统的采样定理对LFP信号进行采样,将会产生庞大的数据量,为LFP信号的传输、存储及处理带来巨大压力。为降低LFP信号的采样速率,减少有效的采样样本,提出压缩感知的局部场电位信号重构的新方法。利用LFP信号在变换域上的稀疏性,通过随机高斯测量矩阵将LFP信号重构模型转化为压缩感知理论中的稀疏向量重构模型。仿真结果表明,采样速率为奈奎斯特采样速率的一半即可准确重构LFP信号,且正交匹配追踪(OMP)重建算法要优于基追踪(BP)重建算法;当选用离散余弦矩阵(DCT)作为稀疏表示矩阵时,信号在正交匹配追踪和基追踪两种重构算法下都有很高的重构精度。展开更多
基金The National Basic Research Program of China under contract Nos 2010CB428902 and 2006CB400007the National Natural Science Foundation of China under contract No.40876088
文摘Many studies have revealed that anchovy has exhibited large variability in population size on decadal tim-escales. However, such works concerning anchovy population are mainly based on short historical catch records. In order to understand the causes of variability in fish stocks （natural and/or anthropogenic） and calibrate the error between catches and standing stocks, it is essential to develop long-term time series of fish stocks from the time when human impacts are minimal or negligible. Well preserved fish scales from sediment record are regarded as useful indicators revealing the history of fish population dynamics over the last centuries. Anchovy scales was first analyzed over the Yellow Sea and East China Sea and the largest abundance was found in the central South Yellow Sea where is regarded as the largest overwintering ground for Japanese anchovy （Engraulis japonicas）. Thus in the central South Yellow Sea, two cores covering the last 150 years were collected for estimating fish scale flux. The scale deposition rate （SDR） records show that the decadal scale SDRs were obviously coherent between cores with independent chronologies. Thecalibration of downcore SDRs to the standing stocks of anchovy further validated that SDR is a reliable proxy to recon-struct the long-term anchovy population dynamic in the central South Yellow Sea where anoxic conditions prevail in the sediment. When assembled with other productivity proxies, it would be expected that SDR could be associated with changes in oceanic productivity and may make a contribution to determine the forcing factors and elucidate the mechanism of the process in future.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10573003 and 10703001)Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20070141034)
文摘In this paper, the properties of dark energy are investigated according to the parameterized deceleration parameter q（z）, which is used to describe the extent of the accelerating expansion of the universe. The potential of dark energy V（φ） and the cosmological parameters, such as the dimensionless energy density Ωφ, Ωm, and the state parameter wφ, are connected to it. Concretely, by giving two kinds of parameterized deceleration parameters q（z） = a ＋ bz/（1 ＋ z） and q（z） = 1/2 ＋ （az ＋ b）/（1 ＋ z）^2, the evolution of these parameters and the reconstructed potentials V（φ） are plotted and analysed. It is found that the potentials run away with the evolution of universe.
基金Supported by Major State Basic Research Program of China ("973" Program,No. 2011CB610505)Specialized Research Fund for the Doctoral Program of Higher Education (No. 20120032110029)
文摘The degradation process of organosol coated tinplate in beverage was investigated by electrochemical noise (EN) technique combined with morphology characterization.EN data were analyzed using phase space reconstruction theory.With the correlation dimensions obtained from the phase space reconstruction,the chaotic behavior of EN was quantitatively evaluated.The results show that both electrochemical potential noise (EPN) and electrochemical current noise (ECN) have chaotic properties.The correlation dimensions of EPN increase with corrosion extent,while those of ECN seem nearly unchanged.The increased correlation dimensions of EPN during the degradation process are associated with the increased susceptibility to local corrosion.
基金the National Natural Science Foundation of China(No.51871001)Excellent Youth Fund of Anhui Province(No.2108085Y17)+2 种基金Innovation and Entrepreneurship Support Plan of Anhui Province for Returned Personnels Studying Abroad(No.2022LCX001)Project supported by the Program of State Key Laboratory of Quantum Optics and Quantum Optics Devices(No.KF202212)Hundred-Talent Program of Anhui Province.
文摘The low anodic oxidation potential severely suppresses the output voltage(≤0.6 V)of MXene-based symmetrical aqueous microsupercapacitors(MSA-MSCs)employing acidic electrolytes.Herein,a surface terminals reconstruction mechanism on cathode of MSA-MSCs adopting aqueous neutral electrolyte(1 M Na_(2)SO_(4))is first revealed by systematical electrochemical experiments and in/ex-situ spectral analysis,which indicates that:the-O terminals on Ti3C2Tx flakes of cathode can combine with intercalated Na+cations during charging process to reconstruct into-ONa units to(i)inhibit the splitting reaction of adjacent water molecules,decreasing cathodic hydrogen evolution potential,more significantly,(ii)lower the potential of zero voltage(P0V)between the symmetrical electrodes to avoid anode oxidation,enabling full use of the unexploited potential range of cathode.Thus,the output voltage of the MSA-MSCs tremendously expanded from 0.6 V in acidic polyacrylamide(PAM)/1 M H_(2)SO_(4)hydrogel electrolyte to 1.5 V in neutral polyacrylamide/1 M Na2SO4 hydrogel electrolyte,boosting the corresponding areal energy density from 9.9 to 34.6μW·h·cm^(-2).The demonstrated deep insight on the surface terminals reconstruction mechanism for synchronously modulating the P0V between symmetrical electrodes and hydrogen evolution potential on cathode provides critical guidance for widening the cell voltage of MSA-MSCs with safer and more inexpensive neutral electrolytes.
文摘农村居民点整治潜力测算及模式确定是土地整治规划的重要组成部分。该文针对灾后重建区农村居民点整治的复杂状况,采用实地调查数据与户均建设用地标准法,以行政村为单元,介绍了一种灾后重建区农村居民点整治潜力的测算方法;在此基础上,选取了包括整治潜力在内的影响重建区整治模式的15个典型指标,通过分析处理土地利用、数字高程模型及社会经济与人口等数据,运用地理信息系统软件ArcGIS对各指标进行定量描述,并结合多元统计分析软件SPSS(statistical productand service solutions)提取6个主成份指标,通过层次聚类法将155个行政村进行量化分析,最终确定了5种农村居民点整治模式。研究表明,绵竹市农村居民点整治潜力为1763.23hm2;适宜改造提升模式的村有81个、适宜特色整治模式的村15个、适宜迁村并点模式的村16个、适宜集聚扩展模式的村28个、适宜生态搬迁模式的村15个。该研究成果可为灾后重建地区农村居民点整治规划及整治模式的选择提供理论支撑和实践指导。
文摘目的比较Prolift盆底重建术与传统手术(阴式子宫全切加阴道前后壁修补手术)的临床疗效,比较术后盆底功能恢复情况。方法回顾性分析2010年12月—2012年1月北京大学人民医院34例行Prolift盆底重建术的重度盆腔器官脱垂(POP-QⅢ和Ⅵ度)患者(研究组),与同期19例传统手术的重度盆腔脏器脱垂患者(对照组)的临床资料,包括一般情况、围手术期情况、POP-Q指示点分值等,利用法国杉山公司的PHNIX USB 8盆底功能诊断治疗仪对2组患者盆底功能进行生物电生理评估。结果研究组手术时间、手术出血量明显少于对照组,但术后保留导尿时间、住院天数2组相比未见统计学差异(P>0.05)。2组自身POP-Q指示点术前、术后测量值变化有统计学意义(P<0.05);2组间术后各指示点数值相比较,仅TVL差异有统计学意义(P>0.05);2组患者盆底肌肌电位无统计学差异(P>0.05),研究组盆底肌力、肌张力明显高于对照组(P<0.05)。结论 Prolift盆底重建术纠正子宫脱垂解剖恢复率高,更好地恢复盆底肌肉功能,优于传统手术。
文摘研究局部场电位信号(Local Field Potential,LFP)的重构问题。依据传统的采样定理对LFP信号进行采样,将会产生庞大的数据量,为LFP信号的传输、存储及处理带来巨大压力。为降低LFP信号的采样速率,减少有效的采样样本,提出压缩感知的局部场电位信号重构的新方法。利用LFP信号在变换域上的稀疏性,通过随机高斯测量矩阵将LFP信号重构模型转化为压缩感知理论中的稀疏向量重构模型。仿真结果表明,采样速率为奈奎斯特采样速率的一半即可准确重构LFP信号,且正交匹配追踪(OMP)重建算法要优于基追踪(BP)重建算法;当选用离散余弦矩阵(DCT)作为稀疏表示矩阵时,信号在正交匹配追踪和基追踪两种重构算法下都有很高的重构精度。
