The laser-induced damage threshold(LIDT) of optical coating is a limited factor for development of a high peak power laser. The automatic damage testing facility was built to determine the LIDT of optics at 1 064 nm a...The laser-induced damage threshold(LIDT) of optical coating is a limited factor for development of a high peak power laser. The automatic damage testing facility was built to determine the LIDT of optics at 1 064 nm and 355 nm.. The cleanning and processing procedure of the substrate and coating technique were improved, and the damage resistance of high-reflective coating at 1 064 nm was increased.展开更多
The possibility of using 209Bi as a new threshold detector to measurc high-energy neutrons was investigated for the first time. At the same time the experiment measured successfully the emitted neutron fiuence rate, e...The possibility of using 209Bi as a new threshold detector to measurc high-energy neutrons was investigated for the first time. At the same time the experiment measured successfully the emitted neutron fiuence rate, energy spectrum and dose equivalent rate distributions in the heavy ion target area using a detector complex including 209Bi, 115In, 27A1, 19F and 12C samples.展开更多
目的探讨改良版中文数字三联音测试的有效性,提高老年听力筛查的准确性。方法设计开发改良版中文数字三联音测试材料,选取60岁以上老年人203例进行声导抗、纯音听阈测试、安静和噪声条件下的改良版数字三联音测试,分析该测试与纯音听阈...目的探讨改良版中文数字三联音测试的有效性,提高老年听力筛查的准确性。方法设计开发改良版中文数字三联音测试材料,选取60岁以上老年人203例进行声导抗、纯音听阈测试、安静和噪声条件下的改良版数字三联音测试,分析该测试与纯音听阈测试结果的相关性,得出受试者工作特征曲线(receiver operating characteristic,ROC)以计算曲线下面积(area under the curve,AUC),最佳截断值及其对应的敏感度特异度,诊断符合率。结果(1)改良版数字三联音测试与纯音听阈测试存在显著正相关(安静下r=0.86,噪声下r=0.71,P=0.001);(2)基于较好耳分类,在区分是否存在听力损失(PTA_(0.5~4 kHz)<20 dB HL为不存在)时,安静条件下AUC=0.90,最佳截断值=28.71 dB,特异度=0.96,敏感度=0.75和噪声条件下AUC=0.78,最佳截断值=-9.16 dB,特异度=0.68,敏感度=0.82(P均<0.001)。在区分是否存在中度及以上听力损失(PTA_(0.5~4 kHz)<35 dB HL为不存在)时,在安静条件下AUC=0.94,最佳截断值=38.08 dB,特异度=0.95,敏感度=0.78与噪声条件下AUC=0.87,最佳截断值=-6.85 dB,特异度=0.89,敏感度=0.73(P均<0.001)。结论改良版中文数字三联音筛查测试在安静与噪声环境下均能有效区分不同程度的老年听力损失,其中安静环境下区分更有效,可作为老年听力筛查的有效工具。展开更多
目的本研究旨在探讨无偿献血人群中隐匿性乙型肝炎感染(occult hepatitis B infection,OBI)与丙氨酸氨基转移酶(alanine aminotransferase,ALT)的相关性,评估ALT对OBI的筛查效能,并为优化血液筛查策略提供依据。方法本研究收集了2024—2...目的本研究旨在探讨无偿献血人群中隐匿性乙型肝炎感染(occult hepatitis B infection,OBI)与丙氨酸氨基转移酶(alanine aminotransferase,ALT)的相关性,评估ALT对OBI的筛查效能,并为优化血液筛查策略提供依据。方法本研究收集了2024—2025年度哈尔滨市血液中心210629例献血者样本,并对其进行血液筛查同时记录其ALT值,鉴别出OBI的感染数量,采用非参数检验、回归分析和受试者工作特征(receiver operating characteristic,ROC)曲线分析,比较OBI感染者与健康献血者的ALT水平差异,评估ALT的诊断价值。结果共检出27例OBI感染者(检出率0.13‰)。所有OBI感染者ALT均≤50 U/L(符合献血标准),其中位数为20 U/L,显著高于健康献血者(中位数为18 U/L,P<0.05)。ROC曲线分析显示,ALT诊断OBI的曲线下面积(area under the curve,AUC)为0.641(95%置信区间:0.532~0.750),最佳检测阈值为17 U/L时,灵敏度77.8%、特异度49.3%。虽然OBI感染者ALT水平存在轻度异常趋势,但ALT单独用于筛查OBI的效力不足。OBI感染者病毒载量与ALT无线性关联(R^(2)=0.0421)。结论本研究显示ALT对OBI的筛查价值有限,无法有效区分OBI与健康人群。建议结合病毒核酸检测技术提高OBI检出率,优化或取消ALT筛查阈值,以减少健康献血者资源的浪费。展开更多
This paper presents a minimum error thresholding (MET) algorithm under the hypothesis that the gray level histogram of SAR image fits to a mixture model of shifted Rayleigh distribution. This algorithm is applied to r...This paper presents a minimum error thresholding (MET) algorithm under the hypothesis that the gray level histogram of SAR image fits to a mixture model of shifted Rayleigh distribution. This algorithm is applied to real SAR images and compared with traditional Otsu algorithm and other MET algorithms based on various models of histogram. The hypothesis of using Rayleigh distribution model is confirmed by Kolmogorov-Smirnov testing and the comparison results obtained show that the proposed new algorithm has good performance in thresholding SAR images.展开更多
It is demonstrated that inherent coating adhesion and damage threshold are correlated for Ta2O5 and HfO2 coatings widely used in optoelectronic devices. By utilizing a newly proposed 1-h boiling water test combined wi...It is demonstrated that inherent coating adhesion and damage threshold are correlated for Ta2O5 and HfO2 coatings widely used in optoelectronic devices. By utilizing a newly proposed 1-h boiling water test combined with the optical aging under high-power laser irradiation, we show that an optical coating that survives the 1-h boiling water test withstands the damage threshold, ensuring the field service life even in harsh environments. Besides the standard evaluation methods, which may have limitations for applications required in harsh environments, the 1-h boiling water test can serve as an alternative method of reliability assessment for optical coatings. A heuristics herein can be used as a gating item for qualification of optical coatings for various applications.展开更多
Objective: To improve the detecting accuracy of chromosomal aneuploidy of fetus by non-invasive prenatal testing (NIPT) using next generation sequencing data of pregnant women’s cell-free DNA. Methods: We proposed th...Objective: To improve the detecting accuracy of chromosomal aneuploidy of fetus by non-invasive prenatal testing (NIPT) using next generation sequencing data of pregnant women’s cell-free DNA. Methods: We proposed the multi-Z method which uses 21 z-scores for each autosomal chromosome to detect aneuploidy of the chromosome, while the conventional NIPT method uses only one z-score. To do this, mapped read numbers of a certain chromosome were normalized by those of the other 21 chromosomes. Average and standard deviation (SD), which are used for calculating z-score of each sample, were obtained with normalized values between all autosomal chromosomes of control samples. In this way, multiple z-scores can be calculated for 21 autosomal chromosomes except oneself. Results: Multi-Z method showed 100% sensitivity and specificity for 187 samples sequenced to 3 M reads while the conventional NIPT method showed 95.1% specificity. Similarly, for 216 samples sequenced to 1 M reads, Multi-Z method showed 100% sensitivity and 95.6% specificity and the conventional NIPT method showed a result of 75.1% specificity. Conclusion: Multi-Z method showed higher accuracy and robust results than the conventional method even at low coverage reads.展开更多
文摘The laser-induced damage threshold(LIDT) of optical coating is a limited factor for development of a high peak power laser. The automatic damage testing facility was built to determine the LIDT of optics at 1 064 nm and 355 nm.. The cleanning and processing procedure of the substrate and coating technique were improved, and the damage resistance of high-reflective coating at 1 064 nm was increased.
基金Supported by the National Natural Science Foundation of China(19875070)
文摘The possibility of using 209Bi as a new threshold detector to measurc high-energy neutrons was investigated for the first time. At the same time the experiment measured successfully the emitted neutron fiuence rate, energy spectrum and dose equivalent rate distributions in the heavy ion target area using a detector complex including 209Bi, 115In, 27A1, 19F and 12C samples.
文摘目的探讨改良版中文数字三联音测试的有效性,提高老年听力筛查的准确性。方法设计开发改良版中文数字三联音测试材料,选取60岁以上老年人203例进行声导抗、纯音听阈测试、安静和噪声条件下的改良版数字三联音测试,分析该测试与纯音听阈测试结果的相关性,得出受试者工作特征曲线(receiver operating characteristic,ROC)以计算曲线下面积(area under the curve,AUC),最佳截断值及其对应的敏感度特异度,诊断符合率。结果(1)改良版数字三联音测试与纯音听阈测试存在显著正相关(安静下r=0.86,噪声下r=0.71,P=0.001);(2)基于较好耳分类,在区分是否存在听力损失(PTA_(0.5~4 kHz)<20 dB HL为不存在)时,安静条件下AUC=0.90,最佳截断值=28.71 dB,特异度=0.96,敏感度=0.75和噪声条件下AUC=0.78,最佳截断值=-9.16 dB,特异度=0.68,敏感度=0.82(P均<0.001)。在区分是否存在中度及以上听力损失(PTA_(0.5~4 kHz)<35 dB HL为不存在)时,在安静条件下AUC=0.94,最佳截断值=38.08 dB,特异度=0.95,敏感度=0.78与噪声条件下AUC=0.87,最佳截断值=-6.85 dB,特异度=0.89,敏感度=0.73(P均<0.001)。结论改良版中文数字三联音筛查测试在安静与噪声环境下均能有效区分不同程度的老年听力损失,其中安静环境下区分更有效,可作为老年听力筛查的有效工具。
文摘目的本研究旨在探讨无偿献血人群中隐匿性乙型肝炎感染(occult hepatitis B infection,OBI)与丙氨酸氨基转移酶(alanine aminotransferase,ALT)的相关性,评估ALT对OBI的筛查效能,并为优化血液筛查策略提供依据。方法本研究收集了2024—2025年度哈尔滨市血液中心210629例献血者样本,并对其进行血液筛查同时记录其ALT值,鉴别出OBI的感染数量,采用非参数检验、回归分析和受试者工作特征(receiver operating characteristic,ROC)曲线分析,比较OBI感染者与健康献血者的ALT水平差异,评估ALT的诊断价值。结果共检出27例OBI感染者(检出率0.13‰)。所有OBI感染者ALT均≤50 U/L(符合献血标准),其中位数为20 U/L,显著高于健康献血者(中位数为18 U/L,P<0.05)。ROC曲线分析显示,ALT诊断OBI的曲线下面积(area under the curve,AUC)为0.641(95%置信区间:0.532~0.750),最佳检测阈值为17 U/L时,灵敏度77.8%、特异度49.3%。虽然OBI感染者ALT水平存在轻度异常趋势,但ALT单独用于筛查OBI的效力不足。OBI感染者病毒载量与ALT无线性关联(R^(2)=0.0421)。结论本研究显示ALT对OBI的筛查价值有限,无法有效区分OBI与健康人群。建议结合病毒核酸检测技术提高OBI检出率,优化或取消ALT筛查阈值,以减少健康献血者资源的浪费。
基金Supported by the National Natural Foundation of China(No.69672029 and No.69772021)
文摘This paper presents a minimum error thresholding (MET) algorithm under the hypothesis that the gray level histogram of SAR image fits to a mixture model of shifted Rayleigh distribution. This algorithm is applied to real SAR images and compared with traditional Otsu algorithm and other MET algorithms based on various models of histogram. The hypothesis of using Rayleigh distribution model is confirmed by Kolmogorov-Smirnov testing and the comparison results obtained show that the proposed new algorithm has good performance in thresholding SAR images.
文摘It is demonstrated that inherent coating adhesion and damage threshold are correlated for Ta2O5 and HfO2 coatings widely used in optoelectronic devices. By utilizing a newly proposed 1-h boiling water test combined with the optical aging under high-power laser irradiation, we show that an optical coating that survives the 1-h boiling water test withstands the damage threshold, ensuring the field service life even in harsh environments. Besides the standard evaluation methods, which may have limitations for applications required in harsh environments, the 1-h boiling water test can serve as an alternative method of reliability assessment for optical coatings. A heuristics herein can be used as a gating item for qualification of optical coatings for various applications.
文摘Objective: To improve the detecting accuracy of chromosomal aneuploidy of fetus by non-invasive prenatal testing (NIPT) using next generation sequencing data of pregnant women’s cell-free DNA. Methods: We proposed the multi-Z method which uses 21 z-scores for each autosomal chromosome to detect aneuploidy of the chromosome, while the conventional NIPT method uses only one z-score. To do this, mapped read numbers of a certain chromosome were normalized by those of the other 21 chromosomes. Average and standard deviation (SD), which are used for calculating z-score of each sample, were obtained with normalized values between all autosomal chromosomes of control samples. In this way, multiple z-scores can be calculated for 21 autosomal chromosomes except oneself. Results: Multi-Z method showed 100% sensitivity and specificity for 187 samples sequenced to 3 M reads while the conventional NIPT method showed 95.1% specificity. Similarly, for 216 samples sequenced to 1 M reads, Multi-Z method showed 100% sensitivity and 95.6% specificity and the conventional NIPT method showed a result of 75.1% specificity. Conclusion: Multi-Z method showed higher accuracy and robust results than the conventional method even at low coverage reads.
