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Analysis of Codon Usage Pattern of Banana Basic Secretory Protease Gene 预览
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作者 Mensah Raphael Anue Sun Xueli +1 位作者 Cheng Chunzhen Lai Zhongxiong 《Plant Diseases and Pests(植物病虫害研究:英文版)》 CAS 2019年第1期1-4,9共5页
[Objective]The objective of this study was to understand the codon usage bias pattern of banana pathogenesis-related 17 gene,Basic Secretory Protease gene(MaBSP).[Method]Relative codon usage patterns of MaBSP were cal... [Objective]The objective of this study was to understand the codon usage bias pattern of banana pathogenesis-related 17 gene,Basic Secretory Protease gene(MaBSP).[Method]Relative codon usage patterns of MaBSP were calculated using the software CodonW version 1.4.2.and the web-based tool(http://kazusa.or.jp/codon/).[Result]Our findings showed that C-ended and G-ended codons were the most preferential except the TER codon UGA which was coded for by just one codon.The ENc value,relationship between AT bias and GC bias,Random synonymous codon usage(RSCU)and CAI all showed that codon bias usage existed in MaBSP gene.[Conclusion]The codon usage patterns of MaBSP gene is principally influenced by natural selection in the third position.However,other multiple factors also influence this pattern. 展开更多
关键词 CODON USAGE CODON BIAS Natural selection Mutation BIAS Random synonymous CODON USAGE Pathogenesis-related(PR)gene
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Common biases in client involved decision-making in the AEC industry
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作者 Sujesh F.SUJAN Arto KIVINIEMI +2 位作者 Steve W. JONES Jacqueline M. WHEATHCROFT Eilif HJELSETH 《工程管理前沿:英文版》 2019年第2期221-238,共18页
Understanding of the constitution of client involved decisions is important for future improvements of the processes. Significant decisions in construction projects are reliant on heuristic processes where assumptions... Understanding of the constitution of client involved decisions is important for future improvements of the processes. Significant decisions in construction projects are reliant on heuristic processes where assumptions are developed from past experience. The paper presents a methodology to collect empirical data in an unstructured manner utilizing participant intuition and experience regarding project level collaboration, a term easily understood by practitioners. Empirical data collected from 6 focus group discussions in Norway and 18 individual interviews in Finland is associated with biases in decision making aimed at bridging the gap of understanding and literature's insufficient coverage. An analytic framework was developed to suit the diverse emergence of concepts to allow application of psychological principles in a structured manner to empirical data. The paper contributes by identifying types of cognitive and motivational biases in client involved decisions. The biases are found to be alleviated by one another depending on the particular application of the decision. Findings suggest that normative beliefs exist developed from past experience and habitual thinking. A number of emerged biases in this domain are alleviated from normative beliefs which are discussed in this paper. 展开更多
关键词 collaboration construction INDUSTRY social science DECISION-MAKING CLIENT cognitive BIAS motivational BIAS HOLISTIC analysis human factor
Rural Migrant Workers' Welfare and Labor Protection in China under the Labor Contract Law 预览
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作者 杜鹏程 徐舒 吴明琴 《中国经济学人:英文版》 2019年第2期81-94,共14页
This paper employs difference-in-differences(DID)approach to evaluate the effects of China’s Labor Contract Law’s implementation on rural migrant workers’welfare.Our findings suggest that the Labor Contract Law has... This paper employs difference-in-differences(DID)approach to evaluate the effects of China’s Labor Contract Law’s implementation on rural migrant workers’welfare.Our findings suggest that the Labor Contract Law has reduced rural migrant workers’ working hours by 23%,and increased their social insurance coverage by 10% to 26%.This conclusion holds true after removal of sample selection bias and policy expectation factor.Further analysis reveals that Labor Contract Law’s welfare improvement effect was more significant for migrant workers in regions where workers had poor bargaining power.Other economic factors during the same period of time did not affect the law’s labor protection effect.Our findings give a clear answer to controversies over whether the Labor Contract Law can improve labor rights for underprivileged groups,and are of reference value for developing labor protection systems. 展开更多
关键词 LABOR PROTECTION MIGRANT workers’welfare SELECTIVE BIAS
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不同来源允许总误差和偏移在西格玛性能评价中的差异 预览
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作者 刘慧玲 王冰 +2 位作者 张颖 朱佳雯 欧阳清慧 《检验医学》 CAS 2019年第7期648-650,共3页
目的探讨由不同来源的允许总误差(TEa)和偏移(Bias)计算出的西格玛(σ)水平的差异对评价临床生化指标检测质量的影响。方法收集绵阳市第三人民医院检验科2017年的室内质量控制(IQC)数据,计算不精密度(CV)。根据国家卫生健康委临床检验中... 目的探讨由不同来源的允许总误差(TEa)和偏移(Bias)计算出的西格玛(σ)水平的差异对评价临床生化指标检测质量的影响。方法收集绵阳市第三人民医院检验科2017年的室内质量控制(IQC)数据,计算不精密度(CV)。根据国家卫生健康委临床检验中心2017年室间质量评价(EQA)和正确度验证计划数据计算Bias。TEa来源分别为国家标准GB/T 20470—2006和行业标准WS/T 403—2012。计算参加正确度验证计划的12个生化项目的σ值,利用SPSS 19.0软件对4组σ值进行两两比较。结果按照行业标准,丙氨酸氨基转移酶、总蛋白、尿素、葡萄糖4个项目的σ水平不佳。TEa来源相同、Bias来源不同,计算出的σ值差异无统计学意义(P>0.05);不同来源TEa计算出的σ水平差异有统计学意义(P<0.05)。结论实验室不同来源的Bias对σ值影响不大,不同来源的TEa会计算出不同的σ值。推荐实验室选择行业标准来源的TEa,以正确度验证的结果为Bias来计算项目的σ值,若条件不允许,也可以EQA结果为Bias参与计算。 展开更多
关键词 允许总误差 偏移 西格玛水平 性能评价
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糖化血红蛋白不同检测系统的偏倚评估和方法学比对研究 预览
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作者 李熙建 张婷婷 +3 位作者 龙琴 谭扬 谭同均 彭宇生 《现代医药卫生》 2019年第1期48-51,共4页
目的比对分析并评估离子交换高效液相色谱法(IE-HPLC)和免疫比浊法的偏倚,为提高糖化血红蛋白(HbA1c)检测质量、推进HbA1c标准化提供依据。方法依据美国临床和实验室标准化协会(CLSI)EP9-A3文件进行方法学比对和偏倚评估。方法学比对前... 目的比对分析并评估离子交换高效液相色谱法(IE-HPLC)和免疫比浊法的偏倚,为提高糖化血红蛋白(HbA1c)检测质量、推进HbA1c标准化提供依据。方法依据美国临床和实验室标准化协会(CLSI)EP9-A3文件进行方法学比对和偏倚评估。方法学比对前进行参比方法正确度验证和试验方法精密度验证。采用经美国国家糖化血红蛋白标准化计划(NGSP)样本赋值传递的新鲜全血实施校准,校准后进行可比性验证。量值溯源分析结果满足临床需要。结果2种试验方法的批内、批间的高、中、低值变异系数均小于2.0%;正确度评估中,检测结果均在靶值×(±6%)内;IE-HPLC与免疫比浊法的医学决定水平偏倚分别为0.1584%和0.1488%,用经NGSP赋值传递的新鲜全血校准后,偏倚为0.0197%和0.0185%,均小于美国病理学家协会2015年能力验证允许误差。结论不同方法对HbA1c的测定结果可能存在差异,但2种方法测定HbA1c的精密度符合要求,检测的正确度水平符合标准,采用赋值传递的新鲜全血对不可比的方法实施校准,可实现检验结果的可比性,完全满足临床对HbA1c检测要求,临床实验室需共同努力来实现我国HbA1c检测的标准化。 展开更多
关键词 糖化血红蛋白 比对研究 方法学 偏倚 溯源性 检验
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基于多种偏置项融合时间信息的协同过滤算法 预览
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作者 李明秀 王淑军 +1 位作者 贾如 陈立荣 《软件工程》 2019年第6期17-21,12共6页
协同过滤算法是实现推荐系统最重要的技术之一。随着时间的推移,用户对物品的偏好会不断地发生变化,物品自身的流行度也会随时间不断地发生变化。目前常用的推荐算法如基于邻域的协同过滤算法itemCF、userCF和隐语义模型算法FunkSVD、Bi... 协同过滤算法是实现推荐系统最重要的技术之一。随着时间的推移,用户对物品的偏好会不断地发生变化,物品自身的流行度也会随时间不断地发生变化。目前常用的推荐算法如基于邻域的协同过滤算法itemCF、userCF和隐语义模型算法FunkSVD、BiasSVD、SVD++都没有考虑到时间因素对推荐系统推荐质量的影响。而时间信息是一种非常重要的上下文信息,应该在算法中加以利用。本文使用Sigmoid函数和流行度函数将时间因素融入到了BiasSVD算法中,成功的设计出了一个融合时间信息的新算法Time-BiasSVD。在MovieLens数据集上的验证结果表明:该算法与已有协同过滤算法,以及融合时间信息的算法timeSVD++相比,能更准确地预测用户实际评分,提高推荐系统的推荐质量。 展开更多
关键词 偏置项 协同过滤 时间因素 SIGMOID函数 流行度函数
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利用先验重力场模型求定GOCE卫星重力梯度仪校准参数 预览 被引量:1
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作者 瞿庆亮 常晓涛 +1 位作者 于胜文 朱广彬 《测绘学报》 EI CSCD 北大核心 2019年第2期176-184,共9页
重力梯度仪校准参数的确定是GOCE重力梯度观测数据处理的关键环节。本文对GOCE卫星重力梯度观测值中的时变信号与粗差进行了分析,利用高精度全球重力场模型,确定了GOCE重力梯度观测值各分量的尺度因子与偏差,并对校准结果进行了精度评... 重力梯度仪校准参数的确定是GOCE重力梯度观测数据处理的关键环节。本文对GOCE卫星重力梯度观测值中的时变信号与粗差进行了分析,利用高精度全球重力场模型,确定了GOCE重力梯度观测值各分量的尺度因子与偏差,并对校准结果进行了精度评定。结果表明,在测量带宽内,海潮对重力梯度观测值影响在mE量级,与重力梯度仪的精度水平相当,陆地水等非潮汐重力场时变信号略小于海潮,量级约为10^-4E;各分量重力梯度观测值的粗差比例均大于0.2%;除EGM96模型外的其他模型对GOCE重力梯度仪进行校准后,Vxx、Vyy、Vzz、Vyz分量上尺度因子的稳定性均在10^-4量级,Vxz分量能达到10^-5量级,Vxy分量为10^-2量级,这与梯度观测值各分量的精度水平一致。 展开更多
关键词 GOCE 重力梯度 校准 尺度因子 偏差
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Spin glassy behavior and large exchange bias effect in cubic perovskite Ba0.8Sr0.2FeO3-δ
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作者 刘宇轩 刘哲宏 +5 位作者 叶旭斌 申旭东 王潇 周博文 周光辉 龙有文 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第6期433-437,共5页
A single-phase iron oxideBa0.8Sr0.2FeO3-δwith a simple cubic perovskite structure in Pm-3 m symmetry is successfully synthesized by a solid-state reaction method in O2 flow. The oxygen content is determined to be abo... A single-phase iron oxideBa0.8Sr0.2FeO3-δwith a simple cubic perovskite structure in Pm-3 m symmetry is successfully synthesized by a solid-state reaction method in O2 flow. The oxygen content is determined to be about 2.81, indicating the formation of mixed Fe3+and Fe4+charge states with a disorder fashion. As a result, the compound shows small-polaron conductivity behavior, as well as spin glassy features arising from the competition between the ferromagnetic interaction and the antiferromagnetic interaction. Moreover, the competing interactions also give rise to a remarkable exchange bias effect in Ba0.8 Sr0.2 FeO2.81, providing an opportunity to use it in spin devices. 展开更多
关键词 high-pressure synthesis exchange BIAS effect SPIN GLASS
利用Westgard 6σ规则建立生化28个检测项目的个性化质控方案 预览
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作者 陈荣贵 张勇刚 黄荣萍 《检验医学与临床》 CAS 2019年第18期2630-2633,共4页
目的 利用韦斯特加氏六西格玛(Westgard 6σ)规则建立生化实验室检测项目的个性化质控方案.方法 将实验室2017年参加原卫生部临检中心(NCCL)室间质评的28个项目回报数据进行汇总,通过线性回归计算偏倚(Bias);通过加权法获得2017年全年... 目的 利用韦斯特加氏六西格玛(Westgard 6σ)规则建立生化实验室检测项目的个性化质控方案.方法 将实验室2017年参加原卫生部临检中心(NCCL)室间质评的28个项目回报数据进行汇总,通过线性回归计算偏倚(Bias);通过加权法获得2017年全年实验室内28个项目的变异系数(CV);根据公式σ=[允许总误差(%)-|Bias(%)|]/[CV(%)],计算出各个检测项目中、高值浓度的σ值,利用Westgard 6σ规则来确定28个项目及中、高值质控品的质控规则.结果 28个检验项目中、高值浓度控制处的σ值参差不齐.高值≥6σ的项目15个(53.57%),5σ~<6σ的项目4个(14.29%),4σ~<5σ的项目2个(7.14%),3σ~<4σ的项目6个(21.43%),<3σ的项目1个(3.57%);中值≥6σ的项目11个(39.29%),5σ~<6σ的项目7个(21.00%),4σ~<5σ的项目1个(3.57%),3σ~<4σ的项目5个(32.14%),<3σ的项目4个(14.29%).结论 不同检测项目、同一项目不同浓度控制处应根据其σ值采取相对应的质控方案;<3σ的项目必须查找和分析原因并采取纠正措施,确保满足性能要求;Westgard 6σ规则是实验室制订个性化的质控方案的便捷途径. 展开更多
关键词 六西格玛 总误差 偏倚 变异系数 质控规则 线性回归
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外场作用下铁电/铁磁双层膜的极化磁化性质 预览
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作者 郑伟 杜安 《物理学报》 SCIE EI CAS CSCD 北大核心 2019年第3期247-253,共7页
建立了铁电/铁磁双层膜模型,铁电层的电矩用连续标量描述,而铁磁层的自旋应用经典矢量描述.利用蒙特卡罗方法模拟了体系的热力学性质和极化、磁化行为.给出了零场下体系的内能、比热、极化和磁化随温度变化的关系,并分别研究了体系在外... 建立了铁电/铁磁双层膜模型,铁电层的电矩用连续标量描述,而铁磁层的自旋应用经典矢量描述.利用蒙特卡罗方法模拟了体系的热力学性质和极化、磁化行为.给出了零场下体系的内能、比热、极化和磁化随温度变化的关系,并分别研究了体系在外磁场和外电场下的极化和磁化行为.模拟结果表明,双层膜体系的内能、比热、极化和磁化性质因层间耦合系数的不同而明显不同,当界面耦合较弱时,双层膜表现出各自的热力学性质,当层间耦合增强到一定程度时,双层膜耦合为一个整体,表现出统一的热力学性质.该双层膜在外场中形成电滞回线和磁滞回线,并表现出偏置特性,界面耦合强度和温度影响滞后回线和偏置现象. 展开更多
关键词 极化强度 磁化强度 滞后回线 偏置现象
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Assessing the Performance of Separate Bias Kalman Filter in Correcting the Model Bias for Estimation of Soil Moisture Profiles
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作者 Bangjun CAO Fuping MAO +2 位作者 Shuwen ZHANG Shaoying LI Tian WANG 《气象学报:英文版》 SCIE CSCD 2019年第3期519-527,共9页
The performance of separate bias Kalman filter (SepKF) in correcting the model bias for the improvement of soil moisture profiles is evaluated by assimilating the near-surface soil moisture observations into a land su... The performance of separate bias Kalman filter (SepKF) in correcting the model bias for the improvement of soil moisture profiles is evaluated by assimilating the near-surface soil moisture observations into a land surface model (LSM). First, an observing system simulation experiment (OSSE) is carried out, where the true soil moisture is known, two types of model bias (i.e., constant and sinusoidal) are specified, and the bias error covariance matrix is assumed to be proportional to the model forecast error covariance matrix with a ratio λ. Second, a real assimilation experiment is carried out with measurements at a site over Northwest China. In the OSSE, the soil moisture estimation with the SepKF is improved compared with ensemble Kalman filter (EnKF) without the bias filter, because SepKF can properly correct the model bias, especially in the situation with a large model bias. However, the performance of SepKF becomes slightly worse if the constant model bias increases or temporal variability of the sinusoidal model bias becomes large. It is suggested that the ratio λ should be increased (decreased) in order to improve the soil moisture estimation if temporal variability of the sinusoidal model bias becomes high (low). Finally, the assimilation experiment with real observations also shows that SepKF can further improve the estimation of soil moisture profiles compared with EnKF without the bias correction. 展开更多
关键词 soil moisture BIAS correction ENSEMBLE KALMAN filter (EnKF) Noah-MP
A general framework for frequentist model averaging In Celebration of Professor Lincheng Zhao’s 75th Birthday
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作者 Priyam Mitra Heng Lian +2 位作者 Ritwik Mitra Hua Liang Min-ge Xie 《中国科学:数学英文版》 SCIE CSCD 2019年第2期205-226,共22页
Model selection strategies have been routinely employed to determine a model for data analysis in statistics, and further study and inference then often proceed as though the selected model were the true model that we... Model selection strategies have been routinely employed to determine a model for data analysis in statistics, and further study and inference then often proceed as though the selected model were the true model that were known a priori. Model averaging approaches, on the other hand, try to combine estimators for a set of candidate models. Specifically, instead of deciding which model is the ’right’ one, a model averaging approach suggests to fit a set of candidate models and average over the estimators using data adaptive weights.In this paper we establish a general frequentist model averaging framework that does not set any restrictions on the set of candidate models. It broaden, the scope of the existing methodologies under the frequentist model averaging development. Assuming the data is from an unknown model, we derive the model averaging estimator and study its limiting distributions and related predictions while taking possible modeling biases into account.We propose a set of optimal weights to combine the individual estimators so that the expected mean squared error of the average estimator is minimized. Simulation studies are conducted to compare the performance of the estimator with that of the existing methods. The results show the benefits of the proposed approach over traditional model selection approaches as well as existing model averaging methods. 展开更多
关键词 ASYMPTOTIC distribution BIAS variance trade-off local mis-specification model AVERAGING ESTIMATORS optimal weight selection
Optoelectronic properties analysis of silicon light-emitting diode monolithically integrated in standard CMOS IC
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作者 陈彦旭 许栋梁 +6 位作者 徐开凯 张宁 刘斯扬 赵建明 罗谦 Lukas W.Snyman Jacobus W.Swart 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第10期115-120,共6页
Si p^+n junction diodes operating in the mode of avalanche breakdown are capable of emitting light in the visible range of 400-900 nm. In this study, to realize the switching speed in the GHz range, we present a trans... Si p^+n junction diodes operating in the mode of avalanche breakdown are capable of emitting light in the visible range of 400-900 nm. In this study, to realize the switching speed in the GHz range, we present a transient model to shorten the carrier lifetime in the high electric field region by accumulating carriers in both p and n type regions. We also verify the optoelectronic characteristics by disclosing the related physical mechanisms behind the light emission phenomena. The emission of visible light by a monolithically integrated Si diode under the reverse bias is also discussed. The light is emitted as spatial sources by the defects located at the p-n junction of the reverse-biased diode. The influence of the defects on the electrical behavior is manifested as a current-dependent electroluminescence. 展开更多
关键词 SILICON LIGHT-EMITTING DIODE REVERSE BIAS ELECTRO-OPTIC modulation
Large lattice mismatch induced perpendicular magnetic anisotropy and perpendicular exchange bias in CoPt/FeMn bilayer films
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作者 PAN ChunJiao GAO TengHua +4 位作者 ITOGAWA Nobuhide HARUMOTO Takashi ZHANG ZhengJun NAKAMURA Yoshio SHI Ji 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第11期2009-2013,共5页
Perpendicular magnetic anisotropy and perpendicular exchange bias of CoPt/FeMn bilayers fabricated by de magnetron sputtering were investigated in this work.Magnetic anisotropy,showing strong dependence on thickness o... Perpendicular magnetic anisotropy and perpendicular exchange bias of CoPt/FeMn bilayers fabricated by de magnetron sputtering were investigated in this work.Magnetic anisotropy,showing strong dependence on thickness of CoPt layer,changes from perpendicular magnetic anisotropy(PMA)into in-plane magnetic anisotropy when CoPt layer is thicker than 4.5 nm.The evolution of internal stress with thickness,from tensile to compressive,has been analyzed by sin2Ψmethod using an equal biaxial stress model.Distinctive perpendicular exchange bias(PEB)has been successfully established due to PMA of CoPt and out-of-plane spin component of 3Q-spin-structured FeMn.FeMn thickness dependence of exchange bias field has been systematically investigated. 展开更多
关键词 perpendicular magnetic anisotropy perpendicular exchange bias X-ray technique magnetic materials
GNSS长度测量不确定性试验分析
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作者 刘以旭 曲国庆 +3 位作者 薛树强 苏晓庆 王胜利 齐珂 《测绘科学》 CSCD 北大核心 2019年第5期157-163,共7页
针对GNSS定位结果总是存在点位误差,由此导出的长度测量值为点位误差的非线性映射,对于长距离定位量测,其非线性影响较小,线性化近似一般可以满足精度要求,但对于短距离量测,其非线性影响不容忽略的问题.该文探讨了GNSS长度测量不确定... 针对GNSS定位结果总是存在点位误差,由此导出的长度测量值为点位误差的非线性映射,对于长距离定位量测,其非线性影响较小,线性化近似一般可以满足精度要求,但对于短距离量测,其非线性影响不容忽略的问题.该文探讨了GNSS长度测量不确定性来源,通过单点定位和差分定位试验验证了长度测量不确定性与定位精度、点间距离的关系,测试不同偏差和方差估计公式的适用性.试验表明,对于GNSS高精度、长基线测量,其长度统计偏差可以忽略,且方差为基线向量的方向方差;现有不确定性评估公式在超短基线情形适用性会变差,在这种情形下,试验表明二阶偏差和方差估计更为精确.通过消除长度统计偏差得到无偏估计量,可以有效提高距离量测的可靠性,为提高用户距离量测精度提供有益帮助. 展开更多
关键词 GNSS基线 长度测量 偏差 方差
对青少年音乐教育的几点思考 预览
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作者 刘静 《浙江工商职业技术学院学报》 2019年第2期95-96,共2页
如今,青少年的音乐培训和教育已经是一种普遍现象。但纵观现在的青少年音乐教育,可以看到,教育以学生的音乐知识和技能提升为主,注重音乐教育的实用性,轻忽了音乐对培养青少年的想象力、认知力以及丰富青少年情感的重要作用,因此有必要... 如今,青少年的音乐培训和教育已经是一种普遍现象。但纵观现在的青少年音乐教育,可以看到,教育以学生的音乐知识和技能提升为主,注重音乐教育的实用性,轻忽了音乐对培养青少年的想象力、认知力以及丰富青少年情感的重要作用,因此有必要对此进行分析,并纠偏。 展开更多
关键词 音乐教育 偏差误区 解决措施
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Investigation and active suppression of self-heating induced degradation in amorphous InGaZnO thin film transistors
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作者 张东 武辰飞 +6 位作者 徐尉宗 任芳芳 周东 于芃 张荣 郑有炓 陆海 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第1期575-579,共5页
Self-heating effect in amorphous InGaZnO thin-film transistors remains a critical issue that degrades device performance and stability, hindering their wider applications. In this work, pulsed current–voltage analysi... Self-heating effect in amorphous InGaZnO thin-film transistors remains a critical issue that degrades device performance and stability, hindering their wider applications. In this work, pulsed current–voltage analysis has been applied to explore the physics origin of self-heating induced degradation, where Joule heat is shortly accumulated by drain current and dissipated in repeated time cycles as a function of gate bias. Enhanced positive threshold voltage shift is observed at reduced heat dissipation time, higher drain current, and increased gate width. A physical picture of Joule heating assisted charge trapping process has been proposed and then verified with pulsed negative gate bias stressing scheme, which could evidently counteract the self-heating effect through the electric-field assisted detrapping process. As a result, this pulsed gate bias scheme with negative quiescent voltage could be used as a possible way to actively suppress self-heating related device degradation. 展开更多
关键词 AMORPHOUS INGAZNO thin-film transistor SELF-HEATING effect THRESHOLD voltage shift PULSED negative gate BIAS
Unbalanced International News Flow and News Bias in Western Media 预览
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作者 孟聪 《海外英语》 2019年第9期241-243,共3页
With the rapid development of mass media, a new media age comes into being. Accompanied with the rising of advanced capitalism, the print media brings us a new“mass sphere”. In the field of international journalism ... With the rapid development of mass media, a new media age comes into being. Accompanied with the rising of advanced capitalism, the print media brings us a new“mass sphere”. In the field of international journalism and communication, it is still exist that international news is unbalanced and biased in first world countries’media. However, the imbalance of international public opinion is just a big problem for third world countries. Therefore, it is very necessary and significant to analyze this subject. Starting from the globalization, this paper argues the imbalance and news bias of reporting upon international issues in western media, so as to provide some ideas and promote the better development of the subject. 展开更多
关键词 International NEWS FLOW WESTERN media NEWS BIAS THIRD world COUNTRIES
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Colour-ring wear and loss effects in citizen science mark-resighting studies 预览
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作者 Andrew M.Allen Bruno J.Ens +6 位作者 Martijn van de Pol Henk van der Jeugd Magali Frauendorf Henk-Jan van der Kolk Kees Oosterbeek Jeroen Nienhuis Eelke Jongejans 《鸟类学研究:英文版》 CSCD 2019年第2期148-162,共15页
Background: Ring wear and loss may have important consequences for mark-recapture studies that aim to estimate survival trends. Our study quantifies the rates of wear and loss from a long-running colour-ringing projec... Background: Ring wear and loss may have important consequences for mark-recapture studies that aim to estimate survival trends. Our study quantifies the rates of wear and loss from a long-running colour-ringing project of the Eurasian Oystercatcher (Haematopus ostralegus) in the Netherlands. Methods: Our analysis included 8909 colour-ringed oystercatchers with 118,071 resightings, predominantly ringed and observed by citizen scientists. We quantified how ring wear and loss may vary with ring colour and age, and how this may impact resighting probabilities. We then determined how ring loss may impact survival estimates and resighting probabilities of mark-recapture models by simulating four scenarios of how citizen scientists may resight and report birds with lost colour rings. Results: Annual rates of colour ring loss averaged 2.5% compared with 1% for ring wear, but lost rings also had a higher reporting probability (31.2%) than worn rings (10.3%). Lost rings may not directly impact survival estimates since 50% of oystercatchers with lost rings could still be uniquely identified. Ring wear and loss rapidly increased between 10 and 15 years after ringing. Rates of ring loss were comparable amongst ring colours, but the wear rate appeared higher for red and white rings compared to other colours. Rates of ring wear and loss varied significantly amongst different regions in our study, which were characterised as having different habitat features. Differential rates of ring wear may have important implications for studies conducted over large geographical scales or of multiple species. Conclusions: Based on simulations of ring loss in our population, estimates of apparent survival may be 0.3–1.2% lower whilst the impact of ring wear was deemed even lower. We developed a table of recommendations containing advice for ring fitting, data collection, study design, and mark-recapture analyses, so that future colour-ringing studies can benefit from our experiences in collecting and analysing data of ring wear and loss th 展开更多
关键词 BIAS BIRD migration CITIZEN science Colour-ring Mark-recapture SHOREBIRDS Survival
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干预性队列研究的偏倚控制及其在中医领域的特殊性
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作者 张彤 何文婷 +2 位作者 费宇彤 张颖 杨宇飞 《中医杂志》 CSCD 北大核心 2019年第11期923-927,共5页
作为真实世界研究方法之一,干预性队列研究具有较好的外部真实性,其证据级别仅次于随机对照试验,但最大的争议是偏倚。从研究设计、实施和统计分析的角度探讨如何控制干预性队列研究的常见偏倚。对于选择性偏倚,强调研究者的角色依然是... 作为真实世界研究方法之一,干预性队列研究具有较好的外部真实性,其证据级别仅次于随机对照试验,但最大的争议是偏倚。从研究设计、实施和统计分析的角度探讨如何控制干预性队列研究的常见偏倚。对于选择性偏倚,强调研究者的角色依然是观察者,不应干涉受试者入组意愿;清晰地界定暴露因素及强度有助于研究者判断受试者的最终暴露归属;部分特殊情况下适当采用随机化原则可减少选择性偏倚发生;可采用匹配法增加组间均衡性。对于信息性偏倚,建议采用客观、量化的指标收集资料,若难以实现,则采用“盲法”收集;在广泛收集资料的同时,需注意内容清晰易懂且不可过于繁琐,以免造成不应答偏倚。对于混杂偏倚,需要设置适当、清晰的纳入排除标准,排除已明确的混杂因素;在分析阶段,校正分析、亚组分析、多元回归分析、倾向性评分等都可用于控制偏倚。此外,中医药的干预性队列研究有其自身的特殊性,选择分中心时需注意不同地区的搭配及中医院、西医院及综合医院的搭配等。期待通过控制偏倚、优化设计以增加干预性队列研究的内部真实性及证据级别,使研究者在面对中医治疗这样个体化强、干预体系复杂、无法随机化、存在伦理学问题等情况下,转换研究思路,让更多患者因临床试验获益。 展开更多
关键词 干预性队列研究 偏倚 真实世界研究 方法学
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