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用于检测过硼酸根离子的新型比值式荧光探针 被引量:3
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作者 臧启光 陈颂 +2 位作者 侯志林 李娟 刘又年 《分析化学》 SCIE EI CAS CSCD 北大核心 2014年第1期118-122,共5页
设计合成了一种基于过硼酸根(BO3^-)催化酯键水解机理的新型比值式荧光探针。此探针在pH=7.4的生理环境下,在BO3^-的存在时,其荧光发射光谱由419nm红移至552nm。利用这一特性,采用此荧光探针对BO3^-进行定量检测,检测的线性响应... 设计合成了一种基于过硼酸根(BO3^-)催化酯键水解机理的新型比值式荧光探针。此探针在pH=7.4的生理环境下,在BO3^-的存在时,其荧光发射光谱由419nm红移至552nm。利用这一特性,采用此荧光探针对BO3^-进行定量检测,检测的线性响应范围为0.1~4.0mmol/L,检出限为7.8μmol/L。且对常见阴离子及氧化性试剂有较好的选择性。通过对响应前后分子的能级计算,解释了分子内电荷转移机理(ICT)导致的光谱红移现象。 展开更多
关键词 荧光探针 过硼酸根 比值式
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基于吲哚半花菁结构的比值式pH荧光探针 被引量:2
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作者 曾科 周彬彬 龙一国 《应用化工》 CAS CSCD 2014年第8期1526-1530,共5页
设计合成了一种基于半花菁类结构的比值式pH荧光探针,能快速响应pH值的变化,对常见金属离子具有较好的抗干扰能力。在pH 5.4~7.2范围内,随着pH值升高,探针紫外可见吸收光谱最大吸收波长由422 nm红移至525 nm。激发波长为430 nm时... 设计合成了一种基于半花菁类结构的比值式pH荧光探针,能快速响应pH值的变化,对常见金属离子具有较好的抗干扰能力。在pH 5.4~7.2范围内,随着pH值升高,探针紫外可见吸收光谱最大吸收波长由422 nm红移至525 nm。激发波长为430 nm时,荧光发射峰峰高之比( I513 nm/I553 nm )与pH值的变化有良好的线性关系,可用于检测生物体内pH的变化。HeLa细胞毒性试验表明,该探针具有较低的细胞毒性。 展开更多
关键词 花菁染料 pH探针 荧光 比值式
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谈一谈“婴幼儿谷类辅助食品”风险监测项目“反式脂肪酸/总脂肪酸比值”的参考值 被引量:1
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作者 林旭彬 《科技视界》 2015年第36期326-326,共1页
本文通过从"婴幼儿谷类辅助食品"产品特性等方面的论述,指出风险监测项目"反式脂肪酸/总脂肪酸比值的参考值定为≤3%"是不能真正反映"婴幼儿谷类辅助食品"产品的特性,是不合理的;为了片面追求比值,造成... 本文通过从"婴幼儿谷类辅助食品"产品特性等方面的论述,指出风险监测项目"反式脂肪酸/总脂肪酸比值的参考值定为≤3%"是不能真正反映"婴幼儿谷类辅助食品"产品的特性,是不合理的;为了片面追求比值,造成对身体有害的反式脂肪酸却增加很多,也没有取得社会效益,是没有意义。 展开更多
关键词 婴幼儿谷类辅助食品 脂肪酸/总脂肪酸比值
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一种新的电力变压器微机保护方案研究
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作者 雷宇凌 雷宇壮 《四川电力技术》 2005年第4期32-34,共3页
针对目前微机变压器保护中广泛使用的二次谐波制动原理的缺陷,介绍一种新的微机变压器保护方案。该方案将比值式电流制动作为变压器的主保护方案。利用变压器处于不同状态时差动电流的不同特性再引入不同的辅助判据进行鉴别。实验表明,... 针对目前微机变压器保护中广泛使用的二次谐波制动原理的缺陷,介绍一种新的微机变压器保护方案。该方案将比值式电流制动作为变压器的主保护方案。利用变压器处于不同状态时差动电流的不同特性再引入不同的辅助判据进行鉴别。实验表明,其具有较好的动作特性。 展开更多
关键词 变压器微机保护 励磁涌流 比值式制动 内部故障 外部故障
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基于BODIPY荧光染料的pH荧光探针
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作者 袁少华 赵诺男 +3 位作者 王飞翼 杨桂春 任君 陈祖兴 《湖北大学学报(自然科学版)》 CAS 2018年第6期551-556,共6页
生物系统、化学反应、环境体系和工业废水等pH值的精密检测是一项非常重要的工作.发展一些能够对pH值进行精确测量的方法将具有非常重要的意义.荧光分子探针以其所具有的便捷性、超高灵敏度、微量检测和较低的生物侵害性等优势成为一种... 生物系统、化学反应、环境体系和工业废水等pH值的精密检测是一项非常重要的工作.发展一些能够对pH值进行精确测量的方法将具有非常重要的意义.荧光分子探针以其所具有的便捷性、超高灵敏度、微量检测和较低的生物侵害性等优势成为一种重要的检测工具.本研究以吲哚衍生物和苯甲酰吡咯氯为原料,通过缩合反应和脱甲基反应得到HO-BODIPY-Cl,然后引入供电子基团吗啡啉,得到新型比值式检测pH的荧光探针HO-BODIPY-N,该探针能够在纯水体系中对9. 06 11. 76范围内的pH值进行精确检测,并成功实现了裸眼观测探针溶液颜色随pH值变化的可逆切换(红/蓝),证明了该探针在检测pH时具有较高的便捷性和较强的可重复利用性.我们期望该工作能够对pH相关的研究工作提供一些参考. 展开更多
关键词 荧光探针 BODIPY PH值 比值式 高灵敏性
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宇宙中的第五种力——旋转力
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作者 徐衡 《太原理工大学学报》 CAS 2000年第6期668-671,675,共5页
实验发现引力异常现象 ,它引起各国科学家的注意 ,却找不到科学的解释。通过对宇宙中有形运动物质绕系心公转而且自转这种普遍现象的研究 ,发现在宇宙中除已知的 4种力外 ,还存在着第五种无形的旋转力 ;得到旋转力作用于有形物质的数学... 实验发现引力异常现象 ,它引起各国科学家的注意 ,却找不到科学的解释。通过对宇宙中有形运动物质绕系心公转而且自转这种普遍现象的研究 ,发现在宇宙中除已知的 4种力外 ,还存在着第五种无形的旋转力 ;得到旋转力作用于有形物质的数学表达式——旋转力定理 ,也得到旋转力与万有引力的能量比值式 ( 4e3) /(π3R3)及形态比值常数为 4 /π3.应用定理、能量比值式、形态比值常数对地球绕太阳形态变化进行计算时 。 展开更多
关键词 宇宙 地球 旋转力 旋转力定理 能量比值式
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Numerical Investigation on Effect of Vapor Split Ratio to Performance and Operability for Dividing Wall Column 被引量:4
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作者 Laleh Torab Maralani 袁希钢 +2 位作者 罗祎青 龚超 余国琮 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第1期72-78,共7页
Operability problem of dividing wall column (DWC) raised by vapor split was investigated by numerically analyzing four cases defined by different compositions of a three-component mixture. DWCs were firstly designed f... Operability problem of dividing wall column (DWC) raised by vapor split was investigated by numerically analyzing four cases defined by different compositions of a three-component mixture. DWCs were firstly designed for each case by optimizing the vapor split to the two sides of the dividing wall, and then their feasibilities and total annual costs in operation were evaluated against different vapor split ratios. The analysis on the operability of the DWC for four cases was made based on two scenarios: (1) vapor split is shifted by the vapor resistance difference between the column sections in the two sides of the dividing wall and (2) the feed composition is changed. It was demonstrated that the positioning of the dividing wall and the decision on the vapor split may affect significantly the operability of a DWC. 展开更多
关键词 dividing wall column vapor split ratio OPERABILITY
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Vertical-to-horizontal response spectral ratio for offshore ground motions:Analysis and simplified design equation 被引量:12
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作者 陈宝魁 王东升 +2 位作者 李宏男 孙治国 李超 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第1期203-216,共14页
In order to study the differences in vertical component between onshore and offshore motions,the vertical-to-horizontal peak ground acceleration ratio(V/H PGA ratio) and vertical-to-horizontal response spectral ratio(... In order to study the differences in vertical component between onshore and offshore motions,the vertical-to-horizontal peak ground acceleration ratio(V/H PGA ratio) and vertical-to-horizontal response spectral ratio(V/H) were investigated using the ground motion recordings from the K-NET network and the seafloor earthquake measuring system(SEMS).The results indicate that the vertical component of offshore motions is lower than that of onshore motions.The V/H PGA ratio of acceleration time histories at offshore stations is about 50%of the ratio at onshore stations.The V/H for offshore ground motions is lower than that for onshore motions,especially for periods less than 0.8 s.Furthermore,based on the results in statistical analysis for offshore recordings in the K-NET,the simplified V/H design equations for offshore motions in minor and moderate earthquakes are proposed for seismic analysis of offshore structures. 展开更多
关键词 offshore ground motion vertical component simplified design equation vertical-to-horizontal response spectral ratio (V/H) vertical-to-horizontal peak ground acceleration ratio (V/H PGA ratio) K-NET network seafloor earthquake measuring system (SEMS)
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Study on algorithm of dynamic uncalibrated eye-in-hand visual servoing system
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作者 赵杰 李牧 +2 位作者 闫继红 李戈 曹宇 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第4期445-449,共5页
Currently, most visual servoing system must be calibrated, while it is impossible to calibrate cameras and robot models precisely in industrial practice, so a novel dynamic uncalibrated eye-in-hand visual servoing sys... Currently, most visual servoing system must be calibrated, while it is impossible to calibrate cameras and robot models precisely in industrial practice, so a novel dynamic uncalibrated eye-in-hand visual servoing system of tracking a moving target is proposed. The method does not require calibration of camera and robot kinematic models. Vision guided algorithm for tracking dynamic image is developed through minimizing nonlinear objective function. For the large residual has not been approximated in dynamic environment and the change of composite image Jacobian with time increment has not been computed in visual servoing system now,large residuals are dynamic approximated and the change of composite image Jacobian at each iterative step is computed. Simulation results demonstrate the validity of these approaches. 展开更多
关键词 uncalibrated visual servoing composite image Jacobian approximation large residual estimation change of Jacobian with time
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OUTLIER TEST IN RANDOMIZED LINEAR MODEL 被引量:2
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作者 XIANGLIMING SHILEI 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1994年第1期65-75,共11页
In this papert we give an approach for detecting one or more outliers inrandomized linear model.The likelihood ratio test statistic and its distributions underthe null hypothesis and the alternative hypothesis are giv... In this papert we give an approach for detecting one or more outliers inrandomized linear model.The likelihood ratio test statistic and its distributions underthe null hypothesis and the alternative hypothesis are given. Furthermore,the robustnessof the test statistic in a certain sense is proved. Finally,the optimality properties of thetest are derived. 展开更多
关键词 Randomized Linear Model.Outliers Likelihood Ratio Test UNIFORMLY
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A Qualitative Analysis of How and Why People Use SNSs: A Cross-cultural Comparison of Korea and the U.S.
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作者 Jinnie Jin Young Yoo 《Journalism and Mass Communication》 2012年第6期701-716,共16页
While participation in Social Network Sites (SNSs) has grown rapidly in recent years and is a highly popular and global phenomenon, only few research examined how the different cultural values and attitudes impact t... While participation in Social Network Sites (SNSs) has grown rapidly in recent years and is a highly popular and global phenomenon, only few research examined how the different cultural values and attitudes impact the way people adopt and use this new media platform. Employing qualitative approach, this study attempts to uncover the cross-cultural differences in motivations and behavioral patterns for using SNSs among the Korean and American users. The finding of this study shows the explicit differences in the motivations and strategies for using SNSs between Korean and American users, which is supported by the independent and interdependent self-construals theory proposed by Markus and Kitayama (1991). The motivational themes and usage patterns emerged from Korean participants are more other- or relationship-focused, pursuing social/emotional support, while those of Americans are more ego- or self-focused, pertaining to entertainment or information seeking. 展开更多
关键词 Social Network Sites (SNS) qualitative CROSS-CULTURAL MOTIVATION SELF-CONSTRUAL
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On the Ratio Inequalities for Locally Square Integrable Martingales
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作者 任耀峰 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2004年第1期64-69,共6页
In this paper, we establish some ratio inequalities for locally square inte-grable martingales, and give some extensions of the related results for continuous local martingales.
关键词 stopping time locally square integrable martingale SUPERMARTINGALE ratio inequality.
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Comparison of Some Means
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作者 刘证 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2002年第4期583-588,共6页
The known results on comparison of extended mean values are used to compare power means, Stolarsky means and Heron mean. Some proofs of well known results are simplified with several new results obtained.
关键词 extended mean value power mean Stolarsky mean Heron mean
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Eigenvalue Comparison Theorems on Finsler Manifolds 被引量:1
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作者 Songting YIN Qun HE 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2015年第1期31-44,共14页
Cheng-type inequality, Cheeger-type inequality and Faber-Krahn-type inequality are generalized to Finsler manifolds. For a compact Finsler manifold with the weighted Ricci curvature bounded from below by a negative co... Cheng-type inequality, Cheeger-type inequality and Faber-Krahn-type inequality are generalized to Finsler manifolds. For a compact Finsler manifold with the weighted Ricci curvature bounded from below by a negative constant, Li-Yau's estimation of the first eigenvalue is also given. 展开更多
关键词 The first eigenvalue Finsler-Laplacian Ricci curvature S-CURVATURE
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