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Search Results: 1 - 10 of 242986 matches for " 张倩慈 "
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可加热塑料食品包装中 VOCs 分析
谢利,贾大鹏,继豪,
包装工程 , 2014,
Abstract: 目的 分析可加热塑料食品包装中的挥发性有机物( VOCs) 。 方法 以甲醇为溶剂,配制异丙醇、乙酸乙酯、苯、乙酸丁酯、乙苯、间 / 对二甲苯、邻二甲苯、环己酮的标准溶液, 利用顶空 / 气相色谱-质谱( HS / GC-MS) 技术对 7 种可加热塑料食品包装进行了检测分析,对比加热前后塑料食品包装中VOCs 的变化。 结果 原味酸牛奶包装袋在加热后环己酮的含量明显增加,小酥肉塑料包装盒在加热后异丙醇的含量增加比较明显,粽子塑料包装袋、玉米塑料包装袋、奶茶塑杯、自加热饭盒、微波饭盒在加热前后 VOCs 含量变化不大。 结论 这 7 种包装中的苯类溶剂残留量均超标。
三氧化铀中硝酸根的拉曼光谱定量分析
Determination of NO3 in UO3 by Raman Spectroscopy
 [PDF]

程充, 朱海巧,
Advances in Analytical Chemistry (AAC) , 2016, DOI: 10.12677/AAC.2016.63011
Abstract:
本文建立了拉曼光谱法测定乏燃料后处理三氧化铀产品硝酸根含量的分析方法。选用乙酸为浸取剂和内标,NO3在1048 cm?1处的拉曼峰与CH3COO?在2948 cm?1处的拉曼峰强度比与NO3浓度之间呈现良好的线性关系,r2 = 0.997。对于含有1 mol/L乙酸0.1 mol/L硝酸的混合溶液,6次检测的相对标准偏差不高于1.1%。在加入的乙酸量确定时,根据三氧化铀的样品量以及上述两个拉曼峰的强度比,可获得三氧化铀样品中硝酸根的含量值,方法的检出限为0.005 mol/L。该方法具有测定简单、方便快捷的优点。
A new method via Raman spectroscopy for determination of NO3 in Uranium trioxide was de-veloped. Acetic acid was selected as the leaching agent and the internal standard, and the concen-tration of NO3 can be quantified by the Raman band of NO3 (1048 cm?1) and CH3COO? (2948 cm?1). A good linear relationship is obtained between the Raman Relative Intensity ratio of ? and CH3COO? and the concentration of NO3 in the range of 0.02~1 mol/L, with the r2 = 0.997. The RSD was not more than 1.1% (n = 6) for detection of 0.1 mol/L HNO3 with 1 mol/L acetic acid. When the amount of acetic acid added was determined, the concentration of nitrate in the Uranium trioxide sample could be obtained according to the amount of sample and Raman intensity ratio of these two substances. The detection limit was 0.005 mol/L. With the advantage of simple and rapid detection, this method is applicable for in-situ detection of NO3 in Uranium trioxide samples.
场独立/依存型认知风格对外语学习影响的实证性研究
An Empirical Study on the Influence of Field-Independence/Dependence of Cognitive Styles on Foreign Language Acquisition
 [PDF]

, 王婷婷
Modern Linguistics (ML) , 2015, DOI: 10.12677/ML.2015.34022
Abstract:
近年来语言学家对认知风格与外语学习的相关研究取得了一定的成果,但是实证性研究偏少且结论并未达成一致。本研究采用定量与定性分析结合的方法,分析文/理科大学生(场独立/混合/依存型)认知风格与外语成绩间的相关性及差异性所在。研究发现场独立/混合型认知风格与外语成绩存在相关性,且理科生比文科生的相关性更加显著。外语教学应关注学生认知风格的差异,帮助学习者发挥认知风格的优势从而提高外语学习的能力。
In recent years, linguists have made some achievements in the study on the relationship between cognitive style and foreign language learning, but relatively few empirical studies have been con-ducted and have produced inconsistent results. Based on the analysis of the quantitative and qua-litative data, the present study investigates college students’ preference for field independence/ blend/dependence cognitive style, explores the correlation between cognitive style and foreign language achievement, and examines the differences among students of different majors. The result shows that correlation exists between field independence/blend cognitive style and foreign language achievement, the correlation is more obvious in students majoring in science than those majoring in humanities. Teachers are supposed to focus on students’ different cognitive styles, make teaching plans according to students’ own features, train and help students to exploit their own advantages in cognitive style to the full so as to enhance their abilities in foreign language learning.
红外成像系统探测和辨认目标最大距离的计算方法
考.,ВГ
红外 , 1996,
Abstract:
硅化合物的沸点和若干其他性质的数值关系

化工学报 , 1965,
Abstract: 本文提出一种专用于硅化合物的分子蒸发热(沸点时,一大气压下)估计法。本文试将Joshi沸点-折射关系式应用于硅化合物的分子R_T值的计算,并求出若干原子团及键的R_T值。
苹果红蜘蛛的生物学观察

昆虫学报 , 1974,
Abstract:
基于双重离散小波变换的遥感图像去噪算法

国土资源遥感 , 2015, DOI: 10.6046/gtzyyg.2015.04.03
Abstract: 结合离散小波变换(discretewavelettransform,DWT)与二维多级中值滤波(two-dimensionalmulti-stagemedianfiltering,TMMF)算法,提出了一种遥感图像自适应去噪(de-noising)算法。该算法首先对噪声图像进行单层DWT,分出低频子图像和高频子图像,由于其中的低频子图像包含了大量背景信息,几乎不受噪声的污染,因而变换后仍保持原样无需再处理;对于高频子图像继续执行单层DWT,获得多方向分布的次低频子图像和次高频子图像;然后对次高频子图像采用改进的TMMF算法进行去噪,对次低频子图像采用改进的小波硬阈值函数模型进行噪声抑制;最后对上述去噪后的子图像进行二次小波重构,得到去噪后的遥感图像。采用3景细节信息丰富的遥感图像进行算法性能测试,并与TMMF算法、改进的TMMF算法以及小波变换硬阈值去噪算法进行比较,结果表明,基于双重离散小波变换算法的去噪性能有所提升。
高层次创造性人才的界定与识别

科技进步与对策 , 2010,
Abstract: 在人类不断向前发展的进程中,国与国之间的竞争日益激烈,而高层次创造性人才是一个国家在未来国际竞争中赢得竞争优势的关键所在。对高层次创造性人才的涵义与特征进行了阐释,在此基础上对高层次创造性人才的识别标准与方法进行了分析。高层次人才创造性人才人才识别
知识管理与学习型组织整合阶段的划分

科技进步与对策 , 2008,
Abstract: 知识管理和学习型组织具有不可分割的密切关系,学习型组织是知识管理得以实施的载体之一,而知识管理又是学习型组织的核心和精髓所在。知识管理与学习型组织的整合模式,是组织模式的一种创新。对知识管理和学习型组织的整合动因进行了分析,并对整合阶段进行了划分。知识管理学习型组织组织模式
谢枋得《注解唐诗绝句》版本源流考

安徽大学学报(哲学社会科学版) , 2009,
Abstract: 谢枋得所撰《注解唐诗绝句》是一部评注著作,见解独到,其评点方法为后世提供了良好的范例。其宋本已佚,国内现存两种明刊本。此书四库未收,清本有清同治二年望三益斋刊本、宛委别藏本、清光绪八年《谢叠山先生评注四种合刻》本。此书在日本广为流传,写本及刻本颇多,国内现存的民国胡光国重刊本据日本弘化丁未长满连刻本重刊,奉天学务公所铅印版《唐诗绝句注解》底本为日本吉田勿来明治戊申刻本。
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