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地球同步轨道卫星在轨异常与空间环境相关性分析 被引量:10
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作者 常峥 王咏梅 +1 位作者 田天 潘业欣 《宇航学报》 EI CAS CSCD 北大核心 2017年第4期435-442,共8页
利用中国FY和美国GOES卫星探测数据,对中国某同步轨道卫星发生在2010年至2015年的44次可能与空间环境相关的异常进行了研究,重点分析了异常发生的时间分布、伴随的空间环境现象和空间粒子分布特征,并利用DICTAT模拟计算了卫星异常期间... 利用中国FY和美国GOES卫星探测数据,对中国某同步轨道卫星发生在2010年至2015年的44次可能与空间环境相关的异常进行了研究,重点分析了异常发生的时间分布、伴随的空间环境现象和空间粒子分布特征,并利用DICTAT模拟计算了卫星异常期间介质内部最大电场强度,结果表明:(1)内部充电是造成"3·17"卫星异常的主要原因。(2)79.5%卫星异常发生在日侧,这与能量>2Me V的高能电子通量随地方时分布非常一致。(3)多达25次(57%)的异常事件伴随高能电子暴。能量>2Me V电子通量的50%位数在异常前3-4天开始出现明显增强,内部充电危险商数ZIC在异常前2天进入黄色风险等级;能量>2Me V电子通量的75%位数在异常前4天开始出现明显增强,ZIC在异常前2天先后2次进入红色风险等级。(4)在II类、III类和IV类情形下,DICTAT模拟计算得到的介质内部最大电场分别在19.2、50.4和9.8小时之后超过并维持在106V.m-1以上,该范围的内部电场强度存在潜在的放电危险,高能电子诱发的内部充电是造成我国同步轨道卫星异常的主要原因。 展开更多
关键词 卫星异常 内部充电 辐射剂量 单粒子效应 危险商数 DICTAT模拟 最大电场
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航天器内部充电风险评估模型的问题及改进 被引量:3
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作者 张振龙 贡顶 +1 位作者 韩建伟 竺礼华 《原子能科学技术》 EI CAS CSCD 北大核心 2017年第1期180-186,共7页
通过与蒙特卡罗计算结果对比,发现现有内部充电风险评估模型(DICTAT)对辐射电子在材料内深度-剂量关系的表述不正确,本文引入Tabata的一组半经验公式重建了电子输运模型,并开发了新的内部充电风险评估模型。利用新模型、DICTAT和三维仿... 通过与蒙特卡罗计算结果对比,发现现有内部充电风险评估模型(DICTAT)对辐射电子在材料内深度-剂量关系的表述不正确,本文引入Tabata的一组半经验公式重建了电子输运模型,并开发了新的内部充电风险评估模型。利用新模型、DICTAT和三维仿真工具,分别针对一组不同厚度的背部接地聚酰亚胺平板的充电电场和电位进行了计算,对比和解释了计算结果的差异。新模型与三维仿真工具的结果具有较好的一致性,其可更准确地评估内部充电风险。 展开更多
关键词 内部充电 风险评估 DICTAT
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图式理论在Compound Dictation中的应用
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作者 王晓丽 王新国 《齐齐哈尔医学院学报》 2003年第5期590-591,共2页
关键词 图式理论 COMPOUND DICTATION 应用 听力测试 听力教学 英语教学
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The Usefulness of Dictation in ELT Classrooms
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作者 徐黄丽 《海外英语》 2015年第4期135-136,共2页
Dictation plays an important role in teaching, learning and testing. But different people have different views about its functions. This paper mainly talks about its advantages—improving students' all-round abili... Dictation plays an important role in teaching, learning and testing. But different people have different views about its functions. This paper mainly talks about its advantages—improving students' all-round ability, exerting positive feedback and practical effect on English teaching and learning, and cultivating students' ability of English comprehension. Then the author puts forward a few suggestions for the training of dictation skills. 展开更多
关键词 DICTATION feedback advantages English teaching and learning
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The heterodimeric structure of heterogeneous nuclear ribonucleoprotein C1/C2 dictates 1,25-dihydroxyvitamin D-directed transcriptional events in osteoblasts 被引量:2
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作者 Thomas S Lisse Kanagasabai Vadivel +4 位作者 S Paul Bajaj Rui Zhou Rene F Chun Martin Hewison John S Adams 《Bone Research》 SCIE CAS 2014年第2期110-120,共11页
Heterogeneous nuclear ribonucleoprotein (hnRNP) C plays a key role in RNA processing but also exerts a dominant negative effect on responses to 1,25-dihydroxyvitamin D (1,25(OH)2D) by functioning as a vitamin D ... Heterogeneous nuclear ribonucleoprotein (hnRNP) C plays a key role in RNA processing but also exerts a dominant negative effect on responses to 1,25-dihydroxyvitamin D (1,25(OH)2D) by functioning as a vitamin D response element-binding protein (VDRE-BP). hnRNPC acts a tetramer of hnRNPC1 (huC1) and hnRNPC2 (huC2), and organization of these subunits is critical to in vivo nucleic acid-binding. Overexpression of either huC1 or huC2 in human osteoblasts is sufficient to confer VDRE-BP suppression of 1,25(OH)2D-mediated transcription. However, huC1 or huC2 alone did not suppress 1,25(OH)2D-induced transcription in mouse osteoblastic cells. By contrast, overexpression of huC1 and huC2 in combination or transfection with a bone-specific polycistronic vector using a "self-cleaving" 2A peptide to co-express huC1/C2 suppressed 1,25D-mediated induction of osteoblast target gene expression. Structural diversity of hnRNPC between human/NWPs and mouse/rat/rabbit/dog was investigated by analysis of sequence variations within the hnRNP CLZ domain. The predicted loss of distal helical function in hnRNPC from lower species provides an explanation for the altered interaction between huC1/C2 and their mouse counterparts. These data provide new evidence of a role for hnRNPC1/C2 in 1,25(OH)2D-driven gene expression, and further suggest that species-specific tetramerization is a crucial determinant of its actions as a regulator of VDR-directed transactivation. 展开更多
关键词 gene The heterodimeric structure of heterogeneous nuclear ribonucleoprotein C1/C2 dictates 1 25-dihydroxyvitamin D-directed transcriptional events in osteoblasts Figure EcoRI
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Effects of Reading-Listening Integrated Dictation on Chinese EFL Students’ Listening Performance 被引量:1
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作者 Haiyan MIAO 《Chinese Journal of Applied Linguistics》 2021年第3期417-429,432,共14页
This study examines the effects of reading-listening integrated dictation on Chinese college-level English as a foreign language(EFL) learners’ listening. Different from previous research that explored reading while ... This study examines the effects of reading-listening integrated dictation on Chinese college-level English as a foreign language(EFL) learners’ listening. Different from previous research that explored reading while listening for listening development, this study combined the two skills in dictation in which listening was a continuation of reading. Participants were two groups of firstyear Chinese EFL learners who were exposed to the target language under two conditions: the traditional dictation(i. e., listening-only) and the reading-listening integrated dictation in a counterbalanced order. Three datasets were collected: listening performance, perception questionnaires and follow-up interviews. Results indicated that the reading-listening integrated dictation was superior in terms of learning gains from listening and that their effect was commensurate with dictation text difficulty. The findings also showed that the reading-listening integrated dictation could enhance EFL students’ confidence and interest and make the use of strategies possible during listening. 展开更多
关键词 reading-listening integrated dictation listening-only listening performance
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Dealing with English Majors' Difficulties with Dictation in Chinese Universities
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作者 张小平 郑红娟 《疯狂英语(教师版)》 2014年第2期39-43,54,共6页
Dictation is a complicated process of decoding information and reorganizing meaning of an utterance and it has long been used to measure students' language proficiency and help them to develop accuracy in listenin... Dictation is a complicated process of decoding information and reorganizing meaning of an utterance and it has long been used to measure students' language proficiency and help them to develop accuracy in listening and writing. However, many English majors have poor performance in dictation of TEM-4. The paper tries to discuss the fundamental factors that prevent students from obtaining a relatively high score in dictation and suggests some ways to deal with the problems. 展开更多
关键词 DICTATION English MAJOR Chinese university TEM-4
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The Effective Techniques of Dictation-based Vocabulary Teaching in English Classes 被引量:1
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作者 张继宁 邢斌 《海外英语》 2017年第15期231-232,236,共3页
Dictation is a traditional but still widely applied method to teach language vocabulary,grammar structures and other language skills.Because of the teachers’negative opinions on dictation and improper ways of dictati... Dictation is a traditional but still widely applied method to teach language vocabulary,grammar structures and other language skills.Because of the teachers’negative opinions on dictation and improper ways of dictation conduction,dictation hasn’t received a satisfying expectation in English vocabulary teaching in China.This research attempts to find out some innovative dictation activities and some effective techniques which can help English teachers in China conduct dictation in these activities to promote the efficiency of language vocabulary teaching. 展开更多
关键词 DICTATION vocabulary teaching Dictation activities Dictation techniques
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The Effect of Dictation Practice on Listening Comprehension of Non-English Major Undergraduates
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作者 陈晓宁 易晓莉 《海外英语》 2017年第23期253-254,256,共3页
This paper aims to explore the effectiveness of dictation practice in improving non-English major undergraduates listening comprehension.35 students were selected into the experiment.For the comparison of the experime... This paper aims to explore the effectiveness of dictation practice in improving non-English major undergraduates listening comprehension.35 students were selected into the experiment.For the comparison of the experimental data,we found that students'listening comprehension do improved after 12 weeks training while some other implications also were discussed for further study in order to promote listening teaching and learning. 展开更多
关键词 Dictation practice listening comprehension non-English major undergraduates
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Insensitivity to Unethical Behavior in Dictator Game When Indirectly Intermediated-Implications of Indirect Blindness for Safety Management
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作者 Atsuo Murata 《Journal of Behavioral and Brain Science》 2016年第5期199-208,共10页
The aim of this study was to demonstrate that indirect mediation in behaviors leads to insensitivity to unethical behavior through a dictator game and to give some implications for safety management. The indirect invo... The aim of this study was to demonstrate that indirect mediation in behaviors leads to insensitivity to unethical behavior through a dictator game and to give some implications for safety management. The indirect involvement in the unethical behavior such as the violation of regulation is believed to lessen the responsibility and the criticism from others for the unethical behavior as compared to the direct involvement in it. The instruction condition for the evaluator of behavior in a dictator game was taken up as an experimental variable. Instruction condition 1 was to pay attention to the behavior of only a dictator. In instruction condition 2, the participant (evaluator) was required to review all players’ behavior and evaluate a dictator. It has been investigated whether allowing indirect actions (mediations) leads to reduced punishment as a function of the instruction condition. While the punishment to the indirectness did not get smaller for instruction condition 2, the punishment to the indirectness tended to get smaller only for instruction condition 1. 展开更多
关键词 Unethical Behavior Punishment and Fairness INTERMEDIATION Dictator Game Decision Making Safety Management
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Teaching Plan of Listening Ⅱ for English Majors
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作者 郭炜峰 《好家长》 2019年第14期142-142,共1页
The teaching plan focuses on marriage patterns in British society. After the study, students are able to detect the main idea and supporting arguments.
关键词 MARRIAGE pattern BRITISH society SPOT DICTATION
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A Retrospective Study on Test-takers' Cognitive and Metacognitive Processes in Taking a Compound Dictation Test 被引量:1
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作者 Gu Xiangdong SHI Chunyan 《Chinese Journal of Applied Linguistics》 2012年第4期400-420,共21页
This study investigates the cognitive and metacognitive processes used by EFL test-takers in completing a compound dictation test through analyses of their verbal protocols obtained immediately after the test and thro... This study investigates the cognitive and metacognitive processes used by EFL test-takers in completing a compound dictation test through analyses of their verbal protocols obtained immediately after the test and through semi-structured retrospective interviews. The study explores relationships between the test-takers' actual performance and the instructions for the compound dictation test, the language abilities measured, any major construct-irrelevant factors affecting the test-taking processes, and the performance patterns of performance across test-takers of different overall proficiency levels. Findings are as follows. (1) Test-takers' actual performance does not apparently relate to the instructions given in the compound dictation test, which may raise doubts over the effectiveness of the instructions, thereby posing a potential threat to test validity. (2) Test-takers may pay more attention to the pronunciation of the words to be used to fill the blanks than to the actual meaning of the words, their difficulties in spelling and sentential expression possibly interfering with test performance even though they appear to use a variety of cognitive and metacognitive strategies throughout the test. (3) A number of construct-irrelevant factors posing a potential threat to test validity were found in the test-taking processes. Some of these factors are related to the test-takers, for example, memory capacity, attention failure and psychological factors, while others relate to the test, including speech rate and time constraints. (4) Test-takers in the study at all three proficiency levels appeared not to follow the instructions given in the compound dictation test. However, higher proficiency test-takers appeared to make more frequent use of cognitive and metacognitive strategies, and they appeared to be less influenced by construct-irrelevant factors. 展开更多
关键词 College English Test Band 4 compound dictation test-taking processes retrospective approach linguistic knowledge strategy use COGNITIVE metacognitive
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Exploratory Analysis on Dictated Handwriting Samples
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作者 Xuelin Gao Yanling Wang 《Journal of Forensic Science and Medicine》 2019年第4期195-203,共9页
Dictated handwriting samples are widely used in practice due to their simplicity,convenience,and practicality.However,dictation is typically listed as one of the many collection methods in textbooks and monographs,and... Dictated handwriting samples are widely used in practice due to their simplicity,convenience,and practicality.However,dictation is typically listed as one of the many collection methods in textbooks and monographs,and there is usually no separate section focusing on dictated handwriting samples.Therefore,further study of dictated handwriting samples will have important practical significance.Consideration of the definition,existing problems,collection techniques,and critical aspects of dictated handwriting samples willsupport investigators and document examiners in their professional abilities and contribute to the theoretical system of document examination.In this article,an exploratory analysis will be conducted and ideas about dictated handwriting samples will be shared,including the definition of dictated samples,their relationship to experimental samples,practical problems,feasible collection methods,and some critical points that require special attention.Dictation is widely used but problematic because of a lack of quantity and low levels of comparability.Those difficulties are mainly caused by a lack of theoreticalstudy and understanding of the requirements and collection techniques of dictated handwriting samples among first‑line investigators.Dictated samples should be collected based on subjective and objective conditions of formation with aims to improve comparability and five similarities.Further studies are needed to improve the theoretical system and practical use of dictated samples so that they can contribute to successfully reaching conclusions in investigations. 展开更多
关键词 COLLECTION critical problems dictated handwriting samples experimental samples exploratory analysis
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Should Government Dictate Students’ Social Practice Activities?
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《Beijing Review》 2010年第48期46-47,共2页
Recently,Chongqing in southwest China announced its education authorities would organize social practice activities for local college students.
关键词 Social Practice Activities Should Government Dictate Students
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