Optically stimulated luminescence(OSL) reading systems are becoming smaller and capable of real-time detection. To improve real-time and multipurpose radiation dosimetry readings, we built a real-time continuous-wave(...Optically stimulated luminescence(OSL) reading systems are becoming smaller and capable of real-time detection. To improve real-time and multipurpose radiation dosimetry readings, we built a real-time continuous-wave(RCW) OSL reading system. This system is both small and lightweight, and it employs powerful laser excitation(478 mW/cm^2) at the dosimetry probe location. We investigate the possibility of using the RCW mode to read the radiation luminescence(RL) or OSL by using a singlecrystal Al_2O_3:C dosimeter in a low-dose-rate137 Cs y field.Our results indicate that the RL/OSL follows a stable and uniform distribution. The minimum detected doses associated with the RL, OSL, and RL + OSL signals are2.1 9 10^(-2), 3.17 9 10^(-1), and 5.7 9 10^(-2) l Gy, respectively. This device provides a framework for the future development of applications for practical radiation dose measurements.展开更多
Objective: To test the hypotheses that reading comprehension difficulties of adolescent students with ADHD: 1) are related not so much to weak verbal abilities or weak basic reading skills, as to impairments of workin...Objective: To test the hypotheses that reading comprehension difficulties of adolescent students with ADHD: 1) are related not so much to weak verbal abilities or weak basic reading skills, as to impairments of working memory and processing speed characteristic of ADHD;and 2) that extended time on a test of reading comprehension would yield significantly higher reading comprehension scores than would standard time. Method: Charts of 145 adolescents 13-18 years diagnosed with DSM-IV ADHD and no specific reading disorder after a comprehensive clinical and psycho-educational evaluation, were reviewed to extract 1) word reading and word attack subtest scores from the Woodcock-Johnson Achievement Test or the Wechsler Individual Achievement Test;2) Index scores from WISC-IV or WAIS-III IQ tests;3) scores from the Nelson-Denny Reading Test. Results: Mean index scores for verbal comprehension abilities not including reading were in the high average range, but working memory and processing speed index scores were significantly weaker. Under standard time limits 53% were unable to complete the reading comprehension test and only 42.8% were able to score within 1 SD of their IQ verbal comprehension index (VCI). When allowed extended time, 77.9% were able to score within 1 SD of their VCI. T-test comparisons between standard time and extended time were significant at < 0.001. Conclusions: Allowing extended time for adolescents with ADHD to complete tests involving reading may help to compensate for their impairments of working memory and processing speed, allowing them to score closer to their actual verbal abilities.展开更多
IN his book I Speak of Ghana, Nana Awere Damoah enumerates 50 things that will indicate you are in Ghana. While all of them are droll they do also contain a small kernel of hard truth. For instance. ＂You know you ar...IN his book I Speak of Ghana, Nana Awere Damoah enumerates 50 things that will indicate you are in Ghana. While all of them are droll they do also contain a small kernel of hard truth. For instance. ＂You know you are in Ghana when street lights are visible decorations by day and invisible shadows by night. You know you are in Ghana when a 60-year-old man is introduced as the Chairman of the Asikuma Youth Association.展开更多
为了解决软击穿导致的压控磁各向异性磁隧道结(voltage-controlled magnetic anisotropy magnetic tunnel junction,VCMA-MTJ)及其读电路性能下降的问题,在对VCMA-MTJ软击穿机理深入分析的基础上,修正了VCMA-MTJ的电学模型,设计了一种...为了解决软击穿导致的压控磁各向异性磁隧道结(voltage-controlled magnetic anisotropy magnetic tunnel junction,VCMA-MTJ)及其读电路性能下降的问题,在对VCMA-MTJ软击穿机理深入分析的基础上,修正了VCMA-MTJ的电学模型,设计了一种具有固定参考电阻的VCMA-MTJ读电路和一种具有参考电阻调控单元的VCMA-MTJ读电路,研究了软击穿对VCMA-MTJ电阻R_(t)、隧穿磁阻比率M、软击穿时间T_(s)以及VCMA-MTJ读电路读错误率的影响。结果表明:软击穿的出现会导致R_(t)和M均随应力时间t的增加而降低,T_(s)随氧化层厚度t_(ox)的增大而缓慢增加,却随脉冲电压V_(b)的增大而迅速减少,与反平行态相比,平行态的T_(s)更短且M降低50%所需时间更少;具有固定参考电阻的VCMA-MTJ读电路可有效避免读“0”错误率的产生,但读“1”错误率却随t的增加而上升,而具有参考电阻调控单元的VCMA-MTJ读电路可在保持读“0”正确率的同时,对读“1”错误率改善达54%,在一定程度上削弱了软击穿对VCMA-MTJ读电路的影响。展开更多
This paper examines the problems existing in Extensive Reading Teaching for Vocational Business English Majors and analyses the contributing factors for the time-consuming and inefficient Extensive Reading Teaching.Ba...This paper examines the problems existing in Extensive Reading Teaching for Vocational Business English Majors and analyses the contributing factors for the time-consuming and inefficient Extensive Reading Teaching.Based on the analysis,the author points out some solutions from the following several aspects:the teachers’ roles,the choice of textbooks and the organization of the class as well as the integrated design of the class activities,be carried out in the student-centered class to be practical and helpful in the Extensive Reading Teaching.展开更多
Most of the proposed concurrency control protocols for real time database systems are based on serializability theorem. Owing to the unique characteristics of real time database applications and the importance of sa...Most of the proposed concurrency control protocols for real time database systems are based on serializability theorem. Owing to the unique characteristics of real time database applications and the importance of satisfying the timing constraints of transactions, serializability is too strong as a correctness criterion and not suitable for real time databases in most cases. On the other hand, relaxed serializability including epsilon serializability and similarity serializability can allow more real time transactions to satisfy their timing constraints, but database consistency may be sacrificed to some extent. We thus propose the use of weak serializability(WSR) that is more relaxed than conflicting serializability while database consistency is maintained. In this paper, we first formally define the new notion of correctness called weak serializability. After the necessary and sufficient conditions for weak serializability are shown, corresponding concurrency control protocol WDHP(weak serializable distributed high priority protocol) is outlined for distributed real time databases, where a new lock mode called mask lock mode is proposed for simplifying the condition of global consistency. Finally, through a series of simulation studies, it is shown that using the new concurrency control protocol the performance of distributed real time databases can be greatly improved.展开更多
基金supported by the International Fusion Reactor Experiment Program(No.2014GB112004)
文摘Optically stimulated luminescence(OSL) reading systems are becoming smaller and capable of real-time detection. To improve real-time and multipurpose radiation dosimetry readings, we built a real-time continuous-wave(RCW) OSL reading system. This system is both small and lightweight, and it employs powerful laser excitation(478 mW/cm^2) at the dosimetry probe location. We investigate the possibility of using the RCW mode to read the radiation luminescence(RL) or OSL by using a singlecrystal Al_2O_3:C dosimeter in a low-dose-rate137 Cs y field.Our results indicate that the RL/OSL follows a stable and uniform distribution. The minimum detected doses associated with the RL, OSL, and RL + OSL signals are2.1 9 10^(-2), 3.17 9 10^(-1), and 5.7 9 10^(-2) l Gy, respectively. This device provides a framework for the future development of applications for practical radiation dose measurements.
文摘Objective: To test the hypotheses that reading comprehension difficulties of adolescent students with ADHD: 1) are related not so much to weak verbal abilities or weak basic reading skills, as to impairments of working memory and processing speed characteristic of ADHD;and 2) that extended time on a test of reading comprehension would yield significantly higher reading comprehension scores than would standard time. Method: Charts of 145 adolescents 13-18 years diagnosed with DSM-IV ADHD and no specific reading disorder after a comprehensive clinical and psycho-educational evaluation, were reviewed to extract 1) word reading and word attack subtest scores from the Woodcock-Johnson Achievement Test or the Wechsler Individual Achievement Test;2) Index scores from WISC-IV or WAIS-III IQ tests;3) scores from the Nelson-Denny Reading Test. Results: Mean index scores for verbal comprehension abilities not including reading were in the high average range, but working memory and processing speed index scores were significantly weaker. Under standard time limits 53% were unable to complete the reading comprehension test and only 42.8% were able to score within 1 SD of their IQ verbal comprehension index (VCI). When allowed extended time, 77.9% were able to score within 1 SD of their VCI. T-test comparisons between standard time and extended time were significant at < 0.001. Conclusions: Allowing extended time for adolescents with ADHD to complete tests involving reading may help to compensate for their impairments of working memory and processing speed, allowing them to score closer to their actual verbal abilities.
文摘IN his book I Speak of Ghana, Nana Awere Damoah enumerates 50 things that will indicate you are in Ghana. While all of them are droll they do also contain a small kernel of hard truth. For instance. ＂You know you are in Ghana when street lights are visible decorations by day and invisible shadows by night. You know you are in Ghana when a 60-year-old man is introduced as the Chairman of the Asikuma Youth Association.
文摘为了解决软击穿导致的压控磁各向异性磁隧道结(voltage-controlled magnetic anisotropy magnetic tunnel junction,VCMA-MTJ)及其读电路性能下降的问题,在对VCMA-MTJ软击穿机理深入分析的基础上,修正了VCMA-MTJ的电学模型,设计了一种具有固定参考电阻的VCMA-MTJ读电路和一种具有参考电阻调控单元的VCMA-MTJ读电路,研究了软击穿对VCMA-MTJ电阻R_(t)、隧穿磁阻比率M、软击穿时间T_(s)以及VCMA-MTJ读电路读错误率的影响。结果表明:软击穿的出现会导致R_(t)和M均随应力时间t的增加而降低,T_(s)随氧化层厚度t_(ox)的增大而缓慢增加,却随脉冲电压V_(b)的增大而迅速减少,与反平行态相比,平行态的T_(s)更短且M降低50%所需时间更少;具有固定参考电阻的VCMA-MTJ读电路可有效避免读“0”错误率的产生,但读“1”错误率却随t的增加而上升,而具有参考电阻调控单元的VCMA-MTJ读电路可在保持读“0”正确率的同时,对读“1”错误率改善达54%,在一定程度上削弱了软击穿对VCMA-MTJ读电路的影响。
文摘This paper examines the problems existing in Extensive Reading Teaching for Vocational Business English Majors and analyses the contributing factors for the time-consuming and inefficient Extensive Reading Teaching.Based on the analysis,the author points out some solutions from the following several aspects:the teachers’ roles,the choice of textbooks and the organization of the class as well as the integrated design of the class activities,be carried out in the student-centered class to be practical and helpful in the Extensive Reading Teaching.
文摘Most of the proposed concurrency control protocols for real time database systems are based on serializability theorem. Owing to the unique characteristics of real time database applications and the importance of satisfying the timing constraints of transactions, serializability is too strong as a correctness criterion and not suitable for real time databases in most cases. On the other hand, relaxed serializability including epsilon serializability and similarity serializability can allow more real time transactions to satisfy their timing constraints, but database consistency may be sacrificed to some extent. We thus propose the use of weak serializability(WSR) that is more relaxed than conflicting serializability while database consistency is maintained. In this paper, we first formally define the new notion of correctness called weak serializability. After the necessary and sufficient conditions for weak serializability are shown, corresponding concurrency control protocol WDHP(weak serializable distributed high priority protocol) is outlined for distributed real time databases, where a new lock mode called mask lock mode is proposed for simplifying the condition of global consistency. Finally, through a series of simulation studies, it is shown that using the new concurrency control protocol the performance of distributed real time databases can be greatly improved.
