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“函数的零点”是上海教育出版社高中一年级第一学期3.4节“函数的基本性质”中的内容,教学要求为:使学生理解用“二分法”求函数零点的算法思想,会借助计算器求函数零点的数值解.笔者在研究教材相关内容的过程中,发现一些值得思考的问题. 相似文献
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借助抽运-探测技术研究了ZnTe晶体中光学整流产生的太赫兹(THz)辐射,利用ZnTe晶体的线性电光效应探测THz辐射场分布,观察到了较窄(约为0.2 ps)的THz场分布及相应较宽(响应超过4 THz,半峰宽约为2.4 THz)的THz频谱,并运用琼斯矩阵对实验结果进行了理论拟合. 研究了飞秒激光脉冲波长(750—850 nm)、脉冲宽度(56—225 fs)和晶体旋转与THz辐射产生的关系. 同时改变探测光偏振方向进行偏振调制,并从理论上分析了偏振调制对THz辐射探测的影响.
关键词:
THz辐射
光学整流
电光探测
ZnTe 相似文献
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抵押贷款信用违约互换的定价 总被引:1,自引:0,他引:1
在结构化方法框架下,用偏微分方程方法,对抵押贷款的信用违约互换进行定价.给出了形式解,并进行数值计算和参数分析. 相似文献
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在教育全球化的背景下,随着课程改革的进行,各国都希望从其他国家借鉴到有益的经验,教材的国际比较成为教育研究的热点.当前普遍认为,我国数学教育注重培养基础知识和基本技能,美国教育擅长对学生创新意识和应用能力的培养.对两国高中数学教材进行比较分析的目的在于发现不同教材之间的具体差异,揭示各自的优势和不足,取长补短,提高我国的数学教育. 相似文献
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在高中数学学习中,审题不清是学生有效解题的第一障碍.特别在解析几何的解题过程中,因为由文字、数式、图形等数学语言堆砌的问题抽象而繁复,且层层设套,使学生眼花缭乱,无从下手,或一不小心走了弯路.笔者就抛物线教学中的一个实例,对课堂教学中学生审题能力的培养进行了思考. 相似文献
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We investigate a peculiar phenomenon by processing ZnO nanobelts with an atomic force microscope (AFM). In the contact mode of AFM, peculiar bending occurs in meso-scale when the nanobelt is applied with force in lateral direction. We study the mechanical properties of ZnO nanobelts under the influence of small size effect, with finite element analysis and mathematical analysis by means of Matlab. Based on this abnormal effect, a novel measuring method is proposed, which allows the surface morphology and surface properties to be characterized at the same time. 相似文献
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Yi-Di Pang 《中国物理 B》2021,30(6):68501-068501
Two-dimensional (2D) transition metal dichalcogenides (TMDCs) such as tungsten diselenide (WSe2) have spead many interesting physical properties, which may become ideal candidates to develop new generation electronic and optoelectronic devices. In order to reveal essential features of 2D TMDCs, it is necessary to fabricate high-quality devices with reliable electrical contact. We systematically analyze the effect of graphene and metal contacts on performance of multi-layered WSe2 field effect transistors (FETs). The temperature-dependent transport characteristics of both devices are tested. Only graphene-contacted WSe2 FETs are observed with the metal-insulator transition phenomenon which mainly attributes to the ultra-clean contact interface and lowered contact barrier. Further characterization on contact barrier demonstrates that graphene contact enables lower contact barrier with WSe2 than metal contact, since the Fermi level of graphene can be modulated by the gate bias to match the Fermi level of the channel material. We also analyze the carrier mobility of both devices under different temperatures, revealing that graphene contact can reduce the charge scattering of the device caused by ionized impurities and phonon vibrations in low and room temperature regions, respectively. This work is expected to provide reference for fabricating 2D material devices with decent performances. 相似文献