随着汽车的电子电气架构向域集中和区域集中方向发展,电子控制单元(Electronic Control Unit,ECU)需要更高的计算能力和更多样的接口,导致核心芯片的工作电压逐渐降低、工作速度加快、功耗增加,对车规微控制器单元(Microcontroller Unit...随着汽车的电子电气架构向域集中和区域集中方向发展,电子控制单元(Electronic Control Unit,ECU)需要更高的计算能力和更多样的接口,导致核心芯片的工作电压逐渐降低、工作速度加快、功耗增加,对车规微控制器单元(Microcontroller Unit,MCU)的性能提出了更高要求。文章提出一种基于目标阻抗的去耦设计方法,结合电容等效模型和电容去耦原理分析了0~50 MHz频率范围内电源分配网络(Power Distribution Network,PDN)的阻抗,通过Cadence Optimize PI电源完整性仿真软件对MCU核心电源进行仿真。结果表明,该方法设计的PDN能够满足芯片的电源需求,避免了过度设计,从而提高了开发效率。展开更多
Flexible strain sensors play an important role in electronic skins,wearable medical devices,and advanced robots.Herein,a highly sensitive and fast response optical strain sensor with two evanescently coupled optical m...Flexible strain sensors play an important role in electronic skins,wearable medical devices,and advanced robots.Herein,a highly sensitive and fast response optical strain sensor with two evanescently coupled optical micro/nanofibers(MNFs)embedded in a polydimethylsiloxane(PDMS)film is proposed.The strain sensor exhibits a gauge factor as high as 64.5 for strain≤0.5%and a strain resolution of 0.0012%which corresponds to elongation of 120 nm on a 1 cm long device.As a proof-of-concept,highly sensitive fingertip pulse measurement is realized.The properties of fast temporal frequency response up to 30 kHz and a pressure sensitivity of 102 kPa^(−1) enable the sensor for sound detection.Such versatile sensor could be of great use in physiological signal monitoring,voice recognition and micro-displacement detection.展开更多
为加速有限元分析流程,提出了一种面向有限元分析的自适应三角网格模型布尔运算方法。将ADT(alternating digital tree)数据结构应用于三角面片的判交计算,提升了布尔运算中三角面片的判交效率;借鉴结合球填充算法和插点/去点算法的网...为加速有限元分析流程,提出了一种面向有限元分析的自适应三角网格模型布尔运算方法。将ADT(alternating digital tree)数据结构应用于三角面片的判交计算,提升了布尔运算中三角面片的判交效率;借鉴结合球填充算法和插点/去点算法的网格重生成方法来重剖分局部区域,保证了算法的效率和生成网格的质量;通过改进的八叉树背景网格来记录和光滑尺寸场,生成了自适应的网格;通过尺寸场合理地控制重剖分区域,使算法效率和生成网格的质量得以很好地平衡。实验结果表明,所提方法可以高效地生成满足有限元分析需求的网格。展开更多
Mesh smoothing is an essential technique for the improvement of mesh quality in finite element analysis,due to the fact that mesh quality has a large impact on the convergence of the computational scheme and the accur...Mesh smoothing is an essential technique for the improvement of mesh quality in finite element analysis,due to the fact that mesh quality has a large impact on the convergence of the computational scheme and the accuracy of the numerical results.A novel mesh smoothing method based on regular-position-guided operations is presented in this paper.The method introduced here contains two main stages:The first stage computes the regular position of each vertex based on the shape of the element and conducts regular-position-oriented-based element transformations independently;the second stage determines the finial position of each vertex according to its surrounding elements with an assembly strategy.This method is not limited to planar triangular mesh,but applicable to surface polygonal mesh.Numerical experiments on various mesh models demonstrate the effectiveness and potential of this method.展开更多
人类世这一概念是伴随从地质概念到文明危机的历史背景下诞生的,其提出迅速超越学科边界,成为理解地球系统与人类文明关系的核心范式.诺贝尔奖得主保罗·克鲁岑(Paul Crutzen)于2000年首次提出该术语,强调人类活动已超越自然营力,...人类世这一概念是伴随从地质概念到文明危机的历史背景下诞生的,其提出迅速超越学科边界,成为理解地球系统与人类文明关系的核心范式.诺贝尔奖得主保罗·克鲁岑(Paul Crutzen)于2000年首次提出该术语,强调人类活动已超越自然营力,成为地球系统演化的主导力量[1].国际地层委员会人类世工作组(Anthropocene Working Group,AWG)进一步建议将20世纪中叶“大加速”时期作为新地质时代的起点,标志化石能源、工业化农业与城市化进程的全球扩散.展开更多
文摘随着汽车的电子电气架构向域集中和区域集中方向发展,电子控制单元(Electronic Control Unit,ECU)需要更高的计算能力和更多样的接口,导致核心芯片的工作电压逐渐降低、工作速度加快、功耗增加,对车规微控制器单元(Microcontroller Unit,MCU)的性能提出了更高要求。文章提出一种基于目标阻抗的去耦设计方法,结合电容等效模型和电容去耦原理分析了0~50 MHz频率范围内电源分配网络(Power Distribution Network,PDN)的阻抗,通过Cadence Optimize PI电源完整性仿真软件对MCU核心电源进行仿真。结果表明,该方法设计的PDN能够满足芯片的电源需求,避免了过度设计,从而提高了开发效率。
基金We are grateful for financial supports from the National Natural Science Foundation of China(No.61975173)the National Key Research and Development Program of China(No.SQ2019YFC170311)+3 种基金the Major Scientific Research Project of Zhejiang Lab(No.2019MC0AD01)the Key Research and Development Project of Zhejiang Province(No.2021C05003)the Quantum Joint Funds of the Natural Foundation of Shandong Province(No.ZR2020LLZ007)the CIE-Tencent Robotics X Rhino-Bird Focused Research Program(No.2020-01-006).
文摘Flexible strain sensors play an important role in electronic skins,wearable medical devices,and advanced robots.Herein,a highly sensitive and fast response optical strain sensor with two evanescently coupled optical micro/nanofibers(MNFs)embedded in a polydimethylsiloxane(PDMS)film is proposed.The strain sensor exhibits a gauge factor as high as 64.5 for strain≤0.5%and a strain resolution of 0.0012%which corresponds to elongation of 120 nm on a 1 cm long device.As a proof-of-concept,highly sensitive fingertip pulse measurement is realized.The properties of fast temporal frequency response up to 30 kHz and a pressure sensitivity of 102 kPa^(−1) enable the sensor for sound detection.Such versatile sensor could be of great use in physiological signal monitoring,voice recognition and micro-displacement detection.
文摘为加速有限元分析流程,提出了一种面向有限元分析的自适应三角网格模型布尔运算方法。将ADT(alternating digital tree)数据结构应用于三角面片的判交计算,提升了布尔运算中三角面片的判交效率;借鉴结合球填充算法和插点/去点算法的网格重生成方法来重剖分局部区域,保证了算法的效率和生成网格的质量;通过改进的八叉树背景网格来记录和光滑尺寸场,生成了自适应的网格;通过尺寸场合理地控制重剖分区域,使算法效率和生成网格的质量得以很好地平衡。实验结果表明,所提方法可以高效地生成满足有限元分析需求的网格。
文摘Mesh smoothing is an essential technique for the improvement of mesh quality in finite element analysis,due to the fact that mesh quality has a large impact on the convergence of the computational scheme and the accuracy of the numerical results.A novel mesh smoothing method based on regular-position-guided operations is presented in this paper.The method introduced here contains two main stages:The first stage computes the regular position of each vertex based on the shape of the element and conducts regular-position-oriented-based element transformations independently;the second stage determines the finial position of each vertex according to its surrounding elements with an assembly strategy.This method is not limited to planar triangular mesh,but applicable to surface polygonal mesh.Numerical experiments on various mesh models demonstrate the effectiveness and potential of this method.
文摘人类世这一概念是伴随从地质概念到文明危机的历史背景下诞生的,其提出迅速超越学科边界,成为理解地球系统与人类文明关系的核心范式.诺贝尔奖得主保罗·克鲁岑(Paul Crutzen)于2000年首次提出该术语,强调人类活动已超越自然营力,成为地球系统演化的主导力量[1].国际地层委员会人类世工作组(Anthropocene Working Group,AWG)进一步建议将20世纪中叶“大加速”时期作为新地质时代的起点,标志化石能源、工业化农业与城市化进程的全球扩散.
