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Effects of Diamond on the Mechanical properties and Thermal Conductivity of Si_(3)N_(4)Composites Fabricated Using Spark plasma Sintering

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1319-1324页

作者： GAO Ying LIU Di wang Aiyang zhang Song he Qianglong rEN Shifeng FANG Jie wang Zihan wang Weimin State Key Laboratory of Advanced Technology for Materials Synthesis and processing Wuhan University of TechnologyWuhan 430070China Jingdezhen Huaxun Special Ceramics Co.ltd. Jingdezhen 333000China Aerospace Science&Industry Defense Technology research and Test Center Beijing 100854China

Micrometer-sized diamonds were incorporated into silicon nitride(Si_(3)N_(4))matrix to manufacture high-performance Si_(3)N_(4)-based composites using spark plasma sintering at 1500℃under 50 *** effects of the diamond content on the phase composition,microstructure,mechanical properties and thermal conductivity of the composites were *** results showed that the addition of diamond could effectively improve the hardness of the *** thermal conductivity of Si_(3)N_(4)increased to 52.97 W/m·k at the maximum with the addition of 15 wt%diamond,which was 27.5%higher than that of the monolithic Si_(3)N_(4).At this point,the fracture toughness was 7.54 Mpa·m^(1/2).Due to the addition of diamond,the composite material generated a new substance,MgSiN2,which effectively combined Si_(3)N_(4)with ***2 might improve the hardness and thermal conductivity of the materials.

关键词： spark plasma sintering Si_(3)N_(4) diamond thermal conductivity mechanical properties

Monte Carlo method for evaluation of surface emission rate measurement uncertainty

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Nuclear Science and Techniques 2024年第7期35卷 126-136页

作者： Yuan-Qiao Li Min Lin Li-jun Xu rui Luo Yu-he zhang Qian-Xi Ni Yun-Tao Liu china institute of Atomic Energy Beijing102413China National Key Laboratory for metrology and Calibration Techniques Beijing102413China Department of radiation Oncology Hunan Cancer HospitalChangsha410031China The Affiliated Cancer Hospital of Xiangya School of Medicine Central South UniversityChangsha410031China

The aim of this study is to evaluate the uncertainty of 2πα and 2πβ surface emission rates using the windowless multiwire proportional counter *** study used the Monte Carlo method (MCM) to validate the conventional Guide to the Expression of Uncertainty in measurement (GUM) method.A dead time measurement model for the two-source method was established based on the characteristics of a single-channel measurement system,and the voltage threshold correction factor measurement function was indirectly obtained by fitting the threshold correction *** uncertainty in the surface emission rate was calculated using the GUM method and the law of propagation of *** MCM provided clear definitions for each input quantity and its uncertainty distribution,and the simulation training was realized with a complete and complex mathematical *** results of the surface emission rate uncertainty evaluation for four radioactive plane sources using both methods showed the uncertainty’s consistency E_(n)r the comparison of each source,and the uncertainty results of the GUM were all lower than those of the ***,the MCM has a more objective evaluation process and can serve as a validation tool for GUM results.

关键词： Surface emission rate Monte Carlo method metrology probability distribution function Dead time Low-energy loss correction Least-squares method

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微波宽带超高精度双向时间比对技术研究

仪器仪表学报 2024年第2期45卷 152-159页

作者：王海峰王学运易航张升康葛军北京无线电计量测试研究所北京100854 计量与校准技术重点实验室北京100854

当前微波双向时间比对技术广泛应用于视距区域站间时间同步领域,能够达到纳秒站间时间同步水平,对于时间同步指标更高的应用场景还有待进一步提升。本文利用大带宽扩频信号和载波相位在时间测量性能方面的潜在优异性能,提出了基于宽带... 详细信息

当前微波双向时间比对技术广泛应用于视距区域站间时间同步领域,能够达到纳秒站间时间同步水平,对于时间同步指标更高的应用场景还有待进一步提升。本文利用大带宽扩频信号和载波相位在时间测量性能方面的潜在优异性能,提出了基于宽带信号调制解调技术的微波双向载波相位时间比对方法,设计了原型试验系统,利用氢原子钟和相位微跃计验证了实验室条件下系统的测量不确定度(A类)0.27 ps和分辨力4 ps,达到了预期效果,为后续远距离试验和应用推广奠定了坚实的技术和试验基础。

关键词：双向时间比对宽带信号载波相位。

Two-dimensional materials for future information technology: status and prospects

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Science china(Information Sciences) 2024年第6期67卷 1-147页

作者： Hao QIU Zhihao YU Tiange ZHAO Qi zhang Mingsheng XU peifeng LI Taotao LI Wenzhong BAO yang CHAI Shula CheN Yiqi CheN Hui-Ming CheNG Daoxin DAI Zengfeng DI Zhuo DONG Xidong DUAN Yuhan FENG Yu FU Jingshu GUO pengwen GUO Yue HAO jun he Xiao he Jingyi HU Weida HU Zehua HU Xinyue HUANG Ziyang HUANG Ali IMrAN Ziqiang KONG Jia LI Qian LI Weisheng LI Lei LIAO Bilu LIU Can LIU Chunsen LIU Guanyu LIU Kaihui LIU Liwei LIU Sheng LIU Yuan LIU Donglin LU Likuan MA Feng MIAO Zhenhua NI Jing NING Anlian pAN Tian-Ling rEN Haowen SHU Litao SUN Yue SUN Quanyang TAO Zi-Ao TIAN Dong wang Hao wang Haomin wang Jialong wang junyong wang Wenhui wang Xingjun wang Yeliang wang Yuwei wang Zhenyu wang Yao WE... School of Electronic Science and Engineering Nanjing University School of Integrated Circuits Interdisciplinary Research Center for Future Intelligent Chips (Chip-X)Nanjing University School of Integrated Circuit Science and Engineering Nanjing University of Posts and Telecommunications State Key Laboratory of Infrared physics Shanghai Institute of Technical Physics Chinese Academy of Sciences School of physics and Key Lab of Quantum Materials and Devices of the Ministry of Education School of Electronic Science & EngineeringSoutheast University College of Integrated Circuits State Key Laboratory of Silicon and Advanced Semiconductor MaterialsZhejiang University Suzhou Laboratory State Key Laboratory of Integrated Chips and Systems School of MicroelectronicsFudan University Shaoxin Laboratory Department of Applied physics The Hong Kong Polytechnic University Key Laboratory for Micro-Nano physics and Technology of Hunan province College of Materials Science and EngineeringHunan University College of Integrated Circuits Zhejiang University Shenzhen Geim Graphene Center Shenzhen Key Laboratory of Layered Materials for Value-Added ApplicationsTsinghua-Berkeley Shenzhen Institute & Institute of Materials ResearchTsinghua Shenzhen International Graduate SchoolTsinghua University State Key Laboratory of Extreme photonics and instrumentation College of Optical Science and EngineeringInternational Research Center for Advanced PhotonicsZijingang CampusZhejiang University National Key Laboratory of Materials for Integrated Circuits Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences CAS Key Laboratory of Nanophotonic Materials and Devices & Key Laboratory of Nanodevices and Applications i-LabSuzhou Institute of Nano-Tech and Nano-Bionics (SINANO)Chinese Academy of Sciences College of Chemistry and Chemical Engineering Hunan University Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education) Department of PhysicsRenmin University of China School

Over the past 70 years, the semiconductor industry has undergone transformative changes,largely driven by the miniaturization of devices and the integration of innovative structures and materials. Two-dimensional(2D) materials like transition metal dichalcogenides(TMDs) and graphene are pivotal in overcoming the limitations of silicon-based technologies, offering innovative approaches in transistor design and functionality, enabling atomic-thin channel transistors and monolithic 3D integration. We review the important progress in the application of 2D materials in future information technology, focusing in particular on microelectronics and optoelectronics. We comprehensively summarize the key advancements across material production, characterization metrology, electronic devices, optoelectronic devices, and heterogeneous integration on silicon. A strategic roadmap and key challenges for the transition of 2D materials from basic research to industrial development are outlined. To facilitate such a transition, key technologies and tools dedicated to 2D materials must be developed to meet industrial standards, and the employment of AI in material growth, characterizations, and circuit design will be essential. It is time for academia to actively engage with industry to drive the next 10 years of 2D material research.

关键词： two-dimensional (2D) materials information technology production technology standardization of characterization microelectronic devices optoelectronic devices multi-functional integration

A polarized^(3)he system based on metastability-exchange optical pumping

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Science china(physics,Mechanics & Astronomy) 2024年第7期67卷 72-81页

作者： Yuting wang Liangyong Wu Kaiyuan zhang Mei peng Siyu Chen Haiyang Yan State Key Laboratory of Nuclear physics and Technology School of PhysicsPeking UniversityBeijing 100871China institute of Nuclear physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Key Laboratory of Nuclear physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Key Laboratory of Neutron physics Institute of Nuclear Physics and ChemistryChina Academy of Engineering PhysicsMianyang 621900China

Hyperpolarized^(3)he nuclei have emerged as a significantly important approach in quantum precision measurement techniques,with extensive applications in fundamental physics,magnetometry,metrology,and *** this study,we report on the design and implementation of a^(3)he polarization system at the china Mianyang research reactor(CMrr),utilizing the metastabilityexchange optical pumping(MEOp)*** employed a Merritt coil system consisting of four square coils to furnish a uniform holding *** deployed a 2 W fiber laser to pump the metastable^(3)he atoms and conducted free induction decay(FID)detection of the polarized^(3)he nuclei using both pickup coil and optical *** the optical method,we used a50 m W linearly polarized distributed Bragg reflector(DBr)laser as the *** applied transverse light absorption polarimetry to measure the absolute nuclear polarization of the ground-state^(3)*** have developed cell fabrication capabilities at the CMrr,and cells at various pressures ranging from 100 to 1000 pa have been fabricated and *** a typical borosilicate cell with 100 pa pressure,the absolute polarization is measured as pn≈70%,and the transverse relaxation time is estimated as T2≈0.5 ***,we constructed a few aluminosilicate cells,each carefully filled with pure^(3)he at a pressure of 100 ***,we conducted a comprehensive evaluation of their performance in the context of MEOp.

关键词： metastability exchange optical pumping polarized^(3)he magnetic resonance

Improvements in Iodine Stabilized he-Ne Easers at 474 THz (633 nm) with Compatible System of Third and Fifth Harmonic Locking

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计量学报 1991年第S1期12卷 1-5页

作者： Shen Naicheng,wang Chu,wang Zhongwu,zhang Xuebin and Sun Yimin(National institute of metrology,beijing,china) (peking University,beijing,china)

We have developed two 474 THz(633 nm)new iodine stabilized he-Ne lasers with compatible system of third and fifth harmonic *** frequency stability is 1.0×10-11/ 1s and 3.5×10-12 / 10s with third harmonic locking,and corresponding values are 1.3×10-11/1s and 4.0×10-12/ 10s with fifth harmonic *** found that the frequency difference between the same component with third and fifth harmonic locking are from 5 kHz to SO *** experiment and analysis indicate that the center of fifth harmonic signals is closer to the Lorentzian center in iodine absorption component than one of the third harmonic signals,and the reproducibility with fifth harmonic locking is also better than one with third harmonic locking.

关键词： locking nm harmonic Iodine fifth iodine compatible closer stabilized insensitive

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水下空间中的光学高精度双向时间比对

应用激光 2024年第2期44卷 125-130页

作者：杨文哲吴寒旭王海峰张升康北京无线电计量测试研究所计量与校准技术国防科技重点实验室北京100854

为探寻水下空间导航定位授时服务的新途径,进一步提升水下空间授时精度,提出一种水下空间中的光学双向时间比对方法,阐述其基本原理和系统组成,利用激光二极管、光束准直器和反射镜等搭建基于玻璃水池的实验系统。最终,实验系统的时间... 详细信息

为探寻水下空间导航定位授时服务的新途径,进一步提升水下空间授时精度,提出一种水下空间中的光学双向时间比对方法,阐述其基本原理和系统组成,利用激光二极管、光束准直器和反射镜等搭建基于玻璃水池的实验系统。最终,实验系统的时间比对结果峰峰值为1.6ns,系统附加时间传递抖动结果为1.05×10^(-11)s/s,6.30×10^(-11)s/10^(3)s。实验结果验证了水下空间中光学双向时间比对方案的可行性,同时纳秒量级的时间比对结果表明具有深入研究的价值。针对实验过程中存在的问题,进行了深入分析和总结,为后续工作和研究提供了理论依据。

关键词：时间比对水下空间激光二极管

Nonlinear time-reversal interferometry with arbitrary quadratic collective-spin interaction

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Chinese physics B 2024年第8期33卷 63-70页

作者：胡知遥李其贤张轩晨张贺宾黄龙刚刘永椿 State Key Laboratory of Low-Dimensional Quantum physics Department of PhysicsTsinghua UniversityBeijing 100084China School of physics Xi'an Jiaotong UniversityXi'an 710049China china Fire and rescue institute Beijing 102202China Frontier Science Center for Quantum Information Beijing 100084China

Atomic nonlinear interferometry has wide applications in quantum metrology and quantum information *** we propose a nonlinear time-reversal interferometry scheme with high robustness and metrological gain based on the spin squeezing generated by arbitrary quadratic collective-spin interaction,which could be described by the Lipkin–Meshkov–Glick(LMG)*** optimize the squeezing process,encoding process,and anti-squeezing process,finding that the two particular cases of the LMG model,one-axis twisting and two-axis twisting outperform in robustness and precision,***,we propose a Floquet driving method to realize equivalent time reverse in the atomic system,which leads to high performance in precision,robustness,and *** study sets a benchmark for achieving high precision and high robustness in atomic nonlinear interferometry.

关键词： time-reversal interferometry spin squeezing quantum metrology

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超声声场激光层析成像及其扫描参数优化研究

中国激光 2024年第5期51卷 36-47页

作者：张小丽何程昊冯秀娟张慧牛锋何龙标中国计量科学研究院力学与声学计量科学研究所北京100029 天津大学精密仪器与光电子工程学院天津300072

空气耦合(简称“空耦”)超声换能器具有非接触检测、适合复杂工况和原位检测等独特优势,已被广泛应用于超声无损检测等领域。声场重建对于开展空耦超声换能器声束宽度、扩散角等声场特性参数的表征,进而保障超声检测系统的横向分辨率及... 详细信息

空气耦合(简称“空耦”)超声换能器具有非接触检测、适合复杂工况和原位检测等独特优势,已被广泛应用于超声无损检测等领域。声场重建对于开展空耦超声换能器声束宽度、扩散角等声场特性参数的表征,进而保障超声检测系统的横向分辨率及定位精度具有重要意义。笔者基于声光效应和层析成像技术对50~200 kHz空耦超声换能器的声场重建开展研究。超声声场的重建质量与空间分辨率密切相关,但高空间分辨率会导致扫描时间呈几何倍数增长。笔者从仿真和实验的角度对声场空间分辨率(即声场扫描参数)进行优化,在保证声场重建图像质量的前提下将扫描效率提高了2~4倍。同时,将优化后的声场重建结果与传声器在相同位置处的声场直接测量结果进行比较,验证了声光效应层析成像进行超声声场重建的可靠性。

关键词：测量层析成像处理声光效应激光测振仪声场表征扫描效率