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Vector meson's spin alignments in high energy reactions

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Science China(physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 5-20页

作者： Jin-Hui Chen Zuo-Tang Liang Yu-Gang Ma Xin-Li Sheng Qun Wang Key Laboratory of Nuclear physics and Ion-beam Application (MoE) Institute of Modern PhysicsFudan University Institute of Frontier and interdisciplinary Science Key Laboratory of Particle Physics and Particle Irradiation (MOE)Shandong University INFN-Firenze department of Modern physics University of Science and Technology of China School of Mechanics and physics Anhui University of Science and Technology

The global spin alignment of vector mesons has been observed by the STAR collaboration at the Relativistic Heavy Ion Collider （RHIC） at Brookhaven National Laboratory （BNL）.It provides a unique opportunity to probe the correlation between the polarized quark and antiquark in the strongly coupled quark-gluon plasma （sQGP） produced in relativistic heavy ion collisions,opening a new window to explore the properties of s *** addition,spin alignments of vector mesons have also been observed in other high-energy particle collisions such as e+e-annihilations at high energies where hadron production is dominated by quark fragmentation *** results obtained are quite different from those obtained in heavy ion collisions where quark coalescence/combination mechanism dominates suggesting strong dependence on hadronization *** comprehensive studies in different hadronization processes are *** this article,we present a brief review of theoretical and experimental advances in the study of vector meson’s spin alignments in a variety of high-energy particle collisions,with emphasis on hadronization mechanisms.

关键词： vector meson spin alignment global polarization relativistic heavy ion collisions fragmentation

Emerging properties of two-dimensional twisted bilayer materials

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Chinese physics B 2019年第10期28卷 83-92页

作者： Yang Cheng Chen Huang Hao Hong Zixun Zhao Kaihui Liu State Key Laboratory for Mesoscopic physics Academy for Advanced Interdisciplinary Studies School of Physics Peking University

Recent studies in van der Waals coupled two-dimensional(2D) bilayer materials have demonstrated a new freedom for material engineering by the formation of moiré pattern. By tuning the twist angle between two layers, one can modulate their electronic band structures and therefore the associated electrical transport and optical properties, which are distinct from the original ones of each individual layer. These new properties excite great passion in the exploration of new quantum states and possible applications of 2D bilayers. In this article, we will mainly review the prevailing fabrication methods and emerging physical properties of twisted bilayer materials and lastly give out a perspective of this topic.

关键词： two-dimensional materials twist angle moiré potential interlayer coupling

Ultrathin ZnO membranes a few atomic layers in thickness

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Science China(Technological Sciences) 2014年第2期57卷 315-321页

作者： YIN JianBo XIA HuaRong LIANG Jia ZHANG GengMin Key Laboratory for the physics and Chemistry of Nanodevices and department of Electronics Peking University academy for advanced interdisciplinary studies Peking University

For the first time we fabricated ZnO membranes with thicknesses of 2.4 nm by a facile one-pot synthesis in aqueous *** crystal analysis revealed that the hexagonal ZnO membranes were about 10 atomic layers in *** ZnO membranes bent,scrolled,intersected with each other,and self-assembled to particles in micrometre *** hierarchical assemblies showed sponge-like structures with room *** the growth process,a cationic polyelectrolyte was utilized to modulate growth behavior of the ZnO *** a result,the preferred growth direction of ZnO membranes is along 0110,which was perpendicular to[0001]growth direction in a typical hydrothermal *** growth mechanism of the membranes was also discussed.

关键词： ZnO 2D materials nanosheets hierarchical structures

Improved atom number with a dual color magneto-optical trap

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Chinese physics B 2012年第4期21卷 10-13页

作者：曹强罗鑫宇高奎意王晓锐陈东敏王如泉 Institute of physics Chinese Academy of SciencesBeijing 100190China academy for advanced interdisciplinary studies Peking UniversityBeijing 100871China

We demonstrate a novel dual color magneto optical trap （MOT）, which uses two sets of overlapping laser beams to cool and trap SrRb atoms. Tile volume of cold cloud in the dual color MOT is strongly dependent on the frequency difference of the laser beams and can be significantly larger than that in the normal MOT with single frequency MOT beams. Our experiment shows that the dual color MOT has the same loading rate as the normal MOT, but much longer loading time, leading to threefold increase in the number of trapped atoms. This indicates that the larger number is caused by reduced light induced loss. The dual color MOT is very useful in experiments where both high vacuum level and large atom mmlbcr are required, such as single chamber quantum memory and Bose-Einstein condensation （BEC） experiments. Compared to the popular dark spontaneous-force optical trap （dark SPOT） technique, our approach is technically simpler and more suitable to low power laser systems.

关键词： inagneto optical trap

Carbon nanotube-based CMOS transistors and integrated circuits

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Science China(Information Sciences) 2021年第10期64卷 136-151页

作者： Yunong XIE Zhiyong ZHANG Key Laboratory for the physics and Chemistry of Nanodevices and department of Electronics and Center for Carbon-based Electronics Department of Electronics Peking University academy for advanced interdisciplinary studies Peking University

Over the last sixty years, the scaling of silicon-based complementary metal-oxide-semiconductor(CMOS) field-effect transistors(FETs) have promoted the rapid development of microelectronic ***, the development of Si CMOS technology is currently subject to serious challenges from various aspects such as physics limit, cost, and power consumption, and is becoming increasingly difficult. Material innovation is exerting an ever-greater role in the integrated circuit design. By looking for thinner semiconductor materials with higher mobility as the active layer to construct smaller and higher-performance transistors, it is possible to further stimulate transistors and integrated circuits on performance, density,power dissipation, and functions. In 1991, Iijima discovered carbon nanotubes(CNTs). Due to its excellent electrical properties and intrinsic nano-scale size, CNT has been considered by academia and industry to have great potential to replace silicon materials in the future for the extremely scaled technology nodes or novel electronic applications. This paper reviews the latest advancements in CNT-based electronics ***, the challenges and pathways for nanotube transistors to transition into commercial applications are discussed.

关键词： carbon nanotube transistor integrated circuit scaling nanoelectronics

A Metal Oxide Heterostructure for Resistive Random Access Memory Devices

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Chinese physics Letters 2013年第4期30卷 197-200页

作者： LIAO Zhao-Liang CHEN Dong-Min department of physics and Astronomy Louisianan State UniversityBaton RougeLA 70810USA academy for advanced interdisciplinary studies Peking UniversityBeijing 100871

We propose and investigate a metal oxide heterostructure(MOH)based resistive switching(RS)*** driving mechanism of resistive switching(RS)in an MOH is more directly related to oxygen ion/vacancy migration around their *** performance of an MOH-based RS device depends on the oxygen mobility,oxygen vacancy concentration as well as its relation to the *** enhanced ratio of high resistance state to low resistance state can be achieved if the two involved metal oxides are mutually complemental metal oxides in which one of them has larger resistivity with increasing concentration of vacancy while the other one is the reverse.

关键词： resistance vacancy resistivity

Application of neutron imaging in observing various states of matter inside lithium batteries

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National Science Review 2023年第11期10卷 192-208页

作者： Lei Gao Songbai Han Haijin Ni Jinlong Zhu Liping Wang Song Gao Yonggang Wang Dubin Huang Yusheng Zhao Ruqiang Zou School of Materials Science and Engineering Peking University academy for advanced interdisciplinary studies Southern University of Science and Technology department of physics Southern University of Science and Technology Eastern Institute for advanced Study

Lithium batteries have been essential technologies and become an integral part of our daily lives, powering a range of devices from phones to electric vehicles. To fully understand and optimize the performance of lithium batteries, it is necessary to investigate their internal states and processes through various characterization methods. Neutron imaging has been an indispensable complementary characterization technique to X-ray imaging or electron microscopy because of the unique interaction principle between neutrons and matter. It provides particular insights into the various states of matter inside lithium batteries,including the Li+concentration in solid electrodes, the Li plating/stripping behavior of Li-metal anodes,the Li+diffusion in solid ionic conductors, the distribution of liquid electrolytes and the generation of *** review aims to highlight the capabilities and advantages of neutron imaging in characterizing lithium batteries, as well as its current state of application in this field. Additionally, we discuss the potential of neutron imaging to contribute to the ongoing development of advanced batteries through its ability to visualize internal evolution.

关键词： lithium battery neutron imaging electrodes electrolytes

Prostate cancer identification: quantitative analysis of T2-weighted MR images based on a back propagation artificial neural network model

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Science China(Life Sciences) 2015年第7期58卷 666-673页

作者： ZHAO Kai WANG ChengYan HU Juan YANG XueDong WANG He LI FeiYu ZHANG XiaoDong ZHANG Jue WANG XiaoYing department of Radiology Peking University First Hospital academy for advanced interdisciplinary studies Peking University

Computer-aided diagnosis(CAD) systems have been proposed to assist radiologists in making diagnostic decisions by providing helpful information. As one of the most important sequences in prostate magnetic resonance imaging(MRI), image features from T2-weighted images(T2WI) were extracted and evaluated for the diagnostic performances by using CAD. We extracted 12 quantitative image features from prostate T2-weighted MR images. The importance of each feature in cancer identification was compared in the peripheral zone(PZ) and central gland(CG), respectively. The performance of the computer-aided diagnosis system supported by an artificial neural network was tested. With computer-aided analysis of T2-weighted images, many characteristic features with different diagnostic capabilities can be extracted. We discovered most of the features(10/12) had significant difference(P<0.01) between PCa and non-PCa in the PZ, while only five features(sum average, minimum value, standard deviation, 10 th percentile, and entropy) had significant difference in CG. CAD prediction by features from T2 w images can reach high accuracy and specificity while maintaining acceptable sensitivity. The outcome is convictive and helpful in medical diagnosis.

关键词： prostate cancer magnetic resonance imaging T2WI diagnosis computer-assisted

A historical overview of nano-optics:From near-field optics to plasmonics

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Chinese physics B 2024年第5期33卷 134-145页

作者：邓妙怡朱星 department of History of Science Technology and MedicineAcademy for Advanced Interdisciplinary StudiesPeking UniversityBeijing 100871China School of physics Peking UniversityBeijing 100871China

Nano-optics is an emergent research field in physics that appeared in the 1980s,which deals with light–matter optical interactions at the nanometer *** early studies of nano-optics,the main concern focus is to obtain higher optical resolution over the diffraction *** researches of near-field imaging and spectroscopy based on scanning near-field optical microscopy(SNOM)are *** exploration of improving SNOM probe for near-field detection leads to the emergence of surface *** the sense of resolution and wider application,there has been a significant transition from seeking higher resolution microscopy to plasmonic near-field modulations in the nano-optics community during the nano-optic ***,studies of nano-optics prefer the investigation of plasmonics in different material *** this article,the history of the development of near-field optics is briefly *** difficulties of conventional SNOM to achieve higher resolution are *** an alternative solution,surface plasmons have shown the advantages of higher resolution,wider application,and flexible nano-optical modulation for new *** typical studies in different periods are introduced and characteristics of nano-optics in each stage are *** this way,the evolution progress from near-field optics to plasmonics of nano-optics research is *** future development of nano-optics is discussed then.

关键词： nano-optics near-field optics surface plasmon plasmonic modulation