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Experimental simulation of the Unruh effect on an NMR quantum simulator

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Science China(Physics,Mechanics & Astronomy) 2016年第3期59卷 48-55页

作者： Fang Zhou Jin Hong Wei chen Xing Rong Hui Zhou Ming jun Shi Qi Zhang chen yong ju Yi Fu Cai Shun Long Luo Xin Hua Peng Jiang Feng Du Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics University of Science and Technology of China High Magnetic Field Laboratory Chinese Academy of Sciences Academy of Mathematics and Systems Science Chinese Academy of Sciences

The Unruh effect is one of the most fundamental manifestations of the fact that the particle content of a field theory is observer dependent. However, there has been so far no experimental verification of this effect, as the associated temperatures lie far below any observable threshold. Recently, physical phenomena, which are of great experimental challenge, have been investigated by quantum simulations in various fields. Here we perform a proof-of-principle simulation of the evolution of ferrnionic modes under the Unruh effect with a nuclear magnetic resonance （NMR） quantum simulator. By the quantum simulator, we experimentally demonstrate the behavior of Unruh temperature with acceleration, and we fiarther investigate the quantum correlations quantified by quantum discord between two fermionic modes as seen by two relatively accelerated observers. It is shown that the quantum correlations can be created by the Unrtfia effect from the classically correlated states. Our work may provide a promising way to explore the quantum physics of accelerated systems.

关键词： quantum simulation Unruh effect quantum correlations

Intensity and Polarization Effects in Short-Pulse Multiphoton Ionization of Xenon

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Chinese Physics Letters 2011年第8期28卷 76-79页

作者： KANG Hui-Peng WANG Chuan-Liang LIN Zhi-Yang chen yong-ju WU Ming-Yan QUAN Wei LIU Hong-Ping LIU Xiao-jun State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071 Graduate School of Chinese Academy of Sciences Beijing 100049

We present photoelectron spectra(PES)of xenon subject to ultrashort intense laser pulses at 400 *** intensity-dependent PES exhibit the dominance of ac-Stark-shifted multiphoton resonances in a multiphoton ionization process.A distinct difference in the spectra with different laser polarization states(i.e.,linearly and circularly polarized states)is revealed and can be understood in terms of the quantum selection rule,which restricts the angular momentum of states that may shift into multiphoton ***,the intensity dependence of the resonance-enhanced electron yield is analyzed in the context of multiphoton Landau–Zener *** model calculation results considering the focal volume effect are in good agreement with the experimental observation.

关键词： process theory Polarization

Dative B–N bonds weaven toward two-dimensional purely organic materials for single crystals

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Science China Chemistry 2025年第1期68卷 12-14页

作者： Wei-Lei Zhou Siwei Wang yong chen College of Chemistry and Materials Science Inner Mongolia Key Laboratory of Chemistry for Nature Products and Synthesis for Functional Molecules Innovation Team of Optical Functional Molecular Devices Inner Mongolia Minzu University College of Chemistry Nankai University

Molecular topology is one of the important topics to study and understand the relationship between molecular structure and properties [1]. Particularly, two-dimensional (2D) materials with extremely high surface area and ultra-thin morphology have attracted considerable attention due to their unexpected properties in materials and chemistry [2,3].

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Robust facial expression recognition via lightweight reinforcement learning for rehabilitation robotics

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Optoelectronics Letters 2025年第2期21卷 97-104页

作者： chen Yifan FAN Weiming GAO Hongwei YU Jiahui ju Zhaojie School of Computing University of Portsmouth School of Automation and Electrical Engineering Shenyang Ligong University Department of Biomedical Engineering Zhejiang University

This paper proposes a lightweight reinforcement network (LRN) and auxiliary label distribution learning (ALDL)based robust facial expression recognition (FER) *** designed representation reinforcement (RR) network mainly comprises two modules,i.e.,the RR module and the auxiliary label space construction (ALSC) *** RR module highlights key feature messaging nodes in feature maps,and ALSC allows multiple labels with different intensities to be linked to one ***,LRN has a more robust feature extraction capability when model parameters are greatly reduced,and ALDL is proposed to contribute to the training effect of LRN in the condition of ambiguous training *** tested our method on FER-Plus and RAF-DB datasets,and the experiment demonstrates the feasibility of our method in practice during rehabilitation robots.

关键词： Reinforcement learning

De novo synthesis of atropisomeric benzofurans via Cu/SPDO complex catalyzed asymmetric formal [3 + 2] annulation

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Science China Chemistry 2025年第1期68卷 174-180页

作者： Fan-Xiao Meng Xing-Yu Wang Ka Lu ju-Song Yang Fu-Min Zhang Ai-jun Ma Bao Du yong-Qiang Tu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University School of Biotechnology and Health Sciences Wuyi University

Herein, the de novo synthesis of atropisomeric benzofurans through the Cu/spirocyclic-pyrrolidine-oxazoline(SPDO) complex catalyze asymmetric formal [3 + 2] cycloaddition between quinones and ynamides is explored, producing a range of structurally diverse axially chiral benzofurans in satisfactory yields with good to excellent enantioselectivities. Furthermore, density functional theory calculations were applied to explain the possible reaction mechanism.

关键词： benzofuran atropisomers novel de novo synthetic strategy asymmetric formal [3 + 2] cycladdition Cu/SPDO complex DFT calculations

Unraveling post-growth mechanisms of monolayer CsPbBr3 nanocubes:Laser-enhanced transformations and cathodoluminescence-electron microscopy correlations

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Journal of Energy Chemistry 2025年第1期100卷 146-156页

作者： Mingxing Li Xiaoge Wang Xiaofan Cao Zhiqun He Chunjun Liang Mingxing chen Jing ju Fangtian You Key Laboratory of Luminescence and Optical Information Ministry of Education Institute of Optoelectronic Technology Beijing Jiaotong University Beijing National Laboratory for Molecular Sciences (BNLMS) College of Chemistry and Molecular Engineering Peking University

Lead-halide perovskite nanoparticles（LHP NPs） are highly promising materials for next-generation displays and solid-state lighting due to their exceptional optical properties. However, their inherent instability presents a significant challenge. Recent advances have demonstrated that optoelectronic devices based on monolayer nanoparticle films exhibit both high luminescence efficiency and long-term *** research demonstrates that mobility limitations and anisotropic alignments in CsPbBr3nanocube monolayer films are key to their stabilization, hindering spontaneous growth through face-to-face fusion and resulting in the formation of connecting necks in a diagonal direction. Introducing laser irradiation confirmed this by significantly accelerating nanocubes growth, increasing mobility, and enhancing local structural ordering, leading to larger and more regularly shaped nanosheets. Fourier transform infrared spectroscopy and energy dispersive spectroscopy line-scan analyses indicated that laser irradiation did not disrupt the ligand structure. Transmission electron microscopy and correlative cathodoluminescence electron microscopy revealed the effects of post-growth and heterogeneous structures, including enhanced luminescence and inhomogeneous intensity in the nanosheets. These findings deepen the understanding of the post-growth mechanism of monolayer nanoparticles and the structure-emission correlation and highlight the unique role of laser irradiation in directing the formation of well-defined and regular nanostructures.

关键词： Energy dispersive spectroscopy

Trinuclear gold-catalyzed site-selective alkylation of peptides

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Science China Chemistry 2025年第1期68卷 249-256页

作者： Qing-Yun Fang chengyihan Gu Yinghan chen Wencheng Yan yong Liang Weipeng Li chengjian Zhu Jie Han Jin Xie State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic Materials Chemistry and Biomedicine Innovation Center (Chem BIC) School of Chemistry and Chemical Engineering Nanjing University Green Catalysis Center College of Chemistry Zhengzhou University State Key Laboratory of Natural Medicines China Pharmaceutical University

Selective modification of peptides has always been a challenging issue. The selective alkylation of peptides can alter the biological activity and physical properties of molecules, and it has gained significant research interest. We herein disclose an intriguing gold-catalyzed alkylation of peptides using bench-stable unactivated alkyl bromides under photoredox catalysis. A wide range of structurally diverse primary, secondary and tertiary alkyl bromides serve as effective coupling partners to precisely connect with the α-C(sp3)–H in glycine residue of peptides. This protocol demonstrates an exceptionally broad scope for alkyl halides and excellent tolerance for a wide range of useful functional groups. A series of relay transformations to construct cyclic peptides, to proceed click reaction and to realize peptide fluorescence labeling further enhance its synthetic practicality. In addition, mechanistic studies and density functional theory(DFT) calculations reveal an inner-sphere and subsequent outersphere single electron transfer(SET) mechanism.

关键词： gold catalysis peptide alkylation C-C coupling radical

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Depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 335-345页

作者： Feng Zhang chenyang Zhang Linlin Wu Wei Sun Hongliang Zhang Jianhua chen yong Pei Songjiang Li Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization Hunan International Joint Research Center for Efficient and Clean Utilization of Critical Metal Mineral ResourcesSchool of Minerals Processing and BioengineeringCentral South UniversityChangsha 410083China State Key Laboratory of Mineral Processing Beijing General Research Institute of Mining&MetallurgyBeijing 100160China Hunan Provincial Key Laboratory of Micro&Nano Materials Interfaces Science College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China School of Resources Environment and MaterialsGuangxi UniversityNanning 530004China Department of Chemistry Xiangtan UniversityXiangtan 411105China China Railway Resource Group Co.Ltd Beijing 102300China

The depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite still lacked in-depth ***,the depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite was further systematically investigated with experiments and density functional theory(DFT)*** X-ray photoelectric spectroscopy(XPS)results,DFT calculation results,and frontier molecular orbital analysis indicated that sulfite ions were difficult to be adsorbed on sphalerite surface,suggesting that sulfite ions achieved depression effects on sphalerite through other non-adsorption ***,the oxygen content in the surface of sphalerite treated with sulfite ions in creased,which enhanced the hydrophilicity of the sphalerite and further increased the difference in hydrophilicity between sphalerite and ***,sulfite ions were chelated with lead ions to form PbSO_(3)in *** hydrophilic PbSO_(3)was more easily adsorbed on sphalerite than *** interaction between sulfite ions and lead ions could effectively inhibit the activation of *** addition the UV spectrum showed that after adding sulfite ions,the peak of perxanthate in the sphalerite treated xanthate solution was significantly stronger than that in the galena with xanthate solution,indicating that xanthate interacted more readily with sulfite ions and oxygen mo lecules within the sphalerite system,leading to the formation of ***,sulfite ions hardly depressed the flotation of ga lena and could promote the flotation of galena to some *** study deepened the understanding of the depression mechanism o sulfite ions on sphalerite and Pb^(2+)activated sphalerite.

关键词： sphalerite galena sulfite ion density functional theory depression mechanism

纤维支气管镜在慢性阻塞性肺疾病机械通气序贯撤机中的应用

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中华急诊医学杂志 2011年第12期20卷 1311-1315页

作者：宋蓉蓉邱艳萍陈永菊季勇南通市通州区人民医院重症医学科江苏省南通226300

目的观察应用纤维支气管镜（纤支镜）辅助慢性阻塞性肺疾病急性发作（AECOPD）并发呼吸衰竭患者机械通气时序贯撤机的临床疗效。方法将106例AECOPD并发呼吸衰竭接受经口气管插管和机械通气者随机分为2组：应用纤支镜辅助有创一无创机械... 详细信息

目的观察应用纤维支气管镜（纤支镜）辅助慢性阻塞性肺疾病急性发作（AECOPD）并发呼吸衰竭患者机械通气时序贯撤机的临床疗效。方法将106例AECOPD并发呼吸衰竭接受经口气管插管和机械通气者随机分为2组：应用纤支镜辅助有创一无创机械通气序贯撤机组（A组，54例）和有创一无创机械通气序贯撤机组（B组，52例）。A组纤支镜从气管导管外进入气道，操作过程中不问断使用呼吸机。两组患者一般治疗相同，达肺部感染控制窗（PIC）后拔除气管导管改无创机械通气模式，然后依情况决定撤机。治疗后比较两组病例下列指标：（1）PIC出现时间、总机械通气时间、住ICU时间、首次撤机成功率、再上机率、呼吸机相关肺炎（VAP）发生率；（2）纤支镜操作对该类患者的安全性。结果A组和B组PIC出现时间分别为（5．01±1．49）d、（5．87±1．87）d，P〈0．05；总机械通气时间分别为（6．98±1．84）d、（8．69±2．41）d，P〈0．01；住ICU时间分别为（9．25±1．84）d、（11．10±2．63）d，P〈0．01；首次撤机成功率分别为96．30％、76．92％，P〈0．01；再上机率分别为5．56％、19．23％，P〈0．05；VAP发生率分别为3．70％、23．07％，P〈0．01。治疗组纤支镜操作简便、安全，未发生明显不良反应。结论AECOPD并发呼吸衰竭进行机械通气患者应用纤支镜辅助治疗可缩短机械通气时间，增加撤机成功率，减少VAP的发生，且方便安全。

关键词：慢性阻塞性肺疾病急性发作呼吸衰竭机械通气序贯撤机纤维支气管镜支气管肺泡灌洗肺部感染控制窗不良反应成功率