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Advanced Photonics 2024年第1期6卷 115-125页

作者： Bingxin Xu yangyang wan Xinyu Fan Zuyuan He Shanghai Jiao Tong University State Key Laboratory of Advanced Optical Communication Systems and NetworksDepartment of Electronic EngineeringShanghaiChina Max-Planck Institute of Quantum Optics Hans-Kopfermann-Straûe 185748 GarchingGermany

Spectroscopy is the basic tool for studying molecular physics and realizing biochemical ***,it is challenging to realize sub-femtometer resolution spectroscopy over broad *** and high-resolution spectroscopy with calibrated optical frequency is demonstrated by bridging the fields of speckle pattern and electro-optic frequency comb.A wavemeter based on a whispering-gallery-mode barcode is proposed to link the frequencies of a probe continuous-wave laser and an ultrastable *** ultrafine electro-optic comb lines are generated from the probe laser to record spectrum of sample with sub-femtometer *** bandwidth is a thousandfold broader than comb bandwidth,by sequentially tuning the probe laser while its wavelength is *** approach fully exploits the advantages of two fields to realize 0.8-fm resolution with a fiber laser and 80-nm bandwidth with an external cavity diode *** spectroscopic measurements of an ultrahigh Q-factor cavity and gas molecular absorption are experimentally *** compact system,predominantly constituted by few-gigahertz electronics and telecommunication components,shows enormous potential for practical spectroscopic applications.

关键词： frequency comb reconstructive wavemeter spectroscopy

Review on Speckle-Based Spectrum Analyzer

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Photonic Sensors 2021年第2期11卷 187-202页

作者： yangyang wan Xinyu FAN Zuyuan HE State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong UniversityShanghai 200240China

Accurate spectral measurement and wavelength determination are fundamental and vital for many fields.A compact spectrum analyzer with high performance is expected to meet the growing requirements,and speckle-based spectrum analyzer is a potential *** basic principle is based on using the random medium to establish a speckle-to-wavelength mapping relationship for spectrum *** article introduces current speckle-based spectrum analyzers with different schemes and reviews recent advances in this ***,some applications by using speckle-based spectrum analyzers are also ***,the existing challenges and the future prospects of using speckle for spectrum recovery are discussed.

关键词： Speckle spectrum analyzer random medium spectroscopy

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落角约束下的高超声速变体飞行器末制导方法

飞行力学 2024年第1期42卷 24-31页

作者：万泱泱郭杰王浩凝葛健豪唐胜景北京理工大学宇航学院北京100081

针对高超声速变体飞行器末段制导问题,提出了一种基于比例控制和预测-校正思想的末制导方法,在满足落角约束的条件下,提升飞行效果。以高超声速飞行器动力学方程为基础、三维偏置比例导引法为框架,构建末制导指令的数学表达。通过实时... 详细信息

针对高超声速变体飞行器末段制导问题,提出了一种基于比例控制和预测-校正思想的末制导方法,在满足落角约束的条件下,提升飞行效果。以高超声速飞行器动力学方程为基础、三维偏置比例导引法为框架,构建末制导指令的数学表达。通过实时预测飞行器落角与目标值的偏差,在线校正导引律的偏置项。开展标称条件和任务变更条件下的仿真测试,并在扰动条件下完成蒙特卡洛打靶仿真试验。仿真结果表明,该末制导方法具有较高的制导精度和较强的抗扰动能力,且具有一定的自主性,能够适应任务变更的情况;该制导律发挥了变体飞行器的优势,相比传统飞行器具有更好的末段飞行性能。

关键词：高超声速变体飞行器三维偏置比例导引预测-校正法落角约束

面向学生就业能力提升的一流课程建设路径探索

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科教文汇 2024年第5期 1-5页

作者：李振江万阳洋甘肃政法大学网络空间安全学院甘肃兰州730000

一流课程建设强调教学质量和效果,关注学生知识、技能和素质的全面发展。在大学生就业日益受到关注的今天,探讨一流课程建设如何助力学生就业能力提升有重大意义。首先,对大学生就业能力的特性和内涵展开分析,提出了专业知识、学习能力... 详细信息

一流课程建设强调教学质量和效果,关注学生知识、技能和素质的全面发展。在大学生就业日益受到关注的今天,探讨一流课程建设如何助力学生就业能力提升有重大意义。首先,对大学生就业能力的特性和内涵展开分析,提出了专业知识、学习能力、自我认知和管理能力、沟通合作能力、解决问题能力这五大核心就业能力,并探讨了这五项能力之间的关系。其次,以信息安全导论课程的具体建设过程为例,分析了课程建设工作如何与就业能力目标对齐。最后,就如何对就业能力培养成效进行评价展开了初步探讨,提出多维度、整体、发展的评价思路。

关键词：一流课程就业能力信息安全导论

Efficient electrooxidation of biomass-derived aldehydes over ultrathin Ni V-layered double hydroxides films

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Journal of Energy Chemistry 2023年第3期78卷 412-421,I0012页

作者： Biying Liu Zhikeng Zheng Yaoyu Liu Man Zhang Yuchen wang yangyang wan Kai Yan Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology School of Environmental Science and EngineeringSun Yat-sen UniversityGuangzhou 510275GuangdongChina Guangdong Laboratory for Lingnan Modern Agriculture South China Agricultural UniversityGuangzhou 510642GuangdongChina Institute for Advanced Materials School of Materials Science and EngineeringJiangsu UniversityZhenjiang 212013JiangsuChina

Selective upgrading of C=O bonds to afford carboxylic acid is significant for the petrochemical industry and biomass *** we declared the efficient electrooxidation of biomass-derived aldehydes family over NiV-layered double hydroxides(LDHs) thin *** studies confirmed the hydroxyl active intermediate(-OH*) generated on the surface of NiV-LDHs films by employing electrochemical impedance spectroscopy and the electron paramagnetic resonance *** using advanced techniques,e.g.,extended X-ray absorption fine structure and high-angle annular dark-field scanning transmission electron microscopy,NiV-LDHs films with 2.6 nm could expose larger specific surface *** benzaldehyde as a model,high current density of 200 mA cm^(-2)at 1.8 V ***,81.1% conversion,77.6% yield of benzoic acid and 90.8% Faradaic efficiency were reached,which was superior to most of previous *** DFT analysis was well matched with experimental findings and documented that NiV-LDHs had high adsorption capacity for the aldehydes to suppress the side reaction,and the aldehydes were oxidized by the electrophilic hydroxyl radicals formed on *** findings offer a universal strategy for the robust upgrading of diverse biomass-derived platform chemicals.

关键词： NiV-LDHs Films Hydroxyl radicals Electrocatalytic oxidation Biomass-derived aldehydes

Data driven discovery of conjugated polyelectrolytes for optoelectronic and photocatalytic applications

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npj Computational Materials 2021年第1期7卷 641-649页

作者： yangyang wan Fernando Ramirez Xu Zhang Thuc-Quyen Nguyen Guillermo C.Bazan Gang Lu Department of Physics and Astronomy California State University NorthridgeNorthridgeCaliforniaUSA Department of Chemistry and Biochemistry University of CaliforniaSanta BarbaraCaliforniaUSA

Conjugated polyelectrolytes(CPEs),comprised of conjugated backbones and pendant ionic functionalities,are versatile organic materials with diverse ***,the myriad of possible molecular structures of CPEs render traditional,trial-and-error materials discovery strategy ***,we tackle this problem using a data-centric approach by incorporating machine learning with high-throughput first-principles *** systematically examine how key materials properties depend on individual structural components of CPEs and from which the structure–property relationships are *** means of machine learning,we uncover structural features crucial to the CPE properties,and these features are then used as descriptors in the machine learning to predict the properties of unknown ***,we discover promising CPEs as hole transport materials in halide perovskite-based optoelectronic devices and as photocatalysts for water *** work could accelerate the discovery of CPEs for optoelectronic and photocatalytic applications.

关键词： conjugated backbone photocatalytic

Programmable meta-holography dynamics enabled by grating-modulation

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Photonics Research 2024年第7期12卷 1522-1526页

作者： RUNLONG RAO SHUAI wan ZHE LI yangyang SHI ZHONGYANG LI Electronic Information School Wuhan UniversityWuhan 430072China Wuhan Institute of Quantum Technology Wuhan 430206China School of Microelectronics Wuhan UniversityWuhan 430072China Suzhou Institute of Wuhan University Suzhou 215123China

Towards next-generation intelligent display devices, it is urgent to find a cheap and convenient dynamic optical control method. Conventional gratings are widely used as cheap diffractive elements due to their effective optical control capabilities. However, they are limited within multi-function or complex optical modulation due to the lack of accurate control of the amplitude/phase at pixel-level. Here, a metasurface-assisted grating-modulation system is originally proposed to achieve switchable multi-fold meta-holographic dynamics. By incorporating metasurfaces with traditional gratings and tuning their relative coupling positions, the modulation system gains the optical modulation capability to realize complex optical functionalities. Specifically, by varying the grating periods/positions relative to the metasurface, 2–8 holographic image channels are programmed to be dynamically exhibited and switched. The proposed metasurface-assisted grating-modulation approach enjoys cost-effective convenience, strong encoding freedom, and facile operation, which promises programmable optical displays,optical sensors, optical information encryption/storage, etc.

关键词： tuning switched holographic

Surface etching induced ultrathin sandwich structure realizing enhanced photocatalytic activity

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Science China Chemistry 2018年第12期61卷 1572-1580页

作者： Bo Yang Wentuan Bi yangyang wan Xiaogang Li Mingcan Huang Ruilin Yuan Huanxin Ju wangsheng Chu Xiaojun Wu Linghui He Changzheng Wu Yi Xie National Laboratory for Physical Sciences at the Microscale Collaborative Innovation Cenof Chemistry for Energy Materials (iChEM) CAS Key Laboratory of Mechanical Behavior and Design of Materials (LMBD) and Department of Modern Mechanics University of Science & Technology of China Hefei 230026 China CAS Key Laboratory of Materials for Energy Conversion CAS Center for Excellence in Nanoscience Synergetic Innovation of Quantum Information & Quantum Technology and Department of Materials Science and Engineering University of Science &Technology of China Hefei 230026 China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230026 China

Photocatalytic conversion efficiency is limited by serious charge carrier recombination. Efficient carrier separation is usually achieved by elegantly-designed multi-component structures connected by directional electric field. Herein, we developed a twodimensional(2 D) sandwich structure, as a new photocatalytic system, to realize high-efficiency carrier separation. This strategy integrated multifunction into a single structure for the first time, which successfully introduces a stable built-in electric field,realizing high-effective carrier separation. Besides, the carrier concentration is dramatically increased due to dimensional confinement. Benefiting from above synergic advantages, 2 D sandwich photocatalyst achieves the highest nitrogen fixation rate(435 μmol g^(-1) h^(-1)) in inorganic solid photocatalysts under visible light irradiation. We anticipate that 2 D sandwich photocatalyst holds promises for the application and expansion of 2 D materials in photocatalysis research.

关键词： two-dimensional materials photocatalysis sandwich structure surface modification nitrogen fixation

High-metallic-phase-concentration MO1-xWxS2 nanosheets with expanded interlayers as efficient electrocatalysts

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Nano Research 2018年第3期11卷 1687-1698页

作者： Qun He yangyang wan Hongliang Jiang Chuanqiang Wu Zhongti Sun Shuangming Chen Yu Zhou Haiping Chen Daobin Liu Yasir A. Haleem Binghui Ge Xiaojun Wu Li Song National Synchrotron Radiation Laboratory CAS Center for Excellence in Nanoscience University of Science and Technology of China Hefei 230029 China CAS Key Lab of Materials for Energy Conversion CAS Center for Excellence in Nanoscience Hefei National Laboratory for Physical Science at the Microscale Synergetic Innovation of Quantum Information & Quantum Technology University of Science and Technology of China Hefei 230026 China Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China

In most cases, layered transition metal dichalcogenides （LTMDs）, containing metallic phases, show electrochemical behavior different from their semiconductor counterparts. Typically, two-dimensional layered metallic 1T-MoS2 demonstrates better electrocatalytic performance for water splitting compared to its 2H counterpart. However, the characteristics of low metallic phase concentration and poor stability limit its applications in some cases. Herein, we demonstrate a simple and efficient bottom-up wet-chemistry strategy for the large-scale synthesis of nanoscopic ultrathin Mo1-xWxS2 nanosheets with enlarged interlayer spacing and high metallic phase concentration. Our characterizations, including X-ray absorption fine structure spectroscopy （XAFS）, high-angle annular dark-field- scanning transmission electron microscopy （HAADF-STEM）, and X-ray photoelectron spectroscopy （XPS） revealed that the metallic ultrathin ternary Mo1-xWxS2 nanosheets exhibited distorted metal-metal bonds and a tunable metallic phase concentration. As a proof of concept, this optimized catalyst, with the highest metallic phase concentration （greater than 90%）, achieved a low overpotential of about -155 mV at a current density of -10 ma/cm^2, a small Tafel slope of 67 mV/dec, and an increased turnover frequency （TOF） of 1.3 H2 per second at an overpotential of -300 mV （vs. reversible hydrogen electrode （RHE））, highlighting the importance of the metallic phase. More importantly, this study can lead to a facile solvothermal route to prepare stable and high-metallic- phase-concentration transition-metal-based two-dimensional materials for future applications.

关键词： wet-chemistr gram-scale synthesis interlayer intercalation metallic transition metaldichalcogenide electrocatalytic water splitting

Dynamic emission characteristics and control strategies of air pollutants from motor vehicles in downtown Beijing,China

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Journal of Environmental Sciences 2024年第2期136卷 637-646页

作者： Yan Shen Tongran Wu Aiping Lian Jie Gao Fei Peng Guohua Song Xuefang Wu yangyang Cui Xinyu Liu Yunfei wan Jing Yan Yifeng Xue National Engineering Research Center of Urban Environmental Pollution Control Beijing Municipal Research Institute of Eco-Environmental ProtectionBeijing 100037China Beijing Municipal Ecology and Environment Bureau Beijing 100048China Beijing Jiaotong University Beijing 100091China

This study combined the real-time monitoring and investigation of traffic flows to comprehensively analyze the road traffic flow and vehicle structure in downtown Beijing.A dynamic emission inventory of motor vehicle air pollutants in downtown Beijing in 2021 was established,and the impact of these emissions on air quality was simulated and quantified,and different emission reduction control scenarios were proposed to evaluate their environmental improvement effects and explore measures to mitigate the impact of pollution *** results show that the high traffic flow and the structure of the motor vehicle emissions in downtown Beijing are the main causes of severe motor vehicle *** data shows that traffic flow in central Beijing is dominated by small passenger vehicles,while the vehicle mix is better than in other regions,with 72.0%of vehicles meeting"National V"or higher emission ***,to achieve higher air quality goals,further reducing vehicle emissions is *** on dynamic traffic flow,the average daily emissions of nitrogen oxides(NOX),particulate matters(PM_(2.5))and volatile organic compounds(VOC)from motor vehicles in central Beijing are 17.7 tons,0.6 tons and 14.0 tons,respectively,accounting for 23.0%of the city’s average daily motor vehicle *** a zero-emission zone for motor vehicles were implemented in central Beijing,the annual average emission level of pollutants will be reduced by 10.4%to 21.0%.The designation of ultra-low emission zones for motor vehicles could be effective in improving the air quality in the center of Beijing.

关键词： Motor vehicle Air pollutant Emission characteristics Control strategy Beijing