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Double [5]carbohelicene: facile synthesis, chiroptical properties,isomerization study, and lasing application

Science China Chemistry 2025年第1期68卷 233-240页

作者： Peipei Liu Yantong Li Meng-Xiang Wu Hao Kang Xiao-Li Zhao Lin Xu Linlin Liu Xiaodong Li Junfeng Fang Zhiwei Fang Ya Cheng Hai-Bo Yang Huakang Yu Xueliang Shi state key laboratory of Petroleum Molecular & Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular Engineering East China Normal University School of Physics and Optoelectronics South China University of Technology Institute of Polymer Optoelectronic Materials & Devices State Key Laboratory of Luminescent Materials & Devices South China University of Technology School of Physics and Electronic Science Engineering Research Center of Nanophotonics & Advanced Instrument Ministry of EducationEast China Normal University state key laboratory of precision Spectroscopy School of Physics and Electronic Science East China Normal University

Double carbohelicenes have attracted considerable attention due to their aesthetic structures, distinct π-conjugation extension, inherent chirality, and intriguing optical and electronic properties. Herein, the concise de novo synthesis of a new double[5]carbohelicene 1 together with its chiroptical properties, isomerization process and lasing application is presented. 1 was synthesized by a simple protocol involving the formation of a 6,6′-bipentacene as the key intermediate. It is worth noting that1 existed as two diastereomers 1-PP/MM and 1-PM, which were successfully isolated and unambiguously confirmed by Xray crystallography. The optical resolution of the racemic 1-PP/MM was successfully achieved by chiral-phase highperformance liquid chromatography（HPLC）, and 1-PP and 1-MM were characterized by circular dichroism. Interestingly, it was found that 1-PP/MM could be completely isomerized to 1-PM upon heating, and the detailed thermodynamics and kinetics of the isomerization process were systematically investigated. 1-PM exhibited deep-red luminescence with emission maximum at 723 nm and fluorescence quantum yield as high as 32.95%. Consequently, we can showcase the lasing application of 1-PM by doping with epoxy resin to assemble a bottle microlaser spontaneously, which the lasing wavelength is 796.6 nm at a threshold of 0.8 m J cm-2. We believe that our studies, including the facile synthesis methodology, detailed isomerization studies, and lasing application, will shed some light on the design and synthesis of novel carbohelical systems with more functions.

关键词： double carbohelicene optical resolution organic laser isomerization X-ray diffraction

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Non-intrusive Load Monitoring Using Gramian Angular Field Color Encoding in Edge Computing

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Chinese Journal of Electronics 2022年第4期31卷 595-603页

作者： CHEN Junfeng WANG Xue Department of precision instrument State Key Laboratory of Precision Measurement Technology and Instrument Tsinghua University

Non-intrusive load monitoring(NILM)can infer the status of the appliances in operation and their energy consumption by analyzing the energy data collected from monitoring devices. With the rapid increase of electric loads in amount and type, the traditional way of uploading all energy data to cloud is facing enormous challenges. It becomes increasingly significant to construct distinguishable load signatures and build robust classification models for NILM. In this paper, we propose a load signature construction method for load recognition task in home scenarios. The load signature is based on the Gramian angular field encoding theory,which is convenient to construct and significantly reduces the data transmission volume of the network. Moreover,edge computing architecture can reasonably utilize computing resources and relieve the pressure of the *** experimental results on NILM datasets demonstrate that the proposed method obtains superior performance in the recognition of household appliances under insufficient resources.

关键词： energy consumption data transmission volume monitoring devices load recognition task Gramian angular field color encoding edge computing architecture energy data NILM Distributed systems software load signature construction method pattern classification nonintrusive load monitoring load monitoring Power system management, operation and economics power engineering computing Data handling techniques Power engineering computing edge computing electric loads

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A sensitive method of determining optic axis azimuth based on laser feedback

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Chinese Physics B 2013年第12期22卷 272-275页

作者：吴云张鹏陈文学谈宜东 The state key lab of precision measurement technology and instrument Department of Precision Instruments Tsinghua University

A sensitive method to determine the optic axis azimuth of the birefringence element is presented, which is based on laser feedback. The phase difference between the two intensities in birefringence feedback changes with the angle between the optic axis of the birefringence element and laser original polarization. The phase difference is highly sensitive to the relative position of the optic axis and the laser original polarization. This method is used to highly precisely determine the optic axis azimuth, and is able to distinguish between the fast axis and the slow axis of the birefringence element. Theoretical analysis and experimental results are both demonstrated.

关键词： laser feedback optic axis differential method phase difference

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Prediction-based Manufacturing Center Self-adaptive Demand Side Energy Optimization in Cyber Physical Systems

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Chinese Journal of Mechanical Engineering 2014年第3期27卷 488-495页

作者： SUN Xinyao WANG Xue WU Jiangwei LIU Youda state key laboratory of precision measurement technology and instrument Tsinghua University

Cyber physical systems（CPS） recently emerge as a new technology which can provide promising approaches to demand side management（DSM）, an important capability in industrial power systems. Meanwhile, the manufacturing center is a typical industrial power subsystem with dozens of high energy consumption devices which have complex physical dynamics. DSM, integrated with CPS, is an effective methodology for solving energy optimization problems in manufacturing center. This paper presents a prediction-based manufacturing center self-adaptive energy optimization method for demand side management in cyber physical systems. To gain prior knowledge of DSM operating results, a sparse Bayesian learning based componential forecasting method is introduced to predict 24-hour electric load levels for specific industrial areas in China. From this data, a pricing strategy is designed based on short-term load forecasting results. To minimize total energy costs while guaranteeing manufacturing center service quality, an adaptive demand side energy optimization algorithm is presented. The proposed scheme is tested in a machining center energy optimization experiment. An AMI sensing system is then used to measure the demand side energy consumption of the manufacturing center. Based on the data collected from the sensing system, the load prediction-based energy optimization scheme is implemented. By employing both the PSO and the CPSO method, the problem of DSM in the manufac^ring center is solved. The results of the experiment show the self-adaptive CPSO energy optimization method enhances optimization by 5% compared with the traditional PSO optimization method.

关键词： cyber physical systems manufacturing center self-adaptive demand side management particle swarm optimization

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Underground laboratories · Deep underground observation ·Scientific questions—Insights from observations of multi-physic fields in deep underground labs

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Science China Earth Sciences 2025年

作者： Huiqi REN Yun WANG Chang CHEN Guangyu FU Longqing QIU Lianghui GUO Chengliang XIE Yongsheng HE Heping SUN Jiwen TENG Institute of Defense Engineering Academy of Military Sciences state Kay laboratory of Geological Processes and Mineral Resources Key Laboratory of Intraplate Volcanoes and Earthquakes Ministry of Education China University of Geosciences (Beijing) Shanghai Institute of Microsystem and Information technology Chinese Academy of Sciences Innovation Academy for precision measurement Science and technology Chinese Academy of Sciences Institute of Geology and Geophysics Chinese Academy of Sciences

This paper presents a comprehensive review on recent development and research conducted in domestic and international underground laboratories. We first introduce the differences in three environments—surface, mountain tunnel cavities and underground coal mine tunnels—by examining cosmic ray background, ambient noises related to gravity and seismic measurement, and electromagnetic noises in magnetic and magnetotelluric measurements. We highlight potential misuse of the term Underground lab or Deep Underground lab when describing observations in different physical fields. We introduce unique features of underground coal mine tunnels in China, such as large spaces, ultra-quiet conditions, and ultra-clean environments. When comparing with mountain tunnel cavities and borehole observations, coal mine tunnel observations have superior long-term stability and high precision. Through observations and comparisons of multi-physic fields at surface and the deep underground, we find that the higher SNR seismic observations conducted in deep underground tunnels in coal mines are beneficial to improve velocity tomography of the solid earth. The gravity observation with a Superconducting Quantum Interference Device(SQUID) makes it possibly to capture slow earthquake, which has not been observed previously in the Chinese mainland. SQUID magnetic observations can detect fluctuations as weak as femto-Tesla(fT), enabling us to explore the attenuation of Schumann Resonance down to the solid Earth. This opens opportunities to investigate the connections between the Earth's magnetic field and the interactions within the human brain and heart. To improve the precision of quantum measurement,we should consider the possible effects of weak magnetic disturbances in deep underground environments. Finally, we discuss the importance of deep underground laboratories, observing facilities and techniques deployed in these laboratories, and their possible connection with respect to “deep space” an

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Effects of surface adsorbed oxygen, applied voltage, and temperature on UV photoresponse of ZnO nanorods

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Chinese Physics B 2015年第10期24卷 501-506页

作者：宗仙丽朱荣 state key laboratory of precision measurement technology and instruments Department of Precision InstrumentTsinghua University

The ultraviolet（UV） photoresponses of ZnO nanorods directly grown on and between two micro Au-electrodes by using electric-field-assisted wet chemical method are measured comprehensively under different conditions, including ambient environment, applied bias voltage, gate voltage and temperature. Experimental results indicate that the photoresponses of the ZnO nanorods can be modulated by surface oxygen adsorptions, applied voltages, as well as temperatures. A model taking into account both surface adsorbed oxygen and electron-hole activities inside ZnO nanorods is proposed. The enhancement effect of the bias voltage on photoresponse is also analyzed. Experimental results shows that the UV response time（to 63%） of ZnO nanorods in air and at 59°C could be shortened from 34.8 s to 0.24 s with a bias of 4 V applied between anode and cathode.

关键词： ZnO nanorods UV photoresponse surface effect applied voltage effect

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A new method of continuous blood pressure monitoring using multichannel sensing signals on the wrist

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Microsystems & Nanoengineering 2023年第5期9卷 141-150页

作者： Liangqi Wang Shuo Tian Rong Zhu state key laboratory of precision measurement technology and instrument Department of Precision InstrumentTsinghua University100084 BeijingChina

Hypertension is a worldwide health problem and a primary risk factor for cardiovascular *** monitoring of blood pressure has important clinical value for the early diagnosis and prevention of cardiovascular ***,existing technologies for wearable continuous blood pressure monitoring are usually inaccurate,rely on subject-specific calibration and have poor generalization across individuals,which limit their practical ***,we report a new blood pressure measurement method and develop an associated wearable device to implement continuous blood pressure monitoring for new *** wearable device detects cardiac output and pulse waveform features through dual photoplethysmography(PPG)sensors worn on the palmar and dorsal sides of the wrist,incorporating custom-made interface sensors to detect the wearing contact pressure and skin *** detected multichannel signals are fused using a machine-learning algorithm to estimate continuous blood pressure in real *** dual PPG sensing method effectively eliminates the personal differences in PPG signals caused by different people and different wearing *** proposed wearable device enables continuous blood pressure monitoring with good generalizability across individuals and demonstrates promising potential in personal health care applications.

关键词： multichannel continuous method

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measurement of Refractive Index Ranging from 1.42847 to 2.48272 at 1064 nm Using a Quasi-Common-Path Laser Feedback System

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Chinese Physics Letters 2015年第9期32卷 21-24页

作者：徐玲谈宜东张书练孙利群 The state key lab of precision measurement technology and instrument Department of Precision InstrumentsTsinghua University

Wavelength 1064 nm is one of the most widely used laser wavelengths in industries and science. The high-precision measurement of the refractive index of optical materials at 1064 nm is significant for improving the optical design. We study the direct measurement of refractive index at 1064nm of lasers, including cMcium fluoride （CaF2）, fused silica and zinc selenide （ZnSe）, whose refractive indices cover a large range from 1.42847 to 2.48272. The measurement system is built based on the quasi-common-path Nd：YAG laser feedback interferometry. The thickness can be measured simultaneously with the refractive index. The results demonstrate that the system has absolute uncertainties of ~10-5 and ~10-4 mm in refractive index and thickness measurement, respectively.

关键词： In measurement of Refractive Index Ranging from 1.42847 to 2.48272 at 1064 nm Using a Quasi-Common-Path Laser Feedback System AOM

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Spectral distortion of dual-comb spectrometry due to repetition rate fluctuation

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Chinese Physics B 2016年第4期25卷 161-165页

作者：杨宏雷尉昊赟李岩 state key laboratory of precision measurement technology & instruments Department of Precision InstrumentTsinghua University

Dual-comb spectrometry suffers the fluctuations of parameters in combs. We demonstrate that the repetition rate is more important than any other parameter, since the fluctuation of the repetition rate leads to a change of difference in the repetition rate between both combs, consequently causing the conversion factor variation and spectral frequency misalignment. The measured frequency noise power spectral density of the repetition rate exhibits an integrated residual frequency modulation of 1.4 Hz from 1 Hz to 100 kHz in our system. This value corresponds to the absorption peak fluctuation within a root mean square value of 0.19 cm-1 that is verified by both simulation and experimental result. Further, we can also simulate spectrum degradation as the fluctuation varies. After modifying misaligned sPectra and averaging, the measured result agrees well with the simulated spectrum based on the GEISA database.

关键词： optical frequency comb Infrared spectra molecular spectra

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Semi-classical theory and experimental research for polarization flipping in a single frequency laser with feedback effect

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Chinese Physics B 2012年第9期21卷 76-80页

作者：陈文学张书练张鹏曾召利 The state key laboratory of precision measurement technology and instrument Department of Precision InstrumentsTsinghua University

In this paper, we propose a semi-classical theory to successfully explain the polarization flipping in a single frequency laser. An experimental setup is built to verify this theory. The observed experimental phenomena are consistent with the theoretical analysis. We perform phase retardation measurements of birefringent components using this experimental system. The results show that the measurement repeatability is 0.12° and the measurement accuracy is 0.22°.

关键词： semi-classical theory interference birefringence

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