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Laser manufacturing of spatial resolution approaching quantum limit

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Light(Science & Applications) 2024年第3期13卷 421-428页

作者： Xiao-Jie Wang Hong-Hua Fang Zhen-Ze Li Dan Wang Hong-Bo Sun State key laboratory of precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China State key laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin University2699 Qianjin StreetChangchun 130012China

Atomic and close-to-atom scale manufacturing is a promising avenue toward single-photon emitters,single-electron transistors,single-atom memory,and quantum-bit devices for future communication,computation,and sensing applications.Laser manufacturing is outstanding to this end for ease of beam manipulation,batch production,and no requirement for photomasks.It is,however,suffering from optical diffraction limits.Herein,we report a spatial resolution improved to the quantum limit by exploiting a threshold tracing and lock-in method,whereby the two-order gap between atomic point defect complexes and optical diffraction limit is surpassed,and a feature size of<5 nm is realized.The underlying physics is that the uncertainty of local atom thermal motion dominates electron excitation,rather than the power density slope of the incident laser.We show that the colour centre yield in hexagonal boron nitride is transformed from stochastic to deterministic,and the emission from individual sites becomes polychromatic to monochromatic.As a result,single colour centres in the regular array are deterministically created with a unity yield and high positional accuracy,serving as a step forward for integrated quantum technological applications.

关键词： quantum limit resolution

Kinematic calibration method with high measurement efficiency and robust identification for hybrid machine tools

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Chinese Journal of Aeronautics 2024年第3期37卷 468-482页

作者： Liping WANG Mengyu LI Guang YU Weitao LI Xiangyu KONG State key laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Beijing key laboratory of precision/Ultra-precision Manufacturing Equipment and Control Beijing 100084China

Geometric error is the main factor affecting the machining accuracy of hybrid machine tools.Kinematic calibration is an effective way to improve the geometric accuracy of hybrid machine tools.The necessity to measure both position and orientation at each pose,as well as the instability of identification in case of incomplete measurements,severely affects the application of traditional calibration methods.In this study,a kinematic calibration method with high measurement efficiency and robust identification is proposed to improve the kinematic accuracy of a five-axis hybrid machine tool.First,the configuration is introduced,and an error model is derived.Further,by investigating the mechanism error characteristics,a measurement scheme that only requires tool centre point position error measurement and one alignment operation is proposed.Subsequently,by analysing the effects of unmeasured degrees of freedom(DOFs)on other DOFs,an improved nonlinear least squares method based on virtual measurement values is proposed to achieve stable parameter identification in case of incomplete measurement,without introducing additional parameters.Finally,the proposed calibration method is verified through simulations and experiments.The proposed method can efficiently accomplish the kinematic calibration of the hybrid machine tool.The accuracy of the hybrid machine tool is significantly improved after calibration,satisfying actual aerospace machining requirements.

关键词： Hybrid machine tool Calibration Measurement scheme Improved nonlinear least squares method Virtual measurement values

Particle distributions in Lamb wave based acoustofluidics

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Nanotechnology and precision Engineering 2024年第2期7卷 60-68页

作者： Chuanchao Zhang Xian Chen Wei Wei Xuejiao Chen Quanning Li Xuexin Duan key laboratory of precision Measuring Technology and Instruments College of Precision Instrument and Optoelectronics EngineeringTianjin UniversityTianjin300072China

Acoustic streaming enabled by a Lamb wave resonator(LWR)is efficient for particle trapping and enrichment in microfluidic channels.However,because Lamb waves combine the features of bulk acoustic waves and surface acoustic waves,the resulting acoustic streaming in the LWR occurs in multiple planes,and the particle flow behavior in this acoustofluidic system is largely unknown.Reported here are numerical simulations and laboratory experiments conducted to investigate the boundary conditions for particle motion inside a microvortex induced by an LWR.Upon dynamic capture,the particles’trajectories become orbital paths within an acoustic vortex.The suspended particles encounter two distinct acoustic phenomena,i.e.,the drag force resulting from acoustic streaming and the acoustic radiation force,which exert forces in various directions on the particles.When the acoustic radiation force and the fluid drag force are dominant for large and small particles in a mixed solution,respectively,the large particles reside within the vortex while the small particles remain at its periphery.Conversely,when the acoustic radiation force is dominant for both types of particles,the distribution pattern is reversed.

关键词： Acoustoﬂuidics Lamb wave resonator Particle manipulation Microvortex

Spatial light modulation for femtosecond laser manufacturing:Current developments and challenges

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Science China(Technological Sciences) 2024年第1期67卷 60-72页

作者： ZANG Xue LIU ZiTing XU YiShi WANG Yi WANG Qing LI ZhenZe WANG Lei State key laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China State key laboratory of precision Measurement and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Since the invention of lasers,spatial-light-modulated laser processing has become a powerful tool for various applications.It enables multidimensional and dynamic modulation of the laser beam,which significantly improves the processing efficiency,accuracy,and flexibility,and presents wider prospects over traditional mechanical technologies for machining three-dimensional,hard,brittle,or transparent materials.In this review,we introduce:(1)The role of spatial light modulation technology in the development of femtosecond laser manufacturing;(2)the structured light generated by spatial light modulation and its generation methods;and(3)representative applications of spatial-light-modulated femtosecond laser manufacturing,including aberration correction,parallel processing,focal field engineering,and polarization control.Finally,we summarize the present challenges in the field and possible future research.

关键词： femtosecond laser manufacturing spatial light modulation structured light aberration correction parallel processing focal field engineering polarization control

Tactile-sensing-based robotic grasping stability analysis

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Science China Technological Sciences 2024年第6期67卷 1817-1828页

作者： HUANG YanJiang WANG HaoNan ZHANG XianMin South China University of Technology Guangdong Provincial key laboratory of precision Equipment and Manufacturing Technology

Tactile signals play a crucial role in enabling robots to successfully manipulate unfamiliar objects. For robots to grasp unknown objects securely and without causing damage, it is essential that they can analyze grasping stability in real time through tactile signals and respond promptly. This study introduces a novel method for analyzing the stability of robotic hand grasping, utilizing the Wilcoxon signed rank test. The efficacy of this method is demonstrated through its static and dynamic performance, and evaluated across a series of experiments. The findings of this research highlight the method’s ability to accurately detect when an object begins to slip from the robot’s grasp. Employing this method allows the gripper to maintain a secure hold on objects by applying the minimal necessary force. It also enables the gripper to dynamically adjust the force it applies in real time, thus preventing the object from slipping during the movement of the robotic arm. Moreover, the gripper demonstrates the ability to stably grasp objects of varied weights and with unknown characteristics, showcasing the versatility and effectiveness of the proposed method.

关键词： grasping stability manipulation tactile sensors

Advances in microfluidic-based DNA methylation analysis

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Nanotechnology and precision Engineering 2024年第1期7卷 116-134页

作者： Jiwen Li Tiechuan Li Xuexin Duan State key laboratory of precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation studies to both clinical medicine and scientiﬁc research.Microﬂu-idic chips are excellent carriers for molecular analysis,and their use can provide improvements from multiple aspects.On-chip molecular analysis has received extensive attention owing to its advantages of portability,high throughput,low cost,and high efﬁciency.In recent years,the use of novel microﬂuidic chips for DNA methylation analysis has been widely reported and has shown obvious superiority to conventional methods.In this review,weﬁrst focus on DNA methylation and its applications.Then,we discuss advanced microﬂuidic-based methods for DNA methylation analysis and describe the great progress that has been made in recent years.Finally,we summarize the advantages that microﬂuidic technology brings to DNA methylation analysis and describe several challenges and perspectives for on-chip DNA methylation analysis.This review should help researchers improve their understanding and make progress in developing microﬂuidic-based methods for DNA methylation analysis.

关键词： Microﬂuidic chip DNA methylation analysis Molecular analysis High throughput Low cost

Investigation of high-quality-factor aluminum nitride MEMS cantilever resonators

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Nanotechnology and precision Engineering 2024年第1期7卷 32-43页

作者： Shuai Shi Qingrui Yang Yi Yuan Haolin Li Pengfei Niu Wenlan Guo Chen Sun Wei Pang State key laboratory of precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

This paper presents the design,fabrication,and characterization of cantilever-type resonators with a novel stacked structure.Aluminum nitride is adopted as the material for both the structural layer and the piezoelectric layer;this simpliﬁes the fabrication process and improves the quality factor of the resonator.Both in-plane and out-of-planeﬂexural modes were investigated.The effect of the structural dimensions and electrode patterns on the resonator’s performance were also studied.Finite-element simulations and experiments examining anchor loss and thermoelastic damping,which are the main loss mechanisms affecting the quality factor of these resonators,were carried out.The optimal structural dimensions and electrode patterns of the cantilever-type resonators are presented.A quality factor of 7922 with a motional impedance of 88.52 kΩand a quality factor of 8851 with a motional impedance of 67.03 kΩwere achieved for the in-plane and out-of-planeﬂexural-mode resonators,respectively.The proposed resonator design will contribute to the development of high-performance devices such as accelerometers,gyroscopes,and pressure sensors.

关键词： MEMS Cantilever-type micro-resonator AlN Finite-element simulation

Selective type II TRK inhibitors overcome xDFG mutation mediated acquired resistance to the second-generation inhibitors selitrectinib and repotrectinib

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Acta Pharmaceutica Sinica B 2024年第2期14卷 517-532页

作者： Shuang Xiang Xiaoyun Lu International Cooperative laboratory of Traditional Chinese medicine Modernization and Innovative Drug Discovery of Chinese Ministry of Education(MOE) Guangdong Provincial Key Laboratory of New Drug Design and EvaluationGuangzhou City Key Laboratory of Precision Chemical Drug DevelopmentSchool of PharmacyJinan UniversityGuangzhou 510632China

Neurotrophic receptor kinase(NTRK) fusions are actionable oncogenic drivers of multiple pediatric and adult solid tumors,and tropomyosin receptor kinase(TRK) has been considered as an attractive therapeutic target for "pan-cancer" harboring these fusions.Currently,two generations TRK inhibitors have been developed.The representative second-generation inhibitors selitrectinib and repotrectinib were designed to overcome clinic acquired resistance of the first-generation inhibitors larotrectinib or entrectinib resulted from solvent-front and gatekeeper on-target mutations.However,xDFG(TRKAG667C/A/S,homologous TRKCG696C/A/S) and some double mutations still confer resistance to selitrectinib and repotrectinib,and overcoming these resistances represents a major unmet clinical need.In this review,we summarize the acquired resistance mechanism of the first-and second-generation TRK inhibitors,and firstly put forward the emerging selective type Ⅱ TRK inhibitors to overcome xDFG mutations mediated resistance.Additionally,we concluded our perspectives on new challenges and future directions in this field.

关键词： NTRK fusions TRK kinase Clinical resistance xDFG mutations Selective type II inhibitors

Enhanced high-temperature mechanical properties of laser-arc hybrid additive manufacturing of Al-Zn-Mg-Cu alloy via microstructure control

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Journal of Materials Science & Technology 2024年第2期169卷 220-234页

作者： Dehua Liu Dongjiang Wu Yunsong Wang Zhuo Chen Changrong Ge Qingyu Zhao Fangyong Niu Guangyi Ma State key laboratory of High-performance precision Manufacturing Dalian University of TechnologyDalian 116024China

Recently,rapid and cost-effective additive manufacturing solutions for lightweight aluminum alloys with excellent high-temperature mechanical properties have been increasingly in demand.In this study,we combined laser-arc hybrid additive manufacturing with solution and artificial aging treatments to achieve Al-Zn-Mg-Cu alloy with favorable high-temperature strength via microstructure control.Hydrogen pores became the major defect in the as-deposited and heat-treated specimens.The continuous distribution of eutectics with hard-brittle characteristics at the grain boundaries was destructed following heat treat-ment.High-densityηprecipitates were uniformly dispersed in the heat-treated Al-Zn-Mg-Cu alloy,whereas appeared coarsened and dissolved at 473 K,owing to the rapid diffusion of Zn and Mg.The average 0.2%yield strength(318±16 MPa)and ultimate tensile strength(362±20 MPa)at 473 K af-ter heat treatment were enhanced by approximately 58%and 51%,respectively,compared to those of the as-deposited specimen.In addition,theηprecipitates contributed to lattice distortions and strain fields,which prevented dislocation motion and increased slip deformation resistance at high temper-atures.The as-deposited specimen exhibited intergranular fracture at 473 K,with cracks preferring to propagate along the aggregated eutectics.However,crack propagation proceeded in the sections with more pores in the heat-treated specimen.Our approach may provide a valid option for achieving alu-minum alloys with excellent high-temperature mechanical properties.

关键词： Laser-arc hybrid additive manufacturing Al-Zn-Mg-Cu alloy High-temperature strength Heat treatment,Microstructure evolution