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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 *** 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 *** 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 ***,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

Metalens with tilted structures for high-efficiency focusing at large-angle incidences

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Chinese Optics Letters 2024年第5期22卷 117-123页

作者：王月陈晨吴圣杰叶欣祝世宁李涛 National laboratory of Solid state Microstructures Key Laboratory of Intelligent Optical Sensing and ManipulationsJiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210093China

The metalens has attracted remarkable attention due to its ultra-thin and ultra-light characteristics,which indicate great potential for compact ***,the limited efficiency at a large angle incidence severely hinders the application of wide-angle focusing and imaging,which is pursued in the fast-developing imaging ***,new strategies to improve the lens performance at large incident angles are in *** this work,we propose tilted structures for largeangle focusing with improved *** based on dynamic phase and geometric phase are designed and systematically characterized by numerical *** show that tilted structures of unit cells significantly improve the lens performance at oblique *** detail,the focusing efficiency of the metalens with tilted structures is increased over 25%at 30°incidence,as well as the modulation transfer *** addition,we develop a hybrid metalens array achieving highly efficient wide-angle imaging up to 120°.We believe this design provides a feasible route toward wide-field and high-performance imaging applications.

关键词： metalenses tilted structures large-angle incidence high efficiency

Ordered mesoporous materials for water pollution treatment: Adsorption and catalysis

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Green Energy & Environment 2024年第8期9卷 1239-1256页

作者： Peng Zhang Mingming He Wei Teng Fukuan Li Xinyuan Qiu Kexun Li Hao Wang College of Environmental Science and Engineering MOE Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution TreatmentTianjin Key Laboratory of Environmental Technology for Complex Trans-Media PollutionNankai University Department of Chemistry and state key laboratory Marine Pollution Hong Kong Institute for Advanced Study City University of Hong Kong state key laboratory for Pollution Treatment College of Environmental Science and EngineeringShanghai Institute of Pollution Treatment and Ecological SecurityTongji University state key laboratory of Simulation and Regulation of Water Cycles in River Basins China Institute of Water Resources and Hydropower Research

To meet the growing emission of water contaminants,the development of new materials that enhance the efficiency of the water treatment system is *** mesoporous materials provide opportunities in environmental processing applications due to their exceptionally high surface areas,large pore sizes,and enough pore *** properties might enhance the performance of materials concerning adsorption/catalysis capability,durability,and *** this review,we enumerate the ordered mesoporous materials as adsorbents/catalysts and their modifications in water pollution treatment from the past decade,including heavy metals (Hg2+,Pb2+,Cd2+,Cr6+,etc.),toxic anions （nitrate,phosphate,fluoride,etc.）,and organic contaminants （organic dyes,antibiotics,etc.）.These contributions demonstrate a deep understanding of the synergistic effect between the incorporated framework and homogeneous active ***,the challenges and perspectives of the future developments of ordered mesoporous materials in wastewater treatment are *** work provides a theoretical basis and complete summary for the application of ordered mesoporous materials in the removal of contaminants from aqueous solutions.

关键词： Water pollution treatment Ordered mesoporous materials Toxic contaminants Adsorption Catalysis

Palladium-catalyzed multi components oxy-aminofluorination and aminofluorination of gem-difluoroalkenes

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Chinese Chemical Letters 2024年第2期35卷 420-425页

作者： Fen Wu Xin Li Junbiao Chang Dachang Bai state key laboratory of Antiviral Drugs NMPA Key Laboratory for Research and Evaluation of Innovative DrugKey Laboratory of Green Chemical Media and ReactionsMinistry of EducationSchool of Chemistry and Chemical EngineeringPingyuan LaboratoryHenan Normal UniversityXinxiang 453007China state key laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Organofluorine compounds are widely used in the realm of drug discovery and material ***,we developed palladium catalyzed intermolecular aminofluorination and oxy-aminofluorination of gem‑difluoroalkenes with N-fluorobenzenesulfonimide(NFSI),in which NFSI was used as the nitrogen source and *** reaction provides an efficient and straightforward synthesis route of a series ofα-trifluoromethyl benzylic ***,three/four components oxy-aminofluorination processes were realized to giveα-trifluoromethyl benzylic ether with a terminal amino group,which proceed through C(sp^(3))-O bond cleavage of easily available ether and simultaneous introduced a fluorine,an amino and an oxy substituent in one pot with excellent *** divergent reactivity not only included the incorporation of one ether molecular,but also much more challenged two ether insertion with excellent selectivity through succession C(sp^(3))-O bonds *** protocol allows for concise synthesis of high value amines with fluoroalkyl-substituents and selectively transformation of easily available ethers by high-valent palladium catalysis.

关键词： Palladium Multi components Aminofluorination Oxy-aminofluorination C(sp^(3))-O bond cleavage

Reactive molecular dynamics insight into the thermal decomposition mechanism of 2,6-Bis(picrylamino)-3,5-dinitropyridine

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Defence Technology（防务技术） 2024年第3期33卷 134-146页

作者： Jianbo Fu Hui Ren Xinzhou Wu Yongjin Chen Mi Zhang Yazhi Cheng state key laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

2,6-bis(picrylamino)-3,5-dinitropyridine(PYX)has excellent thermostability,which makes its thermal decomposition mechanism receive much *** this paper,the mechanism of PYX thermal decomposition was investigated thoroughly by the ReaxFF-lg force field combined with DFT-B3LYP(6-311++G)*** detailed decomposition mechanism,small-molecule product evolution,and cluster evolution of PYX were mainly *** the initial stage of decomposition,the intramolecular hydrogen transfer reaction and the formation of dimerized clusters are earlier than the denitration *** the progress of the reaction,one side of the bitter amino group is removed from the pyridine ring,and then the pyridine ring is *** final products produced in the thermal decomposition process are CO_(2),H_(2)O,N_(2),and H_(2).Among them,H_(2)O has the earliest generation time,and the reaction rate constant(k_(3))is the *** clusters are formed during the decomposition of PYX,and the formation,aggregation,and decomposition of these clusters are strongly affected by *** low temperatures(2500 K-2750 K),many clusters are *** high temperatures(2750 K-3250 K),the clusters aggregate to form larger *** 3500 K,the large clusters decompose and become *** the late stage of the reaction,H and N in the clusters escaped almost entirely,but more O was trapped in the clusters,which affected the auto-oxidation process of ***'s initial decomposition activation energy(E_(a))was calculated to be 126.58 kJ/*** work contributes to a theoretical understanding of PYX's entire thermal decomposition process.

关键词： PYX Thermal decomposition ReaxFF-lg MD simulations Excellent thermostable explosives

Mesoscale Mechanical Properties and Influencing Factors of Concrete under Uniaxial Tension

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1156-1168页

作者： CHEN Tao LI Kungang XIAO Shiyun state key laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

Monte Carlo simulations were carried out to generate a mesoscale model of concrete with randomly packed aggregates with different shapes and *** mechanical properties of concrete specimens under uniaxial tensile loads were studied using statistical *** results indicated that the entire process of damage and failure of specimens exhibited mainly two failure types:fracture patternsⅠandⅡ.Furthermore,the influences of the aggregate content ratio,aggregate shape,aggregate size,interfacial transition zone(ITZ)strength,and porosity ratio on the concrete specimens were *** numerical simulation results showed that the elastic modulus of the concrete specimens increased approximately linearly with the aggregate volume ratio but decreased linearly with the porosity and was not affected by the ITZ *** tensile strength decreased with the increases in the aggregate content and porosity of the sample,but increased linearly with the ITZ *** addition,the aggregate shape led to a difference in the tensile strength of the concrete.

关键词： concrete mechanical behavior aggregate interfacial transition zone pore

Frequency-modulated continuous-wave multiplexed gas sensingbased on optical frequency comb calibration

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Chinese Physics B 2024年第9期33卷 152-163页

作者： Linhua Jia Xinghua Qu Fumin Zhang state key laboratory of Precision Measurement Technology and Instruments Tianjin UniversityTianjin 300072China

Laser absorption spectroscopy has proven to be an effective approach for gas sensing, which plays an important rolein the fields of military, industry, medicine and basic research. This paper presents a multiplexed gas sensing system basedon optical frequency comb (OFC) calibrated frequency-modulated continuous-wave (FMCW) tuning nonlinearity. Thesystem can be used for multi-parameter synchronous measurement of gas absorption spectrum and multiplexed opticalpath. Multi-channel parallel detection is realized by combining wavelength division multiplexing (WDM) and frequencydivision multiplexing (FDM) techniques. By introducing nonlinear optical crystals, broadband spectrum detection is simultaneouslyachieved over a bandwidth of hundreds of nanometers. An OFC with ultra-high frequency stability is used asthe frequency calibration source, which guarantees the measurement accuracy. The test samples involve H13C14N, C_(2)H_(2)and Rb vapor cells of varying densities and 5 parallel measurement experiments are designed. The results show that themeasurement accuracies of spectral absorption line and the optical path are 150 MHz and 20 m, respectively. The schemeoffers the advantages of multiplexed, multi-parameter, wide spectrum and high resolution detection, which can realize theidentification of multi-gas components and the high-precision inversion of absorption lines under different *** proposed sensor demonstrates great potential in the field of high-resolution absorption spectrum measurement for gassensing applications.

关键词： frequency-modulated continuous-wave (FMCW) technology optical frequency comb multiplexing absorption spectroscopy

Shock-induced chemical reaction characteristics of PTFE-Al-Bi_(2)O_(3)reactive materials

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Defence Technology（防务技术） 2024年第6期36卷 1-12页

作者： Chunlan Jiang Rong Hu Jingbo Zhang Zaicheng Wang Liang Mao state key laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

A ternary system of PTFE/Al/Bi_(2)O_(3)is constructed by incorporating PTFE-based reactive material and thermite for enhancing the energy release of the PTFE-based reactive *** effects of Bi_(2)O_(3)in the PTFE/Al/Bi_(2)O_(3)on both mechanical properties and the energy release were investigated through various tests such as thermogravimetry-differential scanning calorimetry,adiabatic oxygen bomb test and split Hopkinson pressure bar *** microstructure observed through scanning electron microscope and Xray diffraction results are used to analyze the ignition and reaction mechanism of PTFE/Al/Bi_(2)O_(3).The results indicate that the PTFE/Al/Bi_(2)O_(3)are capable of triggering the exothermic reaction of molten PTFE/Bi_(2)O_(3)and Al/Bi_(2)O_(3)over the PTFE/Al reactive materials,thereby promoting *** excessive aluminum in the ternary system is beneficial for increasing energy *** ignition of shock-induced chemical reactions in PTFE/Al/Bi_(2)O_(3)is closely related to the material *** dominant mechanism for hot-spot generation under Split Hopkinson Pressure Bar test is the frictional temperature rise at the microcrack after failure.

关键词： PTFE/Al/Bi_(2)O_(3) Shock-induced chemical reaction Energy release

Propagation Properties of Shock Waves in Polyurethane Foam based on Atomistic Simulations

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Defence Technology（防务技术） 2024年第1期31卷 117-129页

作者： Zhiqiang Hu Jianli Shao Shiyu Jia Weidong Song Cheng Wang state key laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Porous materials are widely used in the field of protection because of their excellent energy absorption *** this work,a series of polyurethane microscopic models are established and the effect of porosity on the shock waves is studied with classical molecular dynamics ***,shock Hugoniot relations for different porosities are obtained,which compare well with the experimental *** pores collapse and form local stress wave,which results in the complex multi-wave structure of the shock *** microstructure analysis shows that the local stress increases and the local velocity decreases gradually during the process of pore collapse to complete ***,it leads to stress relaxation and velocity *** shock stress peaks can be fitted with two exponential functions,and the amplitude of attenuation coefficient decreases with the increase of ***,the pore collapse under shock or non-shock are discussed by the entropy increase rate of the *** energy is dissipated mainly through the multiple interactions of the waves under *** energy is dissipated mainly by the friction between atoms under non-shock.

关键词： Polyurethane foam Shock wave Attenuation Atomistic simulation