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Synthesis and Crystal Structure of 3-Nitrophthalic Acid·3-methyl-4-nitropyridine N-Oxide Adducts

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Chinese Journal of Structural Chemistry 2006年第8期25卷 923-926页

作者： WANG Yi feng wei XUE lin ZHENG Ji-Min Department of Chemistry Nankai University Tianjin 300071 China

The title compound, a 1：1 molecular adduct of 3-nitrophthalic acid and 3-methyl- 4-nitropyridine N-oxide （PPOM）, has been synthesized and characterized by X-ray single-crystal structure analysis. It crystallizes in triclinic, space group PI with α = 7.6076（15）, b = 7.8180（16）, c = 14.546（3）A, α= 93.90（3）, β = 97.21（3）, γ= 114.43（3）°, C14H1N3O9, Mr = 365.26, Z = 2, V = 774.6（3） A^3, Dc = 1.566 g/m^3,μ（MoKa） = 0.134 mm^-1, F（000） = 376, R = 0.0538 and wR = 0. 1460 for 885 observed reflections （1 〉 2σ（I））. The protons of the carbonylic acids in the molecule are not transferred and the O-H…O and C-H…O hydrogen bonds form zigzag chains in the molecule.

关键词： crystal structure synthesis 3-methyl-4-nitropyridine N-oxide adduct

Polymerization of isoprene catalyzed by neodymium heterocyclic Schiff base complex

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Chinese Chemical Letters 2008年第6期19卷 734-738页

作者： Lei Zhang Xu feng Ni wei lin Sun Zhi Quan Shen Institute of Polymer Science Key Laboratory of Macromolecule Synthesis and Functionalization Ministry of Education Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China

Neodymium-based heterocyclic Schiff base complex was prepared and applied for the coordination polymerization of isoprene. This complex polymerized isoprene to afford products featuring high cis-1,4 stereospecificity （ca. 95%） and high molecular weight （ca, 10^5） in the presence of the triisobutyl aluminium （AliBu3） as cocatalyst, The microstructure of obtained polyisoprene was investigated by FTIR, 1^H NMR. Two different kinds of active centers in the catalyst system were examined by GPC method.

关键词： Heterocyclic Schiff base Neodymium complex Isoprene Coordination polymerization

Tetrahydrosalen backboned gadolinium complex as initiator for the ring-opening polymerization of ε-caprolactone

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Chinese Chemical Letters 2008年第6期19卷 681-684页

作者： Guang Ming Wu Xu feng Ni wei lin Sun Zhi Quan Shen Key Laboratory of Maeromoleeule Synthesis and Functionalization Ministry of Education Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China

Tetrahydrosalen ligand was employed in the synthesis of gadolinium complex. The ligand was deprotoned by LiBu, and the afforded lithium salt was reacted with anhydrous GdCl3 to produce the gadolinium complex through salt metathesis. This complex was successfully used to initiate the ring-opening polymerization of ε-caprolactone. The initiation conditions in different temperature, monomer-to-initiator ratio and time were investigated. Under the condition： [ε-caprolactone]：[catalyst] = 600, 56 ℃, toluene： 2 ml, poly（ε-caprolactone）（PCL） with Mw = 11,2782 and PDI = 1.96 was achieved.

关键词： Tetrahydrosalen complex Rare earth catalyst ε-Caprolactone Ring-opening polymerization

基于注意力和对比学习的轻量级交通标志检测方法

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南通职业大学学报 2024年第1期38卷 63-69页

作者：邵叶秦王梓腾张若为胡彬曹秋阳周瑞冯林威南通大学交通与土木工程学院江苏南通226019 南通大学电气工程学院江苏南通226019 南通大学信息科学技术学院江苏南通226019 南通大学张謇学院江苏南通226019

为提升交通标志检测精度和速度,针对交通标志目标小、尺度变化大等问题,提出一种基于注意力和对比学习的轻量级交通标志检测算法:首先,在特征提取主干网络中采用通道和空间分离方法依次进行卷积操作,构建多层次的特征提取网络,减少运算... 详细信息

为提升交通标志检测精度和速度,针对交通标志目标小、尺度变化大等问题,提出一种基于注意力和对比学习的轻量级交通标志检测算法:首先,在特征提取主干网络中采用通道和空间分离方法依次进行卷积操作,构建多层次的特征提取网络,减少运算量;其次,采用基于注意力的上下文特征金字塔网络,获取目标的代表性特征,提升模型准确率;最后,采用监督对比学习损失(Supervised Contrastive Loss,SCL)函数,提高模型的特征判别能力。实验结果表明,该交通标志检测算法的平均检测精度达95.8%,相比于YOLOX-Tiny提升了4.5%,检测速度为79帧/s,能够满足实际应用需要。

关键词：交通标志检测特征金字塔注意力对比学习 YOLOX-Tiny模型

Model-based offline reinforcement learning framework for optimizing tunnel boring machine operation

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Underground Space 2024年第6期19卷 47-71页

作者： Yupeng Cao wei Luo Yadong Xue weiren lin feng Zhang Department of Urban Management Kyoto UniversityKyoto 615-8540Japan Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China

Research on automation and intelligent operation of tunnel boring machine(TBM)is receiving more and more attention,benefiting from the increasing construction ***,most studies on TBM operations optimization were trained by the labels of human drivers’decisions,which were subjective and *** a result,the control parameters suggested by these models could hardly surpass the performance of a human driver,even the possibility of subjective incorrect *** that the geomechanical feedback to TBM under drivers’actions is objective,in this paper,a transformer-based model called the geological response for tunnel boring machine(GRTBM),is proposed to learn the relationship between operation-adjust and TBM monitoring ***,with the model-based offline reinforcement learning,this paper provided a novel approach to optimizing the TBM excavation *** decision processes,recorded in the Yin-song TBM project for a waterway tunnel in Jilin Province of China,were used for the validation of the *** adopting an implicit perception of geological conditions in the GRTBM model,the suggested method achieved the desired state within a single action,greatly outperformed the practical adjustments where 500 s were taken,revealing the fact that the proposed model has the potential to surpass the capability of human beings.

关键词： TBM Reinforcement learning Transformer Data mining

Tailoring chaotic motion of microcavity photons in ray and wave dynamics by tuning the curvature of space

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 107-112页

作者： wei lin Yechun Ding Yongsheng Wang Peng Li Yanpeng Zhang feng Yun feng Li Key Laboratory for Physical Electronics and Devices of the Ministry of Education Shaanxi Key Lab of Information Photonic TechniqueSchool of Electronic Science and EngineeringFaculty of Electronic and Information EngineeringXi’an Jiaotong UniversityXi’an 710049China Department of Electrical and Photonics Engineering Technical University of DenmarkKgs.Lyngby 2800Denmark Center for Regenerative and Reconstructive Medicine Med-X InstituteThe First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061China Solid-State Lighting Engineering Research Center Xi’an Jiaotong UniversityXi’an 710049China

Microcavity photon dynamics in curved space is an emerging interesting area at the crossing point of nanophotonics,chaotic science,and non-Euclidean *** report the sharp difference between the regular and chaotic motions of cavity photons subjected to the varying space *** the island modes of regular motion rise in the phase diagram in the curved space,the chaotic modes show special mechanisms to adapt to the space curvature,including the fast diffusion of ray dynamics,and the localization and hybridization of the Husimi wavepackets among different periodic *** observations are unique effects enabled by the combination of the chaotic trajectory,the wave nature of light,and the non-Euclidean orbital motion,and therefore make the system a versatile optical simulator for chaotic science under quantum mechanics in curved space-time.

关键词： microcavity chaotic motion curved space

Selective O-difluoromethylation of 1,3-diones using S-(difluoromethyl) sulfonium salt

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Chinese Chemical Letters 2019年第8期30卷 1515-1518页

作者： Guo-Kai Liu Xin Li Wen-Bing Qin wei-feng lin Li-Ting lin Jia-Yi Chen Jian-Jian Liu School of Pharmaceutical Sciences Shenzhen University Health Science Centre Shenzhen University

A facile and highly efficient approach for selective O-difluoromethylation of 1,3-diones by recently developed bench-stable S-(difluoromethyl)sulfonium salt was *** a broad range of difluoromthyl enol ethers were readily accessed in good to excellent yields under mild reaction *** studies revealed that the O-difluoromethylation reaction proceeds mainly via a difluorocarbene pathway.

关键词： Difluorocarbene Difluoromethyl enol ethers 1,3-Diones O-Difluoromethylation S-(Difluoromethy)sulfonium salt

Piezotronic neuromorphic devices:principle,manufacture,and applications

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International Journal of Extreme Manufacturing 2024年第3期6卷 363-385页

作者： Xiangde lin Zhenyu feng Yao Xiong Wenwen Sun Wanchen Yao Yichen wei Zhong lin Wang Qijun Sun Department of Research Shanghai University of Medicine and Health Sciences Affiliated Zhoupu HospitalShanghai 201318People’s Republic of China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400People’s Republic of China Center on Nanoenergy Research School of Chemistry and Chemical EngineeringGuangxi UniversityNanning 530004People’s Republic of China Shandong Zhongke Naneng Energy Technology Co. LtdDongying 257061People’s Republic of China Georgia Institute of Technology AtlantaGA 30332-0245United States of America

With the arrival of the era of artificial intelligence(AI)and big data,the explosive growth of data has raised higher demands on computer hardware and *** techniques inspired by biological nervous systems are expected to be one of the approaches to breaking the von Neumann *** neuromorphic devices modulate electrical transport characteristics by piezopotential and directly associate external mechanical motion with electrical output signals in an active manner,with the capability to sense/store/process information of external *** this review,we have presented the piezotronic neuromorphic devices(which are classified into strain-gated piezotronic transistors and piezoelectric nanogenerator-gated field effect transistors based on device structure)and discussed their operating mechanisms and related manufacture ***,we summarized the research progress of piezotronic neuromorphic devices in recent years and provided a detailed discussion on multifunctional applications,including bionic sensing,information storage,logic computing,and electrical/optical artificial ***,in the context of future development,challenges,and perspectives,we have discussed how to modulate novel neuromorphic devices with piezotronic effects more *** is believed that the piezotronic neuromorphic devices have great potential for the next generation of interactive sensation/memory/computation to facilitate the development of the Internet of Things,AI,biomedical engineering,etc.

关键词： piezotronics neuromorphic devices strain-gated transistors piezoelectric nanogenerators synaptic transistors

Dynamic cooperations between lattice oxygen and oxygen vacancies for photocatalytic ethane dehydrogenation by a self-restoring LaVO_(4)catalyst

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Chinese Chemical Letters 2024年第3期35卷 171-176页

作者： Fen wei weichao Xue Zhiyang Yu Xue feng Lu Sibo Wang wei lin Xinchen Wang State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350108China

Thermocatalytic nonoxidative ethane dehydrogenation(EDH)is a promising strategy for ethene production but suffers from intense energy consumption and poor catalyst durability;exploring technology that permits efficient EDH by solar energy remains a giant ***,we present that an oxygen vacancy(O_v)-rich LaVO_(4)(LaVO_(4)-O_v)catalyst is highly active and stable for photocatalytic EDH,through a dynamic lattice oxygen(O_(latt.))and O_(v)co-mediated *** by simulated sunlight at mild conditions,LaVO_(4)-O_(v)effectively dehydrogenates undiluted ethane to produce C_(2)H_(4)and CO with a conversion of 2.3%.By loading a small amount of Pt cocatalyst,the evolution and selectivity of C_(2)H_(4)are enhanced to 275μmol h^(-1)g^(-1)and 96.8%.Of note,LaVO_(4)-O_(v)appears nearly no carbon deposition after the *** isotope tracked reactions reveal that the consumed O_(latt.)recuperates by exposing the used catalyst with O_(2),thus establishing a dynamic cycle of O_(latt.)and achieving a facile catalyst regeneration to preserve its intrinsic *** refreshed LaVO_(4)-O_(v)exhibits superior reusability and delivers a turnover number of about *** O_(v)promotes photo absorption,boosts ethane adsorption/activation,and accelerates charge separation/transfer,thus improving the photocatalytic *** possible photocatalytic EDH mechanism is proposed,considering the key intermediates predicted by density functional theory(DFT)and monitored by in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS).

关键词： Photocatalysis Ethane dehydrogenation Ethene LaVO_(4) Oxygen vacancy