检索结果-南通市图书馆

Chinese Chemical Letters 2006年第8期17卷 1025-1028页

作者： Dong Sen MAO guan zhong lu Research Institute Applied Catalysis Department of Chemical Engineering Shanghai Institute of Technology Shanghai 200235

The addition of platinum over the B2O3/TiO2-ZrO2 remarkably enhanced its catalytic stability in the vapor phase Beckmann rearrangement of cyclohexanone oxime under the carder gas of H2. The content of coke deposited on catalyst surface was decreased from 1.92% over the B2O3/TiO2-ZrO2 to 1.14% over the platinum promoted B2O3/TiO2-ZrO2 after reaction of six hours. This result indicates that the platinum added on the B2O3/TiO2-ZrO2 catalyst plays an important role in reducing the coke formation on the catalyst surface.

关键词： Cyclohexanone oxime vapor-phase Beckmann rearrangement ε-caprolactam B2O3/TiO2-ZrO2 catalyst platinum.

Analysis of photocatalytic degradation of polyamide microplastics in metal salt solution by high resolution mass spectrometry

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第5期139卷 473-482页

作者： Yunjin zhong Lebing Zhuo Wangyang lu National Engineering Lab for Textile Fiber Materials&Processing Technology(Zhejiang) School of Materials Science&EngineeringZhejiang Sci-Tech UniversityHangzhou 310018China

Microplastic pollution has become one of the most concerned focuses in the *** many treatment methods,photocatalysis is considered to be one of the most environmentally friendly *** this work,the photodegradation behavior of polyamide microplastics is studied by using polyamide 6(PA6)as model microplastics and FeCl_(3) as *** is hoped that the PA6 fiber can be effectively degraded by utilizing the strong oxidizing active species that can be produced after FeCl_(3) is irradiated in *** results shows that PA6 fiber can be almost completely degraded after 10 days of irradiation in FeCl_(3) aqueous solution,indicating that it is promising to use this new method to solve the problem of PA6type *** addition,the chain scission mechanism and degradation process of PA6 are analyzed in detail by ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS),which provides a new insight for the study of polymer degradation mechanism.

关键词： FeCl_(3) Photocatalysis Polyamide 6 Chain scission

Poly(GMA/MA/MBAA)Copolymer Beads:a Highly Efficient Support Immobilizing Penicillin G Acylase

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第1期17卷 129-132页

作者： Ping XUE guan zhong lu Wan Yi LIU Key Laboratory of Energy Source and Chemical Engineering Ningxia University Yinchuan 750021 Research Institute of Industrial Catalysis East China University of Science and Technology Shanghai 200237

The hydrophilic, macroporous and beaded ternary copolymer of glycidyl methacrylate （GMA）/methacrylamide（MA）/N,N＇-methylene-bis（acrylamide）（MBAA）was synthesized using the industrial agents by inverse suspension polymerization. The apparent activity of the immobilized penicillin G acylase reached 1096 IU/g for hydrolysis penicillin G on the beads with diameter of 0.11-0.13 ram, and it changed hardly after 50 cycles. It can be expected to be a good potential in industrial application,

关键词： Poly(GMA/MA/MBAA) copolymer beads penicillin G acylase immobilization,inverse suspension polymerization.

Combined UAMP and MF Message Passing Algorithm for Multi-Target Wideband DOA Estimation with Dirichlet Process Prior

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第4期29卷 1069-1081页

作者： Shanwen guan Xinhua lu Ji Li Rushi Lan Xiaonan luo guangxi Key Laboratory of Image and Graphic Intelligent Processing Guilin University of Electronic TechnologyGuilin 541004China Guilin Huigu Institute of AI Industrial Technology Guilin 541004China School of Information Engineering Nanyang Institute of TechnologyNanyang 473000China

When estimating the direction of arrival (DOA) of wideband signals from multiple sources, the performance of sparse Bayesian methods is influenced by the frequency bands occupied by signals in different directions. This is particularly true when multiple signal frequency bands overlap. Message passing algorithms (MPA) with Dirichlet process (DP) prior can be employed in a sparse Bayesian learning (SBL) framework with high precision. However, existing methods suffer from either high complexity or low precision. To address this, we propose a low-complexity DOA estimation algorithm based on a factor graph. This approach introduces two strong constraints via a stretching transformation of the factor graph. The first constraint separates the observation from the DP prior, enabling the application of the unitary approximate message passing (UAMP) algorithm for simplified inference and mitigation of divergence issues. The second constraint compensates for the deviation in estimation angle caused by the grid mismatch problem. Compared to state-of-the-art algorithms, our proposed method offers higher estimation accuracy and lower complexity.

关键词： wideband direction of arrival(DOA)estimation sparse Bayesian learning(SBL) unitary approximate message passing(UAMP)algorithm Dirichlet process(DP)

Grating-free autofocus for single-pixel microscopic imaging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第6期12卷 1313-1321页

作者： guan WANG HUAXIA DENG YU CAI MENGCHAO MA XIANG zhong XINGLONG GONG CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei 230027China School of Instrument Science and Opto-electronics Engineering Hefei University of TechnologyHefei 230009China

As a computational technology,single-pixel microscopic imaging(SPMI)transfers the target’s spatial information into a temporal *** traditional focusing method of imaging before evaluation is not applicable to the SPMI *** propose a grating-free autofocus strategy derived from the physical mechanism of optical *** the amplitude information of just one high-frequency point in the spectrum is all that is needed to achieve fast autofocus with the SPMI ***,only four patterns need to be cyclically projected,enabling efficient localization of the focal plane based on the measurement *** demonstrate SPMI autofocus experiments at micrometer and even nanometer depths of *** proposed method can be extended to achieve SMPI autofocus with invisible optical pattern illumination.

关键词： optical system. illumination

Reversibly Cross-Linking Polyimide and Cyclophosphazene Toward Closed-Loop Recyclable Plastics with High Mechanical Strength,Excellent Flame Retardancy,and Chemical Resistance

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2024年第4期6卷 976-987页

作者： Tingting guan Xiaohan Wang Xi Zhao Xingyuan lu Xiu-Li Wang Yu-zhong Wang Junqi Sun State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012 The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu 610064

Traditional flame-retardant plastics are technically difficult to chemically *** development of newtypes of flame-retardant plastics that are intrinsically capable of being closed-loop recycled and are sufficiently robust and stable to satisfy their practical application is urgently *** this study,closed-loop recyclable flame-retardant plastics with high mechanical strength and excellent chemical resistance are fabricated by cross-linking amino-terminated polyimide(PI-NH_(2))and aldehyde-terminated cyclophosphazene(CP-CHO)with imine *** resultant flame-retardant plastic,which is denoted as PI-CP,exhibits a tensile strength of∼115.6 MPa,Young’s modulus of∼2.5 GPa,and glass transition temperature of 316°*** the PI-CP plastic,the imine bonds are isolated within hydrophobic microenvironments generated by the rigid and hydrophobic polyimide chains and the benzene ring of *** a result,the PI-CP plastics are highly stable in highly acidic and basic aqueous solutions and other commonly used organic *** PI-CP plastic shows outstanding flame retardancy with a limiting oxygen index value of 48.8%.More importantly,the PI-CP plastic can be depolymerized to generate the original PI-NH_(2)and CPCHO monomers in high yields(∼97%)and *** recovered monomers can be used to refabricate the original plastics,establishing highly efficient polymer-monomer-polymer circulation and a sustainable plastics economy.

关键词： closed-loop recyclable plastics recyclable polymers reversibly cross-linked polymers flame retardancy supramolecular polymers

Anisotropy-free arrayed waveguide gratings on X-cut thin film lithium niobate platform of in-plane anisotropy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第7期13卷 1416-1426页

作者： Junjie Yi Changjian Guo Ziliang Ruan Gengxin Chen Haiqiang Wei Liwang lu Shengqi Gong Xiaofu Pan Xiaowan Shen Xiaowei guan Daoxin Dai Kangping zhong Liu Liu State Key Laboratory of Extreme Photonics and Instrumentation College of Optical Science and EngineeringInternational Research Center for Advanced PhotonicsZhejiang UniversityHangzhou 310058China. guangdong Provincial Key Laboratory of Optical Information Materials and Technology South China Academy of Advanced OptoelectronicsSouth China Normal UniversityHigher-Education Mega-CenterGuangzhou 510006China. National Center for International Research on Green Optoelectronics South China Normal UniversityGuangzhou 510006China Photonics Research Institute Department of Electrical and Electronic EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong Kong(SAR)China. Jiaxing Key Laboratory of Photonic Sensing&Intelligent Imaging Intelligent Optics&Photonics Research CenterJiaxing Research Institute Zhejiang UniversityJiaxing 314000China

Arrayed waveguide grating is a versatile and scalable integrated light dispersion device,which has been widely adopted in various applications,including,optical communications and optical ***,thin-film lithium niobate emerges as a promising photonic integration platform,due to its ability of shrinking largely the size of typical lithium niobate based optical *** would also enable multifunctional photonic integrated chips on a single lithium niobate ***,due to the intrinsic anisotropy of the material,to build an arrayed waveguide grating on X-cut thin-film lithium niobate has never been ***,a universal strategy to design anisotropyfree dispersive components on a uniaxial in-plane anisotropic photonic integration platform is introduced for the first *** leads to the first implementation of arrayed waveguide gratings on X-cut thin-film lithium niobate with various configurations and *** best insertion loss of 2.4 dB and crosstalk of−24.1 dB is obtained for the fabricated arrayed waveguide grating *** of such arrayed waveguide gratings as a wavelength router and in a wavelength-division multiplexed optical transmission system are also demonstrated.

关键词： waveguide arrayed lithium

Numerical simulation of transient characteristics in a bulb turbine during the load rejection process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 170-183页

作者： Yue lu Yu-quan Zhang zhong-wei He Yuan Zheng College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China College of Energy and Electrical Engineering Hohai UniversityNanjing210098China Huadong Engineering Corporation Ltd. Hangzhou311122China

To evaluate the safety of the bulb tubular turbine,the dynamic hydraulic characteristics of a hydropower station system during the load rejection process are studied through numerical simulations and a prototype *** the developed model,a dynamic grid technology(DGT)controls the closure of the guide vane and the blade,whilst the moment balance equation and the user-defined function(UDF)provide the runner’s rotation *** 3-D transient simulation method can well predict the rotation speed and mass flow curves in the state of load *** simulation outcomes of the system performance are basically consistent with the measurement data of the *** observed,the runner is subjected to the reversely increased torque and axial force,the system is in a braking phase,and the maximum speed peaks at 144.6%of the rated ***,the internal flow of the runner is greatly affected by the closure of the guide vane,and the draft tube forms an eccentric spiral vortex *** breaks downstream,aggravating the instability of the draft ***,the transient characteristics span for the first five seconds,demonstrating the importance of establishing an efficient governing *** obtained results are useful for designing the turbine’s flow channel with a double regulating function and comprehending the turbine’s transient characteristics.

关键词： Bulb tubular turbine load rejection numerical simulation dynamic grid prototype test

Free-moving-state microscopic imaging of cerebral oxygenation and hemodynamics with a photoacoustic fiberscope

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第1期13卷 33-46页

作者： Xiaoxuan zhong Yizhi Liang Xiaoyu Wang Haoying Lan Xue Bai Long Jin Bai-Ou guan guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications Institute of Photonics TechnologyJinan UniversityGuangzhou510632China

We report the development of a head-mounted photoacoustic fiberscope for cerebral imaging in a freely behaving *** 4.5-gram imaging probe has a 9-µm lateral resolution and 0.2-Hz frame rate over a 1.2-mm wide *** probe can continuously monitor cerebral oxygenation and hemodynamic responses at single-vessel resolution,showing significantly different cerebrovascular responses to external stimuli under anesthesia and in the freely moving *** example,when subjected to high-concentration CO_(2) respiration,enhanced oxygenation to compensate for hypercapnia can be visualized due to cerebral regulation in the freely moving *** studies exhibit significantly weakened compensation capabilities in obese *** new imaging modality can be used for investigating both normal and pathological cerebrovascular functions and shows great promise for studying cerebral activity,disorders and their treatments.

关键词： cerebral anesthesia moving

Exploring a balance between strength and ductility of hexagonal BN nanoplatelet reinforced ZK61 magnesium composite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第5期12卷 1899-1910页

作者： Kewei Zhang Xiaolong lu Yufeng Sun Shaokang guan Yao Chen School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China Key Laboratory of Advanced Magnesium Alloys in Henan Province Zhengzhou UniversityZhengzhou 450002China Key Laboratory of Advanced Materials Processing&Mold Ministry of EducationZhengzhou 450002China School of Mechanical and Electrical Engineering Soochow UniversitySuzhou 215021China

The practical applications of magnesium(Mg)alloys are usually beset by their relatively low strength and limited *** we attempt to fabricate hexagonal BN nanoplatelet(BNNP)reinforced ZK61 magnesium composites using a combination of spark plasma sintering and friction stir *** resulting composites exhibit microstructural characteristics of homogeneous dispersion of BNNP in Mg matrix with refined equiaxed grains and(0002)basal texture roughly surrounding the pin column *** electron microscopy observation illustrates that trace amounts of Mg_(3)N_(2)and MgB_(2)form at BNNP-Mg interface,in which Mg_(3)N_(2)locates at the basal plane of a BNNP and MgB_(2)grows at its open *** spatial distribution of Mg_(3)N_(2)and MgB_(2)facilitates interfacial wetting and stronger BNNP-Mg interface in such a way that interfacial products act as anchors bonding between *** comparison with monolithic ZK61 alloy,the BNNP/ZK61 composites display simultaneous improvements in yield strength,hardness and ductility,achieving good strength-ductility *** research is expected to shed some light on BNNP potentials for designing and producing magnesium composites with high strength and good ductility.

关键词： BN nanoplatelet Magnesium composite Strength Ductility Spark plasma sintering Friction stir processing