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controllable synthesis of novel nanoporous manganese oxide catalysts for the direct synthesis of imines from alcohols and amines

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Chinese Journal of Chemical Engineering 2019年第10期27卷 2438-2446页

作者： Fushan Chen Songlin Zhao Tao Yang Taotao Jiang Jun Ni Houfeng Xiong Qunfeng Zhang Xiaonian Li Industrial Catalysis Institute of Zhejiang University of Technology Hangzhou 310014China Jiangxi Province Engineering Research Center of Ecological Chemical Industry Jiujiang UniversityJiujiang 332005China School of Pharmaceutical and Chemical Engineering Taizhou UniversityTaizhou 318000China

A novel template-free oxalate route was applied to synthesize different mesoporous manganese oxides(amorphous manganese oxide(AMO),Mn5 O8,Mn3 O4,Mn O2)in the narrow temperature range from 350°C to 400°C by controlling the calcination conditions,which were employed as the efficient catalysts for the oxidative coupling of alcohols with amines to imines.The chemical and structural properties of the manganese oxides were characterized by the methods of thermogravimetry analysis and heat flow(TG-DSC),X-ray diffraction(XRD),nitrogen sorption,scanning electron microscope(SEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),H2 temperature-programmed reduction(H2-TPR),and inductively coupled plasma optical emission spectrometry(ICP-OES)techniques.The structures of different manganese oxides were confirmed by characterization.The M-350(AMO)presented the maximum surface area,amorphous nature,the lowest reduction temperature,the higher(Mn3++Mn4+)/Mn2+ratio,and the higher adsorbed oxygen species compared to other samples.Among the catalysts,M-350 showed the best catalytic performance using air as an oxidant,and the conversion of benzyl alcohol(BA)and the selectivity of N-benzylideneaniline(NBA)reached as high as 100%and 97.1%respectively at the lower reaction temperature(80°C)for 1 h.M-350 had also the highest TOF value(0.0100 mmol·mg-1·h-1)compared to the other manganese oxide catalysts.The catalyst was reusable and gave 95.8%conversion after 5 reuse tests,the XRD pattern of the reactivated M-350 did not show any obvious change.Lattice oxygen mobility and(Mn3++Mn4+)/Mn2+ratio were found to play the important roles in the catalytic activity of aerobic reactions.

关键词： Oxalate route controllable synthesis Manganese oxide Imine synthesis Heterogeneous catalysis Aerobic oxidation

controllable synthesis of elongated hexagonal bipyramid shaped La(OH)3 nanorods and the distribution of electric property by off-axis electron holography

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Nano Research 2016年第9期9卷 2561-2571页

作者： Zhiwei Wen Chongyun Liang Han Bi Yuesheng Li Renchao Che Laboratory of Advanced Materials Department of Materials ScienceiChEMCollaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryFudan UniversityShanghai 200438China

Rare earth oxides/hydroxides are important emerging materials owing to their unique properties. Shape-controlled synthesis of elongated hexagonal bipyramid shaped La(OH)3 nanorods with different aspect ratios and trigram-shaped LaCO3OH nanosheets was systematically carried out by controlling the reaction conditions. Hydrazine and polyvinylpyrrolidone (PVP) surfactants used in synthesis are assumed to play a key “dual-template” role in determining the aspect ratio and shape of the resulting nanostructures. Elongated hexagonal bipyramid shaped La(OH)3 nanorods were found to grow along the preferred orientation [0001]. Six equivalent crystallographic facets, $$(20\bar 20)$$ , $$(02\bar 20)$$ , $$(2\bar 200)$$ , $$(0\bar 220)$$ , $$(\bar 2200)$$ , and $$(\bar 2020)$$ lattice planes, were found to be exposed on the side surfaces on each nanorod as confirmed by combined transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) analyses. A double-polarization phenomenon was found to occur at the nanorod surfaces by employing off-axis electron holography, implying that the material could be used as an effective dielectric microwave absorber. La(OH)3 nanorods with larger aspect ratios exhibit better absorption properties with respect to the maximum reflection loss and effective absorbing bandwidth. Thus, a novel method towards the reasonable design of bipyramid shaped La(OH)3 nanorod

关键词： controllable synthesis elongated hexagonal bipyramid lanthanum hydroxide electric property electron holography microwave absorption

controllable growth of GeSi nanostructures by molecular beam epitaxy

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Journal of Semiconductors 2018年第6期39卷 51-65页

作者： Yingjie Ma Tong Zhou Zhenyang Zhong Zuimin Jiang State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences State Key Laboratory of Surface Physics Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education) and Department of PhysicsFudan University School of Physics and Optoelectronic Engineering Shandong University of Technology

We present an overview on the recent progress achieved on the controllable growth of diverse GeSi al- loy nanostructures by molecular beam epitaxy. Prevailing theories for controlled growth of Ge nanostructures on patterned as well as inclined Si surfaces are outlined firstly, followed by reviews on the preferential growth of Ge nanoislands on patterned Si substrates, Ge nanowires and high density nanoislands grown on inclined Si surfaces, and the readily tunable Ge nanostructures on Si nanopillars. Ge nanostructures with controlled geometries, spatial distributions and densities, including two-dimensional ordered nanoislands, three-dimensional ordered quantum dot crystals, ordered nanorings, coupled quantum dot molecules, ordered nanowires and nanopillar alloys, are dis- cussed in detail. A single Ge quantum dot-photonic crystal microcavity coupled optical emission device demon- stration fabricated by using the preferentially grown Ge nanoisland technique is also introduced. Finally, we sum- marize the current technology status with a look at the future development trends and application challenges for controllable growth of Ge nanostructures.

关键词： Ge Si molecular beam epitaxy nanostructures controllable patterned substrates inclinedsurfaces preferential growth

A novel near-infrared light responsive 4D printed nanoarchitecture with dynamically and remotely controllable transformation

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Nano Research 2019年第6期12卷 1381-1388页

作者： Haitao Cui Shida Miao Timothy Esworthy Se-jun Lee Xuan Zhou Sung Yun Hann Thomas J.Webster Brent T.Harris Lijie Grace Zhang Department of Mechanical and Aerospace Engineering The George Washington UniversityWashingtonDC 20052USA Department of Chemical Engineering Northeastern UniversityBostonMA 02115USA Department of Neurology and Pathology Georgetown UniversityWashingtonDC 20007USA Departments of Electrical and Computer Engineering The George Washington UniversityWashingtonDC 20052USA Department of Biomedical Engineering The George Washington UniversityWashingtonDC 20052USA Department of Medicine The George Washington UniversityWashingtonDC 20052USA

Four-dimensional (4D) printing is an emerging and highly innovative additive manufacturing process by which to fabricate pre-designed,self-assembly structures with the ability to transform over time.However,one of the critical challenges of 4D printing is the lack of advanced 4D printing systems that not only meet all the essential requirements of shape change but also possess smart,dynamic capabilities to spatiotemporally and instantly control the shape-transformation process.Here,we present a facile 4D printing platform which incorporates nanomaterials into the conventional stimuli-responsive polymer,allowing the 4D printed object to achieve a dynamic and remote controlled,on-time and position shape transformation.A proof-of-concept 4D printed brain model was created using near-infrared light (NIR) responsive nanocomposite to evaluate the capacity for controllable 4D transformation,and the feasibility of photothermal stimulation for modulating neural stem cell behaviors.This novel 4D printing strategy can not only be used to create dynamic 3D patterned biological structures that can spatiotemporally control their shapes or behaviors of transformation under a human benign stimulus (NIR),but can also provide a potential method for building complex self-morphing objects for widespread applications.

关键词： near-infrared light responsive four-dimensional (4D) printing dynamically and remotely controllable graphene brain neural stem cell

Adiabatic cooling for cold polar molecules on a chip using a controllable high-efficiency electrostatic surface trap

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Chinese Physics B 2014年第12期23卷 148-154页

作者：李胜强许亮夏勇汪海玲印建平 State Key Laboratory of Precision Spectroscopy Department of Physics East China Normal University

We propose a controllable high-efficiency electrostatic surface trap for cold polar molecules on a chip by using two insulator-embedded charged rings and a grounded conductor plate. We calculate Stark energy structure pattern of ND3 molecules in an external electric field using the method of matrix diagonalization. We analyze how the voltages that are applied to the ring electrodes affect the depth of the efficient well and the controllability of the distance between the trap center and the surface of the chip. To obtain a better understanding, we simulate the dynamical loading and trapping processes of ND3 molecules in a ｜J, KM = ｜1,-1 state by using classical Monte–Carlo method. Our study shows that the loading efficiency of our trap can reach ～ 88%. Finally, we study the adiabatic cooling of cold molecules in our surface trap by linearly lowering the potential-well depth（i.e., lowering the trapping voltage）, and find that the temperature of the trapped ND3 molecules can be adiabatically cooled from 34.5 m K to ～ 5.8 m K when the trapping voltage is reduced from-35 k V to-3 k V.

关键词： controllable high-efficiency surface trap cold polar molecules

Micromagnetic studies of perpendicular recording FePt media with controllable grain size distributions

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Rare Metals 2006年第Z1期25卷 436-439页

作者： DONG Zhong PIAO Kun SHE Shengxian WEI Dan LI Zhenghua WEI Fulin Department of Materials Science and Engineering Tsinghua University Beijing 100084 China Department of Materials Science and Engineering Tsinghua University Beijing 100084 China Department of Materials Science and Engineering Tsinghua University Beijing 100084 China Department of Materials Science and Engineering Tsinghua University Beijing 100084 China Research Institute of Magnetic Materials Lanzhou University Lanzhou 730000 China Research Institute of Magnetic Materials Lanzhou University Lanzhou 730000 China

A 3-dimensional (3D) micromagnetic model combined with Fast Fourier Transform (FFT) method was built up to study the writability in the L10 FePt perpendicular medium. The effects of controllable grain size distributions were studied by grain growth simulation. It is found that the cross-track-averaged magnetization changes little between the L10 FePt medium with uniform or non-uniform grain size distribution.

关键词： perpendicular recording L10 FePt medium controllable grain size distributions micromagnetic simulation

Size-controllable synthesis and high-performance formic acid oxidation of polycrystalline Pd nanoparticles

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Rare Metals 2019年第2期38卷 115-121页

作者： Hui-Hui Wang Jin-Feng Zhang Ze-Lin Chen Meng-Meng Zhang Xiao-Peng Han Cheng Zhong Yi-Da Deng Wen-Bin Hu Tianjin Key Laboratory of Composites and Functional Materials and Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education) Tianjin University

A facile approach was developed for the synthesis of polycrystalline palladium nanoparticles(Pd NPs)by using tannic acid(TA) as green reagent and stabilizer in a 30 ℃ water bath. The size of Pd NPs can be tuned in a range of 10–60 nm simply by adjusting the concentration of Pd precursor. The catalytic activity and stability of the as-obtained Pd NPs toward formic acid oxidation were analyzed. It is found that these Pd NPs with different sizes exhibit size-dependent and enhanced formic acid oxidation performance compared to the commercial Pd black catalyst. It should be noted that the Pd catalysts with an average size of 24 nm demonstrate the best catalytic activity and stability among the other prepared Pd NPs, which can be ascribed to its larger electrochemical surface area(ECSA)and polycrystalline structure with defects.

关键词： Polycrystalline palladium nanoparticle Size controllable Tannic acid: Room temperature Formic acid oxidation

Bionic Flapping Pectoral Fin with controllable Spatial Deformation

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Journal of Bionic Engineering 2019年第5期16卷 916-930页

作者： Yueri Cai Lingkun Chen Shusheng Bi Guoyuan Li Houxiang Zhang Robotics Institute Beihang UniversityBeijing 100191China Department of Ocean Operations and Civil Engineering Norwegian University of Science and TechnologyAalesund 6025Norway

This paper presents the design of a bionic pectoral fin with fin rays driven by multi-joint mechanism.Inspired by the cownose ray,the bionic pectoral fin is modeled and simplified based on the key structure and movement parameters of the cownose ray's pectoral fin.A novel bionic propulsion fin ray composed of a synchronous belt mechanism and a slider-rocker mechanism is designed and optimized in order to minimize the movement errors between the designed fin rays and the spanwise curves observed from the cownose ray,and thereby reproducing an actively controllable flapping deformation.A bionic flapping pectoral fin prototype is developed accordingly.Observations verify that the bionic pectoral fin flaps consistently with the design rule extracted from the cownose ray.Experiments in a towing tank are set up to test its capability of generating the lift force and the propulsion force.The movement parameters within the usual propulsion capabilities of the bionic pectoral fm are utilized:The flapping frequency of 0.2 Hz-0.6 Hz,the flapping amplitude of 3°-18°,and the phase di^rence of 10°-60°.The results show that the bionic pectoral fin with actively controllable spatial deformation has expected propulsion performance,which supports that the natural features of the cownose ray play an important role in designing and developing a bionic prototype.

关键词： cownose ray bionic pectoral fin controllable deformation multiple fin rays propulsion perfonnance

Magnetic and thermosensitive luminescent nanocomposites based on Fe_3O_4/SiO_2/poly(N-isopropylacrylamide)/lanthanidepolyoxometalates and their controllable luminescence properties

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Journal of Rare Earths 2018年第7期36卷 733-738页

作者： Jun Wang Si Chen Hao Liu Wuke Li College of Chemistry Central China Normal University

Magnetic and temperature-responsive luminescent composites based on poly（N-isopropylacrylamide）,magnetic nanoparticles and Na9[EuW10O36] were fabricated. The composites were investigated by IR, UV,XRD, TGA, SEM and TEM. The prepared nanocomposites exhibit good superparamagnetic property and thermo-responsive switchable luminescence properties. The multifunctional nanocomposites can be separated by external magnetic field. Moreover, the nanocomposites exhibit an appreciable temperature response, and the red luminescence of the nanocomposites in solution can be controlled by the temperature stimuli. The hydrogel emits strong redluminescence in solution at 25 ℃,which can be seen by naked eyes. When the external temperature is 40 ℃, the red luminescence almost disappears in solution.It is expected that the multifunctional nanoparticles have potential applications in the field of biomedicine.

关键词： Magnetic Lanthanide Luminescence Thermosensitive controllable Rare carths