检索结果-南通市图书馆

Science China Chemistry 2009年第9期52卷 1498-1503页

作者： ZHANG Hui LI DeQian SHAO GaoSong yuan zhongyong Institute of New Catalytic Materials Science Engineering Research Center of Energy Storage and Conversion(Ministry of Education)College of ChemistryNankai UniversityTianjin 300071China Key Laboratory of Rare Earth Chemistry and Physics Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

A simple method to prepare titania nanomaterials of core-shell structure, hollow nanospheres and mesoporous nanoparticles has been developed. The core-shell nanostructures with NH4Cl as core and TiO2·xH2O-NH4Cl as shell were prepared in nonaqueous system by the deposition on the surface of the aggregated NH4Cl crystals, which could be transformed into mesoporous anatase nanoparticles or hollow nanospheres by calcination at 500℃ or extraction with methanol, respectively. The hierarchical mesoporous nanostructures benefited the photocatalytic activities of the resultant titania nanomateri-als, demonstrated by the UV light photodegradation of Methyl Orange.

关键词： titania mesoporous core/shell structure hollow sphere nanoparticle

Syntheses of CuO nanostructures in ionic liquids

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2007年第1期50卷 63-69页

作者： WANG Li ZHAO Bin yuan zhongyong ZHANG XueJun Wu QingDuan CHANG LiXian ZHENG WenJun College of Chemistry Nankai UniversityTianjin 300071China

A simple and efficient approach is developed to fabricate single-crystalline CuO nanostructures through an ionic liquid assisted one-step low-temperature solid-state route.Both nanoparticles(5 nm in size)and nanorods(5-10 nm in diameter and 50-100 nm in length)of monoclinic CuO were obtained. These synthesized CuO nanostructures were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),selected area electron diffraction(SAED),X-ray photoelectron spectros- copy(XPS),energy dispersive spectroscopy(EDS)and nitrogen adsorption analysis.The morpholo- gies of the nanostructures can be controlled by tuning the amount of NaOH and ionic liquids.The growth mechanism of CuO nanostructures is investigated.

关键词： CuO nanostructures ionic liquids low-temperature solid-state route

SYNTHESIS OF NANOPOROUS SILICA WITH INTERIOR COMPOSITE CELLS WITH SYNTHETIC BLOCK COPOLYPEPTIDE AS TEMPLATE

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第4期51卷 493-497页

作者： LIU Yuping ZHOU Huijing SHEN Zhurui LI Liying ZHOU Xingdi SUN Pingchuan yuan zhongyong CHEN Tiehong LI Baohui DING Datong Department of Materials Chemistry Key Laboratory of FunctionalPolymer Materials of Ministry of Education College of ChemistryNankai University Tianjin 300071 China College of Physics Nankai University Tianjin 300071 China

Nanoporous silica with unusual interior composite cells was synthesized with synthetic block copolypeptide Phe20-b-PBLG50 as template for the first time. Anilino-methyl triethoxy silane (AMTS) was used as an intermedium to interact with block co-polypeptide Phe20-b-PBLG50 through π-π interaction between the phenyl groups of block copolypeptide and those of AMTS. Meanwhile, AMTS co-condenses together with tetraethoxylsilane (TEOS) after hy-drolysis. The structure of composite vesicles due to the self-assembly of block copolypeptide in the or-ganic solvent was immobilized and transcribed by the formation of silica. The formation of nanopores could be ascribed to the secondary structure of block co-polypeptide and small molecular amine. Our results provide a new avenue to synthesize porous oxide materials with novel interior structures templated by the copolypeptide self-assembly under ambient con-ditions.

关键词：纳米多孔硅合成模板法 π-π交互作用自组装多肽

Unsteady Turbulent Simulation and Pressure Fluctuation Analysis for Centrifugal Pumps

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2009年第1期22卷 64-69页

作者： yuan Shouqi NI Yongyan PAN zhongyong yuan Jianping Research Center of Fluid Machinery Engineering and Technology Jiangsu University Zhenjiang 212013 China

The pressure fluctuation in the flow passage of both impeller and casing is addressed on design condition. The initial conditions for the unsteady turbulent simulation are resulted from the steady calculations, and the three dimensional unsteady turbulent simulation concerning the rotor-stator interaction is executed by a Navier-Stoke solver embedded with k -ε turbulence model and with appropriate moving interface boundary conditions. Detecting points are distributed in the flow passage in different radial and circumferential positions to capture the static pressure fluctuation character for one cycle of the impeller. The time-domain spectrums show that the static pressure curves are periodic and have five peaks and five valleys. With the radius increasing, the pressure fluctuation peak-to-peak values in the impeller are increasing, and reach the maximum value on the interface. In the casing flow passage, those values are about 7% of local static pressure except some ones near the tongue. The values become decreasingly in the diffuser pipe. The frequency spectrums transformed by fast Fourier transform （FFT） show that the dominant frequency is approximate with the blade passing frequency, and the pressure fluctuations in impeller passage have high frequency content while those in casing ones have no such information.

关键词： centrifugal pump rotor-stator interaction unsteady turbulent flow pressure fluctuation

DETECTION OF CAVITATION IN CENTRIFUGAL PUMP BY VIBRATION METHODS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2008年第5期21卷 46-49页

作者： NI Yongyan yuan Shouqi PAN zhongyong yuan Jianping Research Center of Fluid Machinery Engineering and Technology Jiangsu University Zhenjiang 212013 China

For the purpose of detecting the cavitation of centrifugal pump onsite and real time, the vibration signals on varied operation conditions of both cavitation and non-cavitation obtained through acceleration sensors were analyzed. When cavitation occurs, the cavities near the leading edge of the blade will appear periodic oscillating, which will induce quasi-synchronous vibration. The frequency of the quasi-synchronous vibration symmetrically appears on the two sides of the blade passing frequency, by which the cavitation incipiency can be detected. During the developing process of the cavitation, as the severe complexity of the unsteady flow, it is very difficult to detect the development of cavitation by classical analysis methods. Fractal method of Higuchi is successfully used for detecting the incipiency, fully development of cavitation and the development between them.

关键词： Centrifugal pump Cavitation Vibration Detection

Integrated Ni2P nanosheet arrays on three-dimensional Ni foam for highly efficient water reduction and oxidation

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2017年第6期26卷 1196-1202页

作者： Jintao Ren Zhongpan Hu Chong Chen Yuping Liu zhongyong yuan National Institute for Advanced Materials School of Materials Science and EngineeringNankai UniversityTianjin 300353China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Nankai UniversityTianjin 300071China

The large-scale synthesis of efficient nonprecious bifunctional electrocatalysts for overall water splitting is a great challenge for future renewable energy conversion systems. Herein, Ni2P nanosheet arrays directly grown on three-dimensional(3 D) Ni foam(Ni P/NF) are fabricated by hydrothermal treatment of metallic Ni foam with H2O2solution and subsequent phosphidation with NaH2PO2. The Ni P/NF as electrocatalyst exhibits superior activities for both hydrogen evolution reaction(HER) and oxygen evolution reaction(OER). Most importantly, employing both as the cathode and anode for an alkaline water electrolyzer, Ni P/NF only requires a cell voltage of 1.63 V to reach a current density of 10 mV cm-2, together with stronger durability. Preliminary catalytic information suggests that the tailored 3 D superstructure and integrated electrode configurations afford improved active sties and enhanced electron/mass transfer,responding for the outstanding activity and stability.

关键词： Nickel phosphide Electrocatalyst Hydrogen evolution Oxygen evolution Water splitting

Synthesis of porous hematite nanorods loaded with CuO nanocrystals as catalysts for CO oxidation

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2011年第6期20卷 669-676页

作者： Jianliang Cao Yan Wang Tianyi Ma Yuping Liu zhongyong yuan Institute of New Catalytic Materials science Key Laboratory of Advanced Energy Materials Chemistry （Ministry of Education） College of Chemistry Nankai University Tianjin 300071 China

Porous hematite （α-Fe2O3） nanorods with the diameter of 20-40 nm and the length of 80-300 nm were synthesized by a simple surfactant-assisted method in the presence of cetyltrimethylammonium bromide （CTAB）.The α-Fe2O3 nanorods possess a mesostructure with a pore size distribution in the range of 5-12 nm and high surface area,exhibiting high catalytic activity for CO oxidation.CuO nanocrystals were loaded on the surface of porous α-Fe2O3 nanorods by a deposition-precipitation method,and the catalysts exhibited superior activity for catalytic oxidation of CO,as compared with commercial α-Fe2O3 powders supported CuO catalyst.The enhanced catalytic activity was attributed to the strong interaction between the CuO nanocrystals and the support of porous α-Fe2O3 nanorods.

关键词： porous materials iron oxide nanostructures CuO supported nanocatalysts catalytic CO oxidation

Quantitative analysis of the morphing wing mechanism of raptors: Analysis methods, folding motions, and bionic design of Falco Peregrinus

在线全文

学校读者我要写书评

暂无评论

Fundamental Research 2024年第2期4卷 344-352页

作者： Di Tang Xipeng Huang Jinqi Che Weijie Jin Yahui Cui Yangjun Chen Yuxiao yuan zhongyong Fan Weiwei Lu Siyu Wang Yin Yang Dawei Liu College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310014China Affiliated HangZhou XiXi hospital Zhejiang University School of MedicineHangzhou 310023China Zhejiang Museum of Natural History Hangzhou 310014China High Speed Aerodynamic Institute China Aerodynamics Research and Development CenterMianyang 621000China

Raptors can change the shape and area of their wings to an exceptional degree in a fast and efficient manner,surpassing other birds,insects,or bats.Some researchers have focused on the functional properties of muscle skeletons,mechanics,and flapping robot design.However,the wing motion of the birds of prey has not been measured quantitatively,and synthetic bionic wings with morphing abilities similar to raptors are far from reality.Therefore,in the current study,a 3D suspension system for holding bird carcasses was designed and fabricated to fasten the wings of Falco Peregrinus with a series of morphing postures.Subsequently,the wing skeleton of the falcon was scanned during extending motions using the computed tomography(CT)approach to obtain three consecutive poses.Subsequently,the skeleton was reconstructed to identify the contribution of the forelimb bones to the extending/folding motions.Inspired by these findings,we propose a simple mechanical model with four bones to form a wing-morphing mechanism using the proposed pose optimisation method.Finally,a bionic wing mechanism was implemented to imitate the motion of the falcon wing—divided into inner and outer wings with folding and twisting motions.The results show that the proposed four-bar mechanism can track bone motion paths with high fidelity.

关键词： Falco Peregrinus Raptor Suspension system CT scan Bionic wings Four-bar mechanism

The New Changes in Rural Labor Transfer Mode under New Urbanization: Based on the Survey of 10 Villages in Guizhou Province

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Agricultural Research 2015年第7期7卷 95-100页

作者： Zhuping ZHANG Zongjian WU zhongyong yuan Wen SUN Guizhou University of Finance & Economics Guizhou Provincial Commission on Agriculture Guizhou Academy of Agricultural Sciences

With the full-speed development of economy,the new urbanization has been accelerated in Guizhou Province in order to make the people reach a well-off standard of living by 2020. From the whole society,the key point is the development of the rural economy,and the development of the rural economy depends on the economic development of rural households. The income from rural labor force transfer has become the main income source and accounts for more than half of rural household income,which will play a major role in survival and development of rural households.

关键词： Rural areas Labor transfer Mode Guizhou Province

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

软模板合成有序介孔碳材料

化学进展 2014年第5期26卷 756-771页

作者：刘蕾袁忠勇南开大学化学学院先进能源材料化学教育部重点实验室天津化学化工协同创新中心天津300071 山东科技大学材料科学与工程学院青岛266590

有序介孔碳材料由于其较大的表面积、均一的孔径、良好的热稳定性和化学稳定性,广泛应用于吸附、分离、催化以及能量储存等众多领域。与传统的以硅基介孔材料为硬模板的反向复制方法相比,通过嵌段共聚物和聚合物前驱体之间的有机-有机... 详细信息

有序介孔碳材料由于其较大的表面积、均一的孔径、良好的热稳定性和化学稳定性,广泛应用于吸附、分离、催化以及能量储存等众多领域。与传统的以硅基介孔材料为硬模板的反向复制方法相比,通过嵌段共聚物和聚合物前驱体之间的有机-有机自组装的软模板法简便易行,已成为合成有序介孔碳材料有效方法。本论文综述了介孔碳材料的软模板合成机制、合成方法、功能化及其应用,对合成技术、结构控制、孔径调控以及形貌控制等方面进行了讨论,并探讨了其在吸附、催化、电极材料等领域的应用。

关键词：介孔碳材料自组装改性吸附催化