Wu Z.,Fujian Engineering College |
Li Z.,Fujian Engineering College |
Yang L.,Fujian Engineering College |
Han J.,Xiamen University |
Han S.,Fujian Engineering College
Chemical Communications | Year: 2012
Selective detection of hydrogen sulfide was achieved with 7-o-2′-(azidomethyl)benzoyl-4-methylcoumarin via analyte mediated reductive removal of the 2′-(azidomethyl)benzoyl moiety and concurrent generation of fluorescent 7-hydroxy-4-methylcoumarin. This journal is © The Royal Society of Chemistry 2012.
Zhang B.,Fujian Engineering College |
He M.,Fujian Engineering College |
Hang W.,Fujian Engineering College |
Hang W.,Xiamen University |
Huang B.,Fujian Engineering College
Analytical Chemistry | Year: 2013
Matrix effect is unavoidable in direct solid analysis, which usually is a leading cause of the nonstoichiometric effect in quantitative analysis. In this research, experiments were carried out to study the overall characteristics of atomization and ionization in laser-solid interaction. Both nanosecond (ns) and femtosecond (fs) lasers were applied in a buffer-gas-assisted ionization source coupled with an orthogonal time-of-flight mass spectrometer. Twenty-nine solid standards of ten different matrices, including six metals and four dielectrics, were analyzed. The results indicate that the fs-laser mode offers more stable relative sensitivity coefficients (RSCs) with irradiance higher than 7 × 1013 W·cm-2, which could be more reliable in the determination of element composition of solids. The matrix effect is reduced by half when the fs-laser is employed, owing to the fact that the fs-laser ablation and ionization (fs-LAI) incurs an almost heat-free ablation process and creates a dense plasma for the stable ionization. © 2013 American Chemical Society.
Su Q.,Henan University of Urban Construction |
Li L.,Fujian Engineering College |
Li S.,Henan University of Urban Construction |
Zhao H.,Henan University of Urban Construction
Materials Letters | Year: 2013
Single-crystal nitrogen (N) doped p-type ZnSe nanobelts (NBs) with zinc blende structure were synthesized in ammonia atmosphere via a thermal evaporation method. The p-type conductivity of ZnSe:N NBs was confirmed by field-effect transistors (FETs) based on individual NBs. High-performance photodetectors were constructed based on ZnSe:N NBs, which show high sensitivity and relatively fast response speed to the incident light with a sharp cut-off at 460 nm, corresponding to the band-gap of ZnSe. The high photosensitivity and relatively fast response speed are attributable to the high crystal quality of the ZnTe nanowires. These results reveal that such single-crystalline ZnSe NBs are excellent candidates for optoelectronic applications. © 2012 Elsevier B.V.
Xu X.,Fujian Engineering College |
Ding W.,Fujian Engineering College |
Lin Y.,Huaqiao University |
Song Q.,Fujian Engineering College
Organic Letters | Year: 2015
Copper-catalyzed aerobic oxidative esterification of acetophenones with alcohols using molecular oxygen has been developed to form a broad range of α-ketoesters in good yields. In addition to reporting scope and limitations of our new method, mechanism studies are reported that reveal that the carbonyl oxygen in the ester mainly originated from dioxygen. © 2015 American Chemical Society.
Chen L.,Fujian Engineering College |
Zhu D.,Fuzhou University
Solid State Sciences | Year: 2014
Hydrothermal method synthesis of α-MnO2 nanowires has been achieved at different temperatures in this work. X-ray diffraction and transmission electron microscopy confirmed the pure phase of the α-MnO2 nanowires. All of the samples crystallized in a single-phase nanowires shape. The α-MnO2 nanowires diameter increased from 11 nm to 21 nm with the increase in hydrothermal temperature from 120 C to 200 C. The α-MnO2 catalytic activity on the decomposition of ammonium perchlorate (AP) was characterized through thermogravimetric analysis. The decomposition rate of AP with the addition of α-MnO2 was size relative. The 11 nm MnO2 nanowires exhibited the best catalytic activity, which lowered the high-temperature peak of AP by 130°C. © 2013 Elsevier Ltd. All rights reserved.
Wu Z.-W.,Fujian Engineering College
Guangzi Xuebao/Acta Photonica Sinica | Year: 2012
A novel optical element is presented for solving the problems that energy of non-diffracting-like linear structured beam generated by normal triangular-section prism is evenly distributed and not suitable to be used to three-dimensional surface measurement directly and energy efficiency of central spot is lower. This element is designed by gluing a platform with isosceles trapezoid section on the bottom of triangular-section prism. The beam transformation property of this element is analyzed with geometrical optics theory, and the conclusion shows that its property is the same as the combination of two normal triangular-section prisms with different bottom corner. When a plane wave illuminates on the novel optical element, non-diffracting-like linear structured beam which has higher intensity in the central spot is formed. Finally the intensity distribution is simulated by diffraction and interference theory. The results show that the conclusion of diffraction and interference theory is consistent with the conclusion of geometrical optics theory, and a better non-diffracting-like linear structured beam is generated by this novel optical element. Parameters that the central spot size of beam, non-diffracting range and so on can be adjusted easily through changing the structural parameters of the prism.
Lin Z.-H.,Fujian Engineering College
Guangzi Xuebao/Acta Photonica Sinica | Year: 2012
Fringe center method is an important demodulation method for electronic speckle pattern interferometry fringe. The precondition of this method is to obtain fringe skeletons with high precision. Based on the analysis of carrier-wave electronic interferometry fringe characteristics, a fringe skeletons extracting method based on modulation direction was proposed. Firstly, a homomorphic filtering was used to filter the high frequency multiplicative speckle pattern noise effectively and pick out carrier-wave fringes. Then a fringe skeletons extracting algorithm based on modulation direction was applied to confirm the dots of gray scale extremum and make binarization processing. In order to get whole fringe skeletons map, the mending methods based on skeletons curve fitting or based on the fringe separation were adopted to compensate the edge fringe skeletons. Experimental results show that this method is simple and reliable. It can extract the consecutive fringe skeletons quickly and accurately.
Shen P.H.,Fujian Engineering College
Advanced Materials Research | Year: 2014
The soil compactor is one of the most important construction machineries which play an significant role during our economic development. And the complicated nonlinear characteristic of equipment-material system is an interesting field in recent theoretical and applied investigations. According to experimental datum, a nonlinear model derived from piecewise linear was used to describe the hysteretic behavior of soil material during compaction. Through choosing proper model parameters, the nonlinear dynamic characteristics are commendably controlled which could represent different compacting stages. Furthermore, the series phase diagram and Poincare section were obtained by simulation. The hysteretic characteristics might be incarnating from periodic vibration to chaotic vibration. Further research proved that reducing the angular frequency of rotation may bring the chaotic vibration coming back to periodic vibration, which provided a good assistance for further study on hysteretic character of soil compaction and man-machine engineering on vibratory compacting system. © (2014) Trans Tech Publications, Switzerland.
Yang P.,Fujian Engineering College |
Yang K.-H.,Fujian Engineering College
Advanced Materials Research | Year: 2013
Three groups of commercial 1050 Al alloy were subjected to equal channel angular pressing (ECAP) at room temperature using route A, route C and route Bc, respectively. Mechanical properties and fracture modes of as-annealed and ECAPed samples were investigated. The microhardness of 1050 Al fabricated by ECAP increases by a factor of about 1.5 compared to the as-annealed state. The ultimate tensile strength (UTS) increases significantly after ECAP, while the elongation decreases. But they are strongly dependence on the number of ECAP passes and the pressing route. The UTS and elongation of the samples processed by route Bc are best, consequently, the static toughness U of the samples is enhanced. Besides, all specimens subjected to ECAP deformation failed in a ductile manner. © (2013) Trans Tech Publications, Switzerland.
Wu Z.,Fujian Engineering College
Guangxue Xuebao/Acta Optica Sinica | Year: 2013
A novel optical system is proposed, and it is composed of two biprisms with different bottom corners and one cylindrical lens. The technical problem that the striped regional of grating structure light generating by single biprism is so small that it cannot be applied to wide range measurement is solved. Physical processes of generating grating structure light is analyzed by geometrical optics, and relevant parameters are also calculated. The intensity distribution in different positions after system is simulated by Zemax software, and the intensity distribution with the change of system parameters, e.g. structure parameters of optical elements and relative position between optical elements, are also analyzed. The conclusion of simulation is consistent with that of geometrical optics theory. The result shows that when a plane wave illuminates on the novel optical system, the grating structure light with wide measurement area, low divergence degree and adjustment flexibulity is formed.