Radial stereo imaging system for three-dimensional reconstruction

In this paper, we propose a radial stereo imaging system for three-dimensional reconstruction of an object. This system uses a novel optical device which consists of a camera and two reflected mirrors. It can reconstruct three-dimensional model of an object by capturing one image. Depending on the reflection of the mirrors, each world point in the scene has a pair of points which sit in the inner and outer of the captured image, respectively. We firstly analyze the imaging constraint of the proposed system, and then derive the geometrical relationship between world point and image point pair to calculate the three-dimensional coordinate values of an arbitrary point on the object, which means that the three-dimensional model of the object can be recovered. Experiments are carried out to prove our design, and the results show that our radial stereo imaging system is convenient and effective for the three-dimensional reconstruction of an object. This system can be used in variety of applications, such as virtual reality and commodity show.     

Theoretical and experimental design of Pt-Co(OH)_2 electrocatalyst for efficient HER performance in alkaline solution

Design efficient electrocatalysts become significant for the hydrogen evolution reaction (HER) in alkaline solution.Here,the HER performance on Pt-Co(OH)2 has been investigated by using DFT calculations.Compared with pure Pt,the Pt-Co(OH)2 shows excellent hydrogen binding energy (-0.29 eV) and hydrogen adsorption free energy (0.02 eV).More strikingly,the water dissociation process on Pt-Co(OH)2 is an exothermic reaction while that of Pt is an endothermic reaction,demonstrating that the Pt-Co(OH)_2 is an excellent catalyst for HER in alkaline medium.Then the two-step electrodepositions was used to fabricate Pt-Co(OH)2 on the carbon paper (CP).The Pt-Co(OH)_2/CP shows the lowest overpotential of only 37.6 mV at a current density of 10 mA cm~(-2) in 0.1M KOH,the smallest Tafel slope of58 mV dec~(-1) and the good stability for 20000s without obvious degradation.     

New fluorescent benzocrown ether derivatives of tetrathiafulvalene: facile synthesis and recognition properties

Two new fluorescent crown ether derivatives of tetrathiafulvalene (TTF) (2a and 2b) were synthesized and characterized; their electrochemical response to Na⁺ ions and fluorescence properties were investigated. The mechanism of the strong fluorescence has also been explored.     

后进地区经济发展战略研究

提出将落后地区划分为后进地区、贫困地区、极贫困地区等三种不同类型的观点;通过对渭南地区的研究,探讨了后进地区“工业增长极建设与农村发展建设有机结合”的经济发展战略。     

空间移相干涉仪的移相误差分析和测试

分析研究了一种基于二维正交光栅分光的空间移相干涉仪的移相性能,指出移相器偏振片组中偏振单元的方位角偏差将直接产生2倍的移相误差,同时干涉图的空间一致性失调也会产生一定的移相误差.在根据原理方案搭建的实验系统中,分别采用测量4幅干涉图的对应消光位置法,以及作出干涉图同一行的光强拟合曲线之间的李萨茹图法,来测量出干涉图之间的实际移相量.结果表明,实验系统中经过空间一致性校准的干涉图之间的移相误差在±1.2°以内.     

基于AHP和灰色评价法的武汉市水环境风险评价及管理战略思考

通过构建武汉市城市水环境风险指标体系,综合运用AHP和灰色评价法对当前武汉市水环境总体风险、及其形成原因和结果表现进行评价.结果显示：1）武汉市水环境风险总体处于＂风险较高＂水平;2）成因方面,社会发展对水环境有一定负面影响;3）表现结果方面看,水污染负荷程度较高.最后,基于评价结果和武汉市未来社会经济发展的＂基准情景＂、＂优化情景＂和＂绿色低碳情景＂进行假设,并对科学制定武汉水环境管理战略提出了建议.     

A multifunctional silicotungstic acid-modified Li-rich manganese-based cathode material with excellent electrochemical properties

Journal of Solid State Electrochemistry - Li-rich layered oxide (LrLO) cathode has attracted much attention for Li-ion batteries in recent years due to its superior capacity of exceeding...     

Highly photoluminescent MoOx quantum dots: Facile synthesis and application in off-on Pi sensing in lake water samples

Molybdenum oxide (MoO_x) is a well-studied transition-metal semiconductor material, and has a wider band gap than MoS₂ which makes it become a promising versatile probe in a variety of fields, such as gas sensor, catalysis, energy storage ect. However, few MoO_x nanomaterials possessing photoluminescence have been reported until now, not to mention the application as photoluminescent probes. Herein, a one-pot method is developed for facile synthesis of highly photoluminescent MoO_x quantum dots (MoO_x QDs) in which commercial molybdenum disulfide powder and hydrogen peroxide (H₂O₂) are involved as the precursor and oxidant, respectively. Compared with current synthesis methods, the proposed one has the advantages of rapid, one-pot, easily prepared, environment friendly as well as strong photoluminescence. The obtained MoO_x QDs is further utilized as an efficient photoluminescent probe, and a new off-on sensor has been constructed for phosphate (Pi) determination in complicated lake water samples, attributed to the fact that the binding affinity of Eu³⁺ ions to the oxygen atoms from Pi is much higher than that from the surface of MoO_x QDs. Under the optimal conditions, a good linear relationship was found between the enhanced photoluminescence intensity and Pi concentration in the range of 0.1–160.0 μM with the detection limit of 56 nM (3σ/k). The first application of the photoluminescent MoO_x nanomaterials for ion photochemical sensing will open the gate of employing MoO_x nanomaterials as versatile probes in a variety of fields, such as chemi-/bio-sensor, cell imaging, biomedical and so on.     

Storage Stability of LiFePO4/C in Humid‐hot Air

Storage stabilities of LiFePO₄/C composite at different conditions are investigated in terms of structural and electrochemical evolutions. The results from different aging tests indicate that moisture and temperature are the key factors that have the most profound effects on the structure homogeneity which in turn influences the electrochemical performance of LiFePO₄/C. Although the storage in a humid‐hot environment, such as saturated humidity air at 50°C, does not greatly influence the discharging capacity of LiFePO₄/C, it does reduce the initial charging capacity, thus the amount of reversible Li⁺ ions in a practical LiFePO₄/graphite cell decreases. This impact is explained by the lithium extraction during the storage, forming olivine FePO₄ and associated Li₃PO₄. Elevated storage temperature also favors the delithiation process. The degree of delithiation increases from about 6% at 50°C to 18% at 80°C. It is also found that re‐calcination at 650°C effectively resolves the problem of the structural heterogeneity of the stored LiFePO₄/C. Therefore both the initial charging capacity and coulombic efficiency of the stored sample in the first cycle revert to the original value of the fresh one.     

乙醇酸的合成及应用

综述了乙醇酸的合成方法,分离提纯以及在有机合成和生物中的应用,参考文献25篇。