舞台灯具国家标准特殊要求及LED舞台灯具的适用性

介绍了国家标准GB 7000.217-2008/IEC 60598-2-17：1984＋A2：1990《灯具第2-17部分：特殊要求舞台灯光、电视、电影及摄影场所（室内外）用灯具》的特殊要求,阐述了对该标准特殊要求条文的理解和解释以及其对LED舞台灯具的适用性,以帮助舞台灯具行业的设计、生产、检验和使用人员正确理解和应用舞台灯具国家标准。     

Effects of Nitrogen Doping on Microstructure and Photocatalytic Activity of Nanocrystalline TiO2 Powders

Nitrogen-doped TiO2 nanocrystalline powders were prepared by hydrolysis of tetrachloride titanium （TiCl4） in a mixed solution of ethanol and ammonium nitrate （NH4NO3） at ambient temperature and atmosphere followed by calcination at 400 ℃ for 2 h in air. FTIR spectra demonstrate that amine group in original gel is eliminated by calcination, and the TiO2 powder is liable to absorb water onto its surface and into its capillary pore. XRD and SEM results show that the average size of nanocrystalline TiO2 particles is no more than 60 nm and with increasing the calcination temperature, the size of particles increases. XPS studies indicate the nitrogen atom enters into the TiO2 lattice and occupies the position of oxygen atom. The nitrogen doping not only depresses the grain growth of TiO2 particles, but also reduces the phase transformation temperature of anatase to futile. The photocatalytic activity of the nitrogen-doped TiO2 powders has been evaluated by experiments of photocatalytic degradation aqueous methylene blue.     

Mo掺杂TiO2的制备及其光催化性能

以钛酸四丁酯为原料,采用溶胶-凝胶法制备了纯TiO_2与Mo掺杂TiO_2纳米粒子,并利用XRD、UV-VIS、XPS等测试手段对制备的TiO_2纳米粒子进行表征;以亚甲基蓝为光催化反应模型,考察了煅烧温度、钼掺杂量等对TiO_2晶格畸变,晶粒大小,晶型,光学性能及光催化活性的影响.结果表明:大部分Mo~(6+)取代晶格中Ti~(4+)的位置,引起晶格畸变,抑制晶粒长大与TiO_2由锐钛矿相向金红石相转变;样品经450 ℃煅烧, 随Mo掺杂量增加,激发波长红移增加,当煅烧温度升至600 ℃,1.8%Mo-TiO_2样品中锐钛矿相含量增加,致光激发波长蓝移;适量的Mo掺杂有利于提高TiO_2光催化效果,Mo掺杂物质的量分数为1.8%, 经600 ℃煅烧后样品的光催化性能最佳.     

Dried jujube classification using support vector machine based on fractal parameters and red,green and blue intensity

A new method that combines fractal theory and red, green and blue (RGB) colour intensity was developed to sort dried jujube fruits by using support vector machine (SVM). Our result shows that the new method is fast and accurate in dried jujube fruits classification. The SVM models based on fractal parameters only achieved 85.18–92.73% total accuracy rate. The total classification accuracy of SVM based on RGB intensity values was 94.44%. However, the SVM models based on combining fractal parameters with RGB intensity values achieved 94.44–98.15% total accuracy rate. The best classification accuracy (98.15%) was found when using SVM model based on combining fractal measures (FM) with RGB intensity values (C = 512, γ = 0.0078125). Therefore, the SVM model based on combining FMs with RGB intensity is recommended in dried jujube fruits classification.     

Modified hydrothermal fabrication of a CoS2–graphene hybrid with improved photocatalytic performance

CoS₂ and a CoS₂–graphene composite were synthesized via a facile sonochemical and hydrothermal method. As-prepared samples were characterized by X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis, transmission electron microscopy, and UV-vis diffuse reflectance spectroscopy. The CoS₂–graphene composites exhibited high dye adsorption, extended light absorption, and efficient charge separation properties. Hence, for photodegradation of methylene blue (MB), significant enhancement of the reaction rate was observed for CoS₂–graphene compared to pure CoS₂. The high activity can be attributed to positive synergetic effects between CoS₂ and graphene. The excellent photoinduced charge separation and observed red shift make these hybrid materials potential candidates for the development of high-performance next-generation photocatalyst materials.     

元青花《昭君出塞》罐艺术特征与主题思想研究

"昭君出塞"故事源于汉代,绵延流传,元青花《昭君出塞》罐表现的即为"昭君出塞"故事题材。元青花《昭君出塞》罐具有鲜明的艺术特征,同时,亦具有丰富而深邃的主题思想内涵。     

Molecular design of deep blue fluorescent emitters with 20% external quantum efficiency and narrow emission spectrum

A thermally activated delayed fluorescent (TADF) emitter, 2,7-bis(9,9-dimethylacridin-10(9H)-yl)-9,9-dimethyl-9H-thioxanthene 10,10-dioxide (DMTDAc), was developed as a deep blue TADF emitter using a rigid 9,9-dimethyl-9H-thioxanthene 10,10-dioxide (DMTD) acceptor and an acridine donor. The rigid DMTD acceptor narrowed emission spectrum of DMTDAc by interlocking two phenyl units of diphenylsulfone. A deep blue TADF device with an external quantum efficiency close to 20% with a deep blue color coordinate of (0.15,0.13) was provided using the DMTDAc TADF emitter.     

水热法制备钒酸铋及可见光催化降解亚甲基蓝溶液研究

利用水热法制备了BiVO4粉体,并通过X射线衍射(XRD)、扫描电镜(SEM)、紫外一可见漫反射光谱(DRS)等对催化剂进行了表征。以制备的BiVO4为催化剂,考察了可见光照射下其对亚甲基蓝的降解效果。研究结果表明对初始质量浓度为10 mg/L的亚甲基蓝溶液50 mL,BiVO4加入量为0.6 g/L,经500 W氙灯(可见光)照射6 h后,亚甲基蓝的脱色率可达64%。     

Synthesis,characterisation and structural studies of Rb x Mn[Fe(CN)6]

We present the synthesis and detailed characterisation of the Rb _x Mn[Fe(CN)₆] compound. The composition of the material significantly depends on the applied preparative conditions. Analysis of spectroscopic results (EDX,?Raman) and X-ray powder diffraction data yielded a further assessment of the difference in structural features. The characteristic individual magnetic behaviour, as well as the metal-to-metal charge transfer capabilities of the various samples, could be related to significant changes within the structures that appear to be associated with the synthetic method used.