Microwave-assisted Solvothermal Synthesis of YF_3∶Yb^(3+),Tm^(3+) Nanobundles

Recently, considerable attention has been paid to the synthesis and research of various rare-earth （RE） doped fluoride nanomaterials because of their high refractive index and appropriate phonon energy, which have potential applications in optics, optoelectronics, microelectronics, and tribology. Many methods have been utilized to synthesize the nanomaterials of RE doped fluorides with controllable sizes, shapes, and nanostructures. Comparatively, the microwave irradiation （MWI） method is simple, fast, and unique in its potential for large-scale synthesis without suffering thermal gradient effects.

Studies on Ion-Beam Modified Hydrogen Evolution Electrodes

he present paper focuses on the modifying effects of ion beam mixing, ion im-planting and ion sputtering on hydrogen evolution electrodes. It was discovered thatthe four types of electrodes possessed excellent catalytic activity in acid or alkalinemedia and potential stability in long term electrolysis of water under high currentdensity. Their stability and applying life-span greatly surpass those of other elec-trodes activated by electrodepositing and other method. The effects of temperatureand roughness on function of electrodes were also examined. XPS and AES wereapplied to analyse the surface composition and bond states of the electrodes, andthe distribution of concentration varying with depth, and to explain the law of theexperiments .

籼稻和粳稻品种糙米矿质营养对开放式空气CO_2浓度升高的响应

基于FACE(free-air CO_2enrichment)试验平台,以籼稻IIY084与粳稻WYJ23为试验对象,连续两年(2013、2014)研究糙米产量和矿质元素(Fe、Mn、Cu、Zn、Ni、Se)含量对CO_2浓度升高的响应。结果表明,CO_2浓度升高条件下,IIY084与WYJ23籽粒和糙米产量增加,其中,糙米两年平均增产34.3%和16.3%。CO_2浓度升高连续两年降低IIY084糙米中Fe、Mn、Cu、Zn、Ni、Se含量,其两年平均分别降低了10.4%、13.4%、15.5%、11.7%、25.7%、3.2%,而WYJ23糙米中矿质营养含量未出现一致的下降现象。其中,2014年糙米Mn、Cu、Zn和Ni含量对CO_2浓度升高的负响应达到显著水平(P<0.05)。此外,糙米Fe(P<0.1,2014)、Mn(P<0.01,2013和2014)、Cu(P<0.1,2014)、Zn(P<0.01,2013和2014)、Ni(P<0.01,2014)、Se(P<0.05,2013; P<0.01,2014)含量在水稻品种间存在显著性差异。CO_2浓度升高不同程度地增加糙米中矿质元素积累量,6种元素两年平均增加2.1%～29.2%(IIY084)和12.8%～19.3%(WYJ23)。可见,CO_2浓度升高条件下,IIY084糙米中矿质元素含量较WYJ23有更明显的下降趋势,导致食用IIY084较WYJ23有更大的Fe、Mn、Cu、Zn、Ni、Se缺乏风险。因而,在确保粮食安全而进行增产品种选育时,应该优先选择矿质营养品质较高的水稻品种。