Structure and optical properties of ZnO films

利用金属有机物化学气相沉积(MOCVD)方法在Al2O3(0001)衬底上生长ZnO薄膜,通过改变衬底温度及生长舱压力,得到了各种不同表面形貌的ZnO薄膜。扫描电镜(SEM)用来对样品的形貌进行观察,当衬底温度及生长舱压力分别为400℃,40Pa和450℃,8Pa时,得到了纳米管及纳米墙结构。利用X射线衍射谱(XRD)、透射光谱及光致发光谱对样品的结构及光学性能进行评价。实验结果证明对于较高的生长温度和较低的生长舱压力所生长的样品具有较好的结晶质量。The ZnO films were deposited by metalorganic chemical vapor deposition (MOCVD) method on substrate Al2O3 (0 0 0 1). The different structures of films were obtained by changing the grown temperature and pressure. The morphology was investigated by scanning electron microscopy (SEM). The nanotube and nanowall structures were obtained when grown temperature and pressure were 400 ℃,40 Pa and 450 ℃,8 Pa respectively. X-ray diffraction (XRD),transmission spectra and photolu-minescence (PL) were used to analyze the structure and optical peroperties of the films. The results show that the films deposited at higher temperature and lower pressure have a good crystal quality.吉林省科学技术厅科技发展计划项目(200705C01

The preparation of ZnSe Qdots in aqueous solution and the effects of photo-induced fluorescence enhancement

在水相中,以巯基乙酸(TgA)为稳定剂制备了具有短波长荧光的znSE量子点.研究了znSE量子点光诱导荧光增敏的机理,并提出通过补加zn2+和TgA以提高光诱导荧光增敏效率以及所得znSE量子点的稳定性这一新思路.研究结果表明,提高补加的zn2+和TgA的量即可增加znSE量子点表面znS壳层的厚度,更好地钝化其表面,从而不仅可显著提高znSE量子点的荧光量子产率(最高可接近15%),而且可大大地提高其表面的抗氧化性和荧光稳定性.ZnSe Qdots with short wavelength-fluorescence were prepared in aqueous solution with thioglycolic acid(TGA) as capping reagent.The mechanism of photo-induced fluorescence enhancement was studied and it was proposed a novel approach involved in the addition of compensatory Zn2+ ions and TGA to the original ZnSe solution to increase the efficiency of photo-induced fluorescence enhancement and stability of ZnSe Qdots.The research indicated that the thickness of ZnS shell increases with the increase of the quantity of Zn2+ ions and TGA.The ZnS shell made a better passivation of the ZnSe Qdot surface,thus resulted in not only higher fluorescence quantum yield(maximal 15%),but also higher stability of ZnSe Qdots.It was expected that the proposed approach would also provide a novel route to increase the fluorescence quantum yield and stability of other types of Qdot prepared in aqueous solution.浙江省自然科学基金资助项目(Y4080518

我国油料产业形势分析与发展对策

油料安全事关国计民生，保障油料有效供给是我国必须坚守的国家粮食安全底线。站在全球视角，对2011/2012—2020/2021年度我国油料供需形势、生产形势及市场形势进行分析，明确我国油料产业在生产、加工、贸易等方面面临的挑战，并针对性地提出了统一科学谋划与增强政策扶持精准度相结合，强化科技支撑与耕地资源保护相结合，提高农户油料种植收益与增强自然灾害抵御能力相结合，坚持大宗油料品牌建设与特色油料资源开发相结合，稳定当前农业合作伙伴关系与扩宽油料进口来源相结合，实施差异化市场监管与引导居民科学消费相结合等发展对策，以期为促进油料生产、保障植物油有效供给、降低植物油对外依存度，维护国家粮油安全提供参考。 Oilseed security is related to national economy and people′s livelihood, and ensuring the effective supply of oilseeds is the bottom line of national food security that China must adhere to. From a global perspective, the supply and demand situation, production situation and market situation of oilseeds in China for the period of 2011/2012-2020/2021 were analyzed, further the challenges faced by China′s oilseed industry in terms of production, processing and trade were clarified, and six development countermeasures ,including the combination of unifying scientific planning and enhancing the accuracy of policy support, the combination of strengthening scientific and technological support and protecting arable land resources, the combination of improving farmers′ income from oilseed planting and enhancing natural disaster resistance, the combination of insisting on the brand building of bulk oilseed and developing characteristic oilseed resource, the combination of stabilizing the current agricultural industry cooperative partnership and expanding sources of oilseed imports, and the combination of implementing differentiated market supervision and guiding residents′ scientific consumption,were put forward, in order to provide a reference for promoting oilseed production, ensuring effective supply of vegetable oil, reducing external dependence of vegetable oil and maintaining national food and oil security

宫腔镜微创手术在妇产科中的应用进展

宫腔镜可以直接观察子宫和宫腔病变，凭借其创伤小、并发症少、安全、康复快等特点在妇产科病症治疗中显现出独特优势。近年来，在无创技术、宫腔镜设备及器械和机器人辅助宫腔镜手术等方面的创新更是加速了宫腔镜微创手术的发展。论文讨论了宫腔镜微创手术相关技术的新进展，并分析了宫腔镜微创手术技术的发展前景。</jats:p

浅谈火电厂集控运行人员的激励机制——以云南某大型火电厂为例

论文从云南某大型火电厂集控运行专业技能操作人员的队伍现状、知识结构入手，研究分析其现行的激励措施及存在的不足，探索提出相应的改进方向。</jats:p

Effect of Bubbles Produced from Hydrate-Bearing Particle Dissociation on Particle Motion in Water

Understanding the motion of natural gas hydrate-bearing particles in a pipeline is of great significance for developing natural gas exploitation technology. In this study, the effect of bubbles produced from hydrate dissociation on the particle settling characteristics and the drag coefficient were studied under different Reynolds numbers. In the experiment, two types of porous solid spherical particles, namely, silty clay and quartz, were used to study the settling of ordinary particles and hydrate-bearing particles using a customized experimental apparatus. The settling and dissociation of the particle in water and the motion of bubbles were captured using a high-speed camera. The results showed that the gas from the hydrate dissociation surrounded the particle, which caused the boundary layer at the particle surface to prematurely separate at the back end of the particle, thereby increasing the interaction forces between the particle and the water during motion. The influence of bubbles on the particle motion was closely related to the hydrate dissociation rate and the particle settling velocity. Moreover, a mathematical expression is provided to describe the entire process from sediment particles entering the water to hydrate dissociation. Furthermore, the dissociation rate of the hydrate-bearing sediment particle under water flow was obtained

基于三角形直觉模糊数TOPSIS群决策方法在应急预案有效性评估中的应用

结合三角形直觉模糊数加权集结算子和TOPSIS方法,构建了基于三角形直觉模糊数的突发事件应急预案评估群决策模型.通过对森林大火扑救应急预案方案最优选择这个决策问题的计算和分析,表明了所提模型和方法的有效性、合理性和可行性