Microfluidic Production of Monodispersed Silica Hollow Microspheres with Controlled Size and Morphology

空心SiO2微球由于具有较大的比表面积，较小的密度，表面可渗透性，中空部分可容纳客体分子等优点在制药、生化及化工等多种技术领域都有着巨大的应用价值。本文引用微流控技术在微通道中形成单分散的油包水液滴，并通过在液滴表面的界面聚合反应“一步法”制备出SiO2空心微球，消除了传统模板法制备空心微球时所需的溶剂溶解或高温锻烧等后处理过程，大大简化无机二氧化硅空心微球的制备方法。此外该制备方法所获得的空心微球具有大小可控、单分散性好的优点。并在此基础上，通过调节表面活性剂十八烷基三甲基溴化铵（CTAB）和反应物正硅酸乙酯（TEOS）的浓度，制备出形貌可控的二氧化硅微球，实现其从全空心→部分实心部分空心→...Because of their low density,high specific surface areas and infiltration ability, most importantly, high loading capacity to accommodate guest molecule in their hollow cavity, SiO2 hollow silica microspheres have extensive potential applications in various fields such as medicine, bio-chemistry, chemical engineering. In this study, we developed a facile one-step approach to synthesize monodispers...学位：理学硕士院系专业：化学化工学院化学系_分析化学学号：2052007115095

Controllable Fabrication and Their Lithium Storage and Catalytic Properties of ZnO-Based Hybrid Hollow Micro-nanostructures

过渡金属氧化物作为锂离子电池负极材料时具有比传统的石墨负极更高的理论容量和更好的安全性能，在过去的一二十年里备受研究人员的青睐。在各种过渡金属氧化物中，ZnO除了具有原料丰富、加工成本低廉、无毒性、生物兼容性好、简单易制、形貌多样等优点外，作为锂离子电池负极材料时，还能通过转移反应和合金化反应贡献出高的理论容量（978mAhg-1），这几乎是石墨负极理论容量的三倍，是一种非常有应用前景的负极材料。但是到目前为止相比于NiO、Co3O4等过渡金属氧化物，ZnO微纳米材料的锂存储性能研究较为少见。这主要是由于在充放电循环过程中ZnO材料的体积变化非常大，可达到228%以上。ZnO电极材料剧烈的体积...In the past decades, transition metal oxides have achieved enormous research interest for using as the anode materials in lithium ion batteries due to their higher theoretical capacity and safety in comparison with the conventional graphite-based anodes. In addition to the merits of rich resource, non-toxicity, low processing cost and diverse morphology, ZnO, as a fascinating member of transition ...学位：工学博士院系专业：材料学院_材料物理与化学学号：2072012015331

Controllable Fabrication of Polymer Hollow Spheres through Hydrothermal Route

摘要 高分子材料的发展，在很大程度上依赖于制备方法的创新。开发简单、普适性高、可调控性强的合成路线，一直是高分子材料领域的研究热点。水热法不仅具有操作简单、普适性强、适合量化生产等特点，而且可对材料晶型、尺寸和形貌进行有效调控，已在无机纳米粒子可控构筑领域得到了广泛应用。然而，该方法却极少应用于聚合物纳米材料的可控合成。本研究利用双溶剂反应体系水热法，协同进行酚醛树脂（PF）预聚物的交联固化与苯乙烯（St）单体的自由基聚合，实现了PSt-PF空心纳米微球的形貌调控及功能化。具体研究工作如下： (1) 利用传统的水热合成法，以Resol树脂和St单体为原料，采用乙醇/水或者乙二醇/水的双溶剂...Abstract The development of polymer materials science and engineering depends to a large extent on the exploitation of facile and versatile synthetic approaches that possess high ability of control over composition and morphology. Hydrothermal method has been widely applied in the preparation of various inorganic materials with controllable particle size, morphology and surface properties. In thi...学位：理学硕士院系专业：材料学院_高分子化学与物理学号：2072012115006

Co-seismic ground deformation of Yushu Earthquake detected with D-InSAR technique

An earthquake of magnitude 7.1 suddenly occurred in Yushu county of Qinghai province on April 14, 2010. This paper presents the studies of using the data of Advanced Land Observing Satellite-Phased Array type L-band Synthetic Aperture Radar (ALOS-PALSAR) before and after the earthquake to examine and calculate the co-seismic ground deformation. The differential SAR interferometry (D-InSAR) technique is used. The results show that the earthquake caused the ground deformation over a large area. The extension of the ground deformation followed the south-east to east direction and along the Yushu-Ganzi fault zone. The largest deformation was found about 350 mm at 33.7°N 96.81°E. It is along the line of sight (LOS) of SAR and can be detected with D-InSAR technique. The detected ground deformation was mainly uplifting. The detected ground deformation has an important value for evaluating the extent of ground damage and seismicity in Yushu after earthquake, inferring the nature of the quake faulting, and studying characteristics of seismic deformation. 2010-04-14青海玉树发生7.1级地震后, 作者利用震前和震后获取的日本ALOS卫星PALSAR遥感数据, 开展了差分干涉雷达(D-InSAR)地震同震形变测量与分析。结果表明: 玉树地震引起较大范围地表变形, 地震变形沿玉树—甘孜断裂带向南东东方向扩展, 在N33.7°, E96.81°附近达到最大形变量, D-InSAR监测到雷达视向上的最大形变量为35cm。地表形变特征对于评价玉树地震破坏程度、推断断层性质、研究地震形变和地震孕育特征具有重要的参考价值

Cavitation burst generated by focused ultrasound

強力な１MHz集束超音波を水中に照射すると、焦点付近でチャッという可聴音とともに気泡群が突発的に発生する。このキャビテーションバーストと呼ばれる気泡群の運動を、高速度カメラを用いて15,000-70,000 fpsの速度で撮影した。発生する入力電力の閾値は溶存酸素量に依存し、30-55Ｗであった。0.5 mg/L以下では180Wでも発生しなかった。発生した直後の気泡は60-80μmの球状で、これは１個の大きな気泡というよりも微小な気泡が気泡間ビャークネス力によって集合しているものと想像された。その後、気泡群は音波伝搬方向に垂直に拡大し、集束音場の影響を受けて中心の抜けたリング状に4mm程度まで成長した。気泡群の進行する位置によっては成長せずに潰れてしまうものもあった。並進速度はサイズの小さい発生初期ではおよそ3.5 m/sと大きいが、拡散後は1.6 m/s程度になった。この大きな速度は、気泡によって超音波が散乱・吸収され気泡前後で音圧差が生じて大きな放射力を生んだためである。ハイドロホン測定から、可聴音は2-3kHzで、気泡群がリング状に成長・拡散することに依って発生することがわかった

Vacuum, Space-Time, Matter and the Models of Smarandache Geometry

Hu Chang-Wei considers through analysis on the basis of the derivation of the Lorentz transformation by means of fluid mechanics, that Newtonian absolute space-time theory is most basic and real space-time theory, where the physical vacuum is a compressible superfluid, a change of its density can cause a change of actual space-time standards, and thus, leads up to the quantitative effect deviated absolute space-time theory. The effects of relativity and quantum are all quantitative effects, and the space-times of relativity and quantum physics are the space-times twisted by quantitative effects. For some such descriptions, he calls "returning classics with quantitative effects", which is interesting as well as meaningful

嶺暉 (第99期)

https://commons.ln.edu.hk/campus_glow/1077/thumbnail.jp