UVA Assisted 4-Thiothymidine for Cancer Treatment

This article reviews the developments of 4-thiothymidine analogues, assisted with UVA light, as a novel cancer therapy. First, the key points on synthetic chemistry, photochemistry and cellular toxicity of 4-thiothymidine are summarized. As the chemical structure of 4-thiothymidine is very similar to that of its parent thymidine, thus 4-thiothymidine can be readily incorporated into cellular DNA, and with the help of thymidine kinase, much more preferably into cancerous DNA. Unlike thymidine, 4-thiothymdine can absorb strongly in UVA (longer wavelengths of UV) light. Thus UVA-assisted 4-thiothymidine offers an effective cancer treatment. Some underlying mechanisms of action by 4-thiothymidine/UVA and compares this cancer approach with the commonly used photodynamic therapy are discussed. The various interactions between 4-thiothymidine with human serum albumin are introduced. Finally, a short conclusion on the past efforts and a brief prospect for future work in this exciting research field are given

Study on Preparation and Mechanical Properties of Chemically Modified Graphene Gels

石墨烯作为一种新型的二维碳纳米材料，由于具有独特的物理化学性质，在能量存储与转换、传感器、半导体材料、生物医学等领域有广阔的应用前景。目前石墨烯的制备方法主要包括自上而下和自下而上两类，其中化学氧化还原法制备石墨烯是最有希望实现工业化大量生产的方法。本论文研究了氧化石墨烯的还原过程，发展了一种全新的氧化石墨烯还原手段，并探讨了氧化石墨烯和还原氧化石墨烯自组装气凝胶力学性能与化学结构的关系。本文的结论为还原氧化石墨烯的制备、组装及力学性能开发提供了新的思路。 本文发展了一种非还原性金属离子促进氧化石墨烯还原的方法。选择硫酸铜作为非还原性金属硫酸盐与氧化石墨烯溶液以一定比例混合，90oC下反应2...As a new type of two-dimensional carbon nanomaterials, graphene is widely used in energy conversion and storage devices, sensors, semiconductor and biomedicine, owing to its unique physical and chemical properties. At present, the synthesis methods of graphene can be generally classified into two categories: “top-down” and “bottom-up”, and chemical oxidation-reduction is the most promising method ...学位：理学硕士院系专业：材料学院_高分子化学与物理学号：2072014115006

Progress of dye-sensitized water-splitting for hydrogen production

The mechanism of dye-sensitized water-splitting for hydrogen production is introduced. Research works on the use of different dye molecules and redox mediators are reviewed. It is found that the light absorption characteristics of dye molecules, excited dye potential level, the relative position of semiconductor conduction band, the adsorption of dye molecules on the surface of semiconductor, as well as the bonding between dye molecules and semiconductor, determine the photon absorption and electron injecti...介绍了染料敏化分解水制氢的基本原理。综述了染料分子的选取,使用氧化还原调节剂的机理和研究进展。指出染料分子对光谱的吸收特性,激发态染料分子能级与半导体导带的相对位置,染料分子与半导体的吸附情况,表面键合强度直接影响对光子的吸收,电子的注入,从而影响产氢量。此外,I-/I3-作为氧化还原调节剂可有效还原染料分子,实现持续产氢。最后提出了染料敏化分解水制氢的间歇式反应器结构,以及通过选择用于敏化的半导体来提高产氢率的思路。published_or_final_versio

The Role of Microorganisms in the Geochemical Iron Cycle

铁元素虽然只在地壳含量中位列第4,但却是地球上分布最广的变价金属元素之一,微生物介导的铁循环及其与生源要素碳、氮、氧和硫等耦合的氧化还原反应是微生物地球化学循环的重要驱动力.由于铁循环过程中氧化态三价铁Fe(Ⅲ)在环境p H条件下大多以不溶状态存在,因而由其参与的地球化学循环进程通常较为缓慢.研究表明,微生物在铁元素的地球化学循环过程中起着举足轻重的作用,并在该过程中参与矿物的生成与转化.近年来的最新研究发现,参与地球化学铁循环的微生物之间,微生物与矿物之间,以及矿物介导的微生物之间存在着多样的相互作用,而含铁矿物介导的微生物胞外电子传递机制是其中最受瞩目的研究热点.本文综述了微生物介导的地球..

Effect of Tungsten Oxide Powders with Different Characteristics on the Characterization of Hydrogen Reduced Tungsten Powders

本文详细研究煅烧温度、抽风频率和转速对APT粉末煅烧获得氧化钨粉末特性 的影响，并详细分析了煅烧过程中粉末粒度和形貌变化规律、氧化钨相变机理、WO3 晶粒生长机理及WO2.72晶粒生长机理。而后根据XRD对氧化钨粉末相结构和相成分 及SEM对氧化钨粉末颗粒(晶粒)尺寸和形貌的检测结果，将获得的氧化钨粉末分成 四组，氢还原制备三种粒度级别(0.7μm，2.5μm及8.0μm)的钨粉末，研究氧化钨原 材料中WO3晶粒尺寸，WO2.72晶粒尺寸和形貌，WO3晶体结构及相成分对还原钨粉 末特性的影响，并研究钨晶粒(颗粒)的长大机制。 在400~600°C内，可获得单成分WO3。当煅烧温度...Effect of calcining temperature, exhausting frequency, rotation rate, and furnace atmosphere on the characterization of tungsten oxides powder prepared by calcining APT (ammonium paratungstate) powder have been detailedly studied, and the change mechanisms of particle size and morphology, phase transformation mechanisms of tungsten oxides, and growth mechanisms of WO3 and WO2.72 grains during ...学位：工程硕士院系专业：材料学院_工程硕士(材料工程)学号：X201219303

Visible-Light-Induced Asymmetric Catalysis with Chiral-at-Rhodium Lewis Acids

可见光催化作为一种新兴的有机反应模式，具有条件温和、绿色安全、可用于惰性碳-碳及碳-杂键的切断和重组等特点，将其与不对称催化相结合，能为手性有机分子的合成提供绿色、高效的策略。然而，相比于传统不对称合成，可见光诱导的不对称催化反应中涉及自由基、自由基离子和激发态有机分子等高活性中间体的形成，控制其立体选择性转化是极具挑战性的，具有重要理论和合成应用研究意义。 本论文以课题组原创的新型唯铑中心手性Lewis酸（手性仅存在于金属中心，配体无手性）为催化剂，结合其结构和性能上的特点——特殊手性源、刚性结构、潜在的可见光吸收与激发性能，探索其在可见光诱导不对称催化中的应用。本论文成功地将唯铑中心手性...Interfacing visible light activated photochemistry with asymmetric catalysis therefore provides new opportunities for the efficient and green synthesis of non-racemic chiral molecules. However, the high reactivity of photoexcited substrates, intermediate radical ions or radicals, and the low activation barriers for follow-up reactions provide significant hurdles for the development of efficient tr...学位：理学博士院系专业：化学化工学院_有机化学学号：2052014015391

Preparation and Conformation Control of Twodimensional Nanomaterials

低维纳米材料的制备和应用是近年来材料学科的研究热点。二维纳米材料由于其特殊的形貌和优异的性能，在化学、物理、材料和生物等各个领域都有重要的应用。在本论文中，我们将围绕二维材料的制备和构象控制展开研究，制备一种新的非层状结构材料的二维纳米片，并且提出了使二维石墨烯发生卷曲构象的新方法。本论文的具体研究内容和主要结果如下： 发展了一种新的方法，采用自下而上的策略制备了具有非层状结构材料的超薄二维氧化铝纳米片。首先利用均相沉淀法在氧化石墨烯模板上沉积一层无定形的碱性硫铝，然后经过高温煅烧得到纯的氧化铝纳米片。进一步探索了氧化铝纳米片的形成机理，发现无定形中间体对氧化铝纳米片的形成具有重要作用。将氧...Low-dimentional materials are active area in materials science. Two-dimensional (2D) materials, as a group of low-dimensional materials, have demonstrated their wide applications in chemistry, physics, materials and biology, due to their unique morphology and outstanding performance. In this thesis, we systemastically investigate the preparation and conformation control of 2D materials. A novel 2D...学位：工学硕士院系专业：材料学院_工程硕士(材料工程)学号：2072013115009

Greenhouse gas emissions from croplands of China

China possesses cropland of 1.33 million km 2. Cultivation of the cropland not only altered the biogeochemical cycles of carbon (C) and nitrogen (N) in the agroecosystems but also affected global climate. The impacts of agroecosystems on global climate attribute to emissions of three greenhouse gases, namely carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)

Study of Manganese-Base Catalysts for Catalytic Wet Air Oxidation of Phenol

苯酚为常见水污染物之一，对其进行处理具有深远意义。目前，去除水中苯酚的有效方法之一为催化湿式氧化法（CWAO）。先前众多研究均表明MnCeOx催化剂是一种高效催化湿式氧化苯酚用的催化剂。然而，对其稳定性却并未作出深入研究。因此，本论文基于MnCeOx催化剂为研究基础，通过改良催化剂制备方法以及调控合适的Mn/Ce比，制备出相对高效稳定的MnCeOx催化剂，并初步探究其高效稳定的作用机制。此外，为进一步降低成本，本论文拟用优化后的新型方法即氧化还原-水热法制备单一过渡金属氧化物MnOx催化剂，使其即使不含Ce下也可实现高效稳定的处理苯酚。本论文以自配苯酚溶液为模拟废水，利用TOC、HPLC及AA...Phenol is one of the common water contaminants, decomposed it into harmfulness CO2 or at least less harmful compounds has profound significance. At present, catalytic wet air oxidation (CWAO) is an effective method to degrade phenol in water. Many previous studies have shown that MnCeOx catalysts demonstrating remarkable activity for the degradation of phenol. However, the stability of MnCeOx cata...学位：工学硕士院系专业：化学化工学院_化学工程学号：2062014115139