Photochemical Synthesis and Catalytic Properties of Atomically Dispersed Palladium Catalyst

催化是自然界中普遍存在的重要现象，是化学学科中极为重要的研究方向。深刻理解催化反应的机制是有效设计催化剂和调控反应历程的重要基础。然而，作为最为重要的多相催化剂，负载型的纳米颗粒催化剂的结构复杂，传统的制备方法无法得到均一的反应活性中心。因此，在传统的多相催化体系中，催化的分子机制往往很难被深入理解。 单原子分散催化剂所有的活性中心均暴露在反应环境中且结构均一，使单原子分散催化剂具有优异的催化活性、选择性和特殊的催化能力，为催化机理研究提供了理想的模型体系。因此，单原子分散催化剂在近十年来越来越引起了人们的关注。但目前单原子分散催化剂研究领域仍存在两大问题。其一，活性组分的负载量较低，使催化...Catalysis is essential in nature and a central issue in chemistry. Understanding the molecular mechanism during catalytic process is the fundamental to design catalysts and manipulate reactions. However, for traditional heterogeneous catalysts based on supported nanoparticles, the complexity of the structure makes it impossible to study reaction mechanism on molecular level. As a new class of ca...学位：理学博士院系专业：化学化工学院_无机化学学号：2052012015349

The identity and differences of right colon cancer surgery CME between China and German

德国HOHEnbErgEr先生提出的结肠癌完整系膜切除(COMPlETE MESOCOlIC EXCISIOn,CME)手术概念,已逐渐得到我国外科医生的认可和重视。但右半结肠癌完整系膜的上缘和内侧缘在哪里更符合CME要求呢？d3手术作为右半结肠CME手术的方法合理吗？是否有更符合CME理念的右半结肠癌根治手术方法呢？笔者将腹腔镜右半结肠CME手术方法与HOHEnbErgEr先生的CME进行对比阐述,以探讨右半结肠CME手术方法的合理性。The concept of complete mesocolic excision(CME)in colon cancer surgery proposed by professor Hohenberger from German,has been accepted and valued by Chinese surgeons.However,how to determine the upper edge and medial edge of the complete mesocolic excision for right colon cancer(RCME),and which will be more consistent with the requirements of CME? Whether the D3 surgery(Hemicolectomy with D3 lymph node dissection)is a reasonable surgical approach to RCME or not? Are there other surgical approaches to the right colon cancer radical surgery which are more in line with the concept of CME? By comparing the author's surgical approach to laparoscopic complete mesocolic excision for right colon cancer( L-RCME) with Mr.Hohenberger's surgical method in CME,we investigate the rationality of surgical approach to the complete mesocolic excision for right colon cancer

Study on moire concealed codes

提出根据莫尔理论制作隐型全息密码的方法，对此方法作了理论分析并给出实验结果。此方法有制作过程简单，所制作的密码隐蔽性高，检验密码方便的特点。有效地提高全息标识的防伪能力，因而具有很高的经济价值。A study on concealed codes using moire method is presented.The theoretical analysis and experimental results are given.It is shown that the process is simple, code examination is convenient, and the code is of high cincealment.This technique can dramatically enhance the anticounterfeit capacity of holograms, so it is of very high economic value

A cationic surfactant assisted selective etching strategy to hollow mesoporous silica spheres

通讯作者地址: Zheng, NF (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] mesoporous silica spheres have recently attracted increasing attention. However, effective synthesis of uniform hollow mesoporous spheres with controllable well-defined pore structures for fundamental research and practical applications has remained a significant challenge. In this work, a straightforward and effective "cationic surfactant assisted selective etching" synthetic strategy was developed for the preparation of high-quality hollow mesoporous silica spheres with either wormhole-like or oriented mesoporous shell. The as-prepared hollow mesoporous silica spheres have large surface area, high pore volume, and controllable structure parameters. Our experiments demonstrated that cationic surfactant plays critical roles in forming the hollow mesoporous structure. A formation mechanism involving the etching of solid SiO2 accelerated by cationic surfactant followed by the redeposition of dissolved silica species directed by cationic surfactant is proposed. Furthermore, the strategy can be extended as a general strategy to transform silica-coated composite materials into yolk-shell structures with either wormhole-like or oriented mesoporous shell.NSFC 21021061,20925103 ,20923004 ,20871100 MOST of China 2009CB930703,2011CB932403 Fok Ying Tung Education Foundation 121011 NSF of Fujian 2009J06005 Key Scientific Project of Fujian Province 2009HZ0002-

Study on Microstructure and Surface Characteristicsof Zinc Sulfide Thin Films

对射频磁控溅射法制备的掺铒硫化锌薄膜，运用X射线衍射和X射线光电子能谱技术，获得微晶薄膜的微结构和表面构态信息，揭示了电致发光薄膜的表面构态对激发态的影响。The zinc sulfide thin film devices doped with erbium prepared byRFMS are studied.The information of microstructure and surface structure statesof the crystallite film is obtained by XRD and XPS methods.The effects of the surface structure states of the elcctroluminescent thin film on exciting states are discussed.国家自然科学基金;福建省自然科学基

柱前衍生化高效液相色谱法测定2-去氧葡萄糖的含量

目的建立柱前衍生化高效液相色谱法测定2-去氧葡萄糖(2-DG)含量的方法。方法采用1-苯基-3-甲基-5-吡唑酮(PMP)为柱前衍生化试剂,将2-DG在碱性条件下衍生化后直接进样测定。分离柱为HypersilODS2色谱柱(4.6 mm×250 mm,5μm),流动相为100 mmol·L-1醋酸铵缓冲液(pH 5.5)-乙腈(78∶22),流速1.0 mL·min-1,波长249 nm。结果 2-DG在19.68~393.6μg·mL-1浓度范围内与峰面积具有良好的线性关系(r=0.9997);其定量限(S/N=10)和最低检出限(S/N=3)分别为7.8和3.1 ng;平均回收率为101.21%,RSD 0.63%。结论该方法简便实用、检测灵敏度高、测定结果准确,适用于2-DG的质量控制

Hollow Mesoporous Aluminosilica Spheres with Perpendicular Pore Channels as Catalytic Nanoreactors

通讯作者地址: Zheng, NF (通讯作者),Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 3. Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA 电子邮件地址: [email protected] design and synthesis of hollow/yolk-shell mesoporous structures with catalytically active ordered mesoporous shells can infuse new vitality into the applications of these attractive structures. In this study, we report that hollow/yolk-shell structures with catalytically active ordered mesoporous aluminosilica shells can be easily prepared by using silica spheres as the silica precursors. By simply treating with a hot alkaline solution in the presence of sodium aluminate (NaAlO2) and cetyltrimethylammonium bromide (CTAB), solid silica spheres can be directly converted into high-quality hollow mesoporous aluminosilica spheres with perpendicular pore channels. On the basis of the proposed formation mechanism of etching followed by co-assembly, the synthesis strategy developed in this work can be extended as a general strategy to prepare ordered mesoporous yolk-shell structures with diverse compositions and morphologies simply by replacing solid silica spheres with silica-coated nanocomposites. The reduction of 4-nitrophenol with yolk-shell structured Au@ordered mesoporous aluminosilica as the catalyst has clearly demonstrated that the highly permeable perpendicular pore channels of mesoporous aluminosilica can effectively prevent the catalytically active yolk from aggregating. Furthermore, with accessible acidity, the yolk-shell structured ordered mesoporous aluminosilica spheres containing Pd yolk exhibit high catalytic activity and recyclability In a one-pot two-step synthesis involving an acid catalysis and subsequent catalytic hydrogenation for desired benzimidazole derivative, which makes the proposed hollow ordered aluminosilica spheres a versatile and practicable scaffold for advanced catalytic nanoreactor systems.MOST of China 2011CB932403 2009CB930703 NSFC 21131005 21021061 20925103 Fok Ying Tung Education Foundation 121011 NSF of Fujian Province 2009J06005 U.S. National Science Foundation CHE-092465

An iron silicate based pH-sensitive drug delivery system utilizing coordination bonding

E-mail Addresses: [email protected] we report a drug delivery system based on hollow iron silicate nanospheres. Fe3+ on the nanospheres' surface can effectively bind with doxorubicin (DOX), an anticancer drug, through coordination bonds. The bonds are fairly stable in a neutral environment but could easily break up in an acid environment. The release of DOX from hollow iron silicate nanospheres into cancer cells can be therefore triggered by a pH drop caused by endocytosis. The iron silicate shell allows a DOX loading content of up to 50.2% in weight, which is significantly higher than most drug delivery systems reported. Cell experiments show that DOX-loaded hollow iron silicate nanospheres exhibit a higher efficiency in killing cancer cells than free DOX, and a higher cytotoxicity for human hepatoma cells than hepatocyte cells at the same DOX-loaded nanospheres' concentration. Confocal laser scanning microscopy (CLSM) experiments show the releasing and transportation process of DOX, and confirm the enrichment of DOX in cell nuclei.MOST of China 2011CB932403 NSFC 21131005 21021061 20925103 Fok Ying Tung Education Foundation 12101

Photochemical route for synthesizing atomically dispersed palladium catalysts

该工作由校内外多个课题组共同努力，历时三年多完成。我校郑南峰、傅钢等课题组紧密协作负责催化剂的合成、表征、催化测试及机理研究；中科院物理研究所谷林研究员主要负责催化剂的球差校正透射电子显微研究；加拿大达尔豪斯大学的张鹏课题组参与催化剂的同步辐射X-射线吸收谱研究。该研究工作的第一、二作者刘朋昕、赵云均为我校博士生。【Abstract】Atomically dispersed noble metal catalysts often exhibit high catalytic performances, but the metal loading density must be kept low (usually below 0.5%) to avoid the formation of metal nanoparticles through sintering. We report a photochemical strategy to fabricate a stable atomically dispersed palladium–titanium oxide catalyst (Pd 1 /TiO2 ) on ethylene glycolate (EG)–stabilized ultrathin TiO2 nanosheets containing Pd up to 1.5%.The Pd 1 /TiO2 catalyst exhibited high catalytic activity in hydrogenation of C=C bonds, exceeding that of surface Pd atoms on commercial Pd catalysts by a factor of 9.No decay in the activity was observed for 20 cycles. More important, the Pd 1 /TiO2 -EG system could activate H2 in a heterolytic pathway, leading to a catalytic enhancement in hydrogenation of aldehydes by a factor of more than 55.Supported by Ministry of Science and Technology of China grant 2015CB932303; National Natural Science Foundation of China grants 21420102001, 21131005, 21390390, 21133004, 21373167, 21573178, and 21333008; a NSERC CGS Alexander Graham Bell scholarship (D.M.C.); and a NSERC Discovery grant (P.Z.)

硅 增强 高粱抗 干 旱 、 盐 和 镉 胁迫能力以及缓解 钾 缺乏 的作 用机制

硅是组成地壳的重要元素之一，其含量在所有元素中占第二位，仅次于氧。 尽管硅是否能被认定为一种植物生长的必需元素还存着很大的争议，但是外源施 加硅改善植物对逆境胁迫的抗性已经被广泛的报道。并且对硅改善植物抗逆性的 作用机制进行了大量的研究。过去大量的研究的结果表明：硅沉积在植物组织上 所形成的物理障碍（Physical barrier）是硅增强植物抗生物胁迫和非生物胁迫的 主要作用机理。但是随着对其作用机制进行深入的探讨，越来越多的证据表明外 源施加硅也可以在分子和生理水平上调控植物的生长增强植物的抗逆性。本论文 的主要研究目的是以高粱为研究对象探讨外源施加硅对高粱抗旱，抗盐，镉毒害 以及钾亏缺的影响及作用机制。 1: 硅提高高粱抗旱性 的影响 及其作用机制 硅改善植物抗旱性已经进行了 大量研究，但是其作用机制还不明确，尤其是硅能否可以提高植物的吸水能力还 是空白。本实验通过在水培和沙培的条件下，研究外源施加硅在干旱胁迫下对高 粱幼苗水分吸收及运输的影响。干旱胁迫导致幼苗干重，光合速率，蒸腾速率， 气孔导度以及水分状况下降。外源施加硅可以显著地缓解干旱对上述指标的负效 应。外源施加硅对幼苗茎水分运输效率（L sc ）没有显著影响，但是在干旱条件 下经过硅处理幼苗的整株水导（K plant ）和根水导（Lp）却明显高于不加硅幼苗。 并且在干旱胁迫下硅提高整株蒸腾速率幅度和提高整株水导以及根水导的幅度 变化基本一致。我们通过外源施加水通道蛋白抑制剂 HgCl 2 来验证硅改善高粱的 水导是否与水通道蛋白有关。结果表明：在水分胁迫的条件下，经过 HgCl 2 处理 后幼苗的蒸腾速率迅速下降，并且加硅与不加硅的处理之间蒸腾的差异消失。然 后经过 DTT 恢复后。外源施加硅的幼苗的蒸腾速率显著高于未经过硅处理的幼 苗。除此之外，在水分胁迫的条件下，外源施加硅可以上调水通道蛋白的表达水 平。我们的研究结果表明：在水分胁迫下，硅上调水通道蛋白表达，改善根系水 导，增强根系的吸水，从而维持植物较高的蒸腾和光合速率来增强高粱抗旱能力。2: 硅提高高粱抗盐性 的影响 及其作用机制 施硅改善植物抗盐能力已经在 多种植物上得到了确证，但是关于硅提高植物抗盐的机理研究过去主要集中在外 源施加硅减少植物对钠离子的吸收，从而缓解了盐引起的离子毒害。而关于硅是 否能通过改善高盐引起的渗透胁迫来提高植物抗盐能力一直被忽视。在本实验 中，我们利用高粱为材料，以水培的方式研究硅对缓解盐引起的渗透胁迫的作用 及其机制。结果表明：在正常条件下，外援施加硅对高粱幼苗的生长没有显著影 响。当幼苗遭受到短时间的盐胁迫后，光合速率，蒸腾速率显著下降，但是外源 施加硅可以缓解这种下降趋势。同时加硅处理的幼苗，其叶片水分状况及叶片伸 长速率仍然保持在一个相对较高的水平。短时间的盐胁迫（2 小时），高粱幼苗 的根系水导显著下降，而外源施加硅可以缓解根系水导的下降。在盐胁迫条件下， 外源添加 HgCl 2 降低高粱的蒸腾速率，同时在加硅与不加硅高粱间的蒸腾速率差 异被消除，导致加硅与不加硅幼苗的蒸腾速率下降到同一水平。经过-巯基乙醇 恢复后，加硅处理的幼苗的蒸腾速率仍然高于未加硅处理的幼苗的蒸腾速率。这 个结果表明：硅通过调节水通道蛋白的活性来缓解盐导致的水导的下降。进一步 研究发现，在盐胁迫的条件下，外源施加硅能增强几种水通道蛋白（PIP）基因 的表达水平。同时，外源施加硅可以通过增强抗氧化酶的活性阻止根系 H 2 O 2 的 积累。我们还发现预先经过过氧化氢酶（CAT）处理的幼苗的蒸腾速率与经过硅 处理的幼苗的蒸腾速率相似。说明硅抑制 H 2 O 2 的积累也有可能有利于增强水通 道蛋白活性。本研究结果表明：在短时间盐胁迫条件下，外源施加硅可以通过上 调水通道蛋白的表达水平及缓解由于 H 2 O 2 的积累而导致的水通道蛋白活性的下 降来调节水通道蛋白的活性，从而提高根系水导，促进根系吸水，进而增强对高 盐所引起的渗透胁迫的抗性。 3: 硅提高高粱抗镉毒性 的影响 及其作用机制 硅增强植物的抗镉毒害已经 被广泛的报道，但是其作用机理并不十分明确。本实验利用高粱幼苗在水培的条 件下，研究在镉毒害的条件下，外源施加硅对高粱的生长及抗氧化酶活性，有机 酸含量的影响。结果表明：外源施加硅能显著地缓解镉毒害，表现为在镉胁迫下， 高粱无论地上部分还是地下部分鲜重及干重都高于不加硅的处理。抗氧化酶结果 表明：在正常条件下，外源施加硅对三种抗氧化酶的活性没有显著的影响。但是 在镉毒害的条件下，除 SOD 外，CAT 和 POD 的活性显著增强。与此相对应的是 MDA 的含量在镉胁迫下明显增加，硅显著地降低 MDA 的含量。对有机酸的 分析发现：叶片和根在镉毒害和硅处理下，有机酸的种类，含量及变化趋势不尽 相同。在镉毒害的条件下，叶片中有 3 种有机酸能够检测到：草酸，丙二酸，丁 二酸，并且其含量都在外源施加硅的条件下增加。而在根系中所检测到的 4 种有 机酸中，草酸和丙二酸的含量受到硅的调节而增加，柠檬酸的含量不受影响，而 苹果酸的含量却有下降的趋势。上述结果表明：外源施加硅增强高粱幼苗的抗镉 胁迫与其增强高粱抗氧化酶活性及增加高粱体内有机酸的含量相关。 4: 硅提高高粱抗缺钾能力 的影响 及其作用机制 硅改善植物抗缺钾能力虽 然也有报道，但是其机制也不明确。本实验采用水培方式研究硅对高粱幼苗缺钾 的影响及作用机制。研究结果表明：无论是地上部分，地下部分干重和鲜重在低 钾条件下都会出现显著下降。但是外源施加硅能有效地缓解这种下降的趋势。在 此基础上，我们对老叶和新叶的光合速率，蒸腾速率及气孔导度进行研究。结果 表明：低钾胁迫降低了无论是老叶还是新叶的光合速率。但是值得注意的是：外 源施加硅后，老叶的光合速率下降趋势得到缓解。造成这一现象的主要原因可能 是在缺钾的条件下，外源施加硅能维持老叶的气孔导度，蒸腾速率处在一个相对 较高的水平。外源施加硅对新叶中上述的参数的变化没有显著的影响。 本实验分别研究了外源施加硅增强高粱幼苗抗旱、盐、镉及缓解钾缺乏的影 响及作用机制。实验结果表明：除了&ldquo;物理障碍&rdquo;以外，硅调控植物增强对逆境 抗性的作用机制不完全相同。换句话说：当植物遭受到不同的外界环境胁迫时， 硅通过调控不同的分子和生理功能增强植物的抗逆性。结合过去的研究进展，我 们认为：造成这一现象的原因可能是硅可以作为一种&ldquo;调节器&rdquo;通过感受到不同的 外界刺激，调节下游的相关基因的表达从而调控植物的生理活动的变化，适应外 界环境胁迫。 关键词：硅，干旱，盐胁迫，镉毒害，水通道蛋白，根系水导，有机酸</p