Now showing items 4825-4844 of 14240

    • L -DNA molecular beacon: A safe, stable, and accurate intracellular nano-thermometer for temperature sensing in living cells 

      Ke, Guoliang; Wang, Chunming; Ge, Yun; Zheng, Nanfeng; Zhu, Zhi; Yang, Chaoyong James; 郑南峰; 朱志; 杨朝勇 (American Chemical Society, 2012-11-21)
      Noninvasive and accurate measurement of intracellular temperature is of great significance in biology and medicine. This paper describes a safe, stable, and accurate intracellular nano-thermometer based on an l-DNA molecular ...
    • L-B膜内银超微粒子的电化学制备及表征 

      谢兆雄; 华炳增; 毛秉伟; 陈衍珍; 田昭武; 张韫宏; 李前树 (1996-12-15)
      在8~14层硬脂酸银L-B膜内,用电化学还原法制备了纳米尺度的银超微粒子,实验表明,银超微粒子的形成是观察多层L-B膜高分辨STM图象的必要条件,利用STM技术不仅观察到8层L-B膜的六方排列的硬脂酸脂链结构,还直接观察到2~3nm直径的球形银超微粒子结构;首次报道L-B膜亲水层原子尺度的网状STM图象,该图象显示了脂链六方的(2×1)结构,是羧基之间由氢键自组织的结果;银超微粒子有很强的表面增强Raman散射效应,由此测得了两层L-B ...
    • L-cysteine-assisted synthesis of PbS nanocube-based pagoda-like hierarchical architectures 

      赵仪 (2008)
      Nanocube-based pagoda-like PbS hierarchical architectures have been fabricated by hydrothermal treatment of Pb(Ac)(2) and L-cysteine solution. It was suggested that a biomimetic mineralization process happened during the ...
    • L-DNA Molecular Beacon: A Safe, Stable, and Accurate Intracellular Nano-thermometer for Temperature Sensing in Living Cells 

      Ke, Guoliang; Wang, Chunming; Ge, Yun; Zheng, Nanfeng; Zhu, Zhi; Yang, Chaoyong James; 郑南峰 (2012-11-21)
      Noninvasive and accurate measurement of intracellular temperature is of great significance in biology and medicine. This paper describes a safe, stable, and accurate intracellular nano-thermometer based on an L-DNA molecular ...
    • L-Valine assisted distinction between the stereo-isomers of D-hexoses by positive ion ESI tandem mass spectrometry 

      Li, Gang; Huang, Zhongbin; Fu, Chuan; Xu, Pengxiang; Liu, Yan; Zhao, Yu-fen; 赵玉芬 (JOHN WILEY & SONS LTD, 2010-05)
      The binary mixtures of 7 hexoses and 20 amino acids were investigated by electrospray ionization ion trap mass spectrometry (ESI-ITMS). The adduct ions of the amino acid and the hexose were detected for 12 amino acids but ...
    • L-异亮氨酸型配体交换固定相对DL-氨基酸的拆分研究 

      黄晓佳; 王秋泉; 王俊德; 黄本立 (2005-03-30)
      用自制的新型L 异亮氨酸配体交换固定相在配体交换模式下对 11种DL 氨基酸进行了拆分研究,详细考察了流动相中铜离子浓度、甲醇含量、流速及温度对拆分效果的影响,并探讨了可能的拆分机理。研究结果表明:流动相中高浓度的铜离子不利于DL 氨基酸的拆分;增加流动相中甲醇的含量,降低流动相流速以及提高色谱柱温度均可改善拆分效果。
    • L-羟脯氨酸寡肽混合物的高效液相色谱分离与质谱分析 

      孙艳亭; 卢奎; 马丽; 曹书霞; 赵玉芬 (2007-07-30)
      研究了三氯氧磷辅助下L-羟脯氨酸的成肽反应,建立了采用反相高效液相色谱-质谱/质谱联用技术分离鉴定羟脯氨酸寡肽混合物的方法,优化了L-羟脯氨酸寡肽混合物的色谱分离条件。实验以YWG C8柱(10μm,250mm×10mm)为分离柱,以乙腈-0.06%三氟乙酸水溶液(体积比为2∶98)为流动相进行等度洗脱,在正离子模式下对洗脱物进行了电喷雾电离串联质谱鉴定。结果显示,分离出的各组分分别为L-羟脯氨酸二肽、L-羟脯氨酸环二肽和L-羟脯氨酸三肽。
    • La(NO2)(3), a novel (3,9)-connected lanthanide-based network 

      Kang, Q. Q.; Long, L. S.; Huang, R. B.; Zheng, L. S.; 郑兰荪 (2004-02)
      A novel (3,9)-connected lanthanide-based network of lanthanum trinitrite, La(NO(2))(3), was synthesized and characterized by single-crystal X-ray diffraction. The central La(III). atom is coordinated by nine O atoms from ...
    • La-2@C-72 and Sc-2@C-72: Computational characterizations 

      Zdeněk Slanina; Chen, Zhongfang; Paul v. R. Schleyer; Filip Uhlík; Lu, Xin; 吕鑫; Shigeru Nagase (AMER CHEMICAL SOC, 2006-01)
      The La-2@C-72 and SC2@C-72 metallofullerenes have been characterized by systematic density functional computations. On the basis of the most stable geometry of 39 C-72 hexaanions and the computed energies of the best ...
    • La-3(Si2O7)Cl-3 

      Chen, J. T.; Guo, G. C.; Huang, J. S.; Zhang, Q. E.; 张乾二 (1996)
      The crystal structure of trilanthanum trichloride pyrosilicate, La-3(Si2O7)Cl-3, has been determined. The main building units are La(1)Cl4O5, La(2)Cl5O5 and La(3)Cl3O6 polyhedra, and Si2O7 pyrosilicate groups.
    • La-O小团簇上超氧物种与过氧物种间的连接途径(英文) 

      夏文生; 张达; 翁维正; 万惠霖 (2013-11-20)
      采用密度泛函理论方法考察了lA-O团簇上超氧物种与过氧物种间转化的连接途径.单重态下,团簇上单个超氧物种可通过一系列臭氧物种转化为过氧物种,且转化能垒较高;三重态下,单个超氧物种则并无与过氧物种间连接的途径.然而,lA-O团簇上两超氧物种间的相互作用及其转化也具单重态和三重态两条途径.三重态下,超氧物种可很容易地转化为过氧物种(O2+O2O22+O2),超氧物种与过氧物种处于快速的交换状态之中;单重态下,超氧物种转化为过氧物种则需较高的 ...
    • La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_3与La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05)O_3电导的对比 

      吴玲丽; 王世忠; 梁营 (2006-05-15)
      采用固相合成法制备了La0.8Sr0.2Ga0.8Mg0.2O3(LSGM8282)和La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5),利用四电极交流阻抗法和Hebb-Wagner极化法对比研究了两种材料的总电导率和电子电导率.实验结果表明,LSGM8282的总电导率与氧分压无明显依赖关系,而LSGMC5的总电导率在高氧分压区随氧分压降低而增加,在中等氧分压区域基本保持不变.在973~1173K的温度范围内,L ...
    • La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)Al_xO_(3-δ)(x=0~0.05)电解质电导率的研究 

      吴玲丽; 王世忠; 梁营 (2006-12-25)
      用固相合成法制备了La0.9Sr0.1Ga0.8Mg0.2AlxO3-δ(x=0~0.05)电解质。利用四电极交流阻抗法和Hebb-Wagner极化法测量了电解质的总电导率和电子电导率。结果表明:电解质的总电导率与氧分压无明显依赖关系,且随着Al2O3含量的增加而减小。在800℃下,电解质的自由电子电导率以及电子空穴电导率的氧分压级数分别为-1/4和1/4,符合Hebb-Wagner公式。随着Al2O3含量的增加,电子空穴电导率变化不明 ...
    • La_(2-x)Sr_xCuO_(4-λ)复合氧化物的合成、表征和氨的氧化催化性能的研究 

      吴越; 高利珍; 于作龙 (1997)
      合成了X值不同的lA_(2-X)Sr_XCuO_(4-λ)(X=0~1)系列复合氧化物,用Xrd研究了这一系列氧化物的结构,结果表明X在0~0.3之间可形成k_2nIf_4结构单相化合物.用化学分析方法测定了过渡金属Cu的价态及含量,并计算出复合氧化物中的非计量氧数.用TPd,TPr,Tg,XPS,SEM等方法研究了这类复合氧化物的氧化还原性能,所含氧种及表面形态,考察了对nH3氧化的催化活性,并对其催化活性与化学组成及结构的关系进行了讨论.
    • La_2O_3-BaO系复氧化物的现场拉曼光谱研究 

      陈笃慧; 廖远琰; 万惠霖 (1997)
      对于lA0.2bA0.8-XCAX(O,CO3)其中X=0.0、0.2、0.4、0.6氧化物在973k及甲烷氧化偶联(OCM)条件下,无CA2+的样品可用表面bACO3和(lAO)2CO3的rAMAn谱及810CM-1附近的O2-2特征峰来表征;含CA2+的样品,则表现了混合碳酸盐(CA,bA)CO3的特征,还有位于1135CM-1(W)和810CM-1(W)的O-2、O2-2瞬时态氧物种;973~1053k发现OCM反应活性随温度和C ...
    • La_2O_3-ZrO_2缺陷萤石型燃烧催化剂的制备 

      杨乐夫; 陈笃慧; 缪建英; 毛通双; 蔡俊修 (1999)
      缺陷萤石型lA_2Q_3-zrO_2固溶体的催化燃烧活性受制备条件的影响,本文通过对其共沉淀前体的表面结构和热分解过程的分析,发现共沸蒸馏的办法可以有效地控制前体表面羟基的缩合过程,减少团聚,保持前体中金属离子均匀分散,为生成缺陷有序的烧绿石型的lA_2zr_2O_7复氧化物提供了可能,复合氧化物固溶体的表面阳离子配置情况与样品的催化氧化性能密切相关,软团聚前体的烧结产物对甲烷燃烧反应具有更高的催化活性。
    • La_2O_3掺杂低温合成介孔锐钛矿相二氧化钛 

      方舒玫; 欧延; 林敬东; 廖代伟 (《中国稀土学报》编辑部, 2006-12)
      [中文文摘]采用非离子型表面活性剂EO20PO70EO20(P123)为模板剂,钛酸丁酯为钛源,La2O3为促进剂,无水乙醇为萃取剂,使用溶胶-凝胶法合成了具有锐钛矿相介孔结构和高比表面积的纳米TiO2。XRD,BET,IR和HRTEM等表征表明,La2O3的掺杂量对TiO2锐钛矿相的形成具有明显影响,当La2O3掺杂量为0.1%(摩尔分数)时,合成的TiO2锐钛矿相晶型最好,且为介孔结构,孔径大小均一,比表面积达到367.7 ...
    • Label-free aptasensor based on ultrathin-linker-mediated hot-spot assembly to induce strong directional fluorescence 

      Cao, Shuo-Hui; Cai, Wei-Peng; Liu, Qian; Xie, Kai-Xin; Weng, Yu-Hua; Huo, Si-Xin; Tian, Zhong-Qun; Li, Yao-Qun; 翁玉华; 田中群; 李耀群 (AMER CHEMICAL SOC, 2014 May 1)
      We have demonstrated the proof-of-concept of a label-free biosensor based on emission induced by an extreme hot-spot plasmonic assembly. In this work, an ultrathin linking layer composed of cationic polymers and aptamers ...
    • Label-Free Detection of Native Proteins by Surface-Enhanced Raman Spectroscopy Using Iodide-Modified Nanoparticles 

      Xu, Li-Jia; Zong, Cheng; Zheng, Xiao-Shan; Hu, Pei; Feng, Jia-Min; Ren, Bin; 冯加民; 任斌 (AMER CHEMICAL SOC, 2014-02-18)
      Proteins perform vital functional and structural duties in living systems, and the in-depth investigation of protein in its native state is one of the most important challenges in the postgenomic era. Surface-enhanced : ...
    • Label-free fluorescence strategy for sensitive detection of adenosine triphosphate using a loop DNA probe with low background noise 

      Lin, Chunshui; Cai, Zhixiong; Wang, Yiru; Zhu, Zhi; Yang, Chaoyong James; Chen,; 王翊如; 朱志; 杨朝勇; 陈曦 (AMER CHEMICAL SOC, 2014 July )
      A simple, rapid, label-free, and ultrasensitive fluorescence strategy for adenosine triphosphate (ATP) detection was developed using a loop DNA probe with low background noise. In this strategy, a loop DNA probe, which is ...