Interaction Between HMG Proteins (1+2) and the Negative Regulatory Region 1(NCR1) in the 5''''-flanking Sequence of the Human β-globin Gene

The pattern of high mobility group proteins 1 and 2 (HMG1,2) interaction with the 5'-flanking sequence of the human β-globin gene has been analyzed by scanning tunnelling microscopy (STM). A 200 bp negative regulatory region in the 5'-flanking sequence of the human β-globin gene can be folded by HMG proteins 1 and 2 into a circular structure (diameter 70±6) with a linear tail which seems to be a left-handed double helix structure.     

Co处理的γ-Fe2O3薄膜的界面研究

本文中对CoO与Fe₂O₃的界面进行了研究,结果表明,简单的CoO-γ-Fe₂O₃界面对于磁性能基本无影响。分析表明,“复杂的扩散界面”不大可能象以往认为的那样是矫顽力增长的主要原因。矫顽力的增长可能是由掺Co造成的一种体效应而不是界面效应。 关键词：     

超高效液相色谱-串联质谱法快速同时测定生姜中10种营养成分

建立了超高效液相色谱-串联质谱（UHPLC-MS/MS）快速同时测定生姜中姜辣素类和姜黄素类营养成分的分析方法，具体包括6-姜酚、8-姜酚、10-姜酚、6-姜烯酚、8-姜烯酚、10-姜烯酚、四氢姜黄素、姜黄素、去甲氧基姜黄素、双去甲氧基姜黄素10种目标物。采用ZORBAX RRHD Eclipse Plus C18色谱柱（100 mm×2.1 mm，1.8 μm）分离，以0.1%（v/v）甲酸水溶液和0.1%（v/v）甲酸甲醇溶液为流动相进行梯度洗脱，采用电喷雾电离（ESI）源、正离子和多反应监测（MRM）模式对目标物进行定性确证和定量分析。10种营养成分的线性相关系数（r）均≥ 0.9995，方法的定量限为0.10~7.71 μg/L，样品基质在3个水平下的平均加标回收率为82.8%~115.3%，相对标准偏差（RSD）为0.58%~11.49%。分析结果显示，生姜中10种营养成分均有检出，其中6-姜酚的含量最高且集中分布于373.35~702.48 mg/kg。该法简便快速，准确可靠，适用于生姜中姜辣素类和姜黄素类营养成分的分析，可为生姜质量鉴定和控制提供技术手段。     

聚环氧氯丙烷氨酯阻尼材料的阻尼性能研究

<正> 一般来讲,聚合物材料的阻尼性能来源于分子链运动带来的内摩擦力以及分子间物理键的破坏与再生,分子链运动所产生的阻尼在聚合物的玻璃化转变温度范围内最为有效。因此具有极性较强、体积较大的一CH_2Cl侧基的环氧氯丙烷聚合物应具有优异的阻尼性能,专利文献[1—2]报道过由多羟基(官能度≥2)聚环氧氯丙烷预聚物为原料制得的聚氨酯泡沫具有良好的阻燃性能,作者在聚环氧氯丙烷氨酯阻尼材料方面进行了尝试。     

1-氟代糖在化学-酶法合成糖类中的应用

化学-酶法合成糖类具有立体选择性和区域选择性, 逐渐成为糖类合成的主流. 1-氟代糖作为糖基供体应用于化学-酶法合成反应, 显示出越来越重要的作用, 综述了1-氟代糖在糖基转移酶和糖苷酶催化的糖类合成中的应用.     

D,L-1,2,2-三甲基环戊烷-1,3-二胺硝酸镍配合物的合成、结构及其和手性D-(+)-1,2,2-三甲基环戊烷-1,3-二胺氯化镍配合物的对比分析(英)

A nickel(Ⅱ) complex [Ni(La)₂](NO₃)₂ (1) with bidentate racemic 1,2,2-trimethylcyclopentane-1,3-diamine ligand has been synthesized and characterized by IR, EA, ES-MS, and its X-ray diffraction study reveals that the nickel(Ⅱ) center is tetra-coordinated by one D- and one L- diamine ligands, and a three-dimensional hydrogen-bond-sustained network is formed in the solid state by means of the eight-membered N-H…O hydrogen bond cycle. This compound also supplies a good comparison to the chiral complex [Ni(L_b)₂]Cl₂·2H₂O (2) (L_b=D-(+)-1,2,2-trimethylcyclopentane-1,3-diamine). CCDC: 218122.     

FREQUENCY DEPENDENCE OF THE DIELECTRIC RELAXATION OF 1,2-POLYBUTADIENES

The dielectric loss factor and permittivity of a series of 1, 2-polybutadienes with different contents of 1, 2-units and different contents of syndiotactie 1, 2-units were determined over a frequency range from 30Hz to 100KHz at different temperatures. The WLF equation was evaluated for various samples with T_θat 100KHz as a reference temperature and the master curves of various samples have been constructed, which are in accordance with those calculated by Havriliak-Negami equation. The frequency dependence of the dielectric relaxation of 1, 2-polybutadienes was investigated over a frequency range from 10~0 Hz to 10~(12) ZHz in terms of the experimental data and the master curves.     

THE SOLID STATE REACTIONS AND TRANSITIONS IN HIGH POLYMERIC SYSTEMS Ⅲ. THE BULK CRYSTALLIZATION OF LANTHANIDECATALYTICALLY POLYMERIZED POLYDIENES

For the mechanism of isothermal bulk crystallization of high polymers, beside the nucleation and growth steps, the unimpingement of growing crystal aggregates should be taken into account for the modification of the Avrami equation. Starting from Poisson distribution function of growing crystal aggregates, the probability of the unimpinging ones should be P(0)+P(1), then the Q-modified Avrami equation thus derived can be expressed aswhere V0 represents the volume fraction of crystal aggregates at crystallization time t at a given temperature, while the exponent n on t relates to the mode of nucleation and growth, and K_q is the corresponding shape factor. This Q-modified one is verified satisfactory by the isothermal bulk crystallization of lanthanidecatalytically polymerized polybutadiene (Ln-PB), polyisoprene (Ln-PIR) and their copolymers (LnPB/IR). Furthermore, the proposed mechanism is well identified by the change of morphological state during the course of crystallization of the corresponding east film of Ln-PB TR (92/8) at-60°(Fig. 1).Upon examination of the influence of the number of entanglement on crystallization rate, it reveals the existence of two stages of entanglementation, the primary and the secondary ones (Fig. 19)The equation for dependence of molecular weight and entanglement on bulk crystallization rate has been derived as Eq. 13 or 18 for Ln-PB, and verified by the experimental rate data of well fractionated Ln-PB samples crystallized at -9.1 to -15℃(Fig.20).     

开链冠醚Schiff碱-稀土配合物的合成、表征及近红外发光光谱研究

合成了3个新型开链冠醚Schiff碱-稀土离子三元配合物RE(H2L)(Mq)(NO3)3,其中RE=Nd3 ,Er3 ,Yb3 ,配体H2L=N,N-双(邻羟苯亚甲基)-3,6-二氧杂-1,8-二氨基辛烷,Mq为8-羟基喹哪啶.采用元素分析、红外光谱(IR)、紫外-可见吸收光谱(UV-vis)、热重-差热分析(TG-DTG)等手段对配合物的组成结构进行了表征.测定了3种新型结构稀土三元配合物在不同温度(77 K和300 K)时的近红外发光光谱.     

气相[（SiO2）nX]^—团簇产生机理

利用ＸｅＣｌ准分子激光烧蚀多种硅氧多孔结构材料，在负离子通道测得丰富的「（ＳｉＯ２）ｎＸ」＾－负离子团簇，并讨论了多孔网结构和表面活性基团的分布对激光能量的吸收，传输及团簇产生的重要作用。