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71.
合成了硝酸铒与四功能团含磷萃取剂6,6'-二(二苯基氧化膦甲基)-1,1'-氮氧化-2,2'-联吡啶的配合物。用四圆衍射仪测定了配合物的晶体结构。晶体属单斜晶系,空间群C2/c,晶体学参数,a=1.9830(4)nm,b=2.3135(4)nm,c=1.8600(3)nm;β=96.18(2)°,z=4。配合物中有机配体以四齿形式与中心离子铒配位,金属离子的配位数为8。配位几何构形为稍变形的四方反棱柱。金属离子周围的配位水分子已全部被取代。  相似文献   
72.
An experimental investigation on shortening of travelling-wave ASE employing a transversal pumping is presented. A N2 laser with =337.1 nm, pulsewidth: 700 ps is used as a pump source. An ASE pulse with duration of 45, 55 and 45 ps from dye solution of Rh 6G, Rh B and C311, respectively, is obtained. Pulse shapes of output signals generated from these solutions in three different pumping schemes are compared.  相似文献   
73.
α核素211At具有良好的辐射生物学性质,以对肿瘤细胞具有高亲和性的单克隆抗体或多肽类配体为载体则是实现211At肿瘤靶向治疗的最理想方式之一。本文介绍了211At标记蛋白质或多肽的方法的现状与进展,对存在的一些问题及今后的发展方向进行了讨论。  相似文献   
74.
The streaming potential of supersaturated solution of binary carboxylic acids, which have even carbon atoms, was determined to characterize crystallization under different temperatures. The value of the streaming potential was related to the type and solubility of the acids and the starting temperature of crystallization, and was easily influenced by the pressure difference of the liquid or the rate of temperature decline. When the temperature was declined to the point where a crystal nucleus appeared, the streaming potential reached the minimum. Thereafter, as the temperature was sequentially lowered, some minicrystals grew, and the streaming potential presented an ascendant tendency. The higher the starting temperature of the acids saturated solution, the higher is the temperature corresponding to the streaming potential minimum. The less the carbon atoms in the acids and the greater the solubility of the acids are, the higher is the temperature of the streaming potential minimum. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
75.
制备了一系列硼掺杂的还原氧化态石墨烯催化剂并应用于蒽加氢反应。结果表明,随着催化剂处理温度的升高,催化剂中有序碳结构会发生变化,硼会取代材料骨架中的碳,进而影响蒽和氢气的吸附活化。经硼改性后,催化剂对蒽加氢反应表现出了很高的加氢活性,蒽的最高转化率可达97%,深度加氢产物八氢蒽的最高选择性可达19%。  相似文献   
76.
钇对金属陶瓷力学性能和组织的影响   总被引:6,自引:0,他引:6  
研究了添加钇对Ti(C,N)基金属瓷力学性能和组织的影响。结果表明,加入适量的钇能提高Ti(C,N)基金属陶瓷的抗变强度和硬度,其原因是由于钇与杂质硫起反应在化合物,净化了陶瓷相-金属相,陶瓷相-陶瓷相界面提高子界面结合强度  相似文献   
77.
Liu J  Bi S  Yang L  Gu X  Ma P  Gan N  Wang X  Long X  Zhang F 《The Analyst》2002,127(12):1657-1665
The biological effects of aluminium have received much attention in recent years. Speciation of Al is of basic relevance as it concerns its reactivity and bioavailability. A differential pulse voltammetry (DPV) procedure is proposed for speciation analysis of Al(III) in natural waters and biological fluids using six catechols (L-dopa, dopamine, epinephrine, norepinephrine, caffeic acid and o-benzenediol) as electroactive ligands. The decrease of the DPV anodic peak current for each catechol ligand is linear with the increase of Al concentration. This speciation analysis idea is based on the measurement of the complexation capacity, namely, different affinities of Al(III) for catechols and organic ligands under two pH conditions. The labile monomeric Al fraction (mainly inorganic aluminium) is determined at pH 4.6, while the total monomeric Al fraction is determined at pH 8.5. The principle for Al(III) speciation analysis by an electrochemical method is discussed. This sensitive and simple fractionation method is successfully applied to the speciation analysis of Al in natural waters and the results agree well with those of Driscoll's method. The speciation analysis of Al in biological fluids is also explored and the results are compared with those obtained by ultrafiltration and dialysis. Compared with other speciation protocols the electrochemical method possesses some remarkable advantages: rapidity, high sensitivity, cheap instrumentation and a simple operation procedure.  相似文献   
78.
合成多肽的电喷雾质谱研究   总被引:1,自引:2,他引:1  
利用电喷雾多极串联质谱对3种合成多肽进行了系统的鉴定和分析研究。首先通过全扫描模式测定了其分子量,然后选择[M H]^ 或[M 2H]^2 离子通过串联质谱(MS/MS)得到碎片离子,采用y离子和b离子互补的方法测定了多肽序列。利用文献数据对这种方法进行了验证,实验结果表明,该方法简便、快速、实用。  相似文献   
79.
Ning  Weimin  Wang  Han  Gong  Shaolong  Zhong  Cheng  Yang  Chuluo 《中国科学:化学(英文版)》2022,65(9):1715-1719

Due to narrowband emission and high quantum efficiencies, polycyclic aromatic heterocycles with multi-resonance thermally activated delayed fluorescence (MR-TADF) properties have recently gained considerable attention in the organic optoelectronic field. Albeit their great promise in the full visible region covering from blue to red, MR-TADF emitters with ultraviolet emission have been rarely reported. Through locking the two ortho-positions of a triphenylamine core by sulfone groups, a simple polycyclic aromatic heterocycle, BTPT, was facilely constructed, exhibiting 368 nm ultraviolet emission with a narrow full width at half maximum (FWHM) of 33 nm. Its neat film exhibited distinct TADF property with a main emission peak at 388 nm. Noteworthily, the enantiomeric crystals of BTPT not only demonstrated significant circularly polarized luminescence (CPL) with large luminescence dissymmetry factor in the 10?3 order but also displayed obvious room temperature phosphorescence (RTP). The relationship between this innovative helical unit and unique photophysical properties, including ultraviolet MRTADF, CPL, and RTP, was reasonably revealed.

  相似文献   
80.
Polystyrene (PS) fibers with core-shell structure were prepared by coaxial electrostatic spinning using liquid epoxy or curing agent as the core and PS solution as the shell. Scratch self-healing coatings were realized by using the healant-loaded core-shell fibers in the matrix.  相似文献   
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