多价抗衡离子诱导聚甲基丙烯酸N,N-二甲基氨基乙酯(PDMAEMA)刷构象转变的UCST行为

本文应用分子场理论,研究pH、[Fe(CN)_6]~(3-)诱导聚甲基丙烯酸N,N-二甲基氨基乙酯(PDMAEMA)刷的上临界溶解温度(UCST)构象转变与结构特性.理论模型考虑p H和[Fe(CN)_6]~(3-)对PDMAEMA刷体系的静电调控作用.研究发现,在不同[Fe(CN)_6]~(3-)浓度、不同p H条件下,PDMAEMA刷呈现了UCST构象转变行为.由于p H调节PDMAEMA单体质子化,[Fe(CN)_6]~(3-)通过与PDMAEMA带正电荷的单体结合,形成了在PDMAEMA链内以[Fe(CN)_6]~(3-)为中介的带电单体间的静电吸引结合.随着温度升高,[Fe(CN)_6]~(3-)与PDMAEMA带正电荷的单体结合被破坏,[Fe(CN)_6]~(3-)在链内凝聚导致的静电屏蔽效应减弱,PDMAEMA链内带电单体间的静电排斥增强,PDMAEMA刷的构象呈现了从塌缩到溶胀的UCST转变行为,并且在较高[Fe(CN)_6]~(3-)浓度条件下,PDMAEMA刷构象转变的UCST增高.在较低p H值条件下,较多的PDMAEMA单体被质子化,[Fe(CN)_6]~(3-)与PDMAEMA带正电单体的结合增强,PDMAEMA刷构象转变的UCST增大.基于pH和[Fe(CN)_6]~(3-)对PDMAEMA刷体系中的静电调控效应,可以预言,在较小p H和较大[Fe(CN)_6]~(3-)浓度条件下,PDMAEMA链在垂直培基表面沿着链方向形成结节状结构.这是由于以[Fe(CN)_6]~(3-)为中介的链内带电单体间的静电吸引作用增强,导致临近单体间汇聚结节.我们的理论结果符合实验观测,由此表明,pH调节PDMAEMA单体的带电状态,以及[Fe(CN)_6]~(3-)在PDMAEMA链内凝聚导致的静电屏蔽效应,决定着PDMAEMA刷的UCST构象转变和结构特性.     

Investigation of the photoelectron decay of silver halide microcrystal

The microwave absorption dielectric spectrum can be used to study the decay process of free photoelectrons and shallow-trapped electrons in semiconductor crystals. The decay curve of free photoelectrons and shallow-trapped electrons of silver halide grains is measured using this technique. The influence of iodide and K_4Fe(CN)_6 shallow electron trap dopants on the photoelectron lifetime of silver halide grains is studied. For the unsensitized cubic AgCl crystals, when the free photoelectron lifetime (FLT) reaches a maximum, the photographic efficiency is optimal. From our analysis, we conclude that FLT is the longest for the cubic AgCl crystals doped with 0.5% iodide at 80% doping position and 1×10^{-6} mol K_4Fe(CN)_6/molAg, whereas, for the highly photosensitized cubic AgBrCl crystals doped with K_4Fe(CN)_6, the photographic efficiency is optimal when the FLT reaches its minimum. The free photoelectron lifetime reaches minimum and the sensitivity of AgBrCl emulsion reaches maximum when the doping position is 30%Ag at K_4Fe(CN)_6 content of 10^{-6}mol/molAg.     

[Cu~ⅡEDTA]~(2-)与[Fe~Ⅱ(CN)_6]~(4-)反应产物的分子光谱研究

按1:1(摩尔比)混合[Cu EDTA]~(2-)和[Fe(CN)_6]~(4-)溶液(pH=8)时,得到一种深红棕色溶液。测定并讨论了此红棕色溶液的电予光谱和红外光谱,据此确定此溶液中生成了不太稳定的氰桥配合物——[EDTA Cu~Ⅱ—NC—Fe~Ⅱ(CN)_5]~(6-)。     

Cu／Fe（CN）6^3—／4—界面的动态FT—IR光谱

采用现场FT-IR光谱电化学研究了Cu/Fe(CN)_6~(3-/4-)界面的化学反应、电化学反应及其随电位、时间的变化关系,并从C≡N基振动频率的改变详细分析和讨论了Cu与Fe(CN)_6~(3-/4-)的作用及成膜过程。     

无机铬化合物的光声光谱研究

本文测定了某些无机铬化合物(K_2CrO_5,K_2Cr_2O_7,Cr_2O_3,Cr(NO_3)_3·6H_2O)的固体光声光谱图,并对Cr_2O_3含量进行了定量分析研究。     

受限体相分子的超快微观结构动力学

利用飞秒二维红外光谱实验手段,我们比较研究了两个典型的微乳液体系,即反胶束和双连续相体系,二者的微观超快结构动力学。以六氰基亚铁酸钾[K_4Fe(CN)_6]和六羰基钨[W(CO)_6]分别为水相和油相(异辛烷)的探针分子,在AOT作为表面活性剂所形成的反胶束和双连续相体系中,受限水相和受限油相各自表现出了不同的分子微观结构动力学性质。此外,我们还在分子水平上解释了为什么双连续相体系比反胶束体系具有更好的导电性能。     

流动注射抑制化学发光法测定异烟肼

以异烟肼与K3 Fe(CN) 6的氧化还原反应对Luminol K3 Fe(CN) 6的化学发光反应的抑制为基础 ,设计出一种简便、快速、灵敏度高的流动注射抑制化学发光测定异烟肼的新方法。测定线性范围为 1 4× 10 -3 ～5 5 μg·mL-1,检出限为 4 8× 10 -4 μg·mL-1(3σ) ,RSD小于 3 5 % (n =9) ,并对 45种物质进行了干扰试验。本法成功地应用于药剂中异烟肼含量测定 ,回收率为 98 2 %～ 10 1%。本法与DSC法进行了对照 ,结果满意。     

双齿配位过渡金属化合物化学——Ⅱ.化合物(Et_4N)_2[Ni_2(SC_6H_4O)_2(μ-SC_6H_4OH)_2]和(Ph_4P)_2[Ni_3(SCH(CH_3)CH_2S)_4]·2CH_3CN的核磁共振研究(英文)

测定并分析了化合物(Et4_N)_2[Ni_2(SC_6H_4O)_2(μ-SC_6H_4OH)_2]和(Ph_4P)_2[Ni_3(SCH(CH_3)CH_2S)_4]·2CH_3CN的_1H NMR数据,计算了模拟谱,确认它们在DMSO溶液中仍保持原有固体状态的分子结构,它们的抗磁性质得到~(13)C NMR的证实。     

K3[Re（CN）4O2]晶体发光特性及高激发态的研究

本文通过低温下的发射光谱,吸收光谱,发光衰减等实验,系统地研究了K_3[Re(CN)_2O_2]晶体的发光特性,确定了激发态的能级结构,提出了相应的能级模型.     

液相基质中微量金属元素Pb的激光诱导击穿光谱研究（英文）

通过单脉冲激光诱导击穿光谱技术(LIBS),测定了Pb(NO_3)_2水溶液中微量重金属元素Pb的LIBS光谱.实验研究溶液中Pb元素的LIBS光谱信号的时间(300 ns-1300 ns)演化特性,得到了本实验的优化实验条件,光谱探测相对激光的延时为800 ns,单脉冲激光能量35 m J.在最佳实验条件下测得Pb微量元素的LIBS定标曲线,计算得到单脉冲LIBS用于Pb(NO_3)_2水溶液中微量金属元素分析的检测限177 ppm.     

K7[P2Mo4W13M(H2O)O61]及其有机复合材料的合成及光谱研究

用降解法制得了Dawson结构铬、铁取代的磷钼钨酸钾,并将其与溴化(E)-N-丁基-4-(2-(4-二甲氨基苯基)乙烯基)吡啶反应制备了有机复合材料.通过元素分析和TG-DTA确定了配合物的组成分别为K7[P2Mo4W13M(H2O)O61](M=Cr(1),Fe(2))和(C19H25N2)6K3[P2Mo4W13MO62](M=Cr(3),Fe(4)).利用红外光谱、紫外-可见光谱、固体漫反射紫外-可见-近红外光谱、X射线光电子能谱以及荧光光谱对上述化合物进行了表征,并研究了复合材料中无机与有机组分间的相互作用及其荧光性质.     

Tm掺杂的激光晶体生长、结构和光谱性能研究

采用顶部籽晶生长法从K2Mo3O10-B2O3助熔剂中生长出15 mm×15 mm×25 mm优质TmxGd1-x Al3(BO3)4(x=1,0.06)晶体.利用X射线单晶衍射仪测定了TmAl3(BO3)4晶体的结构.对Tm3+GAB晶体进行定向切割,测量得到了σ和π方向的偏振的吸收和发射光谱,并根据Judd-Ofelt理论计算了Tm3+在GdAl3(BO3)4中的J-O参数、各个能级的振子强度、自发辐射几率、荧光分支比等参数.     

氰桥配合物[Co^Ⅱ（L）3]2[Fe^Ⅱ（CN）6]的光谱研究

亚铁氰化钾水溶液和[CoL_3]~(2+)(L=en和pn,分别表示乙二胺和1,2-丙二胺)溶液反应得到了比较稳定的棕红色晶体。经元素分析、紫外可见光谱及红外光谱测试,证明它们是氰桥配合物[Co(L)_3-NC-Fe(CN)_4-CN-Co(L)_3]。     

K_2C_2O_4,Mg(NO_3)_2和Na_2S_2O_3过饱和水溶液瑞利弛豫的不连续行为

本文用瑞利散射强度相关的方法求得了K_2C_2O_4,Mg(NO_3)_2和Na_2S_2O_3水溶液的弛豫时间常数。结果表明当达到过饱和态时,弛豫时间常数有不连续增大的趋势。连同过去关于NH_4H_2PO_4的报导,显示这是过饱和体系的一个共同特征。此弛豫时间常数因此可以做为标度从不饱和相至饱和相转变的有序度参数。     

Influences of different oxidants on characteristics of La_2O_3/Al_2O_3 nanolaminates deposited by atomic layer deposition

A comparative study of two kinds of oxidants(H_2O and O_3) with the combination of two metal precursors(TMA and La(~iPrCp)_3) for atomic layer deposition(ALD) La_2O_3/Al_2O_3 nanolaminates is carried out. The effects of different oxidants on the physical properties and electrical characteristics of La_2O_3/Al_2O_3 nanolaminates are studied. Initial testing results indicate that La_2O_3/Al_2O_3 nanolaminates could avoid moisture absorption in the air after thermal annealing. However, moisture absorption occurs in H_2O-based La_2O_3/Al_2O_3 nanolaminates due to the residue hydroxyl/hydrogen groups during annealing. As a result, roughness enhancement, band offset variation, low dielectric constant and poor electrical characteristics are measured because the properties of H_2O-based La_2O_3/Al_2O_3 nanolaminates are deteriorated. Addition thermal annealing effects on the properties of O_3-based La_2O_3/Al_2O_3 nanolaminates indicate that O_3 is a more appropriate oxidant to deposit La_2O_3/Al_2O_3 nanolaminates for electron devices application.     

Eliminating and inhibiting hydroxylamine oxidation in DEPMPO spin trapping experiments

There exists hydroxylamine impurity in 5-(diethoxyphosphoryl)-5-methyl-l-pyrroline-l-oxide (DEPMPO) despite the purification by column separation and molecular distillation. Slow oxidation of hydroxylamine impurity to nitroxide is caused by a trace amount of transition metal ions in the solution instead by oxygen, and it can be conveniently inhibited upon the addition of diethylene-triaminepentaacetic acid, a transition metal ion chelator. Hydroxylamine impurity in DEPMPO, can also be oxidized to electron spin resonance detectable paramagnetic nitroxide in the presence of mild oxidants, such as K₃Fe(CN)₆ and CuSO₄. The previously recommended procedure for elimination of hydroxylamines was further simplified in the present study. Both hydroxylamine and nitroxide impurities can be removed from the aqueous solution of DEPMPO, by activated charcoal treatment.     

清代绿色蟠龙邮票印刷材料无损分析

利用超景深三维视频显微镜, 激光显微共聚焦拉曼光谱仪和扫描电镜-能谱仪对一张清代绿色蟠龙邮票样品的纸张, 油墨等印刷材料进行无损分析。结果表明,该样票采用手工雕刻凹版印刷,所用承印物为长纤维机制纸,未经过涂布, 无水印, 背胶;纸张填料中含有Al, Si等元素,推断纸张填料可能是高岭土(Al₂O₃·2SiO₂·2H₂O)之类的物质。绿色油墨包含了蓝色普鲁士蓝(Prussian Blue,Fe₄[Fe(CN)₆]₃·14-16H₂O)和黄色铬酸铅[Lead(Ⅱ) chromate,PbCrO₄]颜料,根据印刷色彩学色料减色和色光加色理论分析,邮票样品呈现的绿色是由蓝色颜料普鲁士蓝和黄色颜料铬酸铅混合呈色的结果;油墨填料中含有Na, Mg, S, Cl, K, Ca, V, Zn, Ba等元素,推断油墨填料为MgCO₃, CaCO₃, BaSO₄等物质。上述三项技术联用,在邮票等纸质品的无损分析中具有广阔的应用前景。     

Mössbauer study on characterization of Co[Fe(CN)5NH3 \cdot x H2O

The electronic states of Fe atoms in Co[Fe(CN)₅NH₃ H₂O were studied by means of ⁵⁷Fe Mössbauer spectroscopy. The Mössbauer spectra of Co[Fe(CN)₅NH₃ 6H₂O show the coexistence of mixed valences for the Fe atoms and a magnetic relaxation at 4 K. When water molecules were removed, electron transfer from Co to Fe occurred.