pH值致变色高分子材料的合成与制备

本文研究和开拓了一类pH值致变色的高分子材料，它们的响应机理是分子链中有pH值致变色的基团，即PH值的变化使生色基团的结构发生变化，并最终导致其吸收光谱（吸收型）或发射光谱（荧光型）的变化。这类材料在如下领域，例如：光纤pH值传感膜材料，可重复使用的PH值指示材料，滤光材料，颜色材料，以及离子交换和离子选择性透过材料等领域有很好的应用前景。本文在总结前人研究的基础上，采用简单程序制备了多种响应快，长期稳定性好的光纤pH值传感膜材料，其可望用于制备光纤PH值传感器以满足不同领域的需求。工作大致包括以下五个方面。（一）采用一步法在碱性条件下让酚酞和邻甲酚酞分别与甲醛反应生成各自的高分子型pH值指示剂（PPF和cPF），GPc曲线表明它们的产物含有很多预聚物（如二聚体，三聚体和四聚体）和少量的高分子量组分。（二）分别制备了固定有PPF和CPF的两种聚合物膜（纤维素膜和聚乙烯醇膜）。沿用物理"包埋"的方法将PPF和CPF等低聚物固定在水解的二醋酸纤维素膜中，同时也开拓了共价键键接酚酞等到新的基质（PVA）上的方法，测试表明该类膜在pH8.0-14.0范围内具有很好的响应。（三）开拓了一种膜动力学分光光度法用于测定高碱度([OH-]=1-8SM），实验结果表明该方法可以提供一个快速（605）和准确（相对标准偏差为2．6％）的测定高碱度的方法。（四）制备了固定有酚红的PvA膜用于近中性pH值（6．5-10．5）和高酸度（5M[H+]-pH3．0）测定，该膜长期稳定性好，至少能连续使用3个月，特别适合生物学，海水，氨水溶液和高酸度的测量。（五）采用一步法在碱性条件下让荧光素与甲醛反应生成荧光齐聚物型pH值指示剂FLF，激光质谱表明它们的产物含有很多预聚物。可见光谱测试表明FLF-PVA膜的吸收光谱在pH0．0-10．0的范围内有很好的响应。

镧系氨基酸配合物在生理pH条件下的结构特性及其对DNA的特异性识别

DNA是重要的生物大分子，也是主要的抗癌药物靶分子。小分子与DNA之间的相互作用是以DNA为靶分子的各种物质生物效应的基础，它们之间的特异性结合导致了癌变、突变及细胞的死亡。能够与DNA特异性结合的小分子很多都是临床上广泛应用的抗癌药物。因此，小分子与DNA之间的相互作用不论是对阐述抗癌、抗病毒药物的作用，还是对致癌机理的研究，尤其对抗癌药物的体内筛选都有重要意义。近十年来，开发新型的抗癌药物小分子，使它们具有对DNA序列特异性的识别能力己成为国内外研究的热点。斓系配合物由于具有广泛的光学、磁学和电学等特性使得有可能成为新的DNA特异性识别分子。然而，斓系离子在中性条件下极其容易水解的特性又极大的阻碍了斓系配合物对于DNA的识别性研究。本文在中性条件下合成了铜系氨基酸配合物，并成功的获得了这些配合物的晶体结构，利用这些有确定结构的I系氨基酸配合物与特定的DNA序列相作用，通过多种生物物理方法研究了它们对DNA序列特异性识别。主要的结果如下：1．在近中性条件下，合成了Eu-Val（［Eus_8（L-HVal）_(16)（H_2O）_(32)］Cl_(24)·12.5H_2O），Eu-Asp（［Eu_4（μ3-OH）_4（L-Asp）_2（L-HAsp）_3（H_2O）_7］Cl·11.5H_2O）和Tb-Cys（「Th_2（DL-Cys）_4（H_2O）_8]Cl_2）三种铜系氨基酸配合物，这些配合物的结构由于合成条件（温度，反离子及合成比例）上的差异与已报到的类似配合物的结构具有明显的不同。三种配合物的结构各具特色，从而在与DNA作用时将表现出各自特有的识别性能。2．Eu-Val配合物在与单链DNA作用时，配合物能键合到DNA碱基所在的疏水区，在与富含dC和dT碱基的序列相结合时，发生显著的能量传递，从而极大的增强了配合物中Eu的发射光谱。配合物结合DNA的化学计量比随序列中dC含量的降低而降低。配合物同样能够与处于DNA疏水区的富含dA和dG序列相结合，这种结合不能够产生能量传递，但使得DNA的紫外-可见光谱出现明显的减色和红移现象。此外，这一配合物还能够诱导单链DNApoly（dA）及p01y（rA）产生自身的二级结构，形成双链结构。这为进一步认识斓系离子的生物学效应奠定了基础，斓系氨基酸配合物可以诱导单链poly（dA）及poly（rA）形成自身结构尚无文献报道。3．Eu一AsP配合物能够选择性的稳定非B一构象的Poly（dA）Poly（dT），而使B一构象的印oly（dAdT）］2和［Poly（dGdC）］2变得不稳定。如在1：2比例时，该配合物可使Poly（dA）Polv（dT）的融化温度提高4℃，而使印oly（dAdT）｝2的融化温度降低6℃，［Poly（dGdC）］2则出现了两个转变温度。进一步的圆二色实验结果充分表明Eu一Asp配合物对于富含Poly（dA）Poly（dT）和［Poly（dAdT）］2的双链DNA没有构象上的改变，而对于［Poly（dGdC）］2的双链DNA则产生了显著的构象上的改变，很有可能正是这一改变使得［Poly（dGdC）］2变得极其的不稳定。配合物对［Poly（dGdC）］2的这种不稳定影响随着配合物浓度的逐步升高而越来越明显。变温实验结果清楚的表明，在37℃时，Eu-AsP使[Poly（dGdC）JZ发生了构象转化，并且这种转化是可逆的。4．Tb-Cys配合物与单链（除了poly（dA））和双链DNA都能发生能量传递，从而使得配合物的荧光显著增强。不同的DNA表现出不同的增强效果，表明TbCys配合物对DNA的序列存在选择性，单链要强于双链，富含Poly（dAdG）的序列增强效果最好。单链和双链能量传递的差异表明了配合物能够区分DNA的单链和双链，配合物在与单链作用时结合更强。TbCys配合物在与DNA作用时存在不同的结合位点，而且单链和双链的结合位点明显不同。TbCys配合物能够引起富含dC和dT的单链DNA发生减色效应，而能够引起富含poly（dA）、poly（dAdG）的单链DNA和富含poly（dA）poly（dT）、[Poly（dAdT）］2和［poly（dGdC）］2的双链DNA发生明显的红移。此外，这一配合物同样能够影响双链DNA的稳定性，使得富含poly（dA）Poly（dT）序列变得稳定，而使得富含印oly（dAdT）］2和富含印oly（dGdC）］2的序列变得不稳定。这些结果都表明了配合物对DNA存在选择性。比较不同配合物的差别后能够发现DNA对于不同的配合物同样具有选II择性，这种选择性能够用来区分配合物。一这些钢系氨基酸配合物由于选择了天然的氨基酸作为配体，从而大大的降低了对人体的毒性，进一步表现出的对不同的DNA序列的选择型则使其有望成为新型的抗癌诊疗试剂。

PH值、氯离子浓度和监酸浓度对于铁的腐蚀电化学行为的影响

本文研究了Armco铁在盐酸溶液中的腐蚀电化学行为，探讨了ψ~-离子和PH值对铁的阳极溶解过程的影响，并进而讨论了ψ~-离子浓度和PH值对铁的腐蚀电化学行为的影响之间是否存在交互效应。在本工作中，作者提出了两个新的研究方法：(a) 从单支弱极化曲线测定腐蚀电流和阴、阳极反应的Tafep斜率；(b)根据交流方波电流扰动的响应函数方程测定极化电阻Rp和界面电容C。设I_c、I_(2c)、I_(3c)及I_(4c)分别为对应于弱极化区内极化电位为ΔE、2ΔE、3ΔE和4ΔE的极化电流，且令a = I_(2c)/I_c, b = I_(3c)/I_c, c = I_(4c)/I_(2c), 而(4b-3a~2)~(1/2)、(3c-2b)~(1/2)、(2c-a~2)~(1/2)则以S_j表示之，则可得到：I_(corr) = I_c/S_j b_c = ΔE/lg((a+s_j)/2) b_a = -ΔE/lg((a-s_j)/2)为了方便，准确地求出动力学参数，可选用一系列的ΔE值，得出相应的极化电流I_λ，求出S_λ，应用统计方法处理数据，可得：I_(corr) = ∑ from i=1 to n I_λ/∑ from i=1 ton S_λ b_c = ∑ form λ to n ΔE_λ/∑ form i=1 to n lg ((a_λ+S_λ)/2) b_a = ∑ form i=1 ton ΔE_λ/∑ form i=1 to n lg ((a_λ-S_λ)/2)在线性极化区间内向腐蚀金属电极体系施加一交流方波电流扰动讯号时，通过Laplace变换分析，得到相应的响应函数方程为：E_1(t) = λ_o(R_s+R_p) - 2λ_oR_p (e~(-(τ-λ)/RpC))/(1+e~(λ/RpC)) (o<τ<λ) E_2(t) = -λ_o(R_s+R_p) + 2λ_oR_p (e~(-(τ-λ)/RpC))/(1+e~(λ/RpC)) (λ<τ<2λ)由此方程可知，它们在E～λ坐标系统中的轨迹为对称兴致勃勃原点的两条直线。由此方程可进一步得到:ΔE = 2λ_oR_p (e~(λ/RpC)-1)/(e~(λ/RpC)+1) = 2λ_oR_p t_(anh)(λ/(2RpC)) Δh = 2λ_o Rs式中ΔE为单支响应直线的长度，Δh则为两条直线最高点之间的距离。上述公式可进一步简化为：Rp =(ΔE)/(2λ_o) λ>>RpC (λ_o)/(ΔE) = C/λ + 1/(2Rp) λ<

PEO／PH共混体系的相容性、结晶结构、等温及非等温结晶动力学研究

PEO／PH共混体系的组份之间存在着氢键的相互作用，从偏光显微镜观察及熔点下降法测定，PEO／PH共混体系是相容体系，且PEO是在非晶区与PH相容，PH分子链不进入到PEO的晶格中，不引起晶胞参数的改变。对PEO／PH共混体系的等温结晶动力学研究表明，随共混体系中非晶组份PH含量的增加，体系的结晶生长方式由盘状生长转化为原纤状生长，成核方式由方式I(Kg=Kg(I)=4b. σσeTm/ΔHf.K)转化为方式II(Kg=Kg(Ii)=2b. σσeTm/ΔHf.K)析叠链表面自由能（σe）逐渐增大，体系的平衡溶点降低。在PEO／PH共混体系非等温结晶动力学的研究中，DSC实验表明，在常冷却速率下，PEO／PH共混体系符合Avrami方程所揭示的规律，为更好地反映非等温结晶特点，从Avrami方程和Ozawa方程出发，导出一个新的基本方程，根据这个方程，获得了描述非等温结晶过程的一些基本参数，在一定冷却速率下，随非晶组份PH含量的增加，东混体系的结晶速率降低；对于同一组成，冷却速率越大，体系结晶速率越快。WAXD和SAXS分析表明，随非晶组份PH含量的增加，PEO／PH共混体系的结晶度降低，长周期增大，过渡层厚略有变化，但变化很小。进一步表明，过渡层基本上是PEO的非晶相的贡献，PH不进入到PEO的晶格中，PEO是在非晶区与PH相容。

Measurement of trace phosphorus in dichlorosilane by high-temperature hydrogen reduction gas chromatography

Dichlorosilane, a gas at normal temperature with a boiling point of 8.3 degrees C, is very difficult to sample and detect using conventional methods. We reduced phosphorus in dichlorosilane to PH3 by hydrogen at high temperature, then PH3 was separated from chlorosilanes by NaOH solution and from other hydrides by chromatographic absorption. Thus the problem of interference of chlorosilanes and other hydrides was overcome and PH, was measured by a double flame photometric detector at 526 nm. This method was sensitive, reliable and convenient and the sensitivity reached as low as 0.04 mu g/l.

Determination of AlxGa1-xAs Auger sensitivity factors

AlxGa1-xAs Auger sensitivity factors have been determined by using PHI610 scanning Auger microprobe with pure elemental standards Al, Ag and matrix GaAs. The quantitative results of AlxGa1-xAs measured by the present method are in very good agreement with X-ray double crystal measurements. it is shown that by using sensitivity factors obtained from the self-instrument, the accuracy of the quantitative AES analysis can be considerably improved compared with that using elemental relative sensitivity factors given by the PHI handbook or internal standard method.

BACKGATING AND LIGHT SENSITIVITY IN GAAS METAL-SEMICONDUCTOR FIELD-EFFECT TRANSISTORS

Three different types of GaAs metal-semiconductor field effect transistors (MESFET) by employing ion implantation, molecular beam epitaxy (MBE) and low-temperature MBE (LT MBE) techniques respectively were fabricated and studied in detail. The backgating (sidegating) measurement in the dark and in the light were carried out. For the LT MBE-GaAs buffered MESFETs, the output resistance R(d) and the peak transconductance g(m) were measured to be above 50 k Omega and 140 mS/mm, respectively, and the backgating and light sensitivity were eliminated. A theoretical model describing the light sensitivity in these kinds of devices is given. and good agreement with experimental data is reached.

Sensitivity of Total-Dose Radiation Hardness of SIMOX Buried Oxides to Doses of Nitrogen Implantation into Buried Oxides

In order to improve the total-dose radiation hardness of the buried oxides(BOX) in the structure of separa tion-by-implanted-oxygen(SIMOX) silicon-on-insulator(SOI), nitrogen ions are implanted into the buried oxides with two different doses,2 × 1015 and 3 × 1015 cm-2 , respectively. The experimental results show that the radiation hardness of the buried oxides is very sensitive to the doses of nitrogen implantation for a lower dose of irradiation with a Co-60 source. Despite the small difference between the doses of nitrogen implantation, the nitrogen-implanted 2 × 1015 cm-2 BOX has a much higher hardness than the control sample (i. e. the buried oxide without receiving nitrogen implantation) for a total-dose irradiation of 5 × 104rad(Si), whereas the nitrogen-implanted 3 × 1015 cm-2 BOX has a lower hardness than the control sample. However,this sensitivity of radiation hardness to the doses of nitrogen implantation reduces with the increasing total-dose of irradiation (from 5 × 104 to 5 × 105 rad (Si)). The radiation hardness of BOX is characterized by MOS high-frequency (HF) capacitance-voltage (C-V) technique after the top silicon layers are removed. In addition, the abnormal HF C-V curve of the metal-silicon-BOX-silicon(MSOS) structure is observed and explained.

采用离子注入方法调整和控制氢离子敏场效应管（PH-ISFET）阈值电压

于2010-11-23批量导入

A novel high sensitivity CE-PTHPT for optical fiber communication

Planar punch through heterojunction phototransistors with a novel emitter control electrode and ion- implanted isolation (CE-PTHPT) are investigated. The phototransistors have a working voltage of 3-10V and high sensitivity at low input power. The base of the transistor is completely depleted under operating condition. Base current is zero. The CE-PTHPT has an increased speed and a decreased noise. The novel CE-PTHPT has been fabricated in this paper. The optical gain of GaAlAs/GaAs CE-PTHPT for the incident light power 1.3 and 43nw with the wavelength of 0.8 mu m reached 1260 and 8108. The input noise current calculated is 5.46 x 10(-16) A/H-z(1/2). For polysilicon emitter CE-PTHPT, the optical gain is 3083 at the input power of 0.174 mu w. The optical gain of InGaAs/InP CE-PTHPT reaches 350 for an incident power of 0.3 mu w at the wavelength of 1.55 mu m. The CE-PTHPT detectors is promising as photo detectors for optical fiber communication system.

The development of long - Term ambulatory pH monitoring system and its clinical application

This paper introduced a long-term ambulatory intragastric pH monitoring system, which is designed for prolonged ambulatory studies of Gastroesophageal Reflux Diseases. The whole system is composed of the gastric catheter with two pH sensors, a small data logger (Microdatalog), and a notebook PC. In this paper, the design of monitoring system hardware and software are described in detail. Clinical applications reveal good results.