粘土胶体表面双电层重叠时ψδ及ψd的计算

本文依据Gouy-Chapman双电层理论导出了描叙粘土胶体表面压电层重叠时对阴离子负吸附方程。以实验为基础, 利用该方程通过计算机数值解解出粘土胶体表面外Helmhotz面(OHP)处的电位ψ_δ和两粘粒之间的中点电位ψ_d, 并对所得结果进行了讨论。     

粘土胶体表面双电层重叠时ψ_δ及ψ_d的计算

本文依据Gouy-Chapman双电层理论导出了描叙粘土胶体表面压电层重叠时对阴离子负吸附方程。以实验为基础,利用该方程通过计算机数值解解出粘土胶体表面外Helmhotz面(OHP)处的电位~ψδ和两粘粒之间的中点电位~ψd,并对所得结果进行了讨论。     

NaCl介质中盐浓度、pH对α－Al~2O~3表面相互作用力的影响

利用原子显微镜研究NaCl介质浓度及体pH值对氧化铝表面作用力的影响规律。发现较低的盐浓度下,相互作用表示为长程排斥力,双电层厚度的实际值与理论值较好地吻合,随NaCl介质浓度的提高,双电层压缩长程斥力减弱,测定了pHMH4.0变化到9.67的作用力曲线,发现当pH等于7/90时,两表面的相互作用表现为吸引力,通过恒电荷、恒电位拟合,发现氧化铝的等电点在pH8.2处,与Zeta电位的测定结果相一致。     

氧化铝／水界面上表面络合模型的参数

本文报道了由氧化铝的水悬浮液的电位滴定数据得到的扩散双层模型，恒定电容模型和三层模型的参数，即本征表面酸度常数，本征表面络合常数和双电层的电容，并用这些参数计算作为ｐＨ值和离子强度函数的表面电荷密度，表面电势和表面各组分的分布。     

双电层相互重叠时蒙脱胶体表面阴离子的负吸附

本文用Ag-AgCl电极判断平衡,测定双电层处于不同重叠程度下肢体表面阴离子的负吸附量Γ.结果表明,胶体表面双电层相互重叠程度可由两胶体表面间的中点电位φd与外Helmhotz面处的电位φd之比表征;阴离子负吸附随双电层重叠程度和电解质浓度的增加而显著减小.     

球型胶体颗粒的表面电位和表面电荷密度的关系

胶体颗粒的表面电荷密度和表面电位之间的关系是颗粒表面的基本性质之一．要确定这个关系,需要解Poisson-Boltzmann(PB)方程,求出颗粒外的电位分布．然而对于球形颗粒,PB方程却没有解析解．Loeb等,求出了数值解,近似解析表达式虽然很多,也比较复杂,     

泛函数法研究柱状反胶束双电层

利用泛函数分析理论中的迭代方法, 建立并在泛电位下求解了柱状反胶束水池内关于双电层电位的Poisson-Boltzmann (PB)方程, 推导出了该方程的第一、二次迭代解及电荷密度表达式, 并将其与Debye-Hückel(DH)的低电位线性近似方法得到的结果进行了比较.     

关于扩散双电层中影响电位分布因素的讨论

本文根据Ｇｏｕｙ－Ｃｈａｐｍａｎ扩散双电层模型，通过Ｄｅｂｙｅ－Ｈｉｃｋｅｌ近似处理以及严格解的推导来讨论双电层中电位分布的影响因素，得出结论：对双电层中电位分布起作用的是离子强度，电解质溶液中的同离子的作用是不容忽视的。用计算机进行数据处理，得出在离子强度相同时，四种不同类型电解质溶液中ψ－ｘ关系曲线图，进一步证实了本文的结论。     

计算机控制电毛细曲线测量

电毛细曲线在双电层结构的研究中应用十分广泛。表面张力随电位的变化能给出电极表面电荷量及其符号的信息。在电毛细曲线的最高点，表面张力相对于电位的变化为零，因而为电极的零电荷电位。电极一溶液界面的许多性质与电位偏离零电荷电位的程度有关。电毛细曲线在电极表面吸附现象的研究中也是重要的手段。     

一种评估阳离子交换吸附活化能的方法（英文）

离子和带电粒子之间的相互作用受纳米/胶体颗粒表面上离子吸附控制,同时它决定着颗粒的微观性质、界面反应过程以及颗粒间相互作用。现有的离子界面反应理论没有考虑到离子特异性对离子-表面相互作用的影响。本研究建立了带电颗粒表面离子吸附模型。结果表明蒙脱石胶体表面离子吸附平衡存在着强烈的离子特异性效应。离子和表面之间的吸附能随离子浓度的增加而降低,随着粒子电荷密度(绝对值)升高而增加。根据建立的模型还可预测吸附反离子在扩散层中的位置,进而可计算出离子的吸附能与活化能。活化能直接决定了离子的吸附饱和度,且不同的离子遵循相同的规律。本研究表明建立的离子-表面相互作用模型在固/液界面反应中具有普适性的应用。     

聚对-亚苯基苯并二噻唑的导电性能

聚对-亚苯基苯并二噻唑(PBZT)的取向薄膜是由苯环及苯杂环组成的直棒状刚性大分子组成.分子链上的非定域π电子是其具有导电性能的基本条件.经交流复阻抗谱法测得PBZT簿膜在取向方向的电导率σ_∥为10~(-6)s·cm~(-1),在簿膜厚度方向的电导率σ_⊥为10~(-10)s·cm~(-1).PBZT取向簿膜电导率具有很大的各向异性,σ∥/σ⊥=10~4.在460℃以上热处理,PBZT分子的共轭结构可进一步改善,共轭链长增加了,可使电导率提高一个数量级.     

ELECTRIC DICHROISM OF PURPLE MEMBRANE SUSPENSIONS

Abstract— Suspensions of purple membranes were exposed to reversing rectangular pulses of relatively low electric field (less than 100V/cm) at various frequencies. Orientation of the membranes was estimated by measuring linear dichroism at 565nm. In the electric field of frequency lower than about 10Hz the purple membranes tended to align perpendicular to the electric field. This orientation was induced mostly by permanent dipole which was perpendicular to the membrane surface. The value of permanent dipole moment was determined to be 140D per protein at pH 7.0, 25°C, in the presence of 5m M phosphate buffer.
In an electric field of frequency more than 100Hz the membrane tended to align parallel to the electric field. Electric polarizability parallel to the membrane surface was estimated to be 1 ± 10⁻¹² cm³ under the same conditions.
Electric dichroism of light-adapted and dark-adapted purple membranes was found to coincide with each other at high frequency. From this result the angle of retinal to the membrane surface was concluded to be the same between light-adapted and dark-adapted bacteriorhodopsins.     

ROLE OF ELECTRIC POLARIZATION IN THE THERMOLUMINESCENCE OF CHLOROPLASTS

Abstract Effect of an external electric field on thermoluminescence and thermodepolarization currents were studied in suspensions and dry films of pea chloroplasts. The external electric field was applied either during interrupted heating at a given temperature ("direct effect") or was "stored" in the sample during cooling in the range –25°C and –70°C ("electret effect").
It is shown that in chloroplast suspension both the luminescence burst upon "direct effect" and the new band peaking between –40°C and –50°C induced by the "electret effect" are accompanied by a preferential decrease in the intensity of the thermoluminescence band around +10°C.
A correlation was established between the polarized state of thylakoids and the thermoluminescence burst induced by the external field. In electret samples of chloroplast suspension the intensity of field induced low temperature thermoluminescence band under different experimental conditions varied in parallel with the intensity of thermodepolarization current. In dry films of chloroplasts, in addition to parallel changes in intensities of thermoluminescence and thermodepolarization current, also the peak positions shifted in the same manner when either humidity of samples or temperature of illumination and of application of external field were varied.
We conclude that the polarization state of thylakoid membrane, which can be governed by an external electric field, plays an important role in determining charge stabilization and recombination properties of photosynthetic units. Our results implicate that electric field induces conformational changes in the membranes which increases the frequency factor ascribed to the recombination processes.     

亲水/疏水半互穿网络凝胶在直流电场作用下的响应

研究了一种亲水 疏水型半互穿网络水凝胶 (PAAc QPVPDgels)对直流电场的刺激应答 .该凝胶中的疏水型N 十二烷基聚 (4 乙烯吡啶 )溴化盐 (QPVPD)高分子链与亲水型聚丙烯酸水凝胶 (PAAc)网络通过物理缠绕复合 .由于疏水力和亲水力的共同作用 ,在接触电场下 ,该凝胶在阳极端发生消溶胀 ,疏水相互作用对消溶胀有一定的影响 ;在非接触电场下 ,该凝胶在弱碱性溶液中迅速向阴极方向弯曲 ,在弱酸性溶液中首先发生消溶胀 ,然后向阳极方向弯曲     

电场对聚肽液晶相行为的影响

聚合物液晶的相转变不仅可以通过溶液温度或聚合物的浓度的改变来实现,也可以通过施加外电场、磁场等取向场来达到．在二氧六环、氯仿、间甲酚等支持聚肽a一螺旋构象的溶剂中,当PBLG(聚L-谷氨酸γ-苯甲酯)达到一定的浓度会形成胆甾型溶致液晶．对这种液晶施加强度足够     

溴碘化银T-颗粒晶体中的电子和空穴行为研究

利用Wagner极化法研究了掺杂K₄[Fe(CN)₆]浅电子陷阱掺杂剂的溴碘化银T 颗粒晶体的电子电导率和空穴电导率,并与未掺杂的晶体样品进行对比,分别考察了实验温度、掺杂剂用量、掺杂位置等因素对实验结果的影响.结果表明,随掺杂剂用量的增加,晶体的电子电导率和空穴电导率都相应增加,这说明浅电子陷阱掺杂剂的掺杂有效地抑制了电子和空穴的复合.但其抑制作用却因掺杂位置的不同而不同,当掺杂量一定,掺杂剂掺在碘区附近时,晶体的电子电导率和空穴电导率的变化较明显.随着实验温度的增加,乳剂晶体的电子电导率和空穴电导率都下降.     

THE EFFECT OF A PERMANENT ELECTRIC FIELD ON THERMOLUMINESCENCE OF CHLOROPLASTS

Abstract— The effect of a permanent electric field on the thermoluminescence (TL) of pea chloroplasts was studied. The field was applied to suspensions at lowtemperatures(–15 to -40_oC) and to dry films of various humidity. A permanent electric field increased TL at low temperatures at the expense of the peaks above OA_oC. When the field strength was high, an increase in the quantum yield could be observed. When a field was applied at -15_OC, the band around +10_oC was reduced preferentially, but when a field was applied at – 40_AoC, TL bands emitted above OA_oC decreased to a similar extent. Analogies between the behaviour of solid suspensions and dry films of various humidity, and the isotope effect with D₂O, indicated that the efficiency and mode of action of an electric field on TL depends on the conformational mobility of the microsurroundings of the traps in the membrane.     

抗早孕药Ru486三个中间体的实验电偶极矩

抗早孕药Ｒｕ４８６三个中间体的实验电偶极矩杨左海（咸宁医学院化学教研室湖北４３７１００）王成瑞（武汉大学化学系武汉４３００７２）关键词Ｒｕ４８６中间体电偶极矩电偶极矩是分子的一种物理量，其数据对研究分子的结构及物理化学性质具有重要的作用［１］。分子间...     

白皎煤及其充甲烷样品电极化特征的研究

研究了四川白皎无烟煤在交变和恒电场中的极化特征。结果表明,在恒电场中主要由于位移极化和空间极化的作用,使通过煤和充甲烷煤的电流随时间按下式：Ｉ＝Ｉｓ＋ａｅｂｔ逐渐衰减至一稳定值,且高压电下达到稳定的时间比低电压时要长,ａ随外加电压的升高而增大,衰减系数λ随电压的升高有减小的趋势,高电压时常数ｂ与甲烷平衡压力Ｐ的关系为：１００ｂ＝１０．１１５ｅｘｐ（０．３３８０Ｐ）;在交变电场中,由于极化作用的影响,使得通过煤和充甲烷煤的电流不随时间而变。