12硫醇修饰金电极K3Fe（CN）6／K4Fe（CN）6体系的 …

采用自组装（ＳＡ）技术制备了正十二硫醇的ＳＡ单分子层膜,应用电化学交流固抗及循环伏安研究了１２硫醇ＳＡ单分子层膜在Ｋ３Ｆｅ（ＣＮ）６／Ｋ４Ｆｅ（ＣＮ）６ 的电化学行为,测得了表观电子传递系数α＋β≠１,电子隧穿系数为（０．８３￣１．１１）／ＣＨ２。     

用谱学方法研究铜在Fe（CN）_6~（3－）溶液中的腐蚀行为

用ＦＴ－ＩＲ、ＵＶ－Ｖｉｓ和ＸＰＳ等分子光谱和电子能谱方法研究了铜在Ｆｅ（ＣＮ）溶液中的腐蚀过程，表面膜的形成及其改性。结果表明，腐蚀膜主要由（ＣＮ）６（大量）和（ＣＮ）６（少量）组成，并夹杂有Ｋ４Ｆｅ（ＣＮ）６和Ｋ３Ｆｅ（ＣＮ）６．     

Fe（CN）_6~（3－）／Fe（CN）_6~（4－）体系扩散系数测定方法的比较

本文用循环伏安法、计时电位法、计时电流法、计时电量法和旋转圆盘电极研究了Ｆｅ（ＣＮ）_６~（３－）／Ｆｅ（ＣＮ）_６~（４－）体系的电化学反应过程，用上述几种电化学方法测定了Ｆｅ（ＣＮ）_６~（３－）／Ｆｅ（ＣＮ）_６~（４－）离子的扩散系数，对测定的方法和结果作了全面的分析比较．     

用谱学方法研究铜在Fe（CN）^3—6溶液中的腐蚀行为

用ＦＴ－ＩＲ、ＵＶ－Ｖｉｓ和ＸＰＳ等分子光谱和电子能谱方法研究了铜在Ｆｅ（ＣＮ）＾３－６溶液中的腐蚀过程，表面膜的形成及其改性。结果表明，腐蚀膜主要由Ｃｕ＾１＋４Ｆｅ＾Ⅱ（ＣＮ）６（大量）和Ｃｕ＾２＋２Ｆｅ＾Ⅱ（ＣＮ）６（少量）组成，并夹杂有Ｋ４Ｆｅ（ＣＮ）６和Ｋ３Ｆｅ（ＣＮ）６；     

Fe(CN)_6~(3-)/Fe(CN)_6~)4-)与Ag/AgNO_3体系的热电化学研究

用差示测温技术测定了Ｆｅ（ＣＮ）３－６／Ｆｅ（ＣＮ）４－６体系及Ａｇ／ＡｇＮＯ３体系阳极过程的热效应，实验中采用热敏电阻测定电极表面的温度变化，利用电流、电极电位、温差和极化时间等数据，运用热电化学基本方程得出电极反应的焓变值．实验结果表明，由热电化学方法决定的焓变与由相对应的离子的热力学数据计算得来的焓变的差值为一恒定值，进一步得出２９８．１５Ｋ下标准氢电极反应的绝对熵值为８８．４Ｊ·Ｋ－１·ｍｏｌ－１．     

（C6Me6）2Fe.PCNP2类化合物的导电模型

用ＣＮＤＯ／２Ｍ方法计算了（Ｃ６Ｍｅ６）２Ｆｅ．ＰＣＮＰ２和（１，３，５－Ｍｅ３Ｃ６Ｈ３）２Ｆｅ．ＰＣＮＰ２有机导体分子的电荷密度、键级等量子化学参数。计算表明，（Ｃ６Ｍｅ６）２Ｆｅ．ＰＣＮＰ２分子中两个苯环骨架Ｃ原子和Ｆｅ所带的电荷密度分别大于（１，３，５－Ｍｅ３Ｃ６Ｈ３）２Ｆｅ．ＰＣＮＰ２分子的。     

铁氰化镍膜的分子组成及电化学行为

研究了沉积在玻碳（ＧＣ）基体上的铁氰化镍（ＮｉＨＣＦ）膜的电化学行为。详细分析了制备条件对膜的循环伏安（ＣＶ）行为的影响，结合能量色散Ｘ射线（ＥＤＸ）分析技术，提出膜是可溶组分Ｋ２ＮｉＦｅ（ＣＮ）６和不可溶组分Ｎｉ２Ｆｅ（ＣＮ）６共存的混合态，精确控制沉积条件，可分别获得不同组分占优势的膜。在此基础上研究了两组分的电化学特征，初步探讨了不可溶组分的电化学反应机制，得到描述其电极反应的方程式为：（Ｋ     

光谱电化学法测准可逆体系电子转移速率常数

采用单电势跃——计时吸收光谱法（ＳＰＳ－ＣＡ）测量了准可逆体系的电子转移速率常数。首先通过测Ｋ３Ｆｅ（ＣＮ）６—Ｋ４Ｆｅ（ＣＮ）６体系的标准速率常数ｋｓ０′，证实了理论公式、实验方法及数据处理的合理性，而后以ＳｎＯ２－Ｉｎ２Ｏ３膜玻璃电极为工作电极，分别测定了亚甲基蓝还原和无色亚甲蓝氧化的电子转移速率常数及该体系的ｋｓ０′，结果较为理想。     

3,3‘,5,5’—四甲基联苯胺比色测定铬（Ⅵ）的人工标准色列

本提出了一套人工标准色列用于３，３’，５，５’－四甲基联苯胺（ＴＭＢ）比色测定铬（Ⅵ），该色列以Ｈ２ＳＯ４为介质，以不同含量的Ｋ２ＣｒＯ７，Ｋ４Ｆｅ（ＣＮ）６和Ｋ３Ｆｅ（ＣＮ）６溶液组成，其颜色与ＲＭＢ和铬（Ⅵ）的显色产物相近，使用本色列，铬（Ⅵ）测定范围为０．０１￣０．３０ｍｇ／Ｌ，用本法对电镀废水中的铬（Ⅵ）进行了测定，六次测定的相对标准偏差为３．５％，平均值与ＴＭＢ测定铬（Ⅵ）的分光光度法     

Fe（CN）6^3—／4—在铂电极上氧化还原过程的表面拉曼光…

本文运用共聚焦显微拉曼仪结合特殊的电极表面粗糙方法首次获得了Ｆｅ（ＣＮ）６＾３／４－在铂电极表面氧化还原过程的拉曼光谱图。研究结果表明Ｆｅ（ＣＮ）６＾３－在电极表面的吸附能力比Ｆｅ（ＣＮ）＾４－强，它们都是通过ＣＮ上的Ｎ原子和电极表面成键而发生化学吸附的。     

电子传输过程对硫醇自组装单层膜结构的影响

应用交流阻抗技术及循环伏安技术研究了十八硫醇修饰的金电极在Fe(CN)63-/4-溶液中的电化学行为,提出电化学氧化还原过程中的电子传输可以诱导十八烷基硫醇自组装单分子层膜结构的一定重组,使其变得更加均一有序.     

TCNQ修饰的金/18硫醇-卵磷脂双层膜在Fe(CN)_6~(3-/4-)溶液中的单向导电性

固体支撑的双层类脂膜不仅是研究和模拟发生在生物膜上各种过程的重要模型，而且也成为研制生物分子电子器件的重要工具．在固体支撑的双层类脂膜中，金／硫醇－类脂双层膜以其缺陷少、稳定性高等特性而倍受关注［１］．本文报道了修饰７，７，８，８－四氰基奎诺二甲烷（...     

Reconstitution of a phospholipid flippase from rat liver microsomes

The endoplasmic reticulum is the principal site of synthesis and initial incorporation of membrane lipids in eukaryotic cells; the enzymes of glycerolipid biosynthesis are exclusively located on its cytoplasmic surface. To maintain a phospholipid bilayer in this organelle, newly synthesized phospholipids must be translocated to the lumenal surface. Consistent with this are measurements indicating that movement of phospholipids across microsomal membranes is rapid, with a half-time less than 5 min (refs 3 and 4). Rapid movement of phospholipids has also been detected across the plasma membrane of Bacillus megaterium, another site of de novo lipid biosynthesis. The rapid transmembrane movement of phosphatidylcholine has not been detected, however, in vesicles prepared from microsomal lipids. These latter data suggest involvement in the endoplasmic reticulum of a phospholipid-translocating protein, as was first proposed by Bretscher who called it 'flippase'. Here we report reconstitution of a phospholipid flippase from rat liver microsomes into lipid vesicles.     

Keggin型杂多酸H3PMo12O40对磷脂双层膜电化学行为的影响

利用循环伏安法和交流阻抗谱,以铂电极支撑的磷脂双层膜（s-BLM）作为生物膜的模型,Fe（CN）6^3-和Fe（CN）6^4-为探针分子,研究了Keggin型杂多酸H3 PMo12 O40对磷脂双层膜电化学行为的影响,结果显示s-BLM与杂多酸H3PMo12 O40之间可以发生比较强烈的相互作用,使8-BLM的通透性发生变化．这种现象的出现可能是由予在杂多酸H3PMo12O40与磷脂双层膜发生作用时引起s-BLM表面分子的排列变化,进而在膜的表面形成不可逆的微孔,而探针分子Fe（CN）6^3-/4-可以通过这些微孔接近电极,产生氧化还原响应。     

Active transport of Ca2+ by an artificial photosynthetic membrane

Transport of calcium ions across membranes and against a thermodynamic gradient is essential to many biological processes, including muscle contraction, the citric acid cycle, glycogen metabolism, release of neurotransmitters, vision, biological signal transduction and immune response. Synthetic systems that transport metal ions across lipid or liquid membranes are well known, and in some cases light has been used to facilitate transport. Typically, a carrier molecule located in a symmetric membrane binds the ion from aqueous solution on one side and releases it on the other. The thermodynamic driving force is provided by an ion concentration difference between the two aqueous solutions, coupling to such a gradient in an auxiliary species, or photomodulation of the carrier by an asymmetric photon flux. Here we report a different approach, in which active transport is driven not by concentration gradients, but by light-induced electron transfer in a photoactive molecule that is asymmetrically disposed across a lipid bilayer. The system comprises a synthetic, light-driven transmembrane Ca2+ pump based on a redox-sensitive, lipophilic Ca2+-binding shuttle molecule whose function is powered by an intramembrane artificial photosynthetic reaction centre. The resulting structure transports calcium ions across the bilayer of a liposome to develop both a calcium ion concentration gradient and a membrane potential, expanding Mitchell's concept of a redox loop mechanism for protons to include divalent cations. Although the quantum yield is relatively low (approximately 1 per cent), the Ca2+ electrochemical potential developed is significant.     

合成肽脂与天然磷脂混合囊泡的制备及表征

将天然磷脂1,2-二-十四烷基磷脂酰乙醇胺(DMPE)与合成肽脂N,N-二-十六烷基-Nα-6-三甲胺基己酰基-L-甘氨酰胺混合,制得了混合双层膜囊泡,对制备过程中的超声条件进行了探讨.用透射电子显微照相、动态光散射及差示扫描量热等手段表征了混合囊泡的形态及粒径大小,确认了混合囊泡的稳定性.     

镁合金表面MoS2/树脂杂化涂层的制备及其摩擦磨损和电化学性能研究

以水作为分散介质,制备了含丙烯酸树脂和MoS2颗粒的分散液,以阳极氧化为前处理,采用电化学共沉积法在镁合金表面制备了MoS2/树脂杂化涂层;采用MR 060型多功能摩擦磨损试验机考察涂层的摩擦磨损性能,并分析其磨损机制;采用PARSTAT2273型电化学工作站测试涂层的电化学阻抗谱及极化曲线;利用扫描电子显微镜和能谱仪分析涂层的表面形貌及结构.结果表明：所制备的涂层厚度高达50 μm,在质量分数为3.5%的NaCl溶液中表现出优异的耐腐蚀性能;MoS2的加入,能够有效降低涂层的摩擦系数,提高其耐磨性.     

Three-dimensional model of purple membrane obtained by electron microscopy.

A 7-A resolution map of the purple membrane has been obtained by electron microscopy of tilted, unstained specimens. The protein in the membrane contains seven, closely packed, alpha-helical segments which extend roughly perpendicular to the plane of the membrane for most of its width. Lipid bilayer regions fill the spaces between the protein molecules.     

Mode of action of yeast killer toxins: channel formation in lipid bilayer membranes

The toxic action of yeast killer proteins seems to involve selective functional damage to the plasma membrane of the sensitive cell. Physiological effects include leakage of K+ (refs 1, 2), inhibition of active transport of amino acids and acidification of the cell interior. These effects are strikingly similar to the effects of certain bacterial colicins which have been demonstrated previously to form channels in membranes. Proposed mechanisms of action have usually postulated a limited permeability change induced by the toxin in the plasma membrane. We report here that a killer toxin from the yeast Pichia kluyveri forms ion-permeable channels in phospholipid bilayer membranes, and we propose that the in vitro electrophysiological properties of these channels account for the morbid effects observed in intoxicated cells. A preliminary account of this work has appeared elsewhere.