基于咔唑和噻吩的2种聚合物的电化学性能

利用斯蒂尔偶联反应合成了2种基于咔唑和噻吩的有机共轭单体,通过电化学方法聚合成导电聚合物,并对其进行了结构表征和电化学性能研究。核磁共振1H谱和13C谱验证了单体与理论结构一致,红外测试验证了电化学聚合位点为噻吩的α位。在-0.1 V到1.2 V电压范围内,2种聚合物膜都表现出良好的电致变色特性。循环伏安法和热重表明,相比于聚合物P1,共平面性更好的聚合物P2的电化学和热稳定性更优。以上结论表明聚合物P2在电化学领域是一种更有前景的材料,单体结构差异对聚合物性能有很大影响。     

两种苯并硒二唑类电致变色聚合物的制备和性能研究

利用斯蒂尔偶联反应合成了两种有机共轭单体,通过电化学方法聚合成导电聚合物,并对其进行了结构表征和电化学性能研究。核磁共振1 H谱和13 C谱验证了单体与理论结构一致,红外测试验证了电化学聚合位点为噻吩的α位。在0~1.2V电压范围内,两种聚合物膜都表现出电致变色特性。相比于聚合物P1,结合力更强的聚合物P2的电化学和热稳定性更优。结论表明,苯并硒二唑类聚合物在电致变色领域是一种有前景的材料,单体结构差异对聚合物性能有很大影响。     

基于噻吩-蒽单元的无规共聚物电化学制备及其电致变色性能研究EI北大核心CSCD

蒽单元嵌入聚噻吩主链能显著调控聚合物的变色性能,但其聚合电位偏高易导致聚合物的成膜质量和性能较差。为降低含蒽单元的单体电聚合电位,通过Stille偶联反应合成了9,10-二(2-噻吩基)蒽单体(Th-An-Th),并分别在BFEE,BFEE+CF_(3)COOH,LiClO_(4)/ACN和LiClO_(4)/PC等聚合媒介中进行电化学聚合。结果表明:Th-An-Th难以通过电化学反应共聚,但可以作为共单体与噻吩(Th),3-甲基噻吩(MeTh),3,4-亚乙基二氧噻吩(EDOT)和硒酸(SePh)在低电位下进行无规共聚,得到系列无规共聚薄膜P1,P2,P3,P4。循环伏安和FTIR测试证实了聚合过程和共聚物的特征结构,光谱电化学测试结果表明,系列共聚物均具有丰富的颜色变换性能,在-0.6 V到1.0 V扫描下,P1,P3,P4膜可实现4种颜色的变化,且表现出良好的近红外变色能力。共聚物薄膜具有较快的开关响应速度和良好的电化学稳定性,P4膜在521 nm处漂白和着色响应时间分别为1.9 s和3.4 s,光学对比度为35.6%,在210次循环变色后,共聚物光学对比度仅损失2.3%,电化学循环400次仍保持82%的电化学活性。     

新型噻吩单体的合成与电化学聚合

以3,4-二溴噻吩(DBrT)为原料,通过亲核取代和醚交换反应制备了带有羟基的双烷氧基取代噻吩,再采用开环-取代反应引入磺酸官能团,得到新型取代噻吩单体EDOT-S。采用红外光谱、紫外光谱和核磁共振氢谱、碳谱对此单体进行了表征。采用循环伏安法进行电化学聚合制得PEDOT-S,该聚合物的氧化电位和还原电位分别为442mV和371mV(vs.SCE)。PEDOT-S膜具有可逆的电致变色性能,在氧化态呈蓝绿色,还原态呈紫红色。     

聚2,3-二(4'-辛氧基苯基)-5,8-二硒吩基喹喔啉的合成及电致变色性能

通过Stille偶联反应合成了一种D-A-D型单体2,3-二(4'-辛氧基苯基)-5,8-二硒吩基喹喔啉(M7),通过紫外-可见光谱、傅里叶变换红外光谱、核磁共振氢谱等测试手段进行了结构表征。通过电化学聚合制备了聚(5,8-二溴-2,3-双(4'-辛氧基苯基)喹喔啉)。从聚合物薄膜的紫外-可见光谱与循环伏安图计算的光学能隙和电化学能隙分别为1.48 e V和1.45 e V。从光谱电化学结果可以看出,电压从0~1.0 V阶梯变化时,聚合物显示电致变色并且聚合物薄膜颜色由深蓝色(中性态)变成透明的浅黄色(氧化态)。聚合物薄膜在603 nm处的紫外-可见吸收峰随着电压的增加而降低,而在863 nm出现的新吸收峰强度增强。聚合物薄膜在863 nm处的光学对比度和响应时间分别为59%和1.74 s。     

3,4-乙撑二氧噻吩水相的电化学聚合

以水为溶剂,在不添加乳化剂的条件下,分别以高氯酸锂、聚苯乙烯磺酸钠(PSS)、硫酸钠、氟硼酸钠、对甲苯磺酸为电解质进行电化学聚合,得到了不同氧化态的聚3,4-乙撑二氧噻吩薄膜(PEDOT)。探讨了这5种电解质对单体初始氧化电位和薄膜电化学稳定性的影响。结果表明,采用PSS为电解质时初始氧化电位最低为878mV,得到的聚合物薄膜电化学稳定性最好。并采用扫描电镜表征了以PSS为电解质电化学聚合所得薄膜的表面形貌,采用光谱电化学法表征了薄膜的电致变色性能,结果表明聚合物薄膜均质连续,具有优异的电致变色性能。     

吩噻嗪衍生物电致变色材料的合成及其性能研究

合成了系列10-N取代的吩噻嗪衍生物(phenothiazine derivatives,PDs),利用氢谱、碳谱、红外光谱等方法对其结构进行表征,并使用电化学工作站和紫外光谱对其电化学性质作了初步研究。组装了以PDs作为阳极电致变色材料,紫罗精作为阴极电致变色材料的新型阴极-阳极复合电致变色器件。当施加2.4V电压时器件阴极材料显示蓝色,而施加反向电压时阳极材料显示为红色,颜色可逆转换且其响应时间250ms,循环次数超过104,可实现寻址。PDs作为阳极材料具有优良的电致变色性能并且廉价环保,是一种令人瞩目的新型电致变色阳极材料。     

聚(联吡啶亚甲基苯乙烯-甲基丙烯酸齐聚氧化乙烯酯)薄膜修饰电极

合成了一种兼具电致变色性能及离子电导性的新型梳型联吡啶聚合物PVSEO_(21)。测试了其修饰热解石墨电极在液体电解质中的循环伏安特性及其电致变色性能。该聚合物具有可逆性好、响应速度快等特点。其高速响应与聚合物本身的离子电导性有关。薄膜厚度为1.85μm时,该聚合物修饰电极在0～—0.8V和—0.8～—1.3V(vs.SCE)之间发生一电子和二电子氧化-还原反应,相应的电致变色响应时间分别为3ms和7ms。     

用脉冲电沉积法制备两类纳米介孔氧化镍电致变色薄膜的研究

采用脉冲电沉积技术在ITO导电玻璃上制备了NiO电致变色薄膜,并用X射线衍射仪、扫描电镜和能谱仪分析薄膜的结构、形貌和成份,用紫外-可见光分光光度计测试薄膜的光学性能,用循环伏安法测试薄膜的电化学性能,对比研究了Co掺杂对NiO薄膜电致变色性能的影响。结果表明Co掺杂优化了NiO薄膜表面形貌,形成了均匀分布的纳米介孔微结构,从而提高了薄膜电化学活性,同时提高了薄膜的光调制幅度。     

聚邻甲基苯胺的电化学合成与电色及光伏性能

为了得到平整并与基底结合牢固的聚邻甲苯胺,使之在电致变色和光伏材料上得到应用,用电化学的方法在ITO电极上制备了聚邻甲苯胺.考察了聚合条件对成膜的影响,对聚合物薄膜进行了红外、拉曼、紫外、荧光等结构表征,利用电子扫描显微镜(SEM)观测了复合膜形貌特征,采用原位电化学-光谱技术研究了聚合物的电致变色行为.首次以聚邻甲苯胺/TiO2复合膜为工作电极,铂电极为对电极,制成太阳能电池模型,测试了器件的光伏性能.研究表明:在聚合条件为单体浓度0.2 mol/L,硫酸浓度在0.5～1 mol/L、扫描速度0.02 V/s、扫描电压0～1.0 V时得到膜牢固平整;薄膜呈现岛状突起结构;电压从0增加至0.8 V,薄膜颜色从绿到蓝变化,且过程可逆;复合电极显示出明显的光伏特性.因此,说明聚邻甲苯胺是一种双功能性材料.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.