含席夫碱生色团聚合物的合成及其光学性能

合成含席夫碱生色团的单体,并使之与丙烯酸酯类单体共聚制备了带有席夫碱生色团侧基的丙烯酸酯类聚合物.并利用傅立叶红外光谱、核磁共振氢谱及紫外可见光谱等测试手段,对所合成的席夫碱生色团单体及聚合物的结构进行了表征.此外,还探讨了含席夫碱生色团聚丙烯酸酯的全光开关特性及双折射性能.     

含偶氮结构超支化聚合物的合成、表征及其光致变色性能研究

以硝基还原法合成得到的偶氮苯甲酰氯为A_2单体,三羟甲基丙烷和二乙醇胺分别作为B_3和BC_2单体,利用一步法,通过控制反应条件,合成了2种含偶氮苯生色团的超支化聚合物(Pol-1和Pol-2)。采用傅里叶变换红外(FT-IR)和紫外-可见分光光度计(UV-Vis)对两种聚合物进行了结构表征。深入研究了这2种超支化偶氮聚合物在紫外光诱导下的光致变色行为。结果表明,在365nm紫外光照射下,两种聚合物均能发生光致变色现象,对于实现此类材料在分子开关及光存储中的应用提供了相关的依据。     

点击化学法制备主链型偶氮苯聚合物及其表征

合成了含偶氮苯基团的双烯单体二丙烯酸己氧基偶氮苯基二酯(DAHAE)和二巯基单体二巯基丙酸丁二酯(DMPBE),经点击反应成功制备出主链型偶氮苯聚合物。利用核磁共振氢谱、凝胶渗透色谱等测试方法对聚合物进行了结构表征。热重分析法、差示扫描量热法测试表明聚合物具有优异的热稳定性和一定的结晶性能。通过偏光显微镜观察发现聚合物结晶形态为球晶。使用紫外-可见分光光度计研究聚合物的光致顺反异构化行为表明聚合物的光致反-顺异构化速率常数(ke)为0.10s-1,主链型偶氮苯聚合物具有快速光响应性能。     

含苯乙烯基噻吩生色团聚合物的制备及与纳米金的相互作用

合成了含苯乙烯基噻吩生色团,通过酰氯化反应制备出含苯乙烯基噻吩生色团单体,将单体与丙烯酸酯类单体进行自由基共聚反应制备出侧链上含生色团的高分子.利用1H-NMR、FTIR等对分子结构进行了表征.应用荧光发射光谱研究了纳米金对含生色团高分子的荧光猝灭作用.通过温度对猝灭常数Ksv的影响说明了猝灭是动态猝灭,同时考察了溶剂极性对猝灭常数Ksv的影响,发现了猝灭的原因是纳米金与聚合物发生了电子转移,并阐述了猝灭机理.     

主链型偶氮聚酰胺的合成及光致变色性能

以4,4′-二氨基偶氮苯、丁二酸为原料,首先将丁二酸转化为丁二酰氯,利用酰氯基团和氨基的反应活性,通过低温溶液缩聚法合成主链型偶氮聚酰胺。采用红外光谱、热分析等表征了聚合物结构,通过紫外-可见光谱研究了合成偶氮聚合物的光致变色性能。研究结果表明,合成的偶氮聚合物和单体在365nm紫外光照下均能实现较好的反-顺异构化转化,同时偶氮聚合物的π-π*跃迁最大吸收波长相对于单体发生了紫移,并随聚合物链中偶氮苯结构单元的减少,紫移波长增大。异构反应为一级动力学反应,且聚合物的反顺异构化反应速率比单体的大,并随着有机溶剂极性的增加而减小。     

聚乙烯咔唑侧基含偶氮对硝基苯非线性光生色基团的合成及表征

研究了一种可作为聚合物类光折变材料中半功能型的基体材料——聚乙烯侧基含偶氮对硝基苯。以聚乙烯咔唑和偶氮盐为原料,以十二烷基苯磺酸钠为相转移催化剂,通过后重氮偶合方法,制备出聚乙烯咔唑侧基含生色团偶氮对硝基苯。用IR、UV-v is、1H-NM R、GPC对聚合物偶合前后进行了分析和表征。IR、UV-v is、1H-NM R测试表明了偶氮苯已经接到咔唑环上。UV-v is结果表明偶合反应时间对聚合物的偶氮含量有很大的影响。GPC结果表明,聚合物与重氮盐偶合后,分子量增大。     

三类偶氮聚合物的合成及表征

合成了具有大π共轭体系的偶氮染料单体4-(二羟乙胺基)-4‘-硝基偶氮苯(DR-19),选择不同单体与之反应,通过酯化、氨基甲酸酯化反应合成了偶氮聚酯、偶氮聚氨酯Ⅰ和偶氮聚氨酯Ⅱ三种偶氮聚合物.UV-vis、RF光谱研究发现,聚合物具有很好的光性能,且与之反应的单体对紫外、荧光性能有较大影响;DSC、TGA热性能研究发现,与之反应的单体决定了聚合物的热性能.     

偶氮苯功能化聚酯的合成与二阶非线性光学特性

合成了３种含偶氮苯侧基的聚酯并研究了其二阶非线性光学（ＮＬＯ）的特性。这类聚酯具有较好的成膜性能，聚合物的极性、链结构、生色团含量以及生色团不同聚集状态膜的吸民光谱和极化膜的二次谐波产生，其中以４－（Ｎ，Ｎ－二羟 在）－胺基－４－硝基偶氮苯与丁二酸酐合成的聚酯具有较强的ＮＬＯ效应，且在玻璃化温度以上极化膜的极化膜的二次谐波衰减较慢，以４－（Ｎ，Ｎ－二羟乙基）胺基－４－硝基偶氮苯与己二酰氯合成的聚酯     

含可加成反应偶氮苯聚合物的制备及表征

经过Diels-Alder反应等步骤制备了新型马来酰亚胺单体——甲基丙烯酸-4-(呋喃-马来酰亚胺乙基)酯(MMA-FMI),经过重氮、偶合等步骤制备了新型含呋喃环的偶氮苯单体——甲基丙烯酸-4-(4-呋喃-2-甲基-2-乙酸酯基偶氮)苯酯(MMA-FAzo),MMA-FMI、MMA-FAzo再与甲基丙烯酸-4-(4-甲氧基偶氮)苯酯(MMA-Azo-OCH_3)无规共聚得到含可加成反应偶氮苯聚合物(PAzo)。采用核磁共振氢谱、傅里叶变换红外光谱、凝胶渗透色谱对聚合物结构进行表征;使用紫外-可见分光光度计研究聚合物的顺反异构化行为,发现聚合物的光致顺反异构化速率常数为0.217 s~(-1),聚合物PAzo具有快速光响应性能;通过热失重分析仪研究聚合物的可加成特性;通过热可逆实验证明,交联的聚合物仍具有可回收与再加工性。     

偶氮苯功能聚合物的合成及光响应性

采用4-羟基偶氮苯和2-溴异丁酰溴反应制备了引发剂溴代异丁酸偶氮苯酯(AZO-Br),利用原子转移自由基聚合(ATRP)反应,以AZO-Br为引发剂,甲基丙烯酸二甲氨基乙酯(DMAEMA)为单体,通过改变AZO-Br和DMAEMA的配比,设计制备了一系列偶氮苯封端的聚甲基丙烯酸二甲氨基乙酯(AZO-PDMAEMA)。利用红外光谱、核磁和凝胶渗透色谱等对所得的AZO-Br引发剂及AZO-PDMAEMA聚合物的结构和相对分子质量及其分布等进行表征。利用紫外-可见光分光光度计对AZO-PDMAEMA聚合物的光响应性进行了测试。结果表明,聚合物在325 nm处的特征吸收峰的强度随着紫外光照时间的延长而下降,照射37 min后达到平衡;聚合物中偶氮苯基团的相对含量越少越有利于光异构化反应的发生;在紫外光和可见光的交替照射下,AZO-PDMAEMA聚合物表现出了可循环的光响应性。     

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.     

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.……     

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...     

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.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

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.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...