新方法合成PBMA-b-PSt嵌段磺化离聚体及其结构表征

采用二步加料的方式利用原子转移自由基聚合方法（ATRP），合成结构可控的PBMA－b-PSt嵌段共聚物，再通过磺化，离子交换等手段，将嵌段共聚物转化为嵌段磺化离聚体，方法简单，操作方便，同时对嵌段离聚体的结构进行了表征。     

嵌段离聚体包覆DCOIT纳米胶囊的合成、表征及其释放特性的研究

以PEG/IPDI/DMPA为原料,通过溶液聚合法,获得了嵌段离聚体溶液(溶剂为N,N-二甲基甲酰胺),然后在水相界面上对疏水功能性有机分子DCOIT进行自组装包覆制备DCOIT纳米胶囊。实验最终通过FT-IR、表面张力测试表征了嵌段离聚体的结构及性能,粒径分布和冷冻切片TEM和紫外-可见分光光度计对DCOIT纳米胶囊的形貌和释放特性进行了研究。研究结果表明,实验制备出了预期结构的聚氨酯嵌段离聚体,并形成了DCOIT纳米胶囊;DCOIT纳米胶囊的释放特性表现为,当壁芯比在1∶1至2∶1之间变化时,纳米胶囊都在释放初期速率较快,然后经历一个减速期,随后速率再次增加;且随着壁芯比的减小,DCOIT纳米胶囊的减速期越来越短。最后,对DCOIT纳米胶囊的释放机理进行了初步探讨。     

嵌段共聚物偶联剂的合成及其胶束化行为

采用阴离子聚合反应合成了可作为纤维增强聚合物复合材料界面改性偶联剂的苯乙烯/丁二烯/乙烯基三乙氧基硅烷及苯乙烯/异戊二烯/乙烯基三乙氧基硅烷嵌段共聚物,通过傅立叶红外光谱(FT-IR)、核磁共振氢谱(1H-NM R)等分析手段对合成产物进行了表征,并采用透射电镜(TEM)、动态激光光散射(DLLS)等技术研究了嵌段共聚物在溶剂中的组装行为。结果表明,反应合成了预定结构的嵌段共聚物偶联剂,该共聚物在选择性溶剂中能形成以可溶性链段为壳、难溶性链段为核的胶束结构,胶束的粒径与共聚物分子链及各嵌段的长度有关。     

带有羧基基团荧光聚氨酯材料的合成与表征

由聚乙二醇(PEG)、对苯二异氰酸酯(PPDI)、2,2-双(羟基甲基)丙酸(DMPA)和藻红B(EB)为主要原料,采用一步合成法合成了一系列带有自由羧基的荧光聚氨酯多嵌段共聚物。通过核磁共振氢谱、傅里叶变换红外光谱、凝胶渗透色谱法等测试方法表征了聚合物的结构。荧光光谱证实EB被成功地接在聚氨酯多嵌段共聚物上;动态激光光散射法测得该嵌段聚合物胶束粒径为208nm左右;透射电子显微镜表明该胶束粒子呈现出球型形态。     

PtBA嵌段长度对PEO-b-PtBA-b-PS三嵌段共聚物溶液分级自组装行为的影响

通过原子转移自由基聚合法合成了三嵌段共聚物聚环氧乙烷-b-聚丙烯酸叔丁酯-b-聚苯乙烯[PEO45-bPtBAx-b-PSy(x=35、100;y≈140)]。通过体积排斥色谱法和核磁测试对嵌段共聚物化学结构和分子量及分子量分布进行了表征。结果表明:各共聚物结构明确,分子量分布较窄;采用两步分级自组装方法对所得样品进行了溶液自组装行为研究。通过透射电镜对嵌段共聚物自组装形成的胶束的形貌、尺寸进行了表征。结果表明:通过溶剂条件的改变,成功诱导球形胶束形成了二级组装体。改变PtBA段长度使得嵌段共聚物自组装聚集体由球形胶束转变为直径分布均匀,长度在500nm以内的占多数的胶束串。     

离聚体的聚集态结构特性及性质

介绍了离聚体的定义，发展过程，合成方法和目前的应用情况，研究了离聚体的聚集态结构，总结了目前离聚体的主要聚集态模型，研究了影响聚集态结构的主要因素，介绍了离聚体所特有的力学性质，介电谱和溶液性质，指出了目前尚待研究的问题。     

双亲性嵌段共聚物PS-b-PNVA的RAFT制备及其自组装行为研究

以偶氮二异丁氰(AIBN)为引发剂,二硫化二异丙基黄原酸酯(DIP)为RAFT试剂,引发活性较大的单体苯乙烯(S)和活性较小的单体N-乙烯基乙酰胺(NVA)聚合,成功合成了结构明确、分子量分布较窄(Mw/Mn=1.39)的PSb-PNVA嵌段共聚物并对嵌段共聚物的自组装行为进行了研究。利用凝胶渗透色谱、傅里叶变换红外光谱、核磁共振、纳米粒度仪和透射电镜对嵌段共聚物的分子量、结构及其在水溶液中的聚集行为进行了研究。详细考察了聚合反应温度、RAFT试剂用量、聚苯乙烯分子量等条件对嵌段共聚物的分子量及分布的影响以及嵌段共聚物结构、浓度和水含量等因素对嵌段共聚物形成的胶束的粒径的影响。     

聚砜—热致液晶嵌段共聚物的合成

针对聚砜—热致液晶聚合物 (PSF TLCP)共混体系相容性差的问题 ,在合成不同分子量羟基封端聚砜 (PSF -OH)低聚体的基础上 ,通过溶液缩聚反应 ,合成了以下 3类嵌段共聚物增容剂 :聚砜—对羟基苯甲酸 (PSF—PHB) ,聚砜—对苯二甲酸乙二醇酯 (PSF -PET)和聚砜—对苯二甲酸对苯二酚酯 (PSF—PHQT)。红外光谱和流变性分析表明 ,合成了具有预期结构的嵌段共聚物 ,并且所合成的嵌段共聚物包含了较长的聚酯链段。     

红外光谱法研究热历史对磺化聚苯乙烯离聚体结构的影响 Ⅰ.冷却速率对离聚体离子聚集态的影响

合成了一系列离子浓度不同的磺化聚苯乙烯钠盐和锌盐离聚体，用红外光谱考察了经不同冷却速率处理后的离聚体结构。所得结果表明，冷却速率越快，离子簇越难形成。冷却速率对钠盐和锌盐离聚体离子簇形成影响的差异可用它们偶极－偶极运动对温度的敏感性不同来解释。高离子浓度的离聚体在５８４ｃｍ－１出现的新吸收带被认为是与离子簇内受限聚苯乙烯链形成的某种构象规整性有关     

红外光谱法研究热历史对磺化聚苯乙烯离聚体结构的影响：？…

合成了一系列离子浓度不同的磺化聚苯乙烯钠盐和锌盐离聚体，用红外不谱考察了经不同冷却强度处理后的离聚体结构。所得结构表明，冷却速率越快，离子簇越难形成。冷却速率对钠盐和锌盐离聚体离子簇形成影响的差异不用它们偶极－偶极运动对温度的敏感性不同来解释。高离子浓度的离聚体在５８４ｃｍ＾－１出现的新吸收带被认为是与离子簇内受限聚苯乙烯链形成的某种构象规整性有关。     

凝固科学技术与材料

从凝固科学与实践发展的角度介绍了当前凝固材料体系的基本框架和凝固科学主要发展阶段的基本理论。作为材料科学与工程的基本组成，凝固科学技术正在现代科学理论的基础上针对传统材料的改性提高和新材料的发展需求，以控形、控构、控性为目标开展优质铸件的定向、晶体生长、快凝、深过冷及各种新型和超常领域凝固过程的研究，并介绍了其中某些方面和展望了可能的发展趋势。     

Creation and motion of dislocations and fracture in metal and silicon crystals

By making a step on one surface ( ) of a rectangular small paralellepiped copper crystal, dislocations could be created by the molecular dynamic method. The dislocation created was not a complete edge dislocation but a pair of Heidenreich-Shockley partial dislocations. Each time a dislocation was created, the stress on the surface was released. Small copper crystals having a notch were pulled (until fracture), compressed and buckled by use of the molecular dynamic method. An embedded atom potential was used to represent the interaction between atoms. Dislocations were created near the tip of the notch. A very sharp yield stress was observed. The results of high speed deformations of pure silicon small crystals using the molecular dynamics are presented. The results suggest that plastic deformation may be possible for the silicon with a high speed deformation even at room temperature. Another small size single crystal, the same size and the same surfaces, was compressed using molecular dynamic method. The surfaces are {110}, {112} and {111}. The compressed direction was [111]. It was found that silicon crystals are possible to be compressed with a high speed deformation. This may suggest that silicon may be plastically deformed with high speed deformation.     

The Candela and Photometric and Radiometric Measurements

The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements.     

PSD和PWELCH函数的分析改进及应用

针对MATLAB中两个内建功率谱密度计算函数psd()和pwelch()计算结果迥异的现象,在功率谱密度估计理论的基础上,根据经典的周期图理论和Welch平均周期图方法,通过详细分析源程序,解析计算方法,发现psd()计算的并不是工程单边功率谱密度,而是采样信号双边谱,故与pwelch()结果迥异,另外pwelch()不能对分段信号数据进行预处理。就上述不足提出了相应的改进措施,比较验证表明改进措施行之有效。     

Development and challenges of planning and scheduling for petroleum and petrochemical production

Production planning and scheduling are becoming the core of production management, which support the decision of a petrochemical company. The optimization of production planning and scheduling is attempted by every refinery because it gains additional profit and stabilizes the daily production. The optimization problem considered in industry and academic research is of different levels of realism and complexity, thus increasing the gap. Operation research with mathematical programming is a conventional approach used to address the planning and scheduling problem. Additionally, modeling the processes, objectives, and constraints and developing the optimization algorithms are significant for industry and research. This paper introduces the perspective of production planning and scheduling from the development viewpoint.     

Miniature and MEMS-type vacuum sensors and pumps

In the paper, the observable trends of the actual research and development of selected types of miniature and MEMS-type vacuum sensors are presented. Some information about the new types of active vacuum gauges, which are offered by the leading manufacturers of the vacuum measurement instruments, is given. Next, the list of MEMS devices that need vacuum for proper operation is presented. Some aspects of vacuum-encapsulation of MEMS devices, on wafer level and package level are shown. The new conceptions of obtaining and maintenance of high and ultra-high vacuum in MEMS devices are described. They concern the conception of integration of a miniature orbitron pump on-chip with MEMS-type device or with vacuum part of the portable advanced instruments such as electron microscope, ion mass spectrometer, and free electron laser.     

甲壳素与壳聚糖的改性及应用

甲壳素、壳聚糖及其衍生物是一种天然高分子,随着对其研究的深入发展,涉及的内容和应用范围越来越广泛.概述了甲壳素、壳聚糖的结构、性质及其化学改性和共混改性的方法,简单介绍了它们的应用领域.     

ATP-Responsive and ATP-Fueled Self-Assembling Systems and Materials

Adenosine triphosphate (ATP) is a central metabolite that plays an indispensable role in various cellular processes, from energy supply to cell-to-cell signaling. Nature has developed sophisticated strategies to use the energy stored in ATP for many metabolic and non-equilibrium processes, and to sense and bind ATP for biological signaling. The variations in the ATP concentrations from one organelle to another, from extracellular to intracellular environments, and from normal cells to cancer cells are one motivation for designing ATP-triggered and ATP-fueled systems and materials, because they show great potential for applications in biological systems by using ATP as a trigger or chemical fuel. Over the last decade, ATP has been emerging as an attractive co-assembling component for man-made stimuli-responsive as well as for fuel-driven active systems and materials. Herein, current advances and emerging concepts for ATP-triggered and ATP-fueled self-assemblies and materials are discussed, shedding light on applications and highlighting future developments. By bringing together concepts of different domains, that is from supramolecular chemistry to DNA nanoscience, from equilibrium to non-equilibrium self-assembly, and from fundamental sciences to applications, the aim is to cross-fertilize current approaches with the ultimate aim to bring synthetic ATP-dependent systems closer to living systems.