染料前体对光热敏微胶囊光聚合的影响

利用界面聚合技术获得了新型光信息记录材料光热敏微胶囊。借助荧光光谱及红外光谱技术研究了染料前体ODB-2对光引发剂激发态及光热敏微胶囊内部光聚合特性的影响。实验结果表明染料前体在紫外的光吸收竞争造成光引发剂荧光激发谱与发射光谱强度的降低,引起光引发剂激发态分子数的减少,进而影响到光引发剂初级自由基的量子产率以及光聚合的反应过程;在光热敏微胶囊内部发现单体光聚合速度与最终聚合程度随染料前体浓度的增加均减小,且不同种类染料前体对微胶囊内部光聚合的影响程度也不相同。     

可见激光立体光造型树脂协同引发体系引发机理的研究

用紫外／可见光谱及荧光／磷光光谱研究了在514nm波长下能引发丙烯酸－环氧树脂聚合的由染料，紫外光引发剂，叔胺组成的协同引发体系的引发机理，染料吸收可见光被激发，其激发三线态与叔胺形成激基复合物，并由此生成叔胺自由基，叔胺自由基与紫外引发剂发生电子转移作用生成活性更大的自由基引发聚合。     

双咪唑光敏引发体系在可见光胶印PS版中的应用

本文选取三种不同的光敏剂，与光引发剂六芳基双咪唑相复合，构成了四种可见光光敏引发体系，我们将三种可见光光敏引发体系应用于可见光胶印ＰＳ版的研究中，通过曝光实验，得到了制备可见光胶印ＰＣ版的初步条件，为以后的激光直接制版材料的研究打下基础。     

两种新型咔唑类双光子光聚合引发剂的合成与光学性质

报道了两种新型的咔唑类双光子光聚合引发剂,3,6-双[2-（4-吡啶基）乙烯基]-9-苯基咔唑（1） 和 3,6-双[2-（2-吡啶基）乙烯基]-9-苯基咔唑（2）,它们是通过钯催化的Heck偶连反应合成得到,并用元素分析,红外光谱,核磁共振氢谱和电喷雾电离质谱等对它们进行了全面的表征.这两个A-π-D-π-A结构的咔唑衍生物具有很好的单光子和双光子荧光行为,我们也详细研究了它们的溶剂效应和作为双光子引发剂用于微结构的制备,并讨论了它们的引发聚合的机理.     

新型双光子聚合引发剂的合成和非线性光学性质的研究

合成了两种新的双光子聚合引发剂反式-二苯基-{{4-[2-(4-吡咯基-1-苯基)-乙烯基]-苯基}胺(简称DPVPA)和反式-9-{4-[2-(4-吡咯基-1-苯基)-乙烯基]-苯基]-9-氢咔唑(简称PPVPA).用1H NMR谱和元素分析进行了表征.测试了紫外吸收光谱、单光子荧光光谱、单光子荧光寿命和双光子荧光光谱.在760 nm的飞秒脉冲激光激发下,DPVPA和PPVPA均发出较强的上转换荧光,荧光峰分别位于468和452 nm.以DPVPA做引发剂,加入丙烯酸酯型齐聚物(CN120C80),用DATACHROOM-5000纳秒激光器辐射出600nm的激光做光源,实现了双光子聚合反应,并定性地解释了其聚合机理.     

光聚合法制备水稳定性荧光纳米颗粒及其表征

以3,6-二氧杂-1,8-辛烷二硫醇(EGDT)和己二酸二丙烯酯(DAA)为单体,苝四羧酸丙烯酯为荧光染料,采用"巯基-双键"光聚合法制备了粒径均一、水稳定性的苝荧光纳米颗粒。通过扫描电子显微镜、红外光谱仪、荧光光谱仪和紫外-可见分光光度计等手段对其进行表征。结果表明:所制备的荧光纳米颗粒具有良好的单分散性且荧光性能好。     

丙烯基醚-丙烯酸酯杂化单体的合成及光聚合动力学研究

自由基光聚合和阳离子光聚合技术中各自存在着固有不足之处，诸如挥发性强，氧气阻聚作用大，收缩率高或者固化速度慢，水分影响严重等。 杂化光聚合体系是一种可以改善这些不足的方法，它可以分为混合杂化体系和杂化单体体系两种。其中杂化单体是指包含两种不同反应机理的活性基团，并通过化学键连结的单体，这种结构将改变两种官能团的光聚合动力学性质，并且使通过两种光聚合机理形成的聚合物成为均匀一致的、通过化学键相连的互穿网络结构，从而提高其机械物理性能。 本文合成了一种新型的丙烯基醚-丙烯酸酯杂化单体-丙烯氧基丙氧基丙烯酸酯（PPA），并应用实时变换傅立叶红外光谱法（RT—FTIK）对其进行了光聚合动力学研究。结果表明，在以硫锚盐为光引发剂时，这种杂化单体可以有效进行杂化光聚合反应，丙烯基醚和丙烯酸酯双键都显示出了较快的反应速度和较高的最终转化率。与混合杂化体系相比，每种基团的反应动力学性质都得到了促进，同时这种杂化单体结构还降低了羟基对于烯基醚基团光聚合的影响。这将为开发新型的光聚合活性单体开创新的途径和方法。     

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。     

樟脑醌(CQ)/脂肪胺引发牙科复合树脂的光聚合动力学研究

采用实时红外技术研究了樟脑醌（CQ）／脂肪胺可见光引发牙科复合树脂聚合的动力学过程。考察了不同胺链长、胺浓度以及光强对牙科修复复合树脂光聚合动力学的影响。结果表明：随着链长的增加，反应速率和转化率都有一定程度的降低，增加引发体系的浓度和增加光强都可以增加反应速率和转化率。     

咔唑和二氰基蒽掺杂纳米粒子的制备及光学性质

以蓝光染料咔唑为电子给体,黄光染料9,10-二氰基蒽为电子受体,采用再沉淀法制备了咔唑和二氰基蒽等摩尔掺杂的纳米粒子。掺杂纳米粒子与纯咔唑聚集体或二氰基蒽聚集体的形貌和发射光颜色明显不同,说明咔唑和二氰基蒽很好的掺杂到一起。吸收光谱表明咔唑和二氰基蒽在掺杂纳米粒子中没有形成电荷转移复合物,荧光发射光谱和荧光寿命表明咔唑和二氰基蒽在掺杂纳米粒子中形成激基复合物,激基复合物的出现使得掺杂纳米粒子的发射光颜色为橙色。     

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.……     

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.……     

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 ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from