非线性光学含氟PI/SiO2杂化波导纳米材料的研究

以含氟的二胺5,5'-(六氟异丙基)-二-(2-氨基苯酚)及二酐4,4'-(六氟异丙基)-苯二酸酐为单体.首先合成了经酰胺化的主链上带有活性羟基的含氟聚酰亚胺,再通过Mitsunobu反应将活性生色分子分散红1共价链接到聚酰亚胺的侧链骨架上,合成了二阶非线性光学(NLO)含氟聚酰亚胺.采用溶胶-凝胶技术,利用偶联剂APTES制备带有发色团的及含有硅氧烷端分子的聚酰胺酸,其中的Si(OR)3基经水解、缩合后,与正硅酸乙酯在催化剂作用下反应,经杂化、凝胶后,得到热稳定性高的杂化材料.将制得的含氟聚酰亚胺/SiO2杂化材料,利用FT-IR、SEM、TEM、XRD、DSC等手段对其进行了表征.杂化材料的玻璃化转变温度(Tg)为382℃,比纯聚酰亚胺的Tg(306℃)高76℃,表现出优良的高温热稳定性.     

聚酰亚胺基偶氮聚合物的合成及热光性能的研究

4,4'-二胺基二苯醚(4,4'-ODA),4,4'-(六氟异丙基)-苯二酸酐(6FDA)和分散红1(DR1)合成了可制作光波导器件的聚酰亚胺基偶氮聚合物;采用示差扫描量(DSC)、热失重分析(TGA)等方法对该聚合物的热稳定性进行了表征.示差扫描量热和热失重分析结果显示,该聚合物的玻璃化转变温度(Tg)为223℃,5%的热失重温度为282℃,表明具有非常好的热稳定性.测定了材料在复合光和577nm单波长光照射下该的折射率(n)和热光系数(dn/dT);通过热光系数的测量,计算了聚合物的介电常数(ε)、介电热光系数(dε/dT)、体积热膨胀系数β和(dβ/dT)值.制得的聚合物材料在复合光下的热光系数(dn/dT)值为(-2.1464～-3.8857)×10-4/℃,体积热膨胀系数变化率(dβ/dT)为(2.13～7.44)×10-7/℃;在577nm单波长光照射下的热光系数(dn/dT)值为-3.8445×10-4/℃,体积热膨胀系数变化率(dβ/dT)为7.81×10-7/℃,表明该聚合物在低驱动功率的新型数字热光开关、光通信器件等领域具有潜在的应用前景.     

含氟和氧膦的二胺及其聚酰亚胺的合成

从3,5-二(三氟甲基)溴苯出发,经格氏、硝化、还原反应合成了含氟和氧膦的新型二胺单体.然后用常规的二步法,和4,4'-二氨基苯氧醚(ODA)与2,2'-六氟异叉丙基二苯四酸二酐(6FDA)进行共缩聚并经化学酰亚胺化法制备了共缩聚型聚酰亚胺.     

可溶性聚酰亚胺规整多孔膜的形成与控制

选用4种聚合单体:4,4'-六氟亚异丙基一邻苯二甲酸酐(6FDA)、双酚A二酐(BPA-DA)、4,4'-二氨基二苯甲烷(MDA)、3,3'-二甲基-4,4'-二氨基二苯甲烷(DMMDA),采用低温溶液缩聚-化学亚胺化合成了3种可溶性的聚酰亚胺:6FDA-MDA,6FDA-DMMDA,BPADA-DMMDA,利用FI-IR、NMR等对其结构进行了分析表征,测试了它们的溶解性能与热性能.将这3种聚酰亚胺溶于氯仿溶液中,在高湿度环境下浇铸形成规整多孔膜结构;研究了其规整孔结构的拉伸与吹扫特定形变,最后还研究了所得的规整多孔膜的高温热稳定性,发现在350℃仍能保持规整结构的稳定.     

聚酰胺酸亚胺化动力学研究

采用热失重(TG)非等温法研究了4,4'-二氨基二苯醚(ODA)与4,4'-六氟亚异丙基-邻苯二甲酸酐(6FDA)合成的聚酰胺酸(PPA)在整个亚胺化温度范围内的动力学.依据不同升温速率等温法结合23种机理函数推到出亚胺化反应的机理函数:g(a)=(1-a)-1-1利用迭代的等转化率法得到了活化能Ea的平均值为94.64kJ/mol,由此得到指前因子A的范围为9.05×107～2.62×1013s-1.     

RTM成型聚酰亚胺树脂的合成与性能研究

使用4-苯乙炔苯酐(4-PEPA),3,3',4,4'-二苯醚四酸二酐(ODPA),3,4-二氨基二苯醚(3,4-ODA),1,3-双(4-氨基苯氧基)苯(1,3,4-APB)和1,4-双(4'-氨基-2'-三氟甲基苯氧基)苯(6FAPB)分别合成了六种设计分子量为1250的聚酰亚胺低聚物RTM1-6,并对低聚物的熔体黏度及熔体黏度稳定性和热性能等进行了系统研究.实验结果表明,用含有醚键及氟原子的混合二胺合成的系列树脂,其熔体黏度较低,熔体稳定性较好,可用于RTM成型工艺.但树脂的玻璃化转变温度相对较低.     

有机生色团掺杂有机／无机复合基质非线性光学材料的制备与性能

以4-[乙基-（2-羟乙基）胺]-4’-硝基偶氮苯（DRl）为生色团，甲基丙烯酸甲酯（MMA）和正硅酸乙酯frEOS）为先体，通过原位溶胶-凝胶技术制备了新型的以PMMA／SiO2复合材料为掺杂基质的二阶非线性光学杂化材料，并运用提拉法在洁净的ITO导电玻璃上制备出均匀、透明的厚度为1μm左右的杂化薄膜。DSC测得杂化材料的玻璃化转变温度为130℃；二次谐波产生（SHG）测量结果表明杂化薄膜在电晕极化后二阶非线性系数d33为1．02×10^7esu；用UV-vis光谱对杂化膜在极化前后的取向和取向稳定性进行的研究表明此材料具有较高的取向度，且常温下的取向稳定性也较好，60d后取向序参数φ仍有初始值的85％。     

热重法研究含氟聚酰胺酸的亚胺化反应动力学

采用动态热重法(TG)对4,4’-二氨基二苯氧基丙烷(BAPP)和4,4’-六氟亚异丙基-邻苯二甲酸酐(6FDA)缩聚生成的含氟聚酰胺酸动力学进行研究。采用积分法结合31种动力学函数来判断亚胺化反应的函数g(α),由Ozawa、KAS和迭代法求取活化能Ea值。从而得到了亚胺化反应的动力学参数,即反应的动力学函数为g(α)=(1-α)-1-1,平均活化能Ea=81.93 kJ/mol,指前因子A的平均值为1.91×109s-1。     

基于ATR技术的有机聚合物二次电光系数的测量

二次电光效应是有机聚合物材料一种重要的电光特性,利用这种特性可以制备有机聚合物电光调制器等电光器件.有机聚合物材料的二次电光系数是衡量其二次电光效应的一个重要参数,其可以用一个6×6阶的张量来表示.利用该张量的对称特性、各个元素之间的已知关系以及折射率椭球公式,本文提出了一种基于衰减全反射(ATR)技术的测量有机聚合物二次电光系数的方法.在测量中,通过选用TM偏振光以及TE偏振光作为测量光束,可以分别获得二次电光系数张量中S11以及S12元素.利用已知关系,可以计算得到S44以及直流克尔系数.从而得到二电光系数张量中所有元素的值.     

含螺环结构的二胺及其聚酰亚胺的合成与性能

首先,以双酚A和甲磺酸反应合成出3,3,3',3'-四甲基-6,6'-二羟基-1,1'-螺旋双茚满,然后与2-氯-5-硝基三氟甲苯反应得到3,3,3',3'-四甲基-6,6'-双[4-硝基-2-三氟甲基苯氧基]-1,1'-螺旋双茚满,最后在Pd/C-水合肼还原作用下得到3,3,3',3'-四甲基-6,6'-双[4-氨基-2-三氟甲基苯氧基]-1,1'-螺旋双茚满。采用上述二胺单体分别与1,2,3,4-环丁烷四酸二酐、均苯四甲酸二酐、联苯二酐、3,3',4,4'-二苯醚四酸二酐、3,3',4,4'-二苯酮四酸二酐和六氟二酐通过两步法制备出6种含螺环结构的聚酰亚胺(PI)。采用核磁、红外光谱、X射线衍射、紫外-可见光谱、热重分析、差示扫描量热分析和溶解性测试等手段表征了所得化合物和PI的结构与性能。研究结果表明,这些含螺环的PI主要表现为非晶结构和较大的分子链间距离,且具有良好的溶解性、光学性能和热性能。     

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 ...     

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     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.