共缩聚型可溶性聚酰亚胺的合成与性能研究(3)

以４,４′－二（４－氨基苯氧基）二苯砜及４,４′－二氨基二苯醚或４,４′－二氨基二苯甲烷为共缩聚二胺单体与二苯醚３,３′,４,４′－四甲酸二酐缩聚并经化学亚胺化合成了共缩聚型聚酰亚胺。当共缩聚二胺单体中４,４′－二（４－氨基苯氧基）二苯砜／４,４′－二氨基二苯甲烷和４,４′－二（４－氨基苯氧基）二苯砜／４,４′－二氨基二苯醚的摩尔比分别为１０∶０～５∶５及１０∶０～３∶７时,所得聚酰亚胺可溶于强极性溶剂。可溶性聚酰亚胺的玻璃化转变温度（Ｔｇ）在２５５～２６５℃,并随结构中４,４′－二（４－氨基苯氧基）二苯砜的摩尔比上升而略有下降。聚酰亚胺在Ｎ２中的热降解起始温度在５５５～５９０℃,并且与二胺单体的结构及比例基本无关。     

以脂肪二胺为单体的聚酰亚胺的合成与性能研究

以α,ω－二氨基ｎ烷及二苯醚３,３′,４,４′－四甲酸二酐为单体,在ＮＭＰ中及室温下进行缩聚,然后在１６０℃进行溶液热亚胺化６ｈ得到聚酰亚胺,所得到的聚酰亚胺不能溶于有机溶剂,聚酰亚胺的玻璃化转变温度随结构中－（ＣＨ２）ｎ－基团长度的增加而线下降,这一系列聚酰亚胺具有较高的热稳定性,热降解起始温度在５００℃左右。     

4，4＇－二苯醚二甲酸改性PET的合成与表征

４，４＇－二苯醚二甲酸（ＯＢＢＡ）是一种重要的液晶聚合物单体。以此作为改性组分，合成了一系列ＰＥＴ共聚酯，并用１Ｈ－ＮＭＲ、ＦＴ－ＩＲ、ＧＰＣ、二甘醇和端羧基测定等方法进行了表征，同时对改性单体的转化率和合成共聚酯的反应速率进行了测定，结果表明，所选择的合成方法可以获得较高的转化率；反应速率则随ＯＢＢＡ的增加而增大。     

二胺改性BPDA—ODA型聚酰亚胺的H2／N2分离性能

本文合成了一系列二胺改性的ＢＰＤＡ－ＯＤＡ型共聚酰亚胺膜，改性聚酰亚胺与未改性的ＢＰＤＡ－ＯＤＡ相比，透气性得到了明显的改善，改善的程度与第二种二胺单体的结构和用量有关。３０℃时，在ＢＰＤＡ－ＯＤＡ中加入２０ｍｏｌ％三甲基间苯二胺（３ＭＰＤＡ）或四甲基对苯二胺（４ＭＰＤＡ）时，共聚酰亚胺ＢＰＤＡ－ＯＤＡ／３ＭＰＤＡ（８０／２０）或ＢＰＤＡ－ＯＤＡ／４ＭＰＤＡ（８０／２０）的透Ｈ２系数和Ｈ２／Ｎ２分     

含介晶基因的半刚性共聚酯的合成及其性能研究

通过介晶单体４,４’联苯分别与对苯二甲酰氯及４,４’（对苯二甲酰氧基）二苯甲酰氯进行高温溶液缩聚反应合成了两种含介晶基团的半刚性共聚酯ＢＨＨＢＰ／ＴＰＣ与ＢＨＨＢＰ／ＴＯＢＣ。利用ＤＳＣ、ＴＧ－ＤＴＡ、偏光显微镜和Ｘ射线衍射等手段对介晶体ＢＨＨＢＰ与共酯的相变行为以及共聚酯的热分解动力学及结晶性能进行了研究。结果表明,两共聚酯均为结晶性聚合物,其中ＢＨＨＢＰ／ＴＯＢＣ具有向列相液晶相存在;共聚酯Ｂ     

二甲基杂萘联苯聚醚砜的合成与表征

以新型类双酚单体４－（２,６－二甲基－４－羟基苯基）－２,３－二氮杂萘－１－酮,与４,４′－二氯二苯砜反应,合成了一种新型聚芳醚砜,对其聚合条件作了初步探讨;并利用核磁共振、红外光谱分析研究了双酚单体及聚合物的结构,利用ＤＳＣ、ＴＧＡ对聚合物的耐热性进行了分析。实验结果表明,该类双酚单体具有与双酚类似的活必珂以进行聚合反应。     

含萘环新型芳醚酮砜的合成与表征

以４,４’－二（β－萘氧基）二苯砜的合成与表征（ＢＮＯＤＰＳ）,２,５－二氯对苯二甲酰氯（ＤＣＴＰＣ）和二苯醚为单体,通过亲电缩聚反应,合成了一系列主链含萘环的新聚芳醚酮砜。     

二胺改性BPDA－ODA型聚酰亚胺的H_2／N_2分离性能

本文合成了一系列二胺改性的ＢＰＤＡ－ＯＤＡ型共聚酰亚胺膜，改性聚酰亚胺与未改性的ＢＰＤＡ－ＯＤＡ相比，透气性得到了明显的改善，改善的程度与第二种二胺单体的结构和用量有关。３０℃时，在ＢＰＤＡ－ＯＤＡ中加入２０ｍｏｌ％三甲基间苯二胺（３ＭＰＤＡ）或四甲基对苯二胺（４ＭＰＤＡ）时，共聚酰亚胺ＢＰＤＡ－ＯＤＡ／３ＭＰＤＡ（８０／２０）或ＢＰＤＡ－ＯＤＡ／４ＭＰＤＡ（８０／２０）的透Ｈ２系数和Ｈ２／Ｎ２分离系数分别大于６．５ｂａｒｒｅｒ和１６０，是比较好的气体分离膜材料。     

手性近晶C(Sc*)相串型液晶共聚酯的合成与表征

以２,５－二「４－（Ｓ）－２－甲基丁氧基（苯甲酰氧基」对苯二酚,４,４′－二羟基－,α,ω－二苯氧丁烷和对苯二甲酰氯为单体,采用溶液共缩聚的方法。合成了一系列新的手性近晶Ｃ（Ｓｃ＊）相串型液晶共聚酯,单体的结构通过元素分析、ＩＲ、＾１Ｈ－ＮＭＲ和ＭＳ等方法确证,共聚物通过ＧＰＣ、ＤＳＣ、ＴＧ、ＷＡＸＤ、偏光显微镜和旋光仪等方法表征,发现所有共聚物加热至各自的熔点以上都能形成液晶态,在液晶态可以观察     

聚醚酮酮/聚醚酮醚酮酮无规共聚物的合成与表征

以二苯醚,４,４‘－二苯氧基二苯甲酮,对－苯二甲酰氯和间－苯二甲酰氯为单体,在无水三氯化铝存在下,通过低温溶液缩聚合成了一系列聚醚酮酮／聚醚酮醚酮酮无规共聚物。经ＩＲ,ＷＡＸＤ,ＤＳＣ,ＴＧ及耐溶剂抗化学腐蚀试验等方法研究表明,共聚物的对数比浓粘度随４,４’－二苯氧基二苯甲酮含量的增加而增大;共聚物是半结晶性能聚合物,具有比聚醚酮酮更高的玻璃化学转变温度,而其热分解温度和耐溶剂抗化学腐性能则与聚醚     

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.