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91.
Synthesis, characterization and properties of tetramethyl stilbene-based epoxy resins for electronic encapsulation 总被引:1,自引:0,他引:1
Two novel tetramethyl stilbene-based novolac (II and IV) were synthesized from 2,6-dimethyl phenol and chloroacetaldehyde dimethylacetal or chloroacetone, and then the resulted novolacs were epoxidized to tetramethyl stilbene-based epoxy resins (III and V). The proposed structures were confirmed by FTIR, elemental analysis, mass spectra, NMR spectra and epoxy equivalent weight titration. The synthesized tetramethyl stilbene-based epoxy resins were cured with 4,4-diaminodiphenyl methane (DDM) and 4,4-diaminodiphenyl sulfone (DDS). Thermal properties of cured epoxy resins were studied using dynamic mechanical analyzer, differential scanning calorimeter, thermal expansion analyzer and thermal gravimetric analyzer (TGA). These data were compared with that of the commercial tetramethyl biphenol (TMBP) epoxy system. According to the experimental data, the order of Tg for cured epoxy system is III>TMBP>V. The order of moisture absorption for cured epoxy system is V<III<TMBP. According to TGA, the 5% degradation temperatures in nitrogen atmosphere were in the range 370-377 and 397-412 °C for DDM and DDS curing systems, respectively. In air atmosphere, the 5% degradation temperatures were in the range 372-385 and 410-411 °C for DDM and DDS curing systems, respectively. The CTE is in inverse order with Tg, therefore, III/DDS<TMBP/DDS<V/DDS. 相似文献
92.
Alex Ching‐Wei Lin Ting‐Kuo Chang Chueh‐Kuei Jan Meng‐Hsun Hsieh Chung‐Yang Tsai James Shih‐Chang Chang Alan Yaw‐Ming Tsai 《Journal of the Society for Information Display》2006,14(4):353-362
Abstract— A 3.5‐in. QVGA‐formatted driving‐circuit fully integrated LCD has been developed using low‐temperature poly‐Si (LTPS) technology. This display module, in which no external ICs are required, integrates all the driving circuits for a six‐bit RGB digital interface with an LTPS device called a “FASt LDD TFT” and achieves a high‐quality image, narrow frame width, and low power consumption. The LTPS process, device, and circuit technologies developed for system‐on‐glass LCD discussed. The development phase of LTPS circuit integration for system‐on‐glass LCDs is also reviewed. 相似文献
93.
In this paper, we propose a robust PID controller tuning method for parametric uncertainty systems (or interval plant family) using fuzzy neural networks (FNNs). This robust controller is based on robust gain and phase margin (GM/PM) specifications that satisfy user requirements. Here, the FNN system is used to identify the relation between the PID controller parameters and robust GM/PM. We can use the trained FNN system to determine the parameters of the PID controllers in order to satisfy robust GM/PM specifications that guarantee robustness and performance. Simulation results are shown to illustrate the effectiveness of the robust controller scheme. 相似文献
94.
Methionine-enriched protein was produced from an enzymatically pre-hydrolyzed milk protein using an enzymatic peptide modification (EPM) method with α-chymotrypsin as catalyst. Methionine of the product was twice as high as that of the substrate protein. The incorporated methionine formed a covalent bond with the peptide chain in the product protein. The change in the number of peptide bonds was monitored by the degree of hydrolysis (DH). The slight change of the DH values revealed that a portion of the free amino acids was bound to the peptide chains during the reaction and that transpeptidation was the main process during the EPM treatment. The location of the newly incorporated amino acids was determined by identification of the terminal amino acids. The covalently bound methionine was located in C- and N-terminal positions in a ratio of 3:1. 相似文献
95.
The family physician occupies a front-line position in the detection and treatment of emotional problems and psychiatric illnesses. The practice pattern of the family physician necessitates an efficient, effective model of psychotherapy The BATHE technique is a brief psychotherapeutic method that addresses the patient's background issues, affect and most troubling problem. The emphasis of the interview then shifts to how the patient is handling the problem and a demonstration of empathy by the physician. Some of the challenges in psychotherapy are presented, and cases in which the BATHE technique was used are described. 相似文献
96.
Ching J.Y. Wong A.K.C. Chan K.C.C. 《IEEE transactions on pattern analysis and machine intelligence》1995,17(7):641-651
Inductive learning systems can be effectively used to acquire classification knowledge from examples. Many existing symbolic learning algorithms can be applied in domains with continuous attributes when integrated with a discretization algorithm to transform the continuous attributes into ordered discrete ones. In this paper, a new information theoretic discretization method optimized for supervised learning is proposed and described. This approach seeks to maximize the mutual dependence as measured by the interdependence redundancy between the discrete intervals and the class labels, and can automatically determine the most preferred number of intervals for an inductive learning application. The method has been tested in a number of inductive learning examples to show that the class-dependent discretizer can significantly improve the classification performance of many existing learning algorithms in domains containing numeric attributes 相似文献
97.
After drinking a small dose of alcohol, Orientals flushed, their heart rates increased and their diastolic pressures decreased; Caucasians' skin reflectance did not change, but their heart rates and systolic blood pressures decreased. In both groups, flushing was associated with an increase in feelings of vigor. Other mood correlates depended on condition. 相似文献
98.
99.
Masashi?Hosokawa Ching?T.?HouEmail author Dave?Weisleder 《Journal of the American Oil Chemists' Society》2003,80(11):1085-1091
Clavibacter sp. ALA2 oxidized n−3 and n−6 PUFA into a variety of oxylipins. Structures of products converted from EPA and DHA were determined
as 15,18-dihydroxy-14,17-epoxy-5(Z),8(Z),11(Z)-eicosatrienoic acid and 17,20-dihydroxy-16,19-epoxy-4(Z),7(Z),10(Z),13(Z)-docosatetraenoic acid by GC-MS and NMR analyses. In contrast, γ-linolenic acid and arachidonic acid were converted to diepoxy
bicyclic FA, tetrahydrofuranyl monohydroxy FA, and trihydroxy FA. Thus, the structures of bioconversion products were different
between n−3 and n−6 PUFA. Furthermore, strain ALA2 placed hydroxy groups and cyclic structures at the same position from the
ω-terminal despite the number of carbons in the chain and the double bonds in the PUFA. 相似文献
100.
Wan Ching; Chiu Chi-yue; Tam Kim-pong; Lee Sau-lai; Lau Ivy Yee-man; Peng Siqing 《Canadian Metallurgical Quarterly》2007,92(2):337
Cross-cultural psychologists assume that core cultural values define to a large extent what a culture is. Typically, core values are identified through an actual self-importance approach, in which core values are those that members of the culture as a group strongly endorse. In this article, the authors propose a perceived cultural importance approach to identifying core values, in which core values are values that members of the culture as a group generally believe to be important in the culture. In 5 studies, the authors examine the utility of the perceived cultural importance approach. Results consistently showed that, compared with values of high actual self-importance, values of high perceived cultural importance play a more important role in cultural identification. These findings have important implications for conceptualizing and measuring cultures. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献