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81.
Patricia S. C. Pereira L. C. Mendes M. L. Dias Lys Sirelli 《Journal of Thermal Analysis and Calorimetry》2007,87(3):667-671
The effects of processing time
and concentration of cobalt acetylacetonate III complex in poly(ethylene terephthalate)/polycarbonate
reactive blending were investigated. The blend was prepared in an internal
mixer at 270°C, 60 rpm, at different processing times (5–20 min)
and catalyst concentration (0.00625–0.075 mass%). The reaction product
was evaluated by differential scanning calorimetry (DSC), thermogravimetry
(TG) and wide angle X-rays scattering (WAXS).
In general, the
DSC curves showed two glass transition temperatures (T
g’s)
close to each homopolymer, independent of the processing time and complex’s
concentration, suggesting the presence of two phases: one rich in PET and
other one rich in PC. In all cases, melting temperature (T
m),
cold crystallization temperature (T
cc)
and crystallinity degree (X
c)
were progressively reduced with blending conditions. The TG curves presented
two decays. The first one represented the PET rich phase and the other one
was related to the PC phase. The WAXS diffractograms showed that the Bragg’s
angle and interplanar spacing of PET remaining practically unchanged. 相似文献
82.
A computational strategy is presented for the nonlinear dynamic analysis of largescale combined finite/discrete element systems
on a PC cluster. In this strategy, a dual-level domain decomposition scheme is adopted to implement the dynamic domain decomposition.
The domain decomposition approach perfectly matches the requirement of reducing the memory size per processor of the calculation.
To treat the contact between boundary elements in neighbouring subdomains, the elements in a subdomain are classified into
internal, nterfacial and external elements. In this way, all the contact detect algorithms developed for a sequential computation
could be adopted directly in the parallel computation. Numerical examples show that this implementation is suitable for simulating
large-scale problems. Two typical numerical examples are given to demonstrate the parallel efficiency and scalability on a
PC cluster.
The project supported by the National Natural Science Foundation of China (10372114) and the Engineering and Physical Sciences
Research Council (EPSRC) of UK (GR/R21219) 相似文献
83.
Ah-Reum Han Hae Ran Park Geum Jin Kim Bo-Ram Kim Ye-Ram Kim Hyeon Hwa Park Jisu Park Chang Hyun Jin Jung Min Kim Soon-Jae Kwon Jin-Baek Kim Shugeng Cao Joo-Won Nam Hyukjae Choi 《Molecules (Basel, Switzerland)》2021,26(24)
Lentil (Lens culinaris; Fabaceae), one of the major pulse crops in the world, is an important source of proteins, prebiotics, lipids, and essential minerals as well as functional components such as flavonoids, polyphenols, and phenolic acids. To improve crop nutritional and medicinal traits, hybridization and mutation are widely used in plant breeding research. In this study, mutant lentil populations were generated by γ-irradiation for the development of new cultivars by inducing genetic diversity. Molecular networking via Global Natural Product Social Molecular Networking web platform and dipeptidyl peptide-IV inhibitor screening assay were utilized as tools for structure-based discovery of active components in active mutant lines selected among the lentil population. The bioactivity-based molecular networking analysis resulted in the annotation of the molecular class of phosphatidylcholine (PC) from the most active mutant line. Among PCs, 1-stearoyl-2-hydroxy-sn-glycero-3-phosphocholine (18:0 Lyso PC) was selected for further in vivo study of anti-obesity effect in a high-fat diet (HFD)-induced obese mouse model. The administration of 18:0 Lyso PC not only prevented body weight gain and decreased relative gonadal adipose tissue weight, but also attenuated the levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol, and leptin in the sera of HFD-induced obese mice. Additionally, 18:0 Lyso PC treatment inhibited the increase of adipocyte area and crown-like structures in adipose tissue. Therefore, these results suggest that 18:0 Lyso PC is a potential compound to have protective effects against obesity, improving obese phenotype induced by HFD. 相似文献
84.
85.
本文介绍了机动车动态称重计费系统中由PC/XT为主机,多个单片机为从机所构成的主从分布式系统的计算机通信,并给出了该多机通信系统的硬件结构和多机通信软件的设计。 相似文献
86.
Review on recent and advanced applications of monoliths and related porous polymer gels in micro-fluidic devices 总被引:1,自引:0,他引:1
Mercedes Vázquez 《Analytica chimica acta》2010,668(2):100-8248
This review critically summarises recent novel and advanced achievements in the application of monolithic materials and related porous polymer gels in micro-fluidic devices appearing within the literature over the period of the last 5 years (2005-2010). The range of monolithic materials has developed rapidly over the past decade, with a diverse and highly versatile class of materials now available, with each exhibiting distinct porosities, pore sizes, and a wide variety of surface functionalities. A major advantage of these materials is their ease of preparation in micro-fluidic channels by in situ polymerisation, leading to monolithic materials being increasingly utilised for a larger variety of purposes in micro-fluidic platforms. Applications of porous polymer monoliths, silica-based monoliths and related homogeneous porous polymer gels in the preparation of separation columns, ion-permeable membranes, preconcentrators, extractors, electrospray emitters, micro-valves, electrokinetic pumps, micro-reactors and micro-mixers in micro-fluidic devices are discussed herein. Procedures used in the preparation of monolithic materials in micro-channels, as well as some practical aspects of the micro-fluidic chip fabrication are addressed. Recent analytical/bioanalytical and catalytic applications of the final micro-fluidic devices incorporating monolithic materials are also reviewed. 相似文献
87.
PET/PC共混体系结晶行为研究进展 总被引:1,自引:0,他引:1
聚对苯二甲酸乙二醇酯(PET)/聚碳酸酯(PC)合金材料是综合性能优异的工程塑料,对其结晶行为的研究,可为设计,调节及控制材料的性能提供理论基础。评述了近年来PET/PC共混体系结晶行为研究的最新工作和理论进展,包括PET/PC共混体系酯交换、相容性及结晶性的关系,退火对PET/PC共混体系结晶行为的影响,第三组分对PET/PC共混体系结晶行为的影响,PET/PC共混体系结晶动力学以及PET/PC共混体系高压结晶行为的研究。并对今后的深入研究作了展望。 相似文献
88.
以聚对苯二甲酸乙二酯(PET)瓶片为主要原料, 加入聚碳酸酯(PC)、热塑性弹性体及扩链剂, 采用低温固相反应挤出制备了具有良好强度与韧性的新型合金. 在加工过程中产生PET相和PC相互穿的网络结构的同时, 反应性扩链剂在PET相中发生交联反应, 形成了次级网络结构. 由于这些网络结构的存在, 使合金材料的力学性能得到明显提高, 特别是缺口冲击性能有了明显的改善. 相似文献
89.
90.
An investigation was conducted on enhanced scratch resistance of polycarbonate (PC) substrates by low temperature plasma-polymerized organo-silicon oxynitride (SiOxCyNz) with various N2 flow rates. It was found that the low temperature plasma-polymerized SiOxCyNz with tetramethylsilane (TMS)-O2-N2 plasmas in room temperature (23 °C) can be used for improving the scratch resistance of PC substrates. Scratch test demonstrates this improvement. The scratch resistance of PC substrates was greatly enhanced from the overwhelming presence of scratching (90%) on un-treated PC substrates to a complete lack of scratching (0%) on TMS-O2-N2 plasma-polymerized PC substrates with steel wool for 200 cycles at 300 g loading. The results of this study indicate the performance of scratch resistance on PC substrates was highly dependent on the surface characteristics of PC substrates. The hardness of PC substrates was determined by the pencil test. The surface morphology of PC substrate was monitored by atomic force microscopy (AFM) and field emitted scanning electron microscopy (FESEM). The atomic compositions and chemical bondings of TMS-O2-N2 plasma-polymerized SiOxCyNz were analyzed by X-ray photoelectron spectroscopy (XPS). 相似文献