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161.
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163.
Ying‐Hung So Pamela Foster Jang‐Hi Im Philip Garrou Jack Hetzner Edmund Stark Kayla Baranek 《Journal of polymer science. Part A, Polymer chemistry》2006,44(5):1591-1599
Divinylsiloxane‐bisbenzocyclobutene (DVS‐bisBCB) polymer has very low dielectric constant and dissipation factor, good thermal stability, and high chemical resistance. The fracture toughness of the thermoset polymer is moderate due to its high crosslink density. A thermoplastic elastomer, polystyrene–polybutadiene–polystyrene triblock copolymer, was incorporated into the matrix to enhance its toughness. The cured thermoset matrix showed different morphology when the elastomer was added to the B‐staged prepolymer or when the elastomer was B‐staged with the DVS‐bisBCB monomer. Small and uniformly distributed elastomer domains were detected by transmission electron micrographs (TEM) in the former case, but TEM did not detect a separate domain in the latter case. A high percentage of the polystyrene–polybutadiene–polystyrene triblock copolymer could be incorporated into the DVS‐bisBCB thermoset matrix by B‐staging the triblock copolymer with the BCB monomer. The elastomer increased the fracture toughness of DVS‐bisBCB polymer as indicated by enhanced elongation at break and increased K1c values obtained by the modified edge‐lift‐off test. Elastomer modified DVS‐bisBCB maintained excellent electrical properties, high Tg and good thermal stability, but showed higher coefficient of linear thermal expansion values. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1591–1599, 2006 相似文献
164.
Yan Zhao Xingbin Yang Ru Jiang Xiaoli Sun Wenmin Liu Shengyong Zhang 《Analytical sciences》2006,22(5):747-751
The investigation on capillary electrophoretic enantioseparation of six synthetic compounds containing vicinal diol groups has been undertaken to acquire the optimum conditions using native beta-cyclodextrin (beta-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in an uncoated capillary (58.5 cm x 75 microm i.d., effective length 48.5 cm) and the effects of several important factors were investigated in detail. The results showed that beta-CD as a chiral selector exhibited good enantioselectivity and that the enantioseparation was greatly influenced by the structure of the diols, the borate concentration and the buffer pH. The optimum performance was obtained for the chiral vicinal diols under the conditions of 200 mM borate buffer of pH 9.8 containing 1.7% beta-CD at an applied voltage of 15 kV and a capillary temperature of 20 degrees C. Under the conditions, four diols were baseline separated with fast analysis time and the good theoretical plate numbers (above 10 x 10(4)) and favorable migration-time reproducibilities (RSDs below 3.0%) were obtained. The separation results were satisfactory. 相似文献
165.
V. N. Manuilov T. Idehara M. Kamada T. Hayashi La Agusu T. Kanemaki K. Yatsui Wiehua Jiang 《International Journal of Infrared and Millimeter Waves》2006,27(9):1183-1193
High power Large Orbit Gyrotron (LOG) [1] is now under development at FIR FU. First version of this device was recently manufactured
and then assembled with power supply ETIGO-IV [2]. Results of preliminary tests of electron-optic system are presented. The
conditions when stableflat form of current pulse realized are discussed. Analytical estimations of cathode-anode distance
to achieve small influence of cathode plasma during high voltage (HV) pulse are performed.
Two new electron gun versions with decreased influence of the cathode plasma on its impedance and pulse form are suggested
and optimized. New optimal magnetic field distributions are found. First gun has quiasi-flat cathode configuration near the
anode diaphragm and provides operating current about 60 A. Second one uses blade cathode with operating current about 30 A.
Beam quality for both guns is suitable for LOG operation. 相似文献
166.
用飞秒激光(200 fs,1 kHz,800 nm)脉冲在掺杂稀土离子Ce3 的聚甲基丙烯酸甲酯(PMMA)膜中进行了光存储实验研究,包括对样品的吸收光谱、激光照射前后的电子旋转共振(Electron spin resonance,ESR)光谱的测量和讨论。结果表明掺杂稀土离子Ce3 的聚甲基丙烯酸甲酯膜具有较低的写入阈值,有利于高速、并行的三维光存储。实验结果采用传统光学显微镜并行读出。给出了四层存储结果(点间距和层间距分别是4μm和16μm),并讨论了脉冲能量的大小对空腔尺寸的影响,进行高密度存储时,在保证读出信号灰度值足够大的情况下,应选择尽量小的激光脉冲写入能量。实验结果表明这种材料可以应用于三维光信息存储。 相似文献
167.
采用溶胶-凝胶方法在Si(111)上制备了LSMO(x=0.17)薄膜.研究了块体材料和不同厚度薄膜R -T曲线、红外光谱和X射线衍射.结果表明,LSMO薄膜属于正交晶体结构,薄膜取向与膜厚度 有关,当膜厚度为450nm或680nm时,主要取向〈200〉,而膜厚度为900nm时取向为〈020〉 :根据离子对相互作用能和谐振子模型,得到了红外吸收与Mn—O—Mn键长和键角关系式,6 00cm-1附近红外吸收与晶格常数b的变化有关;块体与薄膜的金属—绝缘体转变 温度(TMI)存在较大差别,薄膜转变温度显著低于块体,并与厚度有一定关系. 认为是LSMO薄膜中的应力诱导了晶格常数变化,引起键角改变及JT效应是转变温度变化的主 要原因.
关键词:
单晶硅
晶格常数
金属—绝缘体转变温度
应力诱导 相似文献
168.
A simple “chimney” method was used to eliminate the voids in an arrangement of quantum dots sized 2 nm on a solid substrate, which resulted in a large well ordered superlattice of area in the order more than 1 μm2. Based on the principle of speeding up the interparticle interaction of nanoparticles to overcome the particle-substrate one, a lateral centripetal force originated from a glass tube acting as a chimney in a simple evaporation device is imposed. This method allows the packing process to be controlled in a mechanical force field, that is, with the same nanogold dispersion different patterns on a substrate—from separate dots to an ordered compact monolayer or even a multilayer structure—could be easily obtained. 相似文献
169.
170.
合肥同步辐射软X射线显微术研究 总被引:1,自引:0,他引:1
合肥国家同步辐射实验室首期建设的光束线之一用于软X射线显微成像研究。实验站现已装置初型的扫描透射X射线显微镜,并正在进行亲一代的扫描显微建设,同时还使同步辐射光进行接触软X射线呈微成像研究,并对选取的一些生物样品进行了成像试验。本文介绍了合肥同步辐射光源上软X射线显微术实验线站的建设及完成的一些实验结果。 相似文献