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101.
102.
采用CoCrPtNb四元合金作磁记录介质,并采用多层膜结构(CoCrPt)100-Nbx/CrTi/C/Glass制备玻璃盘基硬盘。实验结果表明:采用适宜厚度的籽晶层与合适组分的底层和磁性层的多层膜结构,即使在室温下溅射,此种薄膜磁记录介质也可得到高达260kA/m的矫顽力;在550℃高温下,经过30min真空退火后,其矫顽力有较大幅度提高,并在Nb含量为2.4%(原子分数)时达到极大值386kA/m,适用于高密度磁记录。同时,也详细分析了磁性层和底层组分、籽晶层厚度以及真空退火对磁记录介质磁性能和微结构的影响。  相似文献   
103.
季胺萃取锌的动力学研究   总被引:1,自引:0,他引:1  
以恒界面池法研究了氯化物介质中季胺萃锌的动力学。考查了搅拌转速、传质界面积和温度对萃取速率的影响,判定季爱萃锌为界面化学反应的动力学模式。进一步研究了季胺萃取剂浓度和水相Zn^2+浓度对萃取速率的影响,得到了与理论推断相吻合的速率方程。  相似文献   
104.
撞击流—旋转填料床反应器的微观混合性能研究   总被引:10,自引:0,他引:10  
采用化学偶合法 ,对撞击流—旋转填料床反应器内微观混合进行了实验研究 ,得到了转速、喷嘴间距、射流速度及浓度等因素对离集指数Xs的影响规律 ,并对其进行了定性的分析。结果表明撞击流—旋转填料床反应器中微观混合能被极大地强化 ,可成为适合快速反应新型反应设备  相似文献   
105.
We prepared biodegradable extruded starch blends by first mixing starch with additives and then processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, solubility, biodegradability, rheological properties, molecular weight, and glass‐transition temperature of the extruded blends were studied. Glycerol and urea, to some extent, could both decrease the tensile strength and increase the percentage elongation at break because the former acts as a plasticizer and the latter can break down interactions among starch macromolecules. The extruded starch blends showed thermoplasticity, and their melts behaved as pseudoplastic liquids at a comparatively low shear rate. The biodegradability of the extruded starch was slightly higher than that of native starch. The molecular weight of starch displayed a decreasing tendency after extruding modification. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 627–635, 2003  相似文献   
106.
Electrospinning of poly(lactic‐co‐glycolic acid) (PLGA) in chloroform or 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) was investigated, focusing on its solution parameters, to develop nonwoven biodegradable nanofibrous structures for tissue engineering. PLGA nanofibers were obtained by electrospinning of 15 wt % PLGA solution and the resulting average fiber diameters were varied with the range of 270–760 nm, depending on solution property. When small amounts of benzyl triethylammonium chloride (BTEAC) was added to the PLGA/chloroform solution, the average diameter was decreased from 760 to 450 nm and the fibers were densely amounted in a straight shape. In addition, the average fiber diameter (270 nm) of nanofibers electrospun from polar HFIP solvent was much smaller than that (760 nm) of nanofibers electrospun from nonpolar chloroform solvent. Therefore, it could be concluded that conductivity or dielectric constant of the PLGA solution was a major parameter affecting the morphology and diameter of the electrospun PLGA fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1214–1221, 2006  相似文献   
107.
Yun-Hi Kim  Hong You 《Polymer》2005,46(19):7969-7973
A blue electroluminescent polymer, random copolymer of fluorenylstilbene and fluorene, was prepared by the nickel catalyzed coupling reaction. The structure and properties of the copolymer were analyzed by various spectroscopic methods. The obtained polymer had good solubility and thermal stability with high Tg. The polymer in thin film emits strong blue luminance (max=468 nm) with narrow bandwidth upon photoexcitation. PL spectrum of the polymer in the film is almost consistent with that of solution one as well as the EL spectrum, indicating that the aggregation and the excimer fluorescence are suppressed by the introduction of fluorenylstilbene comonomer. Moreover, the introduction of fluorenylstilbene comonomer lowered the oxidation potential to lead feasible hole injection, when the compared with poly(fluorene) homopolymer. The ITO/PEDOT/polymer/LiF/Al device showed the maximum brightness of 3500 cd/m2 with a turn on voltage of 4.4, the maximum efficiency of 0.878 lm/W and blue emission with CIE chromaticity coordinates of ((x,y)=(0.17, 0.25)).  相似文献   
108.
由世岐  沈玄 《粉煤灰》2005,17(2):39-42
为了探讨自燃煤矸石轻集料混凝土结构耐久性能.通过对自燃煤矸石轻集料、自燃煤矸石轻集料混凝土的耐久性科研成果分析、工程应用情况、有关耐久性调查及长期自然环境下自燃煤矸石混凝土碳化试验研究后说明,只要制定合理标准。严格执行、精心设计、合理选材、加强管理、自燃煤矸石混凝土是可以满足结构耐久性要求。  相似文献   
109.
二-(4-羟基丁基)四甲基二硅氧烷的合成研究   总被引:1,自引:0,他引:1  
采用一步法以二甲基二氯硅烷、四氢呋喃和金属镁粉为原料,在碘乙烷和单质碘催化下合成二-(4-羟基丁基)四甲基二硅氧烷。产物温合物减压过滤,以除去镁盐。滤液无需蒸馏提纯,而直接水解,干燥,减压蒸馏,收集71℃/1333Pa馏份。还探讨和优化合成条件:四氢呋喃与二甲基二氯硅烷之摩尔比应大于3.5;Grignard反应停止后应继续加热回流1小时;蒸馏时系统压力为1333Pa。  相似文献   
110.
This study measures the neutralizing capacity of bottom ash from municipal solid waste incineration of different particle sizes. We examine the effect of particle size on the weathering process, a method popularly used for stabilization of heavy metals in incineration of bottom ash. The distribution of particle sizes in municipal solid waste incineration bottom ash is rather broad, ranging from fine powder to as large as 40 mm in diameter. Although considered a by-product highly suitable as a road construction material, the high level of heavy metal leaching is an obstacle to its reuse. Weathering, a method used to reduce heavy metal leaching, is a lengthy process taking over thee months to complete. The chief reaction involved in weathering is carbonation occurring between Ca(OH)2 in bottom ash and CO2(g) in the atmosphere. During this process, CaCO3 is produced, causing the pH level to drop from over 12 to about 8.2 and reducing heavy metal leaching. In this paper, we attempt to determine the particle size best suited for reducing the period required for weathering bottom ash by identifying characteristics of different particle sizes that affect heavy metal leaching and neutralization.  相似文献   
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