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以甲基磺酸和碳酸镉为原料,采用普通溶液法制备甲基磺酸镉(Ⅱ),其产物为白色结晶固体。采用红外、核磁、热重、扫描电镜和X射线单晶衍射多种方法对化合物进行表征。结果表明:甲基磺酸镉含有两个结晶水,热稳定性好,属于三斜晶系,■空间群;晶胞参数a=0.4785(5)nm,b=0.6101(5)nm,c=0.8232(5)nm,α=87.137(5)°,β=84.461(5)°,γ=85.614(5)°,V=0.2383(3)nm~3,Z=1。以N1-甲基3,4-二氢嘧啶酮的合成为探针反应,考察了甲基磺酸镉对Biginelli反应的催化性能。在无溶剂、绿色条件下,产品收率达90.1%,重复使用三次后。产品收率仍可以达到80.3%。最后,对甲基磺酸镉连续催化后,催化活性略有下降的原因进行了分析。 相似文献
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PULSED LASER DEPOSITION AND CHARACTERIZATION OF FERHOELECTHIC Pb(Zr, Ti)O3 THIN FILMS ON SILICON-ON-INSULATOR SUBSTRATES 下载免费PDF全文
Ferroelectric Pb(Zr, Ti)O3 thin films were prepared by pulsed exeimer laser deposition on silicon-on-insulator and Pt-coated silicon-on-insulator substrates, and rapid thermal annealing was per-formed to crystallize the films, Based on the analysis by X-ray diffraction, Rutherford backscattering spectroscopy and measurements of electrical properties, the films were revealed to be polycrystalline perovskite structure with mainly (100) and (110) orientations, and their crystallization was found to be dependent on annealing temperature and annealing time. The films show good ferroelectricity, with Pr=15μC/cm2, Ec= 50kV/cm, high resistivity and high dielectric constant. 相似文献
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PULSED LASER DEPOSITION AND CHARACTERIZATION OF FERHOELECTHIC Pb(Zr,Ti)O3 THIN FILMS ON SILICON-ON-INSULATOR SUBSTRATES 下载免费PDF全文
Ferroelectric Pb(Zr, Ti)O3 thin films were prepared by pulsed exeimer laser deposition on silicon-on-insulator and Pt-coated silicon-on-insulator substrates, and rapid thermal annealing was per-formed to crystallize the films, Based on the analysis by X-ray diffraction, Rutherford backscattering spectroscopy and measurements of electrical properties, the films were revealed to be polycrystalline perovskite structure with mainly (100) and (110) orientations, and their crystallization was found to be dependent on annealing temperature and annealing time. The films show good ferroelectricity, with Pr=15μC/cm2, Ec= 50kV/cm, high resistivity and high dielectric constant. 相似文献
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以魔芋葡甘聚糖(KGM)为原料,浓硫酸为催化剂,乙酸酐为改性剂,制备了KGM醋酸酯.研究了反应条件对KGM醋酸酯取代度(DS)的影响,KGM醋酸酯制备的最佳反应条件是乙醇∶水量比5∶5,反应时间2h,反应温度75℃,催化剂浓硫酸的浓度0.1mol/L,KGM与乙酸酐的量比5∶40(g/mL),取代度高达2.93,其分子量与KGM相比,则明显降低.运用傅立叶红外光谱仪(FTIR)、X射线衍射仪(XRD)、扫描电镜(SEM)、热重分析仪(TGA)、示差扫描量热仪(DSC)和旋转流变仪对KGM和高取代度KGM醋酸酯进行了表征.结果表明,KGM醋酸酯的羰基(CO)特征吸收峰较KGM明显增强,其表观形貌大部分为疏松絮状,KGM及其醋酸酯均为非晶态结构.与KGM相比,KGM醋酸酯的热稳定性下降,分解温度(Td)由KGM的261.10℃降低至KGM醋酸酯的204.56℃,KGM醋酸酯出现了明显的玻璃化转变,其玻璃化转变温度(Tg)为128.49℃.KGM醋酸酯是典型的黏弹性材料,其弹性比率占21.27%,其剪切黏度η对温度变化非常敏感,可通过温度的改变来调节KGM醋酸酯的加工流动性.KGM醋酸酯具有较好的热塑性. 相似文献
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Based on the isomorphic relation between operator space L(H) and Hilbert space H^2, Cirac et al. mapped the global superoperator to a mixed state E which has the same separability of the initial superoperator. Zhang et al. [Phys. Rev. A 76 (2007) 012334] provided a calculable lower bound for both the linear and nonlinear witness. We use this bound to detect the entanglement of E to judge the separability of the initial superoperator. With the help of local orthogonal observables, we directly describe the separable condition of superoperator by its each operator. Lastly, using the lower bound of the nonlinear witness, we provide a calculable entanglement factor of bipartite superoperator. 相似文献