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首先给出了希尔波特解调过程,研究了相位编码信号的识别算法,接着对识别过程中存在的相位模糊问题提出了针对性的解决方法。基于上述算法,文中对二相编码信号、四相编码信号及多相码调制信号进行了仿真试验,得到了较好的效果,验证了文中算法的正确性和有效性,最后将算法应用于某雷达接收机的测试系统中,验证了其经济性和实用性。 相似文献
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A new Mn (III) Schiff-base coordination compound, [Mn(L)(NCS)]2 (H2L = N,N′-bis(5-chlorosalicylidene)-1,2-diaminoethane), has been synthesized and characterized structurally and magnetically. The target compound is a phenoxo-bridged dimeric compound with the isothiocyanate coordinating in a usual bent mode. A magnetic susceptibility study reveals that the target compound exhibits antiferromagnetic intra-dimer coupling between Mn (III) ions. The low temperature heat capacity of the compound over the temperature range (2 to 300) K has been measured using the heat capacity option of a Quantum Design Physical Property Measurement System (PPMS). The thermodynamic functions in the experimental temperature range have been determined by curve fitting. The standard entropy and enthalpy of the as-prepared compound at T = 298.15 K have been calculated to be (924.52 ± 10.17) J · K−1 · mol−1 and (133.47 ± 1.47) kJ · mol−1, respectively. 相似文献
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PCB设计管理过程涉及的一个重要方面就是有效性管理,体现在资源的有效利用和设计项目的及时处理,即有计划、有目的地进行PCB设计工作的安排和管理.在已有PCB设计管理系统(PPMS)的设计基础上,通过建立需求和资源数学模型,预计需求趋势,做到资源的科学分配和使用率最大化管理. 相似文献
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The heat capacities of D-galactose and galactitol were measured on a quantum design physical property measurement system(PPMS) over a temperature range of 1.9―300 K, and the experimental data were fitted to a function of T using a series of theoretical and empirical models in appropriate temperature ranges. The fit results were used to calculate thermodynamic function values,Cp,mθ,Δ0TSmθ, and Δ0THmθfrom 0 K to 300 K. The standard molar heat capacity, entropy and enthalpy values of D-galactose and galactitol at 298.15 K and 0.1 MPa were determined to be Cp,mθ =(227.96±2.28) and (239.50±2.40) J·K-1·mol-1,Smθ= (211.22±2.11) and (230.82±2.30) J·K-1·mol-1 and = Hmθ (33.95±0.34) and (36.57± 0.37) kJ/mol, respectively. 相似文献
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聚苯基硅氧烷与聚甲基苯基硅氧烷改性环氧树脂的合成与性能比较 总被引:3,自引:0,他引:3
热熔法制备了一系列聚苯基甲氧基硅氧烷(PPMS)、聚甲基苯基甲氧基硅氧烷(PMPS)改性环氧树脂,通过环氧值、红外光谱(IR)分析表明聚硅氧烷接枝了E-20环氧树脂且环氧基保持不变.探讨了有机硅含量对改性树脂固化体系耐热性能及韧性的影响.实验表明,当E-20环氧树脂与PPMS、PMPS的质量比为7∶3时,改性树脂固化体系的耐热性能明显提高,玻璃化转变温度(Tg)为95.8、88.3℃,分别比改性前提高了9.0℃和1.5℃;质量损失50%时的热分解温度(Td)为476.5、487.8℃,分别比改性前提高了58.3℃和69.5℃.与ED-30固化体系相比,EPMS-30固化物的耐热性能,韧性等力学性能提高的更加明显,并且还具有优良的涂膜性能. 相似文献
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