准循环重复累积(Quasi⁃Cyclic Repeat Accumulate,QC⁃RA)码具有准循环低密度奇偶校验(Low Density Parity Check,LDPC)码的优点,同时能实现差分编码且为系统码,非常适用于编码协作系统,文中研究采用QC⁃RA码的编码协作系统。首先,提出基...准循环重复累积(Quasi⁃Cyclic Repeat Accumulate,QC⁃RA)码具有准循环低密度奇偶校验(Low Density Parity Check,LDPC)码的优点,同时能实现差分编码且为系统码,非常适用于编码协作系统,文中研究采用QC⁃RA码的编码协作系统。首先,提出基于最大公约数(Greatest Common Divisor,GCD)定理的QC⁃RA码构造方法;然后,进一步基于GCD定理联合构造编码协作系统信源节点与中继节点采用的QC⁃RA码,并从理论上证明基于该联合构造方法得到的编码协作系统QC⁃RA码无girth⁃4、girth⁃6环。仿真结果表明,采用QC⁃RA码的编码协作系统相对于点对点系统具有明显的性能增益;同时,与采用大列重构造QC⁃RA的编码协作相比,采用文中基于GCD定理联合构造的QC⁃RA码的编码协作误码率性能更加优异。展开更多
构造成图是油气勘探开发中非常重要的环节之一,它是进行构造研究、井位设计、储量计算等的基础。目前,这项工作主要利用大型解释软件在工作站上完成。但在成图的后期工作上,工作站却不如微机操作简便,或在某些方面不如微机完善,难以满...构造成图是油气勘探开发中非常重要的环节之一,它是进行构造研究、井位设计、储量计算等的基础。目前,这项工作主要利用大型解释软件在工作站上完成。但在成图的后期工作上,工作站却不如微机操作简便,或在某些方面不如微机完善,难以满足用户的需求。针对这种情况,本文提出利用CGG工作站中的Integral P lus解释系统与微机上的Surfer及CorelDRAW软件,根据各自特色,取长补短,进行微机与工作站联合构造成图。在实际工作中,取得了良好的效果。展开更多
The structure of the title compound consisting of N,N-1,3-dibenzyl-benzimidazole ion, Cl- anion and hydrate was determined by X-ray diffraction method. It crystallizes in the triclinic system, space group P with a = 9...The structure of the title compound consisting of N,N-1,3-dibenzyl-benzimidazole ion, Cl- anion and hydrate was determined by X-ray diffraction method. It crystallizes in the triclinic system, space group P with a = 9.320(2), b = 9.850(2), c = 11.510(2) ? = 68.75(3), = 80.57(3), = 70.20(3)? C21H19ClN2H2O, Mr = 352.85, V = 925.6(3) 3, Z = 2, Dc = 1.266 g/cm3, F(000) = 372, = 0.217 mm-1, R = 0.0452 and wR = 0.1372. The total reflections were 3462 and 3244 (Rint = 0.0206) were independent, of which 1666 were observed with I > 2s(I). The planes of benzyl group are nearly perpendicular to each other. The water molecules with Cl-anions and C(8) atom are involved in hydrogen bonds and interactions, and - stacking interaction exists obviously between the adjacent phenyl and imidazole rings. The title complex forms a three-dimensional network throughout the structure through these hydrogen bonds and interactions.展开更多
文摘准循环重复累积(Quasi⁃Cyclic Repeat Accumulate,QC⁃RA)码具有准循环低密度奇偶校验(Low Density Parity Check,LDPC)码的优点,同时能实现差分编码且为系统码,非常适用于编码协作系统,文中研究采用QC⁃RA码的编码协作系统。首先,提出基于最大公约数(Greatest Common Divisor,GCD)定理的QC⁃RA码构造方法;然后,进一步基于GCD定理联合构造编码协作系统信源节点与中继节点采用的QC⁃RA码,并从理论上证明基于该联合构造方法得到的编码协作系统QC⁃RA码无girth⁃4、girth⁃6环。仿真结果表明,采用QC⁃RA码的编码协作系统相对于点对点系统具有明显的性能增益;同时,与采用大列重构造QC⁃RA的编码协作相比,采用文中基于GCD定理联合构造的QC⁃RA码的编码协作误码率性能更加优异。
文摘构造成图是油气勘探开发中非常重要的环节之一,它是进行构造研究、井位设计、储量计算等的基础。目前,这项工作主要利用大型解释软件在工作站上完成。但在成图的后期工作上,工作站却不如微机操作简便,或在某些方面不如微机完善,难以满足用户的需求。针对这种情况,本文提出利用CGG工作站中的Integral P lus解释系统与微机上的Surfer及CorelDRAW软件,根据各自特色,取长补短,进行微机与工作站联合构造成图。在实际工作中,取得了良好的效果。
基金The project was supported by the Educational Administration Key Project of Shandong province (No. J01C05) and Natural Science Foundation of Shandong province (No.Y2002B06)
文摘The structure of the title compound consisting of N,N-1,3-dibenzyl-benzimidazole ion, Cl- anion and hydrate was determined by X-ray diffraction method. It crystallizes in the triclinic system, space group P with a = 9.320(2), b = 9.850(2), c = 11.510(2) ? = 68.75(3), = 80.57(3), = 70.20(3)? C21H19ClN2H2O, Mr = 352.85, V = 925.6(3) 3, Z = 2, Dc = 1.266 g/cm3, F(000) = 372, = 0.217 mm-1, R = 0.0452 and wR = 0.1372. The total reflections were 3462 and 3244 (Rint = 0.0206) were independent, of which 1666 were observed with I > 2s(I). The planes of benzyl group are nearly perpendicular to each other. The water molecules with Cl-anions and C(8) atom are involved in hydrogen bonds and interactions, and - stacking interaction exists obviously between the adjacent phenyl and imidazole rings. The title complex forms a three-dimensional network throughout the structure through these hydrogen bonds and interactions.
