排序方式: 共有66条查询结果,搜索用时 13 毫秒
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含环偶磷氮烷配体的羰基铁衍生物的合成和晶体结构 总被引:1,自引:0,他引:1
用Fe3(C0)12与顺-2,4-二(叔丁基胺基)-1,3-二(叔丁基)-1,3,2,4-环偶磷氮烷cis-[P(NHBu-t)NBu-t]2(L)反应,得到两个新的含偶磷氮环的单核羰基铁衍生物:Fe(C0)4[{P(NHBu-t)NBu-t}2](1)和Fe(C0)4[P(NHBu-t)(NBu-t)2P(0)H](2).对它们进行了元素分析,IR和1H NMR谱表征,并用X-ray单晶衍射法测定了晶体结构.1:正交晶系,Pna2(1)空间群,a=1.7038(9)nm,b=0.8856(5)nm,c=3.5659(18)nm,V=5.381(5)nm3,Dc=1.275g/cm3,Z=8.2:单斜晶系,P2(1)/n空间群,a=0.9999(2)nm,b=1.4476(3)nm,c=1.5559(3)nm,β=92.40(3)°,V=2.2504(8)nm3,Dc=1.361g/cm3,Z=4.在两个羰基铁化合物中,配位基偶磷氮烷环以单齿P原子与Fe原子配位.2中,未配位P(Ⅲ)被氧化成具有膦酰基结构[(==)P(O)H]的P(Ⅴ). 相似文献
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E·M·Evleth等曾用正丁基锂合成对位-苯基二膦H_2PC_6H_4PH_2及其相关化合物。但制备手续较烦,产率不高。P·G·Chanfrell等从格氏试剂出发,合成了P,P,P′,P′-四(二乙胺基)-1,4-苯基二膦[(C_2H_5)_2N]_2PC_6H_4P[N(C_2H_5)_2]_2。本文报导改进和简化了的E.M.Evleth法反应,第一次合成三个对位-联苯基二膦及其衍生物,即4,4′- 相似文献
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In recent years, the chaos based cryptographic algorithms have
suggested some new and efficient ways to develop secure image
encryption techniques. This paper proposes a new approach for image
encryption based on a high-dimensional chaotic map. The new scheme
employs the Cat map to shuffle the positions, then to confuse the
relationship between the cipher-image and the plain-image using the
high-dimensional Lorenz chaotic map preprocessed. The results of
experimental, statistical analysis and key space analysis show that
the proposed image encryption scheme provides an efficient and secure
way for real-time image encryption and transmission. 相似文献
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具强迫项高阶非线性中立型差分方程的振动性与渐近性 总被引:1,自引:1,他引:0
讨论具强迫项高阶非线性中立型差分方程△m(xn ∑si=1pi(n)xγi(n)) ∑kj=1qj(n)hj(xσj(n))=fn,n=0,1,2,…及其相关联的差分方程△m(xn ∑si=1pi(n)xγi(n)) ∑kj=1qj(n)hj(xσj(n))=0,n=0,1,2,…的振动性与渐近性,得到了所有解振动或趋于零的充分性判据. 相似文献
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Modified projective synchronization with complex scaling factors of uncertain real chaos and complex chaos 下载免费PDF全文
To increase the variety and security of communication, we present the definitions of modified projective synchronization with complex scaling factors (CMPS) of real chaotic systems and complex chaotic systems, where complex scaling factors establish a link between real chaos and complex chaos. Considering all situations of unknown parameters and pseudo-gradient condition, we design adaptive CMPS schemes based on the speed-gradient method for the real drive chaotic system and complex response chaotic system and for the complex drive chaotic system and the real response chaotic system, respectively. The convergence factors and dynamical control strength are added to regulate the convergence speed and increase robustness. Numerical simulations verify the feasibility and effectiveness of the presented schemes. 相似文献
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用Co2(CO)3和杂环硫代酰胺SCXCH2CH2NH(X=NH,S,O)反应,得到两类6个新的可能具有手征性的三核钴羰基硫簇合物Co3(CO)7(μ3-S)(μ-SCXCH2CH2N)(Ⅰ)和Co3(CO))6(μ3-S)(:CXCH2CH2NH)(μ-SCXCH2N)(Ⅱ).Ⅰ和Ⅱ的分子骨架Co3S为四面体结构,其中SCXCH2CH2NH是通过S、N与2个Co键合的3e桥基配体,而:CXCH2CH2NH为2e杂环卡宾配体,对6个簇合物进行了表征,并对反应条件做了初步研究。 相似文献
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