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A facile stereospecific synthesis of (Z)-2-sulfonyl-substituted 1,3-enynes via Sonogashira coupling of (E)-α-iodovinyl sulfones with 1-alkynes
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作者 Wen Yan Hao Jian Wen Jiang Ming Zhong Cai 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第7期773-776,共4页
(E)-α-Iodovinyl sulfones 1 underwent the Sonogashira coupling reactions with terminal alkynes 2 in piperidine at room temperature in the presence of 5 mol% of Pd(PPh3)4 and 10 mol% of CuI to stereospecifically af... (E)-α-Iodovinyl sulfones 1 underwent the Sonogashira coupling reactions with terminal alkynes 2 in piperidine at room temperature in the presence of 5 mol% of Pd(PPh3)4 and 10 mol% of CuI to stereospecifically afford the corresponding (Z)-2-sulfonyl-substituted 1,3-enynes 3 in high yields. 展开更多
关键词 (E)-α-Iodovinyl sulfone 1 3-Enynylsulfone Sonogashira coupling terminal alkyne
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A Facile Stereospecific Synthesis of 1, 3-Enynylsulfides via Sonogashira Coupling of (E)-a-Iodovinyl Sulfides with 1-Alkynes
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作者 Jian Wen JIANG Ming Zhong CAI 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第6期757-760,共4页
(E)-α-Iodovinyl sulfides 1 underwent the Sonogashira coupling reactions with terminal alkynes 2 in piperidine at room temperature in the presence of 5 mol % of Pd(PPh3)4 and 10 mol % of CuI to afford the correspo... (E)-α-Iodovinyl sulfides 1 underwent the Sonogashira coupling reactions with terminal alkynes 2 in piperidine at room temperature in the presence of 5 mol % of Pd(PPh3)4 and 10 mol % of CuI to afford the corresponding 1, 3-enynylsulfides 3 stereospecifically in high yields. 展开更多
关键词 (E)-α-Iodovinyl sulfide 1 3-enynylsulfide Sonogashira coupling terminal alkyne.
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A Corrugated 2D Mn(Ⅱ) Network:[Mn_3(μ-oxalate)_3(μ-4,4'-bpy)_2(4,4'-bpy)_2]_n
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作者 YANG E WANG Xiao-Qin CHEN Shun-Yu 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第7期873-877,共5页
The title complex, [Mn3(μ-oxalate)3(μ-4,4′-bpy)2(4,4′-bpy)2]n, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in the monoclinic, space group P2 1/c with a = 16.3222... The title complex, [Mn3(μ-oxalate)3(μ-4,4′-bpy)2(4,4′-bpy)2]n, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in the monoclinic, space group P2 1/c with a = 16.3222(6), b = 16.2594(5), c = 16.4885(5) A, β = 94.9900(10)°, V= 4359.3(2) A^3, Z = 4, Mn3C46N8O12H32, Mr = 1053.62, Dc = 1.605 g/cm^3, F(000) = 2140 and μ(MoKa) = 0.932 mm^-1. The structure was refined to R = 0.0578 and wR = 0.1061 for 4795 observed reflections (I 〉 2σ(I)). The oxalate anions behave as the bridging ligand and link two manganese atoms repeatedly to form infinite one-dimensional chains which further extend into a two-dimensional network by bridging 4,4′-bpy ligands. 展开更多
关键词 crystal structure one-dimensional chain two-dimensional layer bridging 4 4′-bpy ligands terminal 4 4′-bp)- ligands
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Efficient Early Termination Strategy for LDPC Codes in GPS Systems
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作者 Feng Wang Jin-Hai Li +1 位作者 Jin-Hai Sun Yue-Peng Yan 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第6期118-122,共5页
By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is b... By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is based on the cyclic redundancy check( CRC) of the messages in the subframes 2 and 3. The simulation results show that average number of iterations of the proposed strategy is less than that of the standard ET strategy,with nearly no degradation in decoding performance. Besides,the proposed ET strategy can be efficiently implemented in a sequential or parallel manner. Thus,the proposed ET strategy is attractive for practical purposes. 展开更多
关键词 GPS system low-density parity-check (LDPC) codes early termination (ET) strategy cyclic redundancy check (CRC)CLC number:TN911.22 Document code:AArticle ID:1005-9113(2013)06-0118-05
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新型苯并环丁烯封端的聚醚酰亚胺的合成与表征 被引量:2
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作者 张英强 沈学宁 +1 位作者 蔡春华 黄发荣 《石油化工》 EI CAS CSCD 北大核心 2005年第8期786-790,共5页
合成了4种不同相对分子质量的含双酚A醚结构的新型苯并环丁烯封端的聚醚酰亚胺树脂,并用质谱、傅里叶变换红外光谱、核磁共振氢谱、凝胶渗透色谱、差示扫描量热及热重分析表征其结构和性能。研究结果表明,树脂的相对分子质量对其固化反... 合成了4种不同相对分子质量的含双酚A醚结构的新型苯并环丁烯封端的聚醚酰亚胺树脂,并用质谱、傅里叶变换红外光谱、核磁共振氢谱、凝胶渗透色谱、差示扫描量热及热重分析表征其结构和性能。研究结果表明,树脂的相对分子质量对其固化反应、固化产物的玻璃化转变温度和热性能等均有影响。随树脂相对分子质量的增加,树脂的玻璃化转变温度提高,其起始固化温度提高,而固化产物的玻璃化转变温度则降低,固化产物的热分解温度提高。所合成的聚醚酰亚胺树脂显示出优良的加工性能和耐热性能。 展开更多
关键词 苯并环丁烯封端 聚醚酰亚胺 热固性树脂 合成 表征 耐热性
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一种基于FTU的馈线自动化系统 被引量:2
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作者 王碧 《科技信息》 2008年第4期302-303,共2页
本文介绍了一种基于FTU(现场终端装置)的馈线自动化,探讨了馈线自动化的主要功能、实施的先决条件;并就一次设备、控制箱(FTU)、通信系统、FA控制主站及SACDA(配电管理系统)主站等五个层次讨论了基于FTU馈线自动化系统的构成,同时介绍... 本文介绍了一种基于FTU(现场终端装置)的馈线自动化,探讨了馈线自动化的主要功能、实施的先决条件;并就一次设备、控制箱(FTU)、通信系统、FA控制主站及SACDA(配电管理系统)主站等五个层次讨论了基于FTU馈线自动化系统的构成,同时介绍了基于FTU模式下的故障处理,指出馈线自动化是提高配电网络电能质量、供电可靠性的有效手段。 展开更多
关键词 馈线自4E(FA-Feeder Automation) FTU(Field terminAL Unit) SCADA系统 配网自动化(Distribution automation) r▲~▲'….·.1 l 1.1 r l-r… ' .1. p ^. ...-. ....
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The Influence of Aziridine on the Aging of Composite Solid Rocket Propellant
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作者 AMGED A. Ali 《Computer Aided Drafting,Design and Manufacturing》 2008年第1期88-93,共6页
Aging of a solid composite propellant containing HTPB/AP/AL was performed in order to validate the conformance of the accelerated aging data to the Arrhenius law. The main objective of the work was to examine the infl... Aging of a solid composite propellant containing HTPB/AP/AL was performed in order to validate the conformance of the accelerated aging data to the Arrhenius law. The main objective of the work was to examine the influence of the aziridine bonding agents family on the propellant aging. Aging of the prepared propellant samples was conducted as follows: 1. Four samples, one free of bonding agents, and three containing aziridine based bonding agents MAPO,HX-752, MAT4 were aged at 65°C. 2. Another four samples based on HX-752, MAT4 with different curing agents were aged at 65°C. The measured mechanical properties of the free bonding agent propellant samples were very far from the specifications and this illustrates the importance of the bonding agents in both the preparation and the aging phases.The prepared bonding agent 'MAT4' gave remarkable improvements of the mechanical properties comparing with HX-752 and MAPO. The aziridine bonding agents family inhibited the rate of decomposition of the propellant during the aging periods and supported the propellant matrix against decomposition at the elevate temperatures. Using of HMDI as curing agent gave slight better mechanical properties to the IPDI. 展开更多
关键词 AGING solid propellant bonding agents curing agents hydroxy terminated poly butadiene (HTPB) l l(Phenyl Dicarbonyl) bis (2- Methyl Aziridine) (HX-752) Tries[l-(2-methyl) aziridinyl] phosphine oxide (MAPO) reaction product of 2.0 mole of MAPO 0.7mole of adipic acid 0.3 mole of tartaric acid (MAT4) hexamethylene diisocyanate. (HMDI) isophoron diisocyanate (IPDI)
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