在具有终对象的范畴内的正合列

本文对于具有终对象的范畴定义了四个一般正合列．在Ａｂｅｌ范畴同调代数里，对于具有零对象的任何范畴四个一般正合列与通常的正合列相同     

使用光学自反关联存储技术的符号替换运算

介绍了使用光学自反关联存储技术进行符号替换运算的数学模型、数字模拟结果以及使用可编程ＬＣＴＶ液晶空间光调制器组成光电混合系统的实现符号替换的方法。这种符号替换运算具有很强的容错能力。     

丁二烯聚合反应用FeCl3-Al(i-Bu)3-Phen催化剂体系相态的研究

通过Ｔｙｎｄａｌｌ效应，电镜观察和超过滤实验，发现ＦｅＣｌ３－Ａｌ（ｉ－Ｂｕ）３－Ｐｈｅｎ，催化剂在溶有丁二烯的加氢汽油介质中为胶体分散系，活性中心位于胶体催化剂的胶粒表面，催化剂各组分间的配比影响有胶粒形态，以较佳配所得到的催化剂颗粒较小，分布均匀，催化活性高。     

The designed synthesis and crystallographic characterization of three novel heterotrimetallic linear complexes of [Et4N][(Ph3P)2{M′S2 MS2Fe}Cl2] (M=Mo,M′=Ag;M=W,M′=Cu,Ag)

The complexes [Et₄N][(Ph₃P)₂{MS₂ MS₂Fe}Cl₂] (M=Mo,M=Ag;M=W,M=Cu, Ag) have been obtained by reaction of [Et₄N]₂[S₂ MS₂FeCl₂] (M=Mo, W) with Cu(PPh₃)₃Cl or Ag(PPh₃)₃NO₃ in MeCN/CH₂Cl₂, respectively. Crystal data for [Et₄N][(PPh₃)₂ {AgS₂MoS₂Fe}Cl₂] (I): triclinic, P (No. 2),Z=2,a=13.41(1)Å,b=15.54(1)Å,c=12.30(1)Å, =105.24(6)°, =94.63(7)°, =101.38(6)°, andV=2399(4)ų. The bond lengths of Mo-Fe bond and the Mo-Ag distance are 2.756(2)Å and 3.033(2)Å, respectively. Crystal data for [Et₄N][(PPh₃)₂ {AgS₂WS₂Fe}Cl₂] (II): triclinic, P (No. 2),Z=2,a=13.457(5))Å,b=15.601(6)Å,c=12.338(4)Å, =105.20(3)°, =94.61(4)°, =101.43(4)°, andV=2426(2)ų. The bond length of W-Fe bond and the W-Ag distance are 2.786(2)Å and 3.076(1)Å, respectively. Crystal data for [Et₄N][(PPh₃)₂ {CuS₂WS₂Fe}Cl₂] (III): triclinic, P (No. 2),Z=2,a=13.498(5)Å,b=15.372(4)Å,c=12.340(4)Å, =105.54(2)°, =93.32(3)°, =101.40(3)°, andV=2401(1)ų. The bond lengths of W-Fe bond and the W-Cu bond are 2.800(1)Å and 2.851(1)Å, respectively.     

Rare‐Earth Metal Alkyl Complexes with 3‐Arylamido‐Functionalized Indolyl Ligands: Synthesis,Characterization and Reactivity†

A series of dinuclear rare‐earth metal alkyl complexes {[μ‐η²:η¹:η¹‐3‐( L NCH)(CH₂SiMe₃)Ind]RE(CH₂SiMe₃)(THF)}₂ ( L ¹ = 2‐^tBuC₆H₄, RE = Y, Gd, Dy, Er, Yb; L ² = 2,4,6‐Me₃C₆H₂, RE = Dy, Er; Ind = indolyl) and {[μ‐η²:η¹:η¹‐3‐( L NCH₂)Ind]RE(CH₂SiMe₃)(THF)}₂ ( L ¹, RE = Y, Dy, Er, Yb; L ², RE = Er, Yb) bearing 3‐arylamido functionalized indolyl ligands having diverse bonding modes with metal ions were synthesized either by the insertion reaction of the imino group to the RE—C bond or by the alkane elimination reaction. In the preparation of above complexes, rare‐earth metal alkyl complexes [μ‐η⁵:η¹:η¹‐3‐( L ²NCH)(CH₂SiMe₃)Ind]Gd(CH₂SiMe₃)(THF)}₂ with a μ‐η⁵:η¹:η¹ coordination mode to the gadolinium ion and {[μ‐η³:η¹:η¹‐3‐( L ²NCH₂)Ind]Dy(CH₂SiMe₃)(THF)}₂ with a μ‐η³:η¹:η¹ coordination mode to the dysprosium ion were unexpectedly isolated. The reactions of 3‐( L ²N=CH)Ind with Er(CH₂SiMe₃)₃(THF)₂ at room temperature, generated a tetranuclear imino‐indolyl erbium intermediate {[μ‐η¹:η¹‐3‐( L ²N=CH)Ind]Er(CH₂SiMe₃)₂(THF)}₄, which can transform into the amido functionalized indolyl erbium complex in hot toluene. Moreover, the reactivities of the newly synthesized ytterbium complex with N‐heterocyclic compounds were investigated, affording the corresponding products of the mixed pyridyl‐indolyl, imidazolyl‐indolyl, and ortho‐metalated complexes. The yttrium complexes showed a high regioselectivity and steroselectivity for the isoprene polymerization with 1,4‐trans selectivity up to 91.7% and 1,4‐cis selectivity up to 96.1% in the presence of cocatalysts, respectively.     

大学物理实验中学生的心理障碍及克服

影响学生实验的心理因素较多。本就学生们的自卑心理进行剖析并提出教师在实验教学中应注意的问题。     

Synthesis and crystal structures of multidimensional coordination polymers based on W/Cu/S clusters with flexible imidazole ligands

Reactions of [WES3]2- (E = S, O) with CuX (X = NCS, CN, I) in the presence of bix (bix = 1,4-bis(imidazole-1-ylmethyl)benzene) in DMF or CH3CN resulted in the formation of two novel 2D --> 3D interpenetrating coordination polymers [S2W2S6Cu4(bix)2]n (1) and {[WS4Cu4(NCS)2(bix)3].CH3CN}n (2), a noninterpenetrating 3D polymer {[WS4Cu2(bix)].DMF}n (3), and two 2D sheet polymers [WS4Cu3(CN)(bix)]n (4) and {[OWS3Cu3(bix)2][I].DMF.2H2O}n (5), depending on the reaction temperature and the reagents used. Compound 1 contains a hexagonal prism of W2Cu4S6 cluster core, which serves as a 4-connecting node to link equivalent nodes via bix ligands, forming a 2D (4,4) net. In 2, a WCu4S4 core, which also acts as a 4-connecting node, connects the neighboring nodes either through single or double bix bridges, affording a different 2D (4,4) sheet. Inclined interpenetration occurs between two stacks of 2D sheets in the total structure of 1, while 2 involves a parallel interpenetration between the adjacent layers, both creating a 3D network. Compounds 1 and 2 represent the first examples of interpenetrating (4,4) frameworks with clusters as nodes and bidentate pyridyl-based ligands as linkers. Unlike 1 and 2, compound 3 has a noninterpenetrating 3D network, which is composed of the inorganic 1D (WS4Cu2)n chains linked by cis and trans bix ligands. Compound 4 features an inorganic 1D (WS4Cu3)n chain structure, which is linked by CN groups and bix ligands to form an infinite 2D network. Compound 5 is a 2D layer polymer with large inner cavities.     

Tuned C?H Functionalization to Construct Aza‐Podophyllotoxin/Aza‐Conidendrin Derivatives by Means of Domino Cyclization

An efficient domino cyclization method for the construction of aza‐podophyllotoxin/aza‐conidendrin derivatives has been established. Reactions of different dienes with aryl halides in the presence of a palladium catalytic system produced different kinds of podophyllotoxin derivatives through a highly regioselective C? H functionalization. Treatment of dienes with aryl halides that have electron‐withdrawing substituents on the phenyl ring created aza‐podophyllotoxin derivatives by means of the functionalization of the C? H bonds ortho to the C? halide bonds of the incoming aryl halides. The reaction of dienes with 1‐iodobenzene or aryl halides that incorporate electron‐donating groups produced aza‐conidendrin derivatives by means of the functionalization of both sp³ C? H and sp² C? H bonds. The regioselective C? H functionalization for the formation of different pseudo‐podophyllotoxin/‐conidendrin derivatives is proven by analyses of the ¹H NMR spectra of the products and selective X‐ray analyses of the structures of the products. Thus, the palladium‐catalyzed domino cyclization of 1,6‐dienes for the preparation of aza‐podophyllotoxin/aza‐conidendrin derivatives can be controlled by selectively controlling the C? H functionalization.