一个二维梯状化合物[Ni(μ1，5-dca)2(en)]n的合成，结构和磁性(英)

A new nickel(Ⅱ)-dicyanamide compound, [Ni(dca)₂(en)]_n (1) (dca=dicyanamide anion, [N(CN)₂]^-); en=ethylene diamine), has been synthesized and its structure has been determined by single crystal X-ray diffraction analysis. The crystal is monoclinic, space group P2₁/n with unit cell dimensions: a=0.694 3(1) nm, b=1.041 5(2) nm, c=1.4132(2) nm, and β=90.381°, Z=4, V=1.011 0(3) nm³. In this compound, the adjacent nickel atoms are connected by dca all in μ_1，5-bridging mode to form ladder-like units, which are linked with double dca bridges to generate a regular infinite stair-like structure. Temperature-dependent magnetic susceptibility was also characterized for this compound. CCDC: 208276.     

AlN粉体及高导热陶瓷散热罩的制备

以Al2O3和碳粉为原料,采用碳热还原法制备了AlN粉体,探讨了原料摩尔比、合成温度和保温时间等因素对AlN粉体合成的影响.通过XRD,SEM等测试对粉体进行了表征.在1650℃保温4h,合成出粒径约为1～5μm的纯AlN粉末,原料粒度越细越有利于AlN的生成,C/Al2O3摩尔比应略大于3.以石蜡为主粘结剂,通过热压铸成型方法成型AlN陶瓷散热罩素坯,经低温排胶、无压烧结工艺后得到高导热率AlN基陶瓷散热罩.研究了素坯排胶过程及陶瓷烧结过程的影响因素,排胶过程中缓慢升温至300℃,可避免素坯坍塌;排胶后素坯在1800℃无压烧结4h制得的AlN陶瓷LED散热罩密度为3.24 g/cm3,室温热导率高于100 W/m·K.     

A Cadmium(II) Coordination Polymer:Crystal Structure and Fluorescent Property of [CdCl2(4,4''-bipyridine)]∞

The reaction of L-histidine,CdCl2(2.5H2O and 4,4'-bipyridine in methane/water gave rise to a two-dimensional coordination polymer [CdCl2(4,4'-bipyridine)]( which has been characterized by single-crystal X-ray diffraction.The polymer crystallizes in the orthorhombic sys-tem,space group Cmmm with a = 12.083(7),b = 11.771(7),c = 3.781(2)(A),V = 537.8(6)(A)3,Z = 2,C10H8N2CdCl2,Mr = 339.48,Dc = 2.097 g/cm3,F(000) = 328 and μ(MoKα) = 2.490 mm-1.The final R = 0.0658 and wR = 0.1398 for 257 observed reflections with I≥2σ(I).     

Synthesis, Crystal Structure and Magnetic Property of the Polymeric Ribbon： [Co（ip）（phen）]n

1 INTRODUCTION The design and synthesis of metal-organic coor- dination polymers are of current interest owing to their intriguing architectures and potential applica- tions, such as catalysis, fluorescence and magne- tism[1～4]. Many transition metal-organic polymers have been synthesized and exhibit interesting magneticproperties[5～9]. Among them, coordination polymers constructed by dicarboxylate ligands have attracted considerable attention due to their rich coordination modes and di…     

空气-氩气混合气冷却ICP-AES中钙、钡、铜、锌元素的谱线强度和信背比的研究

研究了小功率空气－氩气混合气冷却ＩＣＰ中４种元素（钙、钡、铜、锌）、８条谱线的强度和信背比随冷却气组成及观测高度的变化,并估算了折中条件下的检出限。对于离子线及激发电位较高的原子线,冷却气中引入体积分数为５％～１０％空气后,谱线强度最大并大于Ａｒ－ＩＣＰ中数值;对于激发电位较低的原子线,随着冷却气中空气含量的增大其谱线强度逐渐减小。谱线的信背比则与激发电位及谱线波长有关     

Doping Effect of Bi~(3+) on the Properties of YAG:Ce~(3+),Mn~(2+) Phosphor Ceramics for Warm WLEDs

A series of Bi³⁺-doped YAG:Ce³⁺, Mn²⁺ ceramics was synthesized successfully by gel-casting method and structurally characterized by XRD and SEM. The doping effect and related mechanism of Bi³⁺ upon the luminescent property were studied. It can be assigned to the energy transfer of multipolar interaction from Bi³⁺ to Ce³⁺, leading to the improvement of emission intensity about 58% for 0.0001 Bi³⁺ and 0.05 Mn²⁺ doping. In addition, the emission is significantly red-shifted with the peak at 590 nm for the Y2.9939 Ce0.006 Bi0.0001 Al4.96 Mn0.02 Si0.02 O12 ceramic specimen with in-line transmittance 81.6% at 1100 nm. The LED module assembled from Y2.9939 Ce0.006 Bi0.0001 Al4.96 Mn0.02 Si0.02 O12 ceramic owns correlated color temperature(CCT) of 3960 K and luminous efficiency(LE) of 92 lm/W, implying that doping Bi³⁺ shows a good sensitization effect in the YAG:Ce³⁺, Mn²⁺ ceramic system and further serving as an attracting phosphor candidates for warm WLEDs applications.     

Synthesis of High-purity Fe2AlB2 and the Effect as Sintering Additive for ZrB2

Fe₂AlB₂ powder material was prepared by the direct reaction of iron,aluminum and boron powders in a tubular furnace.The effects of different Al contents,temperature and raw material pretreatment on the purity of product were studied.The mixed powder with the stoichiometric ratio of 1.5Al/2Fe/2B was processed by CIP (Cold Isostatic Pressing),and then calcined at 1150℃ for 120 min.The product containing a small amount of impurities is treated with alkaline solution to obtain high-purity Fe₂Al B₂ powder.Zr B₂-Fe₂Al B₂ composite ceramic was successfully prepared at 1250℃ by hot pressing sintering.The density,hardness and fracture toughness were 96.2%,22±0.3 GPa and 5.78±0.5 MPa·m^1/2,respectively.