高能X射线的硬化校正

根据原子的跃迁能量和能量吸收限,确定用与靶材料相同的材料做成滤波片,可以很好的吸收靶物质所产生的低能射线,使最初的多色X射线谱近似单色化,并用基于蒙特卡罗方法的Egsnrc软件对硬化校正方案进行了仿真分析,获得了较好的结果.     

氯,2,2′-二联呲啶铜络合物的TCNQ盐的晶体结构和分子结构

氯,2,2′-二联吡啶铜络合物TCNQ盐采用电化学方法培养出供X射线结构分析用的单晶。结构分析确定它属三斜晶系,a=7.920,b=13.140,c=19.126,α=100.77°,β=94.45°和γ=101.08°,空间群为P,每一个结晶学不对称单位含一个[Cu(bipy)_2Cl]·TCNQ_2分子。用量子化学处理(CNDO/2)其结构参数,对TCNQ的电子结构,以及在晶胞中的堆积方式进行了讨论。     

烯烃配位的过渡金属卡宾配合物的研究——ⅩⅥ.四氟苯并双环[2.2.2]辛三烯三羰基铁的新奇开环反应——新型螯合双烯丙基二羰基铁配合物的合成和结构

四氟苯并双环[2.2.2]辛三烯三羰基铁(C_(12)H_6F_4)-Fe(CO)_3(1)与芳基锂试剂ArLi(Ar=C_6H_5ο-,m-,ρ-CH_3C_6H_4、ρ-CH_3OC_6H_4、ρ-ClC_6H_4),在低温下反应,生成的酰羰基锂盐中间体用三乙基氧铃一四氟硼酸盐(Et_3OBF_4)在水溶液中于O℃进行烷基化时,双环烯烃配体开环,生成组成为(C_(12)H_6F_4)(CO)_2FeC(OC_2H_5)Ar的螯合双烯丙基二羰基铁配合物(2—7)。配合物5的晶体属单斜晶系,晶胞参数为:a=16.870(4),b=13.707(4),c=19.361(4)A,β=107.92(2)°,v=4259(1)A~3,z=8,空间群为C_(2h)~6—C2/c,最后的偏离因子R=O.0409,R_w=O.0391。     

含烯烃配体的过渡金属卡宾配合物的研究 Ⅴ.新型异构化的环己二烯(二羰基)[乙氧基(芳基)卡宾]铁配合物的合成和结构

最近,我们报道了含直链共轭双烯配体和支链共轭双烯配体的金属羰基化合物,丁二烯三羰基铁和异戊二烯三羰基铁与亲核试剂芳基锂在低温下反应,继后用Et_3OBF_4烷基化,分别生成一族新奇的异构化的丁二烯和异戊二烯烷氧基卡宾铁配合物。这些配合物的结构显示的中心金属和烯烃配体的键合方式是非常有趣的。本文选择含环状共轭双烯配体的1,3-环己二烯三羰基铁(1)与芳基锂在低温下进行类似的反应,以观察环烯烃配体的反应活性及其     

THE CRYSTAL STRUCTURE OF THE ADDITION COMPOUND OF SODIUM TETRAHYDROGEN DECAVANADATE AND HEXAMETHYLENETETRAMINE

The title compound crystallizes in the space group C_i~1-Pī with cell constants a=9.589, b=10.486, c=11.139, α=103.27° β=98.20° and γ=103.16°. After deriving the position parameters of all V atoms by Patterson method, the coordiuates of all the non-hydrogen and hydrogen atoms were obtained from successive Fourier and difference syntheses, and the leastsquares refinement for all atoms gave a final discrepancy factor R=0.0279. The chemical content within a unit cell has been identified definitely as (Na~+)_2·(H_2V_(10)O_(28)~(4-))·2((CH_2)_6N_3N-H~+)·8H_2O.     

溴酸钾-酸性铬蓝K新化学发光体系检测水中亚硝酸根

研究发现亚硝酸根对溴酸钾-酸性铬蓝K体系的化学发光有显著的增强作用,从而建立一种快速、准确的检测亚硝酸盐的新方法.本方法检测亚硝酸根的线性范围为1.0×10-8～8.0×10-5mol/L,检测限为1.1×10-10mol/L;对1.0×10-7mol/L和1.0×10-5mol/L的亚硝酸根进行11次平行测定,标准偏差分别为1.6%和2.1%.     

THE STUDY OF SPECTRA AND X-RAY CRYSTAL STRUCTURE OF A NOVEL BIONICS INSECTICIDE——(CH_3)_2NHCH(CH_2S_2O_3)_2Na·H_2O

IR and NMR spectra of novel bionics insecticide—C_5NS_4O_6H_(12)Na·H_2O have been studied. The molecular and crystal structures of the compound also have been determined. The compound crystallizes in the monoclinic space group C_(2h)~5, - P2_1/n with α= 8.0972. (9) , b =16.262(4), c = 10.370(3), β= 94.26(2)° and z = 4.The result shows that N atom in this compound captures a proton to form HN~ group, Na~ is in statistical disorder. Therefore, the structural formula of tho compound is (CH_3)_2HN~ —CH(CH_2S_2O_3~-)_2·1/2 (Na~ )_2·H_2O.     

2-(2′-噻唑偶氮)-5-二乙胺基酚的晶体结构

用 Philips PW-1100型单晶衍射仪收集了2-(2′-噻唑偶氮)-5-二乙胺基酚晶体的三维衍射数据.应用最小函数法和直接法测定了晶体结构.在衍射仪上测得晶胞常数 a=20. 018(±0. 005),b=8. 894(±0. 03) (?),c=7. 658(±0. 002) ,z=4. 空间群为P2_12_12_1. 原子的坐标参数、温度因子参数及非氢原子的各向异性温度因子参数一起进行了全矩阵最小二乘修正,最后 R 因子为0. 072,加权以后 R_W 为0. 051. 晶体结构分析结果表明:二乙胺基有效地参与了共轭体系,使二乙胺基的强助色性能得到了很好的解释.     

Thermal stability of Mg2Si epitaxial film formed on Si（111） substrate by solid phase reaction

A single crystalline Mg2 Si film was formed by solid phase reaction(SPR) of a Si(111) substrate with an Mg overlayer capped with an oxide layer(s),which was enhanced by post annealing from room temperature to 100 ℃in a molecular beam epitaxy(MBE) system.The thermal stability of the Mg2 Si film was then systematically investigated by post annealing in an oxygen-radical ambient at 300℃,450℃ and 650 ℃,respectively.The Mg2 Si film stayed stable until the annealing temperature reached 450 ℃ then it transformed into amorphous MgO x attributed to the decomposition of Mg2 Si and the oxidization of dissociated Mg.     

Magnetic Properties and Antiferromagnetic Coupling in Inhomogeneous Zn1-xFexO Magnetic Semiconductor

Zn1-xFexO inhomogeneous oxide magnetic semiconductor films with high Fe concentration are prepared by sputtering, and fast annealing is carried out at different temperatures. It is found that magnetic properties are greatly modulated by controlling the composition inhomogeneity and subsequently fast annealing. Both ferromagnetic and paramagnetie components are found to coexist in the as-deposited Zn1-xFexO magnetic semiconductor. In particular, the antiferromagnetic coupling between the neighbouring local ferromagnetic regions is found in the as-deposited Zn0.23Fe0.77O film, and the antiferromagnetic coupling strength increases with increasing temperature from 110K to 300 K. We believe that this unusual antiferromagnetic coupling is mediated by thermally activated hopping carriers.