Z.Wang1)
,
Q.H.Zhao2)
,
D.Z.Liao2)
,
Z.H.Jiang1)
,
S.P.Yana and G.L.Wang1) 1) Department of Chemistry
,
Nankai University
,
Tianjin 300071
,
China. 2) State Key Laboratory Coordination Chemistry
,
Nanjing University
,
Nanjing 210008
,
China
金属学报(英文版)
Five novelcomplexesofformula 〔Ln( pfpr)3〕2 NITRS·nH2 O, where Ln = Nd, Sm , Eu, Gd, Dy; pfpr= pentafluoropropionate; NITRS= 2 - (2’- thienyl) - 4,4 ,5 ,5 te tramethylimidazoline 1 oxyl 3 oxide, and n= 6(for Nd);4(for Eu and Gd) ;2(for Sm and Dy), have been synthesized. Thesecomplexes werecharacterized by elemental analysis, IR, electronicspectra and EPR. Thevariabletemperature(2 300 K) magneticsusceptibility ofthecomplex 〔Gd(pfpr)3〕2 NITRS·4 H2 Owas determined and discussed. Theexchange integral,J= 0 44 cm 1 , wasfoundtobepositive,indicating a weakferromagneticspin ex changeinteraction between theradicaland Gd(III) ion.
关键词:
ferromagnetism
,
null
,
null
,
null
余庚华
,
仲嘉琪
,
王谨
,
詹明生
量子电子学报
doi:10.3969/j.issn.1007-5461.2012.03.001
Ba原子是光频标的候选者之一,对其进行有效的激光冷却与囚禁需要相关能级的寿命和跃迁几率的信息.Ba原子激发态6s6p3P1能级在激光冷却实验中很重要,通过Hanle效应实验测量了这一能级的寿命和自发辐射率,从理论和实验上研究了探测激光有限线宽和光强对Ba原子基态6s21S0与激发态6s6p3P1之间跃迁(波长791nm)Hanle效应荧光信号的影响.在考虑了激光线宽和光强因素后所得到的激发态6s6p3P1的能级寿命和自发辐射率与其他方法给出的结果符合很好.
关键词:
光谱学
,
能级寿命
,
Hanle效应
,
线宽
,
Ba原子
,
原子频标
Yongtao Zhao Junhui Dong Yonglin Ma Liping Zhao Xiaobing Pei
材料科学技术（英）
The purpose of this study is to discuss the microstructure and properties variation of the weld metal in the dissimilar stainless steels during the argon tungsten-arc welding process. Because of the existence of different materials and chemistry variation within welds, properties, such as tensile and fracture properties and so on, are expected to show spatial variation. In the study, microstructures were observed by optical and electron microscopy. Good appearance and uniform structure and typical dendrite structure were observed in welding joint. The micro-hardness tester and electronic universal stretcher were used to measure the mechanical properties of the weldments and base metals. The heat affected zone (HAZ) near 1Cr13 hardness is up to peak value of 1150 HV, the strength of weldments is nearly same as austenite stainless steel. In addition,
through seawater immersion test, polarization curves and AC impedance spectroscopy of the weldments and base metals are obtained. It was found that corrosion resistance at welding joint lies between 1C13 and 1Cr18Ni9Ti.
关键词:
1Cr13
,
1Cr18Ni9Ti
,
welding joint
,
mechanical and galvano－chemistry
刘国华
,
杨平
,
蒋宛莉
,
郭晓稚
,
许贵宝
,
蒋雪璋
,
沈梁
,
王筱梅
功能材料
选择氮杂芴(咔唑)为π-中心,分别以三苯胺和噁二唑取代基为"枝",合成了两个强双光子吸收的氮杂芴衍生物-2,8-双(4-三苯胺乙烯基)-N-乙基氮杂芴(简称NT-G1)和2,8-双(2-(4'-乙氧基)-5-(4'-苯乙烯)-1,3,4- 噁二唑)-N-基氮杂芴(简称NO-G1),进行了核磁共振谱和质谱等表征.飞秒钛宝石激光器泵浦下,NT-G1和NO-G1溶液发出强双光子上转换荧光,且后者的双光子荧光发射截面是前者的7倍;双光子荧光法计算出NT-G1和NO-G1双光子吸收截面分别为215GM和454GM.分子构型优化表明,NT-G1分子中心"氮杂芴"所在平面与两端苯环呈螺旋桨式排布;而NO-G1分子共轭长度增大,且中心的"氮杂芴"与两端延伸的"枝"呈平面构型;从结构上看,NO-G1分子属"D-A-π-A-D"型,具有明显的pn结模式,这些都使NO-G1分子具有更好的分子内电荷转移能力,因而有较高的双光子吸收截面.
关键词:
2,8-双(4-三苯胺乙烯基)氮杂芴
,
2,8-双(2-(4'-乙氧基)-5-(4'-苯乙烯)-1,3,4- 噁二唑)-N-乙基氮杂芴
,
双光子吸收
,
双光子荧光
汪山山
,
毛昌辉
,
杨剑
,
梁秋实
,
孙波
稀有金属
doi:10.3969/j.issn.0258-7076.2012.01.029
搅拌摩擦焊的旋转速度对接头焊缝形貌、微观组织和力学性能均有较大的影响.采用搅拌摩擦焊方法对5 mm厚的(WC+ B4C)p/6063Al复合材料进行焊接试验,固定焊接速度为100 mm·min -1,旋转速度分别为900,1100,1300和1500 r·min -1,焊后观察焊缝宏观形貌和各种缺陷,并对接头的微观组织和力学性能进行了分析.焊缝宏观缺陷研究结果表明,随着旋转速度的升高,焊接热输入量增大,金属流动性得到改善,飞边、沟槽等宏观缺陷显著增多,焊缝形貌越来越粗糙；接头微观组织研究表明,由于搅拌头的搅拌作用,相比于母材,在焊核区增强相颗粒分布更加均匀,更多增强相颗粒发生破碎,且随着旋转速度的增加,这种趋势增强.对接头的抗拉强度研究表明,在1300 r·min-1以内时,随着旋转速度增加,接头抗拉强度随之增加,最大值为166 MPa,进一步增加到1500 r·min -1时,强度又有所降低,为154 MPa.
关键词:
搅拌摩擦焊
,
铝基复合材料
,
旋转速度
,
接头组织
P.Manivel
,
G.Venkatachari
材料科学技术（英）
Poly p-aminobenzoic acid has been synthesized by chemical oxidation method. The inhibitive effect of poly p-aminobenzoic acid on iron in 1 mol/L HCl solution was investigated by polarization and electrochemical impedance spectroscopy and compared with that of monomer p-aminobenzoic acid. The effectiveness of poly p-aminobenzoic acid is very high in comparison with that of monomer. The results show that both cathodic and anodic processes were suppressed by p-aminobenzoic acid and poly p-aminobenzoic acid of iron dissolution in 1 mol/L HCl by their adsorption on the iron surface. The inhibition efficiency of both p-aminobenzoic acid and poly p-aminobenzoic acid were found to increase with the inhibitor concentrations. Ultraviolet (UV) reflectance studies of the iron surface after exposure to inhibitor acid show that poly p-aminobenzoic acid is strongly adsorbed on iron surface.
关键词:
p-aminobenzoic acid
,
null
,
null
,
null
,
null
邱元进
,
杨方
,
刘正才
,
林永辉
,
刘素珍
色谱
doi:10.3724/SP.J.1123.2012.01020
建立了畜禽产品中维吉尼亚霉素M1和S1药物残留检测的液相色谱-串联质谱分析方法.样品以甲醇-乙腈溶液(1:1,V/v)提取,上清液经0.01 mol/L磷酸二氢铵溶液稀释后,Oasis HLB固相萃取小柱净化,Luna C18色谱柱分离,以乙腈和含0.1％(体积分数)甲酸的5 mmol/L乙酸铵水溶液作为流动相进行梯度洗脱,电喷雾正离子模式电离(ESI+).多反应监测(MRM)模式检测,外标法定量.该方法对两物质线性范围均为0.15～10.O μg/L,相关系数r2均大于0.999；定量下限均为0.25 μg/kg.在不同基质中,0.25、0.50、2.5 μg/kg 3个添加水平的平均回收率范围为71.2％～98.4％,精密度范围为3.6％～15.4％.该方法具有快速简便、灵敏度高、准确性强等特点,适用于畜禽产品中维吉尼亚霉素的检测.
关键词:
液相色谱-串联质谱(LC-MS/MS)
,
维吉尼亚霉素M1
,
维吉尼亚霉素S1
,
残留
,
畜禽产品
Journal of Superconductivity and Novel Magnetism
The zero-field splittings (D and E) and the g factor of Gd(x)Eu(1-x)Ba(2)Cu(3)O(7-delta) are theoretically investigated from the superposition model formulas or the zero-field splittings and the approximation formula of the g factor containing the admixtures of the ground (8)S(7/2) and the excited (6)L(7/2) (L = P, D, F, G) states, respectively. Based on the studies, the impurity-ligand bond angles related to the crystalline c axis in the impurity Gd(3+) center are about 1.1 degrees smaller than those in the host Eu(3+) site of EuBa(2)Cu(3)O(7-delta). The calculated D, E, g factor and the effective magnetic moment mu(eff) show reasonable agreement with the experimental data. Particularly, the improvement for the theoretical D is achieved in the present work by considering the above angular distortion.
关键词:
Crystal fields and spin Hamiltonians;EPR;Superposition model;Gd(x)Eu(1-x)Ba(2)Cu(3)O(7-delta);spin-hamiltonian parameters;gd3;superconductor;euba2cu3oy
Journal of Alloys and Compounds
The local structures and the EPR g factors of three Ni3+ centers (1)-(3) in LaSrAl1-xNixO4 (LSAN) are theoretically investigated from the perturbation formulas of the g factors for a 3d(7) ion of low spin (S = 1/2) in tetragonally and orthorhombically distorted octahedra. In these formulas, the contributions to the g factors from the low symmetrical parts of the crystal-fields, characterized by the crystal-field parameters D-s, D-t, D-xi and D-eta are taken into account. Based on the studies, it is found that the ligand octahedra are elongated along [0 0 1] axis by about 0.9, 0.7 and 1.0% for centers (1)-(3). The above distortions have a Jahn-Teller nature instead of ordinary lattice deformation, leading to the ligand octahedra less elongated than that (approximate to 1.3%) in the host. Apart from the axial elongation, center (3) suffers additional orthorhombic distortion due to inequivalent variation by about +/- 0.3% of the planar bonding lengths along [10 0] and [0 101 axes, respectively. The calculated g factors show good agreement with the observed values. (c) 2006 Elsevier B.V. All rights reserved.
关键词:
defect structures;electron paramagnetic resonance;crystal-fields and;spin Hamiltonians;Ni3+;LaSrAl1-xNixO4 (LSAN);transition-metal ions;optical-spectra;brillouin-scattering;superposition model;single-crystals;cr3+ ions;srlaalo4;vacancy;epr
