Topological order in the phase diagram for high-temperature superconductors with point defects

Applying a Lindemann like criterion obtained previously by Kierfeld et al. [J. Kierfeld, T. Nattermann, T. Hwa, Phys. Rev. B 55 (1997) 626], we estimate the magnetic field and temperature for a high-T_c superconductor, at which a topologically ordered vortex glass phase becomes unstable with respect to a disorder-induced formation of dislocations. The employed criterion is shown to be equivalent to a conventional phenomenological Lindemann criterion including the values for the numerical factors, i.e., for the Lindemann number. The positional correlation length of the topologically ordered vortex glass is calculated.     

Synthesis in solid state, structural regularity and reaction mechanism for [VS_4-Cu_n] clusters

The reaction system (NH4)3VS4/CuCl/PPh3/Et4NBr afforded a series of [VS4-Cun] dusters with various core configurations in the solid state at low heating temperature. The structural regularity of [VS4-Cun] dusters and the influence of the CuCl:(NH4)3VS4 ratio as well as that of reaction temperature and time on the formation of duster core have been summarized. The reaction mechanism of forming V-Cu-S clusters has also been explored.     

荧光光度法直接测定高纯氧化钕中的痕量镨和铈

使用Ｐ－ＥＬＳ５０荧光光谱仪，在盐酸介质中，用同一激发波长激发，分别测定Ｐｒ（Ⅲ）（ｎｍ）和Ｃｅ（Ⅲ）（３５６ｎｍ）发射峰强度。     

Syntheses and Characterizations of Two Copper Coordination Polymers Constructed by 4,4''''-Bipyridine

1 INTRODUCTION Self-assembly of coordination polymers fromthe basic building blocks is of considerable interestdue to their intriguing diverse architectures and po-tential applications in catalysis and advanced mater-ials, such as magnetic, optical a…     

恒电流吸附计时电位法的研究 Ⅱ.铜、铅的微分吸附计时电位法连测

研究了ＮＨ３／ＮＨ４Ｃｌ底液中，铜、铅与水杨基荧光酮（ＳＡＦ）形成的络合物在悬汞电极上的恒电流吸附计时电位溶出行为。讨论了富集时间，溶液ｐＨ值，溶出恒电流大小及铜、铅浓度比值等对ｄｔ／ｄＥ～Ｅ溶出曲线的影响。并得出了连测铜铅的条件。     

2,3-吡啶二羧酸铜(Ⅰ)配合物的合成与结构

铜配合物具有多变的配位结构,可活化小分子,可用于氧转移、氧化加成、新陈代谢、均相催化等许多领域。还可以用作金属酶的化学模拟和配合物结构及反应性能研究方面[1-3]。本文以2,3 二羧酸 吡啶为辅助配体及[(PPh3)2Cu(BH4)]作为起始原料,室温下,通过取代反应合成了单核铜(Ⅰ)配合物[(PPh3)2Cu(C7H4NO4)],经元素分析、电导、光电子能谱、红外光谱及单晶XRD方法对配合物进行了表征。1　实验部分1 1　仪器和试剂意大利ERBA 1106元素分析仪,JA96 970等离子光谱仪,Nicolet170SX分析仪(CsI压片),AV 300Bruker分析仪(CDCl3溶剂,8…     

催化动力学光度法测定痕量铜的研究

本研究了在氨水介质中铜（Ⅱ）催化过氧化氢氧化亮黄的褪色反应及其动力学条件，建立了一种超高灵敏、高选择性的测定环境试样中痕量铜的新方法，可测定０．００４～０．５μｇ／２５ｍＬ范围内的铜（Ⅱ）。     

Decomposition of EuPdIn and EuPtIn at high temperature and high pressure—formation of the hexagonal Laves phases EuPd0.72In1.28 and EuPt0.56In1.44

EuPd_0.72In_1.28 and EuPt_0.56In_1.44 were prepared under multianvil high-pressure (10.5 GPa) high-temperature (1500 and 1400 K) conditions from the precursor compounds EuPdIn and EuPtIn. They were investigated by X-ray diffraction on both powders and single crystals: MgZn₂-type, space group P6₃/mmc, a=578.7(1) pm, c=944.9(3) pm, wR2=0.0734, 263 F² values for EuPd_0.72In_1.28 and a=591.1(2) pm, c=933.8(2) pm, wR2=0.0853, 151 F² values for EuPt_0.56In_1.44 with 13 variable parameters per refinement. Both structures are built up from face- and corner-sharing tetrahedra of palladium (platinum) and indium atoms. The europium cations are located in cavities within the three-dimensional [Pd_0.72In_1.28] and [Pt_0.56In_1.44] networks. The 2a and 6 h positions of the tetrahedral networks show mixed Pd/In and Pt/In occupancy in EuPd_0.72In_1.28 and EuPt_0.56In_1.44, respectively. The crystal chemistry of these indides is briefly discussed.     

N-(邻-氯苯基)氨基乙酸铜(Ⅱ)和N-(邻-甲基苯基)氨基乙酸铜(Ⅱ)的合成、晶体结构和电子结构

合成了N-(邻氯苯基)氨基乙酸铜(Ⅱ)和N-(邻甲基苯基)氨基乙酸铜(Ⅱ)的单晶体,测定了它们的晶体结构,并对其电子结构进行EHMO计算。N-(邻氯苯基)氨基乙酸铜(Ⅱ)属单斜晶系,空间群P2₁/a.a=8.786(4),b=7.777(2),c=11.956(2)Å,β=96.01(3)°,V=812.4ų,Z=2,D_c=1.77g·cm^-3;N-(邻甲基苯基)氨基乙酸铜(Ⅱ)属单斜晶系,空间群P2₁/a,a=8.925(6),b=7.973(8),c=11.856(9)Åβ=96.23(6)°,V=838.6Å,Z=2,D_c=1.55g·cm^-3。两配合物互为异质同晶。配合物中,铜原子为分子的对称中心,并与两个配位体的两个羧基氧和两个氨基氮原子形成四方形配位结构,平均Cu-O键长为1.902Å,Cu-N为2.050Å。量子化学计算表明,在配位键的形成中,铜原子的d轨道的作用均不大,但配体中苯环上取代基的性质对Cu-N键强度有一定影响。     

添加有机肥和葡萄糖对铜毒害旱地红壤微生物生物量的影响

在预培红壤中加入定量的有机肥和葡萄糖及不同浓度的Cu,25℃培养14d，测定了土壤微生物生物量C（Cmic),N(Nmic)。结果表明，存在有机肥和葡萄糖时，土壤中Cmic和Nmic随着Cu浓度的增加而降低；Cmic/Nmic随着Cu浓度的增加而增大。施加有机肥和葡萄糖的土壤中，在所有Cu处理浓度下，土壤中Cmic和Nmic均比未加有机物质处理高，特别是有机肥处理中土壤Cmic和Nmic均比其它处理高得多，说明有机肥可明显减轻Cu对土壤微生物生物量的毒性，同时也说明有机肥可提供微生物N源。不含Cu时，加入有机肥和葡萄糖导致土壤中Cmic和Nmic增加，其中有机肥明显。