2，5，7，9－四硝基－2，5，7，9－四氮杂双环［4，3，0］壬－8－酮的合成及其性能

以２，５，７，９－四氮杂双环［４，３，０］壬－８－酮盐酸盐为母体化合物，合成了一种多硝基氮杂环化合物２，５，７，９－四硝基－２，５，７，９．四氮杂双环［４，３，０］壬－８－酮，用核磁共振、质谱和元素分析进行了结构鉴定。研究了母体化合物在硝酸乙酸酐体系中的硝化反应和炸药的性能。     

2,5,7,9—四硝基—2,5,7,9—四氮杂双环〔4,3,0〕壬—8—酮的合…

以２，５，７，９－四氮杂双环〔４，３，０〕壬－８－酮盐酸盐为母体化合物，合成了一种多硝基氮杂环化合物２，５，７，９－四硝基－２，５，７，９－四氮杂双环〔４，３，０〕壬－８－酮，用核磁共振、质谱和元素分析进行了结构鉴定。研究了母体化合物在硝酸－乙酸酐体系中的砂化反应和炸药的性能。     

柠檬酸钛（Ⅳ）化合物的合成和热性质研究

四氯化钛与柠檬酸反应，制得新的固态化合物Ｔｉ２Ｏ２（ＯＨ）２（Ｃ６Ｈ５Ｏ７）·３Ｈ２Ｏ．通过元素分析和容量滴定法确定了化合物的组成；用Ｘ射线粉末衍射，ＩＲ等对其结构进行了表征；用ＴＧ和ＤＴＡ研究了化合物在空气氛下的热分解特性，计算机求解化合物热分解过程的反应级数ｎ，活化能Ｅａ，频率因子Ａ，焓变ΔｒＨ和熵变ΔｒＳ．     

dl－樟脑双官能团衍生物的多环硫代磷酰胺酯的合成及生物活性

ｄｌ－樟脑经氧化、氨化或经肟化、还原，分别制得双官能基的１，２，２，－三甲基－１，３－环戊二胺５和１，７，７－三甲基－３－氨基双环［２．２．１］庚－２－醇９．化合物５和９分别与硫代磷酰二氯酯６发生关环反应，得到新型的多环硫代磷酰二胺酯７和硫代磷酰胺酯１０．本文合成化合物７１４个；化合物１０１７个．这些化合物大都具有一定的杀菌、除草或植物激素活性．     

dl—樟脑双官能团衍生物的多环硫代磷酰胺酯的合成及生物…

ｄｌ－樟脑经氧化、氨化或经肟化、还原，分别制得双官能基的１，２，２，－三甲基－１３－环戊二胺５和１，７，７－三甲基－３－在双环「２．２．１』庚－２－醇９，化合物５－９分别与硫代磷酰二氯酯６发生关环反应，得到新型的多环硫磷酰二胺酯７和硫化磷酰胺酯１０．本文合成化合物７１４个；化合物１０ １７个，这些化合物大都具有一定的杀菌、除草或植物激素活性。     

3──肉桂酰基-5─溴酚酮的合成

本文研究了３－肉桂酰基革酚酮的５位单溴代产物的合成，设计路线为：以２－肉桂酰基－７－甲氨基革酮（１）为起始原料，首先进行溴化得到２－肉桂酰基－４─溴－７─甲氨基酮（２）：化合物（２）在氢氧化钠碱性溶液中水解得到目标物３─肉桂酰基－５－溴酚酮（３），化合物２，３为尚未见文献报道的新化合物，它们的结构经物质性质的测定，光谱数据和元素分析得到证实。     

2，3，7－三取代双环吡唑啉的合成

研究了双环吡唑啉的形成及它们的酰化和磺酰化反应，合成了１１个７－取代苯亚甲基－２－酰基－３－取代苯基－３，３ａ，４，５，６，７－六氢－２Ｈ－吲唑及其苯并三唑乙酰基双环吡唑啉；讨论了部分化合物的波谱特征。化合物经ＩＲ，１ＨＮＭＲ和元素分析给以确证。     

2,3,7—三取代双环吡唑啉的合成

研究了双环吡唑啉的形成及它们的酰化和磺酰化反应，合成了１１个７－取代苯亚甲基－２－酰基－３－取代苯基－３，３ａ，４，５，６，７－六氢－２Ｈ－吲唑及其苯并三唑乙酰基双环吡唑啉，讨论了部分化合物的波谱特征，化合物经ＩＲ，＾１ＨＮＭＲ和元素分析给以确证。     

乙酰基取代的酮和酚酮化合物与芳醛了缩合反应──缩杂环酮化合物的合成(V)

为寻找具有生理活性的Ｔｒｏｐｏｎｏｉｄｓ，选择３－乙酰基■酚酮（１）和２－乙酰基－７－甲基■酮（６）与ＴＭＢ等取代醛反应得到缩合产物（２－５），（７－９）；缩合产物３－（３，４，５，－三甲氧基）肉桂酰基酚酮（２）和３－（３，４－亚甲二氧基）肉桂酰基■酚酮（４）与羟氨和苯肼进行缩合成环得到苯乙烯基取代的缩杂环■酮化合物（１０－１３）；化合物（１）与３，４，５－三甲氧基苯甲醛在原甲酸三乙酯和高氯酸存在下反应一步得到２－（３，４，５－三甲氧基）苯基－４，９－二氢环庚并吡喃－４，９－二酮（１４）。以上化合物（２－５），（７－１４）为尚未见文献报道的新化合物，其结构经光谱分析和元素分析予以证实。     

5,5′-二甲酰基-3,3′,4,4′-四甲基-2,2′-二吡咯基苯基甲烷的合成

合成了５，５′＿二甲酰基＿３，３′，４，４′＿四甲基＿２，２′＿二吡咯基苯基甲烷〈７〉，经核磁共振氢谱和元素分析表征了结构．初步探讨了这种新化合物的性质．     

氧化物超导材料的键价计算

Y-Ba-Cu—O和Tl(Bi)-Ba-Cu-O氧化物体系的晶体结构与其超导转化温度T_c存在密切关系。以统计法则为基础的键价计算结果表明,具有超导性的 Y系、Tl系氧化物晶体中各离子接近其正常价态,CuO-维链与CuO_2二维面中的铜离子的价态无显著差异。这和对Y-Ba-Cu-O 系进行的紧束缚带电子结构计算的结果不同,所以CuO-维链的存在与否对氧化物超导性的出现不一定必需,Tl(Bi)系不存在CuO-一链,而它的T_c甚至比Y系更高就是个很好的实例。     

Temperature-induced valence transition and associated lattice collapse in samarium fulleride

The different degrees of freedom of a given system are usually independent of each other but can in some materials be strongly coupled, giving rise to phase equilibria sensitively susceptible to external perturbations. Such systems often exhibit unusual physical properties that are difficult to treat theoretically, as exemplified by strongly correlated electron systems such as intermediate-valence rare-earth heavy fermions and Kondo insulators, colossal magnetoresistive manganites and high-transition temperature (high-T(c)) copper oxide superconductors. Metal fulleride salts-metal intercalation compounds of C60--and materials based on rare-earth metals also exhibit strong electronic correlations. Rare-earth fullerides thus constitute a particularly intriguing system--they contain highly correlated cation (rare-earth) and anion (C60) sublattices. Here we show, using high-resolution synchrotron X-ray diffraction and magnetic susceptibility measurements, that cooling the rare-earth fulleride Sm2.75C60 induces an isosymmetric phase transition near 32 K, accompanied by a dramatic isotropic volume increase and a samarium valence transition from (2 + epsilon) + to nearly 2 +. The negative thermal expansion--heating from 4.2 to 32 K leads to contraction rather than expansion--occurs at a rate about 40 times larger than in ternary metal oxides typically exhibiting such behaviour. We attribute the large negative thermal expansion, unprecedented in fullerene or other molecular systems, to a quasi-continuous valence transition from Sm(2+) towards the smaller Sm((2+epsilon)+), analogous to the valence or configuration transitions encountered in intermediate-valence Kondo insulators like SmS (ref. 3).     

高温铜氧化物超导体能隙问题研究最新进展

高温铜氧化物超导体的超导机制是最近20多年凝聚态物理中的重大难题之一,而蕴含其中的高温超导体的能隙问题,特别是赝能隙的起源及其与超导能隙之间的关系,一直是凝聚态物理实验和理论研究的重要内容。我们从实验和理论两方面,概括综述了近年来针对高温铜氧化物超导体能隙问题研究的最新进展,对几种能够直接探测赝能隙和超导能隙特性的实验方法,如角分辨光电子能谱、扫描隧穿谱和电子拉曼光谱等主要实验结果进行了系统的梳理,同时介绍了与这些实验结果紧密联系的几种较为流行的理论模型及其结果。最后针对这些问题给出了简单的讨论,并展望了下一步的发展,期望对高温超导体物理性质的进一步理解和研究具有积极的帮助作用。     

Superconductivity in single crystals of the fullerene C70.

The observation of superconductivity in doped C60 has attracted much attention, as these materials represent an entirely new class of superconductors. A maximum transition temperature (Tc) of 40 K has been reported for electron-doped C60 crystals, while a Tc of 52 K has been seen in hole-doped crystals; only the copper oxide superconductors have higher transition temperatures. The results for C60 raise the intriguing questions of whether conventional electron-phonon coupling alone can produce such high transition temperatures, and whether even higher transition temperatures might be observed in other fullerenes. There have, however, been no confirmed reports of superconductivity in other fullerenes, though it has recently been observed in carbon nanotubes. Here we report the observation of superconductivity in single crystals of electric-field-doped C70. The maximum transition temperature of about 7 K is achieved when the sample is doped to approximately four electrons per C70 molecule, which corresponds to a half-filled conduction band. We anticipate superconductivity in smaller fullerenes at temperatures even higher than in C60 if the right charge density can be induced.     

Resonance as a measure of pairing correlations in the high-Tc superconductor YBa2Cu3O6.6

One of the most striking properties of the high-transition-temperature (high-Tc) superconductors is that they are all derived from insulating antiferromagnetic parent compounds. The intimate relationship between magnetism and superconductivity in these copper oxide materials has intrigued researchers from the outset, because it does not exist in conventional superconductors. Evidence for this link comes from neutron-scattering experiments that show the unambiguous presence of short-range antiferromagnetic correlations (excitations) in the high-Tc superconductors. Even so, the role of such excitations in the pairing mechanism for superconductivity is still a subject of controversy. For YBa2Cu3O(6+x), where x controls the hole-doping level, the most prominent feature in the magnetic excitation spectrum is a sharp resonance (refs 6-11). Here we show that for underdoped YBa2Cu3O6.6, where x and Tc are below their optimal values, modest magnetic fields suppress the resonance significantly, much more so for fields approximately perpendicular to the CuO2 planes than for parallel fields. Our results indicate that the resonance measures pairing and phase coherence, suggesting that magnetism plays an important role in high-Tc superconductivity. The persistence of a field effect above Tc favours mechanisms in which the superconducting electron pairs are pre-formed in the normal state of underdoped copper oxide superconductors, awaiting transition to the superconducting state.     

Quantum magnetic excitations from stripes in copper oxide superconductors

In the copper oxide parent compounds of the high-transition-temperature superconductors the valence electrons are localized--one per copper site--by strong intra-atomic Coulomb repulsion. A symptom of this localization is antiferromagnetism, where the spins of localized electrons alternate between up and down. Superconductivity appears when mobile 'holes' are doped into this insulating state, and it coexists with antiferromagnetic fluctuations. In one approach to describing the coexistence, the holes are believed to self-organize into 'stripes' that alternate with antiferromagnetic (insulating) regions within copper oxide planes, which would necessitate an unconventional mechanism of superconductivity. There is an apparent problem with this picture, however: measurements of magnetic excitations in superconducting YBa2Cu3O6+x near optimum doping are incompatible with the naive expectations for a material with stripes. Here we report neutron scattering measurements on stripe-ordered La1.875Ba0.125CuO4. We show that the measured excitations are, surprisingly, quite similar to those in YBa2Cu3O6+x (refs 9, 10) (that is, the predicted spectrum of magnetic excitations is wrong). We find instead that the observed spectrum can be understood within a stripe model by taking account of quantum excitations. Our results support the concept that stripe correlations are essential to high-transition-temperature superconductivity.     

超导电性理论特征

超导材料的种类非常广泛,有单质金属、合金材料、有机化合物、非金属单质、金属与非金属掺杂材料、金属氧化物等.从超导电性特征又分为非常规超导材料和常规超导材料.因此从超导电性的起源研究超导电性理论的特征具有重要的意义,既是重要的理论研究,又对合成、制备各种新型超导材料具有指导意义.分析研究了超导电性的本征特点,分别从超导的基本物理图像、同位素效应、超导转变温度计算公式表示等方面给出了常规超导体和非常规超导体的全面描述.同时理论上计算了一种有机复合超导材料.     

Bi2O3氧化物掺杂对单畴YBCO超导块材磁悬浮力的影响

采用顶部籽晶熔渗工艺（TSIG）制备出了配比为Bi2O3：Y2BaCu05=x：（1吨）的系列单畴YBCO超导块材（其中x=0．1,0.3,0．5,0．7,0．9,2,单位为wt％）,并且研究了不同比例的氧化物Bi2O3掺杂对样品的生长形貌、磁悬浮力以及其微观结构的影响．实验结果表明了,Bi20,粒子的掺杂在样品中生成Y2Ba4CuBiOx（YBi2411）纳米粒子从而可以有效地提高样品的磁悬浮性能．当Bi203粒子掺杂量x从0．1wt％（质量分数,下同）增加到0．7wt％时,样品的磁悬浮力从7N增加到25N;当其掺杂量从0．7wt％增加到2wt％时,样品的磁悬浮力从25N降低到6N．该实验结果对于我们进一步研究氧化物掺杂对磁通钉扎作用的影响以及提高YBCO超导块材的性能有着重要的影响．     

Electronic structure of the iron-based superconductor LaOFeP

The recent discovery of superconductivity in the iron oxypnictide family of compounds has generated intense interest. The layered crystal structure with transition-metal ions in planar square-lattice form and the discovery of spin-density-wave order near 130 K (refs 10, 11) seem to hint at a strong similarity with the copper oxide superconductors. An important current issue is the nature of the ground state of the parent compounds. Two distinct classes of theories, distinguished by the underlying band structure, have been put forward: a local-moment antiferromagnetic ground state in the strong-coupling approach, and an itinerant ground state in the weak-coupling approach. The first approach stresses on-site correlations, proximity to a Mott-insulating state and, thus, the resemblance to the high-transition-temperature copper oxides, whereas the second approach emphasizes the itinerant-electron physics and the interplay between the competing ferromagnetic and antiferromagnetic fluctuations. The debate over the two approaches is partly due to the lack of conclusive experimental information on the electronic structures. Here we report angle-resolved photoemission spectroscopy (ARPES) of LaOFeP (superconducting transition temperature, T(c) = 5.9 K), the first-reported iron-based superconductor. Our results favour the itinerant ground state, albeit with band renormalization. In addition, our data reveal important differences between these and copper-based superconductors.