傅里叶变换中红外光谱法检测脑膜瘤的研究

采用傅里叶变换衰减全反射中红外光谱法检测了24例液氮冻存的脑膜瘤离体样品(其中良性肿瘤12例,有恶性倾向的肿瘤12例),对得到的红外光谱进行整理分析,发现不同类型脑膜瘤组织(如纤维型脑膜瘤和内皮型脑膜瘤)的红外光谱存在着差异,并且同一种类型的脑膜瘤组织,其恶性倾向的程度不同,他们的红外光谱也表现出较为明显的区别,因此,我们可以从各个特征吸收峰的峰位、峰形及峰强等信息的变化来区分脑膜瘤,并可以初步鉴别脑膜瘤的性质;研究结果发现,通过某些特征吸收峰(如1 160cm-1)峰位的变化来鉴别脑膜瘤的性质与病理诊断结果的符合率大于85%,说明傅里叶变换衰减全反射中红外光谱法有可能发展成为一种对样品无损伤、快速的脑肿瘤诊断新方法。     

低孔隙度疏松铝的高压声速与冲击熔化

对含微孔洞疏松度m=1.04的疏松铝进行了冲击加载-卸载实验,利用DISAR(distance interferometer system for any reflector)测得了53至99 GPa五个冲击压力下疏松铝/LiF界面粒子速度波剖面,获得了各压力下的纵波声速和其中三个压力点的体波声速,确定出疏松铝的冲击熔化压力约为81 GPa,确定出高压下冲击熔化前的泊松比约为0.372.通过分析,微孔洞明显降低了冲击熔化压力,引起的非谐振效应明显,状态方程计算中考虑非谐效应,非谐因子l 关键词： 低孔隙度 疏松铝 声速 冲击熔化     

Multivariate risk models under heavy‐tailed risks

In this paper, we consider four common types of ruin probabilities for a discrete‐time multivariate risk model, where the insurer is assumed to be exposed to a vector of net losses resulting from a number of business lines over each period. By assuming a large initial capital for the risk model and regularly varying distributions for the net losses, we establish some interesting asymptotic estimates for ruin probabilities in terms of the upper tail dependence function of the net loss vector. Our results insightfully characterize how the dependence structure among the individual net losses affect the ruin probabilities in an asymptotic sense, and more importantly, from our main results, explicit asymptotic estimates for those ruin probabilities can be obtained via specifying a copula for the net loss vectors. Copyright © 2013 John Wiley & Sons, Ltd.     

catena‐Poly­[[[bis­(perchlorato‐O)­(1,10‐phenanthroline‐N,N′)­copper(II)]‐μ‐4,4′‐bi­pyridine‐N:N′] monohydrate]

The Cu atom in the title complex {[Cu(C₁₀H₈N₂)(C₁₂H₈N₂)(ClO₄)₂]·H₂O}_n, has an N₄O₂ octahedral coordination geometry, the Cu atoms being bridged by the bi­pyridine and chelated by the phenanthroline heterocycles. Adjacent mol­ecules are linked into a zigzag chain running along the c axis of the monoclinic unit cell. The chains are connected through lattice water mol­ecules to produce a layer structure.     

Luminescent Property of a Supramolecular Silver(I)‐Thiolate Complex Based on Secondary Ag‐S Interactions and Hydrogen Bonds

The supramolecular silver(I)‐thiolate complex [Ag(μ₂‐SC₄N₂H₄)₂(SCN)]_n has been prepared from the reaction of AgSCN and pyrimidine‐2‐thiol in DMF. X‐ray diffraction analysis shows that the supramolecular structure exhibits one‐dimensional chain through the secondary Ag‐S interactions and the chains are further linked by strong hydrogen bonds to form a three dimensional network. The luminescence effect from the silver‐centered state of S→Ag LMCT in solid state is different from that in solution due to the secondary Ag‐S interactions.     

Di­methyl 2‐(4‐bromo­phenyl)‐10,11‐di­methoxy‐2,3,7,8‐tetra­hydro­spiro­[azepino[2,1‐a]­iso­quinoline‐3,9′‐fluorene]‐4,5‐di­carboxyl­ate

The title compound, C₃₈H₃₂BrNO₆, is a new photochromic tetra­hydro­azepinoiso­quinoline (THAI). The longest spiro bond [1.589 (4) Å] can be broken very easily by UV light, leading to ring opening. This explains the photochromic behaviour.     

Correlation between hydrocarbon distribution and water-hydrocarbon ratio in Fischer-Tropsch synthesis

In order to shorten the evaluation cycle of cobalt catalyst before the optimized catalyst is fixed on, a mathematical method is proposed to calculate weight percentage of C5+ hydrocarbons. Based on the carbide polymerization mechanism and the main hydrocarbons being linear alkanes and α-olefins, the correlation between hydrocarbon distribution and the molecular mass ratio of water to hydrocarbons is discussed. The result shows the ratio was within the range of 1.125-1.286 and the lower the ratio, the more gaseous hydrocarbons were obtained. Moreover, a linear equation between the weight percentage of C5+ hydrocarbons and the weight ratio of C5+ hydrocarbons to the total water is established. These results are validated by corresponding experiments. The weight percentage of C5+ hydrocarbons could be immediately calculated by this linear equation without detailed gas chromatography (GC) analysis of them.     

Photosensitization of nanocrystalline TiO2 electrodes with II B group metal-ion-bridged self-assembled films of 3,4,9,10-perylenetetracarboxylic acid

Self-assembled films (SA films) of 3,4,9,10-perylenetetracarboxylic acid (PTA) (Film P) and II B group metal-ion-bridged PTA (Film PMP, M=Zn²⁺, Cd²⁺, or Hg²⁺) were fabricated on nanocrystalline TiO₂ electrodes and characterized with UV–VIS and IR spectra and XPS. Compared with Film P sensitized solar cell, Grätzel cells based on individual PMP electrodes are more efficient regarding photocurrent generation. Synchrotron radiation photoelectron spectroscopy (SRPES) study reveals that those HOMO energy levels of PMP films are greater than that of Film P. The higher HOMO energy levels will lead to higher excited state energy levels that benefit electron injection, and hence, increase efficiencies for photocurrent generation. In view of the invariable valence of Zn²⁺, Cd²⁺, and Hg²⁺ ions, electron injection should be attributed to ligand, but not to the central metal ions, like the case of Ru(II)–bipyridyl complex.