The electronic structure of angular polyphenes

SCF calculations of molecular orbitals and electronic transition energies for angular polyphenes of two through nine benzene rings have been made. The calculated sequences of the singlet and triplet energies of the , , , and p bands (Clar's notation) are compared to the limited available experimental data.

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Zusammenfassung PPP-Rechnungen mit begrenzter Konfigurationenwechselwirkung wurden für die Reihe der angular anellierten Polyphene durchgeführt. Die berechneten -, -, - und p-Banden werden mit den wenigen vorhandenen experimentellen Daten verglichen.

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Résumé Calculs SCF des orbitales moléculaires et des énergies de transition électronique pour les polyphenés angulaires de deux à neuf cycles benzeniques. Les séries calculées pour les énergies singulet et triplet des bandes -, -, et p (notation de Clar) sont comparées aux quelques données expérimentales disponibles.

     

Nitrogen balance and delta15N: why you're not what you eat during pregnancy

Carbon (13C/12C) and nitrogen (15N/14N) stable isotope ratios were longitudinally measured in human hair that reflected the period from pre-conception to delivery in 10 pregnant women. There was no significant change in the delta13C results, but all subjects showed a decrease in delta15N values (-0.3 to -1.1 per thousand) during gestation. The mechanisms causing this decrease in hair delta15N have not been fully elucidated. However, since the delta15N values of dietary nitrogen and urea nitrogen are significantly lower compared to maternal tissues, it is hypothesized that the increased utilization of dietary and urea nitrogen for tissue synthesis during pregnancy resulted in a reduction of the steady state diet to a body trophic level effect by approximately 0.5-1 per thousand. An inverse correlation (R2 = 0.67) between hair delta15N and weight gain was also found, suggesting that positive nitrogen balance results in a reduction of delta15N values independent of diet. These results indicate that delta15N measurements have the ability to monitor not only dietary inputs, but also the nitrogen balance of an organism. A potential application of this technique is the detection of fertility patterns in modern and ancient species that have tissues that linearly record stable isotope ratios through time.     

氯化三有机基锡和氯化三有机基铅与三苯基氧胂配合物的合成和晶体结构研究

描述了一事三苯基氧胂Ｐｈ３ＡｓＯ．Ｈ２Ｏ（１）及其与氯化三苯基锡,氯化三对氯苯基锡及氯化三苯基铅配合物「Ｐｈ３ＳｎＣｌ（ＯＡｓＰｈ３）」（２）,「（ＣｌＰｈ）３ＳｎＣｌ（ＯＡｓＰＨ３）」（３）和」Ｐｈ３ＰｂＣｌ（ＯＡｓＰｈ３）（４）的合成和晶体结构,晶体数据分别为（１）单斜晶系,空间群Ｐ２、／ｎ,ａ＝９．４６０４（７）,ｂ＝１６．６３４７（７）,ｃ＝１１．１５４４（１１）Ａ,Ｂ＝１１３．２３３（６     

A Lattice Model for Bidirectional Pedestrian Flow on Gradient Road

Ramps and sloping roads appear everywhere in the built environment. It is obvious that the movement pattern of people in the sloping path may be different as compared with the pattern on level roads. Previously, most of the studies, especially the mathematical and simulation models, on pedestrian movement consider the flow at level routes. This study proposes a new lattice model for bidirectional pedestrian flow on gradient road. The stability condition is obtained by using linear stability theory. The nonlinear analysis method is employed to derive the modified Korteweg-de Vries (mKdV) equation, and the space of pedestrian flow is divided into three regions: the stable region, the metastable region, and the unstable region respectively. Furthermore, the time-dependent Ginzburg—Landan (TDGL) equation is deduced and solved through the reductive perturbation method. Finally, we present detailed results obtained from the model, and it is found that the stability of the model is enhanced in uphill situation while reduced in downhill situation with increasing slope.     

μ介子寿命与μ-e对称性的实验限度

μ介子有反常作用,破坏了μ-e对称性。本文讨论了反常作用对弱作用过程的影响,分析了反常作用的电荷无关性和r₅变换性质与μ蜕变弱作用常数的重正化之间的联系,证明了重正化后G_V=G,G_A=εG,ε=1+δ。利用这一结果,可以解释矢量流守恒假定下普适V-A费米弱作用理论在解释μ介子寿命时遇到的困难。从理论和实验的比较中定出δ=0.04,这是由μ蜕变定出的μ-e对称性的实验限度。     

动量为6.8BeV/cπ-介子与核子的非弹性作用

本工作共积累了317个非弹性作用事例。作用中的次级带电粒子在(π^--N)质心系中的角分布与动量分布等和前人结果一致,并且基本上可以用边缘碰撞机制来说明。对带有次级质子的事例作了如下分析:(1)计算全部次级粒子(质子除外)在它们自己系统中的总能量ω。作ω分布,并与边缘碰撞1π交换近似计算的理论曲线比较,在ω=1.5BeV附近观察到有突出于理论曲线之外的高峯,并对峯区内事例进行了初步分析。(2)综合我们的和联合原子核研究所的数据,计算了次级质子在镜象系的非弹性系数K_з,并使K_з值的分布与根据Барашенков等人理论计算的K_з分布曲线作了比较。此外,还试从靶质量观点出发,利用Duller-Walker的F图方法,对不同K_з值的各类事例进行了分析和讨论。     

Preparation and relaxation of very stable glassy states of a simulated liquid

We prepare metastable glassy states in a model glass former made of Lennard-Jones particles by sampling biased ensembles of trajectories with low dynamical activity. These trajectories form an inactive dynamical phase whose "fast" vibrational degrees of freedom are maintained at thermal equilibrium by contact with a heat bath, while the "slow" structural degrees of freedom are located in deep valleys of the energy landscape. We examine the relaxation to equilibrium and the vibrational properties of these metastable states. The glassy states we prepare by our trajectory sampling method are very stable to thermal fluctuations and also more mechanically rigid than low-temperature equilibrated configurations.