Negative differential resistance behaviour in N-doped crossed graphene nanoribbons

By using first-principles calculations and nonequilibrium Green’s function technique, we study elastic transport properties of crossed graphene nanoribbons. The results show that the electronic transport properties of molecular junctions can be modulated by doped atoms. Negative differential resistance (NDR) behaviour can be observed in a certain bias region, when crossed graphene nanoribbons are doped with nitrogen atoms at the shoulder, but it cannot be observed for pristine crossed graphene nanoribbons at low biases. A mechanism for the negative differential resistance behaviour is suggested.     

玉米kn-1同源盒的高效表达

同源盒基因(homeoboxgenes)在植物,动物,真菌的广泛存在说明这种结构在真核生物进化过程中高度保守,并暗示其具有重要功能.本文将玉米kn-1同源盒插入表达载体pGEM△XbaI,并将形成的重组克隆pGEM△MK转化BL21(DE3)而获得高效表达;表达产物的分子量为29×103,并主要以可溶性蛋白形式存在.Kn-1,Quox-1,OSIH-1间的交叉免疫反应证实三者在蛋白质水平具同源性.而Kn-1同源结构域(Homeodomain)高效表达有助于进一步寻找其靶基因.     

偶交叉双积Hopf代数B RH的构造

本文给出了Doi Y.构造的偶交叉积B H的代数结构与Reshetikhim～N.构造的双代数BRH的余代数结构在张量空间B H上构成双代数(记为BRH)的充要条件,利用此结论具体构造了一个有趣的例子H4 KZ2,证明了当B,H均为Hopf.代数时BRH也为Hopf代数,最后给出这类双代数的映射刻划.     

Compatible actions of Lie algebras

Abstract

We study compatible actions (introduced by Brown and Loday in their work on the non-abelian tensor product of groups) in the category of Lie algebras over a fixed ring. We describe the Peiffer product via a new diagrammatic approach, which specializes to the known definitions both in the case of groups and of Lie algebras. We then use this approach to transfer a result linking compatible actions and pairs of crossed modules over a common base object L from groups to Lie algebras. Finally, we show that the Peiffer product, naturally endowed with a crossed module structure, has the universal property of the coproduct in XMod_L(Lie_R).     

On the first passage times of reflected O-U processes with two-sided barriers

In this article, we give the Laplace transform of the first passage times of reflected Ornstein-Uhlenbeck process with two-sided barriers. AMS Subject Classifications 60H10 · 60G40 · 90B05 Supported by NSF of China.     

Statistical medium formulation and process modeling by mixture design of experiment for peptide overexpression in recombinant Escherichia coli

The medium formulation and robust process modeling for anti-HIV peptide (T-20) production by recombinant Escherichia coli overexpression were studied by employing a crossed experimental design. The crossed design, a mixture design combined with process factor (induction duration), was used to find the optimal medium formulation and process time. The optimal settings for three major components, (7.75 mL of NPK sources, 5.5 mL of glucose, and 11.75 mL of MgSO₄) characterized by %T-20 (14.45%), the proportion of peptide to the total protein, were observed in a total of 100 mL of medium inducted at an optical density of 0.67 with 0.7 mM isopropyl-β-d-thiogalactopyranoside) for a 3-h induction duration at shake-flask scale. These conditions were further investigated to find robust, process conditions (8.2 mL of NPK sources, 5.6 mL of glucose, and 11.3 mL of MgSO₄, and a 3.5-h induction duration time) for T-20 production (13.9%) by applying propagation of error. Coauthors     

反散射理论导出He-Ne相互作用势

以Ｈｅ原子束与Ｎｅ原子束交叉碰撞实验数据为基础。以反散射方法为手段，理论上导出Ｈｅ－Ｎｅ原子相互作用势，所得的势呈显出ｖａｎ ｄｅｒ Ｗａａｌｓ势的特征，即短程为强排斥，中程为碗形吸收，远程为零，这样的势能正确的，符合实验的弹发型用射微分截面。     

Crossed product of C*‐algebras by hypergroups

The crossed product of ‐algebras by groups, groupoids and semigroups are well studied. In this paper we introduce and study the crossed product of ‐algebras by (locally compact) hypergroups. We calculate the crossed products by finite hypergroups of orders 2 and 3.     

Analysis of a drawdown-based regime-switching Lévy insurance model

In this paper, we propose a new drawdown-based regime-switching (DBRS) Lévy insurance model in which the underlying drawdown process is used to model an insurer’s level of financial distress over time, and to trigger regime-switching transitions. By some analytical arguments, we derive explicit formulas for a generalized two-sided exit problem. We specifically state conditions under which the survival probability is not trivially zero (which corresponds to the positive security loading conditions of the proposed model). The regime-dependent occupation time until ruin is later studied. As a special case of the general DBRS model, a regime-switching premium model is given further consideration. Connections with other existing risk models (such as the loss-carry-forward tax model of Albrecher and Hipp, 2007) are established.