Enzymatic Synthesis of a CCK-8 Tripeptide Fragment

A process for the synthesis of CCK-8 tripeptide H-Gly-Trp-Met-OH catalyzed by immobilized enzyme was reported. Enzymes were used for the formation of peptide bonds and the removal of protecting group. Starting with phenylacetyl (PhAc) glycin, N-protected dipeptide PhAc-Gly-Trp-OMe was obtained by coupling PhAc-protected glycine carboxamidomethyl ester (OCam) with Trp-OMe catalyzed by immobilized papain in buffered ethyl acetate. Then the condensation between PhAc-Gly-Trp-OMe and Met-OEtoHC1 was carried out by immobilized α-chymotrypsin catalysis in solvent free system. Basic hydrolysis was followed getting PhAc-Gly-Trp-Met-OH. The PhAc-group was removed with penicillin G amidase and H-Gly-Trp-Met-OH was obtained in an overall yield of 43.9%. The reaction conversion of tripeptide in solvent free system was strongly affected by the system of basic salts added. The influence of the support materials used to deposit enzymes and structures of acyl donor and nucleophile on the reaction was also investigated.     

Finite morphisms of projective and K■hler manifolds

In this paper we study finite morphisms of projective and compact K■hler manifolds, in particular,positivity properties of the associated vector bundle,deformation theory and ramified endomorphisms.     

CHARACTERIZATION OF NANOSTRUCTURES:TOOLS AND CHALLENGES

Apart from long-known and applied nanostructures like carbon black for tyres or pigments for coatings nanotechnology has created highly sophisticated structures used for nano/molecular electronics,diagnostics,drug delivery, UV-absorbers etc.Often the main question to be solved analytically is the local determination of tiny amounts of chemicals resulting in an ever increasing need for highly sensitive as well as locally resolved techniques.Applications of techniques like mass spectroscopy,transmission el...     

The double Ringel-Hall algebra on a hereditary abelian finitary length category

In this paper, we study the category H (ρ) of semi-stable coherent sheaves of a fixed slope ρ over a weighted projective curve. This category has nice properties: it is a hereditary abelian finitary length category. We will define the Ringel-Hall algebra of H (ρ) and relate it to generalized Kac-Moody Lie algebras. Finally we obtain the Kac type theorem to describe the indecomposable objects in this category, i.e. the indecomposable semi-stable sheaves.     

Preface

The 11th IUMRS-ICA 2010 (ICA-2010) conference organized by C-MRS was held in Qingdao city, China from 25th to 28th September 2010. The event was timely and impressive not only due to the rapid development of science and technology in China and Asian areas but also due to the emerging cultural and economic transformation. I had been invited to take part in Session Q: Magnetic Materials at Nano-scale, and gave an invited talk about the magnet-     

条形爆炸逻辑器件之功能研究

通过敞式观察条纹技术(OVST)和火花隙或者多条纹技术(MST)相配合,可以较为简单地让条形起爆逻辑器件(这里是指一种8管条形同步引信)理想引爆,随之使传爆药栓点火并妥善传爆到总管烈性炸药。     

铈基模型催化剂的纳米结构:有序CeO2(111)薄膜上的Pt-Co纳米颗粒

制备并表征了原子分散的模型体系:氧化铈负载的Pt-Co核壳催化剂.采用超高真空物理气相沉积法制备了有序CeO2(111)膜上的Pt@Co和Co@Pt核壳纳米结构,并用同步辐射光电子能谱和共振光发射光谱对其进行了研究.在低Co覆盖率(0.5 ML)下Co在CeO2(111)上沉积生成Co-CeO2(111)固溶体,然后在更高Co覆盖率下生长为金属Co纳米粒子.Pt@Co和Co@Pt两种模型结构在300-500 K温度范围内都能稳定地抗烧结.在500 K退火后, Pt@Co纳米结构含有接近纯的钴壳,而Co@Pt中的铂壳部分被金属钴覆盖.在550 K以上,在Pt@Co和Co@Pt纳米结构中近表面区域的重新排序中产生了次表层的Pt Co合金和富铂外壳.对于Co@Pt纳米粒子,近表面区域的化学有序性取决于沉积铂壳的初始厚度.无论初始铂壳的厚度如何,在有氧存在下对Co@Pt纳米结构进行退火,都会导致Pt-Co合金的分解以及Co的氧化.Co的逐步氧化与吸附质诱导的Co偏析共同导致在负载的Co@Pt纳米结构表面形成厚的Co O层.这一过程伴随着CeO2(111)薄膜的裂解,以及在550K以上氧气中退火后CeO2包裹氧化的Co@Pt纳米结构.很明显,于不同温度下在氧气和氢气的氧化-还原循环过程中,无论铂的初始厚度是多少,负载的Co@Pt纳米颗粒的结构和化学成分的变化主要是由氧化所致,而还原处理的影响则很小.     

CONVERGENCE OF ADAPTIVE EDGE ELEMENT METHODS FOR THE 3D EDDY CURRENTS EQUATIONS

We consider an Adaptive Edge Finite Element Method （AEFEM） for the 3D eddy currents equations with variable coefficients using a residual-type a posteriori error estimator. Both the components of the estimator and certain oscillation terms, due to the occurrence of the variable coefficients, have to be controlled properly within the adaptive loop which is taken care of by appropriate bulk criteria. Convergence of the AEFEM in terms of reductions of the energy norm of the discretization error and of the oscillations is shown. Numerical results are given to illustrate the performance of the AEFEM.     

SYNTHESIS AND CHARACTERIZATION OF PHENOTHIAZINE-BASED PPV-TYPE COPOLYMERS CONTAINING FLUORENE AND THIOPHENE MOIETIES

1. INTRODUCTION Since the first report of efficient polymer light emitting diode (PLED) in 1990, conjugated polymers have intrigued great interests because of substantial promise for electro-optical applications [1,2]. It is essential to develop novel str…