部分辽河稠油油藏中含氧化合物的分布

非烃化合物作为石油的重要组成部分 ,在油藏地球化学研究中应受到足够的重视。在辽河油田冷 4 3块北部雷家场地区、牛心坨油田茨榆坨地区、高升油田高Ⅰ区和高Ⅲ区的沙一段到沙四段 10个稠油样品中 ,酸性馏分占正己烷可溶性非烃馏分的 70 %以上。由气相色谱可检测非烃化学组成的分析结果可知 ,辽河稠油中有着丰富的非烃化合物类型 ,其中各类含氧化合物占总非烃的 92 %～ 97%。含氧化合物的存在和分布特征表明 ,这些稠油油藏接受了非母岩来源的近期菌藻类有机质输入。以正构羧酸和甾醇为例 ,指出含氧化合物的存在与分布不是由油藏的原始油源 (母源岩 )所决定的 ,也不能简单地以油藏所在区域来划分 ,而很可能与发生在储集层中的、受到储集层构造条件控制的后期地球化学过程 (如后期有机质输入、生物降解和水洗作用等 )有关。原油中含氧化合物的化学组成与储集层构造条件相关这一特性为多方面的油藏地球化学研究提供了基础性条件。     

权回归扰动模型的影响分析

针对线性加权回归模型，从统计诊断的角度分析了协方差阵扰动的影响度量和回归系数的估计效率，并给出了2种效率的下界。     

Efficient Stacking on Protein Amide Fragments

The less polar π‐surface of protein amide groups is exposed in many receptor binding sites, either as part of the backbone or in Gln/Asn side chains. Using quantum chemical calculations and Protein Data Bank (PDB) searches on model systems, we investigate the energetics and geometric preferences for the stacking on amide groups of a large number of heteroarenes that are relevant to medicinal chemistry. From this study, we discern that the stacking energy of an aromatic ligand substituent can be improved by: 1) orienting the fragment dipole vector such that it is aligned in an antiparallel fashion with the dipole of the interacting protein amide group, 2) increasing its dipole moment, and 3) decreasing its π‐electron density. These guidelines should be helpful to more rationally exploit this interaction type in future structure‐based drug design.     

A Novel Test for the Appraisal of Solid/Solid Interfacial Interactions

The Johnson, Kendall and Roberts (JKR) technique has been used with considerable success for assessing solid/solid interfacial interactions over the past 25 years or so. Nevertheless, the contact zone between the two spherical solids is often small and the energy of adhesion scales with the cube of the contact radius (at low load), thus potentially magnifying errors in adhesion assessment. The theoretical aspects of a novel technique are presented here, in which a hollow, slightly inflated, spherical membrane replaces a full sphere, and is placed in contact with a flat rigid solid. A judicious choice of experimental conditions should lead to increased contact radius and the energy of adhesion scales with its square (at low load), thus reducing possible errors. An added advantage is that the effective elasticity of the sphere depends on internal gas pressure. Thus surface and bulk effects are decoupled.     

Comprehensive Refurbishment of 200 MW Thermal Power Generating Units

l-Introducti0nUptol995,powerplantsdirectlyunderNortheastChinaElectricP0werGroupCorPorati0n(NEPGC)possessed44setsof2O0MWthermalp0wergeneratingunits.Theseunitstake0nthemajorelectricit}generationofthepowernetwork.Most0ftheirb0ilersareHG670/l40typesuperhighpressure,intermediatereheat,singledrumnaturalcirculationpulverized-c0alfiredboilersproducedbyHarbinBoilerWorks,andthemainandauxiliaryequipmentweremadeintheperiodfromthelatel97Ostotheearlyl980s.Owingt0thebackwardnessinequipmenttechnology…     

Relationship Between Microstructure, Hardness, XRD, TGDTA Analysis, and Wear Performance of a Cast ZA Alloy

In the present article, microstructure, hardness, X-ray diffraction (XRD), thermal gravimetric and differential thermal analysis (TGDTA), and wear performance of a Cast ZA Alloy were studied by using scanning electron microscopy (SEM), XRD analysis, thermal gravimetric and differential thermal analysis and tensile strength, hardness, and wear test techniques. Wear performance of the alloy was investigated on a pin-on-disk wear tester under dry sliding conditions, rubbing against nitrided steel. The wear performance of some specimens was superior to others, for which microstructure and precipitated particulates were important. It has showed that some important phases occurred and improved the wear performance after solution-treatment.     

Type IIa RPTPs and Glycans: Roles in Axon Regeneration and Synaptogenesis

Type IIa receptor tyrosine phosphatases (RPTPs) play pivotal roles in neuronal network formation. It is emerging that the interactions of RPTPs with glycans, i.e., chondroitin sulfate (CS) and heparan sulfate (HS), are critical for their functions. We highlight here the significance of these interactions in axon regeneration and synaptogenesis. For example, PTPσ, a member of type IIa RPTPs, on axon terminals is monomerized and activated by the extracellular CS deposited in neural injuries, dephosphorylates cortactin, disrupts autophagy flux, and consequently inhibits axon regeneration. In contrast, HS induces PTPσ oligomerization, suppresses PTPσ phosphatase activity, and promotes axon regeneration. PTPσ also serves as an organizer of excitatory synapses. PTPσ and neurexin bind one another on presynapses and further bind to postsynaptic leucine-rich repeat transmembrane protein 4 (LRRTM4). Neurexin is now known as a heparan sulfate proteoglycan (HSPG), and its HS is essential for the binding between these three molecules. Another HSPG, glypican 4, binds to presynaptic PTPσ and postsynaptic LRRTM4 in an HS-dependent manner. Type IIa RPTPs are also involved in the formation of excitatory and inhibitory synapses by heterophilic binding to a variety of postsynaptic partners. We also discuss the important issue of possible mechanisms coordinating axon extension and synapse formation.     

Zustimmung des Eigentümers zur Bauführung; Zurückziehung der Zustimmung

Die Erledigung eines Bauansuchens erfordert die Zustimmung des (hier: Mit-) Eigentümers zur Bauführung. Die Zustimmung des (hier: Mit-) Eigentümers kann auch noch im Berufungsverfahren mit der Wirkung zurückgezogen werden, dass die Baubewilligung nicht mehr erteilt werden kann.