The L(2,1)-labeling and operations of graphs

Motivated by a variation of the channel assignment problem, a graph labeling analogous to the graph vertex coloring has been presented and is called an L(2,1)-labeling. More precisely, an L(2,1)-labeling of a graph G is a function f from the vertex set V(G) to the set of all nonnegative integers such that |f(x)-f(y)| /spl ges/ 2 if d(x,y)=1 and |f(x)-f(y)| /spl ges/ 1 if d(x,y) = 2. The L(2,1)-labeling number /spl lambda/(G) of G is the smallest number k such that G has an L(2,1)-labeling with max{f(v):v/spl isin/V(G)}=k. A conjecture states that /spl lambda/(G) /spl les/ /spl Delta//sup 2/ for any simple graph with the maximum degree /spl Delta//spl ges/2. This paper considers the graphs formed by the Cartesian product and the composition of two graphs. The new graph satisfies the conjecture above in both cases(with minor exceptions).     

Local Phenomena in Oxides by Advanced Scanning Probe Microscopy

In the last two decades, scanning probe microscopies (SPMs) have become the primary tool for addressing structure and electronic, mechanical, optical, and transport phenomena on the nanometer and atomic scales. Here, we summarize basic principles of SPM as applied for oxide materials characterization and present recent advances in high-resolution imaging and local property measurements. The use of advanced SPM techniques for solutions of material related problems is illustrated on the examples of grain boundary transport in polycrystalline oxides and ferroelectric domain imaging and manipulation. Future prospects for SPM applications in materials science are discussed.     

Experiment and simulation investigations for effects of flow channel patterns on the PEMFC performance

Experiments and simulations are presented in this paper to investigate the effects of flow channel patterns on the performance of proton exchange membrane fuel cell (PEMFC). The experiments are conducted in the Fuel Cell Center of Yuan Ze University and the simulations are performed by way of a three‐dimensional full‐cell computational fluid dynamics model. The flow channel patterns adopted in this study include the parallel and serpentine flow channels with the single path of uniform depth and four paths of step‐wise depth, respectively. Experimental measurements show that the performance (i.e. cell voltage) of PEMFC with the serpentine flow channel is superior to that with the parallel flow channel, which is precisely captured by the present simulation model. For the parallel flow channel, different depth patterns of flow channel have a strong influence on the PEMFC performance. However, this effect is insignificant for the serpentine flow channel. In addition, the calculated results obtained by the present model show satisfactory agreement with the experimental data for the PEMFC performance under different flow channel patterns. These validations reveal that this simulation model can supplement the useful and localized information for the PEMFC with confidence, which cannot be obtained from the experimental data. Copyright © 2007 John Wiley & Sons, Ltd.     

堆焊层中球状碳化物形成机理的研究

通过同时加入球化剂和碳化物形成元素，成功地在堆焊层中形成了球状碳化物，并对这种碳化物的形成过程进行了理论上的探讨。     

模拟二元复合驱采出液破乳研究

用模拟碱／聚合物二元复合驱采出液，以脱出水色为主要评价项目，对新开发的若干系列的破乳剂＋净水剂复配物的破乳性能进行了室内评价。聚丙烯酰胺含量最高达１１６０ｍｇ／ｌ、碳酸钠含量最高达８０００ｍｇ／ｌ的模拟采出液破乳实验结果表明，聚合物含量是影响破乳效果的主要因素。破乳性能最好的破乳剂是ＡＥＤ７８和ＡＥＤ２３（甲苯二异氰酸酯扩链的双嵌段聚醚），净水剂是ＱＢＳ０５（阳离子苄基淀粉）和ＱＳ０６（阳离子淀粉）。     

用多参量法计算薄层和薄互层厚度

薄层、薄互层厚度预测是储层横向预测的一重要环节。常规计算薄层厚度的方法是在时间域或频率域实现，主要使用单参数计算。本文利用对薄层厚度敏感的地震特征参数之间的非线性关系，使用神经网络算法，建立了一套计算薄层及薄互层厚度方法。通过模型的正反演结果表明：该算法对薄层厚度及薄互层累积厚度的预测均有较好的效果，具有一定的抗噪声能力。对塔中ＤＬ９２－０４测线部分剖面的石炭系Ｉ油组薄互层砂岩的累积厚度进行了预测     

Si(Au)探测器的快中子辐射损伤

在核实验中,半导体硅探测器常用来对带电粒子和中子进行探测。其能量响应和时间响应特性均十分良好,但是耐辐射性能却较差,尤其在伴有γ和中子本底的环境中,由于辐照引起探测器晶格损伤,导致半导体探测器性能退化,如探测器漏电流增大、能量分辨本领变差、能量亏损增加、时间响应增长等,严重影响探测器的使用和寿命。     

煤的新型气化技术与多联产理论

介绍以煤炭、石英矿资源和电力资源，采用电热还原法生产高纯CO（煤）气并伴生四高SiC栽能新材料的煤的新型气化技术．阐述在循环经济理念下，研发并实施以煤、电为基础资源实现煤的新型气化生产大气量高纯CO-醋酸-四高SiC栽能新材料产品的多联产理论及意义．     

多渠道筹措资金服务工程建设

简要介绍了洞坪工程通过各种融资渠道,保证资金及时到位、确保工程建设顺利进展和努力降低财务成本的经验.     

苏州市危险废物填埋场防渗工程简介

介绍了苏州危险废物填埋场防渗工程的组成和构造设计,对填埋库的防渗系统尤其是采用带嵌钉的HDPE土工膜施工工艺作了重点阐述.