多源多目标网络下基于包聚合的选择协作方法

针对实际应用中广泛存在的源-目节点不等的无线传感网,提出一种基于包聚合的选择协作方法,以提升传输可靠性。首先,通过建立源-目节点间的关联矩阵将多源多目标传感网分解为多个多源单目标传感网;其次,将包聚合策略引入协作传输中,对多源单目标网络实施基于包聚合的选择协作通信;再次,考虑传输顺序对各源节点的影响,将3种调度方法引入选择协作方法中;最后,在保证系统传输可靠性的前提下,为方便系统的多目标优化,提出了3种中继选择策略。仿真结果表明,所提选择协作方法不仅能提高系统传输可靠性且能满足不同的网络需求。     

中国城市空间结构的思考——浅析20世纪80年代后城市发展演进中城市空间的变化与发展

通过同一时期中国与西方国家城市规划空间结构方面的比较，概括了20世纪80年代后中国城市空间结构的基本特点，并从城市空间聚集效应、城市规划管理、房地产、交通技术等方面分析了影响城市空间结构的相关因素，对中国城市空间结构的优化提出了一些对策。     

50 ku keratin-like protein and -microtublin coexist in higher plant cells

IF-like proteins have been obtained from suspension cells of Nicotiana tabacum by selective extraction. Western blot analysis shows that the major components of IF-like proteins are 6 keratin-like proteins of 64, 58, 55, 54, 50 and 45 ku. Specially the 50 ku protein also reacts with polyantibody against microtublin. Two-dimensional gel electrophoresis shows that the 50 ku protein is composed of two different proteins and their amino acid sequences have been determined. Part of the sequence of one protein is identical to that of -microtublin and the other protein's sequence has no significant homologue, which should be a new sequence-unknown protein. These results suggest that 50 ku keratin-like protein and -microtublin coexist in higher plant cells, and that may lead to the phenomenon of co-distribution of IF and microtuble in plant cells.     

红细胞聚集的微观力学分析

红细胞聚集是一种细胞间表面电荷群决定的互相吸附 ,是由分散的单个细胞发展而成的三维网络结构 ,是血液流变学中一个重要的研究课题。从微观力学角度对红细胞的聚集进行了分析 ,讨论了影响血液屈服应力的因素     

河蟹大眼幼体至Ⅲ期幼蟹对蛋白质、脂肪、复合矿物盐及维生素适宜需求量的初步研究

采用四因子三水平的正交实验法,研究了河蟹大眼幼体至Ⅲ期幼蟹阶段对饲料中蛋白质、脂肪、矿物盐及复合维生素的适宜需求量.结果表明,影响河蟹大眼幼体至Ⅲ期幼蟹成活率的因素主次顺序为蛋白质＞矿物盐＞脂肪＞维生素,其最优水平分别为蛋白质35.50 %;矿物盐6 %;脂肪17.39 %;复合维生素1 %.河蟹从大眼幼体发育到Ⅲ期幼蟹,对饲料中蛋白质的适宜需要量有逐渐减少的趋势,即从45.52 %减至35.50 %;对矿物盐适宜添加量的要求有逐渐上升的趋势,即由2 %升至6 %;而对复合维生素适宜添加量的要求则有下降的趋势,即由3 %降至4 %;但对脂肪的适宜需要量一直是较稳定且较调换,即为17.39 %.     

转牛酪蛋白基因(α_(s1)—CaseinB)cDNA花生后代的种子蛋白质及叶片Gus酶活性检测

对花生转牛酪蛋白基因cDNA子二代 ,1 4株种子胚和子叶全蛋白的SDS—PAGE电泳分析表明 ,与对照比较 7株子二代中均有一条新的蛋白质带 ,并在子叶和胚中大量表达 .对 3株子二代及对照花生幼苗叶片的Gus酶活性检测表明 :1株 ( 2 0 1 1 )Gus酶活性较强     

营养元素调控热休克蛋白研究进展

热休克蛋白(Heat Shock Protein,HSP)是生物体在受热或其他不利环境因素刺激下应激合成的一组特殊蛋白质.HSP的生物学功能广泛,不仅表现在热应激条件下参与细胞的抗损伤、修复和热耐受过程,保护细胞生命活动,而且在蛋白质折叠、跨膜运输、细胞骨架及核骨架稳定等方面发挥重要作用.由于机体的营养状况与应激能力密切相关,本文主要综述了营养元素对HSP合成的调控作用.     

Evolutionary Mode of Metallothioneins Inferred from Cd-MT Genes of Tetrahymena

From Tetrahymena thermophila （strain BF5）, the coding region of Cd-MT gene was cloned and sequenced. and identified as MTT1 isoform. A serial duplicate structure is discovered in its amino acid sequence, which separates the coding region into three parts （Part 1：7-61; Part 2：64-118; Part 3：122-162）. The alignments among them and comparison with the corresponding parts of MT1 isoform suggest that MT1 and MTT1 isoforms both come from the same ancient gene that is homologous to Part 1, and Cd-MTs of Tetrahymena are aroused by such ancient gene duplication. The prediction of secondary structures and the analysis of the disulfide-bonding state of cysteine show that there are a lot of differences between MT1 and MTT1 isoforms, which maybe relate to their function mechanism.     

Prediction of β -turns using double BP network with novel coding schemes of amino acids

Protein structure prediction is one of the most important problems in structural biology. β-turns are always at the turn of a protein tertiary structure and thus β-turn’s prediction is a key step in tertiary structure prediction. There are some methods to predict β-turns based on machine learning techniques such as k-nearest method, neural networks and support vector machine. In this paper, we construct a classifier using double BP networks and put forward two novel methods to code amino acids in the second network. When trained and tested on different datasets, they achieve more accuracy than other coding methods.