山西省孝义市近40年气候变化特征分析

为了深入研究山西省孝义市气候变化特征,采用Mann-Kendall检验、滑动T检验及Morlet小波变换等方法对孝义市1975-2015年气候要素进行趋势估计、突变检验、周期分析及发展趋势预测。结果表明:近40年来,孝义市年平均气温呈显著上升趋势,突变年份为1996年,存在32、9 a长周期;年降雨量呈不显著下降趋势,突变年份为1990年,存在32、6 a长周期;年蒸发量呈显著性上升趋势,突变年份为1997年,存在32、10 a长周期;年平均相对湿度呈显著下降趋势,突变年份为1982、2003年,存在15、32 a长周期。孝义市1975-2015年年代际气候经历了"冷湿-暖湿-暖干"的变化过程,预测全境2017-2030年年代际气候将经历"冷湿-暖干"的变化过程。     

异养培养光合细菌产5-氨基乙酰丙酸发酵条件的研究

从废水处理厂的活性污泥中筛选出产5 氨基乙酰丙酸(ALA)的红假单胞菌原始菌株,可产生7 35mg/L的ALA,采用亚硝基胍(NTG)以及紫外线对该菌株进行诱变处理,得到产量为19 12mg/L的菌株C-1。在摇瓶实验过程中,对培养基组成和培养条件进行了初步优化,使菌株产ALA的能力达到了38 9mg/L。     

带两类正态变异的PSO 算法

针对基本粒子群优化算法(PSO)容易陷入局部最优点和收敛速度较慢的缺点,提出在PSO更新过程中加入两类基于正态分布投点的变异操作。一类变异用来增强局部搜索能力,另一类变异用来提高发现全局最优点的能力,避免所有粒子陷入到一个局部最优点的邻域内。数值结果表明,所提出算法的全局搜索能力有显著提高,并且收敛速度更快。     

A multiobjective hybrid ant colony optimization approach applied to the assignment and scheduling problem

The assignment and scheduling problem is inherently multiobjective. It generally involves multiple conflicting objectives and large and highly complex search spaces. The problem allows the determination of an efficient allocation of a set of limited and shared resources to perform tasks, and an efficient arrangement scheme of a set of tasks over time, while fulfilling spatiotemporal constraints. The main objective is to minimize the project makespan as well as the total cost. Finding a good approximation set is the result of trade‐offs between diversity of solutions and convergence toward the Pareto‐optimal front. It is difficult to achieve such a balance with NP‐hard problems. In this respect, and in order to efficiently explore the search space, a hybrid bidirectional ant‐based approach is proposed in this paper, which is an improvement of a bi‐colony ant‐based approach. Its main characteristic is that it combines a solution construction developed for a more complicated problem with a Pareto‐guided local search engine.     

Bioleaching of chalcocite by mixed microorganisms subjected to mutation

Mixed microorganisms with elevated activity of chalcocite-leaching were screened by mutation methods. The original microorganisms collected from acid mine drainage of different sites were mixed and then treated with mutagens NO₂⁻, diethyl sulfate (DES), UV and their combinations, respectively. Five groups of mixed microorganisms with much stronger ore-leaching ability were obtained by screening on the leaching media. Among them, group E of mixed microorganisms (treated with 1% DES for 60 min) with the best performance on chalcocite-leaching, increases the content of Cu²⁺ by 101.4% in 20 d of leaching compared with the control culture. In addition, group E is more tolerant to Cu²⁺ in media than the control without mutation treatment. Analysis for the diversity of microbial clones indicates that half of operational taxonomic units (OTUs) in group E are Acidithiobacillus ferrooxidans. These observations suggest that group E might have potentials for industrial application. Foundation item: Project(50321402) supported by the National Natural Science Foundation of China; Project(2004CB619201) supported by the Major State Basic Research and Development Program of China     

全局最优位置变异粒子群优化算法

针对粒子群优化算法的早熟收敛,容易陷入局部最优且搜索精度不高等缺点,在现有的粒子群优化算法的基础上对其进行了若干改进,提出了避免微粒群陷入局部最优的全局最优位置变异的粒子群算法,并与其他算法做了比较,体现了其优越性.     

超声引导下肝细胞癌穿刺组织中Ezrin表达的临床意义

探讨Ezrin表达及超声引导下穿刺活检对肝细胞癌（HCC）的应用价值,实验方法如下：36例经超声引导下穿刺所得的HCC组织作肝穿癌组;45例手术切除的HCC组织作手术癌组,同时取12个癌旁肝组织作癌旁组;用免疫组化方法检测两组标本的Ezrin蛋白表达,并与临床病理学参数做统计学分析。得出结果：肝穿癌组Ezrin阳性表达...     

Differential multiuser detection using a novel genetic algorithm for ultra-wideband systems in lognormal fading channel

We employ a multiuser detection (MUD) method using a novel genetic algorithm (GA) based on complementary error function mutation (CEFM) and a differential algorithm (DA) for ultra-wideband (UWB) system...     

胆固醇氧化酶高产菌株的诱变选育及产酶条件优化

在对细脚拟青霉、玫烟色拟青霉、粉拟青霉、香菇、平菇、金针菇等胆固醇氧化酶产生菌初筛的基础上．选择以产酶较高的玫烟色拟青霉作为紫外诱变的出发菌株,筛选出一株相对高产突变菌株MFEC006,其酶活达到了0．5483U／mL,比出发菌株提高了154％,经8次传代培养,突变株性质稳定．对MFEC006菌株产酶条件进行优化,得出其最佳产酶条件为：pH为6．5,温度27℃,接种量10％,摇床转速180r／min．     

基于PWAS的层合板导波传播特性和损伤响应FEM分析及试验验证

导波无损检测（Non-Destructive Testing, NDT）技术由于适用范围广、检测速度快等优势,已成为结构安全性检测的重要技术手段之一。不过,导波在各向异性介质中的传播表现为频散特性与波传播方向的关联性、多模态特性与各向异性的相互作用以及不同模态与损伤的相互作用。导波在复合材料无损检测应用中的复杂性对检测技术和检测方法提出了更高的要求,所以对碳纤维复合材料层合板中的导波传播特性和损伤响应进行分析具有十分重要的意义。文中采用理论分析、仿真和试验相结合的方法,对不同碳纤维增强聚合物基（Carbon Fiber Reinforced Polymer, CFRP）层合板中的导波传播特性和各模态波与损伤的相互作用进行了分析。首先根据群速度、波长等参数建立有限元模型,并在边界设置阻尼递增吸收区域来弱化边界反射波的干扰;然后分析基于压电晶片有源传感器（Piezoelectric Wafer active Sensors, PWAS）的不同层合板中导波传播差异,之后在结构中引入损伤来分析不同模态波与不同损伤的相互作用;最后通过试验分析和验证有限元仿真的准确性。