基于PCA-IBAS-ELM的海底多相流管道内腐蚀速率预测

海底多相流管道运输介质中油、气、水共存,极易发生化学反应引发一系列腐蚀问题。为预测其腐蚀速率,对管内腐蚀机理及影响因素进行分析,提出基于主成分分析法（PCA）和改进甲虫天牛须算法（IBAS）的极限学习机（ELM）预测模型。PCA 筛选腐蚀因素,降低预测模型的输入指标维数,IBAS优化ELM的关键性能指标--输入权值及隐层阈值,提升预测精度。为检验模型效能,以我国海南东部某海底油气管道50组数据为例进行研究,并与其他两种模型对比分析。结果表明：温度、pH值、流体流速和CO2分压是影响该类型管道腐蚀的关键因素,PCA-IBAS-ELM预测结果与实际值拟合度更高,其均方根误差（RMSE）,平均绝对误差(MAE)和平均绝对百分误差（MAPE）和均小于比较模型。 可见构建模型对于海底多相流管道内腐蚀速率预测具有优越性。     

Chemical Composition and Insecticidal Activities of Essential Oils against the Pulse Beetle

Pulse beetles, Callosobruchus chinensis and Callosobruchus maculatus, are essential pests of cowpea, gram, soybean and pulses. Application of synthetic insecticides against the pulse beetle has led to insect resistance; insecticide residues on grains affect human health and the environment. Essential oils (EOs) are the best alternatives to synthetics due to their safety to the environment and health. The main objective of the investigation was to study the chemical composition and insecticidal activities of EOs, their combinations and compounds against the pulse beetle under laboratory. Neo-isomenthol, carvone and β-ocimene are the significant components of tested oils using GC-MS. Mentha spicata showed promising fumigant toxicity against C. chinensis (LC₅₀ = 0.94 µL/mL) and was followed by M. piperita (LC₅₀ = 0.98 µL/mL), whereas M. piperita (LC₅₀ = 0.92 µL/mL) against C. maculatus. A combination of Tagetes minuta + M. piperita showed more toxicity against C. chinensis after 48 h (LC₅₀ = 0.87 µL/mL) than T. minuta + M. spicata (LC₅₀ = 1.07 µL/mL). L-Carvone showed fumigant toxicity against C. chinensis after 48 h (LC₅₀ = 1.19 µL/mL). Binary mixtures of T. minuta +M. piperita and M. spicata showed promising toxicity and synergistic activity. EOs also exhibited repellence and ovipositional inhibition. The application of M. piperita can be recommended for the control of the pulse beetle.     

基于BAS-2D-VMD的图像去噪算法

针对2D-VMD(2D-Variational Mode Decomposition)算法需要人为预设K值的问题,提出了一种基于BAS-2D-VMD(Beetle Antennae Search Algorithm-2D-Variational Mode Decomposition)的图像去噪算法.该方法首先用BAS算...     

保卫德对黄曲条跳甲田间控制作用研究

田间应用植物保护剂保卫德后可显著控制黄曲条跳甲种群数量 ,9、4 .5 L/hm2 浓度处理对成虫忌避率分别达 80 .90 %和 77.5 3%,持续为害指数分别是对照的 6 .95 %和 0 .0 9%,显著降低成虫为害量 ,保苗效果分别达 97.2 4 %和 89.2 2 %。     

重采样和天牛须协同演化粒子群的WSN覆盖控制算法

为了最大程度提升无线传感器网络(WSN)的覆盖范围并降低能耗,延长网络生命周期,提出了基于重采样技术和天牛须搜索的协同演化粒子群优化(RBASPSO)算法来优化WSN的覆盖控制问题。重采样技术平衡了粒子群算法的全局搜索能力和收敛速度,增加了粒子群整体多样性,防止算法过早收敛,加强粒子在搜索过程中跳出低质量谷底的能力; 天牛须搜索依靠个体的两个触角搜索其邻域,增强了粒子群中单个粒子的搜索能力。RBASPSO算法采用覆盖率和节点休眠率的加权作为优化WSN覆盖控制的目标函数,通过重采样技术和天牛须搜索的协同演化,既加强了单个粒子的搜索能力,又确保粒子群的多样性及活跃性,提升WSN覆盖性能。实验结果表明,RBASPSO算法不仅能有效处理复杂多峰问题; 而且可以有效提高WSN网络覆盖率,延长网络生命周期。     

Photonic nanoarchitectures in butterflies and beetles: valuable sources for bioinspiration

Nature began developing photonic nanoarchitectures millions of years before humankind. Often, in the living world, color is a communication channel that may influence the chance of the individual surviving as well as the chance to reproduce. Therefore, natural color‐generating structures are highly optimized by many millennia of evolution. In this review, a survey is presented of the development of natural photonic crystal‐type nanoarchitectures occurring in butterflies and beetles from the standpoint of physics and materials science, covering the past ten years. One‐, two‐, and three‐dimensional structures are reviewed, emphasizing the role that disorder, or irregularity, may play in natural nanoarchitectures to achieve certain visual effects. The characterization, modeling methods, and rapidly growing number of bioinspired or biomimetic applications are discussed.     

dl－日本丽金龟性信息素合成方法研究

以丙炔醇为原料，应用功能基团的保护、格氏交换与格氏偶联、脱保护基氧化、亲核加成、闭环反应、氧化仲醇成内酯、选择性催化等合成方法合成了ｄｌ－日本丽金龟性信息素．原料易得，操作路线简单，产率较高     

Synthesis of (S)-6-methylhept-5-en-2-ol, the aggregation pheromone ofGnathotrichus sulcatus

An enantioselective (ee−50%) four-step synthesis of (S)-6-methylhept-5-en-2-ol (“sulcatol”), which is the aggregation pheromone ofGnathotrichus sulcatus, from 3S,7-dimethylocta-1,6-diene was developed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 713–717, April, 2000.     

小油菜不同播期与密度下黄条跳甲为害情况的研究

本文报道了黄条跳甲类害虫在油菜不同播期与密度条件下的发生为害情况，从四个播种日期与五个播种密度的试验结果表明，黄条跳甲随播期推迟发生为害加重，播种量大，为害较严重，并且，在西宁地区为害小油菜的主要种类是黄宽条跳甲，其次为黄曲条跳甲，二者比例为３．３：１，适时早播，严格控制播种量是减轻黄条跳甲发生为害的重要农业技术措施。     

柑桔缠皮虫Agrilus inamoenus Kerremans的鉴定和生物学简记(鞘翅目:吉丁虫科)

本文鉴定描述一种柑桔吉丁虫——柑桔缠皮虫的学名、形态特征.并简要记述该虫在福建的发生情况.