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21.
为了提高微电网的经济运行水平,提出考虑分时电价并计及制热收益的微电网多目标能量调度模型,该模型以微网发电成本最低与环境效益最优为目标。首先,利用权重系数将多目标经济调度问题化成单目标优化问题。其次,针对遗传算法局部搜索能力差的问题,提出了天牛须搜索算法改善遗传算法的变异操作,利用自身对空间的判断,加强局部搜索能力,在此基础上将Metropolis接受准则加入天牛须搜索算法中,增加变异的概率。最后,以一个微电网为例,将改进的算法与标准遗传算法进行对比,验证了所改进的算法的全局最优解的搜索能力,使得微网获得更佳的综合效益,降低了系统经济运行成本。  相似文献   
22.
A new sesquiterpene, eupatolide 13-O-β-d-glucopyranoside (eupatolide-II, 1), lactone glucoside, along with 15 known compounds, were isolated from the whole plant of Inula salsoloides (Asteraceae). Dichloromethane extract and compounds 111 were used to investigate insecticidal activities against vegetable important pest, striped flea beetle (Phyllotreta striolata Fabricius). None of the samples show any toxicity under concentration of 500 times, while compound 1 and the extract had toxic effect when the concentration increased to 250 times. But the corrected mortality of compound 1 and the extract were only 44.83 and 13.80%, respectively. Compound 11 (inulasalene) showed repellency effect in the no-choice test, and the repellency rate was 70%. Compounds 1 and 3 (inulasalsolide) showed the antifeeding rates of 65.22 and 47.06%, respectively. Compound 10 (11β,13-dihydrogeneupatolide) showed strong attractive effects on the adults, while the difference of injured area between the treatment and control was also not significant.  相似文献   
23.
古昆  李鲜  陈静波  刘复初  林军 《应用化学》2001,18(8):662-663
手性试剂;烟草甲虫性信息素(7S)-(-)-4;6-二甲基-7-羟基-3-壬酮的立体选择性合成  相似文献   
24.
25.
江斯琦  刘强 《科学技术与工程》2020,20(22):9243-9247
台风风暴潮是影响我国最严重的海洋灾害之一,台风风暴潮经济损失的预评估对防灾减灾有重要作用。针对目前大量单机器学习模型评估效果不佳的问题,提出基于天牛须搜索算法优化的BP神经网络及GIS空间分析的台风风暴潮经济损失评估模型。该模型在神经网络训练前,先利用天牛须搜索算法对神经网络的初始权值阈值进行优化,以提高网络的寻优精度;在网络输出计算结果后,借助GIS空间分析功能找出待评估台风风暴潮的相似样本,并用相似样本对待评估台风风暴潮进行结果调整;最后基于悲观、乐观估计思想,给出台风风暴潮经济损失预评估区间。计算结果表明,结合GIS空间分析调整能给出更有效的模型评估结果。  相似文献   
26.
The recent identification of a male-produced aggregation pheromone [(S)-3,7-dimethyl-2-oxo-6-octene-1,3-diol, (S)-CPB] offers a new tool for Colorado potato beetle (CPB) management. We developed a novel synthetic approach to produce CPB pheromone in seven steps and 46.54% overall yield. Grignard reaction, oxidation, and stereoselective methylation using organometallic reagent are the key steps in the commercially viable total synthesis, generating CPB pheromone in 98.6% enantiomeric purity and gram quantity.  相似文献   
27.
二种捕食性瓢虫人工饲养繁殖技术的研究   总被引:1,自引:0,他引:1  
1990年用日本龟蜡蚧和人工代饲料饲养矢尖蚧的天敌优势种湖北红点唇瓢虫与二双斑唇瓢虫,结果表明:用日本龟蜡蚧饲养湖北红点唇瓢虫,其产卵量比二双斑唇瓢虫高3倍以上;而用人工代饲料饲养,两种瓢虫的产卵量极低。人工繁殖的湖北红点唇瓢虫能在施秉县农业局柑桔园正常发育,顺利越冬,现已对此园的矢尖蚧起到了明显的防治效果。  相似文献   
28.
项林川 《大学物理》2007,26(6):24-25
给出“甲虫和橡胶带”问题的一种简便的新解法.  相似文献   
29.
Volatile cues can play a significant role in the location and discrimination of food resources by insects. Dung beetles have been reported to discriminate among dung types produced by different species, thereby exhibiting behavioral preferences. However, the role of volatile organic compounds (VOCs) in dung localization and preference remains largely unexplored in dung beetles. Here we performed several studies: firstly, cage olfactometer bioassays were performed to evaluate the behavioral responses of Bubas bison (Coleoptera: Scarabaeidae) to VOCs emanating from fresh horse, sheep, and cattle dung; secondly, concurrent volatilome analysis was performed to characterize volatilomes of these dung types. Bubas bison adults exhibited greater attraction to horse dung and less attraction to cattle dung, and they preferred dung from horses fed a pasture-based diet over dung from those fed lucerne hay. Volatilomes of the corresponding dung samples from each livestock species contained a diverse group of alkanes, alkenes, alkynes, alcohols, aldehydes, ketones, esters, phenols, and sulfurous compounds, but the composition and abundance of annotated VOCs varied with dung type and livestock diet. The volatilome of horse dung was the most chemically diverse. Results from a third study evaluating electroantennogram response and supplementary olfactometry provided strong evidence that indole, butyric acid, butanone, p-cresol, skatole, and phenol, as well as toluene, are involved in the attraction of B. bison to dung, with a mixture of these components significantly more attractive than individual constituents.  相似文献   
30.
为了提升传统3DDV-Hop算法的定位精度和稳定性,提出了MIDBO-3DDV-Hop算法。该算法利用多策略改进蜣螂搜索算法(multi strategy improvement dung beetle optimizer,MIDBO)来提高3DDV-Hop算法的定位精度。该算法通过通信半径分级方法细化跳数,使用加权平均跳距来修正节点之间的跳距误差。MIDBO算法引入立方混沌初始化和反向折射机制来初始化算法种群,采用变螺旋策略增强全局搜索能力。算法还融入Levy飞行策略和自适应权重因子,以避免陷入局部最优,并平衡算法的收敛性和搜索多样性。通过MIDBO算法对3DDV-Hop算法中未知节点位置进行优化。仿真结果显示,与传统的3DDV-Hop、IPSO-3DDV-Hop和IGA-3DDV-Hop算法相比,MIDBO-3DDV-Hop算法在定位精度、稳定性和收敛速度方面均达到最优水平。  相似文献   
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