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1.
基于多变异分组遗传算法的多机协同作业静态任务分配   总被引:2,自引:0,他引:2  
为解决农业机械(简称农机)多机协同作业前的任务分配问题,提出了基于多变异分组遗传算法的同种农机多机协同作业静态任务分配方法。首先,根据农机合作社实际作业模式,基于农机性能参数和任务参数,综合考虑机群的作业时间、作业油耗和路程代价等因素,建立了多机协同代价函数;根据多机协同作业特点,构建了多变异分组遗传算法,设计了两段式编码、分组交叉算子和多种变异算子,并建立了农机多机协同作业静态任务分配模型;通过仿真试验对比分析了算法的性能,并采用不同的代价权重进行了任务分配仿真试验;最后,采用不同的权重对实际深松作业进行任务分配试验,对本文提出算法进行了验证。结果表明:在不同权重下,基于多变异分组遗传算法的多机协同静态任务分配的机群代价比实际作业代价降低了29.48%~55.00%,选取合理权重的静态任务分配具有较高的分配效率和分配性能,能够满足实际多机协同作业中任务分配的要求。  相似文献   
2.
为了评估长牡蛎(GG)和近江牡蛎(AA)的配子兼容性和合子育性,本实验探究了盐度(16、20、24、28和32)、温度(18、21、24、27和30 ℃)和精子浓度(100、101、102、103和104个/μL)对受精率、胚胎畸形率和孵化率的影响。结果显示,随盐度的增加,GG组的受精率和孵化率逐渐上升,而AA组和AG组的受精率和孵化率先上升后下降;GA组和AG组分别在盐度28和24时具有较优的配子兼容性和合子育性,受精率、畸形率、孵化率分别为7.45%±5.05%、2.00%±0.90%、63.60%±9.88%和14.26%±9.26%、1.74%±0.93%、66.16%±9.43%。随温度上升,AA、GA和GG组的受精率和孵化率先升高后下降,而畸形率先下降后上升;GA组和AG组均在27 ℃时表现出较优的配子兼容性和合子育性,此时GA组和AG组的受精率、畸形率、孵化率分别为7.95%±4.04%、1.79%±1.04%、57.11%±9.95%和14.70%±7.27%、1.66%±0.85%、67.25%±15.19%。随精子浓度的增加,GG组的受精率逐渐上升,孵化率逐渐下降,GA组和AG组的受精率逐渐上升;GA组和AG组均在104个/μL时表现出较优的配子兼容性和合子育性,此时二者的受精率、畸形率、孵化率分别为9.09%±7.53%、1.59%±0.48%、67.97%±19.96%和14.30%±6.04%、1.06%±0.68%、67.33%±12.65%。研究表明,温度、盐度和精子浓度对长牡蛎和近江牡蛎种间配子兼容性影响较小,但对合子育性影响较大。  相似文献   
3.
随着人类观察世界的能力大幅提升,设计与研究的尺度得到了极大拓展,星球化(planetarization)与在地性(locality)同时成为空间设计学科重点关注的议题,近年来涌现出多个新思潮。基于克莱因四元群模型构建的风景园林思潮研究计划旨在建立一套理论框架以对不同研究实践进行更系统的讨论分析,为国内风景园林学科与行业带来新的思考,并运用新理论框架重点介绍了4个风景园林思潮,包括星球城市化背景下的风景园林理论、新地理视角中的空间叙事、关注本土议题的风景园林研究以及直觉导向的在地探索。  相似文献   
4.
Chestnut blight, caused by Cryphonectria parasitica, was identified in Devon, UK, in December 2016. Intensive surveys detected the disease at further sites in Devon (seven), Berkshire (one), Dorset (one), Derbyshire (four) and a cluster of eight sites in southeast London. Over 570 survey samples were tested, and 227 were positive for C. parasitica by isolation and real-time PCR. A total of 227 isolates were tested for mating type, and 197 screened for vegetative compatibility group (VCG) and compared with VCGs known from mainland Europe. The same isolates were also screened for the presence of Cryphonectria hypovirus 1 (CHV-1). Eleven VCGs were identified within the UK population. Five corresponded to already known European VCGs but six were unique. The European VCGs mainly came from the Devon, Dorset, Berkshire and Derbyshire disease outbreaks, whilst unique VCGs were almost exclusively from the southeast London cluster. Both mating types were detected, but only one mating type was present at each site, with the exception of a single Devon site. Perithecia of C. parasitica were never observed at any site. CHV-1 was found in seven isolates from three different locations and was always subtype-I, which has limited hypovirulence. Therefore, although CHV-1 is associated with C. parasitica at some outbreaks, it probably has limited impact on virulence. The diversity of VCGs and their distribution at outbreak sites, together with findings of CHV-1, suggests C. parasitica has been introduced to the UK multiple times over at least two decades through international plant trade.  相似文献   
5.
Ectophylla alba is a tent-making bat that roosts in mixed-sex clusters comprising adults and offspring. Our goal was to determine the genetic identity of individuals belonging to different roosting groups. We tested the hypothesis of kin selection as a major force structuring group composition. We used 9 microsatellites designed for E. alba to determine the genetic identity and probability of parentage of individuals. We analyzed parentage and kinship using the software ML-Relate, GenAIEx, and Cervus. The obtained relationship probabilities (0.5) revealed a clear maternal relationship between female adults and offspring with allele compatibility, and at least 5 relationships between male adults and pups. We found a low degree of relatedness within roosting groups. Between roosting groups at different sites, the mean probability of a half-sibling relationship ranged from 0.214 to 0.244 and, for full-sibling relationship, from 0.383 to 0.553. Genetically, adult individuals were poorly related within clusters, and kinship as an evolutionary force could not explain group membership.  相似文献   
6.
纵横刀组协同式马铃薯种薯切块装置设计与试验   总被引:1,自引:0,他引:1  
针对马铃薯种薯切块机械化程度低的问题,设计了一种纵横刀组协同式马铃薯种薯切块装置,对其关键部件进行设计,通过对马铃薯种薯切割过程的力学分析、运动学分析和能量学分析,建立了切种能量的数学模型,确定了影响马铃薯切种效果的主要因素。以切种效率、切种合格率为评价指标,以圆盘刀半径、输送辊与圆盘刀垂直中心距、圆盘刀轴转速和夹持辊轴转速为试验因素,进行了四因素四水平正交试验。对正交试验结果进行方差和极差分析,结果表明:当圆盘刀半径为180 mm、输送辊与圆盘刀垂直中心距为190 mm、圆盘刀轴转速为115 r/min、夹持辊轴转速为56 r/min时,切种效率为74.5 kg/min,切种合格率为98.8%,满足马铃薯切种作业要求。  相似文献   
7.
8.
Fusarium wilt, caused by Fusarium oxysporum, is a major disease of jojoba, causing serious economic losses. This study was aimed at characterizing the Fusarium populations associated with jojoba in Israel. Fifty Fusarium isolates used in this study included 23 isolates from the 1990s (“past”) and 27 recently isolated (“recent”). All the isolates were characterized by arbitrarily primed (ap)-PCR and 16 representatives were additionally delineated using multilocus (tef1, rpb1, rpb2) phylogeny and evaluated for their pathogenic potential. Consequently, 88% of the isolates were identified and characterized to the F. oxysporum species complex. The remaining 12% grouped within the F. fujikuroi, F. solani, and F. redolens species complexes. Variations in the infection rate (16.7%–100%), disease symptoms (0.08–1.25, on a scale of 0–3), and fungal colonization index (0.67–2.17, on a scale of 0–4) were observed within the tested isolates, with no significant differences between the past and recent isolates. The representative isolates were assigned to 11 groups based on ap-PCR. Pathogenicity tests showed that isolates from Groups II, IV, and V were the most aggressive, whereas isolates from Groups III, VIII, and IX were the least aggressive. Among the tested isolates, F. oxysporum sensu lato was the most aggressive, followed by F. proliferatum, while F. nygamai was the least aggressive. This study demonstrates the complexity and genetic diversity of Fusarium wilt on jojoba in Israel, indicating possible multiple introductions of infected germplasm into the country.  相似文献   
9.
旨在研究胶霉毒素菌渣对5种土传病菌的抑制性,寻找到一种胶霉菌素菌渣的综合利用方法。以辣椒炭疽病菌、水稻纹枯病菌、苹果腐烂病菌、油菜菌核病菌和棉花枯萎病菌为供试菌,采用菌丝生长速率法,对胶霉毒素菌渣的抑菌活性进行了研究,并比较了10%菌渣、10%豆粕、无豆粕和菌渣的培养基对木霉孢子和胶霉毒素含量的影响。以木霉干重孢子数为指标,确定了菌渣最佳添加量。胶霉毒素菌渣对5种土传病菌具有一定的抑菌效果,浓度为40 mg/mL时,对4种土传病菌菌丝的生长的抑制率为100%。胶霉毒素菌渣添加量为30%时,木霉的发酵效果最佳,其干重孢子数达到22亿/g。综上所述,胶霉毒素菌渣具有良好的抑制土传病菌生长的效果,且可作为氮源循环利用培养木霉。  相似文献   
10.
Schiff-base polydentate ligands types of salen and salophen can form stable complexes with Zn2+ and these metal complexes can act as a source of zinc (Zn) to plant's body if they are used as micronutrient supplements. Inspired by these facts, four different Schiff-base ligands and their Zn2+ complexes were first synthesized and then characterized by different analytical and spectroscopic techniques. To investigate their effects local chickpea seeds were treated with each ligands and complexes and different morphological and biochemical parameters were monitored. Among all the complexes and ligands it was found that the C4 complex, that is, [N,N'-(o-phenylene)bis-(3-methoxysalicylidenediamine)] monohydrate showed the maximum efficacy when treated as a micronutrient supplement for Cicer arietinum L. So that these complexes especially the C4 can act as an potential source of Zn.  相似文献   
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