无线传感器网络三维定位交叉粒子群算法

针对标准粒子群算法进化后期收敛速度慢、易陷入局部极小点、早熟收敛等问题,提出一种基于交叉粒子群的农业无线传感器网络三维定位算法。该方法主要包括汇聚节点选取、测量距离修正、节点定位3个阶段,通过借鉴遗传算法交叉操作的思想,增加粒子的多样性,减小测距误差、锚节点数量对定位结果的影响,有效提高定位算法全局搜索能力。仿真结果表明,该方法的稳定性和定位精度均优于标准粒子群算法。在测距误差和锚节点数量相同的条件下,与混合蛙跳定位算法进行性能比较,两种算法的最大定位误差分别为1.337 8 m、1.747 3 m,最小定位误差分别为0.258 3 m、0.561 5 m,平均定位误差分别为0.651 2 m、1.044 7 m。     

“甜樱桃”跨气候带引种栽培研究

2010年开始,从山东等温带地区引进了12个“甜樱桃”新品种,在汉中北亚热带气候条件下种植,对其适应性、开花、着果、成熟期、口感等方面进行了试验研究。并以适应性、早熟性等综合性状为目标,筛选出了在口感、抗逆性、着色、丰产等方面表现良好的早、中熟品种7个,可适宜于广泛种植的早熟、矮化品种3个,为汉中甜樱桃产业发展提供了参考。     

小麦与钩刺山羊草杂种的育性,抗病性和细胞遗传学研究

钩刺山羊草高抗条锈、叶锈等病害。以钩刺山羊草为母本与小麦品种鲁麦１５杂交,杂交结实率为５５．２６％,利用鲁麦１５作父本与杂种Ｆ１回交结实率为２２．０９％。Ｆ１和Ｆ２的自交结实率分别为１３．８％和８．２５％。细胞学观察结果表明,Ｆ１、Ｆ２和ＢＣ１ＰＭＣ ＭＩ的平均染色体构型分别为２５．３４Ｉ＋４．２３Ⅱ＋０．１２Ⅲ＋０．２１Ⅳ、１８．６２Ｉ＋９．１３Ⅱ＋０．０７Ⅲ＋０．４２Ⅳ和８．５６Ｉ＋１６．８１     

小型拖拉机阶梯轴类锻坯楔横轧成形

分析了采用楔横轧工艺生产小型拖拉机阶梯轴精密锻坯的节材效益,提出了几种复杂阶梯轴锻坯的楔横轧成形方法。这几种首次提出的成形方法,提高了锻坯的制造精度,扩大了楔横轧工艺的应用范围。     

红掌种子结实性、发育周期及杂交后代发芽力的变异分析

本文对红掌部分种质资源进行了育种相关的生殖特性研究。结果表明：红掌种质存在不同程度的自交结实能力,不同品种自交结实率在0-100%之间差别较大;种子发育周期4-6月,具体表现出母本效应;杂交种子播种4周后即多数萌发,发芽率变异在4.7%-100%之间,具体随双亲、杂交方式的不同而变化。结果为红掌遗传和育种的研究提供了有益借鉴。     

黄秋葵与红秋葵杂交育种的初步研究

以9个黄秋葵品种为基本材料,通过连续多代自交获得自交系后,分析和比较了各个自交系的性状特点,选择了8个性状较为优良的自交系作为亲本进行配对,制成了14个单交种材料,同时,首次尝试将黄秋葵与红秋葵进行杂交,获得了果实颜色介于两亲本之间的中间类型。通过调查和比较,筛选出2个具有产量优势的杂交组合。在杂交育种过程中,也发现了可利用叶柄颜色作为标记性状来生产杂交黄秋葵种苗的新方法。     

Sensitivity to fluopicolide of wild type isolates and biological characteristics of fluopicolide-resistant mutants in Pseudoperonospora cubensis

Cucurbit downy mildew caused by the oomycete pathogen Pseudoperonospora cubensis is a devastating disease that is distributed worldwide and affects cucumber in open fields and greenhouses. Fluopicolide, which was a novel systemic fungicide and was released in 2008, it is very effective in controlling downy mildew on cucumber and grape, potato late blight and pepper Phythophthora blight and reduces the loss caused by the diseases, but so far the potential for P. cubensis to develop resistance to fluopicolide has not been investigated. Hence, a laboratory study was undertaken to assess the risk of P. cubensis developing resistance to fluopicolide. Baseline sensitivity to fluopicolide was determined by using 75 P. cubensis isolates collected from cucumber-growing greenhouses in Hebei province, where no fluopicolide had been used for control of cucumber downy mildew before. Values of effective concentrations for 50% inhibition (EC₅₀) of sporulation ranged from 0.02 to 0.40 μg ml⁻¹ and were distributed as a unimodal curve, indicating that all 75 isolates were sensitive to fluopicolide. Sporangia of nine sensitive isolates were ultraviolet (UV)-irradiated, and four fluopicolide-resistant mutants were acquired at a mutation frequency of 7.4 × 10⁻⁷. Seven mutants resistant to fluopicolide were obtained from seven isolates by sporangia adaptation on fluopicolide-treated leaves of cucumber. The EC₅₀ values for all eleven fluopicolide-resistant mutants ranged from 3.37 to 13.06 μg ml⁻¹ with mean resistance factors of 7.9–118.0. After 10 sporangia transfers on fungicide-free leaves of cucumber, all eleven resistant mutants remained resistant to fluopicolide with mean resistance factors of 8.2–81.3. Seven resistant mutants from the selection for resistance and one resistant mutant from UV mutagenesis exhibited stable resistance; however, the other three resistant mutants from UV irradiation became significantly less resistant. Compared to their respective sensitive parents, the eleven resistant mutants exhibited diversity in latent period, infection frequency, lesion extension and sporulation ability. Five out of the eleven resistant mutants exhibited prolonged latent period and three out of the eleven resistant mutants provided decreased infection frequency (IF) compared to their respective parents, indicating that in some cases, resistance mutation might affect the latent period and IF of P. cubensis. There were significant differences in pathogenicity and ability to produce sporangia, but this seemed not to be caused by resistance mutation. No cross-resistance was detected between fluopicolide and azoxystrobin, metalaxyl, dimethomorph, or cymoxanil. In all, there could be a moderate to high risk of field populations of P. cubensis developing resistance to fluopicolide, and populations of P. cubensis should be monitored regularly for their shift of sensitivity over years of application.     

唐菖蒲不同品种杂交F1代性状初步观察

通过对大田以及温室栽培唐菖蒲品种进行杂交育种试验，共选用7个亲本配置1个自交系和6个杂交系，对其F1代的性状表现进行初步观察。结果发现，母本为深色系的品种性状表现较好，其中303x301组合和201×301组合的籽球性状表现较突出。在杂交组合内呈现主要性状的优良单株有（以A．G分别代表7组杂交组合）A3、B1、c1、D3、E2、F2和G1这7株是本次试验发现呈现出良好的表现型的杂交种。     

家蚕细纤度三眠蚕品种“芊春×知日”的选育研究

采用杂交育种和系统选择方法,用显性三眠蚕品种和经济性状优良的四眠蚕品种单杂交,育成了经济性状优良、眠性稳定的三眠蚕品种芊春和知日。通过杂交选配,育成了强健好养、眠性稳定、茧丝纤度细、茧丝质优的三眠蚕品种"芊春×知日"。经实验室、北方蚕业科研协作区及农村试养成绩表明,该品种孵化良好、齐一,发育整齐,眠起快齐、上蔟齐涌,生命力强,三眠率达99%以上,全龄经过21 d左右,茧丝长1 100~1 200 m,解舒丝长800~900 m,净度93~95分,茧丝纤度1.9~2.1D,适于缫制细纤度高品位生丝。     

用于谷物复脱分离和清选的横流风机

提出一种横流风机应用的新方案。在横流风机下方安装筛状凹板,使其具有对谷物进行复脱、分离和清选的综合功能。分析和试验研究了这种风机的工作特点、分离性能和清选性能。