风电-串补输电系统次同步谐振特性与风电机组数量及线路参数关系研究

针对双馈风电-串补系统次同步谐振特性,针对风电-串补系统次同步谐振问题,在RT-LAB中建立风电-串补送出系统等值模型,利用阻抗分析方法,对SSR风险与风电机组数量以及线路参数关系进行研究.得到主要结论:1)在不同风速下,均存在使系统阻尼特性最差的并网风电机组数量;2)线路串补度减小,系统的次同步谐振风险逐渐降低;3)...     

利用青海大黄油菜和芥蓝合成大粒甘蓝型油菜

利用青海大黄油菜（QD,2n=20,AA）与几种不同的甘蓝（CC,2n=18）正反杂交,辅以幼胚抢救、子房培养和染色体加倍技术人工合成甘蓝型油菜。结果表明：以QD为母本的多个杂交组合获得69株杂种苗,反交组合均未得到正常发育的胚。与中迟芥蓝杂交后的QD子房在MS、1/2MS、MS＋0.2mg/L 6-BA三种培养基中得胚率依次为15.5%、8.9%和4.4%,共获得24个杂种胚,而在MS＋1.5mg/L 6-BA＋0.25mg/L NAA分化培养基上角果内未发现成熟胚。染色体加倍处理结果表明,在培养基中添加秋水仙素后加倍率最高（59.4%～86.4%）。SSR分子标记结果显示：受试材料全部为真杂种,并且没有出现新增带和缺失带。人工甘蓝型油菜在形态上介于双亲之间,千粒重较高,达到5.48g～7.45g,显著高于甘蓝型油菜品种青油14号和中双4号。     

基于SSR标记的花生品种遗传多样性分析

从212对SSR标记引物中筛选出48对引物,对63份花生品种进行遗传多样性分析,共得到251个等位变异,变异范围为2~13个,平均每个标记位点有5.23个变异;48个SSR标记的多态性信息含量为0.252~0.873,平均为0.647;63份材料的遗传多样性指数为0.508~2.243,平均值为1.272;品种间的遗传相似系数在0.657~0.960之间,不同类型的花生品种间的遗传相似性较小,不同来源花生品种间的亲缘关系也较远;聚类分析结果表明,63个花生品种在遗传相似系数为0.74处分为4大类,聚类分析结果与传统的花生分类结果吻合。     

甘蓝型油菜SSR核心引物研究

为了确定一组适用于品种纯度鉴定和遗传多样性分析的SSR核心引物,以100份具有代表性的甘蓝型油菜品种（系）为研究材料对746对SSR引物进行筛选,综合考虑PIC（平均多态信息量）值大小、引物重复性、扩增带型清晰度、连锁群分布等因素,确定44对引物为甘蓝型油菜核心引物,其中20对引物为首选核心引物,24对引物为备选核心引物。20对首选核心引物每对可检测到3~9个多态性位点,PIC值介于0.56~0.80,共检测到102个位点,分布于11个连锁群上。随机抽取1对核心引物对一个杂交组合大田制种F1纯度进行鉴定,其鉴定结果与田间自然鉴定结果一致,并可同时鉴别出来源于父本及外来的混杂单株。将44对核心引物应用于品种的系谱分析和100份品种遗传多样性聚类分析,同样得到了很好的验证结果。该套SSR核心引物适用于甘蓝型油菜品种鉴定及遗传多样性研究。     

香菇EST资源的SSR信息分析

对来源于NCBI 公共数据库的12144 条香菇(Lentinus edodes)EST 序列进行简单重复序列SSR 搜索。结果表明：在这些香菇EST 序列中共有359 个SSR 位点,46 种SSR 的重复单元,其中2 碱基重复243 条(67.69%),3 碱基重复114 条(31.76%),5 碱基重复1 条(0.28%),6 碱基重复1 条(0.28%)。平均33.8 条EST 序列中有1 个SSR。SSR的碱基总数达7727kb,约占整个EST 序列碱基数的2.94%。本实验还根据搜索结果设计了100 条香菇EST-SSR 引物,并随机合成了20 对引物。以4 个野外采集的香菇DNA 为模板,对引物进行了筛选与评价,有16 对引物有较清晰且稳定的目标扩增产物,其中11 对引物的产物存在遗传多态性。结果表明本实验设计开发的香菇的EST-SSR标记是可行且有效的。     

Molecular evidence for maternal inheritance of the chloroplast genome in tea,Camellia sinensis (L.) O. Kuntze

BACKGROUND: Tea is the most consumed beverage worldwide after water. Yet very little is known about the genetics of tea in comparison with other crop species. Here we have taken advantage of the polymorphic nature of microsatellite DNA to investigate the mode of chloroplast inheritance in tea, Camellia sinensis (L.) O. Kuntze. This is important for the correct interpretation of phylogeny and introgression data as well as assessing the suitability of chloroplast transformation as a means for transgene containment in tea. RESULTS: The study was based on six Japanese tea cultivars, namely Aj2, CK23, Hatsumomiji, Nka05, Yamanoibuki and Kanayamidori used to generate four informative families. The parental pairs in the crosses differed at a single chlroroplast locus with respect to an imperfect microsatellite repeat of 16 nucleotide bases. In agreement with earlier cytological studies, all 61 progeny displayed a cpDNA profile that was consistent with the maternal inheritance of chloroplasts in tea. CONCLUSIONS: The data generated here provide the first molecular evidence of the plastid inheritance in tea. However, we suggest that additional families and polymorphic markers be screened for increasing the confidence in the observed maternal inheritance of chloroplasts in this important crop species. Copyright © 2011 Society of Chemical Industry     

Olive oil traceability by means of chemical and sensory analyses: A comparison with SSR biomolecular profiles

The relationship between genetic diversity and phenotype in olive, instrumental to improve the efficacy of olive clonal selection, is still far from being fully understood. This work reports on a comparison made between plant SSR genetic data and quality of monovarietal olive oils. Nine monovarietal oils produced by selected genotypes were characterised under chemical and sensory profiles. Fatty acid compositions were determined to evaluate quantitative differences among oils; some fatty acids are actually highly correlated with the genetic matrix, and PCA of fatty acids composition explains 85.53% variability. Moreover some oils characterised by high levels of oleic acid appeared interesting from a nutritional standpoint. Organoleptic profiles evidenced differences especially for the attributes defined as “pleasant flavours”; oils obtained by different genetic matrices were characterised by different flavour intensities of tomato or artichoke, almond or aromatic herbs, correspondence analysis among sensory pleasant attributes and olive oil samples explaining 91.68% variability.     

A vertex‐fed hexa‐band frequency reconfigurable antenna for wireless applications

Present article embodies the design and analysis of an octagonal shaped split ring resonator based multiband antenna fed at vertex for wireless applications with frequency‐band reconfigurable characteristics. The proposed antenna is printed on FR4 substrate with electrical dimension of 0.4884 λ × 0.4329 λ × 0.0178 λ (44 × 39 × 1.6 mm³), at lower frequency of 3.33 GHz. The antenna consists of SRR based vertex fed octagonal ring as the radiation element and switchable reclined L‐shaped slotted ground plane. Antenna achieves six bands for wireless standards viz: upper WLAN (5.0/5.8 GHz), lower WiMAX (3.3 GHz), super extended C‐band (6.6 GHz), middle X band (9.9 GHz—for space communication), and lower K_U band (15.9 GHz—for satellite communication systems operating band). Stable radiation patterns are observed for the operating bands with low cross polarization. The proposed design achieves hexa band characteristics during switching ON state of PIN diode located at reclined L‐shaped slot in the ground plane. Experimental characteristic of antenna shows close agreement with those obtained by simulation of the proposed antenna.     

强度折减有限元法土坡失稳判据分析均质土坡

目前强度折减法分析土坡稳定一般有三种判断依据:位移突变法、求解过程中计算的不收敛、塑性区的贯通情况.针对典型均质土坡算例,采用强度折减有限元方法进行稳定分析,并与极限平衡方法所得到的安全系数进行对比.对比分析表明,三种判别法得到的安全系数与极限平衡法计算的结果接近,说明对均质土坡有适用性.     

S模式地面二次监视雷达及其关键技术分析

介绍了S模式地面二次监视雷达的组成和工作原理,结合实际情况与工程经验提出了实现S模式二次监视雷达的关键技术,并逐一进行了论述,最后提出了我国空管监视技术从A/C模式过渡到S模式的建议.