模拟发电机组专用可控硅直流调速系统     

刘觉民  夏永祥 《湖南农业大学学报(自然科学版)》1995,22(3)

本文从分析同步发电机原动系统基本数学模型入手，提出了一种实现同步发电机原动系统仿真的专用可控硅直流调速系统及其实用装置。该控制系统采用有差调节的模拟调速器，水汽管道特性模拟、自平衡特性模拟和集成块模拟触发器，以及过流与超速保护，并可实现有差－无差调节的转换。  相似文献   

Preparation and Characterization of Luminescent Alkylated Porous Silicon     

LI Xue-ming  XU Lin  LIU Ping-ping  ZHANG Yu-qi  WANG Nan 《保鲜与加工》2005,(9):120-123

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Method for Stabilization of n-Type Porous Silicon via Photochemical Reaction     

LI Xue-ming~  JI Xin-rui~  YANG Jian-chun~  PAN Jin~ 《保鲜与加工》2004,(7):68-71

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Multi-channel and High Precise Time Relay Verification Instrument     

LUO Jun  SU Ji-wen  CHENG Jie 《保鲜与加工》2004,(12):24

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Effects of foliar- and root-applied silicon on the enhancement of induced resistance to powdery mildew in Cucumis sativus   总被引：3，自引：0，他引：3  

Y. C. Liang †  W. C. Sun  J. Si ‡  V. Römheld 《Plant pathology》2005,54(5):678-685

Two cucumber ( Cucumis sativus ) cultivars differing in their resistance to powdery mildew, Ningfeng No. 3 (susceptible) and Jinchun No. 4 (resistant), were used to study the effects of foliar- and root-applied silicon on resistance to infection by Podosphaera xanthii (syn. Sphaerotheca fuliginea ) and the production of pathogenesis-related proteins (PRs). The results indicated that inoculation with P. xanthii significantly suppressed subsequent infection by powdery mildew compared with noninoculation, regardless of Si application. Root-applied Si significantly suppressed powdery mildew, the disease index being lower in Si-supplied than in Si-deprived plants, regardless of inoculation treatment. The resistant cultivar had a more constant lower disease index than the susceptible cultivar, irrespective of inoculation or Si treatment. Moreover, with root-applied Si, activities of PRs (for example peroxidase, polyphenoloxidase and chitinase) were significantly enhanced in inoculated lower leaves or noninoculated upper leaves in inoculated plants of both cultivars. Root-applied Si significantly decreased the activity of phenylalanine ammonia-lyase in inoculated leaves, but increased it in noninoculated upper leaves. However, Si treatment failed to change significantly the activity of PRs in plants without fungal attack. Compared to the control (no Si), foliar-applied Si had no effects either on the suppression of subsequent infection by P. xanthii or on the activity of PRs, irrespective of inoculation. Based on the findings in this study and previous reports, it was concluded that foliar-applied Si can effectively control infections by P. xanthii only via the physical barrier of Si deposited on leaf surfaces, and/or osmotic effect of the silicate applied, but cannot enhance systemic acquired resistance induced by inoculation, while continuously root-applied Si can enhance defence resistance in response to infection by P. xanthii in cucumber.  相似文献   

三唑酮种衣剂对小麦白粉菌侵染和非侵染位点硅等元素含量的影响   总被引：3，自引：0，他引：3  

李健强  刘西莉  杨峻  慕康国  吴学宏  刘鹏飞 《植物病理学报》2001,31(1):26-30

 借助扫描电子显微镜-X射线能谱分析方法从超微结构和元素水平观测了三唑酮种衣剂包衣处理和空白对照的小麦幼苗上白粉病菌侵染及非侵染位点硅等元素含量的变化。结果表明,接种后20~36 h内三唑酮种衣剂处理的麦苗侵染位点细胞内元素硅含量由5.204%上升为42.064%,非侵染位点由5.821%上升为12.342%;空白对照中侵染位点元素硅含量由低于检测水平上升为17.388%,非侵染位点接种后36 h时为19.460%。在处理和空白对照的麦苗上侵染和非侵染位点均检测到了含量不等的磷、硫、氯等元素存在。  相似文献   

猪CTSD全长cDNA的克隆和表达分析   总被引：1，自引：0，他引：1  

梅盈洁  李加琪  陈瑶生  李晓筠  朱良瑞  凌飞  王翀  张豪 《畜牧兽医学报》2007,38(5):432-436

以人CTSD mRNA全长序列为基序,在db EST库中搜索同源性大于80%、重叠大于40个碱基的猪EST下载经Seqman软件装配后,利用RT-PCR扩增到猪CTSD基因部分cDNA序列,进一步通过RACE技术获得cDNA全长（GenBank登录号为DQ018727）,猪CTSD基因cDNA全长2032 bp包括93 bp 5′UTR区、706 bp 3′UTR区和1 233bp ORF,编码410个氨基酸残基。其编码区与人、鼠、牛、羊CTSD编码区同源性分别为87.9%、78.2%、86.6%和85.0%,其氨基酸序列与人、鼠、牛、羊氨基酸序列同源性分别为86.6%、80.1%、86.0%和84.7%。疏水性分析和信号肽预测发现猪CTSD氨基酸序列存在至少7个疏水性区域,信号肽位点为第1-20个氨基酸残基。在NCBI进行Blast P搜索结果显示猪CTSD氨基酸结构中含有Asn（Asparagine,天门冬酰胺）结构域,与天冬氨酸蛋白酶3D结构同源性高达99.7%,具有真核生物天冬氨酸蛋白酶的典型结构。以猪多组织RNA池为模板,以1026 bp部分cDNA序列作为杂交探针进行Northern杂交,得到一条2000 bp左右特异条带,从而验证了RACE产物为全长cDNA并揭示该基因只有一个转录本。为了研究猪CTSD基因在体内不同组织内表达的特点,采用半定量RT-PCR对CTSD基因在猪10个组织中的表达进行研究,结果表明在10个组织中均有表达,且表达量与-βactin内参接近。  相似文献   

Effects of NaCl and silicon on ion distribution in the roots, shoots and leaves of two alfalfa cultivars with different salt tolerance     

Xiao Shan WANG  Jian Guo HAN 《Soil Science and Plant Nutrition》2007,53(3):278-285

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冀西北半干旱区硅钾复合肥在玉米上的应用效果     

俞凤芳  吕爱枝 《湖北农业科学》2009,48(6)

在冀西北半干旱区,按照标准的田间试验设计方法开展硅钾复合肥在玉米上的应用研究.结果表明,硅钾复合肥对玉米的农艺性状、果穗性状及产量均具有显著的影响,说明硅钾复合肥在冀西北地区施用,具有显著的增产效果.  相似文献   

硅镁锌不同配比对水稻光合作用及产量的影响   总被引：1，自引：0，他引：1  

尹振功  栾海  于金海  丛万彪  张弘强  方仁柱  王翠娟 《黑龙江农业科学》2014,(7):51-54

为探究硅、镁、锌互作最优配比以提高水稻产量,以水稻品种龙粳29为试材,利用二次回归正交旋转设计方案研究硅镁锌不同配比用量对水稻光合作用及产量的影响。结果表明:净光合速率与产量呈负相关,气孔导度、胞间二氧化碳浓度和蒸腾速率与产量呈正相关,气孔导度对产量的影响最大,施用中间量的硅镁锌肥能使气孔导度达到最大值。  相似文献