改善E1级胶合板用UF胶粘剂预压性能的研究   总被引：1，自引：0，他引：1  

焦德贤  唐朝发 《吉林林业科技》2005,34(5):45-47

利用氧化淀粉在树脂合成后期、API在调胶时加入分别对脲醛树脂进行改性，探讨改性UF对胶合板预压强度的影响。采用正交实验法对比改性后胶合板的预压性能和改性后胶合板的甲醛释放量的变化。结果表明：随着API量的加大，胶合板的预压性能得以提高；而氧化淀粉改性后则随着量的加大，一定范围内胶合板的预压性能得以提高，加入量继续加大后反而下降。  相似文献   

鸡新城疫病毒F基因和鸡IL—2重组DNA疫苗的构建   总被引：40，自引：0，他引：40  

姜永厚  陈奖励  宋秀龙  童光志  孔宪刚  刘忠贵 《中国预防兽医学报》2001,23(2):81-84

利用已克隆到的新城疫D26株F基因和鸡IL－2基因，经过载体改建，将他们共同克隆于真核表达质粒pCDNA3上，经酶切分析、PCR鉴定证实成功构建了共表达鸡新城疫病毒F基因和鸡IL－2的重组质粒，为探讨禽类重组基因疫苗的构建及鸡IL－2在基因疫苗中的作用奠定了基础。  相似文献   

Physiological Basis of Irrigation Scheduling for Seed Production in Egyptian Clover Syn. Berseem (Trifolium alexandrinum L.) Crop     

N. C. Sinha  R. P. Singh 《Journal of Agronomy and Crop Science》1986,156(4):246-252

A field experiment was conducted to find out the critical physiological stages of irrigation schedules inducing better growth, physiological efficiency and seed yield potential of berseem ( Trifolium alexandrinum L., Var. S-99-1). For this purpose eight irrigation treatments were made comprised of four treatments of three irrigation (W₁, W₂, W₃ and W₄), three treatments of four irrigation (W₅, W₇ and W₈) and one treatment of five irrigation (W₆) at various physiological stages i. e. regeneration, flower initiation, full bloom, seed initiation and advance seed development stage.
Thus based on the experimental results the physiological role of watering in berseem seed production could be discussed as:
With-holding of irrigation either at regeneration or at full bloom stage developed potential water stress in plants as indicated by high proline content of irrigation treatments — W₄, W₁ and W₇; and further brought out disturbance on the formation of carotene, synthesis of water soluble sugar and translocation of sugar towards reproductive organs during grain development stage. These stresses adversely affected the plant growth and flowering behaviour. The irrigation at seed initiation stage increased the seed yield. Continuous irrigation did not appear to be useful. Thus it can be concluded that irrigation at three critical physiological stages i. e. regeneration, full bloom and seed initiation was found to be essential for obtaining potential seed yield of berseem.  相似文献   

苜蓿施用污泥效果的研究Ⅰ对苜蓿生长及元素含量的影响   总被引：5，自引：2，他引：3  

付华  周志宇  张洪荣  李雪瑞  左秀娟 《草业学报》2001,10(4):67-71

将兰州市七里河污水处理厂生活污泥施用于人工种植的新疆大叶苜蓿草地，探讨了不同施用量对苜蓿生长及各元素含量的影响。研究结果表明，施用1.0-2.0kg/m^2污泥，苜蓿地上生物量显著增加，第一年增产23％－31％，第二年增产15％－31％。施用污泥苜蓿地上和地下部组织中N，P，Ca,Mg和Mn的含量总体呈增加趋势，Fe含量显著增加，而K和重金属元素Ni、Pb、As和Hg的含量与对照无显著差异，Zn和Cu的积累增多，但地上部组织中重金属元素均未超过植物中的平均含量，施用污泥未对新疆大叶苜蓿造成重金属污染。  相似文献   

RAPD技术对地方鸡种群体遗传结构的分析   总被引：16，自引：1，他引：15  

周怀军  陈宽维 《中国家禽》1997,(5):7-10

利用ＲＡＰＤ技术对４个地方鸡种和１个引进鸡种的群体遗传结构进行分析，通过筛选的５个随机引物ＯＰＨ－０２、ＯＰＨ－０５、ＯＰＨ－１３、ＯＰＨ－１６、ＯＰＧ－０７对５个鸡种的池ＤＮＡ进行多态性研究，结果表明：５个引物共产生条带６１个，扩增产物片段的长度一般从１５０ｂｐ－４ｋｂ。  相似文献   

近交系大鼠DNA指纹图与微卫星DNA比较分析     

李瑞生  王承利  赵林山  陈振文 《中国兽医学报》2003,23(3):297-299

为了建立一种对近交系大鼠遗传物质进行精确可靠、快速简便的监测方法,利用DNA指纹技术对国内6个品系8个近交系大鼠群体进行了DNA多态性的分析,并与PCR扩增微卫星DNA技术进行了比较.其结果显示(1)不同品系之间DNA指纹图差异较大,同一群体不同个体间DNA指纹图带的相似系数和共有带率除SHR(哈)和WKY(哈)小于0.7外,其他均大于0.9.不同地区同一SHR间和WKY间DNA指纹图也存在差异,相同DNA不同次制作的DNA指纹图谱基本一致.(2)不同品系个体间微卫星DNA具有显著多态性;同一群体不同个体之间除SHR(哈)的SMST位点和WKY(哈)的AGT位点出现一定的差异外,其他均没有差异.DNA指纹图能更精确可靠地反映出动物个体间的遗传背景,而微卫星DNA遗传监测方法比较简便快捷.  相似文献   

毛白杨苗木失水对造林效果的影响   总被引：2，自引：1，他引：1  

李淑玲  侯建治 《河南农业大学学报》1993,27(1):46-51

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植物活体水分探测仪的研制及测试初报     

贡小虎  张国桢 《甘肃农业大学学报》1993,28(4):391-394

利用NIM插件探测器及金硅面垒探头组装了植物活体水分探测仪;筛选并分析了仪器的最佳工作条件;检测了春小麦、玉米、苜蓿、豌豆、红豆草叶片鲜重的变化。结果表明;叶片水分随时间损失大的,其抗旱性差。叶片保水的秩序为:红豆草、豌豆>苜蓿>春小麦>玉米。  相似文献   

Effect of Nitrogen Rate and Stubble Height on Dry Matter Yield,Crude Protein Content and Crude Protein Yield of a Sorghum–Sudangrass Hybrid[Sorghum bicolor (L.) Moench × Sorghum sudanense (Piper) Stapf.] in the Three‐Cutting System     

S. Iptas  A. R. Brohi 《Journal of Agronomy and Crop Science》2003,189(4):227-232

In this study, the effects of nitrogen (N) rate (60, 120, 180 and 240 kg N ha^?1 applied in three equal dressings at seeding and after the first and second cuttings) and stubble height (7, 14 and 21 cm) on the dry matter (DM) yield, crude protein (CP) content, and CP yield of a sorghum–sudangrass hybrid [Sorghum bicolor (L.) Moench × Sorghum sudanense (Piper) Stapf., cv. Pioneer 988] in the three‐cut system was investigated. The N rate had no significant effect in the first and third cuttings, but in the second cutting DM yields increased significantly with increase in N rate. The highest yield of 9.1 t ha^?1 was obtained with 80 kg N ha^?1 for the average of 2 years at the second cutting, but no significant difference was found among the 40, 60 and 80 kg N ha^?1 rates. CP content and yield were not significantly affected by N rate at the first and third cuttings, but CP content and yield were significantly affected by application of N at the second cutting. Stubble height had a significant effect on CP content at the third cutting. However, it had no significant effect on CP content at the first and second cuttings. Stubble height had a significant effect on the CP yield at the first cutting, but no significant effect on CP yield at the second and third cuttings.  相似文献   

Non-destructive determination of fat content in frozen and thawed mackerel by near infrared spectroscopy     

Junji  SHIMAMOTO  Kaoru  HASEGAWA  Minoru  SATO  Sumio  KAWANO 《Fisheries Science》2004,70(2):345-347

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