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农业科研经费执行层管理模式初探 总被引:1,自引:1,他引:0
针对农业科研的特点和农业科研经费管理存在的主要问题,提出了以做实预算、全面核算、经费使用评估、纠正偏差、良性循环为核心的农业科研经费执行层的科学、高效管理模式。 相似文献
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用被动保护试验的方法,通过比较抗脂多糖(LPS)血清组与LPS中和抗鸡白痢血清组的LD50,证明了LPS的保护性作用。与攻菌对照组的LD50相比,抗LPS血清组有非常显著的差异(0.002>P>0.005),LPS中和抗鸡白痢血清组有显著差异(0.02>P>0.05)。试验证明,LPS是鸡白痢沙门氏菌(Salmonelapulorum)菌体主要的保护性抗原之一。 相似文献
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供应链环境下的库存管理不同于单个企业传统库存控制,使库存保持一个合理的水平,既要降低成本,又要增加客户满意度.是现代企业管理的一个重要方面.本文利用系统动力学及Vensim建模平台构建了库存控制模型,以研究双边供应链库存补充.通过定义一种新的库存控制评价指标,零满意度出现频率,并将追求其最小化作为库存控制的目标之一.表明通过库存间的互助补货,可以有效减小零满意度出现的频率,提高企业信誉,从而增加经营利润. 相似文献
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X. Y. Wang C. W. Zhang W. T. Huang J. Yue J. J. Dou L. Y. Wang Q. Wang Y. Q. Cheng 《Plant pathology》2020,69(1):149-158
Efforts to control viral diseases of grapevine include the production of certified material and development of virus-resistant transgenic grapevines. However, effective antiviral agents, once the viruses have infected the plants, are still lacking. This study shows that a crude garlic extract has significant antiviral activity against grapevine viruses. Replication of grapevine leafroll-associated virus 2 (GLRaV-2) was obviously inhibited in grapevine cv. Cabernet Sauvignon calli treated with diluted (1:100) garlic extract. The relative RNA levels of GLRaV-2 and grapevine fleck virus (GFkV) in cv. Summer Black grapevine in in vitro-grown plantlets 10 days after treatment with diluted (1:100) garlic extract were about 22% and 20%, respectively, of that in controls. The viral RNA accumulation of GLRaV-2, GFkV, grapevine virus A (GVA), grapevine fanleaf virus (GFLV) and grapevine rupestris stem pitting-associated virus (GRSPaV) in field-grown grapevine cv. Centennial Seedless plants sprayed with diluted (1:100) garlic extract were about 31–40%, 26–38%, 18–31%, 17–42% and 15–18%, respectively, of that in controls. Moreover, the garlic extract treatment led to a significant decrease in viral RNA accumulation of GLRaV-3, GLRaV-2, GVA, GFkV, GFLV, GRSPaV and grapevine Pinot Gris virus in pot-grown grapevine cv. Shine Muscat plants, and viral disease symptoms in these plants were obviously attenuated. In addition, this extract significantly induced expression of pathogenesis-related protein genes and stimulated activity of antioxidant enzymes in grapevines. Taken together, these results indicate that the crude garlic extract acts as a significant inhibitor against a broad range of grapevine viruses. 相似文献
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The ontogenetic development of the digestive enzymes amylase, lipase, trypsin, and alkaline phosphatase and the effect of
starvation in miiuy croaker Miichthys miiuy larvae were studied. The activities of these enzymes were detected prior to exogenous feeding, but their developmental patterns
differed remarkably. Trypsin activity continuously increased from 2 days after hatching (dah), peaked on 20 dah, and decreased
to 25 dah at weaning. Alkaline phosphatase activity oscillated at low levels within a small range after the first feeding
on 3 dah. In contrast, amylase and lipase activities followed the general developmental pattern that has been characterized
in fish larvae, with a succession of increases or decreases. Amylase, lipase, and trypsin activities generally started to
increase or decrease at transitions from endogenous to exogenous feeding or diet changes, suggesting that these enzymatic
activities can be modulated by feeding modes. The activities of all the enzymes remained stable from 25 dah onwards, coinciding
with the formation of gastric glands and pyloric caecum. These results imply that specific activities of these enzymes underwent
changes due to morphological and physiological modifications or diet shift during larval development but that they became
stable after the development of the digestive organs and associated glands was fully completed and the organs/glands functioned.
Trypsin and alkaline phosphatase were more sensitive to starvation than amylase and lipase because delayed feeding up to 2 days
after mouth opening was able to adversely affect their activities. Enzyme activities did not significantly differ among feeding
groups during endogenous feeding; however, all activities were remarkably reduced when delayed feeding was within 3 days
after mouth opening. Initiation of larvae feeding should occur within 2 days after mouth opening so that good growth and survival
can be obtained in the culture. 相似文献
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控释肥用量对棉花生长特性和土壤肥力的影响 总被引:11,自引:0,他引:11
以国抗棉GK12号为供试材料,以等养分量复合肥作对照,研究不同控释肥施用量对大田棉花生长和土壤肥力的影响。结果表明,控释肥处理的棉花株高、茎粗、叶面积均较普通复合肥具有优势。控释肥对大田果枝数、桃数影响显著。在施氮量为75 kg hm-2和150 kg hm-2条件下,控释肥处理的棉花产量较复合肥处理分别增加18.9%和13.6%。在多个棉花生育期,与复合肥处理相比,控释肥处理提高了0~20 cm和20~40 cm土层硝态氮含量,未对土壤的铵态氮含量造成显著影响,土壤中有效磷和速效钾含量与普通复肥处理间未出现显著的差异。 相似文献