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201.
芽苗砧嫁接及在我国的研究现状与展望 总被引:1,自引:0,他引:1
倪穗 《宁波大学学报(理工版)》2006,19(4):451-456
芽苗砧嫁接是嫁接中的1种新型嫁接技术,它是利用尚未展叶或刚展叶的芽苗作为砧木,嫁接所需繁殖对象的1项无性繁殖新技术,具有很多独特的优点和较高的生产实用价值.到目前为止,我国主要对油茶、银杏、板栗、核桃、梅花、茶梅等植物展开过此类研究.本文主要论述了芽苗砧嫁接技术及其研究现状和应用前景. 相似文献
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化学科普图书是传播化学知识和化学思想的重要载体。采用内容分析法,以国内线上图书交易平台在售的74种化学科普图书为研究对象,从化学科普图书的出版数量、作者和读者群体、内容类型、形式特征以及用户评价5个维度对化学科普图书进行统计与分析,总结国内在售化学科普图书的现状,挖掘其中存在的问题,并在此基础上提出几点建议。 相似文献
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References: 《声学学报:英文版》2008,27(1):23-33
The performance of port/starboard discrimination of dual-line array will be seriously degraded when the space between the two line arrays of the dual-line array is mismatched. The directivity function of the delay-sum and delay-subtract beamforming is deduced and the port/starboard discrimination of the delay-sum and delay-subtract beamforming is also studied both under the ideal status and the status under which the space between the two line arrays of the dual-line array is mismatched. Analysis results show the delay-subtract beamforming has better performance of port/starboard discrimination. At last, the sea trial results demonstrate the theoretical results. 相似文献
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纳米纤维素因其独特的结构及优越的性能引起了学术和企业界的广泛关注与重视,日渐成为新材料和纤维素科学领域的研究热点。以木质纤维资源为原料,可分离出两种主要类型的纳米纤维素:纤维素纳米晶体(CNC)和纤维素纳米纤丝(CNF)。本文详细综述了CNC和CNF的制备方法,着重介绍了近几年新兴的制备方法,包括可回收的有机酸水解法综合制备CNC和CNF,美国高附加值制浆(AVAP)法制备木质素包覆的CNC和CNF,低共熔溶剂预处理结合机械剪切高效制备CNC和CNF,以及微极性环境下可调控机械剥离制备亲疏水性CNF等。同时,讨论了各种制备方法的优缺点,并介绍了国内外纳米纤维素的产业化研究进展。最后,我们提出纳米纤维素的制备方法未来将朝着绿色、高效和可持续的方向发展。 相似文献
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In the status forecasting problem, classification models such as logistic regression with input variables such as physiological, diagnostic, and treatment variables are typical ways of modeling. However, the parameter value and model performance differ among individuals with different baseline information. To cope with these difficulties, a subgroup analysis is conducted, in which models’ ANOVA and rpart are proposed to explore the influence of baseline information on the parameters and model performance. The results show that the logistic regression model achieves satisfactory performance, which is generally higher than 0.95 in AUC and around 0.9 in F1 and balanced accuracy. The subgroup analysis presents the prior parameter values for monitoring variables including SpO, milrinone, non-opioid analgesics and dobutamine. The proposed method can be used to explore variables that are and are not medically related to the baseline variables. 相似文献
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Dana Kumprechtov Thibaut Chabrillat Simon Guillaume Sylvain Kerros Romana Kadek Eva Indrov Josef Illek 《Molecules (Basel, Switzerland)》2022,27(18)
(1) Background: This study evaluated the effects of a plant bioactive (Phyto Ax’Cell, Phytosynthese, Mozac, France) on the inflammatory status and health of dairy cows during calving. (2) Methods: 46 Holstein crossbred cows were randomized into a control group (CON, n = 23) and the Phyto Ax’Cell group (PAC, n = 23). PAC received Phyto Ax’Cell at 25 g/cow/day, from 15 days prepartum to 7 days postpartum. Blood analyses were performed weekly from D-7 to D14 to evaluate the energy metabolism and inflammatory status; rectal temperature was measured daily within 14 days from calving day (D0). (3) Results: PAC showed lower serum haptoglobin at D7 (0.55 vs. 0.79 mg/mL; p < 0.05) and D14 (0.44 vs. 0.66 mg/mL; p < 0.05). CON had a higher number of circulating white blood cells and granulocytes on D7 (p < 0.05). Fewer cows from PAC showed hyperthermia (≥39 °C) during the first 2 weeks postpartum (−7%, p < 0.05). Energy metabolism, which was represented by the NEFA/cholesterol ratio, improved (0.21 vs. 0.36 at D0, p < 0.1; 0.19 and 0.15 vs. 0.36 and 0.32, respectively, at D+7 and D+14, p < 0.05) under the plant bioactive supplementation. (4) Conclusions: The results suggest that the anti-inflammatory plant bioactive compound with Brazilian green propolis administered during calving had a beneficial effect on the energy and inflammatory status of dairy cows. 相似文献
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连作花生的土传病害问题突出,但土传病害发生与土壤环境尤其是根际土壤中可溶性有机质(DOM)组成结构的内在联系尚不清楚.通过在县域范围内多点采集连作地的花生健康植株和发病植株及根际土壤,测定根际土壤性质的部分指标,利用三维荧光光谱(3DEEM)技术和平行因子方法(PARAFAC)表征根际土DOM的组成特征,探究花生病害对... 相似文献