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1.
李昂 《吉林农业科技学院学报》2012,(4):81-83
语境即言语环境,它包括语言因素,也包括非语言因素,上下文、时间、空间、情景、对象、话语前提等与话词使用有关的都是语境因素。关于语境,国内外很多学者都做过大量系统的研究。本文通过对语境在言语交际中的应用,分析了语境对语义所产生的影响,以期对语言的教学有所借鉴与帮助。 相似文献
2.
麻栎 马尾松天然次生混交林生物量结构及根系分布特征调查研究 总被引:11,自引:0,他引:11
杨涛 《信阳农业高等专科学校学报》2004,14(4):4-6,9
通过对马尾松、麻栎天然次生混交林林分生物量的测定,对林分生物量积累、根系分布特征的差异进行了研究。结果表明,两类树种混交造林方式能在一定程度上提高树干的生产量,天然次生麻栎较马尾松具有主根、水平根系均发达,且须根分布均匀的特点。 相似文献
3.
杨衡 《农业图书情报学刊》2005,17(3):154-157
本文从语言特点、编排体例及内容特点出发,对《中图法》(第四版)类目注释进行了系统的认识,并就此提出了自己的一些看法。 相似文献
4.
在课程思政的理念下,通过介绍开展"烘焙食品加工技术"课程思政的目的和意义,以"泡芙制作"为例,从教学任务、教学目标、学情分析、教学重难点、教学方法、设计方案等6个方面进行教学设计。通过将课程内容和思政元素相结合,更好地在教学环节中实现立德树人的根本任务。 相似文献
5.
The strongly incised mountain landscape of northern Thailand has changed dramatically during the last few decades due to increased population pressure, agricultural commercialization, limitation to use old fallows and reforestation of upper catchments. The traditional shifting cultivation with fallow periods of 7 years and longer was gradually replaced by 1 to 4 year fallow periods. As a result, in high population areas the landscape became dominated by fields planted to rainfed upland crops, wetland rice terraces, fallow vegetation, and patches of secondary forest. This new land-use system seems to have triggered new land degradation processes that are easy to observe when travelling through this landscape. 相似文献
6.
7.
孔海苏 《青海畜牧兽医杂志》2006,36(2):19-20
对0.13%百瓒防蛀气雾剂及其主要有效成分辛硫磷进行了毒理学研究。结果表明:急性吸入毒性(LC50):雌、雄小鼠均大于2150mg/m3;急性经口毒性(LD50):小鼠为9 210mg/kg;皮肤刺激实验:无刺激作用;皮肤变态反应:致敏率为“0”;眼刺激试验:无刺激性;辛硫磷原药(85%)对大鼠28d亚急性吸入毒性:对雄、雌性大鼠无作用浓度(NOAEL)均为10mg/m3。 相似文献
8.
High temperature is an environmental factor that impairs sow fertility. In this study, we identified the critical weeks for heat stress effects on aspects of fertility performance, namely weaning-to-first-service interval (WSI) and farrowing rate (FR). We also examined the threshold temperatures above which the fertility performance deteriorated and whether there were any differences between parities regarding heat stress effects or thresholds. Performance data of sows in 142 herds from 2011 to 2016 were matched to appropriate weekly averaged daily maximum temperatures (Tmax) from weather stations close to the herds. Two types of ratios (i.e., ratio for WSI and odds ratio for FR) were used to identify the critical weeks for heat stress by comparing the respective measures for two sow groups based on Tmax in different weeks around weaning or service events. The ratios for WSI were calculated between groups of sows exposed to Tmax ≥ 27 °C or <27 °C in each week before weaning, with the Tmax cutoff value based on a recent review study. Similarly, the odds ratios for FR for the two groups were calculated in weeks around service. The weeks with the largest differences in the fertility measures between the two Tmax groups (i.e., the highest ratio for WSI and the lowest odds ratio for FR) were considered to be the critical weeks for heat stress. Also, piecewise models with different breakpoints were constructed to identify the threshold Tmax in the critical week. The breakpoint in the best-fit model was considered to be the threshold Tmax. The highest ratios for WSI were obtained at 1 to 3 wk before weaning in parity 1 and 2 or higher sow groups. The threshold Tmax leading to prolonged WSI was 17 °C for parity 1 sows and 25 °C for parity 2 or higher sows. Increasing Tmax by 10 °C above these thresholds increased WSI by 0.65, and 0.33 to 0.35 d, respectively (P < 0.01). For FR, the lowest odds ratios were obtained at 2 to 3 wk before service in parity 0, 1, and 2 or higher sow groups. The threshold Tmax leading to reductions in FR was 20, 21, and 24 to 25 °C for parity 0, 1, and 2 or higher sow groups, respectively. Increasing Tmax by 10 °C above these thresholds decreased FR by 3.0%, 4.3%, and 1.9% to 2.8%, respectively (P < 0.01). These results indicate that the critical weeks for heat stress were 2 to 3 wk before service for FR and 1 to 3 wk before weaning for WSI. The decreases in fertility performance in parity 0 to 1 sows started at temperatures 3 to 8 °C lower than in parity 2 or higher sows. 相似文献
9.
P J Timoney P B Dillon V P Geraghty J F McArdle 《Comparative immunology, microbiology and infectious diseases》1983,6(3):227-234
Aspects of experimental transmission of the causal bacterium of contagious equine metritis (CEM) to albino Swiss mice were investigated. Whereas infection was established in the majority of female mice, the organism was recovered from only a limited number of male mice after challenge. No clinical evidence of infection was observed in the experimental mice. There was only one instance of presumptive venereal transmission of the CEM bacterium. One third of infected females conceived and had normal litters. 相似文献
10.
五节芒的分化类型及生产性状的比较研究 总被引:2,自引:0,他引:2
通过长期的引种栽培,发现五节芒分化出宽叶和窄叶类型。经对形态特征、生产性状的比较研究,证明两个类型差异显著,性状稳定。还证明,宽叶类型的生产性状明显优于窄叶类型。 相似文献