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基层农业科研单位加快科技创新的对策探讨 总被引：1，自引：12，他引：1
文章以信阳市农科所为研究对象,提出了把握科技的发展背景、坚持科学的发展方略、明确发展的重点任务、落实发展的保障措施等加快科技创新的对策建议。 相似文献
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《Agricultural Water Management》2006,81(3):257-281
The Hargreaves equation provides reference evapotranspiration (ETo) estimates when only air temperature data are available, although it requires previous local calibration for acceptable performance. This equation has been evaluated under semiarid conditions in Southern Spain using data from 86 meteorological stations, comparing daily estimates against those from the FAO-56 Penman–Monteith equation, which was used as standard. Variability of results among location was clearly apparent, with MBE ranging from 0.74 to −1.13 mm d−1 and RMSE from 0.46 to 1.65 mm d−1. Maxima under- and overestimation amounted to 24.5 and 22.5%, respectively. In general, larger under- and overestimations occurred in stations located close to the coast and at inland areas, respectively. Yearly means of windspeed (V) and daily temperature range (ΔT) fairly influenced the accuracy of the equation. It was more accurate for windy locations with large ΔT, and for locations with light wind conditions combined with low to moderate values of ΔT. According to the values taken by V and ΔT, the stations were represented by points on the ΔT–V coordinate plane, in which four regions were delimited. A regional calibration was carried out considering only temperature and wind conditions. Correction was not necessary for stations located within two of them; for the other two regions, new values for the empirical coefficient of the equation are suggested (0.0027 and 0.0021). After correction, average RMSE and maximum and minimum MBE decreased substantially (12, 24 and 41%, respectively), and 74 out of the 86 locations gave quite accurate results, with relative values of MBE lower than 10% in most cases. Alternatively, another method based on kriging interpolation was proposed to obtain, for each individual station, locally adjusted values for the empirical coefficient as a function of the same variables. This second correction procedure behaved even better than the first one. There was a 15% improvement in the average RMSE, and maximum and minimum MBE values decreased 50 and 70%, respectively. At all locations, relative values of MBE were less than 10% and in 70% of them were lower than 5%. Validation was done by using data from 14 meteorological stations for other Spanish regions, and the consequences from the application of the corrections proposed for an irrigation district are discussed. 相似文献
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【目的】观察猪圆环病毒2型（PCV-2）感染对猪肾传代细胞（PK-15细胞）炎性细胞因子白细胞介素（IL） mRNA转录水平的影响,探讨宿主与病毒之间的作用关系及细胞炎性反应机制。【方法】以未感染PCV-2的PK-15细胞为对照组,运用相对定量PCR技术,测定和分析PCV2感染PK15细胞后,PCV-2 DNA相对含量的变化,以及炎性细胞因子IL-6、IL-8、IL-12p35、IL-12p40、IL-13、IL-17、IL-18 mRNA转录水平在1,6,12,24,48,和72 h的变化。【结果】PCV-2感染后,PK-15细胞的IL-6、IL-13、IL-17、IL-18 的mRNA转录水平在12 h显著增加,24 h后mRNA转录水平下降;IL-8的mRNA转录水平在48 h时最高,为对照组的2.5倍,但72 h时恢复至与对照组水平相当;随着感染时间的延长,IL-12p35、IL-12p40 的mRNA转录水平显著下降。【结论】PCV-2感染后可引起PK-15细胞中IL-6、IL-8、IL-13、IL-17、IL-18等细胞因子mRNA转录水平增加,而IL-12 mRNA转录水平下降,提示PCV-2感染后引起的PK-15细胞炎性反应与其分泌的炎性细胞因子的改变有关。 相似文献
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In arid and populated areas or countries, water shortage and heavy carbon emissions are threatening agricultural sustainability with food security severely, and becoming a major issue. It is unclear whether improved farming systems can be developed to tackle those issues through a sustainable agriculture. Here three farming practices that have proven to be essential and successful, which were: (a) crop intensification through strip intercropping, (b) water harvesting through conservation tillage; and (c) carbon sequestration through improved crop residue management options, were integrated in one cropping system. We hypothesize that the integrated system allows the increase of crop yields with improved water use efficiency, while reducing carbon emissions from farming. The hypothesis was tested in field experiments at Hexi Corridor (37°96′N, 102°64′E) in northwest China. We found that the integrated system increased soil moisture (mm) by 7.4% before sowing, 10.3% during the wheat–maize co-growth period, 8.3% after wheat harvest, and 9.2% after maize harvest, compared to the conventional sole cropping systems. The wheat/maize intercrops increased net primary production by 68% and net ecosystem production by 72%; and when combined with straw mulching on the soil surface, it decreased carbon emissions by 16%, compared to the monoculture maize without mulch. The wheat/maize intercrops used more water but increased grain yields by 142% over the monoculture wheat and by 23% over the monoculture maize, thus, enhancing water use efficiency by an average of 26%. We conclude that integrating strip intercropping, conservation tillage as well as straw mulching in one cropping system can significantly boost crop yields, improve the use efficiency of the limited water resources in arid areas, while, lowering the carbon emissions from farming. The integrated system may be considered in the development of strategies for alleviating food security issues currently experienced in the environment-damaged and water-shortage areas. 相似文献
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文章总结了最近几年笔者辅导选手参加河南省中等职业教育技能大赛车工技能竞赛的经验,并重点就如何挑选竞赛选手、合理制定训练计划、注重训练的方式方法等等方面作具体分析,以促进师生专业能力的提高。 相似文献
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平顶山旅游气候资源分析及评价 总被引：1，自引：0，他引：1
利用平顶山1971～2000年5个气候代表站（汝州、鲁山、宝丰、郏县、叶县）30年气候整编资料,结合人体舒适度指数对平顶山旅游气候资源优势进行综合分析及评价。认为平顶山旅游气候适宜期长达7个月,其中4～5月、9～10月为最舒适月,可根据不同季节开展特色旅游。 相似文献
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