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调光地膜对烟草生长及地温的影响 总被引:1,自引:0,他引:1
与普通薄膜覆盖相比,田间覆盖调光膜可使5 cm日均地温升高0.8℃,10 cm日均地温升高0.3℃,膜下温度平均升高1.3℃;可使烟株生育期提前,其中团棵期比对照提前3d,全生育期比对照缩短6d;调光膜处理的最大叶长、最大叶宽、株高、茎围等农艺性状均高于对照,移栽后55 d株高比对照增加4.71 cm,最大叶宽增加3.16 cm,茎围增加0.45 cm;调光膜处理的产量比普通膜处理的产量增加了2.69%,产值提高了8.66%,烟叶化学成分也比较协调,有利于烟叶品质的改善.结果表明,调光膜具有显著增加地温和促进烟苗生长的作用. 相似文献
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贵州烟区烟蚜发生规律及其预测模型的初步研究 总被引:2,自引:0,他引:2
通过2002-2008年对贵州代表性烟区烟蚜的系统调查,初步了解了有翅蚜迁飞规律、烟田蚜虫种群消长动态及其历史演变情况,分析了烟蚜发生期内气温、雨日雨量、相对湿度和日照时数对烟蚜发生量的影响效应。在此基础上,结合以往的调查数据,应用DPS统计软件进行逐步回归分析,初步建立了烟蚜发生程度短期预测模型Y=-24.87+1.27X1+0.13X2+1.54X4+2.70X6+4.06X11-3.85X13(其中,X1=移栽前期10 d内日诱蚜量;X2=上年12月日气温≥10℃的积温;X4=2月均温;X6=3月均温;X11=4月均温,X13=4月雨日数),经显著性检验和预报验证,回归方程达极显著水平,回测准确率平均达93.45%,实报验证误差率仅为1.80%~5.11%,说明入选预报因子比较切合贵州实际,预测模型具有较大的实用价值。 相似文献
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Quality, composition, and characteristics of fuel from 7 areas of P. R. China were analyzed. Fuel quality factors influencing engine emission performance were studied. Using fuel from the HuaZhong and XiNan areas, engine COx, HC, and NOx emissions were tested by adjusting the excess air coefficient and the advanced ignition angle. In light of the characteristics of aromatic hydrocarbon and alkenes of fuel from different areas in P. R. China, we have shown engines can operate smoothly and engine emissions can be decreased when the excess air coefficient and the advanced ignition angle are properly adjusted. 相似文献
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Sensitivity analysis of motorcycle frames is useful for improving the design success rate. Based on sensitivity analysis theory and using the Monte Carlo and numerical simulation methods, a new 250 type integral motorcycle model was built and dynamic sensitivity analysis conducted. Sensitive design parameters that have great influence on frame vibration were discovered. By modifying the values of sensitive design parameters, the vibration of some measuring points was reduced. This reduction shows that the sensitivity analysis method is reliable and practical, and it can be used in sensitivity analyses of other complicated structures. 相似文献
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贵州省兴义市烟草赤星病发生情况调查 总被引:4,自引:0,他引:4
为了弄清烟草赤星病在兴义烟区的发生情况,以便于更准确预防此病,于2011年选择不同烟草品种、海拔高度、连轮作条件的烟草种植区对烟草赤星病发生情况进行了调查。结果表明,不同烟草品种间病害的发生情况不同,南江三号的抗病性远强于云烟87和云烟85,云烟85的抗病性最差;不同海拔高度田块的病害发生情况差异较大,病害流行严重程度表现为:山脚>山腰>山顶;不同连轮作地块病害的发生情况同样存在很大的差异,隔年轮作地烟草赤星病发病情况最轻,连作地发病较重,且连作年限越长,发病越重。烟草赤星病在兴义普遍发生,且烟草品种、海拔高度、连轮作条件对该病的发生与流行影响较大。 相似文献
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