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种植方式和密度对夏玉米光合特征及产量的影响 被引量:3
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作者 吕元锋 《江西农业》 2018年第16期51-51,共1页
夏玉米在我国农业经济发展中种植范围比较广、种植面积比较大,所以如何进一步提高夏玉米的种植技术水平已经成为集中关注的问题。基于此,以夏玉米种植技术为研究对象,针对夏玉米种植方式以及种植密度对夏玉米的光合特性以及产量所带来... 夏玉米在我国农业经济发展中种植范围比较广、种植面积比较大,所以如何进一步提高夏玉米的种植技术水平已经成为集中关注的问题。基于此,以夏玉米种植技术为研究对象,针对夏玉米种植方式以及种植密度对夏玉米的光合特性以及产量所带来的影响展开分析讨论。希望为玉米高产种植技术的推广应用提供一些参考。 展开更多
关键词 夏玉米 光和特征 产量 种植方式 种植密度
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不同磷添加梯度对荆条幼苗光合特性的影响 被引量:8
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作者 赵琛迪 刘雅辰 +4 位作者 杨子 范世献 胡启立 余洁 赵勇 《西部林业科学》 CAS 北大核心 2020年第6期94-99,共6页
为探究不同梯度磷添加对荆条幼苗光合特征的影响,设置4个磷添加水平0、10、20、30 gP/(m 2·a)(分别以CK、LP、MP、HP表示)的荆条幼苗盆栽试验。结果表明,4种施磷处理下的荆条叶片在净光合速率、胞间CO 2浓度、气孔导度和蒸腾速率... 为探究不同梯度磷添加对荆条幼苗光合特征的影响,设置4个磷添加水平0、10、20、30 gP/(m 2·a)(分别以CK、LP、MP、HP表示)的荆条幼苗盆栽试验。结果表明,4种施磷处理下的荆条叶片在净光合速率、胞间CO 2浓度、气孔导度和蒸腾速率上整体表现为前期低、后期高;不同施磷处理下荆条幼苗叶片的净光合速率、胞间CO 2浓度、蒸腾速率、气孔导度最低值均出现在CK处理,净光合速率、胞间CO 2浓度、气孔导度最高值出现在MP处理,分别为10.5μmol/(m 2·s),311μmol/mol,153.6 mmol/(m 2·s),蒸腾速率最高值出现在HP处理,为4.4 mmol/(m 2·s)。相比较CK以上4项指标分别增加108.7%、52.7%、113.4%和73.7%。说明施磷能够显著提高荆条叶片的光合水平,对荆条的生长发育有促进作用,且20 gPm 2/a施磷量即MP处理对荆条光合作用的提升效果最显著。 展开更多
关键词 磷添加 光和特征 合速率 相关性
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Traffic Noise Pollution: Spectra Characteristics and Windows Sound Insulation in Laboratory and Field Measurements 被引量:2
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作者 C. Buratti E. Moretti 《Journal of Environmental Science and Engineering》 2010年第12期28-36,共9页
The traffic spectra influence on indoor noise through windows is evaluated with laboratory and field measurements. Different traffic noise spectra were registered and reproduced, simulating the outdoor traffic conditi... The traffic spectra influence on indoor noise through windows is evaluated with laboratory and field measurements. Different traffic noise spectra were registered and reproduced, simulating the outdoor traffic conditions through different windows. Spectrum adaptation terms for the recorded spectra were different from the ones obtained from the Standards, showing that Normative gives a safe evaluation of the Weighted Sound Insulation Index. In field measurements, the level abatements calculated from the Facade Acoustic Insulation Index corrected with the adaptation terms shows that the ones from the Standard do not give a good approximation, while if the level abatements is calculated using the adaptation terms from the registered spectra, a more reliable approximation is achieved. Furthermore, comparing the level abatements for two windows having both Rw equal to 41 dB, very different values were obtained at different frequencies; therefore to characterize acoustic performances of windows, sound insulation curves are also needed. The correlation between the mean difference between adaptation terms calculated from the standard and the one between abatements obtained with pink noise and the ones obtained with the registered spectra is good, but different for road traffic and trains. In both, the difference diminishes when the difference between the abatements increases. 展开更多
关键词 Traffic noise pollution traffic noise spectra spectrum adaptation terms level abatements
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Ultra High Energy Cosmic Rays: Spectral Signatures and Observations
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作者 Svetlana Grigorieva 《Journal of Physical Science and Application》 2014年第6期393-397,共5页
The observations of Ultra High Energy Cosmic Rays (UHECR) are renewed, focusing on the energy spectra as measured by HiRes, Telescope Array (TA) and Auger detectors (PAO). It is found that highest energy Auger s... The observations of Ultra High Energy Cosmic Rays (UHECR) are renewed, focusing on the energy spectra as measured by HiRes, Telescope Array (TA) and Auger detectors (PAO). It is found that highest energy Auger steepening does not agree with GZK cutoff, which is most probably explained by the nuclei mass composition detected by Auger. At present the difference in mass composition in Auger and HiRes/TA data remains the main unsolved problem of UHECR origin. 展开更多
关键词 Ultrahigh energy cosmic ray origin CMB radiation GZK cutoff.
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