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Paddy and Water Environment - This paper revealed the irrigation rate by groundwater, evapotranspiration (ET), total water balance and yield in the experimental rice and mung bean fields in a...  相似文献   
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Paddy and Water Environment - Models for predicting hourly canopy resistance (r c) and latent heat flux (LET) based on the Penman–Monteith (PM) and bulk transfer methods are presented. The...  相似文献   
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A new equine coronavirus was isolated from the feces of adult horses with pyrogenic and enteric disease. The disease outbreak was mainly observed among 2- to 4-year-old horses living in stables of a draft-horse racetrack in Japan. On comparing the isolated virus (isolate Tokachi09) with the equine coronavirus NC99 strain, no significant differences were observed in several biological properties such as hemagglutinating activity, antigenicity (in indirect immunofluorescence and neutralization tests), and one-step growth (in cell culture). The sequences of the nucleocapsid and spike genes of isolate Tokachi09 showed identical size (1341 and 4092 nucleotides, 446 and 1363 amino acids, respectively) and high similarity (98.0% and 99.0% at the nucleotides, 97.3% and 99.0% at the amino acids, respectively) to those of strain NC99. However, the isolate had a 185-nucleotide deletion from four bases after the 3'-terminal end of the spike gene, resulting in the absence of the open reading frame predicted to encode a 4.7-kDa nonstructural protein in strain NC99. These results suggest that the 4.7-kDa nonstructural protein is not essential for viral replication, at least in cell culture, and that the Japanese strain probably originated from a different lineage to the North American strain. This is the first equine coronavirus to be isolated from adult horses with pyrogenic and enteric disease.  相似文献   
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The energy flux on the ground surface depends not only on climatological and biophysical controls in the vegetative canopy, but also on the available energy and energy partitioning beneath the canopy. Quantifying the evaporation and energy partitioning beneath the canopy is very important for improving water and energy utilization, especially in arid areas. In this study, we measured meteorological data, the net radiation and latent heat flux beneath the rice canopy, and then applied the radiation and energy balance equations to get the water surface temperature beneath the rice canopy. To apply the equations, we constructed shortwave and longwave radiation beneath the canopy sub-models and a bulk transfer coefficient sub-model. A plant inclination factor was parameterized with plant area index for the shortwave and longwave radiation sub-models. Bulk transfer coefficient was parameterized by plant area index and soil heat flux was predicted by the force restore model. With calculated water surface temperature and constructed sub-models, we reproduced net radiation and latent heat flux beneath the rice canopy. As a result, the reproduced water surface temperature, net radiation, and latent heat flux beneath the rice canopy were very close to the measured values and no significant differences were found according to 2-tail t test statistical analysis. Therefore, we conclude that these constructed sub-models could successfully represent water surface temperature, net radiation, and latent heat flux beneath the rice canopy.  相似文献   
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Paddy and Water Environment - This paper proposes a new approach to predicting dry season periods by using annual cumulative rainfall for the past 35 years to determine dry season...  相似文献   
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sd1-d originating from ‘Dee-geo-woo-gen’ has been utilized to develop short-culmed indica varieties adaptable to higher fertilizer-application. Its tall alleles SD1-in and SD1-ja are harbored in indica and japonica subspecies, respectively. The sd1-d of indica IR36 was substituted with SD1-in or SD1-ja by recurrent backcrossing with IR36, and two tall isogenic lines (“5867-36” and “Koshi-36”) were developed. IR36, 5867-36 and Koshi-36 were grown in a paddy field in three years, and yield and related traits were measured, the effects of SD1-in and SD1-ja on yielding ability and related characteristics were examined on the genetic background of IR 36. SD1-in decreased panicle number per m2 but increased spikelet number per panicle, ripened-grain percentage and 1000-grain weight, compared with sd1-d, resulting in the increase of yield. The increase of 1000-grain weight by SD1-in, caused by the increases of length, width and thickness of grain, was due to the increases of the length and width of lemma. SD1-ja did not significantly affect yield, mainly because the decrease of panicle number per m2 was compensated by the enlarged 1000-grain weight owing to the increase of lemma length. Serious lodging was observed in long-culmed 5867-36, suggesting that sd1-d is indispensable for indica breeding programs.  相似文献   
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表层有效土壤水分参数化及冠层下土面蒸发模拟   总被引:1,自引:7,他引:1  
通过观测田间微气象数据、土壤表层水分变化状况及荞麦作物冠层下土面蒸发等资料,引进一个表面体积含水率的函数,构建了基于表层有效土壤水分的土壤蒸发模型。该模型包含了土面蒸发的2个过程:水蒸气从土壤孔隙中扩散到地表面及水蒸气由地表面传输到大气中。模型中表层有效土壤水分参数不仅取决于表层土壤含水状况,而且受风速影响。采用波文比能量平衡法及微型蒸发器观测荞麦地实际蒸腾蒸发量及冠层下土面蒸发的变化规律,并验证模型精度。结果表明,所构建模型可以成功预测冠层下土面蒸发,其平均相对误差为13.5%。该研究对于实现土壤蒸发及作物蒸腾的分离估算,减少无效水分消耗具有重要意义。  相似文献   
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