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81.
微波辐射技术在淀粉改性中的应用 总被引:4,自引:0,他引:4
简要介绍微波技术的原理,以及目前在淀粉改性方面的应用状况及发展趋势。 相似文献
82.
Margaret C. McEntee DVM Rodney L. Page DVM MS J. Mark Cline DVM Donald E. Thrall DVM PhD 《Veterinary radiology & ultrasound》1992,33(4):190-197
Radiation pneumonitis developed within the radiation treatment field in three dogs with soft tissue sarcomas located on or adjacent to the thoracic wall. Radiographic signs compatible with a diagnosis of radiation pneumonitis developed from one (n = 2 dogs) to two (n = 1 dog) months after completion of therapy. The initial radiographic sign was an alveolar infiltrate in all three dogs. At subsequent examinations at variable time periods after treatment, radiographic findings included: bronchiectasis (n = 3 dogs), alveolar infiltrate (n = 2 dogs), decreased lung volume (n = 2 dogs), and unstructured interstitial opacification (n = 1 dog). Necropsy examination of one dog at fourteen months after the completion of radiotherapy showed evidence of pulmonary fibrosis within the irradiated lung. Necropsy examination of the second dog did not show any evidence of radiation induced changes. It is possible that histopathologic examination did not include irradiated lung. No clinical signs that could be attributed to the radiation pneumonitis were observed in any dog. It appears that approximately 25% of the lung can be safely irradiated to high doses, if indicated, in order to deliver an adequate dose of radiation to a primary tumor site. 相似文献
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Summary Male-sterile mutants were isolated from M2 and M3 generations of indica rice variety 26 Zhaizao, dry seeds of which had been exposed to 60Co- rays at a dose of 290 Gy. The mutants were planted in early season and ratooned in late season for two successive years for identification of fertility conversion in different growing seasons. One of the mutant lines was further observed in a growth chamber and in the field. Results showed that daily average temperature might be the major factor conditioning the male fertility conversion at a moderate daylength. The critical temperature for the male fertility conversion of the mutant grown under 12.5 h and 14.0 h daylength is about 23°C, below which the plant becomes completely male sterile. Its male fertility conversion character differs from other EGMS lines so far developed. The performance of the hybrids between the mutant and some other indica varieties demonstrated its good combining ability and its potential value in hybrid rice production. The obtained mutant line still sheds KI-stainable pollen grains under male sterilizing conditions. Nevertheless, pollen grains shed from the male sterile plants were much more vulnerable than from normal plants. At sucrose concentration below 1.5 M, the pollen grains from the mutant grown under male sterilizing conditions almost completely broke down, while above 1.5 M they became plasmolysed and shrunken. This is indicative of poor development of the membrane and walls of the pollen grains from the male sterile mutant, causing the pollen grains to be unfunctional. NBT test also clarified the abortion of the pollen grains from the mutant, which were formed in the male sterilizing environment. 相似文献
86.
棉花光合生产与干物质积累过程的模拟 总被引:13,自引:2,他引:13
在综合已有作物模拟模型优点的基础上,构建了基于生态生理过程的棉花光合生产与干物质积累动态模拟模型。模型中引用了高斯积分法计算冠层每日的PAR总截获量和光合同化量,考虑了PAR的日变化规律和太阳高度角变化对直射PAR消光系数的影响,在量化直射辐射对光合作用贡献的同时,分别计算了天空散射辐射、冠层和土壤散射辐射的强度。模型充分考虑了温度、生理年龄、氮素、水分等因子对光合作用和呼吸作用的影响。利用不同遗传类型品种、不同管理方式下的棉花干物质积累动态对模型进行了检验,结果表明模拟值与观测值吻合度较好,模型不仅具有较强的机理性而且具有较高的预测性和实用性。 相似文献
87.
淀粉高吸水剂微波辐射合成研究 总被引:11,自引:0,他引:11
以N,N’-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,丙烯酸为淀粉接枝单体,采用微波技术合成淀粉高吸水剂。并用FTIR对产物结构进行了表征。实验结果表明,微波技术合成淀粉高吸水剂,具有节能、省时、高效,工艺简单的显著特点,具有生物可降解性,产物吸水速率明显高于传统化学法,是值得推广的清洁生产工艺。 相似文献
88.
A. Soltani M. J. Robertson A. Rahemi-Karizaki J. Poorreza H. Zarei 《Journal of Agronomy and Crop Science》2006,192(5):379-389
Quantitative information regarding biomass accumulation and partitioning in chickpea (Cicer arietinum L.) is limited or inconclusive. The objective of this study was to obtain baseline values for extinction coefficient (KS), radiation use efficiency (RUE, g MJ?1) and biomass partitioning coefficients of chickpea crops grown under well‐watered conditions. The stability of these parameters during the crop life cycle and under different environmental and growth conditions, caused by season and sowing date and density, were also evaluated. Two field experiments, each with three sowing dates and four plant densities, were conducted during 2002–2004. Crop leaf area index, light interception and crop biomass were measured between emergence and maturity. A KS value of 0.5 was obtained. An average RUE of 1 g MJ?1 was obtained. Plant density had no effect on RUE, but some effects of temperature were detected. There was no effect of solar radiation or vapour pressure deficit on RUE when RUE values were corrected for the effect of temperature. RUE was constant during the whole crop cycle. A biphasic pattern was found for biomass partitioning between leaves and stems before first‐seed stage. At lower levels of total dry matter, 54 % of biomass produced was allocated to leaves, but at higher levels of total dry matter, i.e. under favourable and prolonged conditions for vegetative growth, this portion decreased to 28 %. During the period from first‐pod to first‐seed, 60 % of biomass produced went to stems, 27 % to pods and 13 % to leaves. During the period from first‐seed to maturity, 83 % of biomass was partitioned to pods. It was concluded that using fixed partitioning coefficients after first‐seed are not as effective as they are before this stage. Environmental conditions (temperature and solar radiation) and plant density did not affect partitioning of biomass. 相似文献
89.
Field studies on differentially irrigated wheat ( Triticum aestivum L.) crops were conducted at Pantnagar for two years to evaluate the use of thermal infrared radiation to detect crop water stress. Data show that the stress-degree-day index (mid day canopy-air temperature difference) is influenced by environmental variability other than soil moisture. Improvement in the stress-degree-day (SDD) index was achieved by including the measurements of vapor pressure deficit and approach was termed as plant water stress index (PWSI). Observations indicated that daily variation in SDD values due to meteorological changes was removed through PWSI. Better correlation was found between soil-induced leaf water potential and plant water stress index than between total leaf water potential and plant water stress index. It is concluded that remote sensing of thermal infrared radiation offers a promising technique which can be incorporated into irrigation management programme. 相似文献
90.