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91.
DPC对棉花叶片发育及活性氧代谢的影响 总被引:11,自引:4,他引:11
以中棉所18为材料,研究了大田条件下DPC(缩节安)系统化控对棉叶发育和活性氧代谢的影响,结果表明,DPC提高了叶片中叶绿素、可溶性蛋白的含量,降低和减轻了膜脂过氧化产物丙二醛(MDA)的积累,提高了超氧物歧化酶(SOD)活性,降低了过氧化氢酶(CAT)、过氧化物酶(POD)活性,改善了活性氧代谢。DPC具有显著延缓叶片衰老的效应,可能与改变了内源激素系统、改善了活性氧代谢有关。 相似文献
92.
张俊能 《农产品加工.学刊》2006,(3):51-53
将废活性炭用水洗净后,在110℃烘箱中干燥4h,然后将其按不同温度和时间在马福炉中加热和冷却,采用碘量法测定活性炭对碘的吸附率。分析活性炭的脱色能力,找出实验最佳方案,最后利用糖浆脱色实验与新的活性炭比较。实验结果,经过再生的活性炭脱色能力达到原来的73.53%(脱色率比较),脱色糖浆的使用性能及使用寿命与新的活性炭相当。 相似文献
93.
This paper deduceS the control algorithm ,which can both regulate the active and reactive power of the novel dual-frequency dual-Buck inverter, and the control function. The control function based on one cycle control can control the AC-side active and reactive power by simple circuit. The simulation is given and the results prove the validity of the theory analysis. This inverter is valuable for the research of grid-connected inverters. 相似文献
94.
A shunt active power filiter(APF) used for harmonic treatment isintroduced in this paper. Basic circuit-theory and main configuration are analyzed. Control scheme and its realization are discussed. Computer simulation is used to verity theoretical analysis. It shows that APF is an interesting alternative for hasmonic treatment compared with conventional passive filter. 相似文献
95.
96.
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
97.
小麦灌浆后期青枯骤死原因分析及控制 总被引:6,自引:1,他引:6
小麦灌浆后期植株衰老与活性氧自由基毒害和膜脂质过氧化密切相关。灌浆后期株体内活必砼谢平衡失调是青枯发生的主要内因:造成青枯的外因除与“V”型变温有关外,雨后骤晴的强光与高温协同作用亦是青枯发生的重要外因一。灌浆后期“V”型变温使麦株各器均受到伤害,尤其穗下茎受到伤害。青枯能否发生取决于植体内酶活力的高低、非酶清除剂含量的多少以及“V”型变温的强度和持续时间。选择优良品种、适时播种、合理施肥和加强 相似文献
98.
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
99.
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
100.