共查询到18条相似文献,搜索用时 234 毫秒
1.
以大豆(Glycine max)为实验材料,利用统计分析的方法研究了微波热击对种子萌发特性及活力的影响。结果表明:热击处理可提高大豆种子的发芽率,复合微波处理显著促进了芽长和芽活力指数,抑制了电解质渗漏,提高可溶性糖含量和过氧化物酶(POD)活性,萌芽蛋白质含量及氨基酸总量均升高,其中以45℃热击5min及50℃热击2min加微波处理后的大豆芽长、芽活力指数与对照比达极显著水平,蛋白质和氨基酸总量的影响也分别达到显著和极显著水平。同一处理随时间延长,生理效应呈下降趋势。因此,适宜剂量的微波热击复合效应可以促进大豆种子萌发和早期代谢。 相似文献
2.
微波处理菘蓝种子的子叶发育与生物光子辐射的相关性 总被引:2,自引:0,他引:2
比较研究不同时间长度的微波辐照菘蓝种子对种子萌发率、淀粉酶活性、转氨酶活性、蛋白酶活性、蛋白质含量、游离氨基酸含量、总DNA含量、子叶发育状况及其生物光子辐射强度的影响.采用微波辐射浸泡3h的菘蓝(Isatis ind igotica Fort)种子.与对照相比,四种处理均能不同程度提高菘蓝种子萌发率、淀粉酶活性、转氨酶活性、蛋白酶活性,促进蛋白质、游离氨基酸、DNA合成,促进子叶发育,提高了生物光子辐射强度.低剂量微波辐射能提高种子生理生化代谢机能,促进种子萌发和幼苗生长发育,研究发现8 s微波预处理效果最为显著. 相似文献
3.
4.
5.
6.
7.
激光的生物学效应,一方面依赖于激光特性,另一方面依赖于生物体内部对激光的敏感性。本文介绍应用He-Ne激光处理油松种子获得了有益的试验结果,并从植物细胞的双分子层结构模型出发,讨论了对生物细胞膜物理特性及膜渗透性的影响,并探讨了激光处理油松种子提高萌发率的作用机理。 相似文献
8.
种子萌发作为植物生命历程的开端,直接影响作物的最终产量。种子萌发常遭遇低温的影响,严重威胁粮食生产安全。利用傅里叶变换红外光谱结合曲线拟合研究低温对谷物种子(藜麦、青稞、水稻和小麦)萌发的影响。研究结果显示,4种谷物种子的发芽势、发芽率和发芽指数都随温度的降低而下降,青稞种子在4℃低温下的发芽率和发芽指数仍然较高,表明青稞种子的耐低温能力更强。红外光谱结果显示,低温胁迫下的谷物种子原始红外光谱整体特征相似,主要由多糖、脂肪和蛋白质的特征吸收峰组成。对低温胁迫下的谷物种子多糖(1200~950 cm-1)和酰胺Ⅰ带(1700~1600 cm-1)进行曲线拟合,结果显示:藜麦种子的多糖含量上升,蛋白质含量下降;青稞种子的多糖和蛋白质含量均呈先升后降的趋势;水稻种子的多糖含量下降,蛋白质含量上升;小麦种子的多糖含量呈先升后降的趋势,蛋白质含量呈先降后升的趋势。另外,在低温胁迫下,藜麦、青稞、水稻和小麦种子中都有不同比例的蛋白质二级结构从无序转向有序。因此,傅里叶变换红外光谱结合曲线拟合是一种研究低温胁迫对种子萌发影响的有效方法。 相似文献
9.
含水薄层多孔介质的微波干燥处理是实现长期保存的有效方法之一。本文推导了微波干燥含水薄层介质过程中温度梯度与含水率变化的关系,可以适用于多种不同材质的含水薄层多孔介质;利用多物理场仿真软件,建立了电磁场、温度场及速度场的耦合模型,仿真了薄层多孔介质在微波干燥过程中温度梯度与含水率变化的关联关系。选取黄豆作为薄层多孔介质样本进行微波干燥的实验,测量其在微波干燥过程中温度梯度变化和含水率变化的关系及不同干燥阶段对黄豆发芽率的影响。实验结果表明黄豆在微波干燥过程中,温度梯度与干燥程度存在固定关系,通过控制梯度趋于0时的干燥时间可以达到设定的干燥程度,并且对其发芽率影响较小。 相似文献
10.
激光对油松在干旱胁迫下萌发及酶活性的影响 总被引:1,自引:0,他引:1
在干旱胁迫条件下,对激光辐照的油松种子进行了萌发试验,并对其幼苗进行了超氧化物歧化酶(SOD)、过氧化物酶(POD)的活性和丙二醛(MDA)含量的测定。结果表明:激光辐照油松种子在干旱胁迫条件下的发芽率、根长、活力指数、生物量等显著提高,萌发期油松幼苗保护酶系统的超氧化物歧化酶和过氧化物酶活性明显提高,膜脂的过氧化物丙二醛含量下降,减少了膜脂过氧化作用对膜的伤害。从而说明,激光辐照油松种子在干旱胁迫条件下萌发及幼苗生长的抗旱性效应明显增强。 相似文献
11.
12.
V. V. Elesin G. V. Chukov D. V. Gromov V. V. Repin V. A. Vavilov 《Russian Microelectronics》2010,39(2):122-133
The effect of ionizing radiation on the characteristics of silicon-germanium microwave ICs has been experimentally studied.
Radiation tolerance criteria have been established and absolute tolerance levels of the SiGe ICs to dose and pulse ionizing
radiation have been determined. Comparative analysis of the tolerance factors of the microwave ICs fabricated using different
technologies is made. 相似文献
13.
针对传统的暗通道先验算法在处理带有大面积天空区域的有雾图像时出现明显的块效应、色彩失真和亮度偏低等问题,提出了一种结合区域生长与容差机制的去雾算法。首先通过灰度图腐蚀求出暗通道;接着利用种子区域生长法分割出天空区域,并把天空区域的平均灰度值作为大气光值估计;然后结合大气散射模型得到粗略的透视率,并采用改良的容差机制和引导滤波对透视率进行修正和细化;最后,引入Retinex法对图像进行后处理,进一步调整色彩和亮度。实验结果表明,本文提出的去雾算法对带有天空区域的图像去雾效果明显,天空区域的色彩有了显著改善,图像整体清晰明亮。 相似文献
14.
15.
Salinity Effects on the Microwave Emission of Soils 总被引:4,自引:0,他引:4
Passive microwave remote sensing has been proposed as a method for measuring both surface soil moisture and soil salinity. Since both of these characteristics will vary over an area, it is important to know how information about one of them can be isolated from the remotely sensed data. Water in the soil changes the microwave dielectric constant, which in turn changes the emission. Several dielectric mixing models have been developed and evaluated to describe soil-water-air systems. However, the concentration of salts in water also affects its dielectric properties in a well-known manner. When saline water is mixed with soil, the dielectric properties of this mixture will be different from those of a pure water and soil mixture. Although there are a few theories available to describe this process, very little verification of these theories has been done. In this study, a series of controlled field experiments were conducted using truck-mounted L-and C-band microwave radiometers. Experiments were designed to develop a data set that isolated the effects of salinity and soil moisture. This data set was used to evaluate the importance of each variable and to test proposed dielectric mixing models. The mixing models explained the observed data trends and range of values; however, the observed effects of salinity were not as large as predicted by the models. These differences may be related to model structure or field sampling problems. Variation in profile properties near the surface may also introduce some error. 相似文献
16.
Lasne Y. Paillou P. Freeman A. Farr T. McDonald K.C. Ruffie G. Malezieux J.-M. Chapman B. Demontoux F. 《Geoscience and Remote Sensing, IEEE Transactions on》2008,46(6):1674-1688
We consider the exploitation of dielectric properties of saline deposits for the detection and mapping of moisture in arid regions on both Earth and Mars. We present simulated and experimental study in order to assess the effect of salinity on the complex permittivity of geological materials and, therefore, on the radar backscattering coefficient in the [1-7 GHz] frequency range. Laboratory measurements are performed on sand/sodium chloride aqueous mixtures using a vectorial network analyzer coupled to an open-ended coaxial dielectric probe. We aim at calibrating and validating semiempirical dielectric mixing models. In particular, we evaluated the dependence of the real and imaginary parts of complex permittivity on the microwave frequency, water content, and salinity. Our results confirm that if the real part is mainly affected by the moisture content, the imaginary part is more sensitive to salinity. In addition to the classic formulas of mixing models, the ionic-conductivity losses, which are due to mobile ions in the saline solution, are taken into account in order to better assess the effect of salinity on the dielectric properties of mixtures. Dielectric mixing models are then used as input parameters for the simulation of the radar backscattering coefficients by means of an analytical model: the integral equation model. Simulation results show that salinity should have a significant impact on the radar backscattering recorded in synthetic aperture radar data in terms of the magnitude of the backscattering coefficient. Moreover, our results suggest that VV polarization provides a greater sensitivity to salinity than HH polarization. 相似文献
17.
18.
工艺因素对Ba_(6-3x)(Sm_(1-y)Nd_y)_(8+2x)Ti_(18)O_(54)陶瓷微波特性的影响 总被引:7,自引:2,他引:7
探讨了研磨时间,黏合剂浓度、用量,压力,保压时间,预烧温度,烧结温度,烧结时间等工艺因素对Ba6-3x(Sm1-yNdy)8+2xTi18O54陶瓷(x=0.6,y=0.2,0.3)微波性能的影响,试验结果表明,在其他工艺因素控制得当时,预烧温度和烧结温度对微波性能的影响最大。在预烧温度1050℃,烧结温度1200℃下,其微波特性参数εr=76.19,Q·f=10.2THz,(f=4.5GHz)。本系统陶瓷的烧结温度比一般文献低100℃左右,性能仍不错。进一步研究可为制备低温烧结微波陶瓷提供可能。 相似文献