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1.
在营养液培养条件下,研究了水分轻度胁迫、氮素有限胁迫对冬小麦小偃22拔节期NR活性、根系活力等生理特性、养分累积及小麦产量的影响。结果表明,水分、氮素亏缺使叶绿素含量及叶片NR活性低于对照水平,根系活力,K3Fe(CN)6还原活性降低;水分胁迫影响大于氮素亏缺影响,水分和氮素亏缺之间有显著地交互作用。水分胁迫下,小麦植株地上部氮、磷、钾含量高于对照水平,但根系含量降低;氮素亏缺下,地上和根系的养分含量均低于对照水平;水分和氮素之间有极显著地交互作用。拔节时期水分、氮素亏缺使小麦成熟期的产量降低。  相似文献   

2.
本试验对两个耐铝毒性不同的玉米自交系幼苗进行了叶绿素含量、光合速率、以及干物重、可溶性蛋白质和游离脯氨酸含量等生理指标的测定,分析玉米耐铝性的基因型之间差异。试验结果表明,在铝胁迫下,玉米叶片中的叶绿素含量下降.并且Chla/Chlb的比值也下降,造成光合速率明显降低,使干物质积累减少,但敏感自交系(C)受到的影响较大,耐性白交系(T)受到的影响较小。铝胁迫使幼苗组织内可溶性蛋白和游离脯氨酸的含量增加,不同的自交系之间存在差异性。  相似文献   

3.
以钾高效大豆品种九农15和低效品种GD8521为材料,在溶液培养条件下研究低钾胁迫对其叶绿素含量、光合特性及叶绿素荧光参数等生理指标的影响,从光合物质生产方面探讨不同效应型品种对低钾胁迫的耐性机制。结果表明:在低钾胁迫下,高效品种的叶绿素a、b及a+b总含量与对照之间没有差异,但叶绿素a/b值较对照显著提高,而低效品种的叶绿素a及a+b总量较对照显著降低,叶绿素b的含量及a/b值没有显著变化;低钾胁迫下高效品种仍保持较高的光合速率,但气孔导度和胞间CO2浓度则显著低于对照,低效品种的各参数下降幅度远大于高效品种,处理间均达到极显著差异;随着供钾水平的降低,高效品种叶绿素荧光各参数中仅Fv显著增加。而低效品种F0、Fm、Fv、Fv/Fm、Fv/F0等参数的变化均达到显著或极显著水平;低钾胁迫下低效品种反应中心耗散的能量较多,用于电子传递的能量减少,而高效品种处理间无明显变化。由此可见,在低钾胁迫下高效型品种仍能保持较高的叶绿素含量,尤其是叶绿素a的比例显著提高,其光合电子传递过程受低钾胁迫的影响也较小,因而能保持较高的光合生产能力,而低效品种受低钾胁迫时各参数则发生显著变化.导致光合生产能力降低。  相似文献   

4.
研究了偏低温弱光条件对两个辣椒品种株高、茎粗和根系等生长发育状况,以及叶面积、叶片中叶绿素含量和净光合速率影响,研究结果表明:低温弱光胁迫使辣椒株高和茎粗增长及叶面积扩展变慢,但低温对植株生长的抑制作用比弱光更明显;低温弱光下辣椒植株根系活力下降;低温弱光胁迫下,叶片中叶绿素含量下降,净光合速率下降。  相似文献   

5.
遥感提取叶绿素含量的方法是精准农业的重要研究方向之一,但是如何用冠层光谱数据有效地提取叶绿素含量仍然是一个难点。本文用光谱指数TCARI和OSAVI的组合建立提取冬小麦冠层叶绿素含量的关系式,并使用实验田获取的冬小麦冠层光谱以及与之同步的机载高光谱传感器OMIS数据进行了验证。通过误差分析讨论了该方法用于遥感高光谱数据时需要注意的问题,表明大气校正的精度,传感器的信噪比以及波段中心的漂移是模型反演精度的主要制约因素。  相似文献   

6.
在水培条件下,研究了营养液低氧胁迫对网纹甜瓜幼苗生长指标、光合作用和生理代谢物质含量的影响。结果表明,低氧处理显著抑制了幼苗的生长,鲜重、干重等生长指标和叶绿素含量、净光合速率等光合指标均显著降低;低氧胁迫诱导幼苗不定根和根系活力显著增加;低氧胁迫下幼苗MDA、H2O2含量显著增加,但是幼苗体内可溶性糖、氨基酸、游离态多胺和热稳定蛋白含量也显著提高。与西域一号相比,星光生长较快,较高的光合速率、根系活力和生理代谢物质含量,缓解了低氧胁迫对幼苗的伤害。  相似文献   

7.
为深入了解蚯蚓粪基质茄果类蔬菜穴盘苗的耐热性,以常规草炭系基质为对照,测定了番茄、茄子、辣椒穴盘苗叶片叶绿素含量、抗氧化酶(SOD、POD、CAT)活性、电解质渗出率和丙二醛(MDA)含量等指标。结果表明:高温胁迫下对照叶绿素总量降低幅度较大,比蚯蚓粪基质穴盘苗提高3.13%~246.02%;蚯蚓粪基质穴盘苗在高温胁迫下叶片抗氧化酶活性增强,对照抗氧化酶活性有所减弱;高温胁迫下对照穴盘苗叶片电解质渗出率和MDA含量增加幅度较大,分别比蚯蚓粪基质穴盘苗提高20.21%~122.53%和13.88%~58.14%,说明蚯蚓粪基质茄果类蔬菜穴盘苗具有较强的耐热性。  相似文献   

8.
冬小麦品质的影响因素及高光谱遥感监测方法   总被引:19,自引:0,他引:19       下载免费PDF全文
研究了小麦品质的分类及其构成因素与环境条件之间的关系,各品质因素之间的关系。运用相同栽培条件下不同品种品质指标间的关系和变化规律,研究了品种因素对小麦品质的影响程度以及品种因素与品质指标之间的相关性,得出相同环境条件下籽粒的蛋白质含量与湿面筋含量、沉降值、吸水率、形成时间和稳定时间之间存在极显著的相关性。并利用不同品种、不同肥水条件下的作物关键生育时期的生化参量与光谱指数进行分析,得出开花期冬小麦叶片的类胡萝卜素与叶绿素a的比值与结构不敏感植被指数(SIPI)之间存在极显著的正相关,决定系数达到0.7207,冬小麦体内的全氮含量与类胡萝卜紊与叶绿素口的比值之间存在极显著的负相关,决定系数为0.7245,并通过分析开花期冠层生化组分与籽粒品质指标间的相关性,得出开花期叶片全氮与籽粒蛋白质、湿面筋、干面筋和沉降值之间存在极显著的正相关,表面运用开花期光谱指数来反演叶片全氮含量,进而用来预测预报籽粒品质是切实可行的。  相似文献   

9.
因为磷素重要的营养作用,其胁迫的存在影响冬小麦的正常生长。借助地面遥感仪器获取冬小麦在磷营养胁迫下的多个生育期里的冠层光谱数据并对其影响特征进行了分析。利用因子分析方法提取主因子与含有丰富信息的光谱变量,并结合极显著水平(0.01)的均值比较与检验过程考察了冬小麦冠层光谱,确定了对磷营养胁迫敏感的光谱波段:760nm,810nm和870nm与950nm,并在此基础上结合冬小麦对磷素的吸收利用特征选定了运用冠层光谱敏感波段反射率探测和区分磷营养胁迫的关键生育期:拔节期。结果同时表明,对冬小麦磷营养胁迫而言,近红外区间(760nm~1100nm)光谱反射特征的区分能力要强于可见光区。本文同时指出了研究与发展利用遥感技术进行营养胁迫监测的方法和着重点。  相似文献   

10.
基于植被指数的叶绿素密度遥感反演建模与适用性研究   总被引:1,自引:0,他引:1  
利用遥感数据反演叶绿素密度是对作物长势进行评估的有效手段.本文利用实测冬小麦和夏玉米两种作物、不同生育期的冠层光谱和叶片叶绿素含量数据,收集了14种光谱指数,分析各种光谱指数的叶绿素密度遥感模型的精度.优选了其中的8种植被光谱指数,建立了植被指数与叶绿素密度之间的回归模型,并利用不同生育期小麦数据和玉米数据对各模型进行验证,分析评价它们对不同生育期、不同作物类型的适用性.研究发现:利用SRI、RVI I、R-M和MTCI 4种植被指数所建模型对冬小麦不同生育期数据适用性较好,各生育期冠层叶绿素密度反演相对误差优于27%.其中,MTCI模型对不同作物类型的适用性最好,冠层叶绿素密度反演相对误差优于35%.  相似文献   

11.
原油减压蒸馏塔侧线温度多变量预测控制   总被引:2,自引:0,他引:2  
本文研究了原油减压蒸馏塔侧线抽出温度多变 量控制问题.针对减压塔各个侧线之间存在单向关联的特点,通过建立各个侧线以及相邻侧 线之间的温度动态特性,设计了减压塔侧线温度多变量预测控制系统.在某炼油厂减压塔中 应用表明,采用本文提出的侧线温度多变量预测控制,具有较显著的控制品质.  相似文献   

12.
Agitation in a mixer-settler is one of the most common operations, yet presents one of the greatest challenges in the area of computer simulation. Mixer-settlers typically contain an impeller mounted on a shaft, and optionally can contain baffles. The hydrodynamic characteristics of mixer-settlers have been studied in the present study. The effect of different geometrical parameters on the efficiency characteristics of the system has been investigated. The effects of different width of impellers, impeller speed, inlet velocity, impeller diameter, etc. have been studied. Computational fluid dynamics (CFD) model has been developed to predict the efficiency characteristics. The model has been validated with the help of experimental data for different velocity outlets used in the work. This work has enabled developing efficiency that can produce higher condition than those reported in previous literature. From the CFD simulations results, optimum mixer-settler geometry has been proposed.  相似文献   

13.
The dynamic characteristics of an electrostatically actuated double cantilever beam, often found in asymmetric comb drive microstructures, have been investigated in the present paper. A coupled electromechanical problem is formulated and solved to obtain different performance parameters like pull-in voltage, frequency response etc. Effects of various critical factors on the dynamic pull-in characteristics have been discussed elaborately. It has been further observed through extensive studies that, the dynamic pull-in characteristics differ considerably from the static characteristics for the double beam configuration. Finally, these observations have been supported by experimental results with a fabricated (in SOIMUMPS process) double cantilever based microstructure, using a simple in-house developed low cost test set up. A typical case of design of a closed loop MEMS (microelectromechanical systems) capacitive accelerometer has also been discussed where the present study finds ready applications to predict the dynamic pull-in characteristics more accurately than the conventional lumped model.  相似文献   

14.
In this paper a simple measurement of dynamic B-H characteristics of grain-oriented silicon has been made by peak voltmeter under a biased condition pertinent to a self-saturating condition. A method of steady-state analysis of a self-saturating magnetic amplifier of grain-oriented silicon steel has been described from the non-linear characteristics obtained from the measurement. No approximation has been made. The transfer characteristies of a half wave as well as a full wave amplifier have been calculated and verified from the data of actual measurements. The results shown are quite encouraging.  相似文献   

15.
Modified Sierpinski gasket fractal patch antenna for earth exploration satellite services has been proposed in this article. The proposed antenna is designed up to third iterative fractal geometry on the FR4 substrate having dielectric constant of 4.4 with height of 0.8 mm. The proposed design shows multiband characteristics at 2.8, 6.1, 7.96, 16, and 17 GHz frequencies. The maximum gain of the proposed design is 9.6 dBi has been achieved in Ku‐band. The resonating performance characteristics and radiation characteristics of the final iteration are investigated using simulator and experimentally to verify the results of the proposed design. The simulated and measured performance parameters show quite resemblance. Further, proposed design has been simulated on the micro‐machined high resistive silicon substrate which causes the improvement in gain and efficiency. Micro‐machined fractal antenna is compatible with monolithic microwave integrated circuits (MMICs).  相似文献   

16.
Software Quality Journal - Although extensive research has been conducted on the characteristics of the agile developer, little attention has been given to the features of the software-testing...  相似文献   

17.
一种基于遗传算法的软件测试用例生成新方法   总被引:4,自引:0,他引:4  
建立了一个基于遗传算法测试用例生成的系统模型,在该模型下通过分支函数插装的方法构造遗传算法所需的评价函数并针对软件测试用例生成问题的特点对传统遗传算法进行了改进;最后,给出了一个实例并分析了实例的执行情况。  相似文献   

18.
A new aerodynamic model for obtaining the performance characteristics of a vertical axis wind turbine (VAWT) developed by the authors has been used to obtain estimates of aerodynamic loading, which are subsequently used for the dynamic analysis of a VAWT. The model incorporates gyroscopic effects, structural damping and also power generation through an induction or synchronoustype generator. A computer code written in MS-DOS FORTRAN has been developed for the dynamic analysis of a vertical axis wind turbine, and has been implemented on an IBM compatible 386 AT, for studying the dynamic characteristics of a VAWT. The results obtained from this analysis compare fairly well with other published theoretical and experimental data, and demonstrate that the incorporation of the new wind loading estimation model leads to a definite qualitative improvement in the theoretical predictions of the dynamic characteristics of vertical axis wind turbines.  相似文献   

19.
介绍了一种基于圆感应同步器的经纬仪方位测角系统的电路与软件设计,并简要阐述了该测角系统的主要特点。关健词:圆感应同步器;经纬仪;方位角  相似文献   

20.
The problem of the processing and automatic analysis of video information formed by a computer capillaroscope has been investigated. The specific features of original video data have been studied, an algorithm to eliminate the drift of frames and form an averaged image has been proposed. The problem of detecting and analyzing the capillaries has been solved, which is comprised of the stages of forming and filtering the map of contour lines of capillaries, the syntactic analysis of contours, the selection of the major capillary, and the prepartion and analysis of the morphological characteristics of contour lines. A homeomorphic straightening mapping of the capillary area into rectangular shape area is proposed. The transformed data are used to determine the characteristics of capillary blood flow. An algorithm for measuring the velocity of instantaneous blood flow as a function of time and location along the capillary has been developed.  相似文献   

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