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131.
针对黄顶菊种子人工识别时存在的主观性强、效率低、可重复性差等缺点,提出利用计算机视觉和图像处理技术提取黄顶菊种子特征参数的方法,研究了黄顶菊种子图像的分割方法、目标提取及种子图像中形态和颜色特征的提取方法,分析了各形态特征参数的相关性,筛选出了能精确反映黄顶菊种子几何特征的参数,验证了各特征参数提取方法的有效性,为后期的种子自动识别提供了依据。 相似文献
132.
CAI Jing zhi 《保鲜与加工》2003,(4):93-95
With the development and application of information and internet and virtual instrument technology ,the virtual globular company based on internet arises .To study remote state monitoring, remote fault detection and diagnosis about large scale, complicated and integrative equipment become very important. In the whole fault diagnosis system , the detecting ,data acquisition is original ,processing; transform and extracting features with the signal detected is a key factor. The theories and methods used in mechanical fault diagnosis is stated. The application of signal process and its feature extracting methods is introduced which are time domain, frequency domain and time frequency domain analysis, in state monitoring and fault diagnosis with its signal analysis. The processing method of random time variant special signal is given also. 相似文献
133.
采用机械损伤和(Z)-3-已烯醛熏蒸的方法,借助于叶绿素荧光手段,研究了伤害信息在合作杨檀株体内的系统性传递.结果表明,伤害信息在植株体内的系统性传递是双向的,不同部位叶片Fv/Fm的异质性为伤害信息在植物体内的双向系统性传递提供了直观的证据. 相似文献
134.
135.
论述了监控系统图象信号传输中同轴电缆、双绞线和光纤的特点和传输特性,并对其技术性能进行了分析。 相似文献
136.
葡聚六糖诱导后黄瓜幼苗细胞内Ca2+水平变化的细胞化学研究 总被引:1,自引:0,他引:1
采用改进的焦锑酸钙细胞化学方法 ,探讨了葡聚六糖诱导后Ca2 在黄瓜幼苗细胞中超微结构定位变化动态。结果表明 ,在正常情况下 ,黄瓜幼苗的细胞壁和细胞间隙存在大量Ca2 。葡聚六糖诱导后2h,细胞壁和细胞间隙Ca2 沉淀物明显减少 ;诱导后4h ,细胞壁和细胞间隙只偶尔能看到有少量Ca2 沉淀物 ,细胞质中Ca2 沉淀物增多 ;诱导后7h ,Ca2 又重新流回细胞壁和细胞间隙 相似文献
137.
138.
Electroencephalogram (EEG) signals are the electrical activities in the cortex or on the surface of scalp caused by the physiological activities of the brain which play a key role in the diagnosis of brain and the functional determination of brain. The authors discuss some methods for processing EEG signals from the view of the frequency domain and time domain, especially introduce some time-frequency analysis methods such as Wigner distribution, wavelet transform and matching pursuit etc. , ANN and non-linear analysis for EEG signals processing. 相似文献
139.
During the period of the primary contact time,there are series of recognition between the Fungal pathogens and the plant cell,which include physical and biochemical recognition.The results affect the infection directly.In the process of penetrating plant cell walls,there is not only an emzymolysis to plant cell wall,but also a mechanical squeeze to the cell wall.The latter almost trigger cell-associated defense response,such as extracellular hydrogen peroxide generation and callose doposition The complete cell wall-related defence response will be induced by mechanical signal and chemical signal together.Being to with the mammalian cell,in plant cell wall intergrin-like proteins have response to perceive the mechanical signal,which is via RGD(Arg-Gly-Asp)motif,and the plasma membrane-cell wall adhesion is required for expression of plant defense responses during fungal penetration. 相似文献
140.
A fully digitized electric vehicle direct torque control system with DSPTMS320LF2407 controller is described. The system hardware and software structures are presented. The performance of the direct torque control system is studied by simulation with MATLAB. Based on the simulation of the induction motor, waveform of current, speed, torque and flux are obtained. The testing results are also presented. Experimental results show that the design is feasible. 相似文献