spectrum n. (pl. -tra ) 1.【物理学】谱,光谱;波谱;能谱,质谱。 2.【无线电】射频频谱;无线电(信号)频谱。 3.【心理学】(眼睛的)余像;残像。 4.〔转义〕范围,幅度;(连续的)系列。 an absorption spectrum 吸收(光)谱。 a bright line spectrum 线状光谱。 an optical spectrum 光谱。 a solar spectrum 太阳光谱。 a wide spectrum of opinion 意见的不同幅度甚大。
pulse n. 1.脉搏;有节奏的跳动;【动物;动物学】脉冲(波);脉动。 2.意向;倾向。 3.【音乐】拍子,律动。 His pulse was at a hundred. 他的脉搏(每分钟)一百次。 a galloping pulse 急脉。 a high pulse 强脉。 a long [ slow ] pulse 缓脉。 a weak pulse 弱脉。 an action pulse (火箭)触发脉冲。 a carry pulse 进位脉冲。 a driving pulse 起动脉冲。 feel sb.'s pulse =have one's fingers on the pulse of sb. 按某人的脉;探某人的意向。 stir sb.'s pulses 鼓动某人的情绪;使人兴奋。 with quickened pulses 心跳得更快地。 vi. 脉跳动;震动;脉动。 vt. 使发生脉冲;用脉冲输送(血等) (in out)。 n. 〔sing., pl. 〕 豆类;豆。
Then the effect is to steepen the flanks of the pulse spectrum . 因此在效果上是加大了脉冲谱翼部的陡度。
Numerical examples illustrated the spatiotemporal properties such as spectrum redshifting , narrowing and pulse distortion , etc . it is stressed that the " antibeam " behavior of ultrashort pulsed beams can be avoided , if a suitable truncation function is introduced to the initial pulse spectrum 数值计算例说明了在色散介质中会出现谱红移、变窄、及脉冲形变等传输效应,而且对初始光谱引入截断函数可以避免“非光束”行为。
Especially , in the solution of pulse spectrum , the negative frequency form of nls equation should be solved by the negative frequency form of fourier transformation , while the positive frequency form of nls equation is solved by the positive frequency form of fourier transformation 尤其在脉冲频谱的求解问题中,如果采用负频形式的非线性薛定谔方程则必须选取负频形式的傅里叶变换;如果采用正频形式的非线性薛定谔方程则必须选取正频形式的傅里叶变换。
A technique for identifying total parameters ( titp ) is employed in the inverse problem of heat and moisture migration research in porous structures , accordingly the basic principle and implementary approach is presented to obtain the temperature and humidity dependent thermal and humid physical parameters . it is indicated theoretically that the applications of pulse spectrum technique ( pst ) to the inverse problem are feasible 在多孔结构内热湿迁移反问题研究中引入全参数辨识方法,提出了求解温度和湿度依赖型热湿迁移物性参数的基本思想和途径,从理论上指出了应用脉冲谱技术研究多层多孔结构热湿迁移反问题的可行性。
High - frequency link power converters are receiving increasing attention . when the input frequency of ac - ac converter is quite high , such as 20khz or above , in order to make sure the converter switching action is restricted to the zero crossing point of the link voltage , the switching cycle becomes discrete pulse spectrums , however , the conventional pwm converters are ruled out because they would fail either to the efficiency or the low - distortion criteria 当交-交变频器的输入频率非常高,通常为20khz时,为了在零电压条件下实现逆变器开关管的通断,变换器的开关时刻必须选择在高频交流电压脉冲为零时,这意味着变换器开关时刻在时间轴上成为不连续的点,而常规的硬开关pwm变换器是将开关时刻选择在任意时刻。