( 3 ) the common detonator was firstly applied in the removing temporary concrete beering for the convert of the continous beem system , the character of the method is quickly converted speed and no damnification for engineering structure ( 3 )在铁路预应力混凝土连续梁体系转换中，首次采用普通炸药爆除混凝土临时支座，转换速度快，对工程结构无损伤。
They are voltage scaling , current scaling and charge scaling . by compare , current scaling dac is the most fast and occupies the least area . the current - steering structure is a type of improved current scaling structure 传统dac的转换按其缩放方式进行分类,主要有:电流按比例缩放、电压按比例缩放和电荷按比例缩放,通过比较可知,电流按比例缩放转换速度快且占用芯片面积小。
3 . adopting changes the speed coefficient and analyses our country district industrial structure change speed to the industrial structure , and reaches : since the reform and open , our country industrial structure change speed assumes east and middle and west weakens the power 3 、采用对产业结构转换速度系数分析我国地区产业结构转换速度，得出：改革开放以来，我国产业结构转换速度呈东、中、西减弱之势。
At last we introduce the realization of all the parts , the problem in the circuit design and the measured data . the results show that the designed system has met the requirement . in this dissertation , direct digital synthesis technology has been used in the phase - locked frequency synthesizer , which can make full use of the characteristics of direct digital synthesis technology such as flexible output wave shape and continuous 本课题将直接数字式合成技术用于锁相频率合成器中,该方法将直接数字合成的特点,如输出波形灵活且相位连续、频率稳定度高、输出频率分辨率高、频率转换速度快、输出相位噪声低、集成度高、功耗低、体积小等与锁相环路的频带宽、工作频率高、频谱质量好等优点有机的结合起来,从而在宽带的条件下实现了比较好的杂散性能和相噪。
I designed both hardware and software to develop the multi - channel analyzer , of which the key is the pc / 104 embedded computer . in a word , it has five traits as follows : ( 1 ) the key of apparatus is the pc / 104 embedded computer ; ( 2 ) on the hardware , we introduce the high - speed a / d conversion component - max191 to improve the mca ' s conversion speed and meet the demand on the spot ; ( 3 ) adopting high frequency module of electrical source to reduce its volume . ( 4 ) the mca consumes low power no more than 3 . 9 watt 以国土资源部项目为依托，以pc 104嵌入式微机为平台，完成了小型、低功耗能谱采集系统，特点是： ( 1 )以pc 104嵌入式微机为平台，实现了采集系统微机化； ( 2 )采用高速低功耗a d器件maxl91 ，与现有的mca相比，提高了转换速度，降低了mca的功耗； ( 3 )采用高频模块电源，减小了采集系统的体积； ( 4 )整机功耗低，小于3 . 9w ； ( 5 )仪器重量轻。
Its specifications show that the system have basically realized within the range of 2 ~ 12ghz : the phase noise is superior to - 72dbc / hz @ 10khz , spurious is superior to - 55dbc , harmonic restrain is superior to 30dbc , step is 10mhz , hopping time is 14 s . so the feasibility has been verified 测试结果表明系统在2 ~ 12ghz范围内基本实现了相位噪声优于- 72dbc / hz @ 10khz ,杂散抑制大于- 55dbc ,谐波抑制大于30dbc ,跳频间隔10mhz ,频率转换速度14 s ,验证了该方案的可行性。
