period n. 1. 時(shí)代;期;時(shí)期;期間;階段。 2.〔the period〕現(xiàn)代,當(dāng)代。 3.周期;【地質(zhì)學(xué);地理學(xué)】紀(jì)。 4.終結(jié);句號。 5.【語法】長復(fù)合句,圓周句;【修辭學(xué)】掉尾句。 6.〔pl.〕美詞麗句;華麗的詞藻。 7.學(xué)時(shí),課時(shí),一節(jié)課;(比賽的)一節(jié)時(shí)間。 8.【醫(yī)學(xué)】過程,周期。 9.〔pl.〕月經(jīng)(期)。 10.【數(shù)學(xué)】(循環(huán)小數(shù)的)循環(huán)節(jié)。 11.【音樂】樂段。 the transitional period 過渡時(shí)期。 the warm-up period 【火箭】備射階段。 the catchwords of the period 現(xiàn)代流行話。 a turned period (字母上面的)上點(diǎn)。 the incubation period (病的)潛伏期。 monthly period 月經(jīng)。 at fixed periods 定期。 at stated periods 相隔一定時(shí)期;在一定時(shí)期。 come to a period 完結(jié)。 for a period of time 一個(gè)時(shí)期,一些時(shí)候。 put a period to sth. 使某事終止;取締某事。 round a period 練句。 adj. 1.(家具、服裝、建筑等)某一時(shí)代的。 2.(小說、戲劇等)逼真地描寫某一特定歷史時(shí)代的。 period furniture 仿古家具。 a period novel 描寫特定歷史時(shí)代的小說。 int. 〔口語〕就這樣〔強(qiáng)調(diào)話已經(jīng)講完了,=That's it! That's final!〕。
multiple adj. 1.多重的;復(fù)合的,復(fù)式的,多數(shù)的,多樣的。 2.倍數(shù)的,倍。 3.【電學(xué)】并聯(lián)的;多路的,復(fù)接的。 4.【植物;植物學(xué)】聚花的。 a man of multiple interests 興趣廣博的人。 n. 1.【數(shù)學(xué)】倍數(shù)。 2.【電學(xué)】并聯(lián);多路系統(tǒng)。 3.相聯(lián)成組。 4.成批生產(chǎn)的藝術(shù)品〔畫、雕塑、工藝品等〕。 common multiple 公倍數(shù)。 least common multiple 最小公倍數(shù)。
In this thesis, the main contents are following : 1 . reviewing the theory of nonlinear frequency conversion . quasi-phase-matching is discused . presenting the method for configuring periodically poled as well as multiple period superlattice 闡述了非線性頻率變換的原理,討論了相位匹配和準(zhǔn)相位匹配技術(shù),著重說明了周期和準(zhǔn)周期光學(xué)超晶格的工作原理。
The method can be used in the measurement of periodic and nonperiodic signal . according to the high accuracy and fixed gate-time measurement method, based on the multiple period synchronization method, the high speed, high accuracy and continuous frequency measurement is accomplished 將其再與一種從多周期同步法發(fā)展而來的高精度、定閘門法相結(jié)合,從而實(shí)現(xiàn)了高速、高精度、連續(xù)頻率測量,這非常適合非頻率量的頻率傳感信號的測量。
Analysis of ambiguity-function of lfmcw radar, including symmetrical triangular lfmcw signal and multiple periods ’ symmetrical triangular lfmcw signal . 3 . this dissertation advances new theories of lfmcw radar signal detection and estimation, including method for acceleration and velocity estimation based on polynomial phase transform; method for multi-target acceleration and velocity estimation based on modification polynomial phase transform 包括基于多項(xiàng)相位變換的lfmcw雷達(dá)速度和加速度估計(jì)方法;基于修正多項(xiàng)相位變換的多目標(biāo)lfmcw雷達(dá)速度和加速度估計(jì)方法;基于一般高斯噪聲環(huán)境下的lfmcw雷達(dá)速度和加速度聯(lián)合估計(jì)方法;另外提出了基于頻域增采樣內(nèi)插方法以提高lfmcw雷達(dá)測距精度。
In the paper, prescale technology, interpolate method, averaging method and multiple period synchronization method are used to measure the frequency accurately . diode demodulating technology, and power attenuated method or probe coupling & water load technology are employed to measure the power of high power microwave . isothermal technology is used to improve the stability of demodulator and to expend the range of square linear region 本文采用預(yù)分頻法、內(nèi)插法、多周期同步法、平均法實(shí)現(xiàn)了頻率的精確測量;利用二極管檢波技術(shù),結(jié)合衰減法或探針耦合+水負(fù)載技術(shù)實(shí)現(xiàn)了大功率微波功率的測量;采用恒溫技術(shù)提高了二極管檢波器穩(wěn)定度;完成了單片機(jī)串口通信協(xié)議設(shè)計(jì)和系統(tǒng)電磁兼容的分析和設(shè)計(jì)。
In this paper, a mixed method with the combination of advantages of analog and digital is discussed . it consists of two parts, analog and digital . first capacitance is converted to frequency by analog part, which makes the relations between capacitance and frequency, then high accuracy and instantaneous frequency measurement is accomplished by digital part based on the multiple period synchronization method 隨著數(shù)字電路的成熟,也有數(shù)字方法。本文結(jié)合模擬和數(shù)字方法兩者的優(yōu)點(diǎn),采用模/數(shù)混合方法。該方法由模擬和數(shù)字電路兩部分組成,首先由模擬電路建立電容到頻率的函數(shù)對應(yīng)關(guān)系;然后由數(shù)字電路對頻率計(jì)數(shù)。