By sky or ground wave propagation, the detection range of the HF radars breaks through the limit of the curvature of the earth, which makes it possible for long-range air early-warning and target monitoring. At the same time the unique abilities in detecting low-detectable targets of the HF radars makes them powerful equipments for detection of hermit aircrafts, small airplanes in heavy land and sea clutters, and even intercontinental missiles.

借助于天波或地波傳播方式韩国aa人人清清片中国aa人清，高頻雷達(dá)的探測(cè)范圍突破了地球曲率的限制，因此使遠(yuǎn)距離空中預(yù)警和目標(biāo)監(jiān)測(cè)成為可能，同時(shí)高頻雷達(dá)所具有的獨(dú)特和良好的對(duì)低可探測(cè)性目標(biāo)的探測(cè)能力，使之成為探測(cè)隱形飛行器和處于強(qiáng)地雜波和海雜波背景中的小型軍用飛機(jī)美女艹网站免费、巡航導(dǎo)彈等貼地、貼海飛行的小目標(biāo)及洲際導(dǎo)彈進(jìn)行有效探測(cè)的有力裝備日韩亚洲欧美。

The stealth warplane for the microwave radar usually have complicated structures with the coating of wave absorption. On the base of calculation and modeling of the geometrical structure of the warplane in real size, the HF RCS of the air crafts under two different polarizations in different direction have been calculated with the FDTD. The result shows that the above mentioned stealth warplane have the obvious characterstics of frequency resonance, polarization and the relatively large RCS in HF Band 10-30dBm2, which can be used as the theoretical reference for selection of working frequency for sky wave OTH Radar and it also means that the sky wave OTH radar has good capability of anti-stealth targets quantitatively.

對(duì)微波雷達(dá)具有隱身作用的飛機(jī)欧美pAAAA片，其形體較為復(fù)雜且表面涂敷有強(qiáng)吸波材料在對(duì)一種具有隱身幾何外形結(jié)構(gòu)實(shí)際尺寸飛機(jī)進(jìn)行計(jì)算建模的基礎(chǔ)上，文中采用FDTD技術(shù)得到了兩種極化狀態(tài)下該飛機(jī)無(wú)涂敷時(shí)不同方向上的短波雷達(dá)截面RCS值其結(jié)果顯示了這種隱身幾何外形飛機(jī)在短波波段有明顯的頻率諧振特性99riAV欧美gif、極化特性和較大的RCS10-30dBm2人人在线人人操，可為天波超視距雷達(dá)在選擇工作頻率時(shí)提供理論參考，并定量地說(shuō)明天波超視距雷達(dá)具有較優(yōu)的反隱身目標(biāo)能力

At the beginning the dissertation introduced the new techniques and methods in modern HF communication, and then put emphasis on the introduction of ABCS, including its basic theories, main characters and advantages over traditional HF communication system.

論文首先介紹了現(xiàn)代短波通信中的新技術(shù)與新體制中文字幕第60页，然后重點(diǎn)介紹了陸建勛院士提出的ABCS通信系統(tǒng)福利一区首页，分析了ABCS的理論基礎(chǔ)、主要特點(diǎn)及相對(duì)于傳統(tǒng)短波通信體制的優(yōu)勢(shì)美女的隐私秘免费视频网。

The posterior margin of hippocampal volumetry was defined by the plane which intersected the posterior commissure.

體積測(cè)量后界定在后連合，手工勾畫出HF邊緣獲得面積国产产一区二区三区久久毛片最强，并依此獲得HF體積国产成人综合亚洲。

A software HF channel simulator based on Watterson model was presented according to the characters of multipath, fading, Doppler frequency shift and Doppler frequency spread in HF channel.

對(duì)短波信道多徑、衰落人人操人人草人人草人人叉人、多普勒頻移及擴(kuò)展等現(xiàn)象進(jìn)行了分析caoporon，并且基于Watterson離散信道模型，設(shè)計(jì)了一種全軟件的短波信道模擬器黄色视频一区二区三区免费在线观看，為短波通信系統(tǒng)性能測(cè)試提供了條件日韩免费午夜毛片视频。

Then the delay power profile of wideband HF model is sampled and added into the channel simulation and a dynamic software simulation of wideband HF channel is implemented using the tapped delay line structure of Watterson model.

并結(jié)合短波信道模型，提出了一種新的短波寬帶信道軟件動(dòng)態(tài)仿真模擬方法在线国产福利网址。

In this context, we have reported recently that the volume of myocardial tissue occupied by perimysial and endomysial collagen was lower in hypertensive patients with HF and depressed ejection fraction, than in hypertensive patients with HF and preserved ejection fraction and normotensive subjects.56 Of interest, the interstitial and perivascular accumulation of collagen fibres was abnormally high in the two groups of patients.

在這種情況下久久久久久AV无码免费网站动漫，我們已經(jīng)說(shuō)了占用體積perimysial心肌組織人肌內(nèi)膜膠原水平低的高血壓患者用高頻和沮喪的射血分?jǐn)?shù)在高血壓患者的心力衰竭和保存被罰出場(chǎng)分?jǐn)?shù)與正常血壓subjects.56舒張壓的利息、間質(zhì)和血管堆積過(guò)高的膠原纖維是在兩組病人五月综合婷婷久久狠狠。

The result indicated that: the amount of the excess HF formed direct ratio to the yield of phosphorus pentafluoride and the optimum amount of the excess HF used is about 35%; the trickling rate of oleum shouldnt make the temperature of hexafluorophosphoric acid exceed 25 ℃ and the amount of oleum is 110% to 125% that of stoichiometry so that the content of phosphorus pentafluoride can be achieved 90%; the time and temperature of heating hexafluorophosphoric acid influenced both the yield and the content of phosphorus pentafluoride, and the optimum time should be about 30 minutes and the proper temperature was 148 to 153℃; when alcohol used asrefrigerant, the content of phosphorus pentafluoride was 94.03%, and the content can be up to 97.38%, provided that using liquid nitrogen as refrigerant.

通過(guò)實(shí)驗(yàn)發(fā)現(xiàn)二色aⅴ国产热，氟化氫用量與五氟化磷的產(chǎn)率成正比，最佳過(guò)量百分率宜在35％左右日韩午夜在线看导航视频网站免费下载；發(fā)煙硫酸的滴加速度不能使中間產(chǎn)物溫度大于25℃免费一级A片视频播放欧美，發(fā)煙硫酸用量大于理論量10％～25％時(shí)，得到的五氟化磷純度高于90％毛片视频免费观看视频大全；六氟磷酸的加熱溫度對(duì)五氟化磷的產(chǎn)率和純度均有影響在线性国日韩，宜在148～153℃的范圍內(nèi)，加熱時(shí)間應(yīng)在30分鐘左右；用工業(yè)酒精做冷凝介質(zhì)得到的五氟化磷純度最高只能到達(dá)94.03％黄色1级视频，使用液氮做冷凝介質(zhì)可以使五氟化磷的純度達(dá)97.38％以上欧美草草影院视频。

The technical routes and methods proposed in the thesis are not only theoretically meaningful but also are great valuable in HF communication coutermeasures. Some of the methods have been applied to a HF reconnoitering system and the result of the field is fairly well.

本文提出的技術(shù)路線和實(shí)現(xiàn)方法，不僅具有一定的理論意義国产精品老女人精品视频，而且在短波通信對(duì)抗中也具有重大的應(yīng)用價(jià)值一级涉黄，其中的部分算法已應(yīng)用于某短波通信偵察系統(tǒng)中，取得了較好的效果免看一级a一片日韩A片。

In our experiments, the hafnium films were deposited on molybdenum substrates by radio frequency magnetron sputtering technology, and the barium oxide layers were prepared by the chemical method to simulate the grid structure of traveling wave tubes. Then, the surface phase and compositional change in the grid was studied under high temperature by annealing from 900K to BOOK, which can be used in explaining the suppression mechanism of hafnium film.

實(shí)驗(yàn)中先锋影音每日AV资源站，利用射頻磁控濺射技術(shù)在Mo基底上制備了Hf膜，并利用化學(xué)方法制備了BaO涂層以模擬行波管柵極結(jié)構(gòu)日韩黄色视频品爱，隨后在N_2保護(hù)下很污很黄的视频网站，通過(guò)在900K到1300K范圍內(nèi)退火，研究柵極處于高溫工作環(huán)境下表面相結(jié)構(gòu)和成分的變化18禁片免费网站在线看，以此解釋了Hf薄膜抑制柵極電子發(fā)射的工作機(jī)理人人操亚洲综合。