課程設(shè)計(jì)基于MATLAB的語(yǔ)音信號(hào)分析與處理的課程設(shè)計(jì)實(shí)驗(yàn)報(bào)告

1、目 錄緒論1正文：一、設(shè)計(jì)目的及要求2二、設(shè)計(jì)過(guò)程2三、調(diào)試分析6四、結(jié)果分析與體會(huì)11五、參考文獻(xiàn)12六、謝辭12緒 論數(shù)字信號(hào)處理（digital signal processing,dsp）是從20世紀(jì)60年代以來(lái)，隨著信息學(xué)科和計(jì)算機(jī)學(xué)科的高速發(fā)展而迅速發(fā)展起來(lái)的一門新興學(xué)科。它的重要性日益在各個(gè)領(lǐng)域的應(yīng)用中表現(xiàn)出來(lái)。簡(jiǎn)言之，數(shù)字信號(hào)處理是把信號(hào)用數(shù)字或符號(hào)表示的序列，通過(guò)計(jì)算機(jī)或通用（專用）信號(hào)處理設(shè)備，用數(shù)字的數(shù)值計(jì)算方法處理（例如濾波、變換、壓縮、增強(qiáng)、估計(jì)、識(shí)別等），以達(dá)到提取有用信息便于應(yīng)用的目的。數(shù)字信號(hào)處理的應(yīng)用包括濾波與變換、通信、語(yǔ)音、語(yǔ)言、圖像、圖形、消費(fèi)電子、儀器

2、、工業(yè)控制與自動(dòng)化、醫(yī)療、軍事等。其發(fā)展方向也是多方面的，包括數(shù)字匯聚、遠(yuǎn)程會(huì)議系統(tǒng)、融合網(wǎng)絡(luò)、數(shù)字圖書館、圖像與文本合一的信息檢索業(yè)務(wù)、多媒體通信、個(gè)人信息終端等。在本次設(shè)計(jì)中，就以設(shè)計(jì)一個(gè)數(shù)字濾波器系統(tǒng)為目的。濾波器按頻率劃分有低通、高通、帶通、帶阻全通等類型。一個(gè)數(shù)字濾波器可以用一個(gè)系統(tǒng)函數(shù)來(lái)表示，若要得到該系統(tǒng)函數(shù)，就要得到以z(-1)升冪排列的傳輸函數(shù)的分子和分母多項(xiàng)式的系數(shù)，即向量num、den，而這兩個(gè)參數(shù)由num den=butter(n,wn)、n,wn=buttord(wp,ws,rp,rs)這一函數(shù)得出，這是巴特沃思濾波器的設(shè)計(jì)過(guò)程。由于頻率響應(yīng)的周期性，頻率變量以數(shù)字頻

3、率來(lái)表示，=2*f/fc，f為模擬域頻率，fc為抽樣頻率，所以數(shù)字濾波器設(shè)計(jì)中必須給出抽樣頻率。在這次設(shè)計(jì)中采用了巴特沃思和切比雪夫兩種濾波器，這兩種濾波器又分別采用了高通、低通、帶通、帶阻四種頻率特性實(shí)現(xiàn)，從橫向上和縱向上都可以進(jìn)行對(duì)比，表現(xiàn)出各種濾波器的不同特性。 一、設(shè)計(jì)目的及要求1課程設(shè)計(jì)目的 綜合運(yùn)用數(shù)字信號(hào)處理的理論知識(shí)進(jìn)行頻譜分析和濾波器設(shè)計(jì)，通過(guò)理論推導(dǎo)得出相應(yīng)結(jié)論，再利用 matlab 作為編程工具進(jìn)行計(jì)算機(jī)實(shí)現(xiàn)，從而加深對(duì)所學(xué)知識(shí)的理解，建立概念。2課程設(shè)計(jì)基本要求 1） 學(xué)會(huì) matlab 的使用，掌握 matlab 的程序設(shè)計(jì)方法。 2） 掌握在 windows 環(huán)境下

4、語(yǔ)音信號(hào)采集的方法。 3） 掌握數(shù)字信號(hào)處理的基本概念、基本理論和基本方法。 4） 掌握 matlab 設(shè)計(jì) fir 和iir 數(shù)字濾波器的方法。 5） 學(xué)會(huì)用 matlab 對(duì)信號(hào)進(jìn)行分析和處理。3課程設(shè)計(jì)內(nèi)容錄制一段自己的語(yǔ)音信號(hào)，并對(duì)錄制的信號(hào)進(jìn)行采樣；畫出采樣后語(yǔ)音信號(hào)的時(shí)域波形和頻譜圖；給定濾波器的性能指標(biāo)，設(shè)計(jì)數(shù)字濾波器，并畫出濾波器的頻率響應(yīng)；然后用自己設(shè)計(jì)的濾波器對(duì)采集的語(yǔ)音信號(hào)進(jìn)行濾波，畫出濾波后信號(hào)的時(shí)域波形和頻譜，并對(duì)濾波前后的信號(hào)進(jìn)行對(duì)比，分析信號(hào)的變化；回放語(yǔ)音信號(hào)；最后，用 matlab 設(shè)計(jì)一信號(hào)處理系統(tǒng)界面。二、設(shè)計(jì)過(guò)程1、 打開(kāi)gui窗口：file new g

5、ui create new gui blank gui(default) ok2、 控件設(shè)計(jì)：在控件布局設(shè)計(jì)區(qū)放置四個(gè)axes控件、六個(gè)push button控件、一個(gè)button group控件和兩個(gè)radio button控件、四個(gè)static text控件。3、 修改控件屬性：選中需要修改屬性的控件，雙擊打開(kāi)屬性查看器，具體設(shè)置如下：1) 五個(gè)axes控件 tag作用axes1提供坐標(biāo)畫出原始信號(hào)波形axes2提供坐標(biāo)畫出原始信號(hào)頻譜axes3提供坐標(biāo)畫出濾波后信號(hào)波形axes4提供坐標(biāo)畫出濾波后信號(hào)頻譜axes5提供坐標(biāo)畫出濾波器頻率響應(yīng)2) 六個(gè)push button控件：strin

6、gtagstringtag低通pushbutton1帶阻pushbutton4高通pushbutton2原始信號(hào)pushbutton5帶通pushbutton3關(guān)閉窗口pushbutton63) 一個(gè)button group控件和兩個(gè)radio button控件： stringstyletag請(qǐng)選擇濾波器種類button groupuipanel5巴特沃思radio buttonradiobutton1切比雪夫radio buttonradiobutton24) 五個(gè)static text控件（這五個(gè)static text控件是對(duì)坐標(biāo)軸中圖形的說(shuō)明）：tagstringtext1原始信號(hào)波形t

7、ext2原始信號(hào)頻譜text3濾波后信號(hào)波形text4濾波后信號(hào)頻譜text5濾波器頻率響應(yīng)4、 保存：設(shè)置好各個(gè)控件的屬性，回到gui主窗口保存，給文件命名為hy，同時(shí)hy.m文件打開(kāi)。5、 設(shè)置回調(diào)函數(shù)：在hy.m文件窗口中設(shè)置回函數(shù)。這里，雖然gui自動(dòng)生成了回調(diào)函數(shù)，但是回調(diào)函數(shù)是空的，需要在hy.m文件中對(duì)它進(jìn)行定義說(shuō)明。該程序只需要對(duì)六個(gè)push button控件的回調(diào)函數(shù)進(jìn)行定義說(shuō)明。六個(gè)push button控件的回調(diào)函數(shù)：1）“低通”按鍵的回調(diào)函數(shù)function pushbutton1_callback(hobject, eventdata, handles)y,fs,bi

8、ts=wavread(e:hy.wav); %函數(shù)wavread是對(duì)語(yǔ)音信號(hào)進(jìn)行 采樣，格式是y,fs,nbit=wavread，返回采樣值放在向量y中，fs表示采樣頻率（hz），nbit表示采樣位數(shù)。fp=1000;fs=2000;rp=0.5;rs=40;fc=40000;%設(shè)定通帶截止頻率（fp）、阻帶截止頻率（fs）、通帶波紋系數(shù)（rp）、阻帶波紋系數(shù)（rs）、抽樣頻率（fc）。wp=2*fp/fc;ws=2*fs/fc; %將模擬域轉(zhuǎn)化成數(shù)字域。if get(handles.radiobutton1,value) %如果選擇radiobutton1，則制做巴特沃思濾波器。n,wc=b

9、uttord(wp,ws,rp,rs); %估算巴特沃思濾波器的階數(shù)n和3db截止頻率wc。num,den=butter(n,wc); %求傳輸函數(shù)的分子和分母多項(xiàng)式的系數(shù)。else %選擇radiobutton2，則制做切比雪夫型濾波器。n,wc=cheb1ord(wp,ws,rp,rs); %估算切比雪夫型濾波器的階數(shù)n和截止頻率wc。num,den=cheby1(n,rp,wc); %求傳輸函數(shù)的分子和分母多項(xiàng)式的系數(shù)。endx=filter(num,den,y); %根據(jù)傳輸函數(shù)的分子和分母多項(xiàng)式的系數(shù)得到模擬濾波器，并將y通過(guò)該濾波器，得到x。sound(x,fc,bits); %將

10、濾波后的信號(hào)x進(jìn)行回放。x=fft(x); %將x信號(hào)進(jìn)行快速傅里葉變換。axes(handles.axes3);plot(x); %在axes3坐標(biāo)軸上畫出x信號(hào)的波形圖。axes(handles.axes4);plot(abs(x); %在axes4坐標(biāo)軸上畫出x信號(hào)的頻譜圖。h,f=freqz(num,den,256,fc); %求濾波器的頻率響應(yīng)。axes(handles.axes5);plot(f,abs(h),k); %在axes5坐標(biāo)軸上以黑線畫出濾波器的頻率響應(yīng)。2）“高通”按鍵的回調(diào)函數(shù)function pushbutton2_callback(hobject, eventd

11、ata, handles)y,fs,bits=wavread(e:hy.wav);fp=2000;fs=1000;rp=0.5;rs=40;fc=40000;wp=2*fp/fc;ws=2*fs/fc;if get(handles.radiobutton1,value)n,wc=buttord(wp,ws,rp,rs);num,den=butter(n,wc,high); %返回n階高通濾波器。else n,wc=cheb1ord(wp,ws,rp,rs);num,den=cheby1(n,rp,wc,high);endx=filter(num,den,y);sound(x,fc,bits);

12、x=fft(x);axes(handles.axes3);plot(x);axes(handles.axes4);plot(abs(x);h,f=freqz(num,den,256,fc);axes(handles.axes5);plot(f,abs(h),k);3）“帶通”按鍵的回調(diào)函數(shù)function pushbutton3_callback(hobject, eventdata, handles)y,fs,bits=wavread(e:hy.wav);fp=3000,8000;fs=1000,10000;rp=0.5;rs=40;fc=40000;wp=2*fp/fc;ws=2*fs/f

13、c;if get(handles.radiobutton1,value)n,wc=buttord(wp,ws,rp,rs);num,den=butter(n,wc); %wc為雙元素向量，返回2n階帶通濾波器。else n,wc=cheb1ord(wp,ws,rp,rs);num,den=cheby1(n,rp,wc);endx=filter(num,den,y);sound(x,fc,bits);x=fft(x);axes(handles.axes3);plot(x);axes(handles.axes4);plot(abs(x);h,f=freqz(num,den,256,fc);axes

14、(handles.axes5);plot(f,abs(h),k);4）“帶阻”按鍵的回調(diào)函數(shù)function pushbutton4_callback(hobject, eventdata, handles)y,fs,bits=wavread(e:hy.wav);fp=1000,10000;fs=3000,8000;rp=0.5;rs=40;fc=40000;wp=2*fp/fc;ws=2*fs/fc;if get(handles.radiobutton1,value)n,wc=buttord(wp,ws,rp,rs);num,den=butter(n,wc,stop); %返回2n階帶阻濾波

15、器。else n,wc=cheb1ord(wp,ws,rp,rs);num,den=cheby1(n,rp,wc,stop);endx=filter(num,den,y);sound(x,fc,bits);x=fft(x);axes(handles.axes3);plot(x);axes(handles.axes4);plot(abs(x);h,f=freqz(num,den,256,fc);axes(handles.axes5);plot(f,abs(h),k);5）“原始信號(hào)”按鍵的回調(diào)函數(shù)function pushbutton5_callback(hobject, eventdata,

16、handles)y,fs,bits=wavread(e:hy.wav);sound(y,fs,bits);y=fft(y);axes(handles.axes1);plot(y);axes(handles.axes2);plot(abs(y);6）“關(guān)閉窗口”按鍵的回調(diào)函數(shù)function pushbutton6_callback(hobject, eventdata, handles)close6、 保存修改后的hy.m文件，單擊gui主窗口工具欄中的“激活運(yùn)行”按鈕，在gui界面中按下“原始信號(hào)”按鍵就可以看到原始信號(hào)的波形和頻譜，并播放原始信號(hào)；選擇濾波器種類（巴特沃思或切比雪夫），然后

17、按下“高通”、“低通”、“帶通”、“帶阻”其中一個(gè)按鍵，就可以看到原信號(hào)經(jīng)過(guò)濾波器后的信號(hào)的波形與頻譜，并播放該信號(hào)。三、調(diào)試分析圖1 控件布局圖2 單擊“激活運(yùn)行”后界面圖3 巴特沃思高通濾波器圖4 切比雪夫高通濾波器圖5 巴特沃思低通濾波器圖6 切比雪夫低通濾波器 圖7 巴特沃思帶通濾波器 圖8 切比雪夫帶通濾波器 圖9 巴特沃思帶阻濾波器圖10 切比雪夫帶阻濾波器圖3圖10為巴特沃思和切比雪夫型濾波器在不同頻率特性下產(chǎn)生的信號(hào)波形與頻譜，同時(shí)有原信號(hào)作對(duì)比。可以看出，巴特沃思濾波器的頻率特性曲線無(wú)論在通帶還是在阻帶內(nèi)，都是頻率的單調(diào)函數(shù)，切比雪夫型濾波器的幅頻特性在通帶內(nèi)是等波紋的，阻帶

18、內(nèi)是單調(diào)的。因?yàn)樵诨卣{(diào)函數(shù)中，高通和低通、帶通和帶阻濾波器的截止頻率、波紋系數(shù)、抽樣頻率設(shè)定的值是相同的，所以在下圖中縱向?qū)Ρ瓤梢钥闯?，信?hào)通過(guò)高通和低通濾波器之后頻譜相對(duì)于原信號(hào)是互補(bǔ)的，如果對(duì)于高通濾波器在某一頻率段上有幅值，那么對(duì)于低通濾波器該頻率幅值為零。同理于帶通和帶阻濾波器。橫向上對(duì)比可以看出不同濾波器選頻特性也不同，特別是在圖7圖10中選頻邊界處的頻譜處理可以看出，切比雪夫?yàn)V波器比巴特沃思濾波器的選頻特性好。四、結(jié)果分析與體會(huì)濾波器的作用就是濾除掉阻帶內(nèi)有頻率分量，保留通帶內(nèi)的頻率分量。在圖3圖10的波形圖和頻譜圖中可以看出，經(jīng)過(guò)濾波器處理后，不僅濾除掉了原信號(hào)的部分頻率分量，原

19、信號(hào)的幅度也會(huì)有所衰減，而低通和帶阻濾波器產(chǎn)生的信號(hào)相對(duì)于原信號(hào)變化不大，是因?yàn)樵O(shè)定的選頻范圍是原信號(hào)的頻率段中較集中的部分，所以與此同時(shí)，高通和帶通濾波器產(chǎn)生的信號(hào)相對(duì)于原信號(hào)的幅度就會(huì)大大衰減，其原因也是在于高通和帶通濾波器的選頻范圍是原信號(hào)頻率范圍中較少的一部分。在信號(hào)回放時(shí)，低通和帶阻濾波器回放的音頻信號(hào)與原信號(hào)相比，音色有一點(diǎn)低沉；而高通和帶通濾波器回放的音頻信號(hào)，幾乎已經(jīng)聽(tīng)不到什么聲音，這也說(shuō)明了這兩種濾波器產(chǎn)生的信號(hào)頻率只占原信號(hào)頻率范圍中較少的部分。所以根據(jù)各個(gè)濾波器的選頻范圍及濾波后信號(hào)的音效，可大致判斷原信號(hào)的頻率多集中在1000hz以下。通過(guò)這次課設(shè)，使我對(duì)濾波器有了更深

20、的認(rèn)識(shí)，特別是濾波器參數(shù)對(duì)濾波器性能的影響，因?yàn)橥◣Ы刂诡l率、阻帶截止頻率、通帶波紋系數(shù)、阻帶波紋系數(shù)都是要影響濾波器的階數(shù)，而濾波器的階數(shù)越大，其選頻特性就越好。因?yàn)闉V波器處理的音頻信號(hào)是我自己的聲音，所以通過(guò)濾波器處理后音頻信號(hào)的變化，能大致得出自己聲音的頻率范圍，也是挺有意思的。在做課程設(shè)計(jì)之前覺(jué)得內(nèi)容挺難的，但經(jīng)過(guò)查閱圖書館的資料和同學(xué)們的努力與幫助，最后還是以比較短的時(shí)間完成了這次課程設(shè)計(jì)。以前學(xué)matlab的時(shí)候，最后的大作業(yè)也是用gui設(shè)計(jì)了一個(gè)可視化界面，所以在本次設(shè)計(jì)中可視化界面的設(shè)計(jì)也沒(méi)有覺(jué)得很難。但是看到其他同學(xué)有用到edit text控件來(lái)作濾波器參數(shù)的輸入，感覺(jué)到自己

21、的能力還是很有限，所以還需要加強(qiáng)學(xué)習(xí)。但最重要的還是感覺(jué)到通過(guò)課程設(shè)計(jì)能夠?qū)W以致用，并且運(yùn)用以前學(xué)過(guò)的工具來(lái)更好的理解所學(xué)的內(nèi)容，收獲還是挺大的。五、參考文獻(xiàn)程佩青 數(shù)字信號(hào)處理教程（第三版） 清華大學(xué)出版社羅軍輝、羅勇江、白義臣等 matlab7.0在數(shù)字信號(hào)處理中的應(yīng)用 機(jī)械工業(yè)出版社劉波、文忠、曾涯等 matlab信號(hào)處理 電子工業(yè)出版社六、謝辭在本次設(shè)計(jì)中，借閱了圖書館的一些書籍，比自己的幫助比較大，同學(xué)間的相互討論與幫助也起到了很重要的作用。此外還要特別感謝指導(dǎo)老師耐心的輔導(dǎo)，并幫助我糾正錯(cuò)誤，授予以魚，亦之以漁，使我不僅能夠按時(shí)完成課程設(shè)計(jì)，也從中對(duì)本課程有了更深的認(rèn)識(shí)與理解，同時(shí)

22、也注意到自己在學(xué)習(xí)方法中的不足，并會(huì)在日后加以改正。g an employment tribunal claimemployment tribunals sort out disagreements between employers and employees.you may need to make a claim to an employment tribunal if: you dont agree with the disciplinary action your employer has taken against you your employer dismisses you a

23、nd you think that you have been dismissed unfairly.for more information about dismissal and unfair dismissal, seedismissal.you can make a claim to an employment tribunal, even if you haventappealedagainst the disciplinary action your employer has taken against you. however, if you win your case, the

24、 tribunal may reduce any compensation awarded to you as a result of your failure to appeal.remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are complaining about happened. if your application is received after this

25、time limit, the tribunal will not usually accept it.if you are worried about how the time limits apply to you, take advice from one of the organisations listed underfurther help.employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evi

26、dence under an oath or affirmation.most people find making a claim to an employment tribunal challenging. if you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the organisations listed underfurther help.if you are being represented by a sol

27、icitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your compensation if you win the case. this is known as adamages-based agreement. in england and wales, your solicitor cant charge you more than 35% of your compensation if you win the case.if you are thinki

28、ng about signing up for a damages-based agreement, you should make sure youre clear about the terms of the agreement. it might be best to get advice from an experienced adviser, for example, at a citizens advice bureau. to find your nearest cab, including those that give advice by e-mail, click onne

29、arest cab.for more information about making a claim to an employment tribunal, seeemployment tribunals.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskforce, is in london for the football associations 150th anniversary celebrations and will attend citys

30、 premier league match at chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the

31、 racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said they were surprised and disappointed by toures complaint. in a statement the russian side added: we foun

32、d no racist insults from fans of cska.age has reached the end of the beginning of a word. may be guilty in his seems to passing a lot of different life became the appearance of the same day; may be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been v

33、ery messy, in my mind constantly. always feel oneself should go to do something, or write something. twenty years of life trajectory deeply shallow, suddenly feel something, do it.一字開(kāi)頭的年齡已經(jīng)到了尾聲?；蛟S是愧疚于自己似乎把轉(zhuǎn)瞬即逝的很多個(gè)不同的日子過(guò)成了同一天的樣子；或許是追溯過(guò)去，對(duì)自己那些近乎偏執(zhí)的怪異信念的醒悟，這些天以來(lái)，思緒一直很凌亂，在腦海中不斷糾纏?？傆X(jué)得自己自己似乎應(yīng)該去做點(diǎn)什么，或者寫點(diǎn)什么

34、。二十年的人生軌跡深深淺淺，突然就感覺(jué)到有些事情，非做不可了。the end of our life, and can meet many things really do?而窮盡我們的一生，又能遇到多少事情是真正地非做不可？during my childhood, think lucky money and new clothes are necessary for new year, but as the advance of the age, will be more and more found that those things are optional; junior high s

35、chool, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isnt really grow up, it seems is not so important; then in high school, think dont want to give vent to out your inner voice can be in the high

36、school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already cant remember his appearance.童年時(shí)，覺(jué)得壓歲錢和新衣服是過(guò)年必備，但是隨著年齡的推進(jìn)

37、，會(huì)越來(lái)越發(fā)現(xiàn)，那些東西根本就可有可無(wú)；初中時(shí)，以為要有一場(chǎng)暗戀才意味著真正的成長(zhǎng)，但三年過(guò)去后，自己心平氣和的寫同學(xué)錄的時(shí)候，突然就發(fā)現(xiàn)是不是真正的成長(zhǎng)了，好像并沒(méi)有那么重要了；然后到了高中，覺(jué)得非要吐露出自己的心聲才能為高中生涯里的懵懂情愫劃上一個(gè)句點(diǎn)，但畢業(yè)晚會(huì)的時(shí)候最終還是被梗塞在了咽喉，后來(lái)再次站在他曾經(jīng)揮汗如雨的球場(chǎng)，看著他投過(guò)籃球的球框時(shí)，突然間發(fā)現(xiàn)自己已經(jīng)想不起他的容顏。originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to d

38、o, and time.原來(lái)，這個(gè)世界上，對(duì)某個(gè)事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅(jiān)決，還有，時(shí)間。a persons time, your ideas are always special to clear. want, want, line is clear, as if nothing could shake his. also once seemed to be determined to do something, but more often is he backed out at last. dislike his cowardice, finally found that t

39、here are a lot of love, there are a lot of miss, like shadow really have been doomed. those who do, just green years oneself give oneself an arm injection, or is a self-righteous spiritual.一個(gè)人的時(shí)候，自己的想法總是特別地清晰。想要的，不想要的，界限明確，好像沒(méi)有什么可以撼動(dòng)自己。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時(shí)候是最后又打起了退堂鼓。嫌惡過(guò)自己的怯懦，最終卻發(fā)現(xiàn)有很多緣分，有很多錯(cuò)過(guò)，好像冥

40、冥之中真的已經(jīng)注定。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說(shuō)，是自以為是的精神寄托罷了。at the moment, the sky is dark, the air is fresh factor after just rained. suddenly thought of blue plaid shirt; those were broken into various shapes of stationery; from the corner at the beginning of deep friendship; have declared the end

41、 of the encounter that havent start planning. those years, those days of do, finally, like youth, will end in our life.此刻，天空是陰暗的，空氣里有著剛下過(guò)雨之后的清新因子。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還有那場(chǎng)還沒(méi)有開(kāi)始就宣告了終結(jié)的邂逅計(jì)劃那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。baumgartner the disappointing news: mission aborted. r plays a

42、n important role in this mission. starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day

43、 weather lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the supersonic descent could happen as early as s