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1、<p><b> 摘 要</b></p><p> 用MATLAB對(duì)于語(yǔ)音信號(hào)進(jìn)行分析和處理,采集語(yǔ)音信號(hào)后,在MATLAB軟件平臺(tái)進(jìn)行頻譜分析;并對(duì)所采集的語(yǔ)音信號(hào)加入干擾噪聲,對(duì)加入噪聲的信號(hào)進(jìn)行頻譜分析,設(shè)計(jì)合適的濾波器濾除噪聲,恢復(fù)原信號(hào)。本次設(shè)計(jì)介紹了基于MATLAB的對(duì)語(yǔ)音信號(hào)的采集,處理及濾波器的設(shè)計(jì),并使之實(shí)現(xiàn)的過(guò)程。</p><p>
2、 關(guān)鍵詞:MATLAB;語(yǔ)音信號(hào);濾波器;加噪;除噪</p><p><b> 目 錄</b></p><p><b> 摘要1</b></p><p><b> 1 設(shè)計(jì)原理1</b></p><p> 1.1 理論原理1</p><p
3、> 1.1.1采樣頻率1</p><p> 1.1.2采樣位數(shù)1</p><p> 1.1.3采樣定理1</p><p> 1.1.4時(shí)域信號(hào)的FFT分析2</p><p> 1.1.5數(shù)字信號(hào)的濾波器原理和方法2</p><p> 1.1.6 各種不同類型濾波器的性能比較3</p
4、><p> 1.1.7離散傅立葉變換3</p><p> 2 信號(hào)采集及讀取4</p><p> 3 構(gòu)造受干擾信號(hào)并對(duì)其進(jìn)行FFT頻譜分析........................…...6</p><p> 4 數(shù)字濾波器設(shè)計(jì)8</p><p> 4.1 用窗函數(shù)法設(shè)計(jì)IIR帶通濾波器8&
5、lt;/p><p> 4.2 用窗函數(shù)法設(shè)計(jì)FIR低通濾波器10</p><p><b> 5信號(hào)處理12</b></p><p> 5.1 IIR帶通濾波12</p><p> 5.2 FIR低通濾波14</p><p><b> 6心得體會(huì)16</b>&l
6、t;/p><p> 7 參考文獻(xiàn):16</p><p><b> 1設(shè)計(jì)原理</b></p><p><b> 1.1 理論原理</b></p><p> 1.1.1采樣頻率</p><p> 也稱為采樣速度或者采樣率,定義了每秒從連續(xù)信號(hào)中提取并組成離散信號(hào)的采樣
7、個(gè)數(shù),它用赫茲(Hz)來(lái)表示。采樣頻率只能用于周期性采樣的采樣器,對(duì)于非周期性采樣的采樣器沒(méi)有規(guī)則限制。通俗的講采樣頻率是指計(jì)算機(jī)每秒鐘采集多少個(gè)聲音樣本,是描述聲音文件的音質(zhì)、音調(diào),衡量聲卡、聲音文件的質(zhì)量標(biāo)準(zhǔn)。采樣頻率越高,即采樣的間隔時(shí)間越短,則在單位時(shí)間內(nèi)計(jì)算機(jī)得到的聲音樣本數(shù)據(jù)就越多,對(duì)聲音波形的表示也越精確。</p><p><b> 1.1.2采樣位數(shù)</b></p&g
8、t;<p> 即采樣值或取樣值,用來(lái)衡量聲音波動(dòng)變化的參數(shù),是指聲卡在采集和播放聲音文件時(shí)所使用數(shù)字聲音信號(hào)的二進(jìn)制位數(shù)。</p><p><b> 1.1.3采樣定理</b></p><p> 在進(jìn)行模擬/數(shù)字信號(hào)的轉(zhuǎn)換過(guò)程中,當(dāng)采樣頻率fs.max大于信號(hào)中最高頻率fmax的2倍時(shí)(fs.max>=2fmax),采樣之后的數(shù)字信號(hào)完整地保
9、留了原始信號(hào)中的信息,一般實(shí)際應(yīng)用中保證采樣頻率為信號(hào)最高頻率的5~10倍;采樣定理又稱奈奎斯特定理。</p><p> 1.1.4時(shí)域信號(hào)的FFT分析</p><p> 信號(hào)的頻譜分析就是計(jì)算信號(hào)的傅立葉變換。連續(xù)信號(hào)與系統(tǒng)的傅立葉分析顯然不便于用計(jì)算機(jī)進(jìn)行計(jì)算,使其應(yīng)用受到限制。而FFT是一種時(shí)域和頻域均離散化的變換,適合數(shù)值運(yùn)算,成為用計(jì)算機(jī)分析離散信號(hào)和系統(tǒng)的有力工具。對(duì)連續(xù)信
10、號(hào)和系統(tǒng),可以通過(guò)時(shí)域采樣,應(yīng)用DFT進(jìn)行近似譜分析。</p><p> 1.1.5數(shù)字信號(hào)的濾波器原理和方法</p><p> IIR數(shù)字濾波器系統(tǒng)函數(shù):</p><p> H(z)=··············
11、3;·(1.1)</p><p> 其中H(z)稱為N階IIR數(shù)字濾波器系統(tǒng)函數(shù)。IIR濾波器設(shè)計(jì)方法有間接和直接法,間接法是借助于模擬濾波器的設(shè)計(jì)方法進(jìn)行的。其步驟是:先設(shè)計(jì)過(guò)度模擬濾波器得到系統(tǒng)函數(shù)Ha(s),然后將Ha(s)按某種方法轉(zhuǎn)換成數(shù)字濾波器的系統(tǒng)函數(shù)H(z)。</p><p> 利用有限脈沖響應(yīng)(FIR)設(shè)計(jì)濾波器。有限脈沖響應(yīng)濾波器在保證幅度特性滿足技術(shù)要求
12、的同時(shí),很容易做到有嚴(yán)格的線性相位特性。用N表示FIR濾波器單位脈沖響應(yīng)h(n)的長(zhǎng)度,其系統(tǒng)函數(shù)H(z)為</p><p> ··················(1.2)</p><p> H(z)是z-
13、1的N-1次多項(xiàng)式,它在z平面上有N-1個(gè)零點(diǎn),在原點(diǎn)z=0處有一個(gè)N-1重極點(diǎn)。因此,H(z)永遠(yuǎn)穩(wěn)定。穩(wěn)定和線性相位是FIR濾波器最突出的優(yōu)點(diǎn)。</p><p> 1.1.6 各種不同類型濾波器的性能比較</p><p> 巴特沃斯濾波器具有單調(diào)下降的幅頻特性;切比雪夫?yàn)V波器的幅頻特性在通帶或阻帶有波紋特性,可以提高選擇性;貝塞爾濾波器通帶內(nèi)有較好的線性相位特性;橢圓濾波器的選擇性
14、相對(duì)前三種是最好的,但通帶和阻帶內(nèi)均呈現(xiàn)等波紋幅頻特性,線性特性的非線性稍重。</p><p> IIR數(shù)字濾波器最大的優(yōu)點(diǎn)是給定一組指標(biāo)時(shí),它的階數(shù)要比相同組的FIR濾波器低得多。IIR數(shù)字濾波器的設(shè)計(jì)方法是利用模擬濾波器成熟的理論及設(shè)計(jì)圖進(jìn)行的,因而保留了一些典型模擬濾波器優(yōu)良的幅度特性。但設(shè)計(jì)中只考慮了幅度特性,沒(méi)考慮相位特性,所設(shè)計(jì)的濾波器一般是某種確定的非線性相位特性。為了得到線性相位特性,對(duì)IIR濾
15、波器必須另外增加相位校正網(wǎng)絡(luò)。FIR濾波器在保證幅度特性滿足技術(shù)要求的同時(shí),很容易做到有嚴(yán)格的線性相位特性。穩(wěn)定和線性相位是FIR濾波器最突出的優(yōu)點(diǎn)。</p><p> 1.1.7離散傅立葉變換</p><p><b> 1.3</b></p><p> 其中,N為DFT變換的區(qū)間長(zhǎng)度。</p><p> 2
16、信號(hào)采集及讀取</p><p> 用錄音工具錄一段自己的聲音,轉(zhuǎn)化為wav格式的文件,然后保存到MATLAB的文件夾下的work文件夾中。在MATLAB軟件平臺(tái)下,利用wavread函數(shù)對(duì)語(yǔ)音信號(hào)進(jìn)行采樣,記住采樣頻率和采樣點(diǎn)數(shù)。</p><p> Wavread函數(shù)調(diào)用格式:</p><p> y=wavread(file),讀取file所規(guī)定的wav文件,
17、返回采樣值放在向量y中。</p><p> [y,fs,nbits]=wavread(‘1.wav’);把語(yǔ)音信號(hào)進(jìn)行載MATLAB仿真軟件平臺(tái)中,采樣值放在向量y中,fs表示采樣頻率(hz),nbits表示采樣位數(shù)。</p><p> sound(y,fs,nbits);回放語(yǔ)音信號(hào)</p><p> N=length(y);求出語(yǔ)音信號(hào)的長(zhǎng)度</p&
18、gt;<p> Y=fft(y,N);傅立葉變換</p><p> 調(diào)用函數(shù)y為被變換的時(shí)域系列向量,N是DFT變換區(qū)間長(zhǎng)度,當(dāng)N大于y的長(zhǎng)度時(shí),fft函數(shù)自動(dòng)在y后面補(bǔ)零,函數(shù)返回y的N點(diǎn)DFT變換結(jié)果向量Y。當(dāng)N小于y的長(zhǎng)度時(shí),fft函數(shù)計(jì)算y的前面N個(gè)元素構(gòu)成的N點(diǎn)DFT,忽略y后面的元素。首先畫出語(yǔ)音信號(hào)的時(shí)域波形,然后對(duì)語(yǔ)音信號(hào)進(jìn)行頻譜分析。在MATLAB中利用fft對(duì)新號(hào)進(jìn)行快速傅立
19、葉變換,得到信號(hào)的頻譜特性。</p><p> subplot(2,1,1);plot(y);title(‘原始信號(hào)波形’);</p><p> subplot(2,1,2);plot(abs(Y));title(‘原始信號(hào)頻譜’);</p><p><b> 程序如下:</b></p><p> [y,fs,n
20、bits]=wavread('1.wav');</p><p> sound(y,fs,nbits);</p><p> N=length(y);</p><p> Y=fft(y,N);</p><p> subplot(2,1,1);</p><p><b> plot(y);&
21、lt;/b></p><p> title('原始信號(hào)波形');xlabel('時(shí)間');ylabel('幅度');</p><p> subplot(2,1,2);</p><p> plot(abs(Y));</p><p> title('原始信號(hào)頻譜');x
22、label('時(shí)間');ylabel('幅度');</p><p><b> 程序結(jié)果如下圖:</b></p><p><b> 程序如下:</b></p><p> [y,fs,nbits]=wavread ('1.wav');</p><p>
23、; N = length (y) ; %求出語(yǔ)音信號(hào)的長(zhǎng)度</p><p> noise=0.2*randn(N,1); %隨機(jī)函數(shù)產(chǎn)生噪聲</p><p> Si=y+noise; %語(yǔ)音信號(hào)加入噪聲 </p><p> sound(Si);</p>
24、<p> subplot(2,1,1);</p><p><b> plot(Si);</b></p><p> title('加噪語(yǔ)音信號(hào)的時(shí)域波形');xlabel('時(shí)間');ylabel('幅度');</p><p> S=fft(Si);
25、 %傅里葉變換</p><p> subplot(2,1,2);</p><p> plot(abs(S)); </p><p> title('加噪語(yǔ)音信號(hào)的頻域波形'); xlabel('時(shí)間');ylabel('幅度');</p><p><b>
26、程序結(jié)果如下圖:</b></p><p><b> 4 數(shù)字濾波器設(shè)計(jì)</b></p><p> 4.1 用窗函數(shù)法設(shè)計(jì)IIR帶通濾波器</p><p><b> 程序如下:</b></p><p> wp=0.2*pi; ws=0.3*pi; %性能指標(biāo)</p>
27、;<p> wdelta=ws-wp; %過(guò)渡帶寬度</p><p> M=ceil(3.32*pi/wdelta); %濾波器長(zhǎng)度,朝正無(wú)窮方向舍入</p><p> N=2*M+1; %窗口長(zhǎng)度</p><p> wc=(ws+wp)/2; %截止頻率</p>
28、<p> win=hamming(N); %因?yàn)樗p不小于50dB,所以選擇海明窗,這里得到海明窗的時(shí)域響應(yīng)</p><p> b=fir1(N-1,wc/pi,win);</p><p><b> n=0:1:N;</b></p><p> [hi t]=impz(b,1,n);%得到脈沖響應(yīng)</p&
29、gt;<p> [hf w]=freqz(b,1,512); %得到頻率響應(yīng)</p><p> subplot(3,1,1); stem(n,hi);</p><p> xlabel('n'); ylabel('幅度'); title('脈沖響應(yīng)');</p><p> subplot(3,1,
30、2); plot(w/pi,20*log10(abs(hf)));</p><p> xlabel('頻率(Hz)'); ylabel('幅度(dB)');</p><p> title('頻率響應(yīng)');</p><p> subplot(3,1,3); plot(w/pi,180/pi*unwrap(angle
31、(hf)));</p><p> xlabel('頻率(Hz)'); ylabel('相位(degrees)');</p><p> title('頻率響應(yīng)');</p><p><b> 程序結(jié)果如下圖:</b></p><p> 4.2 用窗函數(shù)法設(shè)計(jì)FIR低通
32、濾波器</p><p><b> 程序如下:</b></p><p><b> Ft=8000;</b></p><p><b> Fp=1000;</b></p><p><b> Fs=1200;</b></p><p&
33、gt; wp=2*Fp/Ft;</p><p> ws=2*Fs/Ft;</p><p><b> rp=1;</b></p><p><b> rs=50;</b></p><p> p=1-10.^(-rp/20);</p><p> s=10.^(-rs/2
34、0);</p><p> fpts=[wp,ws];</p><p> mag=[1,0];</p><p> dev=[p,s];</p><p> [n21,wn21,beta,ftype]=kaiserord(fpts,mag,dev);</p><p> b21=fir1(n21,wn21,kaise
35、r(n21+1,beta));</p><p> [h,w]=freqz(b21,1);</p><p> plot(w/pi,abs(h));</p><p> title('FIR低通濾波器');</p><p><b> grid;</b></p><p><b
36、> 其程序結(jié)果如下圖:</b></p><p><b> 5信號(hào)處理</b></p><p> 用設(shè)計(jì)好的數(shù)字濾波器對(duì)含噪聲的語(yǔ)音信號(hào)進(jìn)行濾波,在MATLAB中FIR濾波器利用函數(shù)fftfilt對(duì)信號(hào)進(jìn)行濾波,IIR濾波器利用函數(shù)filter對(duì)信號(hào)進(jìn)行濾波,在一個(gè)窗口同時(shí)畫出濾波前后的波形及頻譜如下圖。</p><p>
37、 5.1 IIR帶通濾波</p><p><b> 程序如下:</b></p><p> [y,fs,nbits]=wavread('1.wav');</p><p> N=length(y);</p><p> Noise=0.2*randn(N,1);</p><p>
38、; Si=y+Noise; %語(yǔ)音信號(hào)加入噪聲 </p><p> nn=0:1:50;</p><p> y=filter(b,1,Si);</p><p> subplot(2,1,1); stem(Si);</p><p> xlabel('n'); ylabel('幅度'
39、;);</p><p> title('濾波前信號(hào)頻譜'); axis([0 50 -2 2]);</p><p> subplot(2,1,2); stem(out);</p><p> xlabel('n'); ylabel('幅度');</p><p> title('濾波
40、后信號(hào)頻譜'); axis([0 50 -1 1]);</p><p><b> sound(y);</b></p><p><b> 程序結(jié)果如下圖:</b></p><p> 5.2 FIR低通濾波</p><p><b> 程序如下:</b></p&
41、gt;<p> [y,fs,nbits]=wavread('1.wav');</p><p> N = length (y) ; </p><p> noise=0.2*randn(N,1); </p><p> Si=y+noise; </p><p>
42、 S=fft(Si);</p><p> z21=fftfilt(b21,Si);</p><p> sound(z21);</p><p> m21=fft(z21);</p><p> subplot(2,2,1);</p><p> plot(abs(S),'g');</p>
43、<p> title('濾波前信號(hào)的頻譜');xlabel('時(shí)間');ylabel('幅度');</p><p><b> grid;</b></p><p> subplot(2,2,2);</p><p> plot(abs(m21),'r');<
44、/p><p> title('濾波后信號(hào)頻譜');xlabel('時(shí)間');ylabel('幅度');</p><p><b> grid;</b></p><p> subplot(2,2,3);</p><p><b> plot(S);</b>
45、;</p><p> title('濾波前信號(hào)波形');xlabel('時(shí)間');ylabel('幅度');</p><p><b> grid;</b></p><p> subplot(2,2,4);</p><p> plot(z21);</p>
46、<p> title('濾波后信號(hào)波形');xlabel('時(shí)間');ylabel('幅度');</p><p><b> grid;</b></p><p><b> 程序結(jié)果如下圖:</b></p><p><b> 6心得體會(huì)</b&
47、gt;</p><p> 通過(guò)這次課程設(shè)計(jì),我學(xué)到了很多東西。進(jìn)一步加深了對(duì)MATLAB的了解。在設(shè)計(jì)的過(guò)程中我遇到了不少的問(wèn)題,比如剛開(kāi)始要處理的是WAV格式的語(yǔ)音信號(hào),可是我發(fā)現(xiàn)不是所有的WAV文件都可以用WAVREAD函數(shù)讀取,通過(guò)軟件轉(zhuǎn)化了才可以使用。在編寫程序的時(shí)候遇到了很多錯(cuò)誤,最后經(jīng)過(guò)查找一些資料和自己的理解都一一糾正了??偟膩?lái)說(shuō),通過(guò)這次的課程設(shè)計(jì)我對(duì)語(yǔ)音信號(hào)有的更多的認(rèn)識(shí),對(duì)數(shù)字信號(hào)處理的知識(shí)
48、有了更多的理解,鍛煉了我的理論與實(shí)際相結(jié)合的能力,并且熟練的應(yīng)用MATLAB也加深了我對(duì)課程的理解。這次設(shè)計(jì)使我更深刻的了解MATLAB的使用方法,同時(shí)我相信,進(jìn)一步加強(qiáng)對(duì)MATLAB的學(xué)習(xí)對(duì)我今后的學(xué)習(xí)將會(huì)起到很大的幫助。</p><p><b> 7 參考文獻(xiàn):</b></p><p> 高西全,丁玉美編著?!稊?shù)字信號(hào)處理》西安,西安電子科技大學(xué)出版社,200
49、8</p><p> 鄭君里等主編,《信號(hào)與系統(tǒng)》,北京,高等教育出版社。2000</p><p> 陳懷琛等編著,《MATLAB及在電子信息課中的應(yīng)用》,北京,電子工業(yè)出版社,2002</p><p> g an employment tribunal claim</p><p> Employment tribunals sort
50、 out disagreements between employers and employees.</p><p> You may need to make a claim to an employment tribunal if:</p><p> you don't agree with the disciplinary action your employer ha
51、s taken against you</p><p> your employer dismisses you and you think that you have been dismissed unfairly.</p><p> For more information about dismissal and unfair dismissal, see Dismiss
52、al.</p><p> You can make a claim to an employment tribunal, even if you haven't appealed against the disciplinary action your employer has taken against you. However, if you win your case, the
53、 tribunal may reduce any compensation awarded to you as a result of your failure to appeal.</p><p> Remember that in most cases you must make an application to an employment tribunal within three months of
54、the date when the event you are complaining about happened. If your application is received after this time limit, the tribunal will not usually accept it.</p><p> If you are worried about how the time limi
55、ts apply to you, take advice from one of the organisations listed under Further help.</p><p> Employment tribunals are less formal than some other courts, but it is still a legal process and you will n
56、eed to give evidence under an oath or affirmation.</p><p> Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you shou
57、ld get help straight away from one of the organisations listed under Further help.</p><p> If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you p
58、ay their fee out of your compensation if you win the case. This is known as a damages-based agreement. In England and Wales, your solicitor can't charge you more than 35% of your compensation if you win th
59、e case.</p><p> If you are thinking about signing up for a damages-based agreement, you should make sure you're clear about the terms of the agreement. It might be best to get advice from an exper
60、ienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by e-mail, click on nearest CAB.</p><p> For more information about making a c
61、laim to an employment tribunal, see Employment tribunals.</p><p> The (lack of) air up there </p><p> Watch mCayman Islands-based Webb, the head of Fifa's anti-racism taskforce, is in
62、 London for the Football Association's 150th anniversary celebrations and will attend City's Premier League match at Chelsea on Sunday.</p><p> "I am going to be at the match tomorrow and I hav
63、e asked to meet Yaya Toure," he told BBC Sport.</p><p> "For me it's about how he felt and I would like to speak to him first to find out what his experience was."</p><p> U
64、efa has opened disciplinary proceedings against CSKA for the "racist behaviour of their fans" during City's 2-1 win.</p><p> Michel Platini, president of European football's
65、 governing body, has also ordered an immediate investigation into the referee's actions.</p><p> CSKA said they were "surprised and disappointed" by Toure's complaint. In a statement the R
66、ussian side added: "We found no racist insults from fans of CSKA."</p><p> 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
67、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 very messy, in my mind constantly. Always feel oneself should go to do something
68、, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.</p><p> 一字開(kāi)頭的年齡已經(jīng)到了尾聲。或許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
69、??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。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。</p><p> The end of our life, and can meet many things really do?</p><p> 而窮盡我們的一生,又能遇到多少事情是真正地非做不可?</p><p> During my chil
70、dhood, 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 school, thought to have a crush on just means th
71、at the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isn't really grow up, it seems is not so important; Then in high school, think don't want to give vent
72、to out your inner voice can be in the high school chil</p><p> 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),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
73、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。</p><p> Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time.
74、</p><p> 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。</p><p> A person's time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed
75、 to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, j
76、ust green years oneself give oneself an arm injection, or is a self-righteous spiritual.</p><p> 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
77、像冥冥之中真的已經(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。</p><p> 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
78、 various shapes of stationery; From the corner at the beginning of deep friendship; Have declared the end of the encounter that haven't start planning... Those years, those days of do, finally, like youth, will end i
79、n our life.</p><p> 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。</p><p> Baumgartner the disappointing news: Missio
80、n aborted. r plays an 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
81、 attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher th
82、an the cruising al</p><p> The supersonic descent could happen as early as Sunda.</p><p> The weatheThe balloon will slowly drift to the edge of space at 120,000 feet (</p><p> T
83、hen, I would assume, he will slowly step out onto something resembling an Olympic diving platform.</p><p> Below, the Earth becomes the concrete bottom of a swimming pool that he wants to land on, but not t
84、oo hard. Still, he'll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. </p><p> Skydiver preps for t
85、he big jump</p><p> When he jumps, he is expected to reach the speed of sound -- 690 mph (1,110 kph) -- in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches th
86、e more dense air closer to Earth. But this will not be enough to stop him completely.</p><p> If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him d
87、own. His team hopes it's not needed. Instead, he plans to deploy his 270-square-foot (25-square-meter) main chute at an altitude of around 5,000 feet (1,524 meters).</p><p> In order to deploy this chut
88、e successfully, he will have to slow to 172 mph (277 kph). He will have a reserve parachute that will open automatically if he loses consciousness at mach speeds.</p><p> Even if everything goes as planned,
89、 it won't. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).</p><p> cause there</p&g
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