【正文】 Chinese President Xi Jinping proposed that China and Central Asia join hands to build a Silk Road economic belt to boost cooperation. The idea has been widely echoed in Central Asian countries, being an encouraging blueprint for Chinese areas along the Silk Road that has linked Asia and Europe for more than 2,000 years. In the next three weeks, China Daily reporters will travel through the belt in China and in Kazakhstan, Uzbekistan and Turkey. They will show the progress and expectations of the countries, businesses and peoples on the route. Shaanxi the start of the ancient Silk Road has positioned itself as the new starting point for the development of the Silk Road Economic Belt, which will strengthen China39。s ancient indigenous religion, while Du jiang yan is considered to be the oldest functioning watercontrol project in the world. Chengdu ranked third in tourist facilities, management and services among 60 Chinese cities in a customer satisfaction survey released last year. But, Li added that efforts are still needed to develop more tourism products, improve English services and provide accurate translation of traffic signs and scenic billboards. Zhao Yun, chairwoman of British Chamber of Commerce Southwest China, told China Daily that his colleagues found the policy very convenient. A British cl ient once flew here and stayed for just one day to check her ordered goods, she said. Zhao was born in Shanxi province, but she has lived in Chengdu for more than 10 years. My life was like a running race moving from place to place. I also lived in Beijing and Shanghai before, she said. But Chengdu is a place that you never want to leave once settling down. It is now my second hometown, she said. If the environment is further improved, the city will attract more people to visit and live, with the 72hour visafree policy and pelling conditions in transportation, culture, climate and cuisine, he said. Foreigners also gave positive feedback on the policy. A spokesman from Dell Inc said the pany has a global hub of operatio n in Chengdu, so the threeday visa has an immediate and positive influence on the pany39。PWM 輸出低電平 RETI PWMH: SETB CLR TR0 MOV TH0,PWM1H MOV TL0,PWM1L SETB TR0 。T1 賦值 MOV TL0,TESTL SETB TR0 SETB TR1 LJMP ED NEXT2:MOV A,PWMT MOV B,04H DIV AB 。功能選擇 ORG 0100H 22 MAIN: MOV A,00H MOV LED,A MOV P1,07FH CLR TESTV MOV PWMT,200 。PWM 輸出標(biāo)志位 PWM1H EQU 71H 。 19 致謝 在 畢業(yè)設(shè)計 即將完成之際，我的心情無法平靜，從開始進(jìn)入課題到 畢業(yè)設(shè)計 的順利完成，有多少可敬的師長、同學(xué)、朋友給了我無言的幫助，在這里請接受我誠摯的謝意 ! 葛老師認(rèn)真負(fù)責(zé)的工作態(tài)度，嚴(yán)謹(jǐn)?shù)闹螌W(xué)精神和深厚的理論水平都使我收益匪淺。點擊運行，也基本達(dá)到預(yù)期的效果。 數(shù)據(jù)采集及模數(shù)轉(zhuǎn)換程序 數(shù)據(jù)采集及數(shù)模的轉(zhuǎn)換主要 ADC0808 完成，然后傳遞給 AT89C51 進(jìn)行數(shù)據(jù)的處理后產(chǎn)生預(yù)期的效果。其工作過程為：電路初始化，輸出功能選擇，選擇確定輸出電流電壓，為移動設(shè)備充電直至完成，程序整體框架如圖 31 所示。 數(shù)碼管顯示電路 的設(shè)計 綜合各種因素，本 設(shè)計 采用 LED 數(shù)碼管靜態(tài)顯示電路 ,每一個顯示器都要占用單獨的具有鎖存功能的 I/O 接口。可以應(yīng)用在電動機(jī)控制等電路上； （ 2） 、具有精確的低偏置線性霍爾傳感器電路，在電路的應(yīng)用中便于控制盒檢測； （ 3） 、具有較低的功率損耗（內(nèi)電阻一般情況下為 ）； （ 4） 、接線端與傳感器引腳之間電氣絕緣。 A、 B、 C：地址輸入線。 圖 24 ADC0808 的引腳結(jié)構(gòu) ADC0808 各腳功能如下： IN0IN7： 8 位模擬量輸入引腳。 7805 具有輸入電壓范圍寬、工作電流大、輸出精 度高、工作及其穩(wěn)定以及外圍電路簡單等特點，即使太陽能電池電壓有較大的波動，也能穩(wěn)定的輸出 5V 電壓，從而為整個電路的正常運行提供了保障。圖 22 為 AT89C51的引腳排列圖。而且在西藏等地區(qū)對于電能的傳輸較內(nèi)地更為麻煩，對于太陽能的采集有更高的優(yōu)勢，因此能夠得到更好 的應(yīng)用。本 設(shè)計 中將采用 AT89C51 單片機(jī)做為充電電路的控制器，從而實現(xiàn)充電過程的智能化。 當(dāng)然，在太陽能充電器的能源采集的利用也存在分散、不穩(wěn)定、效率低以及成本高的不利條件，但是，隨著科技的發(fā)展以及人們理念問題的變化，太陽能的完美發(fā)展將呈現(xiàn)在我們面前。然而隨著光伏發(fā)電技術(shù)的成熟，太陽能的利用已經(jīng)走進(jìn)了千家萬戶。portable 目錄 1. 緒論 ................................................. 1 太陽能充電器的研究背景 ...................................... 1 太陽能充電器的優(yōu)點 .......................................... 1 本課題研究的主要內(nèi)容 ........................................ 2 2. 硬件設(shè)計 ............................................. 3 總體方案的設(shè)計 .............................................. 3 太陽能光伏發(fā)電系統(tǒng)簡介 ...................................... 3 太陽能電池參數(shù)及選用標(biāo)準(zhǔn) .................................... 4 51 系列單片機(jī)處理器 .......................................... 5 穩(wěn)壓器件的選擇 .............................................. 6 電壓電流的 A/D 采集 .......................................... 6 ACS712 的選用 ................................................ 8 按鍵電路的選擇及設(shè)計 ........................................ 9 數(shù)碼管顯示電路的設(shè)計 ....................................... 10 3. 軟件設(shè)計 ..................................