【正文】 s Day. More and more young Chinese people begin to celebrate this day in a very similar way as that in western countries. Fewer people than ever will gaze at the heavens on Saturday to pick out the two stars shining bright on either side of the Milky Way, that is, if people even know on which day Qixi falls. There are ready reminders dotted about, in the form of big ads saying Sales on Chinese Valentine39。 Festival. In this day, girls will throw a sewing needle into a bowl full of water on the night of Qixi as a test of embroidery skills. If the needle floats on top of the water instead of sinking, it proves the girl is a skilled embroiders. Single women also pray for finding a good husband in the future. And the newly married women pray to bee pregnant quickly. Tradition transformed The love story of Niulang and Zhinu, and the Qixi Festival have been handed down for generations. Yet these ancient traditions and customs are slowly dying out. Many modern Chinese, particularly youngsters, seem to know more about St Valentine39。s time for the wild fruits to ripe. The picturesque Arxan in Autumn is indeed a fairyland only exists in a dream that satisfies all your fantasies. If it rains heavily on Saturday night, some elderly Chinese will say it is because Zhinu, or the Weaving Maid, is crying on the day she met her husband Niulang, or the Cowherd, on the Milky Way. Most Chinese remember being told this romantic tragedy when they were children on Qixi, or the Seventh Night Festival, which falls on the seventh day of the seventh lunar month, which is usually in early August. This year it falls on Saturday, August 2. Folklore Story As the story goes, once there was a cowherd, Niulang, who lived with his elder brother and sisterinlaw. But she disliked and abused him, and the boy was forced to leave home with only an old cow for pany. The cow, however, was a former god who had violated imperial rules and was sent to earth in bovine form. One day the cow led Niulang to a lake where fairies took a bath on earth. Among them was Zhinu, the most beautiful fairy and a skilled seamstress. The two fell in love at first sight and were soon married. They had a son and daughter a nd their happy life was held up as an example for hundreds of years in China. Yet in the eyes of the Jade Emperor, the Supreme Deity in Taoism, marriage between a mortal and fairy was strictly forbidden. He ordered the heaven troop to catch Zhinu back. Niulang grew desperate when he discovered Zhinu had been taken back to heaven. Driven by Niulang39。 ll wait in the line for one hour to get a ticket, and another two hours at the site, to only see a tiny bit of the place due to the crowds. Last year, 428 million tourists traveled in China over the weeklong holiday in October. Traveling during this period is a matter that needs thorough preparation. If you are short on time to plan the uping Golden Week it may not be a bad idea to avoid some of the most crowded places for now. There is always a place so fascinating that everyone yearns for. Arxan is a place like this. The beauty of Arxan is everlasting regardless of the changing of four seasons. Bestowed by nature, its spectacular seasonal landscape and mountains are just beyond word. Arxan is a crucial destination for the remended travelling route, China Inner Mongolia Arxan — Hailar — Manzhouli. It is also the joint of the four prairies across the SinoMongolian border, where people gravitate towards the exotic atmosphere mixed with Chinese, Russian, and Mongolia elements. As a historic site for the Yitian Battle, Arxan still embodies the spirit of Genghis Khan. Walking into Arxan, you will be amazed by a kaleidoscope of geous colors all the year round the Spring azaleas blooming red in the snow, the Summer sea wavering blue in the breeze, the Autumn leaves painted in yellow covering volcanic traces, and the Winter woods shining white on the vast alpine snowscape. Hinggan League Arxan city is situated in the far eastern area of Inner Mongolia Autonomous Region. Its full name Haren Arxan means hot holy water in the Mongolian language. Arxan is a tourism city in the northern frontier with a blend of large forest, grand prairies, vast snowfield, heaven lake cluster, thermium, as well as volcanic cluster. It is a rare and unique ecotourism base filled with healthy sunshine, clean air and unspoiled green. Nestled close to the country39。 中南大學(xué)選修課《新能源概論》期末論文 中南大學(xué)文學(xué)院穆昱帆 參考文獻(xiàn) : [1] 太陽(yáng)能光伏發(fā)電應(yīng)用技術(shù) /楊金煥，于化叢，葛亮編著。本文重點(diǎn)研究一種帶有雙向變換器功能的太陽(yáng)能獨(dú)立光伏發(fā)電系統(tǒng)，對(duì)該系統(tǒng)主電路的參數(shù)進(jìn)行了設(shè)計(jì)計(jì)算。 本文主要研究功率為1KW 的離網(wǎng)型光伏發(fā)電系統(tǒng)，主要內(nèi)容有： （ 1） 介紹了太陽(yáng)能光伏發(fā)電的系統(tǒng)的基本組成和特性，并詳細(xì)說(shuō)明了太陽(yáng)能電池的原理，特性以及太陽(yáng)能電池工程模型 （ 2） 太陽(yáng)能電池最大功率跟蹤的原理以及一些常用的方法，并比較了他們的優(yōu)缺點(diǎn) 。太陽(yáng)能光伏發(fā)電技術(shù)作為太陽(yáng)能利用的一個(gè)重要組成部分，并被認(rèn)為是二十一世紀(jì)最具發(fā)展?jié)摿Φ囊环N發(fā)電方式。太陽(yáng)能具有取之不盡、用之不竭和清潔安全等特點(diǎn)，是理想的可再生能源。在實(shí)際的光伏系統(tǒng)中，增量電導(dǎo)法的實(shí)現(xiàn)中南大學(xué)選修課《新能源概論》期末論文 中南大學(xué)文學(xué)院穆昱帆 對(duì)硬件的要求相對(duì)較高，控制系統(tǒng)需采用高速微處理器完成數(shù)據(jù)處理 。如同擾動(dòng)觀察法一樣，增量電導(dǎo)法的變化步長(zhǎng)也是固定的， 步長(zhǎng)過(guò)小會(huì)使跟蹤速度變慢，太陽(yáng)能電池陣列較長(zhǎng)時(shí)間工作在低功率輸出區(qū) 。 增量電導(dǎo)法的優(yōu)點(diǎn)是 :在日照強(qiáng)度發(fā)生變化時(shí)，太陽(yáng)能電池陣列輸出電壓能以平穩(wěn)的方式追隨其變化，而且穩(wěn)態(tài)的電壓振蕩也較擾動(dòng)觀察法小。 （三） 增量電導(dǎo)法 為 了解決擾動(dòng)觀察法導(dǎo)致的功率損失問(wèn)題， 在 1995 年提出了增量電導(dǎo)法。其次，難以選擇合適的變化步長(zhǎng)，步長(zhǎng)過(guò)小，跟蹤的速度緩慢，太陽(yáng)能電池陣列可能長(zhǎng)時(shí)間運(yùn)行于低功率輸出區(qū)，步長(zhǎng)過(guò)大太陽(yáng)能電池陣列在最大功率點(diǎn)附近的振蕩又會(huì)加大，跟蹤精度下降，從而導(dǎo)致更多的功率損失 。 擾動(dòng)觀察法的最大優(yōu)點(diǎn)就是結(jié)構(gòu)簡(jiǎn)單，被測(cè)參數(shù)少，容易實(shí)現(xiàn)。 （二） 擾動(dòng)觀察法 擾動(dòng)觀察法的原理是 :在每個(gè)控制周期用較小的步長(zhǎng)改變太陽(yáng)能電池陣列的輸出，改變的步長(zhǎng)是一定的，方向