【正文】 s health. Poor technique harms the muscles and skeleton, and can cause secondary injures. And, jogging in a bad environment can cause circulation problems, said Lu Zhiyong, attending doctor, Sports Hospital, General Admin. of . Lu has some tips for joggers, and those who are thinking of 。ll hold off jogging for a while. But if I really want to get away from work, I39。s work can be a way to unwind. It is true for He Wenjun, whose workplace is right near the forest park. She discovered her athletic aptitude at the age of seven, when she began playing tennis. Then she turned to jogging, and she has persevered with it for 10 years. I e to jog almost every day after work, whenever I have time. I think jogging is good for my health. And for me, a girl, it helps me to achieve to eternal goal, to keep slim, He said. He says she prefers jogging alone, so she can focus better. She loves jogging, even during Beijing39。s digitized society, will also be attached on the report.Myopia is not only a disease that makes people see things blurrily, but also leads to severeplications, such as glaua (increased pressure within the eyeball), and can causeblindness, said Zhou Yuehua, an established eye care specialist with Beijing TongrenHospital.It is very important for parents and children to know about the risk and care for their eyes.There are about 450 million myopia patients in China. Among Chinese myopia patients,30million are severe patients, according to ZhouThe prevalence of myopia among high school and college students is more than 70 percent,and the situation is continuously worsening, he Zhu, director with the China Youth Development Service Center, said long hours ofstudy, lack of exercise, especially outdoor activities, and attachment to electronic screen aresome of the top reasons behind the widespread myopia problems, and the increase ofyounger patients, although China has made great progress in improving the hardwarefacilities and lighting conditions in said he hopes the survey will alert people on the threatening situation, and also helpmedical experts to better guideline parents and children39。 第 36 頁 共 34 頁 參考文獻 [1] 宋光鈴 .鎂合金腐蝕與防護 [M].北京 :化學(xué)工業(yè)出版社， 2021. [2] 蔡啟舟，王立世，魏伯康 .鎂合金防蝕處理的研究現(xiàn)狀及動向 [J].特種鑄造及有色合金， 2021(3):3335. [3] MORDIKE B L ， EBERT propertiesapplications potential[J]. .， 2021， A302:3745. [4] K. Liu, Y. C. Ma, M. Gao. Single Step Centrifugal Casting TiAl Automotive Valves. Intermetallics. 2021,13(9):925~928 [5] A Choudhury, M Blum. Economical Production of TitaniumAluminide Automotive Valves using Cold Wall Induction Melting and Centrifugal Casting in A Permanent Mold Vacuum. Proceedings of the 13th International Vacuum Congress and the 9th International Conference on Solid Surfaces 1996, 47(6~8): 829~831 [6] 唐兆麟，王福會 . Cr 對 TiAl 金屬間化合物高溫氧化性能的影響 [J]. 金屬學(xué)報， 1997，（ 10）： 1028～ 1033 [7] 唐兆麟，王福會 . Cr 對 TiAl 金屬間化合物抗循環(huán)氧化性能的影響 [J]. 中國有色金屬學(xué)報， 1998，（ 2）： 245～ 249 [8] D. M. Dimiduk. Gamma Titanium Aluminide Alloys—an Assessment Within the Competition of Aerospace Structural Materials. Materials Science and Engineering A. 1999,263: 281~288 [9] 葉喜蔥，小型薄壁 TiAl 基合金件底注式真空吸鑄技術(shù)基礎(chǔ)研究 [D]. 哈爾濱 :哈爾濱工業(yè)大學(xué)材料科學(xué)與工程學(xué)院， 2021： 1～ 135 [10] . Kim, JOM 46 (1994) 30. [11] T. Noda, Intermetallics 6 (1998) 709. [12] M. Blum, A. Choudhury, H. Scholz, G. Jarczyk, S. Pleier, P. Busse, , S. Knippscheer, in: . Kim, . Dimiduk, (Eds.), GammaTitaniumAluminides 1999, TMS, 1999, p. 35. [13] D. Rugg, in: . Kim, . Dimiduk, . Loretto (Eds.), GammaTitanium Aluminides 1999, TMS, 1999, p. 11. 14] . Varma, C. Hernandez, E. Corral, A. Chan, R. Mahapatra, in: . Kim, . Dimiduk, . Loretto (Eds.), Gamma TitaniumAluminides 1999, TMS, 1999, p. 823. 第 37 頁 共 34 頁 [15] 傅恒志，丁宏升，陳瑞潤 .鈦鋁合金電磁冷坩堝定向凝固技術(shù)的研究 . 稀有金屬材料與工程 . 2021,37(4):565～ 570 [16] 江和甫 . 燃?xì)鉁u輪發(fā)動機發(fā)展與制造技術(shù) . 航空制造技術(shù) . 2021,5:36～ 39 [17] 王建國，周中波，王一川，商國強，李金山 .TiAl 合金鑄造工藝數(shù)值模擬及分析 .特種鑄造 . 2021,30(8):1054～ 1057 [18] H. Razavi, P. Davami, Solidi?cation simulation of gravity casting of Al–12% Si in permanent mould with puter simulation of heat transfer in air gap, in: Proceedings of the 59th World Foundry Congress, CIATF, 1992. [19] . Nichols, . Hirt, Lost foam casting simulation, Flow Science Inc. Available at [20] P. Davami, . Mirbagheri, Solidi?cation simulation of parts casting. Available at [21] . Lipinski, Mould ?lling simulation for casting processes, . Thesis, Rheinischwestfalischen Technischen Hochschule Aachen, Germany, 1996 (in English). [22] C. Wang, Computer modelling of ?uid ?ow and heat transfer in metal casting, . Thesis, Pittsburgh University, USA, 1990. 第 38 頁 共 34 頁 a 您好，為你提供優(yōu)秀的畢業(yè)論文參考資料，請您刪除以下內(nèi)容， O(∩_∩)O 謝謝?。。 national survey was recently launched to evaluate the eye health of Chinese children June 6, China39。畢業(yè)論文的完成，同樣也意味著新、生活的開始。 寫作畢業(yè)論文是一次再系統(tǒng)學(xué)習(xí)的過程，在做畢業(yè)論文的過程中，通過查看文獻，查找資料，讓我對澆鑄整個過程有了更深刻、更系統(tǒng)的了解，尤其對澆鑄過程中的澆注溫度、澆鑄速度和鑄型溫度對澆鑄件的影響更深刻。 其次，還要感謝這四年來教我知識的每位老師們，畢 業(yè)論文能夠順利完成，你們也都有很大的功勞。尤其記得在做開題報告時，我說 TiAl 基合金的尺寸效應(yīng)不知道怎么開筆寫，葉老師當(dāng)時思考了下，立馬給我換了個課題。每次遇到難題，我最先做的就是向葉喜蔥老師尋求幫助，而葉老 師每次不管忙或閑，總會抽空來找我面談，或說定時間讓我去找他，然后教我如何解決。做設(shè)計的過程是艱辛的，但是在我的努力之下還是完成了。 第 35 頁 共 34 頁 致謝 畢業(yè)設(shè)計已經(jīng)接近了尾聲，這也意味著我的大學(xué)生活就要結(jié)束了，大學(xué)生活一晃而過，回首走過的歲月，心中倍感充實，當(dāng)我寫完這篇畢業(yè)論文的時候，有一種如釋重負(fù)的感覺，感慨良多。這是我們從圖可以直觀的看出來的。 第 34 頁 共 34 頁 圖 總結(jié)，從圖 32圖 32圖 326 和圖 327 這四幅圖很容易看出，晶粒尺寸隨著組織距離薄板底部的距 離增大而普遍增大，片層間距也隨著組織距離薄板底部的距離增大而普遍增大。 圖 327 為晶粒尺寸與晶粒距離薄板底部距離的大小的圖。當(dāng)在距離薄板底部 15mm 到 27mm 這段距離時，片層間距增長率最大，并且成直線式上升。金屬液在結(jié)晶時，如果施加外力，就會增加鑄型中金屬液的運動，就會造成枝晶破碎，而破碎后的晶 塊又充當(dāng)晶核作用，金屬液就再在破碎后的晶塊上結(jié)晶，從而使得晶核變多，晶粒變小。 (2) 變質(zhì)處理也稱調(diào)質(zhì)處理：即在金屬液結(jié)晶前，向金屬液中加入某些物質(zhì)（稱為變質(zhì)劑），這些物質(zhì)將分散在金屬液中，形成大量的非自發(fā)形核界面，或起阻礙晶體長大的作用，從而使得晶粒組織比較小，這種細(xì)化晶粒的方法，稱為變質(zhì)處理。在連續(xù)冷卻情況下，冷卻速度越大，則過冷度越大，而理論上過冷度越大，鑄件的晶粒越小。組織越細(xì)小，晶粒則越小，單位體積的晶粒數(shù)越多，當(dāng)材料收到一定作用力時分配到各晶粒的力就越小，組織性能就越好。所以組織粗大會使得材料的強度、塑性及韌性降低，從而使