At last time的問題，透過圖書和論文來找解法和答案更準確安心。 我們找到下列特價商品、必買資訊和推薦清單

Arthur Frommer’’s Europe

為了解決At last time的問題，作者Frommer, Arthur,Ames, Paul,Barron, Peter 這樣論述：

Arthur Frommer The son of a Polish-born mother and an Austrian-born father, Frommer was drafted into the U.S. Army during the Korean War, but was stationed in Europe because of his fluency in German and Russian. During his service, he wrote and self-published a guidebook called The GI’s Guide to Tra

veling in Europe in 1955 that was an immediate hit among his fellow soldiers. In 1957, Frommer created a civilian version called Europe on 5 Dollars a Day, which became an overnight best seller. He subsequently published guidebooks covering all parts of the globe. Frommer licensed his travel guide b

ook business to Simon & Schuster in 1977. Eventually, the Frommer’s series was purchased by John Wiley & Sons, and in August 2012, Google purchased the travel guides. Through all the exchanges, Arthur Frommer was always deeply involved with the guide books. In 2013, Frommer reacquired control of the

guidebooks bearing his name and has come full circle, now self-publishing his iconic travel books again. Additionally, Arthur Frommer writes a travel column syndicated through King Features, and co-hosts a weekly syndicated radio show with his daughter Pauline, ＂The Travel Show with Arthur & Paulin

e Frommer.＂ Arthur resides in New York City. Paul Ames (author Portugal): A native of England’s East Anglia region, Ames has been fascinated by Portugal since a childhood visit in the 1970s when the country was gripped by revolutionary fervor. After 20 years based in Brussels covering Europe for Th

e Associated Press and other international media, he returned to Lisbon in 2013. Paul works as a freelance journalist and never tires of exploring the delights of his adopted homeland, from the green hills of the Minho to sub-tropical Madeira island and all the beaches in between. Peter Barron (auth

or Spain): After careers at the BBC and Google, Peter Barron turned his attention to restoring a barn with his wife Julia at their finca on the border between Andalucía and Extremadura. He has been visiting Spain for over thirty years and loves flamenco guitar, ibérico ham, and manzanilla sherry. He

is one of the authors of Frommer’s Spain and blogs about Extremaduran life at adventuresinextremadura.com. He divides his time between Spain and London. Anna E. Brooke (author France) relocated from her native Britain to Paris in 2000 and hasn’t looked back since. She is now a full-fledged bohemian

, juggling life between freelance travel writing (Frommer’s, Sunday New York Times Travel, Time Out Paris and the Financial Times), children’s fiction, acting and songwriting for film. Jennifer Ceaser (author Belgium and The Netherlands) is a freelance writer and editor who has specialized in travel

journalism for two decades. A former New Yorker and staff editor at the New York Post, Jennifer has lived in Europe since 2016, including Amsterdam, Berlin and Barcelona. She contributes to a variety of publications including Condé Nast Traveler, AFAR, New York magazine, BBC, Time Out, Delta Sky, a

nd Wine Enthusiast. Jason Cochran (author, England & Scotland) was twice awarded Guide Book of the Year by the Lowell Thomas Awards (Society of American Travel Writers) and once by the North American Travel Journalists Association for his book Frommer’s EasyGuide to London. His writing has appeared

in the New York Post, Entertainment Weekly, Travel + Leisure, USA Today, and Budget Travel , among many others. Jason has appeared as a host and commentator on CBS, Fox and AOL, to name a few. He currently is the Editor in Chief of Frommers.com. Donald Strachan (author Italy) is a writer and journal

ist who has written about Italy for publications worldwide, including National Geographic, the Guardian, Sunday Telegraph, and the Independent. Rachel Glassberg (author Austria, Germany, Switzerland) is a Berlin-based journalist last seen traversing the Alps for Frommer’s Switzerland and ruining he

r friends’ favorite bars for Frommer’s Germany. Formerly deputy editor of the English-language city magazine Exberliner, she now divides her time between writing, music, and travel -- sometimes two or even all three of those simultaneously.

At last time進入發燒排行的影片

用於染料敏化電池的無金屬有機染料之結構設計

為了解決At last time的問題，作者吳杰畢 這樣論述：

摘要第三代光伏的染料敏化太陽能電池 (DSSC)的興起，造成在過去的三十年中被廣泛地探索，因為它們具有的獨特特性，例如成本低、製造工藝簡單、輕巧、柔韌性好、對環境友善，並且在弱光條件下，仍具備突破性的高效率。儘管， DSSCs 依然有許多須待優化的部分，但藉由光捕獲染料光敏劑的分子結構設計，在優化 DSSCs 性能參數方面扮演關鍵的作用。因此，尋找符合DSSC需求的光敏染料，是該研究領域的關鍵研究方向之一。本論文的最終目標是在標準日照和弱光條件下，尋找高效穩定的有機光敏染料。這項工作是藉由無金屬有機光敏劑的系統結構工程來完成的，針對分子結構設計與光電特性的關聯及DSSC的效能表現。在本論文中

，我們已經合成了各種新型光敏染料，並對這些無金屬有機光敏染料進行了逐步的結構修飾，例如在單個敏化染料中引入一對輔助受體，在 D-A-π-A 框架中引入龐大的芴基實體，並增加共平面性以及延伸喹喔啉染料主要框架的共軛。通過使用各種光譜、電化學和理論計算來研究這些光敏染料的結構性質，以符合它們在DSSC主要特徵之應用前景。最後，在本論文中，我們展示了一組無金屬有機光敏劑，其元件效率高，在標準太陽照射下的效率超過 9%，在 6000 lux 的弱光照下，效率超過 30%，這將是一個具有未來發展潛力的結構設計，可以在沒有共吸附劑的情況下實現高效率。

Research Magnet Technology: Forty Years of Creating High Magnetic Fields

為了解決At last time的問題，作者Jones, Harry (EDT) 這樣論述：

Research Magnet Technology presents an overview of the technologies necessary to provide high magnetic fields as a research tool mainly, but by no means exclusively, for condensed matter physics. Taken from the perspective of the author's career spanning four decades, it contains a historical com

ponent while at the same time deals with state-of-the-art and future developments. Several technologies are described: classical electrical engineering (copper/water-cooled multi-megawatt), superconducting magnets (both low and high temperature), hybrid magnets, non-destructive pulsed magnets, and d

estructive non-continuous techniques for ultra-high fields. The world's dedicated magnet laboratories are described parallel to the involvement of the industry. Examples of major scientific advances that have used high fields will be explored and future applications indicated. Moreover, the many dis

tinguished and colorful scientists and engineers who have made an impression on the author over the last 40 years are featured anecdotally where appropriate.Unlike most books on magnet technology and related topics that are either rigorous textbooks with a heavy mathematical content or popular works

which treat the magnet as an interesting curiosity, this book adopts a unique approach by balancing the two extremes.

低腔壓高濃度過氧化氫混合式火箭引擎之研究

為了解決At last time的問題，作者林育宏 這樣論述：

本論文為混合式火箭系統入軌段火箭引擎的前期研究，除了高引擎效率的要求外，更需要精準的推力控制與降低入軌段火箭的結構重量比，以增加入軌精度與酬載能力。混合式火箭引擎具相對安全、綠色環保、可推力控制、管路簡單、低成本等優點，並且可以輕易地達到引擎深度節流推力控制，對於僅能單次使用、需要精準進入軌道的入軌段火箭推進系統有相當大的應用潛力。其最大的優點是燃料在常溫下為固態、易保存且安全，即使燃燒室或儲存槽受損，固態的燃料也不會因此產生劇烈的燃燒而導致爆炸。雖然混合式推進系統有不少優於固態及液態推進系統的特性，相較事先預混燃料與氧化劑的固態推進系統及可精準控制氧燃比而達到高度燃燒效率的液態推進系統，混

合式推進系統有擴散焰邊界層燃燒特性，此因素導致混合式推進系統的燃料燃燒速率普遍偏低，使得設計大推力引擎設計時需要長度較長的燃燒室來提供足夠的燃料燃燒表面積，也導致得更高長徑比的火箭設計。針對此問題，本論文利用渦漩注入氧化劑的方式，增加了氧化劑在引擎內部的滯留時間，並藉由渦旋流場提升氧化劑與燃料的混合效率以及燃料耗蝕率；同時降低引擎燃燒室工作壓力以研究其推進效能，並與較高工作壓力進行比較。本論文使用氮氣加壓供流系統驅動90%高濃度過氧化氫 (high-test peroxide) 進入觸媒床，並使用三氧化二鋁 (Al2O3) 為載體的三氧化二錳 (Mn2O3) 觸媒進行催化分解，隨後以渦漩注入的

方式注入燃燒腔，並與燃料聚丙烯（polypropylene, PP）進行燃燒，最後經由石墨鐘形噴嘴 (bell-shaped nozzle) 噴出燃燒腔後產生推力。實驗部分首先透過深度節流測試先針對原版腔壓40 barA引擎在低腔壓下的氧燃比 (O/F ratio)、特徵速度 (C*)、比衝值 (Isp) 等引擎性能進行研究，提供後續設計20 barA低腔壓引擎的依據，並整理出觸媒床等壓損以及燃燒室等流速的引擎設計轉換模型；同時使用CFD模擬驗證渦漩注射器於氧化劑全流量下 (425 g/s) 的壓損與等壓損轉換模型預測的數值接近 (~1.3 bar)。由腔壓20 barA 引擎的8秒hot-f

ire實驗結果顯示，由於推力係數 (CF) 在低腔壓引擎的理論值 (~1.4) 相較於腔壓40 barA引擎的推力係數理論值 (~1.5) 較低，因此腔壓20 barA引擎的海平面Isp相較於腔壓40 barA引擎的Isp 低了約13 s，但是兩組引擎具有相近的Isp效率 (~94%)，且長時間的24秒hot-fire測試顯示Isp效率會因長時間燃燒而提升至97%。此外，氧化劑流量皆線性正比於推力與腔壓，判定係數 (R2) 也高於99%，實現混合式火箭引擎推力控制的優異性能。透過燃料耗蝕率與氧通量之關係式可知，低腔壓引擎在相同氧化劑通量下 (100 kg/m2s) 較腔壓40 barA引擎降低

了約15%的燃料耗蝕率，因此引擎的燃料耗蝕率會受到腔體壓力轉換的影響而變動，本論文也針對此現象歸納出一校正方法以預測不同腔壓下的燃料耗蝕率，此校正後的關係式可提供未來不同腔壓引擎燃料長度設計上的準則。最後將雙氧水貯存瓶的上游氮氣加壓壓力從約58 barA降低至38 barA並進行8秒hot-fire測試，結果顯示仍能得到與過往測試相當接近的Isp效率 (~94%)，而此特性除了能讓雙氧水及氮氣貯存瓶擁有輕量化設計的可能性，搭配具流量控制的控制閥也有利於未來箭體朝向blowdown type型式的設計，因此雙氧水加壓桶槽上的氮氣調壓閥 (N2 pressure regulator valve)

將可省去，得以降低供流系統的重量，並增加箭體的酬載能力，對於未來箭體輕量化將是一大優勢。