nasa的問題，透過圖書和論文來找解法和答案更準確安心。 我們找到下列問答集和資訊懶人包

The Textbook of Nanoneuroscience and Nanoneurosurgery: Second Edition

為了解決nasa的問題，作者 這樣論述：

Babak Kateb, founding chairman of the board of SBMT and Brain Mapping Foundation, Scientific Director of SBMT, and President of Brain Mapping Foundation, West Hollywood, CA, USA, Director of the National Center for Nano-Bio-Electronics, NASA Research Park, Moffet, CA, USA, Senior Editor of SBMT-Neur

oMapping & Therapeutics, Research Scientist, Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA, and Visiting Scientist, NASA/Jet Propulsion Laboratory (JPL), Pasadena, CA, USA. John D. Heiss, chair of the Surgical Neurology Branch, National Institute of Neurological Diso

rders and Stroke, National Institutes of Health, and Clinical Professor of Neurosurgery, George Washington University, Washington, DC, USA.＂...a significant contribution to the field of nanoneuroscience and nanoneurosurgery ... the reader will come away with a deeper understanding of the history of

nanotechnology and medicine.＂ --Neuroscience＂This is a monumental first textbook on nanoneurosurgery. ... recommended reading for neurosurgeons, neurologists, neuroradiologists and neuroscientists involved in research on new techniques for application in neurosurgery. Biomedical engineers and variou

s companies developing instruments and devices would benefit from the wealth of information about trends for development of new technologies for neurosurgery.＂ --K. K. Jain, MD, Basel, Switzerland

nasa進入發燒排行的影片

低腔壓高濃度過氧化氫混合式火箭引擎之研究

為了解決nasa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。

Universal Principles of Design, Completely Updated and Expanded Third Edition: 200 Ways to Enhance Usability, Influence Percepti

為了解決nasa的問題，作者Lidwell, William,Holden, Kritina,Butler, Jill 這樣論述：

William Lidwell is the Chief R&D Officer at Avenues: The World School, where he leads teams tasked with conducting research in education and the learning sciences; the development of new educational curricula, programming, and technologies; and the architecture and design of new campuses around the

world. The co-author of Universal Principles of Design and The Pocket Universal Principles of Design, he has written other books in a variety of disciplines, including design, education, and management. His online lectures on the psychology of color are available at TheGreatCourses.com, and his onli

ne courses on the universal principles of design and logo design are available at LinkedInLearning.com. He lives in Houston, Texas.Kritina Holden is a Human Factors Technical Fellow with Leidos at the NASA Johnson Space Center. She has over thirty years of experience working in the area of Human Fac

tors, with a focus on human-computer interaction (HCI), human-centered design, and usability. She has served as Principal Investigator for several NASA-funded research efforts, including studies onboard the International Space Station. She is also a subject-matter expert for all of the major spacefl

ight programs. Tina received her Ph.D. in Engineering Psychology from Rice University. She lives in Houston, Texas.Jill Butler is the founder and president of Stuff Creators Design, an interaction design consultancy. She has over twenty years of experience designing, teaching, and consulting in the

areas of graphic design, information design, and typography. She has designed covers, layouts, and typography for more than a hundred published novels and children’s books, and more websites than she can count. Her current focus is the UI/UX design of global online K-12 learning systems. Her online

courses on the universal principles of design and typography are available at LinkedInLearning.com. She lives in Houston, Texas.

改良翼型葉片提升冷卻水塔風機效率及降低氣動噪音技術之研究

為了解決nasa的問題，作者郭祐豪 這樣論述：

摘 要 iABSTRACT ii誌謝 iv目錄 v表目錄 vii圖目錄 viii第一章 緒論 11.1研究動機與背景 11.2文獻回顧與探討 31.3研究目的 81.4研究流程 9第二章 冷卻水塔噪音理論分析 102.1冷卻水塔噪音相關法規 102.2冷卻水塔氣動噪音產生因素 142.3風扇葉形與設計 172.4氣動噪音型態 192.5聲學模擬理論模式 212.6噪音偵測點配置 24第三章 數值模式 253.1數值模擬方法架構 253.2理論模式 263.2.1統御方程式 263.2.2紊流流場模式 283.3數值方法 293.3.1對流-擴散方程式的差分形式 313.3.2壓力-速度耦合

關係的處理 323.4多參考框架模型與滑動網格 363.5多孔性區域 37第四章 冷卻水塔噪音模擬 384.1模型概述 384.1.1幾何模型 394.1.2設定邊界條件 434.1.3網格獨立測試 444.1.4時間步階獨立測試 464.2冷卻水塔氣流場模擬結果分析 474.2.1冷卻水塔外部環境流場分佈 474.2.2冷卻水塔內部塔體流場分佈 524.3冷卻水塔氣動噪音模擬結果分析 584.3.1冷卻水塔風扇渦流場分佈 584.3.2冷卻水塔風扇噪音結果 63第五章 結論 68致謝 69參考文獻 70