襯度增強 的英文怎麼說
中文拼音 [chèndùzēngqiáng]
襯度增強
英文
contrast enhancement-
Since the shallow depth excavation is the main factor to cause ground settlement in shenzhen subway tunnel, this paper discusses some corresponding countermeasures including the improvement of ground property, appropriate draining of groundwater, scheduled excavation depth and width, etc, to control strata distortion and surface settlement, and argues that these measures are expected to effectively control surface settlement while constructing city subway in soft ground excavation
摘要針對深圳地鐵淺埋暗挖隧道施工中影響地表下降及地層變形的因素，提出了遵循「十八字」原則、改善土體特性、適度排放地下水、根據地層條件選擇施工方法、增大左右線隧道開挖面的距離、合理確定開挖進尺、提高施工效率、加強初期支護、及時施作二次襯砌等對策。Furthermore, the growth and the study of self - organized quantum dots structures become more and more important recently, and the application of self - organization technique become wider and wider in this thesis, we address the theory of film growth and the growth technique firstly more, the ways and characteristics of surface detection are prescribed we mainly report the growth process, results and discuss of self - organized quantum dots structures in the a12o3 substrates by s - k mode using ecr - mocvd, in the espd - u device the growth art of ain epilayer which is the preliminary foundation of self - organized gan / ain quantum dots structures, including the substrate cleaning, nitridation, the growth of buffer and the growth of gan and ain epilayer, is discussed we deliberately compare the test result of rheed xrd and afm and achieved the optimalized condition of ain at last we have successfully realized the growth of ain which is much smooth and better crystal quality moreover, we grow the self - organized gan / ain quantum dots structure in s - k mode because the limits of the heater temperature, we can not grow the atom - smooth epilayer of ain until now so we could not grow better quantum dots which have small diameter and big density but the self - organized quantum dots structures with better quality will be realized successfully if the substrate temperature is increased the thesis study belong to my tutor subject of national nature science foundation ( 69976008 )
本論文主要論述了在espd - u裝置上，採用電子迴旋共振等離子體增強mocvd （ ecr - pamocvd ）方法，在藍寶石襯底上通過s - k模式自組裝生長gan aln量子點結構的生長工藝、結果及討論。而重點分析了自組裝生長量子點之前的aln外延層生長工藝，包括襯底清洗、氮化、緩沖層的生長和gan 、 aln外延層的生長；通過高能電子衍射、 x射線衍射和原子力顯微鏡測試，並且對這些測試結果進行了詳細的比較研究，得出了較優化的工藝條件，生長出了晶質較好、表面較平整的aln外延層；進而採用s - k模式自組裝生長了gan aln量子點結構。由於實驗裝置加熱爐溫度的限制，我們沒有能夠生長出原子級平滑的aln外延層表面，因而沒能夠生長出密度比較大和直徑比較小的量子點。The properties of cn thin films such as their morphology, component, crystal structure and the bonding structure and the relation between those properties and the gas - phase reaction parameters were discussed, showing that the deposition of p - c3n4 thin film is the compete result of various reaction processes in the dynamics balance conditions ; the process of cn films depo sition is diagnosed in situ through the optical emission spectra technique, the effects of experimental parameters on the concentration of the precursors and the gas - phase reactions in the plasma have been obtained ; the main reaction precursors for film deposition identified ; the relation between the characteristics of cn thin films and the reaction process in the plasma is analyzed. the cn thin films deposition under different substrate temperatures in high pressure pe - pld shows that the si atom of the substrate has participated the cn films growth process, based on this the growth mode of cn thin films on the si substrate is proposed. the further experiment of cn thin films deposition on si substrate scratched by diamond as well as covered with fe catalyzer has been attempted, which indicates that changing the dynamics conditions of the surface reaction can alter the growth characteristic of the cn thin films and can enhance obviously the films growth rate
採用pld技術進行了碳氮化合物薄膜沉積，得到了含氮量為21at的cn薄膜；研究了襯底溫度和反應氣體壓強對薄膜結構特性的影響，給出了cn薄膜中n含量較小、 sp ~ 3鍵合結構成分較少和薄膜中僅含有局域cn晶體的原因；引入脈沖輝光放電等離子體增強pld的氣相反應，給出了提高薄膜晶態sp ~ 3鍵合結構成分和薄膜的含n量可行性途徑；應用pe - cvd技術以ch _ 4 + n _ 2為反應氣體並引入輔助氣體h _ 2 ，得到了含n量為56at的晶態cn薄膜；探討了cn薄膜形貌、成分、晶體結構、價鍵狀態等特性及其與氣體壓強和放電電流的關系，證明了- c _ 3n _ 4薄膜沉積為滿足動力學平衡條件的各種反應過程的競爭結果；採用光學發射譜技術對cn薄膜生長過程進行了實時診斷，得到了實驗參量對等離子體中活性粒子相對濃度和氣相反應過程的影響規律，給出了cn薄膜沉積的主要反應前驅物，揭示了cn薄膜特性和等離子體內反應過程之間的聯系；採用高氣壓pe - pld技術研究了不同襯底溫度條件下cn化合物薄膜的結構特性，揭示了si原子對薄膜生長過程的影響，給出了si基表面碳氮薄膜的生長模式；在金剛石研磨和催化劑fe處理的si襯底上進行cn薄膜沉積，證明了通過控制材料表面動力學條件可以改變碳氮薄膜結構特性，並可顯著提高晶態碳氮材料的生長速率。In this paper, we employ the plasma enhanced chemical vapor deposition ( pecvd ) to prepare high quality zno thin film at low temperature using a zinc organic source ( zn ( c2h5 ) 2 ) and carbon dioxide ( co2 ) gas mixtures. the effect of the substrate temperature and annealing temperature on the quality of zno thin films was studied in detail
為了在低溫下制備高質量的氧化鋅薄膜，我們採用金屬有機源和二氧化碳氣源，首次利用等離子體增強化學氣相沉積的技術在低溫下制備了高質量的氧化鋅薄膜，確定了生長高質量氧化鋅薄膜的優化條件；研究了不同的襯底溫度和退火溫度對氧化鋅納米薄膜質量的影響。In order to otain high quality zno thin films, we, for the first time, employ the plasma enhanced chemical vapor deposition ( pecvd ) to prepare high quality zno thin film at low temperature using a zinc organic source ( zn ( c2h5 ) 2 ) and carbon dioxide ( co2 ) gas mixtures. the effects of the growing condiction and the native oxide layer of si substrate on the quality of zno thin films was studied in detail. to prepare p - zno and overcome the dufficulty of reverse due to the interaction between the n atomic, we obtain high qulaity p - zno by a easy way of thermal zn3n2
為了在低溫下制備高質量的氧化鋅薄膜，我們採用金屬有機源和二氧化碳氣源，首次利用等離子體增強化學氣相沉積的技術在低溫下制備了高質量的氧化鋅薄膜，系統地研究了生長條件以及襯底表面氧化層對薄膜質量的影響，確定了生長高質量氧化鋅薄膜的優化條件；為獲得p - zno材料，克服在zno中摻n雜質間相互作用影響摻雜效率不易獲得p - zno的困難，我們通過熱氧化zn3n2的方法制備了p - zno ，獲得了一系列研究結果： 1 、詳細研究了氣體流速比，襯底溫度和射頻功率實驗參數對氧化鋅薄膜特性的影響。Distance between target and substrate get longer also increase the transmission of aln films. as the temperature of substrate get higher, the transmission of ultrathin aluminum films decrease slightly. nitrogen gas concentration and sputtering time barely take effect on the transmission of aln films
發現，隨著工作壓強的升高、靶距的增加，薄膜的透光率上升;基片溫度的升高在非晶襯底上會導致樣品透光率的下降;而氮氣濃度和濺射時間對薄膜的透光率影響不大。分享友人