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Highly Sensitive Photo-activated Sensors Based on Iron, Nitrogen Co-modified Peroxo Titanic Thin Film for Gas and Humidity Sensing
No full text氣體感測器可以利用於有機氣體感測以及濕度感測上。有機氣體感測可以應用在醫學領域而濕度感測則廣泛應用於各種生活相關領域中。本研究開發了一種高靈敏性的溼度感測器並且可以偵測有機氣體。我們利用溶膠凝膠法合成任意比例的鐵氮共摻雜氧化鈦，並利用旋塗機旋塗在指叉狀金電極上，封裝在8 PIN 的 IC 腳座上，利用氣體產生系統量測對於水氣以及有機氣體的反應。
本氣體感測器對於水氣有極佳的感測效能，在不同頻率下對於水氣的阻抗值變化有極大的差異，用阻抗分析儀量測阻抗變化時在頻率為100 Hz時在相對溼度11-75%的變化可以達到近乎五個數量級的反應，並且在中低濕度時阻抗量測的反應呈現線性變化，中高濕度時電容量測的反應呈現線性變化。
在有機氣體方面本感測器可以有效偵測到甲苯以及甲醇在6000-10000ppm的濃度變化，我們利用紫外光對感測器進行照射15分鐘後，證明感測器在光激發後對於甲醇以及甲苯有良好的增益，並且本感測器對於甲醇以及乙醇有良好的分辨性。
本感測器在水氣的反應時間以及回復時間的表現上擁有小於兩秒的表現，在針對有機性氣體上則大約為20秒。推測因本研究材料表面親水，與氣體中水分結合後，有機氣體需和水分子搶結合位置，因此反應時間較慢。Gas sensors can be utilized to detect volatile organic compounds (VOCs) or humidity. Volatile organic compound sensors and humidity sensors can be applied in many fields. In this research, we synthesized a new material consisting of iron and nitrogen co-modified peroxo titanium oxide, for the VOCs and humidity sensing applications. We developed a sol-gel technology to synthesize iron, nitrogen co-modified peroxo titanium oxide and the ratio of iron, nitrogen and titanium can be adjuted. UV light was used to improve the sensing performance of humidity and VOCs.
This sensor has great response to humidity and the impedance value varies a lot with different frequencies. When using a impedance analyzer to measure the impedance change, the impedance change spanned almost five orders of magnitude during the measurement of relative humidity (RH) from 11%-75% under 100Hz.
On the other hand, the sensor can measure the methanol and toluene from 6000 to 10000 ppm. We proved that our sensors have good improvements after illuminating 365nm ultraviolet light for 15 minutes. Our sensors have good selectivity between methanol and ethanol .
Our sensors’ response time and recovery time are less than 2s to water, and approximately 20s to VOCs. Because the material surface is hydrophilic so water molecules can easily be adsorbed. It is believed that VOCs have to compete to the water molecules for reaction sites and thus the response time is slower than water.口試委員會審定書--------------------------------------------------------------Ⅰ
誌謝--------------------------------------------------------------------------------Ⅱ
中文摘要 III
ABSTRACT IV
目錄 VI
圖目錄 X
表目錄 XIV
第 1 章 緒論 1
1.1 研究背景 1
1.1.1 有機氣體感測器之應用 1
1.1.2 濕度感測器之應用 5
1.2 氣體感測器研究回顧 7
1.2.1 氣體感測器介紹 7
1.3 相關論文回顧 11
1.4 論文架構 17
第 2 章 感測材料與感測機制 18
2.1 回顧二氧化鈦材料 18
2.1.1 二氧化鈦之種類 18
2.1.2 二氧化鈦之光激發 19
2.2 鐵氮共摻雜氧化鈦 21
2.3 薄膜感應機制 24
2.3.1 水層吸附之感應機制 24
2.3.2 有機氣體之感應機制 26
2.4 鐵氮共摻雜氧化鈦溶膠之合成 28
2.4.1 實驗用藥品 28
2.4.2 溶膠的配製 28
第 3 章 氣體感測器元件之製作與量測 31
3.1 晶片平台 31
3.1.1 電子束蒸鍍 32
3.1.2 微影 33
3.1.3 晶圓切割 36
3.2 薄膜塗佈 38
3.2.1 晶片清洗 38
3.2.2 旋塗薄膜 38
3.3 晶片封裝 41
3.4 實驗量測方式 42
3.4.1 實驗儀器 42
3.4.2 揮發性有機化合物氣體生成系統 42
3.4.3 氣體感測器讀取 46
第 4 章 氣體感測器量測結果與討論 48
4.1 量測相關參數定義 48
4.2 氣體生成系統量測-電阻變化 50
4.2.1 氣流對氣體感測器反應之影響 50
4.2.2 水氣對氣體感測器反應之影響 51
4.3 氣體生成系統量測-阻抗變化 58
4.3.1 水氣對氣體感測器的影響 58
4.3.2 有機氣體對氣體感測器之影響 66
4.3.3 UV光對感測的影響 68
4.4 反應時間與再現性之討論 70
第 5 章 結論與未來展望 74
5.1 結論 74
5.2 未來展望 75
參考資料 7
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
[[alternative]]Examinees’ Cognition and Coping Strategies towards the Recommendation and Screening System of Higher Education Entrance Exam
No full text[[abstract]]Abstract
This study investigates the Recommendation and Screening System of higher education entrance exams, aiming to clarifying the mechanism guiding the functioning of the system. Cultural capital and social capital perspectives are employed to exam how the system assigns examinees to different departments and schools. The Recommendation and Screening system is newly established as part of the higher education entrance exams. However, critiques follow. Doubts about the fairness of the recommendation and screening system have been raised. Among all of the critiques, empirical investigation is still missing.
To understand the mechanism behind the function of the Recommendation and Screening system, interviews were conducted. Data was collected from 18 interviewees who participated in the Recommendation and Screening System of higher education entrance exam in 2004. All of the interviewees came from senior high schools in Taipei city. The findings are as follows:
1. Examinees’ cognition toward the system:
(1) Examinees’ understanding towards the system principally came from their school.
(2) Most examinees did not completely understand the system until their last year in senior high school.
(3) Most examinees had very limited understanding about the standards of primary selection for participating in the Recommendation and Screening System at their school.
2. The examinees’ coping strategies toward the system:
(1) Each examinee’s choices of the department and schools were based on rationally calculation of their own interests and abilities.
(2) Many examinees did not zealously prepare the recommendation and screening exam until their last year in senior high school.
(3) Examinees used all possible resources to prepare for the Recommendation and Screening system.
3. The function of cultural capital within the system:
(1) Family cultural capital did not seem to function too much in the system.
(2) The content of the interviews in the Recommendation and Screening system is closely related to cultural capital.
(3) The impact of cultural capital was not obvious on the result of recommendation and screening exam.
(4) Cultural capital worked only when the examinees actively used it.
4. The function of social capital within the system:
(1) Social capital influenced examinees’ choice of the department and university.
(2) Social capital affected examinees’ coping strategy in preparing for the recommendation and screening exam.
(3) Parental social capital offered limited help to the examinees during the interview.
(4) Social capital needed to be actively used by the examinees.
Suggestions for students and senior high schools were offered at the end. Ideas for future study are also provided.
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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