4,402 research outputs found
白金微粒/Ru錯合物/高分子薄磨修飾電極之製備及其電催化應用
No full text[[abstract]]Membrane-metal modified cells are usually applied to the field of membrane cells, such as fuel cells, light cells… etc. Some hydrogen evolution catalysts, for example Pt metal, are used as the cathodes in these cells. Therefore, in this research, we try to dose a series of Ru complexes into the intervals between the cathode and the thin film electrode to improve the hydrogen evolution efficiency of the membrane-metal modified cells.
Ru complex (chosen from Ru(bpy)2phenNH2, Ru(dmb)2 phenNH2, Ru(tmb)2phenNH2, Ru(bpy)2Cl2, Ru(dmb)2Cl2, Ru(tmb)2Cl2) doped Nafion solution was drop-coated onto glassy carbon (GC) electrode and formed a thin film after drying. Then, the GC electrode was immersed into H2PtCl6 solution, and the Pt/Ru complex/polymer modified electrode was obtained by reducing Pt with a DPTB method. Different amount of Pt was electroplated on the GC electrode even at the same conditions (the same potential, the same time interval) when different consistency or kinds of Ru complexes were used, suggesting the influence of the ligands on the red-ox property of Ru complexes. The effective surface area (estimated by CV method) of Pt in the modified electrode is also varied with different species of Ru complexes, which in turn affect on the efficiency of hydrogen evolution.
Furthermore, from the information obtained by SEM and EDS, the alignment and the density of Pt particles growing on the GC electrode are figured out. From the fluorescence lifetime and luminescence spectra, a good electron-transfer is considered to have occurred between D series Ru complexes and Pt modified electrode that explained why a high hydrogen evolution efficiency has been obtained. The modified electrodes are still stable one month after fabricated and their hydrogen evolution efficiency was as good as a newly prepared one.
All-optical RZ data conversion with temporally and spectrally gain-sliced semiconductor optical amplifier via broadband optical injection
No full textDynamic chirp control of all-optical format-converted pulsed data from a multi-wavelength inverse-optical-comb injected semiconductor optical amplifier
No full textFIGURES 1–6 in Description of a new subspecies of Dodona dipoea Hewitson, [1866] (Lycaenidae Riodininae) from S.W. Chongqing, China
No full textFIGURES 1–6. Adults of Dodona dipoea pseudokaterina. 1–3. male. 4–6. female. 1. holotype. 2–6. paratypes. A. dorsal side. B. ventral side. Scale bar = 1 cm.Published as part of Xue, Guo-Xi, Lai, Da-Kun & Xu, Ru-Yan, 2020, Description of a new subspecies of Dodona dipoea Hewitson, [1866] (Lycaenidae Riodininae) from S.W. Chongqing, China, pp. 440-444 in Zootaxa 4895 (3) on page 441, DOI: 10.11646/zootaxa.4895.3.9, http://zenodo.org/record/432693
reilability of flip-chip package
No full text在以往電子構裝相關研究之文獻中，分析一構裝體受力後之應力、應變及最後所得之壽命經常為一定值，然而實驗或實測所得的結果卻往往具有相當的離散性，而需以韋伯等機率分佈函數來呈現。本研究為了探討此隨機疲勞壽命分佈從何而來的問題，就以下兩種狀況探討之，一為構裝體之元件尺寸因加工誤差而有所變異，另一為疲勞壽命預估公式之參數有所變異。研究方法為在適當隨機考量下，利用有限元素軟體，模擬覆晶構裝體受溫度循環負載，得到等效非彈性應變範圍，再經由壽命預估公式求得構裝體的隨機疲勞壽命及其量化可靠度。研究結果顯示：考慮實際製造所產生的合理誤差範圍下，錫鉛凸塊半徑變異較晶片厚度變異更易影響覆晶構裝體之疲勞壽命變異，而在疲勞壽命預估公式並非一完全確定公式之假設下，構裝體因壽命預估公式參數變異而產生之隨機疲勞壽命分佈現象已不可忽略，我們也進一步發現當預估公式參數的變異係數夠大時，可以光就指數參數變異來探討對構裝體壽命的變異與分佈之影響。並且進一步可以了解就實際面而言，各參數變異對疲勞壽命影響程度的大小為：凸塊>晶片>係數A>係數B。In study the reliability of electronic packages from mechanics point of view, the analytical of stress and strain obtained from finite element analysis and fatigue life prediction based on a Coffin-Manson equation are always constant values. However, the real outcomes of package life have probability distributions and frequently plotted in Weibull probability papers. In order to find out this contradiction, we suppose two kind of possible causes to investigate. One is the geometric parameters of a flip-chip package are random variables. The other is parameters of the Coffin-Manson equation are also random variables. The method of investigation is using finite element software to simulate a flip-chip package on thermal-cyclic loading. Then the cyclic equivalent inelastic strain range of a certain type of flip-chip package is found, and the fatigue life of the package is determined base on a Coffin-Manson equation. It is found that among different geometric parameters, the radius of solder bump affects the fatigue life of the package the most when considering the actually manufacturing tolerance. Considering parameters of the Coffin-Manson equation are random variables, we found the exponent parameter affects the fatigue life distribution more than the other parameter.中文摘要..................................................I
英文摘要.................................................II
目錄....................................................III
表目錄...................................................VI
圖目錄...................................................IX
符號目錄.................................................XI
第一章 緒論
1-1前言...............................................1
1-2 文獻回顧..........................................2
1-3 研究動機與目的....................................4
1-4論文架構...........................................4
第二章 基本理論
2-1 應變硬化模型.....................................6
2-2 潛變模型.........................................7
2-3六標準差...........................................8
2-4金屬凸塊疲勞壽命預估公式..........................10
2-5連續機率分佈......................................12
2-6機率點圖..........................................16
2-7卡方檢定..........................................18
第三章 不考慮參數變異之有限元素分析與結果
3-1模型基本假設......................................21
3-2模型尺寸與材料性質................................22
3-3模擬分析程序......................................23
3-4模擬結果..........................................23
第四章 尺寸參數(尺寸大小)變異的影響
4-1 前言.............................................31
4-2金屬凸塊尺寸變異對疲勞壽命影響....................32
4-3 晶片厚度變異對疲勞壽命影響.......................34
4-4 小結.............................................35
第五章 疲勞壽命預估式中參數變異的影響
5-1前言..............................................47
5-2係數A為隨機變數與疲勞壽命之關係...................47
5-3係數B為隨機變數與疲勞壽命之關係...................49
5-4係數A與B皆為隨機變數與疲勞壽命之關係..............50
5-5 參數變對與疲勞壽命的影響之綜合比較...............51
5-6以隨機抽樣探討A&B參數皆為常態分佈時對疲勞壽命的影響.......................................................52
5-7 小結.............................................54
第六章 結論與未來展望
6-1結論..............................................71
6-2未來展望..........................................73
附錄.....................................................76
參考文獻.................................................7
Photophysical Characterization of Ru Nanoclusters on Nanostructured TiO<sub>2</sub> by Time-Resolved Photoluminescence Spectroscopy
No full textDespite the promising performance of Ru nanoparticles or nanoclusters on nanostructured TiO2 in photocatalytic and photothermal reactions, a mechanistic understanding of the photophysics is limited. The aim of this study is to uncover the nature of light-induced processes in Ru/TiO2 and the role of UV versus visible excitation by time-resolved photoluminescence (PL) spectroscopy. The PL at a 267 nm excitation is predominantly due to TiO2, with a minor contribution of the Ru nanoclusters. Relative to TiO2, the PL of Ru/TiO2 following a 267 nm excitation is significantly blue-shifted, and the bathochromic shift with time is smaller. We show by global analysis of the spectrotemporal PL behavior that for both TiO2 and Ru/TiO2 the bathochromic shift with time is likely caused by the diffusion of electrons from the TiO2 bulk toward the surface. During this directional motion, electrons may recombine (non)radiatively with relatively immobile hole polarons, causing the PL spectrum to red-shift with time following excitation. The blue-shifted PL spectra and smaller bathochromic shift with time for Ru/TiO2 relative to TiO2 indicate surface PL quenching, likely due to charge transfer from the TiO2 surface into the Ru nanoclusters. When deposited on SiO2 and excited at 532 nm, Ru shows a strong emission. The PL of Ru when deposited on TiO2 is completely quenched, demonstrating interfacial charge separation following photoexcitation of the Ru nanoclusters with a close to unity quantum yield. The nature of the charge-transfer phenomena is discussed, and the obtained insights indicate that Ru nanoclusters should be deposited on semiconducting supports to enable highly effective photo(thermal)catalysis.QN/Afdelingsburea
Genomic splice site prediction algorithm based on nucleotide sequence pattern for RNA viruses
No full textMorphological and molecular evidence for the recognition of Caloglossa fonticola sp. nov. (Delesseriaceae, Rhodophyta) from an underground spring in Guangxi, China
No full textFang, Kun-Peng, Nan, Fang-Ru, Feng, Jia, Liu, Qi, Liu, Xu-Dong, Xie, Shu-Lian (2021): Morphological and molecular evidence for the recognition of Caloglossa fonticola sp. nov. (Delesseriaceae, Rhodophyta) from an underground spring in Guangxi, China. Phytotaxa 522 (1): 15-26, DOI: 10.11646/phytotaxa.522.1.2, URL: http://dx.doi.org/10.11646/phytotaxa.522.1.
All-Optical Decision-Gating of 10-Gb/s RZ Data in a Semiconductor Optical Amplifier Temporally Gain-Shaped With Dark-Optical-Comb
No full textRu-Substituted MnO<sub>2</sub> for Accelerated Water Oxidation: The Feedback of Strain-Induced and Polymorph-Dependent Structural Changes to the Catalytic Activity and Mechanism
No full textHeteroatomic modulation of MnO2 is an effective
way
to introduce and tailor the catalytically active sites for electrochemical
water oxidation. While great efforts have been devoted to parsing
the configuration and coordination of dopants in dictating the catalytic
activity, less is considered about the feedback from the structurally
adapted MnO2 host to the intrinsic activity of catalytic
sites. In this study, the topological effect on oxygen evolution reaction
(OER) activity was systemically investigated for partially Ru-substituted
MnO2 of various polymorphs. We show that MnO2 of different porosities responds differently to the Ru integration,
thereby resulting in varied lattice strains and morphological changes.
While the highly porous τ-MnO2 undergoes amorphization
upon Ru substitution, the closely packed β-MnO2 suffers
crystal splintering with drastically enhanced structural defects,
which lends to a low OER overpotential of 278 mV at 10 mA cm–2 and a high turnover frequency of 2022.2 h–1 that
is 19.6-fold higher than that of the commercial RuO2 benchmark.
Therefore, the integration of Ru does not simply append active sites
to the relatively inert metal oxides but simultaneously modifies the
crystal structure of MnO2 to retroactively modulate the
catalytic activity. We further show that OER on the Ru-substituted
β-MnO2 follows a lattice oxygen mechanism as a result
of the adapted oxide substrate. This study furnishes a fresh and systemic
view on the dopant–substrate interplay for modulating the electrocatalytic
activity of tunneled MnO2 structures
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