Browsing by Issue Date, starting with "2016-09-07"

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Small molecule based N-phenyl carbazole substituted diketopyrrolopyrroles as donors for solution-processed bulk heterojunction organic solar cells
(2016-09-07)
Patil, Yuvraj
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Misra, Rajneesh
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Chen, F. C.
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Sharma, Ganesh D.
;
光電工程學系
We report two acetylene-bridged small molecules DPP5 and DPP6 with low HOMO-LUMO gaps as donors along with PC71BM as an acceptor for the fabrication of solution-processed bulk heterojunction solar cells. After the optimization, i.e. weight ratio of donor to acceptor and surface treatment of the active layer, we achieved overall power conversion efficiencies up to 4.65% (J(SC) = 8.19mA cm(-2), V-OC = 0.98 V and FF = 0.58) and 5.73% (J(SC) = 9.58 mA cm(-2), V-OC = 0.98 V and FF = 0.61), for DPP5:PC71BM and DPP6:PC71BM respectively, which are superior to those for the devices based on as-cast active layers. The significant change in the power conversion efficiency is attributed to the improvement in nanoscale morphology, balanced charge transport and charge collection efficiency, induced through the surface treatment.
A flatter gallium profile for high-efficiency Cu(In,Ga)(Se,S)(2) solar cell and improved robustness against sulfur-gradient variation
(2016-09-07)
Huang, Chien-Yao
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Lee, Wen-Chin
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Lin, Albert
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Co-optimization of the gallium and sulfur profiles in penternary Cu(In,Ga)(Se, S)(2) thin film solar cell and its impacts on device performance and variability are investigated in this work. An absorber formation method to modulate the gallium profiling under low sulfur-incorporation is disclosed, which solves the problem of Ga-segregation in selenization. Flatter Ga-profiles, which lack of experimental investigations to date, are explored and an optimal Ga-profile achieving 17.1% conversion efficiency on a 30 cm x 30 cm sub-module without anti-reflection coating is presented. Flatter Ga-profile gives rise to the higher V-oc x J(sc) by improved bandgap matching to solar spectrum, which is hard to be achieved by the case of Ga-accumulation. However, voltage-induced carrier collection loss is found, as evident from the measured voltage-dependent photocurrent characteristics based on a small-signal circuit model. The simulation results reveal that the loss is attributed to the synergistic effect of the detrimental gallium and sulfur gradients, which can deteriorate the carrier collection especially in quasi-neutral region (QNR). Furthermore, the underlying physics is presented, and it provides a clear physical picture to the empirical trends of device performance, I-V characteristics, and voltage-dependent photocurrent, which cannot be explained by the standard solar circuit model. The parameter "FGa" and front sulfur-gradient are found to play critical roles on the trade-off between space charge region (SCR) recombination and QNR carrier collection. The co-optimized gallium and sulfur gradients are investigated, and the corresponding process modification for further efficiency-enhancement is proposed. In addition, the performance impact of sulfur-gradient variation is studied, and a gallium design for suppressing the sulfur-induced variability is proposed. Device performances of varied Ga-profiles with front sulfur-gradients are simulated based on a compact device model. Finally, an exploratory path toward 20% high-efficiency Ga-profile with robustness against sulfur-induced performance variability is presented. Published by AIP Publishing.
Identification of Inhibitors for the DEDDh Family of Exonucleases and a Unique Inhibition Mechanism by Crystal Structure Analysis of CRN-4 Bound with 2-Morpholin-4-ylethanesulfonate (MES)
(2016-09-08)
Huang, Kuan-Wei
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Hsu, Kai-Cheng
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Chu, Lee-Ya
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Yang, Jinn-Moon
;
Yuan, Hanna S.
The DEDDh family of exonucleases plays essential roles in DNA and RNA metabolism in all kingdoms of life. Several viral and human, DEDDh exonucleases can serve as antiviral drug targets due to their critical roles virus replication. Here using RNase T and CRN-4 as the model systems, we identify potential inhibitors for DEDDh exonucleases. We further show that two of the inhibitors, ATA and PV6R, indeed inhibit the exonuclease activity of the viral protein NP exonuclease of Lassa fever virus in vitro. Moreover, we determine the crystal structure of CRN-4 in complex with MES that reveals a unique inhibition Mechanism, by inducing the general base His179 to shift out of the active site. Our results not only provide the structural basis for the inhibition mechanism but also suggest potential lead inhibitors for the DEDDh exonucleases that may pave the way for designing nuclease inhibitors for biochemical and biomedical applications.
3D Ta/TaOx/TiO2/Ti synaptic array and linearity tuning of weight update for hardware neural network applications
(2016-09-09)
Wang, I-Ting
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Chang, Chih-Cheng
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Chiu, Li-Wen
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Chou, Teyuh
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Hou, Tuo-Hung
The implementation of highly anticipated hardware neural networks (HNNs) hinges largely on the successful development of a low-power, high-density, and reliable analog electronic synaptic array. In this study, we demonstrate a two-layer Ta/TaOx/TiO2/Ti cross-point synaptic array that emulates the high-density three-dimensional network architecture of human brains. Excellent uniformity and reproducibility among intralayer and interlayer cells were realized. Moreover, at least 50 analog synaptic weight states could be precisely controlled with minimal drifting during a cycling endurance test of 5000 training pulses at an operating voltage of 3 V. We also propose a new state-independent bipolar-pulse-training scheme to improve the linearity of weight updates. The improved linearity considerably enhances the fault tolerance of HNNs, thus improving the training accuracy.
Use of Selective Serotonin Reuptake Inhibitors and Risks of Stroke in Patients with Obsessive Compulsive Disorder: A Population-Based Study
(2016-09-09)
Chu, Che-Sheng
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Chou, Po-Han
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Lin, Ching-Heng
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Cheng, Chin
;
Tsai, Chia-Jui
Background Previous research has suggested a link between antidepressants use and the development of cerebrovascular events, but there has never been any study investigating the risk of stroke in obsessive-compulsive disorder (OCD) patients treated with a selective serotonin reuptake inhibitor (SSRI). Methods A retrospective observational cohort study was conducted using data from the National Health Insurance Database of Taiwan between the year of 2001 and 2009. A total of 527 OCD patients with 412 subjects in the SSRI use group and 115 in the non SSRI use group were included. Multivariable Cox proportional-hazards models were used to explore the associations between SSRI use and the occurrence of stroke, controlling for age, gender, concomitant medications, and comorbid medical illnesses. Results A total of nineteen OCD patients were diagnosed with new onset of stroke during the follow-up period including six cases in the SSRI group and thirteen in the non SSRI use group. SSRI use was demonstrated to be associated with a decreased risk of stroke (hazard ratio [HR] = 0.30; 95% confidence interval [CI] = 0.10-0.86, P = 0.02). The increase in age-related risk of strokes was 2.55 per decade (HR = 2.55; 95% CI = 1.74-3.75, P<0.001). Alternatively, sex, concomitant use of aspirin and non-steroidal anti-inflammatorydrugs, and comorbidities with angina pectoris, diabetes mellitus, hypertension, and hyperlipidemia were not found to be associated with an increased risk for stroke in OCD patients. Conclusions Our study showed that SSRI use was associated with decreased risk of stroke in OCD patients. Further investigation into the possible biological mechanisms underlying the relationship between stroke and SSRI use in OCD patients is warranted.
ProbeBuilder: Uncovering Opaque Kernel Data Structures for Automatic Probe Construction
(2016-09-10)
Wang, Chi-Wei
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Wang, Chia-Wei
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Shieh, Shiuhpyng
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資訊工程學系
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Department of Computer Science
VM-based inspection tools generally implement probes in the hypervisor to monitor events and the state of kernel of the guest system. The most important function of a probe is to carve information of interest out of the memory of the guest when it is triggered. Implementing probes for a closed-source OS demands manually reverse-engineering the undocumented code/data structures in the kernel binary image. Furthermore, the reverse-engineering result is often non-reusable between OS versions or even kernel updates due to the rapid change of these structures. In this paper, we propose ProbeBuilder, a system automating the process to inference kernel data structures. Based on dynamic execution, ProbeBuilder searches for data structures matching the "pointer-offset-pointer" pattern in guest memory. The sequences of these offsets, which are referred to as dereferences, are then verified by ProbeBuilder with instruction evidence that traverse them. The experiment on Windows kernel shows that ProbeBuilder efficiently narrows thousands of choices for kernel-level probes down to dozens. The finding allows analysts to quickly implement probes, facilitating rapid development/update of inspection tools for different OSes. With these features, ProbeBuilder is the first system capable of automatically generating practical probes that extracts information through dereferences to opaque kernel data structures.
Combined vitamin C sonophoresis and neodymium-doped yttrium aluminum garnet (NdYAG) laser for facial hyperpigmentation: An outcome observation study in Asian patients
(2016-09-10)
Chen, Yu-Tsung
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Chang, Chang-Cheng
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Hsu, Cherng-Ru
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Shen, Jen-Hsiang
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Shih, Chao-Jen
Background: The neodymium-doped yttrium aluminum garnet (NdYAG) laser therapy has been a popular technique for facial rejuvenation but certain adverse effects like post-inflammatory hyperpigmentation are issues of concern to Asian patients. Aims: To assess the outcome following combined treatment with vitamin C sonophoresis and NdYAG laser, in selected cases of facial hyperpigmentation. Methods: Twenty three women with dyschromia or melasma who had undergone five sessions of Q-switched NdYAG laser therapy followed by transdermal delivery of vitamin C via sonophoresis were selected after a retrospective review of case records. The objective and subjective clinical outcomes and the side effects, including erythema, scaling, pruritus, dryness and post-inflammatory hyperpigmentation were evaluated. Results: In both objective or subjective outcomes, 91.3% (21/23) of the patients showed an excellent or better outcome, while 8.7% (2/23) showed no change. A majority of the patients (73.9%, 17/23) experienced no post-inflammatory hyperpigmentation or had slight post-inflammatory hyperpigmentation which quickly resolved within 1 week. Only one (4.3%) patient had extreme post-inflammatory hyperpigmentation which lasted for over a month. Limitations: This was a retrospective study without a control group; a comparative study with a control group (patients treated with the laser alone, without vitamin C sonopheresis) is needed to determine the difference in the outcome. Conclusion: The use of vitamin C sonophoresis along with NdYAG laser may reduce the incidence of adverse effects in Asian patients. Patients experienced obvious improvement in hyperpigmentation and had lower chances of experiencing extreme or severe post-inflammatory hyperpigmentation.
Industrial energy-pollution performance of regions in China based on a unified framework combining static and dynamic indexes
(2016-09-10)
Li, Lan-Bing
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Hu, Jin-Li
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Xia, Nian-Cheng
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經營管理研究所
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Institute of Business and Management
Energy and environmental concerns have attracted more and more worldwide attention. As industrialization leads to serious environmental effects on sustainable development, China urgently needs to improve its energy-pollution performance without harming industrial growth. This paper proposes two indexes, the energy-pollution efficiency index and the energy-pollution productivity change index, in a unified framework that not only enables a more comprehensive analysis by simultaneously allowing for both static and dynamic performance evaluations, but also sets a sounder best target environmental effect by jointly considering energy conservation and pollution reduction. This research evaluates the industrial energy-pollution performance of regions in China during the period 1995-2014. Findings reveal that its energy-pollution efficiency was unbalanced and hovered at a low level, showing an urgent need for improvement; however, energy-pollution productivity did gradual increase and technology progress was its main contributor. Energy efficiency was higher than pollution efficiency, and their gap increased instead of narrowing. The east area\'s energy-pollution efficiency ranked first, while its regional discrepancy presented an increasing trend. Energy-pollution productivity improvement was mainly driven by technology progress, while efficiency change exhibited a negative effect. Finally, energy utilization contributed less to energy-pollution productivity improvement than pollution emissions. (C) 2016 Elsevier Ltd. All rights reserved.
Understanding Morphology Compatibility for High-Performance Ternary Organic Solar Cells
(2016-09-13)
Mai, Jiangquan
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Lau, Tsz-Ki
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Li, Jun
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Peng, Shih-Hao
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Hsu, Chain-Shu
Ternary organic solar cells are emerging as a promising strategy to enhance device power conversion efficiency by broadening the range of light absorption via the incorporation of additional light-absorbing components. However, how to find compatible materials that allow comparable loadings of each component remains a challenge. In this article, we focus on studying the donor polymer compatibilities in ternary systems from a morphological point of view. Four typical donor polymers with different chemical structures and absorption ranges were mutually combined to form six distinct ternary systems with fullerene derivative acceptors. Two compatible ternary systems were identified as showing significant improvements of efficiency from both binary control devices. Ternary morphologies were characterized by grazing incident X-ray scattering and correlated with device performance. We find that polymers that have strong lamellar interactions and relatively similar phase separation behaviors with the fullerene derivative are more likely to be compatible in ternary systems. This result provides guidance for polymer selection for future ternary organic solar cell research while relaxing the limitation of chemical structure similarity and greatly extends the donor candidate pool.
Depth-Profiling Electronic and Structural Properties of Cu(In,Ga)(S,Se)(2) Thin-Film Solar Cell
(2016-09-14)
Chiang, Ching-Yu
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Hsiao, Sheng-Wei
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Wu, Pin-Jiun
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Yang, Chu-Shou
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Chen, Chia-Hao
Utilizing a scanning photoelectron microscope (SPEM) and grazing-incidence X-ray powder diffraction (GIXRD), we studied the electronic band structure and the crystalline properties of the pentanary Cu(In,Ga)(S,Se)(2) (CIGSSe) thin-film solar cell as a function of sample depth on measuring the thickness-gradient sample. A novel approach is proposed for studying the depth-dependent information on thin films, which can provide a gradient thickness and a wide cross-section of the sample by polishing process. The results exhibit that the CIGSSe absorber layer possesses four distinct stoichiometries. The growth mechanism of this distinctive compositional: distribution formed by a two stage process is described according to the thermodynamic reaction and the manufacturing, process. On the basis of the depth-profiling results, the gradient profiles of the conduction and valence bands were constructed to elucidate the performance of the electrical properties (in this case, V-oc = 620 mV, J(sc) = 34.6 mA/cm(2), and eta = 14.04%); the valence-band maxima (VBM) measured with a SPEM in the spectroscopic mode coincide with this band-structure model, except for a lowering of the VBM observed in the surface region of the absorber layer due to the ordered defect compound (ODC). In addition, the depth-dependent texturing X-ray diffraction pattern presents the crystalline quality and the residual stress for each depth of a thin-film device. We find that the randomly oriented grains in the bottom region of the absorber layer and the different residual stress between the underlying Mo and the absorber interface, which can deteriorate the electrical performance due to peeling-off effect. An anion interstitial defect can be observed on comparing the anion concentration, of the elemental distribution with crystalline composition; a few excess sulfur atoms insert in interstitial sites at the front side of the absorber layer, whereas the interstitial selenium atoms insert at the back side.
Generation of self-clusters of galectin-1 in the farnesyl-bound form
(2016-09-14)
Yamaguchi, Kazumi
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Niwa, Yusuke
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Nakabayashi, Takakazu
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Hiramatsu, Hirotsugu
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應用化學系
Ras protein is involved in a signal transduction cascade in cell growth, and cluster formation of H-Ras and human galectin-1 (Gal-1) complex is considered to be crucial to achieve its physiological roles. It is considered that the complex is formed through interactions between Gal-1 and the farnesyl group (farnesyl-dependent model), post-translationally modified to the C-terminal Cys, of H-Ras. We investigated the role of farnesyl-bound Gal-1 in the cluster formation by analyzing the structure and properties of Gal-1 bound to farnesyl thiosalicylic acid (FTS), a competitive inhibitor of the binding of H-Ras to Gal-1. Gal-1 exhibited self-cluster formation upon interaction with FTS, and small-and large-size clusters were formed depending on FTS concentration. The galactoside-binding pocket of Gal-1 in the FTS-bound form was found to play an important role in small-size cluster formation. Large-size clusters were likely formed by the interaction among the hydrophobic sites of Gal-1 in the FTS-bound form. The present results indicate that Gal-1 in the FTS-bound form has the ability to form self-clusters as well as intrinsic lectin activity. Relevance of the self-clustering of FTS-bound Gal-1 to the cluster formation of the H-Ras-Gal-1complex was discussed by taking account of the farnesyl-dependent model and another (Raf-dependent) model.
Mechanism transition and strong temperature dependence of dislocation nucleation from grain boundaries: An accelerated molecular dynamics study
(2016-09-14)
Du, Jun-Ping
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Wang, Yun-Jiang
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Lo, Yu-Chieh
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Wan, Liang
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Ogata, Shigenobu
Accelerated molecular dynamics reveals a mechanism transition and strong temperature dependence of dislocation nucleation from grain boundaries (GBs) in Cu. At stress levels up to similar to 90% of the ideal dislocationnucleation stress, atomic shuffling at the E structural unit in a GB acts as a precursor to dislocation nucleation, and eventually a single dislocation is nucleated. At very high stress levels near the ideal dislocation-nucleation stress, a multiple dislocation is collectively nucleated. In these processes, the activation free energy and activation volume depend strongly on temperature. The strain-rate dependence of the critical nucleation stress is studied and the result shows that the mechanism transition from the shuffling-assisted dislocation-nucleation mechanism to the collective dislocation-nucleationmechanism occurs during the strain rate increasing from 10(-4) s(-1) to 10(10) s(-1).
Catalytic performance and SO2 tolerance of tetragonal-zirconia-based catalysts for low-temperature selective catalytic reduction
(2016-09-14)
Liu, Rong
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Ji, Lingchen
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Xu, Yifan
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Ye, Fei
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Jia, Feng
MnOx-CeO2/t-ZrO2 catalyst was prepared by impregnation of nanotetragonal zirconia. The NO conversion of 5 wt% MnOx-CeO2/t-ZrO2 catalyst was 68.1% at 100 degrees C while that of 30 wt% MnOx-CeO2/t-ZrO2 catalyst was 97.4%. The x-ray diffraction, Brunner-Emmet-Teller measurements (BET), and H-2-TPR showed surface properties of the prepared catalysts were good for selective catalytic reduction reactions. X-ray photoelectron spectroscopy analysis indicated that Mn4+ and Ce4+ oxidation states were predominant on the surface of the catalyst and so was lattice oxygen which was conducive to Lewis acid sites. NH3-TPD test results demonstrated that Lewis acid sites are predominant on the surface of catalyst. The presence of SO2 reduced the catalyst activity. The realized conversion dramatically decreased to 47% from nearly 100% after 8 h. Characterization of fresh and spent catalysts indicated the deterioration of active component and deposition of NH4HSO4 or (NH4)(2)SO4 contribute to SO2 poisoning.
CRP-Cyclic AMP Regulates the Expression of Type 3 Fimbriae via Cyclic di-GMP in Klebsiella pneumoniae
(2016-09-15)
Lin, Ching-Ting
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Lin, Tien-Huang
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Wu, Chien-Chen
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Wan, Lei
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Huang, Chun-Fa
Klebsiella pneumoniae is the predominant pathogen isolated from liver abscesses of diabetic patients in Asian countries. However, the effects of elevated blood glucose levels on the virulence of this pathogen remain largely unknown. Type 3 fimbriae, encoded by the mrkABCDF genes, are important virulence factors in K. pneumoniae pathogenesis. In this study, the effects of exogenous glucose and the intracellular cyclic AMP (cAMP) signaling pathway on type 3 fimbriae expression regulation were investigated. The production of MrkA, the major subunit of type 3 fimbriae, was increased in glucose-rich medium, whereas cAMP supplementation reversed the effect. MrkA production was markedly increased by cyaA or crp deletion, but slightly decreased by cpdA deletion. In addition, the mRNA levels of mrkABCDF genes and the activity of P-mrkA were increased in Delta crp strain, as well as the mRNA levels of mrkHIJ genes that encode cyclic di-GMP (c-di-GMP)-related regulatory proteins that influence type 3 fimbriae expression. Moreover, the activities of P-mrkHI and P-mrkJ were decreased in Delta lacZ Delta crp strain. These results indicate that CRP-cAMP down-regulates mrkABCDF and mrkHIJ at the transcriptional level. Further deletion of mrkH or mrkI in Delta crp strain diminished the production of MrkA, indicating that MrkH and MrkI are required for the CRP regulation of type 3 fimbriae expression. Furthermore, the high activity of P-mrkHI in the Delta lacZ Delta crp strain was diminished in Delta lacZ Delta crp Delta mrkHI, but increased in the Delta lacZ Delta crp Delta mrkJ strain. Deletion of crp increased the intracellular c-di-GMP concentration and reduced the phosphodiesterase activity. Moreover, we found that the mRNA levels of multiple genes related to c-di-GMP metabolism were altered in Delta crp strain. These indicate that CRP regulates type 3 fimbriae expression indirectly via the c-di-GMP signaling pathway. In conclusion, we found evidence of a coordinated regulation of type 3 fimbriae expression by the CRP-cAMP and c-di-GMP signaling pathways in K. pneumoniae.
Nanomechanical, structural, and transport properties of Bi3Se2Te thin films
(2016-09-15)
Phuoc Huu Le
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Chiu, Shao-Pin
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Jian, Sheng-Rui
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Luo, Chih Wei
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Lin, Jiunn-Yuan
New ternary phase of Bi3Se2Te thin films were successfully grown through pulsed laser deposition with a single Bi2Se2Te crystal as the target. Bi-rich and Se-and Te-deficient compositions deposited at a substrate temperature (T-s) of 250 degrees C and helium gas pressures (P-He) ranging from 2.0 x 10(-5) to 6.5 x 10(-1) Torr aided the formation of the dominant Bi-rich phase: Bi3Se2Te. The films were grown epitaxially on Al2O3 (001) substrates with Bi3Se2Te [001]//Al2O3 [001] and Bi3Se2Te [110]//Al2O3 [210]. An increase in P-He remarkably enhanced the hardness and Young\'s modulus of the films, primarily because of the decrease in nanograin size, following the HallePetch relationship. Moreover, the Bi3Se2Te films present linear magnetoresistance under a high perpendicular magnetic field (B >= 4 T) and twodimensional weak antilocalization effect under a low B (+/- 1 T) which may be attributed to topological insulator surface state (TSS). Clearly, further theoretical calculations and experiments are needed to confirm the suggested interpretation. (C) 2016 Elsevier B.V. All rights reserved.
Oxygen Vacancy in Hafnia as a Blue Luminescence Center and a Trap of Charge Carriers
(2016-09-15)
Gritsenko, Vladimir A.
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Islamov, Damir R.
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Perevalov, Timofey V.
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Aliev, Vladimir Sh.
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Yelisseyev, Alexander P.
The electronic properties of HfO2, in particular, luminescence and charge transport, are determined by defects and traps. The origin of luminescence centers and traps of charge carriers in a HfO2 crystal was studied using luminescence spectroscopy, charge transport, and quantum chemical calculation. The 2.7 eV luminescence band and 5.2 eV absorption/luminescence excitation band are associated with an oxygen vacancy. The thermal activation energy 1.25 eV, estimated from the charge transport and thermoluminescence experiment, is equal to half of the Stokes shift in photoluminescence spectra. Hence, oxygen vacancies are supposed to operate as electron traps in HfO2, and the charge transport is described by phonon-assisted tunneling between traps.
Study of electromigration-induced formation of discrete voids in flip-chip solder joints by in-situ 3D laminography observation and finite-element modeling
(2016-09-15)
Chang, Yuan-Wei
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Cheng, Yin
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Xu, Feng
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Helfen, Lukas
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Tian, Tian
In the microelectronics industry the flip-chip (FC) technology is broadly used to enhance the packaging density. However, the small size and the unique geometry of the FC solder joints induce the electro-migration (EM) reliability issue. In this study, a pair of lead-free solder joints (SAC1205) was EM tested by a current of 7.5 x 10(3) A/cm(2). During the tests, X-ray laminography was applied to observe the microstructure evolution in-situ. Laminography enables the non-destructive observation of the bump microstructure and allows for a quantitative three-dimensional (3D) analysis. After EM testing for 650 h, a new EM failure mechanism was found, differing from the two well-known models, the pancake void propagation and the under-bump-metallization dissolution. Here, a few pre-existing small voids grew and simultaneously many new voids formed and grew over the entire EM testing period. Most of the nucleating voids were distributed in the current crowding region, a few also located in the low-current density region. As the testing time increased, voids increasingly coalesced with each other, forming a porous network which occupied a large part of the interface area and caused the EM failure. A finite element (FE) method was then applied to analyze the interplay between the microstructure evolution and current density redistribution. A series of 3D FE models was built based on the laminography images for the different testing stages. The current density distribution from the FE analysis indicates that the formation of discrete voids did not affect the global current density distribution until a major coalescence of the voids occurred. The relieving of the global current crowding in the pancake void model was not found in this new EM failure mechanism. It was the local current crowding around individual void found in the new mechanism that is held responsible for the EM retardation. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
製備高分子球的方法
(2016-09-16)
陳俊太
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邱俞靜
;
張鈞?
製備高分子球的方法，包含將高分子溶液塗佈於基板上以形成高分子薄膜。接著，將高分子薄膜置於非溶劑中進行熱退火處理，使高分子薄膜形變成複數個高分子球。非溶劑不溶解高分子，且沸點高於高分子之玻璃轉化溫度。熱退火處理係在高於高分子之玻璃轉化溫度且低於非溶劑之沸點下進行，且熱退火處理的時間約為1~180分鐘。
薄型平面生醫感測器
(2016-09-16)
林進燈
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游奕欣
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呂紹瑋
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廖倫德
一種薄型平面生醫感測器，其係包括至少一用以接觸受測者之皮膚，以量測其生醫訊號之可撓性電極。此種可撓性電極係以矽膠銀玻璃導電材質製成，且矽膠與銀玻璃組成比例係為七比三。導電薄板係電性連接該可撓性電極，一緩衝層係包覆該可撓性電極與導電薄板，且一電路基板係可接收測得之生醫訊號。利用此種創新之薄型平面生醫感測器，不僅可應用於生醫訊號的量測，由於電極更兼具有輕、薄、可彎曲、導電性佳且不誘發皮膚過敏之特性，有別於已知之濕式電極與微結構乾式電極，用以量測腦波、心電、肌電、眼動等生醫訊號，實具有極佳之發展潛力與產業利用性。
A Comparison of Independent Event-Related Desynchronization Responses in Motor-Related Brain Areas to Movement Execution, Movement Imagery, and Movement Observation
(2016-09-16)
Duann, Jeng-Ren
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Chiou, Jin-Chern
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Electroencephalographic (EEG) event-related desynchronization (ERD) induced by movement imagery or by observing biological movements performed by someone else has recently been used extensively for brain-computer interface-based applications, such as applications used in stroke rehabilitation training and motor skill learning. However, the ERD responses induced by the movement imagery and observation might not be as reliable as the ERD responses induced by movement execution. Given that studies on the reliability of the EEG ERD responses induced by these activities are still lacking, here we conducted an EEG experiment with movement imagery, movement observation, and movement execution, performed multiple times each in a pseudorandomized order in the same experimental runs. Then, independent component analysis (ICA) was applied to the EEG data to find the common motor-related EEG source activity shared by the three motor tasks. Finally, conditional EEG ERD responses associated with the three movement conditions were computed and compared. Among the three motor conditions, the EEG ERD responses induced by motor execution revealed the alpha power suppression with highest strengths and longest durations. The ERD responses of the movement imagery and movement observation only partially resembled the ERD pattern of the movement execution condition, with slightly better detectability for the ERD responses associated with the movement imagery and faster ERD responses for movement observation. This may indicate different levels of involvement in the same motor-related brain circuits during different movement conditions. In addition, because the resulting conditional EEG ERD responses from the ICA preprocessing came with minimal contamination from the non-related and/or artifactual noisy components, this result can play a role of the reference for devising a brain-computer interface using the EEG ERD features of movement imagery or observation.