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Design of Low Power CMOS LNA with Current-Reused and Notch Filter Topology for DS-UWB Application

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Wireless Engineering and Technology 2012年第3期3卷 167-174页

作者： Meng-Ting Hsu Jhih-Huei Du wen-chen chiu Microwave Communication and Radio Frequency Integrated Circuit Lab. Department and Institute of Electronic Engineering National Yunlin University of Science and Technology Yunlin Taiwan Chinese Taipei.

This paper presents the design of a low power LNA with second stage that uses a notch filter for DS-UWB application. The LNA employs a current reuse structure to reduce the power consumption and an active second order notch filter to produce band rejection in the 5 - 6 GHz frequency band. The input reflection coefficient S11 and output reflection S22 are both less than –10 dB. The maximum power gain S21 is 15 dB while the maximum rejection ratio is over –10 dB at 4.8 GHz. The minimum noise figure is 5 dB. The input referred third-order intercept point (IIP3) is –7 dBm at 6 GHz. The power consumption is 6.4 mW from a 1-V power supply.

关键词： Low Noise Amplifier (LNA) Low Power Low Voltage Ultra-Wideband (UWB) Active Notch Filter

Distribution and contamination status of chromium in surface sediments of northern Kaohsiung Harbor, Taiwan

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Journal of Environmental Sciences 2013年第7期25卷 1450-1457页

作者： cheng-Di Dong chiu-wen chen Chih-Feng chen Department of Marine Environmental Engineering "National" Kaohsiung Marine University

Thedistribution, enrichment, accumulation, and potential ecological risk of chromium （Cr） in the surface sediments of northern Kaohsiung Harbor, Taiwan, Chinawere investigated. Sediment samples from ten locations located between the river mouths and harbor entrance of northern Kaohsiung Harborwere collected quarterly in 2011 and characterized for Cr, aluminum,water content, organic matter, total nitrogen, total phosphorous, total grease, and grain size. Results showed that the Cr concentrations varied from 27.0 to361.9 mg/kgwith an average of （113.5 ± 87.0） mg/kg. High Cr concentrationwas observed near the Jen-Gen River mouth. The mean Cr concentrationwas high at 255.5 mg/kg,whichwas at least 2 to 7 times than that of other sites. This might imply significant Cr contribution from upstream receiving tannerieswastewater into the Jen-Gen River. The spatialdistribution of Cr reveals relatively high in the river mouth region, especially in Jen-Gen River, and graduallydiminishes toward the harbor entrance region. This indicates that the major sources of Cr pollution from upstream industrial and municipalwastewatersdischarged along the river bank; and Cr maydriftwith sea current and bedispersed into open sea. Moreover, Cr concentrations correlated closely to the physical-chemical properties of the sediments,which suggested the influence of industrial and municipalwastewatersdischarged from the neighboring industrial parks and river basins. Results from the enrichment factor andgeo-accumulation index analyses imply that the Jen-Gen River sediments can be characterized as moderate enrichment and none to medium accumulation of Cr, respectively. However, results of potential ecological risk index indicate that the sediment has low ecological potential risk. The results can provide valuable information todeveloping future strategies for the management of river mouth and harbor.

关键词： accumulation chromium ecological risk enrichment sediment

Observing the evolution of graphene layers at high current density

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Nano Research 2016年第12期9卷 3663-3670页

作者： Chun-Wei Huang Jui-Yuan chen Chung-Hua chiu cheng-Lun Hsin Tseung-Yuen Tseng wen-Wei Wu Department of Materials Science and Engineering Chiao Tung University 1001 University Road Hsinchiu 30010 Taiwan China Department of Electrical Engineering Central University Chung-Li City Taoyuan 32001 Taiwan China Department of Electronics Engineering and Institute of Electronics Chiao Tung University 1001 University Road Hsinchiu 30010 Taiwan China

Graphene has demonstrated its potential in several practical applications owing to its remarkable electronic and physical properties. In this study, we successfully fabricated a suspended graphene device with a width down to 20 nm. The morphological evolution of graphene under various electric field effects was systematically examined using an in-situ transmission electron microscope （TEM）. The hourglass-shaped graphene sample instantly broke apart at 7.5 mA, indicating an impressive breakdown current density. The current-carrying capacity was calculated to be -1.6 × 10^9 ***-2, which is several orders higher than that of copper. The current-carrying capacity depended on the resistivity of graphene. In addition, atomic volume changes occurred in the multilayer graphene samples due to surface diffusion and Ostwald ripening （OR）, indicating that the breakdown mechanism is well approximated by the electric field. This study not only provides a theory to explain the breakdown behavior but also presents the effects on materials contacted with a graphene layer used as the transmission path.

关键词： graphene breakdown high current density in-situ transmissionelectron microscope (TEM) Ostwald ripening

Review of Computational Approaches to Optimization Problems in Inhomogeneous Rods and Plates

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Communications on Applied Mathematics and Computation 2024年第1期6卷 236-256页

作者： Weitao chen chiu-Yen Kao Department of Mathematics University of California at Riverside900 University AveRiversideCA92521USA Department of Mathematical Sciences Claremont McKenna College850 Columbia AveClaremontCA91711USA

In this paper,we review computational approaches to optimization problems of inhomogeneous rods and *** consider both the optimization of eigenvalues and the localization of *** problems are motivated by physical problems including the determination of the extremum of the fundamental vibration frequency and the localization of the vibration *** demonstrate how an iterative rearrangement approach and a gradient descent approach with projection can successfully solve these optimization problems under different boundary conditions with different densities given.

关键词： Inhomogeneous rods and plates Bi-Laplacian Optimization of eigenvalues Localization of eigenfunctions Rearrangement

Highly Sensitive and Portable Gas Sensing System Based on Reduced Graphene Oxide

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Tsinghua Science and Technology 2016年第4期21卷 435-441页

作者： wentian Mi Shih-wen chiu Tao Xue Yuanquan chen Hanyu Qi Yi Yang Kea-Tiong Tang Tian-Ling Ren Institute of Microelectronics&Tsinghua National Laboratory for Information Science and Technology(TNList) Tsinghua University Department of Electrical Engineering Tsing Hua University

Graphene has been widely used in gas-sensing applications due to its large specific surface area and strong adsorption ability. Among different forms of graphene used as gas-sensing materials, reduced graphene oxide is one of the most convenient and economical materials to integrate with Si-based electronics, which is very important to graphene-based gas sensors. In addition, the stacking structure of graphene oxide flakes facilitates absorption and detection of gas molecules. Based on reduced graphene oxide, a highly sensitive and portable gas-sensing system was demonstrated here. Solution-based graphene oxide was cast on a chip like a TF memory card and then reduced thermally. A signal acquisition system was designed to monitor resistance variation as a sign of gas concentration. This miniature graphene-based gas sensor array demonstrates a new path for the use of graphene in gas-detection technologies. And the creation of a sensitive and portable graphene gas sensor also shows great potential in fields such as medicine and environmental science.

关键词： reduced graphene oxide gas sensor signal acquisition system thermal reduction

Local inhibition of matrix metalloproteinases reduced M2 macrophage activity and impeded recovery in spinal cord transected rats after treatment with fibroblast growth factor-1 and nerve grafts

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Neural Regeneration Research 2018年第8期13卷 1447-1454页

作者： Chuan-wen chiu wen-Hung Huang Huai-Sheng Kuo May-Jywan Tsai Ching-Jung chen Meng-Jen Lee Henrich cheng Department and Institute of Pharmacology National Yang-Ming University Taipei Taiwan China Neural Regeneration Laboratory Department of Neurosurgery Neurological Institute Taipei Veterans General Hospital Taipei Taiwan China Department of Applied Chemistry Chaoyang University of Technology Taichung Taiwan China Center for Neural Regeneration Department of Neurosurgery Neurological Institute Taipei Veterans General Hospital Taipei Taiwan China

Alternatively activated macrophages （M2 macrophages） promote central nervous system regeneration. Our previous study demonstrated that treatment with peripheral nerve grafts and fibroblast growth factor-1 recruited more M2 macrophages and improved partial functional recovery in spinal cord transected rats. The migration of macrophages is matrix metalloproteinase （MMP） dependent. We used a general inhibitor of MMPs to influence macrophage migration, and we examined the migration of macrophage populations and changes in spinal function. Rat spinal cords were completely transected at Ts, and 5 mm of spinal cord was removed （group T）. In group R, spinal cord-transected rats received treatment with fibroblast grow th factor- 1 and peripheral nerve grafts. In group RG, rats received the same treatment as group R with the addition of 200 μM GM6001 （an MMP inhibitor） to the fibrin mix. We found that MMP-9, but not MMP- 2, was upregulated in the graft area of rats in group R. Local application of the MMP inhibitor resulted in a reduction in the ratio of arginase-1 （M2 macrophage subset）/inducible nitric oxide synthase-postive cells. When the MMP inhibitor was applied at 8 weeks postoperation, the partial functional recovery observed in group R was lost. This effect was accompanied by a decrease in brain-derived neurotrophic factor levels in the nerve graft. These results suggested that the arginase-1 positive population in spinal cord transected rats is a migratory cell population rather than the phenotypic conversion of early iNOS^＋ cells and that the migration of the arginase-1^＋ population could be regulated locally. Simultaneous application of MMP in- hibitors or promotion of MMP activity for spinal cord injury needs to be considered if the coadministered treatment involves M2 recruitment.

关键词： spinal cord injury fibroblast growth factor-1 matrix metalloproteinase GM6001 macrophage

Clinical utility of hepatitis B surface antigen kinetics in treatment-na?ve chronic hepatitis B patients during longterm entecavir therapy

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World Journal of Gastroenterology 2018年第6期24卷 725-736页

作者： Tien-Ching Lin Yen-cheng chiu Hung-Chih chiu wen-Chun Liu Pin-Nan cheng chiung-Yu chen Ting-Tsung Chang I-Chin Wu Department of Internal Medicine National Cheng Kung University HospitalCollege of MedicineNational Cheng Kung UniversityTainan City70403Taiwan Infectious Disease and Signaling Research Center National Cheng Kung UniversityTainan 70403Taiwan

AIM To investigate the utility of hepatitis B surface antigen(HBsAg) kinetics in chronic hepatitis B patients during long-term entecavir *** This retrospective study included treatment-na?ve chronic hepatitis B patients who received at least 2 years of consecutive entecavir treatment. Patients were followed up at three to six month intervals with liver biochemistry, hepatitis B virus DNA, and abdominal sonography. In hepatitis B e antigen(HBeAg)-positive patients, HBeAg levels were assessed every three to six month until results became negative. Serum HBsAg levels were determined at the baseline, oneyear and five-year time points. Liver cirrhosis was diagnosed through liver biopsy, imaging examinations, or clinical findings of portal hypertension. Hepatocellular carcinoma was diagnosed by histological examination or dynamic image *** A total of 211 patients were enrolled. The median treatment time was 5.24(2.00-9.62) years. Multivariate analysis showed that lower baseline HBsAg levels were associated with an earlier virological response, earlier hepatitis B e antigen(HBeAg) seroconversion, and earlier biochemical response in HBeAg-positive patients(cut-off value: 4 log IU/mL) and an earlier virological response in HBeAg-negative non-cirrhotic patients(cut-off value: 2.4 log IU/mL). Although HBsAg levels decreased slowly during long-term entecavir treatment, higher HBsAg decrease rates were found in the first year for HBeAg-positive non-cirrhotic patients, and patients with higher baseline HBsAg levels. More favorable clinical outcomes were not observed by a rapid HBsAg decline per se, but depended on lower baseline HBsAg *** Baseline HBsAg can be used to predict treatment responses. HBsAg levels and decrease rates should be considered together according to disease status while interpreting HBsAg changes.

关键词： Chronic hepatitis B Entecavir Hepatitis B e antigen Hepatitis B surface antigen Kinetics

*** acknowledges the financial support from the Engineering and Physical Sciences Research Council(***/L022559/1,EP/L022559/2,EP/V050311/1,and EP/W004399/1);Royal Society(***130230 and IE161214);H2020 Marie Skłodowska-Curie Actions(No.790666);*** supported by a PhD Studentship provided by Queen Mary University of London and China Scholarship Council(CSC).

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Nano Research 2022年第8期15卷 7432-7452页

作者： Lumin chen Somia Yassin Hussain Abdalkarim Houyong Yu Xiang chen Dongping Tang Yingzhan Li Kam chiu Tam The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education Zhejiang Sci-Tech UniversityHangzhou 310018China Department of Chemical Engineering University of WaterlooWaterlooOntario N2L 3G1Canada

Advanced energy and sensor devices with novel applications(e.g.,mobile equipment,electric vehicles,and medical-healthcare systems)are one of the important foundations of modern intelligent ***,there are still some scientific issues that seriously hinder the further development of devices,including unsustainability,high material cost,complex fabrication process,safety issues,and unsatisfactory *** has aroused tremendous attention in recent decades,because of its abundant resources,renewability,degradability,low-cost,and unique physical/chemical *** merits make nanocellulose as matrix materials to fabricate advanced functional composites for use in energy-related fields extremely ***,we comprehensively discuss the recent progress of nanocellulose for emerging energy storage/harvesting and sensor *** preparation methodologies of nanocellulose combined with conductive materials are firstly highlighted,including carbon materials,conductive polymers,metal/metal oxide nanoparticles,metal-organic frameworks(MOFs),and covalent organic frameworks(COFs).We then focus on the nanocellulose-based advanced materials for the application in the areas of supercapacitors,lithium-ion batteries,solar cells,triboelectric nanogenerators,moisture-enabled electric generators,and ***,the future research directions of nanocellulose-based functional materials in energy-related devices are presented.

关键词： nanocellulose conductive composites supercapacitors lithium-ion batteries solar cells nanogenerators sensors

MULTIPHOTON MICROSCOPY:A NEW APPROACH IN PHYSIOLOGICAL STUDIES AND PATHOLOGICAL DIAGNOSIS FOR OPHTHALMOLOGY

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Journal of Innovative Optical Health Sciences 2009年第1期2卷 45-60页

作者： chiu-MEI HSUEH wen LO SUNG-JAN LIN TSUNG-JEN WANG FUNG-RUNG HU HSIN-YUAN TAN chen-YUAN DONG Department of Physics National Taiwan University Taipei 106 Taiwan Institute of Biomedical Engineering National Taiwan University Taipei 106 Taiwan Department of Dermatology National Taiwan University Hospital Taipei 100 Taiwan Department of Ophthalmology Taipei Medical University Hospital Taipei 100 Taiwan Department of Ophthalmology National Taiwan University College of Medicine and Hospital Taipei 100Taiwan Department of Ophthalmology Chang-Gung University Linko 333 Taiwan Institute of Biomedical Engineering National Taiwan University Taipei 100 Taiwan

Multiphoton microscopy(MPM),with the advantages of improved penetration depth,decreased photo-damage,and optical sectioning capability,has become an indispensable tool for biomedical *** combination of multiphoton fluorescence(MF)and second-harmonic generation(SHG)microscopy is particularly effective in imaging tissue structures of the ocular *** work is intended to be a review of advances that MPM has made in ophthalmic *** MPM not only can be used for the label-free imaging of ocular structures,it can also be applied for investigating the morphological alterations in corneal pathologies,such as keratoconus,infected keratitis,and corneal ***,the corneal wound healing process after refractive surgical procedures such as conductive keratoplasty(CK)can also be studied with ***,qualitative and quantitative SHG microscopy is effective for characterizing corneal thermal *** additional development,multiphoton imaging has the potential to be developed into an effective imaging technique for in vivo studies and clinical diagnosis in ophthalmology.

关键词： Multiphoton microscopy fluorescence second harmonic generation cornea sclera