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An Easily Operating Polymer 1×4 Optical Waveguide Switch Matrix Based on Vertical Couplers

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Chinese Physics letters 2007年第6期24卷 1728-1730页

作者： Kaixin Chen Pak l Chu Hau Ping Chan Kin S. Chiang Department of Electronic Engineering City University of Hong Kong Kowloon Hong Kong Cotco Holdings ltd Science Park Hong Kong

A three-dimensional （3D） polymer thermo-optic （TO） 1 × 4 waveguide switch matrix based on vertical couplers is demonstrated. It consists of four basic 3D switch units and because of its 3D structure, its construction is compact, only 9 mm in length; moreover, the control logic of the entire switch is very simple, the light signal can be easily switched to any output port by operating only a single switch unit. The finished devices exhibit a switching extinction ratio greater than 21 dB for all of four output ports and the crosstalk between two adjacent output ports is lower than -19 dB. The rise time and the fall time of the switch matrix are 0.8ms and 1.4ms, respectively. The required electrical power to initiate the switching function for M1 switching units is about 50mW.

关键词： Operating Waveguide Vertical

Effect of Fuel to Oxidant Molar Ratio on Structural and DC Electrical Conductivity of ZnO Nanoparticles Prepared by Simple Solution Combustion Method

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Journal of Materials Science & Technology 2013年第10期29卷 898-902页

作者： C.S.Naveen M.l.Dinesha H.S.Jayanna Department of PG Studies and Research in Physics Kuvempu University

ZnO nanoparticles of different sizes were prepared by varying the molar ratio of glycine and zinc nitrate hexahydrate as fuel and oxidizer （0.1, 0.8, 1.11, 1.3, 1.5, 1.7, 2.0） by simple solution combustion method. UV-Visible spectrophotometry studies show that, the band gap of the prepared ZnO nanoparticles increases with increasing fuel to oxidant （F/O） molar ratio up to 1.7 revealing the formation of ZnO nanoparticles. The decrease in band gap for the sample of F/O molar ratio 2.0 is due to an increase in particle size. Powder X-ray diffraction patterns of the prepared samples show the formation of single phase ZnO nanoparticles and the particle size decreases with increasing F/O molar ratio up to 1.7. Surface morphology of the prepared samples was studied by scanning electron microscopy and it was observed that, the porosity increases with increasing F/O molar ratio. DC electrical conductivity at room temperature and in the temperature range of 303-563 K was studied for all the samples and the results revealed that, the sample of F/O molar ratio 1.7 has low electrical conductivity at room temperature and high EAR （high temperature activation energy） compared to other samples.

关键词： ZnO nanoparticles Structural characterization Electrical conductivity

Reduction of friction by normal *** of contact stiffness

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Friction 2017年第1期5卷 45-55页

作者： M.POPOV V.l.POPOV N.V.POPOV Berlin University of Technology Berlin 10623 GermanyTomsk Polytechnic University Tomsk 634050 RussiaTomsk State University Tomsk 634050 Russia Berlin University of Technology Berlin 10623 Germany

The present paper is devoted to a theoretical analysis of sliding friction under the influence of oscillations perpendicular to the sliding *** contrast to previous works we analyze the influence of the stiffness of the tribological contact in detail and also consider the case of large oscillation amplitudes at which the contact is lost during a part of the oscillation period,so that the sample starts to 'jump'.It is shown that the macroscopic coefficient of friction is a function of only two dimensionless parameters-a dimensionless sliding velocity and dimensionless oscillation *** function in turn depends on the shape of the contacting *** the present paper,analysis is carried out for two shapes:a flat cylindrical punch and a parabolic *** we consider 'stiff systems',where the contact stiffness is small compared with the stiffness of the *** role of the system stiffness will be studied in more detail in a separate paper.

关键词： sliding friction out-of-plane oscillation contact stiffness coefficient of friction active control of friction

Experience on offshore cathodic protection retrofitting in the northern South China Sea

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Acta Oceanologica Sinica 2003年第4期22卷 679-688页

作者： l. Patterson A. Amorelli D. Condanni B. Bazzoni CACT Operators Group ENI S.P.A.-Exploration & Production DivisionENI S.P.A.-Exploration & Production DivisionENI S.P.A.-Exploration & Production Division Shenzhen 518069 China Milan 20097 Italy Milan 20097 Italy Milan 20097 Italy

Platforms I and II are steel structures located in offshore areas southeast of the Zhujiang (Pearl) River Delta, the northern South China Sea,. in about 110 in water depth. The jackets, with aluminum sacrificial anodes for cathodic protection (CP) of the immersed zone, were launched in March 1995. In May 096 a CP survey showed that, after almost one year of service, a low polarization level had been achieved and some extended unprotected zones existed; mainly in the deepest part of the Platform II. Further to this, a joint activity was decided in order to assess the need of a possible retrofitting of the CP systems. The results of the activity carried out are dealt with, including technical and economical comparisons amongst several retrofitting options, both with sacrificial anodes and with impressed current systems. The adopted solution is illustrated and data are reported on the level of protection presently achieved.

关键词： cathodic protection retrofitting offshore the South China Sea

Wideband tunable passively Q-switched fiber laser at 2.8 μm using a broadband carbon nanotube saturable absorber

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Photonics Research 2019年第1期7卷 14-18页

作者： YANJIA lü CHEN WEI HAN ZHANG ZHE KANG GUANSHI QIN YONG lIU State Key laboratory of Electronic Thin Films and Integrated Devices School of Optoelectronic Science and EngineeringUniversity of Electronic Science and Technology of China College of Electrical Engineering and Information Technology Sichuan University Changchun Observatory National Astronomical Observatories Chinese Academy of Sciences State Key laboratory on Integrated Optoelectronics College of Electronic Science & Engineering Jilin University

We propose and demonstrate a widely tunable passively Q-switched Ho^(3+)∕Pr^(3+)-codoped ZrF_4-BaF_2-laF_3-AlF_3-NaF fiber laser operating in the 2.8 μm mid-infrared(MIR) waveband based on a single-walled carbon nanotube(SWCNT) saturable absorber(SA). The SWCNTs have diameters ranging from 1.4 to 1.7 nm. The modulation depth and saturation intensity of the SWCNT SA measured at 2850 nm are 16.5% and 1.66 MW∕cm^2, respectively. Stable Q-switched pulses with the shortest pulse duration of 1.46 μs and the maximum pulse energy of 0.43 μJ are achieved at a launched pump power of 445.6 mW. The combined use of a broadband SWCNT SA and a plane ruled grating ensures a broad continuously tuning range of 55.0 nm from 2837.6 to 2892.6 *** output powers, emission spectra, repetition rates, and pulse durations at different tuning wavelengths are also characterized and analyzed. Our results indicate that SWCNTs can be excellent broadband SAs in the 3 μm MIR region. To the author's knowledge, this is the first demonstration of a widely tunable carbon-nanotubeenabled passively Q-switched fiber laser operating in the 2.8 μm MIR waveband.

关键词： broadband carbon excellent SWCNTs pulse Ho^3+ SAs pump

Smart COVID-3D-SCNN: A Novel Method to Classify X-ray Images of COVID-19

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Computer Systems Science & Engineering 2022年第6期41卷 997-1008页

作者： Ahed Abugabah Atif Mehmood Ahmad Ali A.l Zubi louis Sanzogni College of Technological Innovation Zayed UniversityAbuDhabi CampusUAE School of Artificial Intelligence Xidian UniversityXian710071China Computer Science Department Community CollegeKing Saud UniversityP.O.Box 28095Riyadh 11437Saudi Arabia Nathan campus Griffith UniversityBrisbaneAustralia

The outbreak of the novel coronavirus has spread worldwide,and millions of people are being *** or detection classification is one of the first application areas of deep learning,which has a significant contribution to medical image *** classification detection,one or more images(detection)are usually used as input,and diagnostic variables(such as whether there is a disease)are used as *** novel coronavirus has spread across the world,infecting millions of ***-stage detection of critical cases of COVID-19 is essential.X-ray scans are used in clinical studies to diagnose COVID-19 and Pneumonia *** extracting the discriminative features through these modalities,deep convolutional neural networks(CNNs)are used.A siamese convolutional neural network model(COVID-3D-SCNN)is proposed in this study for the automated detection of COVID-19 by utilizing X-ray *** extract the useful features,we used three consecutive models working in parallel in the proposed *** acquired 575 COVID-19,1200 non-COVID,and 1400 pneumonia images,which are publicly *** our framework,augmentation is used to enlarge the *** findings suggest that the proposed method outperforms the results of comparative studies in terms of accuracy 96.70%,specificity 95.55%,and sensitivity 96.62%over(COVID-19 ***-COVID19 ***).

关键词： Convolutional neural network classification X-ray deep learning

PARP inhibitors as precision medicine for cancer treatment

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National Science Review 2017年第4期4卷 576-592页

作者： Yi Du Hirohito Yamaguchi Jennifer l.Hsu Mien-Chie Hung Department of Molecular and Cellular Oncology The University of Texas MD Anderson Cancer Center Graduate Institute of Biomedical Sciences and Center for Molecular Medicine China Medical University Department of Biotechnology Asia University Graduate Institute of Biomedical Sciences and Center for Molecular Medicine China Medical UniversityTaichung

Personalized or precision medicine is an emerging treatment approach tailored to individuals or certain groups of patients based on their unique characteristics. These types of therapies guided by biomarkers tend to be more effective than traditional approaches, especially in cancer. The inhibitor against poly(ADP-ribose) polymerase(PARP), olaparib(lynparza, Astra Zeneca), which was approved by the US Food and Drug Administration(FDA) in 2014, demonstrated efficacy specifically for ovarian cancer patients harboring mutations in BRCA genes, which encode proteins in DNA double-strand break ***, the response to PARP inhibitors has been less encouraging in other cancer types that also carry defects in the BRCA genes. Thus, furthering our understanding of the underlying mechanism of PARP inhibitors and resistance is critical to improve their efficacy. In this review, we summarize the results of preclinical studies and the clinical application of PARP inhibitors, and discuss the future direction of PARP inhibitors as a potential marker-guided personalized medicine for cancer treatment.

关键词： PARP inhibitor kinase DNA damage precision medicine combination therapy

Growth-Defense Tradeoffs in Plants： A Balancing Act to Optimize Fitness

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Molecular Plant 2014年第8期7卷 1267-1287页

作者： Bethany Huot Jian Yao Beronda l. Montgomery' Sheng Yang He Department of Energy Plant Research laboratory Michigan State University MI 48824 USA Cell and Molecular Biology Program Michigan State University MI 48824 USA Department of Biochemistry and Molecular Biology Michigan State University MI 48824 USA Department of Plant Biology Michigan State University MI 48824 USA Howard Hughes Medical Institute-Gordon and Betty Moore Foundation Michigan State University MI 48933 USA

Growth-defense tradeoffs are thought to occur in plants due to resource restrictions, which demand prior- itization towards either growth or defense, depending on external and internal factors. These tradeoffs have profound implications in agriculture and natural ecosystems, as both processes are vital for plant survival, reproduction, and, ulti- mately, plant fitness. While many of the molecular mechanisms underlying growth and defense tradeoffs remain to be elucidated, hormone crosstalk has emerged as a major player in regulating tradeoffs needed to achieve a balance. In this review, we cover recent advances in understanding growth-defense tradeoffs in plants as well as what is known regard- ing the underlying molecular mechanisms. Specifically, we address evidence supporting the growth-defense tradeoff concept, as well as known interactions between defense signaling and growth signaling. Understanding the molecular basis of these tradeoffs in plants should provide a foundation for the development of breeding strategies that optimize the growth-defense balance to maximize crop yield to meet rising global food and biofuel demands.

关键词： plant immunity plant hormone salicylic acid jasmonate PAMP plant growth.

Role of oxygen and ammonium ions in silver leaching with thiosulfate–ammonia–cupric ions

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Rare Metals 2014年第2期33卷 225-229页

作者： Valentin Ibarra-Galvan Alejandro lópez-Valdivieso Xiong Tong Yi-Qi Cui Faculty of Chemistry Colima University Minerals Engineering Area Institute of Metallurgy Autonomous University of San Luis Potosi Faculty of land and Resource Engineering Kunming University of Science and Technology

The dissolution of silver with thiosulfate and copper ions was studied in a batch-stirred reactor at 25 °C in the absence and presence of various ammonium ions and oxygen concentrations in the aqueous solution. leaching silver with 4 mg l-1oxygen in the aqueous solution requires high concentration of ammonium and thiosulfate ions. High silver dissolution is achieved at pH of high cupric tetraamine concentration, around pH 9.8, but a high degradation of thiosulfate ions is resulted from their oxidation by the presence of oxygen. When the oxygen concentration is below 1 mg l-1, dissolved silver thiosulfate species are fairly stable and the degradation of thiosulfate ions in the aqueous solution is low. Under these conditions,high silver dissolution is attained using low thiosulfate concentration. At the oxygen concentration of 4 mg l-1,dissolved silver thiosulfate species precipitate out of the aqueous solution significantly affecting silver *** of dissolved silver thiosulfate species occurs because of oxidation of the thiosulfate bonding to the silver.

关键词： Silver Thiosulfate leaching Non-cyanide silver leaching Cupric tetraamine Oxygen