http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Intramolecular electron transfer reactions in <i>meso</i>-(4-nitrophenyl)-substituted subporphyrins
Copley, Graeme,Oh, Juwon,Yoshida, Kota,Shimizu, Daiki,Kim, Dongho,Osuka, Atsuhiro The Royal Society of Chemistry 2016 Chemical communications Vol.52 No.7
<P>A(2)B-type meso-(4-nitrophenyl)-substituted subporphyrins have been synthesized and shown to undergo very fast photoinduced intramolecular charge separation (CS) and charge recombination (CR) between the subporphyrin core and the meso-4-nitrophenyl group in CH2Cl2 as probed by femtosecond time-resolved transient absorption spectroscopy. Red-shifted emissions were detected from charge-separated states as a rare case for porphyrinoids.</P>
Developmental changes in hematopoietic stem cell properties
Michael R Copley,Connie J Eaves 생화학분자생물학회 2013 Experimental and molecular medicine Vol.45 No.s
Hematopoietic stem cells (HSCs) comprise a rare population of cells that can regenerate and maintain lifelong blood cell production. This functionality is achieved through their ability to undergo many divisions without activating a poised, but latent,capacity for differentiation into multiple blood cell types. Throughout life, HSCs undergo sequential changes in several key properties. These affect mechanisms that regulate the self-renewal, turnover and differentiation of HSCs as well as the properties of the committed progenitors and terminally differentiated cells derived from them. Recent findings point to the Lin28b-let-7 pathway as a master regulator of many of these changes with important implications for the clinical use of HSCs for marrow rescue and gene therapy, as well as furthering our understanding of the different pathogenesis of childhood and adult-onset leukemia.
Performances of photodiode detectors for top and bottom counting detectors of ISS-CREAM experiment
Hyun, H.J.,Anderson, T.,Angelaszek, D.,Baek, S.J.,Copley, M.,Coutu, S.,Han, J.H.,Huh, H.G.,Hwang, Y.S.,Im, S.,Jeon, H.B.,Kah, D.H.,Kang, K.H.,Kim, H.J.,Kim, K.C.,Kwashnak, K.,Lee, J.,Lee, M.H.,Link, J Elsevier 2015 Nuclear Instruments & Methods in Physics Research. Vol.787 No.-
<P><B>Abstract</B></P> <P>The Cosmic Ray Energetics and Mass (CREAM) experiment at the International Space Station (ISS) aims to elucidate the source and acceleration mechanisms of high-energy cosmic rays by measuring the energy spectra from protons to iron. The instrument is planned for launch in 2015 at the ISS, and it comprises a silicon charge detector, a carbon target, top and bottom counting detectors, a calorimeter, and a boronated scintillator detector. The top and bottom counting detectors are developed for separating the electrons from the protons, and each of them comprises a plastic scintillator and a 20×20 silicon photodiode array. Each photodiode is 2.3cm×2.3cm in size and exhibits good electrical characteristics. The leakage current is measured to be less than 20nA/cm<SUP>2</SUP> at an operating voltage. The signal-to-noise ratio is measured to be better than 70 using commercial electronics, and the radiation hardness is tested using a proton beam. A signal from the photodiode is amplified by VLSI (very-large-scale integration) charge amp/hold circuits, the VA-TA viking chip. Environmental tests are performed using whole assembled photodiode detectors of a flight version. Herein, we present the characteristics of the developed photodiode along with the results of the environmental tests.</P>
Park, J.M.,Amare, Y.,Anderson, T.,Angelaszek, D.,Anthony, N.,Arnold, H.,Choi, G.H.,Copley, M.,Coutu, S.,Derome, L.,Ebongue, C.,Eraud, L.,Faddis, I.,Han, J.H.,Howley, I.J.,Huh, H.G.,Hwang, Y.S.,Hyun, H Elsevier 2018 ADVANCES IN SPACE RESEARCH Vol.62 No.10
<P><B>Abstract</B></P> <P>The Cosmic Ray Energetics and Mass experiment at the International Space Station (ISS-CREAM) is developed for studying the origin, acceleration and propagation mechanism of high energy cosmic rays. The Top and Bottom Counting Detectors (TCD/BCD), sub-detectors of the ISS-CREAM instrument, are developed for electron/ γ -ray physics. The TCD/BCD help distinguish electrons from protons by comparing the hit and shower width distributions for electrons and protons. The e/p separation capability of the TCD/BCD is studied by using the GEANT3 simulation package, and optimal parameters for the e/p separation are obtained.</P>
Measurement of delayed fluorescence in plastic scintillator from 1 to 10 μ s
Nutter, S.,Amare, Y.,Anderson, T.,Angelaszek, D.,Anthony, N.,Cheryian, k.,Choi, G.H.,Copley, M.,Coutu, S.,Derome, L.,Eraud, L.,Hagenau, L.,Han, J.H.,Huh, H.G.,Hwang, Y.S.,Hyun, H.J.,Im, S.,Jeon, H.B. Elsevier 2019 Nuclear instruments & methods in physics research. Vol.942 No.-
<P><B>Abstract</B></P> <P>The time dependence of the relative light emission of Eljen Technology EJ-200 polyvinyltoluene-based plastic scintillator was measured between 1 and 10 μ s after the passage of a particle shower, a singly charged particle (atmospheric muon), and with a UV LED exciting the fluor. This was compared in magnitude to the integrated response for the prompt light (within 500 ns of excitation). A model with a time-dependent yield consisting of three exponentially decaying components (fast, medium, and slow) was developed to fit the data. Note that the exact time structure of early (< 1 μ s ) light emission was not measured for individual components, only for all three components together This model assumes all three components share the same rise time. The decay time constants of the fast, medium and slow components are, respectively, 7.8 ns, 490 ns, and 2370 ns. The relative total normalized yields for each component are: fast 95.8%, medium 2.2%, and slow 2.0%.</P>
Lee, J.,Amare, Y.,Anderson, T.,Angelaszek, D.,Anthony, N.,Cheryian, K.,Choi, G.H.,Copley, M.,Coutu, S.,Derome, L.,Eraud, L.,Hagenau, L.,Han, J.H.,Hong, G.,Huh, H.G.,Hwang, Y.S.,Hyun, H.J.,Im, S.,Jeon, Elsevier 2019 Astroparticle physics Vol.112 No.-
<P><B>Abstract</B></P> <P>The Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) is a space-borne mission designed for the precision measurement of the energy and elemental composition of cosmic rays. The Silicon Charge Detector (SCD), placed at the top of the ISS-CREAM payload, consists of 4 layers. Each layer has 2688 silicon pixels and associated electronics arranged in such a fashion that its active detection area of 78.2 × 73.6 cm<SUP>2</SUP> is free of dead area. The foremost goal of the SCD is to efficiently and precisely measure the charge of cosmic rays passing through it. The 4-layer configuration was chosen to achieve the best precision in measuring the charge of cosmic rays within the constraints on the mass, volume and power allotted to it. The amount of material used for its support structure was minimized as well to reduce the chance of interactions of the cosmic ray within the structure. Given the placement of the SCD, its 4-layer configuration and the minimal amount of material in the cosmic-ray trajectory, the SCD is designed to measure the charge of cosmic rays ranging from protons to iron nuclei with excellent detection efficiency and charge resolution. We present the design and fabrication of the SCD as well as its performance during space environment tests which it underwent successfully. We also present its performance in charge measurement using heavy ions in a beam test at CERN, the European Organization for Nuclear Research.</P>
The boronated scintillator detector of the ISS-CREAM experiment
Amare, Y.,Anderson, T.,Angelaszek, D.,Anthony, N.,Cheryian, K.,Choi, G.H.,Copley, M.,Coutu, S.,Derome, L.,Eraud, L.,Hagenau, L.,Han, J.H.,Huh, H.G.,Hwang, Y.S.,Hyun, H.J.,Im, S.,Jeon, H.B.,Jeon, J.A. Elsevier 2019 Nuclear Instruments & Methods in Physics Research. Vol.943 No.-
<P><B>Abstract</B></P> <P>The Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) instrument is a next-generation experiment for the direct detection and study of cosmic-ray nuclei and electrons. With a long exposure in low Earth orbit, the experiment will determine the particle fluxes and spectral details of cosmic-ray nuclei from hydrogen to iron, over an energy range of about 1 <SUP> 0 12 </SUP> eV to > 1 <SUP> 0 15 </SUP> eV, and of cosmic-ray electrons over an energy range of about 5 × 1 <SUP> 0 10 </SUP> eV to > 1 <SUP> 0 13 </SUP> eV. The instrument was deployed to the ISS in August 2017 on the SpaceX CRS-12 mission. We review the design, implementation and performance of one of the ISS-CREAM detector systems: a boron loaded scintillation detector used in discriminating electron-induced events from the much more abundant cosmic-ray nuclei.</P>