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31.
32.
Deutseche Atomgewitchs-Kommision G. P. Baxter Union internationale de chemiepure et appliquée C. G. Addingley R. Whytlaw-Gray H. W. Starkweather L. R. Pire E. Moles A. S. King R. T. Birge M. Ritchie Th. W. Richards A. W. Philips W. D. Harkins B. Mortimer A. Cousen W. E. St. Turner R. K. Mc Alphine S. D. Muzaffar W. Noddack Ida Noddack und J. Shimaru 《Fresenius' Journal of Analytical Chemistry》1930,81(1-2):42-45
Ohne Zusammenfassung 相似文献
33.
A Three‐Photon Active Organic Fluorophore for Deep Tissue Ratiometric Imaging of Intracellular Divalent Zinc 下载免费PDF全文
Divya Susan Philips Dr. Sivaramapanicker Sreejith Prof. Dr. Tingchao He Nishanth Venugopal Menon Palapuravan Anees Dr. Jomon Mathew Prof. Dr. Sreedharan Sajikumar Prof. Dr. Yuejun Kang Prof. Dr. Mihaiela Corina Stuparu Prof. Dr. Handong Sun Prof. Dr. Yanli Zhao Prof. Dr. Ayyappanpillai Ajayaghosh 《化学:亚洲杂志》2016,11(10):1523-1527
Deep tissue bioimaging with three‐photon (3P) excitation using near‐infrared (NIR) light in the second IR window (1.0–1.4 μm) could provide high resolution images with an improved signal‐to‐noise ratio. Herein, we report a photostable and nontoxic 3P excitable donor‐π‐acceptor system (GMP) having 3P cross‐section (σ3) of 1.78×10?80 cm6 s2 photon?2 and action cross‐section (σ3η3) of 2.31×10?81 cm6 s2 photon?2, which provides ratiometric fluorescence response with divalent zinc ions in aqueous conditions. The probe signals the Zn2+ binding at 530 and 600 nm, respectively, upon 1150 nm excitation with enhanced σ3 of 1.85×10?80 cm6 s2 photon?2 and σ3η3 of 3.33×10?81 cm6 s2 photon?2. The application of this probe is demonstrated for ratiometric 3P imaging of Zn2+ in vitro using HuH‐7 cell lines. Furthermore, the Zn2+ concentration in rat hippocampal slices was imaged at 1150 nm excitation after incubation with GMP, illustrating its potential as a 3P ratiometric probe for deep tissue Zn2+ ion imaging. 相似文献
34.
A new technique of synthesis of near-field (NF) amplitude and phase patterns of linear, planar, of volume arrays of finite size or arrays located on a planar contour of finite size is presented. The array could consist of point dipoles or directive elements. The criterion for prescribing the NF (amplitude and phase) pattern information in the synthesis problem for unique determination of array excitation currents is also stated. The proposed near-field synthesis technique is based on the potential integral solution of source currents, Nyquist sampling of the near-field data and the technique of linear least square approximation (LLSA). The NF pattern synthesis technique is illustrated to synthesize a variety of NF patterns with a number of array configurations. Application of the proposed NF pattern synthesis technique to minimize distortion in far-field patterns of arrays mounted on a conducting platform and to realize array antennas with low sidelobes in the near and far field is also presented. 相似文献
35.
S. Croft R. D. McElroy Jr. S. Philips R. Venkataramen D. Curtis 《Journal of Radioanalytical and Nuclear Chemistry》2008,276(3):677-683
The application of quantitative high-resolution gamma-ray spectrometry for the non-destructive assay of plutonium bearing
items, such as waste drums, is complicated by self-attenuation if the plutonium is present as lumps. By definition, lumps
are small compared to the bulk matrix and so are not accounted for in the gross matrix correction yet can exert a significant
influence on the assay result. Compared to a calibration using dilute standards, self-attenuation results in an under-reporting
of the mass of plutonium present. The availability of representative standards is unrealistic for diverse waste streams and
so a means to detect and compensate for the presence of lumps is needed. An experimental approach that can in principle generate
an item specific correction factor is to exploit the differential attenuation between a set of gamma-lines of known relative
emission intensity. In the case of routine measurements of drummed Pu wastes the choice of lines is often limited, the most
appropriate often being those at 129 keV and 414 keV from 239Pu. This paper discusses the problems and potential of exploiting this pairing in a simple dual energy approach to the long
standing and challenging problem of self-attenuation. 相似文献
36.
Divya S. Philips Kalathil K. Kartha Antiope T. Politi Timo Krüger Rodrigo Q. Albuquerque Gustavo Fernndez 《Angewandte Chemie (International ed. in English)》2019,58(14):4732-4736
Cooperative π–π interactions and H‐bonding are frequently exploited in supramolecular polymerization; however, close scrutiny of their mutual interplay has been largely unexplored. Herein, we compare the self‐assembly behavior of a series of C2‐ and C3‐symmetrical oligophenyleneethynylenes differing in their amide topology (N‐ or C‐centered). This subtle structural modification brings about drastic changes in their photophysical and supramolecular properties, highlighting the reciprocal impact of H‐bonding vs. preorganization on the evolution and final outcome of supramolecular systems. 相似文献
37.
David A. Philips Riccardo Rossi Gianluca Iaccarino 《International Journal of Heat and Fluid Flow》2011,32(5):943-963
A numerical study of scalar dispersion is presented to investigate the effectiveness of pairing the v2–f turbulence model with algebraic models for the scalar flux. This approach is contrasted with utilizing a full Second Moment Closure (SMC) as the flow field input to the scalar model. Predictions of scalar transport in a turbulent channel and over a wavy wall are compared to available DNS databases. The latter case includes a scalar release from a point source and therefore detailed comparisons of the three-component turbulent scalar flux are reported. It is found that the transported variable v2, representing the near wall turbulent velocity fluctuation scale, can be used to increase the level of normal stress anisotropy provided to algebraic scalar models and thereby improve mean scalar prediction over that of the Standard Gradient Diffusion Hypothesis (SGDH). Improvement is most significant in the near wall region. Three specifications of the normal stresses, derived from v2, are considered to provide the link from the v2–f model to the algebraic flux models used to close the scalar transport equation. Barycentric maps are used to examine the state of turbulence anisotropy in each case. As the anisotropy in the normal stress specification becomes more accurate, improvements are realized in the prediction of the spanwise flux as well as the mean concentration. 相似文献
38.
Philips JD Nachtigall PE Au WW Pawloski JL Roitblat HL 《The Journal of the Acoustical Society of America》2003,113(1):605-616
The Risso's dolphin (Grampus griseus) is an exclusively cephalopod-consuming delphinid with a distinctive vertical indentation along its forehead. To investigate whether or not the species echolocates, a female Risso's dolphin was trained to discriminate an aluminum cylinder from a nylon sphere (experiment 1) or an aluminum sphere (experiment 2) while wearing eyecups and free swimming in an open-water pen in Kaneohe Bay, Hawaii. The dolphin completed the task with little difficulty despite being blindfolded. Clicks emitted by the dolphin were acquired at average amplitudes of 192.6 dB re 1 microPa, with estimated sources levels up to 216 dB re 1 microPa-1 m. Clicks were acquired with peak frequencies as high as 104.7 kHz (Mf(p) = 47.9 kHz), center frequencies as high as 85.7 kHz (Mf(0) = 56.5 kHz), 3-dB bandwidths up to 94.1 kHz (M(BW) = 39.7 kHz), and root-mean-square bandwidths up to 32.8 kHz (M(RMS) = 23.3 kHz). Click durations were between 40 and 70 micros. The data establish that the Risso's dolphin echolocates, and that, aside from slightly lower amplitudes and frequencies, the clicks emitted by the dolphin were similar to those emitted by other echolocating odontocetes. The particular acoustic and behavioral findings in the study are discussed with respect to the possible direction of the sonar transmission beam of the species. 相似文献
39.
Bockstael A de Greve B Van Renterghem T Botteldooren D D'Haenens W Keppler H Maes L Philips B Swinnen F Vinck B 《The Journal of the Acoustical Society of America》2008,124(2):973-981
The use of in situ measurements of hearing protectors' (HPD's) attenuation following the microphone in real ear (MIRE) protocol is increasing. The attenuation is hereby calculated from the difference in sound levels outside the ear and inside the ear canal behind the HPD. Custom-made earplugs have been designed with an inner bore that allows inserting a miniature microphone. A thorough understanding of the difference, henceforth called transfer function, between the sound pressure of interest at the eardrum and the one measured at the inner bore of the HPD is indispensable for optimizing the MIRE technique and extending its field of application. This issue was addressed by measurements on a head-and-torso-simulator and finite difference time domain numerical simulations of the outer ear canal occluded by an earplug. Both approaches are in good agreement and reveal a clear distinction between the sound pressure at the MIRE microphone and at eardrum, but the measured transfer functions appear to be stable and reproducible. Moreover, the most striking features of the transfer functions can be traced down to the geometrical and morphological characteristics of the earplug and ear canal. 相似文献
40.
S. Velicu C.H. Grein P.Y. Emelie A. Itsuno J.D. Philips P. Wijewarnasuriya 《Journal of Electronic Materials》2010,39(7):873-881
In this work, we analyze Auger suppression in HgCdTe alloy-based device structures and determine the operation temperature
improvements expected when Auger suppression occurs. We identified critical material (absorber dopant concentration and minority-carrier
lifetime) requirements that must be satisfied for optimal performance characteristics. Calculated detectivity values of Auger-suppressed
and standard double-layer planar heterostructure (DLPH) devices demonstrate consistently higher maximum background-limited
temperatures over a range of cutoff wavelengths and generally higher detectivity values achieved by Auger-suppressed detectors.
Furthermore, these devices can operate with comparable performance at up to 100 K higher than DLPH detectors operating at
reference temperatures above 100 K. Results of these simulations demonstrate that Auger-suppressed detectors provide a significant
advantage over DLPH devices for high-temperature operation and are a viable candidate for thermoelectrically cooled detectors.
Experimental dark current–voltage (I–V) characteristics between 120 K and 300 K were fitted using numerical simulations. By fitting the temperature-dependent I–V experimental data, we determined that the observed negative differential resistance (NDR) is due to Auger suppression. More
specifically, NDR is attributed to full suppression of Auger-1 processes and partial (~70%) suppression of Auger-7 processes.
After Auger suppression, the remaining leakage current is principally limited by the Shockley–Read–Hall recombination component.
Part of the leakage current is also due to a residual Auger-7 current in the absorber due to the extrinsic p-type doping level. Analysis and comparison of our theoretical and experimental device results in structures where Auger suppression
was realized are also presented. 相似文献