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71.
LIU Yan-Ping CHEN Zhao-Yang BA Wei-Zhen FAN Yan-Wei DU Yan-Zhao PAN Shi-Lie GUO Qi 《中国物理C(英文版)》2008,32(5)
The optically stimulated luminescent (OSL) radiation dosimeter technically surveys a wide dynamic measurement range and a high sensitivity.Optical fiber dosimeters provide capability for remote monitoring of the radiation in the locations which are difficult-to-acoess and hazardous.In addition.optical fiber dosimeters are immune to electrical and radio-frequency interference.In this paper,a novel remote optical fiber radiation dosimeter is described.The optical fiber dosimeter takes advantage of the charge trapping materials CaS:Ce, Sm that exhibit OSL.The measuring range of the dosimeter is from 0.1 to 100 Gy.The equipment is relatively simple and small in size,and has low power consumption.This device is suitable for measuring the space radiation dose and also can be used in high radiation dose condition and other dangerous radiation occasions. 相似文献
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Co-extraction of lipid materials is the major source of interference in determinations of low-polarity compounds in many biological matrixes. "SFE-plus-C(18)", a recently developed supercritical fluid extraction method employing C(18) adsorbent in the extraction chamber, can enable selective extraction of low-polarity compounds in lipid-rich biological matrixes without a cleanup step. This study reports the application of the SFE-plus-C(18) method to the quantification of: 1. polycyclic aromatic hydrocarbons (PAH) in commercially purchased smoked fish; and 2. anti-cancer agents cyclophosphamide (CP) and suberoylanilide hydroxamic acid (SAHA) spiked into homogenized whole bovine milk.Over the course of SFE-plus-C(18)extraction, indigenous lipids are preferentially retained on the C(18) adsorbent. Compared with the conventional method, only 8-15% of the lipids in the smoked fish sample, and only 6-18% of the lipids in the milk sample, were co-extracted by SFE-plus-C(18). This reduction in the quantity of background lipids significantly improved chromatographic separations, retarded deterioration of the column, and dramatically improved the ability to quantify PAH present at trace levels in smoked fish by GC-MS. Using the SFE-plus-C(18) method, ten targeted PAH were detected in the range 9.5-13.5 ng g(-1) in the smoked fish sample. Compared with these levels, PAH extractions by use of conventional SFE gave values that were lower by 38-86%. Recoveries of CP and SAHA spiked into milk were close to 100% in both SFE-plus-C(18)and conventional SFE, where the lipid background during the chromatographic elution of CP and SAHA was not so severe. 相似文献
77.
De Vita R Anghinolfi M Burkert VD Dodge GE Minehart R Taiuti M Weller H Adams G Amaryan MJ Anciant E Armstrong DS Asavapibhop B Asryan G Audit G Auger T Avakian H Bagdasaryan H Ball JP Barrow S Battaglieri M Beard K Bektasoglu M Bianchi N Biselli AS Boiarinov S Bonner BE Bosted P Bouchigny S Branford D Brooks WK Bueltmann S Calarco JR Capitani GP Carman DS Carnahan B Cazes A Ciciani L Cole PL Coleman A Connelly J Cords D Corvisiero P Crabb D Crannell H Cummings JP De Sanctis E Degtyarenko PV 《Physical review letters》2002,88(8):082001
The double spin asymmetry in the (-->)e(-->)p --> e(prime)pi(+)n reaction has been measured for the first time in the resonance region for four-momentum transfer Q2 = 0.35-1.5 GeV(2). Data were taken at Jefferson Lab with the CLAS detector using a 2.6 GeV polarized electron beam incident on a polarized solid NH3 target. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity-1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistent with a faster rise with Q(2) of the helicity asymmetry A1 for the F(15)(1680) resonance than expected from the analysis of the unpolarized data. 相似文献
78.
Joo K Smith LC Burkert VD Minehart R Aznauryan IG Elouadrhiri L Stepanyan S Adams GS Amaryan MJ Anciant E Anghinolfi M Armstrong DS Asavapibhop B Audit G Auger T Avakian H Barrow S Bagdasaryan H Battaglieri M Beard K Bektasoglu M Bertozzi W Bianchi N Biselli AS Boiarinov S Bonner BE Brooks WK Calarco JR Capitani GP Carman DS Carnahan B Cole PL Coleman A Cords D Corvisiero P Crabb D Crannell H Cummings J De Sanctis E De Vita R Degtyarenko PV Demirchyan RA Denizli H Dennis LC Deppman A 《Physical review letters》2002,88(12):122001
Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q2 dependence of the magnetic (M1+), electric (E1+), and scalar (S1+) multipoles in the gamma*p-->Delta(+)-->p pi(0) transition. We report new experimental values for the ratios E(1+)/M(1+) and S(1+)/M(1+) over the range Q2 = 0.4-1.8 GeV2, extracted from precision p(e,e(')p)pi(0) data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role. 相似文献
79.
A. J. Cole 《Zeitschrift für Physik A Hadrons and Nuclei》1985,322(2):315-319
A model for peripheral heavy ion reactions is proposed in which the reaction mechanism is governed by the number of nucleon-nucléon collisions taking place during the interaction. A general random walk process leads to simple expressions for the mass yields. Angular distributions are obtained as the convolution of distributions due to deflection by the ion-ion potential and recoil effects due to the change in mass. 相似文献
80.
Tin(II) chloride inserts into the ironcarbon σ-bond in MeFe(CO)2Cp (Cp = cyclopentadienyl), in refluxing methanol or THF, to give MeClSnFe(CO)2- Cp and traces of Cl3SnFe(CO)2Cp, but, with EtFe(CO)2Cp, a mixture of the insertion product, Cl3SnFe(CO)2Cp, and Cl2Sn[Fe(CO)2Cp]2 is formed. Insertion of tin(II) chloride was not observed for MeMo(CO)3Cp and MeMn(CO)5; in these reactions, and in those between tin(II)_bromide and MeFe(CO)2Cp, EtFe(CO)2Cp and Memo(CO)3Cp, mixtures of halo—metal carbonyls and halotin—metal carbonyls result. 相似文献