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| 1 | High precision in-situ Pb isotopic analysis of sulfide minerals by femtosecond laser ablation multi-collector inductively coupled plasma mass spectrometry显示文摘An in-situ microanalysis of Pb isotopic compositions in sulfide minerals is carried out by using femtosecond laser-ablation multi-collector inductively coupled plasma mass spectrometry(fs LA-MC-ICP-MS).High-temperature-activated carbon was used to filter Hg contained in the carrier gas,which reduced the Hg background signal by 48%and also lowered the detection limit of the analysis.Fractionation and mass discrimination effects existing in the ICP-MS analytical processes were corrected using an internal reference Tl in conjunction with an external reference NIST SRM 610.The proposed method was used to analyze the Pb isotopic compositions of chalcopyrite,pyrite,and sphalerite from the Dulong Sn-Zn-In polymetallic ore district.The results showed that in this ore district,the sulfide minerals and different grains of the same sulfide mineral show a large variation in Pb content up to 1000-fold.The studied pyrites show relatively higher Pb contents and homogeneous Pb isotopic compositions,whereas the sphalerites have low Pb contents but most variable Pb isotopic compositions.It is suggested that the large variation of Pb isotopic composition may reflect a late hydrothermal superimposition on the primary sulfide formation.In addition,radiogenic Pb accumulated by radioactive decay of trace amounts of U over time in the host minerals may also be one of the causes for the large variation range of Pb content and Pb isotopic composition of those low-Pb sphalerites.Chalcopyrite and sphalerite grains with Pb content greater than 10 ppm presented a consistent Pb isotopic distribution,whereas all the sulfide grains with Pb content greater than 100 ppm had consistent Pb isotopic composition within 2s measurement uncertainties.The in-situ analysis of Pb isotopic composition agreed well with the results obtained by conventional chemical methods within2s measurement uncertainties,indicating that the data obtained by fs LA-MC-ICP-MS are reliable.Additionally,this study indicates that the Pb isotopic composition could truthfully record the source of ore-forming minerals only for sulfide minerals with high Pb content.On the contrary,the Pb isotopic composition of low-Pb sulfide minerals may be affected by trace amounts of U in the host minerals that may lead to a highly radiogenic Pb isotope ratio.Alternatively,it is also possible that late fluid metasomatic overprinting may alter the Pb isotopic compositions. | YUAN HongLin YIN Cong LIU Xu CHEN KaiYun BAO ZhiAn ZONG ChunLei DAI MenNing LAI ShaoCong WANG Rong JIANG ShaoYong | 2015 | Science China Earth Sciences2015，58，10： | 14 |
| 2 | Sparing lung tissue with virtual block method in VMAT planning for locally advanced non-small cell lung cancer显示文摘This study aimed to exploit a new virtual block method to spare normal lung tissue in VMAT planning for patients with locally advanced non-small cell lung cancer(LA-NSCLC).The previous method was used to manually restrict the angle of the beam passing through,which ignored the location and shape of large targets that varied between different slices and did not block the beamlets precisely.Unlike the previous method,this new virtual block method was used to block the beamlets when necessary by closing the multi-leaf collimator(MLC)at prerequisite angles.The algorithm for closing the MLC depended on the thickness of the beamlets passing through the lungs and avoided only the entrance radiation beamlet.Moreover,this block can be automatically contoured.A retrospective study was performed to compare the VMAT plans with and without the virtual block method for 17 LANSCLC patients,named the block plan(B-plan)/non-block plan(N-plan).All cases were selected in this study because of the large tumor size and unmet dose constraints of the lungs.In addition to the maximum dose constraint for the virtual block,B-plans adopted identical optimization parameters to N-plans for each patient.These two types of plans were compared in terms of dosimetric indices and plan scores.The results were statistically analyzed using the Wilcoxon nonparametric signed-rank test.B-plans have advantages in the following dosimetric metrics that have statistical significance(p<0.05):(1)lower V_(5)/V_(10)/D_(mean)/normal tissue complication probability(NTCP)of total lungs;(2)reductions in V_(5)/V_(10)for the contralateral lung;(3)decrease in Dmean/V_(40)of the heart;(4)decrease in esophagus V_(40);(5)reductions in Dmean,V_(5)/V_(10) of normal tissue.B-plans(82.51±7.07)achieved higher-quality scores than N-plans(80.74±7.22).The new virtual block spared the lungs as well as other normal structures in VMAT planning for LA-NSCLC.Thus,the block method may decrease the risk of radiation-related toxicity in patients. | Jia-Yun Chen Da-Quan Wang Xiao-Dong Zhang Qi Fu Xue-Na Yan Kuo Men Jian-Rong Dai Nan Bi | 2022 | Nuclear Science and Techniques2022，33，4： | 3 |
| 3 | Preparation and Properties of High-performance Polyimide Copolymer Fibers Derived from 5-Amino-2-(2-hydroxy-5-aminobenzene)-benzoxazole显示文摘A series of polyamic acid copolymers(co-PAAs) with para-hydroxyl groups was synthesized using two diamine monomers,namely p-phenylenediamine(p-PDA) and 5-amino-2-(2-hydroxy-5-aminobenzene)-benzoxazole(m-pHBOA), of different molar ratios through copolymerization with 3,3′,4,4′-biphenyltetracarboxylic dianhydride(BPDA) in N,N-dimethyacetamine(DMAc). The co-PAA solutions were used to fabricate fibers by dry-jet wet spinning, and thermal imidization was conducted to obtain polyimide copolymer(coPI) fibers. The effects of the m-pHBOA moiety on molecular packing and physical properties of the prepared fibers were investigated.Fourier transform infrared(FTIR) spectroscopic results confirmed that intra/intermolecular hydrogen bonds originated from the hydroxyl group and the nitrogen atom of the benzoxazole group and/or the hydroxyl group and the oxygen atom of the carbonyl group of cyclic imide. As-prepared PI fibers displayed homogenous and smooth surface and uniform diameter. The glass transition temperatures(Tgs) of PI fibers were within 311-337 °C. The polyimide fibers showed 5% weight loss temperature(T5%) at above 510 °C in air. Twodimensional wide-angle X-ray diffraction(WXRD) patterns indicated that the homo-PI and co-PI fibers presented regularly arranged polymer chains along the fiber axial direction. The ordered molecular packing along the transversal direction was destroyed by introducing the m-pHBOA moiety. Moreover, the crystallinity and orientation factors increased with increasing draw ratio. Small-angle X-ray scattering(SAXS) results showed that it is beneficial to reduce defects in the fibers by increasing the draw ratio. The resultant PI fibers exhibited excellent mechanical properties with fracture strength and initial modulus of 2.48 and 89.73 GPa, respectively, when the molar ratio of p-PDA/m-pHBOA was 5/5 and the draw ratio was 3.0. | Xue-Min Dai Hong Gao Ran Zhang Zhi-Jun Du Tong-Fei Shi Xiang-Ling Ji Xue-Peng Qiu Yong-Feng Men | 2019 | Chinese Journal of Polymer Science2019，37，5： | 1 |
| 4 | Observatory science with eXTP显示文摘In this White Paper we present the potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies related to Observatory Science targets. These include flaring stars, supernova remnants, accreting white dwarfs, low and high mass X-ray binaries, radio quiet and radio loud active galactic nuclei, tidal disruption events, and gamma-ray bursts. eXTP will be excellently suited to study one common aspect of these objects: their often transient nature. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Science, the eXTP mission is expected to be launched in the mid 2020s. | Jean J.M.in 't Zand Enrico Bozzo JinLu Qu Xiang-Dong Li Lorenzo Amati Yang Chen Immacolata Donnarumma Victor Doroshenko Stephen A.Drake Margarita Hernanz Peter A.Jenke Thomas J.Maccarone Simin Mahmoodifar Domitilla de Martino Alessandra De Rosa Elena M.Rossi Antonia Rowlinson Gloria Sala Giulia Stratta Thomas M.Tauris Joern Wilms XueFeng Wu Ping Zhou Iván Agudo Diego Altamirano Jean-Luc Atteia Nils A.andersson M.Cristina Baglio David R.Ballantyne Altan Baykal Ehud Behar Tomaso Belloni Sudip Bhattacharyya Stefano Bianchi Anna Bilous Pere Blay Joao Braga Sφren Brandt Edward F.Brown Niccolo Bucciantini Luciano Burderi Edward M.Cackett Riccardo Campana Sergio Campana Piergiorgio Casella Yuri Cavecchi Frank Chambers Liang Chen Yu-Peng Chen Jér?me Chenevez Maria Chernyakova ChiChuan Jin Riccardo Ciolfi Elisa Costantini Andrew Cumming Antonino D'Aì Zi-Gao Dai Filippo D'Ammando Massimiliano De Pasquale Nathalie Degenaar Melania Del Santo Valerio D'Elia Tiziana Di Salvo Gerry Doyle Maurizio Falanga XiLong Fan Robert D.Ferdman Marco Feroci Federico Fraschetti Duncan K.Galloway Angelo F.Gambino Poshak Gandhi MingYu Ge Bruce Gendre Ramandeep Gill Diego G?tz Christian Gouiffès Paola Grandi Jonathan Granot Manuel Güdel Alexander Heger Craig O.Heinke Jeroen Homan Rosario Iaria Kazushi Iwasawa Luca Izzo Long Ji Peter G.Jonker Jordi José Jelle S.Kaastra Emrah Kalemci Oleg Kargaltsev Nobuyuki Kawai Laurens Keek Stefanie Komossa Ingo Kreykenbohm Lucien Kuiper Devaky Kunneriath Gang Li En-Wei Liang Manuel Linares Francesco Longo FangJun Lu Alexander A.Lutovinov Denys Malyshev Julien Malzac Antonios Manousakis Ian McHardy Missagh Mehdipour YunPeng Men Mariano Méndez Roberto P.Mignani Romana Mikusincova M.Coleman Miller Giovanni Miniutti Christian Motch Joonas Nättilä Emanuele Nardini Torsten Neubert Paul T.O'Brien Mauro Orlandini Julian P.Osborne Luigi Pacciani Stéphane Paltani Maurizio Paolillo Iossif E.Papadakis Biswajit Paul Alberto Pellizzoni Uria Peretz Miguel A.Pérez Torres Emanuele Perinati Chanda Prescod-Weinstein Pablo Reig Alessandro Riggio Jerome Rodriguez Pablo Rodríguez-Gil Patrizia Romano Agata Rózańska Takanori Sakamoto Tuomo Salmi Ruben Salvaterra andrea Sanna andrea Santangelo Tuomas Savolainen Stéphane Schanne Hendrik Schatz LiJing Shao andy Shearer Steven N.Shore Ben W.Stappers Tod E.Strohmayer Valery F.Suleimanov Jirí Svoboda F.-K.Thielemann Francesco Tombesi Diego F.Torres Eleonora Torresi Sara Turriziani andrea Vacchi Stefano Vercellone Jacco Vink Jian-Min Wang JunFeng Wang Anna L.Watts ShanShan Weng Nevin N.Weinberg Peter J.Wheatley Rudy Wijnands Tyrone E.Woods Stan E.Woosley ShaoLin Xiong YuPeng Xu Zhen Yan George Younes WenFei Yu Feng Yuan Luca Zampieri Silvia Zane andrzej A.Zdziarski Shuang-Nan Zhang Shu Zhang Shuo Zhang Xiao Zhang Michael Zingale | 2019 | Science China(Physics,Mechanics & Astronomy)2019，62，2： | 0 |
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