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Formation of AgI/Ag_3PO_4 solid solution on alumina for enhancing radioactive iodine adsorption at high temperatures

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Nuclear Science and Techniques 2018年第5期29卷 25-35页

作者： Xin Wang tai-Wei Chu Beijing National Laboratory for Molecular Sciences Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science College of Chemistry and Molecular Engineering Peking University

Radioiodine-131 is one of the pernicious radionuclides released during nuclear accidents, as its radioactivity can potentially affect public health and *** prevent radioiodine-131 from being released into the environment, the use of adsorbents that are highly efficient at high temperatures is significantly important. The radioactive gas from the nuclear core in an accident, such as the Fukushima nuclear accident, is usually released occurs under high-temperature conditions. Therefore, in this study, a 10 wt% silver phosphate-loaded alumina(Ag_3 PO_4/Al_2 O_3) adsorbent was prepared. Further, its performance toward radioiodine adsorption was tested at high temperatures up to 750 0 C, using Al_2 O_3 and traditional 10 wt% Ag/Al_2 O_3 adsorbent as controls. The results of the iodine adsorption test indicated that the 10 wt% Ag_3 PO_4/Al_2 O_3 adsorbent showed a higher decontamination factor than did the 10 wt% Ag/Al_2 O_3 adsorbent by two orders of magnitude at 650 and 750℃. Results of the iodine desorption test revealed that the new adsorbent could be effectively used at 750 ℃. The characteristic powder X-ray diffraction, nitrogen adsorption-desorption isotherm,X-ray photoelectron spectroscopy, and thermogravimetric analysis-differential scanning calorimetry data indicated that the enhanced adsorption ability at high temperatures was attributed to the formation of a solid solution between silver iodide and Ag_3 PO_4.

关键词： Nuclear accident Radioiodine Solid adsorbent High-temperature adsorption

Quantum Decoherence of Macroscopic Object Induced by Inner Environments： an Exactly Solvable Model

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Communications in Theoretical Physics 2007年第2期47卷 229-234页

作者： ZHENG Li ZHENG tai-Yu College of Info Science and Engineering Dalian Institute of Light Industry Dalian 116034 China Institute of Theoretical Physics the Chinese Academy of Sciences Beijing 100080 China The Institute of Theoretical Physics Northeast Normal University Changchun 130022 China

We revisit the quantum decoherence problem of the center of mass motion of a macroscopic object, which is modelled as a one-dimensional atom chain. Induced by the coupling of the center of mass （C.M） motion with the inner degrees of freedom, this inner-environment-induced decoherence is reflected by the localization of the C.M wave packet. We show that, the C.M motion is coupled to the inner states only when the chain has interaction with the external potential. This result provides a realistic mechanism for the analysis of the inner-environment-induced localization of a macroscopic object.

关键词： quantum decoherence macroscopic object inner environments

Astrocytic Gap Junctions Contribute to Aberrant Neuronal Synchronization in a Mouse Model of MeCP2 Duplication Syndrome

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Neuroscience Bulletin 2022年第6期38卷 591-606页

作者： Shengnan Xia Hua-tai Xu Institute of Neuroscience and State Key Laboratory of Neuroscience CAS Center for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghai 200031China University of Chinese Academy of Seciences Beijing 100049.China Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology Shanghai 201210China

Abnormal synchronous neuronal activity has been widely detected by brain imaging of autistic patients,but its underlying neural mechanism remains *** with wild-type mice,our in vivo two-photon imaging showed that transgenic(Tgl)mice over-expressing human autism risk gene MeCP2 exhibited higher neuronal synchrony in the young but lower synchrony in the adult ***-cell recording of neuronal pairs in brain slices revealed that higher neuronal synchrony in young postnatal Tgl mice was atributed mainly to more prevalent giant slow inward currents(SICs).Both in vivo and slice imaging further demonstrated more dynamic activity and higher synchrony in astrocytes from young Tgl *** astrocytic gap junctions markedly decreased the generation of SICs and overall cell synchrony in the Tgl ***,the expression level of Cx43 protein and the coupling efficiency of astrocyte gap junctions remained unchanged in Tgi ***,astrocytic gap junctions facilitate but do not act as a direct trigger for the abnormal neuronal synchrony in young Tgl mice,revealing the potential role of the astrocyte network in the pathogenesis of MeCP2 duplication syndrome.

关键词： Autism spectrum disorder Astrocyte Gap junction Neuronal synchrony MeCP2-Slow inward current Neuronal development

LOCALLY STABILIZED FINITE ELEMENT METHOD FOR STOKES PROBLEM WITH NONLINEAR SLIP BOUNDARY CONDITIONS

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Journal of Computational Mathematics 2010年第6期28卷 826-836页

作者： Yuan Li Kai-tai Li College of Mathematics and Information Science Wenzhou University Wenzhou 325035 China School of Science Xi'an Jiaotong University Xi'an 710049 China School of Science Xi'an Jiaotong University Xi'an 710049 China

Based on the low-order conforming finite element subspace （Vh, Mh） such as the P1-P0 triangle element or the Q1-P0 quadrilateral element, the locally stabilized finite element method for the Stokes problem with nonlinear slip boundary conditions is investigated in this paper. For this class of nonlinear slip boundary conditions including the subdifferential property, the weak variational formulation associated with the Stokes problem is an variational inequality. Since （Vh, Mh） does not satisfy the discrete inf-sup conditions, a macroelement condition is introduced for constructing the locally stabilized formulation such that the stability of （Vh, Mh） is established. Under these conditions, we obtain the H1 and L2 error estimates for the numerical solutions.

关键词： Stokes Problem Nonlinear Slip Boundary Variational Inequality Local Stabilized Finite Element Method Error Estimate.

Analysis of Two-sample Censored Data Using a Semiparametric Mixture Model

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Acta Mathematicae Applicatae Sinica 2009年第3期25卷 389-398页

作者： Gang Li Chien-tai Lin Department of Biostatistics University of California Los Angeles CA 90095 U.S.A. Department of Mathematics Tamkang University Tamsui 251 Taiwan

In this article we study a semiparametric mixture model for the two-sample problem with right censored data. The model implies that the densities for the continuous outcomes are related by a parametric tilt but otherwise unspecified. It provides a useful alternative to the Cox （1972） proportional hazards model for the comparison of treatments based on right censored survival data. We propose an iterative algorithm for the semiparametric maximum likelihood estimates of the parametric and nonparametric components of the model. The performance of the proposed method is studied using simulation. We illustrate our method in an application to melanoma.

关键词： Biased sampling EM algorithm maximum likelihood estimation mixture model semiparametric model

An extension result for the Landau-Lifshitz equation with Neumann boundary condition

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Applied Mathematics(A Journal of Chinese Universities) 2012年第1期27卷 34-48页

作者： LI tai-long LI Na School of Economics&:Management Zhejiang Sci-Tech UniversityWest DistrictXiasha Higher Education ZoneHangzhou 310018China School of Mathematics Shandong UniversityJinan 250100China Mathematics Department QiLu Normal InstituteJinan 250013China

We establish an extension result of existence and partial regularity for the nonzero Neumann initial-boundary value problem of the Landau-Lifshitz equation with nonpositive anisotropy constants in three or four dimension space. The partial regularity is proved up to the boundary and this result is an important supplement to those for the Dirichlet problem or the homogeneous Neumann problem.

关键词： Landau-Lifshitz equation anisotropy partially regular solution Neumann boundary condition.

Preparation of Ultrafine Tungsten Powder by Sol-Gel Method

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Journal of Materials Science & Technology 2008年第5期24卷 816-818页

作者： Yuxian HAN tai QIU Tao SONG College of Materials Science and Engineering Nanjing University of Technology Nanjing 210009 China

Sol-gel method was employed for the preparation of nanoscale tungsten powder. The effects of different preparation conditions on particle size were discussed and the optimum preparation condition was found. The products were characterized by X-ray diffraction, scan electron microscopy and so on. The results show that the intermediate is monoclinic WO3, its particle shape is approximately spherical, and the particle size distribution is narrow. The average particle size is about 60 nm. After deoxidization, WO3 turns into cubic tungsten powder with small particle size （average particle size about 120 nm） and narrow size distribution.

关键词： Sol-gel method Tungsten trioxide Deoxidize Ultra-fine tungsten powder

Reliability ensemble averaging reduces surface wind speed projection uncertainties in the 21st century over China

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Advances in Climate Change Research 2024年第2期15卷 222-229页

作者： Zheng-tai ZHANG Chang-Ai XU Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric SciencesLanzhou UniversityLanzhou 730000China

Accurate prediction of future surface wind speed(SWS)changes is the basis of scientific planning for wind *** studies have projected SWS changes in the 21st century over China on the basis of the multi-model ensemble(MME)of the 6th Coupled Model Intercomparison Project(CMIP6).However,the simulation capability for SWS varies greatly in CMIP6 multi-models,so the MME results still have large *** this study,we used the reliability ensemble averaging(REA)method to assign each model different weights according to their performances in simulating historical SWS changes and project the SWS under different shared socioeconomic pathways(SSPs)in *** results indicate that REA considerably improves the SWS simulation capacity of CMIP6,eliminating the overestimation of SWS by the MME and increasing the simulation capacity of spatial *** spatial correlations with observations increased from 0.56 for the MME to 0.85 for ***,REA could eliminate the overestimation of the SWS by 33%in *** for southeastern China,the SWS generally decreases over China in the near term(2020-2049)and later term(2070-2099),particularly under high-emission *** SWS reduction projected by REA is twice as high as that by the MME in the near term,reaching-4%to-3%.REA predicts a larger area of increased SWS in the later term,which expands from southeastern China to eastern *** study helps to reduce the projected SWS uncertainties.

关键词： Surface wind speed Uncertainty Multi-model ensemble Reliability ensemble averaging CMIP6

The Faber Operator Acting on BMOA,BMO-Teichmüller Space and Chord-arc Curves

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Acta Mathematica Sinica,English Series 2024年第10期40卷 2359-2387页

作者： tai Liang LIU Yu Liang SHEN Department of Mathematics Soochow UniversitySuzhou 215006P.R.China

After reviewing Grunsky operator and Faber operator acting on Dirichlet space,we discuss the boundedness of Faber operator on BMOA,a new subject which turns out to be closely related to the BMO theory of the universal Teichmüller *** particular,we show that the Faber operator acts as a bounded operator on BMOA if the symbol conformal map stays nearly to the base point in the BMO-Teichmüller ***,we obtain several results on quasiconformal mappings,BMOTeichm¨uller space and chord-arc curves as *** by-products,this provides a complex analysis approach to the boundedness of the Cauchy integral acting on BMO functions on a chord-arc curve near to the unit circle in the BMO-Teichmüller space.

关键词： Faber operator quasiconformal mapping quasicircle BMO-Teichmüller space chord-arc curve Grunsky operator BMO BMOA Carleson measure Cauchy integral