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Radionuclides in primary coolant of a fluoride salt-cooled hightemperature reactor during normal operation

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Nuclear Science and Techniques 2017年第3期28卷 109-114页

作者： Guo-Qing Zhang Shuai Wang hai-Qing Zhang Xing-Wang Zhu Chao Peng Jun Cai zhao-zhong He Kun Chen Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049China

The release of fission products from coated particle fuel to primary coolant, as well as the activation of coolant and impurities, were analysed for a fluoride saltcooled high-temperature reactor(FHR) system, and the activity of radionuclides accumulated in the coolant during normal operation was calculated. The release rate(release fraction per unit time) of fission products was calculated with STACY code, which is modelled mainly based on the Fick's law, while the activation of coolant and impurities was calculated with SCALE code. The accumulation of radionuclides in the coolant has been calculated with a simplified model, which is generally a time integration considering the generation and decay of radionuclides. The results show that activation products are the dominant gamma source in the primary coolant system during normal operation of the FHR while fission products become the dominant source after shutdown. In operation condition,health-impacts related nuclides such as ~3H, and ^(14)C originate from the activation of lithium and coolant impurities including carbon, nitrogen, and oxygen. According to the calculated effective cross sections of neutron activation,~6Li and ^(14)N are the dominant ~3H production source and ^(14)C production source, respectively. Considering the high production rate,~3H and ^(14)C should be treated before being released to the environment.

关键词： Source term FHR Primary coolant Fick’s law Diffusion

Applications of a Few Lie Algebras

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Acta Mathematicae Applicatae Sinica 2016年第2期32卷 289-304页

作者： Yu-feng ZHANG zhong HAN zhong-long zhao College of Sciences China University of Mining and Technology

Two isomorphic groups R2 and M are firstly constructed. Then we extend them into the differential manifold R2n and n products of the group M for which four kinds of Lie algebras are obtained. By using these Lie algebras and the Tu scheme, integrable hierarchies of evolution equations along with multi-component potential functions can be generated, whose Hamiltonian structures can be worked out by the variational identity. As application illustrations, two integrable Hamiltonian hierarchies with 4 component potential functions are obtained, respectively, some new reduced equations are followed to present. Specially remark that the integrable hierarchies obtained by taking use of the approach presented in the paper are not integrable couplings. Finally, we generalize an equation obtained in the paper to introduce a general nonlinear integrable equation with variable coefficients whose bilinear form, BEcklund transformation, Lax pair and infinite conserved laws are worked out, respectively, by taking use of the Bell polynomials.

关键词： group Lie algebra bilinear Lax pair conservation law

Empirical Likelihood Inference for Functional Coefficient ARCH-M Model

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Acta Mathematica Sinica,English Series 2019年第2期35卷 270-296页

作者： hai Qing zhao Yuan LI Yan Meng zhao School of Mathematics and Information Science Guangzhou University School of Mathematics and Statistics Lingnan Normal University School of Economics and Statistics Guangzhou University School of Mathematics and Statistics Shenzhen University

Empirical likelihood inference for parametric and nonparametric parts in functional coefficient ARCH-M models is investigated in this paper. Firstly, the kernel smoothing technique is used to estimate coefficient function δ(x). In this way we obtain an estimated function with parameter β.Secondly, the empirical likelihood method is developed to estimate the parameter β. An estimated empirical log-likelohood ratio is proved to be asymptotically standard chi-squred, and the maximum empirical likelihood estimation(MELE) for β is shown to be asymptotically normal. Finally, based on the MELE of β, the empirical likelihood approach is again applied to reestimate the nonparametric part δ(x). The empirical log-likelohood ratio for δ(x) is proved to be also asymptotically standard chi-squred. Simulation study shows that the proposed method works better than the normal approximation method in terms of average areas of confidence regions for β, and the empirical likelihood confidence belt for δ(x) performs well.

关键词： ARCH-M model empirical likelihood relative risk aversion

Cross-domain identity authentication scheme based on blockchain and PKI system

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High-Confidence Computing 2023年第1期3卷 8-17页

作者： hai Zhang Feng zhao School of Information and Communication Guilin University of Electronic TechnologyGuilin 541004China School of Artificial Intelligence and Information Engineering Guangxi Electrical Polytechnic InstituteNanning 530299China

In vehicular ad hoc networks(VANET),the cross-domain identity authentication of users is very important for the development of VANET due to the large cross-domain mobility of vehicle *** Public Key Infrastructure(PKI)system is often used to solve the identity authentication and security trust problems faced by ***,the PKI system has challenges such as too centralized Authority of Certification Authority(CA),frequent cross-domain access to certificate interactions and high authentication volume,leading to high certificate management costs,complex cross-domain authentication paths,easy privacy leakage,and overburdened *** address these problems,this paper proposes a lightweight blockchain-based PKI identity management and authentication architecture that uses smart contracts to reduce the heavy burden caused by CAs directly managing the life cycle of digital *** this basis,a trust chain based on smart contracts is designed to replace the traditional CA trust chain to meet the general cross-domain requirements,to effectively avoid the communication pressure caused by a mass of certificate *** the cross-domain scenario with higher privacy and security requirements the identity attribute authentication service is provided directly while protecting privacy by using the Merkle tree to anchor identity attribute data on and off the blockchain ***,the proposed scheme was comprehensively analyzed in terms of cost,time consumption and security.

关键词： Vehicular ad hoc network PKI Blockchain Cross-domain authentication

Hexahedral constraint-free finite element method on meshes with hanging nodes

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Science China Mathematics 2019年第12期62卷 2591-2616页

作者： Xuying zhao zhong-Ci Shi LSEC Institute of Computational Mathematics and Scientific/Engineering ComputingNCMISAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences Capital Normal UniversityBeijing 100048China

Nonconforming grids with hanging nodes are frequently used in adaptive finite element comput at *** all earlier works on such methods,proper cons train ts should be enforced on degrees of freedom on edges/faces with hanging nodes to keep continuity,which yield numerical computations much *** 2014,zhao et al.(2014)presented quadrilateral constraint-free finite element methods on quadrilateral grids with hanging *** paper further develops a hexahedral constraint-free finite element method on hexahedral grids with hanging nodes,which is of greater challenge than the two-dimensional ***-based a posteriori error reliability and efficiency are also established in this paper.

关键词： adaptive finite element a posteriori error estimate hexahedral nonconforming element hangingnode

Intermolecular hydrogen-bond interaction to promote thermoreversible 2'-deoxyuridine-based AIE-organogels

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Chinese Chemical Letters 2021年第4期32卷 1363-1366页

作者： Xuan zhao Long zhao Qiuyun Xiao hai Xiong Institute for Advanced Study Shenzhen University.Shenzhen 518060China

Fluorescent supramolecular nucleoside-based organogels or hydrogels have attracted increasing attention owing to their tunable stability,drug delivery,tissue engineering,and inherent biocompatibility for applications in designing *** the temperature of a constant TPE-Octa-dU gelato r at MGC as low as 0.2 wt%was increased with gel to sol transition,a progressive decrease in the fluorescence intensity was observed.~1 H NMR study in ethanol-d_(6)/H_(2)O revealed the existence of intermolecular hydrogen-bond interaction between uridine nucleobase and triazole *** on these experiments,thus organogels induced by hydrogen bonding can promote an aggregation-induced emission(AIE)of TPE *** gelation properties have been investigated systematically,including AIE-shapemorphing architecture owing to their unique solid-liquid interface and easy *** the same line,the related TPE-EdU derivative which was synthesized from 5-ethynyl-2'-deoxyuridine does not delive r organogels or hydrogels,a nd under similar circumstances TPE moiety of TPE-EdU does not efficiently exhibit AIE phenomenon either.

关键词： Supramolecular Organogel Aggregation-induced emission Nucleoside Click chemistry

Smoothness preserving layout for dynamic labels by hybrid optimization

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Computational Visual Media 2022年第1期8卷 149-163页

作者： Yu He Guo-Dong zhao Song-hai Zhang Department of Computer Science and Technology Tsinghua UniversityBeijingChina Department of Computer Science and Technology Tianjin University of TechnologyTianjinChina

Stable label movement and smooth label trajectory are critical for effective information *** label changes cannot be avoided by whatever forced directed methods due to the unreliability of resultant force or global optimization methods due to the complex trade-off on the different *** solve this problem,we proposed a hybrid optimization method by taking advantages of the merits of both *** first detect the spatial-temporal intersection regions from whole trajectories of the features,and initialize the layout by optimization in decreasing order by the number of the involved *** label movements between the spatial-temporal intersection regions are determined by force directed *** cope with some features with high speed relative to neighbors,we introduced a force from future,called temporal force,so that the labels of related features can elude ahead of time and retain smooth *** also proposed a strategy by optimizing the label layout to predict the trajectories of features so that such global optimization method can be applied to streaming data.

关键词： label layout smoothness preserving dynamic label forced based static optimization hybrid optimization

Geology and mineralization of the Dongping supergiant alkalic-hosted Au-Te deposit(>100 t Au)in Northern Hebei Province,China:A review

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China Geology 2024年第3期7卷 533-550页

作者： Shi-min Zhen Da-zhao Wang zhong-jian Zha hai-jun Bai Jiang Wang Development and Research Center of China Geological Survey Ministry of Natural ResourcesBeijing 100037China Technical Guidance Center for Mineral Resources Exploration Ministry of Natural ResourcesBeijing 100037China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China Institute of Geological Surveying and Mapping Technology of Anhui Province Hefei 230022China Third Geological Brigade of Hebei Bureau of Geology and Mineral Resources Zhangjiakou 075000China Ulanqab Real Estate Registration Center Ulanqab 012099China

The Dongping deposit is the largest alkalic-hosted gold deposit in China containing>100 t of *** paper presents a new understanding for Dongping ore system,based on the previous *** mineralization originally occurred at 400-380 Ma,simultaneous with emplacement of the Shuiquangou alkaline complex,and was overprinted by the hydrothermal activity in the *** compositions of ores indicate metals of the deposit are mainly provided by the Shuiquangou ***-forming fluids are characterized by increasing oxygen fugacity and decreasing sulfur fugacity,while tellurium fugacity increased in the Stage II-2 and decreased in Stage *** systematic changes are closely related to the processes of mineral precipitation and fluid *** precipitation from Stage Ⅰ to Stage Ⅱ was triggered by fluid boiling,which leads to the precipitation of Pb-Bi-Te,due to decrement of sulfur *** of gas phase containing high concentration of H_2Te leads to precipitation of Te-Au-Ag minerals and native *** on these hypotheses,this paper present a polyphase metallogenic model as *** the Devonian,fluids were released from alkaline magmas,which carried ore-forming materials form the surrounding rocks and precipitate the early *** the Jurassic-Cretaceous,fluorine-rich fluids exsolved from highly factionated Shangshuiquan granite,which extracted and concentrated Au from the Shuiquangou complex and the Sanggan Group metamorphic rocks,and finally formed the Dongping gold deposit.

关键词： Mineralization and alteration Alkaline intrusion Au deposit Physicochemical conditions Metallogenic model Oxygen fugacity Sulfur fugacity Mechanisms of mineral precipitation Fluid boiling Fluorine-enriched fluid Dongping gold deposit North China Craton Mineral exploration engineering

An Effective Green Porous Structural Adhesive for Thermal Insulating,Flame-Retardant,and Smoke-Suppressant Expandable Polystyrene Foam

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Engineering 2022年第10期17卷 151-160页

作者： Meng-En Li hai-Bo zhao Jin-Bo Cheng Ting Wang Teng Fu Ai-Ning Zhang Yu-zhong Wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE)&State Key Laboratory of Polymer Materials Engineering&National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan) College of ChemistrySichuan UniversityChengdu 610064China

To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a novel"green"porous bio-based flame-retard ant starch(FRS)coating was designed from starch modified with phytic acid(PA)that simultaneously acts as both a flame retardant and an *** porous FRS coating has open pores,which,in combination with the closed cells formed by EPS beads,create a hierarchically porous structure in FRS-EPS that results in superior thermal insulation with a lower thermal conductivity of 27.0 mW·(m·K)^(-1).The resultant FRS-EPS foam showed extremely low heat-release rates and smoke-production release,indicating excellent fire retardancy and smoke *** specific optical density was as low as 121,which was 80.6%lower than that of neat EPS,at *** FRS-EPS also exhibited self-extinguishing behavior in vertical burning tests and had a high limiting oxygen index(LOI)value of 35.5%.More interestingly,after being burnt with an alcohol lamp for 30 min,the top side temperature of the FRS-EPS remained at only 140℃with ignition,thereby exhibiting excellent fire *** analysis confirmed the intumescent action of FRS,which forms a compact phosphorus-rich hybrid barrier,and the phosphorus-containing compounds that formed in the gas phase contributed to the excellent flame retardancy and smoke suppression of *** novel porous biomass-based FRS system provides a promising strategy for fabricating polymer foams with excellent flame retardancy,smoke suppression,and thermal insulation.

关键词： Biomass porous coating Expanded polystyrene foam Low thermal conductivity Flame retardancy Smoke suppression