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Decomposition of fissile isotope antineutrino spectra using convolutional neural network

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Nuclear Science and Techniques 2023年第5期34卷 183-191页

作者： yu-Da zeng Jun Wang Rong Zhao Feng-Peng An Xiang xiao yuenkeung Hor Wei Wang School of Physics Sun Yat-sen UniversityGuangzhou510275China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai519082China

Recent reactor antineutrino experiments have observed that the neutrino spectrum changes with the reactor core evolution and that the individual fissile isotope antineutrino spectra can be decomposed from the evolving data,providing valuable information for the reactor model and data inconsistent *** propose a machine learning method by building a convolutional neural network based on a virtual experiment with a typical short-baseline reactor antineutrino experiment configuration:by utilizing the reactor evolution information,the major fissile isotope spectra are correctly extracted,and the uncertainties are evaluated using the Monte Carlo *** tests show that the method is unbiased and introduces tiny extra uncertainties.

关键词： Reactor antineutrino Isotope antineutrino spectrum decomposition Convolutional neural network

Microbiological quality of roof tank water in an urban village in southeastern China

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Journal of Environmental Sciences 2023年第3期125卷 148-159页

作者： Dong Hu Jie zeng Jing Chen Wenfang Lin Xinyan xiao Mingbao Feng Xin yu Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Shitang Community Health Service Center Xiamen 361026China College of the Environment and Ecology Xiamen UniversityXiamen 361005China

Urban villages are unique residential neighborhoods in urban areas in China. Roof tanks are their main form of water supply, and water quality deterioration might occur in this system because of poor hygienic conditions and maintenance. In this study, water samples were seasonally collected from an urban village to investigate the influence of roof tanks as an additional water storage device on the variation in the microbial community structure and pathogenic gene markers. Water stagnation in the roof tank induced significant decreases in chlorine(p < 0.05), residual chlorine was as low as 0.02 mg/L in spring. Propidium monoazide(PMA)-qPCR revealed a one-magnitude higher level of total viable bacterial concentration in roof tank water samples(2.14 ± 1.81 × 105gene copies/mL) than that in input water samples(3.57 ± 2.90 × 104gene copies/mL, p < 0.05), especially in spring and summer. In addition,pathogenic fungi, Mycobacterium spp., and Legionella spp. were frequently detected in the roof tanks. Terminal users might be exposed to higher microbial risk induced by high abundance of Legionella gene marker. Spearman’s rank correlation and redundancy analysis showed that residual chlorine was the driving force that promoted bacterial colonization and shaped the microbial community. It is worth noted that the sediment in the pipe will be agitated when the water supply is restored after the water outages, which can trigger an increase in turbidity and bacterial biomass. Overall, the findings provide practical suggestions for controlling microbiological health risks in roof tanks in urban villages.

关键词： Urban village Water storage tank Microbiological water quality Propidium monoazide(PMA)-qPCR Illumina sequencing

Equality-constrained minimization of polynomial functions

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Science China Mathematics 2015年第10期58卷 2181-2204页

作者： xiao ShuiJing zeng GuangXing Department of Mathematics Nanchang University

This paper investigates the equality-constrained minimization of polynomial functions. Let R be the field of real numbers, and R[x1,..., xn] the ring of polynomials over R in variables x1,..., xn. For an f ∈ R[x1,..., xn] and a finite subset H of R[x1,..., xn], denote by V(f : H) the set {f( ˉα) | ˉα∈ Rn, and h( ˉα) =0, ? h ∈ H}. We provide an effective algorithm for computing a finite set U of non-zero univariate polynomials such that the infimum inf V(f : H) of V(f : H) is a root of some polynomial in U whenever inf V(f : H) = ±∞.The strategies of this paper are decomposing a finite set of polynomials into triangular chains of polynomials and computing the so-called revised resultants. With the aid of the computer algebraic system Maple, our algorithm has been made into a general program to treat the equality-constrained minimization of polynomials with rational coefficients.

关键词： polynomial function equality constraints equality-constrained minimization constrained infimum Wu’s algorithm triangular decompo

Mean flow and turbulence structure of open channel flow with suspended vegetation

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Journal of Hydrodynamics 2020年第2期32卷 314-325页

作者： Qian Li yu-hong zeng yu Bai State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China

In combination with a channel bed,suspended vegetationin an open channel can alter flow structure and generate vertically asymmetric *** study investigated the mean flow and turbulence structure of an open channel with suspended vegetation through theoretical analysis and laboratory *** patterns of bionic leaves with different roughness were adopted to imitate suspended vegetation,and three-dimensional velocity field was measured by using an acoustic Doppler *** measured data showed that the vertical profile of streamwise velocity obeys a two-power law and that the maximum velocity at the middle depth is close to the smooth boundary(i.e.,the channel bed in the experiment)under the combined action of vegetation cover and channel *** stress is linearly distributed along the vertical axis,and the vertical profile of turbulence intensity obeys an exponential ***,a two-power law expression was adopted to predict the vertical profile of streamwise *** models for the vertical distribution of shear stress and turbulence intensity were also *** predicted results validated by measurements showed that the different magnitudes of vegetation cover and channel bed boundary roughness exert an obvious impact on flow structure.

关键词： Suspended vegetation streamwise velocity shear stress turbulence intensity boundary roughness

阿拉善-华北北缘晚古生代-早中生代岩浆作用:对古亚洲洋俯冲-闭合过程的制约

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岩石学报 2025年第1期41卷 66-90页

作者：曾浩宋东方肖文交李普庆中国科学院地质与地球物理研究所岩石圈演化与环境演变全国重点实验室北京100029 中国科学院地球科学研究院北京100029 中国科学院新疆生态与地理研究所干旱区生态安全与可持续发展全国重点实验室乌鲁木齐830011 中国科学院大学地球与行星科学学院北京100049

位于中亚造山带南部的阿拉善-华北北缘地区保存了丰富的晚古生代-早中生代岩浆记录,为理解古亚洲洋从俯冲至闭合的构造演化过程提供了关键信息。本文对位于内蒙古西部的甘其毛都地区的4个侵入体进行了岩相学、地球化学、锆石U-Pb年代学... 详细信息

位于中亚造山带南部的阿拉善-华北北缘地区保存了丰富的晚古生代-早中生代岩浆记录,为理解古亚洲洋从俯冲至闭合的构造演化过程提供了关键信息。本文对位于内蒙古西部的甘其毛都地区的4个侵入体进行了岩相学、地球化学、锆石U-Pb年代学和Lu-Hf同位素分析。锆石U-Pb定年表明这些岩体分别形成于早二叠世(283±3Ma、273±5Ma、272±5Ma)和中三叠世(238±3Ma)。早二叠世岩体以石英闪长岩和闪长玢岩为主,富集轻稀土与大离子亲石元素,亏损高场强元素Nb、Ta等,Hf同位素显著亏损(-4.0~+15.6)。它们可能是由俯冲板片流体交代地幔楔部分熔融形成的基性岩浆经分离结晶演化而成。中三叠世侵入体为花岗闪长岩,轻重稀土元素强烈分异,锆石ε_(Hf)(t)值均为正值(+5.0~+8.5),可能代表了碰撞造山阶段新生下地壳物质部分熔融的产物。在此基础之上,本文系统收集并分析了阿拉善-华北北缘地区晚古生代-早中生代岩浆岩的时空分布规律与地球化学特征,以限定其构造背景与深部动力学过程。结合前人研究成果提出:石炭纪时期,古亚洲洋向南俯冲至阿拉善-华北克拉通之下并不断向北后撤;至早二叠世,俯冲板片转变为前进式俯冲,整体处于挤压环境,发育大规模岩浆活动与弧背前陆盆地;早-中三叠世,古亚洲洋闭合,阿拉善-华北克拉通沿索伦缝合带与北侧的中亚弧增生体系发生碰撞-拼贴。

关键词：阿拉善华北北缘晚古生代-早中生代古亚洲洋俯冲-闭合

STUDIES ON ION BEAM APPLICATION TO IMPROVE AQUATIC MACROPHYTE REMEDIATION CAPACITY IN EUTROPHIC WATERS

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水生生物学报 2006年第6期30卷 711-717页

作者： LI Miao1, WU yue-Jin 1, ZHANG Jun 1, yu Han-Qing 2, WU xiao-Lei 3 and yu zeng-Liang 1 (1. Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, the Chinese Academy of Sciences, Hefei, China 230031 2. School of Chemistry and Material Science, the University of Science and Technology of China, Hefei, China 230026 3. Department of Environmental Science and Engineering, Tsinghua University, Beijing, China 100084 ) Institute of Plasma Physics the Chinese Academy of Sciences Key Laboratory of Ion Beam Bioengineering CAS Hefei 230031 School of Chemistry and Material Science the University of Science and Technology of China Hefei 230026 Department of Environmental Science and Engineering Tsinghua University Beijing 100084

Using ion beam biotechnology in combination with soil-less plant cultivation on artificial substratum (floating beds), the experiments were conducted with Ipomoea aquatica Forsk. Plants were attached to floating-beds which were placed on the surface of artificially nutrient-enriched tank water, in order to study the purification and remediation efficiency of ion beam-treated I. aquatica cultivars. The results show that N + ion beams with 25keV energy and dosages of 0, 2.6, 3.9, 5.2, 6.5, 7.8, 9.1×10 13N +(ions)/cm 2 affected I. aquatica dry seeds differently, with the dose of 3.9×10 13N + (ions)/cm 2 improving effectively the performance as expressed by various biological indices. After ion beam application, I. aquatica cultivars grew well in nutrient-enriched water bodies, increasing the growth of leaves and stem, number of leaves, length and area of roots, plant height, and weight more remarkably than observed in the control. The net removing rates of TN, TP were as high as 75% and 82%, respectively. Especially under the dose of 3.9×10 13N +(ions)/cm 2, the net removing rates of TN, TP were highest, for 77% and 85%, respectively. It was proved that ion beam application improves phytoremediation and may be used to purify nutrient rich water bodies.

关键词： Ion beam treatment Aquatic macrophyte Ipomoea aquatica Forsk Nutrient-enriched waters Remediation capacity

The hydrodynamic interactions of an array of truncated circular cylinders as each cylinder oscillates independently with different prescribed modes

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Journal of Hydrodynamics 2013年第1期25卷 27-38页

作者： zeng xiao-hui TANG Si-yi Institute of Mechanics Chinese Academy of Sciences

An analytical method based on the eigenfunction expansion and the Graf＇s addition theorem for Bessel functions is developed to study the hydrodynamic interactions of an array of truncated circular cylinders with each cylinder oscillating independently in different prescribed modes. The hydrodynamic radiation and diffraction of linear waves by such an array of cylinders are investigated and the analytical solutions of the velocity potentials are obtained. After comparisons for degenerated cases and program verifications, several cases for an array of truncated cylinders with each cylinder oscillating independently in surge, sway, heave, roll, and pitch modes with different prescribed amplitudes, are studied and the hydrodynamic forces and moments acting on the cylinders are obtained.

关键词： array of truncated circular cylinders independent oscillation radiation hydrodynamic interaction

Neutronics analysis of a subcritical blanket system driven by a gas dynamic trap-based fusion neutron source for ^(99)Mo production

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Nuclear Science and Techniques 2023年第4期34卷 14-25页

作者： Hou-Hua Xiong Qiu-Sun zeng yun-Cheng Han Lei Ren Isaac Kwasi Baidoo Ni Chen Zheng-Kui zeng xiao-yu Wang School of Nuclear Technology and Chemistry&Biology and Hubei Key Laboratory of Radiation Chemistry and Functional Materials Hubei University of Science and TechnologyXianning 437100China Institute of Nuclear Energy Safety Technology Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Nuclear Reactors Research Centre National Nuclear Research InstituteGhana Atomic Energy CommissionBox LG 80Legon-AccraGhana Teaching and Research Section of Nuclear Medicine School of Basic Medical SciencesHefei Institutes of Physical ScienceAnhui Medical UniversityHefei 230031China

Gamma-emitting radionuclide ^(99m)Tc is globally used for the diagnosis of various pathological conditions owing to its ideal single-photon emission computed tomography (SPECT) ***,the short half-life of ^(99m)Tc (T_(1/2)=6 h)makes it difficult to store or ***,the production of ^(99m)Tc is tied to its parent radionuclide ^(99)Mo (T_(1/2)=66 h).The major production paths are based on accelerators and research *** reactor process presents the potential for nuclear proliferation owing to its use of highly enriched uranium (HEU).Accelerator-based methods tend to use deuterium–tritium(D–T) neutron sources but are hindered by the high cost of tritium and its challenging *** this study,a new ^(99)Mo production design was developed based on a deuterium–deuterium (D–D) gas dynamic trap fusion neutron source (GDT-FNS) and a subcritical blanket system (SBS) assembly with a low-enriched uranium (LEU) ***-FNS can provide a relatively high-neutron intensity,which is one of the advantages of ^(99)Mo *** provide a Monte Carlo-based neutronics analysis covering the calculation of the subcritical multiplication factor (k_(s)) of the SBS,optimization design for the reflector,shielding layer,and ^(99)Mo production *** calculations,including the neutron flux and nuclear heating distributions,are also provided for an overall evaluation of the production *** results demonstrated that the SBS meets the nuclear critical safety design requirement (k_(s)<0.97) and maintained a high ^(99)Mo production *** proposed system can generate approximately 157 Ci ^(99)Mo for a stable 24 h operation with a neutron intensity of 1×10^(14) n/s,which can meet 50%of China’s demand in 2025.

关键词： Gas dynamic trap Fusion neutron source Molybdenum-99 Low-enriched uranium Subcritical blanket system

Effect of Screw-Dislocation on Electrical Properties of Spiral-Type Bi2Se3 Nanoplates

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Chinese Journal of Chemical Physics 2016年第6期29卷 687-692,I0001页

作者： yu-kun Wu A-wei Zhuang Chun-miao Ye Jie zeng Nan Pan xiao-ping Wang HefeiNationalLaboratoryforPhysicalSciencesattheMicroscaleandDepartmentofPhysics UniversityofScienceandTechnologyofChinaHefei230025China

We systematically investigated the electrical nanoplates through field effect transistor and properties of spiral-type and smooth Bi2Se3 conductive atomic force microscopy （CAFM） measurement. It is observed that both nanoplates possess high conductivity and show metallic-like behavior. Compared to the smooth nanoplate, the spiral-type one exhibits the higher carrier concentration and lower mobility. CAFM characterization reveals that the conductance at the screw-dislocation edge is even higher than that on the terrace, implying that the dislocation can supply excess carriers to compensate the low mobility and achieve high conductivity. The unique structure and electrical properties make the spiral-type Bi2 Se3 nanoplates a good candidate for catalysts and gas sensors.

关键词： Bi2Se3 nanoplates Screw-dislocation Electrical properties Field effect tran-sistor Conductive atomic force microscopy