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A refined Monte Carlo code for low-energy electron emission from gold material irradiated with sub-keV electrons

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Nuclear Science and Techniques 2023年第4期34卷 79-92页

作者： Li-Heng Zhou shui-yan Cao Tao Sun Yun-Long Wang Jun Ma Department of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China College of Physics MIIT Key Laboratory of Aerospace Information Materials and PhysicsNanjing University of Aeronautics and AstronauticsNanjing 211106China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China

Considering the significance of low-energy electrons(LEEs;0–20 eV) in radiobiology, the sensitization potential of gold nanoparticles(AuNPs) as high-flux LEE emitters when irradiated with sub-keV electrons has been suggested. In this study, a track-structure Monte Carlo simulation code using the dielectric theory was developed to simulate the transport of electrons below 50 keV in gold. In this code, modifications, particularly for elastic scattering, are implemented for a more precise description of the LEE emission in secondary electron emission. This code was validated using the secondary electron yield and backscattering coefficient. To ensure dosimetry accuracy, we further verified the code for energy deposition calculations using the Monte Carlo toolkit, Geant4. The development of this code provides a basis for future studies regarding the role of AuNPs in targeted radionuclide radiotherapy.

关键词： Monte Carlo code Secondary electron emission Low-energy electrons

Study on the Method of Soil Productivity Assessment in Black Soil Region of Northeast China

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Agricultural Sciences in China 2009年第4期8卷 472-481页

作者： DUAN Xing-wu XIE Yun FENG yan-jie YIN shui-qing State Key Laboratory of Earth Surface Processes and Resource Ecology School of Geography Beijing Normal University Beijing 100875P.R. China

The objective of this paper is to investigate a simple and practical method for soil productivity assessment in the black soil region of Northeast China. Firstly, eight kinds of physicochemical properties for each of 120 soil samples collected from 25 black soil profiles were analyzed using cluster and correlation analysis. Subsequently, parameter indices were calculated using physicochemical properties. Finally, a modified productivity index （MPI） model were developed and validated. The results showed that the suitable parameters for soil productivity assessment in black soil region of Northeast China were soil available water, soil pH, clay content, and organic matter content. Compared with original productivity index （PI） model, MPI model added clay content and organic matter content in parameters while omitted bulk density. Simulation results of original PI model and MPI model were compared using crop yield of land block where investigated soil profiles were located. MPI model was proven to perform better with a higher significant correlation with maize yield. The correlation equation between MPI and yield was： Y= 3.2002Ln（MP/）＋ 10.056, R^2 = 0.7564. The results showed that MPI model was an effective and practical method to assess soil productivity in the research area.

关键词： PI MPI soil productivity black soil region of Northeast China

ELECTROCHEMICAL POLYMERIZATION OF 5-CyanOINDOLE IN MIXED ELECTROLYTES OF BORON TRIFLUORIDE DIETHYL ETHERATE AND DIETHYL ETHER

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Chinese Journal of Polymer Science 2006年第1期24卷 47-52页

作者： Jing-kun Xu Wei-qiang Zhou Jian Hou Shou-zhi Pu Jing-wu Wang Liu-shui yan Jiangxi Key Laboratory of Organic Chemistry Jiangxi Science and Technology Normal University Nanchang 330013 China Department of Chemistry Nanchang University Nanchang 330047 China Department of Environmental and Chemical Engineering Nanchang Institute of Aeronautical Technology Nanchang 330034 China

High quality poly（5-cyanoindole）（P5CI） films were electrosynthesized by direct anodic oxidation of 5-cyanoindole on stainless steel sheet in the mixed electrolytes of boron trifluoride diethyl etherate （BFEE） and diethyl ether （EE）（by volume 1：1）＋ 0,05 mol L^-1 Bu4NBF4. The film formed can be peeled off the electrode into freestanding films, The addition of EE into BFEE can improve the solubility of monomer. P5CI films obtained from this medium showed excellent electrochemical behavior with conductivity of 10^-2 S cm^-1, Structural studies showed that the polymerization of 5-cyanoindole occurred at the 2,3 position. As-formed P5CI films were thoroughly soluble in strong polar organic solvent dimethyl sulfoxide （DMSO） while partly soluble in tetrahydrofuran （THF） or acetone. Fluorescence spectral studies indicated that P5CI was a good blue-ight emitter.

关键词： Electrochemical polymerization Conducting polymers Polyindole Poly(5-cyanoindole) Boron trifluoride diethyl etherate.

Optimal State Estimation for Discrete-time Systems with Random Observation Delays

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自动化学报 2009年第11期35卷 1446-1451页

作者： HAN Chun-yan ZHANG Huan-shui School of Control Science and Engineering Shandong UniversityJinan 250061 P R. China

This paper investigates the linear minimum mean square error state estimation for discrete-time systems with Markov jump delays. In order to solve the optimal estimation problem, the single Markov delayed measurement is rewritten as an equivalent measurement with multiple constant delays, then a delay-free Markov jump linear system is obtained via state augmentation. The estimator is derived on the basis of the geometric arguments in the Hubert space, and a recursive equation of the filter is obtained by solving the Riccati equations. It is shown that the proposed state estimator is exponentially stable under standard assumptions.

关键词：最小均方误差离散系统马尔可夫系统延迟时间

16S rRNA gene sequencing analysis on changes in the intestinal flora of Procambarus clarkii with“Black May”disease

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Journal of Oceanology and Limnology 2022年第5期40卷 2068-2079页

作者： Jie GONG Guoqing SHEN Mengru ZHU Ming ZHAN Changjun XI yan shui Zenghong XU Huaishun SHEN Wuxi Fisheries College Nanjing Agricultural UniversityNanjing 210095China Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization Ministry of AgricultureFreshwater Fisheries Research CenterChinese Academy of Fishery SciencesWuxi 214081China

The morbidity and mortality peak of farmed Procambarus clarkii occurs around May every year,a phenomenon known as"Black May"disease(BMD).Increasing evidence shows that the intestinal flora is closely related to host *** analyzed and compared the microbiota of healthy and BMDaffected *** *** results show that there was no significant difference in bacterial a-diversity(richness P=0.59;evenness P=0.43;and diversity P=0.052)between the diseased group and the control *** dominant phyla in the intestines of crayfish in the control group,namely Tenericutes(30.86%),Bacteroidetes(29.99%),Firmicutes(22.23%),and Proteobacteria(15.23%),were ***,a striking shift in the microbial compo sition were found in the intestines of *** with *** was a dominant phylum in healthy ***,whereas the prevalence was low in diseased ***(1.87%).By contrast,the prevalence of Proteobacteria was significantly higher(P<0.05)in *** with BMD than in *** without *** Bacilloplasma,Bacteroides,Vibrio,and Aeromonas showed significant differences(P<0.05)at the genus ***4 Fun function prediction indicated that the relative abundance of genes involved in energy metabolism in the intestinal flora of *** with BMD was significantly reduced(P<0.05).Therefore,BMD can change the composition of the intestinal microbiota of *** study contributes to the understanding of the relationship between intestinal flora and host especially in aquatic animals.

关键词： Procambarus clarkii “Black May”disease(BMD) intestinal flora high-throughput sequencing

Emission and Fixation of CO_2 from Soil System as Influenced by Long-Term Application of Organic Manure in Paddy Soils

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Agricultural Sciences in China 2006年第6期5卷 456-461页

作者： CHEN Yi WU Chun-yan shui Jian-guo WANG Jia-yu Institute of Environmental Resources ＆ Soil Fertilizer Zhejiang Academy of Agricultural Sciences Hangzhou 310021 P.R.China

The observations of 25-yr long-term experiment in Zhejiang paddy soils showed that the soil organic matter could increase continuously with applying organic manure, and the increase in rate enhanced along with the application rates of organic manure. By mathematical modeling, the soil organic matter increased by 22 kg when 1 t of fresh FYM was applied. The CO2 emission resulting from the mineralization of soil organic matter increased with the increase in the application rate of the organic manure as well as the increase in the root residues. It is expected that the CO2 emission will be at 10.04-21.61 t ha-1 yr-1 when 16.5-49.5 t ha-1 yr-1 of fresh FYM is applied. The soil organic carbon from mineralization and release of applied organic carbon (fresh FYM and root residues) will affect the CO2 concentration in the atmosphere. So, the higher the application rate of organic manure, the more is the fixed organic carbon. The CO2 fixation will be at 1.885-3.463 t ha-1 yr-1 when 16.5-49.5 t ha-1 yr-1 of fresh FYM is applied. Thus, the CO2 fixation will increase by 46.7 kg by applying 1 t fresh FYM. To apply organic manure continuously in rice fields may reduce the contribution to the increase of CO2 concentration in the atmosphere.

关键词： paddy soil organic manure carbon cycle carbon dioxide global climatic changes

Directional solidification casting technology of heavy-duty gas turbine blade with liquid metal cooling(LMC) process

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China Foundry 2019年第1期16卷 23-30页

作者： Xiao-fu Liu yan-chun Lou Bo Yu Gui-qiao Su Chang-chun Li Xin-li Guo Biao Li Guo-yan shui State Key Laboratory of Light Alloy Casting Technology for High-end Equipment Shenyang Research Institute of Foundry Co.Ltd.Shenyang 110022China

In this work, some important factors such as ceramic shell strength, heat preservation temperature, standing time and withdrawal rate, which influence the formability of directionally solidified large-size blades of heavy-duty gas turbine with the liquid metal cooling(LMC) process, were studied through the method of microstructure analysis combining. The results show that the ceramic shell with medium strength(the high temperature flexural strength is 8 MPa, the flexural strength after thermal shock resistance is 12 MPa and the residual flexural strength is 20 MPa) can prevent the rupture and runout of the blade. The appropriate temperature(1,520 ℃ for upper region and 1,500 ℃ for lower region) of the heating furnace can eliminate the wide-angle grain boundary, the deviation of grain and the run-out caused by the shell crack. The holding time after pouring(3-5 min) can promote the growth of competitive grains and avoid a great deviation of columnar grains along the crystal orientation , resulting in a straight and uniform grain structure. In addition, to avoid the formation of wrinkles and to ensure a smooth blade surface, the withdrawal rate should be no greater than the growth rate of grain. It is also found that the dendritic space of the blade decreases with the rise of solidification rate, and increases with the enlarging distance between the solidification position and the chill plate.

关键词： liquid metal cooling (LMC) heavy-duty gas turbine large-size blade directional solidification microstructure

Development of 3D printing entity slicing software

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China Foundry 2021年第6期18卷 587-592页

作者： yang Guan Xun Sun Lei Jin Xin-li Guo Zhi-min Zhang Guo-yan shui Lan-bo Ma Shenyang Research Institute of Foundry Co. Ltd.Shenyang 110022China State Key Laboratory of Light Alloy Casting Technology for High-end Equipment Shenyang 110022China

Based on STL(stereo lithography)format file and with Microsoft Visual C^(++)6.0 programming language,a 3D printing slicing software appropriate for the surface strengthening of the parts has been developed,which includes three functions:3D model import,model slicing and data *** the grouping of STL model triangle facets before slicing,the judgment times of the relationship between the triangle facets and the cutting planes are reduced,and the slicing efficiency is *** at the fact that the surface should be strengthened when the part is formed by using of 3D printing process,the function of identifying and marking the surface of the geometric entity is accomplished in the slicing software,which can strengthen the surface of the part according to the user’s *** developed slicing software can provide an entity slicing file for 3D printing *** related functions can be adjusted and improved according to user’s needs,which makes the software convenient and flexible to use.

关键词： STL format 3D printing slicing surface strengthening

Properties of alumina-based ceramic cores

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China Foundry 2021年第6期18卷 593-598页

作者： Xiao-fu Liu Xin-li Guo Guo-yan shui Chang-chun Li Gui-qiao Su Xun Sun yang Guan Lei Jin Shenyang Research Institute of Foundry Co. Ltd.Shenyang 110022China

Fused corundum is a rather promising raw material for preparing an alumina-based ceramic core due to its excellent high temperature resistance and chemical *** this study,alumina-based ceramic cores were prepared using fused corundum as the matrix material,and the effect of varying silica powder contents on the properties of the alumina-based ceramic cores,including the sintering shrinkage,the flexural strength,and the high temperature deformation was *** mineralization mechanisms of the silica on the alumina-based ceramic core were also *** optimum addition amount of silica in this experiment is 8% in *** that moment,the aluminum-based core has both a low sintering shrinkage coefficient of 0.66% and better properties:the room temperature flexural strength is 22.19 MPa,the high temperature flexural strength is 21.54 MPa,the high temperature deformation is 0.93 mm,and the residual flexural strength is 47.41 MPa.

关键词： fused corundum ceramic core mineralization mechanism silica powder