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Chemical Research in Chinese Universities 2017年第4期33卷 672-677页

作者： AN tong DANG Dan CHENG yi Department of Chemical Engineering Tsinghua University Beijing 100084 P. R. China

Effect of reduction and carburization pretreatment on iron catalyst for CO hydrogenation to light olefins was investigated. The bulk structure and surface composition of the catalysts during pretreatment were characterized by means of X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS） and high-resolution transmission elec- tron microscopy（HRTEM）. The results indicated that phase transformation of iron phases involved a-Fe203---~Fe304 --,a-Fe both in the bulk and on the surface layers in hydrogen atmosphere. However, a-Fe203 was firstly transformed to Fe3C and then to Fe5C2 in CO atmosphere, while in syngas atmosphere directly to Fe5C2. As carburization pretreatment time was prolonged, the degree of carburization on the surface increased, and the increase degree of iron catalyst carburization in CO pretreatment was stronger than that in syngas pretreatment. It inferred that surface carbon species was more easily formed in syngas pretreatment instead of iron carbide in CO pretreatment. After hydrogen pretreatment, when the catalyst was reduced to a mixture of magnetite and metallic iron, the selectivity to light olefins was relatively low. Under the joint effects of the active sites from surface iron carbide and surface carbon layers blocking the active sites, longer CO pretreatment time resulted in higher methane selectivity and less light olefins. The selectivity to methane on H2-pretreated catalyst was lower than that of CO-pretreated catalyst.

关键词： Light olefin Fischer-Tropsch synthesis CO hydrogenation Iron catalyst Pretreatment

ITO thin films prepared by electron beam evaporation with End-Hall ion source assisted without heating to the substrate

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光学精密工程 2005年第4期13卷 397-402页

作者： GAO Jin-song XU ying WANG Xiao-yi WANG tong-tong Optical Technology and Research Center Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130022 China

ITO （indium oxide doped with tin） thin films were deposited on glass substrates by using ITO pellet with a composition of w（In2O3）=90% and w（SnO2）=10% by electron beam evaporated with End-Hall ion source assisted without extra heating. The rate of deposition and flow rate of oxygen were measured and changed to obtain the best properties of ITO thin films. Furthermore, the post annealing process was done in vacuum at different annealing temperatures for 2 h and at 400℃ for different keeping time, respectively. The relation between optical, electrical properties and structure was discussed in detail.

关键词： ITO 薄膜电子束离子源

River Chief System (RCS):An experiment on cross-sectoral coordination of watershed governance

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Frontiers of Environmental Science & Engineering 2019年第4期13卷 1-3页

作者： Longfei Wang Jiaxin tong yi Li Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes Ministry of EducationCollege of EnvironmentHohai UniversityNanjing 210098China Basin Water Environmental Research Department Changjiang River Scientific Research InstituteWuhan 430010China

The trans-regional characteristics of watershed governance produce more problems beyond the capacity of each individual water-related department, leading to the fragmentation of watershed management. The River Chief System (RCS) has experienced swift developments over the past decade in China by appointing the local government heads as river chiefs. RCS works efficiently in the short-term due to its superiority in the inclusion of clear responsibility, authority, and multi-sectoral collaboration. However, the characteristics of the authority-based vertical coordination of the hierarchical system remain unchanged, and therefore the problems of organizational logic and the responsibility dilemma still exist. Tasks including perfecting of laws, integrated watershed management, and public participation still need to be completed. RCS reflects the routine and characteristics of the migration of national governance, and as such provides new insights for other developing countries in the design of river management systems.

关键词： River Chief System Watershed governance Cross-sectoral coordination Environmental protection

Mechanism of stall and surge in a centrifugal compressor with a variable vaned diffuser

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Chinese Journal of Aeronautics 2018年第6期31卷 1222-1231页

作者： Xiang XUE tong WANG tongtong ZHANG bo YANG Gas Turbine Research Institute Shanghai Jiao Tong University

To expand the stable operating range of compressors, understanding the mechanism of flow instability at low flow rates is necessary. In this paper, the mechanism of stall and surge in a centrifugal compressor with a variable vaned diffuser is experimentally investigated, where the diffuser blade setting angle can be adjusted. Many dynamic pressure transducers are mounted on the casing surface of the compressor. From the design condition to surge, dynamic pressure data is recorded throughout the gradual process. According to the signal developing status, the typical modes of compressor instability are defined in detail, such as stall, mild surge, and deep surge. A relatively high-frequency stall wave originates in the impeller and propagates to the diffuser, and finally stimulates a deep surge in the compressor. The compressor behavior during surge differs at different diffuser vane angles. When the diffuser vane angle is adjusted, both the unstable form and the core factor affecting the overall machine stability change. A specific indicator is proposed to measure the instability of each component in a compressor, which can be used to determine the best region for stability extension technologies, such as a holed casing treatment, in different compressor applications.

关键词： Centrifugal compressor Flow instability Stall Surge Vaned diffuser

Stable Label-Specific Features Generation for Multi-Label Learning via Mixture-Based Clustering Ensemble

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IEEE/CAA Journal of Automatica Sinica 2022年第7期9卷 1248-1261页

作者： yi-bo Wang Jun-yi Hang Min-Ling Zhang School of Computer Science and Engineering Southeast UniversityNanjing 210096China IEEE

Multi-label learning deals with objects associated with multiple class labels,and aims to induce a predictive model which can assign a set of relevant class labels for an unseen *** each class might possess its own characteristics,the strategy of extracting label-specific features has been widely employed to improve the discrimination process in multi-label learning,where the predictive model is induced based on tailored features specific to each class label instead of the identical instance *** a representative approach,LIFT generates label-specific features by conducting clustering ***,its performance may be degraded due to the inherent instability of the single clustering *** improve this,a novel multi-label learning approach named SENCE(stable label-Specific features gENeration for multi-label learning via mixture-based Clustering Ensemble)is proposed,which stabilizes the generation process of label-specific features via clustering ensemble ***,more stable clustering results are obtained by firstly augmenting the original instance repre-sentation with cluster assignments from base clusters and then fitting a mixture model via the expectation-maximization(EM)*** experiments on eighteen benchmark data sets show that SENCE performs better than LIFT and other well-established multi-label learning algorithms.

关键词： Clustering ensemble expectation-maximization al-gorithm label-specific features multi-label learning

How about the reporting quality of case reports in nursing field?

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World Journal of Clinical Cases 2019年第21期7卷 3505-3516页

作者： Ke-Lu Yang Cun-Cun Lu Yue Sun yi-tong Cai bo Wang yi Shang Jin-Hui Tian Evidence-Based Nursing Center School of NursingLanzhou UniversityLanzhou 730000Gansu ProvinceChina Evidence-Based Medicine Center School of Basic Medical SciencesLanzhou UniversityLanzhou 730000Gansu ProvinceChina Gansu Province Hospital Rehabilitation Center Lanzhou 730000Gansu ProvinceChina Lanzhou University Second Hospital Lanzhou UniversityLanzhou 730000Gansu ProvinceChina

BACKGROUND As a significantly important part of clinical practice,the professional nursing process can be advanced in many *** the fact that case reports are regarded to be of a lower quality grade in the hierarchy of evidence,one of the principles of evidence-based medicine is that decision-making should be based on a systematic summary of ***,the evidence on the reporting characteristics of case reports in the nursing field is *** To use the CARE guidelines to assess reporting quality and factors influencing the quality of case reports in the nursing *** Nursing science citation indexed(SCI-indexed)journals were identified from the professional *** of the identified journals was searched on their website for articles published before December ***-one sub-items on the CARE checklist were recorded as“YES”,“PARTLY”,or“NO”according to information reported by the included *** responses were assigned corresponding scores of 1,0.5,and 0,*** overall score was the sum of the 21 sub-items and was defined as“high”(more than 15),“medium”(10.5 to 14.5),and“low”(less than 10).The means,standard deviations,odds ratios(OR),and the associated 95%confidence interval(CI)were determined using Stata 12.0 *** Ultimately,184 case reports from 16 SCI-indexed journals were identified,with overall scores ranging from 6.5 to 18(mean=13.6±2.3).Of the included case reports,10.3%were regarded low-quality,52.7%were considered middle-quality,and 37%were regarded *** were statistical differences in the mean overall scores of the included case reports with funding versus those without funding(14.2±1.7 vs 13.6±2.4,respectively;P=0.4456)and journal impact factor<1.8 versus impact factor≥1.8(13.3±2.3 vs 13.6±2.4,respectively;P=0.4977).Five items from the CARE guidelines,5a(Patient),6(Clinical findings),8c(Diagnostic reasoning),9(Therapeutic intervention),and 11d(The main take-away lessons)were

关键词： Systematic review Case reports Case report guidelines Nursing Reporting quality Science citation indexed journals

Grain boundary segregation and relaxation in nano-grained polycrystalline alloys

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Science China(Physics,Mechanics & Astronomy) 2021年第2期64卷 72-90页

作者： tong-yi Zhang ying-Xin Gao Sheng Sun Materials Genome Institute Shanghai UniversityShanghai200444China

The present study carries out systematic thermodynamics analysis of Grain boundary(GB)segregation and relaxation in NanoGrained(NG)polycrystalline *** segregation and relaxation is an internal process towards thermodynamic equilibrium,which occurs naturally in NG alloys without any applied loads,causes deformation and generates internal *** analysis comprehensively investigates the multiple coupling effects among chemical concentrations and mechanical stresses in GBs and grains.A hybrid approach of eigenstress and eigenstrain is developed herein to solve the multiple coupling *** analysis results indicate that the GB stress and grain stress induced by GB segregation and relaxation can be extremely high in NG alloys,reaching the GPa level,which play an important role in the thermal stability of NG alloys,especially via the coupling terms between stress and *** present theoretic analysis proposes a novel criterion of thermal stability for NG alloys,which is determined by the difference in molar free energy between a NG alloy and its reference single crystal with the same nominal chemical *** the difference at a temperature is negative or zero,the NG alloy is thermal stable at that temperature,otherwise unstable.

关键词： nano-grained alloys thermal stability grain boundary segregation eigenstress eigenstrain

Machine learning of phases and mechanical properties in complex concentrated alloys

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Journal of Materials Science & Technology 2021年第28期87卷 133-142页

作者： Jie Xiong San-Qiang Shi tong-yi Zhang School of Materials Science and Engineering Harbin Institute of TechnologyShenzhenChina Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong KongChina Shenzhen Research Institute The Hong Kong Polytechnic UniversityShenzhenChina Material Genome Institute Shanghai UniversityShanghaiChina

The mechanical properties of complex concentrated alloys(CCAs)depend on their formed phases and corresponding *** data-driven prediction of the phase formation and associated mechanical properties is essential to discovering novel *** present work collects 557 samples of various chemical compositions,comprising 61 amorphous,167 single-phase crystalline,and 329 multiphases crystalline *** classification models are developed with high accuracies to category and understand the formed phases of ***,two regression models are constructed to predict the hardness and ultimate tensile strength of CCAs,and the correlation coefficient of the random forest regression model is greater than 0.9 for both of two targeted ***,the Shapley additive explanation(SHAP)values are calculated,and accordingly four most important features are identified.A significant finding in the SHAP values is that there exists a critical value in each of the top four features,which provides an easy and fast assessment in the design of improved mechanical properties of *** present work demonstrates the great potential of machine learning in the design of advanced CCAs.

关键词： Materials informatics SHAP Complex concentrated alloys High entropy alloys

Design and Properties of Fluoroelastomer Composites via Incorporation of MWCNTs with Varied Modification

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Chinese Journal of Polymer Science 2020年第9期38卷 983-992,I0007页

作者： Guang-Yao Yang Li-Fen tong Xiao-bo Liu Research Branch of Advanced Functional Materials School of Materials and EnergyUniversity of Electronic Science and Technology of ChinaChengdu 610054China

Multi-walled carbon nanotubes(MWCNTs)modified with silane coupling agent A-1120(MWCNTs-A1120)were *** with the raw MWCNTs,acidified MWCNTs(MWCNTs-COOH),and MWCNTs grafted with EDA(MWCNTs-NH2),MWCNTs-A1120 have the best dispersion in fluoroelastomer at the same doping ***,fluoroelastomer/MWCNTs-A1120 composite has the best mechanical properties with tensile strength of 13.92 MPa and elongation at break of 111.78%.Then,the effects of doping amount of MWCNTs-A1120 on the electrical properties of the composites were *** dielectric constant of the composite increases with the increase of MWCNTs-A1120,and the dielectric loss does not change much at the low doping amount such as 0.5 wt%.When the doping amount of MWCNTs-A1120 is 5 wt%,the dielectric constant and the dielectric loss value are greatly increased,and the volume resistivity is greatly decreased,which proves that the conductive network is formed in the composite,so the filling amount of 5 wt%is the percolation *** tensile deformation of the sample also affects the electrical properties of the *** the tensile deformation increases,the dielectric constant and dielectric loss of the composite *** the composite with 5 wt%MWCNTs-A1120,excessive tensile deformation will destroy the conductive network structure of the composite,so the composite will change from conductive material to dielectric ***,such composite is a good candidate for flexible conductive material or flexible dielectric material used in harsh environments such as high temperatures and various aggressive solvents.

关键词： Modified-MWCNTs Fluoroelastomer nanocomposite Interface compatibility Dielectric properties Volume resistivity

MeshCNN-based BREP to CSG conversion algorithm for 3D CAD models and its application

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Nuclear Science and Techniques 2022年第6期33卷 75-88页

作者： Yue-tong Luo Hua Du yi-Man Yan Hefei University of Technology Hefei 230009China University of Science and Technology of China Hefei 230027China Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China State Power Investment Corporation Research Institute National Energy Key Laboratory of Nuclear Power SoftwareBeijing 102209China

In the field of neutronics analysis, it is imperative to develop computer-aided modeling technology for Monte Carlo codes to address the increasing complexity of reactor core components by converting 3D CAD model(boundary representation, BREP) to MC model(constructive solid geometry, CSG). Separation-based conversion from BREP to CSG is widely used in computer-aided modeling MC codes because of its high efficiency, reliability, and easy implementation. However, the current separation-based BREP-CSG conversion is poor for processing complex CAD models, and it is necessary to divide a complex model into several simple models before applying the separation-based conversion algorithm, which is time-consuming and tedious. To avoid manual segmentation, this study proposed a MeshCNN-based 3D-shape segmentation algorithm to automatically separate a complex model. The proposed 3D-shape segmentation algorithm was combined with separation-based BREP-CSG conversion algorithms to directly convert complex *** proposed algorithm was integrated into the computeraided modeling software cosVMPT and validated using the Chinese fusion engineering testing reactor model. The results demonstrate that the MeshCNN-based BREP-CSG conversion algorithm has a better performance and higher efficiency, particularly in terms of CPU time, and the conversion result is more intuitive and consistent with the intention of the modeler.

关键词： BREP to CSG conversion Computer-aided modeling cosVMPT Intelligent pre-segmentation MeshCNN