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A machine learning approach to query generation in plagiarism source retrieval

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Frontiers of Information Technology & Electronic Engineering 2017年第10期18卷 1556-1572页

作者： Lei-lei KONG Zhi-mao LU Hao-liang QI Zhong-yuan han College of Information and Communication Engineering Harbin Engineering University Harbin 150001 China School of Computer Science and Technology Heilongjiang Institute of Technology Harbin 150050 China State Key Laboratory of Digital Publishing Technology Beijing 100871 China

Plagiarism source retrieval is the core task of plagiarism detection. It has become the standard for plagiarism detection to use the queries extracted from suspicious documents to retrieve the plagiarism sources. Generating queries from a suspicious document is one of the most important steps in plagiarism source retrieval. Heuristic-based query generation methods are widely used in the current research. Each heuristic-based method has its own advantages, and no one statistically outperforms the others on all suspicious document segments when generating queries for source retrieval. Further improvements on heuristic methods for source retrieval rely mainly on the experience of experts. This leads to difficulties in putting forward new heuristic methods that can overcome the shortcomings of the existing ones. This paper paves the way for a new statistical machine learning approach to select the best queries from the candidates. The statistical machine learning approach to query generation for source retrieval is formulated as a ranking framework. Specifically, it aims to achieve the optimal source retrieval performance for each suspicious document segment. The proposed method exploits learning to rank to generate queries from the candidates. To our knowledge, our work is the first research to apply machine learning methods to resolve the problem of query generation for source retrieval. To solve the essential problem of an absence of training data for learning to rank, the building of training samples for source retrieval is also conducted. We rigorously evaluate various aspects of the proposed method on the publicly available PAN source retrieval corpus. With respect to the established baselines, the experimental results show that applying our proposed query generation method based on machine learning yields statistically significant improvements over baselines in source retrieval effectiveness.

关键词： Plagiarism detection Source retrieval Query generation Machine learning Learning to rank

Strengthening of Ultrafine Lamellar-Structured Martensite Steel via Tempering-Induced Nanoprecipitation

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Acta Metallurgica Sinica(English Letters) 2022年第11期35卷 1812-1824页

作者： Xinbo Ji Liming Fu han Zheng Jian Wang Hengchang Lu Wei Wang mao Wen han Dong Aidang Shan School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of High Temperature Materials and Precision Forming Shanghai JiaoTongUniversityShanghai 200240China Zhejiang Institute of Advanced Materials Shanghai UniversityJiaxing 314113China Baowu Steel Research Institute Baoshan Iron and Steel Co.Ltd.Shanghai 201900China

An ultrafine lamellar-structured martensite steel fabricated by heavy warm rolling(HWR)has shown an excellent combination of strength and *** appending tempering at 400℃to HWR,we show that the comprehensive mechanical property of a lamellar-structured low-carbon martensite steel can be further improved to reach a yield strength of~1.8 GPa,an ultimate tensile strength of~2.0 GPa and a total elongation of~9.3%.This is achieved by tempering the HWR steel from 300 to 750℃,and the optimum tempering temperature is thus *** find that the tempered ultrafine lamellar martensite contains high-density nanoprecipitates dispersed within the aligned martensite laths with reduced crystallographic *** ultrahigh strength of the steel is rationalized as mainly the result of grain boundary strengthening and precipitation strengthening,which contribute to yield stress by 610 MPa and 440 MPa,*** good ductility is believed to be closely related to the capacity of the tempered grains to accommodate dense dislocations upon plastic *** present thermomechanical processing provides a feasible routine for producing steels with ultrahigh-strength and good-ductility.

关键词： Low-carbon steel Heavy warm-rolling Ultrafi ne lamellar-structured martensite Precipitation strengthening Mechanical property

Clinical characteristics and treatment of splenic infarction in children with systemic lupus erythematosus

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World Journal of Pediatrics 2024年第5期20卷 525-531页

作者： Yan Li Yu-Rong Piao Tong-Xin han Hua-Wei mao Department of Immunology Ministry of Education Key Laboratory of Major Diseases in ChildrenBeijing Key Laboratory for Genetics of Birth DefectsNational Center for Children’s HealthBeijing Children’s HospitalCapital Medical UniversityNo.56 Nan Li Shi LuBeijing100045China

Splenic infarction(SI)is a rare clinical phenomenon that occurs when the blood supply to the spleen is interrupted,resulting in tissue ischemia and necrosis[1].There are many causes of SI;in adult patients,cardioembolism,hematological malignancy,and infectious disease are the most common[2].Rheumatic diseases,especially systemic lupus erythematosus(SLE)and granulomatosis with polyangitis,can also lead to SI[3];however,only a few cases have been *** are currently no statistically meaningful data on the etiology of SI in *** most patients with SI can recover after conservative treatment,a small number of patients develop complications,such as splenic abscess,splenic rupture,splenic hemorrhage,and hemoperitoneum,and may even undergo splenectomy in severe cases.

关键词： erythematosus lupus treatment

Effect of Sulfur Content and Sulfide Shape on Fracture Ductility in Case Hardening Steel

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Journal of Iron and Steel Research International 2011年第8期18卷 58-64页

作者： XIAO Guo-hua DONG han WANG mao-qiu HUI Wei-jun National Engineering Research Center of Advanced Steel Technology Central Iron andSteel Research Institute Beijing 100081 China

The effects of sulfur content and calcium addition on smooth axisymmetric tensile fracture ductility of case hardening steel DIN 18CrNiMo7-6 have been investigated. The quantitative metallographic analysis of sulfide inclusions and the correlations between sulfide inclusions and fracture ductility were examined. Sulfide inclusions were found to have deleterious effect on fracture ductility, whereas the effect can be offset to some extent by calcium-treat- ment due to less easily deforming of sulfides during hot-working. The product （AA·λAW） of sulfide inclusion area fraction （An） and its area-weighted aspect ratio （λAW） can be used as a parameter to describe the effect of sulfide inclusions on fracture true strain.

关键词： case hardening steel calcium treatment sulfide fracture ductility

Microstructure and Mechanical Properties of Gear Steels After High Temperature Carburization

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Journal of Iron and Steel Research International 2013年第12期20卷 140-145页

作者： YANG Yan-hui WANG mao-qiu CHEN Jing-chao DONG han Faculty of Materials Engineering Kunming University of Science and Technology National Engineering Research Center of Advanced Steel Technology Central Iron and Steel Research Institute

High temperature carburization is becoming more and more attractive because it can remarkably reduce processing time and increase productivity. However, the commonly used gear steels which are microalloyed by Al are not suitable for high temperature carburization due to abnormal grain coarsening. The gear steel 20CrMnTiNb, which is microalloyed with 0. 048% Nb and 0. 038% Ti, has been compared with the gear steel 20CrMn in terms of microstructure in the case of hardened layer and in the core after carburizing at 1000 ℃ for 4 h and mechanical prop- erties after carburizing and pseudo-carburizing. The results indicate that the fine austenite grains exist in the carbu- rized case of 20CrMnTiNb steel, while there is abnormal coarsening and duplex grain structure in the case and core of steel 20CrMn. The average prior austenite grain sizes are 19.5 and 34.2 μm for the steels 20CrMnTiNb and 20CrMn, respectively. In addition, the mechanical properties of 20CrMnTiNb steel are superior to those of 20CrMn steel. In particular, the HV hardness of the former is higher than that of the latter by about 40--70 in the range of less than 0. 7 mm in depth. Therefore, the steel 20CrMnTiNb is suitable for high temperature carburization.

关键词： gear steel high temperature carburization austenite grain size effective case depth

Preparation of ZnO Nanoparticles from Zn-containing Rotary Hearth Furnace Dust

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Journal of Wuhan University of Technology(Materials Science) 2022年第1期37卷 32-37页

作者： YAO Haiwei MA han mao Rui QIU Jiayong CHEN Chunyu JU Dianchun School of Metallurgy and Materials Engineering Jiangsu University of Science and TechnologyZhangjiagang 215600China Shagang Iron&Steel Research Institute of Jiangsu Province Zhangjiagang 215625China

To solve the problem of the low added value Zn-containing rotary hearth furnace(RHF)dust,two deep eutectic solvents(DESs)were employed,such as choline chloride-urea(ChCl-urea)and choline chloride-oxalic acid dihydrate(CC-OA)solvent and Zn-containing RHF dust(water-washed)as the research ***,we prepared ZnO nanoparticles using two DESs or their combination,namely,ChCl-urea(Method A),CC-OA(Method B),first CC-OA and then ChCl-urea(Method B-A)and first ChCl-urea and then CCOA(Method A-B),*** effects of these methods on the properties of as-obtained precursors and ZnO nanoparticles were investigated in *** results indicated that the precursor obtained by Method A was Zn_(4)CO_(3)(OH)_(6)·H_(2)O,and those by Methods B,B-A,and A-B were all ZnC_(2)O_(4)·2H_(2)***,the decomposition steps of the last three methods were *** ZnO contents of 95.486%,99.768%,99.733%,and 99.76%were obtained by Methods A,B,B-A,and A-B,*** A,B,and B-A led to the formation of spherical and agglomerated ZnO nanoparticles with normal size distributions,where Method B showed the best distribution with an average diameter 25 *** ZnO nanoparticles obtained by the Method A-B did not possess good properties.

关键词： rotary hearth furnace Zn-containing dust deep eutectic solvent ZnO nanoparticle

Carbon nanotube network film-based ring oscillators with sub l O-ns propagation time and their applications in radio-frequency signal transmission

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Nano Research 2018年第1期11卷 300-310页

作者： Yingjun Yang Li Ding Hengjia Chen Jie han Zhiyong Zhang Lian-mao Peng Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics Peking University Beijing 100871 China

We have fabricated top-gated ambipolar field-effect transistors （FETs） based on solution-derived carbon nanotube （CNT） network films, and then constructed inverters and ring oscillators （ROs） that can work under supply voltages as low as 0.2 V owing to the high uniformity of the devices. Significant improvements were achieved in the performance of these CNT-based ambipolar FETs and CMOS-like circuits by scaling down the gate length of the CNT FETs and optimizing the device structure and RO layout. In particular, the optimized five-stage RO is shown to present a record high oscillation frequency of up to 17.4 MHz with a propagation time of 5.6 ns at a 12-V working voltage. The CNT film-based ROs were used as carrier-wave generators in radio-frequency systems to demonstrate a complete signal transmission process. These results suggest that CNT thin film-based FETs and integrated circuits may soon find their way to radio-frequency applications with a frequency band of 13.56 MHz.

关键词： carbon nanotube nanoelectronics field-effect transistors radio-frequency ring oscillator

The effects of maltodextrin/starch in soy protein isolate–wheat gluten on the thermal stability of high-moisture extrudates

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Journal of Integrative Agriculture 2023年第5期22卷 1590-1602页

作者： XIE Si-han WANG Zhao-jun HE Zhi-yong ZENG mao-mao QIN Fang Benu ADHIKARI CHEN Jie State Key Laboratory of Food Science and Technology Jiangnan UniversityWuxi 214122P.R.China Collaborative Innovation Center of Food Safety and Quality Control Jiangnan UniversityWuxi 214122P.R.China Analysis Centre Jiangnan UniversityWuxi 214122P.R.China School of Science RMIT UniversityMelbourneVIC 3083Australia

This study aimed to investigate the interaction between maltodextrin/starch of different molecular weight distributions and soy protein isolate (SPI)–wheat gluten (WG) matrix during high-moisture *** maltodextrins (dextrose equivalent (DE):10 and 20) and wheat starch were extruded with SPI–WG blend in a system of 65,70,and 75%moisture to investigate their effects on texture and thermal *** 5%maltodextrin (DE10) in the SPI–WG matrix improved the fiber structure and thermal *** wheat starch was thoroughly gelatinized during subsequent sterilization,the fiber structure and thermal stability were also *** was found that the plasticization caused by small-molecular weight saccharides and enhanced phase separation caused by large-molecular weight saccharides changed the melting temperature of blends and significantly improved the texture and thermal stability of extrudates.

关键词： high-moisture extrusion protein saccharide fiber structure textural properties rheology plasticization phase separation

Selective capture of silver ions from aqueous solution by series of azole derivatives-functionalized silica nanosheets

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Chinese Journal of Chemical Engineering 2023年第5期57卷 319-328页

作者： Shanshan mao Tao Shen Qing Zhao Tong han Fan Ding Xin Jin Manglai Gao State Key Laboratory of Heavy Oil Processing College of ScienceChina University of PetroleumBeijing 102249China Unconventional Natural Gas Institute China University of PetroleumBeijing 102249China

The introduction of bifunctional groups into low-cost adsorbents for selective adsorption of Ag(I) through synergistic effect will have a profound impact on the recovery of precious metals. Organo silica nanosheets(organo-Si NSs) functionalized by series of azole derivatives(2-mercaptoimidazole(MI), 2-mercaptobenzimidazole(MBT) and 1H-1,2,4-triazole-3-thiol(MTT)), are fabricated and employed for selective removal of Ag(I). The structures of the organo-Si NSs are investigated using several characterization methods. The results of batch adsorption experiments display that the maximum adsorption amounts are 70.3, 103.2 and 139.5 mg·g^(-1) on MI-Si NSs, MBI-Si NSs and MTT-Si NSs for Ag(I) ions, and reach rapid equilibrium within 10–30 min. The adsorption processes are chemisorption and fit pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Notably, MTT-Si NSs is greatly selective for Ag(I) in multicomponent system, and the distribution coefficient value of Ag(I) ions reaches 2331.26 ml·g^(-1). The reusability of organo-Si NSs is verified by four cycles of regeneration tests with 0.1 mol·L^(-1) HNO_(3) as the eluent. A combination of experimental, structural along with theoretical analysis is conducted to proclaim the structure-adsorptivity relationship:(i) The adsorption mechanisms are attributed to complexation.(ii) The amino group and sulfhydryl group of MTT-Si NSs as well as MBISi NSs may have synergistic impacts on Ag(I) capture.(iii) The differences in adsorption behavior and selectivity of the three organo-Si NSs are mainly related to the form of function groups, charge density and steric hindrance of adsorbent. This work not only sheds light on the promise of functionalized organo-Si NSs for the rapid and selective removal/enrichment of Ag(I) ions in complex water systems,but also provides new insights for designing cost-effective Si NSs-based adsorbents.

关键词： Organo silica nanosheets Adsorption Silver ions Selectivity Mechanism Waste treatment