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Evolution of inclusions in vacuum induction melting of superalloys containing 70%return material

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Journal of Iron and Steel Research(International) 2024年第3期31卷 719-728页

作者： jin-guo Gao Shu-lei Yang Shu-feng Yang jing-she Li Wei Liu Meng-jing zhao An-ren Wang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Metallurgical and Building Materials Business Department China International Engineering Consulting CorporationBeijing 100048China

The variation law of inclusions type and size in the vacuum induction melting process and ingot of Ni-based superalloy containing 70%return material was studied by industrial test sampling,and the mechanism of inclusions formation was analyzed with thermodynamic calculations.The results show that there are mainly two types of composite inclusions in the vacuum induction melting of Ni-based superalloys,which are nitride-and oxide-based composite inclusions,like Al_(2)O_(3)-SiO_(2)-Cr_(2)O_(3),TiN-(Mo,Nb)C,etc.The type and proportion of inclusions from the center to the edge of the vacuum induction ingot did not change significantly.The number density of inclusions from the center to the edge of the ingot varied less,and the size of inclusions became smaller from the center to the edge.In addition,thermodynamic calculations show that oxides(M_(2)O_(3))are present in the liquid phase and mainly contain Al,Ti,Cr,Fe and O elements.The nitride consists mainly of Ti and N and contains small amounts of Cr,C,Nb,and Mo elements.This is consistent with the results of industrial tests.As the temperature decreases,the precipitation phases such as M_(2)O_(3),MN,γ,MC,δ,γ'andμphases are gradually precipitated,where oxides and nitrides are present in the liquid phase.The contents of O and N elements are the main influencing factors for the inclusions content and precipitation temperature;when the nitrogen content is reduced to below 0.0015%,it can make MN precipitate below the liquid-phase line.

关键词： Ni-based superalloy Vacuum induction melting Return material Inclusion Thermodynamic

Recent Progress in Fabrication and Structural Design of Thermal Conductive Polymer Composites

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Chinese Journal of Polymer Science 2024年第3期42卷 277-291,I0004页

作者： Yuan-Kai Du Zheng-Xue Shi Shan Dong Hui jin Xue Ke Pei zhao Bing-Bing Jiang Feng You Hubei Key Laboratory of Plasma Chemistry and Advanced Materials School of Material Science and EngineeringWuhan Institute of TechnologyWuhan 430205China Key Laboratory of Green Preparation and Application of Functional Materials Ministry of EducationHubei UniversityWuhan 430062China Institute of Molecular Aggregation Science Tianjin UniversityTianjin 300072China

In recent years, the demand direction for electronic equipment has expanded into embedded and miniaturized devices. The heat radiation problem has become one of the most significant factors for hindering the development of electronic devices. Since heat radiation material is one of the important components in electronic devices, the demand for enhancing thermal conductivity is also increasingly urgent. Research on thermal conductive polymer composites has become a major direction for developing functional composites. This work reviewed the recent progress in the fabrication of thermal conductive polymer composites. Five different structures are presented, including the using of single fillers,hybrid fillers, double threshold percolation structure, segregated structure and other complex multiphase structures. Specifically, the preparation of high-performance thermal conductive polymer composites was introduced through the combination of various thermal conductive fillers.Finally, the development direction of high thermal conductive polymer composites was briefly explored.

关键词： Thermal conductive polymer Hybrid fillers Polymer composite Thermal resistance

Development of lithium-free P2-type high-sodium content cathode materials with enhanced cycle and air stability for sodium-ion batteries

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Rare Metals 2024年第1期43卷 113-123页

作者： jin-Lv Tian Lin-Rong Wu Hai-Jun zhao Shou-Dong Xu Liang Chen Ding Zhang Xiao-Chuan Duan College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China College of Chemistry Taiyuan University of TechnologyTaiyuan 030024China School of Chemical Engineering and Pharmacy Wuhan Institute of TechnologyWuhan 430205China

The effect of partial substitution of Mg for Ni on a high-sodium and lithium-free layered P2-type Na_(45/54)Mg_(6)/_(54)Ni_(12/54)Mn_(34/54)O_(2) cathode with high initial Coulombic efficiency and excellent cyclic stability has been investigated in this study.Based on the crystal structural analysis,the Mg doping can retain the P2 structure up to 4.3 V,thus restraining the detrimental phase transformation of P2-02during the Na-ion intercalation/deintercalation process.Therefore,the obtained Mg-doped P2-type cathode exhibits a reversible specific capacity of 109 mAh·g^(-1) at 0.1C between 2.0 and 4.3 V and a retention rate of 81.5% after 200cycles at 1C.In addition,the full cell consisting of Mg-doped P2-type cathode and hard carbon anode shows a capacity retention rate of 85.6% after 100 cycles.This study provides new insight into the development of durable cathode materials for sodium-ion batteries.

关键词： Sodium-ion batteries Cathode material High sodium content Air stability

Catalytic conversion of mixed polyolefins under mild atmospheric pressure

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The Innovation 2024年第2期5卷 98-106页

作者： Binzhi zhao Hui Tan Jie Yang Xiaohui Zhang Zidi Yu Hanli Sun Jialiang Wei Xinyi zhao Yufeng Zhang Lili Chen Dali Yang jin Deng Yao Fu Zheng Huang Ning Jiao State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100191China Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China The Institute for Advanced Studies Wuhan UniversityWuhan 430072China Hefei National Laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Urban Pollutant ConversionAnhui Province Key Laboratory of Biomass Clean EnergyiChEMUniversity of Science and Technology of ChinaHefei 230026China State Key Laboratory of Organometallic Chemistry Chinese Academy of SciencesShanghai 200032China

The chemical recycling of polyolefin presents a considerable challenge,especially as upcycling methods struggle with the reality that plastic wastes typically consist of mixtures of polyethylene(PE),polystyrene(PS),and polypropylene(PP).We report a catalytic aerobic oxidative approach for polyolefins upcycling with the corresponding carboxylic acids as the product.This method encompasses three key innovations.First,it operates under atmospheric pressure and mild conditions,using O_(2) or air as the oxidant.Second,it is compatible with high-density polyethylene,low-density polyethylene,PS,PP,and their blends.Third,it uses an economical and recoverable metal catalyst.It has been demonstrated that this approach can efficiently degrade mixed wastes of plastic bags,bottles,masks,and foam boxes.

关键词： mixed Catalytic oxidative

Characteristics of Paleontological Communities in Surface Sediments of the Southern South China Sea and Their Paleoclimatic and Paleoenvironmental Significance

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Journal of Earth Science 2024年第1期35卷 144-154页

作者： jing zhao Li Zhang Xiaoyan Wang jinglian ge Min Xu Wei Chen Mao Luo Qianyong Liang Qiuhua Yu Shuaibing Luo Wenkun Qie Key Laboratory of Marine Mineral Resoures Ministry of Natural ResourcesGuangzhou Marine Geological SurveyChina Geological SurveyGuangzhou 511458China National Engineering Research Center for Gas Hydrate Exploration and Development Guangzhou 511458China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China

Understanding the spatial and temporal distribution of different paleontological communities in the southern South China Sea(SCS)is fundamental to explore its paleoclimatic and paleoenvironmental changes.In this study,foraminifera,pollen and diatoms from 100 surface sediment samples covering 40000 km^(2) of sea floor in the southern SCS were comprehensively investigated in terms of their assemblage and distribution.The results showed the existence of abundant foraminifera and pollen in most of the samples,although diatom communities were relatively scarce.Foraminifera were dominated by G.sacculifer,G.menardii,G.ruber,while diatoms were characterized by T.simonsenii,T.nitzschioides and T.longissima,indicating a typical tropical marine environment.The pollen assemblages showed a better reflection of montane rainforest,tropical rainforest and mangrove.The spatial differences among foraminifera assemblages may indicate the effect of water depth and a warmer environment in the southeast part of the study area,while the spatial patterns of diatom and pollen assemblages imply the influence of coastal current.Our study also noted that the compositions of paleontological communities in the SCS can vary significantly in a short distance,and synthesized studies on multiple biological groups are needed to reconstruct the Quaternary climate and the oceanographic environment.

关键词： southern South China Sea sediments foraminifera diatom pollen

Modularized viromimetic polymer nanoparticle vaccines(VPNVaxs) to elicit durable and effective humoral immune responses

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National Science Review 2024年第3期11卷 200-214页

作者： Zichao Huang Xinyu Zhuang Liping Liu Jiayu zhao Sheng Ma Xinghui Si Zhenyi Zhu Fan Wu Ningyi jin Mingyao Tian Wantong Song Xuesi Chen Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of Sciences School of Applied Chemistry and Engineering University of Science and Technology of China Changchun Veterinary Research Institute Chinese Academy of Agricultural Sciences Jilin Biomedical Polymers Engineering Laboratory State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences

Virus-like particle(VLP) vaccines had shown great potential during the COVID-19 pandemic, and was thought to be the next generation of antiviral vaccine technology due to viromimetic structures. However,the time-consuming and complicated processes in establishing a current recombinant-protein–based VLP vaccine has limited its quick launch to the out-bursting pandemic. To simplify and optimize VLP vaccine design, we herein report a kind of viromimetic polymer nanoparticle vaccine(VPNVax), with subunit receptor-binding domain(RBD) proteins conjugated to the surface of polyethylene glycol-b-polylactic acid(PEG-b-PLA) nanoparticles for vaccination against SARS-CoV-2. The preparation of VPNVax based on synthetic polymer particle and chemical post-conjugation makes it possible to rapidly replace the antigens and construct matched vaccines at the emergence of different viruses. Using this modular preparation system, we identified that VPNVax with surface protein coverage of 20%–25% had the best immunostimulatory activity, which could keep high levels of specific antibody titers over 5 months and induce virus neutralizing activity when combined with an aluminum adjuvant. Moreover, the polymer nano-vectors could be armed with more immune-adjuvant functions by loading immunostimulant agents or chemical chirality design. This VPNVax platform provides a novel kind of rapidly producing and efficient vaccine against different variants of SARS-CoV-2 as well as other viral pandemics.

关键词： vaccine polymer nanomaterials SARS-CoV-2

Clinical observation of extraction-site incisional hernia after laparoscopic colorectal surgery

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World Journal of Gastrointestinal Surgery 2024年第3期16卷 710-716页

作者： Bao-Hang Fan Ke-Li Zhong Li-jin Zhu zhao Chen Fang Li Wen-Fei Wu Second Clinical Medical College of jinan University Jinan UniversityShenzhen 518020Guangdong ProvinceChina Department of Gastrointestinal Surgery Shenzhen People’s Hospital(The Second Clinical Medical CollegeJinan UniversityThe First Affiliated HospitalSouthern University of Science and Technology)Shenzhen 518020Guangdong ProvinceChina Department of Radiation Oncology Shenzhen People’s Hospital(The Second Clinical Medical CollegeJinan UniversityThe First Affiliated HospitalSouthern University of Science and Technology)Shenzhen 518020Guangdong ProvinceChina

BACKGROUND Laparoscopic colorectal cancer surgery increases the risk of incisional hernia(IH)at the tumor extraction site.AIM To investigate the incidence of IH at extraction sites following laparoscopic colo-rectal cancer surgery and identify the risk factors for IH incidence.METHODS This study retrospectively analyzed the data of 1614 patients who underwent la-paroscopic radical colorectal cancer surgery with tumor extraction through the abdominal wall at our center between January 2017 and December 2022.Diffe-rences in the incidence of postoperative IH at different extraction sites and the risk factors for IH incidence were investigated.RESULTS Among the 1614 patients who underwent laparoscopic radical colorectal cancer surgery,303(18.8%),923(57.2%),171(10.6%),and 217(13.4%)tumors were ex-tracted through supraumbilical midline,infraumbilical midline,umbilical,and off-midline incisions.Of these,52 patients developed IH in the abdominal wall,with an incidence of 3.2%.The incidence of postoperative IH was significantly higher in the off-midline incision group(8.8%)than in the middle incision groups[the supraumbilical midline(2.6%),infraumbilical midline(2.2%),and umbilical incision(2.9%)groups](χ^(2)=24.985;Pge,obesity,sex,chronic cough,incision infection,and combined diabetes,anemia,and hypopro-teinemia(Pge,sex(female),obesity,incision infection,combined chronic cough,and hypoproteinemia were independent risk factors for IH at the site of laparoscopic colorectal cancer surgery(Pgery.The infraumbilical midline incision is associated with a lower hernia rate and is thus a suitable tumor extraction site.

关键词： Incisional hernia Laparoscopy Colorectal cancer Incision infection

Clinical value of oral contrast-enhanced ultrasonography in diagnosis of gastric tumors

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World Journal of Gastrointestinal Oncology 2024年第1期16卷 110-117页

作者： Chuan-Yu Wang Xiao-jing Fan Fei-Liang Wang Yue-Yue ge zhao Cai Wei Wang Xin-Ping Zhou Jun Du De-Wei Dai Department of Ultrasound Medicine Beijing HospitalBeijing 100005China Department of Gastroscopy Beijing HospitalBeijing 100005China Department of general Surgery Beijing HospitalBeijing 100005China Department of Pathology Beijing HospitalBeijing 100005China

BACKGROUND The incidence of gastric cancer remains high,and it is the sixth most common cancer and the fourth leading cause of cancer deaths worldwide.Oral contrastenhanced ultrasonography is a simple,non-invasive,and painless method for the diagnosis of gastric tumors.AIM To explore the diagnostic value of oral contrast-enhanced ultrasonography for the detection of gastric tumors.METHODS The screening results based on oral contrast-enhanced ultrasonography and electronic gastroscopy were compared with those of the postoperative pathological examination.RESULTS Among 42 patients with gastric tumors enrolled in the study,the diagnostic accordance rate was 95.2%for oral contrast-enhanced ultrasonography(n=40)and 90.5%for electronic gastroscopy(n=38)compared with postoperative pathological examination.The Kappa value of consistency test with pathological findings was 0.812 for oral contrast-enhanced ultrasonography and 0.718 for electronic gastroscopy,and there was no significant difference between them(P=0.397).For the TNM staging of gastric tumors,the accuracy rate of oral contrast enhanced ultrasonography was 81.9%for the overall T staging and 50%,77.8%,100%,and 100%for T1,T2,T3,and T4 staging,respectively.The sensitivity and specificity were both 100%for stages T3 and T4.The diagnostic accuracy rate of oral contrast-enhanced ultrasonography was 93.8%,80%,100%,and 100%for stages N0,N1-N3,M0,and M1,respectively.CONCLUSION The accordance rate of qualitative diagnosis by oral contrast-enhanced ultrasonography is comparable to that of gastroscopy,and it could be used as the preferred method for the early screening of gastric tumors.

关键词： Oral contrast-enhanced ultrasonography Gastric tumor Electronic gastroscopy Controlled study Pathological examination Diagnosis

Two-dimensional conjugated coordination polymer monolayer as anode material for lithium-ion batteries:A DFT study

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Chinese Chemical Letters 2024年第6期35卷 180-184页

作者： Xin-Tong zhao jin-Zhi Guo Wen-Liang Li jing-Ping Zhang Xing-Long Wu MOE Key Laboratory for UV Light-Emitting Materials and Technology Northeast Normal UniversityChangchun 130024China Faculty of Chemistry Northeast Normal UniversityChangchun 130024China Key Laboratory of Organo-Pharmaceutical Chemistry of Jiangxi Province Gannan Normal UniversityGanzhou 341000China

Nowadays,lithium-ion batteries(LIBs)play a crucial role in modern society in the aspect of portable electronic devices and large-scale smart grids.However,the current performance of lithium-ion batteries has been unable to meet the growing expectations of society and scientific community.Herein,we have synthetically investigated availability of 2D Ni-TABQ monolayer as anode based on DFT for LIBs applications.Our findings have demonstrated that 2D Ni-TABQ monolayer is a semiconductor with a small band gap of 0.2 eV,which suggest that the electronic property of 2D Ni-TABQ monolayer would take place an evident shift from semiconductor property to metallic property after Li adsorption.Furthermore,we checked the stability of 2D Ni-TABQ monolayer and investigated the viability of exfoliation from bulk multilayer Ni-TABQ to form 2D Ni-TABQ monolayer in the light of exfoliation energy and binding energy.We continuously studied electrochemical properties of 2D Ni-TABQ monolayer with respect of theoretical specific capacity,Li-ion diffusion barriers and open-circuit voltage.During the charging process,2D Ni-TABQ monolayer can achieve a high specific capacity of 722 m Ah/g with an open-circuit voltage range from 1.12 V to 0.22 V.These aforementioned results make the 2D Ni-TABQ monolayer a promising anode for LIBs.

关键词： The first principles Density functional theory Lithium-ion battery Anode material Two-dimensional material