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Chinese Journal of Polymer Science 2024年第12期42卷 1976-1985,I0010页

作者： Jian-Wen shan Yan-Bo Zhu Ling-Ling Ni Peng-Ju pan State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou310058China Department of Polymer Science and Engineering Zhejiang UniversityHangzhou310058China

Viscoelastic properties of thermoplastic polyurethane(TPU)is of fundamental importance for its *** this work,we prepared different TPUs from polycaprolactone(PCL)diol,diphenylmethane-4,4′-diisocyanate(MDI),and 1,4-butanediol(BDO),and investigated the viscoelastic behavior of three TPUs with different hard segment content during thermal annealing *** storage modulus(G′)of TPU increases over time in a medium annealing temperature(T_(a))region,but remains unchanged at both high and low temperature *** growth of loss modulus(G″)over time is slower than that of G′.At medium T_(a),both G′and G″increase during the repeating frequency(ω)sweep,due to the gradual crystallization of hard *** indicates that the crystallites primarily restrain the relaxation of unit with large *** increments of G′and G″are weakened when the content of hard segment in TPU is *** TPU with high content of hard segments,a complete high elastic platform with a width of 3 orders of magnitude was observed only through one frequency scan test at medium T_(a).In addition,the crystallites of hard segments grow up continuously during frequency scan test(isothermal annealing treatment)and cause the extreme increase in G′and G″withωin lowωregion.

关键词： Thermoplastic polyurethane Viscoelastic properties Annealing Crystalization

Dispersion values in solute migration tests

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Yantu Lixue/Rock and Soil Mechanics 2020年 41卷 277-282页

作者： Yuan, shao-Dong Zhang, Wen-Jie Yuan, shan-shan School of Civil Engineering Qingdao University of Technology Qingdao 266033 China Department of Civil Engineering Shanghai University Shanghai 200072 China

There is controversy in determining the dispersion value, which is regarded as one of the most commonly adjusted parameter in pollutant migration simulation. For most dispersion tests, the diffusion effect is usually ignored, and only the high-Peclet-number is considered. In this paper, the effective diffusion coefficient of chloride ion is obtained in the steady-state pure diffusion test using inert solute chloride ion as the tracer. Soil column penetration tests are performed at different flow rates, different particle sizes, and different migration distances. The hydrodynamic dispersion coefficient is computed from the solute penetration curve fitted by the convection-diffusion equation, and the variation trend of dispersion value is analyzed considering the effective diffusion coefficient. The results show that the corresponding proportion of molecular diffusion to hydrodynamic dispersion is 3% to 21% when the Peclet number is in the range of 0.19-1.39. The smaller the Peclet number, the larger the proportion of molecular diffusion will be. Diffusion should be considered in the calculation of dispersion at a low Peclet number. Dispersivity increases with the flow velocity. Under the same flow velocity and migration distance, the dispersivity in the coarse-grained soil is much larger than that of the fine-grained soil. Dispersivity increases with the migration distance, and the increment is more evident in the much coarser-grained soil. The variation trend of dispersivity in this paper can provide a basis for pollutant migration in numerical simulation. © 2020, Science Press. All right reserved.

关键词： Flow velocity

Oxidation damage and interfacial failure of dissimilar metal welds containing ferritic heat resistant steels

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Journal of Iron and Steel Research International 2021年第11期28卷 1439-1450页

作者： Xiao-gang Li Zhi-peng Cai Xin Chen Shu-qing Dong Wen-he Cai Yu Zhang shan-lin Li Ke-jian Li shao-shi Rui Ji-luan pan Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Collaborative Innovation Center of Advanced Nuclear Energy Technology Tsinghua UniversityBeijing 100084China China Datang Corporation Science and Technological Research Institute Thermal Power Technology Research InstituteBeijing 100040China

The ex-service steam tubes containing dissimilar metal weld(DMW)between high Cr ferritic steel T91 and austenitic stainless steel TP347H and the ex-service steam tubes containing DMW between low Cr ferritic steel G102 and austenitic stainless steel TP347H were obtained from coal-fired thermal power plants in China,and their microstructures at the nickel-based weld metal(WM)/ferritic steel interfaces and oxidation characteristics were *** operating for 15,000 h at steam temperature of 541 C and steam pressure of 17.5 MPa,a G102/TP347H DMW failed along the WM/G102 steel interface,which was a dangerous premature failure mode without obvious plastic *** interfacial failure was attributed to the interaction between oxidation and cracking along the interface,where fracture appeared to be related with the strain concentration at the *** notch along the WM/G102 steel interface was the precursor of premature interfacial failure of DMW involving *** the DMW involving high Cr ferritic steel T91,ferritic steel side could form a Cr-rich passive film during service and thus would not be further oxidized after operating for 67,000 h at steam temperature of 541 C and steam pressure of 3.5 *** was concluded that oxidation played a more important role in failure of these DMWs,and retarding the development of oxidation and avoiding the interfacial oxide notch would dramatically improve the service performance of steam tubes containing DMWs.

关键词： Dissimilar metal weld Ferritic heat resistant steel Nickel-based weld metal Oxidation Interfacial failure High-temperature service

Aggregate Characteristics During Natural Revegetation on the Loess Plateau

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Pedosphere 2008年第6期18卷 809-816页

作者： AN shao-shan HUANG Yi-Mei ZHENG Fen-Li YANG Jian-Guo State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Yangling 712100 （China） Northwest Agriculture and Forestry University Yangling 712100 （China） College of Water Conservancy and Civil Engineering China Agricultural University Beijing 100083 （China） Institute of Agricultural Resources and Environment Ningxia Academy of Agriculture and Forestry Sciences Yinchuan 750002 （China）

Field investigations and laboratory analysis were conducted to study the characteristics of soil water-stable aggregates during vegetation rehabilitation in typical grassland soils of the hilly-gullied loess area. The relationship between water- stable aggregates and other soil properties was analyzed using canonical correlation analysis and principal component analysis. The results show that during the natural revegetation, the aggregates 〉 5 mm dominated and constituted between 50% and 80% of the total soil water-stable aggregates in most of the soil layers. The 2-5 mm aggregate class was the second main component. The mean value of water-stable aggregates 〉 5 mm within the 0-2 m soil profile under different plant communities decreased in the following order： Stipa grandis 〉 Stipa bungeana Trin. 〉 Artemisia sacrorum Ledeb. 〉 Thymus mongolicus Ronn. 〉 Hierochloe odorata （L.） Beauv. Clay, organic matter, and total N were the key factors that influenced the water stability of the aggregates. Total N and organic matter were the main factors that affected the water stability of the aggregates 〉 5 mm and 0.5-1 mm in size. The contents of Fe2O3, Al2O3, and physical clay （〈 0.01 mm） were the main factors which affected the water stability of the 1-2 and 0.25-0.5 mm aggregates.

关键词： canonical correlation analysis loess area natural revegetation principal component analysis soil water- stable aggregates

Pleomorphic rhabdomyosarcoma of the vagina: A case report

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World Journal of Clinical Cases 2024年第14期12卷 2396-2403页

作者： pan Xu shan-shan Ling E Hu Bi-Xia Yi Department of Gynecology The Affiliated Jinhua Hospital of Wenzhou Medical UniversityJinhua 321000Zhejiang ProvinceChina Zhejiang University School of Medicine Hangzhou 310006Zhejiang ProvinceChina

BACKGROUND Rhabdomyosarcoma(RMS)of the vagina in postmenopausal women is an extre-mely rare malignant tumor that was originally described as a unique group of soft tissue sarcomas originating from primitive mesenchymal *** was first re-ported in postmenopausal women in 1970,and fewer than 50 postmenopausal patients have been reported to *** SUMMARY A 68-year-old multiparous female was admitted to the hospital on October 11,2023,with the chief complaint of a mass causing vaginal prolapse with incomplete urination that had persisted for 4 *** vaginal mass was approximately the size of a pigeon egg;after lying down,the vaginal mass *** resection was performed,and vaginal pleomorphic RMS was diagnosed based on pathology and immunohistochemical staining *** patient is currently undergoing *** present study also reviewed the clinical,histolo-gical,and immunohistochemical features and latest treatment recommendations for vaginal *** abnormal vaginal mass should be promptly investigated through pelvic examination and appropriate *** current initial treat-ment for vaginal RMS is biopsy and primary *** When surgery is planned for vaginal RMS,an organ-preserving approach should be considered.

关键词： Rhabdomyosarcoma Vagina Postmenopausal woman Pleomorphic Case report

Experimental comparison between aircraft fuel tank inerting processes using NEA and MIG

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Chinese Journal of Aeronautics 2018年第7期31卷 1515-1524页

作者： Lei shao Weihua LIU Chaoyue LI Shiyu FENG Chenchen WANG Jun pan Key Laboratory of Aircraft Environment Control and Life Support of MIIT Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Aeronautics Chongqing Jiaotong University Chongqing 400074 China Jiangsu Province Key Laboratory of Aerospace Power System Nanjing Engineering Institute of Aircraft Systems Nanjing 210016 China

Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generation System（GOBIGGS） is a novel technology based on flameless catalytic combustion, and owning to its simple structure and high inerting efficiency, it has received a lot of attentions. The inert gas in the GOBIGGS is mainly comprised of CO2, N2, and O2（hereinafter, Mixed Inert Gas（MIG））, while that in the On-Board Inert Gas Generation System（OBIGGS）, which is one of the most widely used fuel tank inerting technologies, is NitrogenEnriched Air（NEA）. The solubility of CO2 is nearly 20 times higher than that of N2 in jet fuels,so the inerting capability and performance are definitely disparate if the inert gas is selected as NEA or MIG. An inerting test bench was constructed to compare the inerting capabilities between NEA and MIG. Experimental results reveal that, if ullage washing is adopted, the variations of oxygen concentrations on the ullage and in the fuel are nearly identical no matter the inert gas is NEA or MIG. However, the ullage and dissolved oxygen concentrations of MIG scrubbing are always higher than those of NEA scrubbing.

关键词： Dissolved oxygen Experiment Fuel tanks Inert gases Mixed Inert Gas(MIG) Nitrogen-Enriched Air(NEA) Oxygen

N-heterocyclic carbene-catalyzed radical reactions

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Science China Chemistry 2021年第1期64卷 7-16页

作者： Kun-Quan Chen He Sheng Qiang Liu pan-Lin shao Xiang-Yu Chen School of Chemical Sciences University of the Chinese Academy of SciencesBeijing 100049China College of Innovation and Entrepreneurship Southern University of Science and TechnologyShenzhen 518055China

While N-heterocyclic carbene(NHC)catalyzed electron-pair-transfer processes have been developed into an important tool for synthetically important bond formations during the past decades,the corresponding radical reactions via NHC catalysis have only received growing attention in the past six *** into account the advantages NHC-catalyzed radical reactions might bring,such as creating new activation modes that were previously unobtainable,it is worthwhile to provide a conceptual understanding of this emerging ***,herein we give an overview of NHC-catalyzed radical reactions via different synthetic techniques.

关键词： N-heterocyclic carbene radical one-electron oxidant photochemistry electrochemistry

The Proportional Mean Residual Life Regression Model with Cure Fraction and Auxiliary Covariate

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Acta Mathematicae Applicatae Sinica 2022年第2期38卷 312-323页

作者： shao-jia JIN Yan-yan LIU Guang-cai MAO Ming-yu shan School of Mathematics and Statistics Wuhan UniversityWuhan 430072China School of Mathematics and Statistics Central China Normal UniversityWuhan 430079China

As biological studies become more expensive to conduct,it is a frequently encountered question that how to take advantage of the available auxiliary covariate information when the exposure variable is not *** this paper,we propose an induced cure rate mean residual life time regression model to accommodate the survival data with cure fraction and auxiliary covariate,in which the exposure variable is only assessed in a validation set,but a corresponding continuous auxiliary covariate is ascertained for all subjects in the study *** studies elucidate the practical performance of the proposed method under finite *** an illustration,we apply the proposed method to a heart disease data from the Study of Left Ventricular Dysfunction.

关键词： auxiliary covariate Kernel smoothing logistic regression mean residual life mixture cure model

Hepatic metastases in ovarian cancer

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Hepatobiliary Surgery and Nutrition 2022年第6期11卷 924-926页

作者： Ying shan Ying Jin Lingya pan Department of Obstetrics and Gynecology National Clinical Research Center for Obstetric&Gynecologic DiseasesPeking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijingChina

Ovarian cancer is the most lethal disease among gynecologic malignancies(1);about 1/4 of ovarian cancer patients are in stage IV when *** ovarian epithelial cancer patients with stage IV disease,the mean overall survival(OS)is around 20 months,and the 5 year-OS is about 20%.About 1 in 5 patients with advanced-stage ovarian cancer have hepatobiliary involvement.

关键词： cancer involvement patients

Photocatalytic vinyl radical-mediated multicomponent 1,4-/1,8-carboimination across alkynes and olefins/(hetero)arenes

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Science China Chemistry 2024年第2期67卷 558-567页

作者： shan-shan Li Yu-Shi Jiang Xue-Ling Luo Xuming Ran Yuqiang Li Dong Wu Cheng-Xue pan Peng-Ju Xia School of Chemistry and Pharmaceutical Sciences Guangxi Normal UniversityGuilin541004China shanghai Artificial Intelligence Laboratory Shanghai200433China The Institute for Advanced Studies Wuhan UniversityWuhan430064China

We developed a highly selective and efficient multicomponent transformation by utilizing alkynes and olefins/(hetero)arenes through photoinduced energy-transfer *** reaction involves the formation of three distinct chemical bonds,namely C(sp~3)–C(sp~2),C(sp~2)–C(sp~3),and C(sp~3)–N,in a single coordinated *** strategy used a vinyl radical-mediated radical relay approach under mild conditions,exhibiting a broad substrate scope(>70 examples),excellent functional-group tolerance,and remarkable regio-and *** the utilization of a combination of experimental techniques and density functional theory(DFT),we delved deeper into the mechanistic intricacies of this distinctive *** revealed that the selective radical addition to electron-deficient alkynes,rather than olefins,was governed by the inherent reactivity of alkyl *** discovery presented a highly effective approach for the synthesis of stereodefined multisubstituted alkenes.

关键词： alkyne-olefin coupling DFT studies regio-and anti-stereoselectivity multisubstituted alkenes