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Study on Catalytic Behavior of Iron-based Catalyst with IITP as Electron Donor in the Polymerization of Butadiene

Chinese Journal of Polymer Science 2024年第5期42卷 612-619,I0007页

作者： Shi-Liang xu Ying-Nan Zhao Yao Yu Qi yang Li-Hua Na heng Liu Chun-Yu Zhang xue-Quan Zhang Key Laboratory of Advanced Rubber Material Ministry of EducationSchool of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China Shandong Provincial College Laboratory of Rubber Material and Engineering School of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China Key Lab of Rubber-Plastics Ministry of Education/Shandong Provincial Key Lab of Rubber-plasticsSchool of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China

In this study,a novel iron-based catalyst system,Fe(acac)3/(isocyanoimino)triptenylphosphorane(IITP)/AlR3,was employed for the synthesis of syndiotactic 1,2-polybutadiene in *** catalyst system exhibits remarkably high catalytic activity,achieving a polymerization activity of 762 kgpolymer·molcatalyst^(-1)·h^(-1)at 50℃with a[BD]/[Fe]molar ratio of ***,living polymerization characteristic were observed during the investigation of the polymerization kinetics of 1,3-butadiene *** characteristics were well demonstrated by a narrow molecular weight distribution(PDI≈2.0)of the resulting polybutadiene and a linear relationship between-ln(1-c)and polymerization time as well as number average molecular weight and polymer *** resultant polymer showed a 1,2-selectivity of approximately 76%and stereoregularity ranging from 62%to 73%(rrrr).Additionally,through kinetic studies on polymerization reaction,an apparent activation energy Ea value of this catalytic system was calculated to be 84.98 kJ·mol^(-1),which suggests that high polymerization temperature favors efficient polymerization.

关键词： Iron catalyst Syndiotactic 1,2-polybutadiene Elastomers Donor Selectivity

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Strategies for improving extraction capacity through preorganization structure:A novel 5,6-bicyclicmalonamide extractant(THPPD)

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Journal of Rare Earths 2024年第4期42卷 768-774页

作者： Miaomiao Zhang Zhen yang Yuhua Cui Jianhui Su heng Zhao Chengjin xu Xiaolei Liu Guoxin Sun Xiujing Peng Yu Cui School of Chemistry and Chemical Engineering University of JinanJinan250022China Institute for Smart Materials&Engineering University of JinanJinan250022China Shandong Institute for Food and Drug Control Jinan250101China

Rational design of extractant structure to improve the extraction and separation capacity of rare earth elements(REEs)is a long-standing ***,a new strategy was proposed to improve the stability of the chelating structure formed by malonamide and *** stability of the chelating structure is greatly improved by using a double-ring framework structure which makes the two carbonyl groups of malonamide unable to rotate freely and both of them point to the metal ion *** benzyl groups were used to construct the hydrophobicity of the extractant and the organic shell of the extracted ***-pyrrolo-pyridine-dione(THPPD)was designed and *** structure reduces the energy consumed by rotating carbonyl group in the coordination with metal ions and then improves the extraction ability of *** crystal structure was preorganized as expected,with the two carbonyls pointing in a favorable coordination direction to the structural complement of the metal *** extraction behaviors of REEs with THPPD in a nitric acid medium were *** with N,N’-dibenzyl-N,N’-dimethylmalonamide(DBDM-MA)with a chain structure,the extraction capacity of THPPD is 360 times higher than that of DBDM-MA at 5.0 mol/L sodium ***,the binding energy and Gibbs free energy were investigated by density functional theory(DFT)in conjunction with the *** theoretical results show that THPPD has more effective interaction with Pr(NO_(3))3 than *** construction of chelating groups conformation is a worthy direction to improve the coordination ability and even selectivity of extractant.

关键词： Rare earth elements Extraction separation 5,6-bicyclicdiamide extractant

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Template synthesis of copper azide primary explosive through Cu2O@HKUST-1 core-shell composite prepared by “bottle around ship” method

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Defence Technology（防务技术） 2023年第7期25卷 99-111页

作者： xu-wen Liu Yan Hu Jia-heng Hu Jia-xin Su Cai-min yang Ying-hua Ye Rui-qi Shen School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing210094China Micro-Nano Energetic Devices Key Laboratory Ministry of Industry and Information TechnologyNanjing210094China

Copper azide(CA), as a primary explosive with high energy density, has not been practically used so far because of its high electrostatic sensitivity. The Cu2O@HKUST-1 core-shell structure hybrid material was synthesized by the “bottle around ship” methodology in this research by regulating the dissolution rate of Cu2O and the generation rate of metal-organic framework(MOF) materials. Cu2O@HKUST-1 was carbonized to form a Cu O@porous carbon(CuO@PC) composite material. CuO@PC was synthesized into a copper azide(CA) @PC composite energetic material through a gas-solid phase in-situ azidation *** is encapsulated in PC framework, which acts as a nanoscale Faraday cage, and its excellent electrical conductivity prevents electrostatic charges from accumulating on the energetic material’s surface. The CA@PC composite energetic material has a CA content of 89.6%, and its electrostatic safety is nearly 30times that of pure CA(1.47 mJ compared to 0.05 mJ). CA@PC delivers an outstanding balance of safety and energy density compared to similar materials.

关键词： Composite energetic materials Copper azide Carbonization Template method Core-shell composite Electrostatic safety

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Predictive value of tumor markers in patients with recurrent hepatocellular carcinoma in different vascular invasion pattern

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Hepatobiliary & Pancreatic Diseases International 2016年第4期15卷 371-377页

作者： Feng Gao heng-Kai Zhu yang-Bo Zhu Qiao-Nan Shan Qi Ling xu-Yong Wei Hai-yang Xie Lin Zhou Xiao xu Shu-Sen Zheng Division of Hepatobiliary and Pancreatic Surgery Department of Surgery First Affiliated Hospital Zhejiang University School of Medicine Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases Zhejiang University Key Lab of Combined Multi-Organ Transplantation Ministry of Public Health First Affiliated Hospital Zhejiang University School of Medicine

BACKGRouND： Four tumor markers for hepatocellular carcinoma（HCC）, alpha-fetoprotein（AFP）, glypican-3（GPC3）, vascular endothelial growth factor（VEGF） and des-gammacarboxy prothrombin（DCP）, are closely associated with tumor invasion and patient＇s survival. This study estimated the predictability of preoperative tumor marker levels along with pathological parameters on HCC recurrence after ***： A total of 140 patients with HCC who underwent hepatectomy between January 2012 and August 2012 were enrolled. The demographics, clinical and follow-up data were collected and analyzed. The patients were divided into two groups： patients with macroscopic vascular invasion（Ma VI ＋） and those without Ma VI（Ma VI-）. The predictive value of tumor markers and clinical parameters were evaluated by univariate and multivariate ***： In all patients, tumor size（〉8 cm） and Ma VI were closely related to HCC recurrence after hepatectomy. For Ma VI＋ patients, VEGF（〉900 pg/m L） was a significant predictor for recurrence（RR=2.421; 95% CI： 1.272-4.606; P=0.007）. The 1- and 2-year tumor-free survival rates for Ma VI＋ patients with VEGF ≤900 pg/m L versus for those with VEGF 〉900 pg/m L were 51.5% and 17.6% versus 19.0% and 4.8%（P〈0.001）. For Ma VI- patients, DCP 〉445 m Au/m L and tumor size 〉8 cm were two independent risk factors for tumor recurrence（RR=2.307, 95% CI： 1.132-4.703, P=0.021; RR=3.150, 95% CI： 1.392-7.127, P=0.006; respectively）. The 1- and 2-year tumor-free survival rates for the patients with DCP ≤445 m Au/m L and those with DCP 〉445 m Au/m L were 90.4% and 70.7% versus 73.2% and 50.5% respectively（P=0.048）. The 1-and 2-year tumor-free survival rates for the patients with tumor size ≤8 cm and 〉8 cm were 83.2% and 62.1% versus 50.0% and 30.0%, respectively（P=0.003）.CONCLUSIONS： The Ma VI＋ patients with VEGF ≤900 pg/m L had a relatively high tumor-free survival than those with VEGF 〉900 pg/m L. In the Ma VI- patients, DCP 〉445 m Au/m L and tumor size 〉8

关键词： tumor markers hepatocellular carcinoma recurrence vascular invasion prediction

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Molecular mechanisms for interaction of glycine betaine with supra-molecular phycobiliprotein complexes

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Science China Chemistry 2009年第11期52卷 1865-1870页

作者： xu XiuLing LI heng XIE Jie ZHAO JingQuan Beijing National Laboratory for Molecular Sciences(BNLMS) Photochemistry LaboratoryInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

Glycine betaine(GB) is a biologically important small molecule protecting cells,proteins and enzymes in vivo and in vitro under environmental ***,it was found that GB could also relax the structure and inactivate the function of phycobiliproteins and phycobilisome(PBS),a kind of supramolecular complexes,in cyanobacterial *** molecular mechanisms for the opposite phenomena are quite *** PBS and a trimeric or monomeric C-phycocyanin(C-PC) as models,the molecular mechanism for the interaction of GB with supra-molecular complexes or nuclear proteins was *** energetic decoupling of PBS components induced by GB suggests that the PBS core-membrane linking polypeptide was the most sensitive site while the rod-core linker was the *** analysis proves that PBS structure was loosened but not dissociated into the *** the basis of the results and structure knowledge,it was proposed that GB screened the electrostatic attraction of the opposite charges on a linker and a protein leading to a much looser *** was observed that GB induced a spectral blue shift for trimeric C-PC but a red shift for a monomeric C-PC(a nuclear protein),which were ascribed to GB's screening of the electrostatic attraction of a linker to a protein and strengthening of the hydrophobic interaction between C-PC *** trimers and monomers' forming of the same products under high concentration of GB was ascribed to a compromise of the opposite interaction forces.

关键词： glycine betaine phycobiliproteins phycobilisome supra-molecular complex molecular interaction mechanism

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Power outage and environmental justice in Winter Storm Uri: an analytical workflow based on nighttime light remote sensing

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International Journal of Digital Earth 2023年第1期16卷 2259-2278页

作者： Jinwen xu Yi Qiang heng Cai Lei Zou GIS Center Florida International UniversityMiamiFLUSA School of Geosciences University of South FloridaTampaFLUSA Department of Geography Texas A&M UniversityCollege StationTXUSA

The intensity of extreme weather events has been increasing,posing a unique threat to society and highlighting the importance of our electrical power system,a key component in our *** severe weather events,quickly identifying power outage impact zones and affected communities is crucial for informed disaster ***,a lack of household-level power outage data impedes timely and precise *** address these challenges,we introduced an analytical workflow using NASA’s Black Marble daily nighttime light(NTL)images to detect power outages from the 2021 Winter Storm *** workflow includes adjustments to mitigate viewing angle and snow reflection *** outage is detected by comparing storm-time and baseline(normal condition)NTL images using an empirical adjusted *** outcomes of the workflow are 500-meter resolution power outage maps,which have the optimal correlation with real outage tracking data when NTL intensity is reduced by 26%.With the resultant power outage maps,we analyzed the relations between power outages and disadvantaged populations in 126 Texas counties and 4182 census tracts to evaluate environmental justice in the *** results show that Latino/Hispanic communities tend to suffer more from power outages at both the county and census tract levels.

关键词： Nighttime light disaster resilience natural disaster spatial analysis environmental justice power outage

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Rainfall occurrence and its relation to flood damage in China from 2000 to 2015

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Journal of Mountain Science 2018年第11期15卷 2492-2504页

作者： WEI Li HU Kai-heng HU xu-dong Key Laboratory of Mountain Hazards and Earth Surface Processes Chinese Academy of Sciences Chengdu 610041China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China University of Chinese Academy of Sciences Beijing 100049 China

China is highly susceptible to flood disasters and subjected to great damage every ***, the flood frequency has exhibited an increasing trend in recent years. Most flood events,including flash floods and river flood, are induced by rainfall. This study investigates annual variations of rainfall occurrence over China during the period from 2000 to 2015 at the national and regional scale using daily rainfall data from the Tropical Rainfall Measuring Mission. The Mann-Kendall test is performed for trend detection, and statistical data of flood damage published by China's government,including destroyed crop area, damaged buildings,direct economic loss, percentage of GDP(gross domestic product), and death toll are correlatively analysed with rainfall occurrences. The results show that storm rain events show the greatest variation among three rainfall types(moderate rain, heavy rain and storm rain). The variation coefficients of rainfall over Northeast China, North China, and Northwest China are the highest, whereas that for Southwest China is the smallest. Moderate rain, heavy rain over Central China, and moderate rain over Southwest China exhibits decreasing trends, whereas the remaining exhibit increasing trends. The correlation between the rainfall occurrences and these flood damage indices at the national scale shows that only direct economic loss has a strong positive correlation with rainfall occurrences, and the other indices have weaker correlations. The correlation is strong in three north regions, except for death toll in Northwest China. In contrast, the correlation between flood damage and rainfall is weak in East China, Central China, Southwest China, and South China. Overall,death toll is strongly correlated with the number of damaged buildings, implying that flood fatalities in China are likely associated with building collapse, and are dominated by specific extreme events. This study can provide a scientific reference for flood management in

关键词： Flood damage Rainfall occurrence Storm rainfall Coefficient of variation

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Probing the limits of plasmonic enhancement using a two-dimensional atomic crystal probe

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Light(Science & Applications) 2018年第1期7卷 500-510页

作者： Wen Chen Shunping Zhang Meng Kang Weikang Liu Zhenwei ou yang Li Yexin Zhang Zhiqiang Guan Hongxing xu School of Physics and Technology Center for Nanoscience and Nanotechnologyand Key Laboratory of Artificial Micro-and Nano-structures of Ministry of EducationWuhan UniversityWuhan 430072China The Institute for Advanced Studies Wuhan UniversityWuhan 430072China

Achieving larger electromagnetic enhancement using a nanogap between neighboring metallic nanostructures has been long pursued for boosting light–matter ***,the quantitative probing of this enhancement is hindered by the lack of a reliable experimental method for measuring the local fields within a subnanometer ***,we use layered MoS2 as a two-dimensional atomic crystal probe in nanoparticle-on-mirror nanoantennas to measure the plasmonic enhancement in the gap by quantitative surface-enhanced Raman *** designs ensure that the probe filled in the gap has a well-defined lattice orientation and thickness,enabling independent extraction of the anisotropic field *** find that the field enhancement can be safely described by pure classical electromagnetic theory when the gap distance is no<1.24 *** a 0.62 nm gap,the probable emergence of quantum mechanical effects renders an average electric field enhancement of 114-fold,38.4%lower than classical predictions.

关键词： dimensional crystal render

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Technical efficiency and its determinants in China's hog production

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Journal of Integrative Agriculture 2015年第6期14卷 1057-1068页

作者： TIAN xu SUN Fei-fei ZHou Ying-heng College of Economics and Management Nanjing Agricultural University

China＇s hog production is undergoing a great transformation due to the soaring demand and changing raising system. Regarding the essential role of pork in Chinese diet, a systematic analysis on the productivity and efficiency of hog production can provide significant implications for policy makers. This paper investigates the productivity and efficiency of hog production and the determinants of technical efficiency in China using a household level panel data（2004–2010）. A stochastic frontier translog production function with scaling property in inefficiency term is adopted for hog production analysis, and the determinants of technical efficiency are incorporated in a one-step estimation using maximum likelihood estimation. our results show that the average technical efficiency of hog production in China is 0.5914. More importantly, we find that specialized farmers have higher technical efficiency than others, and technical efficiency in the eastern region is higher than that in Central and West China.

关键词： frontier specialized household stochastic productivity panel raising husbandry scaling incorporated

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Recent Development in X-Ray Imaging Technology:Future and Challenges

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Research 2021年第1期2021卷 1565-1582页

作者： Xiangyu ou xue Chen Xianning xu Lili Xie Xiaofeng Chen Zhongzhu Hong Hua Bai Xiaowang Liu Qiushui Chen Lin Li Huanghao yang MOE Key Laboratory for Analytical Science of Food Safety and Biology College of ChemistryFuzhou UniversityFuzhou 350108China Frontiers Science Center for Flexible Electronics Xi’an Institute of Flexible Electronics(IFE)and Xi’an Institute of Biomedical Materials&EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi’an 710072China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

X-ray imaging is a low-cost,powerful technology that has been extensively used in medical diagnosis and industrial nondestructive *** ability of X-rays to penetrate through the body presents great advances for noninvasive imaging of its internal *** particular,the technological importance of X-ray imaging has led to the rapid development of highperformance X-ray detectors and the associated imaging ***,we present an overview of the recent development of X-ray imaging-related technologies since the discovery of X-rays in the 1890s and discuss the fundamental mechanism of diverse X-ray imaging instruments,as well as their advantages and disadvantages on X-ray imaging *** also highlight various applications of advanced X-ray imaging in a diversity of *** further discuss future research directions and challenges in developing advanced next-generation materials that are crucial to the fabrication of flexible,low-dose,highresolution X-ray imaging detectors.

关键词： diagnosis directions instruments

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