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Rational design of ZnCdS/TpPa-1-COF heterostructure photocatalyst by strengthening the interface connection in solar hydrogen production reactions

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Nano Research 2024年第3期17卷 1027-1034页

作者： Di Yang Zhi-Gang Li Xinghao zhang Zenghuan Ren Weihan Lu Haining Liu Xiaomeng Guo Jijie zhang xian-He Bu Tianjin Key Laboratory of Metal and Molecule-Based Material Chemistry School of Materials Science and EngineeringNankai UniversityTianjin 300350China College of Chemistry and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang 050018China State Key Laboratory of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin 300071China

ZnCdS quantum dots(QDs)are highly coveted in photocatalysis research for their exceptional visible-light responses and high light-absorption ***,their practical application is hindered by their tendency to aggregate,due to having high surface *** address this issue,herein,a heterostructure is synthesized by growing ZnCdS QDs with a size of approximately 5 nm onto the surface of a two-dimensional(2D)covalent organic framework(COF),*** approach suppresses the aggregation of the QDs and improves their *** ZnCdS/TpPa-1-COF composite exhibited a peak hydrogen evolution rate of 6244.16μmol·g^(-1)·h^(-1),which was 2.89 and 4.18 times greater than that of ZnCdS and TpPa-1-COF,*** zero-dimensional/two-dimensional(0D/2D)heterojunction formed by ZnCdS and TpPa-1-COF generates a strong interfacial force,which is attributed to the intimate contact between the *** connections accelerate charge separation,improve the utilisation of reduced electrons,and reduce the extent of agglomeration of the ZnCdS QDs,thereby resulting in high hydrogen production activity of the ***,the photocatalytic mechanism is studied using Kelvin probe force microscopy and theoretical *** study offers a novel approach for creating sulfide photocatalysts and is crucial for investigating the potential practical applications of the related photocatalysts.

关键词： covalent organic frameworks quantum dots photocatalysis hydrogen generation heterojunction

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High-current pulsed electron beam modification on microstructure and performance of Cu/CuW diffusion bonding joints

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Rare Metals 2024年第6期43卷 2819-2831页

作者： Na-Na Tian Cong-Lin zhang Peng Lyu Jin-Tong Guan Jie Cai Qing-Feng Guan shun Guo School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China School of Material Science and Engineering Yancheng Institute of TechnologyYancheng 221051China Engineering Institute of Advanced Manufacturing and Modern Equipment Technology Jiangsu UniversityZhenjiang 212013China

This study investigates the influence of high-current pulsed electron beam(HCPEB)modification on the microstructure and shear strength of Cu/CuW *** solid-state diffusion bonding of modified-Cu(MCu)and modified-CuW(M-CuW)was achieved by HCPEB modification pretreatment at a temperature of 800-900℃and a pressure of 5 MPa for 10-50 *** demonstrate that HCPEB modification facilitates the dissolution of W and Cu,resulting in the formation of a Cu_(0.4)W_(0.6)solid solution and thus enhancing the uniform distribution of ***,HCPEB-induced defects play a beneficial role in promoting the diffusion process by providing fast diffusion paths for *** optimal joints with the maximum shear strength of 213.7 MPa were obtained through bonding M-Cu and M-CuW at 900℃and 5 MPa for 30 min,which attributes to the combined effects of fine-grained strengthening and solid solution ***,the application of HCPEB modification showcases its effectiveness in promoting element diffusion and enhancing the mechanical performance of the joints.

关键词： HCPEB Element diffusion Shear strength Crystal defects Surface modification

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Experimental Study on Mixed-Mode(Ⅰ–Ⅱ)Fracture Toughness of Freshwater Ice

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Acta Mechanica Solida Sinica 2024年第2期37卷 252-264页

作者： Yaozhong Xu Mao Zhou xian Yi Wen Hua Jiuzhou Huang Wenyu zhang Shiming Dong Key Laboratory of Deep Underground Science and Engineering Ministry of EducationCollege of Architecture and EnvironmentSichuan UniversityChengdu610065China Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan Province Sichuan UniversityChengdu610065China China Aerodynamics Research and Development Center/Low Speed Aerodynamics Research Institute Mianyang621000China College of Mechanical and Electrical Engineering Xichang UniversityXichang615000China

In recent years,the issue of aircraft icing has gained widespread *** breaking and detachment of dynamic ice can pose a threat to flight ***,the shedding and fracture mechanisms of dynamic ice are unclear and cannot meet the engineering needs of ice-shedding hazard ***,studying the fracture toughness of ice bodies has extremely important practical *** address this issue,this article uses a centrally cracked Brazilian disk(CCBD)specimen to measure the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice at different loading *** mixed-mode(Ⅰ–Ⅱ)fracture characteristics of ice are discussed,and the experimental results are compared and analyzed with the theoretical values of the generalized maximum tangential stress(GMTS)criterion considering the influence of *** results indicated that as the loading rate increases,the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice decrease,and the fracture toughness of freshwater ice is more sensitive to the loading rate.Ⅰn terms of fracture criteria,the theoretical value of the ratio of pure modeⅡfracture toughness to pure modeⅠfracture toughness based on the GMTS criterion is in good agreement with the experimental value,while the theoretical value based on the maximum tangential stress(MTS)criterion deviates significantly from the experimental value,indicating that the GMTS criterion considering the influence of T-stress can better predict the experimental results.

关键词： Freshwater ice Fracture criteria Centrally cracked Brazilian disk(CCBD) Mixed-mode(Ⅰ-Ⅱ) Loading rate

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Syntheses and properties of associative acrylamide copolymers containing short hydrophobic chains used in a friction reducer for slick-water fracturing

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Petroleum Science 2024年第3期21卷 1889-1901页

作者： Ya-Xing Dai xian-Li zhang Si-Yuan Liu Feng-Run-Ze zhang Yi-Xi zhang Yu-Tong Sang Jing-Xi Zheng Zhao-Sheng Liu Peng zhang College of Chemistry and Chemical Engineering Chongqing University of Science and TechnologyChongqing401331China College of Ecology and Environment Chongqing Resources and Environmental Protection of UniversityChongqing401331China China China Property Project Department of Dezhou Mining Property Service CenterShengli Oilfield Company of SinopecDezhou253000ShandongChina

Two allyldimethylalkyl quaternary ammonium salt(AQAS)monomers,N,N-dimethylallylphenylpropylammonium bromide(AQAS1)and N,N-dimethylallylnonylammonium bromide(AQAS2),were synthesized and used to prepare modified polyacrylamide *** new drag reducers were synthesized from acrylamide(AM),sodium acrylate(Na AA)and a cationic modified monomer(AQAS1 or AQAS2)via aqueous solution polymerization,and the copolymers were named P(AM/Na AA/AQAS1)and P(AM/Na AA/AQAS2),*** structures of the drag reduction agents were confirmed by IR and1H NMR *** molecular weight(Mw)of P(AM/Na AA/AQAS1)was 1.79×10^(6)g/*** the copolymer concentration was 1000 mg/L and the flow rate was 45 L/min,in fresh water the highest drag reduction rate was 75.8%,in 10,000 mg/L Na Cl solution the drag reduction rate decreased to 72.9%.The molecular weight of P(AM/Na AA/AQAS2)was 3.17×10^(6)g/*** the copolymer concentration was500 mg/L and the flow rate was 45 L/min,the drag reduction rate reached 75.2%,and in 10,000 mg/L Na Cl solution the drag reduction rate was 73.3%,decreased by approximately 1.9%.The drag reduction rate for partially hydrolyzed polyacrylamide(HPAM)was also investigated,and the results showed that the drag reduction rates for 500 and 1000 mg/L HPAM solutions were merely 43.2%and 49.0%in brine,*** with HPAM,both of the above copolymers presented better drag reduction capacities.

关键词： Shale gas Slick water Drag reducer Modified monomer Copolymerization

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Highly Hydrolysis-Resistant Polyimide Fibers Prepared by Thermal Crosslinking with Inherent Carboxyl Groups

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Chinese Journal of Polymer Science 2024年第2期42卷 247-255,I0010页

作者： Can-Can zhang Jun-Long Yang Ya-Jiang Huang Guang-xian Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Easy hydrolysis in alkaline environments limits the use of polyimide fibers in environmental protection. The hydrolysis resistance levels of polyimide fibers can be improved by crosslinking of the macromolecular chains. In this work, crosslinked polyimide fibers(CPI fibers) were produced by intrinsic carboxyl decarboxylation for the first time. The thermal stability of the polyimide fibers containing the intrinsic carboxyl groups(PIC fibers) was studied, and the temperature of the decarboxylation-crosslinking reaction was determined to be 450 ℃. The PIC fibers were hotdrawn to initiate thermal crosslinking of the carboxyl groups and molecular chain orientation at high temperature. The CPI fibers had high tensile strengths(0.72-1.46 GPa) and compressive strengths(401-604 MPa). The oriented macromolecules and chemically crosslinked structure improved the tightness of the molecular chains and endowed the CPI fibers with excellent hydrolytic resistance. The CPI-50 fiber did not dissolve in a 0.5 wt% NaOH solution during heating at 90 ℃ for 10 h, and the tensile strength retention reached 87% when treated in 0.5 wt% NaOH solutions at 90 ℃ for 1 h, providing a guarantee for its application in alkaline corrosive environments.

关键词： Polyimide Carboxyl group Crosslinking Hydrolysis-resistance

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Highly efficient catalyst for 1,1,2-trichloroethane dehydrochlorination via BN_(3) frustrated Lewis acid-base pairs

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Nano Research 2024年第6期17卷 4773-4781页

作者： Yuxue Yue Fangmin Zuo Bolin Wang Xiaoling xian Jun Tang Haifeng zhang Zilong zhang Qingping Ke Wei Chen School of Chemical Engineering Northeast Electric Power UniversityJilin 132012China Industrial Catalysis Institute of Zhejiang University of Technology Hangzhou 310014China Key Laboratory of Carbon Materials of Zhejiang Province College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China College of Chemistry and Chemical Engineering Anhui University of TechnologyMaanshan 243002China

In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully *** precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selectively modified the doping site structure,ultimately constructing a B,N co-doped frustrated Lewis acid-base pair *** catalyst exhibited remarkable catalytic activity,selectivity,and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane(TCE).Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN_(3)*** to conventional graphitic N structures,the BN_(3)structure had a higher p-band center,ensuring superior adsorption and activation capabilities for TCE during the *** the BN_(3)site,three negatively charged nitrogen atoms acted as Lewis bases,while positively charged boron atoms acted as Lewis *** synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE,significantly enhancing the 1,1-dichloroethene *** this research,we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient,selective,and stable catalyst for the dehydrochlorination of TCE,contributing significantly to the development of non-metallic catalysts.

关键词： B N co-doped sites dehydrochlorination frustrated Lewis acid-base pairs catalytic mechanism

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Nitrogen and phosphorus fertilization leads to soil arbuscular mycorrhizal fungal diversity changes and rainfed crop yield increase on the Loess Plateau of China:A 37-year study

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Pedosphere 2024年第2期34卷 328-338页

作者： Yi WANG Wenting zhang Chunyue LI shun CHANG Yu MIAO Qianxue LI Zhaoyang KOU Tinghui DANG State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China Institute of Soil and Water Conservation Northwest A&F UniversityYangling 712100China

More than 80%of plants form mutualistic symbiotic relationships with arbuscular mycorrhizal fungi(AMF),and the application of fertilizers,such as nitrogen(N)and phosphorus(P)fertilizers,is a common agricultural management practice to improve crop yield and ***,the potential effects of long-term N and P fertilization on the AMF community in the rainfed agricultural system of the Loess Plateau of China are still not well *** this study,a long-term field experiment was conducted based on orthogonal design,with three N levels(0,90,and 180 kg ha^(-1)year^(-1))and three P levels(0,90,and 180 kg ha^(-1)year^(-1))for wheat *** in AMF community and correlations between AMF community composition,soil environmental factors,and wheat yield component traits were analyzed using traditional biochemical methods and high-throughput sequencing *** results showed that long-term N and P addition had a significant effect on the AMF community structure and *** application alone significantly reduced the richness and diversity of AMF community,whereas the combined application of N and P significantly increased the richness and diversity of AMF *** AMF community was driven mainly by soil available P,total P,and *** was a significant positive correlation between Glomus abundance and wheat yield and a significant negative correlation between Paraglomus abundance and wheat ***-term N and P addition directly increased crop yield and affected yield indirectly by influencing soil chemical properties and the AMF *** application of N and P both at90 kg ha^(-1)year^(-1)could improve the ecological and physiological functions of the AMF community and benefit the sustainable development of rainfed agriculture.

关键词： Glomus long-term fertilization microbial community Paraglomus rainfed agriculture wheat

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Chemical modification of barite for improving the performance of weighting materials for water-based drilling fluids

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Petroleum Science 2024年第1期21卷 551-566页

作者： Li-Li Yang Ze-Yu Liu Shi-bo Wang xian-Bo He Guan-Cheng Jiang Jie zhang MOE Key Laboratory of Petroleum Engineering State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum(Beijing)Changping DistrictBeijing102249China MOE Key CNPC Drilling Research Institute Changping DistrictBeijing102206China

With increasing drilling depth and large dosage of weighting materials,drilling fluids with high solid content are characterized by poor stability,high viscosity,large water loss,and thick mud cake,easier leading to reservoir damage and wellbore *** this paper,micronized barite(MB)was modified(mMB)by grafting with hydrophilic polymer onto the surface through the free radical polymerization to displace conventional API barite *** suspension stability of water-based drilling fluids(WBDFs)weighted with API barite:mMB=2:1 in 600 g was significantly enhanced compared with that with API barite/WBDFs,exhibiting the static sag factor within 0.54 and the whole stability index of *** viscosity and yield point reached the minimum,with a reduction of more than 40%compared with API barite only at the same *** multi-stage filling and dense accumulation of weighting materials and clays,filtration loss was decreased,mud cake quality was improved,and simultaneously it had great reservoir protection performance,and the permeability recovery rate reached 87%.In addition,it also effectively improved the lubricity of *** sticking coefficient of mud cake was reduced by 53.4%,and the friction coefficient was ***,mMB can serve as a versatile additive to control the density,rheology,filtration,and stability of WBDFs weighted with API barite,thus regulating comprehensive performance and achieving reservoir protection *** work opened up a new path for the productive drilling of extremely deep and intricate wells by providing an efficient method for managing the performance of high-density WBDFs.

关键词： Drilling fluids Weighting materials Filtration control Reservoir protection Stability property

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Vanadium(V) Complexes Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

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Chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： Yi-Cong Wang Hui Zhat Pei-Yi Cheng Shu zhang xiang-Wei Liu Yi-xian Wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination *** methodology has also been used to synthesize the novel vanadium complexes containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination *** catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky *** vanadium complex V5' containing unsymmetrical NHC ligand exhibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ***,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complexes containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

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Unexpected divergence in magnetoreceptor MagR from robin and pigeon linked to two sequence variations

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Zoological Research 2024年第1期45卷 69-78页

作者： shun Wang Peng zhang Fan Fei Tianyang Tong Xiujuan Zhou Yajie Zhou Jing zhang Mengke Wei Yanqi zhang Lei zhang Yulong Huang Lin zhang Xin zhang Tiantian Cai Can Xie Institutes of Physical Science and Information Technology Anhui UniversityHefeiAnhui 230039China High Magnetic Field Laboratory Hefei Institutes of Physical ScienceChinese Academy of SciencesScience IslandHefeiAnhui 230031China Science Island Branch of Graduate School University of Science and Technology of ChinaHefeiAnhui 230036China Department of Anatomy Anhui Medical UniversityHefeiAnhui 230032China Department of Mechanical and Aerospace Engineering University at BuffaloState University of New YorkBuffaloNY 14260 USA International Magnetobiology Frontier Research Center Science IslandHefeiAnhui 230031China

Birds exhibit extraordinary mobility and remarkable navigational skills,obtaining guidance cues from the Earth’s magnetic field for orientation and long-distance *** species also show tremendous diversity in navigation strategies,with considerable differences even within the same taxa and among individuals from the same *** highly conserved iron and iron-sulfur cluster binding magnetoreceptor(MagR)protein is suggested to enable animals,including birds,to detect the geomagnetic field and navigate ***,MagR is also implicated in other functions,such as electron transfer and biogenesis of iron-sulfur clusters,raising the question of whether variability exists in its biochemical and biophysical features among species,particularly *** the current study,we conducted a comparative analysis of MagR from two different bird species,including the migratory European robin(Erithacus rubecula)and the homing pigeon(Columba livia).Sequence alignment revealed an extremely high degree of similarity between the MagRs of these species,with only three sequence ***,two of these variations underpinned significant differences in metal binding capacity,oligomeric state,and magnetic *** findings offer compelling evidence for the marked differences in MagR between the two avian species,potentially explaining how a highly conserved protein can mediate such diverse functions.

关键词： Homing and migration Animal navigation Magnetoreceptor(MagR) Diverse navigation pattern Conserved protein

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