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Copper-catalyzed oxidative phosphonoheteroarylation of alkenes with phosphonates and N-heteroarenes via P-H/C-H functionalization

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Organic Chemistry Frontiers 2022年第2期9卷 476-480页

作者： chong-hui xu Zhi-Qiang Xiong Yang Li Yan-Ping Zhu Jin-Heng Li Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle Nanchang Hangkong UniversityNanchang 330063China School of Pharmacy Key Laboratory of Molecular Pharmacology and Drug EvaluationMinistry of EducationCollaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of ShandongYantai UniversityYantaiShandong264005China State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhou 730000China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiangHenan 475004China

A copper-catalyzed oxidative intermolecular phosphonoheteroarylation of alkenes with phosphonates and nucleophilic N-heteroarenes(such as indoles and pyrroles)involving P-H/C-H functionalization for the synthesis of highly valuable β-(N-heteroaryl)-alkylphosphonates is *** method allows the incorporation of two functional groups,a phosphonate and a N-heteroarene,into the alkene in a single reaction step through oxidative formation of the P-centered radicals,addition across the CvC bond,single electron oxidation and C-H functionalization cascades.

关键词： oxidative phosphonate catalyzed

Doping engineering of iron oxide nanoparticles towards high performance and biocompatible T_(1)-weighted MRI contrast agents

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Rare Metals 2024年第1期43卷 298-308页

作者： xue xu Ping-Li Dong Yu-Yun Chai Run Yang Zhen-hui Ma Chi-chong Lu Department of Chemistry College of Chemistry and Materials EngineeringBeijing Technology and Business UniversityBeijing 100048China Department of Physics Beijing Technology and Business UniversityBeijing 100048China

Extremely small-sized iron oxide nanoparticles(IONPs) are of great interest in magnetic resonance imaging(MRI) due to their biosafety as an alternative to clinical gadolinium(Ⅲ) complexes-based contrast *** when the particle size is less than 10 nm,it has strong diffusion ability and deep penetration distance in tumor *** doping can significantly enhance the T_(1)contrast effect of nanoparticles by regulating the surface exposed ***,the nucleation and growth processes of multi-component synthesis systems are complex and difficult to be accurately controlled,leading to great challenges in the synthesis of ultra-small-sized nanoparticles with different components and ***,extremely smallsized superparamagnetic gadolinium-doped iron oxide nanoparticles(GdIONPs,Gd_(x)Fe_(3-x)O_(4) NPs) with adjustable doping amount and controllable size in the range of 3.5-7.5 nm were synthesized by thermal ***,as-synthesized GdIONPs were surface modified with a highly water-soluble and biocompatible carboxyl-polyethylene glycol-phosphoric acid ligand with high binding ***_(0.65)Fe_(2.35)O_(4) NPs exhibited very high r_(1) relaxivity of 10.6 mmol^(-1)·L·s^(-1) in terms of all metal concentrations and 49.0 mmol^(-1)·L·s^(-1) in terms of gadolinium alone,respectively,3 and 14 times higher than clinical T_(1) contrast agents(Gd-DTPA).GdIONPs can continuously obtain high resolution images of blood vessels,and can be used as an efficient and multifunctional contrast agent for MR T_(1)*** stable and efficient doping strategy provides an easy and effective method to individually optimize the magnetic properties of complex oxides and their relaxation effects for a variety of biomedical applications.

关键词： Iron oxide nanoparticles Small size Magnetic resonance imaging Substitutional doping Gd dopant

Toward tunable shape memory effect of NiTi alloy by grain size engineering:A phase field study

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Journal of Materials Science & Technology 2024年第1期168卷 276-289页

作者： Bo xu chong Wang Qingyuan Wang Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan ProvinceSichuan UniversityChengdu 610065China Department of Mechanical Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China Key Laboratory of Deep Underground Science and Engineering (Sichuan University)Ministry of EducationChengdu 610065China

The inelastic deformations of shape memory alloys(SMAs)always show poor controllability due to the avalanche-like martensite transformation,and the effective control for the deformation of precision de-vices has been not yet *** this work,the phase field method was used to investigate the shape memory effects(SMEs)of NiTi SMAs undergoing grain size(GS)engineering,to obtain tunable one-way and stress-assisted two-way SMEs(OWSME and SATWSME).The OWSME and SATWSME of the systems with various gradient-nanograin structures and bimodal grain structure,as well as that with geometric gradients were *** simulated results indicate that due to the GS dependences of martensite transformation and reorientation,the occurrence and expansion of martensite reorientation,martensite transformation and its reverse can be efficaciously controlled via the GS *** combining the GS engineering and geometric gradient design,since the effects of GS and stress gradient can be su-perimposed or competing,and the responses of martensite reorientation,martensite transformation and its reverse to this are different,the OWSME and SATWSME of the geometrically graded systems with various nanograin structures can exhibit different improvements in *** short,the reorienta-tion hardening modulus during OWSME is increased and the transformation temperature window during SATWSME is widened by GS engineering,indicating the improved controllability of *** optimal GS engineering schemes revealed in this work provide the basic reference and guidance for designing tun-able SMEs and producing NiTi-based driving devices catering to desired functional performance in various engineering fields.

关键词： Phase field NiTi Shape memory effect Grain size engineering Geometric gradient

Effect of Texture on the Grain-Size-Dependent Functional Properties of NiTi Shape Memory Alloys and Texture Gradient Design:A Phase Field Study

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Acta Mechanica Solida Sinica 2024年第1期37卷 10-32页

作者： Bo xu Beihai Huang chong Wang Qingyuan Wang Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan ProvinceSichuan UniversityChengdu 610065China Department of Mechanical Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China Key Laboratory of Deep Underground Science and Engineering Ministry of EducationSichuan UniversityChengdu 610065China

Texture is inevitably introduced during the manufacturing of most NiTi shape memory alloys(SMAs),and the textured nanocrystalline NiTi has been extensively employed in ***,the effect of texture,and the joint effect of grain size(GS)and texture on the functional properties of NiTi SMAs and the corresponding microscopic mechanisms have not been clearly understood *** this work,based on the phase field method,the effect of texture on the GS-dependent functional properties of NiTi SMAs,including super-elasticity(SE),one-way shape memory effect(OWSME),and stress-assisted two-way shape memory effect(SATWSME),is investigated,and the corresponding microscopic mechanisms are ***,the samples with discrete geometrical gradients and/or texture gradients are designed to achieve graded functional *** simulation results indicate that the dependence of functional properties on texture is due to the effect of crystallographic orientation on martensite transformation and reorientation,which can lead to different inelastic *** the designed samples with texture gradients,the stress–strain responses of sheets with various textures are different,allowing for the coordination of overall deformation of the sample by combining such sheets,with varying inelastic deformation ***,the overall response of the sample differs from that without texture gradient,leading to the achievement of graded functional *** simulation results and new findings in this work contribute to a deeper understanding of the effects of texture,GS,and their interaction on the functional properties of SMAs,and provide valuable reference for the design and development of SMA-based devices with desired functional properties.

关键词： Phase field NiTi shape memory alloy Texture Grain size Functional property Texture gradient

Bibliometric analysis of hotspots and trends of global myopia research

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 940-950页

作者： Xing-Yang Wu hui-hui Fang Yan-Wu xu Yan-Ling Zhang Shao-chong Zhang Wei-Hua Yang Shenzhen Eye Institute Shenzhen Eye HospitalJinan UniversityShenzhen 518040Guangdong ProvinceChina School of Future Technology South China University of TechnologyGuangzhou 510641Guangdong ProvinceChina

AIM:To gain insights into the global research hotspots and trends of ***:Articles were downloaded from January 1,2013 to December 31,2022 from the Science Core Database website and were mainly statistically analyzed by bibliometrics ***:A total of 444 institutions in 87 countries published 4124 *** 2013 and 2022,China had the highest number of publications(n=1865)and the highest H-index(61).Sun Yat-sen University had the highest number of publications(n=229)and the highest H-index(33).Ophthalmology is the main category in related *** from 2020 to 2022 highlight keywords of options and reference,child health(pediatrics),myopic traction mechanism,public health,and machine learning,which represent research ***:Myopia has become a hot research *** and Chinese institutions have the strongest academic influence in the field from 2013 to *** main driver of myopic research is still medical or *** study highlights the importance of public health in addressing the global rise in myopia,especially its impact on children’s *** present,a unified theoretical system is still *** surgical and therapeutic solutions must be proposed for people with different characteristics to manage and intervene refractive *** addition,the benefits of artificial intelligence(AI)models are also reflected in disease monitoring and prediction.

关键词： bibliometric analysis myopia global trends

Validity of self-reported male sexual function scales in a young Chinese population:a comparative study with clinician-assisted evaluation

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Asian Journal of Andrology 2024年第3期26卷 321-327页

作者： hui Zhang Elena Colonnello Erika Limoncin Tommaso B Jannini xu-chong Tu Andrea Sansone Emmanuele A Jannini Yan Zhang Department of Infertility and Sexual Medicine Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510000China Chair of Endocrinology and MedicalSexology(ENDOSEX) Department of Experimental MedicineUniversity of Rome Tor VergataRome 00133Italy Department of Urology First Affiliated Hospital ofGuangzhou University of Chinese MedicineGuangzhou 510000China Section of Medical Pathophysiology Food Science and EndocrinologySapienza University of RomeRome 00133Italy School of Psychiatry Department of Systems MedicineUniversity of Rome Tor VergataRome 00133Italy

Psychometric scales,commonly used to gauge sexual function,can sometimes be influenced by response *** our researchfrom June 2020 to April 2021,we examined the accuracy of self-reported sexual function *** invited patients from theDepartment of Infertility and Sexual Medicine at the Third Affiliated Hospital of Sun Yat-sen University(Guangzhou,China),whohave male sexual dysfunction,to participate by filling out a self-reported version of a specific *** addition,they wentthrough a clinician-assisted version of this questionnaire,encompassing tools such as the Premature Ejaculation Diagnostic Tool(PEDT),the 6-item International Index of Erectile Function(IIEF-6),the Erection Hardness Scale(EHS),and the MasturbationErection Index(MEI).Using the clinician-assisted version as a reference,we categorized patients and applied various statisticalmethods,such as the Chi-square test,intraclass correlation coefficient(ICC),logistic regression,and the Bland–Altman plot,to gauge *** our study with 322 participants,we found that while there were no notable discrepancies in error ratesbased on our categorization,certain scales showed significant differences in terms of overestimation and underestimation,withthe exception of the *** positive diagnosis rate consistency between the self-reported and clinician-assisted versions *** ICC values between the two versions across the scales were indicative of remarkable *** findings showthat the self-reported versions of tools such as EHS,IIEF-6,MEI,and PEDT are credible and hold clinical ***,employing a dual-diagnosis approach might be more prudent to circumvent potential misdiagnoses.

关键词： psychometry scale sexual function sexual health

Spatial distribution of shallow landslides caused by Typhoon Lekima in 2019 in Zhejiang Province, China

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Journal of Mountain Science 2024年第5期21卷 1564-1580页

作者： CUI Yulong YANG Liu xu chong ZHENG Jun School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan 232001China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Department of Civil Engineering Zhejiang UniversityHangzhou 310058China

In recent years, the coastal region of Southeast China has witnessed a significant increase in the frequency and intensity of extreme rainfall events associated with landfalling typhoons. The hilly and mountainous terrain of this area, combined with rapid rainfall accumulation, has led to a surge in flash floods and severe geological hazards. On August 10, 2019, Typhoon Lekima made landfall in Zhejiang Province, China, and its torrential rainfall triggered extensive landslides, resulting in substantial damage and economic losses. Utilizing high-resolution satellite images, we compiled a landslide inventory of the affected area, which comprises a total of 2,774 rainfallinduced landslides over an area of 2965 km2. The majority of these landslides were small to mediumsized and exhibited elongated, clustered patterns. Some landslides displayed characteristics of high-level initiation, obstructing or partially blocking rivers, leading to the formation of debris dams. We used the inventory to analyze the distribution pattern of the landslides and their relationship with topographical, geological, and hydrological factors. The results showed that landslide abundance was closely related to elevation, slope angle, faults, and road density. The landslides were predominantly located in hilly and low mountainous areas, with elevations ranging from 150 to 300 m, slopes of 20 to 30 degrees, and a NE-SE aspect. Notably, we observed the highest Landslide Number Density(LND) and Landslide Area Percentage(LAP) in the rhyolite region. Landslides were concentrated within approximately 4 km on either side of fault zones, with their size and frequency negatively correlated with distances to faults, roads, and river systems. Furthermore, under the influence of typhoons, regions with denser vegetation cover exhibited higher landslide density, reaching maximum values in shrubland areas. In areas experiencing significantly increased concentrated rainfall, landslide density also showed a corr

关键词： Typhoon rainfall Landslide characteristics Spatial distribution Southeast coastal region

Preweaning period is a critical window for rumen microbial regulation of average daily gain in Holstein heifer calves

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Journal of Animal Science and Biotechnology 2024年第1期15卷 396-411页

作者： Shengyang xu chong Jiao Qiyu Diao Yan Tu Beijing Key Laboratory for Dairy Cow Nutrition Institute of Feed ResearchChinese Academy of Agricultural SciencesBeijing 100081People’s Republic of China

Background Rumen bacterial groups can affect growth performance,such as average daily gain(ADG),feed intake,and *** study aimed to investigate the inter-relationship of rumen bacterial composition,rumen fermentation indicators,serum indicators,and growth performance of Holstein heifer calves with different *** calves were chosen from a trail with 60 calves and divided into higher ADG(HADG,high pre-and post-weaning ADG,n=6)and lower ADG(LADG,low pre-and post-weaning ADG,n=6)groups to investigate differences in bacterial composition and functions and host *** During the preweaning period,the relative abundances of propionate producers,including g_norank_f_Butyricicoccaceae,g_Pyramidobacter,and g_norank_f_norank_o_Clostridia_vadin BB60_group,were higher in HADG calves(LDA>2,P<0.05).Enrichment of these bacteria resulted in increased levels of propionate,a gluconeogenic precursor,in preweaning HADG calves(adjusted P<0.05),which consequently raised serum glucose concentrations(adjusted P<0.05).In contrast,the relative abundances of rumen bacteria in post-weaning HADG calves did not exert this ***,no significant differences were observed in rumen fermentation parameters and serum indices between the two *** The findings of this study revealed that the preweaning period is the window of opportunity for rumen bacteria to regulate the ADG of calves.

关键词： Average daily gain Calves Preweaning period Rumen microbiota

An effective catalyst carrier SiO_(2):Enhancing catalytic and combustion properties of CuFe_(2)O_(4)on energetic components

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Defence Technology（防务技术） 2024年第2期32卷 383-392页

作者： Li Ding chong Wan Suhang Chen Zhao Qin Kangzhen xu School of Chemical Engineering/Xi'an Key Laboratory of Special Energy Materials Northwest UniversityXi'an710069China Xi’an Modern Chemistry Research Institute Xi'an710065China

To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_(4)/SiO_(2)binary composites via solvothermal *** phase structure,morphology and catalytic activity of CuFe_(2)O_(4)/SiO_(2)composites were studied firstly,and thermal decomposition,combustion and safety performance of ammonium perchlorate(AP)and 1,3,5-trinitroperhydro-1,3,5-triazine(RDX)with it affecting were then systematically *** results show that CuFe_(2)O_(4)/SiO_(2)composite can remarkably either advance the decomposition peak temperature of AP and RDX,or reduce the apparent activation energy at their main decomposition ***,the flame propagation rate of RDX was promoted by about 2.73 times with SiO_(2)content of 3 wt%,and safety property of energetic component was also improved greatly,in which depressing the electrostatic discharge sensitivity of pure RDX by about 1.89 *** addition,the effective range of SiO_(2)carrier content in the binary catalyst is found to be 3 to 5 wt%.Therefore,SiO_(2)opens a new insight on the design of combustion catalyst carrier and will promote the application of CuFe_(2)O_(4)catalyst in solid propellant.

关键词： Copper ferrite Silicon dioxide Combustion catalyst Thermal decomposition Laser ignition