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Boosting thermal stability and crystallization of closed-loop-recyclable biodegradable poly(p-dioxanone) by end-group regulation

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Science China Chemistry 2024年第2期67卷 642-651页

作者： Jin Lei Zhu-Xin Gui Wan-Ting Xiong Gang Wu si-Chong chen Yu-Zhong Wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu610064China

A chemically closed-loop-recyclable biodegradable polymer,poly(p-dioxanone)(PPDO),is one of the ideal candidates for single-use plastic products due to its suitability for different application ***,when PPDO wastes can be collected,its monomer p-dioxanone(PDO) will be obtained through chemical recycling of these wastes;when cannot be collected,the wastes are able to be biodegraded into harmless ***,unsatisfied thermal stability and low crystallization rate of PPDO restrict its wider ***,based on end-group regulation,we simultaneously realized the significant enhancement of thermal stability and crystallization of PPDO through the simple melt processing with tributyl phosphite(TBP) or triphenyl phosphite(TPP).The model reactions were conducted to investigate the reaction mechanism and theoretical products during the preparation of PPDO/phosphite *** kinds of phosphites were proved to act as the end-capped reagent and chain extender in the melt processing,while TBP presented better *** a result,the activation energy of thermal decomposition was largely elevated,and the unprecedented T_(5%)(the temperature at a weight loss of 5%) and Tmax(the temperature at a maximum rate of weight loss) of PPDO were obtained,i.e.,T_(5%)of ~330 ℃ and Tmaxof ~385 ℃ in N_(2) atmosphere,T_(5%)of ~240 ℃ and Tmaxof ~317 ℃ in air atmosphere,***,the increased crystallization rate,crystallinity,crystalline orderliness,and realizable monomer recovery(yield >90%,purity >99.9%) of PPDO/phosphite compounds were confirmed.

关键词： poly(p-dioxanone) phosphite thermal stability crystallization end-group regulation

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Facile Synthesis of Polyisothioureas via Alternating Copolymerization of Aziridines and Isothiocayanates

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Chinese Journal of Polymer Science 2024年第3期42卷 292-298,I0005页

作者： hao-Tian Zhang Ming-Xin Niu Qi Zhang chen-Yang Hu Xuan Pang Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of Materials Science and Engineering Jilin UniversityChangchun 130025China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Isothiourea is an important class of sulfur-containing molecules showing unique catalytic and biological activities. As such,polyisothiourea is envisioned to be an interesting type of polymer that potentially exhibits a number of interesting properties. However, there is no access to synthesizing well-defined polyisothiourea, and currently isothiourea-containing polymers are mainly prepared by immobilizing onto other polymer's side chain. Herein, we report the first facile synthesis of polyisothioureas via alternating copolymerization of aziridines and isothiocayanates. Mediated by the catalytic system of phosphazene superbases/alcohol, a broad scope of aziridines and isothiocayanates could be transformed into polyisothioureas with adjustable substitutions(11 examples). The structures of obtained polyisothioureas were fully characterized with ^(1)H-NMR, ^(13)C-NMR, and ^(1)H-^(13)C HMBC NMR. Moreover, the polyisothioureas show tunable thermal properties depending on substitutions on the isothiourea linkages. The novel structure of these polyisothioureas will enable a powerful platform for the discovery of nextgeneration functional plastics.

关键词： Polyisothioureas Alternative copolymer Aziridines Isothiocayanates

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Research on simulation of gun muzzle flow field empowered by artificial intelligence

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Defence Technology（防务技术） 2024年第2期32卷 196-208页

作者： Mengdi Zhou Linfang Qian Congyong Cao Guangsong chen Jin Kong Ming-hao Tong School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China Northwest Institute of Mechanical and Electrical Engineering Xianyang712099ShaanxiChina School of Automation Nanjing University of Science and TechnologyNanjing210094China

Artificial intelligence technology is introduced into the simulation of muzzle flow field to improve its simulation efficiency in this paper.A data-physical fusion driven framework is ***,the known flow field data is used to initialize the model parameters,so that the parameters to be trained are close to the optimal *** physical prior knowledge is introduced into the training process so that the prediction results not only meet the known flow field information but also meet the physical conservation *** two examples,it is proved that the model under the fusion driven framework can solve the strongly nonlinear flow field problems,and has stronger generalization and *** proposed model is used to solve a muzzle flow field,and the safety clearance behind the barrel side is *** is pointed out that the shape of the safety clearance under different launch speeds is roughly the same,and the pressure disturbance in the area within 9.2 m behind the muzzle section exceeds the safety threshold,which is a dangerous *** with the CFD results shows that the calculation efficiency of the proposed model is greatly improved under the condition of the same calculation *** proposed model can quickly and accurately simulate the muzzle flow field under various launch conditions.

关键词： Muzzle flow field Artificial intelligence Deep learning Data-physical fusion driven Shock wave

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Response of soil nutrients to terracing and environmental factors in the Loess Plateau of China

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Geography and Sustainability 2024年第2期5卷 230-240页

作者： Die chen Wei Wei Liding chen Bojun Ma hao Li Department of Soil and Water Conservation Changjiang River Scientific Research InstituteWuhan 430010China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Research Center on Mountain Torrent&Geologic Disaster Prevention of Ministry of Water Resources Wuhan 430010China

Terracing is a widely adopted agricultural practice in mountainous regions around the world that aims to conserve soil and water *** nutrients play a crucial role in determining soil quality,particularly in landscapes prone to *** are influenced by factors such as land-use type,slope aspect,and *** this study,we sought to examine the impact of terracing on soil nutrients(soil organic content(SOC),total nitrogen(TN),nitrate-nitrogen(NO3–-N),ammonium nitrogen(NH4+-N),total phosphorus(TP),available phosphorus(AP),total potassium(TK),and available potassium(AK))and how they vary with environmental factors in the Chinese Loess *** the growing season,we collected 540 soil samples from the 0 to 100 cm soil layer across five major land-use types,different slope aspects,and varying ***,a meta-analysis of literature data further corroborated the effective accumulation of soil nutrients through terracing in the Loess *** findings are as follows:(1)Terraced fields,regardless of land-use type,showed a significant improvement in SOC and TN content.(2)Soil nutrient contents within terraced fields were predominantly higher on sunny slopes.(3)Terraces at lower altitudes are characterized by elevated SOC concentrations.(4)A meta-analysis of literature data pertaining to terracing and soil nutrients in this region confirmed the effective accumulation of soil nutri-ents through *** elucidated outcomes of this study offer a profound theoretical underpinning for the accurate planning and management of terraces,the scientific utilization of land resources,and the enhancement of land productivity.

关键词： Terrace Soil nutrients Land-use Slope aspect Altitude Loess Plateau

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The Combination of Achnatherum inebrians Extracts and Soil Microorganisms Inhibited Seed Germination and Seedling Growth in Elymus nutans

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Phyton-International Journal of Experimental Botany 2024年第3期93卷 567-580页

作者： Rui Zhang Taixiang chen Zhenjiang chen hao chen Xuekai Wei Malik Kamran Chunjie Li State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems Key Laboratory of Animal Husbandry InnovationMinistry of Agriculture and Rural AffairsEngineering Research Center of Grassland AgricultureMinistry of EducationWest Gansu Province Prataculture Technology Innovation CenterCollege of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou730020China Center for Grassland Research National Forestry and Grassland AdministrationCaFBeijing100091China

In a greenhouse experiment,the effects of soil microorganisms and extracts of Achnatherum inebrians on the seed germination and seedling growth of Elymus nutans were *** results showed that both the extracts from aboveground and belowground parts of *** signiﬁcantly inhibited the germination rate,germination potential,germination index,vigor index,seedling height,root length,and fresh weight of ***,but increased malondialdehyde content,catalase,peroxidase and superoxide dismutase activity of *** seedlings(p<0.05).The allelopathy of aqueous extracts of the aboveground parts of *** was stronger than that of the *** extracts of the aboveground parts of *** decreased seed germination rate,germination potential,germination index,vigor index,seedling length,root length,and seedling fresh weight by 10.45%-74.63%,24.18%-32.50%,19.03%-73.36%,37.83%-88.41%,21.42%-53.14%,2.65%-40.21%,and 20.45%-61.36%,respectively,and malondialdehyde content,peroxidase,catalase,and superoxide dismutase activity increased by 8.09%-62.24%,27.83%-86.47%,22.90%-93.17%,and 11.15%-75.91%,*** above indexes were higher in live soil than in sterilized *** microorganisms increased the allelopathy of *** seed germination rate,germination potential,germination index,vigor index,seedling length,and seedling fresh weight of *** planted in live soil decreased by 8.22%-48.48%,10.00%-51.85%,8.19%-53.26%,16.43%-60.03%,12.91%-28.81%,and 9.09%-22.86%compared with sterilized soil,*** content,peroxidase,catalase,and superoxide dismutase activity of *** planted in live soil increased by 53.91%-81.06%,15.71%-57.34%,33.33%-86.31%,and 9.78%-52.51%compared with sterilized soil,*** existence of soil microorganisms enhanced the allelopathy of the secondary metabolites of ***.A combination of microorganisms and aqueous extracts from the aboveground parts of *** had the s

关键词： Achnatherum inebrians water immersion liquid aqueous leachate precipitate allelopathy Elymus nutans soil microorganisms

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Journal of Rare Earths 2024年第4期42卷 743-748页

作者： hao Zhang Yi Bian Yuxuan Xia Yuchen Cui Ziang Li Fang Zhang Yiming Bai Nuofu chen Jikun chen School of New Energy North China Electric Power UniversityBeijing102206China School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China

While the metal to insulator transition(MIT)of d-band correlated perovskite nickelates(RENiO_(3))are widely adjustable via their rare-earth composition,the roles of potential valence variabilities associated with the rare-earth elements were rarely ***,we demonstrate the material synthesis and MIT properties of RENiO_(3) containing valence variable rare-earth compositions,such as Ce,Pr,Sm,Eu and *** metastable perovskite structure of SmNiO_(3) and EuNiO_(3) with a rare-earth valence states variable towards+2 can be effectively synthesized under high oxygen pressures as it is necessary to reduce their formation free *** is in contrast to Ce and Tb,in which situations the variable rare-earth valence state towards+4 reduces their ionic radius and prohibits their occupation or co-occupation of the rare-earth site within the perovskite structured RENiO_(3).Nevertheless,PrNiO_(3) with MIT properties can be effectively synthesized at lower oxygen pressures,owing to the higher stability to form a fully occupied 6s orbit associated Pr3+compared to the half-filled one related to Pr4+.The present work provides guidance for regulating the MIT properties of RENiO_(3).

关键词： Metal to insulator transition Metastable perovskites Rare-earth nickelates Oxides

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Biomimetic natural biomaterials for tissue engineering and regenerative medicine:new biosynthesis methods,recent advances,and emerging applications

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Military Medical Research 2024年第1期11卷 50-79页

作者： Shuai Liu Jiang-Ming Yu Yan-Chang Gan Xiao-Zhong Qiu Zhe-chen Gao Huan Wang Shi-Xuan chen Yuan Xiong Guo-Hui Liu si-En Lin Alec McCarthy Johnson V.John Dai-Xu Wei Hong-hao Hou Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering the Fifth Affiliated HospitalSchool of Basic Medical ScienceSouthern Medical UniversityGuangzhou 510900China Department of Orthopedics Tongren HospitalShanghai Jiao Tong UniversityShanghai 200336China The Eighth Affiliated Hospital Sun Yat-Sen UniversityShenzhen 518033GuangdongChina Engineering Research Center of Clinical Functional Materials and Diagnosis&Treatment Devices of Zhejiang Province Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhou 325011ZhejiangChina Department of Orthopedics Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China Department of Orthopaedics and Traumatology Faculty of Medicinethe Chinese University of Hong KongHong Kong SAR 999077China Department of Functional Materials Terasaki Institute for Biomedical InnovationLos AngelesCA 90064USA Mary&Dick Holland Regenerative Medicine Program College of MedicineUniversity of Nebraska Medical CenterOmahaNE 68130USA Zigong Affiliated Hospital of Southwest Medical University Zigong Psychiatric Research CenterZigong Institute of Brain ScienceZigong 643002SichuanChina Key Laboratory of Resource Biology and Biotechnology in Western China Ministry of EducationSchool of MedicineDepartment of Life Sciences and MedicineNorthwest UniversityXi’an 710127China

Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative *** contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix(ECM).Additionally,such materials have mechanical adaptability,micro-structure interconnectivity,and inherent bioactivity,making them ideal for the design of living implants for specific applications in TE and regenerative *** paper provides an overview for recent progress of biomimetic natural biomaterials(BNBMs),including advances in their preparation,functionality,potential applications and future *** highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ***,we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE ***,we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.

关键词： Biomimic Scaffold Biosynthesis Natural biomaterial Tissue engineering

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Analysis of secondary makeup characteristics of drill collar joint and prediction of downhole equivalent impact torque of Well SDTK1

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Petroleum Exploration and Development 2024年第3期51卷 697-705页

作者： WANG Chunsheng MING Chuanzhong ZHANG hao chen Jialei QU hao WANG Wenchang DI Qinfeng PetroChina Tarim Oilfield Company Korla 841000China Shanghai Institute of Applied Mathematics and Mechanics Shanghai UniversityShanghai 200072China

Based on the three-dimensional elastic-plastic finite element analysis of the 8"(203.2 mm)drill collar joint,this paper studies the mechanical characteristics of the pin and box of NC56 drill collar joints under complex load conditions,as well as the downhole secondary makeup features,and calculates the downhole equivalent impact torque with the relative offset at the shoulder of internal and external *** the basis of verifying the correctness of the calculation results by using measured results in Well GT1,the prediction model of the downhole equivalent impact torque is formed and applied in the first extra-deep well with a depth over 10000 m in China(Well SDTK1).The results indicate that under complex loads,the stress distribution in drill collar joints is uneven,with relatively higher von Mises stress at the shoulder and the threads close to the *** 203.2 mm drill collar joints pre-tightened according to the make-up torque recommended by American Petroleum Institute standards,when the downhole equivalent impact torque exceeds 65 kN·m,the preload balance of the joint is disrupted,leading to secondary make-up of the *** the downhole equivalent impact torque increases,the relative offset at the shoulder of internal and external threads *** calculation results reveal that there exists significant downhole impact torque in Well SDTK1 with complex loading *** is necessary to use double shoulder collar joints to improve the impact torque resistance of the joint or optimize the operating parameters to reduce the downhole impact torque,and effectively prevent drilling tool failure.

关键词： Well SDTK1 drill tool threaded joint secondary makeup relative offset equivalent impact torque

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Proangiogenic Macrophage Development in Human Prenatal Stage:A Key Element in Maternal-Fetal Medicine Puzzle

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Maternal-Fetal Medicine 2024年第1期6卷 5-8页

作者： Xiaoyan chen hao Wang Yuanfang Zhu Maternal-Fetal Medicine Institute Department of Obstetrics and GynaecologyShenzhen Baoan Women's and Children's HospitalShenzhen 518000China

Introduction Macrophages,a major immune cell type constituting the human innate immune system,are involved in various physiological processes,such as tissue development,remodeling,homeostasis,and repair,crucial for maintaining normal growth and development of embryos/fetuses.1-3 Influenced by their cellular origin and specific tissue environments,macrophages exhibit a diverse range of phenotypes.

关键词： Macrophages Maternal-fetal medicine Angiogenesis Vasculogenesis

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Self‑Assembly of Binderless MXene Aerogel for Multiple‑Scenario and Responsive Phase Change Composites with Ultrahigh Thermal Energy Storage Density and Exceptional Electromagnetic Interference Shielding

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Nano-Micro Letters 2024年第3期16卷 367-382页

作者： Chuanbiao Zhu Yurong hao hao Wu Mengni chen Bingqing Quan Shuang Liu Xinpeng Hu Shilong Liu Qinghong Ji Xiang Lu Jinping Qu Key Laboratory of Material Chemistry for Energy Conversion and Storage of Ministry of Education School of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China Qingdao Mental Health Center Qingdao 266034People’s Republic of China Hubei Engineering Research Center for Biomaterials and Medical Protective Materials Huazhong University of Science and TechnologyWuhan 430074People’s Republic of China Hubei Key Laboratory of Material Chemistry and Service Failure School of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China National Engineering Research Center of Novel Equipment for Polymer Processing Key Laboratory of Polymer Processing Engineering(South China University of Technology)Ministry of EducationGuangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced ManufacturingSchool of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510641People’s Republic of China

The severe dependence of traditional phase change materials(PCMs)on the temperature-response and lattice deficiencies in versatility cannot satisfy demand for using such materials in complex application ***,we introduced metal ions to induce the self-assembly of MXene nanosheets and achieve their ordered arrangement by combining suction filtration and rapid ***,a series of MXene/K^(+)/paraffin wax(PW)phase change composites(PCCs)were obtained via vacuum impregnation in molten *** prepared MXene-based PCCs showed versatile applications from macroscale technologies,successfully transforming solar,electric,and magnetic energy into thermal energy stored as latent heat in the ***,due to the absence of binder in the MXene-based aerogel,MK3@PW exhibits a prime solar-thermal conversion efficiency(98.4%).Notably,MK3@PW can further convert the collected heat energy into electric energy through thermoelectric equipment and realize favorable solar-thermal-electric conversion(producing 206 mV of voltage with light radiation intensity of 200 mw cm^(−2)).An excellent Joule heat performance(reaching 105℃with an input voltage of 2.5 V)and responsive magnetic-thermal conversion behavior(a charging time of 11.8 s can achieve a thermal insulation effect of 285 s)for contactless thermotherapy were also demonstrated by the MK3@***,as a result of the ordered arrangement of MXene nanosheet self-assembly induced by potassium ions,MK3@PW PCC exhibits a higher electromagnetic shielding efficiency value(57.7 dB)than pure MXene aerogel/PW PCC(29.8 dB)with the same MXene *** work presents an opportunity for the multi-scene response and practical application of PCMs that satisfy demand of next-generation multifunctional PCCs.

关键词： Self-assembly Multiple-scenario Phase change composites Thermal energy storage Electromagnetic interference shielding

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