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Facile Synthesis of Functional Poly (ε-caprolactone) via Janus Polymerization

Chinese Journal of Polymer Science 2019年第9期37卷 858-865页

作者： Huan Qiu zhe-ning yang Jun Ling Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University

Functionalized aliphatic polyesters attract increasing attentions as biocompatible and biodegradable polymers with broad applications in biological science. In this contribution, we propose a facile and controllable synthetic technique for functional poly(ε-caprolactone)(PCL) via Janus polymerization, which comprises cationic ring-opening copolymerization (ROP) of ε-caprolactone (CL) with 3,3-bis(chloromethyl)oxacyclobutane (CO) and (coordinated) anionic ROP of CL at a single propagating chain by rare earth metal triflates (RE(OTf)3)and propylene oxide, thus generating block copolymers in one step. The compositions of the copolymers of poly(CLb-(CL-r-CO)) can be modulated by various RE(OTf)3. Scandium triflate catalyzes Janus polymerization to yield the copolymers containing the highest CO contents among all the RE(OTf)3 catalysts used with complete conversion of CL. The chlorine in CO repeating units is ready to be transferred into azide group which affords the modification sites to react with 9-ethynyl-9-fluorenol and mPEG-alkyne, respectively, via copper(I)-catalyzed azide-alkyne cycloaddition reaction with quantitative conversions of azides, as confirmed by FTIR analyses. According to NMR and SEC analyses, copolymers (PCC-g-PEG) bearing a homo-PCL block and a PEG-grafted block of poly(CO-co-CL) demonstrate well-defined chemical structures. The investigations on thermal properties reveal the strong phase separation between PCL and PEG blocks. The amphiphilic PCC-g-PEG is able to sei住assemble into micelles in aqueous solution while cylindrical and lamellar morphologies are observed in bulk. We provide an efficient protocol to synthesize functional PCL combining onestep Janus polymerization and precise post-polymerization click reaction.

关键词： Janus polymerization Functional poly(ε-caprolactone) Poly(3,3-bis(chloromethyl)oxacyclobutane) Ring-opening polymerization Rare earth metal catalysts

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A novel Bayesian-based INS/GNSS integrated positioning method with both adaptability and robustness in urban environments

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Chinese Journal of Aeronautics 2024年第6期37卷 205-218页

作者： zhe yang Hongbo ZHAO School of Electronics and Information Engineering Beihang UniversityBeijing 100191China

Achieving higher accuracy positioning results in urban environments at a lower cost has been an important pursuit in areas such as autonomous driving and intelligent *** Inertial Navigation System and Global Navigation Satellite System(INS/GNSS)integrated navigation systems have been an important means of fulfilling the above quest due to the complementary error characteristics between INS and *** complex urban driving environment requires the system sufficiently adaptive to keep up with the time-varying measurement noise and sufficiently robust to cope with measurement outliers and prior ***,many efforts lack a balance between adaptability and *** this paper,a novel positioning method with both adaptability and robustness is proposed by coupling the Mahalanobis distance method,the Variational Bayesian method and the student’s t-distribution in one process(M-VBt method).This method is robust against non-Gaussian noise and priori uncertainties,plus adaptive against measurement noise uncertainty and time-varying *** field test results show that the M-VBt method(especially the Mahalanobis distance part)has significantly improved the system performance in the complex urban driving environment.

关键词： Urban environments Mahalanobis distance Adaptability Robustness Integrated navigation

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Selectively T cell phosphorylation activation of azvudine in the thymus tissue with immune protection effect

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Acta Pharmaceutica Sinica B 2024年第7期14卷 3140-3154页

作者： ning Sheng Rui Li yang Li zhe Wang Lulu Wang Yuhuan Li Jinlan Zhang Jiandong Jiang State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

Thymus is the important immune organ,responsible for T cell development and *** lower circulating T counts have been observed in patients who died from COVID-19 compared with ***,also known as FNC,is a thymus-homing anti-SARS-CoV-2 drug in treating COVID-19 *** this study,single-cell transcriptome,proteomics,and parallel reaction monitoring(PRM)were applied to insight into the activation process of FNC in rat and SARS-CoV-2 rhesus monkey *** results indicated that thymic immune cells possess a robust metabolic capacity for cytidine-analogue drugs such as *** enzymes involved in the FNC phosphorylation process,such as Dck,Cmpk1,and Nme2,were highly expressed in CD4+ T cells,CD8+ T cells,and DP(CD4+ CD8+)***,FNC could upregulate multiple phosphorylated kinases in various cell types while downregulating the phosphatases,phosphoribosyl transferases,and deaminases,*** robust phosphorylation capacity of the thymus for cytidine analogue drug FNC,and the activation effect of FNC on the NAs metabolism system potentially contribute to its enrichment in the thymus and immune protection *** suggests that it is crucial to consider the expression level of phosphorylation kinases when evaluating NA drug properties,as an important factor during antiviral drug design.

关键词： Azvudine T cell Thymus Phosphorylation activation Nucleoside analogue

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Volume-averaged modeling of multiphase solidification with equiaxed crystal sedimentation in a steel ingot

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China Foundry 2024年第3期21卷 229-238页

作者： Xiao-lei Zhu Shuang Cao Rui Guan Ji yang zhe ning Xin-gang Ai Sheng-li Li Xin-cheng Miao The key Laboratory of Material Forming and Structure Property Control Anshan 114051LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan 114009LiaoningChina School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina

Macrosegregation is a critical factor that limits the mechanical properties of *** impact of equiaxed crystal sedimentation on macrosegregation has been extensively studied,as it plays a significant role in determining the distribution of alloying elements and impurities within a *** improve macrosegregation in steel connecting shafts,a multiphase solidification model that couples melt flow,heat transfer,microstructure evolution,and solute transport was established based on the volume-averaged Eulerian-Eulerian *** this model,the effects of liquid phase,equiaxed crystals,columnar dendrites,and columnar-to-equiaxed transition(CET)during solidification and evolution of microstructure can be considered *** sedimentation of equiaxed crystals contributes to negative macrosegregation,where regions between columnar dendrites and equiaxed crystals undergo significant A-type positive macrosegregation due to the ***,noticeable positive macrosegregation occurs in the area of final solidification in the *** improvement in macrosegregation is beneficial for enhancing the mechanical properties of connecting *** mitigate the thermal convection of molten steel resulting from excessive superheating,reducing the superheating during casting without employing external fields or altering the design of the ingot mold is indeed an effective approach to control macrosegregation.

关键词： ingot casting multiphase solidification model equiaxed crystal sedimentation microstructure macrosegregation

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Effects of the initiation position on the damage and fracture characteristics of linear-charge blasting in rock

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 443-451页

作者： Chenxi Ding Renshu yang Xiao Guo zhe Sui Chenglong Xiao Liyun yang School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China State Key Lab of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

To study the effects of the initiation position on the damage and fracture characteristics of linear-charge blasting, blasting model experiments were conducted in this study using computed tomography scanning and three-dimensional reconstruction methods. The fractal damage theory was used to quantify the crack distribution and damage degree of sandstone specimens after blasting. The results showed that regardless of an inverse or top initiation, due to compression deformation and sliding frictional resistance, the plugging medium of the borehole is effective. The energy of the explosive gas near the top of the borehole is consumed. This affects the effective crushing of rocks near the top of the borehole, where the extent of damage to Sections Ⅰ and Ⅱ is less than that of Sections Ⅲ and Ⅳ. In addition, the analysis revealed that under conditions of top initiation, the reflected tensile damage of the rock at the free face of the top of the borehole and the compression deformation of the plug and friction consume more blasting energy, resulting in lower blasting energy efficiency for top initiation. As a result, the overall damage degree of the specimens in the top-initiation group was significantly smaller than that in the inverse-initiation group. Under conditions of inverse initiation, the blasting energy efficiency is greater, causing the specimen to experience greater damage. Therefore, in the engineering practice of rock tunnel cut blasting, to utilize blasting energy effectively and enhance the effects of rock fragmentation, using the inverse-initiation method is recommended. In addition, in three-dimensional(3D) rock blasting, the bottom of the borehole has obvious end effects under the conditions of inverse initiation, and the crack distribution at the bottom of the borehole is trumpet-shaped. The occurrence of an end effect in the 3D linear-charge blasting model experiment is related to the initiation position and the blocking condition.

关键词： blasting linear charge initiation position computed tomography three-dimensional reconstruction damage

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Data-driven Reactive Power Optimization of Distribution Networks via Graph Attention Networks

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 874-885页

作者： Wenlong Liao Dechang yang Qi Liu Yixiong Jia Chenxi Wang zhe yang Wind Engineering and Renewable Energy Laboratory Ecole Polytechnique Federale de Lausanne(EPFL)Lausanne 1015Switzerland the College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China the College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China the Department of Electrical and Electronic Engineering(Energy Digitalization Laboratory) The University of Hong KongHong KongChina the Department of Electrical Engineering The Hong Kong Polytechnic UniversityHong KongChina

Reactive power optimization of distribution networks is traditionally addressed by physical model based methods,which often lead to locally optimal solutions and require heavy online inference time *** improve the quality of the solution and reduce the inference time burden,this paper proposes a new graph attention networks based method to directly map the complex nonlinear relationship between graphs(topology and power loads)and reactive power scheduling schemes of distribution networks,from a data-driven *** graph attention network is tailored specifically to this problem and incorporates several innovative features such as a self-loop in the adjacency matrix,a customized loss function,and the use of max-pooling ***,a rulebased strategy is proposed to adjust infeasible solutions that violate *** results on multiple distribution networks demonstrate that the proposed method outperforms other machine learning based methods in terms of the solution quality and robustness to varying load ***,its online inference time is significantly faster than traditional physical model based methods,particularly for large-scale distribution networks.

关键词： Reactive power optimization graph neural network distribution network machine learning data-driven

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Disease and Economic Burden of Kashin-Beck Disease—China,2021

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China CDC weekly 2024年第2期6卷 40-44页

作者： Silu Cui Wenjun Que zhe Jiao Qing Deng Xufeng Zhang Yanhong Cao ning Liu Ailin Li Alphonse Sowanou zhe Li Tuo Wang yang Li Jun Yu Junrui Pei NHC Key Laboratory of Etiology and Epidemiology(Harbin Medical University) Key Laboratory of Etiology and EpidemiologyEducation Bureau of Heilongjiang ProvinceInstitute of Kashin-Beck Disease ControlCenter for Endemic Disease ControlChinese Center for Disease Control and PreventionHarbin Medical UniversityHarbin CityHeilongjiang ProvinceChina NHC Key Laboratory of Etiology and Epidemiology(Harbin Medical University) Heilongjiang Provincial Key Laboratory of Trace Elements and Human HealthKey Laboratory of Etiology and EpidemiologyEducation Bureau of Heilongjiang ProvinceInstitute of Endemic Fluorosis ControlCenter for Endemic Disease ControlChinese Center for Disease Control and PreventionHarbin Medical UniversityHarbin CityHeilongjiang ProvinceChina

What is already known about this topic?Kashin-Beck disease(KBD)is a chronic and degenerative osteoarthropathy characterized by cartilage *** is an endemic disease that is highly prevalent among the Chinese population and poses a significant health *** is added by this report?This is the first national report on the economic burden of KBD in *** to the data from 2021,KBD has caused significant disease and economic *** most substantial reduction in healthy life expectancy was observed among patients with degree II severity and those aged 60 years and older,resulting in a total indirect economic burden of 112.74 million Chinese Yuan(CNY).What are the implications for public health practice?The results of this study will contribute to informing the development of tailored prevention and control strategies by the *** strategies will include targeted policies and recommendations for appropriate healthcare and financial subsidies,which will be based on the demographic characteristics of the endemic areas.

关键词： prevention degeneration burden

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Sub-10-nm-sized Au@AuxIr1-x metal-core/alloy-shell nanoparticles as highly durable catalysts for acidic water splitting

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National Science Review 2024年第4期11卷 130-140页

作者： Huimin Wang zhe-ning Chen Yuanyuan Wang Dongshuang Wu Minna Cao Fanfei Sun Rong Cao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences University of Chinese Academy of Sciences School of Materials Science and Engineering Nanyang Technological University Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied Physics Chinese Academy of Sciences Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China

The absence of efficient and durable catalysts for oxygen evolution reaction（OER） is the main obstacle to hydrogen production through water splitting in an acidic ele ***,we report a controllable synthesis method of surface IrOxwith changing Au/Ir compositions by constructing a range of sub-10-nm-sized core-shell nanocatalysts composed of an Au core and AuxIr1-xalloy *** particular,Au@Au0.43Ir0.57exhibits 4.5 times higher intrinsic OER activity than that of the commercial Ir/*** X-ray-based spectroscopies,electron microscopy and density functional theory calculations revealed a balanced binding of reaction intermediates with enhanced *** water-splitting cell using a load of 0.02 mgIr/cm2of Au@Au0.43Ir0.57as both anode and cathode can reach 10 mA/cm2at 1.52 V and maintain activity for at least194 h,which is better than the cell using the commercial couple Ir/C‖Pt/C（1.63 V,0.2 h）.

关键词： controllable synthesis of surface IrOx oxygen evolution reaction acidic water splitting catalytic stability transition metal catalysts

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Unraveling electrolyte solvation architectures for high-performance lithium-ion batteries

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Science China(Technological Sciences) 2024年第3期67卷 958-964页

作者： yang MengHao SHI zhe HE ZhiYuan WANG Dan School of Materials Science and Engineering Tongji UniversityShanghai 201804China Department of Nuclear Science and Engineering Massachusetts Institute of Technology CambridgeMassachuseis 02139USA School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China

The design of advanced electrolytes hinges critically on a comprehensive comprehension of lithium-ion migration mechanisms within these electrochemical systems. Fluorination generally improves the stability and reduces the reactivity of organic compounds, making them potentially suitable for use in harsh conditions such as those found in a battery electrolyte. However,the specific properties, such as the solvation power, diffusivity, ion mobility, and so forth, would depend on the exact nature and extent of the fluorination. In this work, we introduce a theoretical framework designed to facilitate the autonomous creation of electrolyte molecular structures and craft methodologies to compute transport coefficients, providing a physical interpretation of fluoride systems. Taking fluorinated-1,2-diethoxyethanes as electrolyte solvents, we present and analyze the relationship between the electronic properties and atomic structures, and further correlate these properties to the transport coefficients, resulting in a good alignment with the experimental diffusion behaviors and Li-solvation structures. The insights derived from this research contribute to the methodological basis for high-throughput evaluation of prospective electrolyte systems, and consequently, propose strategic directions for the improvement of electrochemical cycle characteristics. This comprehensive exploration of the transport mechanisms enhances our understanding, offering avenues for further advancements in the field of lithium-ion battery technology.

关键词： Unraveling electrolyte solvation architectures for high-performance lithium-ion batteries

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Biological sources, paleoenvironment, and organic matter enrichment in source rocks of the Ordovician Majiagou Formation, Ordos Basin, China:Evidence from biomarkers,microfossils, and inorganic geochemical analyses

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Journal of Palaeogeography 2024年第1期13卷 92-115页

作者： Jing-Jing Cao Wen-zhe Gang Shang-Ru yang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Bejing)Beijing 102249China College of Geosciences China University of Petroleum(Bejing)Beijing 102249China Oil and Gas Technology Research Institute PetroChina Changqing Oifield CompanyXi'an 710018Shaanxi ProvinceChina

Carbonate deposits in the Ordovivian Majiagou Formation are significant source rocks for natural gas generation in the Ordos Basin, northwestern China. Previous studies mainly focused on the organic matter enrichment mechanism of shales rather than carbonate rocks. The biological sources and paleoenvironment of carbonate source rocks, and the main controlling factors of organic matter enrichment in the carbonate source rocks were studied in this paper in combination with evidence from biomarkers, microfossils and inorganic geochemistry analysis. The results show that four types of microfacies were identified in the Majiagou Formation, respectively as: mud flat microfacies, mud-dolomite flat microfacies, dolomite flat microfacies, and open marine microfacies. The biological sources of organic matter are chiefly planktonic algae, followed by bacteria. The mud flat and mud-dolomite flat contain a high abundance of terrigenous detrital inputs, as indicated by the high content of Al_(2)O_(3), TiO_(2), Th, and Zr. The low Sr/Cu and high Rb/Sr values reveal warm and humid paleoclimate conditions in the mud flat and mud-dolomite flat, whereas the dolomite flat and open marine were likely formed in hot and arid paleoclimate conditions. The mud flat and mud-dolomite flat deposits were characterized by high paleoproductivity of the Majiagou Formation. Low Sr/Ba values were found in the mud flat samples, indicating fresh to brackish water condition, whereas samples of other facies have a relatively high degree of salinity. Based on U_(auth), Mo_(auth), Cr_(auth), Co_(auth), δCe, and δEu values, the mud flat microfacies was formed in a suboxic and anoxic environment, whereas the mud-dolomite flat, dolomite flat and open marine microfacies were within dysoxic to oxic conditions. A model of organic matter enrichment in the Majiagou Formation is thus established. The level of terrigenous detrital inputs is the principal factor of organic matter enrichment in the Majiagou Formation,

关键词： Biological source Microfacies Trace elements Organic matter Majiagou Formation Ordos Basin

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