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Amine-Actuated Catalyst Switch for One-Pot Synthesis of Ether-Ester Type Block Copolymers

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Chinese Journal of Polymer Science 2024年第12期42卷 1925-1932,I0008页

作者： Hong Qiu peng-Fei Zhang jun-peng Zhao Faculty of Materials Science and Engineering South China University of TechnologyGuangzhou 510640China

Organocatalysis has shown special potency for simplifying the construction of complex polymer *** are reporting here a one-pot synthetic pathway using amine as a selectivity-switching agent in the two-component catalytic system consisting of triethylborane(Et_(3)B)and a phosphazene *** first modelled the interactions of a variety of amines with Et_(3)B by density functional theory *** results indicate that the aliphatic diamines comprising both primary and tertiary amino groups,capable of forming stable intramolecular hydrogen bonds,undergo the strongest complexation with Et_(3)***,experimental results demonstrate that the addition of such amines promptly actuates the in situ selectivity switch from Lewis pair-catalyzed ring-opening polymerization(ROP)of epoxide(propylene oxide,n-butylglycidyl ether,or glycidyl phenyl ether)to organobase-catalyzed ROP ofδ-valerolactone,allowing one-pot continuous synthesis of ether-ester type block *** thus exploited the noncovalent interaction between amine and Et_(3)B to refine the catalyst switch strategy by exempting it from loading of extra catalyst.

关键词： Ring-opening polmerization Block copolymers Organocatalysis

Numerical investigation and optimisation of heat transfer performance in a vertical sinter cooling packed bed using Taguchi and ANOVA methods

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Journal of Iron and Steel Research International 2020年第8期27卷 898-912页

作者： jun-peng Fu Jiu-ju Cai Department of Thermal Engineering SEP Key Laboratory of Eco-IndustrySchool of MetallurgyNortheastern UniversityShenyang 110819LiaoningChina

The Taguchi and analysis of variance (ANOVA) methods were applied to investigate the effects of the structural and operational parameters on the heat transfer performance of a vertical sinter cooling packed bed. The analysed parameters were the gas flow rate, the air inlet temperature, the sinter inlet temperature, the cooling bed diameter and the cooling bed height, all of which contain three levels. The purpose was to improve the heat transfer performance of a vertical sinter cooling bed. A numerical analysis model was established to assess the heat transfer performance with respect to the varying parameters and their different levels. This mathematical model was validated by using data from practical industrial processes. The Taguchi method for the L27 (35) orthogonal design experiment was selected to evaluate the impacts of the design parameters on the heat transfer performance and to acquire the optimum combination of parameters. The analysis of variance was applied to assess the impact weights and the order of significance of the design parameters. The results show that the sinter inlet temperature and cooling bed diameter have great influences and impact the exergy of the wasted heat recovery by 61.65% and 23.31%, respectively. However, the gas flow rate and the air inlet temperature have small effects on the response. Furthermore, the air and sinter inlet temperatures have the most significant impacts on the efficiency of heat transfer by 68.83% and 23.31%, respectively. The optimal parameter combination (A1B1C3D3E3) was obtained, and the optimal results were validated by confirmation tests.

关键词： Vertical sinter packed bed Wasted heat recovery Taguchi method Analysis of variance(ANOVA) Gas–solid heat transfer

Self-adaptive Processing and Forecasting Algorithm for Univariate Linear Time Series

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Chinese Journal of Electronics 2017年第6期26卷 1147-1153页

作者： LIU Shufen GU Songyuan peng jun College of Computer Science and Technology Jilin University

As the Box-Jenkins method could not grasp the non-stationary characteristics of time series exactly, nor identify the optimal forecasting model order quickly and precisely, a self-adaptive processing and forecasting algorithm for univariate linear time series is proposed. A self-adaptive series characteristic test framework which employs varieties of statistic tests is constructed to solve the problem of inaccurate identification and inadequate processing for non-stationary characteristics of time series. To achieve favorable forecasts, an optimal forecasting model building algorithm combined with model filter and candidate model pool is proposed, in which a univariate linear time series forecasting model is built. Experimental data demonstrates that the proposed algorithm outperforms the comparative method in all forecasting performance statistics.

关键词： Time series Self-adaptivity Unit root Autoregressive moving average(ARMA)

Spin-orbit coupling in Bose-Einstein condensate and degenerate Fermi gases

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Frontiers of physics 2014年第5期9卷 598-612页

作者： peng-jun Wang Jing Zhang State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-Electronics Shanxi University Taiyuan 030006 China

We review our recent experimental realization and investigation of a spin orbit （SO） coupled Bose Einstein condensate （BEC） and quantum degenerate Fermi gas. By using two counter-propagathlg Ranlan lasers and controlling the different frequency of two R,aman lasers to engineer the atom light interaction, we first study the SO coupling in BEC. Then we study SO coupling in Fermi gas. We, observe the spin dephasing in spin dynamics and momentum distribution asymmetry of the equilibrium state as halhnarks of SO coupling in a Fermi gas. To clearly reveal the, property of SO coupling Fermi gas, we also study the momentmn-resolved radio-frequency spectroscopy which characterizes the energy momentum dispersion and spin composition of the quantum states. We observe the change of errmion surfaces in different helieity branches with different atomic density, which indicates that a Lifshitz transition of the Fermi surface topology change can be found by further cooling the system. At last, we study the momentum-resolved Raman spectroscopy of an ultracoht Fermi gas.

关键词： spin-orbit coupling Bose Einstein condensate Fermi gases topological change momentum-resolved radio-frequency spectroscopy momentum-resolved Raman spectroscopy

Modular Verification of SPARCv8 Code

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Journal of Computer Science & Technology 2020年第6期35卷 1382-1405页

作者： jun-peng Zha Xin-Yu Feng Lei Qiao Department of Computer Science and Technology Nanjing UniversityNanjing 210023China State Key Laboratory for Novel Software Technology Nanjing UniversityNanjing 210023China Beijing Institute of Control Engineering Beijing 100080China

Inline assembly code is common in system software to interact with the underlying hardware platforms. The safety and correctness of the assembly code is crucial to guarantee the safety of the whole system. In this paper, we propose a practical Hoare-style program logic for verifying SPARC (Scalable Processor Architecture) assembly code. The logic supports modular reasoning about the main features of SPARCv8 ISA (instruction set architecture), including delayed control transfers, delayed writes to special registers, and register windows. It also supports relational reasoning for refinement verification. We have applied it to verify that there is a contextual refinement between a context switch routine in SPARCv8 and a switch primitive. The program logic and its soundness proof have been mechanized in Coq.

关键词： Scalable Processor Architecture Version 8(SPARCv8) assembly code verification context switch Coq refinement verification

Proton Irradiation Effects on the Structural and Tribological Properties of Polytetrafluoroethylene

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Chinese Journal of Polymer Science 2016年第12期34卷 1448-1455页

作者：刘百幸 jun Liang Zhen-jun peng Xiang-li Wang State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of Sciences Key Laboratory for Electronic Materials of the State Ethnic Affairs Commission College of Electric EngineeringNorthwest University for Nationalities

Polytetrafluoroethylene （PTFE） was irradiated with protons in a ground-based simulation facility to study the effects of proton irradiation on the structural and tribological properties of PTFE. The structural changes were characterized by X-ray photoelectron spectroscopy （XPS） and attenuated total-reflection FTIR （ATR-FTIR）, while the tribological properties were evaluated by friction and wear tests. It was found that proton irradiation induced the degradation of PTFE molecular chains, resulting in the increase of C concentration and the decrease in F concentration on the sample surfaces, and the surface chemical structure and morphology of the samples changed, which affected the friction coefficient and decreased the wear rate of the specimens as the friction and wear tests revealed.

关键词： Polytetrafluoroethylene Proton irradiation Degradation Friction and wear.

The magnetic properties of sediment and sedimentary environment in the Huanghe Delta area after the last glacial maximum

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Acta Oceanologica Sinica 2016年第5期35卷 113-123页

作者： peng jun LI Ping CHEN Hongquan School of Urban and Planning Yancheng Teacher's University First Institute of Oceanography State Oceanic Administration

On the basis of measuring the magnetic parameters of sediment in Core YDZ1, combined with a grain size analysis and Carbon-14 dating, the magnetic properties of sediment and sedimentary environment in the Huanghe（Yellow River） Delta area after the last glacial maximum have been studied. The results show that the ferrimagnetic minerals of a pseudo single domain and multi domain particles dominate the magnetic properties of sediment in Core YDZ1. The imperfect anti ferrimagnetic minerals have more contribution on sediment in a depth of 24.0–22.1 m, and more stable-single domain and pseudo single domain particles exist. The susceptibility of anhysteretic remanent magnetization and the ratio of the susceptibility of anhysteretic remanent magnetization to saturation isothermal remanent magnetization show a decrease trend below depth of 24 m, a marked increase trend in a depth of 24.0–13.5 m, and a rapid decrease at depth of 13.5 m, then a fluctuation trend upward. The above two magnetic parameters and the ratio of the susceptibility of anhysteretic remanent magnetization to the mass susceptibility can be regarded as the proxy indicators for the content of clay（〈4 μm）and the fine-grained size（〈32 μm）. The sedimentary environment after the last glacial maximum in the Huanghe Delta area has experienced the fluvial facies, the tidal flat facies, the neritic facies, the pro delta facies, the delta front facies and the floodplain facies. Thickness of the Holocene transgression layer is 10.5 m and the depth of substrate is about 24 m according to the YDZ1 core. The sedimentary dynamic has a variation trend with strongweak-strong, which has been proved by the Flemming triangular schema.

关键词： the Huanghe(Yellow River) Delta magnetic properties sedimentary environment grain size dating

INFLUENCE OF MINERAL ADMIXTURES ON MECHANICAL PROPERTIES OF HIGH-PERFORMANCE CONCRETE

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Journal of Wuhan University of Technology(Materials Science) 1999年第2期14卷 1-7页

作者： Ma, Baoguo Li, Jinzong peng, jun Wuhan Univ Technol Coll Mat Sci & Technol Wuhan 430070 Peoples R China Hong Kong Univ Sci & Technol Hong Kong Hong Kong

The improvements of the mechanical properties, including bulk density of fresh mixtures, elastic modulus, and compressive strengths of four high-performance concrete mixtures, made with the addition of fly ash, refined ground blast - furnace microslag (microslag) and silica fume are studied. The concrete mixtures were determined based on the dispersion testing results. The study indicates that the elastic modulus at 28 and 91 days, and compressive strengths of the concretes are improved a lot when fly ash and microslag by 25 percent by weight of cement are added into the mixtures individually. The improvement is especially evident when silica fume by 5 percent and fly ash by 25 percent by weight of cement are added together into the mixture, while the fresh concrete mixture keeps a good workability. Through the analysis of chemically combined water ratios of the four mixtures at various hydration ages, it is found that the addition of all these mineral mixtures are beneficial to the hydration process, especially, at later stages, which might be one of the reasons for the improvement of mechanical properties. (Author abstract) 4 Refs.

关键词： high-performance concrete mineral admixture mechanical properties

Genetic and Association Mapping Study of English Grain Aphid Resistance and Tolerance in Bread Wheat Germplasm

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Journal of Integrative Agriculture 2014年第1期13卷 40-53页

作者： LI Feng-qi peng jun-hua Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture Wuhan Botanical GardenChinese Academy of Sciences University of Chinese Academy of Sciences Department of Soil and Crop Sciences Colorado State University

English grain aphid （EGA） is a destructive insect pest of wheat. To identify the loci associated with EGA resistance and tolerance, 70 bread wheat accessions mainly from central Asia were evaluated for EGA resistance and tolerance traits at two locations, and genotyped with 51 SSR markers. Totally, three accessions showed high or moderate levels resistance and 17 genotypes displayed highly or moderately tolerate to EGA. Genetic diversity of these lines was investigated also. After 97 SSR loci which evenly covered all wheat chromosomes were scanned for association, four SSR loci were significantly associated with EGA resistance and four with EGA tolerance. After association analysis was conducted with dynamic aphid densities, we found four loci Xgwm192b, Xgwm391, Xbarc98, and Xgwm613b were detected continuously at different growing stages of wheat. In addition, the loci of EGA resistance/tolerance and Russian wheat aphid resistance were compared. The results generated in this study would be helpful for utilization of the EGA resistance/tolerance germplasm, and for development of mapping populations in EGA resistance breeding programs.

关键词： English grain aphid resistance tolerance association mapping Triticum aestivum