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Transformation power or development pressure:economic growth targets and urban carbon productivity

Chinese Journal of Population,Resources and Environment 2024年第2期22卷 176-184页

作者： Longtao chen Yi Zheng xianfeng Han Juan Liu School of Management and Economics Kunming University of Science and TechnologyKunming 650500China School of Foreign Languages and Literatures Chongqing Normal UniversityChongqing 401331China

Maintaining moderate economic growth targets(EGTs)is the key for local governments to effectively implement the“carbon peak and carbon neutrality”goals under the refreshed development *** panel data of 276 prefecture-level cities in China's Mainland from 2010 to 2020,and employing methods such as intermediary and threshold models,this study empirically analyzes the internal mechanism of EGT’s impact on urban carbon productivity(UCP).Our findings demonstrate that:①The overall EGT during the analyzed period is not conducive to improving *** conclusion remains valid after a series of robustness *** effect is more pronounced in the central region and resource-based cities than in the east-west region and non resource-based cities.②EGT not only directly suppresses UCP but also exerts indirect negative impacts on UCP from three aspects:delaying the digital economy(DE),constraining financial expansion(FE),and hindering green technology innovation(GTI).This negative indirect effect is similar to or even surpasses the direct effect,suggesting that the internal relationship between EGT and“dual-carbon”goals should be re-evaluated from a new compound perspective.③EGT not only has a simple linear impact on UCP but also significantly exhibits a dynamic evolution pattern in inverted“U”*** is,as EGT continuously upgrades,a nonlinear impact on UCP emerges in the form of“promoting first,suppressing later”.This indicates that surpassing the“degree”limit for EGT will be detrimental to the improvement of *** study broadens the scope of carbon productivity analysis by introducing a new perspective centered on *** insights gleaned from this research offer valuable guidance for local governments to effectively manage economic growth expectations and promote the synchronized achievement of dual-carbon objectives.

关键词： Economic growth target Urban carbon productivity Mediating effects Dynamic evolution

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Enhancement of stimulated emission by a metallic optofluidic resonator

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Photonics Research 2018年第6期6卷 597-600页

作者： BEI JIANG HAILANG DAI xianfeng chen State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and AstronomyShanghai Jiao Tong University Collaborative Innovation Center of IFSA (CICIFSA) Shanghai Jiao Tong University

Stimulated emission can be controlled by a material molecular energy band and the intensity of a pump laser, which can provide some population inversion and promote ground electron transition, respectively. We use a metallic optofluidic resonator to enhance stimulated emission intensity. The quality factor Q and the spontaneous emission coupling factor β of the metallic optofluidic resonator are discussed in detail to explain the enhancement mechanism. Experimental data demonstrate that the operated emission from rhodamin 6G solution can be observed due to the enhancement of stimulated emission from the optofluidic resonator.

关键词： Enhancement of stimulated emission by a metallic optofluidic resonator

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奥氏体不锈钢材料劣化快速评价技术

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理化检验（物理分册） 2024年第4期60卷 17-24,30页

作者：陈仙凤周彬余焕伟肖飚任绪凯杜锡勇唐艳同绍兴市特种设备检测院绍兴312071 绍兴市特种设备智能检测与评价重点实验室绍兴312071 浙江德力装备有限公司绍兴312500 上海市特种设备监督检验技术研究院上海200062

对不同状态下304不锈钢的里氏硬度分布、超声回波信号、显微组织等进行研究,阐明了里氏硬度离散率、超声波频谱分布等指标与材料劣化状态之间的关系,并运用D-S证据理论将多指标信息融合后,对奥氏体不锈钢材料进行评价。结果表明:正常固... 详细信息

对不同状态下304不锈钢的里氏硬度分布、超声回波信号、显微组织等进行研究,阐明了里氏硬度离散率、超声波频谱分布等指标与材料劣化状态之间的关系,并运用D-S证据理论将多指标信息融合后,对奥氏体不锈钢材料进行评价。结果表明:正常固溶处理的304不锈钢的硬度离散率小于1.5%,而当材料劣化时,其硬度离散率会显著增大,且超声回波信号的频谱能量分布特征也存在显著变化;采用D-S证据理论对里氏硬度离散率、超声回波的低频能量下降比和高频能量下降比3个指标进行融合,可有效解决评价指标之间的相互冲突问题,显著提高奥氏体不锈钢现场快速评价结果的置信度。

关键词：奥氏体不锈钢 D-S证据理论超声回波里氏硬度离散率置信度

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Comparative Study of the Effects of Nano ZnO and CuO on the Biodegradation,Biocompatibility,and Antibacterial Properties of Micro-arc Oxidation Coating of Magnesium Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 242-254页

作者： Ying Shen xianfeng Shan Iniobong P.Etim Muhammad Ali Siddiqui Yang Yang Zewen Shi Xuping Su Junxiu chen Key Laboratory of Materials Surface Science and Technology of Jiangsu Province Changzhou UniversityChangzhou213164China Department of Stomatology The Affiliated Xinhua Hospital of Dalian UniversityDalian116000China Department of Physics University of CalabarCalabar540242Nigeria Metallurgical Engineering Department NED University of Engineering and TechnologyUniversity RoadKarachi75270Pakistan Ningbo No.2 Hospital Ningbo315010China

This research systematically examined the degradation,antibacterial effects,and biocompatibility of micro-arc oxidation(MAO)coatings with nano CuO and ZnO on extruded Mg *** copper(Cu)and Zinc(Zn)possess antibacterial *** findings demonstrated that adding ZnO will appreciably reduce the degradation rate of MAO-coating alloy due to the self-sealing micro ***+MAO coating exhibited excellent antibacterial performance,with an antibacterial rate of over 90%within 6 h co-cultured with Staphylococcus ***,the antibacterial rate of ZnO+MAO coating reached 90%after 12 h *** test using MG63 cell indicated that the incorporation of CuO and ZnO did not notably affect the cell viability rate of the ***,after 14 days of culture,the CuO+MAO and ZnO+MAO coated samples exhibited higher alkaline phosphatase(ALP)activity than the MAO-coated and uncoated samples,suggesting favorable osteogenic properties.

关键词： Copper oxide Zinc oxide Micro-arc oxidation(MAO)coating Corrosion behavior Antibacterial characteristics

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Carrier dynamic process in all-inorganic halide perovskites explored by photoluminescence spectra

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Photonics Research 2021年第2期9卷 151-170页

作者： JING chen CHAO ZHANG XIAOLIN LIU LIN PENG JIA LIN xianfeng chen Department of Physics Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric PowerShanghai University of Electric PowerShanghai 200090China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of Light Manipulation and Applications Shandong Normal UniversityJinan 250358China

Recently, all-inorganic halide perovskites have received enormous attention because of their excellent optoelectronic properties. Among them, the power conversion efficiency(PCE) of all-inorganic halide perovskite solar cells has made rapid progress in the last few years. However, understanding the intrinsic physical nature of halide perovskites, especially the dynamic process of photo-generated carriers, is a key for improving the PCE. In this review, we introduced and summarized the photoluminescence(PL) technique used to explore the carrier dynamic process in all-inorganic halide perovskites. Several physical models were proposed to investigate the dynamic parameters, i.e., recombination lifetime and diffusion length, by analyzing the steady-state PL as well as the time-resolved PL spectra. We also discussed the distinction of PL spectral behavior between bulk halide perovskite samples and those grown with transport layers due to the participation of different dominant dynamic ***, we briefly described some other optical techniques reported to study the relevant physical properties of all-inorganic halide perovskites.

关键词： properties. perovskite halide

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Detecting soil salinity with arid fraction integrated index and salinity index in feature space using Landsat TM imagery

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Journal of Arid Land 2013年第3期5卷 340-353页

作者： Fei WANG Xi chen GePing LUO JianLi DING xianfeng chen State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences University of Chinese Academy of Sciences College of Resources and Environmental Science Xinjiang University Slippery Rock University of Pennsylvania Slippery RockPA16057USA

Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter） and the weak spectral features of salinized soil. Therefore, an index such as the salinity index （SI） that only uses soil spectra may not detect soil salinity effectively and quantitatively. The use of vegetation reflectance as an indirect indicator can avoid limitations associated with the direct use of soil reflectance. The normalized difference vegetation index （NDVI）, as the most common vegetation index, was found to be responsive to salinity but may not be available for retrieving sparse vegetation due to its sensitivity to background soil in arid areas. Therefore, the arid fraction integrated index （AFⅡ） was created as supported by the spectral mixture analysis （SMA）, which is more appropriate for analyzing variations in vegetation cover （particularly halophytes） than NDVI in the study area. Using soil and vegetation separately for detecting salinity perhaps is not feasible. Then, we developed a new and operational model, the soil salinity detecting model （SDM） that combines AFⅡ and SI to quantitatively estimate the salt content in the surface soil. SDMs, including SDM1 and SDM2, were constructed through analyzing the spatial characteristics of soils with different salinization degree by integrating AFⅡ and SI using a scatterplot. The SDMs were then compared to the combined spectral response index （COSRI） from field measurements with respect to the soil salt content. The results indicate that the SDM values are highly correlated with soil salinity, in contrast to the performance of COSRI. Strong exponential relationships were observed between soil salinity and SDMs （R2〉0.86, RMSE〈6.86） compared to COSRI （R2=0.71, RMSE=16.21）. These results suggest that the feature space related to biophysical properties combined with AFII and SI can effectively pr

关键词： soil salinity spectrum halophytes Landsat TM spectral mixture analysis feature space model

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Optical vortex copier and regenerator in the Fourier domain

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Photonics Research 2018年第6期6卷 641-646页

作者： XIAODONG QIU FANGSHU LI HAIGANG LIU xianfeng chen LIXIANG chen Department of Physics Jiujiang Research Institute and Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient DevicesXiamen Universi~ Xiamen 361005 China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and AstronomyShanghai Jiao Tong University Shanghai 200240 China

The generation and manipulation of optical vortices are of fundamental importance in a variety of promising applications. Here, we develop a nonlinear optical paradigm to implement self-and cross-convolution of optical vortex arrays, demonstrating the features of a vortex copier and regenerator. We use a phase-only spatial light modulator to prepare the 1064 nm invisible fundamental light to carry special optical vortex arrays and use a potassium titanyl phosphate crystal to perform type Ⅱ second-harmonic generation in the Fourier domain to achieve 532 nm visible structured vortices. Based on pure cross-convolution, we succeed in copying arbitrary-order single vortices as well as their superposition states onto a prearranged array of fundamental Gaussian spots. Also, based on the simultaneous effect of self-and cross-convolutions, we can expand the initial vortex lattices to regenerate more vortices carrying various higher topological charges. Our presented method of realizing an optical vortex copier and regenerator could find direct applications in optical manipulation, optical imaging, optical communication, and quantum information processing with structured vortex arrays.

关键词： Optical vortex copier and regenerator in the Fourier domain SHG LG exp KTP

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On-chip erbium-doped lithium niobate microcavity laser

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Science China(Physics,Mechanics & Astronomy) 2021年第3期64卷 2-6页

作者： YiAn Liu XiongShuo Yan JiangWei Wu Bing Zhu YuPing chen xianfeng chen State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China

The commercialization of lithium niobate on insulator(LNOI) wafer has resulted in significant on-chip photonic integration application owing to its remarkable photonic,acousto-optic,electro-optic,and piezoelectric *** recent years,a variety of high-performance on-chip LNOI-based photonic devices have been *** this study,we developed a 1-mol% erbium-doped lithium niobate crystal and its LNOI on a silicon substrate and fabricated an erbium-doped LNOI microdisk with high quality factor(~1.05×105).C-band laser emission at ~1530 and ~1560 nm(linewidth 0.12 nm) from the high-Q erbium-doped LNOI microdisk was demonstrated with 974-and 1460-nm pumping,with the latter having better thermal *** microlaser would play an important role in the photonic integrated circuits of the lithium niobate platform.

关键词： erbium-doped lithium niobate on insulator on-chip laser microdisk

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A 15-user quantum secure direct communication network

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Light(Science & Applications) 2021年第12期10卷 2322-2329页

作者： Zhantong Qi Yuanhua Li Yiwen Huang Juan Feng Yuanlin Zheng xianfeng chen State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and AstronomyShanghai Jiao Tong University200240 ShanghaiChina Department of Physics Jiangxi Normal University330022 NanchangChina Shanghai Research Center for Quantum Sciences 201315 ShanghaiChina Collaborative Innovation Center of Light Manipulation and Applications Shandong Normal University250358 JinanChina

Quantum secure direct communication(QSDC)based on entanglement can directly transmit confidential ***,the inability to simultaneously distinguish the four sets of encoded entangled states limits its practical ***,we explore a QSDC network based on time–energy entanglement and sum-frequency *** total,15 users are in a fully connected QSDC network,and the fidelity of the entangled state shared by any two users is>97%.The results show that when any two users are performing QSDC over 40 km of optical fiber,the fidelity of the entangled state shared by them is still>95%,and the rate of information transmission can be maintained above 1 Kbp/*** result demonstrates the feasibility of a proposed QSDC network and hence lays the foundation for the realization of satellite-based long-distance and global QSDC in the future.

关键词： quantum hence realization

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Highly stable side-chain-type cardo poly(aryl ether ketone)s membranes for vanadium flow battery

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Chinese Chemical Letters 2024年第3期35卷 167-170页

作者： Ziming Zhao Qing Dai Sihan Huang Wenjing Lu Yaohan chen Jifu Zheng Suobo Zhang Shenghai Li xianfeng Li Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Division of Energy Storage Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous ***,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable *** assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.

关键词： Vanadium flow battery Energy storage technology Ion exchange membrane Ion transport mechanism Poly(arylene ether ketone)s(PAEKs)

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