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S1-supported Pd@CeO_(2) quasi-core@shell materials as advanced catalysts for selective hydrogenation of furfural

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Chinese Chemical Letters 2024年第3期35卷 493-496页

作者： Xiang Chu lingling Zhang Ke wang Rui Zhang Xiao wang Shuyan Song Hongjie Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Bare Pd metal nanoparticles invariably suffer from poor selectivity in furfural hydrogenation by forming flat configurations,with the aromatic ring of the substrate molecules parallel to the metal ***,we put forward a promising solution by using CeO_(2)as promoters to modify Pd nanoparticles for modulating the adsorption behaviors of furfural *** achieve the highly-desired ultra-small Pd@CeO_(2)core@shell nanostructure,a“constrained auto-redox”synthesis is developed,in which silicalite-1 supports play the key role of providing their surface as the landing place of PdO_(x)precursors for inhibiting the overgrowth and the *** the best of our knowledge,this is one of the smallest core@shell materials obtained from aqueous *** evaluated as catalysts,Pd@CeO_(2)/S-1 gives 98.9%conversion of furfural with 94.3%selectivity for furfural alcohol in 15 h,which is much better than that of Pd/S-1(88.6%conversion with 44.3%selectively).The DFT simulation reveals a strong interaction between the defects of CeO_(2)and the oxygen atom of the–CHO group in furfural molecules,which benefits the selective hydrogenation occurred in the–CHO group rather than the furan ring.

关键词： Core@shell Palladium Ceria Auto-redox synthesis Hydrogenation

Lorentz violation induces isospectrality breaking in Einstein-bumblebee gravity theory

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 87-96页

作者： Wentao Liu Xiongjun Fang Jiliang Jing Jieci wang Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China

In this study,we investigate the quasinormal modes(QNMs)of a Lorentz-violating spacetime,factoring in a cosmological constant,within the framework of Einstein-bumblebee *** findings reveal that the interaction of spacetime with an anisotropic bumblebee field imparts distinct contributions to the axial and polar sectors of the vector *** subsequently breaks the isospectrality typically observed in vector *** evidence strongly indicates isospectral breaking in the vector modes of Einstein-bumblebee black holes:a pronounced breakage in the real part of the frequencies,while the imaginary component seems less *** isospectral breaking indicates the existence of two different waveforms in the Ringdown phase of the black hole,which provides a potential signal of quantum gravity observable in current experiments.

关键词： Lorentz-violating isospectral breaking quasinormal modes

Finely regulated luminescent Ag-In-Ga-S quantum dots with green-red dual emission toward white light-emitting diodes

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Opto-Electronic Advances 2024年第9期7卷 54-63页

作者： Zhi Wu Leimeng Xu Jindi wang Jizhong Song Key Laboratory of Materials Physics of Ministry of Education Laboratory of Zhongyuan LightSchool of PhysicsZhengzhou UniversityDaxue Road 75Zhengzhou 450052China

Ag-In-Ga-S(AIGS)quantum dots(QDs)have recently attracted great interests due to the outstanding optical properties and eco-friendly components,which are considered as an alternative replacement for toxic Pb-and Cd-based ***,enormous attention has been paid to how to narrow their broadband spectra,ignoring the application advantages of the broadband *** this work,the AIGS QDs with controllable broad green-red dual-emission are first reported,which is achieved through adjusting the size distribution of QDs by controlling the nucleation and growth of AIGS ***,the AIGS QDs exhibit broad dual-emission at green-and red-band evidenced by photoluminescence(PL)spectra,and the PL relative intensity and peak position can be finely ***,the dual-emission is the intrinsic characteristics from the difference in confinement effect of large particles and tiny particles confirmed by temperature-dependent PL ***,the AIGS QDs(the size consists of 17 nm and 3.7 nm)with 530 nm and 630 nm emission could successfully be synthesized at 220°*** combining the blue light-emitting diode(LED)chips and dual-emission AIGS QDs,the constructed white light-emitting devices(WLEDs)exhibit a continuous and broad spectrum like natural sunlight with the Commission Internationale de l’Eclairage(CIE)chromaticity coordinates of(0.33,0.31),a correlated color temperature(CCT)of 5425 K,color rendering index(CRI)of 90,and luminous efficacy of radiation(LER)of 129 lm/W,which indicates that the AIGS QDs have huge potential for lighting applications.

关键词： quantum dots Ag-In-Ga-S dual emission white light-emitting diodes

碱性过氧化氢处理对藕渣不溶性膳食纤维结构及功能特性的影响

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中国食品学报 2024年第2期24卷 53-61页

作者：张倩王佩瑶王子成黄琳茜何玲徐磊淮阴工学院生命科学与食品工程学院江苏淮安223003

采用碱性过氧化氢(AHP)处理藕渣,比较处理前、后藕渣不溶性膳食纤维(IDF)结构和功能特性的变化。结果表明:AHP处理后藕渣IDF的D-葡萄糖质量分数显著增加了9.52%(P0.05),而膨胀力显著降低(P<0.05)。综上,AHP处理使藕渣IDF的结构发生变化... 详细信息

采用碱性过氧化氢(AHP)处理藕渣,比较处理前、后藕渣不溶性膳食纤维(IDF)结构和功能特性的变化。结果表明:AHP处理后藕渣IDF的D-葡萄糖质量分数显著增加了9.52%(P0.05),而膨胀力显著降低(P<0.05)。综上,AHP处理使藕渣IDF的结构发生变化,功能性质得到改善。

关键词：碱性过氧化氢藕渣不溶性膳食纤维结构功能特性

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全球视域下国际形势、粮食安全与中国方案

农业经济与管理 2024年第2期 13-24页

作者：王旖旎吴玲哈尔滨师范大学马克思主义学院哈尔滨150025 东北农业大学马克思主义学院哈尔滨150030 东北农业大学现代农业发展研究中心哈尔滨150030

粮稳天下安。基于全球视角,坚持系统观念,立足世界政治深度调整、经济全球化链条重塑的大势,研判世界粮食安全的新形势与新特点,审视国际形势与我国经济社会深度联动的大局,在中国与世界的互动中把握我国粮食安全发展的新态势,辨析我国... 详细信息

粮稳天下安。基于全球视角,坚持系统观念,立足世界政治深度调整、经济全球化链条重塑的大势,研判世界粮食安全的新形势与新特点,审视国际形势与我国经济社会深度联动的大局,在中国与世界的互动中把握我国粮食安全发展的新态势,辨析我国粮食安全面临的“内忧”与“外患”。研究表明,应积极应对外部环境变化,推进全球粮食治理体系变革,坚守“立足国内、以我为主”的粮食安全观,提升全球粮食市场掌控能力,全方位夯实粮食安全根基,从顶层设计和战略维度擘画确保粮食安全的中国方案,努力提升粮食安全保障水平。

关键词：国际形势粮食安全食物安全粮食安全战略

Comparison of engineering failures and seismic responses of 500 kV transformer-bushing systems in the 2022 Luding earthquake

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 1029-1041页

作者： Zhu wang Wu Ming’er Xie Qiang Department of Structural Engineering Tongji UniversityShanghai 200092China Key Laboratory of Performance Evolution and Control for Engineering Structures(Tongji University) Shanghai 200092China

Cemented and mechanically clamped types of end fittings(fitting-C and fitting-M)are commonly used in transformer *** the Luding Ms 6.8 earthquake that occurred in China on September 5,2022,all transformer bushings with the two types of end fittings in a 500 kV substation were ***-earthquake field investigations were conducted,and the failures of the two types of bushings were *** elementary simulation models of the transformer-bushing systems were developed to simulate the engineering failures,and further compute their seismic responses for *** results indicate that the hitch lugs of the connection flange are structurally harmful to seismic ***-M can decrease the bending stiffness of the bushing due to the flexible sealing rubber *** it provides a more flexible connection that dissipates energy,the peak accelerations and relative displacements at the top of the bushing are significantly lower than those of the bushing with *** with fitting-C,fitting-M transfers the high-stress areas from the connection flange to the root of the porcelain,so the latter becomes the most vulnerable ***-M increases the failure risk of the low-strength porcelain,indicating the unsuitability of applying it in high-intensity fortification regions.

关键词： transformer bushing end fitting Luding earthquake,engineering failure seismic responses

Double Moving Extremes Ranked Set Sampling Design

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 75-90页

作者： Meng Chen wang-xue Chen Rui yang Department of Mathematics and Statistics Jishou UniversityJishou416000China

The traditional simple random sampling(SRS)design method is inefficient in many *** proposed some new designs to increase *** this paper,as a variation of moving extremes ranked set sampling(MERSS),double MERSS(DMERSS)is proposed and its properties for estimating the population mean are *** turns out that,when the underlying distribution is symmetric,DMERSS gives unbiased estimators of the population ***,it is found that DMERSS is more efficient than the SRS and MERSS methods for usual symmetric distributions(normal and uniform).For asymmetric distributions considered in this study,the DMERSS has a small bias and it is more efficient than SRS for usual asymmetric distribution(exponential)for small sample sizes.

关键词： double moving extremes ranked set sampling symmetric distribution efficiency

Spatial impact of digital finance on carbon productivity

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Geoscience Frontiers 2024年第3期15卷 358-372页

作者： Huaping Sun Tingting Chen Christoph Nedopil wang School of Finance and Economics Jiangsu UniversityZhenjiangChina School of Economics and Management University of Science and Technology BeijingBeijingChina Fanhai International School of Finance Fudan UniversityShanghaiChina

Low carbon productivity has been identified as a key direction for China’s future *** an important driving force for economic growth,the question of whether digital finance that is reliant on digital technology can support the development of a low-carbon urban economy remains *** on the carbon productivity measured by panel data from 201 cities for the period 2011-2020,this study applies the spatial Dubin model and threshold regression model to explore the impact of digital finance on carbon productivity,yielding the following key ***,the spatial distribution heterogeneity of carbon productivity in China’s eastern region is higher than that in the western region,and both productivity and digital finance are characterized by high(low)-high(low)dotted spatial ***,digital finance can significantly improve carbon productivity via two transmission channels:the human capital and marketization *** the same time,digital finance exerts a spatial spillover effect on carbon productivity,and rising local digital finance levels will increase carbon productivity in neighboring *** analysis indicates that the spillover effect of digital finance in urban agglomerations and eastern regions is more ***,fixed-asset investment has a positive nonlinear moderating effect on digital finance,thus improving carbon *** the per capita investment in fixed assets does not exceed 682.73 yuan,digital finance exerts only a limit pulling effect on carbon productivity;when it is higher than this value,the pulling effect is intensified.

关键词： Digital finance Carbon productivity Spatial spillover effect Fixed-asset investment Spatial heterogeneity

Physical layer security of FSO communication system based on G-G correlation channel

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Optoelectronics Letters 2024年第11期20卷 658-662页

作者： ZHONG Ruijing JI Jianhua wang Zhenhong wang Ke SONG Yufeng College of Electronics and Information Engineering Shenzhen University

In this paper, the eavesdropping model based on eavesdroppers near legitimate users, and the effect of atmospheric channel correlation on the physical layer security(PLS) of the free-space optical(FSO) link are analyzed.

关键词： A