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Influence of Kerr Effect on Second-Order Nonlinearity Induced Transparency

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Wuhan university Journal of Natural Sciences 2024年第1期29卷 67-73页

作者： ZHANG Zhiqiang ZHOU yanhui College of Architectural Engineering Zhengzhou Business UniversityZhengzhou 451200HenanChina Quantum Information research Center Shangrao Normal UniversityShangrao 334001JiangxiChina

We theoretically study the effect of Kerr effect on the second-order nonlinearity induced transparency in a double-resonant optical cavity *** show that in the presence of the Kerr effect,as the strength of the Kerr effect increases,the absorption curve exhibits an asymmetric-symmetric-asymmetric transition,and the zero absorption point shifts with the increase of the Kerr ***,by changing the strength of the Kerr effect,we can control the width of the transparent window,and the position of the zero-absorption point and meanwhile change the left and right width of the absorption *** asymmetry absorption curve can be employed to improve the quality factor of the cavity when the frequency detuning is tuned to be around the right *** simple dependence of the zeroabsorption point on the strength of Kerr effect suggests that the strength of Kerr effect can be measured by measuring the position of the zero-absorption point in a possible application.

关键词： Kerr effect second-order nonlinearity induced transparency nonlinear optics quantum optics

Two Peaks of Seasonal Influenza Epidemics -china, 2.2.

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china CDC weekly 2024年第36期6卷 905-910页

作者： Yiran Xie Shuxia Lin Xiaoxu Zeng Jing Tang yanhui Cheng Weijuan Huang Jiandong Li Dayan wang National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Disease National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina.

Introduction:Influenza is a communicable respiratory disease that causes annual epidemics and occasional unpredictable *** study examines the occurrence of two unexpected influenza peaks within the year ***:Influenza-like illness(ILI)data were reported,and specimens of ILI were collected by designated surveillance *** cases were confirmed using real-time reverse transcription polymerase chain reaction(rRT-PCR)testing conducted at national surveillance network *** data were then submitted to the Chinese Influenza Surveillance Information ***:From December 2.2. to January 2.2.,influenza activity was minimal until a spring epidemic began in February,peaking in late *** outbreak spread from the north to the south,with A(H1N1)pdm09 being the predominant strain and A(H3N2.also circulating *** positivity rate in northern and southern provincial-level administrative divisions(PLADs)reached 60.0%(week 10)and 60.2.(week 13),respectively,before dropping to below 5%from May to ***,rates surged starting in week 41 in the south and week 44 in the north,peaking at 54.4%(week 50)and 44.0%(week 49),respectively,and remained high until the end of 2.2..A(H3N2.became the prevailing strain,with a notable increase in B/Victoria lineage viruses from December,resulting in two peaks during the 2.2. influenza ***:The pattern of the influenza epidemic shifted due to the coronavirus disease 2.19(COVID-19)outbreak and is gradually returning to its usual seasonal and intensity *** is,therefore,crucial to continuously strengthen influenza surveillance,enhance the influenza surveillance network,and lay the groundwork for advancing integrated surveillance of multiple pathogens in china.

关键词： prevailing surveillance Influenza

Dual-objective two-photon microscope for volumetric imaging of dense scattering biological samples by bidirectional excitation and collection

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Photonics research 2024年第6期12卷 1351-1361页

作者： MUYUE ZHAI JING YU yanhui HU HANG YU BEICHEN XIE YI YU DAWEI LI AIMIN wang HEPING CHENG National Biomedical Imaging Center College of Future TechnologyPeking UniversityBeijing 100871China research Unit of Mitochondria in Brain Diseases Chinese Academy of Medical SciencesPKU-Nanjing Institute of Translational MedicineNanjing 211500China Beijing Transcend Vivoscope Biotech Beijing 100085China College of Engineering Peking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China Center for Quantitative Biology Peking UniversityBeijing 100871China School of Electronics Peking UniversityBeijing 100871China State Key Laboratory of Advanced Optical Communication System and Networks Peking UniversityBeijing 100871China

Full view observation throughout entire specimens over a prolonged period is crucial when exploring the physiological functions and system-level ***-photon microscopy(MPM)has been widely employed for such purposes owing to its deep penetration ***,the current MPM struggles with balancing the imaging depth and quality while avoiding photodamage for the exponential increasement of excitation power with the imaging ***,we present a dual-objective two-photon microscope(Duo-2.),characterized by bidirectional two-photon excitation and fluorescence collection,for long-duration volumetric imaging of dense scattering ***-2. effectively doubles the imaging depth,reduces the total excitation energy by an order of magnitude for samples with a thickness five times the scattering length,and enhances the signal-to-noise ratio up to 1.4 *** these advantages,we acquired volumetric images of a 380-μm suprachiasmatic nucleus slice for continuous 4-h recording at a rate of 1.67 s/volume,visualized the calcium activities over 4000 neurons,and uncovered their state-switching *** conclude that Duo-2. provides an elegant and powerful means to overcome the fundamental depth limit while mitigating photodamages for deep tissue volumetric imaging.

关键词： excitation overcome exponential

Generation of input spectrum for electrolysis stack degradation test applied to wind power PEM hydrogen production

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Global Energy Interconnection 2024年第4期7卷 462-474页

作者： yanhui Xu Guanlin Li Yuyuan Gui Zhengmao Li School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206P.R.China School of Electrical Engineering Aalto UniversityFinland

Hydrogen production by proton exchange membrane electrolysis has good fluctuation adaptability,making it suitable for hydrogen production by electrolysis in fluctuating power sources such as wind ***,current research on the durability of proton exchange membrane electrolyzers is *** the typical operating conditions of wind power electrolysis for hydrogen production can provide boundary conditions for performance and degradation tests of electrolysis *** this study,the operating condition spectrum of an electrolysis stack degradation test cycle was *** on the rate of change of the wind farm output power and the time-averaged peak-valley difference,a fluctuation output power sample set was *** characteristic quantities that played an important role in the degradation of the electrolysis stack were *** reduction of the operating data was performed using principal component *** analysis of the data segments was completed using an improved Gaussian mixture clustering *** the annual output power data of wind farms in Northwest china with a sampling rate of 1 min as an example,the cyclic operating condition spectrum of the proton-exchange membrane electrolysis stack degradation test was *** preliminary simulation analysis,the typical operating condition proposed in this paper effectively reflects the impact of the original curve on the performance degradation of the electrolysis *** study provides a method for evaluating the degradation characteristics and system efficiency of an electrolysis stack due to fluctuations in renewable energy.

关键词： Hydrogen production by electrolysis of water Wind power Proton exchange membrane electrolyzer Gaussian mixture model Cyclic operating condition

Tuning interaction strength between CeO_(2. and iridium to promote CO oxidation over Ir/TiO_(2.

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Journal of Rare Earths 2024年第4期42卷 651-659页

作者： Lu Dai Binghua Li Yuhan Peng Xianwei Hao Runquan Xuan Hua Huang Yiming Bi Liping Xu yanhui Zhang Yun Guo Fangqi Du Li wang Hui wang Technology Center China Tobacco Zhejiang Industrial Co.Ltd.Hangzhou310024China research institute of Industrial Catalysis East China University of Science and TechnologyShanghai200237China

The interaction between support and noble metal plays a crucial role in heterogeneous catalysis ***,how to tune metal support interactions to optimize the activity still needs further ***_(2. was introduced to promote CO oxidation ove r Ir/TiO_(2. by adjusting the interaction strength between iridium(Ir)and CeO_(2..The strong interaction between Ir and CeO_(2. blocks CO adsorption and causes low CO oxidation ***,introducing CeO_(2. on Ir/TiO_(2. produces localized interaction between Ir and CeO_(2.,which can tune the surface electronic state of Ir,so a"volcano curve"relationship between CO oxidation activity and electronic state is *** amount of CeO_(2. on Ir/TiO_(2.(Ir/Ce_(0.2.Ti)leads to CO complete oxidization at 2.℃,and a new pathway for CO oxidation was *** study demonstrates that the utilization of tuning interaction strength between active metal and support is a potential method to increase the catalytic activity.

关键词： CO oxidation CeO_(2. Localized interaction Interaction strength Supported Ir catalysts Rareearths

The transition from 2. to 3G-feedstocks enabled efﬁcient production of fuelsand chemicals

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Green Energy & Environment 2024年第11期9卷 1759-1770页

作者： Kai wang Changsheng Su Haoran Bi Changwei Zhang Di Cai yanhui Liu Meng wang Biqiang Chen Jens Nielsen Zihe Liu Tianwei Tan College of Life Science and Technology Beijing University of Chemical TechnologyBeijing Advanced Innovation Center for Soft Matter Science and EngineeringNo.15 North 3rd Ring Rd EastBeijing100029China National Energy R&D Center for Biorefnery Beijing Key Lab of BioprocessBeijing University of Chemical TechnologyNo.15 North 3rd Ring Rd EastBeijing100029China Department of Life Sciences Chalmers University of TechnologyGothenburgSE41296Sweden

For decades micoorganisms have been engineered for the utilization of lignocellulose-based second-generation (2.) feedstocks, but with theconcerns of increased levels of atmospheric CO_(2. causing global warming there is an emergent need to transition from the utilization of 2.feedstocks to third-generation (3G) feedstocks such as CO_(2. and its derivatives. Here, we established a yeast platform that is capable ofsimultaneously converting 2. and 3G feedstocks into bulk and value-added chemicals. We demonstrated that by adopting 3G substrates such asCO_(2. and formate, the conversion of 2. feedstocks could be substantially improved. Speciﬁcally, formate could provide reducing power andenergy for xylose conversion into valuable chemicals. Simultaneously, it can form a concentrated CO_(2. pool inside the cell, providing thermodynamically and kinetically favoured amounts of precursors for CO_(2. ﬁxation pathways, e.g., the Calvin–Benson–Bassham (CBB) ***, we demonstrated that formate could directly be utilized as a carbon source by yeast to synthesize endogenous amino acids. Theengineered strain achieved a one-carbon (C1) assimilation efﬁciency of 9.2., which was the highest efﬁciency observed in the co-utilization of2. and 3G feedstocks. We applied this strategy for productions of both bulk and value-added chemicals, including ethanol, free fatty acids(FFAs), and longifolene, resulting in yield enhancements of 18.4%, 49.0%, and ~100%, respectively. The strategy demonstrated here for coutilization of 2. and 3G feedstocks sheds lights on both basic and applied research for the up-coming establishment of 3G bioreﬁneries.

关键词： transition utilized Benson

Atomic-level insights into the initial oxidation mechanism of high-entropy diborides by first-principles calculations

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Journal of Materiomics 2024年第2期10卷 423-430页

作者： Yiwen Liu Hulei Yu Hong Meng yanhui Chu School of Materials Science and Engineering South China University of TechnologyGuangzhou510641China

Understanding the initial oxidation mechanism is critical for studying the oxidation resistance of high-entropy ***,related studies are ***,the initial oxidation mechanism of(Zr_(0.2.)Ti_(0.2.)Nb_(0.2.)Ta_(0.2.))B_(2.high-entropy diborides(HEB_(2.-1)is investigated by first-principles calculations at the atomic *** employing the two-region model method,the most stable surface of HEB_(2.-1 is determined to be(112.)*** dissociative adsorption process of the oxygen molecule on the HEB_(2.-1-(112.)surface is predicted to proceed spontaneously,where OeO bond breaks and each oxygen atom is chemisorbed on the most preferable hollow *** adsorption energy and the diffusion barrier of the oxygen atom on the(112.)surface of HEB_(2.-1 are in the vicinity of the average level of the cor-responding four individual *** addition,ab initio molecular dynamics simulations indicate a high initial oxidation resistance of HEB_(2.-1 at 1000 *** results are beneficial to further designing the high-entropy diborides with excellent oxidation resistance.

关键词： High-entropy diborides Oxidation First-principles calculations

Introducing sulfur to nickel-iron selenide for high-efficiency alkaline seawater electrolysis

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Science china Chemistry 2024年第8期67卷 2747-2754页

作者： Xuanwa Chen yanhui Yu Xingqi Han Huan wang Yingjie Hua Daoxiong Wu Peilin Deng Juanxiu Xiao Xinlong Tian Jing Li School of Marine Science and Engineering Hainan Provincial Key Lab of Fine ChemistrySchool of Chemistry and Chemical EngineeringHainan UniversityHaikou 570228China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province School of Chemistry and Chemical EngineeringHainan Normal UniversityHaikou 571158China

Seawater electrolysis is an effective way to obtain hydrogen(H_(2.)in a sustainable ***,the lack of electrocatalysts with high activity,stability,and selectivity for oxygen evolution reaction(OER)severely hinders the development of seawater electrolysis ***,sulfur-doped nickel-iron selenide nanosheets(S-NiFeSe_(2.)were prepared by an ion-exchange strategy and served as highly active OER electrocatalyst for alkaline seawater *** overpotential is 367 m V,and it can run stably for over 50 h at 100 m A cm^(-2..Excitingly,the S-NiFeSe_(2.||Pt/C pair exhibits cell voltage of 1.54 V at 10 m A cm^(-2.under alkaline seawater conditions,which can run smoothly for 100 h without decay,and the efficiency of electricity-tohydrogen(ETH)energy conversion reaches more than 80%.Such electrode,with abundant accessible reactive sites and good corrosion resistance,is a good candidate for seawater ***,density functional theory calculations reveal that the surface sulfur atoms can activate the adjacent Ni sites and decrease the free energy changes of the associated intermediates at the adjacent Ni sites for OER,and the step of~*OH→~*O is the potential rate-limiting *** this work,the true reactive site in nickel-iron selenides is the Ni sites,but not the Fe sites as commonly believed.

关键词： S-doping nickel-iron selenide electrocatalysts oxygen evolution reaction alkaline seawater electrolysis

In situ single iron atom doping on Bi_(2.WO_(6)monolayers triggers efficient photo-fenton reaction

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Environmental Science and Ecotechnology 2024年第4期20卷 315-322页

作者： Wei Liu Peifang wang Juan Chen Xin Gao Huinan Che Xiaozhi Su Bin Liu yanhui Ao Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes Ministry of EducationCollege of EnvironmentHohai UniversityNo.1Xikang RoadNanjing210098China School of Chemical and Biomedical Engineering Nanyang Technological UniversitySingapore637459Singapore Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201204China

Developing an efficient photocatalytic system for hydrogen peroxide(H_(2.O_(2.)activation in Fenton-like processes holds significant promise for advancing water purification ***,challenges such as high carrier recombination rates,limited active sites,and suboptimal H_(2.O_(2.activation efficiency impede optimal *** we show that single-iron-atom dispersed Bi_(2.WO_(6)monolayers(SIAD-BWOM),designed through a facile hydrothermal approach,can offer abundant active sites for H_(2.O_(2.*** SIAD-BWOM catalyst demonstrates superior photo-Fenton degradation capabilities,particularly for the persistent pesticide dinotefuran(DNF),showcasing its potential in addressing recalcitrant organic *** reveal that the incorporation of iron atoms in place of tungsten within the electron-rich[WO_(4)]^(2.)layers significantly facilitates electron transfer processes and boosts the Fe(II)/Fe(III)cycle *** experimental investigations and theoretical analyses further elucidate how the atomically dispersed iron induces lattice strain in the Bi_(2.WO_(6)monolayer,thereby modulating the d-band center of iron to improve H_(2.O_(2.adsorption and *** research provides a practical framework for developing advanced photo-Fenton catalysts,which can be used to treat emerging and refractory organic pollutants more effectively.

关键词： H_(2.O_(2.activation Water treatment Bismuth tungstate Photo-fenton catalysts Emerging organic pollutants