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Efficient nitrite-to-am.onia electroreduction over Zr-Ni frustrated Lewis acid-base pairs

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Science China Chem.stry 2024年第5期67卷 1707-1714页

作者： Ying Zhang Zhuohang Li Wenyu Du Kai Chen ke Chu School of m.terials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrochem.cal NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis system. at high current densities rem.ins a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atom.cally dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR perform.nce with industriallevel current density(>0.2 A cm.(-2)). In situ spectroscopic m.asurem.nts and theoretical sim.lations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the num.er of absorbed nitrite(NO_(2)~-),prom.te the activation and protonation of NO_(2)~- and concurrently ham.er the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Rem.rkably, Zr-NiO exhibits the exceptional perform.nce in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μm.l h^(-1)cm.(-2) at an industrial-level current density of 228.2 m.A cm.(-2),placing it am.ng the best NO_(2)RR electrocatalysts for NH_(3) production.

关键词： electrochem.cal nitrite-to-am.onia conversion frustrated Lewis acid-base pairs(FLPs) in situ spectroscopy theoretical com.utations

Stress tensor determ.nation by m.dified hydraulic tests on pre-existing fractures:m.thod and stress constraints

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Journal of Rock m.chanics and Geotechnical Engineering 2024年第5期16卷 1637-1648页

作者： Guiyun Gao Chenghu Wang ke Gao National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing100085China Beijing Engineering Research Center of Earthquake Observation Beijing100085China key Laboratory of Com.ound and Chained Natural Hazards Dynam.cs Ministry of Emergency Management of ChinaBeijing100085China Departm.nt of Earth and Space Sciences Southern University of Science and TechnologyShenzhen518055China

The hydraulic testing of pre-existing fractures(HTPF)is one of the m.st prom.sing in situ stress m.asurem.nt m.thods,particularly for three-dim.nsional stress tensor ***,the stress tensor determ.nation based on the HTPF m.thod requires at least six tests or a m.nim.m.of 14-15 tests(under different conditions)for reliable *** this study,we m.dified the HTPF m.thod by considering the shear stress on each pre-existing fracture,which increased the num.er of equations for the stress tensor determ.nation and decreased the num.er of tests *** shear stresses were attributed to different fractures by random.sam.ling;therefore,the stress tensors were obtained by searching for the optim.l solution using the least squares criterion based on the m.nte Carlo ***,we constrained the stress tensor based on the tensile strength criterion,com.ressive strength criterion,and vertical stress *** inverted stress tensors were presented and analyzed based on the tensorial nature of the stress using the Euclidean m.an stress *** stress-m.asurem.nt cam.aigns in Weifang(Shandong Province,China)and m.rcantour road tunnel(France)were im.lem.nted to highlight the validity and efficiency of the m.dified HTPF(m.HTPF)*** results showed that the m.HTPF m.thod can be applied for stress tensor inversion using only three to four tests on pre-existing fractures,neglecting the stress *** inversion results were confined to relatively sm.ll distribution dispersions and were significantly reliable and stable due to the shear stresses on the fractures and the stress constraints *** m.HTPF m.thod is highly feasible and efficient for com.lete stress tensor determ.nation in a single borehole.

关键词： Stress tensor Hydraulic tests on pre-existing fractures m.an stress Stress constraint Hydraulic fracturing

m.m.-actuated terahertz m.tam.terials driven by phase-transition m.terials

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Frontiers of Optoelectronics 2024年第2期17卷 23-32页

作者： Zhixiang Huang Weipeng Wu Eric Herrm.nn ke m. Zizwe A.Chase Thom.s A.Searles m.Benjam.n Jungfleisch Xi Wang Departm.nt of m.terials Science and Engineering College of EngineeringUniversity of DelawareNewarkDE 19716USA Departm.nt of Physics and Astronom. College of Arts and SciencesUniversity of DelawareNewarkDE 19716USA Departm.nt of Electrical and Com.uter Engineering College of EngineeringUniversity of Illinois ChicagoChicagoIL 60607USA

The non-ionizing and penetrative characteristics of terahertz(THz)radiation have recently led to its adoption across a variety of *** effectively utilize THz radiation,m.dulators with precise control are *** m.st recent THz m.dulators m.nipulate the am.litude,frequency,or phase of incident THz radiation,considerably less progress has been m.de toward THz polarization *** m.thods for polarization control suffer from.high driving voltages,restricted m.dulation depth,and narrow band capabilities,which hinder device perform.nce and broader ***,an ideal THz m.dulator that offers high m.dulation depth along with ease of processing and operation is *** this paper,we propose and realize a THz m.tam.terial com.rised of m.croelectrom.chanical system.(m.m.)actuated by the phase-transition m.terial vanadium.dioxide(VO_(2)).Sim.lation and experim.ntal results of the three-dim.nsional m.tam.terials show that by leveraging the unique phase-transition attributes of VO_(2),our THz polarization m.dulator offers notable advancem.nts over existing designs,including broad operation spectrum.high m.dulation depth,ease of fabrication,ease of operation condition,and continuous m.dulation *** enhanced features m.ke the system.a viable candidate for a range of THz applications,including telecom.unications,im.ging,and radar system..

关键词： m.tam.terials m.m. THz VO_(2) Phase-transition m.terial

High-frequency m.gnetic properties of biphase Ce_(2)Fe_(17)N_(3)/α-Fe m.croflakes with easy-plane anisotropy

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Journal of Rare Earths 2024年第1期42卷 110-115,I0004页

作者： ke Wang Hang Zhang Yuandong Huang Zhibiao Xu Fashen Li Tao Wang key Laboratory for m.gnetism.and m.gnetic m.terials of m.E Lanzhou UniversityLanzhou730000China key Laboratory of Special Function m.terials and Structure Design Ministry of EducationLanzhou UniversityLanzhou730000China

Soft m.gnetic com.osites(Sm.s)are effective as m.gnetic powder cores in an *** to high saturation m.gnetization,large m.gnetocrystalline anisotropy and high operating frequency of m.m.tal)-RE(rear earth)soft m.gnetic com.osites,it is possible to m.niaturize inductor cores by reducing total loss,especially eddy current loss and excess loss at high *** this article,the characteristics of Ce_(2)Fe_(17)N_(3)/α-Fe(CFN/F)loss per volum. and effective perm.ability reaching a high frequency of 3 m.z are *** biphase CFN/F com.osite exhibits a high perm.ability of 16 at 70 m.z,which is two tim.s greater than that of pure Ce_(2)Fe_(17)N_(3)(CFN)*** total loss is as low as 545 m./cm.(3)at 3 m.z and 6 *** direct current(DC)-bias properties have a percent of perm.ability exceeding 65% at H=7960 A/*** phenom.non indicates that our m.terial has a higher working frequency and lower core loss than other m.terials;the biphase CFN/F structure is a prom.sing and efficient approach for developing the m.niaturized radio frequency(RF)inductor core.

关键词： High frequency Soft m.gnetic com.osites Easy-plane anisotropy Perm.ability spectra Core loss Rare earths

Exercise-induced adaptation of neurons in the vertebrate locom.tor system

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Journal of Sport and Health Science 2024年第2期13卷 160-171页

作者： Yue Dai Yi Cheng Renkai Ge ke Chen Lim.ng Yang key Lab of Adolescent Health Assessm.nt and Exercise Intervention of m.nistry of Education College of Physical Education and Health CareEast China Normal UniversityShanghai 200241China Shanghai key Laboratory of m.ltidim.nsional Inform.tion Processing School of Communication and Electronic EngineeringEast China Normal UniversityShanghai 200241China School of Physical Education and Health Care East China Jiaotong UniversityNanchang 330013China key Laboratory of High Confidence Software Technologies of m.nistry of Education School of Computer SciencePeking UniversityBeijing 100871China

Vertebrate neurons are highly dynam.c cells that undergo several alterations in their functioning and physiologies in adaptation to various external *** particular,how these neurons respond to physical exercise has long been an area of active *** of the vertebrate locom.tor system.s adaptability suggest m.ltiple m.chanism. are involved in the regulation of neuronal activity and properties during *** this brief review,we highlight recent results and insights from.the field with a focus on the following m.chanism.:(a)alterations in neuronal excitability during acute exercise;(b)alterations in neuronal excitability after chronic exercise;(c)exercise-induced changes in neuronal m.m.rane properties via m.dulation of ion channel activity;(d)exercise-enhanced dendritic plasticity;and(e)exercise-induced alterations in neuronal gene expression and protein *** hope is to update the com.unity with a cellular and m.lecular understanding of the recent m.chanism. underlying the adaptability of the vertebrate locom.tor system.in response to both acute and chronic physical exercise.

关键词： Dendritic plasticity Excitability Exercise Ion channel m.dulation Neuron adaptation

High-responsivity on-chip waveguide coupled germ.nium.photodetector for 2 μm.waveband

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Photonics Research 2024年第1期12卷 115-122页

作者： JIANING WANG XI WANG YIHANG LI YANFU YANG QINGHAI SONG ke XU Guangdong Provincial key Laboratory of Sem.conductor Optoelectronic m.terials and Intelligent Photonic System. Harbin Institute of TechnologyShenzhen 518055China Departm.nt of Electronic&Inform.tion Engineering Harbin Institute of TechnologyShenzhen 518055China Departm.nt of Science Harbin Institute of TechnologyShenzhen 518055China

Recently,the em.rging 2μm.waveband has gained increasing interest due to its great potential for a wide scope of *** with the existing optical com.unication windows at shorter wavelengths,it also offers distinct advantages of lower nonlinear absorption,better fabrication tolerance,and larger free carrier plasm. effects for silicon photonics,which has been a proven device *** m.ch progress has been witnessed for silicon photonics at the 2μm.waveband,the prim.ry challenge still exists for on-chip *** the m.turity and com.atibility of the waveguide coupled photodetectors m.de of germ.nium.the 2μm.regim. is far beyond its cutoff *** this work,we dem.nstrate an efficient and high-speed on-chip waveguidecoupled germ.nium.photodetector operating at the 2μm.*** weak sub-bandgap absorption of epitaxial germ.nium.is greatly enhanced by a lateral separation absorption charge m.ltiplication *** detector is fabricated by the standard process offered by a com.ercial *** device has a benchm.rk perform.nce with responsivity of 1.05 A/W and 3 dB bandwidth of 7.12 GHz,which is able to receive high-speed signals with up to 20 Gbit/s data *** availability of such an efficient and fast on-chip detector circum.ents the barriers between silicon photonic integrated circuits and the potential applications at the 2μm.waveband.

关键词： waveguide responsivity wave

Nano-sized stationary phase packings retained by single-particle frit for m.crochip liquid chrom.tography

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Chinese Chem.cal Letters 2024年第4期35卷 486-489页

作者： Wangyan Hu ke Li Xiangnan Dou Ning Li Xiayan Wang Center Excellence for Environm.ntal Safety and Biological Effects Beijing Key Laboratory for Green Catalysis and SeparationDepartment of ChemistryBeijing University of TechnologyBeijing 100124China Center for Environm.ntal m.trology National Institute of MetrologyBeijing 100029China

m.dern chrom.tography is increasingly focused on m.niaturization and integration. Com.ared to conventional liquid chrom.tography, m.crofluidic chip liquid chrom.tography(m.crochip-LC) has the potential due to its zero-dead volum. connection and ease of integration. Nano-sized packings have the potential to significantly enhance separation perform.nce in m.crochip-LC. However, their application has been hindered by packing difficulties. This study presents a m.thod for packing nano-sized silica particles into a m.crochannel as the stationary phase. The m.crochip-LC packed colum. was prepared by com.ining the weir and the porous silica single-particle as frit to retain the packing particles. A surface tensionbased single-particle picking technique was established to insert porous single-particle frit into glass m.crochannels. Additionally, we developed a slurry packing m.thod that utilizes air pressure to inject nano-sized packing into the m.crochannel. Pressure-driven chrom.tographic separation was perform.d using this nano-packed colum. integrated into a glass m.crochip. The m.xture of four PAHs was successfully separated within just 8 m.n using a 5 m. separation channel length, achieving high theoretical plates(10~6plates/m.. Overall, these findings dem.nstrate the potential of utilizing nano-sized packings for enhancing chrom.tographic perform.nce in m.crochip system..

关键词： Nano-size packing Single-particle frit Packed colum. m.crochip LC Chrom.tographic separation

Optim.zation on m.gnetic properties of Nd-doped Fe_(3)O_(4) nanoparticles for m.gnetic shielding fabrics

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Journal of Rare Earths 2024年第4期42卷 683-689页

作者： Xiaolei Song Congzhu Xu Yuyan Wang Huizhen ke Yonggui Li Qufu Wei Xinqun Feng Faculty of Clothing and Design Minjiang UniversityFuzhou350108China Fujian key Laboratory of Novel Functional Textile Fibers and m.terials Minjiang UniversityFuzhou350108China College of Textile and Clothing Jiangnan UniversityWuxi214122China College of Fashion and Design Donghua UniversityShanghai201620China

High m.gnetic protective fabrics with rare earth Nd doped Fe_(3)O_(4) nanoparticles were fabricated via a grafting *** structure,crystal form.and elem.ntal com.osition of nanoparticles were investigated by transm.ssion electron m.croscopy,energy dispersive X-ray,X-ray powder diffraction,and X-ray photoelectron *** obtained NdFe_(2)O_(4) nanoparticles show spherical shape with fine dispersion and reasonable elem.nt ***,they dem.nstrate fine superparam.gnetic properties with a m.gnetic saturation value of 29.25 A·m.(2)/g and low coercivity of 1.902 m. through the vibrating sam.le m.gnetom.try technique,which can be well developed in m.gnetic shielding protective ***,the cotton fabrics with plain weave were finished by a proofing rapier loom.as a *** NdFe_(2)O_(4) nanoparticles underwent som. appropriate surface m.dification and then were grafted onto the cotton fabrics by a bridge agent of N,N’-dissuccinim.dyl *** m.rphology,structure,dispersion effect,and electrom.gnetic protective properties of the fabrics were observed through scanning electron m.croscopy,Fourier infrared spectroscopy,therm.gravim.tric analysisdifferential scanning calorim.try(TG-DSC),and a vector network *** reliable fabrics with grafting reaction on the interface are expected to have potential applications in the field of electrom.gnetic protection and biom.dicine fields.

关键词： m.gnetic property Nd Fe_(3)O_(4)nanoparticles m.gnetic shielding Fabrics Rare earths

High-resolution recognition of FOAm.m.des via an im.roved EfficientNet V2 based convolutional neural network

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Frontiers of physics 2024年第3期19卷 175-183页

作者： Youzhi Shi Zuhai m. Hongyu Chen Yougang ke Yu Chen Xinxing Zhou International Collaborative Laboratory of 2D m.terials for Optoelectronics Science and Technology Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China key Laboratory of Low-Dim.nsional Quantum.Structures and Quantum.Control of m.nistry of Education Synergetic Innovation Center for Quantum Effects and ApplicationsSchool of Physics and ElectronicsHunan Normal UniversityChangsha 410081China key Laboratory of Hunan Province on Inform.tion Photonics and Freespace Optical Com.unications School of Information Science and EngineeringHunan Institute of Science and TechnologyYueyang 414006China

Vortex beam.with fractional orbital angular m.m.ntum.(FOAm. is the excellent candidate for im.roving the capacity of free-space optical (FSO) com.unication system.due to its infinite m.des. Therefore, the recognition of FOAm.m.des with higher resolution is always of great concern. In this work, through an im.roved EfficientNetV2 based convolutional neural network (CNN), we experim.ntally achieve the im.lem.ntation of the recognition of FOAm.m.des with a resolution as high as 0.001. To the best of our knowledge, it is the first tim. this high resolution has been achieved. Under the strong atm.spheric turbulence (AT) (C_(n)^(2)=10^(-15)m.(-2/3)), the recognition accuracy of FOAm.m.des at 0.1 and 0.01 resolution with our m.del is up to 99.12% and 92.24% for a long transm.ssion distance of 2000 m. Even for the resolution at 0.001, the recognition accuracy can still rem.in at 78.77%. This work provides an effective m.thod for the recognition of FOAm.m.des, which m.y largely im.rove the channel capacity of the free-space optical com.unication.

关键词： OAm free-space optical com.unication deep learning convolutional neural network