The acoustic properties of anechoic layers with a singly periodic array of cylindrical scatterers are investigated. A method combined plane wave expansion and finite element analysis is extended for out-of-plane incid...The acoustic properties of anechoic layers with a singly periodic array of cylindrical scatterers are investigated. A method combined plane wave expansion and finite element analysis is extended for out-of-plane incidence. The reflection characteristics of the anechoic layers with cavities and locally resonant scatterers are discussed. The backing is a steel plate followed by an air half space. Under this approximate zero transmission backing condition, the reflection reduction is induced by the absorption enhancement. The absorption mechanism is explained by the scattering/absorption cross section of the isolated scatterer. Three types of resonant modes which can induce efficient absorption are revealed. Due to the fact that the frequencies of the resonant modes are related to the size of the scatterers, anechoic layers with scatterers of mixed size can broaden the absorption band. A genetic optimization algorithm is adopted to design the anechoic layer with scatterers of mixed size at a desired frequency band from 2 kHz to l0 kHz for normal incidence, and the influence of the incident angle is also discussed.展开更多
We report a low noise continuous-wave （CW） single-frequency 1.5-μm laser source obtained by a singly resonant optical parametric oscillator （SRO） based on periodically poled lithium niobate （PPLN）. The SRO was ...We report a low noise continuous-wave （CW） single-frequency 1.5-μm laser source obtained by a singly resonant optical parametric oscillator （SRO） based on periodically poled lithium niobate （PPLN）. The SRO was pumped by a CW single-frequency Nd：YVO4 laser at 1.06μm. The 1.02 W of CW single-frequency signal laser at 1.5 μm was obtained at pump power of 6 W. At the output power of around 0.75 W, the power stability was better than ±l.5% and no mode-hopping was observed in 30 min and frequency stability was better than 8.5 MHz in 1 min. The signal wavelength could be tuned from 1.57 to 1.59 μm by varying the PPLN temperature. The 1.5-μm laser exhibits low noise characteristics, the intensity noise of the laser reaches the shot noise limit （SNL） at an analysis frequency of 4 MHz and the phase noise is less than 1 dB above the SNL at analysis frequencies above 10 MHz.展开更多
Linked partitions were introduced by Dykema(Dykema K J. Multilinear function series and transforms in free probability theory. Adv. Math., 2005, 208(1):351–407) in the study of the unsymmetrized T-transform in free p...Linked partitions were introduced by Dykema(Dykema K J. Multilinear function series and transforms in free probability theory. Adv. Math., 2005, 208(1):351–407) in the study of the unsymmetrized T-transform in free probability theory.Permutation is one of the most classical combinatorial structures. According to the linear representation of linked partitions, Chen et al.(Chen W Y C, Wu S Y J, Yan C H. Linked partitions and linked cycles. European J. Combin., 2008, 29(6): 1408–1426) de?ned the concept of singly covered minimal elements. Let L(n, k) denote the set of linked partitions of [n] with k singly covered minimal elements and let P(n, k) denote the set of permutations of [n] with k cycles. In this paper, we mainly establish two bijections between L(n, k) and P(n, k). The two bijections from a different perspective show the one-to-one correspondence between the singly covered minimal elements in L(n, k) and the cycles in P(n, k).展开更多
Bi-f-harmonic maps are the critical points of bi-f-energy functional. This class of maps tends to integrate bi-harmonic maps and f-harmonic maps. In this paper, we show that bi-f-harmonic maps are not only an extensio...Bi-f-harmonic maps are the critical points of bi-f-energy functional. This class of maps tends to integrate bi-harmonic maps and f-harmonic maps. In this paper, we show that bi-f-harmonic maps are not only an extension of f-harmonic maps but also an extension of bi-harmonic maps, and that there should exist many examples of proper bi-f-harmonic maps. In order to find some concrete examples of proper bi-f-harmonic maps, we study the basic properties of bi-f-harmonic maps from two directions which are conformal maps between the same dimensionM manifolds and some special maps from or into a warped product manifold.展开更多
We report on the generation of self-oscillations from a continuously pumped singly resonant frequency doubler based on a periodically poled potassium titanyl phosphate crystal （PPKTP）. The sustained square-wave and ...We report on the generation of self-oscillations from a continuously pumped singly resonant frequency doubler based on a periodically poled potassium titanyl phosphate crystal （PPKTP）. The sustained square-wave and staircase curve of self-oscillations are obtained when the incident pump powers are below and above the threshold of subharmonic-pumped parametric oscillation （SPO）, respectively. The self-oscillations can be explained by the competition between the phase shifts induced by cascading nonlinearity and thermal effect, and the influence of fundamental nonlinear phase shift by the generation of SPO. The simulation results are in good agreement with the experiment data.展开更多
The establishment of an approach to design tunable yellow emission through singly doped single-phased phosphors to obtain white LED-based InGaN chip was reported. BaY2–xS4：xHo3＋ phosphors were prepared by the high ...The establishment of an approach to design tunable yellow emission through singly doped single-phased phosphors to obtain white LED-based InGaN chip was reported. BaY2–xS4：xHo3＋ phosphors were prepared by the high temperature solid state reaction and characterized by X-ray diffraction and photoluminescence spectra. Under the excitation of 465 nm,the emission spectra of these phosphors exhibited three sharp emission lines peaked at about 492,543 and 661 nm of Ho3＋ corresponding to 5F3,5F4 （5S2） and 5F5→5I8 transitions,respectively,with comparable intensities,resulting in a yellow light emission. The luminescence mechanism for Ho3＋ in BaY2S4 was explained.展开更多
By taking full account of the non-orthogonality of the orbitals between the low-lying doubly excited states ^1po and the singly excited states ^1S^e and ^1D^e of He, the corresponding radiative decay rates have been i...By taking full account of the non-orthogonality of the orbitals between the low-lying doubly excited states ^1po and the singly excited states ^1S^e and ^1D^e of He, the corresponding radiative decay rates have been investigated theoretically via analytic generalized Laguerre-type atomic orbitals at a nearly numerical multi-conflguration self-consistent field accuracy in a general non-orthogonal configuration interaction scheme. From these rates, we calculate the VUV photon emission and metastable atom spectra, and both are found to be in good qualitative agreement with recent excellent measurements. We obtain, successfully, the enhancement of the VUV photon spectrum, experimentally observed at the energy of （2s4p-4s2p）/（2p,3d） ^1po as compared with other nearby lying states. The mechanism proposed by Odling-Smee et al is verified, implying that taking appropriate account of the overlap existing between orbitals of the low-lying doubly excited and singly excited states （especially important for the compact orbitals） can reveal basic physical dominant mechanism and is crucial in understanding these spectra.展开更多
High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared...High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared single crystals exhibit a blue band at 480 nm(3P0→3H4), a green band at 522 nm (3P1→3H5), and a red band at 605 nm (1D2→3H4)when excited at 446 nm;their corresponding average lifetimes are 38.5μs, 37.3μs, and 36.8μs, respectively, which are much longer than those in oxide single crystals. The effects of excitation wavelength and doping concentration on emission intensities and chromaticity coordinates are investigated. The optimal Pr3+ concentration is confirmed to be 0.5%.The temperature dependent emission shows that the emission intensity constantly decreases with the increase of temperature from 298 K to 443 K due to the enhancement of nonradiative quenching at high temperature. The 3P0→3H4 transition is the most vulnerable to temperature, followed by the 3P1→3H5 transition and 1D2→3H4 transition.展开更多
The rigorous calculation of the spin-orbit terms in a three-quark system is realized based on the Gaussian expansion method and the infinitesimally-shifted Gaussian basis functions in the framework of the relativized ...The rigorous calculation of the spin-orbit terms in a three-quark system is realized based on the Gaussian expansion method and the infinitesimally-shifted Gaussian basis functions in the framework of the relativized quark model,by ignoring the mixing between different excited states.Then,the complete mass spectra of the singly heavy baryons are obtained rigorously,under the heavy-quark dominance mechanism.Accordingly,systematical analyses are performed for the reliability and predictive power of the model,the fine structure of the singly heavy baryon spectra,the assignments of the excited baryons,and some important topics about heavy baryon spectroscopy,such as the missing states,"spin-orbit puzzle,"and clustering effect.The results confirm that,under the heavy-quark dominance mechanism,the relativized quark model can describe the excitation spectra and the fine structures of the singly heavy baryons correctly and precisely.展开更多
Mid-infrared（MIR） emissions of 2.4 and 3.5 μm from Tm3＋：LiYF4 single crystals attributed to3H4 →3H5 and3H5 →3F4 transitions as well as MIR emissions of 4.2,4.3,and 4.5 μm from Nd3＋：LiYF4 lasers attributed to...Mid-infrared（MIR） emissions of 2.4 and 3.5 μm from Tm3＋：LiYF4 single crystals attributed to3H4 →3H5 and3H5 →3F4 transitions as well as MIR emissions of 4.2,4.3,and 4.5 μm from Nd3＋：LiYF4 lasers attributed to4I15/2 →4I13/2,4I13/2 →4I11/2,and4I11/2 →4I9/2 transitions,respectively,are observed.LiYF4 single crystals possess high transmittance of over 85% in the 2.5-6 μm range.The large emission crosssections of Tm-doped crystals at 2.4 μm（1.9×10-20cm2） and Nd-doped crystals at 4.2 μm（0.84×10-20 cm2） as well as the high rare-earth doping concentrations,excellent optical transmission,and chemicalphysical properties of the resultant samples indicate that Nd3＋and Tm3＋singly doped crystals may be promising materials for application in MIR lasers.展开更多
The b-factories,such as BelleII,BarBar,and LHCb,emphasize the increasing importance of exotic hadron research.In this paper,we discuss the possible production of singly anti-charmed pentaquark states cqqqq from B meso...The b-factories,such as BelleII,BarBar,and LHCb,emphasize the increasing importance of exotic hadron research.In this paper,we discuss the possible production of singly anti-charmed pentaquark states cqqqq from B mesons in a b-factory under SU(3)symmetry analysis.Discussions of both possibilities have been driven by the hypothesis that the pentaquark state considered in this work,known as the lowest lying state P_(c),could be bound or unbound.We find the golden channels for the production of the pentaquark ground states,such as B^(0)→P_(csudu)^((′)0)Σ^(0).We further estimate the branching ratios for the production of the ground states P_(c) from B meson decays.Thus,multiple channels are available for experiments,which may remove certain obstacles to the discovery of new pentaquark states.展开更多
Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection ...Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection challenging,they are linked to problems.Diagnostic methods like imaging and tissue biopsy are only effective when the tumor has reached a size that can be identified.The liquid biopsy technique,the least intrusive and most convenient diagnostic method,is the subject of this review.It focuses on the significance of single cell analysis in examining uncommon cancer types.The many biomarkers found in bodily fluids and the cancer types they are linked to in children have been assessed,as has the potential route towards early detection and cancer recurrence forecasting.Combining the single cell liquid biopsy with the newest technologies,such as computational and multi-omics approaches,which have improved the efficiency of processing massive and unique genetic data,appears promising.This article discusses on a number of case reports for uncommon pediatric malignancies,such as Neuroblastoma,Medulloblastoma,Wilms Tumor,Rhabdomyosarcoma,Ewing Sarcoma,and Retinoblastoma,as well as their liquid biopsy profiles.Furthermore,the findings raise ethical questions regarding the therapeutic application of the technology as well as possible difficulties related to clinical translation.The likelihood that this single cell liquid biopsy will be clinically validated and eventually used as a routine diagnostic tool for uncommon pediatric cancers will rise with the realistic approach to sensitivity monitoring,specificity upgrading,and optimization.展开更多
Unlike mammals,zebrafish possess a remarkable ability to regenerate their spinal cord after injury,making them an ideal vertebrate model for studying regeneration.While previous research has identified key cell types ...Unlike mammals,zebrafish possess a remarkable ability to regenerate their spinal cord after injury,making them an ideal vertebrate model for studying regeneration.While previous research has identified key cell types involved in this process,the underlying molecular and cellular mechanisms remain largely unexplored.In this study,we used single-cell RNA sequencing to profile distinct cell populations at different stages of spinal cord injury in zebrafish.Our analysis revealed that multiple subpopulations of neurons showed persistent activation of genes associated with axonal regeneration post injury,while molecular signals promoting growth cone collapse were inhibited.Radial glial cells exhibited significant proliferation and differentiation potential post injury,indicating their intrinsic roles in promoting neurogenesis and axonal regeneration,respectively.Additionally,we found that inflammatory factors rapidly decreased in the early stages following spinal cord injury,creating a microenvironment permissive for tissue repair and regeneration.Furthermore,oligodendrocytes lost maturity markers while exhibiting increased proliferation following injury.These findings demonstrated that the rapid and orderly regulation of inflammation,as well as the efficient proliferation and redifferentiation of new neurons and glial cells,enabled zebrafish to reconstruct the spinal cord.This research provides new insights into the cellular transitions and molecular programs that drive spinal cord regeneration,offering promising avenues for future research and therapeutic strategies.展开更多
High-throughput transcriptomics has evolved from bulk RNA-seq to single-cell and spatial profiling,yet its clinical translation still depends on effective integration across diverse omics and data modalities.Emerging ...High-throughput transcriptomics has evolved from bulk RNA-seq to single-cell and spatial profiling,yet its clinical translation still depends on effective integration across diverse omics and data modalities.Emerging foundation models and multimodal learning frameworks are enabling scalable and transferable representations of cellular states,while advances in interpretability and real-world data integration are bridging the gap between discovery and clinical application.This paper outlines a concise roadmap for AI-driven,transcriptome-centered multi-omics integration in precision medicine(Figure 1).展开更多
Alzheimer’s disease(AD)is the most common form of dementia.In addition to the lack of effective treatments,there are limitations in diagnostic capabilities.The complexity of AD itself,together with a variety of other...Alzheimer’s disease(AD)is the most common form of dementia.In addition to the lack of effective treatments,there are limitations in diagnostic capabilities.The complexity of AD itself,together with a variety of other diseases often observed in a patient’s history in addition to their AD diagnosis,make deciphering the molecular mechanisms that underlie AD,even more important.Large datasets of single-cell RNA sequencing,single-nucleus RNA-sequencing(snRNA-seq),and spatial transcriptomics(ST)have become essential in guiding and supporting new investigations into the cellular and regional susceptibility of AD.However,with unique technology,software,and larger databases emerging;a lack of integration of these data can contribute to ineffective use of valuable knowledge.Importantly,there was no specialized database that concentrates on ST in AD that offers comprehensive differential analyses under various conditions,such as sex-specific,region-specific,and comparisons between AD and control groups until the new Single-cell and Spatial RNA-seq databasE for Alzheimer’s Disease(ssREAD)database(Wang et al.,2024)was introduced to meet the scientific community’s growing demand for comprehensive,integrated,and accessible data analysis.展开更多
BACKGROUND Transforming growth factor-β(TGF-β)superfamily plays an important role in tumor progression and metastasis.Activin A receptor type 1C(ACVR1C)is a TGF-βtype I receptor that is involved in tumorigenesis th...BACKGROUND Transforming growth factor-β(TGF-β)superfamily plays an important role in tumor progression and metastasis.Activin A receptor type 1C(ACVR1C)is a TGF-βtype I receptor that is involved in tumorigenesis through binding to dif-ferent ligands.AIM To evaluate the correlation between single nucleotide polymorphisms(SNPs)of ACVR1C and susceptibility to esophageal squamous cell carcinoma(ESCC)in Chinese Han population.METHODS In this hospital-based cohort study,1043 ESCC patients and 1143 healthy controls were enrolled.Five SNPs(rs4664229,rs4556933,rs77886248,rs77263459,rs6734630)of ACVR1C were assessed by the ligation detection reaction method.Hardy-Weinberg equilibrium test,genetic model analysis,stratified analysis,linkage disequi-librium test,and haplotype analysis were conducted.RESULTS Participants carrying ACVR1C rs4556933 GA mutant had significantly decreased risk of ESCC,and those with rs77886248 TA mutant were related with higher risk,especially in older male smokers.In the haplotype analysis,ACVR1C Trs4664229Ars4556933Trs77886248Crs77263459Ars6734630 increased risk of ESCC,while Trs4664229Grs4556933Trs77886248Crs77263459Ars6734630 was associated with lower susceptibility to ESCC.CONCLUSION ACVR1C rs4556933 and rs77886248 SNPs were associated with the susceptibility to ESCC,which could provide a potential target for early diagnosis and treatment of ESCC in Chinese Han population.展开更多
Security and safety remain paramount concerns for both governments and individuals worldwide.In today’s context,the frequency of crimes and terrorist attacks is alarmingly increasing,becoming increasingly intolerable...Security and safety remain paramount concerns for both governments and individuals worldwide.In today’s context,the frequency of crimes and terrorist attacks is alarmingly increasing,becoming increasingly intolerable to society.Consequently,there is a pressing need for swift identification of potential threats to preemptively alert law enforcement and security forces,thereby preventing potential attacks or violent incidents.Recent advancements in big data analytics and deep learning have significantly enhanced the capabilities of computer vision in object detection,particularly in identifying firearms.This paper introduces a novel automatic firearm detection surveillance system,utilizing a one-stage detection approach named MARIE(Mechanism for Realtime Identification of Firearms).MARIE incorporates the Single Shot Multibox Detector(SSD)model,which has been specifically optimized to balance the speed-accuracy trade-off critical in firearm detection applications.The SSD model was further refined by integrating MobileNetV2 and InceptionV2 architectures for superior feature extraction capabilities.The experimental results demonstrate that this modified SSD configuration provides highly satisfactory performance,surpassing existing methods trained on the same dataset in terms of the critical speedaccuracy trade-off.Through these innovations,MARIE sets a new standard in surveillance technology,offering a robust solution to enhance public safety effectively.展开更多
Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-perform...Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-performance biomass-derived ORR catalysts with an asymmetric Fe-N_(3)P configuration was prepared by a simple pyrolysis-etching technique,where carboxymethyl cellulose(CMC)was used as the carbon source,urea and 1,10-phenanthroline iron complex(FePhen)as additives,and Na_(3)PO_(4)as the phosphorus dopant and a pore-forming agent.The CMC-derived FeNPC catalyst displayed a large specific area(BET:1235 m^(2)g^(-1))with atomically dispersed Fe-N_(3)P active sites,which exhibited superior ORR activity and stability in alkaline solution(E_(1/2)=0.90 V vs.RHE)and Zn-air batteries(P_(max)=149 mW cm^(-2))to commercial Pt/C catalyst(E_(1/2)=0.87 V,P_(max)=118 mW cm^(-2))under similar experimental conditions.This work provides a feasible and costeffective route toward highly efficient ORR catalysts and their application to Zn-air batteries for energy conversion.展开更多
In contrast to research on active sites in nanomaterials,lithium tantalate single crystals,known for their exceptional optical properties and long-range ordered lattice structure,present a promising avenue for in-dept...In contrast to research on active sites in nanomaterials,lithium tantalate single crystals,known for their exceptional optical properties and long-range ordered lattice structure,present a promising avenue for in-depth exploration of photocatalytic reaction systems with fewer constraints imposed by surface chemistry.Typically,the isotropy of a specific facet provides a perfect support for studying heteroatom doping.Herein,this work delves into the intrinsic catalytic sites for photocatalytic nitrogen fixation in iron-doped lithium tantalate single crystals.The presence of iron not only modifies the electronic structure of lithium tantalate,improving its light absorption capacity,but also functions as an active site for the nitrogen adsorption and activation.The photocatalytic ammonia production rate of the iron-doped lithium tantalate in pure water is maximum 26.95μg cm^(−2)h^(−1),which is three times higher than that of undoped lithium tantalate.The combination of first-principles simulations with in situ characterizations confirms that iron doping promotes the rate-determining step and changes the pathway of hydrogenation to associative alternating.This study provides a new perspective on in-depth investigation of intrinsic catalytic active sites in photocatalysis and other catalytic processes.展开更多
Transition metal carbides,known as MXenes,particularly Ti_(3)C_(2)T_(x),have been extensively explored as promising materials for electrochemical reactions.However,transition metal carbonitride MXenes with high nitrog...Transition metal carbides,known as MXenes,particularly Ti_(3)C_(2)T_(x),have been extensively explored as promising materials for electrochemical reactions.However,transition metal carbonitride MXenes with high nitrogen content for electrochemical reactions are rarely reported.In this work,transition metal carbonitride MXenes incorporated with Pt-based electrocatalysts,ranging from single atoms to sub-nanometer dimensions,are explored for hydrogen evolution reaction(HER).The fabricated Pt clusters/MXene catalyst exhibits superior HER performance compared to the single-atom-incorporated MXene and commercial Pt/C catalyst in both acidic and alkaline electrolytes.The optimized sample shows low overpotentials of 28,65,and 154 mV at a current densities of 10,100,and 500 m A cm^(-2),a small Tafel slope of 29 m V dec^(-1),a high mass activity of 1203 mA mgPt^(-1)and an excellent turnover frequency of 6.1 s^(-1)in the acidic electrolyte.Density functional theory calculations indicate that this high performance can be attributed to the enhanced active sites,increased surface functional groups,faster charge transfer dynamics,and stronger electronic interaction between Pt and MXene,resulting in optimized hydrogen absorption/desorption toward better HER.This work demonstrates that MXenes with a high content of nitrogen may be promising candidates for various catalytic reactions by incorporating single atoms or clusters.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.1100429 and 51275519)
文摘The acoustic properties of anechoic layers with a singly periodic array of cylindrical scatterers are investigated. A method combined plane wave expansion and finite element analysis is extended for out-of-plane incidence. The reflection characteristics of the anechoic layers with cavities and locally resonant scatterers are discussed. The backing is a steel plate followed by an air half space. Under this approximate zero transmission backing condition, the reflection reduction is induced by the absorption enhancement. The absorption mechanism is explained by the scattering/absorption cross section of the isolated scatterer. Three types of resonant modes which can induce efficient absorption are revealed. Due to the fact that the frequencies of the resonant modes are related to the size of the scatterers, anechoic layers with scatterers of mixed size can broaden the absorption band. A genetic optimization algorithm is adopted to design the anechoic layer with scatterers of mixed size at a desired frequency band from 2 kHz to l0 kHz for normal incidence, and the influence of the incident angle is also discussed.
基金supported by the National Natural Science Foundation of China(Grant No.60878003)the Science Fund for Excellent Research Team of the National Natural Science Foundation of China(Grant No.60821004)the National Basic Research Program of China(Grant No.2010CB923101)
文摘We report a low noise continuous-wave （CW） single-frequency 1.5-μm laser source obtained by a singly resonant optical parametric oscillator （SRO） based on periodically poled lithium niobate （PPLN）. The SRO was pumped by a CW single-frequency Nd：YVO4 laser at 1.06μm. The 1.02 W of CW single-frequency signal laser at 1.5 μm was obtained at pump power of 6 W. At the output power of around 0.75 W, the power stability was better than ±l.5% and no mode-hopping was observed in 30 min and frequency stability was better than 8.5 MHz in 1 min. The signal wavelength could be tuned from 1.57 to 1.59 μm by varying the PPLN temperature. The 1.5-μm laser exhibits low noise characteristics, the intensity noise of the laser reaches the shot noise limit （SNL） at an analysis frequency of 4 MHz and the phase noise is less than 1 dB above the SNL at analysis frequencies above 10 MHz.
基金The NSF(11601020,11501014) of China2017 Commercial Specialty Project(19005757053) of BTBU2018 Postgraduate Research Capacity Improvement Project(19008001491) of BTBU
文摘Linked partitions were introduced by Dykema(Dykema K J. Multilinear function series and transforms in free probability theory. Adv. Math., 2005, 208(1):351–407) in the study of the unsymmetrized T-transform in free probability theory.Permutation is one of the most classical combinatorial structures. According to the linear representation of linked partitions, Chen et al.(Chen W Y C, Wu S Y J, Yan C H. Linked partitions and linked cycles. European J. Combin., 2008, 29(6): 1408–1426) de?ned the concept of singly covered minimal elements. Let L(n, k) denote the set of linked partitions of [n] with k singly covered minimal elements and let P(n, k) denote the set of permutations of [n] with k cycles. In this paper, we mainly establish two bijections between L(n, k) and P(n, k). The two bijections from a different perspective show the one-to-one correspondence between the singly covered minimal elements in L(n, k) and the cycles in P(n, k).
基金Supported by Science Research Project of Higher Schools of Guangxi(2015ZD019)Key Project of Guangxi University for Nationalities(2012MD033)
文摘Bi-f-harmonic maps are the critical points of bi-f-energy functional. This class of maps tends to integrate bi-harmonic maps and f-harmonic maps. In this paper, we show that bi-f-harmonic maps are not only an extension of f-harmonic maps but also an extension of bi-harmonic maps, and that there should exist many examples of proper bi-f-harmonic maps. In order to find some concrete examples of proper bi-f-harmonic maps, we study the basic properties of bi-f-harmonic maps from two directions which are conformal maps between the same dimensionM manifolds and some special maps from or into a warped product manifold.
基金supported by the National Basic Research Program of China (Grant No. 2010CB923101)the National Natural Science Foundation of China (Grant Nos. 61227015 and 61121064)
文摘We report on the generation of self-oscillations from a continuously pumped singly resonant frequency doubler based on a periodically poled potassium titanyl phosphate crystal （PPKTP）. The sustained square-wave and staircase curve of self-oscillations are obtained when the incident pump powers are below and above the threshold of subharmonic-pumped parametric oscillation （SPO）, respectively. The self-oscillations can be explained by the competition between the phase shifts induced by cascading nonlinearity and thermal effect, and the influence of fundamental nonlinear phase shift by the generation of SPO. The simulation results are in good agreement with the experiment data.
基金Project supported by the National Natural Science Foundation of China (20971042 and 50772035)the Science and Technology Office of Educa-tion Department of Hunan Province (10A070)the Science and Technology Bureau of Changsha City Government (K0902014-11)
文摘The establishment of an approach to design tunable yellow emission through singly doped single-phased phosphors to obtain white LED-based InGaN chip was reported. BaY2–xS4：xHo3＋ phosphors were prepared by the high temperature solid state reaction and characterized by X-ray diffraction and photoluminescence spectra. Under the excitation of 465 nm,the emission spectra of these phosphors exhibited three sharp emission lines peaked at about 492,543 and 661 nm of Ho3＋ corresponding to 5F3,5F4 （5S2） and 5F5→5I8 transitions,respectively,with comparable intensities,resulting in a yellow light emission. The luminescence mechanism for Ho3＋ in BaY2S4 was explained.
基金Project supported by the National Natural Science Foundation of China （Grant No 10347126）, National High Technology Development Program of China （Grant No 2004AA306H10） and the Program ＂Excellence in the Research Institutes Supervised by the General Secretariat for Research and Technology / Ministry of Development＂, Greece.Acknowledgments Xiong Zhuang would like to express his appreciation for the partial support from the Greek State Scholarship Foundation （I.K.Y.） and the National Hellenic Research Foundation Scholarship for this work.
文摘By taking full account of the non-orthogonality of the orbitals between the low-lying doubly excited states ^1po and the singly excited states ^1S^e and ^1D^e of He, the corresponding radiative decay rates have been investigated theoretically via analytic generalized Laguerre-type atomic orbitals at a nearly numerical multi-conflguration self-consistent field accuracy in a general non-orthogonal configuration interaction scheme. From these rates, we calculate the VUV photon emission and metastable atom spectra, and both are found to be in good qualitative agreement with recent excellent measurements. We obtain, successfully, the enhancement of the VUV photon spectrum, experimentally observed at the energy of （2s4p-4s2p）/（2p,3d） ^1po as compared with other nearby lying states. The mechanism proposed by Odling-Smee et al is verified, implying that taking appropriate account of the overlap existing between orbitals of the low-lying doubly excited and singly excited states （especially important for the compact orbitals） can reveal basic physical dominant mechanism and is crucial in understanding these spectra.
基金supported by the National Natural Science Foundation of China(No.51772159)the Natural Science Foundation of Zhejiang Province(No.LZ17E020001)K.C.Wong Magna Fund in Ningbo University
文摘High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared single crystals exhibit a blue band at 480 nm(3P0→3H4), a green band at 522 nm (3P1→3H5), and a red band at 605 nm (1D2→3H4)when excited at 446 nm;their corresponding average lifetimes are 38.5μs, 37.3μs, and 36.8μs, respectively, which are much longer than those in oxide single crystals. The effects of excitation wavelength and doping concentration on emission intensities and chromaticity coordinates are investigated. The optimal Pr3+ concentration is confirmed to be 0.5%.The temperature dependent emission shows that the emission intensity constantly decreases with the increase of temperature from 298 K to 443 K due to the enhancement of nonradiative quenching at high temperature. The 3P0→3H4 transition is the most vulnerable to temperature, followed by the 3P1→3H5 transition and 1D2→3H4 transition.
基金Supported by the Open Project of Guangxi Key Lab of Nuclear Physics and Technology(NLK2023-04)the Central Government Guidance Funds for Local Scientific and Technological Development in China(Guike ZY22096024)+3 种基金the Natural Science Foundation of Guizhou Province-ZK[2024](General Project)650the National Natural Science Foundation of China(11675265,12175068)the Continuous Basic Scientific Research Project(WDJC-2019-13)the Leading Innovation Project(LC 192209000701)。
文摘The rigorous calculation of the spin-orbit terms in a three-quark system is realized based on the Gaussian expansion method and the infinitesimally-shifted Gaussian basis functions in the framework of the relativized quark model,by ignoring the mixing between different excited states.Then,the complete mass spectra of the singly heavy baryons are obtained rigorously,under the heavy-quark dominance mechanism.Accordingly,systematical analyses are performed for the reliability and predictive power of the model,the fine structure of the singly heavy baryon spectra,the assignments of the excited baryons,and some important topics about heavy baryon spectroscopy,such as the missing states,"spin-orbit puzzle,"and clustering effect.The results confirm that,under the heavy-quark dominance mechanism,the relativized quark model can describe the excitation spectra and the fine structures of the singly heavy baryons correctly and precisely.
基金supported by the National Natural Science Foundation of China(Nos.51272109 and 50972061)the Natural Science Foundation of Zhejiang Province(No.R4100364)+1 种基金the Natural Science Foundation of Ningbo City(No.2012A610115)the K.C.Wong Magna Fund in Ningbo University
文摘Mid-infrared（MIR） emissions of 2.4 and 3.5 μm from Tm3＋：LiYF4 single crystals attributed to3H4 →3H5 and3H5 →3F4 transitions as well as MIR emissions of 4.2,4.3,and 4.5 μm from Nd3＋：LiYF4 lasers attributed to4I15/2 →4I13/2,4I13/2 →4I11/2,and4I11/2 →4I9/2 transitions,respectively,are observed.LiYF4 single crystals possess high transmittance of over 85% in the 2.5-6 μm range.The large emission crosssections of Tm-doped crystals at 2.4 μm（1.9×10-20cm2） and Nd-doped crystals at 4.2 μm（0.84×10-20 cm2） as well as the high rare-earth doping concentrations,excellent optical transmission,and chemicalphysical properties of the resultant samples indicate that Nd3＋and Tm3＋singly doped crystals may be promising materials for application in MIR lasers.
基金Supported in part by the Youth Foundation of China University of Mining and Technology(JN210003)。
文摘The b-factories,such as BelleII,BarBar,and LHCb,emphasize the increasing importance of exotic hadron research.In this paper,we discuss the possible production of singly anti-charmed pentaquark states cqqqq from B mesons in a b-factory under SU(3)symmetry analysis.Discussions of both possibilities have been driven by the hypothesis that the pentaquark state considered in this work,known as the lowest lying state P_(c),could be bound or unbound.We find the golden channels for the production of the pentaquark ground states,such as B^(0)→P_(csudu)^((′)0)Σ^(0).We further estimate the branching ratios for the production of the ground states P_(c) from B meson decays.Thus,multiple channels are available for experiments,which may remove certain obstacles to the discovery of new pentaquark states.
文摘Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection challenging,they are linked to problems.Diagnostic methods like imaging and tissue biopsy are only effective when the tumor has reached a size that can be identified.The liquid biopsy technique,the least intrusive and most convenient diagnostic method,is the subject of this review.It focuses on the significance of single cell analysis in examining uncommon cancer types.The many biomarkers found in bodily fluids and the cancer types they are linked to in children have been assessed,as has the potential route towards early detection and cancer recurrence forecasting.Combining the single cell liquid biopsy with the newest technologies,such as computational and multi-omics approaches,which have improved the efficiency of processing massive and unique genetic data,appears promising.This article discusses on a number of case reports for uncommon pediatric malignancies,such as Neuroblastoma,Medulloblastoma,Wilms Tumor,Rhabdomyosarcoma,Ewing Sarcoma,and Retinoblastoma,as well as their liquid biopsy profiles.Furthermore,the findings raise ethical questions regarding the therapeutic application of the technology as well as possible difficulties related to clinical translation.The likelihood that this single cell liquid biopsy will be clinically validated and eventually used as a routine diagnostic tool for uncommon pediatric cancers will rise with the realistic approach to sensitivity monitoring,specificity upgrading,and optimization.
基金supported by the Jiangsu Province Traditional Chinese Medicine Technology Development Plan Project,Nos.MS2023113(to JC),MS2022090Young and Middle-aged Academic Leaders of Jiangsu Qing-Lan Project(to GL).
文摘Unlike mammals,zebrafish possess a remarkable ability to regenerate their spinal cord after injury,making them an ideal vertebrate model for studying regeneration.While previous research has identified key cell types involved in this process,the underlying molecular and cellular mechanisms remain largely unexplored.In this study,we used single-cell RNA sequencing to profile distinct cell populations at different stages of spinal cord injury in zebrafish.Our analysis revealed that multiple subpopulations of neurons showed persistent activation of genes associated with axonal regeneration post injury,while molecular signals promoting growth cone collapse were inhibited.Radial glial cells exhibited significant proliferation and differentiation potential post injury,indicating their intrinsic roles in promoting neurogenesis and axonal regeneration,respectively.Additionally,we found that inflammatory factors rapidly decreased in the early stages following spinal cord injury,creating a microenvironment permissive for tissue repair and regeneration.Furthermore,oligodendrocytes lost maturity markers while exhibiting increased proliferation following injury.These findings demonstrated that the rapid and orderly regulation of inflammation,as well as the efficient proliferation and redifferentiation of new neurons and glial cells,enabled zebrafish to reconstruct the spinal cord.This research provides new insights into the cellular transitions and molecular programs that drive spinal cord regeneration,offering promising avenues for future research and therapeutic strategies.
文摘High-throughput transcriptomics has evolved from bulk RNA-seq to single-cell and spatial profiling,yet its clinical translation still depends on effective integration across diverse omics and data modalities.Emerging foundation models and multimodal learning frameworks are enabling scalable and transferable representations of cellular states,while advances in interpretability and real-world data integration are bridging the gap between discovery and clinical application.This paper outlines a concise roadmap for AI-driven,transcriptome-centered multi-omics integration in precision medicine(Figure 1).
文摘Alzheimer’s disease(AD)is the most common form of dementia.In addition to the lack of effective treatments,there are limitations in diagnostic capabilities.The complexity of AD itself,together with a variety of other diseases often observed in a patient’s history in addition to their AD diagnosis,make deciphering the molecular mechanisms that underlie AD,even more important.Large datasets of single-cell RNA sequencing,single-nucleus RNA-sequencing(snRNA-seq),and spatial transcriptomics(ST)have become essential in guiding and supporting new investigations into the cellular and regional susceptibility of AD.However,with unique technology,software,and larger databases emerging;a lack of integration of these data can contribute to ineffective use of valuable knowledge.Importantly,there was no specialized database that concentrates on ST in AD that offers comprehensive differential analyses under various conditions,such as sex-specific,region-specific,and comparisons between AD and control groups until the new Single-cell and Spatial RNA-seq databasE for Alzheimer’s Disease(ssREAD)database(Wang et al.,2024)was introduced to meet the scientific community’s growing demand for comprehensive,integrated,and accessible data analysis.
基金Supported by The National Natural Science Foundation of China,No.82350127 and No.82241013the Shanghai Natural Science Foundation,No.20ZR1411600+2 种基金the Shanghai Shenkang Hospital Development Center,No.SHDC2020CR4039the Bethune Ethicon Excellent Surgery Foundation,No.CESS2021TC04Xuhui District Medical Research Project of Shanghai,No.SHXH201805.
文摘BACKGROUND Transforming growth factor-β(TGF-β)superfamily plays an important role in tumor progression and metastasis.Activin A receptor type 1C(ACVR1C)is a TGF-βtype I receptor that is involved in tumorigenesis through binding to dif-ferent ligands.AIM To evaluate the correlation between single nucleotide polymorphisms(SNPs)of ACVR1C and susceptibility to esophageal squamous cell carcinoma(ESCC)in Chinese Han population.METHODS In this hospital-based cohort study,1043 ESCC patients and 1143 healthy controls were enrolled.Five SNPs(rs4664229,rs4556933,rs77886248,rs77263459,rs6734630)of ACVR1C were assessed by the ligation detection reaction method.Hardy-Weinberg equilibrium test,genetic model analysis,stratified analysis,linkage disequi-librium test,and haplotype analysis were conducted.RESULTS Participants carrying ACVR1C rs4556933 GA mutant had significantly decreased risk of ESCC,and those with rs77886248 TA mutant were related with higher risk,especially in older male smokers.In the haplotype analysis,ACVR1C Trs4664229Ars4556933Trs77886248Crs77263459Ars6734630 increased risk of ESCC,while Trs4664229Grs4556933Trs77886248Crs77263459Ars6734630 was associated with lower susceptibility to ESCC.CONCLUSION ACVR1C rs4556933 and rs77886248 SNPs were associated with the susceptibility to ESCC,which could provide a potential target for early diagnosis and treatment of ESCC in Chinese Han population.
文摘Security and safety remain paramount concerns for both governments and individuals worldwide.In today’s context,the frequency of crimes and terrorist attacks is alarmingly increasing,becoming increasingly intolerable to society.Consequently,there is a pressing need for swift identification of potential threats to preemptively alert law enforcement and security forces,thereby preventing potential attacks or violent incidents.Recent advancements in big data analytics and deep learning have significantly enhanced the capabilities of computer vision in object detection,particularly in identifying firearms.This paper introduces a novel automatic firearm detection surveillance system,utilizing a one-stage detection approach named MARIE(Mechanism for Realtime Identification of Firearms).MARIE incorporates the Single Shot Multibox Detector(SSD)model,which has been specifically optimized to balance the speed-accuracy trade-off critical in firearm detection applications.The SSD model was further refined by integrating MobileNetV2 and InceptionV2 architectures for superior feature extraction capabilities.The experimental results demonstrate that this modified SSD configuration provides highly satisfactory performance,surpassing existing methods trained on the same dataset in terms of the critical speedaccuracy trade-off.Through these innovations,MARIE sets a new standard in surveillance technology,offering a robust solution to enhance public safety effectively.
基金supported by the National Natural Science Foundation of China(No.21571062)the Program for Professor of Special Appointment(Eastern Scholar)at the Shanghai Institutions of Higher Learning to JGL,and the Fundamental Research Funds for the Central Universities(No.222201717003)。
文摘Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-performance biomass-derived ORR catalysts with an asymmetric Fe-N_(3)P configuration was prepared by a simple pyrolysis-etching technique,where carboxymethyl cellulose(CMC)was used as the carbon source,urea and 1,10-phenanthroline iron complex(FePhen)as additives,and Na_(3)PO_(4)as the phosphorus dopant and a pore-forming agent.The CMC-derived FeNPC catalyst displayed a large specific area(BET:1235 m^(2)g^(-1))with atomically dispersed Fe-N_(3)P active sites,which exhibited superior ORR activity and stability in alkaline solution(E_(1/2)=0.90 V vs.RHE)and Zn-air batteries(P_(max)=149 mW cm^(-2))to commercial Pt/C catalyst(E_(1/2)=0.87 V,P_(max)=118 mW cm^(-2))under similar experimental conditions.This work provides a feasible and costeffective route toward highly efficient ORR catalysts and their application to Zn-air batteries for energy conversion.
基金supported by Natural Science Foundation of Shandong Province(Nos.ZR2022YQ42,ZR2021JQ15,ZR2021QE011,ZR2021ZD20,2022GJJLJRC-01)Innovative Team Project of Jinan(No.2021GXRC019)the National Natural Science Foundation of China(Nos.52022037,52202366).
文摘In contrast to research on active sites in nanomaterials,lithium tantalate single crystals,known for their exceptional optical properties and long-range ordered lattice structure,present a promising avenue for in-depth exploration of photocatalytic reaction systems with fewer constraints imposed by surface chemistry.Typically,the isotropy of a specific facet provides a perfect support for studying heteroatom doping.Herein,this work delves into the intrinsic catalytic sites for photocatalytic nitrogen fixation in iron-doped lithium tantalate single crystals.The presence of iron not only modifies the electronic structure of lithium tantalate,improving its light absorption capacity,but also functions as an active site for the nitrogen adsorption and activation.The photocatalytic ammonia production rate of the iron-doped lithium tantalate in pure water is maximum 26.95μg cm^(−2)h^(−1),which is three times higher than that of undoped lithium tantalate.The combination of first-principles simulations with in situ characterizations confirms that iron doping promotes the rate-determining step and changes the pathway of hydrogenation to associative alternating.This study provides a new perspective on in-depth investigation of intrinsic catalytic active sites in photocatalysis and other catalytic processes.
基金the final support of ARC DP220103045the startup support of KFUPMPrince Sultan University for their support。
文摘Transition metal carbides,known as MXenes,particularly Ti_(3)C_(2)T_(x),have been extensively explored as promising materials for electrochemical reactions.However,transition metal carbonitride MXenes with high nitrogen content for electrochemical reactions are rarely reported.In this work,transition metal carbonitride MXenes incorporated with Pt-based electrocatalysts,ranging from single atoms to sub-nanometer dimensions,are explored for hydrogen evolution reaction(HER).The fabricated Pt clusters/MXene catalyst exhibits superior HER performance compared to the single-atom-incorporated MXene and commercial Pt/C catalyst in both acidic and alkaline electrolytes.The optimized sample shows low overpotentials of 28,65,and 154 mV at a current densities of 10,100,and 500 m A cm^(-2),a small Tafel slope of 29 m V dec^(-1),a high mass activity of 1203 mA mgPt^(-1)and an excellent turnover frequency of 6.1 s^(-1)in the acidic electrolyte.Density functional theory calculations indicate that this high performance can be attributed to the enhanced active sites,increased surface functional groups,faster charge transfer dynamics,and stronger electronic interaction between Pt and MXene,resulting in optimized hydrogen absorption/desorption toward better HER.This work demonstrates that MXenes with a high content of nitrogen may be promising candidates for various catalytic reactions by incorporating single atoms or clusters.
