In this article, we define almost prime submodules as a new generalization of prime and weakly prime submodules of unitary modules over a commutative ring with identity. We study some basic properties of almost prime ...In this article, we define almost prime submodules as a new generalization of prime and weakly prime submodules of unitary modules over a commutative ring with identity. We study some basic properties of almost prime submodules and give some characterizations of them, especially for （finitely generated faithful） multiplication modules.展开更多
We report a theoretical work on the properties of modulational instability and bright type nonlinear localized modes in one-dimensional easy-axis weak ferromagnetic spin lattices involving next-nearest-neighbor coupli...We report a theoretical work on the properties of modulational instability and bright type nonlinear localized modes in one-dimensional easy-axis weak ferromagnetic spin lattices involving next-nearest-neighbor couplings.With a linear stability analysis, we calculate the growth rates of the modulational instability, and plot the instability regions.When the strength of the next-nearest-neighbor coupling is large enough, two new asymmetric modulational instability regions appear near the boundary of the first Brillouin zone.Furthermore, analytical forms of the bright nonlinear localized modes are constructed by means of a quasi-discreteness approach.The influence of the next-nearest-neighbor coupling on the Brillouin zone center mode and boundary mode are discussed.In particular, we discover a reversal phenomenon of the propagation direction of the Brillouin zone boundary mode.展开更多
Passive decoy-state quantum key distribution is more desirable than the active one in some scenarios. It is also affected by the imperfections of the devices. In this paper, the influence of modulator attenuation on t...Passive decoy-state quantum key distribution is more desirable than the active one in some scenarios. It is also affected by the imperfections of the devices. In this paper, the influence of modulator attenuation on the passive decoy-state method is considered. We introduce and analyze the unbalanced Mach-Zehnder interferometer, briefly, and combining with the virtual source and imaginary unitary transformation, we characterize the passive decoy-state method using a weak coherent photon source with modulator attenuation. According to the attenuation parameter 6, the pass efficiencies are given. Then, the key generation rate can be acquired. From numerical simulations, it can be seen that modulator attenuation has a non- negligible influence on the performance of passive-state QKD protocol. Based on the research, the analysis method of virtual source and imaginary unitary transformation are preferred in analyzing passive decoy state protocol, and the passive decoy-state method is better than the active one and is close to the active vacuum ＋ weak decoy state under the condition of having the same modulator attenuation.展开更多
Let R be a commutative Noetherian ring and p be a prime ideal of R such that the ideal pRp is principal and ht(p)≠0. In this note, the anthors describe the explicit structure of the injective envelope of the R-module...Let R be a commutative Noetherian ring and p be a prime ideal of R such that the ideal pRp is principal and ht(p)≠0. In this note, the anthors describe the explicit structure of the injective envelope of the R-module R/p.展开更多
We give the Fundamental Theorem for Hopf modules in the category of Yetter-Drinfeld modules , where L is a quasitriangular weak Hopf algebra with a bijective antipode. We also show that H* has a right H-Hopf mod...We give the Fundamental Theorem for Hopf modules in the category of Yetter-Drinfeld modules , where L is a quasitriangular weak Hopf algebra with a bijective antipode. We also show that H* has a right H-Hopf module structure in the Yetter-Drinfeld category. As an application we deduce the existence and uniqueness of right integral from it.展开更多
In this paper we develope the notions of crossed coproduct of Hopf algebras and study an equivalent theorem of generalized crossed coproduct of H weakly comodule coalgebras and H module coalgebras. The main result is ...In this paper we develope the notions of crossed coproduct of Hopf algebras and study an equivalent theorem of generalized crossed coproduct of H weakly comodule coalgebras and H module coalgebras. The main result is to prove a structure theorem about B cocleft H module coalgebras.展开更多
Let U be a weakly closed nest algebra module acting on a Hilbert space H. Given two operators X and Y in B(H), a necessary and sufficient condition for the existence of an operator T in U satisfying TX = Y is provided.
We propose a simple iterative algorithm based on a temporally movable phase modulation process to retrieve the weak temporal phase of laser pulses. This unambiguous method can be used to achieve a high accuracy and to...We propose a simple iterative algorithm based on a temporally movable phase modulation process to retrieve the weak temporal phase of laser pulses. This unambiguous method can be used to achieve a high accuracy and to simultaneously measure the weak temporal phase and temporal profile of pulses, which are almost transform- limited. A detailed analysis shows that this iterative method has valuable potential applications in the charac- terization of pulses with weak temporal phase.展开更多
调制解调法是一种常用的微弱信号检测方法,高精度、低复杂度的解调方法的实现对于调制解调法的应用具有重要的意义.传统坐标旋转数字计算(coordinate rotation digital computer,CORDIC)算法具有占用资源多,需要缩放因子补偿等问题.因...调制解调法是一种常用的微弱信号检测方法,高精度、低复杂度的解调方法的实现对于调制解调法的应用具有重要的意义.传统坐标旋转数字计算(coordinate rotation digital computer,CORDIC)算法具有占用资源多,需要缩放因子补偿等问题.因此设计并实现了一种基于改进CORDIC算法的离散傅里叶变换(discrete Fourier transform,DFT)解调方法用于微弱信号的检测.首先改进了传统的CORDIC算法用于正余弦函数值的计算,该方法不仅免除了缩放因子,而且不需要进行旋转角度的判断,降低了算法的资源占用;然后基于该CORDIC算法设计了DFT解调算法,避免了乘法器与大量查找表的使用.最终仿真结果表明,设计的DFT解调方法在整周期采样的情况下能够实现对调制信号的高精度解调,并且具备良好的抗噪声性能,能够满足微弱信号检测的要求.展开更多
针对设备背景噪声影响机械故障检测的问题,提出一种融合自适应噪声完全集成局部均值分解(Complete Ensemble Local Mean Decomposition with Adaptive Noise,CELMDAN)与改进的多点最优最小熵去卷积调整(Improved Multipoint Optimal Min...针对设备背景噪声影响机械故障检测的问题,提出一种融合自适应噪声完全集成局部均值分解(Complete Ensemble Local Mean Decomposition with Adaptive Noise,CELMDAN)与改进的多点最优最小熵去卷积调整(Improved Multipoint Optimal Minimum Entropy Deconvolution Adjusted,IMOMEDA)的微弱机械特征增强方法。该方法首先利用CELMDAN方法把复杂振动信号分解为多个单模态的乘积函数(Product Functions,PFs),解决了集成局部均值分解(Ensemble Local Mean Decomposition,ELMD)对信号施加噪声幅值和试错次数难以确定的问题。其次,提出一种具有鲁棒性较强、物理意义明确以及尺度不变性的周期调制强度(Periodic Modulation Intensity,PMI),以筛选出有效的PFs。接着,针对所选PFs中的噪声,提出IMOMEDA方法进行消除,该方法通过迭代估计最优模型参数,自适应地提取振动信号中的周期性故障瞬态特征,能够在频域中定位瞬态的谱峭度,从而抽取被背景噪声淹没的微弱故障特征。最后,以煤矿提升机为研究对象,设计了多种振动信号特征增强方法对比实验、机械运行状态诊断性能实验以及信号特征增强算法性能对比实验,多角度验证了本文方法的有效性。展开更多
The weak interlayer van der Waals(vdW) interactions in two-dimensional(2D) vdW materials enable sliding ferroelectricity as an effective strategy for modulating their intrinsic properties. In this work, we systematica...The weak interlayer van der Waals(vdW) interactions in two-dimensional(2D) vdW materials enable sliding ferroelectricity as an effective strategy for modulating their intrinsic properties. In this work, we systematically investigate the influence of interlayer sliding on the electronic behavior of PtSe_(2) using density functional theory(DFT) calculations. Our results demonstrate that interlayer sliding induces a pronounced photocurrent spanning the short-wavelength infrared to visible spectral ranges. Remarkably, under an applied gate voltage, the sliding ferroelectric PtSe_(2) exhibits anomalously enhanced photovoltaic performance and an ultrahigh extinction ratio.Transmission spectral analysis reveals that this phenomenon originates from band structure modifications driven by energy-level transitions. Furthermore, the observed photocurrent enhancement via sliding ferroelectricity demonstrates universality across diverse platinum-based optoelectronic devices. This study introduces a novel paradigm for tailoring the intrinsic characteristics of 2D vdW semiconductors, expanding the design space for next-generation ferroelectric materials in advanced optoelectronic applications.展开更多
Metasurfaces have demonstrated rich electromagnetic control capabilities and degrees of freedom in past years. As is well known, for passive metasurfaces, their functionalities cannot be further expanded accordingly o...Metasurfaces have demonstrated rich electromagnetic control capabilities and degrees of freedom in past years. As is well known, for passive metasurfaces, their functionalities cannot be further expanded accordingly once prototypes are established. Therefore, reconfigurable metasurfaces, utilizing active devices to replace geometric changes in passive structures, have received widespread attention, especially with the development of wireless communication recently. In reconfigurable metasurfaces, artificial meta-atoms are composed of active devices and passive structures combined together. However, these two modules are usually utilized as a whole due to the tight coupling of the active devices and the passive structures, which results in passive structures not receiving sufficient attention and being utilized as independent degrees of freedom. In this article, we propose the concept of weakly coupled reconfigurable metasurfaces in transmissive systems, enabling independent control of active and passive modules through weak coupling. As the proof of concept, a simple weakly coupled system is proposed, which can realize the transmission wavefront engineering through the geometric changes of meta-structures in passive mode, while achieving switching between transmission and reflection states in active mode, respectively. Our exploration lies in making use of the physical structure, which is easily neglected in traditional reconfigurable metasurface design, emphasizing the collaborative work of active and passive modules, exploring more available variables within the same aperture, and providing a potential solution for balancing functionality and resource consumption in practical applications.展开更多
We introduce, in this paper, the right weakly p.p. rings as the generaliza- tion of right p.p. rings. It is shown that many properties of the right p.p. rings can be extended onto the right weakly p.p. rings. Relative...We introduce, in this paper, the right weakly p.p. rings as the generaliza- tion of right p.p. rings. It is shown that many properties of the right p.p. rings can be extended onto the right weakly p.p. rings. Relative examples are constructed. As applications, we also characterize the regular rings and the semisimple rings in terms of the right weakly p.p. rings.展开更多
This article is devoted to the study of the symmetry in the Yetter-Drinfeld category of a finite-dimensional weak Hopf algebra.It generalizes the corresponding results in Hopf algebras.
We experimentally investigate the spectral details of a picosecond supercontinuum pumped at 1064 nm and seeded by a weak continuous wave （～20000 times weaker than the pulse peak power） at several power levels in ph...We experimentally investigate the spectral details of a picosecond supercontinuum pumped at 1064 nm and seeded by a weak continuous wave （～20000 times weaker than the pulse peak power） at several power levels in photonic crystal fibers. Seeding at different wavelengths leads to different spectral details and the effects to the bandwidth of supercontinuum are also distinct. Spectra can be widened when seeded by a continuous wave at 1070 nm and narrowed by ～100 nm when seeded at 1080 nm. The influence is enhanced by increasing the average seeded power.展开更多
Hierarchical porous carbon co-doped with heterogeneous atoms has attracted much attention thanks to sizable internal void space accommodating electrolyte,high-density microporous structure physically con-fining polysu...Hierarchical porous carbon co-doped with heterogeneous atoms has attracted much attention thanks to sizable internal void space accommodating electrolyte,high-density microporous structure physically con-fining polysulfides(LPS),and heterogeneous atoms serving as active sites to capture LPS.However,solely relying on carbon material defects to capture LPS proves ineffective.Hence,metal compounds must be introduced to chemisorb LPS.Herein,cobalt ions are in-situ grown on the polydopamine layer coated on the surface of biomass-derived S,N,P co-doped hierarchical porous carbon(SNP-PC).Then a layer of nitrogen-doped porous carbon(MPC)dotted with CoSe nanoparticles is acquired by selenizing.Thus,a strong-polar/weak-polar composite material of SNP-PC studded with CoSe nanoparticles is obtained(SNP-PC@MPC@CoSe).Button cells assembled with SNP-PC@MPC@CoSe-modified separator enable superb long-cycle stability and satisfactory rate performance.An excellent rate capacity of 796 mAh g^(−1)at a high current rate of 4 C with an ultra-low capacity fading of 0.06%over 700 cycles can be acquired.More impressively,even in a harsh test condition of 5.65 mg cm^(−2)sulfur loading and 4μL mg^(−1)ratio of electrolyte to active materials,the battery can still display a specific capacity of 980 mAh g^(−1)(area capacity of∼5.54 mAh cm^(−2))at 0.1 C.This work provides a promising route toward high-performance Li-S batteries.展开更多
文摘In this article, we define almost prime submodules as a new generalization of prime and weakly prime submodules of unitary modules over a commutative ring with identity. We study some basic properties of almost prime submodules and give some characterizations of them, especially for （finitely generated faithful） multiplication modules.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11604121 and 11875126)the Natural Science Fund Project of Hunan Province,China(Grant No.2017JJ3255)+1 种基金the National College Students’ Innovation Entrepreneurship Training Program,China(Grant No.201810531014)the Scientific Research Fund of Hunan Provincial Education Department,China(Grant No.17B212)
文摘We report a theoretical work on the properties of modulational instability and bright type nonlinear localized modes in one-dimensional easy-axis weak ferromagnetic spin lattices involving next-nearest-neighbor couplings.With a linear stability analysis, we calculate the growth rates of the modulational instability, and plot the instability regions.When the strength of the next-nearest-neighbor coupling is large enough, two new asymmetric modulational instability regions appear near the boundary of the first Brillouin zone.Furthermore, analytical forms of the bright nonlinear localized modes are constructed by means of a quasi-discreteness approach.The influence of the next-nearest-neighbor coupling on the Brillouin zone center mode and boundary mode are discussed.In particular, we discover a reversal phenomenon of the propagation direction of the Brillouin zone boundary mode.
基金supported by the National Natural Science Foundation of China(Grant No.11304397)
文摘Passive decoy-state quantum key distribution is more desirable than the active one in some scenarios. It is also affected by the imperfections of the devices. In this paper, the influence of modulator attenuation on the passive decoy-state method is considered. We introduce and analyze the unbalanced Mach-Zehnder interferometer, briefly, and combining with the virtual source and imaginary unitary transformation, we characterize the passive decoy-state method using a weak coherent photon source with modulator attenuation. According to the attenuation parameter 6, the pass efficiencies are given. Then, the key generation rate can be acquired. From numerical simulations, it can be seen that modulator attenuation has a non- negligible influence on the performance of passive-state QKD protocol. Based on the research, the analysis method of virtual source and imaginary unitary transformation are preferred in analyzing passive decoy state protocol, and the passive decoy-state method is better than the active one and is close to the active vacuum ＋ weak decoy state under the condition of having the same modulator attenuation.
基金This research is in part supported by a grant from IPM.
文摘Let R be a commutative Noetherian ring and p be a prime ideal of R such that the ideal pRp is principal and ht(p)≠0. In this note, the anthors describe the explicit structure of the injective envelope of the R-module R/p.
文摘We give the Fundamental Theorem for Hopf modules in the category of Yetter-Drinfeld modules , where L is a quasitriangular weak Hopf algebra with a bijective antipode. We also show that H* has a right H-Hopf module structure in the Yetter-Drinfeld category. As an application we deduce the existence and uniqueness of right integral from it.
文摘In this paper we develope the notions of crossed coproduct of Hopf algebras and study an equivalent theorem of generalized crossed coproduct of H weakly comodule coalgebras and H module coalgebras. The main result is to prove a structure theorem about B cocleft H module coalgebras.
文摘Let U be a weakly closed nest algebra module acting on a Hilbert space H. Given two operators X and Y in B(H), a necessary and sufficient condition for the existence of an operator T in U satisfying TX = Y is provided.
基金Supported by the National Natural Science Foundation of China under Grant No 61205103
文摘We propose a simple iterative algorithm based on a temporally movable phase modulation process to retrieve the weak temporal phase of laser pulses. This unambiguous method can be used to achieve a high accuracy and to simultaneously measure the weak temporal phase and temporal profile of pulses, which are almost transform- limited. A detailed analysis shows that this iterative method has valuable potential applications in the charac- terization of pulses with weak temporal phase.
文摘针对设备背景噪声影响机械故障检测的问题,提出一种融合自适应噪声完全集成局部均值分解(Complete Ensemble Local Mean Decomposition with Adaptive Noise,CELMDAN)与改进的多点最优最小熵去卷积调整(Improved Multipoint Optimal Minimum Entropy Deconvolution Adjusted,IMOMEDA)的微弱机械特征增强方法。该方法首先利用CELMDAN方法把复杂振动信号分解为多个单模态的乘积函数(Product Functions,PFs),解决了集成局部均值分解(Ensemble Local Mean Decomposition,ELMD)对信号施加噪声幅值和试错次数难以确定的问题。其次,提出一种具有鲁棒性较强、物理意义明确以及尺度不变性的周期调制强度(Periodic Modulation Intensity,PMI),以筛选出有效的PFs。接着,针对所选PFs中的噪声,提出IMOMEDA方法进行消除,该方法通过迭代估计最优模型参数,自适应地提取振动信号中的周期性故障瞬态特征,能够在频域中定位瞬态的谱峭度,从而抽取被背景噪声淹没的微弱故障特征。最后,以煤矿提升机为研究对象,设计了多种振动信号特征增强方法对比实验、机械运行状态诊断性能实验以及信号特征增强算法性能对比实验,多角度验证了本文方法的有效性。
基金supported by the National Key Research and Development Program of China (Grant No. 2024YFB3211701)the National Natural Science Foundation of China (Grant Nos. T2222011, 62174026, and 12274234)+1 种基金the National Key Research and Development Program of China (Grant Nos. 2023YFB3611400 and 2019YFA0308000)the Fundamental Research Funds for the Central Universities (Grant No. 242023k30027)。
文摘The weak interlayer van der Waals(vdW) interactions in two-dimensional(2D) vdW materials enable sliding ferroelectricity as an effective strategy for modulating their intrinsic properties. In this work, we systematically investigate the influence of interlayer sliding on the electronic behavior of PtSe_(2) using density functional theory(DFT) calculations. Our results demonstrate that interlayer sliding induces a pronounced photocurrent spanning the short-wavelength infrared to visible spectral ranges. Remarkably, under an applied gate voltage, the sliding ferroelectric PtSe_(2) exhibits anomalously enhanced photovoltaic performance and an ultrahigh extinction ratio.Transmission spectral analysis reveals that this phenomenon originates from band structure modifications driven by energy-level transitions. Furthermore, the observed photocurrent enhancement via sliding ferroelectricity demonstrates universality across diverse platinum-based optoelectronic devices. This study introduces a novel paradigm for tailoring the intrinsic characteristics of 2D vdW semiconductors, expanding the design space for next-generation ferroelectric materials in advanced optoelectronic applications.
基金National Key Research and Development Program of China (2020YFB1806405, 2023YFB2906102)Major Key Project of PCL (PCL2021A17, PCL2023A04)。
文摘Metasurfaces have demonstrated rich electromagnetic control capabilities and degrees of freedom in past years. As is well known, for passive metasurfaces, their functionalities cannot be further expanded accordingly once prototypes are established. Therefore, reconfigurable metasurfaces, utilizing active devices to replace geometric changes in passive structures, have received widespread attention, especially with the development of wireless communication recently. In reconfigurable metasurfaces, artificial meta-atoms are composed of active devices and passive structures combined together. However, these two modules are usually utilized as a whole due to the tight coupling of the active devices and the passive structures, which results in passive structures not receiving sufficient attention and being utilized as independent degrees of freedom. In this article, we propose the concept of weakly coupled reconfigurable metasurfaces in transmissive systems, enabling independent control of active and passive modules through weak coupling. As the proof of concept, a simple weakly coupled system is proposed, which can realize the transmission wavefront engineering through the geometric changes of meta-structures in passive mode, while achieving switching between transmission and reflection states in active mode, respectively. Our exploration lies in making use of the physical structure, which is easily neglected in traditional reconfigurable metasurface design, emphasizing the collaborative work of active and passive modules, exploring more available variables within the same aperture, and providing a potential solution for balancing functionality and resource consumption in practical applications.
基金The Scientific Research Foundation(12B101)of Hunan Provincial Education Department
文摘We introduce, in this paper, the right weakly p.p. rings as the generaliza- tion of right p.p. rings. It is shown that many properties of the right p.p. rings can be extended onto the right weakly p.p. rings. Relative examples are constructed. As applications, we also characterize the regular rings and the semisimple rings in terms of the right weakly p.p. rings.
基金the National Natural Science Foundation of China(10301033 and 10271113)
文摘This article is devoted to the study of the symmetry in the Yetter-Drinfeld category of a finite-dimensional weak Hopf algebra.It generalizes the corresponding results in Hopf algebras.
基金the National Natural Science Foundation of China(Grant Nos.61235008 and 61077076)the International Science&Technology Cooperation of China(Grant No.2012DFG11470)the Natural Science Foundation for Distinguished Young Scholars of Hunan Province,China(Grant No.12JJ1010)
文摘We experimentally investigate the spectral details of a picosecond supercontinuum pumped at 1064 nm and seeded by a weak continuous wave （～20000 times weaker than the pulse peak power） at several power levels in photonic crystal fibers. Seeding at different wavelengths leads to different spectral details and the effects to the bandwidth of supercontinuum are also distinct. Spectra can be widened when seeded by a continuous wave at 1070 nm and narrowed by ～100 nm when seeded at 1080 nm. The influence is enhanced by increasing the average seeded power.
基金supported by the National Natural Science Foundation of China(No.52003110)the Natural Science Foundation of Jiangxi Province(Nos.20202ACB202002,20202ACB214002).
文摘Hierarchical porous carbon co-doped with heterogeneous atoms has attracted much attention thanks to sizable internal void space accommodating electrolyte,high-density microporous structure physically con-fining polysulfides(LPS),and heterogeneous atoms serving as active sites to capture LPS.However,solely relying on carbon material defects to capture LPS proves ineffective.Hence,metal compounds must be introduced to chemisorb LPS.Herein,cobalt ions are in-situ grown on the polydopamine layer coated on the surface of biomass-derived S,N,P co-doped hierarchical porous carbon(SNP-PC).Then a layer of nitrogen-doped porous carbon(MPC)dotted with CoSe nanoparticles is acquired by selenizing.Thus,a strong-polar/weak-polar composite material of SNP-PC studded with CoSe nanoparticles is obtained(SNP-PC@MPC@CoSe).Button cells assembled with SNP-PC@MPC@CoSe-modified separator enable superb long-cycle stability and satisfactory rate performance.An excellent rate capacity of 796 mAh g^(−1)at a high current rate of 4 C with an ultra-low capacity fading of 0.06%over 700 cycles can be acquired.More impressively,even in a harsh test condition of 5.65 mg cm^(−2)sulfur loading and 4μL mg^(−1)ratio of electrolyte to active materials,the battery can still display a specific capacity of 980 mAh g^(−1)(area capacity of∼5.54 mAh cm^(−2))at 0.1 C.This work provides a promising route toward high-performance Li-S batteries.
