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981.
In this paper, from the index theorem, we present the Hermitian phase operator for fermion, give its eigenvalues and orthogonal, normalized and complete eigenstates. Furthermore, we also get the phase difference operator for two fermions and discuss its quantum properties.  相似文献   
982.
在双原子分子核运动的波动方程中,计入分子的振转相互作用项,得出的波函作与振动量子数有关外,还与转动量子数有关。  相似文献   
983.
探测对流层气溶胶的双波长米氏散射激光雷达   总被引:23,自引:6,他引:17  
研制了一台双波长米氏散射激光雷达,用于532nm和1064nm两个波长对流层气深胶消光系数垂直廓线的长期探测.介绍了该激光雷达的技术参数和总体结构,叙述了各部分的结构和工作原理,给出了合肥地区对流层气溶胶测量的若干典型结果.  相似文献   
984.
熊俊  孙寅官  胡岗 《光学学报》2000,20(2):145-150
在由两块光折变BaTiO3晶体(其中一块晶体为全内反射式自抽运相位共轭镜工作方式,起外反射镜作用)构成的半线性自抽运相位共轭器中观察到了相位共轭光的自脉动现象。自脉动的平均频率f与入射光功率I0的关系为f∝I01.43;相位共轭光的平均维持时间ΔT与入射光功率I0近似成反比。观察到光折变BaTiO3晶体中扇形散射光具有动态的空间结构,扇形散射光的这种特性是引起上述半线性自抽运相位共轭器中相位共轭光脉动的原因  相似文献   
985.
An  Xinlei  Xiong  Li  Shi  Qianqian  Qiao  Shuai  Zhang  Li 《Nonlinear dynamics》2023,111(10):9509-9535

The influence of electromagnetic field to neuron firing rhythm is not negligible. In order to investigate the behavior mechanism, a five-dimensional neuron model based on the Faraday's law of electromagnetic induction is improved by introducing magnetic flux variables and electric field variables on the three-dimensional Hindmarsh–Rose (HR) neuron model, and then, its rich dynamics and application in image encryption are discussed. Specifically, the equilibrium point distribution is analyzed using Matcont software and it is found that there are subcritical Hopf bifurcation and coexisting mode firing first. Second, numerical simulations are performed in terms of two-parameter bifurcation, ISI bifurcation, the maximum Lyapunov exponent and firing sequences, and the experimental results show that the new model exhibits various firing rhythms. The rich dynamic behaviors make the model more suitable for application in image encryption. So in the end, a grayscale image encryption scheme containing five parts called sparse, compression calculation, forward diffusion, rank scrambling and backward diffusion is designed by combining with the compressive sensing theory. The security analysis results show that the designed encryption scheme not only has excellent compression performance and high security, but also displays faster encryption speed. That is to say, the algorithm can be applied to the field of real encryption owning to the advantages of the lower costs of data transmission and higher efficiency of encryption. It is worth mentioning that the influence of different dimensional compression methods on the encryption and reconstruction effects is analyzed for the first time. The research results of this paper provide some ideas for perfecting the neuron model, revealing the influence of electromagnetic field on biological nervous system, and the excellent performance of the new neuron model provides theoretical guidance and experimental basis for the practical application of digital image encryption.

  相似文献   
986.
通过气辉成像仪对电离层气辉进行探测,能够反映电离层中电子总含量、等离子体泡分布等特性,是有效的电离层探测方式之一.电离层的原子分子在白天吸收太阳辐射激发到较高能态,在夜间以气辉的形式将能量辐射出去,辐射强度与所参与反应的电离层成分密度等密切相关,因此气辉是用来观测电离层很好的示踪物.天基气辉成像方法具有全球范围观测的巨...  相似文献   
987.
The electroreduction of CO2(CO2RR) into value-added chemicals is a sustainable strategy for mitigating global warming and managing the global carbon balance. However, developing an efficient and selective catalyst is still the central challenge. Here, we developed a simple two-step pyrolysis method to confine low-valent Ni-based nanoparticles within nitrogen-doped carbon(Ni-NC). As a result, such Ni-based nanoparticles can effectively reduce CO2 to CO, with a max...  相似文献   
988.
The negative impacts on the ecosystem of antibiotic residues in the environment have become a global concern. However, little is known about the transformation mechanism of antibiotics by manganese peroxidase (MnP) from microorganisms. This work investigated the transformation characteristics, the antibacterial activity of byproducts, and the degradation mechanism of tetracycline (TC) by purified MnP from Phanerochaete chrysosporium. The results show that nitrogen-limited and high level of Mn2+ medium could obtain favorable MnP activity and inhibit the expression of lignin peroxidase by Phanerochaete chrysosporium. The purified MnP could transform 80% tetracycline in 3 h, and the threshold of reaction activator (H2O2) was about 0.045 mmol L−1. After the 3rd cyclic run, the transformation rate was almost identical at the low initial concentration of TC (77.05–88.47%), while it decreased when the initial concentration was higher (49.36–60.00%). The antimicrobial potency of the TC transformation products by MnP decreased throughout reaction time. We identified seven possible degradation products and then proposed a potential TC transformation pathway, which included demethylation, oxidation of the dimethyl amino, decarbonylation, hydroxylation, and oxidative dehydrogenation. These findings provide a novel comprehension of the role of MnP on the fate of antibiotics in nature and may develop a potential technology for tetracycline removal.  相似文献   
989.
Multicomponent binary metal oxide-involved hybrid structures with unique physicochemical properties have received extensive attention due to their fascinating electrochemical performance. Herein, a flexible strategy, which involves the preparation of dual-functional heterometallic Fe2M clusters and their subsequent sintering treatment, is developed to engineer novel 3D hierarchical porous structures assembled with MFe2O4(M = Co, Mn, Ni and Zn) nanoparticles confi...  相似文献   
990.
马然  李晨  张熊 《化学通报》2017,80(8):745-750,759
以CO_2为原料,采用金属镁热还原法,制备出富含介孔结构的石墨烯材料。分别利用X射线衍射、扫描电镜、透射电镜、拉曼光谱和N_2吸附-脱附等测试手段对材料的微观结构进行了表征。通过在镁粉中加入不同质量的MgO,可以实现对石墨烯形貌和孔结构的调控,当MgO/Mg质量比为8∶1时,产物(MRG-8)具有均一的介孔结构(4nm)。并对材料的电化学性能进行了测试,在1mol/L KOH的电解液中,MRG-8具有最高的比电容(171F/g),同时具有非常好的倍率特性,循环测试12000周,比电容保持率为94%。当采用[EMIM][BF4]离子液体作为电解液,以MRG-8为电极材料组装成的对称型超级电容器显示出超高功率密度(175k W/kg),对应的能量密度为28.1Wh/kg。因此,采用此方法制备的介孔石墨烯材料在高功率的超级电容器领域具有潜在的应用前景。  相似文献   
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