不可分辨跃迁阵模型下类镍金离子M带谱的理论计算

 用不可分辨跃迁阵模型(UTA model)计算类镍金(Au ⁵¹⁺)谱中8个跃迁阵的特征参数: 平均波数(kav)、半宽度(FWHM)、总强度(W)和谱线数(L)。利用高斯分布线型,根据各个阵的总强度进行叠加,得到了在总体上与实验相一致的结果,使得在实验中对金M带谱进行时间或空间的高分辨率测量成为可能。     

An Active Set Modified Polak–Ribiére–Polyak Method for Large-Scale Nonlinear Bound Constrained Optimization

In this paper, we propose an active set modified Polak?CRibiére?CPolyak method for solving large-scale optimization with simple bounds on the variables. The active set is guessed by an identification technique at each iteration and the recently developed modified Polak?CRibiére?CPolyak method is used to update the variables with indices outside of the active set. Under appropriate conditions, we show that the proposed method is globally convergent. Numerical experiments are presented using box constrained problems in the CUTEr test problem libraries.     

Enhanced high-rate performance of sub-micro Li4Ti4.95Zn0.05O12 as anode material for lithium-ion batteries

Zn-doped Li₄Ti₅O₁₂ was prepared by a ball milling-assisted solid-state method, and the characters were determined by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, cyclic voltammetry, and galvanostatic charge–discharge testing. The results show that Li₄Ti_5?x Zn _x O₁₂ (x?=?0, 0.05) exhibits the pure phase structure, and Zn doping does not change the electrochemical reaction process and basic spinel structure of Li₄Ti₅O₁₂. The particle size of both samples is about 300–500 nm. The prepared Li₄Ti_4.95Zn_0.05O₁₂ presents an excellent rate capability and capacity retention. At the charge–discharge rate of 1C, the initial discharge capacity of Li₄Ti_4.95Zn_0.05O₁₂ is 268 mAh g^?1. After 90 cycles at 5C, the discharge capacity of Li₄Ti_4.95Zn_0.05O₁₂ is obviously higher than that of Li₄Ti₅O₁₂. The excellent electrochemical performance of the Li₄Ti_4.95Zn_0.05O₁₂ electrode could be attributed to the improvement of reversibility by doping zinc and the sub-micro particle size.     

On Minimal Asymptotic Bases

Mathematical Notes - Let $$mathbb N$$ denote the set of all nonnegative integers, and let $$Asubseteqmathbb N$$ . Let $$h,ninmathbb N$$ , $$hge 2$$ and $$r_h(A,n)=#{(a_1,dots,a_h)in...     

Collider search of light dark matter model with dark sector decay

We explore the possibility that the dark matter relic density is not produced by a thermal mechanism directly, but by the decay of other heavier dark-sector particles which themselves can be produced by the thermal freeze-out mechanism. Using a concrete model with light dark matter from dark sector decay, we study the collider signature of the dark sector particles associated with Higgs production processes. We find that future lepton colliders could be a better place to probe the signature of this kind of light dark matter model than hadron colliders such as LHC. Also, we find that a Higgs factory with center-of-mass energy 250 GeV has a better potential to resolve the signature of this kind of light dark matter model than a Higgs factory with center-of-mass energy 350 GeV.     

Natural color low-level-light EBAPS imaging system based on three-color LCTF北大核心CSCD

The high-sensitivity electron bombarded active pixel sensor (EBAPS) not only has the characteristics of high gain and high sensitivity of vacuum imaging devices, but also has the digital characteristics of solid-state imaging devices, which greatly improves the level of night vision imaging. A natural color low-level-light EBAPS imaging system was built based on three-color liquid crystal tunable filter (LCTF). According to the characteristics of low-level-light images, the color enhancement processing such as grayscale stretching, white balance, and color correction was performed on the color images obtained by the system. The experimental results show that the system can realize the natural low-illumination color imaging that reflects the color characteristics of the scene itself, which can effectively improve the observation effect of the characteristics of the target scene at night, and can realize the color imaging under 5×10−4 lx illumination. © 2022 Editorial office of Journal of Applied Optics. All rights reserved.     

BAHADUR ASYMPTOTIC EFFICIENCY IN A SEMIPARAMETRIC REGRESSION MODEL

ＢＡＨＡＤＵＲＡＳＹＭＰＴＯＴＩＣＥＦＦＩＣＩＥＮＣＹＩＮＡＳＥＭＩＰＡＲＡＭＥＴＲＩＣＲＥＧＲＥＳＳＩＯＮＭＯＤＥＬ￥ＬＩＡＮＧＨＵＡ；ＣＨＥＮＧＰＩＮＧＡｂｓｔｒａｃｔ：ＴｈｅａｕｔｈｏｒＳｇｉｖｅＭＬＥθ１ＭＬｏｆθ１ｉｎｔｈｅｍｏｄｅｌＹ＝θ...     

H+和Ar11+激发Si的K壳层X射线发射研究

测量了50–250 keV H⁺和1.0–3.0 MeV Ar¹¹⁺ 轰击Si表面过程中辐射的X射线. 结果表明, 在Ar¹¹⁺入射的情况下, 引起了Si的L壳层上3, 4个电子的多电离.计算了Si的K壳层X射线产生截面, 并将两体碰撞近似(BEA), 平面波恩近似, ECPSSR理论计算与实验值进行了对比. ECPSSR理论与质子产生的截面数据能够很好地符合; 而考虑多电离后, BEA理论与Ar¹¹⁺的实验结果符合较好. 关键词： X射线 高电荷态重离子 多电离     

近玻尔速度Ne2+离子穿过碳膜引起的电子发射

本文测量了入射能为2–25 keV/u的Ne²⁺离子穿过不同厚度碳膜诱导的前向、后向 (分别对应出射表面和入射表面) 电子发射产额. 实验中通过改变炮弹离子的能量, 系统的研究了势能沉积、电子能损以及反冲原子对前向、后向电子发射产额的贡献. 结果表明, 离子的势能沉积只对后向电子发射有贡献, 前向、后向电子发射产额分别与Ne²⁺离子在薄膜出射、入射表面的电子能损近似成正比关系, 其中电子能损很低 (对应于离子能量很低) 的时候, 反冲原子对电子发射的贡献不能忽略. 关键词： 近玻尔速度 电子发射 电子能损 反冲原子     

基于电化学与热能的耦合关系演算聚合物锂离子动力电池的温度状态及分布

基于电化学-热耦合模型研究聚合物锂离子动力电池放电过程热行为, 分析了放电倍率、冷却条件对电池放电过程的温度变化及分布的影响规律. 结果表明: 3C放电时, 模型计算结果与实测结果的平均偏差为0.57 K, 方差为0.15, 说明模型准确度较高. 电芯的平均生热率在整个放电过程中呈现出增加的趋势, 初期和末期增长较快. 大倍率放电时, 与电流密度的平方呈正比的不可逆热所占的比重较大, 小倍率放电时, 电化学反应可逆热占主导. 改善冷却条件能降低电池放电过程的平均温度, 对流传热过程的表面传热系数为5 W/(m²·K), 1 C, 3 C, 5 C放电结束时, 电芯的平均温升为分别为6.46 K, 17.67 K, 27.53 K, 当对流传热过程的表面传热系数增加至25 W/(m²·K)时, 温升比自然对流条件下相同倍率放电时的温度分别降低了2.91 K, 4.68 K, 5.62 K, 但电芯温度分布的不一致性也会加剧. 关键词： 电化学 耦合 锂离子动力电池 温度分布