辅酶B12模型化合物研究 Ⅹ.Costa型模型化合物的合成、表征及电化学性质研究

合成了以N,N′-双(2,3-丁二酮-2-亚胺-3-肟)丙二胺为平面配体的烷基钴Schiff碱一肟类(Costa型)模型化合物[RCo(DO)(DOH)pn(H₂O)]X,(R=n-C₃H₇,n-C₄H₉,i-C₄H₉,n-C₅H₁₁,c-C₆H₁₁,CH₂C₆H₅.X=ClO₄^-,PF₆^-)。用元素分析、紫外可见光谱和1HNMR进行了表征,并用循环伏安法研究了[RCo(DO)(DOH)pn·H₂O]·ClO₄(R为上述六种烷基)化合物的电化学性质,表明随烷基R推电子能力增强,其氧化还原电位变负。     

Fractional collocation boundary value methods for the second kind Volterra equations with weakly singular kernels

Numerical Algorithms - We discuss the numerical solution to a class of weakly singular Volterra integral equations in this paper. Firstly, the fractional Lagrange interpolation is applied to deal...     

基于LPRE和LASSO方法的股指追踪研究

将最小化乘积相对误差(LPRE)和最小绝对压缩选择算子(LASSO)方法应用到乘积回归模型,结合BIC信息准则实现股票指数的追踪,成功选取了26支对上证50指数影响较大的成分股,并比较了所提方法与线性模型下LASSO方法的表现,验证了所提方法的有效性.     

Supercharacters,symmetric functions in noncommuting variables,and related Hopf algebras

We identify two seemingly disparate structures: supercharacters, a useful way of doing Fourier analysis on the group of unipotent uppertriangular matrices with coefficients in a finite field, and the ring of symmetric functions in noncommuting variables. Each is a Hopf algebra and the two are isomorphic as such. This allows developments in each to be transferred. The identification suggests a rich class of examples for the emerging field of combinatorial Hopf algebras.     

Test for scale factor of resonant micro optical gyro based on equivalent input

In accordance with the problems in test for scale factor of resonant micro optical gyro (RMOG) by turntable, a new method based on equivalent input is proposed, and this is by adding sawtooth waveform to the RMOG's phase modulator, the scale factor experimental setup is constructed, the closed-loop transfer functions under turntable input and equivalent input are analyzed, relationship between parameters of the sawtooth waveform and equivalent input is derived, the scale factor and nonlinearity are obtained by the scale factor experimental setup, the scale factor is basically identical to the test result on the turntable, but the nonlinearity also to raise from 0.98% to 0.53%, the results of test demostrate that the method can not only accurately measure the scale factor, but also effectively eliminate the measurement errors due to the vibration and imperfect precision of the turntable.     

三角波调制对谐振微光学陀螺偏置稳定性的影响

谐振式微光学陀螺是一种新型的惯性传感仪器,与传统的机械陀螺与其他光学陀螺相比具有很多理论上的优势。通过分析抑制载波和提高信噪比,深入地研究了三角波调制频率和幅度对谐振式微光学陀螺偏置稳定性的影响。通过理论计算和仿真分析,考虑得到更好的载波抑制效果,调制幅度应选为15.44 V;考虑提高信噪比,调制频率应设为1 MHz。搭建了谐振式微光学陀螺系统,实验测试结果与理论分析吻合较好。此外,采用优化的调制参数,陀螺的偏置稳定性由0.39 ()/s提高到0.18 ()/s(10 s积分时间)。研究结果表明：选择优化的调制三角波参数可以将陀螺偏置稳定性提高一倍,对于其他调制方案,如正弦波相位调制方案,同样可以通过分析载波抑制和信噪比优化调制参数,改善陀螺偏置稳定性。     

X-射线荧光光谱法在线分析硅石中8种元素的含量

以四硼酸锂—偏硼酸锂混合熔剂熔融制备样品，利用X-射线荧光光谱法实现了硅石中硅、铝、钙、镁、磷、钾、钛、铁等元素的在线分析，分析速度快，结果准确。     

Redox-Active Ferrocene Quencher-Based Supramolecular Nanomedicine for NIR-II Fluorescence-Monitored Chemodynamic Therapy

Real-time monitoring of hydroxyl radical (⋅OH) generation is crucial for both the efficacy and safety of chemodynamic therapy (CDT). Although ⋅OH probe-integrated CDT agents can track ⋅OH production by themselves, they often require complicated synthetic procedures and suffer from self-consumption of ⋅OH. Here, we report the facile fabrication of a self-monitored chemodynamic agent (denoted as Fc-CD-AuNCs) by incorporating ferrocene (Fc) into β-cyclodextrin (CD)-functionalized gold nanoclusters (AuNCs) via host–guest molecular recognition. The water-soluble CD served not only as a capping agent to protect AuNCs but also as a macrocyclic host to encapsulate and solubilize hydrophobic Fc guest with high Fenton reactivity for in vivo CDT applications. Importantly, the encapsulated Fc inside CD possessed strong electron-donating ability to effectively quench the second near-infrared (NIR-II) fluorescence of AuNCs through photoinduced electron transfer. After internalization of Fc-CD-AuNCs by cancer cells, Fenton reaction between redox-active Fc quencher and endogenous hydrogen peroxide (H₂O₂) caused Fc oxidation and subsequent NIR-II fluorescence recovery, which was accompanied by the formation of cytotoxic ⋅OH and therefore allowed Fc-CD-AuNCs to in situ self-report ⋅OH generation without undesired ⋅OH consumption. Such a NIR-II fluorescence-monitored CDT enabled the use of renal-clearable Fc-CD-AuNCs for efficient tumor growth inhibition with minimal side effects in vivo.     

In situ formation and assembly of CdS nanocrystallites into polyhedrons on Eggshell membrane at room temperature

A room-temperature soakage procedure was carried out to successfully form and assemble CdS nanocrystallites into polyhedrons on the eggshell membrane (ESM). Based on the biomaterial ESM served as the reactive substrate and some ESM biomacromolecules acted as the surfactants, CdS nanocrystallites were in situ formed, further assembled into well-distributed polyhedrons, and finally performed CdS-ESM hybrid nanocomposites. This moderate bioinspired strategy would also be of great value to prepare novel functional nanocomposites.     

弹体贯穿混凝土数值模拟的改进材料模型

研究混凝土结构在冲击载荷下的力学特性对武器以及防护结构的设计和评估具有重要意义,而合适的材料模型可以更准确地预测混凝土结构的力学行为和破坏模式。因此,本文中提出了一种改进的混凝土塑性损伤材料模型来描述其在冲击载荷下的力学响应。该改进模型考虑了压力-体积应变关系、应变率效应、洛德角效应和塑性损伤累积对混凝土材料力学特性的影响,并引入了一个与损伤相关的硬化/软化函数来描述压缩状态下的应变硬化和软化行为。随后,通过对3个独立的强度面进行线性插值得到了该改进模型的破坏强度面,并采用部分关联流动法则考虑了混凝土材料的体积膨胀特性。最后,开展了单个单元在不同加载条件下和弹体贯穿钢筋混凝土靶的数值模拟,验证了该改进模型的可行性、准确性以及预测性能提升。