基于电化学老化衰退模型的锂离子动力电池外特性

当前锂离子动力电池电化学模型存在模型复杂、建模难度大、计算效率低、老化评估效果差的问题,本文提出一种考虑电池衰退老化的机理模型(ADME).本文首先通过有限差分法对伪二维(P2D)电化学模型进行离散降阶处理,得到简化伪二维(SP2D)模型.在SP2D模型的基础上,基于阴阳两极发生的副反应导致的衰退老化现象,提出一种考虑电池衰退老化的机理模型.其次,使用多变量偏差补偿最小二乘法实现模型参数辨识.最后通过动力电池衰退老化性能循环实验,对比分析了恒流、脉冲工况下SP2D模型和ADME模型的终端电压输出.结果表明:ADME模型较为简单、计算效率和估算精度高,可以有效评估电池容量老化衰退,得到理想的锂离子动力电池外特性曲线.     

Design of a 6-DOF force device for virtual assembly (FDVA-6) of mechanical parts

Among different interaction modalities, force feedback is one of the key technologies to increase the interactivity and immersion of a virtual assembly process. This paper presents a 6-DOF force device with its forward kinematic analysis, workspace simulation, and gravity compensation. To evaluate the device, a prototype system is developed and a case study is conducted to assemble a mechanical product. The users have given positive feedback on the gravity compensation implemented and the general performance of the device.     

电阻应变测试技术中的温度补偿功能辨析

针对基于温度应变补偿的结构电阻应变测试技术,分析了结构温度应变的产生原理与结构温度应变的补偿原理,辨析了结构温度应变与补偿块温度应变二者的相互关联与差异.在此基础上,指出了基于温度应变补偿模式的结构电阻应变测试技术的错误在于:概念上混淆了结构的温度应变与补偿块的温度应变,导致了结构温度应变的错误补偿.同时,给出了正确实现工程结构应变测试的环境条件,以最大限度地保证了结构应变测试数据的客观性与可靠性.     

A rapid dissolution procedure to aid initial nuclear forensics investigations of chemically refractory compounds and particles prior to gamma spectrometry

A rapid and effective preparative procedure has been evaluated for the accurate determination of low-energy (40–200 keV) gamma-emitting radionuclides (²¹⁰Pb, ²³⁴Th, ²²⁶Ra, ²³⁵U) in uranium ores and uranium ore concentrates (UOCs) using high-resolution gamma ray spectrometry. The measurement of low-energy gamma photons is complicated in heterogeneous samples containing high-density mineral phases and in such situations activity concentrations will be underestimated. This is because attenuation corrections, calculated based on sample mean density, do not properly correct where dense grains are dispersed within a less dense matrix (analogous to a nugget effect). The current method overcomes these problems using a lithium tetraborate fusion that readily dissolves all components including high-density, self-attenuating minerals/compounds. This is the ideal method for dissolving complex, non-volatile components in soils, rocks, mineral concentrates, and other materials where density reduction is required. Lithium borate fusion avoids the need for theoretical efficiency corrections or measurement of matrix matched calibration standards. The resulting homogeneous quenched glass produced can be quickly dissolved in nitric acid producing low-density solutions that can be counted by gamma spectrometry. The effectiveness of the technique is demonstrated using uranium-bearing Certified Reference Materials and provides accurate activity concentration determinations compared to the underestimated activity concentrations derived from direct measurements of a bulk sample. The procedure offers an effective solution for initial nuclear forensic studies where complex refractory minerals or matrices exist. It is also significantly faster, safer and simpler than alternative approaches.     

提高旋转载体驱动微机械陀螺标度因数稳定性的算法

旋转载体驱动微机械陀螺是一种新型的振动式MEMS陀螺,它没有微机械陀螺通常所具有的驱动结构,而只有检测模态。它安装于旋转载体上,巧妙地利用了载体的自旋作为驱动,从而使得敏感质量获得角动量。当载体发生横向转动时,敏感质量将受到科里奥利力的作用。在进动力矩、弹性力矩和阻尼力矩的共同作用下,敏感质量将产生周期性振动。振动频率对应于载体自旋频率,振动幅度与载体输入角速度大小成比例。由此工作机理,得出了敏感元件的动力学方程,并基于动力学方程建立了陀螺标度因数的误差模型。接着,根据误差模型,对标度因数的稳定性进行了分析和实际测试。分析和实验数据说明,载体自旋频率的变化是造成标度因数不稳定的主要原因。为了保证陀螺测量精度,提出了一种抑制载体自旋频率变化对标度因数影响的补偿算法,提高标度因数稳定性。最后,针对该算法的有效性,进行了实验验证。实验结果表明,此种方法能有效地提高标度因数的稳定性,标度因数相对于自旋频率变化的影响因子由补偿前的1.31 m V/(°/s)/Hz下降至7.14×10-3 m V/(°/s)/Hz。     

EicC对撞光学设计

EicC是中国科学院近代物理研究所计划建造的中国电子-离子对撞机装置,该对撞机质心能位于20 GeV附近,是研究海夸克的最佳能量窗口,同时还可研究胶子和价夸克。EicC对撞粒子为高极化率质子和电子束团,质子环pRing采用八字环设计方案,可以更好地保持极化质子束团极化率,电子环eRing采用跑道形环设计方案,可以更好地利用隧道空间。该装置电子束流能量中心值为3.5 GeV,电子束RMS发射度为水平方向60 nm·rad,垂直方向60 nm·rad,对撞点b函数为水平方向0.4 m,垂直方向0.12 m;质子束流能量中心值20 GeV,质子束RMS发射度为水平方向300 nm·rad,垂直方向180 nm·rad,对撞点b函数为水平方向0.08 m,垂直方向0.04 m,设计亮度2×1033 cm–2s–1。EicC采用双对撞区非对称光学设计,通过对EicC不同色品补偿方案的研究,最终确定了弧区加短直线节共同补偿的色品补偿方案;通过研究对撞点处b函数以及对撞点间相移对动力学孔径的影响,最终得到pRing动力学孔径大于8 s(s为束团RMS尺寸)、eRing动力学孔径大于20 s,满足大于束团尺寸6 s的要求。     

基于色彩衰减补偿和Retinex的水下图像增强

针对水下图像存在的色偏、雾状模糊、低曝光和非均匀光照问题, 提出一种基于色彩衰减补偿和Retinex的水下图像增强算法. 首先, 为校正水下图像的色偏, 利用水体对不同波长光线衰减不一致的特性自适应地补偿其R、G、B通道. 然后, 使用基于多尺度导向滤波的Retinex去除雾状模糊, 增强对比度. 最后, 根据水下图像和自然图像的直方图分布特征对其进行归一化处理, 从而在保存图像主要信息的前提下增强其纹理和曝光. 实验结果表明, 该算法不但具有较优的视觉感知效果, 而且具有较高的图像质量评价分数. 该算法具有较强的适应性, 有助于计算机视觉算法在水下的应用.     

Widely linear equalization for IQ imbalance contaminated multicarrier systems

In a multicarrier modulated (MCM) wireless communication system, the received bandpass signal is downconverted to the baseband signal for ease of receive processing. During downconversion, a slight mismatch in the amplitude and phase of locally generated sinusoidal signal in the In-Phase and Quadrature (IQ) branches of downconverter results in IQ imbalance of the baseband signal. The IQ imbalance leads to mirror interference between subcarriers of an MCM system and degrades the performance. To compensate for the effects of IQ imbalance, this paper presents widely linear minimum mean square error (WL-MMSE) based equalization technique and compares it with the traditionally used linear minimum mean square error (L-MMSE) based equalization technique. A performance comparison between WL-MMSE and L-MMSE based estimation techniques in terms of mean square error (MSE) and bit error rate (BER) suggests that the former outperforms the latter in the presence of IQ imbalance.     

Error evaluation for Zernike polynomials fitting based phase compensation of digital holographic microscopy

Combining the experimental research with the simulation calculation, the error evaluation for Zernike polynomials fitting (ZPF) based phase compensation of digital holographic microscopy (DHM) is performed. The obtained results show that the reconstructed phase with high precision can be obtained by ZPF phase compensation algorithm. Moreover, the phase error for ZPF based phase compensation algorithm increases with both the variation of object height and object transverse area, the larger variation of object height, the larger of phase error, and the larger of object transverse area, the faster increase of RMS phase error. To decrease the error of ZPF phase compensation algorithm, it is required to ensure one of the variations of object height and object transverse area to be a small value. Importantly, the proposed method supplies a useful tool for the error evaluation of phase compensation algorithm.     

沿海石化基地对地方生态环境补偿的科学基础与系统框架

生态文明建设既需要产业自身绿色发展,又需要利益调节,实现规模性达标排放行业与地方和谐.沿海石化基地既是中国能源与化学工业的集聚地,更是各类规模性达标三废集中排放区域,为此生态文明的地方实践要务就是推进石化基地对地方生态环境补偿.因此系统分析指导中国石化集聚区对地方生态补偿的外部性、公共物品、可持续发展、绿色GDP、博弈论等理论,构建宏观层次的生态环境补偿原则与补偿程序、中观层次的利益主体参与式的补偿运行机制,以及微观层次企业、居民、多层政府协商的生态环境补偿完善机制,并总结国内外实践经验,可以为地方践行生态文明理念、创新生态发展模式提供理论指导.