AGA在太阳能电池阵寿命预测中的应用

针对在轨卫星的GaInP/GaAs/Ge三结太阳能电池阵输出电流衰减模型中参数辨识精度低和后期误差大且实时性不高的问题,提出采用遗传算法(GA)对太阳能电池阵电流衰减模型进行参数辨识。针对GA过早收敛及易陷入局部最优解的缺点,提出了基于自适应交叉变异算子和线性变换适应度函数的自适应遗传算法(AGA)进行参数辨识。然后把模型预测的输出电流与遥感测得的输出电流进行比较。实验结果表明,运用AGA和广义最小二乘法（GLS）得到的均方根误差(RMSE)分别为1.427×10^-4和1.337×10^-3,误差平方和(SSE)分别为2.0571×10^-6和1.92×10^-3,AGA辨识后的模型预测更加准确,对卫星运行后期电源的管理具有实际意义。     

BPA与3种双酚类化合物的联合作用雌激素效应

环境内分泌干扰物的联合作用已经是目前研究的重点.采用重组基因酵母检测法,分别测定了双酚A (BPA)、双酚AF(BPAF)、双酚AP(BPAP)、双酚F(BPF)4种双酚化合物的雌激素活性,并依据其测定结果,按照等效浓度比,设计了浓度比分别为EC₁₀和EC₅₀的6种二元混合物并测定了其雌激素活性.结果表明,这4种化合物的剂量-效应关系都可以用Weibull函数有效描述,BPA、BPAF、BPAP、BPF的EC₅₀值分别为：6.81×10^-6、7.44×10^-7、1.43×10^-5、7.52×10^-6 mol·L^-1,其雌激素活性大小顺序为：BPAF>BPA>BPF>BPAP.依据不同的联合作用判断方法对这4种化合物的联合效应进行判断,结果表明,相同化合物的不同混合比例可能对联合作用方式产生影响,采用DA和IA预测模型可以更加直观、方便地判断联合作用的类型,而且可以反映出不同混合比例对联合作用的影响.     

一种新的两轮自平衡电动车控制方法

为了克服目前两轮自平衡电动车控制系统存在的噪声和漂移误差大, 受扰后调节时间长, 超调量较大等问题, 提出了一种新的控制方法。该方法基于卡尔曼信号融合滤波, 构建了直接转矩电流伺服单元, 对电动车进行滑模变结构控制。实验表明滤波后倾角度噪声误差由6°降到2. 5°; 角速度噪声误差由0. 25 rad·s^-1降到010 rad·s^-1; 零位漂移误差由0. 25 rad·s^-1降为0. 08 rad·s^-1; 系统受扰动后, 该方法调节时间更短、无超调、鲁棒性更强。实验结果均表明该方法有更好的动态性能和稳定性。     

GIS气室SF6气体微水激光检测系统的设计及溯源实验研究

气体绝缘金属封闭式组合电器（GIS）气室中SF₆气体微水测量对电气设备的安全可靠运行意义重大。采用1392 nm分布式反馈激光器（DFB）,基于可调谐二极管激光吸收光谱（TDLAS）技术及赫里奥特（Herriott）长程池的光学系统设计了微水检测系统。气体Lorentz线型仿真光谱分析显示,在7200 cm^-1附近无交叉干扰,其中7181.14 cm^-1（1.392 μm）处H₂O分子吸光强度最强。对系统的可靠性进行实验室溯源标定,二次谐波信号幅值与微水浓度成正比关系,拟合线性系数R²为0.9996。露点及微水浓度实验室标定最大误差分别为1.98%和2.25%。GIS模拟气室实验结果表明：全封闭的光路气室结构设计达到理想的测试效果,5组100次实验数据分析最大测量误差1.89%,绝对误差小于5×10^-6。该系统稳定可靠,具有较好的可行性及实用性。     

带法向约束的隐式T样条曲线重构

目的 隐式曲线能够描述复杂的几何形状和拓扑结构,而传统的隐式B样条曲线的控制网格需要大量多余的控制点满足拓扑约束。有些情况下,获取的数据点不仅包含坐标信息,还包含相应的法向约束条件。针对这个问题,提出了一种带法向约束的隐式T样条曲线重建算法。方法 结合曲率自适应地调整采样点的疏密,利用二叉树及其细分过程从散乱数据点集构造2维T网格;基于隐式T样条函数提出了一种有效的曲线拟合模型。通过加入偏移数据点和光滑项消除额外零水平集,同时加入法向项减小曲线的法向误差,并依据最优化原理将问题转化为线性方程组求解得到控制系数,从而实现隐式曲线的重构。在误差较大的区域进行T网格局部细分,提高重建隐式曲线的精度。结果 实验在3个数据集上与两种方法进行比较,实验结果表明,本文算法的法向误差显著减小,法向平均误差由10^-3数量级缩小为10^-4数量级,法向最大误差由10^-2数量级缩小为10^-3数量级。在重构曲线质量上,消除了额外零水平集。与隐式B样条控制网格相比,3个数据集的T网格的控制点数量只有B样条网格的55.88%、39.80%和47.06%。结论 本文算法能在保证数据点精度的前提下,有效降低法向误差,消除了额外的零水平集。与隐式B样条曲线相比,本文方法减少了控制系数的数量,提高了运算速度。     

一类基于混沌函数的分组密码的安全性评估

评估了一类基于混沌函数的分组密码(generalized Feistel structure,简称GFS)抵抗差分密码分析和线性密码分析的能力.如果轮函数是双射且它的最大差分特征概率和线性逼近概率分别是p和q,则r轮GFS的最大差分特征和线性逼近的概率分别以p^r-1和q^r-1为其上界.     

光纤陀螺输入轴失准角温度补偿研究

提高温度特性是光纤陀螺仪工程化的一个难题,温度补偿是解决该问题的一种有效方法。光纤陀螺与温度相关误差项主要为零漂和标度因数,输入轴失准角也是影响光纤陀螺应用的一个重要误差项。在大量试验的基础上,分析了光纤陀螺输入轴失准角误差产生机理,采用多项式拟合方法建立了输入轴失准角误差全温模型,对多套光纤陀螺进行了全温补偿。试验结果表明,输入轴失准角补偿前全温变化在2?10^-3rad数量级,补偿后全温变化小于3?10^-4rad,精度提高了近一个数量级,大大提高了光纤陀螺仪的全温性能。     

基于Hermite基函数的液位传感器温度补偿方法

针对液位传感器易受温度影响的问题,提出了基于Hermite基函数的液位非线性校正和温度补偿的复合校正方法,该方法使用递推最小二乘法对标定液位进行拟合以获取复合补偿模型的参数,由此根据液位传感器的测量值和环境温度即可高精度计算出实际液位。仿真结果表明,补偿后的最大相对误差不超过1.23×10^-6%,具有良好的非线性校正和温度补偿效果,在液位检测领域具有重要的理论和应用价值。     

虫孔路由Mesh上的连通分量算法及其应用

用倍增技术在带有Wormhole路由技术的n×n二维网孔机器上提出了时间复杂度为O(log²n)的连通分量和传递闭包并行算法,并在此基础上提出了一个时间复杂度为O(log³n)的最小生成树并行算法.这些都改进了Store-and-Forward路由技术下的时间复杂度下界O(n).同其他运行在非总线连接分布式存储并行计算机上的算法相比,此连通分量和传递闭包算法的时间复杂度是最优的.     

5元饱和最优布尔函数的计数问题

同时达到代数次数上界n-m-1和非线性度上界2^n-1-2^m+1的n元m阶弹性布尔函数(m＞n/2-2)具有3个Walsh谱值:0,±2^m+2这样的函数被称为饱和最优函数(saturated best,简称SB).将利用(32,6)Reed-Muller码陪集重量的分布,从一种全新的构造角度出发,给出n=5的饱和最优函数的个数.     

Sharpness and noise characteristics of a half‐mirror stereoscopic display

Stereoscopic displays are becoming popular in entertainment and industrial applications. We characterize the spatial resolution and noise properties of a stereoscopic display with a half‐mirror and passive polarizing glasses. The upper display images reflected off the mirror have slightly degraded sharpness and reduced high spatial‐frequency noise resulting in modulation transfer functions (MTFs) of 0.59 and 0.50 at the Nyquist frequency with corresponding noise power spectra (NPS) values of 4.79 × 10^?6 and 5.17 × 10^?6 mm² at 10 mm^?1 in the horizontal and vertical directions. These results are compared to the characteristics of the individual displays with MTF values of 0.64 and 0.53 and NPS values of 6.24 × 10^?6 and 5.87 × 10^?6 mm². The polarizing glasses cause minimal reduction in sharpness and high‐frequency noise. The MTFs in the upper images observed with glasses are decreased to 0.54 and 0.47, while the NPS are decreased to 2.86 × 10^?6 and 2.01 × 10^?6 mm². When both displays are turned on and using the mirror and glasses, the observed luminance for each eye is increased from the luminance of the individual displays owing to crosstalk. We find that sharpness and noise are not affected by the interaction between the displays at the particular geometry tested in this study.     

Chemiluminescence detection for Cu (II) based on 1,10-Phenanthroline-hydrogen peroxide reaction on a PDMS microfluidic chip

A simple, rapid and effective method for the determination of copper (II) in water on a PDMS microfluidic chip with chemiluminescence (CL) detection is presented. The CL reaction was based on oxidation of 1,10-phenanthroline by hydrogen peroxide in basic aqueous solution. Polydimethylsiloxane (PDMS) was chosen as material for fabricating the microfluidic chip with two steps lithography method. Optimized reagents conditions were found to be 6.0 × 10^?5 mol/L 1,10-phenanthroline, 1.2 × 10^?3 mol/L hydrogen peroxide, 6.5 × 10^?2 mol/L sodium hydroxide and 2.0 × 10^?3 mol/L Hexadecyl trimethyl ammonium Bromide (CTMAB). In the continuous flow injection mode the system can perform fully automated detection with a reagent consumption of only 3.4 μL each time. The linear range of the Cu (II) ions concentration was 1.0 × 10^?8 mol/L to 1.0 × 10^?4 mol/L, and the detection limit was 9.2 × 10^?9 mol/L with the S/N ratio of 3. The relative standard deviation was 2.8 % for 1.0 × 10^?6 mol/L Cu (II) ions (n = 8). The most notable features of the detection method are simple operation, rapid detection and easy fabrication of the microfluidic chip.     

Lidar profiling of aerosol scavenging parameters at a tropical station,Pune, India

In this study, we deal with observations of aerosol column content (height integration of vertical distribution of aerosol number density) that have been carried out using an Ar⁺ lidar for three different measurement cycles (each cycle consisting of three experimental days associated with non-rain, rain, and non-rain, respectively) of weekly spaced observations for pre-monsoon (March/April 1994), monsoon (September 1991), and post-monsoon (October 1998). Based on these observed profiles of aerosol number concentration on rainy days with respect to those on non-rainy days, vertical distributions of scavenging collection efficiencies (SCEs) are computed and discussed in this article. The SCE is found to decrease from 0.3 to 0.01 between the heights, 100 and 800 m for thunderstorm rain in April 1994, and during monsoon, it increases from 0.1 to 0.7. In the October 1998 episode, SCE was found to increase initially from 0.35 to 0.75 for heights between 40 and 200 m and thereafter decrease to 0.35 in the height interval of 200–800 m. For the rainfall intensity increase from 1 to 10 mm hour^?1, the corresponding scavenging coefficient (SC) for atmospheric layer 50–100 m varies from 4 × 10^?6 to 4 × 10^?5 s^?1 for thunderstorm in April 1994 and between 5 × 10^?6 and 5 × 10^?5 s^?1 in October 1998, respectively. During monsoon, these values vary from 3 × 10^?5 to 5 × 10^?4 s^?1. They lie in the range of those observed in the earlier field studies. The results are found useful to establish links between aerosols and cloud properties, and the influence of such interactions on weather and climate.     

Bulk-modified amperometric biosensors for hypoxanthine based on sol–gel technique

Graphite–ceramic amperometric biosensors for hypoxanthine (Hx) have been fabricated and applied to the measurement of fish meat quality. The fabrication process involves the immobilization of xanthine oxidase in the bulk of a silica-graphite matrix by sol–gel techniques and the assembly of the enzyme-modified matrix into a glass tube to form a disk electrode whose surface can be easily renewed by simple mechanical polishing. Michaelis–Menten constants (K_m^app) of 0.45, 0.64, 0.35 mM were determined from three different types of Hx sensors operating in the unmediated hydrogen peroxide oxidation mode, the unmediated and the benzyl viologen-mediated oxygen reduction modes, respectively. The sensors delivered good linear response over a wide range of concentrations of ca. 1×10⁻⁶–1×10⁻³ M, with respective detection limits of 1.3×10⁻⁶, 5.6×10⁻⁶and 3.8×10⁻⁷ M in 0.05 M phosphate buffer (pH 7.6). The use of bulk immobilization and the possibility of renewable surfaces have enabled the easy operation of these sensors with high stability. Satisfactory results were obtained from the determination of the freshness of carp tissues stored under different conditions.     

Selective and in-situ determination of carbonate and oxide particles in aqueous solution using laser-induced breakdown spectroscopy (LIBS) for wearable information equipment

Laser-induced breakdown spectroscopy (LIBS) has been applied for quantitative analysis of Al₂O₃, CaCO₃ and MgO particles suspended in water. In the single elemental system, the plasma emission intensities of Al, Ca and Mg were linearly increased with concentration of elements in the range of 1.0×10^?5–1.0×10^?3  M, 1.0×10^?4–2.0×10^?3 M and 8.0×10^?5 –4.0×10^?3 M, respectively. We also investigated the concentration dependence of breakdown spectra for suspended mixtures of Al₂O₃, CaCO₃ and MgO particles. The emission lines, such as Al I, Ca I, Ca II and Mg I, were appeared in the LIBS spectrum simultaneously, and each emission peak could be deconvoluted. The plasma emission intensities of Al, Ca and Mg in the multielemental system were also linearly increased with their concentrations in the range of 1.0×10^?5–1.0×10^?3 M, 1.0×10^?4–2.0×10^?3 M and 4.0×10^?4–2.0×10^?3 M, respectively. LIBS was found to be available for quantitative and qualitative measurement of the concentrations of Al₂O₃, CaCO₃ and MgO particles suspended in water. The present results suggest that LIBS is a potentially useful tool for in-situ analysis on particles composition and concentrations for environmental monitoring by the wearable information equipments.     

Quantum model and memory of informative biomacromolecules

It is shown, that tubuline informative biomacromolecule has two-well structure potential energy relief for an electron responsible for the switching between conformations of molecules. Therefore the system of conformational excitation in informative biomacromolecules must be described as a two-level quantum system. The energy of the basic electron state ɛ₊ = 1.2 eV and frequency of electron tunneling ω = (6 × 10¹³–6 × 10¹¹) s⁻¹ in a tubuline molecule were calculated. The possibility of data recording by directly collapse of wave function in a two-level cell was shown, thus coherence of quantum state collapses only. The article is published in the original.     

Sublimation enthalpies of terbium and lutetium triiodides and formation enthalpies of their monomer and dimer molecules

The sublimation of terbium and lutetium triiodides was studied by Knudsen effusion mass spectrometry. The temperature dependencies of partial vapor pressures [atm] of the monomer and dimer molecules were determined as: lnp(TbI₃) = – (31.74 ± 0.24)× 10³/T + (21.43 ± 0.29) for 743–906 K; lnp(Tb₂I₆) = – (38.66 ± 0.38)× 10³/T + (25.63 ± 0.46) for 786–906 K; lnp(LuI₃) = – (31.48 ± 0.25)× 10³/T + (22.28 ± 0.30) for 721–951 K; and lnp(Lu₂I₆) = – (36.95 ± 0.37)× 10³/T + (25.21 ± 0.43) for 796–950 K. On the basis of a joint analysis of all literature data, the sublimation enthalpies [kJ mol^–1] at 298.15 K are recommended as 281 ± 3 (TbI₃), 346 ± 30 (Tb₂I₆), 279 ± 12 (LuI₃), and 340 ± 30 (Lu₂I₆). The standard formation enthalpies [kJ mol^–1] of the gaseous species at 298.15 K are –343 ± 4 (TbI₃), –902 ± 30 (Tb₂I₆),–326 ± 12 (LuI₃), and –870 ± 30 (Lu₂I₆).     

An effective PDMS microfluidic chip for chemiluminescence detection of cobalt (II) in water

A microfluidic chip for the chemiluminescence detection of cobalt (II) in water samples, based on the measurement of light emitted from the cobalt (II) catalysed oxidation of luminol by hydrogen peroxide in basic aqueous solution, is presented. The microfluidic chip was designed and fabricated from polydimethylsiloxane using micro-molding method. Optimized reagents conditions were found to be 5.0 × 10^?4 mol/L luminol, 1.0 × 10^?2 mol/L hydrogen peroxide, and 8.0 × 10^?2 mol/L sodium hydroxide. The system can perform fully automated detection with a reagent consumption of only 2.4 μL each time. The linear range of the cobalt (II) ions concentration was 1.0 × 10^?10–1.0 × 10^?3 mol/L and the detection limit was 5.6 × 10^?11 mol/L with the S/N ratio of 3. The relative standard deviation was 4.6 % for 1.0 × 10^?5 mol/L cobalt (II) ions (n = 10).     

Metabolic and perceptual responses while carrying external loads on the head and by yoke

Abstract

The purpose of this study was to determine the metabolic efficiency and perceptual acceptability of transporting external loads on the head and by yoke. Ten young males (24·2 ±3·9 years) of average physical fitness ([Vdot]O_2max=49·8 ± 6·5ml kg^-1 min^-1) walked for 6min on a level motor-driven treadmill at 53·6, 73·8 and 93·9m min^-1. Subsequently, all subjects carried external loads (11·6, 16·1 and 20·6 kg) at the same speeds using the headpack (HP), transverse yoke (TY) and frontal yoke (FY) modes of load carriage. Measurements were obtained for oxygen uptake ([Vdot]O₂ l min^-1), local ratings of perceived exertion (RPE-L) and the overall perceived exertion (RPE-O). The [Vdot]O₂ was used in the computation of the metabolic efficiency ([Vdot]O₂ ml kg total weight^-1 min^-1).

Significant main effects (mode, load and speed) and three interaction effects (mode × load, mode × speed and load × speed) were obtained for metabolic efficiency. Scheffé post hoc analysis revealed that the metabolic efficiency for the TY and HP were greater than the FY while transporting the 16·1 and 20·6kg loads at all walking speeds (p <0·05). No significant loss in metabolic efficiency was found while carrying the 20·6kg load at 53·6 m min^-1. At 93·9 m min^-1, all external loads transported were associated with a loss in metabolic efficiency. The RPE-L for the HP was lower than the FY (p < 0·05). Both the RPE-0 and RPE-L increased as the walking speeds and external loads were increased. The findings suggest that load transportation using the FY system is both physiologically and perceptually unacceptable.