不可逆过程的有效能消耗率及不可逆度

本文从不可逆过程有效能消耗率分析出发,提出一种表征不可逆过程的新参数一不可逆度,定义为不可逆过程的总有效能消耗率与总输入或输出能流流率之比值;在提出热力系的势能概念和多种形态能量的有效能定义式的基础上,阐述了有效能消耗率方程,有效能消耗源强度,有效能消耗率最小原理,给出并比较了有效能消耗率与熵产率和(火积)耗散率的关系;有效能消耗率与过程的能流率量纲一致,克服了熵产率和(火积)耗散率与能流率量纲不一致的缺点;不可逆度的物理意义是不可逆过程有效能消耗系数或功耗系数,与热力循环效率互补.     

修正Poschl—Teller势的Schrodinger方程束缚态的精确解

将修正Ｐｏｓｃｈｌ－Ｔｅｌｌｅｒ势的Ｓｃｈｒｏｄｉｎｇｅｒ方程作自变量双曲函数变换，使其转化为普遍的ａｓｓｏｃｉａｔｅｄ－Ｌｅｇｅｎｄｒｅ方程，用级数法解此方程，得到用普遍的ａｓｓｏｃｉａｔｅｄ－Ｌｅｇｅｎｄｒｅ多项式表示的修正Ｐｏｓｃｈｌ－Ｔｅｌｌｅｒ势的束缚态的归一化波函数，文献［１－５］中的有关结果都作为特例包含在本文的一般结论之中。     

基于荧光玻璃的高效LED白光技术

采用高温熔融法制备了一定质量比例的SiO_2-YAG∶Ce~(3+)片状荧光玻璃,厚度为0.2 mm,分析其XRD物相、光学和SEM微观结构、PL光谱。结果表明:荧光玻璃保留了晶相,荧光粉颗粒在玻璃基质中均匀分布,荧光玻璃和荧光粉的激发响应关系一致。在465 nm蓝光激发下,发射波长均在535 nm附近,表明荧光玻璃除含有玻璃相,还有荧光粉的物质结构特性。将不同波长蓝光芯片与不同荧光粉含量的荧光玻璃进行封装测试,结果表明:器件的流明效率可达到234.81 lm/W;色温和显色指数均随荧光粉含量增加而单调下降,呈现高色温和低显色指数;荧光粉质量分数从6%增加至15%时,不同波长激发下的色坐标x与y呈现大致相同的线性变化率。采用450 nm激光激发荧光玻璃,测试样品温度变化发现温升较缓,温降迅速,耐热性能优越。实验结果表明,将荧光玻璃用于LED白光照明封装,能实现流明效率和耐热性能的大幅提升,形成良好的白光输出。     

Study on electrical defects level in single layer two-dimensional Ta_2O_5

Two-dimensional atomic-layered material is a recent research focus, and single layer Ta_2O_5 used as gate dielectric in field-effect transistors is obtained via assemblies of Ta_2O_5 nanosheets. However, the electrical performance is seriously affected by electronic defects existing in Ta_2O_5. Therefore, spectroscopic ellipsometry is used to calculate the transition energies and corresponding probabilities for two different charged oxygen vacancies, whose existence is revealed by x-ray photoelectron spectroscopy analysis. Spectroscopic ellipsometry fitting also calculates the thickness of single layer Ta_2O_5,exhibiting good agreement with atomic force microscopy measurement. Nondestructive and noncontact spectroscopic ellipsometry is appropriate for detecting the electrical defects level of single layer Ta_2O_5.     

The rotational anisotropies in the ferromagnetism/antiferromagnetism 1/ antiferromagnetism 2 exchange bias structures

The rotational anisotropies in the exchange bias structures of ferromagnetism/antiferromagnetism 1/antiferromagnetism 2 are studied in this paper. Based on the model, in which the antiferromagnetism is treated with an Ising mean field theory and the rotational anisotropy is assumed to be related to the field created by the moment induced on the antiferromagnetic layer next to the ferromagnetic layer, we can explain why in experiments for ferromagnetism (FM)/antiferromagntism 1 (AFM1)/antiferromagnetism 2 (AFM2) systems the thickness-dependent rotational anisotropy value is non-monotonic, i.e. it reaches a minimum for this system at a specific thickness of the first antiferromagnetic layer and exhibits oscillatory behaviour. In addition, we find that the temperature-dependent rotational anisotropy value is in good agreement with the experimental result.     

单粒子束精确定位照射装置在CR-39膜上刻蚀中国地图边界研究

采用自编写的图像处理程序把中国地图处理成为边界点阵图，并根据点阵图每点的坐标位置，利用中国第1台单粒子束精确定位照射装置提供的单质子束在CR-39膜上几百μm×几百μm的范围内辐照并刻蚀出中国地图边界. 研究表明，该单粒子束精确定位照射装置计数准确(98%)，定位精确(平均误差小于3 μm)，辐照路径算法选择合理(近邻法)，预测值和实测值吻合程度高，可以满足刻蚀CR-39膜微图像和生物细胞辐照实验的要求.     

自然地面背景下红外目标检测算法

为了快速准确地检测出以地面物体为背景的红外序列图像中的目标,结合小波变换的特点及其应用于图像边缘检测的优点,提出了一种基于小波技术的图像预处理算法。该方法利用图像边缘在目标识别中的重要作用,讨论了基于小波变换的图像边缘检测方法,并结合地面背景红外图像自身的特点,大大地提高了单帧的检测概率。     

5 TW/40 fs级台式钛宝石激光系统研究

在TSA-25系统输出35 mJ,800 nm啁啾脉冲的基础上,建立了以钛宝石作为增益介质的二级啁啾脉冲放大(CPA)系统。使用0.6 J和1.6 J,532 nm,10 Hz Nd∶YAG激光抽运,输出脉冲能量达到500 mJ,经压缩脉冲宽度为41 fs,压缩器的能量转换效率为63%,峰值功率可达7.6 TW。通过对放大器系统的钛宝石晶体、抽运密度以及多通结构通道数的选择等实验,有效地提高了能量放大器的萃取效率。其主放大器能量萃取效率达到32%,整个系统占用尺寸不到10 m2。     

车载便携式智能桩考训练装置的设计与实现

针对目前部队大型车辆及地方B照以上大中型车辆桩考无人值守训练的实际需求,设计了一种基于接近式开关采集违规信号、单片机控制及语音告警组成的车载便携式智能桩考训练装置;阐述了系统硬件与软件的设计实现;给出了违规信号获取与编码、违规位置自动识别和语音告警等关键技术的具体解决方法;并对系统核心电路控制单元进行验证,输入编码20 H时,软件自动识别后输出6个告警控制脉冲,并判决为右侧违规,与编码设计完全拟合;由此表明该装置设计合理,满足部队训练需求,为部队执行多样化任务提供有力保障。     

Chirality-asymmetry force between ɑ-quartz and copper block

The chirality-asymmetry macroscopic force mediated by light pseudoscalar particles between α -quartz and some achiral matter is studied. If this force between achiral source mass and α -quartz with some chirality is attractive, it will become repulsive when the chirality of the α -quartz crystal is changed. According to the tested limits of the coupling constant g_s g_p /\hbar c< 1.5× 10^-24 at the Compton wavelength λ = 10^-3 m, the force (F) between a 0.08× 0.08× 0.002 m³ block of α -quartz and a 0.08× 0.08× 0.01 m³ copper block with a separation being 0.5× 10^-3 \mbox{m} in between, is estimated from the published data at less than 4.64× 10^-24 N, i.e. F < 4.64× 10^-24 N.