基于PdSe2/GaAs异质结的高灵敏近红外光伏型探测器的制备和图像传感的应用

本文制备了一种基于PdSe₂/GaAs异质结的高灵敏近红外光电探测器,该探测器是通过将多层PdSe₂薄膜转移到平面GaAs上制成的. 所制备的PdSe₂/GaAs异质结器件在808 nm光照下表现出明显的光伏特性,这表明近红外光电探测器可以用作自驱动器件. 进一步的器件分析表明,这种杂化异质结在零偏电压和808 nm光照下具有1.16×10⁵的高开关比. 光电探测器的响应度和比探测度分别约为171.34 mA/W和2.36×10¹¹ Jones. 而且,该器件显示出优异的稳定性和可靠的重复性. 在空气中2个月后,近红外光电探测器的光电特性几乎没有下降,这归因于PdSe₂的良好稳定性. 最后,基于PdSe₂/GaAs的异质结器件还可以用作近红外光传感器.     

Semiclassical description of isoscalar giant multipole resonances

The scaling approximation in a semiclassical theory of nuclear collective motions based on the Vlasov equation is applied to the study of isoscalar giant resonances. Analytic forms are obtained for the frequencies of any multipolarity, expressed just in terms of local density distributions, using realistic nuclear effective forces. The importance of non local interactions and diffuse surfaces is clearly shown. The limits of the scaling picture in describing high multipolarity resonances are finally discussed.     

Anisotropic magnetic susceptibility and phase transitions in intercalated graphite: KC24

We measured the magnetic susceptibility of KC₂₄ from 4.2 to 300 K and found no anomalies near the phase transitions at 95 and 123 K as observed in the resistivity. We conclude that the transitions must be due to order- disorder transitions of the K atoms and not charge density wave formation. The susceptibility is anisotropic; at room temperature $\text{χ}{}_{\mathrm{g}}\text{(}\text{H}\text{6}\text{c}\text{)= + 1.50 × 10}{}^{-6}\text{emu g}{}^{-1}\text{± 2\%}$ and $\text{χ}{}_{\mathrm{g}}\text{(}\text{H}\text{⊥}\text{c}\text{)= + 0.045 × 10}{}^{-6}\text{emu g}{}^{-1}\text{± 50\%}$. This anisotropy is not understood in terms of simple rigid band extensions of the band structure of graphite.     

大鼠脑缺血再灌注后运动皮质细胞凋亡的体视学观察

用体视学方法分析大鼠脑缺血再灌注后大脑运动皮质细胞的凋亡情况。随机将24只SD大鼠分为缺血再灌注后6、12、24 h和对照组。采用结扎大鼠左侧颈总动脉和夹闭右侧颈总动脉15m in后放开的方法制备大鼠脑缺血再灌注模型。应用Hoechst33258荧光染色及免疫组化Bax蛋白表达来检测细     

大气红外辐射传输的简便算法与MODTRAN的比较

以红外辐射的传输理论为基础,考虑高度、倾斜以及气象条件等因素,建立了大气光谱透过率、平均透过率的理论模型与计算方法。利用以此算法为基础的程序进行了模拟计算,可得到3.0～12.0μm的红外大气透过率。将此结果与MODTRAN的计算结果做了比较,在目标高度为20km的范围内,两者吻合较好。该算法简单,便于实际应用。     

α稳定噪声下一类周期势系统的振动共振

将多个低频微弱信号、高频信号和加性α稳定噪声共同激励的一类周期势系统作为研究模型,以平均信噪比增益(MSNRI)为性能指标,对α稳定噪声环境下周期势系统中的振动共振现象进行了研究,分别探究了α稳定噪声的特征参数α、对称参数β、加性噪声强度放大系数D、高频信号幅值B以及频率?对振动共振输出效应的影响.研究结果表明:1)在不同分布的α稳定噪声环境下,固定频率?(或幅值B),当幅值B(或频率?)逐渐增大时,MSNRI-B(或MSNRI-?)曲线出现多个峰值,即存在多个B区间(或?区间)可诱导振动共振,并且这些区间不会随噪声分布参数α或β的变化而变化;2)当加性噪声强度放大系数D发生变化时,幅值B和频率?的共振区间没有随着D的变化而变化,表明只有高频信号能量向待测低频信号转移,噪声能量并没有向待测低频信号转移.另外当幅值B、频率?固定时,随着D的逐渐增大,依然可以实现微弱信号的检测,表明振动共振可以克服工业现场噪声强度不可调控的缺点.本文研究结果提供了一种新的微弱信号检测方法,在信号处理领域有着潜在的应用价值.     

Porous NiO hollow quasi-nanospheres derived from a new metal-organic framework template as high-performance anode materials for lithium ion batteries

Porous hollow metal oxides derived from nanoscaled metal-organic framework (MOF) have drawn tremendous attention due to their high electrochemical performance in advanced Li-ion batteries (LIBs). In this work, porous NiO hollow quasi-nanospheres were fabricated by an ordinary refluxing reaction combination of a thermal decomposition of new nanostructured Ni-MOF, i.e., {Ni₃(HCOO)₆·DMF}_n. When evaluated as an anode material for lithium ion batteries, the MOF derived NiO electrode exhibits high capacity, good cycling stability and rate performance (760 mAh g^?1 at 200 mA g^?1 after 100 cycles, 392 mAh g^?1 at 3200 mA g^?1). This superior lithium storage performance is mainly attributed to the unique hollow and porous nanostructure of the as-synthesized NiO, which offer enough space to accommodate the dramstic volume change and alleviate the pulverization problem during the repeated lithiation/delithiation processes, and provide more electro-active sites for fast electrochemical reactions as well as promote lithium ions and electrons transfer at the electrolyte/electrode interface.