基于新模糊熵和得分函数的区间直觉模糊多属性决策

属性权重的确定以及对区间直觉模糊数的排序是多属性决策问题中两个最为关键的点。本文主要针对属性权重完全未知的多属性决策问题进行了研究,分析了现有大多数研究中关于区间直觉模糊熵和得分函数存在的局限性,进而提出了一种将不确定度和犹豫度相结合的新的模糊熵和得分函数。最后,通过对比实验证实了本文所提出的熵和得分函数应用到多属性决策中的有效性和合理性。     

南极中山站周边水环境冰情监测系统的设计与研究

系统实现对南极中山站周边冰、水环境的长期连续实时监测,可以为分析南极环境变化是否对全球气候异常变化造成影响提供最基本的科学数据.利用空气,冰与水介质的电导率不同的原理用微控制器控制冰情检测传感器来实现冰水环境的自动化监测,设计了可以实现冰厚度、水深度、温度的定点连续冰情监测系统,监测数据可以存储在系统内嵌的SD存储卡中,方便观测人员进行调用.通过卫星实现数据无线传输.     

Phase control of light amplification in steady and transient processes in an inverted-Y atomic system with spontaneously generated coherence

We investigate the effects of spontaneously generated coherence （SGC） on both the steady and transient gain properties in a four-level inverted-Y-type atomic system in the presence of a weak probe, two strong coherent fields, and an incoherent pump. For the steady process, we find that the inversionless gain mainly origins from SGC. In particular, we can modulate the inversionless gain by changing the relative phase between the two fields. Moreover, the amplitude of the gain peak can be enhanced and the additional gain peak can appear by changing the detuning of the coupling field. As for the transient process, the transient gain properties can also be dramatically affected by the SGC. Compared to the case without SGC, the transient gain can be greatly enhanced with completely eliminated transient absorption by choosing the proper relative phase between the two fields. And the inverted-Y-type system with SGC can be simulated in both atomic and semiconductor quantum well systems avoiding the conditions of SGC.     

Acceleration of Flare Protons by Langmuir Plasmons

We analytically study the turbulent acceleration of solar protons by strong Langmuir plasmons in Cerenkov processes.It is shown that among the wave spectra with self-retained source only the Pelletier spectrum (Wk ∝ k^-7/2) can result in the energy spectrum of non-relativistic protons,which gives a good fit to that observed from solar flare events.It is quite possible that strong Langmuir turbulence presents in coronal active region,with three-dimensional,isotropic and stationary spectrum proportional to k^-7/2,and is responsible for the acceleration of flare protons.     

Observation of linewidth narrowing due to a spontaneously generated coherence effect

We investigate the resonance fluorescence spectrum of an atomic three-level ladder system driven by two laser fields.We show that such a system emulates to a large degree a V-type atom with parallel dipole moments-the latter being a system that exhibits spontaneously generated coherence and can display ultrasharp spectral lines.We find a suitable energy scheme in a 85Rb atom and experimentally observe the narrowing of the central peak in a rubidium atomic beam.The corresponding spectrum can convincingly demonstrate the existence of spontaneously generated coherence.     

抗黄曲霉毒素B1多价纳米抗体融合蛋白的构建及活性分析

纳米抗体来源于天然缺失轻链的重链抗体可变区,是已知最小抗原结合单元.该研究构建了抗黄曲霉毒素B1(AFB1)纳米抗体的单价及多价串联体,分别与绿色荧光蛋白(GFP)编码片段融合并克隆至原核表达载体pET30.以大肠杆菌BL21(DE3)作为表达宿主,通过异丙基-β-D硫代吡喃半乳糖苷诱导,亲和层析技术分别纯化单、双及三...     

自由反射面设计中的椭流面光滑化研究

基于配焦椭流面的光学自由曲面设计具有几何意义明确、设计灵活和优化思路清楚等优点,但也存在表面不光滑的弊端。为了将每个椭流面片尽可能地光滑拼接,从边缘一点为起始位置开始构建自由反射面,先在方向构建光滑的椭流面,然后通过调整能量分配的方法,减小曲面在方向的不连续性。通过仿真验证,此方法可在2 min内完成对40 000个椭球面片的计算处理,构建的曲面保证能量在目标面上均匀分配的同时在连续光滑性上也有很大提高。     

Zn1-x HfxO的电子结构和光学性质的第一性原理计算

基于第一性原理密度泛函理论,计算分析了Zn1-xHfxO(x=0,0.0312,0.0417,0.0625和0.1250)体系的晶格结构、电子结构,Mulliken电荷布居和光学性质.计算结果表明,随着Hf掺杂摩尔百分比的增大,晶体体积膨胀,费米能级进入导带,其附近的导带部分主要由杂质原子Hf的5d态贡献,Hf-O离子键成分作用凸显,故Hf的掺杂引入施主能级进而形成n型ZnO材料的可能性较大.且通过比较吸收谱、反射谱和折射谱,发现适量掺入Hf原子可使ZnO体系在高能区的透过率增加,能量损失谱出现红移.这些性质均与实验中Hf掺杂有类似结果,由此可知适量掺杂Hf的ZnO体系有望在制备光电子器件等领域发挥作用.     

Hf、N以不同比例掺杂ZnO的第一性原理计算

基于第一性原理密度泛函理论,计算分析了Hf、N以不同掺杂比例掺杂ZnO（Zn16O16）形成Zn15O16-xHfNx（x=1,2,3,4）体系的结构参数、电子结构、Mulliken电荷布居和光学方面的性质。计算结果表明,掺杂体系晶胞体积不同程度增大;x=1时体系的费米能级上移进入导带使其呈现n型半导体特征,吸收峰和反射峰红移较小,尤其是反射峰,主要表现为强度的变化;但x=2,3,4体系的费米能级均在价带顶附近,且随掺杂比例的增大,掺杂体系的费米能级进入价带的深度逐渐增大,N 2p态的贡献作用也越来越显著,使掺杂体系呈现p型半导体特征,吸收峰和反射峰均有较大的红移,这将有利于ZnO体系在可见光领域的应用。     

定向排列金纳米棒的非线性吸收EI北大核心CSCD

通过静电纺丝技术定向排列群体金纳米棒(GNRs),制备了GNRs-纳米纤维复合薄膜。利用偏振依赖的开孔z扫描技术,发现了薄膜的各向异性饱和吸收性质。该定向排列的GNRs-纳米纤维薄膜在光纤激光器领域具有重要的应用前景。