被动差分光学吸收光谱法监测污染源排放总量研究

研究了一种测量污染源污染气体(如SO2、NO2)排放总量的光学遥测方法,即采用被动差分光学吸收光谱(DOAS)系统在移动平台(如汽车)上对污染源排放烟羽进行扫描测量,利用被动差分光学吸收光谱处理方法对系统采集的天顶太阳散射光谱进行处理获取柱密度,在结合测量时段的气象(风场)信息后获得污染气体的排放通量,最终得到排放总量。着重描述了获得烟羽垂直柱密度的差分光学吸收光谱方法以及污染气体排放通量的计算方法,并利用车载被动差分光学吸收光谱系统对某一热电厂SO2排放进行了外场测量,实验结果与在线设备的对比表明:这种基于被动差分光学吸收光谱光学遥测方法能够用于污染源排放总量的快速测量。     

tetracene 分子在Ru(1010)表面的吸附结构及其电子态研究

利用紫外光电子能谱(UPS)、角分辨紫外光电子能谱(ARUPS)和扫描隧道显微镜(STM)等方法研究了tetracene分子在Ru(1010)表面上吸附的电子态，吸附位置和吸附取向.UPS实验显示，与tetracene分子有关的光电子谱峰在费米能级以下2.1, 3.5, 4.8, 6.0, 7.1和9.2 eV处；ARUPS 结果表明，tetracene分子的分子平面基本平行于衬底表面；从STM图像中可以看到tetracene分子的长轴沿［0001］和［1210］两个晶向.基于密度泛函理论的从头算计算证实了上述结论.当分子长轴沿［0001］晶向时，分子中心位置在衬底表面的“短桥位”上，当分子长轴沿［1210］晶向时，分子中心位置在衬底表面的“四原子中心空位”上. 关键词： tetracene分子 Ru(1010)表面 吸附结构 吸附电子态     

配位场弱场方案的酉群方法（f^N离子）

本文用李代数方法构造了匹配于群链■的对称函数。此群链是f~N离子的配位场弱场方案中的对称群链之一。     

Optical data storage in nonphotosensitive media by femtosecond laser pulses

Ultrashort lasers have become powerful tools by inducing extremely nonlinear effects in a wide variety of materials. Femtosecond laser data storage in non-photosensitive media is promising for its high density and fast retrieval. We reviewed the progress of three types of femtosecond laser storage in transparent materials: three-dimensional bit-oriented storage by micro-voids, holographic data storage by two beam interference and storage by computer-generated holograms.     

基于SOA光开关的高性能计算机全光互连网络

为了实现高性能计算机系统中各处理节点之间的高带宽低延时的互连通信,基于现有的光器件和光互连技术,提出了一种面向高性能计算机的支持组播的全光互连网络SBOS,同时描述了使用单级SBOS网络构建大规模多级互连网络的方法.在高性能计算机系统中采用基于SBOS的全光互连网络,可以有效地提高网络带宽的利用率,降低各级之间的延时,减小网络链路的出错概率,同时在大规模组播应用中,也可以明显地提高其效率.     

浅谈高职高专院校生物化学实验教学现状及对策

本文分析了高职高专生化实验课教学存在的不足,就生物化学实验教学过程的教学环节、教学手段等方面,提出了实施创新教育的措施,以求提高高职高专院校生物化学实验教学质量,获得最佳的实验教学效果。     

集合相交问题的双方保密计算

用公开密钥加密算法解决了集合相交的多方保密计算问题，并提出了3种解决方案，它们均基于参与保密比较的双方都是半诚实的．所提方案既可以使双方知道集合的交集，也可以使双方只知道交集的势，而不知道具体的交集，同时运用模拟范例证明了解决方案的保密性．该方案适用于不暴露交集的元素、向一方暴露交集的元素、向双方暴露交集的元素等3种场合，且计算复杂度较低，可以容易地推广到保密计算的多个集合相交的问题，在网络隐私保护方面具有重要的应用价值．     

Borderline magic clustering: the fabrication of tetravalent Pb cluster arrays on Si(111)-(7x7) surfaces

Well-ordered arrays of identical Pb clusters have been fabricated on a Si(111)-(7x7) substrate by the temperature-mediated surface clustering method. Interestingly, these clusters can easily transform into other forms when the growth temperature deviates slightly from the optimal values. In accord with experiments, first-principle total-energy calculations reveal several cluster structures centered on a mixed cluster model involving surface Pb and Si exchange. This borderline Pb/Si(111) system provides a unique, controlled way to study surface magic cluster formation and breakup dynamics.     

Study the effects of divalent metallic ions on the combination of DNA and histones with fluorescence anisotropy assays

The effects of divalent ions(Mn2 ,Mg2 ,Ca2 ) on the interaction between DNA and histone are studied using a fluorescence anisotropy assay. Fluorescence anisotropies of DNA and DNA-histone in the presence of divalent ions(Mn2 ,Mg2 ,Ca2 ) are measured. The results indicate that histone reduces the fluorescence anisotropy of lambda DNA while the divalent ions(Mn2 ,Mg2 ,Ca2 ) significantly enhance the fluorescence anisotropy. Compared to the case of DNA incubated with histone alone,there are more histones binding to DNA when divalent ion,histone and DNA are incubated together. We also find that Mn2 makes the DNA-histone complexes more condensed than the other ions do.     

Optimization of dual effects of Mg– 1Ca alloys on the behavior of chondrocytes and osteoblasts in vitro

Mg ions can enhance the proliferation and redifferentiation of chondrocytes and the osteogenic differentiation of osteoblasts at specific concentrations, respectively. However, degradation of Mg alloys at varying degradation rates could lead to complex changes in the surrounding tissue environment, such as changes in the dynamic concentration of Mg ions and subsequent p H value. Considering the above mentioned factors, the comprehensive effects of Mg alloys on chondrocytes and osteoblasts behaviors have not yet been optimized. In this study, we evaluated the effects of Mg–1Ca microspheres on cell behavior with an aim to optimize conditions favorable for both cell types. Cells were cultured with Mg–1Ca microspheres prepared using the following concentrations: 250 μg/ml, 500 μg/ml and 1000 μg/ml. At specific time points,cytotoxicity, expression of specific genes and extracellular matrix deposition by cells(Alizarin Red Staining of osteoblasts and Alcian blue staining for chondrocytes) were evaluated. The experimental results revealed that Mg–1Ca microspheres prepared at a concentration of 250 μg/ml were optimum for both cell types, where chondrocytes were found to be in hypertrophy state while osteoblasts in close proximity to the microspheres showed osteogenetic differentiation. Interestingly, a slight change in osteoblasts behavior was observed nearer to and at a relative distance away from Mg–1Ca microspheres, an important observation for administering the application of microspheres as potential scaffolds.