静压下半导体微腔内激子与光子行为的研究

由于腔模与激子对压力的依赖关系不同,所以可以选择不同的压力使激子和光场处于不同的耦合状态,从而实现对耦合的调谐。利用这种办法,我们观测到了代表激子与光场强耦合作用的Rabi分裂。由于在我们现有样品结构中压力对激子本征行为的影响很小,与以前报道的温度、电场等调谐方式相比,这种调谐方法不仅可以有效地调谐半导体微腔内激子与腔模的耦合程度,而且能够保持激子的本征性质在整个调谐过程中基本不变。这有助于研究在强耦合过程中激子极化激元的本征性质。将实验结果与压力下激子与腔模耦合理论进行拟合,得出了正确的Rabi分裂值。     

氧化锰团簇粒子在有序多孔氧化锆孔道中的组装及其特殊性能研究

利用醇溶液浸渍法及后续的热处理工艺成功实现了氧化锰团簇粒子在有序多孔氧化锆孔道中的组装，借助XRD，TEM，UV-vis，EPR以及O~2-TPD等分析手段进行样品结构表征及性能分析。研究表明，氧化锰团簇粒子能比较均匀地分散于规则的孔道中；团簇粒子的生长随着热处理温度的提高受到孔道大小的限制；孔道中的氧化锰团簇粒子能显示出与较大尺寸氧化锰粒子完全不同的强顺磁信号，并且还具有优异的表面氧吸附特性。     

Ultrafast photo-induced turning of magnetization and its relaxation dynamics in GaMnAs

We report that,by linearly polarized pumping of different wavelengths,Kerr transients appear at zero magnetic field only in the case when GaMnAs samples are initialized at 3 K by first applying a 0.8 Tesla field and then returning to zero field.We find that,instead of magnetization precession,the near-band gap excitation induces a coherent out-of-plane turning of magnetization,which shows very long relaxation dynamics with no precession.When photon energy increases,the peak value of the Kerr transient incre...     

磁通量子比特qubit信号强度随势垒偏置电压的变化

在20mK极低温下,测量了超导磁通量子比特的环流方向,并测到量子比特(qubit)信号.通过改变磁通量子比特的势垒高度,得到qubit信号强度随势垒高度的变化的实验数据并建立理论模型解释了实验现象.     

Recent progress in the application of microfluidic systems and gold nanoparticles in immunoassays

Immunoassays are useful for many bioassays. Many new techniques and materials are introduced into the immunoassay to improve the efficiency. This paper reviews recent progress in the application of microfluidic systems and gold nanoparticles in immunoassay. The micro/nano technologies and materials can offer good sensitivity, fast detection, cost-effectiveness and easy signal readout. In particular, the miniaturization of microfluidics and colorimetric assays based on gold nanoparticles have dramatically im...     

Integrating algebra and proof in high school mathematics: An exploratory study

Frequently, in the US students’ work with proofs is largely concentrated to the domain of high school geometry, thus providing students with a distorted image of what proof entails, which is at odds with the central role that proof plays in mathematics. Despite the centrality of proof in mathematics, there is a lack of studies addressing how to integrate proof into other mathematical domains. In this paper, we discuss a teaching experiment designed to integrate algebra and proof in the high school curriculum. Algebraic proof was envisioned as the vehicle that would provide high school students the opportunity to learn not only about proof in a context other than geometry, but also about aspects of algebra. Results from the experiment indicate that students meaningfully learned about aspects of both algebra and proof in that they produced algebraic proofs involving multiple variables, based on conjectures they themselves generated.     

Electromagnetic transmission in configurations composed of two one-dimensional perfect electric conductor metal gratings

We study transmission properties in configurations composed of two single metal gratings with different thicknesses. Choosing the perfect electric conductor excludes the influence of intrinsic material dispersion on transmission behaviors; and as such, we aim to reveal the contribution of geometric dispersion to electromagnetic transmission. Transmission suppression line, instead of a transmission suppression point, is discovered, denoting the curve of the wavelength versus the interval or the lateral displacement between the two single gratings when the transmission suppression appears. A simplified model is proposed to comprehend the underlying physics of this special phenomenon.     

Experimental measurement of single-wall carbon nanotube torsional properties

We report on the characterization of nanometer-scale torsional devices based on individual single-walled carbon nanotubes as the spring elements. The axial shear moduli of the nanotubes are obtained through modeling of device reaction to various amounts of applied electrostatic force and are compared to theoretical values.     

Integrating Algebra and Proof in High School: Students' Work with Multiple Variables and a Single Parameter in a Proof Context

In the United States, researchers argue that proof is largely concentrated in the domain of high school geometry, thus providing students a distorted image of what proof entails, which is at odds with the central role that proof plays in mathematics. Despite the centrality of proof, there is a lack of studies addressing how to integrate proof into other mathematical domains. In this article, we discuss a teaching experiment designed to integrate algebra and proof in the high school curriculum. Algebraic proof was envisioned as the vehicle that would provide high school students the opportunity to learn not only about proof in a context other than geometry but also about aspects of algebra. Results from the experiment indicate that students meaningfully learned about aspects of both algebra and proof in that they produced algebraic proofs involving multiple variables and a single parameter, based on conjectures they themselves generated.