加大教改力度,提高工科物理实验教学质量

指出工科物理实验教学中存在的问题,并提出了提高工科物理实验教学质量的思路     

美国化学会颁发与化学教育相关的奖励

美国化学会(ACS,成立于1876年)在国际上和美国学术界享有很高的声望。一百多年来,ACS通过不懈的努力,卓有成效的工作,对化学科学与化学教育的发展起了巨大的推动作用。为了认定并表彰杰出的化学家和化学工程师所做的贡献,促进化学与化工的发展,ACS设立的全国性奖励项目超过50个。现介绍其中与化学教育相关的几个奖项。     

Entanglement sudden death of two atoms interacting with a cavity via the two-photon process in a strong-driving-assisted system

We examine the entanglement dynamics between two strongly driven atoms off-resonantly coupled with a single-mode cavity via the two-photon process with the help of negativity in two different types of initial states. The results show that entanglement sudden death may occur under both the above conditions and the sudden death effect can be monitored by modulating the atom--cavity detunings. Furthermore, we also find an atomic decoherence-free subspace so that the initial entanglement between two atoms remains invariable in application.     

Quantum superdense coding based on hyperentanglement

We present a scheme for quantum superdense coding with hyperentanglement,in which the sender can transfer four bits of classical information by sending only one photon.The important device in the scheme is the hyperentangled Bell-state analyzer in both polarization and frequency degrees of freedom,which is also constructed in the paper by using a quantum nondemolition detector assisted by cross-Kerr nonlinearity.Our scheme can transfer more information with less resources than the existing schemes and is nearly deterministic and nondestructive.     

锂离子电池负极材料Si-SiO_x-Sn/C的制备及电化学性质

采用碳热还原法在氮气保护下于管式炉中焙烧SiO、SnO2和碳的混合物,制备复合负极材料Si-SiOx-Sn/C。通过X射线衍射(XRD)、扫描电镜(SEM)对材料的结构进行表征,通过电化学阻抗谱(EIS)和充放电测试对材料的电化学性能进行测试和分析。结果表明:900℃焙烧2 h的样品由晶体锡、无定     

Dynamics of Quantum Fisher Information in Homodyne-Mediated Feedback Control

We investigate the quantum Fisher information(QFI) dynamics of a dissipative two-level system in homodynemediated quantum feedback control. The analytical results demonstrate that the maximum values and stable values of the QFI can be greatly enhanced via feedback control. The quantum feedback plays a more evident role in the improvement of classical Fisher information. The classical part can reach a high stable value, while the quantum part eventually decays to zero whatever the feedback parameter is.     

一类Keller-Segel型流体模型的弱熵解献给陈恕行教授80华诞

Keller-Segel型的流体力学模型属于带自吸引力的Euler-Poisson方程组.类似于抛物情形的Keller-Segel方程组,若总质量M＞8π,本文证明了该模型的弱熵解在有限时间内必爆破.对于临界质量M=8π和次临界质量M＜8π的情形,本文得到了相应的弱熵解的先验估计.     

聚乙烯醇/纳米羟基磷灰石/丝素蛋白复合水凝胶的制备及其性能研究

本文以聚乙烯醇(PVA)、纳米羟基磷灰石(n-HA)和丝素蛋白(SF)为原料,采用物理共混法、反复冷冻解冻法和NaCl粒子制孔法制得了具有三维结构的PVA/n-HA/SF多孔复合水凝胶,以作为人工角膜支架材料。测试了这种多孔复合材料的含水率、拉伸强度和断裂伸长率,并对其进行了红外谱图、X射线衍射光谱、热重及电子扫描显微镜分析。结果表明,丝素蛋白的添加量增加时,多孔复合水凝胶的含水率相应提高,含水率稳定在75～82%之间;其拉伸强度在0.43～1.00MPa之间,断裂伸长率在183.76～237.53%之间,可以达到人体正常状态下眼压要求,其中复合水凝胶的最佳配比为:PVA:SF:n-HA=10:5:1。;IR和XRD分析表明复合水凝胶在物理交联过程中,各种成分均匀复合,无化学键变化;扫描电镜显示该水凝胶材料具有均匀的三维多孔结构。     

一种检测汞离子的高灵敏度高选择性电致化学发光传感器

汞是一种常见的有毒重金属,主要以汞离子(Hg~(2+))形式存在,对人的健康和环境都产生极大的危害.传统的检测汞离子的方法有原子吸收/发射光谱法~([1]),荧光法~([2])等,但存在操作繁琐,检测限高等缺陷.这里我们将高灵敏度的ECL和高选择性的寡核苷酸相结合对汞离子进行检测,并得到了较满意的结果.