Experimental long-distance decoy-state quantum key distribution based on polarization encoding

We demonstrate the decoy-state quantum key distribution (QKD) with one-way quantum communication in polarization space over 102 km. Further, we simplify the experimental setup and use only one detector to implement the one-way decoy-state QKD over 75 km, with the advantage to overcome the security loopholes due to the efficiency mismatch of detectors. Our experimental implementation can really offer the unconditionally secure final keys. We use 3 different intensities of 0, 0.2, and 0.6 for the light sources in our experiment. In order to eliminate the influences of polarization mode dispersion in the long-distance single-mode optical fiber, an automatic polarization compensation system is utilized to implement the active compensation.     

巯基棉分离富集-FAAS法测定海水中的痕量镉

借助巯基棉分离富集技术 ,以火焰原子吸收光谱法测定海水中的痕量镉。该方法的回收率为94 .0 %— 97.0 % ,相对标准偏差为 4 .9%。结果表明 ,该方法简单易行 ,具有较好的准确度和精密度     

金属离子和热激处理对菊芋(Helianthus tuberosus L.)类金属硫蛋白基因htMT2表达的影响

使用不同金属离子及热激对菊芋进行了处理，并对菊芋不同组织器官中类金属硫蛋白基因(htMT2)mRNA水平的变化进行了研究．结果表明，htMT2在根中不表达，而且其表达不受金属离子的影响．Cu^2 降低叶中htMT2的表达，Cu^2 浓度与茎、叶中的htMT2 mRNA水平呈负相关性．在低浓度范围内，Zn^2 浓度与茎、叶中的htMT2 mRNA水平呈正相关性，而在高浓度范围内，Zn^2 浓度与htMT2 mRNA水平呈负相关性．Ca^2 对叶中htMT2表达的影响与Zn^2 的作用相似，但Ca^2 诱导茎中htMT2 mRNA水平升高．热激处理对不同组织中htMT2的表达无显著影响．研究的结果表明，htMT2表达受金属离子影响的特征与植物MT基因一致，进一步证实了我们前期工作中分离到的htMT2是一个新的植物MT基因．     

近独立子系系统的统计规律(四)——巨正则分布函数

根据吉布斯系综理论导出了由任意数目刚性粒子构成的力学系统的巨正则分布函数、化学势及粒子数和能量涨落公式.并介绍了刚球模型下,对二维和三维近独立子系系统巨正则分布的计算机模拟,结果与理论完全一致.     

流动注射-氢化物发生原子吸收光谱法测定飞灰、炉渣中的汞和砷

采用流动注射-氢化物发生原子吸收光谱法测定飞灰、炉渣中的汞和砷。在酸性介质中,用硼氢化钾作还原剂,通过载气导入电热石英吸收管,在波长253.7nm和193.7nm处分别对汞、砷进行测定。结果表明,该方法对汞和砷的检出限分别为0.27ng/mL,0.16ng/mL,回收率分别为97.8%、96.7%。该法操作简便、快速、灵敏度高,对实际样品的测定结果令人满意。     

Studies on multi-wavelength fiber Bragg grating laser strain sensor

A novel stable multi-wavelength fiber Bragg grating laser is achieved and its sensing characteristic with the strain is studied. The beat signals generated by the multi-wavelength fiber laser are measured under different strains. Four-wave mixing (FWM) is firstly observed in such a short-cavity fiber laser.     

Tailoring interacting magnetic nanodots via dimensionality variation of mediating electrons

Nature produces ferromagnetic materials based on nearest neighbor exchange interaction between atomic spins. For artificially fabricated nanomagnets, it is those “small” magnetic energies, e.g. anisotropy, dipolar interaction and indirect exchange interaction that play crucial roles against the thermal fluctuation. We have developed strong capabilities to grow nanodot assemblies in ultrahigh vacuum with controllable size and density on/in both metallic and insulating templates. Based on our novel synthesis capability, we have studied artificial nanomagnets with tunable coupling strength via dimensionality control of the mediating electrons in one-dimensional (1-D), 2-D, and 3-D. We show that such kind of dimensional confinement provides a unique way to induce novel magnetic properties and to gain control of them. The research outlined in this work provides the science base to understand, modify, and manipulate the magnetic properties through dimensional confinement.     

High-Power Diode-End-Pumped Slab Composite Tm:YLF Compact Laser

We design a continuous-wave Tm:YLF laser with a composite slab crystal end-pumped by two fiber-coupled laser diodes at room temperature. We achieve a maximum continuous wave output power of 105 W for the bonded slab Tm:YLF laser; the corresponding slope efficiency is 47.7% and the optical-to-optical conversion efficiency is 42.0% with respect to the incident pump power. The laser operated at 1,907.5 nm with a beam quality factor of M² ～3.2 at the highest output power.     

HL-2M极向场线圈电磁力的计算分析

在建的HL-2M装置的PF线圈采用了混合式结构。在放电过程中,线圈之间有很强的电磁耦合,每一个线圈都会受到很大电磁力的作用。采用解析法,在最大I_p=3MA等离子体电流和各种位形的放电条件下,计算分析了PF线圈受到的电磁力。这些计算结果对PF线圈及其支撑结构的设计都是具有参考价值的。