Adiabatic Passage Based on the Calcium Active Optical Clock

We propose a new application of the optical adiabatic passage effect for the excitation of a thermal atomic beam, which will be used in the calcium active optical clock to produce population inversion. A comparison between the optical adiabatic passage effect and the Rabi π pulse is investigated, 99% of the calcium atoms in the atomic beam that has a wide velocity distribution will be excited to the upper state for population inversion using the adiabatic passage, while 76% at most will be excited to the excited state using the π pulse with suitable parameters.     

Another Conserved Quantity by Mei Symmetry of Tzénoff Equation for Non-Holonomic Systems

As a direct result of Mei symmetry of the Ténoff equation for non-holonomic mechanical systems, another conserved quantity is studied. The expression and the determining equations of the above conserved quantity are also presented. Using this method, it is easier to find out conserved quantity than ever. In the last, an example is presented to illustrate applications of the new results.     

Fabrication and Properties of Double-Side Tl2Ba2CaCu2O8 Thin Film on CeO2 Buffered Sapphire Substrate

The double-side Tl2Ba2 CaCu2O8 （Tl-2212） superconducting thin films were fabricated on CeO2 buffered sapphire substrates. The reactive magnetron sputtering technique was used to grow CeO2 buffer thin films on sapphire substrates. Making use of the metal cerium as a sputtering source, the depositing rate is much higher compared with the CeO2 target. The Ti-2212 thin films on CeO2 buffered sapphire substrates were fabricated by adc magnetron sputtering and post-annealing process. The x-ray diffraction indicates that the thin film is pure Tl-2212 phase with the e-axis perpendicular to the substrate surfaces, and epitaxially grown on the CeO2 buffered sapphire. The critical transition temperature Tc is around 106K, the critical current density Jc is around 3.5 MA/cm^2 at 77K, and the microwave surface resistance R8 at 77K and 10 CHz of the film is as low as 390μ Ω.     

Coupled THz Waveguide Utilizing Surface Plasmon Polaritons on Thin Dielectric Slab Sandwiched between Two Corrugated Metallic Claddings

We present a comprehensive experimental study of terahertz （THz） wave propagation utilizing surface plasmon polaritons （SPPs） on the interfaces of a thin dielectric core layer sandwiched between two corrugated metallic claddings. THz wave impinges on the structured surfaces at normal incidence. Long-lasting oscillation propagation features are observed in the temporal waveform after traveling through the periodic arrays. The enhanced THz transmission can be achieved due to the coupling between incident waves to SPPs at the bottom and top interfaces. The finite element method is used to simulate the field distribution and the transmission mode in the waveguide. The hybrid waveguide with low absorption has great potential applications in THz integrated devices.     

Numerical Study on Open-Circuit Voltage of Single Layer Organic Solar Cells with Schottky Contacts: Effects of Molecular Energy Levels, Temperature and Thickness

We numerically investigate the effects of the exciton generation rate G, temperature T, the active layer thickness d and the position of LUMO level EL related to the cathode work function Wc at a given energy gap on the opencircuit voltage Voc of single layer organic solar cells with Schottky contact. It is demonstrated that open-circuit voltage increases concomitantly with the decreasing cathode work function Wc for given anode work functions and exciton generation rates. In the case of given cathode and anode work functions, the open-circuit voltage first increases with the exciton generation rate and then reaches a saturation value, which equals to the builtin voltage. Additionally, it is worth noting that a significant improvement to Voc could be made by selecting an organic material which has a relative high LUMO level （low ｜EL｜ value）. However, Voc decreases as the temperature increases, and the decreasing rate reduces with the enhancement of exeiton generation rate. Our study also shows that it is of no benefit to improve the open-circuit voltage by increasing the device thickness because of an enhanced charge recombination in thicker devices.     

High Efficiency Multi-kW Diode-Side-Pumped Nd：YAG Laser with Reduced Thermal Effect

We demonstrate a high efficiency multi-kW diode-side-pumped Nd：YAG laser. High cooling efficiency of the diode-side-pumped module in the laser is achieved. The middle portion of the Nd：YAG rod in the module is cooled by a coolant jet with screwed side surface, and the end-caps of the rod without screwed side surface are cooled by Au coated on the surface. The thermal effect of the laser rod is reduced, which leads to high output power with high optical-optical conversion efficiency. By using three identical Nd：YAG laser modules, an output power of 4.2 kW and beam quality of 58 mm＆#12539;mrad with an optical-optical efficiency of 35% at 1064 nm is obtained in a laser oscillator. By using four identical Nd：YAG laser modules, an output power of 3.1 kW and beam quality of 17 mm＆#12539;mrad with an optical-optical efficiency of 25.8% is demonstrated in a master oscillator power-amplifier system.     

自由基SiH_2分子配分函数的计算

利用Gaussian03程序包,在B3P86/cc-PV5Z水平上对自由基SiH_2分子基态X~1A_1几何结构进行优化计算,得到其平衡几何结构、谐振频率和转动常数等性质参数;采用乘积近似法计算了自由基SiH_2分子基态X~1A_1从低温20 K到高温6000 K温度范围内的总配分函数.其中,转动配分函数采用WATSON的刚性转子模型,振动配分函数采用谐振子近似.然后我们把20～6000 K的温度范围划分为五个区间段,计算的总配分函数在这五个温度区间分别被拟合到一个温度T的四阶多项式,从而在每个区间均得到五个拟合系数.由这些拟合系数就可以快速、准确的获得该分子在所研究温度范围内任意温度的总的配分函数.     

基于高光谱反射率的冬小麦生长后期氮素丰度监测研究

生物量、氮素含量和LAI(leaf area index)是生态系统中表征作物长势最重要的参数,叶干重、叶片氮素含量和LAI实时动态监测对小麦氮素营养诊断和管理调控具有重要意义。选用了五个小麦品种和四个氮素水平的比较实验,研究不同处理冬小麦抽穗到黄熟期氮素丰度(NR)与光谱反射率差值(ΔR)的关系,建立冬小麦后期氮素丰度监测模型。结果表明,不同品种的冬小麦冠层叶片氮素丰度随生育进程推进而增加,不同氮素处理氮素丰度大小为N0N3N1N2,光谱参量TCARI和VD672与氮素丰度的相关性最好,相关系数(r)分别为0.870和0.855,其建立氮素丰度估测模型的决定系数分别为0.757和0.731,预测准确率达84.56%和80.13%。光谱参数TCARI和VD672可以有效地评价小麦后期冠层叶片氮素状况,可以对氮素丰度进行准确可靠的监测。     

Existence of multiple solutions for a fractional p-Laplacian system with concave-convex term

In this article, we study the existence of multiple solutions for the following system driven by a nonlocal integro-differential operator with zero Dirichlet boundary conditions{(-?)_p~su = a(x)|u|~(q-2) u +2α/α + βc(x)|u|~(α-2) u|v|~β, in ?,(-?)_p~sv = b(x)|v|~(q-2) v +2β/α + βc(x)|u|α|v|~(β-2) v, in ?,u = v = 0, in Rn\?,(0.1) where Ω is a smooth bounded domain in Rn, n ps with s ∈(0,1) fixed, a(x), b(x), c(x) ≥ 0 and a(x),b(x),c(x) ∈L∞(Ω), 1 q p and α,β 1 satisfy pα + βp*,p* =np/n-ps.By Nehari manifold and fibering maps with proper conditions, we obtain the multiplicity of solutions to problem(0.1).?????     

随机利率下的PPP项目实物期权评价研究

PPP项目通常实施周期长,风险突出。传统的实物期权评价方法考虑了未来的不确定性和管理者柔性的价值,但是一般假设无风险利率是固定的,不符合利率长期内波动的特点,会造成投资者决策失误。本文考虑了未来无风险利率波动条件下,PPP项目中实物期权的价值。首先分析了PPP项目中通常存在的期权形式,其次研究了无风险利率三角逆变函数以及在此基础上得出模拟实物期权模型,并用案例对比分析固定利率和随机利率下的期权价值。结果显示,随机利率比固定利率下的期权价值更高,研究结论可以为PPP项目的投资者进行决策提供重要依据。