新大线同沟敷设热力分析

针对新大线同沟敷设管道,采用非结构化有限容积法,分析了不同的物性条件下,常温输送原油对加热输送原油的热力影响.     

Efficient continuous-wave eye-safe region signal output from intra-cavity singly resonant optical parametric oscillator

We report an efficient continuous-wave (CW) tunable intra-cavity singly resonant optical parametric oscillator based on the multi-period periodically poled lithium niobate and using a laser diode (LD) end-pumped CW 1064 nm Nd:YVO₄ laser as the pump source. A highly efficiency CW operation is realized through a careful cavity design for mode matching and thermal stability. The signal tuning range is 1401-1500 nm obtained by varying the domain period. The maximum output power of 2.2 W at 1500 nm is obtained with a 17.1 W 808 nm LD power and the corresponding conversion efficiency is 12.9%.     

Constraints from Type Ia supernovae on the Λ-CDM model in Randers-Finsler space

Gravitational field equations in Randers-Finsler space of approximate Berwald type are investigated. A modified Friedmann equation and a new luminosity distance-redshift relation is proposed. A best-fit to the Type Ia supernovae (SNe) observations yields that the Ω_Λ in the Λ-CDM model is suppressed to almost zero. This fact indicates that the astronomical observations on the Type Ia SNe can be described well without invoking any form of dark energy. The best-fit age of the universe is given. It is in agreement with the age of our galaxy.     

Zig-Zag板条泵浦的2.12μm激光器

 为了实现窄脉宽、高峰值功率2.12 μm激光的稳定输出,设计了基于侧面泵浦Zig-Zag 板条产生1.06 μm基频光,进而泵浦KTP晶体通过II类相位匹配产生2.12 μm激光的光参量振荡实验。对外腔及内腔进行了实验研究,分别获得了1.53%和2.86%的电光转换效率。在20 Hz频率下内腔2.12 μm输出能量达到70 mJ以上,脉宽7 ns~9 ns。其中内腔实验中能量输出稳定度接近8%。     

Spectroscopic properties of thulium ions in bismuth silicate glass

A new type of bismuth silicate glass (Bi2O3-SiO2-ZnO-Al2O3-La2O3) doped with Tm2O3 is prepared by melt-quenching method. The thermal stability of the glass is examined by differential scanning calorimetry. No crystallization peak is found. Using the absorption and emission spectra, the absorption and emission cross-sections are calculated. Their maximum data are 2.9×10-21cm2 at 1663 nm and 4.7×10-21cm2 at 1826 nm, respectively. Using the Judd-Ofelt theory, the radiation transition probabilities and radiative lifetimes are obtained. The extended overlap integral method is applied to analyze energy transfer process among the Tm3+ ions. The transfer constants of cross-relaxation and energy migration among the Tm3+ ions at the 3H4 level are 7.60×10-40 and 14.98×10-40 cm6 /s, respectively. The critical transfer radius for cross-relaxation is 0.99 nm. The cross relaxation process is easy to realize and is favorable for obtaining ～2-μm laser.     

富钙镁离子溶液以碳酸盐沉淀固定CO2的试验研究

提出了利用富钙镁离子溶液（海水淡化产生的浓海水、地下卤水、高硬度工业废水等）以碳酸盐沉淀形式实现CO₂固定的思路,以2倍浓度的海水为例进行分析,表明富钙镁离子溶液具有可观的固碳潜力。考察了氨水-氯化铵溶液、氨水-碳酸氢铵溶液和有机胺（MEA、MDEA）作为添加剂提高溶液pH值的方式对碳酸盐沉淀形成能力的影响。结果表明这三种添加剂均可在一定程度上提高溶液pH值,促进富钙镁离子溶液中难溶碳酸盐沉淀形成。     

由七位日本诺贝尔物理学奖获得者引发的一些思考

对7位日本诺贝尔物理学奖获得者进行了系统的介绍与分析,可为我们提供一些启示.     

高功率固体激光器锥形空间滤波孔应用

锥形空间滤波孔是一种应用于高功率固体激光装置空间滤波的新型结构滤波小孔,其内部光滑的锥形结构可以有效滤除光束中的高频成分且避免等离子堵孔现象的发生。根据神光-Ⅲ主机装置结构特点,设计并加工了适用于主机装置的锥形空间滤波小孔,并开展了应用实验研究。通过与传统的平面结构滤波小孔对比可以看出,锥形小孔有效地避免了等离子体度堵孔现象,在与光束波前补偿技术配合使用条件下,保证光束顺利过孔,并成功实现了基频光7988 J的满能量输出。     

结构与参量不确定的网络与网络之间的混沌同步

进行了结构与参量不确定的网络与网络之间的混沌同步研究．通过设计适当的控制输入,不但实现了两个复杂网络之间的混沌同步,而且网络节点状态方程中的未知参量和网络内部节点之间的耦合强度也被同时确定．通过采用具有调制损耗的CO2激光器的状态方程进行仿真实验,发现网络与网络之间的同步性能非常稳定．     

Induced electric fields and plasmonic interactions between a metallic nanotube and a thin metallic film

We have numerically simulated the induced electric fields and the plasmonic interactions of a metallic nanotube near a thin metallic film. Our study shows that the energies and intensities of the plasmon resonances depend strongly on the aspect ratio (the ratio of the inner to outer radius) of the nanotube as well as the separation between the center of the nanotube and the upper surface of the metallic film and the thickness of the film. The enhancement of the induced electric field of this system reaches ...