808 nm 抽运的Ho3+，Tm3+及Er3+掺杂的氟磷酸盐 玻璃的2.0 μm 光谱性质研究

2.0 μm spectroscopic properties of Er³⁺/Tm³⁺/Ho³⁺ triply-doped fluorophosphate glasses pumped by 808 nm and the energy transfer mechanisms between the three rare earth ions were investigated. J-O theory was used to calculate the parameters of Ho³⁺ in fluorophosphate glasses. Absorption and emission cross-sections and the gain coefficients were calculated. The obtained lifetime r and spontaneous transition probability Ar of Ho³⁺:⁵I7 level were 10.64 ms and 93.95 s^-1 respectively. The calculated maximum emission cross-section of 2.0 μm was 9.26×10^-21 cm². The energy transfer analysis indicated that the cross-relaxation of Tm³⁺ was important and the resonent energy transfer in Er³⁺&rarrHo³⁺, Tm³⁺&rarrHo³⁺, Er³⁺&rarrTm³⁺&rarrHo³⁺ process was the main channel. The study revealed that the Er³⁺/Tm³⁺/Ho³⁺ triply-doped fluorophosphate glass would be a potential material for 2.0 μm emission because of the efficient sensitization of Er³⁺ and Tm³⁺ to Ho³⁺.

栖热菌属高温菌RH99-02菌株产类胡萝卜素的研究

从腾冲热海分离到最高生长温度达80℃的一株嗜热非芽孢菌RH99-02菌株，经鉴定属Thermus属，对其所产类胡萝卜素进行了吸收光谱扫描及薄层层析分析。发酵研究表明振荡培养时的菌体生物量和色素产量上均高于静置培养，培养至50h菌体生物量和色素产量达到最大值，菌体色素产量为762μg/g干重。

微囊藻毒素LR诱导L-02细胞发生凋亡

目的了解微囊藻毒素(MC)LR对L-02细胞的毒性机制。方法以L-02细胞为材料,用不同浓度的MCLR处理该细胞,观察了细胞增殖能力、细胞形态改变、乳酸脱氢酶(LDH)泄漏、细胞凋亡率及凋亡相关基因等一系列指标的变化。结果 MTT细胞增殖实验可知,MCLR在24 h内对L-02细胞有轻微的抑制作用,随后却促进细胞增殖。48 h处理对 LDH泄漏没有显著影响,延时处理导致LDH泄漏发生,且MCLR浓度越高,LDH泄漏越严重,此结果显示发生了细胞氧化损伤。光镜下50μg/ml的毒素浓度在60 h处理后可造成明

S-808为浮选剂的磷矿尾矿水对鱼类的亚致死效应的研究

<正> 磷矿浮选剂S-808是我国新开发的一种浮选剂.对此作者曾进行了鱼类和胚胎的毒性试验.鉴定结果表明该浮选剂的毒性为“毒级”.鱼的胚胎毒性试验发现,即使在较低的浓度情况下,仍发现有致畸现象.但经浮选工艺流程操作后排出的废水,其毒性有明显的降低.那么长期作用于水生生物,

磷矿浮选剂S-808及其尾矿水对鱼类和胚胎的毒性

<正> S-808是我国选矿科技工作者研制的一种新型磷矿浮选剂。湖北省荆襄磷矿矿务局王集矿,在选矿过程中采用S-808作为抑制剂直接浮选中低品位钙质磷块岩,获得特殊的选矿效果。为此化工部矿山局委托我们开展磷矿浮选剂S-808对鱼类的毒性和毒理学的研究。

有机磷农药在水生态系中生物净化机理研究——2.CTP-02降解对硝基酚的特性和动力学

从鸭儿湖氧化塘中分离出具有分解对硝基酚能力的细菌Pseudomonas sp.,代号CTP-02。在实验室条件下,细菌培养物降解对硝基酚的速度与时间之间的动力学方程为dc/dt=-K_1t-K_2,细菌降解对硝基酚的最适温度为35℃,最适pH为7.5。CTP-02菌降解对硝基酚过程中首先发生脱硝基作用。

Theoretical gain of strained GeSn0.02/Ge1-x-y ' SixSny ' quantum well laser

Using effective-mass Hamiltonian model of semiconductors quantum well structures, we investigate the electronic structures of the Gamma-conduction and L-conduction subbands of GeSn/GeSiSn strained quantum well structure with an arbitrary composition. Our theoretical model suggests that the band structure could be widely modified to be type I, negative-gap or indirect-gap type II quantum well by changing the mole fraction of alpha-Sn and Si in the well and barrier layers, respectively. The optical gain spectrum in the type I quantum well system is calculated, taking into account the electrons leakage from the Gamma-valley to L-valley of the conduction band. We found that by increasing the mole fraction of alpha-Sn in the barrier layer and not in the well layer, an increase in the tensile strain effect can significantly enhance the transition probability, and a decrease in Si composition in the barrier layer, which lowers the band edge of Gamma-conduction subbands, also comes to a larger optical gain.

808 nm high-power laser grown by MBE through the control of Be diffusion and use of superlattice

808 nm high-power laser diodes are gown by MBE. In the laser structure, the combination of Si-doped GRIN (graded-index) region adjacent to n-AlGaAs cladding layer with reduced Be doping concentration near the active region has been used to diminish Be diffusion and oxygen incorporation. As compared with the laser structure which has undoped GRIN region and uniform doping concentration for Si and Be, respectively, in the cladding layers, the slope efficiency has increased by about 8%. Typical threshold current density of 300 A/cm(2) and the minimum threshold current density of 220 A/cm(2) for lasers with 500 mu m cavity length are obtained. A high slope efficiency of 1.3 W/A for coated lasers with 1000 mu m cavity length is also demonstrated, Recorded CW output power at room temperature has reached 2.3 W.

808-nm fiber coupled module with a CW output power up to 130 W

A fiber coupled module is fabricated with integrating the emitting light from four laser diode bars into multimode fiber bundle. The continuous wave (CW) output power of the module is about 130 W with a coupling efficiency of around 80%. The output power is very stable after the temperature cycling and vibration test. No apparent power decrease has been observed as the device working continuously for 500 h.

准连续17 kW 808 nm GaAs/AlGaAs叠层激光二极管列阵

高功率激光二极管列阵广泛应用于抽运固体激光器.报道了17 kW GaAs/AlGaAs叠层激光二极管列阵的设计、制作过程和测试结果.为了提高器件的输出功率,一方面采用宽波导量子阱外延结构,降低腔面光功率密度,提高单个激光条的输出功率,通过金属有机物化学气相沉积(MOCVD)方法进行材料生长,经过光刻、金属化、镀膜等工艺制备1 cm激光条,填充密度为80%,单个激光条输出功率达100 W以上;另一方面器件采用高密度叠层封装结构,提高器件的总输出功率,实现了160个激光条叠层封装,条间距0.5 mm.经测试,器件输出功率达17kW,峰值波长为807.6 nm,谱线宽度为4.9 nm.

静压下ZnS（0.02）Te（0.98）混晶的共振喇螺散射研究

于2010-11-23批量导入

甘肃当归新品系DGA2000-02的选育研究

当归新品系DGA2000-02是采用重离子束55MeV/u40Ar+15离子辐照甘肃当归90-01干种子,按新品种选育程序多年选育而成的。2005—2007年,在定西市岷县、渭源县、漳县、陇西县等地当归品系区域试验中,甘肃当归DGA2000-02平均产鲜当归10621.5kg/hm2,较对照品种(甘肃当归90-01)平均增产鲜当归1386.0kg/hm2,增产率15.0%。生育期790d,茎秆深紫色,根系黄白色。测定结果:总灰分4.2%,酸不溶性灰分0.4%,分别优于对照品种16%和33.3%;浸出物61.4%,较规定指标提高4.4%;阿魏酸0.148%,较规定指标提高2.96倍。质量显著优于对照品种和2005年版《中国药典》规定指标。适宜在海拔2000—2600m、年降水量500—600mm的二阴及高寒阴湿生态区栽培。

当归新品系“DGA2000-02”与对照品种的遗传差异分析

当归新品系"DGA2000-02"是利用兰州重离子加速器研究装置(HIRFL)对"岷归1号"进行重离子束辐照选育出来的。与岷归1号相比,DGA2000-02表现出更强的抗病性,产量也有较大提高。对这两个品种的表型、品质及遗传差异进行了系统的分析。为将来进一步选育产量高、品质好及抗逆性强的新品种提供研究基础。

双管B_(02)锯齿波发生器的研制

本论文从理论计算到实验结果详细讨论了B02聚束器双管高压锯齿波直接形成装置的研制过程。在3-18MHz的工作频率范围内，锯齿波德峰-峰电压值都达到了期望指标值1100v。而且理论计算结果与实验结果具有非常好的一致性。 前级脉冲放大器的设计与制作在本论文中也有详细讨论。对于实验中用到的各种附属设备在本文中也有所提及。