共查询到19条相似文献,搜索用时 265 毫秒
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王云萍 《激光与光电子学进展》2001,(9):4
将喷管一维守恒气体动力学方程与振动弛豫方程联立,计算了燃烧驱动气动CO2激光器激光介质的小信号增益沿流场方向的变化;以及小信号增益分别随燃烧室温度、压强及不同组分配比的变化.计算结果表明,气动CO2激光器介质增益区较长且变化缓慢;较高的燃烧室温度、压强和CO2分子含量以及较低H2O含量是产生较高增益的必要条件.本文对气动CO2激光器介质小信号增益的计算结果,可为激光器光腔的设计以及燃料与高压空气的最佳配比提供参考.(OA13) 相似文献
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《电子科技文摘》2001,(2)
0101927燃烧驱动气动 CO_2激光器几种液体燃料性能差异的数值模拟[刊]/王云萍//强激光与粒子束.—2000,12(4).—429~432(D)在甲苯、苯、煤油和乙醇四种不同液体燃料燃烧驱动条件下。对气动 CO_2激光器燃烧室的平衡组分、小信号增益沿流场方向的分布及激光器的输出功率进行了数值模拟,计算对比分析了该四种燃料的性能。计算结果表明甲苯是这四种燃料中最为理想的燃料。参4SPIE-Vol.3631-97 0101928光电子激光器与检测器(含4篇文章)=Session 4:op-toelectronic lasers and detectors[会,英].—97~130(PC)本部分含4篇文章。题名为:宽可调混合半导体激光器,模拟光纤链路与信号处理用的波导异质结光电晶体管,基于硅的集成 Ge/Si 量子阱和超晶格红外 相似文献
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在国内外数值模拟工作的基础上,建立了更加准确的"混合型气动CO2激光器(简称MGDL)"增益场计算程序。利用该程序,一方面研究了基于筛形喷管的混合型气动CO2激光器光腔中的小信号增益分布规律;另一方面着重研究了主喷管入口总温对基于筛形喷管的混合型气动CO2激光器小信号增益系数的影响规律。计算结果表明:当其他参数不变时,主喷管入口总温存在一个最佳值,使得光腔中的小信号增益系数最大;当主喷管入口总温小于这个最佳值时,随着主喷管入口总温的增加,光腔中相同位置处的小信号增益系数逐渐增大;当主喷管入口总温大于这个最佳值时,随着主喷管入口总温的增加,光腔中相同位置处的小信号增益系数逐渐减小。此外,分析了主喷管入口总温对小信号增益系数的影响机制。 相似文献
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本文描述了列阵喷管喉道高度为0.8毫米,马赫数为4.3的CO2气动激光器的实验装置和测量结果。观测了小讯号增益随CO2和H2O浓度、滞止温度和喷管出口下游距离的变化规律。当燃烧气体比在CO2=13%,H2O=1%和N2=86%左右时,平均小讯号增益为每米0.58,单孔耦合的单程稳定腔输出功率为1400瓦。 相似文献
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本文报导了CO_2-N_2-H_2O气动激光器(GDL)的一些实验测量结果。这些测量是用实验室内一种小尺寸试验设备——“微型火箭”——来完成的,对这种设备也作了详述。在火箭引擎的燃烧室中CO和H_2同O_2燃烧生成CO_2和H_2O;N_2作为一种稀释剂加入使混合结果的温度达到1500°K左右。CO_2、N_2和H_2O混合后的热气体经超声速膨胀使CO_2气体分子产生粒子数反转。以增益测量来表征这种粒子数反转。增益测量结果用其对气体组成、滞止压力和频率作图表示。此外又对共振腔的若干实验结果作了详述,其中光功率是作为质量流量、气体组成、频率和面积比的函数来测定。对CO和O_2以外的其他燃料和氧化剂的影响也进行了讨论。 相似文献
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S. D. Jacobs 《Journal of Electronic Materials》1975,4(2):223-241
Measurements performed on hot-pressed samples of ferromagnetic CdCr2S4 and ferrimagnetic CoCr2S4 indicate that they would be useful as optical isolators and modulators for CO2 lasers at 10.6 μm. Based on the Faraday effect, large aperture devices could be fabricated which would operate under modest
cooling and drive power requirements. The various figures of merit needed to evaluate the performance of these materials as
isolators and modulators have been determined optically with a low power CO2 laser. D.C. applied magnetic fields were used to determine the variations in measured Faraday rotation as a function of sample
thickness. Figures of merit pertinent to isolation were also obtained, such as the passive extinction ratio and forward to
backward transmitted energy ratio. A.C. applied magnetic fields were used to determine the frequency response of the materials,
their modulation depths, and drive powers up to 100 kHz. Short duration pulses were used to analyze higher frequency behavior. 相似文献
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采用中红外CO2激光差频产生太赫兹波是提高转换效率和输出功率的一种有效方法。根据差频过程中的三波互作用对AgGaS2晶体进行了理论分析,数值模拟了oeo类和oee类两种匹配条件下差频产生太赫兹波的角度调谐曲线,并计算了光波在晶体中的走离角和允许参量。另外,还考虑了晶体的有效非线性系数和理论功率转换效率。研究结果表明,AgGaS2晶体适用于中红外CO2激光差频产生可广泛调谐的太赫兹波。 相似文献
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Kazuyuki Uno Kenshi Nakamura Tatsumi Goto Takahisa Jitsuno 《Journal of Infrared, Millimeter and Terahertz Waves》2009,30(11):1123-1130
We have developed a longitudinally excited CO2 laser with a short laser pulse similar to that of TEA and Q-switched CO2 lasers. A capacitor transfer circuit with a low shunt resistance provided rapid discharge and a sharp spike pulse with a
short pulse tail. Specifically, a circuit with a resistance of 10 M Ω provided a spike pulse width of 103.3 ns and a pulse
tail length of 61.9 μs, whereas a circuit with a shunt resistance of 100 Ω provided a laser pulse with a spike pulse width
of 96.3 ns and a pulse tail length of 17.2 μs. The laser pulses from this longitudinally excited CO2 laser were used for processing a human tooth without carbonization and for glass marking without cracks.
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Junxiang Zhang Fuhui Wang Guicai Qi Jianli Cheng Lin Chen Huibiao Liu Bin Wang 《Advanced functional materials》2021,31(26):2101423
A rechargeable Li CO2 battery is one of the promising power sources for utilizing the greenhouse gas CO2 in a sustainable approach. However, highly efficient catalysts for reversible formation/decomposition of insulating discharge product, Li2CO3, are the main challenge, which can boost the cycle stability. Herein, 2D single-atom-thick graphdiyne (GDY) with abundant acetylenic bond sites is prepared by a bottom-up cross-coupling reaction strategy and used as metal-free catalysts for reversible Li CO2 batteries. The prepared GDY has a rich diacetylenic unit and atomic-level in-plane pores in the network, which can chemically adsorb the CO2 molecules and easily promote the Li+ diffusion and thereby resulting in uniform nucleation and reversible formation/decomposition of the discharge product. The GDY hybrid cathodes show a small overpotential gap of 1.4 V at a current density of 50 mA · g−1, a high full discharge capacity of 18 416 mAh · g−1 at 100 mA · g−1, and outstanding long-term stability of 158 cycles at 400 mA · g−1 with a curtailing capacity of 1000 mAh · g−1. Furthermore, a flexible belt-shaped Li CO2 battery is fabricated as a proof of concept with a high gravimetric energy density of 165.5 Wh · kg−1 (based on the mass of the whole device) as well as excellent mechanical flexibility. 相似文献