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Particle simulation of grid system for krypton ion thrusters

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Chinese Journal of Aeronautics 2018年第4期31卷 719-726页

作者： Maolin CHEN Anbang SUN Chong CHEN Guangqing XIA Science and Technology on Combustion Internal Flow and Thermo-Structure Laboratory Northwestern Polytechnical University State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong University State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology

The transport processes of plasmas in grid systems of krypton（Kr） ion thrusters at different acceleration voltages were simulated with a 3 D-PIC model, and the result was compared with xenon（Xe） ion thrusters. The variation of the screen grid transparency, the accelerator grid current ratio and the divergence loss were explored. It is found that the screen grid transparency increases with the acceleration voltage and decreases with the beam current, while the accelerator grid current ratio and divergence loss decrease first and then increase with the beam current. This result is the same with Xe ion thrusters. Simulation results also show that Kr ion thrusters have more advantages than Xe ion thrusters, such as higher screen grid transparency, smaller accelerator grid current ratio, larger cut-off current threshold, and better divergence loss characteristic. These advantages mean that Kr ion thrusters have the ability of operating in a wide range of current. Through comprehensive analyses, it can be concluded that using Kr as propellant is very suitable for a multimode ion thruster design.

关键词： Grid system Ion thrusters krypton Particle in cell method Plasma

Photoabsorption Spectrum and Optically Forbidden Transitions of krypton by Electron Impact

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Chinese Physics Letters 2002年第4期19卷 495-496页

作者：苑震生朱林繁等 KeyLaboratoryofBondSelectiveChemistry DepartmentofModernPhysicsUniversityofScienceandTechnologyofChinaHefei230026 KeyLaboratoryofBondSelectiveChemistry DepartmentofModernPhysicsUniversityofSciencea

A high resolution fast electron energy loss spectrometer with multi-channel energy analysis was employed. The maxima just above the threshold 4p^-1(^2P1/2), which is regarded as a shape resonance, was obtained at 16.3 eV. The optically forbidden excitations of 4s electron were measured for the first time, and the energy positions are 23.75 eV (4s^-15s), 25.66 eV (4s^-16s/4d) and 26.60 eV (4s^-17s/5d).

关键词： krypton

Shape coexistence and evolution in neutron-def icient krypton isotopes

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Chinese Physics C 2015年第9期39卷 43-47页

作者：柏志军付熙明焦长峰许甫荣 State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University National Institute for Radiological Protection Chinese Center for Disease Control and Prevention Department of Physics and Astronomy University of North Carolina Chapel Hill North Carolina

Total Routhian Surface （TRS） calculations have been performed to investigate shape coexistence and evolution in neutron-deficient krypton isotopes 72,74,76Kr. The ground-state shape is found to change from oblate in 72Kr to prolate in 74,76Kr, in agreement with experimental data. Quadrupole deformations of the ground states and coexisting 0＋ states as well as excitation energies of the latter are also well reproduced. While the general agreement between calculated moments of inertia and those deduced from observed spectra confirms the prolate nature of the low-lying yrast states of all three isotopes （except the ground state of 72Kr）, the deviation at low spins suggests significant shape mixing. The role of triaxiality in describing shape coexistence and evolution in these nuclei is finally discussed.

关键词： shape coexistence neutron-deficient krypton TRS moment of inertia triaxiality

Generalized oscillator strengths for some higher valence-shell excitations of krypton atom

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Chinese Physics B 2007年第10期16卷 2938-2945页

作者：朱林繁张放心成华东袁慧苑震生李文斌刘小井徐克尊 Hefei National Laboratory for Physical Sciences at Microscale Department of Modern Physics University of Science and Technology of China Hefei 230026 China

The valence-shell excitations of krypton atom have been investigated by fast electron impact with an angle-resolved electron-energy-loss spectrometer. The generalized oscillator strengths for some higher mixed valence-shell excitations in 4d, 4f, 5p, 5d, 6s, 6p, 7s ←4p of krypton atom have been determined. Their profiles are discussed, and the generalized oscillator strengths for the electric monopole and quadrupole excitations in 5p ← 4p are compared with the calculations of Amusia et al. （Phys. Rev. A 67 022703 （2003））. The differences between the experimental results and theoretical calculations show that more studies are needed.

关键词： generalized oscillator strength electric multipolarity krypton

Absorption Spectrum of Neutral krypton in the Near Infrared Region

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Chinese Journal of Chemical Physics 2019年第5期32卷 536-542页

作者： Ruo-yu Jiang Jia Ye Lun-hua Deng Hai-ling Wang State Key Laboratory of Precision Spectroscopy East China Normal University Shanghai 200062 China

High-resolution absorption spectra of atomic krypton in the range of 11870-12700 cm-1 were recorded by employing concentration modulation absorption spectroscopy technique with a tunable single-mode cw Ti:Sapphire laser. The krypton atoms were excited to the absorbing energy states by discharge-burning in a mixture of helium and krypton. A total of 120 lines of neutral krypton were observed, among them 33 lines had already been classified in previous studies, 45 lines were newly classified with the known energy levels, and 42 lines cannot be classified. These unclassified lines indicate that up to now unknown energy levels of Kr must exist. Further, an analysis of the unclassified lines to get possible new energy levels with a classification program is reported.

关键词： Neutral krypton Absorption spectrum Energy levels

Demonstration of a diode-pumped dual-wavelength metastable krypton laser

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High Power Laser Science and Engineering 2023年第6期11卷 223-228页

作者： Qingshan Liu Rui Wang Zining Yang Jianyong Sun Weiqiang Yang Hongyan Wang Xiaojun Xu College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangshaChina Nanhu Laser Laboratory National University of Defense TechnologyChangshaChina Hunan Provincial Key Laboratory of High Energy Laser Technology National University of Defense TechnologyChangshaChina

Diode-pumped rare gas lasers are potential candidates for high-energy and high-beam quality laser ***,most investigations are focused on metastable Ar *** Kr system has the unique advantages of higher quantum efficiency and lower discharge requirements for *** this paper,a diode-pumped metastable Kr laser was demonstrated for the first *** a repetitively pulsed discharge at a Kr/He pressure of up to approximately1500 Torr,metastable Kr atoms of more than 10^(13)cm^(-3)were *** diode pumping,the laser realized a dual-wavelength output with an average output power of approximately 100 mW and an optical conversion efficiency of approximately 10% with respect to the absorbed pump power.A kinetics study involving population distribution and evolution was conducted to analyze the laser performance.

关键词： diode pump krypton metastable rare gas laser

Effects of Pressurized Argon and krypton Treatments on the Quality of Fresh White Mushroom (<i>Agaricus bisporus</i>)

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Food and Nutrition Sciences 2013年第12期4卷 1191-1200页

作者： Camel Lagnika Min Zhang Mohanad Bashari Fatoumata Tounkara State Key Laboratory of Food Science and Technology School of Food Science and Technology Jiangnan University Wuxi China State Key Laboratory of Food Science and Technology School of Food Science and Technology Jiangnan University Wuxi China Ecole Nationale des Sciences et Technique de Conservation et Transformation des Produits Agricoles de Sakété Université d’Agri- culture de Kétou Kétou Benin.

Effects of argon, krypton and their mixed pressure treatments on the quality of white mushrooms were studied during 9 days of storage at 4℃. Among all treatments in this study, the minimum respiration rate, polyphenoloxidase activity, retained color change, antioxidants and delayed pseudomonas growth were observed with pressure argon (5 MPa) followed by mixing argon and krypton (2.5 MPa each) treatments. Respiration rates after 9 days of storage were 5.35%, 6.20%, 7.50%, 7.60%, 7.91% and 8.95% for HA5, HAK, HA2, HK5, HK2 and control, respectively. DPPH inhibition percentages of free radical for HA5, HAK, HK5, HA2, HK2 and control mushrooms were 28.03%, 25.24%, 24.96%, 21.87%, 20.56% and 19.06%, respectively, after 9 days of storage. The pressurized argon treatment was the most effective compared to pressurized krypton. Thus, application of pressurized argon and krypton treatments could extend the storage life of white mushrooms to 9 days at 4℃.

关键词： Pressurized Argon krypton Clathrate Hydrates White Mushroom Storage

krypton K600 DMM在A340中的应用

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航空制造技术 2007年第8期50卷 109-109页

作者：力丰制造科技有限公司力丰制造科技有限公司

　　krypton K600 DMM用于测试A340的主起落架装置.测试过程中,主起落架装置被置于10m高,并能产生1000t压力的测试台上.

关键词： krypton A340 DMM 应用测试过程主起落架测试台装置

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科学亚特兰大公司krypton独立加扰器

卫星电视与宽带多媒体 2005年第5期 39-39页

加扰和条件接收历来和编码器、复用器和专用接口有关。由于采用了象DVB同密等开放式的标准，krypton加扰器排除了这种关联性，允许在前端的任何地点，不使用其它硬件设备实现条件接入。krypton加扰器全内置式的设计(不以PC为基本硬件要... 详细信息

加扰和条件接收历来和编码器、复用器和专用接口有关。由于采用了象DVB同密等开放式的标准，krypton加扰器排除了这种关联性，允许在前端的任何地点，不使用其它硬件设备实现条件接入。krypton加扰器全内置式的设计(不以PC为基本硬件要求)大大降低了维护费用且节省了机架空间。通过内置的、可用任何标准的互联网浏览器登陆的HTML用户界面，krypton的设置变得非常简便易行。

关键词： krypton 加扰器亚特兰大公司科学互联网浏览器条件接收专用接口条件接入硬件设备维护费用硬件要求用户界面 HTML 编码器复用器开放式 DVB 关联性内置式标准同密前端