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An Innovative Gas Sensor with On-Chip Reference Using Monolithic Twin Laser 被引量:6
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作者 张永刚 田招兵 +5 位作者 张晓钧 顾溢 李爱珍 祝向荣 郑燕兰 刘盛 《Chinese Physics Letters》 SCIE CAS CSCD 2007年第10期2839-2841,共3页
An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one p... An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one photodiode is used to catch both absorption and reference signals by time division multiplexing. The detection of nitrous oxide adopting this scheme using a 2.1 I^m antimonide laser and an InGaAs photodiode has been demonstrated experimentally with detection limit below i ppm. Using this on chip reference scheme the fluctuations from the optical path and devices can be compensated effectively; the sensor system is simplified distinctly. 展开更多
关键词 QUANTUM CASCADE LASERS 2.1 mu-m DIODE-LASERS SEMICONDUCTOR-LASERS MQWLASERS ANTIMONIDE TUNABILITY
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Terahertz Quantum Cascade Laser at 3.39 THz 被引量:4
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作者 曹俊诚 黎华 +5 位作者 韩英军 谭智勇 吕京涛 罗辉 LAFRAMBOISE Sylvain 刘惠春 《Chinese Physics Letters》 SCIE CAS CSCD 2008年第3期953-956,共4页
We demonstrate the growth of terahertz quantum cascade laser (THz QCL) by gas source molecular beam epitaxy. X-ray diffraction and cross-sectional transmission electron microscopic measurements show the high crystal... We demonstrate the growth of terahertz quantum cascade laser (THz QCL) by gas source molecular beam epitaxy. X-ray diffraction and cross-sectional transmission electron microscopic measurements show the high crystalline quality of the THz QCL active region, From the cross-sectional transmission electron microscopy image, sharp interfaces are observed and the deduced cascade period thickness is consistent with the result of x-ray diffraction. The test device is lasing at 3.39THz and operating up to lOOK in pulsed mode. At IOK, the maximum output power is greater than 1 mW with a threshold current density of 738 A/cm^2. 展开更多
关键词 CONTINUOUS-WAVE mu-m OPERATION MODE
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Properties of Strain Compensated Symmetrical Triangular Quantum Wells Composed of InGaAs/InAs Chirped Superlattice Grown Using Gas Source Molecular Beam Epitaxy 被引量:3
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作者 顾溢 张永刚 《Chinese Physics Letters》 SCIE CAS CSCD 2008年第2期726-729,共4页
We investigate the properties of symmetrical triangular quantum wells composed of InGaAs/InAs chirped superlattice, which is grown by gas source molecular beam epitaxy via digital alloy method. In the quantum well str... We investigate the properties of symmetrical triangular quantum wells composed of InGaAs/InAs chirped superlattice, which is grown by gas source molecular beam epitaxy via digital alloy method. In the quantum well structure tensile AlInGaAs are used as barriers to partially compensate for the significant compressive strain in the wells, the strain compensation effects are confirmed by x-ray measurement. The photoluminescence spectra of the sample are dominated by the excitonic recombination peak in the whole temperature range. The thermal quenching, peak energy shift and line-width broadening of the PL spectra are analysed in detail, the mechanisms are discussed. 展开更多
关键词 2.1 mu-m TEMPERATURE-DEPENDENCE LASERS PHOTOLUMINESCENCE WAVELENGTH HETEROSTRUCTURE
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Near Infrared Photoluminescence from Yb,Al Co-implanted SiO2 Films on Silicon 被引量:2
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作者 张建国 王晓欣 +2 位作者 成步文 余金中 王启明 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第8期2183-2186,共4页
Intense room-temperature near infrared (NIR) photoluminescence (980 nm and 1032 nm) is observed from Yb,Al co-implanted SiO2 films on silicon. The optical transitions occur between the ^2F5/2 and ^2F7/2 levels of ... Intense room-temperature near infrared (NIR) photoluminescence (980 nm and 1032 nm) is observed from Yb,Al co-implanted SiO2 films on silicon. The optical transitions occur between the ^2F5/2 and ^2F7/2 levels of Yb^3+ in SiO2. The additional Al-implantation into SiO2 films can effectively improve the concentration quenching effect of Yb^3+ in SiO2. Photoluminescence excitation spectroscopy shows that the NIR photoluminescence is due to the non-radiative energy transfer from Al-implantation-induced non-bridging oxygen hole defects in SiO2 to Yb^3+ in the Yb-related luminescent complexes. It is believed that the defect-mediated luminescence of rare-earth ions in SiO2 is very effective. 展开更多
关键词 SI-NANOCRYSTALS mu-m ENERGY-TRANSFER RICH SIO2 LUMINESCENCE EXCITATION EMISSION IONS FLUORESCENCE WAVELENGTH
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Tunable Infrared Luminescence and Optical Amplification in PbS Doped Glasses 被引量:2
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作者 黄纬 池英芝 +5 位作者 王玺 周时凤 王丽 武愕 曾和平 邱建荣 《Chinese Physics Letters》 SCIE CAS CSCD 2008年第7期2518-2520,共3页
PbS-doped glasses are prepared. Absorption and luminescence spectra show that both the absorption and infrared emission can be tuned widely by thermal treatment conditions. Optical amplification at 1300 nm is observed... PbS-doped glasses are prepared. Absorption and luminescence spectra show that both the absorption and infrared emission can be tuned widely by thermal treatment conditions. Optical amplification at 1300 nm is observed, and amplified spontaneous emission (ASE) spectrum is also measured to confirm the optical gain from PbS quantum dots. 展开更多
关键词 QUANTUM DOTS mu-m EMISSION FIBER GAIN
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Modulation Frequency Multiplexed Tunable Diode Laser Spectroscopy System for Simultaneous CO, CO2 Measurements 被引量:2
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作者 陈东 刘文清 +6 位作者 张玉钧 刘建国 魏庆农 阚瑞峰 王敏 崔益本 陈玖英 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第9期2446-2449,共4页
A modulation frequency multiplexed dual diode-laser system is developed for simultaneous detection of the two most common fire gas products CO and CO2. Simultaneous detection is achieved by modulating each laser at di... A modulation frequency multiplexed dual diode-laser system is developed for simultaneous detection of the two most common fire gas products CO and CO2. Simultaneous detection is achieved by modulating each laser at different frequencies, demodulating the signal by a pair of lock-in amplifiers for each gas. Laser beams are combined and detected by one detector after passing through an identical optical path. The experimental results show little performance degradation associated with modulation frequency multiplexing, and no cross-talk between the two multiplexed detection channels is measured. 展开更多
关键词 ABSORPTION-SPECTROSCOPY mu-m SPECTROMETER
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A Laser-Diode-Pumped 7.36 W Continuous-Wave Nd:YVO4 Laser At 1342 nm 被引量:2
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作者 张玉萍 郑义 +1 位作者 张会云 姚建铨 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第2期363-365,共3页
An efficient and high-power diode-laser single-end-pumped Nd:YVO4 laser with cw emission at 1342nm is presented. With a crystal single-end-pumped by a fibre-coupled diode laser, an output power of 7.36 W is obtained ... An efficient and high-power diode-laser single-end-pumped Nd:YVO4 laser with cw emission at 1342nm is presented. With a crystal single-end-pumped by a fibre-coupled diode laser, an output power of 7.36 W is obtained from the laser cavity of concave-convex, eorresponding to an optical-to-optical conversion efficiency of 32.8%. The laser is operated in TEM00 mode with small rms noise amplitude of 0.3%. This represents, to the best of our knowledge, the highest power obtained from a diode-laser single-end-pumped Nd:YVO4 cw laser at 1342nm 80 far. 展开更多
关键词 1.34 mu-m UP-CONVERSION CRYSTALS
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Femtosecond Optical Parametric Amplifier for Petawatt Nd:Glass Lasers 被引量:1
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作者 张小民 钱列加 +5 位作者 袁鹏 罗航 朱鹤元 朱启华 魏晓峰 范滇元 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第5期1204-1206,共3页
We study a femtosecond Ti:sapphire laser pumped optical parametric amplifier (OPA) at 1053nm. The OPA Generates stable signal pulses with duration smaller than l OOfs, wavelength drift smaller than 0.5 nm, and puls... We study a femtosecond Ti:sapphire laser pumped optical parametric amplifier (OPA) at 1053nm. The OPA Generates stable signal pulses with duration smaller than l OOfs, wavelength drift smaller than 0.5 nm, and pulseto-pulse fluctuation of about ±4%, by employinG an external seeder. In a terawatt laser pumped large-aperture LiNbOa OPA, pulse energy at signal has been scaled up to 4mJ. This m J-class femtosecond OPA at 1053nm presents a feasible alternative to optical parametric chirped-pulse amplification, and is ready to be applied to petawatt lasers. 展开更多
关键词 3 mu-m AMPLIFICATION GENERATION PULSES CONVERSION SYSTEM
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Gain Characteristics of Er^3+-Doped Phosphate Glass Fibres 被引量:1
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作者 徐善辉 杨中民 +2 位作者 张勤远 邓再德 姜中宏 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第3期633-634,共2页
An erbium-doped phosphate glass fibre has been drawn by the rod-in-tube technique in our laboratory. The gain for the Er^3+-doped phosphate glass fibre with different pump powers and with different input signal wavel... An erbium-doped phosphate glass fibre has been drawn by the rod-in-tube technique in our laboratory. The gain for the Er^3+-doped phosphate glass fibre with different pump powers and with different input signal wavelengths is investigated. The 2.2-cm-long fibre, pumped by a single-mode 980-nm fibre-pigtailed laser diode, can provide a net gain per unit length greater than 1.SdB/cm. The pump threshold is about 50mW at the wavelength of 1534nm, and below 70roW at 1550nm. The gain linewidth of the Er^3+-doped phosphate glass fibre is greater than 34 nm and can cover the C band in optical communication networks. 展开更多
关键词 WAVE-GUIDE AMPLIFIERS mu-m SILICON
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Temperature Tuning of Casimir Effect
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作者 王晶 张向东 +1 位作者 裴寿镛 刘大禾 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第9期2372-2375,共4页
We theoretically investigate the additional correction to the Casimir effect due to the change of dielectric constant with temperature, which is different from the previous research that have widely taken dielectric c... We theoretically investigate the additional correction to the Casimir effect due to the change of dielectric constant with temperature, which is different from the previous research that have widely taken dielectric constants of materials as a value independent of temperature. It is found that such a correction can go beyond 20% for some cases and it should not be ignored. Due to the prominent correction, it is possible to tune the Casimir force by such an effect. 展开更多
关键词 mu-m FORCE CAVITY FIELD
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Detection Wavelength of Strained InxGa1-xAs/GaAs Very-Long-Wavelength Quantum Well Infrared Photodetectors
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作者 熊大元 李宁 +2 位作者 李志锋 甄红楼 陆卫 《Chinese Physics Letters》 SCIE CAS CSCD 2007年第5期1403-1406,共4页
Detection wavelength is one of the key performance indices of infrared photodetectors. We study the character of detection wavelength of the strained InxGa1-xAs/GaAs very-long-wavelength (〉 12 μm) quantum well inf... Detection wavelength is one of the key performance indices of infrared photodetectors. We study the character of detection wavelength of the strained InxGa1-xAs/GaAs very-long-wavelength (〉 12 μm) quantum well infrared photodetectors (VLW-QWIPs) characterized by the photoluminescence (PL) and photocurrent (PC) measurements. Based on the theoretical calculation and experimental data, we have built a practical model for the Inx Ga1-xAs/GaAs strained VLW-QWIPs, from which the interband transitions, intersubband transition and peak detection wavelength can be determined. Afterwards, the dependences of detection wavelength and device operation mode on the In mole fraction and InxGa1-xAs well width are presented, which will be helpful for device design and optimization. 展开更多
关键词 mu-m ELECTROREFLECTANCE OFFSETS GAAS
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Low Density Self-Assembled InAs/GaAs Quantum Dots Grown by Metal Organic Chemical Vapour Deposition
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作者 李林 刘国军 +3 位作者 王晓华 李梅 李占国 万春明 《Chinese Physics Letters》 SCIE CAS CSCD 2008年第2期667-670,共4页
The self-assembled InAs quantum dots (QDs) on GaAs substrates with low density (5×10^8 cm^-2) are achieved using relatively higher growth temperature and low InAs coverage by low-pressure metal-organic chemic... The self-assembled InAs quantum dots (QDs) on GaAs substrates with low density (5×10^8 cm^-2) are achieved using relatively higher growth temperature and low InAs coverage by low-pressure metal-organic chemical vapour deposition. The macro-PL spectra exhibit three emission peaks at 1361, 1280 and 1204nm, corresponding to the ground level (GS), the first excited state (ES1) and the second excited state (ES2) of the QDs, respectively, which are obtained when the GaAs capping layer is grown using triethylgallium and tertiallybutylarsine. As a result of micro-PL, only a few peaks from individual dots have been observed. The exciton-biexciton behaviour was clearly observed at low temperature. 展开更多
关键词 mu-m SINGLE PHOTONS LIGHT-EMISSION GAAS
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High-Power and Low-Threshold-Current-Density GaAs/AlGaAs Quantum Cascade Lasers
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作者 刘俊岐 刘峰奇 +3 位作者 李路 邵烨 郭瑜 王占国 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第7期1784-1786,共3页
We report on the realization of GaAs/AlGaAs quantum cascade lasers with an emission wavelength of 9.1 μm above the liquid nitrogen temperature. With optimal current injection window and ridge width of 24 and 60μm re... We report on the realization of GaAs/AlGaAs quantum cascade lasers with an emission wavelength of 9.1 μm above the liquid nitrogen temperature. With optimal current injection window and ridge width of 24 and 60μm respectively, a peak output power more than 500mW is achieved in pulsed mode operation. A low threshold current density Jth = 2.6 kA/cm^2 gives the devices good lasing characteristics. In a drive frequency of i kHz, the laser operates up to 20% duty cycle. 展开更多
关键词 CONTINUOUS-WAVE OPERATION HIGH-TEMPERATURE OPERATION mu-m ROOM-TEMPERATURE
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High-Duty-Cycle Operation of GaAs/AlGaAs Quantum Cascade Laser above Liquid Nitrogen Temperature
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作者 刘俊岐 刘峰奇 +4 位作者 邵烨 李路 郭瑜 王占国 王良臣 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第11期2968-2971,共4页
We present a detailed study of λ- 9.75 μm GaAs/AlGaAs quantum cascade lasers. For a coated 2-rmm-long and 40-μm-wide laser, an optical power of 85 μ W is observed at 95% duty cycle at 80K. At a moderate driving pu... We present a detailed study of λ- 9.75 μm GaAs/AlGaAs quantum cascade lasers. For a coated 2-rmm-long and 40-μm-wide laser, an optical power of 85 μ W is observed at 95% duty cycle at 80K. At a moderate driving pulse (1 kHz and 1% duty cycle),the device presents a peak power more than 20mW even at 120K. At 80K, the fitted result of threshold current densities shows evidence of potential cw operation. 展开更多
关键词 CONTINUOUS-WAVE OPERATION ROOM-TEMPERATURE mu-m
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Low Threshold Current Density Operation of Strain-Compensated Quantum Cascade Laser
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作者 邵烨 李路 +2 位作者 刘俊歧 刘峰奇 王占国 《Chinese Physics Letters》 SCIE CAS CSCD 2007年第3期717-720,共4页
We report the low threshold current density operation of strain-compensated In0.64 Ga0.36As/In0.3sAl0.62As quantum cascade lasers emitting near 4.94 μm. By employing an enlarged strain-compensated structure and optim... We report the low threshold current density operation of strain-compensated In0.64 Ga0.36As/In0.3sAl0.62As quantum cascade lasers emitting near 4.94 μm. By employing an enlarged strain-compensated structure and optimizing the injector doping density, a rather low threshold current density of 0.57kA/cm^2 at 80 K is achieved/or an uncoated 20-μm-wide and 2.5-mm-long laser. 展开更多
关键词 mu-m ROOM-TEMPERATURE
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A Wide-Band Thulium-Doped Silica Fibre Amplifier
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作者 杜戈果 黎大军 +3 位作者 李宏伟 麦炳梁 游杰顺 阮双琛 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第12期3291-3293,共3页
We investigate a silica-based thulium-doped fibre amplifier, which is a promising candidate for an amplifying device in the S band, in detail using a single wavelength upconversion pumping scheme centred at 1064nm. Ou... We investigate a silica-based thulium-doped fibre amplifier, which is a promising candidate for an amplifying device in the S band, in detail using a single wavelength upconversion pumping scheme centred at 1064nm. Our experimental results show that in terms of gain and noise figure, the bi-directional pumping scheme is the best one in the three pumping schemes, named forward, backward and hi-directional pumping schemes. The amplifier has a gain not only in the S band, but also in the C band, even in the L band. The gain is above 3dB from 1525nm to 1580nm with a peak of 7.SdB. 展开更多
关键词 1.47 mu-m RAMAN AMPLIFIER
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西方传教士在中国穆斯林中的传教活动研究(1917~1936年) 被引量:3
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作者 韩永静 《北方民族大学学报(哲学社会科学版)》 CSSCI 2012年第5期111-119,共9页
近代西方传教士曾在中国穆斯林中进行过长达百年的传教活动,其宣教活动经过知识与经验方面的准备阶段以后,自1917年开始进入了兴盛阶段。兹威默于1917年和1933年两次来华指导宣教工作,对基督教在华穆斯林传教运动影响深远。此外,基督教... 近代西方传教士曾在中国穆斯林中进行过长达百年的传教活动,其宣教活动经过知识与经验方面的准备阶段以后,自1917年开始进入了兴盛阶段。兹威默于1917年和1933年两次来华指导宣教工作,对基督教在华穆斯林传教运动影响深远。此外,基督教会对中国穆斯林的传教活动也逐步向着跨宗派和组织化的方向发展,在中国出现了专门负责向穆斯林布道的组织——布道回族特委会及其后续组织中国穆民交际会。 展开更多
关键词 西方传教士 中国穆斯林 兹威默(知味墨) 布道回族特委会 中国穆民交际会
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基于C-RAN架构的5G超密集组网技术研究 被引量:2
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作者 陈林 杨波 刘重军 《通信技术》 2021年第6期1400-1405,共6页
通过分析5G室内组网的需求特性,结合5G Multi-TRP标准的最新进展,设计了基于C-RAN架构的5G室内超密集组网解决方案。系统分析基于C-RAN架构下业务的接入过程、激活Multi-TRP组的选择、控制信道和业务信道的设计、参考信号的设计等关键技... 通过分析5G室内组网的需求特性,结合5G Multi-TRP标准的最新进展,设计了基于C-RAN架构的5G室内超密集组网解决方案。系统分析基于C-RAN架构下业务的接入过程、激活Multi-TRP组的选择、控制信道和业务信道的设计、参考信号的设计等关键技术,设计分布式MU-MIMO方案,包括MU-MIMO流程、参考信号设计和配对用户选择过程。此外,从移动性和小区边缘干扰两方面出发,定性分析基于C-RAN的超密组网架构。最后,通过分析仿真和实验测试结果,验证了所提方案的可行性。 展开更多
关键词 C-RAN Multi-TRP mu-mIMO Ultra-dense Network 控制信道 业务信道 参考信号
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雌性棕色田鼠和昆明小鼠血象对急性低氧应答的比较研究
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作者 刘彬 王振龙 +1 位作者 路纪琪 杨艳艳 《郑州大学学报(理学版)》 CAS 北大核心 2010年第4期106-110,共5页
为探明雌性棕色田鼠在急性低氧处理下血象的变化,确定急性低氧对地下鼠的生理学作用,进而揭示地下鼠的血液系统对急性低氧的应答对策,在4 h急性低氧处理条件下,测定雌性棕色田鼠和昆明小鼠的血象指标并进行比较分析.结果显示,棕色田鼠... 为探明雌性棕色田鼠在急性低氧处理下血象的变化,确定急性低氧对地下鼠的生理学作用,进而揭示地下鼠的血液系统对急性低氧的应答对策,在4 h急性低氧处理条件下,测定雌性棕色田鼠和昆明小鼠的血象指标并进行比较分析.结果显示,棕色田鼠和昆明小鼠的红细胞压积和红细胞体积在急性低氧处理下表现不同,但红细胞数均不受急性低氧处理的影响;棕色田鼠和昆明小鼠间血红蛋白含量相近且不受急性低氧处理的影响,两种鼠间平均血红蛋白浓度差异极显著,与红细胞体积变小有关;棕色田鼠的血小板数量显著低于昆明小鼠.研究结果表明,两种鼠均通过减小红细胞体积,增加血小板数量的方式应对急性低氧,并且棕色田鼠对低氧的耐受能力强于昆明小鼠. 展开更多
关键词 棕色田鼠 昆明小鼠 急性低氧 血液 雌性 适应
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明代纳西族文化的奇葩──丽江木氏土司著作 被引量:2
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作者 余海波 余嘉华 《古籍整理研究学刊》 2002年第1期19-25,共7页
[摘翼]明代,丽江纳西族木氏土司在承传东巴文化和民间文化的同时,积极学习和运用汉文化,取得了优异的创作成果,先后有十余部诗文集问世,得到省内外文化界知名人士的好评。不仅使纳西族文化在纵向延伸与横向的发展中得到丰富拓展... [摘翼]明代,丽江纳西族木氏土司在承传东巴文化和民间文化的同时,积极学习和运用汉文化,取得了优异的创作成果,先后有十余部诗文集问世,得到省内外文化界知名人士的好评。不仅使纳西族文化在纵向延伸与横向的发展中得到丰富拓展,开创了纳西族文人文化的先河;也使纳西文化渐为中原所知。《明史·云南土司传》称:“云南诸土官,知书好礼守义,以丽江木氏为首。”本文对这些诗文集逐一提要介绍。 展开更多
关键词 明代 纳西族木氏 诗文集提要
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