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Acclimation and adaptation of gross primary production to global warming depend on water 学位论文  OAI收割
中国科学院地理科学与资源研究所: 中国科学院地理科学与资源研究所, 2020
作者:  王冰雪
  |  收藏  |  浏览/下载：12/0  |  提交时间：2023/07/18
A 2000-year temperature reconstruction in the Animaqin Mountains of the Tibet Plateau, China SCI/SSCI论文  OAI收割
2016
作者:  Chen F.;  Zhang, Y.;  Shao, X. M.;  Li, M. Q.;  Yin, Z. Y.
  |  收藏  |  浏览/下载：31/0  |  提交时间：2017/11/09
A 2000-year temperature reconstruction in the Animaqin Mountains of the Tibet Plateau, China SCI/SSCI论文  OAI收割
2016
作者:  Chen F.;  Zhang, Y.;  Shao, X. M.;  Li, M. Q.;  Yin, Z. Y.
收藏  |  浏览/下载：29/0  |  提交时间：2016/12/16
Thermal analysis for wire scanners in the CSNS Linac 期刊论文  OAI收割
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 2014, 卷号: 760, 页码: 10-18
作者:  Yang T(杨涛);  Fu SN(傅世年);  Xu TG(徐韬光);  Yang, T;  Fu, SN
收藏  |  浏览/下载：29/0  |  提交时间：2016/04/08
Study on ultra-light secondary baffle for coaxial two-mirror telescope (EI CONFERENCE) 会议论文  OAI收割
2012 9th IEEE International Conference on Mechatronics and Automation, ICMA 2012, August 5, 2012 - August 8, 2012, Chengdu, China
作者:  Zhang L.;  Zhang L.
收藏  |  浏览/下载：61/0  |  提交时间：2013/03/25
The coaxial two-mirror telescope consists of two mirrors facing each other. Classical two-mirror arrangements are Gregorian and Cassegrain. These systems are usually applied to space telescopes and often have optical baffles to prevent stray light from entering the focal plane. The optical baffles consist of concentric rings suspended between the secondary and the primary mirror. The secondary baffle for a large two-mirror optical system is designed and analyzed in this paper. According to mission of a telescope  the structure should have high stiffness and high reliability and light weight. Compared with invar  aluminum alloy and titanium alloy  carbon fiber composite is currently the best material in terms of weight-to-strength ratio. It also has advantages of high temperature tolerance and low thermal expansion. So carbon fiber composite is chosen as material to meet requirements of the coaxial telescope. In this paper  optimization method based on finite element analysis (FEA) is used for design the secondary baffle. Minimum weight of the baffle is chosen as an objective function. Thicknesses of former tube and vanes are chosen as variables. Analysis results show that the designed secondary baffle has maximum diameter of 180mm  total length of 120mm and weighs 142g. And its fundamental frequency reaches 651Hz. Therefore the baffle has many advantages  such as ultra-light weight  high stiffness and dimensional stability  etc. The optimization method and the baffle design can be helpful to other coaxial telescopes  such as Cassegrain  Gregorian and their subdivisions. 2012 IEEE.  
Influence of sensitizer concentration on the upconversion luminescence of NaYF4: Yb3+, Er3+ nanoparticles (EI CONFERENCE) 会议论文  OAI收割
2012 2nd International Conference on Machinery, Materials Science and Engineering Applications, MMSE 2012, June 16, 2012 - June 17, 2012, Wuhan, China
作者:  
收藏  |  浏览/下载：24/0  |  提交时间：2013/03/25
A series of NaYF4: Yb3+  Er3+ nanoparticles with different doping concentration were successfully prepared by the combination of coprecipitation and hydrothermal methods using sodium citrate as chelator. Upconversion luminescence can be observed in all of the samples at room temperature. Fixed the Er3+ concentration with 1 mol% unchanged  the effect of the Yb3+ concentration on the upconversion luminescence of NaYF4: Yb3+  Er3+ samples were studied when the doped Yb3+ concentrations were 0 mol%  1 mol%  2 mol%  5 mol%  10 mol% and 20 mol%  respectively. As increasing the Yb 3+ concentration  the total intensity of the upconversion luminescence of the samples is increasing while the ratio of red to green emission increases firstly and then decreases. The maximum ratio value is 22.1 when the Yb3+ concentration is 10 mol%. It is found that the cross relaxation and cooperative sensitization effect are the reasons for the phenomenon above. (2012) Trans Tech Publications.  
Performance test of steel tube enclosed thermistors in air temperature measurements (EI CONFERENCE) 会议论文  OAI收割
3rd International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2011, January 6, 2011 - January 7, 2011, Shanghai, China
作者:  Yang H.;  Yan F.;  Yan F.;  Peng J.
收藏  |  浏览/下载：32/0  |  提交时间：2013/03/25
The performances of two steel tube enclosed precision thermistors are tested in a well controlled air environment to determine if the thermistors have enough accuracy for 0.01C levels of air temperature gradient measurement. Three Fluke's 5641 and three 5610 thermistors were tested for 24 hours in Fluke's 7008 calibration bath in the first step. In the second step  the performances of these two thermistors in steady state and transient state air temperature environments were tested for 8 hours separately. The results illustrate that  two of the 5641s were airproofed in a temperature well controlled tube  when steel tube enclosed precision thermistors are used in air temperature measurement  there are unstable departures from each other with a maximum 8.8 mC in constant air medium and 27 mC in temperature changing air medium. The transient-time errors are too large to show the true amounts of temperature changes for air temperature measurement. 2011 IEEE.  
Dome design and coupled thermal-mechanical analysis of supersonic missile (EI CONFERENCE) 会议论文  OAI收割
2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 22, 2009, Shanghai, China
Xing-qiao A.; Qun W.; Hong-guang J.
收藏  |  浏览/下载：58/0  |  提交时间：2013/03/25
A review of high-speed flow pressure and aerodynamic heating effect on Supersonic missile's dome is given. The dome should have excellent properties in optical  mechanical and chemical characteristics. A design of dome on supersonic mode is described according to tactical guide line of a missile. The dome made of quartz which is about 8mm thick and 141mm in window diameter. To check up the reliability of the dome  a reasonable finite element model (FEM) of dome is established  and a thermal-mechanical Analysis to the dome by finite element software NASTRAN has carried on  through these can obtained the distribution of temperature field and stress field when the speed is 2.3Ma. The results indicated that the stress was concentrated in the joint of the dome end and the Missile Section  and the maximum stress was 16.4Mpa. The stress of other nodes was smaller than the allowable stress of quartz glass. Reference to the results of the analysis  a lightweight revision to the dome structural dimension and a new method of dome fixing have put forward  which can reduce the stress concentration. 2009 SPIE.  
Temperature characteristics of high power vertical cavity surface emitting lasers (EI CONFERENCE) 会议论文  OAI收割
Semiconductor Lasers and Applications III, November 12, 2007 - November 13, 2007, Beijing, China
作者:  Qin L.
收藏  |  浏览/下载：29/0  |  提交时间：2013/03/25
By using oxidation confinement technology high power vertical-cavity surface-emitting lasers are fabricated in experiment. The electrical and optical performance characteristics such as threshold current  efficiency  emission wavelength  and output power are measured under continuous wave (CW) condition at room temperature. The maximum output power is up to watt regime at wavelength of about 980nm. The temperature characteristics of the device are investigated experimentally in detail. The variation in lasing threshold current with temperature is studied. The characteristic temperature T0 of the device is derived  and the value is about 211K. Such a high characteristic temperature T0 of threshold current can lead to good temperature sensitivity of the device. At the same time  the lasing spectrum characteristics with temperature are also measured. The wavelength shift with temperature is just about 0.06nm/K. From the measured results  it is shown that the device can still operate at high temperature condition.  
808nm high-power high-efficiency GaAsP/GaInP laser bars (EI CONFERENCE) 会议论文  OAI收割
Optoelectronic Materials and Devices III, October 27, 2008 - October 30, 2008, Hangzhou, China
作者:  Wang Y.;  Wang L.;  Wang L.;  Wang L.;  Liu Y.
收藏  |  浏览/下载：23/0  |  提交时间：2013/03/25
808nm high power diode lasers  which is rapidly maturing technology technically and commercially since the introduction in 1999 of complete kilowatt-scale diode laser systems  have important applications in the fields of industry and pumping solid-state lasers (DPSSL). High power and high power conversion efficiency are extremely important in diode lasers  and they could lead to new applications where space  weight and electrical power are critical. High efficiency devices generate less waste heat  which means less strain on the cooling system and more tolerance to thermal conductivity variation  a lower junction temperature and longer lifetimes. Diode lasers with Al-free materials have superior power conversion efficiency compared with conventional AlGaAs/GaAs devices because of their lower differential series resistance and higher thermal conductivity. 808nm GaAsP/GalnP broad-waveguide emitting diode laser bars with 1mm cavity length have been fabricated. The peak power can reach to 100.9W at 106.5A at quasicontinuous wave operation (200s  1000Hz). The maximum power conversion efficiency is 57.38%. Based on these high power laser bars  we fabricate a 1 3 arrays  the maximum power is 64.3 W in continuous wave mode when the current is 25.0A. And the threshold current is 5.9A  the slope efficiency is 3.37 W/A. 2008 SPIE.