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Study on Fine Structure of Gas Atomized LaNi_5-based Alloys

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Journal of Materials Science & Technology 2003年第5期19卷 425-427页

作者： Hai JING, Hong GUO, Shuguang ZHANG, Zili MA and Shaoming ZHANGNational Engineering research Center for Non-ferrous Metals Composites, General research Institute for Non-ferrous Metals, Beijing 100088, China natl. Eng. res. ctr. Res. Inst. of Non-Ferrous Metals Beijing 100088 China

The fine structure of hydrogen storage alloy powders MiNi4.3-xCoxMr0.4AI0.3(x=0.75, 0.45, 0.10; Ml: La-rich misch metal) prepared by rapidly solidifying gas atomization was investigated using a Rietveld analysis method. Two sets of CaCu5-type crystal constants were observed in the studied alloys and one set was larger than the other. With decreasing powder radius the solidification rate of powder increased, and so did the percentage of a particle part with larger crystal constants. The reason why there were two sets of crystal constants might be the difference of solidification rate between the outside and inside of a particle.

关键词： Hydrogen storage alloys Gas atomization Rietveld analysis Crystal structure

Microsegregation and Improved Methods of Squeeze Casting 2024 Aluminium Alloy

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Journal of Materials Science & Technology 2003年第5期19卷 413-416页

作者： Yong ZHONG, Guoyue SU and Ke YANGThe National Engineering research Center, the Institute of Metal research, Chinese Academy of Sciences, Shenyang 110016, China natl. Eng. res. ctr. Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China

The squeeze casting of a 2024 Al alloy was carried out to investigate the effect on microsegregation in the alloy of the application of pressure followed by diffusion annealing. The experimental results indicate that an optimum applied pressure followed by an optimum diffusion annealing process can markedly reduce the degree of microsegregation and improve the mechanical properties to a degree that can approach the level of forged 2024 Al alloy.

关键词： 2024 Al alloy Squeeze casting Microsegregation Diffusion annealing

The Production and Release of CFCs from Coal Combustion

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Acta Geologica Sinica(English Edition) 2003年第1期77卷 81-85页

作者： LI Jiaxi, WANG Junzhi, LI Hong, RAO Zhu, LI Qi and LUO Songguang National research Center of Geoanalysis, Chinese Academy of Geological Sciences, Beijing 100037 Chinese Acad Geol Sci Natl Res Ctr Geoanal Beijing 100037 Peoples R China

The destruction of the ozone layer in the atmosphere caused by industriallysynthesized CFCs has aroused greatest concerns from the international society, but the CFCs formedfrom burning of coal containing fluorine have not been recognized by the world yet. In the presentstudy, we condensed the gas through cold traps and used the GC-MS to measure the gas composition,and found that the content of CFC-12 in the smog from coal combustion was significantly higher thanthe background value of the local atmosphere. This proves that CFC- 12 is formed in the process ofcoal combustion. This paper discusses a new source of non-synthesized CFCs.

关键词： CFC-12 in coal combustion measurement of CFC-12 halo hydrocarbons fromcoal

Calibration and brightness temperature algorithm of CE-1 Lunar Microwave Sounder (CELMS)

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Science China Earth Sciences 2010年第9期53卷 1392-1406页

作者： ZhenZhan Wang Yun Li XiaoHui Zhang Jiang JingShan ChuanDong Xu DeHai Zhang WeiGuo Zhang Chinese Acad Sci Natl Microwave Remote Sensing Lab Ctr Space Sci & Appl Res Beijing 100190 Peoples R China

CE-1 Lunar Microwave Sounder (CELMS) is the first passive microwave radiometer in the world to sound the surface of the Moon in the lunar orbit at altitude of 200 km. The scientific objective of CELMS is to obtain global brightness temperature (TB) of the Moon, to retrieve information on lunar regolith, and to evaluate the distribution of helium-3 on the Moon implanted by solar wind. Before launch of CELMS, a series of experiments were carried out in laboratories to test the performances of the systems, and to calibrate the responses between the input of TB and the output of voltage from the receivers. However, the thermal condition exposed to CELMS is more complicated in lunar orbit than on the Earth, which makes the temperatures of different parts of CELMS wave vary greatly, and the cosmic background is not very clean due to the pointing of cold space antenna to the direction of the satellite running, which brings uncertainties into data-processing of CELMS when the temperature of cold space is used as a calibrator. Furthermore, the lack of knowledge on the lunar ingredients and compositions, distributions of physical temperatures, and properties on lunar microwave radiation leads to difficulties in validating the measurements and retrievals of CELMS. By analyzing the results of ground experiments and the measurements of CELMS in-orbit, along with our knowledge of the properties of lunar surface, here we give algorithms on calibration and antenna pattern correction (APC) of CELMS. We also describe in detail the principle of microwave transfer among the elements of CELMS, and discuss the method on testing calibration parameters of the system. In addition, the theory and model on correction antenna pattern of CELMS are developed by comparing antenna temperatures by CELMS with those simulated by microwave radiative transfer models. The global distribution of TB is given and the features of TB are analyzed. Our results show rich information included in TB on the prope

关键词： CE-1 CE-1 Lunar Microwave Sounder/CELMS in-orbit calibration cold space APC algorithm

Summer Arctic sea fog

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Acta Oceanologica Sinica 2001年第2期20卷 183-196页

作者： Xie Simei, Xue Zhenhe, Jiang Dezhong, Zou Bin, Qu Shaohou (1. National research Center for Marine Environment Forecasts, Beijing 100081, China 2. Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China) natl. res. ctr. for Marine Envrn. Fo Beijing 100081 China

Synchronous or quasi-synchronous sea-land-air observations were conducted using advanced sea ice, atmospheric and marine instruments during China's First Arctic Expedition. *** on the Precious data from the expedition, it was found that in the Arctic Ocean, most part of which is covered with ice or is mixed with ice, various kinds of sea fog formed such as advection fog, radiation fog and vapor fog. Each kind he its own characteristic and mechanics of creation. In the southern part of the Arctic Ocean, due to the sufficient warm and wet flow there, it is favorable for advection fog to form, which is dense and lasts a long time. On ice cap or vast floating ice, due to the strong radiation cooling effect, stable radiating fog is likely to form. In floating ice area there forms vapor fog with the appearance of masses of vapor from a boiling pot, which is different from short-lasting land fog. The study indicates that the reason why there are many kinds of sea fog form in the Arctic Ocean is because of the complicated cushion and the consequent sea-air interaction caused by the sea ice distribution and its unique physical characteristics. Sea fog is the atmospheric phenomenon of sea-air heat exchange. Especially, due to the high albedo of ice and snow surface, it is diffcult to absorb great amount of solar radiation during the polar days. Besides, ice is a poor conductor of heat; it blocks the sea-air heat exchange. The sea-air exchange is active in floating ice area where the ice is broken. The sea sends heat to the atmosphere in form of latent heat; vapor fog is a way of sea-air heat exchange influencing the climate and an indicator of the extent of the exchange. The study also indicates that the sea also transports heat to the atmosophere in form of sensible heat when vapor fog occurs.

关键词： Arctic sea fog vapor fog radiation fog advection fog mechanism of the creation of sea fog

A new unequal-weighted triple-frequency first order ionosphere correction algorithm and its application in COMPASS

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Science China(Physics,Mechanics & Astronomy) 2012年第3期55卷 546-552页

作者： WenXiang Liu WeiHua Mou FeiXue Wang natl Univ Def Technol Satellite Nav Res & Dev Ctr Sch Elect Sci & Engn Changsha 410073 Hunan Peoples R China

As the introduction of triple-frequency signals in GNSS,the multi-frequency ionosphere correction technology has been fast *** indicate that the triple-frequency second order ionosphere correction is worse than the dual-frequency first order ionosphere correction because of the larger noise amplification *** the assumption that the variances of three frequency pseudoranges were equal,other references presented the triple-frequency first order ionosphere correction,which proved worse or better than the dual-frequency first order correction in different *** practice,the PN code rate,carrier-to-noise ratio,parameters of DLL and multipath effect of each frequency are not the same,so three frequency pseudorange variances are *** this consideration,a new unequal-weighted triple-frequency first order ionosphere correction algorithm,which minimizes the variance of the pseudorange ionosphere-free combination,is proposed in this *** is found that conventional dual-frequency first-order correction algorithms and the equal-weighted triple-frequency first order correction algorithm are special cases of the new algorithm.A new pseudorange variance estimation method based on the three carrier combination is also *** analysis shows that the new algorithm is *** experiment with COMPASS G3 satellite observations demonstrates that the ionosphere-free pseudorange combination variance of the new algorithm is smaller than traditional multi-frequency correction algorithms.

关键词： GNSS ionospheric delay ionosphere-free combination COMPASS

Southern oceanic oscillation

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Chinese Science Bulletin 1996年第9期41卷 749-753页

作者：解思梅包澄澜薛振和张林郝春江 natl. res. ctr. Mar. Environ. F. Beijing 100081 China

The study on the interaction between the Antarctic sea ice and ENSO event is a com-ponent of the interaction among the atmosphere, ocean and sea ice. The tropical ocean, asa heat source, and the ice and snow in both p... 详细信息

关键词： southern oceanic oscillation ENSO event Antarctic sea ice.

X-ray Diffraction and Electrical Conductivity Studies on Ag-Cu-Se System

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Journal of Materials Science & Technology 1995年第1期11卷 53-55页

作者： S.N.Motafa and S.R.Selim(Chemistry Department, Al-Azhar University, Nasr City. Cairo. Egypt)F.M.Ismail(Inorganic Chemistry Department, National research Center. Dokki. Cairo. Egypt) natl res ctr DEPT INORGAN CHEMCAIROEGYPT AL-AZHAR UNIV DEPT CHEMNASREGYPT

A number of X-ray patterns and electrical conductivities of five different samples of Ag-Cu-Se system have been measured. These samples of Ag-Cu-Se system: (Ag1.188, Cu0.812)Se, (Ag,Cu)Se; (Ag0.9, Cu1.1 )Se, (Ag0.8, Cu1.2)Se and (Ag0.6, Cu1.4)Se were prepared under controlled conditions. Analysis of the experimental data shows that Frenkel defects are predominated in (Ag1.188, Cu0.812)Se and Schottky defects prevailing in the other samples. The activation energy values △E calculated from the linear behaviour of electrical conductivity a with temperature (0-90℃) reveal that the impurity content increases in the direction of (Ag,Cu)Se→(Ag0.8,Cu1.2 )Se

关键词： Ag X-ray Diffraction and Electrical Conductivity Studies on Ag-Cu-Se System Cu

Online application of automatic surface quality inspection system to finishing line of cold rolled strips

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Journal of University of Science and Technology Beijing 2003年第4期10卷 38-41页

作者： Hao Sun, Ke Xu, and Jinwu XuNational Engineering research Center of Advanced Rolling, University of Science and Technology Beijing, Beijing 100083, China natl. Eng. res. ctr. of Adv. Rolling Univ. of Sci. and Technol. Beijing Beijing 100083 China

An automatic surface quality inspection system installed on a finishing lineof cold rolled strips is introduced. The system is able to detect surface defects on cold rolledstrips, such as scratches, coil breaks, rusts, roll imprints, and so on. Multiple CCD area scancameras were equipped to capture images of strip surface simultaneously. Defects were detectedthrough 'Dark-field illumination' which is generated by LED illuminators. Parallel computationtechnique and fast processing algorithms were developed for real-time data processing. Theapplication to the production line shows that the system is able to detect defects effectively.

关键词： surface inspection cold rolled strip finishing line CCD cameras imageprocessing