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The prediction method of similar cycles

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Research in Astronomy and Astrophysics 2011年第12期11卷 1482-1492页

作者： zhan-Le du Hua-Ning Wang Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

The concept of degree of similarity （η）, is proposed to quantitatively describe the similarity of a parameter （e.g. the maximum amplitude Rmax） of a solar cycle relative to a referenced one, and the prediction method of similar cycles is further developed. For two parameters, the solar minimum （Rmin） and rising rate （βa）, which can be directly measured a few months after the minimum, a synthesis degree of similarity （ηs） is defined as the weighted-average of the η values around Rmin and βa, with the weights given by the coefficients of determination of Rmax with Rmin and βa, respectively. The monthly values of the whole referenced cycle can be predicted by averaging the corresponding values in the most similar cycles with the weights given by the ηs values. As an application, Cycle 24 is predicted to peak around January 2013 i8 （month） with a size of about Rmax = 84 ± 17 and to end around September 2019.

关键词： Sun: activity -- Sun: general -- sunspots

Does a low solar cycle minimum hint at a weak upcoming cycle?

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Research in Astronomy and Astrophysics 2010年第10期10卷 950-955页

作者： zhan-Le du Hua-Ning Wang Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

The maximum amplitude （Rm） of a solar cycle, in the term of mean sunspot numbers, is well-known to be positively correlated with the preceding minimum （Rmin）. So far as the long term trend is concerned, a low level of Rmin tends to be followed by a weak Rm, and vice versa. We found that the evidence is insufficient to infer a very weak Cycle 24 from the very low Rmin in the preceding cycle. This is concluded by analyzing the correlation in the temporal variations of parameters for two successive cycles.

关键词： Sun activity -- Sun general -- sunspots

Preparation of ultrafine WC-Co powder via fluidized bed

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Chinese Journal of Chemical Engineering 2024年第9期73卷 15-26页

作者： Huijun Shang Hengli Li Weijun Li Feng Pan zhan du State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of Sciences(CAS)Beijing 100190China College of Chemistry and Chemical Engineering Shihezi UniversityShihezi 832003China College of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Chinalco Environmental Protection and Energy Conservation Group Co. Ltd.Xiong'an 071700China

In this study,the effects of reaction parameters on the deep-reduction and carbonization process of WO_(2)-Co to WC-Co were *** results indicate that the oxygen loss rate of WO_(2) is positively correlated with temperature and methane partial *** partial pressure of methane has no significant effect on the formation rate of *** carbon content and particle size of the product increase with the increase of CH_(4) partial *** synergistically regulating the reaction temperature to 950℃,the CH_(4) partial pressure to 1.25%,and the reaction time to 60 min,ultrafine WC-Co powder without η phase can be *** particle size of the composite powder is 128 nm,with total carbon content of 6.16%,free carbon content of 0.4%,and residual oxygen content of 0.05%,*** growth rate relationship of tungsten carbide is as follows:δ(t)=1.21×10^(-13)exp(-12809.72/T)√t.

关键词： Ultrafine WC-Co powder Gas-solid reaction Fluidization Reaction process regulation Growth rate equation

Oxidation Kinetics,Structural Changes and Element Migration during Oxidation Process of Vanadium-titanium Magnetite Ore

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Journal of Iron and Steel Research International 2016年第11期23卷 1160-1167页

作者： Feng PAN Qing-shan ZHU zhan du Hao-yan SUN State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences(CAS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100039China

The oxidation kinetics, structural changes, and elements migration during the oxidation process of the va- nadium-titanium magnetite （VTM） ore were analyzed. Kinetics analysis indicated that the oxidation process was con- trolled by diffusion control and could be divided into interface diffusion and lattice diffusion with apparent activation energy of 99.69 kJ/mol and 144.08 kJ/mol in the range of 800--1000℃, respectively. The surface structure changed with the oxidization temperature as follows： dense surface→nano sized sheets→submicron particles→molten particles. The compact structure changed into porous one because of the elements migration and enrichment. Both Fe and Ti elements migrated in the opposite direction during the oxidation process. The V etement in the raw ore stably existed in the form of V^5＋ state, some vanadium migrated and occupied the tetrahedral sites of the hematite during the oxidation process.

关键词： vanadium-titanium magnetite ore oxidation kinetics structural change element migration

A New Method to Determine Epochs of Solar Cycle Extrema

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Chinese Journal of Astronomy and Astrophysics 2006年第3期6卷 338-344页

作者： zhan-Lc du Hua-Ning Wang Xiang-Tao He Department of Astronomy Beijing Normal University Beijing 100875 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

A weighted average method is proposed to determine the epochs of solar cycle extrema and hence the solar cycle lengths. Comparing to the previous methods, this method has the advantage that the extremum epochs are eas... 详细信息

关键词： Sun: activity - Sun: sunspots - Sun:general

A substorm-associated enhancement in the XUV radiation measuring channel observed by ESP/EVE/SDO

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Research in Astronomy and Astrophysics 2016年第6期16卷 21-28页

作者： Yan Yan Hua-NingWang Chao Shen zhan-Le du National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Key Laboratory of Solar Activity Chinese Academy of Sciences Beijing 100012 China School of Natural Sciences and Humanity Harbin Institute of Technology Shenzhen Graduate School Shenzhen518055 China University of Chinese Academy of Sciences Beijing 100049 China

Comparing the ESP/EVE/SDO flux data of 2011 Feb 6, with the counterparts of XRS/GOES and SEM/SOHO, we find that there is an enhancement that is not apparent in the two latter datasets. The enhancement, possibly regarded as a flare at first glimpse, nevertheless, does not involve an energy-release from the Sun. Based on the enhancement, we combine data from SXI/GOES 15 into a synthesized analysis, and concluded that it arises from a particle-associated enhancement in the channel that measures XUV radiation. Paradoxically, it seems to be somewhat of a particle-avalanching process. Prior to the event, a moderate geomagnetic storm took place. Subsequently, while the event is proceeding, a geomagnetic substorm is simultaneously observed. Therefore, the particles, though unidentified, are probably energetic electrons induced by substorm injection.

关键词： Sun: X-rays gamma rays -- Sun: flares -- Sun: solar-terrestrial relations

The Relation between the Amplitude and the Period of Solar Cycles

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Chinese Journal of Astronomy and Astrophysics 2006年第4期6卷 489-494页

作者： zhan-Le du Hua-Ning Wang Xiang-Tao He National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Department of Astronomy Beijing Normal University Beijing 100875

The maximum amplitudes of solar activity cycles are found to be well anticorrelated （r = -0.72） with the newly defined solar cycle lengths three cycles before （at lag -3） in 13-month running mean sunspot numbers during the past 190 years. This result could be used for predicting the maximum sunspot numbers. The amplitudes of Cycles 24 and 25 are estimated to be 149.5±27.6 and 144.3±27.6, respectively.

关键词： Sun: activity -- Sun: sunspots -- Sun: general

Pre-reduction of WO_(3)-Co_(3)O_(4)by H_(2)-C_(2)H_4 in a fluidized bed

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Chinese Journal of Chemical Engineering 2024年第2期66卷 273-284页

作者： Huijun Shang Hengli Li Weijun Li Feng Pan zhan du State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences(CAS)Beijing 100190China College of Chemical Engineering Nanjing Technology UniversityNanjing 211816China School of Chemistry and Chemical Engineering Shihezi UniversityShihezi 832003China College of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Chinalco Environmental Protection and Energy Conservation Group Co. Ltd.Xiong’an 071700China

In order to avoid the formation ofηphase(W_(6)Co_(6)C or W_(3)Co_(3)C)that adversely affects the sintering process and its products in the preparation process of ultra-fine WC-Co powder,a technical route of prereduction of WO_(3)-Co_(3)O_(4)to WO_(2)-Co and then deep reduction carbonization to WC-Co powder has been *** study mainly investigates the influence of gas partial pressure on the pre-reduction process of WO_(3)-Co_(3)O_(4)under a mixed atmosphere of H_(2)-C_(2)H_(4)-Ar at 600℃and establishes the kinetic equations of pre-reduction and carbon *** results indicate that increasing the partial pressure of hydrogen is conducive to the rapid and complete conversion of WO_(3) to WO_(2).High carbon content can be generated by the deposition of C_(2)H_(4),and it hinders the diffusion of the reducing gas;WO_(3)still cannot be completely reduced to WO_(2)as the partial pressure of C_(2)H_(4) increases to 60%.For the carbon evolution of C_(2)H_(4),the carbon amount is positively related to the H_(2)partial pressure,but it shows the highest amount and evolution rate when the ethylene partial pressure is 20%.Based on the reduction rate curves of WO_(3) and carbon evolution rate curves of C_(2)H_(4),the rate equations of pre-reduction and carbon evolution of WO_(3)-Co_(3)O_(4)system at 600℃are *** pre-reduction reaction belongs to the first-order reaction,and its equation is expressed as follows:r=-(dw_(WO_(3)))/dt=(9±0.15)×10^(-2)×P_(H_(2))^(0.44)P_(C_(2)H_(4))&(0.57)The carbon deposition rate equation of C_(2)H_(4) can be expressed as follows:r=-(dc_C)/dt=r_f-r_b≌7.35×10^(-2)×P_(C_(2)H_(4))^(0.31)

关键词： Fluidization WO_(3)-Co_(3)O_(4) Reduction Carbon deposition Rate equation

A New Protocol for Solubilization, Refolding and Purification of Recombinant Human Granulocyte Colony-stimulating Factor in Inclusion Bodies

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Chinese Chemical Letters 2006年第6期17卷 799-802页

作者： Jia Hua LIU Chao zhan WANG Xin du GENG Institute of Modem Separation Science Key Laboratory of Separation Science in Shaanxi Province Northwest University Xi＇an 710069

Recombinant human granulocyte colony-stimulating factor （rhG-CSF） in inclusion bodies was solubilized by 8 mol/L urea solution and subsequently precipitated by acetone to improve its purity. After that, the precipitates were solubilized by sodium hydroxide solution containing 2 mol/L urea. Then the solubilized rhG-CSF was passed through a size exclusion chromatography for refolding and extensive purification, and further purified by a weak anion exchange chromatography. The purity and mass recovery of refolded rhG-CSF were 96.5% and 75.6%, respectively. The bioactivity was 8.4x10^7 IU/mg.

关键词： Recombinant human granulocyte colony-stimulating factor alkaline solution,solubilization of inclusion bodies protein refolding.