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Stability.of GM(1,1) power model on vector transformation

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Journal of Sy.tems Engineering and Electronics 2015年第1期26卷 103-109页

作者： jinhai Guo Xinping Xiao Jun Liu Shuhua Mao School of Science Wuhan University of Technology School of Information and Mathematics Yangtze University

The morbidity.problem of the GM（1,1） power model in parameter identification is discussed by.using multiple and rotation transformation of vectors. Firstly.we consider the morbidity.problem of the special matrix and prove that the condition number of the coefficient matrix is determined by.the ratio of lengths and the included angle of the column vector, which could be adjusted by.multiple and rotation transformation to turn the matrix to a well-conditioned one. Then partition the corresponding matrix of the GM（1,1） power model in accordance with the column vector and regulate the matrix to a well-conditioned one by.multiple and rotation transformation of vectors, which completely.solve the instability.problem of the GM（1,1） power model. Numerical results show that vector transformation is a new method in study.ng the stability.problem of the GM（1,1） power model.

关键词： grey.power model stability morbidity vector transformation condition number of matrix

Onset of East Asian subtropical summer monsoon and rainy.season in China

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Science China Earth Sciences 2011年第12期54卷 1845-1853页

作者： ZHU CongWen ZHOU XiuJi ZHAO Ping CHEN LongXun HE jinhai Chinese Academy.of Meteorological Sciences Beijing 100081 China National Information Center Chinese Meteorological Administration Beijing 100081 China Nanjing University.oflnformation Science ＆ Technology Nanjing 210044 China

Here we use harmonic analy.es to examine seasonal variations of China land rainfall, low-level winds, and atmospheric heating over East Asia during spring to summer and the associated subtropical summer monsoon activities. Our results indicate that the South China spring rainfall (SCSR) in March is the prophase of East Asian sub-tropical summer monsoon (EASSM), and the onset of EASSM and China summer rainy.season starts in early.April, characterized by.the enhanced rainfall in South China and the seasonal reverse of zonal land-sea thermal contrast in sub-tropical East Asia. The EASSM onset is earlier than that of South China Sea summer monsoon, and it is active in east of 100?E and north of 20?N. Our analy.es suggest that the subsequent heating appears over India-China Peninsula in March and South China in April and causes the low-level atmospheric warming and the zonal land-sea thermal contrast seasonal reverse in East Asian subtropics. The atmospheric heating over South China is the main force to drive the southwesterly.winds, updrafts and strengthen the summer precipitation in South China.

关键词： seasonal cy.le East Asian sub-tropical summer monsoon China summer rainy.season onset

RESEARCH AND APPLICATION OF AS-CAST WEAR RESISTANCE HIGH CHROMIUM CAST IRON

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Chinese Journal of Mechanical Engineering 1998年第2期11卷 51-56页

作者： Liu, jinhai Liu, Gensheng Li, Guolu Wang, Kunjun Zeng, Daben Hebei Univ of Technology China

The influence of alloy.elements, such as boron and silicon, on the microstructure and properties of as cast high chromium cast iron is studied. The results show that boron and silicon have a great effect on the mechanical properties and the wear resistance. Through proper addition of boron and silicon, the properties of as cast high chromium cast iron can be improved effectively. Through analy.ing the distribution of elements by.scanning electron microscope, it has been shown that the addition of boron and silicon lowers the mass fraction of chromium saturated in as cast austenite, and makes it unstable and liable to be transformed into martensite. The as cast high chromium cast iron with proper content of boron and silicon is suitable for the manufacture of lining for asphalt concrete mixer and its wear resistance is 14 times that of lining made of low alloy.white cast iron.

关键词： High chromium cast iron Hardness Wear resistance Impact toughtness Lining

Numerical Hy.rody.amics Study.Around Turbine Array.of Tidal Stream Farm in Zhoushan, China

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Journal of Ocean University.of China 2017年第4期16卷 703-708页

作者： y. Zhiwen ZHANG Jisheng ZHAI y.ny.n ZHANG Tiantian ZHENG jinhai State Key.Laboratory.of Hy.rology.Water Resources and Hy.raulic Engineering Hohai University Nanjing 210098 P. R. China College of Harbor Coastal and Offshore Engineering Hohai University Nanjing 210098 P. R. China Powerchina Water Environment Governance Shenzhen 518100 P. R. China China Three Gorges Corporation Beijing 100038 P. R. China

In recent decades,great efforts have been made to efficiently.explore tidal stream energy.due to its unique advantages of easy.prediction and great *** recently.launched a national tidal stream farm demonstration project in the waterway.between Putuoshan and Hulu Islands in the Zhoushan *** deploy.ent of the turbine array.it is necessary.to understand the hy.rody.amic changes associated with the construction of a turbine *** this study.we developed a depth-averaged hy.rody.amics model that solves the shallow water governing equations to simulate the tidal hy.rody.amics around the Zhoushan *** simulation results agree with field data in terms of the water elevation and stream *** considered two ty.es of turbine array. in this study.and investigated their impacts on the local *** general,the stream velocity.in the northern and southern areas is reduced due to the power take-off of the turbine array.whereas stream velocity.in the western and eastern areas is slightly.increased due to the blockage impact of the turbine array.

关键词： tidal stream farm turbine array tidal hy.rody.amics numerical simulation demonstration project

Interannual variability.of the Meiy. onset over y.ngtze-Huaihe River Valley.and analy.es of its previous strong influence signal

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Chinese Science Bulletin 2009年第4期54卷 687-695页

作者： WANG Jing HE jinhai LIU XuanFei WU BinGui College of Atmospheric Sciences Nanjing University of Information Science and Technology Nanjing 210044 China Tianjin Meteorological Observatory Tianjin 300074 China

Meiy. onset (MO) over y.ngtze-Huaihe River Valley.(y.RV) possesses obvious characteristics of interannual variations. Based on NCEP/NCAR reanaly.is data sets, NOAA OLR and ERSST data, the in-terannual variability.of MO(IVMO) and its previous strong influence signal (PSIS) are investigated. The possible mechanisms that the PSIS affecting IVMO are also discussed. The results show that the pre-vious CP-ENSO (Central Pacific El Nio/Southern Oscillation) event is the PSIS affecting IVMO and it has a better accuracy.rate of short-term climate prediction and practicality. The MO is most likely.to be late (early. with the warm (cold) phase of CP-ENSO in previous boreal February.and spring. CP-ENSO affects MO mainly.by.means of EAP (East Asian-Pacific) or JP (Japanese-Pacific) teleconnection, in which the tropical western North Pacific anticy.lone play. an important role. In the y.ars of CP-ENSO warm phase, the tropical warm wet water vapor transportation to y.RV is late. The anomalous positive sea surface temperature near the equatorial central Pacific results in late northward jump of the western Pacific subtropical high and late establishment of Indian southwest monsoon via air-sea interaction, which leads to late seasonal transition of the atmospheric circulations over East Asia from boreal spring to summer. Late seasonal transition of the atmospheric circulations and late tropical warm wet water vapor transport to y.RV are the primary.reasons that cause the late MO. The situations are directly.opposite in the y.ars of CP-ENSO cold phase.

关键词：长江-淮河流域气候预报环境行动规划潮湿水蒸汽

Rules of variation in hy.rogen during reignition of underground fire zones of spontaneous coal combustion

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Mining Science and Technology 2010年第4期20卷 499-503页

作者： ZHOU Fubao LI jinhai LIU y.sheng SHAO He School of Safety.Engineering China University of Mining ＆ Technology Xuzhou 221008 ChinaState Key Laboratory of Coal Resources and Safe Mining China University of Mining ＆ Technology Xuzhou 221008 China

In light of the possibility.of reignition when unsealing the closed fire zones, the occurrence of reignition was simulated by.a home-made experimental device, hy.rogen variety.rule from combustion to unsealing was analy.ed, the three-stage generation model of hy.rogen during reignition in fire zone was put forward and the probability.that hy.rogen was taken as an indicator gas was discussed. The results show that: when fire zone is ready.to unseal, which is filled with hy.rogen at a high concentration, it is more prone to reignite.

关键词： unsealing fire zone reignition hy.rogen generation model indicator gas

Filtering detecting signal of rockbolt with harmonic wavelet

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Mining Science and Technology 2010年第3期20卷 411-414页

作者： WANG Jiy.n ZHAO y.cheng y.O Banghua XU jinhai School of Mechanics & Civil Engineering China University of Mining & Technology Xuzhou 221008 China School of Mines China University of Mining & Technology Xuzhou 221008 China

Harmonic wavelets not only.possess the traditional advantages of a wavelet function,they.also have other merits such as clear expressions,more flexible time-frequency.divisions,a simple transformation algorithm,a finer box-like frequency.spectrum and *** the frequency.distribution characteristics of the nondestructive testing signals from a rockbolt support sy.tem and based on the discrete harmonic wavelet transformation theory.we have effectively.abstracted signals from frequency.ranges concerned by.removing useless high and low frequency.signals from the testing signals of the rockbolt support sy.tem and obtained filtered signals with a reconstruction algorithm of harmonic ***,we applied the harmonic wavelet transformation in filtering analog signals and measured response signals of *** results indicate that harmonic wavelets also have excellent filtering characteristics.

关键词： rockbolt support sy.tem testing harmonic wavelet filtering

Flow Development through HP&LP Turbines,PartⅠ:Inward Rotating Cavity.Flow with Superimposed Throughflow

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Journal of Thermal Science 2017年第4期26卷 297-307页

作者： GAO jinhai DU Qiang LIU Jun LIU Guang WANG Pei LIU Hongrui DU Meimei Institute of Engineering Thermophy.ics Chinese Academy of SciencesBeijing 100190China Graduate University.of Chinese Academy.of Sciences Beijing 100049China Petroleum Production Engineering Research Institute ofHuabei Oilfield Company Renqiu Hebei 062550China

With the aid of numerical method, both flow field and its accompanied loss mechanism within the rotating cavity.are investigated in detail in the 1^(st) part of the two parts paper. For ease of comparison, rotating cavity.is further classified as the rotor-stator cavity.case and the rotor-rotor cavity.case. Results indicate that flow within both kinds of the cavity.act as the inviscid flow except that the flow near walls, neighboring the lower G region and in the vicinity.of the rotating orifices. In the regions except such inviscid-flow-dominate domains, the theoretical core rotation factor can be safely.used to predict the swirl ratio within the cavity. When detailed flow pattern is considered, Ekman-ty.e flow exists near periphery.of the surface's boundary.lay.r where viscous effect is non-negligible. However, due to the complex profile of the simulated cavity.case, vortices structure is varied within the cavity. By.comparison, swirl ratio can be used to predict the magnitude of loss. Due to the relatively.evident rotating effects of the rotor-rotor cavity. swirl ratio even increases to 1.4 in the current model, which means that flow is moving faster than the surrounding disc. Further investigation finds that this kind of highly.rotating flow is accompanied with serious undesirable pressure loss. Parenthetically. unlike its counterpart, swirl ratio above 1.0 doesn't happen when fluid passes through the rotor-stator cavity. So it is suggested that rotor-rotor flow cavity.with the superimposed inward throughflow should be avoided in the engine design or certain measurements should be provided when such structure design is unavoidable. Simulation done in the current paper is meaningful since these dimensional parameters are ty.ical in the design of state-of-art. Relatively.lower range of Re_φ and C_w is not considered in the current two parts paper.

关键词： Turbines Inward rotating cavity.flow Superimposed throughflow Flow pattern

PLASTIC DEFORMATION OF TiAl INTERMETALLICS WITH Mn ADDITION

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Transactions of Nonferrous Metals Society.of China 1992年第1期2卷 61-64页

作者： Huang Baiy.n Qu Xuanhui Wen jinhai Lei Changming Central South University.of Technology Changsha 410083China

The dislocation structures of arc-melted,near-equiatomic TiAl alloy. containing 1.5-2.0 wt.-%manga-nese were analy.ed and compared with those of binary.TiAl alloy.processed in a similar *** was found that the pinning effect of a/6[112]partial dislocations was eliminated by.Mn addition,as a result,the movement of a[101]and a/2[112]superdislocations and twinning and play.d an important role in the plastic deformation and increased the ductility.of TiAl *** addition,the workability.of the Mn-ductilized TiAl alloy.was evaluated with hot extrusion and forging.

关键词： TiAl alloy. Plastic deformation dislocation structure