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Kinetics of crystal growth on seeded precipitation of sodium aluminate solutions with new device

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中国有色金属学会会刊：英文版 2004年第4期14卷 824-828页

作者：陈金清张平民甘国耀尹周澜陈启元 School of Chemistry and Chemical Engineering Central South University Guangxi corporation of China Aluminum corporation

A new device was designed,which can effectively avoid the undesired nucleation and agglomeration of fine particles on the experimental results during the sead ed precipitation of sodium aluminate solution,and moreover,the experimental co nditions are nearly kept constant during the experiment. With the new device,it is proven that a good result can be obtained on the kinetics study of the cryst al growth in seeded precipitation of sodium aluminate *** were carried out with the concentration of Na2O （Nk）170 g/L,the mole ratio of Na2O to Al2O3 （αk） all between 1.52 to 2.01,at 65,70,75 ℃,respectively. And the kinetics equation of crystal growth of gibbsite was deduc ed.

关键词：铝酸钠溶液晶种分解晶体生长氧化铝动力学

An Integrated Structural Strength Analysis Method for Spar Type Floating Wind Turbine

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China Ocean Engineering 2016年第2期30卷 217-230页

作者：胡志强刘毅王晋 State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration Shanghai 200240China China National Offshore Oil corporation Research Institute Beo'ing 100028China COTEC Offshore Engineering solution HoustonTexas 77079USA

An integrated structural strength analysis method for a Spar type floating wind turbine is proposed in this paper,and technical issues related to turbine structure modeling and stress combination are also *** NREL-5MW ＂Hywind＂ Spar type wind turbine is adopted as study ***-domain dynamic coupled simulations are performed by a fully-coupled aero-hydro-servo-elastic tool,FAST,on the purpose of obtaining the dynamic characteristics of the floating wind turbine,and determining parameters for design load cases of finite element *** design load cases are identified,and finite element analyses are performed for these design load *** structural stresses due to wave-induced loads and wind-induced loads are calculated,and then combined to assess the structural strength of the floating wind *** feasibility of the proposed structural strength analysis method for floating wind turbines is then validated.

关键词： floating wind turbine structural strength analysis method dynamic coupled simulation finite element analysis

^(27)Al MAS-NMR study of inorganic polymer formation at ambient temperature

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 182-187页

作者： Sang-Wook AHN Hee-Soo LEE Wan-Hee YANG Jung-Woo LEE Young-Keun JEONG National Core Research Center for Hybrid Materials solution Pusan National University School of Material Science and Engineering Pusan National University INTChem Co. Ltd.

Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alkaline solutions to induce a certain amount of Si and AI atoms to dissolve from a feedstock such as aluminosilicate. A study of 27A1 MAS-NMR was carried out in an attempt to understand the reaction mechanism of the inorganic polymerization at ambient temperature. Scanning electron microscopy （SEM） and X-ray diflYactometry （XRD） were also employed to establish the composition and microstructure of the inorganic polymerization. Specimens were prepared with different A1/Si mole ratios from the starting materials. The higher the AI content, the more sufficient the AI atoms that can combine with SiO4, and the longer the reaction time, the more the bonded Si--O--A1--O polymer structure, and then the higher the A1 content, the fewer the octahedral A1 with a uniform Si--O--A1--O structure in four directions, because four AI atoms are combined with SiO4, resulting in a uniform Si--O--AI--O structure in four directions. The results show that they have an amorphous microstructure.

关键词： inorganic polymer amorphous tetrahedral

Analysis and Field Trial Results on C-Plane and U-Plane Split Scheme in Virtual Sectorization System

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China Communications 2015年第11期12卷 53-61页

作者： XIE Weiliang WU Zhouyun YANG Fengyi YANG Tao Technology Innovation Center China Telecom Corporation Limited

Capacity enhancement approaches are being intensively studied in the past few years to address the soaring capacity demands. The network densif ication technology is recognized as one promising solution. However,the ultra-dense network scheme suffers from severe interference and frequent handovers,which degrade the system performance significantly. In this paper,a virtual sectorization system leveraging a C-plane(control signaling plane) and U-plane(user data plane) split scheme is proposed to overcome these two fundamental problems. Besides,a well-designed fi eld trial is conducted to evaluate its performance. The results show that the interference can be avoided,which leads to a tremendous increase in system capacity. In addition,the number of handovers is also greatly decreased. Thus,the trial results verify the huge potential of the C-plane and U-plane split scheme for system capacity and user experience enhancements.

关键词： C-plane/U-plane split virtual sectorization handover interference

Soil-structure interaction on shallow rigid circular foundation:plane SH waves from far-field earthquakes

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Earthquake Engineering and Engineering Vibration 2014年第1期13卷 29-45页

作者： Vincent W.Lee Hao Luo Civil & Environmental Engineering Univ. of Southern California HNTB corporation

A closed-form wave function analytic solution of two-dimensional scattering and diffraction of incident plane SH-waves by a fl exible wall on a rigid shallow circular foundation embedded in an elastic half-space is presented. This research generalizes the previous solution by Trifunac in 1972, which tackled only the semi-circular foundation, to arbitrary shallow circular-arc foundation cases, and is thus comparatively more realistic. Ground surface displacement spectra at higher frequencies are also obtained. As an analytical series solution, the accuracy and error analysis of the numerical results are also discussed. It was observed from the results that the rise-to-span ratio of the foundation profi le, frequency of incident waves, and mass ratios of different media(foundation-structure-soil) are the three primary factors that may affect the surface ground motion amplitudes near the structure.

关键词： SH waves plane wave soil-structure interaction closed-form analytic solution Fourier-Bessel series

SOLVING SECOND ORDER DIFFERENTIAL EQUATIONS IN QUANTUM MECHANICS BYORDER REDUCTION

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Acta Mathematica Scientia 2003年第2期23卷 274-288页

作者： C.Ted Chen Grace Semiconductor Manufacturing corporation 2nd Floor

Solving the famous Hermite, Legendre, Laguerre and Chebyshev equations requires different techniques of unique character for each equation. By reducing these differential equations of second order to a common solvable differential equation of first order, a simple common solution is provided to cover all the existing standard solutions of these named equations. It is easier than the method of generating functions and more powerful than the Probenius method of power series.

关键词： Second order differential equations quantum mechanics common solution

Velocity model and time-depth conversion for the northwestern South China Sea deepwater areas

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Acta Oceanologica Sinica 2015年第4期34卷 56-61页

作者： LIU Aiqun CHEN Dianyuan LI Wentuo FAN Caiwei HE Jianwei Zhanjiang Branch of China National Offshore Oil corporation Limited

There are rich natural gas resources in the northwestern South China Sea deepwater areas, with poor degree of exploration. Because of the unique tectonic, sedimentary background of the region, velocity model building and time-depth conversion have been an important and difficult problem for a long time. Recent researches in this direction have revealed three major problems for deepwater areas, i.e., the way to determine error correction for drilling velocity, the optimization of velocity modeling, and the understanding and analysis of velocity variations in the slope areas. The present contribution proposes technical solutions to the problems：（1） velocity correction version can be established by analyzing the geology, reservoir, water depths and velocity spectrum characteristics;（2） a unified method can be adopted to analyze the velocity variation patterns in drilled pale structural positions;and （3） across-layer velocity is analyzed to establish the velocity model individually for each of the layers. Such a solution is applicable, as shown in an example from the northwestern South China Sea deepwater areas, in which an improved prediction precision is obtained.

关键词： time-depth conversion velocity modeling deepwater areas continental slope South China Sea

Synthesis of kalsilite from microcline powder by an alkali-hydrothermal process

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International Journal of Minerals,Metallurgy and Materials 2014年第8期21卷 826-831页

作者： Shuang-qing Su Hong-wen Ma Jing Yang Pan Zhang Zheng Luo National Laboratory of Mineral Materials China University of Geosciences Blue Sky Technology corporation

The properties of aluminosilicate kalsilite have attracted the interest of researchers in chemical synthesis, ceramic industry, biofuels, etc. In this study, kalsilite was hydrothermally synthesized from microcline powder in a KOH solution. The microcline powder, rich in potassium, aluminum, and silicon, was collected from Mountain Changling in Northwestem China. The effects of temperature, time, and KOH concentration on the decomposition of microcline were investigated. The kalsilite and intermediate products were characterized by means of wet chemistry analysis, X-ray Diffraction （XRD）, infi＇ared spectrometry （IR）, 29Si magic angle spinning nuclear magnetic resonance （29Si MAS NMR）, 27A1 MAS NMR, and scanning electron microscope （SEM）. With increasing temperature, the microcline powder transforms into a metastable KAlSiO4 polymorph before transforming further into pure kalsilite. A mixture of both kalsilite and metastable KAlSiO4 polymorph is obtained when the hydrothermal reaction is carried out within 2 h; but after 2 h, kalsilite is the predominant product. The concentration of KOH, which needs to be larger than 4.3 M, is an important parameter influencing the synthesis ofkalsilite.

关键词： kalsilite microcline potassium hydroxide hydrothermal synthesis

A modified chronic ocular hypertension rat model for retinal ganglion cell neuroprotection

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Frontiers of Medicine 2013年第3期7卷 367-377页

作者： Lichun Zhong Ocular Science Department Toxikon CorporationBedfordMA 01730USA

This study aimed to modify a chronic ocular hypertension(OHT)rat model to screen for potential compounds to protect retinal ganglion cells(RGCs)from responding to increased intraocular pressure(IOP).A total of 266 rats were prepared and randomly grouped according to different time-points,namely,weeks 3,8,16,and *** were sedated and eye examination was performed to score as the corneal damage on a scale of 1 to *** OHT rat model was created via the injection of a hypertonic saline solution into the episcleral veins once weekly for two *** was identified when the IOP at week 0 was≥6 mmHg than that at week-2 for the same *** RGCs were labeled by injecting 4%*** were sacrificed,and the eyes were enucleated and *** fixed retinas were dissected to prepare flat *** viable RGCs were visualized and *** IOP(meanβ±βSD)was calculated,and data were analyzed by the paired t-test and one-way *** OHT model was created in 234 of 266 rats(87.97%),whereas 32 rats(12.03%)were removed from the study because of the absence of IOP elevation(11.28%)and/or corneal damage scores over 4(0.75%).IOP was elevated by as much as 81.35%for 24 *** average IOP was(16.68β±β0.98)βmmHg in non-OHT eyes(n=234),but was(27.95±0.97)βmmHg in OHT eyes(n=234).Viable RGCs in the OHT eyes were significantly decreased in a time-dependent manner by 29.41%,38.24%,55.32%,and 59.30%at weeks 3,8,16,and 24,respectively,as compared to viable RGCs in the non-OHT eyes(P<β0.05).The OHT model was successfully created in 88%of the *** IOP in the OHT eyes was elevated by approximately 81%for 24 *** number of viable RGCs was decreased by 59%of the rats in a time-dependent *** modified OHT model may provide an effective and reliable method for screening drugs to protect RGCs from glaucoma.

关键词： chronic ocular hypertension intraocular pressure retinal ganglion cells neuroprotection glaucoma