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Microstructure and properties of thermal-sprayed NiCrWRE coatings

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Rare Metals 2008年第3期27卷 261-265页

作者： ZHANG Zhenyu WANG Zhiping LIANG Bunv Mechanical Engineering Department Lanzhou Polytechnic College Lanzhou 730050 China State Key Laboratory of New Nonferrous Metal Materials Lanzhou University of Technology Lanzhou 730050 China

The powders of NiCrW and NiCrWRE alloys were flame sprayed on a medium-carbon steel substrate by thermal spray welding. The micro- structure and tribological behavior of coatings were studied experimentally by means of scanning electron microscopy （SEM）, field emission gun scanning electron microscope （FEGSEM）, and wear tests. The addition of CeO2 modifies the coating morphology from a needle-like structure to a roughly cubic morphology; the refining and purifying effect of rare earth elements makes the microstmcture more compact and finer. Analysis of the worn surfaces reveals that the coatings with CeO2 addition show improved abrasive wear resistance over those without CeO2. By adding CeO2, the hardness of the coatings is significantly increased, and the wear resistance of the coatings is enhanced.

关键词： NiCrWRE microstructure thermal-sprayed coatings wear resistance

The Clar covering polynomial of hexagonal systems Ⅱ.An application to resonance energy of condensed aromatic hydrocarbons

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Chinese Journal of Chemistry 1996年第4期14卷 321-325页

作者： ZHANG, Fu-JiDepartment of Mathematics, Xiamen University, Xiamen, Fujian 361005, ChinaZHANG, He-PingDepartment of Mathematics, lanzhou University, lanzhou, gansu 730000, ChinaLIU, Yu-TingDepartment of Chemistry, Xinjiang University, Urumqi, Xinjiang 830046, China Department of Mathematics Xiamen University Xiamen Fujian 361005 China

The Clar covering polynomial of hexagonal systems is a recently proposed1,2 concept which contains much more topological properties of condensed aromatic hydrocarbons, such as Kekule structure count, Clar number, first Herndon number, etc. It is shown that this polynomial can be used for calculating the resonance energy of condensed aromatic hydrocarbons with better accuracy.

关键词： Resonance energy condensed aromatic hydrocarbon Clar covering polynomial.

NONLINEAR MECHANISM OF ABRUPT CHANGE OF ATMOSPHERIC CIRCULATION DURING JUNE AND OCTOBER

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Science in China,Ser.B 1983年第7期26卷 746-754页

作者：李麦村罗哲贤 Institute of Atmospheric Physics Academic Sinica Beijing Department of Meteorology and Physical Oceanography Massachusetts Institute of Technology Meteorological Bureau of gansu Province lanzhou

By the low-order spectral model, the abrupt change of the circulation in the barotropic atmosphere is studied. In certain parametric combinations, along with the gradual change of the external thermal forcing, the quasi-cusp pattern abrupt changes of both the spectral coefficients and the locations of west jet stream are stimulated, which are similar to the rapid northward jumping and suddenly establishing of the 'South-Branch' jet stream during June and October respectively. Depending on the changes of the parametric combinations, the motional form of the abrupt change can be substituted by that of the gradual change of one stable equilibrium, or by that of the branching phenomena of the multiple equilibria. The abrupt change mechanism of the atmospheric circulation is a nonlinear mechanism which contains the thermal forcing, dissipation, and thermal and dynamic effects.

关键词： NONLINEAR MECHANISM OF ABRUPT CHANGE OF ATMOSPHERIC CIRCULATION DURING JUNE AND OCTOBER

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回族起源的DNA证据

回族研究 2002年第3期 75-78页

作者：谢小冬陕雪梅兰州大学民族基因研究所甘肃兰州730000

应用现代DNA分析技术,研究回族的起源、迁徙、融合、演变,探讨回族与其他民族之间的关系及有关发展规律,应是回族学研究的一个值得重视的方面。本文利用本实验室积累,综合国内外其他族群基因资料,以群体角度从DNA水平探讨了回族的起源... 详细信息

应用现代DNA分析技术,研究回族的起源、迁徙、融合、演变,探讨回族与其他民族之间的关系及有关发展规律,应是回族学研究的一个值得重视的方面。本文利用本实验室积累,综合国内外其他族群基因资料,以群体角度从DNA水平探讨了回族的起源、迁徙、演化等问题,证实了以往大多数人类学调查的结果,即回族与北方民族之间有相当大的融合。并且明确了回族中有较大比例的高加索人种的混杂程度,而这种基因流动应该主要与唐宋时期西域商贾、使者留居和蒙元时期蒙古人西征有密切关系,为传统的回族学研究提供了新视角。

关键词：回族起源 DNA证据回族学民族学人类基因组

OXYGENATION OF METHANE TO METHANOL BY METHANE MONOOXYGENASE OF METHYLOMONAS STRAIN GYJ-3

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Journal of Energy Chemistry 1993年第2期 109-118页

作者： LIU Ai-Min Department of Chemistry,Xiamen(Amoy)University Xiamten,Fujian 361005 LI Shu-Ben State Key Laboratory for Oxo Synthesis and Selective Oxidation(OSSO)lanzhou Instetitute of Chemical Physics,Academia Sinica lanzhou,gansu 730000

Both purified methane monooxygenase enzyme system and restingwhole-cell suspensions of Methylomonas *** GYJ-3 were used as biocata-lysts for methanol biosynthesis from *** productivity which cat-alyzed by highly purified enzyme system was 65～70 μmol/mg in the presenceof dioxygen and NADH during 2h reaction *** amounts of methanol（approximately 0.24 mmol/L）accmulated when washed cell suspensions ofMethylomonas *** GYJ-3 were incubated with CH+Omixture in coni-cal *** optimal temperature,pH,buffer concentration and reaction timewere *** results presented here provide a direct evidence for methanemetablism to COvia methanol in whole-cell of the bacterium.

关键词： Pr MMO OXYGENATION OF METHANE TO METHANOL BY METHANE MONOOXYGENASE OF METHYLOMONAS STRAIN GYJ-3

Simulative Measurement of Besetting Bars for Interior Decoration

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Computer Aided Drafting,Design and Manufacturing 2000年第1期10卷 36-40页

作者： Lu Jinbu Jiang Hongying (gansu University of Technology, lanzhou, PR.China 730050)

Generation of besetting bars for interior decoration by means of 3-D scanning is presented Cross-section of besetting bars (the arc length of element's boundary curve) and the trail of element's movement (locus) is si... 详细信息

关键词： besetting bar element locus dynamic measurement

木通科、大血藤科的花粉形态研究及其在分类学中的意义

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植物研究 1989年第4期9卷 99-114页

作者：夏泉彭泽祥兰州大学生物系

应用扫描电镜(SEM)和电子计算机,本文作者对我国的5属21种、1变种木通科植物以及大血藤科植物的花粉形态进行了深入观察和定量研究。文章在电镜水平上概括了木通科及其若干属的花粉特征,归纳了花粉外壁雕纹的基本类型,研究了花粉性状之... 详细信息

应用扫描电镜(SEM)和电子计算机,本文作者对我国的5属21种、1变种木通科植物以及大血藤科植物的花粉形态进行了深入观察和定量研究。文章在电镜水平上概括了木通科及其若干属的花粉特征,归纳了花粉外壁雕纹的基本类型,研究了花粉性状之间的内在联系,从花粉学角度进一步探讨了有关类群之间的亲缘关系,以及木通科花粉形态演化的一般趋势。

关键词：木通科大血藤科花粉形态分类学

A New Method for Locating Calculation of Arbitrary Spatial Straight Line or Plane in NC Machining

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厦门大学学报（自然科学版） 2002年第S1期41卷 149-150页

作者： YAN Shu-tian, LIU Tao, WU Zai-xin, HU Chi-bing, HU Li-zh i (College of Mechano-Electronic Engineering, gansu University of Techn ology, lanzhou 730050, China)

In the manufacturing process, we often encounter so me location machining of space arbitrary straight lines and planes that are not on ly unparalleled but also not vertical with the machine tool spindle or the cutti ng tool. In the past, we can do the location machining through the methods of dr awing line and making level in the ordinary machine tool. In the numerical contr ol machining of the CNC machine tool and manufacturing center, however, the spac e location and angle of the arbitrary straight lines and planes must be precisel y calculated in advance. So that precisely locating can be guaranteed in machini ng. Therefore, how to work out the space location angle of the arbitrary straigh t lines and planes to be machined both conveniently and precisely, turns out to be the must-be-solved chief problem in the numerical control machining. In thi s paper, through the deeply research of this problem, a new kind of calculating formula that calculates and defines the space location angle of the arbitrary st raight lines and planes by using the methods of analytic calculating. The formul a has been applied in the practical manufacturing calculation. It is proved that the new space angle calculating methods of arbitrary straight lines and planes is convenient in calculating and precise in locating. And it provides us a n ew, brief and precise calculating method in the numerical control machining of t he numerical control machine tool and manufacturing center.

关键词： arbitrary straight line arbitrary plane pr ojected angle inclination location

BIFURCATIONS FROM STATIONARY TO PERIODIC STATES AND TWO KINDS OF LOW-FREQUENCY OSCILLATIONS OF SUBTROPICAL FLOW PATTERNS

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Science in China,Ser.B 1987年第3期30卷 304-315页

作者：李麦村罗哲贤 Institute of Atmospheric Physics Academia Sinica Beijing Meteorological Institute of gansu Province lanzhou

A parameterization for convective heating is introduced into the diabatic term of a two-layer, low-or-der spectral model for estimating the effects of moist convection on bifurcations fro mstationary to period-ic states of flow patterns. In certain parameter combinations, thermal forcing with the parameterizationcan generate bifurcations from stationary to periodic states. However, the forcing without it does not ex-cite such bifurcations. The time scales corresponding to their periodic states are about two-three *** other parameter combinations, the thermal forcing either with or without the convective heating cangenerate the bifurcations from stationary to periodic states; but the effects of convective heating shortenthe time scales and accelerate the amplifications of the excited periodic oscillations. The instabilities of the stationary states, which represent a uniform distribution of the subtropicalflow pattern at the upper layer of the model atmosphere, may form two kinds of low-frequency os

关键词： high