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A simple approach for determining the preload of a wire race ball bearing

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第7期11卷 511-519页

作者： Xiao-biao shan li-li WANG Tao XIE Wei-shan CHEN 1School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China College of Science Northeast Forestry University Harbin 150040 China

Wire race ball bearings have been widely used in high-tech weapons. The preload of a wire race ball bearing is crucial in engineering applications. In this study, a more effective approach is proposed for exact determination of the wire race ball bearing preload. A new mathematical model of the preload and the starting torque of the wire race ball bearing was built using the theorem of the 3D rolling friction resistance and the non-conforming contact theory. Employing a wire race ball bearing with a 1000 mm diameter used in a specific type of aircraft simulating rotary table, the numerical analysis in MATLAB～ showed that the preload magnitude can be controlled in the range of 130–140 μm. As verification, the experimental results were in agreement with the theoretical results, and confirm the feasibility of this method. This new approach is more exact in the preload range of 10–158 μm than that computed by the numerical method reported in our previous work (shan et al., 2007b). This implies that the present method contributes to more effectively preventing rolling noise, overturning moments and wear of the wire race ball bearing. The current research provides critical technical support for the engineering application of wire race ball bearings with large diameters.

关键词： Wire race ball bearing Rolling friction Starting torque Contact interface

Characteristics of ocular abnormalities in gout patients

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International Journal of Ophthalmology(English edition) 2013年第3期6卷 307-311页

作者： Jing lin Gui-Qiu Zhao Cheng-Ye Che shan-shan Yang qian Wang Chang-Gui li Department of Ophthalmology the Affiliated Hospital of Medical College of Qingdao University

·AIM: To characterize the clinical features of ocular surface in gout patients in coastal area of shandong Province in China. ·METHODS: A total of 380 consecutive gout patients were examined from January 2011 to May 2011. According to the course of gout, patients were divided into group A (10 years). Group D (control group) was consist of 50 healthy subjects. Eyelids, lateral canthus, medial canthus, palpebral conjunctiva, sclera and cornea, anterior chamber, lens, anterior vitreous were examined by slit lamp to find whether there were deposition of uric acid crystals, ocular vascular tortuosity, redness and subconjunctival hemorrhage. The ophthalmic exams of visual acuity, intraocular pressure, fundus were used to assess any gout-related eye disease. ·RESULTS: Uric acid crystals were found in 3 patients and the positions of the deposite were in corneal stroma, corneal epithelium and superficial stroma, and sclera respectively. The incidence was 0.79% . Dilatated and tortuous blood vessels in conjunctiva and sclera surface were found in 38 (23.8% ), 40 (44.0% ), 58 (45.0% ), 9 (18.0% ) patients in groups A, B, C and D, respectively. The differences between group B and D, group C and D were statistically significant( like reflected light in subconjunctiva were seen in 26 (16.2%), 29 (31.9%), 41 (31.8%), 2 (4.00%) patients in groups A, B, C and D, respectively. The differences between A and D, B and D, C and D were statistically significant ( lities, such as tophi deposition, subconjunctival transparent vesicles and hemorrhage, and vascular changes. These features have important clinical significance in early detection of the gout and prevention of eye injury. ·

关键词： ocular abnormalities gout tophi

Two new pseudo-isomeric nickel(Ⅱ)metal-organic frameworks with efficient electrocatalytic activity toward methanol oxidation

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Rare Metals 2021年第2期40卷 489-498页

作者： shan liu Xiao Wang Hong-Guang Yu Ya-Pan Wu Bo li Ya-qian Lan Tao Wu Jian Zhang Dong-Sheng li College of Materials and Chemical Engineering Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion MaterialsChina Three Gorges UniversityYichang443002China

Searching for non-noble metal catalysts with high activities and low price is critical to the commercialization of methanol oxidation in the process of fuel ***,two new pseudo-isomeric Ni metal-organic frameworks(Ni-MOFs)(CTGU-17/CTGU-18)have been prepared with 1,4-naphthalenedi-carboxylate(H_(2)NDC),4,4’-dipyridyl amine(DPA)and Ni(ClO_(4))_(2)under hydrothermal *** phase contains one water molecule,but differs dramatically in its bonding to the framework,resulting in different topological networks with fourfold interpenetrating 4-connected dia net(CTGU-17)and(3,7)-connected net(CTGU-18)and diverse electrocatalytic performance for methanol oxidation reaction(MOR).Remarkably,by combining each MOF with the conductive additive,acetylene black(AB),a composite material,AB&CTGU-18(2:4)was confirmed to have an excellent performance for MOR with a high mass specific peak current of 442.3 mA·mg^(-1).The enhanced electrocatalytic activities and robustness might be attributed to the synergetic effect of acetylene black and the active metal centers of MOFs particles for methanol *** present work would provide a new insight for the rational design of MOFs-based composites with enhanced methanol oxidation reaction performance.

关键词： Nickel(Ⅱ) MOFs Composite materials Electrocatalysis Methanol oxidation

Revealing the dynamics of the alloying and segregation of Pt-Co nanoparticles via in-situ environmental transmission electron microscopy

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Nano Research 2023年第2期16卷 3055-3062页

作者： Xing li Shaobo Cheng Yanghua He lixiang qian Dmitri Zakharov Gang Wu Chongxin shan liang Zhang Dong Su Henan Key Laboratory of Diamond Optoelectronic Materials and Devices Key Laboratory of Material PhysicsSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China Center for Functional Nanomaterials Brookhaven National LaboratoryUptonNY 11973USA Department of Chemical and Biological Engineering University at BuffaloThe State University of New YorkBuffaloNY 14260USA Center for Combustion Energy School of Vehicle and MobilityTsinghua UniversityBeijing 100084China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Thermal treatment is a general and efficient way to synthesize intermetallic catalysts and may involve complicated physical *** far,the mechanisms leading to the size and composition heterogeneity,as well as the phase segregation behavior in Pt-Co nanoparticles(NPs)are still not well *** in-situ environmental transmission electron microscopy,the formation dynamics and segregation behaviors of Pt-Co alloyed NPs during the thermal treatment were *** is found that Pt-Co NPs on zeolitic imidazolate frameworks-67-derived nanocarbon(NC)are formed consecutively through both particle migration coalescence and the Ostwald ripening *** existence of Pt NPs is found to affect the movement of Co NPs during their *** the help of theoretical calculations,the correlations between the composition and migration of the Pt and Co during the ripening process were *** complex alloying processes are revealed as key factors leading to the heterogeneity of the synthesized Pt-Co alloyed *** oxidation environment,the Pt-Co NPs become surface faceted gradually,which can be attributed to the oxygen facilitated relatively higher segregation rate of Co from the(111)*** work advances the fundamental understanding of design,synthesis,and durability of the Pt-based nanocatalysts.

关键词： intermetallic catalyst alloying ripening segregation dynamics environmental transmission electron microscopy(ETEM)

Approximation Theorems and Fixed Point Theorems for Various Classes of 1-set-contractive Mappings in Banach Spaces

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Acta Mathematica Sinica,English Series 2001年第1期17卷 103-112页

作者： li shan liU Department of Mathematics Qufu Normal University

In this paper, we will prove that Ky Fan’s Theorem (Math. Z. 112(1969), 234-240) is true for 1-set-contractive maps defined on a bounded closed convex subset K in a Banach space with int K≠ . This class of 1-set-contractive maps includes condensing maps, nonexpansive maps, semicontractive maps, LANE maps and others. As applications of our theorems, some fixed point theorems of non-self- maps are proved under various well-known boundary conditions. Our results are generalizations and improvements of the recent results obtained by many authors.

关键词： Approximation theorems Fixed point theorems 1-set-contractive maps Semicontractive maps LANE maps

Wave-induced stress and estimation of its driven effect on currents

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Science China Earth Sciences 2004年第12期47卷 1147-1154页

作者： SUN Fu GAO shan WANG Wei qian Chengchun Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China

A genuine geostrophic small amplitude wave solution is deduced for the first time from the general form of linear fluid dynamic equations with the f-plane approximation, where the horizontal component of angular velocity of the earth rotation is taken into account. The Coriolis- induced stress obtained from this solution consists of lateral and reverse component, while its first order approximation is reduced to the result of Hasselmann or Xu Zhigang. Accordingly, combining the Coriolis-induced wave stress with the virtual wave stress proposed by Longuet-Higgins, the ratio of total wave-induced stress to wind stress on the sea surface is es- timated, through which the importance of the wave-induced stress is emphasized in the study of the currents in the seas around China, especially in the Bohai Sea and the Yellow Sea.

关键词： waves, geostrophy, stress, currents.

Impacts of Land Use and Cover Change on Land Surface Temperature in the Zhujiang Delta

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Pedosphere 2006年第6期16卷 681-689页

作者： qian Le-Xiang CUI Hai-shan CHANG Jie School of Geographical Sciences Guangzhou University Guangzhou 510006China College of Environment ＆ Planning Henan University Kaifeng 475004China program in Geographic Information Sciences University of Texas at Dallas Richardson TX 75083 USA

Remote sensing and geographic information systems (GIS) technologies were used to detect land use/cover changes (LUCC) and to assess their impacts on land surface temperature (LST) in the Zhujiang Delta. Multi-temporal Landsat TM and Landsat ETM+ data were employed to identify patterns of LUCC as well as to quantify urban expansion and the associated decrease of vegetation cover. The thermal infrared bands of the data were used to retrieve LST. The results revealed a strong and uneven urban growth,which caused LST to raise 4.56℃in the newly urbanized part of the study area. Overall, remote sensing and GIS technologies were effective approaches for monitoring and analyzing urban growth patterns and evaluating their impacts on LST.

关键词： land surface temperature land use/cover change Landsat ETM+ Landsat TM Zhujiang Delta

Microstructure and Property of Coarse Grain HAZ X80 Pipeline Steel

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Journal of Iron and Steel Research International 2005年第6期12卷 54-58页

作者： ZHOU Yun XUE Xiao-huai qian Bai-nian li Jing-li shan Yi-Yin LOU Song-nian shanghai Jiaotong University Shanghai 200030 China Academia Sinica Shenyang 110015 China

The coarse grain HAZ microstructure and property of X80 pipeline steel with different carbon content was investigated. The weld thermal simulation test was carried out on Gleeble 1500 thermal mechanical test machine. The Charpy tests were completed at --20 ℃ for evaluating the toughness of coarse grain heat affected zone （CGHAZ）. The microstructure was examined by optical microscope （OM） and transmission electron microscopy （TEM）, and the austenite constituent was quantified by X-ray diffraction. The results showed that the ultra-low carbon can improve the toughness of CGHAZ by suppressing the formation of carbide, decreasing the martensite austenite （M-A） constituent and increasing the residual austenite in the M A.

关键词： X80 pipeline steel CGHAZ weld simulation FesC carbide ultra low carbon M-A constituent bainitic ferrite

Functional characterization of the catalytic and bromodomain of FgGCN5 in development,DON production and virulence of Fusarium graminearum

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Journal of Integrative Agriculture 2020年第10期19卷 2477-2487页

作者： WANG qian-nan HUANG Pan-pan ZHOU shan-yue The Key Lab of Integrated Crop Pests Management of shandong Province/College of Plant Health and Medicine Qingdao Agricultural UniversityQingdao 266109P.R.China

FgGCN5,a GCN5 homolog in Fusarium graminearum,plays a critical role in hyphal vegetative growth,asexual and sexual reproduction,deoxynivalenol(DON)biosynthesis and plant *** nuclear localized GCN5,four conserved sequence motifs(I-IV)are presented in the catalytic domain and a bromodomain in the *** a lysine acetyltransferase,conserved negatively charged residues are present to neutralize the protons from lysine ***,the role of conserved motifs/domains and residues in FgGCN5 are ***,we generated deletion mutant strains for each the conserved motifs/domains and a glutamate residue 130(E130)replacement *** of each conserved motif in the catalytic domain and replacement of E130 site resulted in manifold defects in hyphae growth,asexual and sexual development,DON biosynthesis,and plant *** defects in the mutant strains were similar to deletion *** deletion of the bromodomain led a significant reduction in DON production and virulence,with no effects on hyphae growth,asexual or sexual ***5 was further found to localize to the nucleus in conidia and hyphae *** conclusion,FgGCN5 encodes a nuclear localized *** conserved motifs in the catalytic domain and E130 are essential for correct functions of the *** conserved bromodomain is impotant for DON production and pathogen *** was the first report to identify the functions of conserved motifs/domains in FgGCN5,which will contribute to our understanding of the mechanism(s)by which FgGCN5 regulates ***.

关键词： FgGCN5 catalytic domain bromodomain DON virulence