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多规格转台轴承组件的自动紧钉装置

制造技术与机床 2024年第6期 183-188页

作者：王凯韩银平贾长安黄胜军西安精雕精密机械工程有限公司陕西西安710000 北京精雕科技集团有限公司北京102308

在装配转台轴承组件时,需要按照十字交叉顺序分三步拧紧固定螺钉,现有的装紧钉方式存在效率低和紧钉质量低等问题。文章设计了一种多规格转台轴承组件的自动紧钉装置,实现了多规格转台轴承组件的自动定位夹紧、装钉、按照十字交叉顺序... 详细信息

在装配转台轴承组件时,需要按照十字交叉顺序分三步拧紧固定螺钉,现有的装紧钉方式存在效率低和紧钉质量低等问题。文章设计了一种多规格转台轴承组件的自动紧钉装置,实现了多规格转台轴承组件的自动定位夹紧、装钉、按照十字交叉顺序分三步加扭力和加胶功能。实际使用表明,该设备工作可靠、效率高,紧钉质量得到很大提高。

关键词：转台轴承组件自动拧紧力矩螺钉

Nuclear Planetology:Especially concerning the Moon and Mars

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Research in Astronomy and Astrophysics 2012年第10期12卷 1313-1380页

作者： Kyeong ja Kim Nobuyuki Hasebe Korea Institute of Geoscience and Mineral Resources Daejeon305-350 Korea Research Institute for science and Engineering Waseda UniversityShinjukuTokyo 169-8555 Japan

To approach basic scientific questions on the origin and evolution of plan- etary bodies such as planets, their satellites and asteroids, one needs data on their chemical composition. The measurements of gamma-rays, X-rays and neutrons emit- ted from their surface materials provide information on abundances of major elements and naturally radioactive gamma-ray emitters. Neutron spectroscopy can provide sen- sitive maps of hydrogen- and carbon-containing compounds, even if buried, and can uniquely identify layers of carbon-dioxide frost. Nuclear spectroscopy, as a means of compositional analysis, has been applied via orbital and lander spacecraft to extrater- restrial planetary bodies： the Moon, Venus, Mars, Mercury and asteroids. The knowl- edge of their chemical abundances, especially concerning the Moon and Mars, has greatly increased in recent years. This paper describes the principle of nuclear spec- troscopy, nuclear planetary instruments carried on planetary missions so far, and the nature of observational results and findings of the Moon and Mars, recently obtained by nuclear spectroscopy.

关键词： nuclear planetology: planetary remote sensing -- elemental mapping --nuclear science payloads -- chemical abundance

sensitivity to combustible Gas for ZnO Thin Films

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Journal of Materials science & Technology 1997年第4期13卷 302-305页

作者： Tan, GL Wu, ja Wu, XJ Dept. of Materials science and Engineering Zhejiang University Hangzhou 310027 China

A fine polycrystalline ZnO thin film with 0.3 similar to 0.6 mu m grain size was obtained by sol-gel process and a consequential heat treatment at 500 degrees c. The process of preparing ZnO thin film was analysed. The sensitivity and conductivity of ZnO thin films as combustible gas (cO, cH4, H-2) sensor as well as the influence of catalyst and pH value of the precursor on its sensitivity were studied in detail. The structure characteristics of ZnO thin film by different process were investigated by X-ray diffraction, thermal analysis and photoelectron spectrometer. The atomic ratio of Zn to O on the surface of ZnO thin film was found to be 1.14:1 measured from XPs result. The conductivity of the thin film increases greatly when doped with Al3+ ion but decreases while doped with Na+ ion.

关键词： Zinc oxide

Multirange Fractal Analysis on the Negative correlation between Fractal Dimension of Fractured surface and Toughness of Materials

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Journal of Materials science & Technology 1996年第4期12卷 318-320页

作者： Lung, cW Jiang, ja Zhang, cH International centre for Materials Physics Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

Applying the concept of multirange fractals, a new explanation to the Williford's multifractal curve on the relationship of fractal dimension with fracture properties in materials has been given. It shows the importance of factorizing out the effect of fractal structure from other physical causes and separating the appropriate range of scale from multirange fractals.

关键词： Fracture

Iksan526 Rice callus Extract Induces Dedifferentiation of Rabbit Articular chondrocytes via ERK1/2 and PI-3K/Akt Pathways

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Rice science 2020年第6期27卷 504-514页

作者： seong-Hui EO song ja Kim Department of Biological sciences College of Natural SciencesKongju National UniversityGongju 32588Republic of Korea

The resveratrol-enriched transgenic rice line Iksan526(Is526),first developed by the Rural Development Administration of Korea using genetic engineering techniques,shows beneficial health effects in mitigating metabolic syndrome and ***,the effects of Is526 on the differentiation of chondrocytes and the underlying mechanism have not been investigated in *** this study,the effects and cellular regulatory mechanisms of Is526 on rabbit articular chondrocytes were *** Is526 callus extract treatment,the expression levels of differentiation-related proteins were detected via western blotting,Alcian blue staining and immune-luorescence ***526 decreased the type Ⅱ collagen and proteoglycan levels in dose-and time-dependent *** further analyzed the effects of Is526 on skeleton genesis in zebrafish larvae using Alcian blue staining,which showed a reduction in cartilage formation along with increased production of matrix metalloproteinase(MMP)-***526 also increased the phosphorylation of ERK1/2 and p38 kinase but inhibited the phosphorylation of *** inhibition of MMP-13 blocked the Is526-induced decrease in type Ⅱ collagen *** of p38 kinase or PI-3K/Akt with sB203580 and LY294002 enhanced the suppression of type Ⅱ collagen,but the blockage of ERK-1/2 by PD98059 rescued Is526-induced *** results suggested that Is526 regulates type Ⅱ collagen and MMP-13 expression via the ERK1/2 and PI-3K/Akt pathways in rabbit articular chondrocytes.

关键词： rice chondrocyte typeⅡcollagen matrix metalloproteinase-13 rice callus extract

snowstorm over the southwestern coast of the Korean Peninsula Associated with the Development of Mesocyclone over the Yellow sea

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Advances in Atmospheric sciences 2008年第5期25卷 765-777页

作者： Ki-Young HEO Kyung-ja HA Division of Earth Environmental system College of Natural Sciences Pusan National University Korea

This study investigates the characteristics of a heavy snowfall event over the southwestern part of the Korean Peninsula on 4 December 2005. The snowstorm was a type of mesoscale maritime cyclone which resulted from barotropic instability, and diabatic heating from the warm ocean in continental polar air masses. Based on surface observations, radiosonde soundings, MTsAT-1R satellite data and the 10-km grid RDAPs （Regional Assimilation and Prediction system based on the PsU/NcAR MM5） data, the evolution of the mesocyclone is explained by the following dynamics; （1） In the initial stage, the primary role in the cyclogenesis process of the mesocyclone is a barotropic instability in the horizontal shear zone. （2） In the developing stage, the mesocyclone moves and deepens into a baroclinic zone corresponding to the surface heating and moistening. （3） In the mature stage, it is found that the mesocyclone is intensified by the destabilization caused by enhanced low-level heating and condensation, the moisture flux convergence, and the interaction between upper and lower-level potential vorticity anomalies. We suggest that a checklist with stepwise indicators responsible for development be prepared for the forecasting of heavy snowfall over the southwestern part of the Korean Peninsula.

关键词： heavy snowfall mesocyclone baroclinic instability barotropic instability stepwise roles potential vorticity anomalies

Esophageal resection for high-grade dysplasia and intramucosal carcinoma: When and how?

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World Journal of Gastroenterology 2010年第30期16卷 3786-3792页

作者： Vani ja Konda Mark K Ferguson Department of Medicine The University of Chicago Pritzker School of MedicineChicagoIL 60637United States Department of surgery The University of Chicago Pritzker School of MedicineChicagoIL 60637United States

High-grade dysplasia (HGD) and intramucosal carcinoma (IMc) in the setting of Barrett’s esophagus have traditionally been treated with esophagectomy. However, with the advent of endoscopic mucosal resection and endoscopic ablative therapies, endoscopic therapy at centers with expertise is now an established treatment of Barrett’s-esophagus-related neoplasia, including HGD and IMc. Esophagectomy is today reserved for more selected cases with submucosal invasion, evidence for lymph node metastasis, or unsuccessful endoscopic therapy.

关键词： Barrett’s esophagus High-grade dysplasia Intramucosal carcinoma Endoscopic mucosal resection Esophagectomy

Implementation of Turbulent Mixing over a stratocumulus-Topped Boundary Layer and Its Impact in a GcM

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Advances in Atmospheric sciences 2009年第5期26卷 995-1004页

作者： sun-Hee sHIN Kyung-ja HA Division of Earth Environmental system Pusan National University

The effect of a vertical diffusion scheme over a stratocumulus topped boundary layer （sTBL） was investigated using the YONU AGcM （Yonsei University Atmospheric General circulation Model）. To consider the impact of clouds on the turbulence production, the turbulence mixing term, driven by radiative cooling at the cloud top, is implemented as an extended non-local diffusion scheme. In the model with this new scheme, the sTBL parameterization significantly influences the lower atmosphere over the tropical and subtropical regions. consideration of the turbulent mixing within the cloud layer leads to continuous stratocumulus formation. The cloud-top radiative cooling tends to favor more rapid entrainment and produces top-down turbulent mixing. This cooling develops a mixed layer without initiation of deep convection by surface fluxes. Variations in thermodynamical and dynamical features are produced by planetary boundary layer （PBL） cloud development. The simulated stratocumulus induces more mixing of heat and moisture due to the cloud forcing. Over sTBL regions, the lower boundary layer becomes warmer and drier. It also weakens vertical motion and zonal trade winds in the eastern Pacific, which indicates that stratocumulus cloud cover plays a role in weakening the Walker circulation; that is, cloud cover damps the tropical circulation.

关键词： stratocumulus topped boundary layer non-local diffusion scheme tropical circulation general circulation model

An accelerated K-means clustering algorithm using selection and erasure rules

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Journal of Zhejiang University-science c(computers and Electronics) 2012年第10期13卷 761-768页

作者： suiang-shyan LEE ja-chen LIN Department of computer science National Chiao Tung University

The K-means method is a well-known clustering algorithm with an extensive range of applications,such as biological classification,disease analysis,data mining,and image ***,the plain K-means method is not fast when the number of clusters or the number of data points becomes large.A modified K-means algorithm was presented by Fahim et al.(2006).The modified algorithm produced clusters whose mean square error was very similar to that of the plain K-means,but the execution time was *** this study,we try to further increase its *** are two rules in our method:a selection rule,used to acquire a good candidate as the initial center to be checked,and an erasure rule,used to delete one or many unqualified centers each time a specified condition is *** clustering results are identical to those of Fahim et al.(2006).However,our method further cuts computation time when the number of clusters *** mathematical reasoning used in our design is included.

关键词： K-means clustering Acceleration Vector quantization selection Erasure