60 resultados para Machine components


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Terrigenous components were separated from the bulk sediment of Core A7 from the Okinawa Trough and Core A37 from the Ryukru Trench and grain-size distributions of these sub-samples were analyzed. Based upon an analysis of the grain-size data of the two sedimentary sequences, grain-size populations are identified to be sensitive to sedimentary environmental changes. The modal values and size ranges of the two main grain-size populations in Core A7 are evidently different from those of Core A37, indicating the spatial variability of sediment sources and transport processes between the two places. The downcore variations in the content of the environmentally sensitive grain-size populations reveal that during the accumulation of sedimentary material the environment remained relatively stable at the site where Core A7 was collected, except for the apparent events for the formation of two turbidite layers and a volcanic ash layer. However, the sedimentary sequence of Core A37 shows six sedimentary cycles, indicating a highly variable sedimentary environment at this location.

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Two deep-sea moorings were deployed respectively in the east area and the west area of Chinese Pioneer Area (CPA) in the tropic east Pacific to monitor the regional deep-sea dynamics below 600 meters above bottom (mab) from July 1997 to Oct. 1999. Results of statistics, spectral estimate and correlation analysis of the low-passed velocity data show that time scales of low-frequency components of the near-bottom currents are 25similar to120 days, in which 51-day period dominates the lower band of the frequency domain. Topographic features have obvious effect on low-frequency currents below 50 mab; modulations of the bottom-intensified sheared mean flow to the low-frequency currents are the dynamic mechanism of the frequency shift that occurs in both the east-area and the west-area.

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Barium tungstate crystallites with different sizes and morphologies were successfully synthesized using a simple electro-chemical technique by varying the components of electrolyte solutions. XRD analysis evidenced that the as-prepared samples were a pure tetragonal-phase of BaWO4 with a scheelite structure. Scanning electron microscopy images and PL spectra of BaWO4 crystallites revealed that the presence of OH- ions and the incorporation of absolute ethanol into the electrolyte solution would have important effects on their particle sizes, morphologies, and optical properties.

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A sensitive and specific reversed-phase high performance liquid chromatography (RP-HPLC) method with diode array detection (DAD) was established for the quantitative determination of the nine active components, namely, swertiamarin (SWM, 1), mangiferin (MA, 2), gentipicroside (GE, 3), sweroside (SWO, 4), isoorientin (IS, 5), swertisin (SWS, 6), swertianolin (SWN, 7), 7-O-[alpha-L-rhamnopyranosyl-1 -> 2)-beta-D-xylopyranosyl]-1,8-dihydroxy-3-methoxyxanthone (RX, 8), and bellidifolin (BE, 9) used as the external standard, in Tibetan folk medicinal species Swertia franchetiana. Based on the baseline chromatographic separation of most components from the methanolic extract of Swertia franchetiana on a reversed-phase Eclipse XDB-C8 column with water-acetonitrile-formic acid as mobile phase, the nine components were identified by comparison with standard samples and qualified by using the external standard method with DAD at 254 nm. The correlation coefficients of all the calibration curves were found to be higher than 0.9980. The relative standard deviations (RSDs) of the peak areas and retention times for the nine standards were less than 2.07% and 2.86%, respectively.

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文章介绍了一种新型托辊切管机控制系统的设计,对该系统的硬件组态及控制功能作了主要描述。该机床是托辊自动化加工装配线上的一台机电一体化自动加工设备,其主要功能是对托辊装配所需原料管进行定尺切断,并在整个加工过程中自动上下料。整个机床控制系统主要由SIEMENS Simotion D运动控制系统、触摸屏TP177B、远程输入输出模块ET200M等组成。

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本文介绍了一种新型托辊自动化装配线上的在线检测机床控制系统,对系统的硬件组态及控制功能作了主要描述。该机床的主要功能是对装配完成的托辊进行性能测试,并采集其性能参数,根据采集并处理后的数据来判定检测的产品是否合格。整个机床控制系统主要由SIMOTION运动控制系统、人机操作触摸屏、远程输入输出模块ET200M、数据采集传感器、到位检测开关、电源及控制回路等组成。

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文章介绍了一种新型汽车变速箱压装机控制系统的设计,对系统的硬件组态及控制功能作了主要描述。汽车变速箱压装机是汽车变速箱装配流水线上的一台机电一体化专用自动装配设备,该机除具有自动压装功能、自动检测报警功能外,还能与装配管理系统联网,实现网络化管理与控制功能。整个系统采用了SLC500可编程控制器、触摸屏、安全光幕控制器等控制部件,为机床提供了安全可靠的装配质量保证。

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介绍了一个基于组件的可重构车间管理系统,分别从建模方法、体系结构和组件设计等角度描述了系统的设计思想,并阐述了系统涉及的组件分类、组件粒度划分及XML的应用等关键设计技术。开发的可重构车间管理系统已经用于沈阳第一机床厂两个不同类型生产车间的管理,应用效果良好。

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The Xiangshan U deposit, the largest hydrothermal U deposit in China, is hosted in late Jurassic felsic volcanic rocks although the U mineralization post dates the volcanics by at least 20 Ma. The mineralization coincides with intrusion of local mantle-derived mafic dykes formed during Cretaceous crustal extension in South China. Ore-forming fluids are rich in CO2, and U in the fluid is thought to have been dissolved in the form of UO2 (CO3)22− and UO2 (CO3) 34− complexes. This paper provides He and Ar isotope data of fluid inclusions in pyrites and C isotope data of calcites associated with U mineralization (pitchblende) in the Xiangshan U deposit. He isotopic compositions range between 0.1 and 2.0Ra (where Ra is the 3He/4He ratio of air=1.39×10−6) and correlates with 40Ar/36Ar; although there is potential for significant 3He production via 6Li(n,α)3H(β)3He reactions in a U deposit (due to abundant neutrons), nucleogenic production cannot account for either the 3He concentration in these fluids, nor the correlations between He and Ar isotopic compositions. It is more likely that the high 3He/4He ratios represent trapped mantle-derived gases. A mantle origin for the volatiles of Xiangshan is consistent with the δ13C values of calcites, which vary from −3.5‰ to −7.7‰, overlapping the range of mantle CO2. The He, Ar and CO2 characteristics of the ore-forming fluids responsible for the deposit are consistent with mixing between 3He- and CO2-rich mantle-derived fluids and CO2-poor meteoric fluids. These fluids were likely produced during Cretaceous extension and dyke intrusion which permitted mantle-derived CO2 to migrate upward and remobilize U from the acid volcanic source rocks, resulting in the formation of the U deposit. Subsequent decay of U within the fluid inclusions has reduced the 3He/4He ratio, and variations in U/3He result in the range in 3He/4He observed with U/3He ratios in the range 5–17×103 likely corresponding to U concentrations in the fluids b0.2 ppm.

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The estrogenic activity of the Chinese herb kudzu root was investigated by a recombinant yeast screening assay (YES). Isoflavones are the main components in the plant, of which puerarin is the most abundant one. The kudzu root extract was separated into four fractions according to the polarity. The crude extract and its sub-fractions, except the water fraction, showed clear estrogenic activity and the potencies were in the range of 10(-3) to 10(-1) g/l. The ligand potency was used to compare the estrogenic activity of these fractions. The crude extract and its sub-fractions were further analyzed by high performance liquid chromatography (HPLC) to correlate the activity and the active components. Bioassay and chemical analysis showed that theoretical estrogenic activity expressed as equivalent 17 beta-estradiol concentration or the cumulative effects are comparable to that experimentally determined by YES. The results showed that the high content of isoflavones as well as the high estrogenic activity could make kudzu root extract an interesting candidate for hormone replacement therapy. (c) 2005 Elsevier Ltd. All rights reserved.