116 resultados para Motor parameters


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The surface and bottom waters samples were collected from six locations in Xiamen western sea. The quantified estimation of bacterial production (H-3-thymidine method) and observation of bacterial heterotrophic activity (C-14-glucose method) have been made in order to have a better understanding of the role of marine bacteria and their activities. The results showed that the mean value of bacterial heterotrophic activity was 9 X 10(8) cells/(L. h) in the surface waters and 2.6 X 10(8) cells/(L. h) in the bottom waters. The mean value of bacterial production was 38 X 108 cells/( L. h) in the surface waters and 7.1 X 10(8) cells/(L. h) in the bottom waters. The relationship between bacterial production, heterotrophic activity, PCC and DOC measured during this survey were discussed. The good understanding of the relationship between bacteria activity and total coliform was addressed.

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Substantial nutritional and energetic demands m-e associated with immune activation and the maintenance of an efficient immune system. One-year-old Chlamys farreri (Jones and Preston) scallops were maintained ill lantern nets ill different nutritional conditions (satiation and starvation) for 40 days. After the 40-day treatments, the condition index and the total hemocyte count (THC) decreased significantly in the starved group compared with the satiated and initial control groups. The percentage of phagocytic hemocytes also was significantly reduced with starvation. In contrast. no significant effect of starvation was observed oil reactive oxygen species (ROS) production. The acid phosphatase (ACP) activities in cell-free hemolymph increased significantly in scallops in starved and satiated treatments compared with the initial control. whereas ACP activity in hemocyte lysate was significantly lower ill the starved group. These results indicate that starvation stress compromises immunological activities of scallops.

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Grazing animal excrement plays an important role in nutrient cycling and redistribution in grazing ecosystems, due to grazing in large areas and return in small areas. To elucidate the changes to the soil and pasture caused by sheep urine, fresh dung, and compost patches, a short- term field experiment using artificially placed pats was set up in the autumn of 2003 in the Inner Mongolian steppe. Urine application significantly increased soil pH during the first 32 days in soil layers at depths of both 0 - 5 cm and 5 - 15 cm. Rapid hydrolysis of urea gave large amounts of urine- nitrogen ( N) as ammonium ( NH4+) in soil extracts and was followed by apparent nitrification from day 2. Higher inorganic N content in the urine- treated soil was found throughout the experiment compared with the control. No significant effects of sheep excrement on soil microbial carbon ( C) and soil microbial N was found, but microbial activities significantly increased compared with the control after application of sheep excrement. Forty- six percent of dung- N and 27% of compost- N were transferred into vegetation after the experiment. The results from this study suggest that large amounts of nutrients have been lost from the returned excrement patches in the degraded grassland of Inner Mongolia, especially from sheep urine- N.

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根据跨越超高压输电线路障碍物的类型,提出一种新的双臂自主越障巡检机器人机构。该机器人采用复合轮爪机构在架空地线上连续行走并跨越障碍。由于架空地线呈悬链线状,机器人在连续行走过程中会出现上坡和下坡,对行走动力特性的影响非常明显。在上坡时行走电动机提供驱动力矩,在下坡时行走电动机提供制动力矩,以保持匀速巡线。详细分析了机器人在架空地线上行走时所处的加速、匀速、减速和停止的各个状态,驱动机器人所需的驱动力矩以及它们与机构参数之间的关系,并应用优化方法给出各个状态电动机驱动力矩最小时,机器人机构参数对应的最优解,为巡检机器人的设计和控制系统方案的确定提供了理论依据。

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The ionogram acquired with the ionospheric vertical sounding method is the oldest data in the history of ionospheric research. Using of modern microelectronics and computer technology to digitalize, analyse and preserve the huge amount of historical film ionogram has become more and more important and urgent. This paper introduced the progress of the film ionogram digitalization by using digital image processing technologies to correct and repair film ionogram and convert them in an exchangeable format. An analysis and conversion software, basing on this method, has been developed for the film ionogram analysis, and then it introduces the application of this software by combining the SAO Explorer program for Wuhan film ionogram and pseudo-color ionogram in Yamagawa in Japan. It shows that our method is reliable,and the developed software is used friendly and provides a positive solution in digitalization and analysis of huge amount of historical film ionogram. Firstly, we briefly introduce the film ionogram and the process of its digitalization. By observing a amount of film ionogram, we obtain some common characteristics of the digitalized film ionogram following as: (1) the image rotation are caused by scanning; (2) the vertical axis of a large number of film ionogram exist more or less tilt and bending ; (3) coordinates of the film ionogram appear the non-uniformity phenomena result from the instability of driving motor rotation and the error of altitudinal cursor orientation. Moreover, based on the characteristics of the film ionogram and the SAO Explorer software which is widely used for the digital ionogram analysis in the world, a new method has been developed for film ionogram procession. The method contains the image geometric correction and film ionogram format conversion. The image geometric correction includes such as image rotation correction, vertical correction and coordinates scale correction. After geometric correction, the BMP file format images will be converted to the SBF file format images. Then, we also discuss the data format converting methods, which include two methods of the image data mapping basing on the normalization and logarithm, and the method of the preprocessing of the noise filtering and the threshold setting. Combining with SAO Explorer software, we successfully obtain ionospheric parameters and electron profile from the converted SBF file format digital ionograms. Based on the above method, we developed the software for the film ionogram to realize its correction analysis and conversion of the image format, and then give a introduction for its function and operation. Subsequently, the software are applied into the Wuhan film ionogram which separately observed in the high solar activity year and the low in 1980s last century. The results reveal the converted SBF digital ionogram almost preserve the all echo information of the film ionogram. Furthermore, we expressly discuss the application to the Wuhan film ionogram in 1958 in order to validate the applicability and credibility of the software. And it is showed that the important information of the film ionogram are maintained into the SBF digital ionogram. It is represented that there is credibility for conversion of the software when it applied in the older film ionogram. In sum, this software could apply to the digitalization and analysis of huge amount of historical film ionogram. Last, we extended the function of the software by bring some new conversion method and used it to apply to the pseudo-color ionogram of yamagawa in Japan. The results show that the converted ionogram information basically maintain the importantly ionogram information and the error of scaling of converted SBF file format image is almost acceptable, though there is no preprocessing for the original ionogram. Hence, we could extend the applicable range of the software and apply it to all kinds of simulative ionogram imaging by improving the method and software.

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Expressions used for extracting the population and alignment parameters of a symmetric top molecule from (n + 1) laser-induced fluorescence (LIF) are derived by employing the tensor density matrix method. The molecular population and alignment are described by molecular state multipoles. The LIF intensity is a complex function of the initial molecular state multipoles, the dynamic factors, and the excitation-detection geometrical factors. The problem of how to extract the initial molecular state multipoles from (2 + 1) LIF, as an example, is discussed in detail. (C) 2000 American Institute of Physics. [S0021-9606(00)30744-9].

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Reversed-phase high-performance liquid chromatographic (RP-HPLC) retention parameters, which are determined by the intermolecular interactions in retention process, can be considered as the chemical molecular descriptors in linear free energy relationships (LFERs). On the basis of the characterization and comparison of octadecyl-bonded silica gel (ODS), cyano-bonded silica gel (CN), and phenyl-bonded silica gel (Ph) columns with linear solvation energy relationships (LSERs), a new multiple linear regression model using RP-HPLC retention parameters on ODS and CN columns as variables for estimation of soil adsorption coefficients was developed. It was tested on a set of reference substances from various chemical classes. The results showed that the multicolumn method was more promising than a single-column method was for the estimation of soil adsorption coefficients. The accuracy of the suggested model is identical with that of LSERs.

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The quantitative structure-retention relationship is one of the most actively studied topics in the field of chromatography. In this paper, retention parameters of components were used to discriminate the xanthones in a methanol extract of Swertia franchetiana. The extract was analysed by HPLC under two different multistage linear gradient conditions and the retention parameters calculated from these retention data. It was found that the retention parameters of xanthones are in a specific region in the plot of log k(w) vs. S and the xanthones in the extract could be distinguished from other components by this feature. Furthermore, xanthone aglycones and xanthone glucosides could also be discriminated by retention parameters. Copyright (C) 2005 John Wiley Sons, Ltd.