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81.
Jesus Sanz 《中国电梯》2006,17(18):46-48
我公司最近推出了一种名为Fastline的导轨快速连接产品,并已取得专利。该创新系统显著地改进了导轨安装工序,其主要优点有:(1)减少人工安装的成本;(2)提高了导轨连接处的品质,使其受安装工人的专业水平的影响因素大大降低。 相似文献
82.
MC de Jesus Ferreira C Héliès-Toussaint M Imbert-Teboul C Bailly JM Verbavatz AC Bellanger D Chabardès 《Canadian Metallurgical Quarterly》1998,273(24):15192-15202
The Ca2+-sensing receptor protein and the Ca2+-inhibitable type 6 adenylyl cyclase mRNA are present in a defined segment of the rat renal tubule leading to the hypothesis of their possible functional co-expression in a same cell and thus to a possible inhibition of cAMP content by extracellular Ca2+. By using microdissected segments, we compared the properties of regulation of extracellular Ca2+-mediated activation of Ca2+ receptor to those elicited by prostaglandin E2 and angiotensin II. The three agents inhibited a common pool of hormone-stimulated cAMP content by different mechanisms as follows. (i) Extracellular Ca2+, coupled to phospholipase C activation via a pertussis toxin-insensitive G protein, induced a dose-dependent inhibition of cAMP content (1.25 mM Ca2+ eliciting 50% inhibition) resulting from both stimulation of cAMP hydrolysis and inhibition of cAMP synthesis; this latter effect was mediated by capacitive Ca2+ influx as well as release of intracellular Ca2+. (ii) Angiotensin II, coupled to the same transduction pathway, also decreased cAMP content; however, its inhibitory effect on cAMP was mainly accounted for by an increase of cAMP hydrolysis, although angiotensin II and extracellular Ca2+ can induce comparable release of intracellular Ca2+. (iii) Prostaglandin E2, coupled to pertussis toxin-sensitive G protein, inhibited the same pool of adenylyl cyclase units as extracellular Ca2+ but by a different mechanism. The functional properties of the adenylyl cyclase were similar to those described for type 6. The results establish that the co-expression of a Ca2+-inhibitable adenylyl cyclase and of a Ca2+-sensing receptor in a same cell allows an inhibition of cAMP accumulation by physiological concentrations of extracellular Ca2+. 相似文献
83.
The use of two Advanced Oxidation Processes, constituted by the combinations of ozone and UV radiation, and hydrogen peroxide and UV radiation, in the destruction of the herbicide cyanazine is presented. In both cases, the influence of the operating variables (initial herbicide concentration, ozone partial pressure or initial hydrogen peroxide concentration, temperature and pH) is discussed, and a comparison is made among the efficiencies of the different oxidizing agents used. 相似文献
84.
85.
M. Cristina De Jesus Jason A. Morgan Rajib Ahmed D. S. Rimai 《Particulate Science and Technology》2007,25(1):107-116
The time dependence of the detachment force applied to 7 µm ground polyester particles coated with silica nanoparticles was determined by ultracentrifugation. It was found that the force required to separate the particles from the substrate increased during the first 24 hours and changed very little thereafter. Scanning electron microscopy (SEM) results suggest that the increase in adhesion is due to the particles rotating from their initial positions obtained during deposition. The role of the silica nanoparticles in determining the time dependence of the detachment force is discussed in terms of the JKR and Fuller-Tabor models. 相似文献
86.
Abstract. This paper shows numerically that the lack of power and size distortions of the Dickey-Fuller type tests for unit roots (very well documented in the unit root literature) are similar to and in many situations even smaller than the lack of power and size distortions of the standard Student t tests for stationary roots of an autoregressive model. 相似文献
87.
In part I of this series the results of sedimentation velocity experiments with the polyelectrolyte Polyvinylpyrrolidone-Blancophor are described. The combination of the Svedberg formula and an equation of Tiselius describing the charge- and salt-effects gives the possibility to describe the change of the frictional coefficient as a function of charge and screening quantitatively. The resulting frictional coefficients resp. the dimensions of the coil of this polyelectrolyte change in a wide range with the charge density and the counterion concentration. 相似文献
88.
89.
de Jesus DP Brito-Neto JG Richter EM Angnes L Gutz IG do Lago CL 《Analytical chemistry》2005,77(2):607-614
The use of two additional reservoirs to accommodate the electrodes of the power source is proposed to improve the stability of the running electrolyte in capillary electrophoresis. The basic idea is to use salt bridges to connect those reservoirs to the ones containing the capillary ends. Although simple, there are several issues that can be considered in the design and implementation of such system in order to prevent undesired transference of material between the electrolysis and the main reservoirs. The use of a sealed electrolysis reservoir without a gas phase, the use of materials that ensure volume stability, and the use of bridges as long as possible are three basic directions. A compromise is involved in the dimensions of the sectional area of the bridge, because a small area diminishes the amount of a species transferred by diffusion but leads to an undesirable increase of the electrical field during the electrophoretic running. Thus, a bridge composed of a main wide-bore tube connected to a small-bore capillary seems to give the best performance for practical use. A simple electrolysis-separated system was adapted to a preexisting capillary electrophoresis system, and its performance was evaluated with a mixture of tartaric, malic, and succinic acids that was separated in sodium benzoate solution (pH 5.5) using the original equipment and the modified one. Due to the water electrolysis and the small buffering capacity of the electrolyte, there was a significant pH change and consequently changes in the effective mobilities of the analytes and loss of resolution after a few runs using the original equipment. Using the electrolysis-separated system, no significant change in the migration time and resolution was observed even after 15 runs. Besides the freedom to prepare running electrolytes with electroactive species or unbuffered solution, high throughput and the use of small reservoirs, such as the ones used in microfluidic devices, are the main advantages of the system. 相似文献