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71.
有机盐聚合醇氯化钾钻井液的应用 总被引:5,自引:2,他引:3
霍尔果斯背斜构造极其复杂,内应力极高,地层倾角大,断层、破碎带多,并存在高低压互层;安集海河组的灰绿色软泥岩水化严重并具有粘弹塑性.该区块重点探井霍003井三开、四开井段选用有机盐聚合醇氯化钾钻井液,同时为保证钻井液在高密度下(2.55 g/cm^3)具有好的流变性,使用活化铁矿粉、活化重晶石加重.应用结果表明,由于采用了强抑制和多元封堵的措施,该钻井液具有良好的流变性和较强的携带能力,钻进中曾携带出重2.8 kg和5.1kg的大掉块;滤失量低,泥饼质量好,封堵能力强,造壁能力强,减轻了井下阻卡程度;有良好的储层保护能力;在室内研究的基础上,经过现场合理使用和维护钻井液,霍003井提高了机械钻速,缩短了钻井周期,井身质量优于邻井.指出在高密度下,未选出适合有机盐聚合醇氯化钾钻井液的稀释剂,钻井液流动性较差. 相似文献
72.
A mini spray dryer has been used to investigate morphological changes that occur to milk particles during the spray drying process. We have found that the mini spray dryer is ideal for such investigations, because phenomena such as skin and vacuole formation in particles can be analyzed without the added complication of particle agglomeration, which only occurs in much larger spray dryers where particle number concentrations are higher. We have confirmed observations made by various researchers that the bulk density of spray-dried milk powder is greatly affected by the drying temperature, due to the strong influence of the latter on the porosity of the particles. In addition, we have attempted to explain observations made by various workers that fat accumulates preferentially at the surface of a particle during drying by postulating that fluid fat is transported towards the surface, via a network of cracks and pores, by the development of a vacuole overpressure which is also responsible for the inflation of the particle. Finally, we have shown that milk powders can be spray dried a second time, by reconstitution with water, with no change to the thermodynamic characteristics of the resultant powder. Thus, milk concentrates for spray drying research can be prepared from already-spray-dried milk powders rather than using the more arduous evaporation method to concentrate unprocessed milk. 相似文献
73.
R. Masui 《International Journal of Thermophysics》2002,23(4):921-935
The development of a magnetic suspension densimeter that has been built for measurement of the density of compressed liquid at pressures up to 30 MPa in the temperature range 20 to 150°C is described. The densimeter was first built by the author and his coworkers at NIST. We describe here further improvements made on a second system built at NMIJ based on the same principle. The densimeter uses a small coil suspended from an electronic balance. Within the coil is placed a sample cell in which the pressurized sample and a buoy, which is a permanent magnet, are enclosed. For measurement of density, balance readings are recorded (1) with the buoy at rest and (2) with the buoy in magnetic suspension. The measurement procedure is basically a hydrostatic weighing, which is simpler than those of conventional magnetic densimetry. As an example, measurements of toluene density performed as part of an inter-laboratory comparison are presented. The data agreed with reliable literature values to within a few hundredths of a per cent. 相似文献
74.
Abstract. The estimation of the spectral density function of a stationary Gaussian process at the input of an instantaneous nonlinearity is considered when the nonlinearity is known and a finite set of observations of the output process is given. A class of spectral estimates is considered and their quadratic-mean consistency is established; precise asymptotic expressions for their bias and covariance are derived and their asymptotic normality is obtained. 相似文献
75.
76.
Gregory S. Ho Chen Huang Emily A. Carter 《Current Opinion in Solid State & Materials Science》2007,11(5-6):57-61
Orbital-free density functional theory (OF-DFT) can be made to scale linearly with sample size, allowing thousands of atoms to be treated explicitly with quantum mechanics. State-of-the-art kinetic energy density functionals and ion–electron pseudopotentials are used to obtain accurate structural property predictions for nanoparticles, nanowires, extended surfaces, and nanoindentation of simple metals. 相似文献
77.
Several studies have suggested that primates react differently to spatial reduction. In this article, the authors tested some general hypotheses on primate response to spatial reduction by studying the Apenheul lowland gorillas (Gorilla gorilla gorilla; Apeldoorn, the Netherlands). The frequency of conflicts did not greatly change between the 2 housing settings, thus not supporting the density- aggression model. Indoor, gorillas performed touching behavior more often and increased their level of reconciliation. These findings support the coping model. Indoor, the gorillas also maintained broader interindividual distances by increasing the levels of sitting alone, avoidance, and dismissing behaviors. In conclusion, the Apenheul gorillas modified selectively the distribution of some patterns typical of their behavioral repertoire in response to a high-density condition. Both avoidance and coping tactics were used, thus revealing high levels of behavioral flexibility in this species. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
78.
András Ványolos Balázs Dóra Attila Virosztek 《Journal of Superconductivity and Novel Magnetism》2007,20(7-8):643-645
We report of a theoretical study on quasi-one dimensional unconventional charge density wave (UCDW) driven by electron–phonon
interaction. Within mean field theory, we find that the wavevector dependence of the coupling leads to a momentum dependent
single particle gap on the Fermi surface. The presence of small energy single particle excitations around the gap nodes significantly
changes the optical conductivity compared to the conventional CDW result. In addition to that, the collective phase excitation
arising from fluctuation of the order parameter leads to further qualitative changes of the conductivity and results in an
effective mass that is nonmonotonic in temperature.
相似文献
79.
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