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排序方式: 共有250条查询结果,搜索用时 31 毫秒
1.
从催化裂化柴油中分离高纯度2,6-二甲基萘 总被引:3,自引:0,他引:3
以大庆石油化工总厂炼油厂催化柴油为原料 ,通过精馏分离得到二甲基萘 (DMN)窄馏分 (2 5 8~ 2 70℃ ) ,经糠醛溶剂抽提 ,减压蒸馏后 ,在 -10~ -2 5℃冷冻 2~ 5h ,离心分离制得纯度约 80 %的粗 2 ,6 DMN ,再经无水乙醇在 -10~ -2 5℃重结晶 ,得到纯度大于等于 98%的 2 ,6 DMN。 相似文献
2.
A stochastic model is proposed for a basic mechanism in the formation of uncertainties in physical quantity measurements.
__________
Translated from Izmeritel'naya Tekhnika, No. 1, pp. 12–17, January, 2006. 相似文献
3.
Tony C. Scott Robert Mann Roberto E. Martinez II 《Applicable Algebra in Engineering, Communication and Computing》2006,17(1):41-47
We present a canonical form for a natural and necessary generalization of the Lambert W function, natural in that it requires minimal mathematical definitions for this generalization, and necessary in that it provides a means of expressing solutions to a number of physical problems of fundamental nature. This generalization expresses the exact solutions for general-relativistic self-gravitating N-body systems in one spatial and one time dimension, and a previously unknown mathematical link between the (1+1) gravity problem and the Schrödinger wave equation. 相似文献
4.
Su-Min Baek Seoung-Woo Lee Tae-Un Kim Seong-Kyoon Choi Sungho Yun Won-Jae Lee Se-Hyeon Han Il-Hwa Hong Sang-Joon Park Tae-Hwan Kim Kyu-Shik Jeong Jin-Kyu Park 《International journal of molecular sciences》2021,22(5)
Senescence marker protein 30 (SMP30) is a cell survival factor playing an important role in vitamin C synthesis and antiapoptosis. Moreover, its cytoprotective role suggests a possibility to be related to cancer cell survival. Mammary carcinoma is a common cancer in both humans and animals. Because of its histopathological diversity, especially in the early stage, histopathological diagnosis may be complicated; therefore, a diagnostic marker is helpful for confirmation. The present study analyzed the expression pattern of SMP30 in mammary carcinoma in humans, dogs, and cats. Immunohistochemistry, immunofluorescence, and western blot analysis were used to investigate SMP30 expression patterns. The expression was specifically observed in neoplastic glandular epithelial cells. The expression increased with the malignancy of glandular epithelial cells with a highly proliferative status. However, SMP30 expression was low in normal mammary gland tissues or well-differentiated adenoma tissues. The patterns were consistently reproduced in canine primary mammary carcinoma cells and MCF-7 and MDA-MB-231 human carcinoma cell lines. This study provides useful information to understand SMP30 expression in various stages of mammary carcinoma and to suggest its utility as a pan-species diagnostic marker, thereby helping to establish strategies for diagnosing mammary carcinoma in several species. 相似文献
5.
Yu. V. Vorobiev V. R. Vieira P. P. Horley P. N. Gorley J. González-Hernández 《中国科学E辑(英文版)》2009,52(1):15-18
Considering the hexagonal-shaped quantum-scale formations on the surface of thin semiconductor films, a methodology was developed to obtain the analytical solution of the Schrdinger equation when impenetrable walls of a quantum well are treated as mirrors. The results obtained allowed the calculation of the space probability distributions and the energy spectrum of the particle confined in a hex-agonal-shaped well. 相似文献
6.
7.
Jeremy Brandman 《Journal of scientific computing》2008,37(3):282-315
We demonstrate, through separation of variables and estimates from the semi-classical analysis of the Schrödinger operator, that the eigenvalues of an elliptic operator defined on a compact hypersurface in ? n can be found by solving an elliptic eigenvalue problem in a bounded domain Ω?? n . The latter problem is solved using standard finite element methods on the Cartesian grid. We also discuss the application of these ideas to solving evolution equations on surfaces, including a new proof of a result due to Greer (J. Sci. Comput. 29(3):321–351, 2006). 相似文献
8.
为了得到Schrodinger-KdV方程的行波解,运用平面动力系统理论方法,对其动力学行为进行研究,证明了该方程光滑孤立波解和光滑周期波解的存在性,并在不同的参数条件下,给出了各类解存在的充分条件,求出了所有显式精确行波解。 相似文献
9.
Petru Andrei 《Journal of Computational Electronics》2006,5(4):315-318
A calibration method is developed for the electron effective mass in the Density-Gradient model. This method uses the two- and three-dimensional effective-mass Schrödinger equations, which are solved for bounded quantum systems. The electron effective mass is computed by fitting the electron concentration computed by using the Density-Gradient model to the electron concentration computed by using the Schrödinger equation. Results for strongly confined silicon system with (100), (110), and (111) crystallographic orientations are presented. It is shown that the effective mass varies with the shape and dimensions of the quantum box. In device simulations, one should use the value of m_n that corresponds to the right shape and dimensions of the confinement region in the device. 相似文献
10.
Miklósi áam; Pongrácz Péter; Lakatos Gabriella; Topál József; Csányi Vilmos 《Canadian Metallurgical Quarterly》2005,119(2):179
Dogs' (Canis familiaris) and cats' (Felis catus) interspecific communicative behavior toward humans was investigated. In Experiment 1, the ability of dogs and cats to use human pointing gestures in an object-choice task was compared using 4 types of pointing cues differing in distance between the signaled object and the end of the fingertip and in visibility duration of the given signal. Using these gestures, both dogs and cats were able to find the hidden food; there was no significant difference in their performance. In Experiment 2, the hidden food was made inaccessible to the subjects to determine whether they could indicate the place of the hidden food to a naive owner. Cats lacked some components of attention-getting behavior compared with dogs. The results suggest that individual familiarization with pointing gestures ensures high-level performance in the presence of such gestures; however, species-specific differences could cause differences in signaling toward the human. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献