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本文给出了四次函数实零点的完全判据和正定条件,这一结果在研究多项式系统的奇点分析和分支问题时给出了可以实用的判据. 相似文献
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The historical development of Hensel's lemma is briefly discussed (Section 1). Using Newton polygons, a simple proof of a general Hensel's lemma for separable polynomials over Henselian fields is given (Section 3). For polynomials over algebraically closed, valued fields, best possible results on continuity of roots (Section 4) and continuity of factors (Section 6) are demonstrated. Using this and a general Krasner's lemma (Section 7), we give a short proof of a general Hensel's lemma and show that it is, in a certain sense, best possible (Section 8). All valuations here are non-Archimedean and of arbitrary rank. The article is practically self-contained. 相似文献
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Jeong Gwi-Taek Park Don-Hee Hwang Baik Park Kyungmoon Kim Si-Wouk Woo Je-Chang 《Applied biochemistry and biotechnology》2002,98(1-9):1115-1127
The growth properties of Panax ginseng hairy roots transformed by Agrobacterium rhizogenes were compared between flask and aerated column or stirred bioreactor. In flask cultures, sucrose, initially 30 g/L, was nearly
exhausted after 45 d of culture. The pH of the medium dropped from 5.5 to 4.96 after 10 d, but afterward it gradually increased
to 6.4. After 45 d, hairy roots grew about 16-folds. The growth rate of hairy roots in air-bubble column or stirred bioreactor
cultures was 1.13 (1.11) to 1.23 (1.20) g fresh wt (dry wt)/(g of cells·d), respectively. For both bioreactors, growth was
about three times as high as in the flask cultivation. 相似文献
6.
Khairitdinova E. D. Tsirlina E. M. Spirikhin L. V. Fedorov N. I. Efremov Yu. Ya. Yunusov M. S. 《Russian Chemical Bulletin》2003,52(9):2078-2080
A new norditerpenoid alkaloid has been isolated from the roots of Delphinium cuneatum. On the basis of 1H, 13C NMR, IR, and mass spectra, the structure of the alkaloid was established as 1,6,14-trimethoxy-7,8-dihydroxy-18-(2-methyl)succinylanthranoyloxyaconane (16-demethoxymethyllycaconitine). The roots of Delphinium cuneatum also contain the known alkaloid methyllycaconitine and N,N"-di(methoxycarbonyl)-3,4-diaminotoluene. 相似文献
7.
Sáenz-Carbonell Luis Loyola-Vargas Víctor M. 《Applied biochemistry and biotechnology》1997,61(3):321-337
Hairy roots are less susceptible to manipulation by changes in medium composition than callus and cell suspension cultures.
However, when the individual components of the Gamborg’s B5 medium were modified one by one, several of them modified the yield of root cultures. Nitrogen (N) source changes, the absence
of phosphorus (P), calcium (Ca), and cobalt (Co), and the increase in the sucrose content of the medium increased the level
of alkaloids inDatura stramonium hairy root cultures. The use of ammoniun as N source provoked the alkaloid excretion into the medium. The addition of different
auxins inhibited the alkaloid accumulation, but the addition of abscisic acid (ABA) did not change the alkaloid content of
the cultures. The use of MeJa increased the content of hyoscyamine to 100%. 相似文献
8.
Dr. S. Sasaki 《Colloid and polymer science》1985,263(11):935-940
The theoretical equations for friction coefficients of spheres having sticky or hairy surfaces are presented. In the present treatment, the sticky surface is represented by a higher viscosity of fluid in the surface layer and the hairy surface is assumed to have a porous structure. The friction coefficients are given as functions of the thickness of the surface layer, the fluid viscosity in the surface layer and the segmental density of hairy chains. 相似文献
9.
Cangyi Chen Ping Tang Feng Qiu 《Journal of polymer science. Part A, Polymer chemistry》2014,52(24):1583-1599
Binary polymer brushes, including mixed homopolymer brushes and diblock copolymer brushes, are an attractive class of environmentally responsive nanostructured materials. Owing to microphase separation of the two chemically distinct components in the brush, multifaceted nanomaterials with functionalized and patterned surfaces can be obtained. This review summarizes recent progress on the theory and simulations related to binary polymer brushes grafted to flat, spherical, and cylindrical substrates, with a focus on patterned morphologies of multifaceted hairy nanoparticles, an intriguing class of hybrid nanostructured particles (e.g., nanospheres and nanorods). In particular, powerful field theory and particle-based simulations suitable for revealing novel structures on these patterned surfaces, including self-consistent field theory and dissipative particle dynamics simulations, are emphasized. The unsolved yet critical issues in this research field, such as dynamic response of binary polymer brushes to environmental stimuli and the hierarchical self-assembly of binary hairy nanoparticles, are briefly discussed. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1583–1599 相似文献
10.
J. V. Leyendekkers A. G. Shannon 《International Journal of Mathematical Education in Science & Technology》2013,44(2):303-306
The modular ring ?6 defines integers via (6r i + (i ? 3)) where i is the class and r i the row when tabulated in an array. Since only Classes 26 and 46 contain odd primes, this modular ring is ideally suited to the analysis of twin primes. The calculations are facilitated by the use of the right-end digit (RED) technique. 相似文献