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信息世界（攀钢） 2000年第36期 2-11页

作者： rugh,dg 李炜

在用７００万美元对精轧机和地下卷取机控制系统进行改造之后带钢的厚度精度有了显著的改进，同时也减少了带钢头尾部位的划、擦伤、瓢曲废品和故障率。

关键词：精轧机组地下卷取机自动化改造

Rational maps as Schwarzian primitives

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Science China Mathematics 2016年第7期59卷 1267-1284页

作者： CUI GuiZhen GAO Yan rugh Hans Henrik TAN Lei Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China Department of Mathematics Sichuan University Chengdu 610065 China Faculté des Sciences d'Orsay Université Paris-Sud Paris 91405 France Faculté des Sciences Laboratoire Angevin de Recherche en Mathematiques Université d'Angers Angers 49045 France

We examine when a meromorphic quadratic differential φ with prescribed poles is the Schwarzian derivative of a rational map. We give a necessary and sufficient condition: In the Laurent series of φ around each pole c, the most singular term should take the form(1- d2)/(2(z- c)2), where d is an integer, and then a certain determinant in the next d coefficients should vanish. This condition can be optimized by neglecting some information on one of the poles(i.e., by only requiring it to be a double pole). The case d = 2 was treated by Eremenko(2012). We show that a geometric interpretation of our condition is that the complex projective structure induced by φ outside the poles has a trivial holonomy group. This statement was suggested to us by Thurston in a private communication. Our work is related to the problem of finding a rational map f with a prescribed set of critical points, since the critical points of f are precisely the poles of its Schwarzian ***, we study the pole-dependency of these Schwarzian derivatives. We show that, in the cubic case with simple critical points, an analytic dependency fails precisely when the poles are displaced at the vertices of a regular ideal tetrahedron of the hyperbolic 3-ball.

关键词： Schwarzian derivatives rational maps critical points meromorphic quadratic differentials

A CLASS OF MODIFIED BROYDEN ALGORITHMS

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Journal of Computational Mathematics 1994年第4期12卷 366-379页

作者： PU, dg TIAN, WW SHANGHAI INST RAILWAY TECHNOL DEPT MATHSHANGHAIPEOPLES R CHINA SHANGHAI UNIV SCI & TECHNOL DEPT MATHSHANGHAIPEOPLES R CHINA

In this paper we dicuss the convergence of the modified Broyden algorithms. We prove that the algorithms are globally convergent for the continuous differentiable function and the rate of convergence of the algorithms is one-step superlinear and n-step second-order for the uniformly convex objective function. From the discussion of this paper, we may get some convergence properties of the Broyden algorithms.

关键词： CLASS Powell Fletcher BFGS minimization convergent constrained demon exact symmetric

Studies on the Surface Properties of MCM-41

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Chemical Research in Chinese Universities 2002年第3期18卷 242-245页

作者： HE Jing DUAN Xue EVANS dg LI Cheng yue The Key Laboratory of Science and Technology of Controllable Chemical Reactions Ministry of EducationBeijing University of Chemical TechnologyBeijing 100029P.R.China

MCM 41 materials with a well ordered long range structure, a large pore size and a high surface area have been synthesized. Their surface properties including the number and the nature of the surface hydroxyl groups and surface hydrophobicity/hydrophilicity have been investigated by means of 29 Si MAS NMR and FT IR spectra and TPD of probe molecules. The results clearly show that the surface of MCM 41 has an abundance of acidic silanol groups, and that the hydrophobicity/hydrophilicity can be modified by the introduction of Al and transition metals Ti, Cr, Ni and Fe into it.

关键词： Hydroxyl group Hydrophobicity/Hydrophilicity MCM 41

The effect of retinoic acid on Ito cell proliferation and content of DNA and RNA

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World Journal of Gastroenterology 1999年第5期5卷 443-444页

作者： Gao ZL Li dg Lu HM Gu XH Yangpu Cent Hosp Dept Gastroenterol Shanghai 200092 Peoples R China Shanghai Second Med Univ Dept Gastroenterol Shanghai 200090 Peoples R China

INTRODUCTIONThe development of liver fibrosis is due to an imbalance between synthesis and degradation of extracellular matrix. Recent studies have shown that Ito cells which are located along the sinuses of liver, can store and metabolize Vit A, and are the main cells that produce collagen, among which type Ⅰ, Ⅲ and Ⅳ and laminin, account for 80%-95% of the total hepatic collagen[1]. Ito cells in the course of proliferation and synthesis of collagen showed a reduction of Vit A contents and retinoic acid receptors[2]. This study was designed to investigate the effect of retinoic acid on Ito cell proliferation and the contents of DNA/RNA and to analyse further its mechanism or pathways.

关键词： liver fibrosis retinoic acid Ito cell cell culture microspectrophotometer DNA RNA

Relative efficacy of some prokinetic drugs in morphine-induced gastrointestinal transit delay in mice

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World Journal of Gastroenterology 2003年第4期9卷 779-783页

作者： AD Suchitra SA Dkhar dg Shewade CH Shashindran Department of Pharmacology JIPMERPondicherry 605006INDIA

AIM:To study the relative efficacy of cisapride, metoclopramide,domperidone,erythromycin and mosapride on gastric emptying(GE)and small intestinal transit(SIT) in morphine treated mice. METHODS:Phenol red marker meal was employed to estimate GE and SIT in Swiss albino mice of either *** groups included were control,morphine 1 mg/kg(s.c.15 rain before test meal)alone or with(45 rain before test meal p.o.)cisapride 10 mg/kg,metoclopramide 20 mg/kg, domperidone 20 mg/kg,erythromycin 6 mg/kg and mosapride 20 mg/kg. RESULTS:Cisapride,metoclopramide and mosapride were effective in enhancing gastric emptying significantly(P<0.001) whereas other prokinetic agents failed to do so in normal *** completely reversed morphine induced delay in gastric emptying followed by mosapride. Metoclopramide alone was effective when given to normal mice in increasing the ***,though it did not show any significant effect on SIT in normal mice,was able to reverse morphine induced delay in SIT significantly(P<0.001) followed by metoclopramide and mosapride. CONCLUSION:Metoclopramide and cisapride are most effective in reversing morphine-induced delay in gastric emptying and small intestinal transit in mice respectively.

关键词： Animals Benzamides Cisapride Domperidone Drug Interactions Erythromycin Female Gastric Emptying Gastrointestinal Transit Male Metoclopramide Mice Morphine Morpholines

A New Ursene Type Triterpenoid from Crepis napifera

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Chinese Chemical Letters 2000年第8期11卷 711-712页

作者： Wu, SH Luo, XD Ma, YB Wu, dg Chinese Acad Sci Kunming Inst Bot Lab Phytochem Kunming 650204 Peoples R China

A new triterpenoid, urs-20-en-3 beta-acetoxy-22 alpha-ol, and three known compounds 3 beta-acetoxy-amyrin, 3 beta-acetoxy-lupeol, lupeol were isolated from the leaves of Crepis napifera (Franch.) Babe. Their structure... 详细信息

关键词： Crepis napifera (Franch.) Babc. Compositae triterpenoid urs-20-en-3 beta-acetoxy-22 alpha-ol 3 beta-acetoxy-amyrin 3 beta-acetoxy-lupeol lupeol

Study on the reaction of C60 with DL-valine and cyclohexanone

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Chinese Journal of Chemistry 1996年第6期14卷 555-560页

作者： Zheng, dg Li, YL Mao, Z Zhu, DB CHINESE ACAD SCI INST CHEMBEIJING 100080PEOPLES R CHINA

Reaction of C-60 with DL-valine and cyclohexanone in refluxing chlorobenzene under N-2 yields three [60]fulleropyrrolidine derivatives (mono-, bis- and triadduct) which are characterised on the basis of spectroscopies and cyclic voltammetry. It is found that the ratio of the three products greatly depends on the reaction conditions.

关键词： C-60 1,3-dipolar cycloaddition reaction fulleropyrrolidine

Studies on the Catalytic Properties of Magnesia Supported on γ-Alumina

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Chemical Research in Chinese Universities 2002年第2期18卷 196-199页

作者： JIAO Qing ze ZHAO Yun LI Xiao dan EVANS dg DUAN Xue Key Laboratory of Science and Technology of Controllable Chemical Reactions Ministry of EducationBeijing University of Chemical TechnologyBeijing 100029P.R.China

We have shown that MgO can be dispersed on γ Al 2O 3 with different loadings. The observed dispersion capacity of MgO on the surface of γ Al 2O 3 is higher than the theoretical monolayer dispersion value. The surface area and the maximum in the pore size distribution gradually decrease with the increase in MgO content at low loadings. The surface area and the maximum in the pore size distribution of MgO/ γ Al 2O 3 decrease more rapidly when the MgO content is large because the pores of γ Al 2O 3 become blocked. When small amounts of MgO are dispersed on the surface of γ Al 2O 3, the catalyst is very active and shows a good selectivity for the synthesis of glycol ethers.

关键词： Magnesia Alumina Dispersion Glycol ether

Studies of the Catalytic Activity and Deactivation of Calcined Layered Double Hydroxides in the Reaction of Ethanol with Propylene Oxide

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Chemical Research in Chinese Universities 2002年第2期18卷 192-195页

作者： JIAO Qing ze ZHAO Yun ZHANG Yi qing Evans dg DUAN Xue ZHOU Zi-niu The Key Laboratory of Science and Technology of Controllable Chemical Reactions Ministry of EductionBeijing University of Chemical TechnologyBeijing 100029P.R.China Yixing Auxiliary Chemicals Plant Jiangsu 214262P.R.China

The reaction of ethanol with propylene oxide over calcined layered double hydroxides(CLDH) was investigated. The results show that CLDH has a good activity and a good selectivity, but the activity and the selectivity of CLDH decrease when CLDH reforms LDH- the so called 'memory effect'. The influence of the 'memory effect' on the CLDH returning to LDH was studied by the hydration reaction. It is shown that the 'memory effect' is not complete, and the decreases of the Mg/Al molar ratio of LDH and the crystallite size due to the increase of the hydration reaction time result in the drop of the activity and the selectivity.

关键词： Ethanol, Propylene oxide Calcined layered double hydroxide 'Memory effect' Hydration