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Transesterification catalyzed by samarium tri-2-propoxide

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Chinese Journal of Chemistry 1997年第1期15卷 90-93页

作者： Fu, XL Wu, sh Department of Chemistry Fudan University Shanghai 200433 Chino

A facile method for transesterification was reported. Under catalysis by samarium tri-2-propoxide the yields of transesterification are good to excellent, and this reaction has surprising selectivity and mildness due ... 详细信息

关键词： transesterification samarium tri-2-propoxide catalysis

Effects of Charge Inheritance on High Zn-Al Based Alloy

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Journal of Materials Science & Technology 1995年第2期11卷 153-156页

作者： GENG, H MA, JJ YANG, sh shandong Polytechnic Univ Jinan China

The effects of several kinds of charges on microstructure and mechanical properties of ZA27 zinc alloy have been studied. Experimental results show that a certain amount of the mechining charge, granular charge and remelting charge treated in suitable way can increase greatly the mechanical properties of ZA27 alloy. It is thought that the charges possess microstructure inheritance to ZA27 alloy, so cause the property changes according to the viewpoints of casting alloy inheritance.

关键词： Zinc alloys

Around the World in 20 Days

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英语学习 1999年第9期 24-26页

作者： Nadya labi 天涯

大家可能都看过法国作家儒勒·凡尔纳的小说或改编的影视作品《八十天环游地球》,今天,又是英国人完成了乘热气球二十天环游地球的壮举。

关键词：《八十天环游地球》 In Around the World in 20 Days World

Upconversion optical nanomaterials applied for photocatalysis and photovoltaics:Recent advances and perspectives

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Frontiers of Materials Science 2019年第4期13卷 335-341页

作者： Timur sh.ATABAEV Anara MOLKENOVA Department of Chemistry School of Science and TechnologyNazarbayev UniversityNur-Sultan 010000Kazakhstan

Upconversion(UC)lanthanide nanomaterials have attracted enormous attention in the last two decades thanks to their unique ability to convert low-energy infrared photons into high-energy *** this mini-review,we briefly discussed the recent achievements related to the direct utilization of UC optical nanomaterials for photocatalysis and photovoltaic *** particular,selected examples of UCcontaining devices/nanocomposites with improved performance were *** addition,we outlined some challenges and future trends associated with the widespread usage of UC nanomaterials.

关键词： upconversion process nanoparticle luminescence photocatalysis photovoltaics

REFLEXIVITY OF POWERS OF THE MULTIPLICATION OPERATOR ON SPECIAL FUNCTION SPACES

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Acta Mathematica Scientia 2012年第6期32卷 2279-2284页

作者： B. Yousefi sh. Khoshdel Department of Mathematics Payame Noor UniversityP.O.Box 19395-3697TehranIran

In this paper we present sufficient conditions for reflexivity of any powers of the multiplication operator acting on Banach spaces of formal Laurent series.

关键词： reflexive operator Banaeh space of Laurent series associated with a sequenceβ bounded point evaluation

Dry Sliding Oxidative Wear in Plain Carbon Dual Phase Steel

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Journal of Iron and Steel Research International 2007年第4期14卷 43-48页

作者： V Abouei H Saghafian sh Kheirandish Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyNarmak 16844TehranIran

To investigate the tribological potential of the dual phase （DP） steel as a wear resistant material, the wear and the friction characteristics of this steel, which consists of hard martensite islands embedded in a ductile ferrite matrix, have been investigated and compared with those observed in plain carbon hardened （H） steel that has the same carbon content of 0.2%. Dry sliding wear tests have been carried out using a pin-on-disk wear testing machine at different normal loads of 21.3 N, 28. 5 N, 35.7 N, and 42.6 N and at a constant sliding velocity of 1.20 m/s. The analysis of surface and wear debris of samples showed that the wear mechanism was mainly mild oxidative. The friction and the wear rate of the H steel and the DP Steel have been explained with respect to the microstructure and the wear mechanism.

关键词： dual phase steel wear microstructure heat treatment

Evaluation of Four Coals for Blast Furnace Pulverized Coal Injection

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Journal of Iron and Steel Research International 2010年第3期17卷 8-12,20页

作者： sh Raygan H Abdizadeh A Eskandari Rizi School of Metallurgy and Materials Engineering University of Tehran

One of the effective methods of reducing coke consumption is pulverized coal injection. The most important problems encountered in this method are reduced permeability, unburned and high ash content. To select the best coal for injection, suitable tests can be used. Therefore, experiments such as proximate and ultimate analysis, Rock- Eval and combustion tests were performed on four kinds of coals from different mines, including Sarakhs, Sangrood, Karmozd, and Tabas. The results of proximate and ultimate analysis indicated that although the sulfur content and ash content of selected coals were a little high, they were suitable for coal injection. The results of combustion experiments and Rock-Eval tests showed that Karmozd coal was the best one to be injected into blast furnace. The result indicated that the mixing of coals could improve the combustion properties of pulverized coals.

关键词： pulverized coal blast furnace non-coking coal

Optimum Environmental Load Design Criterion for Marine Structures Based on Investment and Benefit Analysis

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China Ocean Engineering 1998年第2期13卷 235-242页

作者： Zhang, sh Yu, YF Li, BX Ocean Univ Qingdao Qingdao 266003 Peoples R China

Marine structures operating in natural ocean environment are subjected to various stochastic loads. For design of the marine structures, the most important task is to determine environmental load design criterion. This paper presents a method to determine the optimum environmental load design criterion for marine structures. This method is based on the investment and benefit analysis and it can reach the design purpose of decreasing total costs during the service life of the structures and increasing economic benefits.

关键词： marine structures investment-benefit analysis optimum environmental load design criterion

EIGENFUNCTION EXPANSION FOR STURM-LIOUVILLE PROBLEMS WITH TRANSMISSION CONDITIONS AT ONE INTERIOR POINT

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Acta Mathematica Scientia 2015年第3期35卷 639-649页

作者： Oktay sh.MUKHTAROV Kadriye AYDEMIR Institute of Mathematics and Mechanics Azerbaijan National Academy of Sciences Department of Mathematics Faculty of ScienceGaziosmanpasa University

The purpose of this article is to extend some spectral properties of regular Sturm- Liouville problems to the special type discontinuous boundary-value problem, which consists of a Sturm-Liouville equation together with eigenparameter-dependent boundary conditions and two supplementary transmission conditions. We construct the resolvent operator and Green＇s function and prove theorems about expansions in terms of eigenfunctions in modified Hilbert space L2[a, b].

关键词： Boundary-value problems transmission conditions resolvent operator