Approach to the Synthesis of Dimeric Salen-Co(Ⅲ):A Recoverable Catalyst for Rac-Eprichlorohydrin HKR

The synthesis of chiral dimeric Salen ligand 5, 5＇-methylene-di-[（R, R ）-｜ N-（3-tert-butylsalicylidine）-N＇- （ 3＇, 5＇-di- tert-butylsalicylidene） ｜ - 1, 2-cyclohexanediamine ] which using 2-tert-butylphenol as starting material is reported. This compound reacts with cobalt （Ⅱ） acetate and then oxidized by air to give dimeric Salen catalyst 5 in this paper, which catalyzes the hydrolytic kinetic resolution （HKR） of racemic epichlorohydrin to afford biologically important chiral epoxides and diols. Ee values of diol up to 97 % were obtained, and the catalyst was recovered with no apparent loss.     

A Brief Approach to the Improvement of Reading Comprehension

ＡＢｒｉｅｆＡｐｐｒｏａｃｈｔｏｔｈｅＩｍｐｒｏｖｅｍｅｎｔｏｆＲｅａｄｉｎｇＣｏｍｐｒｅｈｅｎｓｉｏｎＳｕｎＹｕｎｂｏ（ＤｅｐａｒｔｍｅｎｔｏｆＦｏｒｅｉｇｎＬａｎｇｕａｇｅｓ，ＫｕｎｍｉｎｇＩｎｓｔｉｔｕｔｅｏｆＴｅｃｈｎｏｌｏｇｙ，Ｋｕｎｍｉｎ...     

Natural Mineral-marine Manganese Nodule as a Novel Catalyst for the Synthesis of Carbon Nanotubes

1 IntroductionCarbon nanotubes (CNTs) are globally in the lime-light as a newfancy material of the 21st century andtheyare broadening their applications to almost all scientificareas . Several methods , such as arc-discharge va-porization[1],laser vaporization[2],chemical vapor depo-sition (CVD)[3-4]and others[5], have been developed tofabricate CNTs (including single and multi wall) up tonow.It is very well possible that the CVD method,be-cause of its simplicity andlowcost ,will provide …     

Synthesis and adsorption properties for Au(Ⅲ) of alkoxycarbonyl thiourea resin

A novel alkoxycarbonyl thiourea resin(ATR) was synthesized by monomer polymerization of oxydiethane-2,1-diyl dicarbonisothiocyanatidate and polyethylene polyamine, and characterized by FT-IR. The adsorption properties of ATR were investigated by batch test. The adsorption capacities for Au(Ⅲ), Ag(Ⅰ), Cu(Ⅱ), Zn(Ⅱ), Fe(Ⅲ), Ca(Ⅱ) and Mg(Ⅱ) are 4.65, 4.40,0.40, 0.90, 0.86, 0.0080 and 0.016 mmol/g, respectively, when the adsorption condition is as follows: contact time 24 h, temperature 30 ℃, initial concentration of Au(Ⅲ) 5.08 mmol/L and that of other metals 0.10 mol/L, and concentration of acid 1.0 mol/L. The adsorption capacity for Au(Ⅲ) increases with the increase of contact time, temperature and initial concentration of Au(Ⅲ). The capacity after five adsorption-desorption cycles remains 90% that of the first time, and the separation factors of ATR for binary metal ion solutions are larger than 995, indicating that ATR is of good regeneration property and selectivity. XPS results show that the functional atoms of ATR supply electrons for Au and coordinate with Au during the adsorption.     

New Approach to the Synthesis of Benzhydryl 6α-Bromopenicillanic Acid -1-Oxide

The synthesis of Benzhydryl 6a-Bromopenicillanic acid -1-oxide with air catalyzed by Fe(NO3)3-FeBr3 using Benzhydryl 6a-Bromopenicillanic acid as starting material was reported. The oxidation was selective and no sulfone was formed. Compared with conventional method, using the Fe(NO3)3-FeBr3 as catalyst, the reaction time was reduced from 4 h to 1 h and the yield was enhanced from 65.0% to 93.5%.     

An Approach to the Design of Learning Controllers

In this paper an approach to the design of learning controllers is studied. The conditions for the convergence of control errors are given by using the Banach Contraction Mapping Theorem It is proved that the design of leaming controllers can be equivalent to that of conventional feedback controllers in a certain sense. Finally, the theoretical results are vcrificd by some design examples of the SISO system, and the simulation results are given herewith.     

A Logical Approach to Emulation of Higher Mental Processes

ＡＬｏｇｉｃａｌＡｐｐｒｏａｃｈｔｏＥｍｕｌａｔｉｏｎｏｆＨｉｇｈｅｒＭｅｎｔａｌＰｒｏｃｅｓｓｅｓＣＨＥＮＺｈｉｑｉａｎｇ；ＨＯＮＧＪｉａｒｏｎｇ（陈志强，洪家荣）（Ｄｅｐｔ．ｏｆＣｏｍｐｕｔｅｒＳｃｉｅｎｃｅ，ＨａｒｂｉｎＩｎｓｔｉｔｕｔｅｏｆＴ...     

Adsorption of D113 Resin for Dysprosium(Ⅲ)

The adsorption behavior and mechanism of D113 resin for Dy(Ⅲ)was investigated by using the method of resin adsorption.Experimental results show that the optimum medium pH of adsorption of D113 resin for Dy~(3 ) is pH=6.00 in the HAc-NaAc medium.The static adsorption capacity of D113 resin for Dy~(?) is 292.7 mg.g~(-1).The optimum eluant is 0.5 mol·L~(-1) HCl.The adsorption rate constant is k_(298)=6.8×10~(-6)s~(-1).The apparent activation energy of D113 resin for Dy(Ⅲ)is 14.79 kJ·mol~(-1).The adsorption behavior of D113 resin for Dy(Ⅲ)obeys the Freundlich isotherm.The adsorption parameters of thermodynamic areΔH=14.48 kJ·mol~(-1) ,ΔS=54.69 J.mol~(-1)·K~(-1),ΔG=-1.82 kJ·mol~(-1).The adsorption mechanism of D113 resin for Dy~(3 ) was confirmed by chemical analysis and IR spectra.     

Van der Waals epitaxy: A new way for growth of Ⅲ-nitrides

正Inorganic semiconductor plays a key role for today's technological progress [1–4]. Comparing with other organic semiconductors [5,6] and two-dimensional(2D) metal sulfides [7–10], Ⅲ-nitrides as direct bandgap semiconductors have achieved enormous success in commercial applications.     

A Feasible Approach for Improving Accuracy of Ground Deformation Measured by D-InSAR

D-InSAR is currently one of the most popular research tools in the field of Microwave Remote Sensing. It is unrivaled in its aspect of measuring ground deformation due to its advantages such as high resolution,continuous spa-tial-coverage and dynamics. However,there are still a few major problems to be solved urgently as a result of the intrin-sic complexity of this technique. One of the problems deals with improving the accuracy of measured ground deforma-tion. In this paper,various factors affecting the accuracy of ground deformation measured by D-InSAR are systemati-cally analyzed and investigated by means of the law of measurement error propagation. At the same time,we prove that the ground deformation error not only depends on the errors of perpendicular baselines as well as the errors of the inter-ferometric phase for topographic pair and differential pair,but also on the combination of the relationship of perpen-dicular baselines for topographic pairs and differential pairs. Furthermore,a feasible approach for improving the accu-racy of measured ground deformation is proposed,which is of positive significance in the practical application of D-InSAR.     

Treatment Methods for the Quality Improvement of Recycled Concrete Aggregate (RCA)–A Review

For the purpose of providing references for further research and practical application about the quality improvement of RCA,in this paper,various treatment methods were firstly classified into four categories:removing old mortar (OM),strengthening OM,multi-stage mixing methods,and combination methods.Thereafter,the improvement mechanisms and important conclusions of various treatment methods were elucidated and summarised respectively.In the section of discussion,the improved effects as well as advantages and disadvantages of various treatment methods were compared and discussed respectively,and recommendations for the selection of treatment methods were proposed.Finally,the further research directions were pointed out,and an integrative programme on the quality improvement of RCA was recommended.     

Self-assembling Synthesis of Vanadium Oxide Nanotubes and Simple Determination of the Content of V(IV)

1　IntroductionInrecentyears ,nanoscaleone dimensionalmaterialsattractmuchattentionduetotheirremarkablephysico chemicalpropertiesandagreatpotentialfornanodevices [1] .Theoutstandingstructuralversatilityofvanadiumox idesandderivedcompoundsisreceivingsignificantatten tionespeciallywithrespecttoapplicationsincatalysisandaselectrochemicaldevices[2 -4] .Recently ,Nesperandco workershavesynthesizedthenovelvanadiumoxidenano tubeinasol gelreactionfollowedbyhydrothermaltreat mentfromvanadiumalkoxidepre…     

Orbital Calculations of Kaolinite Surface:on Substitution of Al~(3 ) for Si~(4 ) in the Tetrahedral Sites

The surface properties of kaolinite were determined using density functional theory discrete variational method(DFT-DVM)and Gaussian 03 program.A SiO_4 tetrahedral hexagonal ring with two Al octahedra was chosen to model the kaolinite crystal.The total density of states of the kaolinite cluster are located near the Fermi level at both sides of the Fermi level.Both the highest occupied molecular orbit (HOMO)and the lowest unoccupied molecular orbit(LUMO)of kaolinite indicate that kaolinite system can not only readily interact with electron-acceptor species,but also readily interact with electron-donor species on the edge surface and the gibbsite layer surface,and thus,shows amphoteric behavior.Substitution of Al~(3 ) for Si~(4 ) in the tetrahedral site linking the vacant Al~(3 ) octahedra does not increase the surface chemical reactivity of kaolinite,while substitution of Al~(3 ) for Si~(4 ) in the tetrahedral site with the apex O linking Al~(3 ) octahedra increase the surface chemical reactivity of the siloxane surface of kaolinite,especially acting as electron donors. Additionally,substitution of Al~(3 ) for Si~(4 ) in the tetrahedral site results in the re-balance of charges,leading to the increase of negative charge of the coordinated O atoms of the AlO_4 tetrahedra,and therefore favoring the formation of ionic bonds between cations and the surface O atoms in the basal plane.     

Synthesis and Characterization of Poly(L-lactide-co-glycolide)

1Introduction Poly(lactide co glycolides)(PLGA)isawidelyin vestigatedbiodegradablecopolymer.Thebiocompatible andbiodegradablepolymersaresafeinthebodyandare hydrolyzedintometabolicby products.Recentlythese polyestermaterialshavebeenextensivelyusedinbiomate…     

A New Calculating Method for the Flowfield of Turbomachinery

In this paper, a new method is developed to solve the N-S equations with vorticity-velocity variables, which is suitable for describing the flow-field of turbomachinery in non-inertia coordinates. It is derived that the expansions of the vorficity-velocity equations (VVE)have the same form in arbitrary non-orthogonal curvilinear coordinates, because the non-inertia effect is only related to the initial and the boundary conditions. This method greatly simplifies the solution for the flowfield of turbomachinery with complicated geometrical domain and reduces the calculation cost.     

An Approach to Evaluate the Implementation Effects of Advanced Manufacturing Technology Based on the Specialists'''' Opinion Selection

Since domestic corporations firstly introduced into and implemented the Advanced Manufacturing Technology (AMT),how to scientifically evaluate the implementation effects of AMT has been an urgent problem.Through the review of for- eign relative studies,this paper constructs an indicator system used to evaluate the implementation effects of AMT.Operational performance,Organizational or managerial performance,Satisfactory performance,and Competitive performance are indicators of first level in the system,and 19 indicators of second level have been selected to estimate the implementation effects of AMT.In this study,a model based on Minkowski distance discriminance to select the specialists' opinion was designed to evaluate the indica- tor system,and the measure's validity and practicability was proved by a case study to a diesel engine factory.     

A Research on the E-commerce Applied to the Construction of Marketing Model

The function of E-commerce is becoming more and more widely applied to many fields,which bring about some new challenges and opportunities for the construction of marketing model.It is proved that the more E-com- merce applied to the construction of marketing,the more precision of forecast for the enterprises can acquire,which is very helpful for the production and marketing of enterprises.Therefore,the research on the E-commerce applied to the construction of marketing is popular today.This paper applied the five important elements which are product, price,place,advertising and sales promotion,as well as,consumer behavior to construct a marketing model with E-commerce.By the analysis,this paper will draw the conclusions that two problems should be faced.One is that available theories and approaches may be insufficient in tackling many E-commerce problems.And the other is that the construction of marketing model for E-commerce can enrich the fields quite remarkably as the new theories,data and methods which can be applied.     

Synthesis of 1,4-benzenedicarbonyl thiourea resins and their adsorption properties for Ag(Ⅰ)

Several 1,4-benzenedicarbonyl thiourea resins (BTR) were synthesized through interfacial polymerization between 1,4-benzenedicarbonyl diisothiocyanate and polyamine. Their structures were confirmed by FT-IR. The adsorption properties (including the effect of adsorption time,pH,initial concentrations and temperature) of BTR-1,BTR-2 and BTR-3 for Ag(I) were investigated by batch tests. The results show that the adsorption equilibria of BTR-1,BTR-2,BTR-3 for Ag(I) are achieved after about 10 h. Their equilibri...