Selective arylation of 2-substituted indoles towards 1,2- and 2,3-functional indoles directed through the catalytic system

A simple palladium catalysed procedure for the synthesis of 1,2- and 2,3-disubstituted indoles is reported. It was found that the selectivity of the reaction, i.e. the N1- versus the C3-arylation of 2-functional indoles was mainly directed by electronic factors. Fine tuning of the reaction conditions and the right choice of the substrates allowed a full selective N1-(ArI, [Pd(OAc)₂], PPh₃) or C3 (ArBr, [Pd(OAc)₂], AgBF₄) arylation. Using only 1 mol% Pd-catalyst gave up to 92% isolated yield of expected compound.     

辛基磺酰氟的合成与表征

在氢氟酸存在下，以正辛硫醇（C8H17SH）为原料，NO2为氧化剂合成了辛基磺酰氟（C8H17SO2F）。运用IR、^1HNMR、GC—MS分析技术对辛基磺酰氟进行了表征。反应不产生副产物，二辛基二硫（C8H17SSC8H17）可回收为反应原料。并探讨了辛基磺酰氟的工业应用前景。     

Novel mass air flow meter for automobile industry based on thermal flow microsensor. I. Analytical model and microsensor

An analytical model of the thermal flow sensor has been developed. The results of analytical model application are utilized to develop a thermal flow microsensor with optimal functional characteristics. The technology to manufacture the microsensor is described. A prototype of the microsensor suitable to be used in the mass air flow meter has been designed. The basic characteristics of the microsensor are presented.     

Cyclic uniaxial and multiaxial loading with yield surface distortion consideration on prediction of ratcheting

In this study, the yield surface distortion was incorporated in the cyclic plasticity modeling as well as its center movement. The combination of Chaboche’s model and the yield surface distortion model of Baltov was used in a set of uniaxial and multiaxial loadings. The variation of the stress amplitude and the mean stress and different multiaxial loadings such as tension-torsion tests were studied. It was shown that the consideration of the distortion of the yield surface via the distortion parameter and its sign in modeling has an important effect on the plastic strain increment determination and so on the ratcheting rate. The combined model was applied to the experimental results. It was shown that the combination of the nonlinear kinematic hardening model of Chaboche and the yield surface distortion leads to a good estimation of the ratcheting strain increment in different uniaxial and multiaxial tests.     

A photoelectrochemical solar cell based on ZnO/dye/polypyrrole film electrode as photoanode

Nanostructured ZnO film electrodes were prepared. A preliminary PEC solar cell based on nanostructured Zno/dye/polypyrrole (PPy) film electrode was fabricated. A fill factor of 0.754 and a high overall light to electricity conversion efficiency of 1.3% for this PEC solar cell were obtained. The sensitization mechanisms of the nanostructured ZnO electrodes were also discussed.     

Crosslinked chitosan doped with Y2(CO3)3 and surface energy and electrorheological properties

Novel electrorheological materials based on crosslinked chitosan doped with Y₂(CO₃)₃ were synthesized with biocompatible chitosan as the substrate of the materials. The electrorheological performance, surface energy, and thermal decomposition behavior of the materials were investigated as functions of the composition change. The results show that doping Y₂(CO₃)₃ can improve effectively the electrorheological performance of crosslinked chitosan with the formation of a metal–polymer complex when the doping degree is suitable. The surface energy plays an important role in influencing the electrorheological properties of the material. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Reflections on Village Planning Path from the Perspective of Participatory Planning

In this study,through village planning practice,we sorted out relevant theories and research foundations,constructed and optimized the participatory planning path of villages,and proposed institutional conditions for upgrading the main status of villagers.It is recommended to understand the working mode of villages,improve the participation ability of villagers,improve the expression of planning,strengthen the planning feedback link,and truly improve the villagers’ participation awareness and ability on the basis of legislative authorization and government empowerment.     

Analysis on the Mode of Supply of Social Housing for Youth in Taiwan: A Case Study of New Taipei City in 2019

This study explores the framework of developmental welfare through means of literature review and case study, analyzes the mode of supply of social housing for youth in New Taipei City of Taiwan, with a view to providing a reference for the inclusive and sustainable social housing mode in Taiwan.     

Solvothermal syntheses and structures of A3AgSn3Se8 (A = Rb,K)

Two new compounds A₃AgSn₃Se₈(A = K, Rb) were synthesized solvothermally and characterized by X-ray single crystal diffraction. These compound are composed of building block [Sn₃Se₈]⁴⁻ formed by three edge-sharing SnSe₄ tetrahedra, and these building blocks are further connected by tetrahedral coordinated Ag⁺ to form infinite chains, alkali cations are located between the chains. Their optical properties were also studied.     

Effect of Ce addition on macroscopic core-shell structure of Cu-Sn-Bi immiscible alloy

To investigate the evolution of bimetallic composite structure of immiscible alloy, a macroscopic core-shell type structure of 24Cu-16Sn-60Bi alloy was fabricated which consisted of (Cu₃Sn, Cu₁₀Sn₃) central core and Bi periphery. Ce addition was found to be capable of enhancing remarkably Marangoni motion of secondary droplets in liquid matrix. The role of Ce addition was attributed to change interfacial tension of droplet/matrix. The results show the possibility of modulating core-shell type structure in immiscible materials by doping rare earth elements.