Abstract A practical palladium‐catalyzed carbonylative Suzuki coupling of aryl halides under carbon monoxide gas‐free conditions has been developed. Here, formic acid was utilized as the source for first time with acetic anhydride additive. variety diarylketones were produced in moderate to excellent yields from corresponding and arylboronic acids.

In order to prepare magnetorheological fluid with excellent sedimentation stability, various surfactants are applied coat carbonyl iron powder. The prepared shows stability when the respectively sodium lauryl alcohol phosphate, compound fatty acid methyl ester sulfonate, ethylene glycol monostearate and glyceride monostearate. Orthogonal tests carried out for optimal combination of thixotropic agent. experimental results show that additives MRF is 1.5 wt% 1.0 MES, monostearate, glycerol...

Abstract Teleoperated robotic systems are widely used in daily life, but the actuators their force feedback devices suffer from large structure volume, poor stability, low torque, and slow response speeds. Based on magnetorheological (MR) effect, a double-coil double-disk MR damper is proposed this paper. According to constitutive model of fluid, torque mathematical double coil disk Damper established. orthogonal experiment method, material, geometry magnetic circuit selected through dynamic...

Abstract A general and convenient palladium‐catalyzed carbonylation procedure for the synthesis of benzofuran‐2(3 H )‐ones from phenols aldehydes has been developed. With formic acid as CO source, a variety were obtained in moderate to good yields.

Abstract Aryl formates have been extensively applied as CO sources in CO‐free carbonylation reactions. However, there are no catalytic synthetic procedures for their preparation. In this manuscript, we developed a convenient palladium‐catalyzed procedure the synthesis of aryl formates. Good yields were achieved under mild reaction conditions with formic acid formyl source.

A palladium-catalyzed carbonylative intramolecular synthesis of benzofuran-2(3<italic>H</italic>)-ones from 2-hydroxybenzyl alcohols has been developed with formic acid as the CO source, various desired products were obtained in moderate to good yields.

A magnetorheological fluid (MR fluid) is mainly composed of soft magnetic particles, surfactants, and the base carrier fluid. Among these, particles influence MR significantly in a high-temperature environment. Therefore, study was carried out to investigate changes properties fluids environments. On this basis, novel with resistance prepared, had excellent sedimentation stability, which rate only 4.42% after heat treatment at 150 °C followed by one-week placement. At 30 °C, shear yield...

Magnetorheological fluids, especially those in high-power magnetorheological devices, inevitably work at high temperatures because of the wall slip, energized coils and frictions between particles. In order to prepare a fluid for temperatures, this investigates properties three main components (soft magnetic particles, surfactants base carrier fluids) temperatures. On basis, novel is prepared. Its sedimentation stability, viscosity shear yield stress are investigated The results show that...

Power transmission is an important application for magnetorheological (MR) fluid, and the cylinder-type power device a novel form due to its high stability, higher torque, large ratio of mass. This work designed multi-cylinder with water-cooling channel because MR device, especially high-power inevitably works in high-temperature environment. Based on Ohm’s law electromagnetism theory, magnetic circuit designed, magnetoresistance was calculated. The finite element method used analyze field...

Abstract Base oil has great influence on the tribological and rheological properties of magnetorheological fluid. In this paper, four types fluid are prepared respectively by silicone oil, mineral synthetic (PAO) castor their investigated. Firstly, viscosity is measured a viscometer. Then friction coefficient wear scar diameter ball testing machine. Next, sedimentation rate fluids calculated observation method. Finally, shear yield stress rheometer. By analyzing experimental data, it...

In order to study the sedimentation stability of silicone oil-based magnetorheological fluids with fumed silica as additive, different mass fractions silica, particle sizes carbonyl iron powder and viscosities oil were prepared. The rate was calculated by observation method, zero-field viscosity measured viscometer. results show that increase gradually fraction silica. should not be constant for fluids, but determined according content in fluids. With average diameter powder, becomes worse....

Rheological property is very important for magnetorheological fluids, but tribological also a crucial factor to determine whether fluids can work stably. In order find suitable carbonyl iron powder three are prepared by ordinary, reduced, and phosphated powders, their properties compared. The microstructures of the different powders observed scanning electron microscopy X-ray diffraction. Sedimentation stability obtained observation. rheological measured friction testing machine rotational...

The proper microenvironment is critical for the storage and transportation of embryonic stem cells (ESCs). To mimic a dynamic 3D as it exists in vivo consider "off-the-shelf" availability reaching destination, we proposed an alternative approach that allows facile form ESCs-dynamic hydrogel construct (CDHC) under ambient conditions. CDHC, mouse (mESCs) were in-situ encapsulated within polysaccharide-based self-biodegradable hydrogel. After storing CDHC sterile hermetic environment 3 days...

Abstract A palladium‐catalyzed intramolecular carbonylation reaction for the synthesis of N ‐acetyl benzoxazinones has been achieved first time. To avoid using toxic and flammable CO gas, formic acid was utilized as source here. This carbonylative process is conducted under mild conditions with high efficiency. variety desired benzoxazinone products were obtained in moderate to excellent yields very good functional group compatibility. The presents anhydride holds two roles here: activator...

In order to study the pore structure change characteristics of basalt fiber reinforced concrete under two sources damage, high temperature and mechanics, nuclear magnetic resonance(NMR) scanning electron microscopy(SEM) techniques were used observe T2 spectrum distribution, size distribution flaw development concrete. The results show that normal concrete, short long a trend decreasing number micropores increasing mesopores after temperature. By comparison, it is found has largest pores in...

The influence of the briquetting process on SO2 and NO release characteristics, combustion properties kinetic characteristics during biomass was investigated. Two (Wheat straw Tree bulk) two obtained briquettes were analysed. helps to prevent NO. experimental results show that once is made into a briquette, when reaction temperature 900 ∘C, sulphur ratio for TB reduced from 34.7% 4.3% WS 12.4% 1.6%. When increases 1000 73.4% 30.4%, it 58.4% 10.2%. SEM micrographs compact structure...