Methods to fabricate tightly packed arrays of nanoparticles are disclosed, without relying on organic ligands or a substrate. In some variations, a method of assembling particles into an array comprises dispersing particles in a liquid solution; introducing a triggerable pH-control substance capable of generating an acid or a base; and triggering the pH-control substance to generate an acid or a base within the liquid solution, thereby titrating the pH. During pH titration, the particle-surface charge magnitude is reduced, causing the particles to assemble into a particle array. Other variations provide a device for assembling particles into particle arrays, comprising a droplet-generating microfluidic region; a first-fluid inlet port; a second-fluid inlet port; a reaction microfluidic region, disposed in fluid communication with the droplet-generating microfluidic region; and a trigger source configured to trigger generation of an acid or a base from at least one pH-control substance contained within the reaction microfluidic region.

Methods to fabricate tightly packed arrays of nanoparticles are disclosed, without relying on organic ligands or a substrate. In some variations, a method of assembling particles into an array comprises dispersing particles in a liquid solution; introducing a triggerable pH-control substance capable of generating an acid or a base; and triggering the pH-control substance to generate an acid or a base within the liquid solution, thereby titrating the pH. During pH titration, the particle-surface charge magnitude is reduced, causing the particles to assemble into a particle array. Other variations provide a device for assembling particles into particle arrays, comprising a droplet-generating microfluidic region; a first-fluid inlet port; a second-fluid inlet port; a reaction microfluidic region, disposed in fluid communication with the droplet-generating microfluidic region; and a trigger source configured to trigger generation of an acid or a base from at least one pH-control substance contained within the reaction microfluidic region.

A high-density micro-chamber array has a translucent flat substrate, a hydrophobic layer in which a plurality of micro-chambers are provided, and a lipid bilayer membrane formed in each of the openings of the micro-chambers, wherein an electrode is provided in each of the micro-chambers, and when the side of the substrate on which the hydrophobic layer is provided is directed upward, the micro-chamber array is configured such that with at least one of the following A) and B) being met, light entering the substrate from below is transmitted through the substrate and penetrates into the micro-chambers' interiors, and light entering the substrate from the micro-chambers' interiors is transmitted through the substrate and escapes toward below the substrate. A) The electrode is provided on an inner side surface of each of the micro-chambers. B) The electrode is transparent and provided on a bottom surface of each of the micro-chambers.

The present invention relates to a method of reducing the deposit of metallic transition metal, particularly palladium, on a metal part in hydrogenation reactions using hydrogen and a heterogenous supported palladium catalyst. These metallic transition metal deposit, particularly palladium deposits, are particularly formed at areas which are exposed to high velocity and shear forces of the hydrogenation mixture comprising the transition metal catalyst, particularly palladium catalyst. They are significantly reduced or even avoided when the surface of the respective metal parts are coated by a plasma sprayed ceramic coating.

A synthetic column for nucleic acid synthesis includes a column body, first helical blades, and second helical blades. The column body has an axis, an inner wall, and an inlet end and an outlet end opposite to each other. The first helical blades helically extend in a first helical direction from the axis toward the inner wall. Two ends of each first helical blade are connected to the axis and the inner wall. The second helical blades helically extend in a second helical direction from the inner wall toward the axis. The first helical direction is different from the second helical direction. The first and second helical blades are arranged in an alternating manner. One end of each second helical blade is connected to the inner wall, and the other end has a second helical side gradually approaching the axis from the inlet end toward the outlet end.