Effect of hybridized local and charge transfer molecules rotation in excited state on exciton utilization.

The fluorescent molecules utilizing hybridized local and charge-transfer (HLCT) state as potential organic light-emitting diodes materials attract extensive attention due to their high exciton utilization. In this work, we have performed the density functional theory method on three HLCT-state molecules to investigate their excited-state potential energy surface (PES). The calculated results indicate the T and T energy gap is quite large, and the T is very close to S in the energy level.

Hemispherical Cesium Lead Bromide Perovskite Single-Mode Microlasers with High-Quality Factors and Strong Purcell Enhancement.

We realized a single-mode laser with an ultra-high quality factor in individual cesium lead bromide (CsPbBr) perovskite micro-hemispheres fabricated by chemical vapor deposition. A series of lasing property analysis based on cavity size was reported under this material system. Due to good optical confinement capability of the whispering gallery resonant cavity and high optical gain of CsPbBr perovskite micro-hemispheres, single-mode lasing behavior was achieved with an ultra-high quality factor as large as 11,460 at room temperature.

Size-Dependent Catalytic Activity of Oxo-Hydroxo Titanium Sub-Nanoislets Grafted on Organically Modified Mesoporous Silica.

The reaction between titanium alkoxides, [Ti(OR)], and surface silanol groups is widely used to generate grafted oxo-hydroxo titanium species, whose size is difficult to control. Partial capping of the surface silanols in the presence of the masking pattern of self-repelling tetramethylammonium ions allows us to isolate surface silanol islets, on which isolated titanium ions and dimeric oxo titanium species can be generated up to 2 Ti/Si mol %. Above this loading, and up to ∼8 Ti/Si mol %, higher oligomers (trimers, hexamers, octamers, and so on) are formed, reaching the size obtained at much lower loadings (<1 Ti/Si mol %) on a nonmodified silica surface.

Synthesis of Extra-Large-Pore Zeolite ECNU-9 with Intersecting 14*12-Ring Channels.

Highly crystalline and (hydro)thermally stable zeolites with extra-large pores [≥14-ring (14-R)] are desirable as catalysts. A novel zeolite, ECNU-9, with an intersecting 14*12-R channel system was rationally designed and synthesized by a building block strategy, in which the interlayer expansion of a two-dimensional silicate structure was realized by combining organic amine assisted layer-stacking reorganization and subsequent silylation with a square-shaped single 4-ring (S4R) silane, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCS). The PLS-3 precursor was disassembled into building blocks and then intercalated with flexible and removable organic amine pillars to offer enough interlayer spacing for accommodating TMCS molecules.

Structural diversity of lamellar zeolite Nu-6(1)--postsynthesis of delaminated analogues.

Nu-6(1) zeolite, the lamellar precursor of NSI topology, was firstly synthesized with 4'4-bipyridine as the structure-directing agent (SDA) and then subjected to HCl-EtOH treatment for the purpose of structural modification. Interlayer deconstruction and reconstruction took place alternately in this acid treatment. An intermediate named ECNU-4 was separated at the initial stage of this continuous treatment process, which exhibited a special X-ray diffraction pattern without obvious reflection peaks at low angles.

Post-synthesis treatment gives highly stable siliceous zeolites through the isomorphous substitution of silicon for germanium in germanosilicates.

Germanosilicates, an important family of zeolites with increasing number of members and attractive porosities, but containing a large quantity of unstable Ge atoms in the framework, meet with great obstacles in terms of limited thermal and hydrothermal stability when it comes to practical use. A facile stabilization method thus has been developed to substitute isomorphously Ge atoms for Si atoms, giving rise to ultrastable siliceous analogues of the pristine germanosilicates.

Linear time probabilistic algorithms for the singular haplotype reconstruction problem from SNP fragments.

In this paper, we develop a probabilistic model to approach two realistic scenarios regarding the singular haplotype reconstruction problem--the incompleteness and inconsistency that occurred in the DNA sequencing process to generate the input haplotype fragments, and the common practice used to generate synthetic data in experimental algorithm studies. We design three algorithms in the model that can reconstruct the two unknown haplotypes from the given matrix of haplotype fragments with provable high probability and in linear time in the size of the input matrix. We also present experimental results that conform with the theoretical efficient performance of those algorithms.