Precision-engineered metal-organic frameworks: fine-tuning reverse topological structure prediction and design.

Digital discoveries of metal-organic frameworks (MOFs) have been significantly advanced by the reverse topological approach (RTA). The node-and-linker assembly strategy allows predictable reticulations predefined by coordination templates; however, reticular equivalents lead to substantial combinatorial explosion due to the infinite design space of building units (BUs). Here, we develop a fine-tuned RTA for the structure prediction of MOFs by integrating precise topological constraints and leveraging reticular chemistry, thus transcending traditional exhaustive trial-and-error assembly.

Transforming CO into Methanol with N-Heterocyclic Carbene-Stabilized Coinage Metal Hydrides Immobilized in a Metal-Organic Framework UiO-68.

By synergizing the advantages of homogeneous and heterogeneous catalysis, single-site heterogeneous catalysis represents a highly promising opportunity for many catalytic processes. Particularly, the unprecedented designability and versatility of metal-organic frameworks (MOFs) promote them as salient platforms for designing single-site catalytic materials by introducing isolated, well-defined active sites into the frameworks. Herein, we design new MOF-supported single-site catalysts for CO hydrogenation to methanol (CHOH), a reaction of great significance in CO valorization.

Decoupled Redox Catalytic Hydrogen Production with a Robust Electrolyte-Borne Electron and Proton Carrier.

Electrolytic water splitting is an effective approach for H mass production. A conventional water electrolyzer concurrently generates H and O in neighboring electrode compartments separated by a membrane, which brings about compromised purity, energy efficiency, and system durability. On the basis of distinct redox electrochemistry, here, we report a system that enables the decoupling of both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) from the electrodes to two spatially separated catalyst bed reactors in alkaline solutions.

Double redox process to synthesize CuO-CeO catalysts with strong Cu-Ce interaction for efficient toluene oxidation.

In this study, a novel double redox (DR) method was developed to synthesize highly active CuO-CeO (CuCe-DR) catalyst for catalytic oxidative decomposition of toluene. Compare with CuCe-C catalyst prepared by co-precipitation method, CuCe-DR catalyst exhibits a higher Ce ion and incorporated Cu ion concentration, and has a stronger Cu-Ce interaction. Ce and incorporated Cu ions can induce the formation of oxygen vacancies, and thus increasing the amount of surface chemisorbed oxygen on CuCe-DR catalyst.

Flexible superhydrophobic surfaces with condensate microdrop self-propelling functionality based on carbon nanotube films.

With the development of flexible electronics and wearable devices, there is strong demand for flexible, superhydrophobic, and multifunctional coatings. Motivated by the promise of attractive multifaceted functionality, various techniques have been developed to fabricate flexible surfaces with non-wetting properties. However, until now, there have been few reports on superhydrophobic surfaces with condensate microdrop self-propelling (CMDSP) functionality on a carbon nanotube film.

Experimental investigation on strength development of lime stabilized loess.

Lime stabilization has been widely used in pavement subbases and ground improvement, but the investigation of the mechanical properties and the microstructure of lime stabilized loess is still insufficient. In this study, the effects of lime content, porosity and curing time on the strength development of lime stabilized loess were investigated through a series of unconfined compression tests. The microstructure of lime stabilized loess with different curing time was also investigated by scanning electron microscopy (SEM).

Enhanced Charge Carrier Transport and Device Performance Through Dual-Cesium Doping in Mixed-Cation Perovskite Solar Cells with Near Unity Free Carrier Ratios.

PbI-enriched mixed perovskite film [FAMAPb(IBr)] has been widely studied due to its great potential in perovskite solar cell (PSC) applications. Herein, a FAMAPb(IBr) film has been fabricated with the temperature-dependent optical absorption spectra utilized to determine its exciton binding energy. A ∼13 meV exciton binding energy is estimated, and a near-unity fraction of free carriers out of the total photoexcitons has been obtained in the solar cell operating regime at equilibrium state.

Anomalous spectral features of a neutral bilayer graphene.

Graphene and its bilayer are two-dimensional systems predicted to show exciting many-body effects near the neutrality point. The ideal tool to investigate spectrum reconstruction effects is angle-resolved photoemission spectroscopy (ARPES) as it probes directly the band structure with information about both energy and momentum. Here we reveal, by studying undoped exfoliated bilayer graphene with ARPES, two essential aspects of its many-body physics: the electron-phonon scattering rate has an anisotropic k-dependence and the type of electronic liquid is non-Fermi liquid.

Design of curved photonic cavities for a narrow-band widely tunable resonance ranging 200 nm.

We propose a type of photonic resonator with a tunable curved cavity that enables efficient tuning of the optical length of a resonant cavity made of a solid material; we call this a "tunable curved resonator" (TCR). Its integration with a "tunable curved waveguide" (TCWG) and their actuation by a MEMS (micro electromechanical systems) electrostatic comb actuator are also designed for integrated photonic circuits. With this kind of structure, a widely and continuously tunable narrow-band resonance ranging up to 200 nm is achieved with a MEMS actuation voltage less than 70 V.

A 2-D MEMS scanning mirror based on dynamic mixed mode excitation of a piezoelectric PZT thin film S-shaped actuator.

A novel dynamic excitation of an S-shaped PZT piezoelectric actuator, which is conceptualized by having two superimposed AC voltages, is characterized in this paper through the evaluation of the 2-D scanning characteristics of an integrated silicon micromirror. The device is micromachined from a SOI wafer with a 5 μm thick Si device layer and multilayers of Pt/Ti/PZT//Pt/Ti deposited as electrode and actuation materials. A large mirror (1.

Double-reflection polygon mirror for high-speed optical coherence microscopy.

We report on a high-speed, high-efficiency, high-duty-cycle, path-length-maintaining and linear beam scanner suitable for en face scanning optical coherence microscopy. Fast transverse beam scanning is achieved by use of a double-reflection polygon mirror (DRPM) rotating at a constant speed. With a motor speed of 18,000 rpm and a scanner diameter of 50 mm, the DRPM provides a line rate up to 3 kHz, +/-1.

Binary-phase spatial filter for real-time swept-source optical coherence microscopy.

We report a novel scheme to optimize the focusing condition for real-time, swept-source optical coherence microscopy. The axial and lateral behaviors of four-zone binary-phase spatial filters are presented numerically. A nearly constant axial intensity distribution along an extended depth of focus of 1.

A feature selection method for multilevel mental fatigue EEG classification.

Two feature selection approaches for multilevel mental fatigue electroencephalogram (EEG) classification are presented in this paper, in which random forest (RF) is combined with the heuristic initial feature ranking scheme (INIT) or with the recursive feature elimination scheme (RFE). In a "leave-one-proband-out" evaluation strategy, both feature selection approaches are evaluated on the recorded mental fatigue EEG time series data from 12 subjects (each for a 25-h duration) after initial feature extractions. The latter of the two approaches performs better both in classification performance and more importantly in feature reduction.

Multiscale modelling of human gastric electric activity: can the electrogastrogram detect functional electrical uncoupling?

During recent years there has been a growing interest in the assessment of gastric electrical health through cutaneous abdominal recordings. The analysis of such recordings is largely limited to an inspection of frequency dynamics, and this has raised doubts as to whether functional gastric electrical uncoupling can be detected using this technique. We describe here a computational approach to the problem in which the equations governing the underlying physics of the problem have been solved over an anatomically detailed human torso geometry.

Strategic environmental assessment in Hong Kong.

This review examines the development and application of strategic environmental assessment (SEA) process in the planning framework of Hong Kong. Two strategic planning case studies are evaluated within the context of SEA, namely the Territorial Development Strategy Review (TDS Review) and the Third Comprehensive Transport Study (CTS-3). Rapid population growth and urbanisation in Hong Kong, coupled with a historic lack of planning controls and inherent conflicts between government departments have been major obstacles to achieving sustainable development in the territory.