Developing broadband and strong visible-light-absorbing photosensitizer is highly desired for dramatically improving the utilization of solar energy and boosting artificial photosynthesis. Herein, we ...develop a facile strategy to co-sensitize Ir-complex with Coumarins and boron dipyrromethene to explore photosensitizer with a broadband covering ca. 50% visible light region (Ir-4). This type of photosensitizer is firstly introduced into water splitting system, exhibiting significantly enhanced performance with over 21 times higher than that of typical Ir(ppy)
(bpy)
, and the turnover number towards Ir-4 reaches to 115840, representing the most active sensitizer among reported molecular photocatalytic systems. Experimental and theoretical investigations reveal that the Ir-mediation not only achieves a long-lived boron dipyrromethene-localized triplet state, but also makes an efficient excitation energy transfer from Coumarin to boron dipyrromethene to trigger the electron transfer. These findings provide an insight for developing broadband and strong visible-light-absorbing multicomponent arrays on molecular level for efficient artificial photosynthesis.
CRC (cyclic redundancy check)-aided decoding schemes are proposed to improve the performance of polar codes. A unified description of successive cancellation decoding and its improved version with ...list or stack is provided and the CRC-aided successive cancellation list/stack (CA-SCL/SCS) decoding schemes are proposed. Simulation results in binary-input additive white Gaussian noise channel (BI-AWGNC) show that CA-SCL/SCS can provide significant gain of 0.5 dB over the turbo codes used in 3GPP standard with code rate 1/2 and code length 1024 at the block error probability (BLER) of 10 -4 . Moreover, the time complexity of CA-SCS decoder is much lower than that of turbo decoder and can be close to that of successive cancellation (SC) decoder in the high SNR regime.
Highly selective separation and/or purification of acetylene from various gas mixtures is a relevant and difficult challenge that currently requires costly and energy‐intensive chemisorption ...processes. Two ultramicroporous metal–organic framework physisorbents, NKMOF‐1‐M (M=Cu or Ni), offer high hydrolytic stability and benchmark selectivity towards acetylene versus several gases at ambient temperature. The performance of NKMOF‐1‐M is attributed to their exceptional acetylene binding affinity as revealed by modelling and several experimental studies: in situ single‐crystal X‐ray diffraction, FTIR, and gas mixture breakthrough tests. NKMOF‐1‐M exhibit better low‐pressure uptake than existing physisorbents and possesses the highest selectivities yet reported for C2H2/CO2 and C2H2/CH4. The performance of NKMOF‐1‐M is not driven by the same mechanism as current benchmark physisorbents that rely on pore walls lined by inorganic anions.
Ultramicroporous MOF (metal–organic framework) physisorbents, NKMOF‐1‐M (M=Cu or Ni), offer high hydrolytic stability and benchmark selectivity towards acetylene versus several gases at ambient temperature. The performance of NKMOF‐1‐M is attributed to exceptional acetylene binding affinity. NKMOF‐1‐M exhibits better low‐pressure uptake than existing physisorbents and possesses the highest selectivities yet reported for C2H2/CO2 and C2H2/CH4.
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Endosomes are dynamic intracellular compartments that control the sorting of a constant stream of different transmembrane cargos either for ESCRT‐mediated degradation or for egress and recycling to ...compartments such as the Golgi and the plasma membrane. The recycling of cargos occurs within tubulovesicular membrane domains and is facilitated by peripheral membrane protein machineries that control both membrane remodelling and selection of specific transmembrane cargos. One of the primary sorting machineries is the Retromer complex, which controls the recycling of a large array of different cargo molecules in cooperation with various sorting nexin (SNX) adaptor proteins. Recently a Retromer‐like complex was also identified that controls plasma membrane recycling of cargos including integrins and lipoprotein receptors. Termed “Retriever,” this complex uses a different SNX family member SNX17 for cargo recognition, and cooperates with the COMMD/CCDC93/CCDC22 (CCC) complex to form a larger assembly called “Commander” to mediate endosomal trafficking. In this review we focus on recent advances that have begun to provide a molecular understanding of these two distantly related transport machineries.
The Retromer and Retriever complexes are structurally related protein assemblies that both play major roles in the sorting of transmembrane cargo proteins through endosomal compartments. This review highlights recent advances in our understanding of the molecular structures of these complexes and their known regulatory interactions, as well as the similarities and differences in their functions in endosomal trafficking.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Crystal engineering, the field of chemistry that studies the design, properties, and applications of crystals, is exemplified by the emergence over the past thirty years of porous coordination ...networks (PCNs), including metal-organic frameworks (MOFs) and hybrid coordination networks (HCNs). PCNs have now come of age thanks to their amenability to design from first principles and how this in turn can result in new materials with task-specific features. Herein, we focus upon how control over the pore chemistry and pore size of PCNs has been leveraged to create a new generation of physisorbents for efficient purification of light hydrocarbons (LHs). The impetus for this research comes from the need to address LH purification processes based upon cryogenic separation, distillation, chemisorption or solvent extraction, each of which is energy intensive. Adsorptive separation by physisorbents (in general) and PCNs (in particular) can offer two advantages over these existing approaches: improved energy efficiency; lower plant size/cost. Unfortunately, most existing physisorbents suffer from low uptake and/or poor sorbate selectivity and are therefore unsuitable for trace separations of LHs including the high volume C2 LHs (C
2
H
x
,
x
= 2, 4, 6). This situation is rapidly changing thanks to PCN sorbents that have set new performance benchmarks for several C2 separations. Herein, we review and analyse PCN sorbents with respect to the supramolecular chemistry of sorbent-sorbate binding and detail the crystal engineering approaches that have enabled the exquisite control over pore size and pore chemistry that affords highly selective binding sites. Whereas the structure-function relationships that have emerged offer important design principles, several development roadblocks remain to be overcome.
Diverse crystal engineering principles employed in the discovery of porous coordination networks for the selective separation of C2 gases reveal that control of pore size and pore chemistry emerges as the key to unlock their outstanding performances.
Electrochemical CO2 reduction offers a compelling route to mitigate atmospheric CO2 concentration and store intermittent renewable energy in chemical bonds. Beyond C1, C2+ feedstocks are more ...desirable due to their higher energy density and more significant market need. However, the CO2‐to‐C2+ reduction suffers from significant barriers of CC coupling and complex reaction pathways. Due to remarkable tunability over morphology/pore architecture along with great feasibility of functionalization to modify the electronic and geometric structures, carbon materials, serving as active components, supports, and promoters, provide exciting opportunities to tune both the adsorption properties of intermediates and the local reaction environment for the CO2 reduction, offering effective solutions to enable CC coupling and steer C2+ evolution. However, general design principles remain ambiguous, causing an impediment to rational catalyst refinement and application thrusts. This review clarifies insightful design principles for advancing carbon materials. First, the current performance status and challenges are discussed and effective strategies are outlined to promote C2+ evolution. Further, the correlation between the composition, structure, and morphology of carbon catalysts and their catalytic behavior is elucidated to establish catalytic mechanisms and critical factors determining C2+ performance. Finally, future research directions and strategies are envisioned to inspire revolutionary advancements.
Carbon‐based catalysts have shown great promise for tuning reaction pathways and the local reaction environment for electrocatalytic CO2 reduction, offering effective solutions to steer valuable multicarbon product evolution. This review provides critical insights and perspectives on design principles, catalytic mechanisms, and future research directions to inspire the rational design of advanced carbon materials for converting CO2 into value‐added feedstocks.
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Metal‐organic frameworks (MOFs) have been important electrochemical energy storage (EES) materials because of their rich species, large specific surface area, high porosity and rich active sites. ...Nevertheless, the poor conductivity, low mechanical and electrochemical stability of pristine MOFs have hindered their further applications. Although single component MOF derivatives have higher conductivity, self‐aggregation often occurs during preparation. Composite design can overcome the shortcomings of MOFs and derivatives and create synergistic effects, resulting in improved electrochemical properties for EES. In this review, recent applications of MOF composites and derivatives as electrodes in different types of batteries and supercapacitors are critically discussed. The advantages, challenges, and future perspectives of MOF composites and derivatives have been given. This review may guide the development of high‐performance MOF composites and derivatives in the field of EES.
Recent applications of metal–organic framework (MOF) composites and derivatives as electrodes in different types of batteries and supercapacitors are presented. Effective material design strategies are raised for obtaining high‐performance MOF composites for electrochemical energy storage (EES) devices. The current issues and future perspectives of MOF composites and derivatives in the field have been given to guide their development in future.
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Conspectus Since the seminal work of Tang and Vanslyke in 1987 on small-molecule emitters and that of Friend and co-workers in 1990 on conjugated-polymer emitters, organic light-emitting diodes ...(OLEDs) have attracted much attention from academia as well as industry, as the OLED market is estimated to reach the $30 billion mark by the end of 2018. In these first-generation organic emitters, on the basis of simple spin statistics, electrical excitation resulted in the formation of ∼25% singlet excitons and ∼75% triplet excitons. Radiative decay of the singlet excitons to the singlet ground state leads to a prompt fluorescence emission, while the triplet excitons only lead to weak phosphorescence due to the very small spin–orbit couplings present in purely organic molecules. The consequence is a ca. 75% energy loss, which triggered wide-ranging efforts to try and harvest as many of the triplet excitons as possible. In 1998, Thompson, Forrest, and their co-workers reported second-generation OLED emitters based on coordination complexes with heavy transition metals (e.g., iridium or platinum). Here, the triplet excitons stimulate efficient and fast phosphorescence due to the strong spin–orbit couplings enabled by the heavy-metal atoms. Internal quantum efficiencies (IQE) up to 100% have been reported, which means that for every electron injected into the device, a photon is emitted. While these second-generation emitters are those mainly exploited in current OLED applications, there is strong impetus from both cost and environmental standpoints to find new ways of exploiting purely organic emitters, which in addition can offer greater flexibility to fine-tune the electronic and optical properties by exploiting the synthetic organic chemistry toolbox. In 2012, Adachi and co-workers introduced a promising strategy, based on thermally activated delayed fluorescence (TADF), to harvest the triplet excitons in purely organic molecular materials. These materials now represent the third generation of OLED emitters. Impressive photophysical properties and device performances have been reported, with internal quantum efficiencies also reaching nearly 100%. Our objectives in this Account are threefold: (i) to lay out a comprehensive description, at the molecular level, of the fundamental photophysical processes behind TADF emitters; (ii) to discuss some of the challenges facing the design of TADF emitters, such as the need to balance the efficiency of thermal activation of triplet excitons into the singlet manifold with the efficiency of radiative transition to the ground state; and (iii) to highlight briefly some of the recent molecular-design strategies that pave the way to new classes of TADF materials.
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Metal–organic frameworks (MOFs), known as porous coordination polymers, have attracted intense interest as electrode materials for supercapacitors (SCs) owing to their advantageous features including ...high surface area, tunable porous structure, structural diversity, etc. However, the insulating nature of most MOFs has impeded their further electrochemical applications. A common solution for this issue is to transform pristine MOFs into more stable and conductive metal compounds/porous carbon materials through pyrolysis, which however losses the inherent merits of MOFs. To find a consummate solution, recently a surge of research devoted to improving the electrical conductivity of pristine MOFs for SCs has been carried out. In this review, the most related research work on pristine MOF‐based materials is reviewed and three effective strategies (chemical structure design of conductive MOFs (c‐MOFs), composite design, and binder‐free structure design) which can significantly increase their conductivity and consequently the electrochemical performance in SCs are proposed. The conductivity enhancement mechanism in each approach is well analyzed. The representative research works on using pristine MOFs for SCs are also critically discussed. It is hoped that the new insights can provide guidance for developing high‐performance electrode materials based on pristine MOFs with high conductivity for SCs in the future.
Three effective strategies (chemical structure design of conductive metal–organic frameworks (MOFs), composite design, and binder‐free structure design) are proposed to increase the conductivity and consequently the electrochemical performance of pristine MOFs in supercapacitors (SCs) through reviewing the works on pristine MOF‐based materials. The conductivity enhancement mechanism using pristine MOFs for SCs are also critically discussed.
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In this review, we discuss the clinical and electrophysiological effects and the future directions of invasive and noninvasive brain stimulations in Parkinson's disease (PD). Deep brain stimulation ...(DBS) can improve motor symptoms in moderate to advanced PD. However, the optimal stimulation paradigm for nonmotor symptoms (NMS), freezing of gait, and the optimal timing of DBS are still under investigation. The findings of pathological oscillations and abnormal frequency to amplitude coupling provide models to develop adaptive DBS. Transcranial magnetic stimulation (TMS) revealed abnormal cortical excitability and plasticity in PD. Consecutive sessions of high‐frequency, repetitive TMS on the motor cortex showed promising results. Paired TMS and DBS at specific times provided a novel way to investigate PD pathophysiology and have potential as a future treatment. Transcranial direct current stimulation or transcranial alternating current stimulation with multifocal electrodes or at specific phases of oscillation are also potential future strategies.
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