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Developing highly active materials that efficiently utilize solar spectra is crucial for photocatalysis, but still remains a challenge. Here, we report a new donor-acceptor (D-A) covalent organic framework (COF) with a wide absorption range from 200 nm to 900 nm (ultraviolet-visible-near infrared light). We find that the thiophene functional group is accurately introduced into the electron acceptor units of TpDPP-Py (TpDPP: 5,5'-(2,5-bis(2-ethylhexyl)−3,6-dioxo-2,3,5,6-tetrahydropyrrolo [3,4-c]pyrrole-1,4-diyl)bis(thiophene-2-carbaldehyde), Py: 1,3,6,8-tetrakis(4-aminophenyl)pyrene) COFs not only significantly extends its spectral absorption capacity but also endows them with two-photon and three-photon absorption effects, greatly enhancing the utilization rate of sunlight. The selective coupling of benzylamine as the target reactant is used to assess the photocatalytic activity of TpDPP-Py COFs, showing high photocatalytic conversion of 99% and selectivity of 98% in 20 min. Additionally, the TpDPP-Py COFs also exhibit the universality of photocatalytic selective coupling of other imine derivatives with ~100% conversion efficiency. Overall, this work brings a significant strategy for developing COFs with a wide absorption range to enhance photocatalytic activity. Creating highly active materials that effectively harness solar spectra is essential for photocatalysis, though challenging. Here the authors introduce a novel donor-acceptor covalent organic framework with a broad absorption range of 200 nm to 900 nm, achieving efficient artificial photocatalytic amine coupling. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) printing, otherwise known as additive manufacturing in a non-technical context, is becoming increasingly popular in the field of dentistry. As an essential step in the 3D printing process, postwashing with organic solvents can damage the printed resin polymer and possibly pose a risk to human health. The development of water-washable dental resins means that water can be used as a washing agent. However, the effects of washing agents and washing times on the mechanical and biocompatibility properties of water-washable resins remain unclear. This study investigated the impact of different washing agents (water, detergent, and alcohol) and washing time points (5, 10, 20, and 30 min) on the flexural strength, Vickers hardness, surface characterization, degree of conversion, biocompatibility, and monomer elution of 3D printed samples. Using water for long-term washing better preserved the mechanical properties, caused a smooth surface, and improved the degree of conversion, with 20 min of washing with water achieving the same biological performance as organic solvents. Water is an applicable agent option for washing the 3D printing water-washable temporary crown and bridge resin in the postwashing process. This advancement facilitates the development of other water-washable intraoral resins and the optimization of clinical standard washing guidelines. [ABSTRACT FROM AUTHOR]

Edge structures, thiophene adsorption and hydrodesulfurization (HDS) mechanisms are investigated on the S-edge of triangular MoS2 nanoclusters using density functional theory. The calculated formation energies for different S coverages on the S-edge suggest that the formation of coordinative unsaturated site at the vertex and edge-I (close to the vertex) sites is preferred over the edge-II (away from the vertex) sites. The adsorption of thiophene on the top site of Mo atom mainly occurs at the edge-I, whereas bridge adsorption occurs at the edge-II. The 92% and 50% S-edge coverages involve relatively larger adsorption energies (− 0.68 and − 0.79 eV) among all the possible adsorption configurations. On the S edge with 92% S coverage, the hydrogenation route is more favorable, producing 1-butene. On the S edge with 50% S coverage, the direct desulfurization route is preferred, yielding butadiene. These findings deepen the understanding of edge structures of MoS2 nanoclusters and the corresponding HDS mechanisms for MoS2-based HDS catalysts. [ABSTRACT FROM AUTHOR]

Awareness of the adverse impact of air pollution on attention-related performance such as learning and driving is rapidly growing. However, there is still little known about the underlying neurocognitive mechanisms. Using an adapted dot-probe task paradigm and event-related potential (ERP) technique, we investigated how visual stimuli of air pollution influence the attentional allocation process. Participants were required to make responses to the onset of a target presented at the left or right visual field. The probable location of the target was forewarned by a cue (pollution or clean air images), appearing at either the target location (attention-holding trials) or the opposite location (attention-shifting trials). Behavioral measures showed that when cued by pollution images, subjects had higher response accuracy in attention-shifting trials. ERP analysis results revealed that after the cue onset, pollution images evoked lower N300 amplitudes, indicating less attention-capturing effects of dirty air. After the target onset, pollution cues were correlated with the higher P300 amplitudes in attention-holding trials but lower amplitudes in attention-shifting trials. It indicates that after visual exposure to air pollution, people need more neurocognitive resources to maintain attention but less effort to shift attention away. The findings provide the first neuroscientific evidence for the distracting effect of air pollution. We conclude with several practical implications and suggest the ERP technique as a promising tool to understand human responses to environmental stressors. [ABSTRACT FROM AUTHOR]

Stretchable neuromorphic optoelectronics present tantalizing opportunities for intelligent vision applications that necessitate high spatial resolution and multimodal interaction. Existing neuromorphic devices are either stretchable but not reconcilable with multifunctionality, or discrete but with low-end neurological function and limited flexibility. Herein, we propose a defect-tunable viscoelastic perovskite film that is assembled into strain-insensitive quasi-continuous microsphere morphologies for intrinsically stretchable neuromorphic vision-adaptive transistors. The resulting device achieves trichromatic photoadaptation and a rapid adaptive speed (<150 s) beyond human eyes (3 ~ 30 min) even under 100% mechanical strain. When acted as an artificial synapse, the device can operate at an ultra-low energy consumption (15 aJ) (far below the human brain of 1 ~ 10 fJ) with a high paired-pulse facilitation index of 270% (one of the best figures of merit in stretchable synaptic phototransistors). Furthermore, adaptive optical imaging is achieved by the strain-insensitive perovskite films, accelerating the implementation of next-generation neuromorphic vision systems.Wearable neuromorphic optoelectronics require stretchable photosensitive materials and multifunctional integration. Here, authors develop intrinsically stretchable neuromorphic vision-adaptive transistors for skin-like neuromorphic vision systems. [ABSTRACT FROM AUTHOR]

Challenges associated with stretchable optoelectronic devices, such as pixel size, power consumption and stability, severely brock their realization in high-resolution digital imaging. Herein, we develop a universal detachable interface technique that allows uniform, damage-free and reproducible integration of micropatterned stretchable electrodes for pixel-dense intrinsically stretchable organic transistor arrays. Benefiting from the ideal heterocontact and short channel length (2 μm) in our transistors, switching current ratio exceeding 106, device density of 41,000 transistors/cm2, operational voltage down to 5 V and excellent stability are simultaneously achieved. The resultant stretchable transistor-based image sensors exhibit ultrasensitive X-ray detection and high-resolution imaging capability. A megapixel image is demonstrated, which is unprecedented for stretchable direct-conversion X-ray detectors. These results forge a bright future for the stretchable photonic integration toward next-generation visualization equipment. Pixel size, power consumption, and stability of stretchable optoelectronic devices limit their application in digital imaging. Bian et al. developed a universal detachable interface technique for damage-free micropattern, reproducible transfer and ideal heterocontact of intrinsically stretchable electrodes. [ABSTRACT FROM AUTHOR]

Nanoclusters with atomically precise structures and discrete energy levels are considered as nanoscale semiconductors for artificial intelligence. However, nanocluster electronic engineering and optoelectronic behavior have remained obscure and unexplored. Hence, we create nanocluster photoreceptors inspired by mantis shrimp visual systems to satisfy the needs of compact but multi-task vision hardware and explore the photo-induced electronic transport. Wafer-scale arrayed photoreceptors are constructed by a nanocluster-conjugated molecule heterostructure. Nanoclusters perform as an in-sensor charge reservoir to tune the conductance levels of artificial photoreceptors by a light valve mechanism. A ligand-assisted charge transfer process takes place at nanocluster interface and it features an integration of spectral-dependent visual adaptation and circular polarization recognition. This approach is further employed for developing concisely structured, multi-task, and compact artificial visual systems and provides valuable guidelines for nanocluster neuromorphic devices. All-in-one multi-task photoperception is desirable for artificial vision systems. Wen et al. present wafer-scale high density integration of artificial photoreceptors that combine photoadaptation and circular polarized light vision, enabled by chiral-nanocluster-conjugated molecule heterostructures. [ABSTRACT FROM AUTHOR]

Metal-nitrogen-carbon catalysts with hierarchically dispersed porosity are deemed as efficient geometry for oxygen reduction reaction (ORR). However, catalytic performance determined by individual and interacting sites originating from structural heterogeneity is particularly elusive and yet remains to be understood. Here, an efficient hierarchically porous Fe single atom catalyst (Fe SAs-HP) is prepared with Fe atoms densely resided at micropores and mesopores. Fe SAs-HP exhibits robust ORR performance with half-wave potential of 0.94 V and turnover frequency of 5.99 e−1s−1site−1 at 0.80 V. Theoretical simulations unravel a structural heterogeneity induced optimization, where mesoporous Fe-N4 acts as real active centers as a result of long-range electron regulation by adjacent microporous sites, facilitating O2 activation and desorption of key intermediate *OH. Multilevel operando characterization results identify active Fe sites undergo a dynamic evolution from basic Fe-N4 to active Fe-N3 under working conditions. Our findings reveal the structural origin of enhanced intrinsic activity for hierarchically porous Fe-N4 sites.Here, authors report an inter-site structural heterogeneity induced effect of hierarchical single atom Fe catalysts for robust oxygen reduction. Dynamic evolutions and insights into structure-activity relationship are presented. [ABSTRACT FROM AUTHOR]

We investigated the critical dynamical scalarization and descalarization of black holes within the framework of the Einstein-Maxwell-scalar theory featuring higher-order coupling functions. Both the critical scalarization and descalarization displayed first-order phase transitions. When examining the nonlinear dynamics near the threshold, we always observed critical solutions that are linearly unstable static scalarized black holes. The critical dynamical scalarization and descalarization share certain similarities with the type I critical gravitational collapse. However, their initial configurations, critical solutions, and final outcomes differ significantly. To provide further insights into the dynamical results, we conducted a comparative analysis involving static solutions and perturbative analysis. [ABSTRACT FROM AUTHOR]

We study the critical dynamics in scalarization and descalarization in the fully nonlinear dynamical evolution in the class of theories with a scalar field coupling with both Gauss-Bonnet (GB) invariant and Ricci scalar. We explore the manner in which the GB term triggers black hole (BH) scalarization. A typical type I critical phenomenon is observed, in which an unstable critical solution emerges at the threshold and acts as an attractor in the dynamical scalarization. For the descalarization, we reveal that a marginally stable attractor exists at the threshold of the first-order phase transition in shedding off BH hair. This is a new type I critical phenomenon in the BH phase transition. Implications of these findings are discussed from the perspective of thermodynamic properties and perturbations for static solutions. We examine the effect of scalar-Ricci coupling on the hyperbolicity in the fully nonlinear evolution and observe that such coupling can suppress the elliptic region and enlarge parameter space in computations. [ABSTRACT FROM AUTHOR]

(Hetero)cycloarenes possessing rigid molecular skeletons and large π-systems are the potential active materials in various electronic devices. However, the development of their organic electronics still lags far behind the synthetic chemistry. Herein, in order to bridge this gap, we reported the study of organic semiconductor materials based on heterocycloarenes in detail about the relationship between structure, properties, and device performance. Three varying straight alkyl chain substituted butterfly-shaped heterocycloarenes PTZs were strategically synthesized. Compared with bulky aryl(mesityl) substituted PTZ1, PTZs show additional self-assembly behavior. Concentration-dependent 1H NMR spectra indicated that the self-assembly behavior can be modulated by the alkyl chain length. Medium alkyl chain length substituted heterocycloarene PTZ-C6 showed the strongest association constants of 490 M−1 in solution, and a similar trend was also observed in solid state by thin film absorption spectra. Remarkably, despite the nonplanar conjugated backbones, solution-processing thin film transistor based on PTZ-C6 exhibits hole mobility up to 0.13 cm2 V−1 s−1 and considerable current on/off ratio of 105. Our study demonstrates that substituent engineering of heterocycloarenes is a powerful strategy for modulating self-assembling structures and promoting transistor device performance. [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to investigate the clinicopathological features of idiopathic membranous nephropathy (IMN) with hyperuricemia (HUA), together with associated factors within 10 years in a single centre in Shandong Province. Methods: In this cross-sectional study, we analysed the clinical and pathological data of 694 IMN patients in our hospital from January 2010 to December 2019. Based on serum uric acid (UA) level, the patients were divided into hyperuricemia (HUA) group (n = 213) and normal serum uric acid (NUA) group (n = 481). Multi-variate logistic regression analysis was conducted on to screen the associated factors of HUA. Results: 213 (30.69%) IMN patient were complicated with HUA. Compared with the patients with NUA, significant increase was noticed in the proportion of patients showing edema, concurrent hypertensive disease or diabetes mellitus (DM), as well as the proportion of positive glomerular capillary loop IgM and positive C1q in the HUA group (P < 0.05). In addition, significant increase was noticed in the 24 h urine protein, serum creatinine, triglycerides, complement C3 and complement C4 in HUA group compared with those of NUA group (all P < 0.05). With gender as a control factor, multi-variate logistic regression analysis showed positive glomerular capillary loops C1q, serum albumin, serum phosphorus were associated with IMN combined with HUA in male, while triglycerides and serum creatinine were associated with IMN combined with HUA in female counterparts. Conclusion: About 30.69% of IMN patients had HUA, with a male predominance than female. In male patients with IMN, higher serum albumin level and serum phosphorus level were associated with higher incidence of HUA, while in female IMN patients, higher serum triglyceridemia and serum creatinine level were associated with higher incidence of HUA. Therefore, it can be targeted to prevent the occurrence of HUA in IMN. [ABSTRACT FROM AUTHOR]

Intrinsically stretchable semiconducting polymers are promising candidates for developing wearable electronics, but remain underdeveloped because the correlation between the microstructural evolution during stretching and the resultant charge transport is not clearly understood. In this study, we clarify the impact of molecular orientation on the dynamic performance of stretched semiconducting polymers, controlling molecular orientations via solvent-dependent spin-coating. We found that strain-enhanced electrical performance is feasible by quelling disorders within the face-on-packed aggregates. Strain facilitates 3D ordering in face-on-packed films, but increase the π-π orientation disorders and lamellar dislocation in the edge-on analogue, which contribute inversely to the charge transport. Consequently, the face-on samples maintain strain-resistant energetic disorder and a 1.5× increase in on-current, achieving a 10-times-higher retention than the edge-on analogue upon 100% strain. Furthermore, we developed a reliable way for measuring the photoelectrical stretchability of semiconducting polymer. This study contributes to developing high-performance stretchable semiconducting polymers. [ABSTRACT FROM AUTHOR]

Polymer nanowire (NW) organic field-effect transistors (OFETs) integrated on highly aligned large-area flexible substrates are candidate structures for the development of high-performance flexible electronics. This work presents a universal technique, coaxial focused electrohydrodynamic jet (CFEJ) printing technology, to fabricate highly aligned 90-nm-diameter polymer arrays. This method allows for the preparation of uniformly shaped and precisely positioned nanowires directly on flexible substrates without transfer, thus ensuring their electrical properties. Using indacenodithiophene-co-benzothiadiazole (IDT-BT) and poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8-BT) as example materials, 5 cm2 arrays were prepared with only minute size variations, which is extremely difficult to do using previously reported methods. According to 2D-GIXRD analysis, the molecules inside the nanowires mainly adopted face-on π-stacking crystallite arrangements. This is quite different from the mixed arrangement of thin films. Nanowire-based OFETs exhibited a high average hole mobility of 1.1 cm2 V−1 s−1 and good device uniformity, indicating the applicability of CFEJ printing as a potential batch manufacturing and integration process for high-performance, scalable polymer nanowire-based OFET circuits. This technique can be used to fabricate various polymer arrays, enabling the use of organic polymer semiconductors in large-area, high-performance electronic devices and providing a new path for the fabrication of flexible displays and wearable electronics in the future. [ABSTRACT FROM AUTHOR]

Post-translational modifications of proteins such as protein ubiquitination are crucial for regulating conformation, stability and localization of the modified protein. Ubiquitin-specific protease 2 (USP2), a multifunctional cysteine protease is reported to be a key regulator of ubiquitylation events in numerous oncogenic proteins e.g., fatty acid synthetase, Mdm2, EGFR, cyclin A1, and cyclin-D1, etc. Thus targeting USP2 is a promising strategy for cancer therapy. USP2 is characterized by a catalytic triad comprising of cysteine, histidine and aspartic acid residues. Five residues including three from the catalytic triad and two from outside of the catalytic triad have been reported as a catalytic site of USP2 that catalyze hydrolysis and stabilizes the oxyanion formed in the intermediate step of catalysis. Here, we report two more novel residues (L269 and Y558) on USP2 involved in the catalysis of Ubiquitin using computational alanine scanning (CAS) followed by molecular dynamic simulation studies. The results obtained from CAS were further validated by a highly reliable, time- and cost-effective SDS-PAGE-based kinetics assay using UBA52 which is a natural substrate of USP2. Our results showed that mutating L269 and Y558 significantly compromised the catalytic efficiency of USP2 in hydrolyzing UBA52 which can further be extended to rational drug design of USP2 selective inhibitors and to explore the catalytic sites of other USPs. Two novel residues take part in catalytic activity of USP2 which were depicted by MD Simulations and were further validated by novel SDS-PAGE-based reliable time- and cost-effective kinetics assay. [ABSTRACT FROM AUTHOR]

The catalytic oxidation of volatile organic compounds (VOCs) is considered a feasible method for VOCs treatment by virtue of its low technical cost, high economic efficiency, and low additionally produced pollutants, which is of important social value. Single-atom catalysts (SACs) with 100% atom utilization and uniform active sites usually have high activity and high product selectivity, and promise a broad range of applications. Precise regulation of the microstructures of SACs by means of defect engineering, interface engineering, and electronic effects can further improve the catalytic performance of VOCs oxidation. In this review, we introduce the mechanisms of VOCs oxidation, and systematically summarize the recent research progress of SACs in catalytic VOCs total oxidation into CO2 and H2O, and then discuss the effects of various structural regulation strategies on the catalytic performance. Finally, we summarize the current problems yet to be solved and challenges currently faced in this field, and propose future design and research ideas for SACs in catalytic oxidation of VOCs. [ABSTRACT FROM AUTHOR]

The development of readily accessible high-mobility n-type semiconducting polymers is in great demand for realizing high-performance p-n junction-based organic electronics. In this study, we demonstrate that with the combination of dual-acceptor strategy and C-H direct arylation polymerization (DArP), unipolar n-type semiconducting polymers can be conveniently synthesized. By tuning the monomer concentration, three dual-acceptor polymers, namely, poly(naphthalene diimide-alt-dithiophenyl pyrrolopyrrole-dione) (PNDI-DPP), poly(naphthalene diimide-alt-dithiophenyl isoindigo) (PNDI-IID), and poly (naphthalene diimide-alt-dithiophenyl bezothiadiazole) (PNDI-BT) can be obtained via C-H activation with decent number average molecular weight of ∼10 to 30 kg mol−1 and relatively narrow polydispersity index of ∼2. In addition, these polymers are defect-free in nature as evidenced by the nuclear magnetic resonance. Moreover, we attribute the different molar masses of the three copolymers under the same DArP condition to the different α-C-H acidity, which may stem from different electron-withdrawing capability of the hydrogenated acceptor units. Furthermore, the influence of the hydrogenated acceptor monomers on the optical, electrochemical and charge transporting properties is comprehensively studied. Among the three dual-acceptor polymers, PNDI-BT demonstrates the highest electron mobilities of up to 0.6 cm2 V−1 s−1 in unipolar n-type organic transistors because of its relatively planar backbone, larger overlaps of the lowest unoccupied molecular orbital and strong H-aggregation. Note that the transistor performance of PNDI-BT synthesized via C-H activation in this study is at least comparable to the one made by conventional C(sp2)-C(sp2) Stille or Suzuki cross-coupling polymerization. This study demonstrates the presented protocol can be a useful platform for sustainable and convenient synthesis of high-performance n-type semiconducting polymers. [ABSTRACT FROM AUTHOR]

We study dynamic processes through which the scalar hair of black holes is generated or detached in a theory with a scalar field non-minimally coupled to Gauss-Bonnet and Ricci scalar invariants. We concentrate on the nonlinear temporal evolution of a far-from-equilibrium gravitational system. In our simulations, we choose the initial spacetime to be either a bald Schwarzschild or a scalarized spherically symmetric black hole. Succeeding continuous accretion of the scalar field onto the original black hole, the final fate of the system displays intriguing features, which depend on the initial configurations, strengths of the perturbation, and specific metric parameters. In addition to the scalarization process through which the bald black hole addresses scalar hair, we observe the dynamical descalarization, which removes scalar hair from an original hairy hole after continuous scalar field accretion. We examine the temporal evolution of the scalar field, the metrics, and the Misner-Sharp mass of the spacetime and exhibit rich phase structures through nonlinear dynamical processes. [ABSTRACT FROM AUTHOR]

Conductive metal-organic frameworks (MOFs) have performed well in the fields of energy and catalysis, among which two-dimensional (2D) and three-dimensional (3D) MOFs are well-known. Here, we have synthesized a one-dimensional (1D) conductive metal-organic framework (MOF) in which hexacoordinated 1,5-Diamino-4,8-dihydroxy-9,10-anthraceneedione (DDA) ligands are connected by double Cu ions, resulting in nanoribbon layers with 1D π-d conjugated nanoribbon plane and out-of-plane π-π stacking, which facilitates charge transport along two dimensions. The DDA-Cu as a highly conductive n-type MOF has high crystalline quality with a conductivity of ~ 9.4 S·m−1, which is at least two orders of magnitude higher than that of conventional 1D MOFs. Its electrical band gap (Eg) and exciton binding energy (Eb) are approximately 0.49 eV and 0.3 eV, respectively. When utilized as electrode material in a supercapacitor, the DDA-Cu exhibits good charge storage capacity and cycle stability. Meanwhile, as thse active semiconductor layer, it successfully simulates the artificial visual perception system with excellent bending resistance and air stability as a MOF-based flexible optoelectronic synaptic case. The controllable preparation of high-quality 1D DDA-Cu MOF may enable new architectural designs and various applications in the future. 2D and 3D conductive MOFs have performed well in the fields of energy and catalysis. Here, authors synthesise a 1D conductive MOF in which DDA ligands are connected by double Cu ions, forming nanoribbon layers with π-d conjugated nanoribbon planes and out-of-plane π-π stacking, which facilitates charge transport along two dimensions. [ABSTRACT FROM AUTHOR]

Hydrogen evolution reaction (HER) in neutral media is of great practical importance for sustainable hydrogen production, but generally suffers from low activities, the cause of which has been a puzzle yet to be solved. Herein, by investigating the synergy between Ru single atoms (RuNC) and RuSex cluster compounds (RuSex) for HER using ab initio molecular dynamics, operando X-ray absorption spectroscopy, and operando surface-enhanced infrared absorption spectroscopy, we establish that the interfacial water governs neutral HER. The rigid interfacial water layer in neutral media would inhibit the transport of H2O*/OH* at the electrode/electrolyte interface of RuNC, but the RuSex can promote H2O*/OH* transport to increase the number of available H2O* on RuNC by disordering the interfacial water network. With the synergy of RuSex and RuNC, the resulting neutral HER performance in terms of mass-specific activity is 6.7 times higher than that of 20 wt.% Pt/C at overpotential of 100 mV. Understanding the slow kinetics of hydrogen evolution reaction in neutral media is of fundamental importance for the rational design of high-performance electrocatalysts for hydrogen energy. Here, by studying Ru single atom and RuSex cluster, the authors report how the rate of hydrogen evolution reaction activity in neutral media is governed by interfacial water. [ABSTRACT FROM AUTHOR]

Large area and highly aligned polymer semiconductor sub-microwires were fabricated using the coaxial focused electrohydrodynamic jet printing technology. As indicated by the results, the sub-microwire arrays have smooth morphology, well reproducibility and controllable with a width of ~110 nm. Analysis shows that the molecular chains inside the sub-microwires mainly exhibited edge-on arrangement and the π-stacking direction (010) of the majority of crystals is parallel to the long axis of the sub-microwires. Sub-microwires based organic field effect transistors showed high mobility with an average of 1.9 cm2 V−1 s−1, approximately 5 times higher than that of thin film based organic field effect transistors. In addition, the number of sub-microwires can be conveniently controlled by the printing technique, which can subsequently concisely control the performance of organic field effect transistors. This work demonstrates that sub-microwires fabricated by the coaxial focused electrohydrodynamic jet printing technology create an alternative path for the applications of high-performance organic flexible device. Here, the authors fabricate large area and highly aligned polymer semiconductor sub-microwires arrays via coaxial focused electrohydrodynamic jet printing technology, achieving high on/off ratio and average mobility that is 5x higher than that of thin film based organic field effect transistors. [ABSTRACT FROM AUTHOR]

The construction of robust coupling catalysts for accelerating electrocatalytic oxygen reduction reaction (ORR) through the modulation of the electronic structure and local atomic configuration is critical but remains challenging. Herein, we report a facile and effective isolation-polymerization-pyrolysis (IPP) strategy for high-precision synthesis of single-atomic Mn sites coupled with Fe3C nanoparticles encapsulated in N-doped porous carbon matrixes (Mn SAs/Fe3C NPs@NPC) catalyst derived from predesigned bimetallic Fe/Mn polyphthalocyanine (FeMn-BPPc) conjugated polymer networks by solid-phase reaction approach. Benefiting from the synergistic effects between the single-atomic Mn-N4 sites and Fe3C NPs as well as the confinement effect of NPC, the Mn SAs/Fe3C NPs@NPC catalyst exhibited excellent electrocatalytic activity and stability for ORR. The assembled Zn-air battery displayed larger power density of 186 mW·cm−2 than that of Pt/C + Ir/C-based battery. It also exhibits excellent stability without obvious voltage change after 106 cycles with 36 h. Combing in-situ Raman spectra with in-situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) characterization results indicated that the Mn-N4 site as an active site for the O2 adsorption-activation process, which effectively facilitates the generation of key *OOH intermediates and *OH desorption to promote the multielectron reaction kinetics. Theoretical calculation reveals that the excellent electrocatalytic performance originates from the charge redistribution and the d orbital shift resulting from Mn-Fe bond, which buffers the activity of ORR through the electron reservoir capable of electron donation or releasing. This work paves a novel IPP strategy for constructing high-performance coupling electrocatalyst towards the ORR for energy conversion devices. [ABSTRACT FROM AUTHOR]

Recent advances in organic electronics of novel materials and optoelectronic devices spark great interest in the design and synthesis of high-performance polymer semiconductors. During the last decade, isoindigo (IID) and its derivatives have sprung up as common electron-deficient building blocks and obtained extensive applications in organic field-effect transistors (OFETs). In this review, we first present the current status, basic principles, and general material design strategies for OFETs. Then, multiple IID-type acceptors, mature synthetic routes to monomers, and typical IIDs-based conjugated polymers are summarized. We also introduce side-chain engineering and cutting-edge applications, like stretchable transistors, sensing, active-matrix driving, etc., of the classic copolymer poly(isoindigo-co-bithiophene). Green polymerization approaches towards conjugated polymers incorporating IIDs are subsequently discussed for efficient polymerization. Finally, we conclude this review and propose in-depth prospects with respect to material synthesis and device applications. Undoubtedly, IIDs-based conjugated polymers would occupy a significant position in the future of organic electronics, due to diverse building blocks, mature synthetic pathways, tunable side chains, and unique optoelectronic properties. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) carbon materials, such as graphene, have attracted particular attention owing to the exceptional carrier transport characteristics that arise from the unique π-electron system in their conjugated carbon network structure1–4. To complement zero-bandgap graphene, material scientists have devoted considerable effort to identifying 2D carbon materials5–8. However, it is a challenge to prepare large-sized single-crystal 2D carbon materials with moderate bandgaps5,9. Here we prepare a single-crystal 2D carbon material, namely monolayer quasi-hexagonal-phase fullerene (C60), with a large size via an interlayer bonding cleavage strategy. In this monolayer polymeric C60, cluster cages of C60 are covalently bonded with each other in a plane, forming a regular topology that is distinct from that in conventional 2D materials. Monolayer polymeric C60 exhibits high crystallinity and good thermodynamic stability, and the electronic band structure measurement reveals a transport bandgap of about 1.6 electronvolts. Furthermore, an asymmetric lattice structure endows monolayer polymeric C60 with notable in-plane anisotropic properties, including anisotropic phonon modes and conductivity. This 2D carbon material with a moderate bandgap and unique topological structure offers an interesting platform for potential application in 2D electronic devices.Using an interlayer bonding cleavage strategy, a two-dimensional monolayer fullerene network is prepared; its moderate bandgap makes it a potential candidate for use in two-dimensional electronic devices. [ABSTRACT FROM AUTHOR]

Electrocatalytic CO2 reduction reaction (CO2RR) is considered an efficient way to convert CO2 into high-value-added chemicals, and thus is of significant social and economic value. Metal single-atomic site catalysts (SASCs) generally have excellent selectivity because of their 100% atomic utilization and uniform structure of active sites, and thus promise a broad range of applications. However, SASCs still face challenges such as low intrinsic activity and low density of active sites. Precise regulation of the microstructures of SASCs is an effective method to improve their CO2RR performance and to obtain deep reduction products. In this article, we systematically summarize the current research status of SASCs developed for highly efficient catalysis of CO2RR, discuss the various structural regulation methods for enhanced activity and selectivity of SASCs for CO2RR, and review the application of in-situ characterization technologies in the SASC-catalyzed CO2RR. We then discuss the problems yet to be solved in this area, and propose the future directions of the research on the design and application of SASCs for CO2RR. [ABSTRACT FROM AUTHOR]

In the epitaxial growth of two-dimensional (2D) materials on substrates, 2D polycrystals with various shapes have been broadly observed, but their formation mechanisms are still highly elusive. Here we present a complete study on the formation mechanisms of various 2D polycrystals. The structures of the 2D polycrystals are dependent on the symmetries of both the 2D material and the substrate. We build four complete libraries of 2D polycrystals for (i) threefold symmetric 2D materials on two- or six-fold symmetric substrates (i.e., family-III/II or -III/VI), (ii) threefold symmetric 2D materials on fourfold symmetric substrates (i.e. family-III/IV), (iii) fourfold symmetric 2D materials on three- or six-fold symmetric substrates (i.e., family-IV/III or -IV/VI), and (iv) sixfold symmetric 2D materials on fourfold symmetric substrates (i.e., family-VI/IV), respectively. The four libraries of 2D polycrystals are consistent with many existing experimental observations and can be used to guide the experimental synthesis of various 2D polycrystals. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) can exhibit high specific surface area and catalytic activity, but traditional solution-based synthesis methods often lead to insoluble and infusible powders or fragile films on solution surface. Herein we report large-area –C=N– linked two-dimensional (2D) COF films with controllable thicknesses via vapor induced conversion in a chemical vapor deposition (CVD) system. The assembly process is achieved by reversible Schiff base polycondensation between PyTTA film and TPA vapor, which results in a uniform organic framework film directly on growth substrate, and is driven by π‐π stacking interactions with the aid of water and acetic acid. Wafer-scale 2D COF films with different structures have been successfully synthesized by adjusting their building blocks, suggesting its generic applicability. The carrier mobility of PyTTA-TPA COF films can reach 1.89 × 10−3 cm2 V−1 s−1. When employed as catalysts in hydrogen evolution reaction (HER), they show high electrocatalytic activity compared with metal-free COFs or even some metallic catalysts. Our results represent a versatile route for the direct construction of large-area uniform 2D COF films on substrates towards multi-functional applications of 2D π‐conjugated systems. Solution-based synthesis of covalent organic frameworks (COFs) often leads to insoluble powders or fragile films on solution surfaces. Here, the authors report large-area two-dimensional (2D) COF films with controllable thicknesses via vapour induced conversion. [ABSTRACT FROM AUTHOR]

Flexible electronics have suggested tremendous potential to shape human lives for more convenience and pleasure. Strenuous efforts have been devoted to developing flexible organic field-effect transistor (FOFET) technologies for rollable displays, bendable smart cards, flexible sensors and artificial skins. However, these applications are still in a nascent stage for lack of standard high-performance material stacks as well as mature manufacturing technologies. In this review, the material choice and device design for FOFET devices and circuits, as well as the demonstrated applications are summarized in detail. Moreover, the technical challenges and potential applications of FOFETs in the future are discussed. [ABSTRACT FROM AUTHOR]

In principle, polymerization tends to produce amorphous or poorly crystalline materials. Efficiently producing high-quality single crystals by polymerization in solvent remains as an unsolved issue in chemistry, especially for covalent organic frameworks (COFs) with highly complex structures. To produce μm-sized single crystals, the growth time is prolonged to >15 days, far away from the requirements in practical applications. Here, we find supercritical CO2 (sc-CO2) accelerates single-crystal polymerization by 10,000,000 folds, and produces two-dimensional (2D) COF single crystals with size up to 0.2 mm within 2~5 min. Although it is the fastest single-crystal polymerization, the growth in sc-CO2 leads to not only the largest crystal size of 2D COFs, but also higher quality with improved photoconductivity performance. This work overcomes traditional concept on low efficiency of single-crystal polymerization, and holds great promise for future applications owing to its efficiency, industrial compatibility, environmental friendliness and universality for different crystalline structures and linkage bonds. Rapid growth of highly crystalline Covalent organic framework (COF) materials remains challenging. Here, the authors accelerate single-crystal polymerization using supercritical CO2 and realize the fabrication of two-dimensional COF single crystals within several minutes. [ABSTRACT FROM AUTHOR]

The cornerstones of emerging high-performance organic photovoltaic devices are bulk heterojunctions, which usually contain both structure disorders and bicontinuous interpenetrating grain boundaries with interfacial defects. This feature complicates fundamental understanding of their working mechanism. Highly-ordered crystalline organic p–n heterojunctions with well-defined interface and tailored layer thickness, are highly desirable to understand the nature of organic heterojunctions. However, direct growth of such a crystalline organic p–n heterojunction remains a huge challenge. In this work, we report a design rationale to fabricate monolayer molecular crystals based p–n heterojunctions. In an organic field-effect transistor configuration, we achieved a well-balanced ambipolar charge transport, comparable to single component monolayer molecular crystals devices, demonstrating the high-quality interface in the heterojunctions. In an organic solar cell device based on the p–n junction, we show the device exhibits gate-tunable open-circuit voltage up to 1.04 V, a record-high value in organic single crystalline photovoltaics. Realizing organic p–n junctions based on ordered crystalline materials with dimensions comparable to the exciton diffusion length of most organic semiconductors remains a challenge. Here, the authors report a strategy to form molecular monolayer crystal-based p–n junctions with thickness below 5 nm. [ABSTRACT FROM AUTHOR]

Large scale synthesis of high-efficiency bifunctional electrocatalyst based on cost-effective and earth-abundant transition metal for overall water splitting in the alkaline environment is indispensable for renewable energy conversion. In this regard, meticulous design of active sites and probing their catalytic mechanism on both cathode and anode with different reaction environment at molecular-scale are vitally necessary. Herein, a coordination environment inheriting strategy is presented for designing low-coordination Ni2+ octahedra (L-Ni-8) atomic interface at a high concentration (4.6 at.%). Advanced spectroscopic techniques and theoretical calculations reveal that the self-matching electron delocalization and localization state at L-Ni-8 atomic interface enable an ideal reaction environment at both cathode and anode. To improve the efficiency of using the self-modification reaction environment at L-Ni-8, all of the structural features, including high atom economy, mass transfer, and electron transfer, are integrated together from atomic-scale to macro-scale. At high current density of 500 mA/cm2, the samples synthesized at gram-scale can deliver low hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) overpotentials of 262 and 348 mV, respectively. [ABSTRACT FROM AUTHOR]

Data play an increasingly crucial role in decision evaluation. However, the noise and redundant information in the data create confusion to the decision makers. To solve this problem, this paper creates a new attribute reduction model based on technique for order preference by similarity to an ideal solution (TOPSIS), grey correlation analysis and coefficient of variation approaches. First, we obtain the time weights of panel data in different years by TOPSIS and then transfer the panel data into a cross-sectional data matrix. Second, we delete the overlapping attributes by grey correlation analysis method. Third, we use the coefficient of variation to select the attributes with the highest information content. Finally, the proposed attribute reduction model has been varied based on the green economy evaluation data of 15 sub-provincial cities in China. The experimental findings provide decision-making reference for the local government policymakers to adjust or formulate green economic development strategies. [ABSTRACT FROM AUTHOR]

Inflammasomes are important for host defence against pathogens and homeostasis with commensal microbes. Here, we show non-haemolytic enterotoxin (NHE) from the neglected human foodborne pathogen Bacillus cereus is an activator of the NLRP3 inflammasome and pyroptosis. NHE is a non-redundant toxin to haemolysin BL (HBL) despite having a similar mechanism of action. Via a putative transmembrane region, subunit C of NHE initiates binding to the plasma membrane, leading to the recruitment of subunit B and subunit A, thus forming a tripartite lytic pore that is permissive to efflux of potassium. NHE mediates killing of cells from multiple lineages and hosts, highlighting a versatile functional repertoire in different host species. These data indicate that NHE and HBL operate synergistically to induce inflammation and show that multiple virulence factors from the same pathogen with conserved function and mechanism of action can be exploited for sensing by a single inflammasome. The Bacillus haemolytic enterotoxin haemolysin BL has been shown to activate the NLRP3 inflammasome. Here the authors show that a non-haemolytic enterotoxin (NHE) from B. cereus can also activate the NLRP3 inflammasome with a similar mechanism of lytic pore formation. [ABSTRACT FROM AUTHOR]

Stretchable organic field-effect transistors (STOFETs) employing organic semiconductors as active layers are highly attractive ongoing from health monitoring to biological research owing to some favorable advantages over their inorganic counterpart, including light weight, low cost, solution processing, high flexibility and simple adjustment of functionalities through molecular design. Although the development of STOFETs with original electrical performances under large mechanical deformation remain rudimentary, major efforts have recently been devoted to the investigation on STOFETs, and remarkable advances in stretchable components and novel fabrication methods have been achieved. A detailed overview of the advantages, challenges and current achievements in STOFETs was given including stretchable electrodes, semiconductors, dielectrics and substrates. Furthermore, conclusions and prospects for the future development of STOFETs with both high stretchability and superb electrical performances fabricated using intrinsically stretchable components are proposed. [ABSTRACT FROM AUTHOR]

Monolayer organic field-effect transistors (OFETs) are attracting worldwide interest in device physics and novel applications due to their ultrathin active layer for two-dimensional charge transport. The monolayer films are generally prepared by thermal evaporation, the Langmuir technique or self-assembly process, etc., but their electrical performance is relatively lower than corresponding thick films. From 2011, the performance of monolayer OFETs has been boosted by using the monolayer molecular crystals (MMCs) as active channels, which opened up a new era for monolayer OFETs. In this review, recent progress of monolayer OFETs, including the preparation of monolayer films, their OFET performance and applications are summarized. Finally, perspectives of monolayer OFETs in the near future are also discussed. [ABSTRACT FROM AUTHOR]

The incorporation of small guest molecules or ions by bottom-up hydrothermal synthesis has recently emerged as a promising new way to engineer 1T-phase MoS2 with high hydrogen evolution reaction (HER) activity. However, the mechanism of the associated structural evolution remains elusive and controversial, leading to a lack of effective routes to prepare 1T-phase MoS2 with controlled structure and morphology, along with high purity and stability. Herein, urea is chosen as precursor of small molecules or ions to simultaneously engineer the phase (~16.4%, ~69.4%, and ~90.2% of 1T phase) and size (~98.8, ~151.6, and ~251.8 nm for the 90.2% 1T phase) of MoS2 nanosheets, which represent an ideal model system for investigating the structural evolution in these materials, as well as developing a new type of 1T-phase MoS2 arrays. Using reaction intermediate monitoring and theoretical calculations, we show that the oriented growth of 1T-phase MoS2 is controlled by ammonia-assisted assembly, recrystallization, and stabilization processes. A superior HER performance in acidic media is obtained, with an overpotential of only 76 mV required to achieve a stable current density of 10 mA·cm-2 for 15 h. This excellent performance is attributed to the unique array structure, involving well-dispersed, edge-terminated, and high-purity 1T-phase MoS2 nanosheets. [ABSTRACT FROM AUTHOR]

In this work, we utilize the quasinormal modes (QNMs) of a massless scalar perturbation to probe the Van der Waals-like small and large black holes (SBH/LBH) phase transition of charged topological Anti-de Sitter (AdS) black holes in four-dimensional massive gravity. We find that the signature of this SBH/LBH phase transition is detected in the isobaric as well as in the isothermal process. This further supports the idea that the QNMs can be an efficient tool to investigate the thermodynamical phase transition. [ABSTRACT FROM AUTHOR]

Annual power load forecasting is essential for the planning, operation and maintenance of an electric power system, which can also mirror the economic development of a country to some extent. Accurate annual power load forecasting can provide valuable references for electric power system operators and economic managers. With the development of Energy Internet and further reformation of electric power market, power load forecasting has become a more difficult and challenging task. In this paper, a new hybrid annual power load forecasting model based on LSSVM (least squares support vector machine) and MFO (Moth-Flame Optimization algorithm) is proposed, which the parameters of LSSVM model are optimally determined by the latest nature-inspired metaheuristic algorithm MFO. Meanwhile, the rolling mechanism is also employed. The forecasting results of China's annual electricity consumption indicate the proposed MFO-LSSVM model shows much better forecasting performance than single LSSVM, FOA-LSSVM (LSSVM optimized by fruit fly optimization), and PSO-LSSVM (LSSVM optimized by particle swarm optimization). MFO, as a new intelligence optimization algorithm, is attractive and promising. The LSSVM model optimized by MFO can significantly improve annual power load forecasting accuracy. [ABSTRACT FROM AUTHOR]

Balanced carrier transport is observed in acceptor-acceptor (A-A′) type polymer for ambipolar organic thin-film transistors (OTFTs). It is found that the incorporation of two electron-accepting moieties (BTz and IIG) into a polymer main chain to form A-A′ polymer PIIG-BTz could lower highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels and facilitate good molecular stacking of the polymer. Ambipolar transistor behaviour for PIIG-BTz, with the balanced hole and electron mobilities of 0.030 and 0.022 cm V s was observed in OTFT devices, respectively. The study in this work reveals that the utilization of acceptor-acceptor (A-A′) structure in polymer main chain can be a feasible strategy to develop ambipolar polymer semiconductors. [ABSTRACT FROM AUTHOR]

NiMo catalysts were prepared using Waugh-type NiMo heteropolycompounds as active phase precursors and evaluated in hydrodesulfurization (HDS) of dibenzothiophene (DBT). These catalysts were compared with corresponding reference catalysts prepared from the conventional precursors (ammonium heptamolybdate and nickel nitrate). Prepared catalysts were characterized by N physisorption, XRD, FT-IR, H-TPR, DRIFT of CO adsorption and HRTEM techniques. It was found that NiMo catalysts prepared from Waugh-type NiMo HPCs showed higher performance in HDS of DBT than their counterparts. Possible reasons of this result were discussed. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A compound catalyst (RA) consisted of Ni, ZnO and HZSM-5 with functions of reactive adsorption desulfurization (RADS) and olefin aromatization for fluid catalytic cracking (FCC) gasoline upgrading was prepared. X-ray powder diffraction (XRD), temperature-programmed reduction and low-temperature N adsorption were used to characterize the properties of the catalysts. Performance evaluation by FCC gasoline was carried out, and the result showed that the catalyst RA performed well in desulfurization and aromatization. For comparison, RADS catalyst (represented by DS) consisted of Ni and ZnO and aromatization catalyst (represented by Ar) consisted of HZSM-5 were prepared, respectively. They were combined in different ways to help investigating interaction between Ni and HZSM-5. Performance evaluated by FCC gasoline showed that catalyst RA performed best in desulfurization with a slight octane number loss. Interaction between Ni and HZSM-5 is a significant factor which influences the performance of the catalyst. [ABSTRACT FROM AUTHOR]

The black hole solutions in higher-dimensional spacetimes with the presence of the power-Maxwell field, surrounded by quintessence, are investigated for Einstein as well as Rastall gravity. The obtained solutions accommodate for spherical, planar and hyperbolic symmetries with the presence of the cosmological constant. Besides, we show that several known black hole solutions in literature such as those for linear Maxwell theory and BTZ black hole can be obtained as special cases. The implications of Rastall's theory related to the present study and the thermodynamics of the black hole solutions are discussed. [ABSTRACT FROM AUTHOR]

Due to ultra-high reactivity, direct determination of free radicals, especially hydroxyl radical (•OH) with ultra-short lifetime, by field-effect transistor (FET) sensors remains a challenge, which hampers evaluating the role that free radical plays in physiological and pathological processes. Here, we develop a •OH FET sensor with a graphene channel functionalized by metal ion indicators. At the electrolyte/graphene interface, highly reactive •OH cuts the cysteamine to release the metal ions, resulting in surface charge de-doping and a current response. By this inner-cutting strategy, the •OH is selectively detected with a concentration down to 10−9 M. Quantitative metal ion doping enables modulation of the device sensitivity and a quasi-quantitative detection of •OH generated in aqueous solution or from living cells. Owing to its high sensitivity, selectivity, real-time label-free response, capability for quasi-quantitative detection and user-friendly portable feature, it is valuable in biological research, human health, environmental monitoring, etc. Field effect transistors based on graphene hold promise for future sensing applications. Here, the authors report a free radical sensor in which the •OH radical cuts cysteamine to release Cd2+ from the electrolyte/graphene interface and selectively detects •OH with a concentration down to 10−9 M. [ABSTRACT FROM AUTHOR]

We study scalar condensations around asymptotically Anti-de Sitter (AdS) regular reflecting shells. We show that the charged scalar field can condense around charged reflecting shells with both Dirichlet and Neumann boundary conditions. In particular, the radii of the asymptotically AdS hairy shells are discrete, which is similar to cases in asymptotically flat spacetimes. We also provide upper bounds for the radii of the hairy Dirichlet reflecting shells and above the bound, the scalar field cannot condense around the shell. [ABSTRACT FROM AUTHOR]