PdPLR1 effectively enhances resistance of Populus deltoides 'shalinyang' to Anoplophora glabripennis by positive regulation of lignan synthesis.

Anoplophora glabripennis (ALB) is one of the most devastating wood boring insects of poplars. Populus deltoides 'Shalinyang (PdS), a new poplar variety, shows strong resistance to ALB infestation. However, the molecular mechanism of insect resistance in PdS is unclear. Here, we found that lignan content was much higher in PdS phloem after ALB infestation than in healthy trees, and that adding lignan to artificial diet significantly reduced: larval weight; digestive enzyme activity (cellulase [CL], polygalacturonase [PG]); detoxification enzyme activity (carboxylesterase [CarE], glutathione S-transferase [GSH-ST]); and defense enzyme activity (Catalase [CAT]). We further identified the lignan biosynthesis-related PdPLR1 gene (Pinoresinol-lariciresinol reductase, PLR) based on transcriptome analysis, and it was significantly up-regulated in the PdS phloem attacked by ALB. Overexpression of PdPLR1 in Arabidopsis increased th lignan content. In contrast, silencing PdPLR1 in PdS significantly decreased expression levels of PdPLR1 and lignan content by 82.45% and 56.85%. However, silencing PdPLR1 increased the number of adults ovipositions and eggs hatching. The activity of CL, PG, CarE, GSH-ST and CAT and the biomass of larvae fed on phloem of PdS with silenced PdPLR1 were significantly higher than in the control. Taken together, up regulation of PdPLR1 enhanced PdS resistance to ALB by regulating lignan synthesis. Our findings provide in-depth insights into the molecular mechanisms of PdS-ALB interactions, which lay the foundation for understanding of defense in poplars to pest infection.

Bayesian hypernetwork collaborates with time-difference evolutional network for temporal knowledge prediction.

A Temporal Knowledge Graph (TKG) is a sequence of Knowledge Graphs (KGs) attached with time information, in which each KG contains the facts that co-occur at the same timestamp. Temporal knowledge prediction (TKP) aims to predict future events given observed historical KGs in TKGs, which is essential for many applications to provide intelligent analysis services. However, most existing TKP methods focus on entity and relation prediction tasks but ignore the importance of time prediction tasks. Furthermore, there is uncertainty in time prediction, and it is difficult for prediction models to model it completely. In this work, we propose a collaboration framework with Bayesian Hypernetwork and Time-Difference Evolutional Network (BH-TDEN) to address these problems. First, we begin with the time prediction task, and we present a Bayesian hypernetwork to model the uncertainty of events time. For the input of Bayesian hypernetwork, we design a novel time-difference evolutional network to obtain the entities and relations embedding. Specifically, we propose an auto-regressive time gate parameterized by the time difference of adjacent KGs in entity and relation encoder to learn the time-sensitive TKG embedding, which not only learns the relationship between the given time information and TKG embedding but also provides more expressive TKG embedding for Bayesian hypernetwork to accurately predict the time of future events. Furthermore, we also present a novel relation updating mechanism that employs the neighbor relations of the subject corresponding to the current relation to learn more adaptive relation embedding. Extensive experiments demonstrate that the proposed method obtains considerable time prediction and link prediction performance on four TKG benchmark datasets.

Covalent Organic Framework Ionomer Steering the CO2 Electroreduction Pathway on Cu at Industrial-Grade Current Density.

CO2 electroreduction holds great promise for addressing global energy and sustainability challenges. Copper (Cu) shows great potential for effective conversion of CO2 toward specific value-added and/or high-energy-density products. However, its limitation lies in relatively low product selectivity. Herein, we present that the CO2 reduction reaction (CO2RR) pathway on commercially available Cu can be rationally steered by modulating the microenvironment in the vicinity of the Cu surface with two-dimensional sulfonated covalent organic framework nanosheet (COF-NS)-based ionomers. Specifically, the selectivity toward methane (CH4) can be enhanced to more than 60% with the total current density up to 500 mA cm-2 in flow cells in both acidic (pH = 2) and alkaline (pH = 14) electrolytes. The COF-NS, characterized by abundant apertures, can promote the accumulation of CO2 and K+ near the catalyst surface, alter the adsorption energy and surface coverage of *CO, facilitate the dissociation of H2O, and finally modulate the reaction pathway for the CO2RR. Our approach demonstrates the rational modulation of reaction interfaces for the CO2RR utilizing porous open framework ionomers, showcasing their potential practical applications.

Hierarchically Porous Covalent Organic Frameworks: Synthesis Methods and Applications.

Covalent organic frameworks (COFs) with high porosity have garnered considerable interest for various applications owing to their robust and customizable structure. However, conventional COFs are hindered by their narrow pore size, which poses limitations for applications such as heterogeneous catalysis and guest delivery that typically involve large molecules. The development of hierarchically porous COF (HP-COF), featuring a multi-scale aperture distribution, offers a promising solution by significantly enhancing the diffusion capacity and mass transfer for larger molecules. This review focuses on the recent advances in the synthesis strategies of HP-COF materials, including topological structure design, in-situ templating, monolithic COF synthesis, defect engineering, and crystalline self-transformation. The specific operational principles and affecting factors in the synthesis process are summarized and discussed, along with the applications of HP-COFs in heterogeneous catalysis, toxic component treatment, optoelectronics, and the biomedical field. Overall, this review builds a bridge to understand HP-COFs and provides guidance for further development of them on synthesis strategies and applications.

Gradient Channel Segmentation in Covalent Organic Framework Membranes with Highly Oriented Nanochannels.

Covalent organic frameworks (COFs) offer an exceptional platform for constructing membrane nanochannels with tunable pore sizes and tailored functionalities, making them promising candidates for separation, catalysis, and sensing applications. However, the synthesis of COF membranes with highly oriented nanochannels remains challenging, and there is a lack of systematic studies on the influence of postsynthetic modification reactions on functionality distribution along the nanochannels. Herein, we introduced a "prenucleation and slow growth" approach to synthesize a COF membrane featuring highly oriented mesoporous channels and a high Brunauer-Emmett-Teller surface area of 2230 m2 g-1. Functional moieties were anchored to the pore walls via "click" reactions and coordinated with Cu ions to serve as segmentation functions. This led to a remarkable H2/CO2 separation performance that surpassed the Robeson upper bound. Moreover, we found that the functionalities distributed along the nanochannels could be influenced by functionality flexibility and postsynthetic reaction rate. This strategy paved the way for the accurate design and construction of COF-based artificial solid-state nanochannels with high orientation and precisely controlled channel environments.

2D Covalent Organic Framework for Water Harvesting with Fast Kinetics and Low Regeneration Temperature.

Atmospheric water harvesting represents a promising technique to address water stress. Advanced adsorbents have been rationally designed to achieve high water uptake, yet their water sorption kinetics and regeneration temperature greatly limit water production efficiency. Herein, we demonstrated that 2D covalent organic frameworks (COFs), featuring hydrophobic skeleton, proper hydrophilic site density, and 1D open channels significantly lowered the water diffusion and desorption energy barrier. DHTA-Pa COF showed a high water uptake of 0.48 g/g at 30 % R.H. with a remarkable adsorption rate of 0.72 L/Kg/h (298 K) and a desorption rate of 2.58 L/Kg/h (333 K). Moreover, more than 90 % adsorbed water could be released within 20 min at 313 K. This kinetic performance surpassed the reported porous materials and boosted the efficiency for multiple water extraction cycles. It may shed light on the material design strategy to achieve high daily water production with low-energy input.

Adaptive pseudo-Siamese policy network for temporal knowledge prediction.

Temporal knowledge prediction is a crucial task for early event warning, which has gained increasing attention recently. It aims to predict future facts based on relevant historical facts using temporal knowledge graphs. There are two main difficulties associated with the prediction task: from the perspective of historical facts, modeling the evolutionary patterns of facts to accurately predict the query and from the query perspective, handling the two cases where the query contains seen and unseen entities in a unified framework. Driven by these two problems, we propose a novel adaptive pseudo-Siamese policy network for temporal knowledge prediction based on reinforcement learning. Specifically, we design the policy network in our model as a pseudo-Siamese network consisting of two sub-policy networks. In the sub-policy network I, the agent searches for the answer to the query along the entity-relation paths to capture static evolutionary patterns. In sub-policy network II, the agent searches for the answer to the query along relation-time paths to deal with unseen entities. Moreover, we develop a temporal relation encoder to capture the temporal evolutionary patterns. Finally, we design a gating mechanism to adaptively integrate the results of the two sub-policy networks to help the agent focus on the destination answer. To assess the performance of our model, we conduct link prediction on four benchmark datasets, and extensive experimental results demonstrate that our method achieves considerable performance compared with existing methods.

Covalent organic framework-based porous ionomers for high-performance fuel cells.

Lowering platinum (Pt) loadings without sacrificing power density and durability in fuel cells is highly desired yet challenging because of the high mass transport resistance near the catalyst surfaces. We tailored the three-phase microenvironment by optimizing the ionomer by incorporating ionic covalent organic framework (COF) nanosheets into Nafion. The mesoporous apertures of 2.8 to 4.1 nanometers and appendant sulfonate groups enabled the proton transfer and promoted oxygen permeation. The mass activity of Pt and the peak power density of the fuel cell with Pt/Vulcan (0.07 mg of Pt per square centimeter in the cathode) both reached 1.6 times those values without the COF. This strategy was applied to catalyst layers with various Pt loadings and different commercial catalysts.

Hydrophilicity gradient in covalent organic frameworks for membrane distillation.

Desalination can help to alleviate the fresh-water crisis facing the world. Thermally driven membrane distillation is a promising way to purify water from a variety of saline and polluted sources by utilizing low-grade heat. However, membrane distillation membranes suffer from limited permeance and wetting owing to the lack of precise structural control. Here, we report a strategy to fabricate membrane distillation membranes composed of vertically aligned channels with a hydrophilicity gradient by engineering defects in covalent organic framework films by the removal of imine bonds. Such functional variation in individual channels enables a selective water transport pathway and a precise liquid-vapour phase change interface. In addition to having anti-fouling and anti-wetting capability, the covalent organic framework membrane on a supporting layer shows a flux of 600 l m-2 h-1 with 85 °C feed at 16 kPa absolute pressure, which is nearly triple that of the state-of-the-art membrane distillation membrane for desalination. Our results may promote the development of gradient membranes for molecular sieving.

Construction of Interlayer Conjugated Links in 2D Covalent Organic Frameworks via Topological Polymerization.

Two-dimensional covalent organic frameworks (2D COFs) are well-defined polymeric sheets that usually stack in an eclipsed mode via van der Waals forces. Extensive efforts have been made to manipulate interlayer interactions, yet there still lack a way to construct conjugated connections between adjacent layers, which is important for (opto)electronic-related applications. Herein, we report an interlayer topological polymerization strategy to transform the well-organized diacetylene columnar arrays in three different 2D COFs (TAPFY-COF, TAPB-COF, and TAPP-COF) into conjugated enyne chains upon heating in the solid state. The resultant COFs (COF-P) with retained high crystallinity possess broadened absorption bands and narrowed band gaps. The newly formed conjugated chains provide extra charge carrier pathways through direct π-electron delocalization. As a proof-of-concept, after topological polymerization, the conductivity of the TAPFY-COF film achieves 2.8 × 10-4 S/cm without doping, and the photothermal, photoacoustic, and oxygen reduction catalytic performance of TAPP-COF is significantly improved.

Synthesis and Structure-Property Relationships of Polyimide Covalent Organic Frameworks for Carbon Dioxide Capture and (Aqueous) Sodium-Ion Batteries.

Covalent organic frameworks (COFs) are an emerging material family having several potential applications. Their porous framework and redox-active centers enable gas/ion adsorption, allowing them to function as safe, cheap, and tunable electrode materials in next-generation batteries, as well as CO2 adsorption materials for carbon-capture applications. Herein, we develop four polyimide COFs by combining aromatic triamines with aromatic dianhydrides and provide detailed structural and electrochemical characterization. Through density functional theory (DFT) calculations and powder X-ray diffraction, we achieve a detailed structural characterization, where DFT calculations reveal that the imide bonds prefer to form at an angle with one another, breaking the 2D symmetry, which shrinks the pore width and elongates the pore walls. The eclipsed perpendicular stacking is preferable, while sliding of the COF sheets is energetically accessible in a relatively flat energy landscape with a few metastable regions. We investigate the potential use of these COFs in CO2 adsorption and electrochemical applications. The adsorption and electrochemical properties are related to the structural and chemical characteristics of each COF, giving new insights for advanced material designs. For CO2 adsorption specifically, the two best performing COFs originated from the same triamine building block, which-in combination with force-field calculations-revealed unexpected structure-property relationships. Specific geometries provide a useful framework for Na-ion intercalation with retainable capacities and stable cycle life at a relatively high working potential (>1.5 V vs Na/Na+). Although this capacity is low compared to conventional inorganic Li-ion materials, we show as a proof of principle that these COFs are especially promising for sustainable, safe, and stable Na-aqueous batteries due to the combination of their working potentials and their insoluble nature in water.

Polytorsional-amide/carboxylates-directed Cd(ii) coordination polymers exhibiting multi-functional sensing behaviors.

By rational assembly of polytorsional-amide [N,N'-bis(4-methylenepyridin-4-yl)-1,4-naphthalene dicarboxamide (L)] and polytorsional-carboxylates [H2ADI = adipic acid, H2PIM = pimelic acid, H2SUB = suberic acid], three new Cd-based coordination polymers (CPs) C30H30CdN4O7 (1), C31H32CdN4O7 (2) and C31.03H30.55CdCl0.24N4O5.52 (3) were successfully synthesized. CPs 1-2 and 3 are 2D networks and a 3D framework, which all display 3,5-connected topologies with different structural details. The effects of carboxylates with different carbon chains on the structure of the complexes were studied. Fluorescence experiments show that CPs 1-3 have good multi-functional sensing ability for metal cations (Fe3+), anions (MnO4 -, CrO4 2-, Cr2O7 2-) and organochlorine pesticides (2,6-dichloro-4-nitroamine) with good anti-interference and recyclable characteristics. The possible sensing mechanism is also investigated in detail.

Supramolecular Alternating Donor-Acceptor Assembly toward Intercalated Covalent Organic Frameworks.

Conventionally, z-direction modulation of two-dimensional covalent organic frameworks (2D-COFs) is difficult to achieve because they rely on spontaneous π-π interactions to form 3D architectures. Herein, we report a facile construction of a novel intercalated covalent organic framework (Intercalated-COF) by synchronizing operations of supramolecular donor-acceptor (D-A) interactions (A unit: 2,5,8,11-tetra(p-formylphenyl)-perylene diimide (PDI) 1; D unit: perylene 3, as intercalator) in the vertical directions, with polymerizations (by only reacting 1 with p-phenylenediamine 2) in the lateral directions. In this Intercalated-COF, the PDI-based covalent 2D layers are uniformly separated by perylene guest layers. This supramolecular strategy opens the possibility for z-direction modulation of 2D-COFs through "intercalating" various guest molecules and thus may contribute to the exploration of advanced applications of these porous and crystalline frameworks.

A Hydrolytically Stable Vanadium(IV) Metal-Organic Framework with Photocatalytic Bacteriostatic Activity for Autonomous Indoor Humidity Control.

Metal-organic frameworks (MOFs) with long-term stability and reversible high water uptake properties can be ideal candidates for water harvesting and indoor humidity control. Now, a mesoporous and highly stable MOF, BIT-66 is presented that has indoor humidity control capability and a photocatalytic bacteriostatic effect. BIT-66 (V3 (O)3 (H2 O)(BTB)2 ), possesses prominent moisture tunability in the range of 45-60 % RH and a water uptake and working capacity of 71 and 55 wt %, respectively, showing good recyclability and excellent performance in water adsorption-desorption cycles. Importantly, this MOF demonstrates a unique photocatalytic bacteriostatic behavior under visible light, which can effectively ameliorate the bacteria and/or mold breeding problem in water adsorbing materials.

Molecular-Sieving Membrane by Partitioning the Channels in Ultrafiltration Membrane by In†Situ Polymerization.

Commercial ultrafiltration membranes have proliferated globally for water treatment. However, their pore sizes are too large to sieve gases. Conjugated microporous polymers (CMPs) feature well-developed microporosity yet are difficult to be fabricated into membranes. Herein, we report a strategy to prepare molecular-sieving membranes by partitioning the mesoscopic channels in water ultrafiltration membrane (PSU) into ultra-micropores by space-confined polymerization of multi-functionalized rigid building units. Nine CMP@PSU membranes were obtained, and their separation performance for H2 /CO2 , H2 /N2 , and H2 /CH4 pairs surpass the Robeson upper bound and rival against the best of those reported membranes. Furthermore, highly crosslinked skeletons inside the channels result in the structural robustness and transfer into the excellent aging resistance of the CMP@PSU. This strategy may shed light on the design and fabrication of high-performance polymeric gas separation membranes.

Synthesis of Two-Dimensional Covalent Organic Frameworks in Ionic Liquids.

Two-dimensional covalent organic frameworks were synthesized in high yields by polycondensation in nonvolatile ionic liquids. The resulting crystallites are highly porous and exhibit exceptional capability of removing bisphenol A from water. The one reported is a general method to synthesize microporous and mesoporous frameworks, it allows to achieve regular macroscopic shapes, and it is effective in a wide range of reaction temperatures.

Electropolymerization of Molecular-Sieving Polythiophene Membranes for H2 Separation.

Membrane technologies that do not rely on heat for industrial gas separation would lower global energy cost. While polymeric, inorganic, and mixed-matrix separation membranes have been rapidly developed, the bottleneck is balancing the processability, selectivity, and permeability. Reported here is a softness adjustment of rigid networks (SARs) strategy to produce flexible, stand-alone, and molecular-sieving membranes by electropolymerization. Here, 14 membranes were rationally designed and synthesized and their gas separation ability and mechanical performance were studied. The separation performance of the membranes for H2 /CO2 , H2 /N2 , and H2 /CH4 can exceed the Robeson upper bound, among which, H2 /CO2 separation selectivity reaches 50 with 626 Barrer of H2 permeability. The long-term and chemical stability tests demonstrate their potential for industrial applications. This simple, scalable, and cost-effective strategy holds promise for the design other polymers for key energy-intensive separations.

Ferrocene-Linkage-Facilitated Charge Separation in Conjugated Microporous Polymers.

Conjugated microporous polymers (CMPs) have full access to the organic synthesis toolbox and feature-rich functionality, structural diversity, and high surface area. We incorporated ferrocene (Fc) into the backbones of CMPs and systematically engineered their optical energy gaps. Compared with the CMPs without Fc units yet adopting a similar molecular orbital level, Fc-based CMPs can sufficiently generate reactive oxygen species (ROS) under visible light. The resultant ROS are able to effectively decompose the absorbed pollutants, including organic dyes and chemical warfare agents. Specifically, Fc-based CMPs significantly outperform commercial TiO2 (P25) in the degradation of methylene blue and are capable of converting 2-chloroethyl ethyl sulfide (a mustard gas simulant) into a completely nontoxic product.

Fast Ion Transport Pathway Provided by Polyethylene Glycol Confined in Covalent Organic Frameworks.

Covalent organic frameworks (COFs) with well-tailored channels are able to accommodate ions and offer their conduction pathway. However, due to strong Coulombic interaction and the lack of transport medium, directly including lithium salts into the channels of COFs results in limited ion transport capability. Herein, we propose a strategy of incorporating low-molecular-weight polyethylene glycol (PEG) into COFs with anionic, neutral, or cationic skeletons to accelerate Li+ conduction. The PEG confined in the well-aligned channels retains high flexibility and Li+ solvating ability. The ion conductivity of PEG included in a cationic COF can reach 1.78 × 10-3 S cm-1 at 120 °C. The simplicity of this strategy as well as the diversity of crystalline porous materials holds great promise to design high-performance all-solid-state ion conductors.

Flexible Films of Covalent Organic Frameworks with Ultralow Dielectric Constants under High Humidity.

Covalent organic framework (COF) films combine the processability of polymers with the porosity and atomic precision of crystalline porous materials, properties that are long-sought-after in electronics yet hard to realize. Herein, we prepared four flexible COF films with different alkoxy side chains via interfacial polymerization. The COF films exhibit an ultralow dielectric constant (κ=1.19±0.04 at 105  Hz), small dielectric loss (<0.02, 103 -106  Hz), high breakdown voltage (>63 kV cm-1 ) and low leakage current (10-10  A cm-2 at 1 kV cm-1 ). They have considerable mechanical strength, and ability to withstand high humidity (RH 70 % for 10 days) and repeated bending (1000 times) without losing their dielectric properties. Extension of the alkoxy chains reduces the film's κ and enhances its moisture resistance, while incorporation of guest molecules further increase the κ value up to 43 times.