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A phosphorylated GQD intercalated COF membrane simultaneously exhibits superhigh proton conductivity and outstanding mechanical strength.

Polymer carbon dot membranes prepared through bioinspired complexation for robust structure and high proton conductivity.

For the first time, we demonstrate the utilization of covalent organic framework (COF) membranes for efficient ethylene/ethane separation.

Controllable ion transport through nanochannels is crucial for biological and artificial membrane systems. Covalent organic frameworks (COFs) with regular and tunable nanochannels are emerging as an ideal material platform to develop synthetic membranes for ion transport. However, ion exclusion by COF membranes remains challenging because most COF materials have large-sized nanochannels leading to nonselective transport of small ions. Here we develop ionic COF membranes (iCOFMs) to control ion transport through charged framework nanochannels, the interior surfaces of which are covered with arrayed sulfonate groups to render superior charge density. The overlap of an electrical double layer in charged nanochannels blocks the entry of co-ions, narrows their passageways, and concomitantly restrains the permeation of counterions

Phosphoric acid group, which possesses a low energy barrier for proton conduction and high water bonding energy, favors proton conduction and water retention. In this study, a phosphoric acid porous organic polymer (PAPOP) with high proton conductivity was synthesized. The diethyl benzylphosphonate (DBP) monomer and the benzyl monomer were directly knitted via the Friedel–Crafts alkylation reaction to form a porous scaffold. The phosphate ester group on DBP not only enhanced the monomer reactivity but also realized the in situ introduction of the phosphoric acid group precursor during the formation of the porous scaffold. It is found that p-dichloroxylene (DCX) monomer, due to its higher electrophilic activity, is easier to react with DBP and thus easier to introduce phosphoric acid groups. The higher ratio of DCX leads to a more continuous hydrogen-bond network within the scaffold, which facilitates the proton-conducting process. The resultant porous organic polymers exhibited high hydrophilicity and excellent stability in strong acid as well as antiswelling ability in water. The highest ion-exchange capacity reached 2.68 mmol g–¹, much higher than that of most reported polymers. The proton conductivity of powders reached the highest value of 7.09 × 10–² S cm–¹ at 348 K and 98% relative humidity.

The field of fabricating three-dimensional (3D) covalent organic framework (COF) membranes is in its infancy. In the current work, we used the interfacial polymerization method to fabricate a free-standing uniform 3D COF membrane, denoted as a COF-300 membrane, consisting of interconnected nanochannels. The COF-300 membrane was found to exhibit good swelling resistance and excellent mechanical strength as well as a dynamic behavior similar to that of its powder counterpart. Also, by encapsulating etidronic acid acting as proton carriers in the nanochannels of the COF-300 membrane, an etidronic acid@COF-300 membrane was made—and it achieved a proton conductivity of 0.650 S cm−1 at 90 °C, a conductivity value among the highest ever reported for COF-based proton conductors. The ultrafast character of the proton conduction at low proton carrier content was primarily due to the highly interconnected nanochannels, which made up the proton conductive “highway” and afforded a low energy barrier to the conduction. This study may open new avenues for fabricating 3D COF membranes and at the same time facilitate their potential applications in the fields of membrane separation and stimulus response.

In recent years, ion exchange membranes with monovalent ion perm-selectivity are highly desirable. Here, two strategies were adopted simultaneously to prepare anion exchange membranes with excellent monovalent anion perm-selectivity. One is to adjust membranes’ hydrophobicity by grafting single long chain tertiary amines of different alkyl chain lengths (N,N-dimethylhexadecylamine (DMA16), N,N-Dimethylhexylamine (DMHA), and trimethylamine (TMA)) onto bromomethylated poly (phenylene oxide) (BPPO) backbones and regulating the molar ratio of the tertiary amine and the bromobenzyl in BPPO. Results show that the obtained membrane C16-0.5, which was grafted with the longest tertiary amine (DMA16) and has the lowest molar ratio of DMA16 and the bromobenzyl in BPPO, exhibits the lowest water uptake (WU) and highest monovalent anion perm-selectivity ( P S O 4 C l ) between Cl− and SO42− (12.84). The other is to regulate membranes’ compactness through post-treatments, including heat treatment and surface modification by forming a polypyrrole layer on the membrane surface. Results show that membrane C16-0.75-H120, which was under the heat treatment of 120 °C, shows a higher P S O 4 C l (7.58) than membrane C16-0.75 (5.02) without any heat treatment; moreover, membrane C16-0.75-pr, which was coated with a polypyrrole layer on the surface, has a higher P S O 4 C l (9.0) than membrane C16-0.75 (5.02) without any surface modification. In addition, membranes C16-0.5, C16-0.75-H120 and C16-0.75-pr have more excellent P S O 4 C l than the commercial membrane ASV (6.52). To sum up, results in this study suggest that both of the two strategies are highly effective to improve membranes’ perm-selectivity.

Ionic covalent organic framework membranes (iCOFMs) hold great promise in ion conduction-relevant applications because the high content and monodispersed ionic groups could afford superior ion conduction. The key to push the upper limit of ion conductivity is to maximize the ion exchange capacity (IEC). Here, we explore iCOFMs with a superhigh ion exchange capacity of 4.6 mmol g−1, using a dual-activation interfacial polymerization strategy. Fukui function is employed as a descriptor of monomer reactivity. We use Brønsted acid to activate aldehyde monomers in organic phase and Brønsted base to activate ionic amine monomers in water phase. After the dual-activation, the reaction between aldehyde monomer and amine monomer at the water-organic interface is significantly accelerated, leading to iCOFMs with high crystallinity. The resultant iCOFMs display a prominent proton conductivity up to 0.66 S cm−1, holding great promise in ion transport and ionic separation applications.

Aroma is a critical factor influencing consumer acceptability of ripe fruit. When fruit are eaten, the aroma travels retronasally from the mouth into the olfactory receptors located in the nose after exhaling. In kiwifruit (Actinidia spp.), terpene volatiles such as α-terpinolene and 1,8-cineole have been shown to contribute to the characteristic aroma of ripe fruit. Notably, 1,8-cineole contributes a key floral/eucalyptus note to the aroma of ripe A. chinensis ‘Hort16A’ kiwifruit, based on sensory descriptive and discriminant analysis. Emission of α-terpinolene and 1,8-cineole in kiwifruit is induced by ethylene, and production peaks when fruit are at eating ripeness. Two monoterpene synthase TPS-b family genes have been isolated from the fruit of A. arguta and A. chinensis that produce α-terpinolene and 1,8-cineole, respectively. Here we discuss terpene volatiles with respect to fruit aroma and consumer sensory evaluation, analyze the gene structure and conserved motifs of TPS-b genes in published kiwifruit genomes and then construct a transcriptional regulatory network based on Actinidia TPS-b. These data provide further insights into the potential molecular mechanisms underlying signature monoterpene synthesis to improve flavor in kiwifruit.

Mixed matrix membranes (MMMs), which are fabricated by incorporating dispersed fillers into a continuous polymeric matrix, have been broadly utilized in gas separation due to their unique hierarchical structures and enhanced separation performance. Fillers of intrinsic nanopores (FINs) have drawn considerable attention because they not only can provide additional molecular transport channels but also have a potential size-sieving property. Although many excellent reviews about MMMs have been published, quite few of them are specifically designed for MMMs containing FINs. This Review focuses on three kinds of FINs, covalent organic frameworks (COFs), zeolites, and metal–organic frameworks (MOFs), as the representatives of organic, inorganic, and inorganic–organic FINs. The typical physical and chemical features of these three kinds of FINs are introduced. Afterward, methods to prepare FIN-based MMMs are briefly introduced. Particularly, solutions to prevent the aggregation and improve the dispersion of FIN...

Covalent organic framework (COF) membranes hold potential for widespread applicability, but scalable fabrication is challenging. Here, we demonstrate the disorder-to-order transformation from amorphous polymeric membrane to crystalline COF membrane via monomer exchange. Solution processing is used to prepare amorphous membrane and the replacing monomer is selected based on the chemical and thermodynamical stability of the final framework. Reversible imine bonds allow the extraneous monomers to replace the pristine monomers within amorphous membrane, driving the transformation from disordered network to ordered framework. Incorporation of intramolecular hydrogen bonds enables the crystalline COF to imprint the amorphous membrane morphology. The COF membranes harvest proton conductivity up to 0.53 S cm-1 at 80 °C. Our strategy bridges amorphous polymeric and crystalline COF membranes for large-scale fabrication of COF membranes and affords guidance on materials processing.

Vision inspection as an important automation technology in manufacturing industry undertakes many appearance quality related tasks, such as product positioning, recognition, and measurement. Intelligent manufacturing increases the demand for vision methods in production scenes. However, the diversity and increment of the targets, and the feature robustness and scheme migration have restricted further implementation of this technology. To address this problem, this study establishes a robust inspection system, including type insensitive target ontology rough localization, component-based model reverse incremental recognition, and geometric attribute extraction, based on the joint strategy of lightweight neural network recommendation and knowledge guidance. Domain common sense and artificial knowledge are integrated into the whole method, of which the reasonable structural design alleviates the limitation of reliance on artificial intelligence or traditional image processing alone. Taking the connector in the electronic and electrical industry as an example, the proposed method demonstrates successful model recognition and component position extraction of 48 types (including two new models) of connectors, and significant adaptivity to the target posture, imaging environment, and feature diversity.

Nanofiltration membranes that can selectively remove multivalent ions from salty water hold great promise in water treatment and salt utilization. However, developing nanofiltration membranes with high rejection to both divalent anions and cations remains a grand challenge. Herein, we design a kind of mix-charged polyamide membranes (MCPMs) via molecular hybridization to achieve the removal of versatile divalent ions. Amino-functionalized polyhedral oligomeric sesquisiloxane (NH2-POSS) was employed as molecular filler added into piperazine and reacted with trimesoyl chloride at the aqueous-organic interface to generate cross-linked polyamide-NH2-POSS mixed network. The protonated amino groups from NH2-POSS offered positively charged sites for enhanced divalent cation repulsion while the deprotonated carboxyl groups from polyamide network can afford negatively charged sites for divalent anion repulsion. The optimized membrane displayed high rejections to both divalent anionic and cationic ions (Na2SO4 rejection of 98.2%, MgCl2 rejection of 98.0%), together with high mono-/divalent salt selectivity (NaCl/Na2SO4 of 48.2, LiCl/MgCl2 of 43.9) that outperformed the benchmark nanofiltration membranes. This molecularly-hybridized charge modulation method may enlighten the structural design of membranes for efficient ionic separations.

Graphene oxide (GO) membrane has triggered great attention in proton conduction, benefitting from the well-aligned interlayer nanochannels and oxygen-containing groups. However, GO membrane exhibited a relatively low proton conductivity because of the deficiency of proton-conducting groups on basal plane. Herein, sulfonated lignin (SL) was explored as a multifunctional intercalator to prepare highly conductive GO/SL membranes. The resultant GO/SL membrane with the SL mass fraction of 100% exhibits the highest proton conductivity of 346 mS cm−1 at 80 °C, 100% RH and 7.5 mS cm−1 at 80 °C, 40% RH, which are 3 times and 13 times higher than that of pristine GO membrane, respectively. Bearing abundant sulfonic acid groups and ether bonds, SL acts as both proton donors and acceptors, affording additional proton hopping sites and forming continuous hydrogen bond network for proton transfer. The continuous interlayer nanochannels along with the low-energy-barrier proton hopping pathways render GO/SL membranes highly elevated proton conductivity. Moreover, the GO/SL membrane with the SL mass fraction of 100% achieves a significantly increased maximum power density by 162.7% up to 169.2 mW cm−2 at 60 °C, 100% RH.

Traditional preparation processes of chloride-free potash fertilizers (KNO3, K2CO3 and K2SO4) have certain limitations, such as complicated operation and existing potential pollution. In this work, electrodialysis metathesis (EDM) was used to prepare these fertilizers using KCl and acid radical salt (nitrate, carbonate and sulfate) as raw materials. Firstly, as current density increases from 10 to 25 mA/cm2, energy consumption grows from 0.41 to 0.64 kW h/kg KNO3, while KNO3 product purity improves from 92.36 to 95.91 wt%. Secondly, different sulfate sources, such as MgSO4, Na2SO4 and (NH4)2SO4, were used to investigate the effects of cation species, showing that the orders of energy consumption and impurity cations in product are E M g SO 4 > E Na 2 SO 4 > E ( NH 4 ) 2 SO 4 and W NH 4 > W Na > W Mg , and (NH4)2SO4 is regarded as the suitable sulfate source. Thirdly, NaNO3, Na2CO3 and Na2SO4 were selected to investigate the effects of anion species. The order of average energy consumption is E ‾ K 2 CO 3 > E ‾ K 2 SO 4 ≈ E ‾ KNO 3 , while that of average current efficiency is η ‾ K 2 SO 4 > η ‾ K 2 CO 3 > η ‾ KNO 3 . Besides, compared with other two fertilizers, generated KNO3 product purity is comparatively higher. Finally, economic evaluation results showed that EDM has great potential applications in preparing chloride-free potash fertilizers, especially for KNO3 and K2CO3.

An experimental study was carried out on the batch preparation of high basicity polyferric sulfate (PFS) by hydroxide substitution from bipolar membrane electrodialysis (BMED) with BP-A configuration. Effects of operation time, current density, and molar feed ratio of FeSO4 to H2SO4 on PFS properties were investigated. Results show that increasing operation time and molar feed ratio may increase the PFS basicity, turbidity removal ratio, and energy consumption simultaneously; meanwhile, increasing current density could increase the basicity and turbidity removal ratio but decrease the energy consumption. When the current density is 20 mA/cm2, the basicity attains to 14.72%, turbidity removal ratio increases to 93.43%, and energy consumption decreases to 2.72 kW·h/(kg H2SO4). Moreover, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) were conducted to determine the structure and morphology analysis of solid PFS.

Exosomes, which are lipid membrane-enclosed nanovesicles (30−150 nm in diameter), contain abundant proteomic and genetic information. Specifically, tumor-derived exosomes have been recognized as ideal biomarkers for cancer diagnosis. However, effective methods for isolating as well as detecting exosomes are still challenging. Herein, we have developed an immunoaffinity-based microfluidic device HBEXO-Chip which can directly separate exosomes from plasma. This separation technology enables capturing the exosomes through tumor specific surface markers, such as the pancreatic cancer target Glypican-1 employed in this study, to prevent the interference of non-specific exosomes. Compared with the traditional exosomes separation workflow, HBEXO-Chip shows excellent specific exosomes separation performance. We demonstrated that GPC1+ exosomes can distinguish pancreatic cancer from Pancreatitis group and healthy control group. Additionally, we identificate a miRNA signature for pancreatic cancer through RNA sequencing. Finally, we found 2 miRNAs with diagnostic value for pancreatic cancer in these differentially expressed miRNAs, namely miR-125b-5p and miR-214−3p.

Harvesting energy from biogas is a potential way to retard the depletion of fossil fuels and fight against global warming simultaneously. Membrane technology holds great promise to achieve cost-effective biogas upgrading, along with advantages of low energy consumption and environmental friendliness, which leads to extensive exploration in fabricating CO2 membranes with high separation performance. In this study, mixed matrix membranes are fabricated by incorporating exfoliation-free layered double hydroxides laminates intercalated with amino acids (Phe with hydrophobic side chains and Glu with hydrophilic side chains) into a low-cost commercial Pebax (poly (amide-b-ethylene oxide)) polymer. Both amino and carboxyl groups can facilitate the transport of CO2 through quadrupole moment interaction, enlarged interlayer spacing and reversible reaction. Particularly, MMM containing 5 wt% AA-LDH exhibits an optimal permeability of 790 Barrer and a promising CO2/CH4 selectivity of 31, which is 64.6% and 83.9% higher than the pristine Pebax membrane, respectively. The distinct advantages in terms of facile fabrication and processability confer the LDH-based membrane with great potential for large-scale CO2 capture and separation.

This paper aims at investigating the nonlinear vibration characteristics of the piezoelectric elliptic thin plate under the combined action of external harmonic excitation and temperature field. Based on the Von-Karman plate theory of large deflection, the nonlinear governing equation is derived by using the Bubnov-Galerkin method. Then, the amplitude-frequency response equations are further obtained using the multi-scale method, and the stability conditions of the steady solution are determined according to the Routh-Hurwitz criterion. The effects of the temperature difference at the plate center, the effective damping coefficient, the external excitation amplitude, and the ratio of the semi-major axis to the semi-minor axis on superharmonic and subharmonic resonances behaviors of the piezoelectric elliptic thin plate are analyzed. It is found that the coexistence region of multiple solutions and the resonant amplitude decrease for superharmonic resonance, as the temperature difference at the plate center increases. For subharmonic resonance, with the increase in the temperature difference at the plate center, the response amplitude increases, while the distance between two branches of the amplitude-frequency response curve has no obvious change. The softened/hardened nonlinear characteristics of the system are determined by the ratio of the semi-major axis to the semi-minor axis of the piezoelectric elliptic thin plate.

Membrane separation is an energy-efficient technology to achieve biogas upgrading. However, their broad application is limited by the relatively low gas permeability and thus the large membrane area. Polymers of intrinsic microporosity (PIMs), as a kind of highly permeable polymers, hold great promise to solve this problem but are restricted by their relatively low selectivity. In this study, significant enhancement in the selectivity of highly permeable PIM-1 membranes was achieved through incorporating amino-functionalized zeolitic imidazolate framework ZIF-7 to prepare mixed matrix membranes (MMMs). NH2-ZIF-7 exhibits not only excellent intrinsic CO2/CH4 separation ability but also favorable interaction with the PIM-1 polymer. The fortified interfacial interaction generates the rigidification of polymer chains at the interface and partial blockage of NH2-ZIF-7 particles, which both contributes to the enhancement of CO2/CH4 diffusion selectivity. Notably, the CO2/CH4 selectivity of the mixed matrix membrane containing 20 wt% NH2-ZIF-7 increased to 20.6 with CO2 permeability of 2953 Barrer, which transcended the reported 2008 upper bound of polymer membranes. To analyze the gas transport behavior within MMMs and explain the enhanced selectivity, a modified Maxwell model considering rigidified polymer region and partially blocked particle skin was proposed and validated by the good consistency between the experimental and predicted data.

Magnetic iron based materials are generally effective for many catalytic reactions and can be magnetically recovered after application, showing advantages than other metal oxides. In the present work, magnetic MnFe2O4 nanoparticle and MnFe2O4-reduced graphene oxide (rGO) hybrid were prepared and used as catalysts to activate peroxymonosulfate (PMS) to oxidatively degrade various organic pollutants in water. From a process of chemical deposition and reduction, MnFe2O4-rGO hybrids were produced with nanosized MnFe2O4 particles (ca. 13.2 nm). It was found that MnFe2O4 or MnFe2O4-rGO presented high activity in activating PMS to produce sulfate radicals for degradation of organic dyes (Methyl violet, Methyl orange, Methylene blue, Orange II and Rhodamine B) and could be separated with a magnet without any loss. The reaction kinetics, effect of different ion species CL(-),HCO3(-),CH3COO(-)and NO3(-) and Cl(-) strength, reaction temperature (25-65°C), catalytic stability, as well as degradation mechanism were comprehensively studied. The lower activation energy on MnFe2O4-rGO (25.7 kJ/mol) justify the higher chemical performance than that of MnFe2O4 (31.7 kJ/mol), suggesting that graphene plays a significant role in the enhanced degradation of dyes. More importantly, the as-prepared MnFe2O4 and MnFe2O4-rGO hybrid exhibited stable performance to remove the organic pollutants in wastewater with easy recycling and good stability by successive degradation experiments.

Three types of supported hybrid membranes and Pd-Cu/MoO3-SiO2 catalyst were prepared. The chemical structure, thermal stability, pore size distribution and gas permeability of hybrid membranes were characterized by methods of scanning electron microscopy (SEM), thermogravimetric analysis (TGA), nitrogen adsorption and gas permeability measurement, and their applications for partial oxidation of propane with carbon dioxide to propylene were studied in membrane catalytic reactors. The experiment results showed that three types of hybrid membranes have good thermal stability, excellent gas permeability and hydrophilic properties. The water vapor could permeate through three types of hybrid membranes in a greater rate than C3H8, C3H6, CO2 and CO gas. Under proper reaction conditions, the reaction results in membrane catalytic reactors are all higher than those in conversional catalytic reaction. The conversion of propane is obviously beyond the equilibrium conversion when the hybrid membrane reactors were used to instantaneously withdraw the product H2O. The effects of the membrane reactors on the catalytic reaction performances were mainly related to the membranes permselectivity and the separation factors of H2O.

PowerPoint as a popular tool is active in forums, including stands, kiosks presentations, Internet format, navigation controls in PowerPoint interactive presentation plays a crucial role in the production. Studied the production problems of interactive presentations in PowerPoint multimedia production in this paper, some methods about how to use the navigation controls in creating interactive presentation were introduced, for example, how to contain Web cross-reference in slides, how to set the hyperlink hidden slides and the invisible “back” button, how to custom show. The specific examples were given. Finally, the kiosk mode in interactive show, as well as the major factors to consider, as published as a CD format, Web formats, and so were described in a simple way.

Excessive and annoying vibrations in buildings, stadiums, and footbridges have become more common in the past two decades due to several reasons including the tendency to optimize the use of building materials, use of higher strength and lighter structural properties, etc. Stair vibrations have also become an important design issue mainly due to the architects’ desire to create more innovative, slender, light, and flexible monumental structures. Large vibrations and movements of stairs can become serious safety and serviceability problems, as they have the potential to disrupt the evacuation during an emergency and also people may feel unsafe during the normal use. Even though over the past two decades a large number of research studies on the floor vibrations have been conducted, very little information is available for stairs. This paper presents experimental and analytical studies of a large monumental stair. Using an electrodynamic shaker and a series of seismic accelerometers, a set of modal tests was performed on the structure. This was done to estimate the dynamic properties of the stair. A computer model of the structure was created using the common practices used in structural engineering design offices. Comparison of the measured stair responses and the results of computer analysis showed reasonable agreement. A Cumulative Modal Assurance Criterion (CMAC) was introduced, and was used to identify the degrees of freedom with low quality measured responses. It was found that CMAC performs better than Enhanced Coordinate Modal Assurance Criterion (ECOMAC) and Coordinate Modal Assurance Criterion (COMAC) when the response is due to the excitation of a single mode. Several walking and running tests were conducted on the structure, which showed the structure may not be susceptible to large levels of vibrations for everyday use.

Starting with the elastic–plastic mechanics theory and the finite element method, the major models of the cockpit, the crew, and others, which have influence on the safety of the crew in the collision, have been established, and then the safety of the crew has been studied. Using the VPG, the free-fall simulation model has been presented, and the test model has been verified in comparison. On this basis, the collision simulation analysis model has been established, and the initial parameters of the speed and position have been set. By analyzing the results, the dynamic movement of the crew under the impact, the dynamic response of the crew under the head-on collision, and the motion curve of the key parts can be obtained, which provide an effective basis for the further study of the crew safety in the head-on collision.

Magnetic iron based materials are generally effective for many catalytic reactions and can be magnetically recovered after application, showing advantages than other metal oxides. In the present work, magnetic MnFe2O4 nanoparticle and MnFe2O4-reduced graphene oxide (rGO) hybrid were prepared and used as catalysts to activate peroxymonosulfate (PMS) to oxidatively degrade various organic pollutants in water. From a process of chemical deposition and reduction, MnFe2O4-rGO hybrids were produced with nanosized MnFe2O4 particles (ca. 13.2 nm). It was found that MnFe2O4 or MnFe2O4-rGO presented high activity in activating PMS to produce sulfate radicals for degradation of organic dyes (Methyl violet, Methyl orange, Methylene blue, Orange II and Rhodamine B) and could be separated with a magnet without any loss. The reaction kinetics, effect of different ion species CL(-),HCO3(-),CH3COO(-)and NO3(-) and Cl(-) strength, reaction temperature (25-65°C), catalytic stability, as well as degradation mechanism were comprehensively studied. The lower activation energy on MnFe2O4-rGO (25.7 kJ/mol) justify the higher chemical performance than that of MnFe2O4 (31.7 kJ/mol), suggesting that graphene plays a significant role in the enhanced degradation of dyes. More importantly, the as-prepared MnFe2O4 and MnFe2O4-rGO hybrid exhibited stable performance to remove the organic pollutants in wastewater with easy recycling and good stability by successive degradation experiments.