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This article presents a model reference adaptive system (MRAS) speed observer based on the power winding (PW) active power and reactive power for dual-cage rotor brushless doubly fed induction generator (DCR-BDFIG). The mathematical relationship between the PW current and control winding (CW) current is derived first. Then, to reduce costs and to improve the reliability, a PW power-MRAS-based speed observer is designed with the stability analyzed. In the proposed speed observer, the PW power is selected as the reference model since it is relatively readily available and smooth due to the clamped PW voltage under grid-connected condition. In addition, only the CW current is required to be measured for the estimated PW power of the adaptive model, being simple and easy implemented. Finally, combining the proposed speed observer and the grid-connected power control system, a complete speed sensorless control system for grid-connected DCR-BDFIG is designed and implemented to regulate the active power and reactive power independently. The detailed simulation and experiments are carried out, showing that the estimated rotor speed can track its real values with minor steady-state errors and fast transient responses. Both simulation and experiments verify the effectiveness of the proposed speed sensorless control method for DCR-BDFIG. [ABSTRACT FROM AUTHOR]

This paper addresses newsvendor problem by endogenizing product availability effect on consumer demand. Specifically, we consider two retailers that sell a same product under a centralized or a decentralized market. The consumers are heterogeneous in their search costs, and make strategic choices based on the probability of product availability of different retailers. Building a game-theoretic model, we show that in addition to a symmetric Nash equilibrium, there may exist asymmetric equilibriums to the inventory competition game in the decentralized market. Nevertheless, the symmetric equilibrium is stable to maximize the total profit of two competing retailers. Then, we find that the retailers' inventory decisions exhibit a "pull-to-center" bias when they ignore the product availability effect on consumer demand. In particular, for a small (large) product valuation, a retailer that ignores this effect will stock more (less) quantities and provide a higher (lower) fill rate than the benchmark optimum, thus pulling the inventory policy upward (downward). More interestingly, we show that such ignorance can be bliss in the decentralized market. Benefiting from the weakened competition, the retailers might perform better than the benchmark when they ignore the product availability effect. The welfare implications for both consumers and whole society are explored in the meantime. The findings also reveal some novel insights into the behavioral newsvendor research. • We study newsvendor problem with product availability effect in different markets. • The optimal/equilibrium inventory policies are derived and analyzed. • Pull-to-center bias exists when retailers ignore the product availability effect. • Ignorance can be bliss due to weakened competition in the decentralized market. • The welfare implications for consumers and society are explored for novel insights. [ABSTRACT FROM AUTHOR]

This article presents a robustness-improved control method combining super-twisting sliding mode control (ST-SMC) based control winding (CW) current controller and PI-based power regulator for cascaded brushless doubly fed induction generator (CBDFIG). To reduce the computation burden of the controller, the strong robustness and the fast dynamic response of the ST-SMC is extremely suitable for the inner CW current loop whose control period is smaller than that in the outer power loop. Therefore, the state-space model of CBDFIG is derived and a robust CW current controller is designed based on the ST-SMC with the stability analyzed. In addition, according to the relationship among the electrical variables of CBDFIG deduced, a PI-based power regulator is designed with the stability analyzed and the parameters selected to achieve a satisfying steady-state performance. Finally, the simulation and experimental results based on a 5-kW prototype CBDFIG demonstrate the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]

With the widespread application of immune checkpoint inhibitors, a series of adverse events (AEs) related to treatment resulting from alterations in the immune system have emerged that warrant attention. The present study report the case of a patient with reactive cutaneous capillary endothelial proliferations (RCCEPs) on the eye lid, following treatment with the programmed cell death protein 1 inhibitor camrelizumab (SHR-1210) for stage IIa2 well- to moderately differentiated squamous cell carcinoma of the cervix. Although RCCEPs have been revealed to be the most common AEs of SHR-1210, they are usually distributed on the head, neck, trunk and extremities. The current study presents a rare case of ocular RCCEPs induced by SHR-1210. Prompt diagnosis and treatment of immune-related AEs is crucial for the optimal management of patients. Although RCCEPs are usually slight-risk toxicities that pose no threat to the continuity of treatment, lesions with unusual distributions that cause disturbances in normal life require proper treatment, such as surgical excision. [ABSTRACT FROM AUTHOR]

This article proposes a dual-objective control method using a sliding-mode control (SMC)-based control winding (CW) current controller for cascaded brushless doubly fed induction generator (CBDFIG), where the smooth grid synchronization and flexible grid-connected power regulation are achieved with the same CW current controller. A so-called virtual grid flux method is introduced to obtain the CW current reference value for the grid synchronization. In addition, according to the relationship between the power winding (PW) power and CW current, a novel direct power control method is proposed for CBDFIG. Furthermore, a unified form of the CW current references is investigated to achieve the dual-objective control for CBDFIG, where no mode switching operation is required and constant switching frequency can be achieved in both the control processes with space vector pulsewidth modulation. The proposed control method shows a strong robustness against the grid voltage disturbances, which is necessarily required in both the grid synchronization and grid-connected power regulation. The simulation and experiments are conducted to validate the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]

Low weight molecules induced self-organization behavior was proposed to tune nanophase separation morphology of sulfonated nonfluoroniated aromatic polymer membrane for improving proton conductivity. Sulfonated poly (ether ether ketone) (SPEEK) was selected as the model polymer here. Hydrophobic tetrachloroethylene (C 2 Cl 4), amphiphilic circular molecule 3,4-dimethylbenzaldehyde (DMBA) and amphiphilic linear alcohols were adopted to induce the self-organization of SPEEK membranes. The self-organization mechanism was investigated by combined experimental and molecular dynamic simulation for the first time. Induced by hydrogen bonding and hydrophobic interaction, the amphiphilic inducers improved both proton conductivity and mechanical properties of SPEEK membranes. Moreover, owing to the effects of multiple hydrogen bonds and linear molecular structure, amphiphilic linear alcohols increased the proton conductivity more significantly than amphiphilic circular molecule DMBA. Among several linear alcohols, the molecular length of n -BuOH (5.0 Å) perfectly matched the distance between hydrogen of the sulfonic acid group and the benzene ring of SPEEK, resulting in the highest proton conductivity. The study provides significant guidance for exploring proton exchange membranes with well-connected proton conductive channel and high proton conductivity. Image 1 • Self-organization behavior tuned nanophase separation morphology of polymer membrane. • Self-organization mechanism was studied by experimental and molecular simulation. • The linear alcohol with L M equaling to D H-B exhibited the strongest inducing effect. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the possible functions and mechanisms of positive and negative costimulatory molecules in the pathological process of myasthenia gravis (MG). The expression levels of membrane-bound inducible costimulator (ICOS) and programmed cell death 1 (PD-1) in peripheral blood T cells, their corresponding ligands ICOSL and PDL-1 on B cells, and their soluble forms (sICOS, sPD-1, sICOSL, and sPDL-1) in plasma were detected in patients with untreated-stage MG (USMG) and remission-stage MG (RSMG). The results showed that the expression levels of membrane-bound ICOS and PD-1 in the peripheral blood T cells of the USMG group and their corresponding ligands ICOSL and PD-L1 on B cells were significantly increased compared to those in the RSMG group and healthy controls (HCs). The levels of sICOSL and sPD-1 were significantly upregulated in USMG patients compared to those in the RSMG and HC groups, while the levels of sICOS and sPD-L1 were not different. The expression of PD-L1 on CD19+ B cells was positively correlated with the concentrations of AchR Ab in the USMG group. The expression of ICOS and PD-1 in CD4+ T cells and the expression of ICOSL and PD-L1 on CD19+ B cells were positively correlated with the quantitative myasthenia gravis (QMG) scores in the USMG group. Also, in the USMG group, the plasma levels of sICOSL and sPD-1 were positively correlated with the QMG scores. In addition, the percentage of peripheral blood follicular helper T (Tfh) cells in the USMG group was positively correlated with ICOS and PD-1 expression on CD4+ T cells and ICOSL and PD-L1 expression on CD19+ B cells. There were positive correlations between sICOSL and sPD-1 levels and the percentage of peripheral blood Tfh cells and plasma interleukin-21 (IL-21) levels in the USMG group. The results suggest that the positive ICOS/ICOSL and negative PD-1/PD-L1 costimulatory molecule pairs participate in the pathological process of MG. Abnormal sICOSL and sPD-1 expression might interfere with the normal signal transduction of ICOS and PD-1 on Tfh cells, causing excessive activation of Tfh cells and promotion of disease progression. sICOSL and sPD-1 have potential value in monitoring MG disease states. • The expression levels of membrane-bound inducible costimulatory (ICOS) and programmed cell death 1 (PD-1) and its ligands in the peripheral blood lymphocyte subsets of MG patients were all significantly increased. • The levels of soluble inducible costimulator ligand (sICOSL) and soluble programmed cell death 1 (sPD-1) were significantly upregulated in MG patients in the untreated stage, and were positively correlated with the percentage of peripheral blood Follicular helper T (Tfh) cells and the level of interleukin-21 (IL-21). • sICOSL and sPD-1 have potential value in monitoring MG disease states. [ABSTRACT FROM AUTHOR]

To achieve a better performance of anion exchange membranes (AEMs), AEMs of a unique structure with flexible and dense side chains are prepared by taking amino groups on poly (aryl ether ketone)s (PAEKs) as reaction sites and grafting four long side chains on each repeat unit of main chains. This chemical synthetic route for the unique structure is simple and controllable, with no obvious side reactions happening during synthetic process. Three different kinds of cycloaminium cations are used as functional groups. The AEMs with this unique structure exhibit limited swelling ratios and improved hydroxide conductivities, of which the highest attains 74.4 mS cm−1 at 80 °C when using N-Methylmorpholine (Mm) as the cation group. The high conductivities are due to the formation of connective ion conducting channels facilitated by this kind of structure inside the membranes. No obvious changes in chemical structures of AEMs with different cations happen after alkali treatment for 768 h at 60 °C, indicating a good alkaline stability of AEMs with such specific structure. Moreover, the PAEK-MmOH yields a maximum power density of 302 mW cm−2 at 640 mA cm−2 when operating in a single fuel cell. Overall, these long-branched and densely functionalized AEMs with cycloaminium cation groups possess good application prospects in fuel cells. • Long-branched and densely functionalized anion exchange membranes are prepared. • The synthesis route for the unique structure is simple and controllable. • The membrane shows excellent performances. [ABSTRACT FROM AUTHOR]

Abstract Friedel-Crafts alkylation route is proposed to synthesis polysulfone based anion exchange membrane (AEM) containing pendent imidazolium-functionalized side chain with the purpose of avoiding conventional carcinogenic chloromethylation. It has no special functional group requirements on the polymer materials, which has advantage over those reported chloromethylation free routes. A novel flexible alkylation reagent containing -(CH 2) 4 - spacer, (1-chlorobutyl-2,3-dimethylimidazole chloride) is synthesized and promotes hydrophilic/hydrophobic micro-phase separation structure in the membranes proved by small angle X-ray scattering (SAXS) and transmission electron microscopy image (TEM). The imidazolium-functionalized polysulfone AEMs prepared by the Friedel-Crafts alkylation route in this study exhibit first level properties compared to other AEMs prepared without chloromethylation. The ion conductivity-normalized swelling ratio (0.08% cm mS−1 at 80 °C) is the lowest, while exhibits higher or equivalent IEC normalized ion conductivity (56.8 S g cm−1 mol−1 at 80 °C). The membranes prepared in this work also display good thermal, mechanical and alkaline stabilities. Graphical abstract fx1 Highlights • Friedel-Crafts alkylation route to synthesis polysulfone based AEM. • A novel flexible alkylation reagent containing -(CH 2) 4 - spacer. • Obvious hydrophilic/hydrophobic micro-phase separation structure. • Low ion conductivity-normalized swelling ratio. [ABSTRACT FROM AUTHOR]

Tuning the hydrophilic/hydrophobic nanophase-separated morphology to enhance the conductivity is a considerable challenge in the field of anion exchange membranes (AEMs). Here, a series of novel aliphatic-aromatic copolymer AEMs were designed by embedding flexible alkyl chains of different lengths into rigid main chain of poly(ether sulfone). Compared to traditional aromatic polymer, the aliphatic-aromatic copolymers had more flexible main chains and longer hydrophobic segments, both of which promoted the nanophase separation and the formation of ionic clusters. Increasing aliphatic chain length made the ionic clusters larger and more interconnected, but too long aliphatic chain led to the formation of smaller ionic clusters because the ionic groups were far away from each other. An optimum length of the aliphatic chain (8 C) existed for the nanophase-separated morphology with the biggest ionic clusters (around 8 nm), with which the membrane showed the highest conductivity. A peak power density of 159 mW cm −2 was obtained for the cell incorporating the 8 C membrane. Based on these, this study reveals a new direction to create a tunable nanophase-separated morphology for high-performance AEMs. [ABSTRACT FROM AUTHOR]

Keratoconus (KC) is a progressive degenerative disease that usually occurs bilaterally and is characterized by corneal thinning and apical protrusion of the cornea. Oxidative stress is an indicator of the accumulation of reactive oxygen species (ROS), and KC keratocytes exhibit increased ROS production compared with that of normal keratocytes. Therefore, oxidative stress in KC keratocytes may play a major role in the development and progression of KC. Here, we investigated the protective effect of sulforaphane (SF) antioxidants using a hydrogel-simulated model of the cell mechanical microenvironment of KC. The stiffness of the KC matrix microenvironment in vitro was 16.70 kPa and the stiffness of the normal matrix microenvironment was 34.88 kPa. Human keratocytes (HKs) were cultured for 24 h before observation or drug treatment with H2O2 in the presence or absence of SF. The levels of oxidative stress, nuclear factor E2-related factor 2 (Nrf-2) and antioxidant response element (ARE) were detected. The high-stress state of HKs in the mechanical microenvironment of KC cells compensates for the activation of the Nrf-2/ARE signaling pathway. H2O2 leads to increased oxidative stress and decreased levels of antioxidant proteins in KC. In summary, SF can reduce endogenous and exogenous oxidative stress and increase the antioxidant capacity of cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Single-atom Co catalysts with more Co-N 4 sites were successfully synthesized. • The catalyst exhibits an excellent ORR electrocatalytic activity. • The catalyst based Zn-air batteries shows higher peak power density. • DFT confirm that more Co-N 4 sites can lower the reaction energy barrier of ORR. Transition metal single atom catalysts (TM SACs) are the most promising oxygen reduction reaction (ORR) catalysts for proton exchange membrane fuel cells (PEMFCs) and metal-air batteries. However, the low density of M-N x active sites seriously hinders further improvement of the ORR electrocatalytic activity. Here, a strategy for encapsulating nitrogen-rich guest molecules (triethylenediamine cobalt complex, [Co(en) 3 ]3+) was proposed to construct a high-performance cobalt single-atom catalyst (Co-encapsulated SAC/NC). With this strategy, the guest molecules are encapsulated into metal–organic framework (MOF) cages as an additional cobalt source to boost cobalt loading, while abundant nitrogen from guest molecules contributes to the formation of Co-N 4 active sites. Remarkably, the resulting Co-encapsulated SAC/NC has a high cobalt loading amount of 4.03 wt%, and spherical aberration-corrected transmission electron microscopy (AC-TEM) has confirmed that most cobalt exists in a single-atom state. As a result, the Co-encapsulated SAC/NC exhibits excellent ORR catalytic performance with a half-wave potential of 0.88 V. Furthermore, Zn-air batteries employing Co-encapsulated SAC/NC as air cathode show high peak power density and excellent cycling stability. Density functional theory (DFT) calculations reveal that adjacent active sites have different rate-determining steps and lower reaction energy barriers than a single active site. [ABSTRACT FROM AUTHOR]

A novel in situ hydrolysis reaction method has been developed for the controllable synthesis of ternary CdIn 2 S 4 /In(OH) 3 /Zn 2 GeO 4 nanocomposite. The CdIn 2 S 4 and In(OH) 3 content in the ternary system can be conveniently tuned by varying the pH value of the reaction system. The ternary CdIn 2 S 4 /In(OH) 3 /Zn 2 GeO 4 (pH = 6.5) nanocomposite sample exhibited the highest photocatalytic H 2 production rate of 1426.90 μmol h −1  g −1 , without the assistance of a noble metal. A possible mechanism of H 2 -production activity was proposed. The photo-generated electrons in the CB of CdIn 2 S 4 can transfer to the CB of In(OH) 3 and Zn 2 GeO 4 , resulting in a rapid separation of photo-generated electrons and holes. This work can not only provide an excellent candidate for visible-light H 2 evolution, but also provide an efficient strategy for designing of new system with high activity for solar hydrogen generation. [ABSTRACT FROM AUTHOR]

A novel long-side-chain sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (S-L-PPO) membrane was successfully prepared for VRFB applications. The long side chains were introduced onto the PPO backbones by a simple and controllable acylation with 4-fluorobenzoyl chloride and a subsequent condensation with sodium 4-hydroxybenzenesulfonate. The introduction of long side chains drives the formation of a good hydrophilic/hydrophobic micro-phase separation structure, which is evidenced by AFM. The S-L-PPO membrane with a degree of sulfonation (DS) of 51% showed an ultralow vanadium permeability (4.3 × 10 −9 cm 2 s −1 ) and a decent proton conductivity (44 mS cm −1 ). As a result, the energy efficiency of VRFB with S-L-PPO-51% membrane was up to 81.8% that was higher than that with Nafion 212 (78.0%) at a current density of 120 mA cm −2 . In addition, the self-discharge duration of the cell with S-L-PPO-51% membrane was 222 h that was nine times longer than that of Nafion 212 (23 h). All these indicate that the membrane prepared here is promising for the application in VRFB. [ABSTRACT FROM AUTHOR]

A novel amphoteric membrane was prepared using imidazolium-functionalized polysulfone (ImPSf) as the base polymer and sulfonated poly (ether ether ketone) (SPEEK) as the acid polymer for vanadium flow battery applications. The introduction of the ImPSf effectively resists the migration of vanadium ions owing to the Donnan repelling effect of the imidazolium cations on the vanadium ions and the low swelling ratio of the amphoteric membranes due to the ionic cross-linked interactions between the imidazolium and sulfonic groups. The amphoteric membrane with an ImPSf mass ratio of 17% shows a vanadium permeability of 1.5 × 10 −8 cm 2 s −1 that is much lower than that of Nafion212 (21 × 10 −8 cm 2 s −1 ). Having a high IEC of 2.04 mmol g −1 , it also exhibits a low area resistance of 0.48 Ω cm −2 that is comparable to that of Nafion212 membrane (0.41 Ω cm −2 ). As a result, the VFB cell with the amphoteric membrane exhibits high performances even at high current densities, i.e. at a current density of 200 mA cm −2 , and the amphoteric membrane achieves a coulombic efficiency of 97.5% and an energy efficiency of 77.3%, both of which are higher than those of Nafion212 (92.4% and 73.4%). These results indicate that the ImPSf/SPEEK amphoteric membrane is promising for VFB applications. [ABSTRACT FROM AUTHOR]

A new series of thermoplastic interpenetrating polymer network (TIPN) anion exchange membranes (AEMs) based on poly [2,2′- (p-oxydiphenylene) −5, 5′-bibenzimidazole] (OPBI) and poly(1, 2-dimethy-3-allylimidazolium) (PDAIm) (PBI/DAIm TIPN) has been developed. With 1, 2-dimethy-3-allylimidazolium (DAIm) polymerization in presence of OPBI polymer chains, two kinds of uncrosslinked polymer chains, i.e. PDAIm and OPBI interpenetrate with each other to form a physically crosslinking network. Small steric hindrance effect of the DAIm monomer and non-covalent crosslinking interpenetrating polymer chains contribute to better compatibility and chains flexibility in the TIPN compared with the blend and semi-interpenetrating networks, which are evidenced by SEM and SAXS, promote the aggregation of hydrophilic groups and induce connective ionic conductive channels. PBI/DAIm TIPN membranes achieve well-balanced performance between high hydroxide conductivity and dimensional stability because of the dynamically forced compatibility feature of TIPN. Especially, the PBI/DAIm TIPN-65/0.5 membrane exhibits high hydroxide conductivity (96.7 mS cm −1 ) and low swelling ratio (4.4%) at 80 °C. With low overall alkali uptake (2.89%) and IEC (0.63 mmol g −1 ) of functional groups, it exhibits excellent chemical stability in 1 M KOH at 60 °C for 96 h (94.0% retention) and high tensile strength (48.2 MPa) in hydrated state. These observations suggest TIPN structure provides a promising solution to the electrochemical-mechanical balance of AEMs. [ABSTRACT FROM AUTHOR]

Hydroxide exchange membrane fuel cells (HEMFCs) are attracting growing interest owing to their advantages such as low cost and high power density. However, their applications are hindered due to the poor stability of the membrane. Here, we proposed a novel strategy to improve the alkaline stability of hydroxide exchange membranes (HEMs) using the interactions between strongly polar nitrile groups and side-chain functional cations. A poly(ether nitrile) (PEN) was synthesized by the polycondensation of bisphenol A and 2,6-difluorobenzonitrile, and then imidazolium and morpholinium functional groups were integrated by the typical chloromethylation-functionalization method. The existence of the interactions between nitrile groups and cation groups i.e. imidazolium and morpholinium, was proved by the density functional theory calculations. The interactions have two positive effects that contribute to the improvement of the alkaline stability of the PEN based membranes. On the one hand, they increase the LUMO energies of the functional groups; and on the other hand they reduce the free volume around hydrated cationic groups. As a result, PEN based membranes showed much better alkaline stabilities compared to the membrane based on commercial polysulfone that has a similar chemical structure. In addition, given similar swelling ratios, PEN based membranes exhibited higher hydroxide conductivities than simple polysulfone based ones. [ABSTRACT FROM AUTHOR]

A novel approach is proposed to design anion exchange membranes (AEMs) containing pendent imidazolium side chains with flexible ether-containing spacer by the Williamson etherification between chloromethylated polysulfone and as-synthesized hydroxyl-bearing imidazolium. The introduction of long flexible ether-containing spacer chains enhances the mobility of terminated imidazolium groups and ion interactions. It facilitates the formation of a good hydrophilic/hydrophobic micro-phase separation structure, which is confirmed by the scattering peak of SAXS. As a result, the membranes exhibit high conductivity and excellent anti-swelling ability. The membrane with IEC of 1.55 mmol g −1 shows considerable hydroxide conductivity (72 mS cm −1 , 60 °C), low swelling ratio (7.3%, 60 °C), and great tensile strength in hydrated state (43.4 MPa, 20 °C). The existence of long spacer chain also improved the alkaline stability. After immersion in 60 °C, 1 M KOH solution for 168 h, hydroxide conductivity and tensile strength of the membrane remain constant. The ether-containing side chains fabricated in this work provides a universal promising method to balance hydroxide conductivity and dimensional and alkaline stability. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the efficacy and safety of microbial transglutaminases (mTGases) during scleral collagen cross-linking (CXL) in vivo. Sixteen New Zealand white albino rabbits were treated with sub-Tenon's injections of 2 ml of 1 U/ml mTGases in the right eye and 2 ml of phosphate buffer saline (PBS) in the left eye. The rabbits were killed 2 weeks after the injection, and all eyeballs, including some scleral strips, were processed. The elastic modulus was measured with a biomaterials tester. Histopathological analysis and transmission electron microscopy (TEM) were used for the morphological observations. The elastic modulus of the mTGase-treated sclera was 15.79 ± 2.93 MPa, and that of the control was 6.91 ± 2.23 MPa, indicating an increase of 129% after the mTGases treatment (P < 0.05). The density of the scleral collagen bundles and diameter of the collagen fibrils increased compared with those in the control group. No apoptosis was detected in the retina or posterior sclera by TUNEL staining, and no histological damage was observed on the TEM scan. This study is based on a short-term study on animal models. These results indicate that mTGase-mediated scleral CXL is a promising approach to effectively stiffen the sclera and safe enough for retina, and may be a useful treatment modality for strengthening scleral tissue. [ABSTRACT FROM AUTHOR]

A novel anion exchange membrane with tri-quaternized side chain has been developed in the present work. Di-cationic quaternary ammonium salt, 1-(4′-{1″-azonia-4″-azabicyclo [2.2.2] octyl} butyl) azonia-4-azabicyclo [2.2.2] octane (AABAA), is synthesized and used as tri-quaternization reagent. The tri-quaternized side chains enhance ionic interactions, which induce good micro-phase separation and excellent swelling resistance. Better aggregation of ionic clusters is observed in transmission electron microscopy (TEM) image in the tri-quaternized poly (ether sulfone) membrane (tri-QPESOH) compared to that in the mono-quaternized membrane (mono-QPESOH). Tri‐QPESOH membranes achieve a well-balanced performance between high hydroxide conductivity and dimensional stability. Especially, the tri-QPESOH membrane with IEC 2.31 mmol g −1 exhibits high hydroxide conductivity of 45.9 mS cm −1 at 25 °C and 130.9 mS cm −1 at 80 °C, and low swelling ratio of 21.5% even at 80 °C. Tri-QPESOH membranes also show improved thermal, mechanical and chemical stabilities. These observations suggest that the tri-cationic side chains provide a promising solution to the electrochemical-mechanical balance of anion exchange membranes. [ABSTRACT FROM AUTHOR]

An imidazolium-functionalized poly(ether ether ketone) containing a long spacer chain between imidazolium group and polymer main-chain (PEEK-AeImBr) was synthesized by the reaction of chloromethylated PEEK and self-synthesized 1-Aminoethyl-2,3-dimethylimidazolium bromide. 1 H NMR spectra confirmed the successful synthesis of PEEK-AeImBr. The corresponding PEEK-AeImOH HEM was prepared by casting the PEEK-AeImBr solution and subsequent ion-exchange process. Ion exchange capacity (IEC) of PEEK-AeImOH membranes ranges from 1.50 to 2.07 mmol g −1 with the degree of chloromethylation from 58% to 92%. Hydroxide conductivity of PEEK-AeImOH membranes increases with increasing IEC. PEEK-AeImOH membrane with IEC of 2.07 mmol g −1 has the highest conductivity of 48 mS cm −1 . The spacer-modified PEEK-AeImOH membrane maintained good alkali stability at 60 °C. The H 2 /O 2 single cell with the PEEK-AeImOH membrane exhibits high open circuit voltage of 1.02 V and peak power density of 120 mW cm −2 at room temperature. [ABSTRACT FROM AUTHOR]

As a popular optimization, particle swarm optimization has attracted many researcher's attention and also been successfully applied to solve many real world problems. As adopting the strategy of history experience, the convergence rate of PSO is faster than other evolutionary algorithms. But the individuals of PSO are easily be trapped into local optimum, which causes the algorithm could not guaranty confidence of the final results. In this paper, for further enhance the global search ability of PSO, based on comparing different chaos based random strategies, we propose a circle chaos based mutation strategy into PSO algorithm. First, compared with other operators, since the circle chaos based operator could generate more even results, we propose the circle operator based random strategy to balance the global and local search of our PSO algorithm. Second, for attracting individuals to precisely search in a promising region, a new historic experience based elite array is proposed to lead the search direction of population. Then the algorithm could achieve more precise results. For further proving the effectiveness of our algorithm, we apply the algorithm into PID fuzzy logic controller design. Compared with other EA algorithms, the experimental results demonstrate our methods achieve better performance on convergence rate and precise of results. [ABSTRACT FROM AUTHOR]

Abstract: A series of quaternary phosphonium-functionalized poly(ether ether ketone)s (PEEK-QPOHs) have been synthesized by phosphorization reaction, and their membranes have been prepared by a solution casting method. Ion exchange capacity (IEC) of PEEK-QPOH membranes ranges from 0.89 to 1.19mmolg−1 with the degree of chloromethylation from 70% to 126%. Not only are PEEK-QPOH polymers soluble in typical high-boiling-point membrane-forming solvents, but also they are soluble in some low-boiling-point water-miscible solvents (low alcohols), implying their ability to serve as both membranes and ionomers. PEEK-QPOH membranes showed high hydroxide conductivity, e.g., a PEEK-QPOH 126% membrane (with IEC of 1.19mmolg−1) exhibited 61 and 89mScm−1 at 20°C and 60°C, respectively. Based on the same polymer backbone of PEEK, quaternary phosphonium-functionalized PEEK membranes are more hydroxide-conductive and more alkali-stable than quaternary ammonium- and imidazolium-functionalized counterparts. All these properties indicate PEEK-QPOH is one of the most promising HEM materials for potential applications in alkaline membrane fuel cells. [Copyright &y& Elsevier]

Using a simple one-period model of a supply chain with one retailer and multiple risky suppliers, this paper studies questions of supplier selection and ordering policies among firms. A supplier is said to be unreliable when the quantity of goods effectively delivered by that supplier cannot correspond exactly to the order quantity. The question facing the retailer is to determine how many suppliers to contract and how much to order from each contracted supplier. We not only present the structural properties of the optimal ordering policy, but also analyze the effect of random yield and fixed ordering cost on the optimal policy and the retailer’s profit. [ABSTRACT FROM PUBLISHER]

ABSTRACT Modification of proton conductive channels (PCCs) in Nafion has been achieved with the assistance of 3, 4-dimethylbenzaldehyde (DMBA). During annealing, ionic clusters develop from small isolated spheres (1.72 nm) to wide continuous channels (5.15 nm), and the crystallinity of Nafion/DMBA membranes is also improved from 17% to 32% as shown by X-ray diffraction. Molecular dynamic simulation reveals that hydrogen bonding and hydrophobic interaction between DMBA and Nafion work synergistically to achieve better phase separation. The morphology-property relationship shows that, versus various PCCs width, the corresponding proton conductivities vary greatly from 0.079 to 0.139 S/cm at 80 °C. By carefully tuning the width of PCCs, the proton conductivity shows an improvement of 22-34% as compared with pristine Nafion. A significant enhancement on the maximum power density is achieved for the membrane electrode assembly on Nafion/DMBA-8h (as high as 1018 mW/cm−2), yielding an enhancement of 39% on pristine Nafion-8h (730 mW/cm−2). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 52, 1107-1117 [ABSTRACT FROM AUTHOR]

A series of imidazolium-functionalized poly(ether ether ketone)s (PEEK-ImOHs) were successfully synthesized by a two-step chloromethylation–Menshutkin reaction followed by hydroxide exchange. PEEK-ImOH membranes with ion exchange capacity (IEC) ranging from 1.56 to 2.24 mmol g−1 were prepared by solution casting. PEEK-ImOHs show selective solubility in aqueous solutions of acetone and tetrahydrofuran, but are insoluble in lower alcohols. PEEK-ImOH membranes with IEC of 2.03 mmol g−1 have high hydroxide conductivity (52 mS cm−1 at 20 °C), acceptable water swelling ratio (51% at 60 °C), and great tensile strength (78 MPa), and surprising flexibility (elongation-to-break of 168%), and high thermal stability (Decomposition temperature: 193 °C). In addition, PEEK-ImOH membranes show low methanol permeability (1.3–6.9 × 10−7 cm2 s−1). PEEK-ImOH membrane was tested in methanol/O2 fuel cell as both the HEM and the ionomer impregnated into the catalyst layer; the open circuit voltage is 0.84 V and the peak power density is 31 mW cm−2. [ABSTRACT FROM AUTHOR]

Substantial progress has been made in the stem cell therapy for liver fibrosis. However, the therapeutic effect is limited by de-creased self - renewal of stem cells during migration. Therefore, to improve the self - renewal of stem cells ater transplantation is urgent and essential for the successful application of stem cells in clinical practice. Current studies have shown that sex hormones have an impact on the self - renewal of stem cells. The effects of estrogens and androgens on the self - renewal of various stem cells and the functional differences between the stem cells from persons of different sexes are reviewed. Moreover, the effect of sex hormones on stem cell therapy for liver fibro-sis is discussed. It is considered that sex hormones have significant theoretical and clinical values for improving the self - renewal of stem cells and selecting appropriate stem cells in the stem cell therapy for liver fibrosis. [ABSTRACT FROM AUTHOR]

A series of soluble quaternized polyetherimides (QAPEIs) have been successfully synthesized by homogeneous quaternization in trimethylamine aqueous solution. 1H NMR spectra confirm the successful synthesis of QAPEI. The QAPEIs exhibit good solubility in membrane-preparation solvents, making it possible to prepare the QAPEI composite membrane. Novel composite hydroxide exchange membranes have been prepared by incorporating QAPEIs with polytetrafluoroethylene (PTFE) membranes. The SEM images, gas permeation measurements and FTIR spectra show that the QAPEI is successfully filled in PTFE membrane and the resulted composite membrane is dense and smooth. The ion exchange capacity of composite membranes ranges from 0.35 to 0.58 mmol g−1. The composite membranes have appropriate water uptake (≤154%) and moderate swelling ratio (≤42%) even at 60 °C. The hydroxide conductivity of the composite membrane reaches 11.9 mS cm−1 at 20 °C that increases to 35.2 mS cm−1 at 60 °C. TGA curve shows that the composite membrane possesses high thermal stability (T OD: 210 °C). All these properties indicate that the QAPEI/PTFE composite membranes are good candidates for use as HEMs in HEM fuel cells. [ABSTRACT FROM AUTHOR]

Abstract: Water sorption, water transport and ion transport are compared for polyether–ether ketone polymers functionalized with sulfonic acid, quaternary amine hydroxide, and imidazolium hydroxide. Water sorption in all three ionomers increases modestly with increasing water activity up to a w =0.6 and then increases more rapidly between 0.60.6. The increase in ion conductivity with increasing water activity is 10 times greater for the proton exchanged polymer compared to the hydroxide exchanged polymers. Water permeation from partially saturated vapor streams is primarily diffusion limited for all three ionomers and the permeation rates were approximately the same. Water pervaporation from liquid water appeared to be interfacial transport limited for membranes<120μm thick; the pervaporation rates at 40 and 60°C were independent of membrane thickness. Water sorption and transport show little dependence on the mobile ion while the ion transport appears to depend on both ion size and hydrophilicity of the fixed ion. [Copyright &y& Elsevier]

In order to increase both of the water uptake and conductivity, the proton exchange membranes were fabricated by sulfonated poly(ether ether ketone) (SPEEK) doped with varied contents of silica sulfuric acid (SSA) which is obtained by treating SiO 2 nanoparticles with more volatile SO 2 Cl 2 . SEM images of the composite membranes show that SSA nanoparticles are dispersed within the membranes uniformly, indicating the good organic compatibility of SSA particles. TEM images show that the composite membranes have improved ionic clusters distribution. The water uptakes of the composite membranes in water and under low relative humidities are all higher than that of the pristine SPEEK membrane. The addition of SSA enhances the conductivity obviously. The composite membrane containing 5wt.% SSA exhibits the highest conductivity of 0.13 Scm −1 at 80 °C, approximately 18.6% higher than that of the pristine SPEEK membrane and 8.6% higher than that of Nafion117. The composite membranes also show good thermal stability. These results imply the potential application of the SPEEK/SSA composite membranes as improved PEMs in PEMFC. [ABSTRACT FROM AUTHOR]

Abstract: In order to increase both of the water uptake and conductivity, the proton exchange membranes were fabricated by sulfonated poly(ether ether ketone) (SPEEK) doped with varied contents of silica sulfuric acid (SSA) which is obtained by treating SiO2 nanoparticles with more volatile SO2Cl2. SEM images of the composite membranes show that SSA nanoparticles are dispersed within the membranes uniformly, indicating the good organic compatibility of SSA particles. TEM images show that the composite membranes have improved ionic clusters distribution. The water uptakes of the composite membranes in water and under low relative humidities are all higher than that of the pristine SPEEK membrane. The addition of SSA enhances the conductivity obviously. The composite membrane containing 5wt.% SSA exhibits the highest conductivity of 0.13 Scm−1 at 80 °C, approximately 18.6% higher than that of the pristine SPEEK membrane and 8.6% higher than that of Nafion117. The composite membranes also show good thermal stability. These results imply the potential application of the SPEEK/SSA composite membranes as improved PEMs in PEMFC. [Copyright &y& Elsevier]

Abstract: A series of imidazolium-functionalized polysulfones were successfully synthesized by chloromethylation-Menshutkin two-step method. PSf-ImOHs show the desired selective solubility: insoluble in alcohols (e.g., methanol and ethanol), and soluble in 50 vol.% aqueous solutions of acetone or tetrahydrofuran, implying their potential applications for both the alcohol-resistant membranes themselves and the ionomer solutions in low-boiling-point water-soluble solvents. PSf-ImOH also possesses very high thermal stability (T OD: 258 °C), higher than quaternary ammonium and quaternary phosphonium functionalized polysulfones (T OD: 120 °C and 186 °C, repsectively). Ion exchange capacity (IEC) of PSf-ImOH membranes ranges from 0.78 to 2.19 mmol g−1 with degree of chloromethylation from 42% to 132% of original chloromethylated polysulfone. As expected, water uptake, swelling ratio, and hydroxide conductivity increase with IEC and temperatures. With 2.19 mmol g−1 of IEC, the PSf-ImOH 132% membrane exhibits the highest hydroxide conductivity (53 mS cm−1 at 20 °C), higher than those of all other reported polysulfone-based HEMs (1.6–45 mS cm−1) and other imidazolium-functionalized HEMs (19.6–38.8 mS cm−1). In addition, PSf-ImOH membranes have low methanol permeability of 0.8–4.7 × 10−7 cm2 s−1, one order of magnitude smaller than that of Nafion212 membrane. All these properties indicate imidazolium-functionalized polysulfone is very promising for potential applications in alkaline membrane direct alcohol fuel cells. [Copyright &y& Elsevier]

Abstract: Chloromethylated PEEK (CMPEEK) was successfully synthesized for the first time by concentrated sulfuric acid as the solvent and its degree of chloromethylation (DC) was controlled (38–98%) by varying the chloromethylation time. The sulfonation of PEEK was confirmed to be negligible during the chloromethylation by 1H NMR analysis. CMPEEKs are soluble in high-boiling-point solvents, which makes it possible to prepare CMPEEK membranes. Subsequently, it was quaternized and ion-exchanged by NaOH to form quaternized PEEK hydroxide (QAPEEKOH) membrane. The ion exchange capacity of QAPEEKOH membranes ranges from 0.43 to 1.35mmolg−1, and the corresponding degree of quaternization of chloromethyl group increases from 35% to 61%. QAPEEKOH membranes from DC of 38–70% have appropriate water uptake (≤145%) and moderate swelling ratio (≤27%) even at 60°C. More importantly, their hydroxide conductivities, such as 12mScm−1 at 30°C and 0.95mmolg−1 of IEC, are higher than those of most other quaternized aromatic polymer membranes. TGA shows that QAPEEKOH has high thermal stability (T OD: 148°C). All the above properties indicate that QAPEEKOH membrane is very promising for the potential application in hydroxide exchange membrane fuel cells. [Copyright &y& Elsevier]

This article considers the problem of joint replenishment and pricing decisions for a single product with fixed ordering costs and random supply in a fluctuated environment. We assume that the environment comprises a Markov chain with finite states and all the parameters are dependent on the environment states, such as supply, demand, and cost structure. Our objective is to maximize the total expected profit during the whole sales horizon by choosing an appropriate replenishment and pricing policy. We show that the form of the optimal ordering and pricing policy has an environment-dependent (s, S, p)-type. Moreover, we analyze the operational effects of random supply on the optimal policy and obtain that the optimal profit increases with the probability of receiving orders. The optimal profit function for the finite horizon problem converges to that for the infinite horizon problem under some mild conditions. [ABSTRACT FROM AUTHOR]

In this article, we consider an economic order quantity (EOQ) model with multiple suppliers and random yield. We show that the structure of the optimal ordering policy is not only dependent on the structure of setup cost but also on the distributions of random yield. For some particular cases of random yield, the optimal order quantity from each supplier can be formulated as an explicit form. [ABSTRACT FROM AUTHOR]

Abstract: The microstructure, phase transformation behavior and the effect of predeformation on the hysteresis of NiTi(Nb) (4.5at.% Nb) shape memory alloys were examined in comparison with the classical Ni47Ti44Nb9 wide hysteresis alloy. It is the Nb dissolved in the NiTi matrix that plays the key role in controlling the martensitic transformation characteristics of NiTi(Nb) shape memory alloys, resulting in the wide hysteresis upon predeformation of the alloys in martensitic state. The isolated β-Nb phase in the matrix contributes little to the hysteresis expansion. [Copyright &y& Elsevier]

To prepare high-performance anion exchange membrane, a twisted ether-free polyarylene piperidinium (QMter-co-Mpi) has been successfully synthesized via simple and controllable acid-catalyzed polycondensation reaction for alkaline water electrolysis. The hydroxide conductivity of QMter-co-Mpi membrane reaches 37 mS cm−1 at 30 °C owing to the fact that an efficient ion-conducting channels are formed by means of this unique molecular structure. Furthermore, the IEC and hydroxide conductivity of the membrane can remain above 80% of the original values after alkali treatment for more than 1000 h, indicating exceptional alkaline stability. As a result, the QMter-co-Mpi based cell presents a high current density of 1064 mA cm−2 at 2.5 V under 1 M KOH and 50 °C and the high frequency resistance of the cell is only 0.165 Ω cm−2 at 1.8 V. The durability test is performed at current density of 200 mA cm−2 for more than 500 h and the voltage is basically remained at 2.1 V, showing excellent electrochemical performance. All these demonstrate a good application prospect for QMter-co-Mpi membrane in water electrolysis. • Twisted ether-free polymer based alkaline membrane has been successfully synthesized. • The membrane showed decent conductivity and exceptional alkaline stability. • The cell with this membrane exhibited excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

A long-side-chain sulfonated polybenzimidazole (PBI-PS) membrane was successfully prepared by the reaction of PBI with 1, 3-propanesultone for improving the efficiencies of vanadium redox flow battery. The interaction between sulfonic acid and imidazole groups provides the PBI-PS membrane with excellent swelling resistance, leading to a swelling ratio of only 13% for the membrane with IEC of as high as 3.18 mmol g−1. This results in an ultra-low vanadium permeability (6.5 × 10−9 cm2 s−1). The introduction of sulfonic acid-terminated flexible side chain in the membrane also constructs good microphase separation structure, leading to a low area resistance of 0.51 Ω cm2, which is close to Nafion 212 (0.41 Ω cm2). This membrane exhibits excellent cell performance. The voltage and energy efficiencies are up to 90.73% and 89.13% at 80 mA cm−2, respectively. Furthermore, the efficiencies remain constant values for 200 cycles, and no changes in chemical structure and cell efficiencies are observed after 720 h immersion in electrolyte solution. • Long-side-chain sulfonated polybenzimidazole membrane was prepared for RFB. • High conductivity and vanadium resistance were achieved. • The cell with this membrane exhibited high efficiencies and good stability. [ABSTRACT FROM AUTHOR]

Purpose: Seizure originates from different pathological substrate; however, the same pathologies may have distinct mechanisms underlying seizure generation. We aimed to improve the understanding of such mechanisms in patients with temporal lobe epilepsy (TLE) by investigating the stereoelectroencephalography (SEEG) ictal onset patterns (IOPs). Methods: We analyzed data from a cohort of 19 consecutive patients explored by SEEG and had 1–3-year seizure-freedom following temporal lobe resection. Results: Six IOPs were identified. They were low voltage fast activity (LVFA) (36.5%), rhythmic spikes or spike-waves at low frequency and with high amplitude (34.1%), runs of spikes (10.6%), rhythmic sharp waves (8.2%), low frequency high amplitude repetitive spiking (LFRS) (7.1%), and delta activity (3.5%). All six patterns were found in patients with mesial temporal onset and only two patterns were found in patients with temporal neocortical onset. The most prevalent patterns for patients with mesial temporal onset were rhythmic spikes or spike-waves, followed by LVFA with a mean discharge rate 74 Hz. For patients with temporal neocortical onset, the most prevalent IOP pattern was LVFA with a mean discharge rate 35 Hz, followed by runs of spikes. Compared with Lateral TLE (LTLE), the duration between the onset of the IOPs to the onset of the symptom was longer for patients with MTLE (Mesial TLE) (MTLE:55.7 ± 50.6 s vs LTLE:19.5 ± 16.4 s). Conclusion: Multiple IOPs underlie seizure generation in patients with TLE. However, the mesial and lateral temporal lobes share distinct IOPs. [ABSTRACT FROM AUTHOR]

Background: Homeodomain-leucine zipper (HD-Zip) transcription factors are plant-specific and play important roles in plant defense against environmental stresses. Identification and functional studies have been carried out in model plants such as rice, Arabidopsis thaliana, and poplar, but comprehensive analysis on the HD-Zip family of Salix suchowensis have not been reported. Results: A total of 55 HD-Zip genes were identified in the willow genome, unevenly distributed on 18 chromosomes except for chromosome 19. And segmental duplication events containing SsHD-Zip were detected on all chromosomes except chromosomes 13 and 19. The SsHD-Zip were classified into 4 subfamilies subfamilies (I-IV) according to the evolutionary analysis, and members of each subfamily shared similar domain structure and gene structure. The combination of GO annotation and promoter analysis showed that SsHD-Zip genes responded to multiple abiotic stresses. Furthermore, the results of qPCR analysis showed that the SsHD-Zip I gene exhibited different degrees of expression under salt stress, PEG treatment and heat treatment. Moreover, there was a synergistic effect between SsHD-Zip I genes under stress conditions based on coregulatory networks analysis. Conclusions: In this study, HD-Zip transcription factors were systematically identified and analyzed at the whole genome level. These results preliminarily clarified the structural characteristics and related functions of willow HD-Zip family members, and it was found that SsHox34, SsHox36 and SsHox51 genes were significantly involved in the response to various stresses. Together, these findings laid the foundation for further research on the resistance functions of willow HD-Zip genes. [ABSTRACT FROM AUTHOR]

Aerobic composting can recycle nutrients from animal manure. Adding microorganism inoculants is an effective way to accelerate composting process. The study aimed to evaluate effects of inoculating with microbial agents on nitrogen conversion and bacterial community succession in pig manure composting. 3 composting treatments were conducted including no microbial inoculant (CK), inoculating thermophilic degrading bacteria (T1), and compound commercial microbial agents (T2). The results showed that T1 advanced the time for entering the thermophilic stage (>50 ℃), and accelerated organic matter degradation. T1 produced more NH 3 than other treatments. TN in group T1 and T2 was significantly greater than CK in composting maturity stage (after 14–15 d, T ≤ 40 ℃). (Final C/N)/(Initial C/N) of group T1 and T2 was 0.66, 0.65, and GI was 90.7 and 87.6, respectively. T1 improved the relative abundance of Actinobacteria, Firmicutes, Proteobacteria at the phylum level and increased Bacillus genera at genus level during the composting process. In conclusion, we demonstrated that pig manure composting added to thermophilic degrading bacteria effectively improved the quality of compost. [Display omitted] • Thermophilic microbial agents shortened the composting process and improved the quality of composting. • Inoculation with microbial agents improved the levels of the nitrate nitrogen and total nitrogen accumulation. • Key microbial groups increased the diversity of the microbial community and changed microbial community structure. [ABSTRACT FROM AUTHOR]

High-performance anion exchange membranes (AEMs) are in need for practical application of AEM fuel cells. Novel branched poly(ether ether ketone) (BPEEK) based AEMs were prepared by the copolymerization of phloroglucinol, methylhydroquinone and 4,4′-difluorobenzophenone and following functionalization. The effects of the branched polymer structures and functional groups on the membrane's properties were investigated. The swelling ratios of all the membranes were kept below 15% at room temperature and had good dimensional stability at elevated temperatures. The branching degree has almost no effect on the dimensional change, but plays a great role in tuning the nanophase separation structure. The cyclic ammonium functionalized membrane showed a lower conductivity but a much better stability than imidazolium one. The BPEEK-3-Pip-53 membrane with the branching degree of 3% and piperidine functionalization degree of 53% showed the best performances. The ionic conductivity was 43 mS cm−1 at 60 °C. The ionic conductivity in 1 M KOH at 60 °C after 336 h was 75% of its initial value (25% loss of conductivity), and the IEC was 83% of its initial value (17% loss of IEC), suggesting good alkaline stability. The peak energy density (60 °C) of the single H 2 /O 2 fuel cell with BPEEK-3-Pip-53 membrane reached 133 mW cm−2 at 260 mA cm−2. • A novel branched poly(ether ether ketone) based AEM was prepared. • The branched AEMs showed high conductivity and low swelling ratio. • A high peak power density was achieved for single cell with the branched AEM. [ABSTRACT FROM AUTHOR]

A high performance of anion exchange membranes (AEMs) is highly demanded in anion exchange membrane fuel cells (AEMFCs) and has been extensively studied. However, the poor ionic conductivities and the alkaline stability might limit their applications. Herein, we developed a novel strategy to improve the ionic conductivity and alkaline stability of AEMs by introducing hydrophilic oligo(ethylene glycol)(OEG) groups. Continuous ion-conducting channels were efficiently formed thanks to the dynamic aggregation of water molecules assisted by the hydrophilic side chains. The resultant AEMs with low IEC values showed significant enhancement in hydroxide conductivity compared to the AEMs functionalized by the conventional 1,2-dimethylimidazolium (PSf-Im), as the hydroxide conductivity of PSf-2 membrane with an IEC of 1.05 mmol g −1 was 59.5 mS·cm −1 at 60 °C while the hydroxide conductivity of PSf-Im membrane with an IEC of 1.27 mmol g −1 was 36.7 mS·cm −1 . In addition, the alkaline stability and the mechanical properties of the resultant AEMs were improved remarkably. The density functional theory (DFT) study showed that the introduction of OEG part can significantly increase the LUMO energy of functional group and then enhance the alkaline stability. [ABSTRACT FROM AUTHOR]

We demonstrate the fabrication ZnO nanostructures with tunable morphology and band gap by polyethylene glycol (PEG) assisted microemulsion strategy. Rectangular and spindle-like ZnO nanoparticles were obtained for PEG 200, 400 and 1000, while ZnO nanorods were achieved by PEG 10000. The formation mechanism was discussed correspondingly. XRD and PL spectra reveal that the defects in ZnO products are enhanced with PEG molecular weight increasing from 200 to 10000, resulting in the band gap energies decreasing from 3.12 eV to 2.95 eV, as demonstrated in the UV–Vis absorption spectra. The present research work can provide a new way to tune the optical property of ZnO. [ABSTRACT FROM AUTHOR]

A hybrid polystyrene sulfate (PSS) modified TiO 2 nanocrystalline (NC) composite film based ultrovilet (UV) photodetector (PD) was proposed in this study. TiO 2 NC film with uniform size distribution was deposited on FTO glass by doctor blading P25 TiO 2 nanoparticles. Through layer-by-layer self-assembly, PSS/TiO 2 composite film was prepared and it exhibits a high responsivity of 602 AW −1 , a large photo-to-dark current ratio of 193200% and a low dark current of 7 nA at only 0.1 V bias. The obtained high responsivity is almost 1–2 orders of magnitude higher than that of mostly reported TiO 2 NC film based UV PDs. The reason is attributed to the injection of electrons from PSS into conduction band of TiO 2 and the separation improvement of photogenerated electrons and holes by the rutile/anatase junction in the TiO 2 NC film. Considering the high responsive performances and facile low-cost fabrication, the proposed PSS/TiO 2 composite film based UV PD shows a bright prospect in large-area UV detection application. [ABSTRACT FROM AUTHOR]

Targeted and high throughput manufacture of crystalline biominerals with diverse morphologies is of importance, due to the significant impact of shape and texture on the material properties, while tunable morphosynthesis of crystalline is restrained by the proper ion transfer process during the reactive crystallization, and is commonly regulated using organic soluble additives. Herein, Janus membranes (JMs) are facilely produced for the continuous confined reactive crystallization of calcium carbonate. Fabricated JM simultaneously achieves rapid and uniform directional CO32− ions transfer in the aqueous solution through the straight, uniform nanoscale hydrophilic channels, and the interfacial reactive crystallization is generated with confined ion adsorption and gating effect at the hydrophobic side. Hollow CaCO3 microcomposites via JM system are continuously and directly synthesized in the aqueous system without any assisted organic solvent or polymer additive, which is green and highly efficient. In addition, the reversed ion transfer direction in JM can be ideally managed resulting in highly selective manufacturing of cube or sphere‐type microcomposites. This study provides a feasible route for the rapid production of advanced particle materials with tunable morphology, displaying great potential applications of JM in material engineering. [ABSTRACT FROM AUTHOR]

Inspired by 'Hufu' in ancient China, we manufactured semiflexible micro crystallizer with two aspectant sessile platforms by 3D-printing technique that can construct a series of heteromorphic droplets (HDs) via stretching droplet height. By coordinating the gas–liquid interface and flow intensity (i.e., Ra/Ma), central-converging micro-flows were generated, which dominated solute and particle motion towards droplet center. Efficient harvest of single cubic NaCl crystal was achieved at platform center under wide volume and concentration ranges. [Display omitted] Droplet crystallization behavior held great potential in crystal preparation, micromaterial engineering, and molecular assembly. However, restricted by natural surface tension, the intrinsic crystallization regulation and efficient harvest of high quality crystal in diverse droplet features were still a great challenge. Herein, we developed a 3D printed semiflexible micro crystallizer with two aspectant sessile platforms that could simultaneously construct a series of heteromorphic droplets (HDs) and controllable HD shape. By shaping HD on the interface of the platform, central-converging micro-flows were generated by coordinating the gas–liquid interface and flow intensity (i.e., Ra/Ma) during HD crystallization from 'barrel', 'can', to 'sand clock' shape, which was validated via simulative and experimental research. Therefore, HDs, constructed in semiflexible micro crystallizer, exhibited efficient screening (>70 %) of single cubic crystal just at the center zone of platform, even under wide ranges of concentration and volume, manifesting excellent repeatability on high quality crystal harvest and relevant interfacial science research. [ABSTRACT FROM AUTHOR]

The permanent magnet synchronous motor is the most commonly used motor in servo systems. Torque ripple caused by the variation of the airgap magnetic field limits the steady-state performance of the servo system. In this article, a novel torque ripple model is established based on the general airgap field modulation theory. A compound control algorithm based on the current feedforward algorithm is proposed to suppress the torque ripple caused by the field modulation behavior. Finite element analysis simulation is conducted to verify the effectiveness of the proposed torque ripple model. Experimental results on a prototype machine show that the proposed torque ripple model is valid and the proposed control algorithm can effectively reduce the torque ripple and improve the steady-state performance of the servo system at medium or high speed. [ABSTRACT FROM AUTHOR]

The trade-off between proton conduction and vanadium permeability is a great challenge for ion conductive membrane to achieve high vanadium redox flow battery (VRFB) performance. Herein, the quinone convertible phenolic hydroxyl group side chain is proposed to endow Donnan effect and continuously narrow ion conductive channel to improve H+/Vn + selectivity. Uniquely, phenol can be chemically converted into quinone of lower electronegativity in-situ in the strong acidic VRFB environment, which greatly increases the Zata potential (from 2.6 to 10.2 mV) and Donnan effect to repel vanadium ions. A high phenol hydroxyl group capacity with 5.43 mmol g−1 can be achieved owing to the swelling restriction by the hydrogen bonding crosslinking between quinone and benzimidazole, which constructs small but densely distributed ion clusters and continuously narrow ion conductive channels for selective proton conduction. The quinone type polybenzimidazole membrane (PBIPhQ-5.43) presents low area resistance and vanadium permeability (0.25 Ω cm2 and 1.3 × 10−9 cm2 s−1, 13.8 % and 99.6 % decreased, respectively, compared with that of Nafion 212). The VRFB exhibits excellent balance between energy efficiency (83.1 %) and discharge capacity decay (0.29 %/cycle) at 100 mA cm−2, far superior to that of Nafion 212 membrane (75.1 %, 0.71 %/cycle). [Display omitted] • Phenol group can be chemically converted to quinone of lower electronegativity. • Quinone conversion greatly increases Donnan effect to repel vanadium ions. • Superior VRFB energy efficiency and capacity retention to Nafion 212 membrane. [ABSTRACT FROM AUTHOR]