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Dialumane 1 reacts with pyridines at elevated temperatures through regioselective reductive dehydrogenation of 4-H, affording a unique hexanuclear Al(III) macrocycle [{LAl(pyridyl)}6], which represents the first dialumane-mediated C–H activation of Py and may suggest a new approach toward organometallo supra-molecules by one-pot small molecule activation and self-assembly.

In the traditional Axiomatic Design (AD) theory, the mapping from the functional domain to the physical domain is based on the designers’ own knowledge and experience, and there is no systematical approach including the design resources provided outside the designers themselves’ access. Thus, the raw materials for the design process are largely limited, which means they can hardly support the designers’ increasingly creative and innovative conceptions. To help AD theory better support the design process, this paper proposes a computer-aided approach for the mapping from the functional domain to the physical domain within a distributed design resource environment, which consists of numerous design resources offered on the Internet by the providers widely distributed in different locations, institutes, and disciplines. To prove the feasibility of this proposed approach, a software prototype is established, and a natural leisure hotel is designed as an implementation case.

The rise of China has shaken, to some extent, the pillars sustaining the US dominance in the world. Facing structural challenges from China, the United States has responded on three levels: political, strategic and policy. The Donald Trump administration has adopted a hard-line approach while attempting to engage China at the structural level. The China–US relationship is entering uncertain times, and the reconstruction of the relationship could take a decade.

Solid polymer electrolyte based on the random copolymer PGO from the monomers of glycidyl methacrylate (GMA) and oligo (ethylene oxide) methyl ether methacrylate (OE) was successfully synthesized and investigated in detail aiming at applications in all solid lithium ion battery. Namely, four polymers PGO-60, PGO-70, PGO-80, PGO-90 with numbers indicating the percentage molar ratio of OE were mixed with LiClO 4 , and studied for their Li conductivity and other electrochemical properties in order to understand the effects from the polar glycidyl moieties. Polymer PGO-70 showed the highest ionic conductivity of 2.08 × 10 −5 S/cm when the LiClO 4 content was 50% and at 50 °C. PGO-60 had the largest lithium ion transference number of 0.549, and exhibited electrochemical stability up to 4.4 V vs. Li + /Li. When the epoxy groups in the polymer were hydrolyzed, two hydroxyl groups as side chain pendants were obtained. When tested, the ring-opening membrane HPGO-70 showed significantly higher ionic conductivity (2.26 × 10 −6 S/cm, LiClO 4 = 30%) than the corresponding PGO-70 (2.58 × 10 −7 S/cm, LiClO 4 = 30%) at room temperature. The maximum lithium ion transport number of ring-opening polymers is 0.693 for HPGO-60, however, it's stability was a little lowered to 4.0 V vs. Li + /Li. Generally, compared with the polymer electrolyte membrane before ring opening, the lithium ion conductivity and lithium ion transference number of the ring-opening polymer electrolyte membrane were improved, however, the electrochemical stability window was slightly reduced. In the preliminary test of the assembled half cell battery using HPGO-60 as the polymer electrolyte and LiFePO 4 as the anode, fairly good charge/discharge cycling can be achieved at 25 °C, but the capacity remained quite low (around 20 mAh/g). When temperature increased to 70 °C, the capacity increased considerably to 99 mAh/g at the first cycle, but quickly decreased to around 50 mAh/g.

Wave energy is clean, renewable, and abundant, awaiting exploitation. A wide range of wave energy converters have been proposed so far. Oscillating body systems are an important class of wave energy converters. Many mechanisms have been invented to absorb the random wave energy. Nowadays, there is a lack of method to design the mechanism for oscillating body systems to extract the wave energy. Parallel mechanism has the advantages of high stiffness and high load, which are suitable for design of the mechanism for wave energy converters. In this paper, a procedural method based on the generalized function ( G F) sets theory is proposed to design parallel mechanisms to capture wave energy. Using this method, numerous parallel mechanisms have been obtained, which provides the foundation of the development of wave energy converters.

Ionogels are ideal candidate materials for flexible sensors, but their stretchability and fatigue resistance are limited. Herein, highly stretchable, fatigue-resistant, electrically conductive, and temperature-tolerant ionogels are investigated and further applied in fabricating high-performance flexible sensors. The ionogels consist of a poly(acrylic acid) (PAA) network and a commonly used room-temperature ionic liquid (RTIL) named 1-ethyl-3-methylimidazolium dicyanamide ([EMIm][DCA]). Dually acrylated Pluronic F127 (F127DA) was utilized to cross-link the PAA network, and [EMIm][DCA] was physically confined in the PAA network. Because of their special cross-linking structure, the PAA ionogels are highly stretchable (>850%), tough, and fatigue-resistant, and they are also conductive, transparent, and temperature-tolerant because of the existence of [EMIm][DCA]. On the basis of their integrated performances, the PAA ionogels were further utilized to fabricate strain sensors and pressure sensors. The ionogel-based strain sensors have high sensitivity, low response time (200 ms), wide strain-sensing range (0-750%), excellent durability (>1400 cycles), and good temperature tolerance and can be applied to detect various human motions. The pressure sensors also have a high response speed (256 ms) and excellent sensitivity (GF = 0.73 kPa-1), which offers an opportunity to detect force generated by finger touching and water droplets.

In the axiomatic design (AD) theory, the transformation from the function requirement (FR) to the design parameter (DP) is the key of the whole design process. The designers need numerous a...

A series of biphenyl ester compounds with alkenyl, alkyl, oxirane, and 1,3-dioxolane as the terminal groups have been synthesised for investigating the mesomorphic and thermal stability. Based on t...

Two nitrogen-rich heterocycle donor dyes, NP-2 and NP-3, have been strategically designed and synthesized to construct functionalized self-assembly layers. Through the formation of N⋯H hydrogen bonds between these nitrogen-rich heterocycle donors and 4-tert-butylbenzoic acid (PTBBA), the electron leak points (imine group ( N )) may be plugged, thus blocking excited-state electron lateral transferring between the adsorbed dyes and electron leaking from electron-transporting channel into the electrolyte. Furthermore, the huge 3-dimensional sizes of such supramolecule sensitizers can not only suppress dye aggregation, but enhance the photoresponse capacity in visible region. Therefore, the devices based on NP-2@PTBBA and NP-3@PTBBA, which obtained by the cocktail sensitization procedures, can be improved by increasing the open-circuit photovoltage (Voc) without any loss of the short-circuit photocurrent density (Jsc) owing to the synergy effect between self-assembly and co-sensitization. Although the device based on NP-3/PTBBA via the stepwise sensitization procedure delivers lower efficiency, it can remain at 103.14% of the initial efficiency as a result of parallel increase in Jsc and Voc values. Overall, the design principles provide a clear road map of supramolecular dye-sensitized solar cells (SDSSCs) and demonstrate the potential of 1,3,5-triazine-based dyes in solar cells research.

Click chemistry is an effective tool to fabricate three-dimensional gel network in an accurate way. In this work, Pluronic F127 gels are prepared by thiol–ene click chemistry, utilizing double-bond end-capped Pluronic F127 (F127DA) and pentaerythritol tetras-mercaptopropionate (PETMP) as the starting materials and triethylamine as the catalyst. Both the mass fraction of F127DA and the initial concentration of PETMP have effects on the properties of the resulting F127 gels. The optimized F127 gel prepared under a F127DA mass fraction of 15 wt% and a PETMP concentration of 17.62 mmol/L exhibits the highest swelling ratio (10) and has the largest elongation at break (194%). When the F127DA mass fraction and PETMP concentration are fixed at 15 wt% and 48.26 mmol/L, respectively, the resulting F127 gel has a high stress of 0.25 MPa. The present example has presented a method to fabricate three-dimensional gel network in a controlled way.

Dialumane 1 reacts with tBuNC to produce a reductive dimerization adduct [LAl(tBuN[double bond, length as m-dash]C-C[double bond, length as m-dash]NtBu)AlL] (2). In the presence of Na, 1 can promote linear- and cyclo-trimerization of isocyanides, affording products [Na][LAl{(tBuNC)3}AlL] (3 and 4) and [Na][LAl{(tBuNC)3}Al(C[triple bond, length as m-dash]N)L] (5), the latter of which features a unique aromatic tri(tert-butylimino)deltate dianion [C3N3(tBu)3]2-.

Photo-controlled release that shows a quick response and high spatial/temporal accuracy has become attractive given its potential applications for biomedicines. A few metal complexes are known for their uses in detoxification, sterilization, and diagnosis and treatment of diseases, but, the encapsulation and controlled release of those metal ions using polymer micelles are challenging. We report an interesting photo-controlled release of metal ions via photo-responsive triazoline-containing amphiphilic polymers. Amphiphilic random copolymers of glycidyl methacrylate and oligo(ethylene oxide) methyl ether methacrylate were prepared through free radical copolymerization. The glycidyl pendants were converted to azide, followed by a 1,3-dipolar cycloaddition reaction to form triazoline with norbornene. The resulting random copolymers containing triazoline formed micelles with a critical micellar concentration (CMC) of 7.68 × 10−3 mg mL−1. The triazoline moieties could coordinate to transition metal ions, e.g. Co2+, and thus encapsulate the metal ions to the core of micelles. Photo-induced denitrogenation of triazoline was able to disrupt the coordination of Co2+ and triazoline, therefore leading to the release of Co2+. Solution viscosity, UV-vis/NMR spectroscopy and TEM were used to show that the coordination and release of Co2+ ions were successful upon exposure to light. The photo-controlled release profile was found to be linearly dependent on the irradiation time, which is potentially useful for the delivery of essential ions in vivo.

Rechargeable zinc-air batteries (ZABs) stand out as promising candidates in the ever increasing search for sustainable energy storage devices. ZABs are inexpensive devices that exhibit relatively high energy density, safe operation with no environmental issues and long shelf life (when sealed). ZABs are composed of an electrolyte and two electrodes parallel to one another: the air electrode and the zinc electrode. The efficiency and cycle life of rechargeable ZABs are affected by the reactions that take place at the air electrode. The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) happen at the air electrode during discharge and charge, respectively. The poor kinetics for ORR/OER necessitate the use of electrocatalysts at the air electrode. Traditionally, precious metals like Pt and Ru have been used as ORR and OER catalysts, respectively, to lower the energy barrier for these reactions. However, these catalysts are rare and expensive and suffer from poor cycling stability. Transition metal oxides are inexpensive, abundant and safe alternative electrocatalyst options for air electrodes in ZABs. Mn and Co based oxides have been shown to have reasonable activities towards ORR and OER, respectively. In this work, high performance and efficient all solid state ZABs were prepared. Mn-Co mixed oxide (MnCo2O4) was employed as the bifunctional electrocatalyst. Hydrogel electrolytes, containing polyacrylic acid (PAA), KOH and N,N’-methylenebis (acrylamide) or MBAA as the crosslinker, were used. MnCo2O4 coated carbon fibers (MnCo2O4/CF) were utilized to prepare the air electrodes, with asphaltene based carbon fibers as a conductive substrate for the MnCo2O4 coating. A facile one pot sonication method for coating MnCo2O4 onto the CF, using an ultrasonic bath, was employed. CFs were sonicated in a mixture of 30 ml of reagent alcohol, 100 mg of NaOH, 167 mg of Mn(II) acetate (Mn(Ac)2 or C4H6MnO4) and 333 mg of Co(II) acetate (Co(Ac)2 or C4H6CoO4) for 5 h. A paste, consisting of 90 mg of MnCo2O4/CF, 5 mg of carbon black and 5 mg of PTFE (polytetrafluoroethylene) was used to prepare the air electrodes. Because all the CFs were coated with MnCo2O4 and then used to prepare the air electrodes, the MnCo2O4 bifunctional electrocatalyst was distributed throughout the whole thickness of the air electrode as opposed to only on the surface (which is the case for methods like electrodeposition or spray coating). Initially, different crosslinker concentrations in the hydrogel electrolytes were tested; a crosslinker concentration of 30 mM (referred to as Hydrogel-30-mM) provided the best ZAB performance. Concentrations higher than 30 mM were too viscous and stiff so the O2/electrocatalyst/electrolyte three phase boundary area was not sufficient for efficient ZAB performance. Concentrations less than 30 mM did not have the rheological performance of a gel polymer electrolyte. Charge/discharge battery performance at different current densities, cycling behavior (at 10 mA cm-2), polarization curves and power density values for MnCo2O4/CF and the benchmark Pt-RuO2 electrocatalyst in Hydrogel-30-mM were evaluated. MnCo2O4/CF had a very efficient and stable performance, compared with that of Pt-RuO2. The initial and final efficiencies for MnCo2O4/CF were 62.6% and 56.1%, respectively, for 200 cycles (100 hours: 10 min charge, 5 min rest, 10 min discharge) at 10 mA cm-2, while the initial efficiency for Pt-RuO2 was 61.3% and the battery failed after ~100 cycles. MnCo2O4/CF also had a superior performance to that of Pt-RuO2 in Hydrogel-30-mM, in terms of the maximum power density delivered; i.e., ~ 240 mW cm-2 for MnCo2O4/CF versus 165 mW cm-2 for Pt-RuO2.

This investigation was designed to study whether strain aging could assist localized corrosion of pipeline steels under realistic conditions, which is an unsolved problem in the evaluation of strain-aging-induced stress corrosion cracking of pipeline steels in the field. It was found that the corrosion severity was significantly aggravated after strain aging because of the increase in yield strength and the transformation of oxide scales on the steel surface. These variations caused by strain aging lead to lesser exfoliation and longer life of the oxide scales under cyclic loading in air and during subsequent corrosion exposure, which enhances the galvanic corrosion between oxide scales and the steel substrate. The composition of oxide scales, mechanical properties of steels, and magnitude of the stress cycles, which could all impact localized corrosion, were studied. The findings of this investigation suggest that the severe localized corrosion leading to crack initiation is a vital factor for the higher SCC susceptibility of pipeline steels associated with strain aging, in addition to the enhanced hydrogen embrittlement as usually believed.

Novel spherical polymer nanoparticles were synthesized by hyperbranched polyethylenimine (hPEI) and 6-hydroxy-2-naphthaldehyde (HNA) via Schiff base reaction (one-pot reaction), which had great advantages in water solubility and green synthesis. Meanwhile, probe PEI-HNA could quickly detect Cu

An in situ strategy was introduced for synthesizing carbon modified graphitic carbon nitride(g-C3N4) by using urea/4-aminobenzoic acid(PABA) co-crystal(PABA@Urea) as precursor materials. Via co-calcination of the PABA co-former and the urea in PABA@Urea co-crystals, C guest species were generated and compounded into g-C3N4 matrix in situ by replacing the lattice N of the carbon nitride and forming carbon dots onto its layer surface. The carbon modification dramatically enhanced visible-light harvesting and charge carrier separation. Therefore, visible light photo-catalytic oxidation of methylene blue(MB) pollution in water over the carbon modified g-C3N4 (C/g-C3N4) was notably improved. Up to 99% of methylene blue(MB) was eliminated within 60 min by the optimal sample prepared from the PABA@Urea co-crystal with a PABA content of 0.1%(mass ratio), faster than the degradation rate over bare g-C3N4. The present study demonstrates a new way to boost up the photocatalysis performance of g-C3N4, which holds great potential concerning the degradation of organic dyes from water.

Interlayer ion modification of MXene is one of the effective ways to improve the pseudocapacitance performance. However, the origin of electrochemical capacitance mechanism still remains elusive due to the effect of different kinds of ion interlayer modification. In this work, interlayer modification of MXene (Ti3C2Cl2) with inorganic ions (NaCl) and organic macromolecular ions (cetyl trimethyl ammonium bromide cation, CTAB) were carried out by ion ultrasonic intercalation and the electrochemical capacitance mechanism was investigated. It was found that MXene- CTAB has higher specific capacitance (258.28 F g-1 Vs 225.55 F g-1) and better cycle stability (93% retention Vs 85% retention after 3000 cycles) than MXene-NaCl. Such a large difference in electrochemical energy storage performance is mainly due to two points : (1) Organic macromolecular CTAB can effectively expand the layer spacing of MXene, which is conducive to the storage of electrolyte ions. (2) Compared with inorganic ions, organic macromolecular ions not only have redox reaction with interlayer ions of MXene, but also can adsorb counter ions in the electrolyte, thus providing additional pseudocapacitance. This work opens up a new way for the development of high-performance MXene based electrode materials.

A ring [Formula: see text] is said to be quasi-central Armendariz if [Formula: see text] and [Formula: see text] satisfy [Formula: see text] then [Formula: see text] for all [Formula: see text] and [Formula: see text]. It is proved that if [Formula: see text] is a quasi-central Armendariz ring then [Formula: see text] implies that all [Formula: see text] are in its Wedderburn radical [Formula: see text], generalizing and improving the existing result in the literature.

Near-neutral pH stress corrosion cracking (SCC) is a significant threat to the operational safety and reliability of gas and oil pipelines. The SCC cracks are typically formed in colonies with different crack density populations on the external surface of the pipe. The density of SCC cracks affect how pipeline integrity and remaining lifetime are assessed. Although sparse and dense crack colonies are commonly observed on pipelines, it has not been well established how these crack colonies with different crack populations were developed in the field. This research was made in an attempt to replicate near-neutral pH SCC cracks with different crack densities in the laboratory with realistic loading conditions commonly found during field operation. An X65 pipeline steel with different surface preparations was used. The results showed that the dense near-neutral pH SCC cracks were successfully reproduced on the primer-coated samples, whereas sparse cracks were reproduced on the mill-scaled and polished samples. The densely spaced cracks could transform into sparsely spaced cracks when most of the primer layer and mill scale had been removed during the long period of corrosion under cyclic loading and further corrosion occurred thinning the crack density. The results of crack initiation obtained from this investigation have also been found to be quite consistent with crack initiation scenarios found during field operation.

Steel pipelines undergo the following sequential stages prior to high pH stress corrosion cracking (HpHSCC) failure, viz., formation of environmental condition, initiation of the intergranular cracks followed by cracks coalescence to form critical crack size (Stage I), mechanically dictated crack growth with higher rate (Stage II) compared to Stage I, rapid crack propagation to failure (Stage III). From fracture mechanics perspective, the crack size reaches the critical value at the onset of stage II; consequently, stress intensity factor (K) ahead of the crack tip exceed the critical value (KISCC). Although many researches have been devoted to understanding HpHSCC behavior, the mechanical conditions that accelerate the onset of stage II remains unknown. This study investigates the mechanical loading conditions that yield to early onset of stage II with respect to the most severe loading condition in operating pipeline, underload-minor-cycle type of pressure fluctuation. In this study, several loading scenarios were applied to pre-cracked CT specimens exposed to 1 N NaHCO3-1N Na2CO3 at 40° C and −590 mVSCE. The first series of tests were conducted through applying variable amplitude loading waveforms to determine the K value below the KISCC. It was observed the crack growth rate decreases from 1.5 × 10−7 mm/s to 2.5 × 10−8 mm/s when Kmax decreases from 36 to 15 MPa·m0.5. Then, both constant amplitude and variable amplitude loading scenarios with the Kmax = 15 MPa·m0.5 were applied to pre-cracked CT specimens. It was observed that low R-ratio constant amplitude cycles yield to highest crack growth rate (3.6 × 10−7 mm/s), which was one order of magnitude higher than other waveforms. However, comparing the intergranular crack advancement per block resulted in similar crack growth rates for those waveforms containing low R-ratio cycles. These results imply that stage I of crack growth is assisted by fatigue due to low R-ratio cycles. It was observed that loading/unloading frequency of low R-ratio cycles has a direct relation with crack growth rate at stage I, i.e., high frequency cycles accelerate onset of stage II. The implication of these results for pipeline operator is that pressure fluctuation, particularly large and rapid pressure fluctuation at the sites susceptible to HpHSCC, threatens the pipeline integrity. Avoiding such pressure fluctuations, if possible, increase pipeline lifespan and prevents catastrophic damages by intergranular stress corrosion crack growth through delaying the onset of stage II of HpHSCC crack growth.

Helicobacter pylori (H. pylori) is proved to be the main pathogenic agent of various diseases, including chronic gastritis, gastric ulcer, duodenal ulcer, and gastric cancer. In addition, chronic cholecystitis and cholelithiasis are common worldwide, which are supposed to increase the total mortality of patients. Epidemiologic evidence on the relationship between H. pylori infection of the gallbladder and chronic cholecystitis/cholelithiasis still remains unclear. We conducted a systematic review and meta-analysis of overall studies to investigate the relationship between H. pylori infection of the gallbladder and chronic cholecystitis/cholelithiasis. Two researchers searched PubMed, Embase, and Cochrane Library databases to obtain all related and eligible studies published before July 2020. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated by the random-effects model. Subgroup analysis, heterogeneity, publication bias, and sensitivity analysis were also conducted. Twenty studies were included in the meta-analysis, involving 1735 participants and 1197 patients with chronic cholecystitis/cholelithiasis. Helicobacter species infection of the gallbladder was positively correlated with increased risk of chronic cholecystitis and cholelithiasis, especially H. pylori (OR = 3.05; 95% CI, 1.81–5.14; I2 = 23.5%). Besides, country-based subgroup analysis also showed a positive correlation between the gallbladder H. pylori positivity and chronic cholecystitis/cholelithiasis risk. For Asian and non-Asian country studies, the ORs were 4.30 (95% CI, 1.76–10.50; I2 = 37.4%) and 2.13 (95% CI, 1.23–3.70; I2 = 0.0%), respectively. The association was more obvious using the bile sample and urease gene primer. In conclusion, this meta-analysis provided evidence that there is a positive correlation between H. pylori infection in the gallbladder and increased risk of chronic cholecystitis and cholelithiasis.

Hydrostatic testing, or hydrotesting, has been widely used as a stress corrosion cracking management method in the pipeline industry, particularly in gas pipelines. Although the technique has been very useful in the prevention of operational failures, it is known that these high pressures can produce significant plastic deformation around stress concentrators, such as pits and other surface flaws, that might be present. This plasticity can temporarily retard long, well-developed cracks; however, the effect of this plasticity on growth of very small cracks has not previously been studied. In this work, a long-term test was conducted to simulate real pipeline pressure cycling conditions by the application of occasional hydrotesting loads on steel samples. Crack initiations from pits were compared between specimens undergoing no hydrotesting load (control specimens) and those that underwent three hydrotest cycles during the test. The results showed that pit-to-crack transition was enhanced by the application of three hydrotesting loads. Seventy percent more cracks were found to have grown beyond ferrite grain boundaries in the hydrotested specimens. This initial study indicated substantial differences between small crack formation with and without hydrotesting. These differences predict significantly higher short crack growth in the hydrotested samples. Further study is necessary to further delineate these effects.

The high overpotentials for oxygen reduction reaction (ORR) create an extremely negative impact on the energy efficiency of the air-based battery systems. To overcome this problem, binuclear ball-type metallophthalocyanines containing methoxy substituents (M2Pc2(EP)4, M = Fe(ІІ), Co(ІІ) and Zn(ІІ)) were wrapped with polystyrene sodium sulfonate (PSS) modified graphene oxide (GO), using a facilely &ldquo, solvothermal &pi, &pi, assembly&rdquo, method to prepare M2Pc2(EP)4/PSS-Gr composites. Compared with the commercial Pt/C catalysts, the M2Pc2(EP)4/PSS-Gr composites enhanced the catalytic activity of oxygen reduction reaction. The &pi, electron conjugated structure of the MN4-type phthalocyanine macrocyclic system strongly influenced the one-step four-electron electrocatalytic process of the M2Pc2(EP)4/PSS-Gr composites. Moreover, the &pi, interactions between the M2Pc2(EP)4 and PSS-Gr dramatically enhanced the &pi, electron density in the conjugated structure and oxygen could be reduced more easily. The electrocatalytic activity test was displayed in the order of Fe2Pc2(FP)4/PSS-Gr &gt, Co2Pc2(EP)4/PSS-Gr &gt, Zn2Pc2(EP)4/PSS-Gr. The results indicated that the catalytic performance of M2Pc2Rn could be enhanced by the modification of &pi, electron conjugated structure of M2Pc2(EP)4 and carbon materials.

The multi-shell composites with carbonyl iron (CIP) and heterogeneous state polypyrrole (PPy) uniformly dispersed in the double SiO

Dinuclear metallophthalocyanines Fe2Pc2(CP)4 containing carboxyl substitutes were wrapped with amino-functionalized carbon nanotubes (MWCNTs-NH2) to enhance electrocatalytic activity for oxygen reduction reaction (ORR) using a facile “in situ” amidation reaction. The morphological characteristics and chemical environment of the Fe2Pc2(CP)4/MWCNTs-NH2 composites were characterized by scanning electron microscope (SEM), X-ray diffraction, Ultraviolet–visible (UV-Vis), Fourier Transform infrared (FTIR), and X-ray photoelectron spectroscopy. The electrocatalytic activity of ORR was tested and analyzed by cyclic voltammetry and linear sweep voltammetry. The results showed that the π–π interactions between the Fe2Pc2(CP)4 and MWCNTs-NH2 dramatically enhanced the π electron density in the conjugated structure, and oxygen could be reduced much more easily. Moreover, the oxygen reduction reactions mainly proceeded a one-step four electron process for Fe2Pc2(CP)4/MWCNTs-NH2 catalysts. The dispersion and electrocatalytic performance of M2Pc2Rn had be enhanced after being loaded on functionalized carbon nanotubes.

Birnessite type Mn oxide (potassium birnessite hydrate) powder (as-δ-MnO2) with a layered microstructure was prepared via a hydrothermal process. To improve its capacitive performance, the microstructure was thermally modified (annealed) at 400 °C (400-δ-MnO2) in a N2 reducing environment. By removing the hydrated cation (K+) layers inserted between the main layers of birnessite, intercalation/deintercalation of the electrolyte species (Li+1) became more effective. Characterization of the as-δ-MnO2 and 400-δ-MnO2 samples revealed that no phase transformation occurred during the annealing process. The microstructure became less crystalline and the total pore volume increased from 0.20 cm3 g−1 to 0.43 cm3 g−1, while the oxidation state of Mn remained 4+ after annealing the as-δ-MnO2 sample at 400 °C. The 400-δ-MnO2 sample was then coated on asphaltene derived activated carbon fibers (ACF-400-δ-MnO2) to improve the performance by making use of the high electrical conductivity and capacitive behavior of ACF. Coating the 400-δ-MnO2 sample led to a significant increase in the capacitance (328 F g−1 and 195 F g−1 for ACF-400-δ-MnO2 and 400-δ-MnO2 at 0.4 A g−1, respectively), improved energy and power values (∼7 kW kg−1 at ∼4.2 Wh kg−1 for ACF-400-δ-MnO2 and 240 W kg−1 at 2.4 Wh kg−1 for 400-δ-MnO2) and improved cycling behavior.

Solid polymer electrolyte plays an important part in the development of flexible solid-state lithium ion battery. However, the low ionic conductivity at room temperature limits its practical application. In this article, graphite carbonitride (g-C3N4) was prepared by thermal polymerization method and was blended with polyethylene oxide/lithium perchlorate (PEO/LiClO4) to prepare composite solid polymer electrolyte. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), optical microscopy (OM), scanning electron microscopy (SEM), differential scanning calorimeter (DSC) and electrochemical workstation were used to characterize the prepared composite solid polymer electrolyte. Results demonstrated that not only the 120 °C annealing and then quenching thermal treatment, but also the interaction among components in composite solid polymer electrolytes could restrict the crystallization of PEO. As a result, the ionic conductivity of composite solid polymer electrolytes at 25 °C could reach to 2.35×10−5 S cm−1, which was three order higher than that of the PEO/LiClO4 polymer electrolyte film.

To improve data transmission efficiency of the apron network, multiple copies of packets are injected into the network. However, this method will result in more redundant data in the network, which further leads to network congestion. To solve the congestion, a Congestion Control Strategy based on Irregular Cellular Automaton (CCSICA) is introduced in this paper. In the apron environment, according to the interaction characteristics of the cellular automaton and surrounding neighbors, the existence of the replica of the neighboring node is fully considered. Then design the corresponding state transfer rules to achieve the purpose of more rational use of limited network resources. The simulation results show that the network overhead ratio and message delivery ratio can be improved dramatically by our proposed strategy.

Most of the fault characteristics of the wind power were manually marked, and the characteristics of manual labeling were based on expert experience, and in some cases, the operation law of the equipment cannot be objectively reflected. Therefore, an improved Denoising Auto-Encoders for multi-sensor data fusion diagnosis (IDAE) method was proposed. A multi-sensors data was constructed by one-dimensional layer-by-layer stacking to construct a two-dimensional matrix to realize data fusion and ensure the robustness of fault diagnosis. Then using the unsupervised learning ability of the convolutional Auto-Encoding neural network enables the network to automatically extract fault features from the unlabeled data, ensuring the comprehensiveness, objectivity and adaptability of the fault features. Experiments on the actual historical data of Huarui FL1500 wind turbine in a wind farm in Shandong show that the proposed method has better robustness and automation in fault diagnosis of bearing fault diagnosis.

Ocean wave energy converters (WECs) are obtaining more and more attentions in the world. So far, many types of converters have been invented. Oscillating body systems are a major class of WECs, which typically have one degree of freedom (DOF), and the power absorption efficiency is not quite satisfactory. In this paper, a 3-DOF WEC is proposed and a simplified frequency-domain dynamic model of the WEC depending on the linear potential theory is conducted. The performances of three geometries of the oscillating body including the cone, the cylinder and the hemisphere have been compared, and the results show that the hemisphere is more suitable for the 3-DOF WEC. Subsequently, the relationship among the parameters of the hemisphere is established based on the equal natural frequencies of the heave and pitch (or roll) motions, and the results show that lowering the center of gravity leads to the better power absorption in the pitch (or roll) motion. In the end, the power matrixes of different sizes of the hemispheres under different irregular waves are obtained, which can give a size design reference for engineers.

Background: Recent studies have shown that microRNA-99a(miR-99a)plays a key role in the development of virious malignancies; however, its relationship with gastric cancer remains unclear. In this study, we investigated the functions and potential mechanisms of miR-99a in gastric cancer. Methods: Real-time qRT-PCR was used to assess the expression levels of miR-99a in gastric cancer tissue samples and cell lines compared to their matched adjacent normal tissues and a normal gastric mucosa epithelial cell line, respectively. SGC-7901 cells were transfected with miR-99a mimics and negative controls to determine the effects of miR-99a overexpression on cell proliferation, cell cycle transition, migration and invasion of gastric cancer cells in vitro . The role of miR-99a in endogenous c-Src expression in gastric cancer cells was also investigated by qRT-PCR and Western blotting. Results: Our results showed a significant increase in miR-99a expression in both gastric cancer tissues and cells compared to normal tissues and cells. Overexpression of miR-99a significantly promoted the cell proliferation, migration and invasion of gastric cancer cells compared to normal cells, with a concurrent increase in the S+G2 phases of the cell cycle. Further investigations found that miR-99a overexpression led to significant upregulation of endogenous c-Src. Conclusion: Taken together, our findings suggest that miR-99a may act as a tumour promoter in the pathogenesis of gastric cancer by indirectly modulating c-Src expression.

The Supervisory Control and Data Acquisition (SCADA) data are primarily used for pipeline-pressure monitoring and control. This investigation aims to develop improved methods of recording, ...

A wide range of wave energy converter technologies has been proposed so far. Oscillating body systems are an important class of wave energy converters, which typically harvest wave energy from a single degree-of-freedom response. This article presents a novel 3-degree-of-freedom (heave, pitch and roll) wave energy converter which extracts and converts wave power efficiently. The 3-degree-of-freedom mechanism is invented to absorb and convert wave energy, no matter which direction the waves propagate. The hydraulic power take-off system comprises novel energy conversion devices which can be superposed to realize high-power conversion to produce electricity. First, the power conversion principle of the wave energy converter is proposed, and the kinematics of the 3-degree-of-freedom mechanism is derived. Then, the governing equations of the 3-degree-of-freedom wave energy converter are established. Linear time-domain simulations are performed to calculate instantaneous and mean power outputs. The numerical results show that the rated power absorbed by the wave energy converter is up to 4.2 MW and the efficiency is over 80%. And the power matrix of the wave energy converter is obtained from a range of simulations under different sea states. Finally, directional performance of the wave energy converter is investigated, and the numerical results show that the wave energy converter can operate across a range of incident wave directions, but is most efficient in head, beam and following seas.

A reversible fluorescein-based fluorescent probe which exhibits high sensitivity and selectivity for Zn2+ and ATP, has been designed and synthesized. The sensing process was completed via fluorescence variation induced by an opening and closing of the spiro-ring of fluorescein. Zn2+/ATP-induced fluorescent intensity shows a good linear relationship with the concentration of Zn2+/ATP in the range of 0–10 μM with a detection limit of 0.1 μM/0.5 μM. Moreover, the probe was further applied to visualize and detect Zn2+and ATP in vitro and in vivo.

Oxidative desulfurization is considered to be one of the promising new methods for super-deep desulfurization of fuel oil. Herein, zinc phthalocyanine/g-C3N4 (g-C3N4/ZnTcPc) composites were synthesized by a facile in situ hydrothermal technique, utilizing g-C3N4, Zn(CH3COO)2 and 1,2,4-benzenetricarboxylic anhydride as the precursors. The crystal structure, morphology and chemical environment of the catalysts were respectively confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity of the resulting g-C3N4/ZnTcPc composites was evaluated by desulfurization of thiophene in fuel under visible light with molecular O2 as the oxidant. Compared with pure g-C3N4 and ZnTcPc, g-C3N4/ZnTcPc presented a significantly enhanced photocatalytic activity for the degradation of thiophene in fuel under visible irradiation. Sulfur content of model gasoline (800 ppm) after desulfurization for 90 min was decreased to 125 ppm. The possible preparation pathway of g-C3N4/ZnTcPc has been proposed according to the results of XRD and TEM. The formation mechanism of g-C3N4/ZnTcPc–O2 complex is proposed to be desulfurization by molecular oxygen.

This work describes the preparation, characterization and removal capability of a novel biomass derived carbonaceous sponges (CS) and their nanocomposites. The CS has hierarchically porous structure which is composed of lamellar structures and secondary porous structures. The pore size is on a scale from 1 nm to 200 μm. Utilizing the CS as adsorbents, rapid removal of model organic molecules, including methylene blue (MB), methyl orange (MO) and crystal violet (CV), from their aqueous solutions can be completed within 1 min with the assistance of pressure and the removal efficiency reaches up to 100%, 81% and 98%, respectively. The removal capabilities for CS towards MB, MO and CV are 0.0769 g/g, 0.2218 g/g and 1.0384 g/g, respectively and 0.0635 g/g, 0.0977 g/g and 0.8634 g/g, respectively for CS nanocomposites.

A planar microwave resonator sensor is designed, customized, and fabricated to detect coating breaches in industrial steel pipelines. The sensor, which utilizes a ring-shaped resonator to maximize the sensitivity at its core, is tuned to 2.5 GHz with a quality factor of 280. In the setup, the sensor is grounded to a piece of steel pipeline with an Epoxy-100 coating, which provides the substrate beneath the microstrip structure. It is demonstrated that any change in the gap height between the substrate layer and the pipeline, from 0 to 3.5 mm, produces a significant resonant frequency variation and bandwidth change in the sensor's response. The sensor structure demonstrates sensitivity and selectivity to air and water penetration to the breach. The sensor structure described in this work is a compact, low-cost solution and has potential for further miniaturization in mobile applications which may serve as a method for pipeline breach detection.