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Separation, purification, and identification of glycoproteins are essential for understanding their vital roles in biological and pathological processes. However, glycoproteins are difficult to be captured due to their low abundance, strong interference from non-glycosylated proteins. Here, we report a promising dipeptide-based saccharide recognition platform to selectively enrich two typical glycoproteins, named immunoglobin G (IgG) and horseradish peroxidase (HRP). Different from the conventional glycoprotein enrichment method based on boronic acid affinity or hydrophilic interaction with glycans, the present method was established based on affinity between Pro-Glu (PE) dipeptide and mannose, which is a key unit in the pentasaccharide core of the IgG and HRP glycans. The prepared PE homopolymer surface was proved to selectively bind IgG and HRP superior to that of bovine serum albumin (BSA). Benefiting from this feature, selective enrichment of IgG and HRP was achieved from a protein mixture containing 200-fold BSA interference by using polyPE@SiO

Due to the complex and changeable operating conditions of spacecraft equipment and the relatively harsh operating environment, the rate of system performance degradation and failure and the probability of failure are increased. Therefore, it is of practical significance to timely and accurately evaluate the health condition of spacecraft equipment in the early stage before serious accidents are caused, especially in the early stage when the performance of the equipment system degrades. In this paper, a new health condition degradation monitoring model called ADF-GMM for spacecraft equipment operation is proposed based on massive condition monitoring data. First, the key features that contain performance degradation information of the space equipment were selected by Augmented Dickey-Fuller (ADF) test. Then, a Gaussian mixture model (GMM) was established to describe the probability density function of the key features and a health condition monitoring index is calculated to implement the equipment condition monitoring. The proposed ADF-GMM method was applied to the Prognostics and Health Management (PHM) of momentum wheel bearing (MWB) degradation, and the feasibility and effectiveness of the proposed method were verified.

Complicated synthesis procedure and instability of 1T-MoS2 impede its practical application for hydrogen evolution reaction. Here, we propose a new strategy to drive the synthesis of stabilized 1T-MoS2 by Ni doping. Ni doping forms the Ni S covalent bonds, inducing the slip of S atoms and stabilizing 1T structure. The materials were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. Electrochemical tests including linear sweep voltammetry etc. indicate that the 1T/2H-MoS2/8%Ni has an overpotential of 162 mV and a Tafel slope of 80 mV dec−1 along with a good stability.

Two-dimensional (2D) piezoelectric materials have attracted wide attention because they are of great significance to the composition of piezoelectric nanogenerators. In this work, we have systematically studied the piezoelectric properties of 2D LiAlTe

Klebsiella pneumoniae is an opportunistic pathogen that mostly affects patients with weakened immune systems, but a few serotypes (especially K1 and K2) are highly invasive and result in systemic infection in healthy persons. The ability to evade and survive the components of the innate immune system is critical in infection. To investigate the role and mechanism of transcription regulator KP1_RS12260 (KbvR) in virulence and defense against the innate immune response, kbvR deletion mutant and complement strains were constructed. The in vivo animal infection assay and in vitro antiphagocytosis assay demonstrate K. pneumoniae KbvR is an important regulator that contributes to virulence and the defense against phagocytosis of macrophages. The transcriptome analysis and phenotype experiments demonstrated that deletion of kbvR decreased production of capsular polysaccharide (CPS) and biosynthesis of partly outer membrane proteins (OMPs). The findings suggest that KbvR is a global regulator that confers pathoadaptive phenotypes, which provide several implications for improving our understanding of the pathogenesis of K. pneumoniae.

Cellulose nanocrystals (CNCs) are powerful photonic building blocks for the fabrication of biosourced colored films. A combination of the advantages of self-assembled CNCs and multiple templating agents offers access to the development of novel physicochemical sensors, structural coatings, and optic devices. However, due to the inherent brittleness and water instability of CNC-derived materials, their further applications are widely questionable and restrictive. Here, a soft polymer of poly(vinyl alcohol) (PVA) was introduced into the rigid CNC system to balance molecular interactions, whereafter two hard/soft nanocomposites were fastened through a cross-linking reaction of glutaraldehyde (GA), resulting in a highly flexible, water-stable, and chiral nematic CNC composite film through an evaporation-induced self-assembly technique. For a 1.5 wt % GA-cross-linked 70 wt % CNC loading film, its treatment with harsh hydrophilic exposure (soaking in a strong acid, strong base, and seawater) and various organic solvents show exceptional solvent-resistant abilities. Furthermore, the film can even withstand a weight of 167 g cm-2 without failure, which is a highly stiff and durable character. Importantly, the film remains a highly ordered chiral nematic organization, being able to act as a highly transparent substrate for selective reflection of left-handed circularly polarized light, preparing fully covered and patterned full-color coatings on various substrates. Our work paves the way for applications in low-cost, durable, and photonic cellulosic coatings.

The effect of alkali extraction (AE), enzymatic extraction (EE), ultrasonic-assisted enzymatic extraction (UAEE), and shear homogeneous-assisted enzymatic extraction (SHAEE) on the physicochemical, structural properties, and in vitro hypoglycemic activity of bamboo shoot dietary fibers (BSDF) were investigated and compared. BSDF obtained by AE had the lowest protein content and crystallinity index. The lowest oil holding capacity (OHC) and highest protein content were observed in EE. BSDF generated highest OHC and glucose adsorption capacity by UAEE. SHAEE obtained the highest SDF content (17.89%), water-holding capacity (8.81 g/g), and α-amylase activity inhibition ratio (19.89%) and the smallest particle size (351.33 μm). BSDF extracted by SHAEE and UAEE presented a porous and loose structure. Furthermore, the in vitro hypoglycemic activity of the four BSDF samples generally followed the order of SHAEE UAEE EE AE. Results show that SHAEE is an innovative and promising method to obtain BSDF with its excellent physicochemical and functional properties.

To compare the mRNA level of cell proliferation-related genes Twist1, SIRT1, FGF2 and TGF-β3 in placenta mesenchymal stem cells (PA-MSCs), umbilical cord mensenchymals (UC-MSCs) and dental pulp mesenchymal stem cells (DP-MSCs).The morphology of various passages of PA-MSCs, UC-MSCs and DP-MSCs were observed by microscopy. Proliferation and promoting ability of the three cell lines were detected with the MTT method. Real-time PCR (RT-PCR) was used to determine the mRNA levels of Twist1, SIRT1, FGF2, TGF-β3.The morphology of UC-MSCs and DP-MSCs was different from that of PA-MSCs. Proliferation ability and promoting ability of the PA-MSCs was superior to that of UC-MSCs and DP-MSCs. In PA-MSCs, expression level of Twist1 and TGF-β3 was the highest and FGF2 was the lowest. SIRT1 was highly expressed in UC-MSCs. With the cell subcultured, different expression levels of Twist1, SIRT1, FGF2, TGF-β3 was observed in PA-MSCs, UC-MSCs and DP-MSCs.Up-regulated expression of the Twist1, SIRT1 and TGF-β3 genes can promote proliferation of PA-MSCs, UC-MSCs and DP-MSCs, whilst TGF-β3 may inhibit these. The regulatory effect of Twist1, SIRT1, FGF2 and TGF-β3 genes on PA-MSCs, UC-MSCs and DP-MSCs are different.

The addition of hydrocolloid is an effective method to improve the properties of native starch. However, few studies have investigated the effects of konjac glucomannan (KGM) on canna starch (CS). In this study, the effects of various KGM concentration on the pasting, rheological, textural, and morphological properties of CS were investigated. The addition of KGM significantly increased CS’s pasting viscosities. Incorporation of KGM in CS at a relatively high level (1.2% w/w) exerted a significant influence on the pasting properties of CS. The consistency coefficient of CS was notably increased by KGM (from 43.6 to 143.3 Pa·sn) and positively correlated positive with KGM concentration. KGM concentration at a relatively high level (1.2% w/w) increased the elasticities and cohesiveness of CS by 53.3% and 88.0%, respectively, in texture profile analysis. The polarized optical microscope images indicated that KGM played an important part in protecting the crystalline structure of CS during heating. A denser porous microstructure with a filamentous network was observed in gelatinized KGM/CS mixtures as compared with the CS control. This research advances the knowledge of interactions between KGM and CS and opens possibilities to improve rheological properties of CS and to develop its new functionalities with KGM addition.

Enhancing the performance of polymer micelles by purposeful regulation of their structures is a challenging topic that receives widespread attention. In this study, we systematically conduct a comparative study between cyclic grafted copolymers with rigid and flexible rings in the self-assembly behavior via dissipative particle dynamics (DPD) simulation. With a focus on the possible stacking ways of rigid rings, we propose the energy-driven packing mechanism of cyclic grafted copolymers with rigid rings. For cyclic grafted copolymers with large ring size (14 and 21-membered rings), rigid rings present a novel channel-layer-combination layout, which is determined by the balance between the potential energy of micelles (Emicelle) and the interaction energy between water and micelles (Eint). Based on this mechanism, we further regulate a series of complex self-assembling structures, including curved rod-like, T-shape, annular and helical micelles. Compared with flexible copolymers, cyclic grafted copolymers with rigid rings provide a larger and loose hydrophobic core and higher structural stability with micelles due to the unique packing way of rigid rings. Therefore, their micelles have a great potential as drug nanocarriers. They possess a better drug loading capacity and disassemble more quickly than flexible counterparts under acidic tumor microenvironment. Furthermore, the endocytosis kinetics of rigid micelles is faster than the flexible counterparts for the adsorption and wrapping process. This study may provide a reasonable idea of structural design for polymer micelles to enhance their performance in biomedical applications.

In this study, the adsorption of gas molecules, such as O2, NH3, CO, CO2, H2O, NOx (x = 1, 2) and SO2, on Janus Te2Se monolayer has been investigated by means of density functional theory (DFT) calculations. We show that Janus Te2Se monolayer is preferable for SO2 and NOx molecules with suitable adsorption strength and apparent charge transfers. We further calculated the current-voltage (I-V) curves using the nonequilibrium Green's function (NEGF) method. The transport feature exhibits distinct responses with a dramatic change of I-V curves before and after NOx (SO2) adsorption on Janus Te2Se. Thus, we predict that Janus Te2Se could be a promising candidate for SO2 and NOx sensors with high selectivity and sensitivity. Moreover, the effect of strain on the gas/substrate adsorption systems was also studied, implying that the strained Janus Te2Se monolayer could enhance the sensitivity and selectivity to SO2 and NO2. The adsorbed SO2 and NO2 on Janus Te2Se could escape by releasing the applied strain, which indicates that the capture process is reversible. Our study widens the application of Janus Te2Se not only as piezoelectric materials, but also as a potential gas sensor or capturer of SO2 and NOx with high sensitivity and selectivity.

The piezoelectric properties of two-dimensional (2D) Janus ZnBrI are predicted by the multiscale method. Based on the density functional theory, the electronic properties and piezoelectric coefficients of 2D Janus ZnBrI are calculated. It is found that the 2D Janus ZnBrI has a large in-plane piezoelectric coefficient d 11 , up to 145.85 pm/V, which is about 40 times that of 2D 2H-MoS 2 . Based on the finite element method and multi-physical field simulation, the large piezoelectric response of 2D Janus ZnBrI is shown intuitively. Based on the nonequilibrium Green's function, the device model of metal-semiconductor-metal is established, and the I-V response of the device model is calculated, which shows the modulation of piezoelectric effect on tunneling current. The simulation results show that 2D Janus ZnBrI is a 2D piezoelectric material with application potential. This multiscale prediction method can comprehensively predict other 2D piezoelectric materials.

With the development of edge computing, internet of things, connected vehicles and big traffic data, future urban traffic signal control will be improved in several aspects. Future urban traffic signal control systems will be a cooperative and network system, which contains abilities of detection data sharing, real-time optimization, synchronized control, comprehensive -monitoring, fault -tolerant and coordination evaluation. With these new features and functions, urban signal control systems will be intelligent and efficient.

The effect of carboxymethyl cellulose (CMC), high-methoxyl pectin (HMP), konjac glucomannan (KGM), and xanthan gum (XG) on the physicochemical, structural properties, and digestibility of rice starch were investigated and compared. The four viscous soluble dietary fibers (VSDFs) increased the viscosity, storage modulus and loss modulus while decreased the pasting temperature and gelatinization enthalpy. Moreover, XG produced the lowest peak viscosity and dynamic modulus compared with the other VSDFs. Furthermore, the degree of short-range ordered structure of starch with KGM increased from 0.8448 to 0.8716; and the relative crystallinity of starch with XG increased by 12%. An ordered and reunited network structure was observed in SEM. In addition, VSDF inhibited the digestibility of rice starch and significantly increased the resistant starch content. This study compared the effect of four VSDFs on the physicochemical, structural and digestion properties of rice starch to fully understand and develop their application to starchy foods.

Treatment resistance leads to physiological, psychological, and economical effects among patients with anti-N-methyl d -aspartate receptor (anti-NMDAR) encephalitis, and the clinical and immune characteristics of these patients remain to be described. According to our clinical experience, bortezomib may be effective due to its plasma-cells depletion ability. Herein, the clinical presentations and immune parameters, including B cell and antibody secreting cell (ASC) abundance, of 5 enrolled treatment-resistant patients are described. When compared with 5 treatment-sensitive cases, the patients had serious clinical presentations but comparable B cells and ASCs. After receiving bortezomib, the ASC count and anti-NMDAR antibody titers decreased effectively. All 5 patients had a favorable prognosis (mRS ≤ 2) with a median follow-up of 31 months without severe side effects or relapse.

Astragaloside IV (AS-IV) is a representative component of astragaloside saponins in dried roots of Astragali Radix. Astragaloside possesses a broad spectrum of pharmacological activities, including antibacterial, anti-fibrosis, antioxidant, anti-inflammatory, and neuroprotective effects. However, the role of AS-IV in antiaging remains unclear. In this article, we studied the function of AS-IV in antiaging by using the

Considering the bright future of intelligent driving and automatic driving technology, many researchers pay attention to the significance of traffic signs detection and recognition. In this paper, a fast and accurate traffic signs detection and recognition model was proposed, which uses a detector similar to the fully convolution network and one stage method in semantic segmentation problem to localize the traffic signs in a pre-pixel fashion. Compared with other state-of-the-art object detection networks such as Faster R-CNN [1] and YOLOv3 [2], the semantic segmentation network proposed in this paper does not need predefined anchor, so it completely avoids the complex calculation and super parameter settings related to anchor boxes, which greatly reduces the workload of training and accelerates the model inference procedure.

Phonon anisotropic properties of 4H, 6H and 15R-SiC were investigated by polarization Raman scattering, and Raman selection rules were explored both theoretically and experimentally. As a function of the relative angles between the incident and the scattered light, Raman intensity of E1, E2 and A1 modes were collected from the (0001) plane, the ( 1 1 ¯ 00 ) plane, and the ( 11 2 ¯ 0 ) plane of wurtzite SiC and the 15R-SiC region in the (0001) plane. Results showed that E1, E2 and A1 modes were anisotropic in the (11 2 ¯ 0) and the ( 1 1 ¯ 00 ) planes of 4H and 6H-SiC, while E2 modes were isotropous in the (0001) plane. Furthermore, E1 mode of 799 cm−1 in the (0001) plane appeared and exhibited anisotropic properties due to the stacking faults in SiC. Otherwise, the anisotropic properties of A1 and E modes of 15R-SiC in the (0001) plane were in agreement with that of wurtzite SiC.

The interfacial transition point isolated by maximum entropy production principle (MEPP) was used to construct a two-dimensional (2D) finite element (FE) model of continuous-drive rotary friction welding (RFW) with GH4169 superalloy. The transition point from sliding friction to shear friction was calculated based on the equal entropy of these two kinds of heat liberation mechanisms at this point. The FE model was shown valid by the consistency of comparison between simulation and experiment. The simulation issued an interfacial distribution of non-uniform heat intensity that determined the corona bond, which corresponded to higher temperature zone over the transition temperature. The influences of linear speed and friction pressure on welding time were examined, which showed that a shorter welding time could be acquired when the linear speed was about 1.96 m/s and the friction pressure is larger.

This paper investigated the effect of extrusion treatment on the rheological properties, in vitro digestibility, and multi-structure of starch with or without bamboo shoot dietary fiber (BSDF). The viscoelasticity and thixotropy decreased after extrusion treatment, however, they increased after BSDF addition, and decreased with increasing BSDF content. The starch granules became smooth and formed big lumps after extrusion treatment. The dense lumps became loose after the addition of BSDF. Extrusion treatment changed the movement and arrangement of starch chains and thus the relative crystallinity and branching degree decreased by 92.6% and 40.9%, respectively. The disruption of starch further increased rapid digestion starch (RDS) content by 10%. The decreased disruption of starch granules and increased entanglement between BSDF and starch decreased the RDS content. The addition of BSDF is a novelty method to enhance the nutritional properties and control the physicochemical properties of extruded starchy foods.

Novel imprinted mesoporous carboxymethyl chitosan films (IMCFs) were investigated in detail. When acting as adsorbents, imprinted mesoporous carboxymethyl chitosan films with highly ordered chiral nematic structures, exhibit efficient adsorption for gadolinium ions (Gd(III)). The maximum adsorption capacity of IMCFs calculated from Langmuir isotherm model was 25.372 mg g−1 at pH 7.0. Due to the presence of highly selective imprinted sites, chitosan films possess significant selectivity for Gd(III), compared with other rare earth ions. More importantly, carboxymethyl chitosan films could be retrieved conveniently and quickly without extra operations, which greatly promote their recycling. Reusability tests further demonstrated films can be considered as stable and reliable adsorbents, enhancing their potential industrial applications.

In this paper, amorphous Ni-B nanoparticles doped with cobalt are successfully prepared by simple chemical reduction to investigate the mechanism by which cobalt enhances the electroactivity. Transmission electron microscopy (TEM) images indicate that the morphology of the Ni-B-(Co) amorphous nanoparticles is uniformly spherical, and that the particle size is about 10–15 nm. X-ray photoelectron spectra (XPS) show that Co electrons shifted to B and Ni. Subsequently, the electrocatalytic characteristics were investigated by cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The results show that the methanol electro-oxidation current of Ni-B-(Co) amorphous nanoparticles initially increased and decreased as the Co content increased. Ni-B-Co0.05 nanoparticles exhibited the best electrocatalytic activity for methanol oxidation. It is proposed that the role of cobalt in methanol catalysis on the surface of amorphous Ni-B-Co nanoparticles is initially to promote the generation of NiOOH by preferentially forming CoOOH. Meanwhile Co could increase the absorption ability of Ni 3d orbit toward the methanol and intermediates, and thus improve the catalytic activity toward methanol. Our study provides a theoretical guide concerning doped atoms raising the electroactivity of the methanol oxidation on amorphous Ni-B nanoparticles.

To explore modification effects of ultrasonic treatment on high-methoxyl pectin (HMP), HMP was used as raw material and processed by ultrasonic treatment under different powers (120, 240, 360 and 480 W). Rheological properties of HMP gel were tested. Moreover, the HMP gel formation process was analyzed through kinetic analysis. Results demonstrate that the viscosity of HMP was reduced significantly by ultrasonic treatment. However, the rheological properties of HMP gel were retained, and they still showed typical pseudoplastic and shear thinning properties. HMP gel of the low-power treatment group showed better viscoelasticity compared with those of the contrast group. The maximum G′ and G″ were achieved after HMP was treated by 120 W ultrasonic power when elasticity of HMP was enhanced significantly. Moreover, the structure of HMP was damaged by the cavitation effect and mechanical effect as ultrasonic power increased, thereby the strength of gel decreased significantly. Ultrasonic treatment could weaken the gel formation ability of HMP. During gel formation, the activation energy difference between the high-temperature and low-temperature stages reduced with increasing ultrasonic power. The 120 W treatment group achieved the maximum activation energy difference between the high-temperature and low-temperature stages, while the 480 W treatment group achieved the minimum activation energy difference.

Continuous drive rotary friction welding was conducted on SUS304 stainless steel rods in diameter of ϕ25 mm under different welding pressures, rotation speeds, and friction time. At the friction interface, the normal stress distributions were measured, and the corona bond (i.e., plasticized metal) was characterized. The results show that, under a constant welding pressure, the normal stress initiates at the periphery of the sample interface, leaving the inner area that seems un-contacted at the very beginning of the friction process. Thereafter, the normal stress extends inside along the radial direction, which leads to its distribution presenting like a “U” shape. The normal stress at the periphery increases much faster than it at the inner area, resulting in the distribution presenting like a “V” shape. Then, the stress in the center continuously increases and the distribution gradually changes into “M” shape. The stress is lastly homogenously distributed. Evolution of the normal stress distribution determines the evolution of the corona bond. At the same time, evolution of the corona bond reacts on the distribution of normal stress. In addition, similar phenomena have been observed under different welding parameters.

Rare earth elements (REEs) are critical materials to many cutting-edge technologies but are difficult to separate from one another because of their chemical similarity. We present ionic imprinted mesoporous bilayer films (IIBFs) as an ideal adsorbent for selective separation of neodymium (Nd) and dysprosium (Dy) from sintered neodymium magnets. IIBFs were prepared according to dual-template docking oriented ionic imprinting (DTD-OII). Due to different imprinted compositions of bilayer films, IIBFs exhibited high specific surface area, fast binding equilibrium, and Janus properties for simultaneous selective adsorption of different rare earth ions, which made our imprinted bilayer mesoporous films a specialized adsorbent for adsorption of Nd(III) and Dy(III) at the same time. The adsorption capacities of optimized IIBFs were 17.50 mg g−1 for Dy(III) and 12.15 mg g−1 for Nd(III) at pH = 4.0. Moreover, we grafted thermo-responsive polymer on the one surface of IIBFs to realize controlled release of Nd(III) and Dy(III) by temperature. IIBFs demonstrate a high degree of reusability by cycling experiments by DTD-OII, which develop their promising applications for the REE recycling and separation industry.

The object of the present work is to research the microstructure evolution of AISI 304 stainless steel (304SS) joined by rotary friction welding. The dynamic recrystallization (DRX) and texture formation process were analyzed by optical microscope and electron back-scattered diffraction (EBSD) technology. The results showed that DRX, which emerges on the torque rising stage, mainly occurs in the welding zone, and completes on the torque quasi-steady stage. Furthermore, obvious shear type texture ({110} ) forms in the joint of 304SS.

The continuous drive rotary friction welding was conducted on AA6061-T6 aluminum alloy rods under different rotation speeds. The effect of rotation speed on friction behavior was investigated via analyzing the friction torque, temperature, microstructure and axial shortening. The results show that the curves of friction time and friction work as a function of rotation speed present like “V-shape” with the minimum values locating at around 900 rpm. Besides, the ratio of friction work in the first stage to that in the whole process increases and then decreases after reaching the maximum value at 900 rpm. As the rotation speed increases, the heat pattern gradually changes from the “scissor-shape” into “double-ellipse shape” that is acquired at 900 rpm and eventually into the “disc-shape.” Additionally, the axial shortening rate at the steady stage initially reaches a high constant value and then drops to another constant value that is nearly half of the high value when the rotation speed is not less than 1500 rpm. The high axial shortening rate can be ascribed to the process of filling the unbonded area remained at the interface after the first friction stage.

TC4 titanium alloy was diffusion bonded under small axial pressure of 0.5 MPa to restrain the deformation. The sample surfaces, prior to bonding, were finely polished to Ra 0.3 μm. The bonding temperatures were used as 860, 890 and 920 °C with holding time of 1 h. The joint microstructure was examined. Tensile test and Charpy impact test were conducted to evaluate the joint strength and toughness. Two parts of the 860 °C bonded sample were then held in 920 °C for 90 min and 180 min, respectively. The results show that the 920 °C joint with high bonding ratio (∼98%) fractured at the base metal during tensile test showing excellent strength of the joint. However, the impact toughness was 14.99 J/cm2 that is much lower than 27.3 J/cm2 of the base metal. The heat treated 860 °C samples had 100% bonding ratio and impact toughness of 15.81 and 20.02 J/cm2 for the 90 and 180 min sample. The microstructure analysis indicates that the joint toughness was affected by the void defects remained and the interface grain boundary migration at the bonding interface.

Cellulose nanocrystals (CNCs)-derived photonic materials have confirmed great potential in producing renewable optical and engineering areas. However, it remains challenging to simultaneously possess toughness, strength, and multiple responses for developing high-performance sensors, intelligent coatings, flexible textiles, and multifunctional devices. Herein, the authors report a facile and robust strategy that poly(ethylene glycol) dimethacrylate (PEGDMA) can be converged into the chiral nematic structure of CNCs by ultraviolet-triggered free radical polymerization in an N,N-dimethylformamide solvent system. The resulting CNC-poly(PEGDMA) composite exhibits impressive strength (42 MPa), stretchability (104%), toughness (31 MJ m

This study focuses on diffusion bonding of WC-Co cemented carbide to a steel using Co and composite Ni/Co interlayers. The typical microstructure and microstructural evolution with variable bonding temperatures were investigated, and mechanical properties of the joint were evaluated. The results illustrated that increasing temperature promoted interdiffusion of interfacial atoms, leading to the elimination of interfacial voids and the enhancement of Fe-Co-Cr interdiffusion zone on steel side. As the temperature increased, so did the thickness of Co6W6C formed near the WC-Co substrate (using Co interlayer). On the other hand, the Co6W6C was inhibited due to the addition of Ni foil, and replaced by the WC and (Ni, Co) solid solution resulting in satisfactory shear strength of the diffusion-bonded joint, where referring to using composite Ni/Co interlayer. The maximum shear strength of 418 MPa was achieved when the joint was diffusion-bonded at 1100 °C for 60 min using composite Ni/Co interlayer. In addition, ductile fracture occurred in the joint indicating propagation of cracks in the Ni-Co interdiffusion zone, and passing through the WC-Co substrate. Added up, this study provided experimental support for reliable joining cemented carbides to Fe- or Co-based alloys.

Lots of gum and asphaltene in heavy oil caused high viscosity, high density and poor fluidity, which makes it very difficult to exploit and transport heavy oil. This paper introduces the mechanism and application of five new viscosity reduction technologies, including microbial viscosity reduction technology, biosurfactant viscosity reduction technology, ultrasonic viscosity reduction technology, magnetic treatment viscosity reduction technology and supercritical carbon dioxide viscosity reduction technology. At present, single viscosity reduction technology is difficult to solve the problem of heavy oil production and transportation. So the development direction of heavy oil viscosity reduction technology is the composite use of various technologies. In the future, it is necessary to develop new viscosity reduction technologies suitable for heavy oil production and transportation from the perspective of studying the structure and performance of heavy oil.

Currently, LiMnPO4 is a highly prevalent cathode material in lithium-ion batteries. However, its low conductivity and Li+ diffusion rate limit its practical application. To overcome these inherent defect, we have modified its properties by doping Fe at the Mn site. In the LiMn1-xFexPO4 system, the total density of states of electrons near the Fermi level and the energy band of the Fermi surface are obtained by first-principles calculation. The adjustment of the energy band width immediately influences the electronic conductivity of LiMn1-xFexPO4 system, which is positively related to the electrochemical performance. According to the results of first-principles calculation, we speculated that x = 1/4 was the optimal doping concentration. Then, the LiMn1-xFexPO4/C systems were compounded by hydrothermal method to verify the first-principles’ hypothesis. The electrochemical tests show that the LiMn3/4Fe1/4PO4/C material has the best cycle performance and rate performance. At the condition of 0.05 C rate, this material possesses an initial discharge capacity of 142.5 mAh g−1. with the capacity retention maintained 93.9% after 100 cycles. The theoretical calculation in consistent with the experimental findings, which accounts for the fact that the first-principles strategy is very effective in the research and development of lithium-ion batteries.

This study aimed to investigate the effect of high-pressure homogenization (HPH) with different pressures, cycles, and starch concentrations on the functional and structural characteristics of chestnut starch. Results showed that the structures of the subcrystalline zone and amorphous region could be destroyed by increasing the pressure for 1 cycle, leading to improved functional properties. Compared with the untreated, the solubility and swelling power of chestnut starch were significantly enhanced by approximately 53.01–86.02% and 64.54–79.50%, the aging value was 48.62–99.00% lower than the original starch, and the transparency increased by 8.55–25.51%. Furthermore, as the cycles increased, the crystal zone structure of starch was damaged. The crystallinity significantly decreased by 28.66–45.60%, compared with the original starch, with particle distribution tending to be uneven and the average particle size decreased by 17.50–90.02%. Besides, solubility, swelling power and transparency could be improved by increasing concentration during HPH.

A long-running SF6 insulating gas decomposes without being detected in time would cause incalculable consequences, therefore, real-time monitoring towards SF6 status is of practical significance. Currently, the gas-sensitive properties of two-dimensional materials are the focus and hotspot of gas sensor research, however, in practical situations, material preparation and device fabrication will inevitably bring about defects. Therefore, the effects of sulfuric vacancy (SV) in molybdenum disulphide are proposed and explored, and a comparative study of gas-sensitive properties (pristine MoS2 vs SV- MoS2) is carried out using density functional theory based on the first principles. Constructing typical adsorption models for SF6 decomposition components on monolayer, together with analyzing the optimum adsorption structures, adsorption energy, density of states, molecular orbitals, electrical conductivity and co-adsorption behaviors. The results show that the SV brings a defective state to MoS2 monolayer, which contributes to an overall increase in the adsorption energy for the decomposition components (the increase > 0.15 eV), making the undifferentiated adsorption effect selective for SO2F2. The physical interaction between the decomposition products and SV-MoS2 monolayer is more favorable for desorption. These results indicate it is appropriate for detecting SF6 status in high-voltage insulation environments, with pointers to practical applications for two-dimensional materials.

Purpose As known, the wire and arc additive manufacture technique can achieve stable process control, which is represented with periodic surface waviness, when using empirical methods or feedback control system. But it is usually a tedious work to further reduce it using trial and error method. The purpose of this paper is to unveil the formation mechanism of surface waviness and develop a method to diminish it. Design/methodology/approach Two forming mechanisms, wetting and spreading and remelting, are unveiled by cross-section observation. A discriminant is established to differentiate which mechanism is valid to dominate the forming process under the given process parameters. Findings Finally, a theoretical method is developed to optimize surface waviness, even forming a smooth surface by establishing a matching relation between heat input (line energy) and materials input (the ratio of wire feed speed to travel speed). Originality/value Formation mechanisms are revealed by observing cross-section morphology. A discriminant is established to differentiate which mechanism is valid to dominate the forming process under the given process parameters. A mathematical model is developed to optimize surface waviness, even forming a smooth surface through establishing a matching relation between heat input (line energy) and materials input (the ratio of wire feed speed to travel speed).

In order to improve the compatibility of polysaccharide-protein mixtures and enhance their performance, a response surface methodology was used to optimize the preparation conditions of konjac glucomannan/casein blend gel. Moreover, the effects of high-pressure processing (HPP) on the gel properties and structure were also investigated.; Results: The optimal preparation parameters were a temperature of 60 °C, a total concentration 40 g kg-1 , and a dietary alkali concentration 5 g kg-1 . Under these conditions, the experimental value of hardness was 38.7 g, which was close to the predicted value. HPP increased gel hardness by 161-223% and led to a more compact structure at 200-600 MPa/10 min, while a hardness increase of ∼120% and damaged structure were observed at 600 MPa/30 min. Fourier transform infrared spectroscopy showed that noncovalent interactions are likely the most important factor in the modification of gel hardness; indeed, hydrogen bonding interactions in the gels are enhanced when subjected to HPP, but are weakened at 600 MPa/30 min.; Couclusion: Protein-polysaccharide complexes with excellent properties could be obtained through this method, with broad application prospects in the food industry. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.

Carbon fiber (Cf)/Al specimens were fabricated by plasma-spraying aluminum powder on unidirectional carbon fiber bundles (CFBs) layer by layer, followed by a densification heat treatment process. The microstructure and chemical composition of the Cf/Al composites were examined by scanning electron microscopy and energy-dispersive spectrometry. The CFBs were completely enveloped by aluminum matrix, and the peripheral regions of the CFBs were wetted by aluminum. In the wetted region, no significant Al4C3 reaction layer was found at the interface between the carbon fibers and aluminum matrix. The mechanical properties of the Cf/Al specimens were evaluated. When the carbon fiber volume fraction (CFVF) was 9.2%, the ultimate tensile strength (UTS) of the Cf/Al composites reached 138.3 MPa with elongation of 4.7%, 2.2 times the UTS of the Al matrix (i.e., 63 MPa). This strength ratio (between the UTS of Cf/Al and the Al matrix) is higher than for most Cf/Al composites fabricated by the commonly used method of liquid-based processing at the same CFVF level.

An optical sulfonamides sensor is fabricated based on a molecular imprinted resin templated by nanocrystalline cellulose. A chiral nematic imprinted composite film is synthesized which is subsequently treated with removal of templates to generate a red reflecting photonic film. The film shows a naked-eye color response to sulfanilamide, which is related to reassemble imprinted sites in the chiral nematic structure, resulting in a yellow reflecting film. Upon exposure to various antibiotics, it can be simultaneously in selectively response to three sulfonamides. This strategy facilitates enormously potential application of the resin as battery-free and portative optical monitoring sensors.

Graphene has attracted intensive attentions due to its significant optoelectronic performances. Photovoltaic effect and photo-thermoelectric effect make graphene to be a hot choice in ultra-wide spectrum band photodetection. Thinking of serious influences such as chemical pollution and mechanical damages of CVD grown and exfoliated graphene caused by transfer and exfoliation processes, the epitaxial graphene on SiC single crystal wafer shows intrinsic and better performances. Here, high quality epitaxial graphene has been successfully synthesized by thermal decomposition of Si-terminated, semi-insulating on-axis oriented 4H-SiC (0001) wafer. Photon response of the graphene has been investigated by employing a metal-graphene-metal photodetector. The largest photo-current value obtained under 780 nm laser illumination and 10 V bias voltage is up to 2.2 × 10−7 A, which is almost 30 times greater than the dark current. While under 0.05 mW/cm2 irradiance, the highest values of responsivity and EQE are 4.48 × 10−2 A/W and 8.13%, respectively. This type of fabricated graphene based photodetector has shown steady and outstanding photo detection performances.

The heterogeneous joint constituted by Al and Cu were diffusion-bonded with Ni or Ag interlayer under different bonding parameters, which was compared with directly bonded Al-Cu joints to analyze the effects of the different intermetallic compounds (IMCs) produced at the joining interface on the joint mechanical properties. The joint microstructure was analyzed by scanning electron microscope (SEM), the compositions profiles across the joining interface were measured by energy dispersive spectroscopy (EDS), and the mechanical properties of joints were evaluated by hardness, indentation fracture toughness, and tensile test. The experiment results demonstrated that the Al-Ag-Cu and Al-Cu joints couldn't avoid the crack due to the thick, hard and brittle IMCs layer formed at the joining interface, while, the thickness of the IMCs in the Al-Ni-Cu joint is less than 3.8 μm, this thin IMCs layer ensured that the joining interface exhibited the lowest hardness and brittleness in microscales, so the Al-Ni-Cu joint was free of cracks not only after bonding but also under the load of indentation fracture toughness test. The tensile test indicated that the Al-Ni-Cu joint had the highest tensile strength (47 MPa), which was bonded with 50 μm thick Ni interlayer at 10 MPa, 520 °C, 60 min.

Two-dimensional (2D) piezoelectric materials have attracted wide attention because they are of great significance to the composition of piezoelectric nanogenerators. In this work, we have systematically studied the piezoelectric properties of 2D LiAlTe2 by using the first-principles calculation and found the 2D LiAlTe2 monolayer exhibits both large in-plane piezoelectric coefficient d 11 (3.73 pm V−1) and out-of-plane piezoelectric coefficient d 31 (0.97 pm V−1). Moreover, the piezoelectric coefficients of 2D LiAlTe2 are highly tunable by strain and stacking. When different uniaxial strains are applied, d 11 changes dramatically, but d 31 changes little. When 2% stretching is applied to 2D LiAlTe2 monolayer along the x-axis, d 11 reaches 7.80 pm V−1, which is twice as large as the previously reported 2D piezoelectric material MoS2. Both AA stacking and AB stacking can enhance the piezoelectric properties of 2D LiAlTe2, but they have different effects on in-plane and out-of-plane piezoelectric coefficients. AA stacking can greatly increase d 31 but has little impact on d 11. In the case of four-layer AA stacking, the d 31 reaches 3.32 pm V−1. AB stacking can both increase d 11 and d 31, but d 11 grows faster than d 31 as the number of layers increases. In the case of four-layer AB stacking, d 11 reaches 18.05 pm V−1. The excellent and highly tunable piezoelectric performance provides 2D LiAlTe2 greater potential for the application of piezoelectric nano-generators and other micro-nano piezoelectric devices.

With the continued recovery of heavy oil, conventional polymer flooding cannot be applied to heavy oil reservoirs gradually due to the characteristics of heavy oil reservoirs. To study oil displacement agent suitable for enhanced heavy oil recovery and investigate the effect of EO chain length on the performances, acrylamide, acrylic acid, lauryl methacrylate and C10-C16 alkylphenol ethoxylates were selected to co-polymerize into the active polymer PAAP-x with different EO chain length (14, 16, 18, 20 and 22). Proton nuclear magnetic resonance analysis indicated PAAP-x as the target product. The optimal EO chain length of PAAP-x was determined to be 18 by the analysis of thickening, salt-tolerance, interfacial activity, wettability, viscosity reduction and recovery. Compared with conventional polymer P1, 1500 mg/L PAAP-18 exhibited superior performances with salinity of 6882.2 mg/L: (1) PAAP-18 could maintain the viscosity of 113.1 mPa.s, while P1was 44.8 mPa.s. (2) PAAP-18 could reduce the water-oil IFT from 44.4 mN/m to 13.0 mN/m, while P1 was to 30.6 mN/m, and the water-oil contact angle was 58.2°and 108.5°, respectively. (3) The heavy oil viscosity reduction rate of PAAP-18 was 81.7% at 50 °C, while P1 was only 33.8%. (4) PAAP-18 enhanced heavy oil recovery by 19.85% on the basis of water flooding while conventional polymer was only 8.69%. This study has theoretical guidance and practical significance for the study on new oil displacement agent to enhance heavy oil recovery.

In this study, we propose an innovative Hf2CO2/WS2 heterostructure with excellent photocatalytic performance for water splitting based on first-principles calculations. The binding energy, and ab initio molecular dynamics (AIMD) simulations exhibit this material's excellent ambient stability. Furthermore, the band structure confirms that the Hf2CO2/WS2 heterostructure possesses the intrinsic type-II semiconductor and are well satisfied with the requirements of redox energy level in water splitting reaction. Meanwhile, the charge transfer occurs from Hf2CO2 to WS2 monolayer, which further induces the separation of photogenerated carriers and prolong the lifetime of carriers. Dramatically high visible-light absorption (~6.3 × 105 cm−1) and carrier mobility (~2.2 × 103 cm2 V-1 s-1) are found, which means that the heterostructure has adequate motive force to make the photogenerated carriers separate into different monolayers quickly before recombination. Moreover, according to Gibbs free energy calculation, HER and OER can be triggered spontaneously under the driving of external potential. The results confirm that the thermodynamic feasibility of water splitting on Hf2CO2/WS2 heterostructure surface. Hence, these distinctive features endow Hf2CO2/WS2 heterostructure with the potential ability of photocatalytic water splitting, which provides a potential avenue for the future experimental project.