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Based on the hole-drilling strain sensing method, a ring Fiber Bragg Grating (FBG) array is proposed to realize comprehensive and convenient measurement of residual stress for homogeneous or inhomogeneous materials. All FBG sensors are arranged tangentially along the edge of the ring. With the ring array around the drilled hole, more detailed information of the residual stress can be obtained such as the location and the degree of inhomogeneity. The tangential arrangement of FBG sensors can achieve comparable measurement results to the radial arrangement but it brings convenience for the drilling process without any overlap upon the hole position. This method promotes the application of the FBG sensors in the residual stress measurement field.

Rational design and fabrication of optimal reversible oxygen electrocatalysts are essential yet still remain great challenges for rechargeable metal-air batteries. Supramolecular coordination polymer-derived strategy for transition metal–nitrogen–doped carbon (M–N/C, M = Co, Fe, etc.) composites catalysts has been deemed promising in preserving rich M–Nx coordination modes and enhancing their intrinsic activities. However, the closely packed and nonporous characteristics of coordination polymer usually lead to the serious agglomeration of metallic nanoparticles and lack of porous channels after pyrolysis, impacting the abundance and accessibility of the exposed active sites during electrocatalysis. In this work, we put forward a new tactic to obtain ultra-small Co nanoparticles confined within N-doped carbon nanotubes grafted to reduced graphene oxide (Co/N-CNTs@rGO) through a coordination-driven in situ self-assembly approach followed by pyrolysis. The integration of high intrinsic activity, enhanced conductivity, populated and richly exposed active species throughout the laminated hierarchical composite structure endows Co/N-CNTs@rGO with appealing bifunctional oxygen electrocatalysis properties. Impressively, Co/N-CNTs@rGO was subsequently fabricated as the air electrode in a rechargeable Zn−air battery, and the device achieves a maximum power density of 168 mW cm−2, a large specific capacity of 765 mA h g−1 while maintaining satisfying cycling durability. This work may provide valuable insights in regulating the coordination polymer derivatives and bring new perspectives for future design of promising composites electrocatalysts for electrochemical conversions and energy storage technologies.

Poor fracture toughness is a major limitation of SiC ceramics, which greatly affects their application range. Herein, a novel strategy is proposed to enhance the fracture toughness of SiC ceramics by cross-linking carbon nanotubes (CNTs) coated with polydopamine (PDA) to Ti3C2 modified with 3-glycidyloxypropyltrime-thoxysilane (KH560) (PDA-CNTs@f-Ti3C2). Then, PDA-CNTs@f-Ti3C2 was added to SiC powder to prepare the final composite. The influence of PDA-CNTs@f-Ti3C2 addition on the microstructure and mechanical properties of the SiC composite is discussed. The results showed that, compared with CNTs and Ti3C2, the PDA-CNTs@f-Ti3C2 composites exhibited better dispersibility in water. The flexural strength was significantly enhanced (~89%) in the SiC composite containing 3 wt% PDA-CNTs@f-Ti3C2, from 228.99 MPa to 433.55 MPa. The fracture toughness of the SiC composite containing 3 wt% PDA-CNTs@f-Ti3C2 improved by 62%, from 3.97 MPa/m1/2 to 6.44 MPa/m1/2.

Laboratory-scale experiments were conducted to investigate the oxygen content of Si-deoxidized H13 die steel by ferrous oxide-containing slags at 1873 K. The calculation of thermodynamics and kinetics was performed to evaluate the oxygen level of molten steel through [Si]–[O] equilibrium and [Fe]–[O] equilibrium. The results show that as the FeO content in slag increases, the oxygen content with [Si]–[O] equilibrium (w([O])Si) has almost no change. When both the oxygen content with [Fe]–[O] equilibrium (w([O])Fe) and w([O])Si are less than the initial oxygen content in steel (w(TO)i), the oxygen content in steel (w([O])) depends on the higher value between w([O])Si and w([O])Fe. In the case of w([O])Fe > w(TO)i, the value of w([O]) is the difference between the sum of w(TO)i and w([O])Si and the value of w([O])Fe. The reaction rates of [Si]–[O] and [Fe]–[O] are equal, which are controlled by the mass transfer of oxygen in molten steel. The evaluation method is suitable to the whole smelting process of Si-deoxidized H13 die steel.

Laboratory-scale experiments were performed to investigate the deoxidation of H13 tool steel with CaF2-MgO-Al2O3-CaO-SiO2 slags at 1873 K. The calculation of thermodynamics and kinetics was also verified through the experimental results. The results show that [Si]-[O] reaction is the control reaction, and with the increase of basicity of slag, the limitation of deoxidation was decreased. The limitation of deoxidation is the lowest for the slag with basicity of 2.0. Under the conditions of the basicity of 2.0 and the content of CaF2 more than 50%, the limitation of deoxidation is less than 10 × 10−6, and it does not depend on the contents of Al2O3 and CaF2 in slags. The mass transport of oxygen in the metal phase is the rate-controlling step, and the slag composition has no effect on the equilibrium time of deoxidation. Based on this finding, the optimized slag composition is designed and it contains the following components: 51.5% CaF2 20.3% MgO, 16.2% Al2O3, 8.2% CaO and 3.8% SiO2. In the case of the optimized deoxidizing slag, the total oxygen content in H13 steel can be reduced from 25 × 10−6 to 6 × 10−6.

We investigated the morphology formed in the binary blend of six-arm star-shaped (poly(methyl methacrylate)-block-polystyrene)6 copolymer [(PMMA-b-PS)6] and PMMA-b-PS linear diblock copolymer by va...

A chirp compensation method of fiber Bragg grating (FBG) is proposed to improve the residual stress measurement accuracy in the hole-drilling method. The effects of the radii of the hole, the distance between the FBG and the hole, the Young’s modulus of the material, and the residual stress on the FBG chirped spectra are analyzed. The relationship between radii of the hole, the distance between the FBG and the hole, the full-width at half maximum (FWHM), and the peak wavelength are established. The feasibility of the method is verified through experiments, which shows that the residual stress measurement error can be reduced by the compensation method.

These years, electronic devices and integrated circuits have a trend of miniaturization and integration with the rapid development of the information industry, higher requirements have been placed on the size, purity, and defect density of silicon wafers. More urgent demands have been placed on the mass production of electronic grade polysilicon. However, the research of electronic grade polysilicon in China is still in its infancy, it is far from meeting the requirements of mass production. This paper studies the influence of the single factor of reaction temperature on the yield of silicon, the surface morphology and power consumption of polysilicon under the certain conditions, which has some reference value for the production of electronic grade polysilicon.

A flexible 3D N-doped reduced graphene oxide (N-RGO)/carbon nanotube (CNT) MnO2 hybrid film was constructed with outstanding supercapacitor, excellent oxygen reduction reaction (ORR) and good sensing performances. The resultant hybrid film possessed large specific capacitances of 418 F g−1 and 209 mF cm−2 in aqueous and solid electrolytes, and outstanding capacitance retentions of 95% and 94% were obtained for both electrolytes after experiencing 5000 cycles. A simple supercapacitor based on the resultant flexible hybrid film was further fabricated with a much smaller time constant τ0 (0.38 s) than that of typical activated-carbon supercapacitors, suggesting a quick response frequency. Moreover, the assembled supercapacitor device showed high energy densities of 45.72 and 92.13 Wh kg−1 and simultaneously sustained large power densities of 12,526 and 15873 W kg−1 under a scan rate of 50 mV s−1 in aqueous and solid electrolytes, respectively. Furthermore, the resultant flexible film showed excellent performance in the ORR and can also be used to assemble a strain sensor with an excellent sensing performance for bending strain.

Separation of dyes and proteins from water remains a significant challenge. Common absorbents without recyclability might bring secondary pollutions, which may be avoided by developing stimuli-responsive smart absorbents. Here in this work, a CO2-responsive polymer poly(2-(dimethylamino) ethyl methacrylate) was grafted from cellulose fibers (Cell-g-PDEA). The chemical structure and surface morphology were confirmed with nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction and scanning electron microscope. The CO2-sensitivity was demonstrated by monitoring the pH, surface Zeta potential and dispersed appearance under stimulus of CO2. Furthermore, the modified cellulose fibers were packed into a syringe to construct a smart separation column that reversibly captured and released anionic dyes and proteins from water under gas stimulus. Comparing with traditional pH or temperature responsive materials, the CO2-responsive cellulose fibers take the advantages on energy-saving, good reversibility and moderate running conditions, thus might find applications in smart separations, clinical diagnose and therapies.

The MWCNT-COOH and CTAB modified MMT were hybridized by the ultrasonic method, and the nylon 66/MMT/WMCNT composite was prepared by in-situ polymerization to study the effect of the introduction of MMT and MWCNT on the properties of nylon 66. A scanning electron micrograph of the composite cross-section shows that the CNTs were uniformly dispersed in the nylon 66 matrix. The XRD patterns show that the introduction of MMT and MWCNT-COOH caused the ratio of α1 and α2 of nanocomposites. The TGA results show that the heat resistance and residual carbon content of the composite material are improved. The mechanical properties of nanocomposites show that the mechanical properties of the material are improved relative to pure PA66.

The thermophysical properties of Ni–Al. Ni–Ti, and Al–Ti alloys, i.e., viscosity and surface tension, have been investigated using the evaluated thermodynamic properties, i.e., enthalpy of mixing $$ \Delta H_{\text{mix}} $$, Gibbs free energy of mixing $$ \Delta G_{\text{mix}} $$, and excess Gibbs free energy $$ \Delta G_{{}}^{\text{E}} $$, by the atom and molecular coexistence theory. Then, the third-degree Redlich–Kister (R–K) parameters for viscosity, surface tension, and excess Gibbs free energy at 1973 K were obtained. Based on this, the isothermal viscosity of Ni–Al–Ti ternary melts was simultaneously determined form the excess viscosity of the above-mentioned three binary systems by CALPHAD model and the similarity coefficients by Chou’s model, and the surface tension of the liquid ternary Ni–Al–Ti alloy systems was investigated with considering the excess surface tension of the three binary systems by Chou’s model as well as the excess Gibbs free energy of Ni–Al–Ti melts by Butler’s model for the multicomponent system at 1973 K. The results showed that the viscosity and surface tension of liquid Ni–Al–Ti alloy increase with the increase in Ti content at a fixed Al/Ni ratio, whereas decreases with increasing Al/Ni ratio at a given alloy composition at 1973 K.

Bacterial cellulose (BC) is a unique nanofibrous biomaterial, and crystalline cadmium sulphide (CdS) is regarded as one of the most attractive visible light-driven photocatalysts. In this study, a BC@CdS nanocomposite for photocatalytic degradation of organic dye methylene blue (MB) was prepared with a facile and highly efficient strategy. The nanocomposite was prepared through a designed “anchoring-reacting-forming” pathway. SEM images showed that the BC-alcogel was the best matrix for nano-fabrication on which nanosized CdS particles were homogeneously distributed (approximately 100 nm). The results from FT-IR, XRD and XPS revealed that the CdS nanoparticles, mainly cubic and hexagonal crystallite, are attached to the BC fibers via coordination effect. The BC-supported adsorbent photocatalytic material was easy to be recycled and followed a new “adsorption–accumulation–degradation” mechanism of photocatalytic degradation. The results showed BC matrix had a strong adsorption effect on MB molecules, which improved local concentration of MB and promoted the rate of photocatalytic reaction. This novel adsorbent photocatalytic nanocomposite material (contained 12.4% CdS, about 0.91 mg for degradation experiment) possessed highly efficient photocatalytic activity with 77.39% removal of MB after 180 min visible light irradiation (the degradation rate was 28.3% mg−1 h−1), and exhibited satisfactory cyclic utilization with slight attenuation. Therefore, BC@CdS nanocomposite is a novel promising candidate as adsorbent photocatalysts with visible light response.

Understanding the conformation of a polyelectrolyte (PE) is not only a fundamental challenge in polymer science but also critical for understanding the folding and aggregation of proteins. Here, we develop a theory by systematically including the electrostatic interactions into the self-consistent field theory for polymers to study the conformational behaviors of a single PE in poor solvents. As the backbone charge fraction of the PE increases, our theory predicts that the spherical globule (Sph) can either be elongated to a series of pearl-necklace (PN) structures or be flattened to two novel structures that have not been reported before: biconcave red cell and toroid. While the PN structures are stable conformations, the two fattened structures are metastable. We find that the cylindrical globule, the stability of which is under debate, is an unstable structure. The signature of the PN structures obtained by our calculation is less pronounced than that reported by other theoretical works due to the continuous change in the curvature from the pearl to the necklace, which, however, is in good agreement with the results from molecular simulations and neutron scattering experiments. In addition, our theory reveals different characteristics of the globule to PN transition: the transition from the Sph to the PN with double pearls is discontinuous, whereas those from adjacent PN structures are continuous at finite salt concentrations. Furthermore, we observe different scaling behaviors: the string width is not a constant as a thermal blob but decays as the backbone charge fraction increases.

In this paper, Schottky-drain reverse-blocking AlN/AlGaN HEMTs with drain field plate (FP) have been investigated by Silvaco-ATLAS tools. For HEMTs without FP, with the increase of Al mole fraction in AlGaN channel from 0 to 0.5, the reverse-blocking voltage increases from −158 V to −720 V. By using the drain field plate technique, a second electric field peak is introduced and the reverse-blocking voltage can be improved. Combined with the optimization of the SiN passivation thickness, optimal electric field management can be achieved to obtain the highest reverse-blocking voltage devices. Since HEMTs with different Al mole fractions possess different critical electric field values, the optimal SiN thickness are varied. With the increase of the Al mole fraction from 0 to 0.5, the reverse-blocking voltage increases from −510 V to −4500 V for HEMTs using drain FP and optimal SiN passivation thickness, and a high power figure-of-merit of 1.171 GW/cm2 is achieved. AlGaN channel HEMTs with Al mole fraction demonstrate great potential for power applications.

Organic luminogens have extensive applications due to their unique photophysical properties. In recent years, nonconjugated organic luminogens, in contrast to traditional conjugated luminogens, have gained much attention because of their facile preparation, environmental friendliness, and biocompatibility. In this study, a new kind of nonconventional luminogen based on dynamic covalent cross-linked polyhydroxyurethane is reported for the first time. The new luminogen not only exhibits intrinsic strong fluorescent emission in the solid state but also possesses high mechanical properties along with good shape memory and self-healing properties. In addition, the new luminogens are synthesized from aliphatic polyfunctional cyclic carbonate and amines via a much more straightforward method, avoiding the use of toxic isocyanates. Investigations indicated that the intrinsic luminescence of the resultant luminogens was induced by the cross-linking of polymer chains and could be well tuned by controlling the degree of cross-linking. By taking advantage of the unique characteristics of the resultant polymer luminogens, we further developed a facile method, named "light-mediated ink-free screen printing", for anticounterfeiting paper fabrication. Different from traditional ink-based printing technology, the new method used UV-light instead of expensive security ink to encode anticounterfeiting information on natural cellulose paper. The anticounterfeiting information is stable under various wet conditions, showing promising applications in the fast-growing counterfeiting of pharmaceuticals, packaging, and the food industry.

Alkaline-earth metal Ca2+ modified CdS nanocrystals have been designed for the first time for highly efficient H2 evolution from hydrogen sulfide (H2S) with Na2SO3 as a favourable reaction medium. The advantage of Na2SO3 was revealed by an electrochemical test, and the conversion of Na2SO3 during the reaction was carefully studied. Particularly, most of Na2SO3 was converted into Na2S2O3. Highly value-added utilization of waste H2S is therefore achieved via photocatalysis.

Wood-based materials are attracting extensive attention for applications in energy storage due to their environmental friendliness and the presence of numerous channels in their structure. However, the poor conductivity and flexibility of wood restrict its application. Although some researchers have made several efforts to improve the conductivity of wood by carbonization, the wood-based materials become brittle instead of flexible. Moreover, the cycling stability of carbonized wood-based materials becomes very poor due to their falling off during the process of electrochemical energy storage. Herein, for the first time, a smart carbonized lignin-free wood (CLFW)@Ni–NiS/vitrimer(V) composite multifunctional material with good reshaping, shape-memory, and self-healing properties was designed and fabricated. When assembled to a symmetric supercapacitor, the resultant CLFW@Ni–NiS/V hybrid showed not only the high gravimetric, areal, and volumetric energy densities of 38 W h kg−1, 687 μW h cm−2, and 58 W h L−1 and simultaneously maintained the high power densities of 56 kW kg−1, 202 mW cm−2, and 39 kW L−1, but also significantly enhanced cycling stability, respectively. In addition, CLFW@Ni–NiS/V presented good ORR and strain sensor properties. These outstanding advantages highlight the huge potential of smart wood-based materials with variable, shape-memory, and self-healing properties for applications in supercapacitors, catalysts, and sensors.

Effects of slag composition and alloy content as well as temperature on the deoxidation and desulfurization of Inconel 718 superalloy by CaF2-CaO-Al2O3-MgO-TiO2 ESR-type slag without the addition of a deoxidizer were systematically investigated by laboratory-scale experiments and the developed mass transfer model. The model predictions were verified through comparison with experimental results in a double-layer crucible. The results showed that the oxygen content decreased with an increase of CaO, MgO and CaF2 content in the slag at 1773 K, and CaO has a great influence on the deoxidation of Inconel 718 alloy compared with MgO and CaF2 in slag, which was responsible for the decrease in equilibrium content of sulfur in the Inconel 718 alloy. The total oxygen and sulfur content decreased from 33.2 and 20 ppm in master alloys to about 10 and 6 ppm in alloy ingots at 1773 K, respectively. Properly increasing the Al and Ti content only lowered the oxygen and sulfur content in the nickel-based alloy to a limited extent when satisfying the mechanical properties of the Inconel 718 alloy. The interfacial oxygen content increased with increasing temperature, giving rise to a decrease in the desulfurization ratio $$ \left( {{{[{\text{pct S}}]_{t = t} } \mathord{\left/ {\vphantom {{[{\text{pct S}}]_{t = t} } {[{\text{pct S}}]_{t = 0} }}} \right. \kern-0pt} {[{\text{pct S}}]_{t = 0} }}} \right) $$. These results show that the lower temperature favored desulfurization of the nickel-based alloy.

We investigated the order-to-order transition (OOT) of the polystyrene-block-polyisoprene-block-polystyrene-block-polyisoprene (S1I1S2I2) linear tetrablock copolymer at the symmetric volume fractio...

The macro- and microstructures, chemical compositions, microsegregations, and nonmetallic inclusion characteristics at different positions of the as-cast IN718 ingots produced by a laboratory-scale electroslag remelting (ESR) furnace under four remelting currents (150, 200, 250, and 300 A) were compared and investigated comprehensively. The results indicate that the average melting rate increases with the increasing remelting current, and the molten pool tends to be deeper. Thus, at the same position of the ESR ingots, the volume fraction of the segregated phase, the degree of elemental segregation, and the secondary dendrite arm spacing have the same tendency to increase with the increasing remelting current and show an increasing trend from the bottom to the top along the height of each ingot. If the current is set relatively low, the oxygen and nitrogen levels in the ingots increase, the conditions that make the contents and distributions of Al and Ti become unstable. In addition, the major nonmetallic inclusions in the IN718 ESR ingots are MgO·Al2O3 complex oxide inclusions with a three-layer structure and (Nb,Ti)N nitrides. The volume fractions and mean equivalent diameters display a downward trend with the increasing remelting current. The size and quantity of these inclusions are always larger in the upper portions of the ingots than those in the lower portions.

Electroslag remelting (ESR) is an advanced secondary refining technology for the production of clean, fully dense, and homogeneous castings of steels and alloys by removal of undesirable elements and nonmetallic inclusions. However, because of some potential reactions between reactive elements, i.e., Al and Ti, in liquid metal and oxygen as well as weak oxides, such as FeO and SiO2, in slag during the ESR process, it is impossible to hold those oxidative elements within specification or to maintain them uniformly from the bottom to top of the resultant ingot. According to a literature survey, recent fundamental research on the oxidation behaviors of Al and Ti in nickel-based alloy by ESR-type slag is scarce. Therefore, summarizing previous knowledge on the controlling loss reactive elements during ESR of Fe- and Ni-based alloys in view of thermodynamics and kinetics is in order to increase the basic understanding of the reaction mechanism between those elements and oxygen and weak oxides in the slag, which can guide the development of a new remelting technique that retards the oxidation of Al and Ti in Inconel 718 alloys during the ESR process. The presence of impurity elements, such as oxygen and sulfur, can also deteriorate the mechanical properties of metal products. Therefore, the inter-related literature about desulfurization during the ESR process is also reviewed in this article.

A novel side-hole fiber Bragg grating (SHFBG)-based sensor is proposed and realized surface tension, refractive index (RI), and temperature of liquid monitoring simultaneously. A segment of side-hole fiber (SHF) is spliced of a single mode fiber (SMF), and a 10 mm long fiber Bragg grating (FBG) is inscribed within the core of the open end of the SHF. Due to the capillary effect, the liquid level in the SHF changes as a function of the surface tension of the liquid, which can be measured by monitoring the liquid level in the hole. The reflectivity of the FBG is affected by the fraction length immersed in the liquid, while the Bragg wavelength is affected by the refractive index and the temperature of the liquid. The absolute shift and relative shift of the Bragg wavelength can be used to measure the temperature and the refractive index of the liquid, respectively. The sensor described in this paper can measure the surface tension and the refractive index easily taking advantage of the simple structure and bring, an additional benefit of the “internal thermometer” provided by the absolute value of the Bragg wavelength.

A novel highly sensitive liquid-level sensor based on an asymmetric dual side-hole fiber (DSHF) using the core mode as the sensing mode and the cladding mode as the reference mode is described. The side-hole located close to the fiber core is opened by polishing and used to access the core mode as the sensing mode, the side hole located furthest from fiber core being used to tightly confine the cladding mode as the reference mode. The small core size of the DSHF further enhances the sensitivity. Pure-water-level sensitivities of 1.496 nm/mm, 2.026 nm/mm and 4.019 nm/mm are demonstrated experimentally when the distance between the DSHF core and its proximal (opened) side hole are 1 . 75 μ m , 1 . 6 μ m and 1 . 1 μ m , respectively. The sensor also exhibits low-temperature cross-sensitivity of ∼ 0.013 mm/°C, ∼ 0.011 mm/°C and ∼ 0.006 mm/°C. The fabrication process in this case is not sensitive to the polishing process and its uniformity is determined mainly by the quality of the DSHF itself, which makes it possible to ensure repeatable fabrication. Such reliability of fabrication lends itself well to good reproducibility for potential multiple sensor unit manufacture.

A thermodynamic model for predicting the phosphorus distribution ratio LP of CaO–SiO2–MgO–FeO–Fe2O3–Al2O3–P2O5 slags was developed by considering the mass action concentration of ion couples or str...

In the present study, effect of CaF2–CaO–Al2O3–MgO–TiO2 slag with various TiO2 contents on the desulfurization of Inconel 718 alloy was investigated at 1773 K to provide the fundamental information for the establishment of desulfurization procedure during electroslag remelting (ESR) process. The melt-quenching method did not accurately determine the change in content of sulfur and oxygen in the nickel-based alloy with time for the present study, which uses a novel experimental apparatus. The results indicated that the final sulfur content in the nickel-based alloy increased from 7 to 9 ppm when the TiO2 content in slag of CaF2–CaO–Al2O3–MgO–TiO2 system increased from 2.17 to 10% without addition of deoxidizer. In order to further expound the desulfurization mechanism, meanwhile, the relationship between the oxygen activity at slag–metal interface and reaction time under conditions of various TiO2 in the slag was studied by coupling with the developed mass transfer model. The calculated oxygen content in bulk metal has a good corresponding relationship with the measured oxygen content in the nickel-based alloy. The oxygen activity at slag–metal interface increased up to 9.6 ppm when TiO2 content was 10% in the slag, giving rise to the decrease in desulfurization ratio in high TiO2 content. The optimal condition for simultaneously ensuring low sulfur content and maintaining oxidative elements, such as Al and Ti, uniformly from bottom to top of the ESR ingot is also discussed. Keywords: Nickel-based alloy, Desulfurization mechanism, Specific reaction interface, Oxygen activity, Mass transfer model, Ion and molecule coexistence theory

Three-Dimensional (3D) porous graphene, a kind of carbon material with in-plane nanopores and hierarchical pores formed between graphene layers, have attracted tremendous interests in application of supercapacitors due to their large specific surface areas, superior conductivity, unique porous structures and diversified compositions. Combining the advantages from both porous materials and graphene, 3D porous graphene has been regarded as an idea scaffold to build hierarchical hybrid with comprehensive electrochemical energy storage performance by introducing other substances. In this review, we aim to summarize the recent advances in fabricating 3D pure self-supported graphene-based porous structures with micro-, meso-, and macro-porous features and investigate the structure–property relationships, and their application in supercapacitors are also discussed.

Linear ABC triblock copolymers with frustrated interactions of χACN ≪ χABN ∼ χBCN can self-assemble into double- and triple-helical superstructures, where the B blocks form the helical domains wrap...

A new kind of biobased material named lignin-containing polyhydroxyurethane (LPHU) is prepared from bis(6-membered cyclic carbonate) (BCC), dimer fatty diamine, and lignin for the first time. The preparation strategy is isocyanate-free, solvent-free, and catalyst-free, representing a green and environmentally friendly method to access polyurethane (PU)/lignin composites. The resultant LPHUs possess dual networks: a dynamic covalent network and a hydrogen bonding network, exhibiting superior mechanical strength, high thermal stability, excellent reprocessability/recyclability, and smart properties such as shape memory and self-healing. Potential application investigations indicate that the resultant LPHUs can be not only used for smart packaging label fabrication for heat-sensitive commodities but also further combined with natural cellulose paper to prepare paper-based electromagnetic shielding materials with high mechanical performance.

The development of eco-friendly adsorbent with perfect solid/liquid separation performance is of great practical importance for the efficient purification of dye-containing wastewater. Herein, cellulose based cation-exchange fibrous bio-adsorbent (CEF) was successfully obtained via an industrialized cellulose etherification process. The fiber morphology can be maintained with the average degree substitution (DS) of CEF as about 0.19. The CEF showed high efficiency adsorption for methylene blue (MB): achieving 82% of equilibrium uptake (447.69 mg·g-1) within 5 min. Especially, the non-woven porous filter material, formed by CEFs and glass fibers, showed the praisable solid/liquid separation characteristics, fast water filtration rate (≈ 6.3 m3·m-2·h-1) and high removal rate (≈ 99.2%) when it was used to adsorb MB (150 ppm) from wastewater. In addition, CEFs filter material can be regenerated via a simple method. This study demonstrates that green natural fiber materials are promising for the economical and efficient purification of dye-containing wastewater.

Ferroalloys serve important functions during the steelmaking process and impart distinctive qualities to steel. High entropy alloy can be also produced by mixing ferroalloy elements in an equimolar ratio because of it has the advantage of low cost compared with using high purity metals. However, fundamental studies about the preparation of the high entropy alloy by using ferroalloy are scarce. Therefore, the CoCrFeMnNi high-entropy alloys (HEAs) were prepared by using ferroalloys as raw material and refined in an induction furnace with magnesia or alumina refractory under pure Ar atmosphere at 1773 K in the current study. The two different CaO-Al2O3-MgO slags saturated with MgO or Al2O3 were designed to investigate the effect of slag composition on the types of inclusions in the HEAs. The results showed that the complex inclusions MnAl2O4-MnS and Al2O3 were formed when the alloys melted in an alumina refractory, whereas MnAl2O4-MnS, MnCr2O4-MnS, as well as MgAl2O4, were found when the alloys melted in a magnesia refractory.

The exploration of advanced functional materials from natural resources is significantly important to green and sustainable development. Herein, we design an ultrafast humidity-driven bending response system using asymmetrically patterned cellulose nanofiber (CNF)/graphene oxide (GO) composite films. The CNF/GO composite films are fabricated by vacuum-assisted filtration, followed by a surface imprinting technique. The results reveal that the composite films possess excellent linear response to humidity change and cycle stability in the relative humidity (RH) range from 25 to 85%. The curvature of the film varies from 0.012 to 0.260 cm-1 as the RH changes from 25 to 85%, and the response time is only 3-5 s. The outstanding humidity response is attributed to the addition of GO that actively interacts with water, enhancing the flexibility and humidity sensitivity of the composite films. In addition, asymmetrical patterning improves the water transfer rate by confinement and renders an easy deformation of composite films under the same stress. Molecular dynamics simulation and finite element analysis are used to further elucidate the mechanism therein. Furthermore, this CNF/GO composite film is also an effective hygroelectric generator, with an output voltage as high as 286 mV. This smart CNF/GO film with responsive humidity-driven deformation shows potential applications as a biomimetic leaf, a proximity sensor, and a moisture-driven electricity generator. This work inspires a new approach of smart material design with nanocellulose and GO and promotes their further applications.

Electrospun nanofiber membrane (ENM) shows great advantage and potential in wastewater treatment due to its unique properties. However, exploring a green and efficient ENM for remediation of complex wastewater, such as simultaneous containing oils, dyes and heavy metal ion, remains challenging. In this work, a cellulose-based photocatalytic ENM, is constructed for this purpose. The hybrid ENM is prepared via electrospinning deacetylated cellulose acetate/polyvinyl pyrrolidone (CeP) nanofibers as skeleton cores and in-situ synthesis of beta hydroxyl oxidize iron decorated iron-based MOF (β-FeOOH@MIL-100(Fe)) heterojunctions as photocatalytic sheaths. The core-sheath structured ENM has ultrahigh MIL-100(Fe) loading (78 wt%), large surface areas (1105 m2/g) and well-dispersed β-FeOOH nanorods. Thanks to these porous and hydrophilic MIL-100(Fe), along with a robust photocatalysis-Fenton synergy from β-FeOOH@MIL-100(Fe), the as-prepared ENM shows outstanding performances with simultaneous high removal efficiency for oils (99.5 %), dyes (99.4 %) and chromium ion (Cr(VI)) (99.7 %). Additionally, the photocatalytic ENM can achieve a long-term reuse owing to its inherent self-cleaning function.

Grouting reinforcement is an important method used to solve problems encountered during tunnel construction, such as collapse and water gushing. The grouting diffusion process is greatly influenced by the structural characteristics of the fractures in a rock mass. First, an analytical grouting diffusion model of a single rough fracture under constant-pressure control is established based on the constitutive equation of a Bingham fluid. Second, the &ldquo, quasi-elliptical&rdquo, grouting diffusion pattern under the influence of roughness is revealed through a grouting diffusion experiment, which is conducted with an independently developed visualized testing apparatus. Furthermore, the analytical formula of roughness-corrected grouting diffusion characterized by the saw tooth density is established. Finally, an elaborate numerical simulation of the diffusion process of cement slurry (Bingham flow type) in a single rough fracture is carried out by introducing the Bingham&ndash, Papanastasiou rheological model. The temporal and spatial distribution characteristics of the velocity field and pressure field during the grouting diffusion process are analyzed as well. Moreover, the method and range of the roughness correction factor in the analytical grouting diffusion model are proposed based on the fracture roughness unit.

A developed and verified thermodynamic model based on the atom and molecule coexistence theory (AMCT) is employed to predict activities relative to pure liquids in standard state in Mg-Al, Mg-Zn, Al-Zn and Mg-Al-Zn melts through the calculated mass action concentrations of structural units, i.e., Ni. According to AMCT, Ni can be extrapolated and calculated by the chemical equilibrium constant of a structural molecule, i.e., Ki, in the Mg-Al-Zn ternary system and binary subsystems. In this paper, the standard Gibbs free energy function, for reported activities and mixing thermodynamic properties in Mg-Al, Mg-Zn and Al-Zn melts, was regressed and optimized. The results showed that Ki and Ni were deduced by Gibbs free energy function at the studied temperature. The results of calculating thermodynamic properties in the full composition range for liquid Mg-Al-Zn from 880 to 1100 K, as well as Mg-Al from 923 to 1073 K, Mg-Zn from 880 to 973 K and Al-Zn from 1000 to 1073 K, are presented in the paper by coupling with Ni and AMCT. An excellent agreement is noticed between the calculated values of this study and measured thermodynamic data from the references, suggesting that the AMCT can be well applied to describe and predict the activities of the Mg-Al-Zn system and its subsystems.

Quasicrystalline (QC) phases have been observed in various condensed matter systems including self-assembling block copolymer (BCP) melts. Theoretical study of the thermodynamic stability of QC phases presents a long-standing unsolved problem because of the aperiodic nature of the structures. Here, we report a combination method to study the thermodynamic stability of two-dimensional dodecagonal quasicrystalline (DDQC) phase with both ideal tiling and random tiling patterns formed by ABCB tetrablock terpolymers. This method applies the self-consistent field theory coupled with the Stampfli self-similarity construction to accurately calculate the free energy of the periodic DDQC approximants and then uses a cluster model to predict the stability of aperiodic DDQC phase. Surprisingly, we find a stable DDQC approximant but metastable ideal tiling DDQC structures. Moreover, the random tiling DDQC structures as a mesoscopic coexistence of two neighboring periodic substructures of DDQC might become stable.

The solidification sequence, microstructural evolution, solid-liquid interface variation, interdendritic segregation, and elemental distribution of as-cast IN718 alloy at three slow-cooling rates (5, 10, and 20 °C/min) were investigated by differential scanning calorimetry (DSC), confocal laser scanning microscopy (CLSM), optical microscopy (OM), field-emission scanning electron microscopy (FESEM), and electron-probe microanalysis (EPMA) techniques. The results indicate that as the cooling rate decreases, the constitutional supercooling at the solidification front affects the solid-liquid interface more significantly, and the size and quantity of the Laves phase increase. However, the composition of the Laves phase is insensitive to the cooling rate in the range of conditions studied here. In dendrite core, the contents of Ni, Cr, Fe, and Al follow a slight downward trend with an increasing cooling rate, whereas the Nb, Mo, and Ti contents show an upward trend. Additionally, Mo shows a stronger propensity to segregate under slow-cooling conditions because its effective partition coefficient almost linearly decreased with decreasing cooling rate, which is same as Nb. Using the parameters experimentally determined in this study and the Clyne–Kurz equation, we achieved reasonable agreement between the calculated and measured liquid composition change during the solidification process at different cooling rates. All experimental and theoretical programs in this research were undertaken with the aim of gaining further understanding of the microsegregation behaviors in large-scale IN718 ingots, whose cooling rates are within a lower range.

In the current research, the influences of sulphur content on precipitates and properties were investigated through thermodynamic calculation and microstructural analysis. The results show that the precipitates of DH36 structural steel are mainly (Nb, Ti)C and Ti(C,N), the size of which ranged from 7 to 220 nm. Plenty of nanoscale MnS was observed by transmission electron microscopy using carbon film replicas with 0.002% S. This is because the temperatures of maximum nucleation rate and fastest precipitation of MnS are much less than soaking temperature when S content is 0.002%, which is the main reason for the formation of nanoscale MnS. What is more, the pinning effect of nanoscale MnS can also refine the grain size. Consequently, ultra-low content of sulphur can be used to optimise the properties of DH36 structural steel.

We investigated morphology transitions of linear tetrablock copolymers of polystyrene-block-polyisoprene-block-polystyrene-block-polyisoprene (S1I1S2I2) by varying volume fraction of PI1 block (fPI1), while maintaining the symmetric volume fraction of total PS blocks and PI blocks (fPS1+fPS2:fPI1+fPI2 ≈ 1:1). An interesting sequence of morphology transitions was observed as fPI1 was increased: lamellae (L) → asymmetric lamellae (aL) → hexagonally packed PI-cylinders (CPI) → double gyroid with PI-network domains (GPI) → short-period lamellae (sL). The domain spacing of sL was nearly half that of L, while aL had asymmetric lamellar width of PS and PI microdomains. It is particularly interesting that cylindrical and gyroid morphologies were observed in linear block copolymers with symmetric overall volume fraction at intermediate segregation. The experimentally observed morphologies are in good agreement with the predicted equilibrium phases by self-consistent field theory (SCFT).

The results of predicting thermodynamic properties in the full composition range of Ti-Al binary melts in a temperature range from 1973 to 2273 K were obtained by coupling with the developed thermodynamic model for calculating mass action concentration Ni of structural units in Ti-Al system based on the atom and molecule coexistence theory (AMCT). Temperature dependence of the activity coefficients of Ti and Al in natural logarithmic form in the infinitely dilute solution (0>xTi

The demanganization reaction kinetics of carbon-saturated liquid iron with an eight-component slag consisting of CaO–SiO2–MgO–FeO–MnO–Al2O3–TiO2–CaF2 was investigated at 1553, 1623, and 1673 K in this study. The rate-controlling step (RCS) for the demanganization reaction with regard to the hot metal pretreatment conditions was studied via kinetics analysis based on the fundamental equation of heterogeneous reaction kinetics. From the temperature dependence of the mass transfer coefficient of a transition-metal oxide (MnO), the apparent activation energy of the demanganization reaction was estimated to be 189.46 kJ·mol–1 in the current study, which indicated that the mass transfer of MnO in the molten slag controlled the overall rate of the demanganization reaction. The calculated apparent activation energy was slightly lower than the values reported in the literature for mass transfer in a slag phase. This difference was attributed to an increase in the “specific reaction interface” (SRI) value, either as a result of turbulence at the reaction interface or a decrease of the absolute amount of slag phase during sampling, and to the addition of calcium fluoride to the slag.

In recent years, the decontamination of heavy metals from bodies of water has become an important topic in China because of rapid industrialization, and it is of both fundamental and practical interest to develop ecofriendly, renewable, and degradable materials for this purpose. In this study, cellulose-based adsorbent materials were prepared, based on the carboxymethylation modification method. A carboxymethylated cellulose fiber (CMF) material with a high carboxyl content and desirable fiber morphology was obtained, and its application in the removal of heavy metal ions, such as copper ions, by a filtration–adsorption process, was investigated. The results showed that the CMF-based adsorbent material displayed an excellent adsorption capacity and regeneration properties because of its high carboxyl content and accessibility to copper ions. Moreover, the CMF material retained a good fiber morphology because of the mild carboxymethylation on the fiber surfaces (exterior and interior), which gives it great...

Among the various ordered morphologies self-assembled from block copolymers, the spherical packing phases are particularly interesting because they resemble the familiar atomic crystals. The commonly observed spherical morphology of block copolymers is the body-centered-cubic phase. Recently, a number of novel spherical packing phases, i.e., the complex Frank-Kasper phases originally obtained in metallic alloys, have been observed in block copolymer melts. Theoretical studies have revealed that conformational asymmetry of the different blocks provides a key mechanism to stabilize the Frank-Kasper phases. Furthermore, local segregation of different copolymers in blends of diblock copolymers and copolymer architectures provides additional mechanisms to enhance the stability of the complex ordered phases. In this Viewpoint we summarize recent advances in our understanding of the formation of the nonclassical spherical packing phases in AB-type block copolymers, emphasizing the formation mechanisms of these fascinating complex ordered structures.

This paper studies the effect of different solution temperature and quenching medium on Microstructure and hardness of Mg-9Li-4Al-1Zn-0.5Y alloy by means of optical microscope (OM), X-ray diffraction (XRD) and hardness testing. The results show that in the solution process, the higher of the solution temperature is, more of the second phase dissolved in β phase. In the quenching process, the higher of the cooling rate is, more of the second phase dissolved in the β phase precipitates from the super-saturation β matrix, which can greatly weaken the solution strengthening effect. The hardness of the investigated alloy reaches its highest value with solution treatment at 648K and water-quenched treatment, increased from 58HB to 108HB.

Membrane technology is one of the most promising technologies for wastewater remedy. However, it remains challenging to prepare high-performance membrane matrix for complex pollutants, e.g. containing both oil and organic dye. In this work, we facilely fabricate a cellulose-fiber-supported MOF photocatalytic membrane, namely Ag@AgCl@MIL-100(Fe)/CCF, which was prepared via carboxymethylation of cotton fabric (CCF) as scaffold and in-situ synthesis of MOF derivative as photocatalyst. The carboxymethylation significantly improves the hydrophilicity of cotton fabric and the deposition amount of MIL-100(Fe). The high hydrophilicity of modified CCF and porous MIL-100(Fe) further enable the membrane with an efficient adsorption capacity of dyes and underwater oleophobicity against oils. The photocatalysts Ag@AgCl nanoparticles anchored onto MIL-100(Fe) promote the photocatalytic activity. As a result, the membrane shows simultaneous high removal efficiency towards dyes (97.3 %) and oils (99.64 %). Additionally, thanks to the good photocatalytic activity against organic pollutants, the membrane exhibits excellent self-cleaning and a long-term reuse capacity.

A new self-crosslinked composite hydrogel is prepared with chitosan (CS) and cationic guar gum (CGG), based on the imine and acetal chemistry for gelation. The CS/CGG hydrogel exhibits thermal/pH responsiveness, injectability, adhesiveness and good compressive strength. The hydrogel is effective in removing phosphate from wastewater through an adsorption process, during which KH2PO4 is used as a phosphate model. The adsorption complies with the Freundlich model, indicating that it is a multilayered process with complex adsorption mechanisms. Considering their porous structure and nitrogen/phosphorus heteroatoms doping, the phosphate-adsorbed hydrogels are made into porous N,P doped carbon aerogels that can be potentially used as electrodes for a supercapacitor. The results indicate that these carbon aerogels possess excellent capacitive performance (best specific capacitance of 302.2 ± 4.9 F/g), as well as good cycling stability after 5000 times of charging/discharging.

Vitrimer, the third category of polymer materials, combines the properties of traditional thermosets and thermoplastics and has gained much interest from industry since the first report in 2011. Currently, many researchers focus on the exploration of new chemistry for novel vitrimer synthesis but pay less attention to the fabrication of vitrimer composites based on known vitrimer systems. The latter can not only largely decrease the cost of vitrimers but also provide a facile way to increase the variety of vitrimer-based materials and extend the applications of vitrimers in different fields. In this study, we developed a new class of vitrimer composite using polycarbonate as a matrix and natural cellulose paper as the reinforcing framework for the first time. The resultant materials possess exceptional mechanical properties and great thermal/chemical stability, simultaneously exhibiting a series of smart properties, such as shape-memory, reshaping, self-healing, and reprocessing. Noteworthily, the two main components of the resultant materials, polycarbonate and natural cellulose, can be easily recycled under mild conditions; thus, these new vitrimer composites qualify as novel green and sustainable materials.

Application of the infrared non-destructive for defect location is presented in this work, including chips, capacitors and connectors. In these failure cases, common inspection equipment such as optical microscope, metallographic microscope and scanning electron microscope are used to inspect the appearance of components. No abnormalities were found. Besides, when the defects penetrate into the components and the size of the defect area is small, the defects cannot be located by the traditional non-destructive analysis method. However, Infrared imaging technology can be used without destroying the sample. Accurate detection of hot spots in components is achieved. Locate internal defects quickly and accurately. Realize the real sense of internal nondestructive positioning. Subsequently, the accuracy of infrared imaging method is verified by the various destructive physical analyses. This work provides a new research idea for the nondestructive defect location of components, including active, passive and electromechanical device. It can effectively guide the application of Infrared Nondestructive Testing Technology in failure location of various components.