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Co-continuous SiC3D/Cu composites are interesting wear-resistant materials with a unique structure. However, their interface reaction limits their practical applications. In this study, co-continuous SiC3D/Cu composites were fabricated by pressureless infiltration, and their interfaces were modified with different interface oxidation states by high-temperature oxidisation and atmospheric treatment. The effects of the different interface oxidation treatments on the interfacial reaction and wear behaviour of the co-continuous composites were investigated. The results revealed that the surface oxidisation of the three-dimensional SiC skeleton by high-temperature oxidisation prevented the interface reaction between the SiC strengthening phase and the Cu alloy matrix phase, thus improving the interface bonding and wear properties of the composites. In addition, the surface oxidisation of the Cu alloy matrix phase prevented the occurrence of the interface reaction and improved the interface bonding of the composites. However, the Cu alloy was oxidised and the hardness of the matrix phase in the composites decreased when the infiltration atmosphere was changed into an air environment. Finally, the co-continuous SiC3D/Cu composite with oxidised SiC and unoxidised Cu showed the best wear-resistance performance (approximately 9.77 × 10-7 cm3·m-1·N-1).

Flow separation due to shock wave/boundary layer interaction is dominated in blade passage with supersonic relative incoming flow, which always accompanies aerodynamic performance penalties. A loss reduction method for smearing the passage shock foot via Shock Control Bump (SCB) located on transonic compressor rotor blade suction side is implemented to shrink the region of boundary layer separation. The curved windward section of SCB with constant adverse pressure gradient is constructed ahead of passage shock-impingement point at design rotor speed of Rotor 37 to get the improved model. Numerical investigations on both two models have been conducted employing Reynolds-Averaged Navier-Stokes (RANS) method to reveal flow physics of SCB. Comparisons and analyses on simulation results have also been carried out, showing that passage shock foot of baseline is replaced with a family of compression waves and a weaker shock foot for moderate adverse pressure gradient as well as suppression of boundary layer separations and secondary flow of low-momentum fluid within boundary layer. It is found that adiabatic efficiency and total pressure ratio of improved blade exceeds those of baseline at 95%-100% design rotor speed, and then slightly worsens with decrease of rotatory speed till both equal below 60% rated speed. The investigated conclusion implies a potential promise for future practical applications of SCB in both transonic and supersonic compressors.

Single-atom catalysis is the new frontier of heterogeneous catalysis, and have attracted considerable attention for they exhibit great potential in hydrogen evolution to mitigate energy crisis and environmental issues. The support materials of single-atom catalysts (SACs) play a significant role in stabilizing the metal atoms, preventing their aggregation, and enhancing the catalytic activity. Two-dimensional sp2 hybridized PHE-graphene might be a real support for SACs due to the potential energy well induced by its enneagon, hexgon and pentagon carbon rings. In this study, eleven transitional metal (TM) atoms adsorbed on the PHE-graphene (TM@PHEs) are taken into account based on density functional theory (DFT) and the PHE-graphene is proved to be an ideal single-atom carrier for water splitting. In particular, the TM@PHEs (TM= Fe, Ni, Ru, and Pd) exhibit high catalytic activity toward hydrogen evolution reaction (HER). The reaction path of water splitting is also determined. Due to much lower energy barrier, both Fe@PHE and Ru@PHE are more promising SACs. In addition, the charge density difference, Bader charge analysis and spin projected density of states (PDOS) are investigated.

There is a large somatosensory gap between the three-dimensional (3D) printing of clothing and traditional garments due to the limitations (e.g., air permeability and skin-friendliness) of the printing materials. For this reason, the application of traditional textile materials in 3D printing has become a hot topic in the field of 3D printed clothing. Based on the above, this work prepared four kinds of cotton-containing composite solutions and then impregnated thermoplastic polyurethane core yarns in these solutions to obtain four types of 3D printed cotton-containing composite core yarns (3Dp-C-CYs). Afterward, based on the two-dimensional (2D) braiding method, four kinds of cotton-containing 3D printing wires used for fused deposition molding technology were prepared by wrapping low-melting polyester filaments around the different 3Dp-C-CYs. After comparing the printing performance of the four cotton-containing 3D printing wires, the wire containing cotton powders had the best comprehensive performance and was selected to print the cotton-containing 3D printed fabrics. The results showed that the cotton-containing 3D printed fabric has good flatness and contains a large number of cotton powders; in addition, compared with the traditional polylactic acid and acrylonitrile butadiene styrene copolymer 3D printed fabrics, the 3D printed fabric made up of cotton-containing 3D printing wire can provide a closer wearing experience to that of cotton fabric. The 3D printing wire produced by the 2D braiding method offers a new idea for applying traditional textile materials in 3D printing, showing great application potentials in the field of 3D printing of clothing.

In this investigation, softwood pulp and bleached wheat straw pulp were used as raw materials, and Calcium Sulfate Whiskers (CSW) were used as fillers. Based on the structural properties and characteristics of CSW, the printing properties of the paper with CSW, such as whiteness, opacity, pH value, uniformity, Z-direction tensile strength and surface strength, were analyzed. The results showed that CSW has low solubility, high retention and fiber-like appearance. The whiteness of the paper is the best when the filling amount of CSW is 20 %. The paper opacity of softwood pulp increases significantly, and the opacity of bleached wheat straw pulp decreases significantly when CSW is more than 30 %. The addition reduces pH and surface strength of the paper. The evenness of the paper does not change obviously. The Z-direction tensile strength of the paper decreases in the softwood paper, but increases obviously in the bleached wheat straw paper.

Organic solar cells are a current research hotspot in the energy field because of their advantages of lightness, translucency, roll to roll printing and building integration. With the rapid development of small molecule acceptor materials with high-performance, the efficiency of organic solar cells has been greatly improved. Further improving the device efficiency and stability and reducing the cost of active layer materials will contribute to the industrial development of organic solar cells. As a novel type of carbon nanomaterials, carbon dots gradually show great application potential in the field of organic solar cells due to their advantages of low preparation cost, non-toxicity and excellent photoelectric performance. Firstly, the synthesis and classification of carbon dots are briefly introduced. Secondly, the photoelectric properties of carbon dots and their adjusting, including adjustable surface energy level structure, good film-forming performance and up/down conversion characteristics are summarized. Thirdly, based on these intrinsic properties, the feasibility and advantages of carbon dots used in organic solar cells are discussed. Fourthly, the application progress of carbon dots in the active layer, hole transport layer, electron transport layer, interface modification layer and down-conversion materials of organic solar cells is also reviewed. Finally, the application progress of carbon dots in organic solar cells is prospected. Several further research directions, including in-depth exploration of the controllable preparation of carbon dots and their application in the fields of interface layer and up/down conversion for improving efficiency and stability of device are pointed out.

Purpose The purpose of this paper is to predict and control the composition during laser additive manufacturing, since composition control is important for parts manufactured by laser additive manufacturing. Aluminum and steel functionally graded material (FGM) were manufactured by laser metal deposition, and the composition was analyzed by means of spectral analysis simultaneously. Design/methodology/approach The laser metal deposition process was carried out on a 5 mm thick 316L plate. Spectral line intensity ratio and plasma temperature were chosen as two main spectroscopic diagnosis parameters to predict the compositional variation. Single-trace single-layer experiments and single-trace multi-layer experiments were done, respectively, to test the feasibility of the spectral diagnosis method. Findings Experiment results showed that with the composition of metal powder changing from steel to aluminum, the spectral intensity ratio of the characteristic spectral line is proportional to the elemental content in the plasma. When the composition of deposition layers changed, the characteristic spectrum line intensity ratio changed obviously. And the linear chemical composition analysis results confirmed the gradient composition variation of the additive manufacturing parts. The results verified the feasibility of composition analysis based on spectral information in the laser additive manufacturing process. Originality/value The composition content of aluminum and steel FGM was diagnosed by spectral information during laser metal deposition, and the relationship between spectral intensity and composition was established.

Lithium-sulfur (Li-S) batteries are recognized as one of the most promising next-generation energy storage devices, but their practical application is greatly limited by several obstacles, such as the highly insulating nature and sluggish redox kinetics of sulfur and the dissolution of lithium polysulfides. Herein, three-dimensional carbon nanosheet frameworks anchored with Ni@Ni3N heterostructure nanoparticles (denoted Ni@Ni3N/CNS) are designed and fabricated by a chemical blowing and thermal nitridation strategy. It is demonstrated that the Ni@Ni3N heterostructure can effectively accelerate polysulfide conversion and promote the chemical trapping of polysulfides. Meanwhile, the carbon nanosheet frameworks of Ni@Ni3N/CNS establish a highly conductive network for fast electron transportation. The cells with Ni@Ni3N heterostructures as the catalyst in the cathode show excellent electrochemical performance, revealing stable cycling over 600 cycles with a low-capacity fading rate of 0.04% per cycle at 0.5 C and high-rate capability (594 mAh g-1 at 3 C). Furthermore, Ni@Ni3N/CNS can also work well in room-temperature sodium-sulfur (RT-Na/S) batteries, delivering a high specific capacity (454 mAh g-1 after 400 cycles at 0.5 C). This work provides a rational way to prepare the metal-metal nitride heterostructures to enhance the performance both of Li-S and RT-Na/S batteries.

By combining the structural properties and characteristics of phosphogypsum whiskers, a preliminary study on the modification of phosphogypsum whiskers and their application in papermaking was carried out. The effects of reaction temperature, reaction time, and reaction concentration on the solubility and retention of modified phosphogypsum whiskers and the effects of phosphogypsum whiskers on the physical properties of paper under different modified conditions were explored. The research results show that, after the phosphogypsum whiskers are modified with calcium stearate, a coating layer will be formed on the surface of the whiskers, which effectively reduces the solubility of the phosphogypsum whiskers. The best modification conditions are: the amount of calcium stearate relative to the absolute dry mass of the phosphogypsum whisker is 2.00%; the modification time is 30 min, and the modification temperature is 60°C. The use of modified phosphogypsum whiskers for paper filling will slightly reduce the whiteness, folding resistance, burst resistance, and tensile strength of the paper, but the tearing degree and retention of the filler will be increased to some extent.

Inverted perovskite solar cells (IPSCs) attract growing interest because of their simple configuration, reliable stability, and compatibility with tandem applications. However, the power conversion efficiency (PCE) of IPSCs still lags behind their regular counterparts, mainly due to the more serious nonradiative loss. Here, we design three donor-π-acceptor (D-π-A) dipoles with various dipole moments to introduce extra electric fields at the interface of perovskites and electron transport materials via the binding between the carboxylate end group and under-coordinated divalent Pb. The chemical binding reduces the recombination centers, while the superposition of the built-in electric field facilitates the electron collection and the hole blocking. As a result, the nonradiative loss is diminished as the dipole moments of D-π-A dipoles increase, which contributes to a PCE of 21.4% with enhancement in both the open-circuit voltage and fill factor. The stability for an unencapsulated device is also improved due to the hydrophobic property of D-π-A dipoles.

Phosphorescent carbon dots (CDs) have great potential in energy, information, biomedicine, and other fields because of their long lifetime, long wavelength emission, and low background interference. However, there are still some challenges in their preparation and understanding their luminescence mechanism. For example, their triplet states are easily affected by the external environment, which leads to phosphorescence quenching. The phosphorescence mechanism and the effects of element doping, rigidity of structure, and conjugated structure on their properties are reviewed to address these issues. The synthesis methods include one step and two step methods. The uses of phosphorescent CDs are summarized and include information security, light emitting diodes, ion detection, and biological imaging. The existing problems are discussed and development directions are proposed.

Accurate measurement of the complex permittivity of plant is essential for remote-sensing applications. The complex dielectric properties of moso bamboo ( Phyllostachys heterocycla ) were measured from 0.5 to 18 GHz based on the coaxial transmission/reflection method. A high-precision numerically controlled machine was used to process the bamboo samples. Based on the measured data, the complex permittivity can be better modeled as a second-order polynomial about the moisture content than the traditional exponential function. The real parts of the relative dielectric permittivity decrease with the increase in the frequency, while the imaginary parts decline first and then rise. The dielectric permittivity of the longitudinal direction is larger than that of the cross-sectional direction due to the anisotropic fibrocyte structure of moso bamboo.

Single-phase polycrystalline Mo2BC ceramic bulks were synthesized successfully from molybdenum, boron, and graphite powders using the spark plasma sintering method. Herein, it was established that the synthesis temperature of the Mo2BC ceramic could be as low as 1300 °C. Transmission electron microscopy (TEM) characterization confirmed that the crystal structure of the Mo2BC ceramic was comparable to that of the MoAlB ceramic. The Vickers hardness of the Mo2BC ceramic was measured to be 18.1 GPa. Additionally, the compressive strength, flexural strength, and fracture toughness were determined to be 1.74 GPa, 457.72 MPa, and 3.26 MPa· m1/2, respectively. The Mo2BC bulk exhibited typical brittle features, in which intergranular and transgranular fractures were the main failure modes.

The cold patch asphalt mixtures (CPAMs) have been manufactured by mixing the cold patch asphalt liquid (CPAL) with type LB-13 mineral mixture. The workability, Marshall stability, Freeze–thaw splitting strength and cohesion of three types of CPAMs were tested in the laboratory. The potholes were repaired using CPAMs on several sites in S101 provincial highway at Feidong. The CPAMs were sampled to measure the bulk density and Marshall stability, and the volume of air voids (VV) of those specimens was calculated. The results indicated that the Brookfield viscosity of CPAL affected the workability of the CPAMs. The Marshall stability of three types of CPAMs was only 3.07, 3.80 and 4.28 kN, respectively. However, the CPAMs had better water stability and met the requirements of hot mix asphalt (HMA) in low-rain regions referring to JTG F40-2004. The VV decreased and Marshall stability increased with the action of the secondary compaction and the volatilization of additives. Beyond 3 months, the Marshall stability of the compacted mixtures tends to be stable. The Marshall stability of type A and B CPAMs changed from 5 to 6 kN, while that of type C CPAM varied between 4 and 5 kN. The products met the requirements of dense-graded HMA on the low-grade highway. Overall, the prepared CPAMs can be used to repair pavement potholes from the perspective of material properties and molding intensity.

Biomass-based materials usually evolve well-developed and unique structures for the transportation of water and nutrition to their pivotal organs. These natural intricate designs allow fascinating properties when harnessed in specific real-world application. Herein, we demonstrate that 3D carbonized corncob (C-corncob) harmoniously coordinates light absorption, water supply, vapor escape, and efficiently utilizes the environmental energy to enhance the performance of the steam generation device due to its multilevel inside and side surface structures. The interfacial solar steam generation based on C-corncob achieves as high as 4.16 kg m−2 h−1 evaporation rate under 1.0 sun illumination and readily overcomes the salt deposition problem. These findings not only demonstrate the competence of the recrement corncob as the lost cost material for interfacial solar steam generation, but also provide inspiration for the creation of solar steam generation devices with the new concept.

A novel method, termed ladder-shape melting temperature isothermal amplification (LMTIA), was developed in this study. As a proof of concept, one pair of primers or two pairs of nested primers and a thermostable DNA polymerase were employed to amplify the internal transcribed spacer of Oryza sativa with the ladder-shape melting temperature curve. Our results demonstrated that the LMTIA assay with nested primers was 50-fold more sensitive than the LAMP assay with the same level of specificity. The LMTIA method has the potential to be used for the prevention and control of emerging epidemics caused by different types of pathogens.

As a novel phosphorus recovery product, vivianite (Fe3(PO4)2·8H2O) has attracted much attention due to its enormous recycling potential and foreseeable economic value. Taking sponge iron as seed material, the effect of different reaction conditions on the recovery of phosphorus in waste activated sludge by vivianite crystallization was studied. Through single factor test, the optimal conditions for vivianite formation were in the pH range of 5.5–6.0 with Fe/P molar ratio of 1.5. Scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) were used to analyze the components of the crystals. The results showed that the vivianite produced with sponge iron as the seed crystal were larger and thicker (300-700 μm) than other seed (200-300 μm) and without seed (50-100 μm). Moreover, vivianite, which was synthesized with sponge iron as seed, was obviously magnetic and could be separated from sludge by rubidium magnet. The Box-Behnken design of the response surface methodology was used to optimize the phosphorus-recovery process with sponge iron (maximum phosphorus recovery rate was 83.17%), and the interaction effect of parameters was also examined. PH had a significant effect on the formation of vivianite. In summary, this research verifies the feasibility of using sponge iron as seed crystal to recover phosphorus in the form of vivianite from waste activated sludge, which is conducive to the subsequent separation and utilization of vivianite.

Directly converting sunlight into hydrogen fuels using particulate photocatalysts represents a sustainable route for clean energy supply. Organic semiconductors have emerged as attractive candidates but always suffer from optical and exciton recombination losses with large exciton "dead zone" inside the bulk material, severely limiting the catalytic performance. Herein, we demonstrate a facile strategy that combines a scalable flash nanoprecipitation (FNP) method with hydrophilic soluble polymers ( PC-PEG5 and PS-PEG5 ) to prepare highly efficient nanosized photocatalysts without using surfactants. Significantly, a 70-fold enhancement of hydrogen evolution rate (HER) is achieved for nanosized PC-PEG5 , and the FNP-processed PS-PEG5 shows a peak HER rate of up to 37.2 mmol h -1 g -1 under full-spectrum sunlight irradiation, which is among the highest results for polymer photocatalysts. Moreover, a scaling-up production of nanocatalyst is demonstrated with the continuously operational FNP, which provides an unprecedented strategy toward practical applications of particulate photocatalysts for sustainable energy production.

n/a Funding Agencies|Knut and Alice Wallenberg Foundation (KAW) through a Wallenberg Scholar grant

The in-situ synthesis of calcium silicate in the fiber can not only meet the requirements for high loading of paper, but also make up and improve the reduction of paper performance caused by filling. In this investigation, the effects of pulp type, beating degree, fiber ratio, reaction time, rotational speed, dosage of lime milk and dispersant on calcium silicate loading and paper properties were investigated. The results showed that when the beating degree was 40 °SR, the ratio of softwood and hardwood pulp was 1:1, the reaction time was 60 min, the rotation speed was 600 r·min−1, the dosage of lime milk was 1.33 times of the theoretical amount, and the dosage of cationic polyacrylamide was 0.3 % (absolutely dry pulp), the ash content of hand-made sheet was 41.2 %, and the loading amount of calcium silicate was 26.3 %. Under this condition, the comprehensive performance of paper was the best.

To better understand the formation and evolution processes of soot, the two-color laser induced incandescence diagnostic method was applied on a single cylinder optical direct injection spark ignition engine. Soot volume fraction was measured, and soot distribution was imaged as cyclic fuel quantity changes. The results show that 45.5 mg/cycle generates the most soot at the same measure plane. Pool fire dominates the formation of soot in the tested engine and generates more soot on the top surface of the piston near the injector. In-cylinder soot increases until 42°CA ATDC and then reduces due to oxidation. Pool fire continues through the expansion stroke till 52°CA ATDC, and then soot cloud gathers near the 10 mm plane. After 82°CA ATDC, in-cylinder soot basically in equilibrium, and residual soot moves follow the in-cylinder flow randomly and evenly distributes within the whole combustion chamber. With increasing cyclic fuel quantity, particles number concentration gradually increases and their distribution present dual-peak shape. In detail, 45.5 mg/cycle emits the most accumulation mode particles while 52 mg/cycle emits the most nucleation mode particles.

As a type of carbon dots (CDs) with a positive charge on their surface, cationic carbon dots (CCDs) can be obtained from CDs and amino-containing cationic compounds by one-step or two-step preparation. They not only retain the good fluorescence performance, low toxicity and biocompatibility of CDs, but also improve their gene delivery efficiency and cell uptake capacity. These excellent properties give CCDs potential advantages in the fields of the targeted fluorescence imaging of cancers and gene therapy. This paper reviews the preparation methods and properties of CCDs, suggesting that they can be used as good targeting carriers for imaging cancer and gene therapy. In addition, the basic principles of CCDs for cancer detection and treatment, and their uses in integrated cancer diagnosis and gene therapy are introduced. Current problems and future development trends of CCDs for this purpose are discussed.

PVDF piezoelectric film is a piezoelectric polymer material with excellent properties. In this paper, the research status of PVDF piezoelectric thin film was summarized, and the working principle of PVDF piezoelectric thin film accelerometer was introduced. On the basis of optimizing parameters, a cantilever PVDF piezoelectric film accelerometer and signal processing circuit were designed. The signal processing circuit which was composed of amplifier circuit and filter circuit was analyzed experimentally,and the frequency characteristic diagram of the filter circuit was obtained.The amplitude-frequency and phase-frequency characteristics of the filter circuit were better in a certain range,which can meet the design requirements.Experiments on the designed PVDF piezoelectric film accelerometer were carried out, including the calibration experiment of the PVDF accelerometer and the performance test of the sensor.The analysis results showed that the sensor has high sensitivity and good linearity, and can meet the measurement requirements.

Refractory lining is an important part of microwave heating equipment, and its wave-transparent effect significantly influences microwave heating efficiency. The complex dielectric constant of the material is the main factor determining its wave-transparent properties. In this study, with aluminium silicate fibreboard (ASF) as the study object, the complex dielectric constant of this material was investigated at temperatures ranging from 25 °C to 1000 °C at 915 MHz and 2450 MHz, respectively. Based on the theory of transmission lines, the wave-transparent properties of the material during the entire microwave heating process were calculated and analysed. It has been found that the dielectric constant and loss factor at both frequencies increase significantly when the temperature exceeds 700 °C; the wave-transparent properties of this material decrease with increasing temperature and present a fluctuating trend as the material thickness increases, with maximum and minimum values; in TM polarization mode, there is an optimal angle of incidence for total transmission, which contributes to a better overall wave-transparent effect of the material in TM polarization mode than that in TE polarization mode. Finally, this study provides the preferred thickness values at different working frequencies and temperatures under vertical incidence of electromagnetic waves for reference. This study is of certain theoretical significance to the research on the change mechanism of the material's dielectric and wave-transparent properties and has practical guidance on the optimization of microwave heating equipment and the selection of the technological parameters of furnace linings.

Raman spectroscopy is a fast, non-destructive and high-resolution characterization tool based on laser physics that can be applied to a wide range of materials science problems. It has proven to be an effective tool in studying phase transitions induced by variables such as temperature, pressure or electrochemical reactions. In-situ Raman spectroscopy can be used to track any microstructural changes of the electrode materials and interface reactions in alkali metal-ion batteries during charging and discharging. Carbon materials have become the most widely used anode materials for lithium-ion batteries because of their good electrochemical reversibility, excellent stability, low electrochemical charge/discharge potential platform, and low cost. The use of in-situ Raman spectroscopy in understanding the reactions occurring in alkali metal-ion batteries using carbon anode materials is summarized with a focus on the energy storage mechanism in Li+/Na+/K+ ion batteries using carbon materials such as graphite and hard carbon as the anode materials. The effects of size, stress, doping, and the solvation-assisted co-intercalation of Li+/Na+/K+ ions on the energy storage behavior in alkali metal-ion batteries are analyzed. Based on the strength and weakness of in-situ Raman spectroscopy, its combination with AFM, in situ XRD and other high-resolution in situ technologies is used to reveal the energy storage mechanisms.

The Cu-12.5Ni-5Sn-xFe alloys were prepared using powder metallurgy. The effect of the amount of Fe addition on the microstructure and mechanical characteristics of Cu-12.5Ni-5Sn-xFe alloys was investigated. The microstructure and morphology of alloys were examined by means of X-ray diffraction, scanning electron microscopy and cold field emission scanning electron microscope. Results indicate that the hardness and yield strength of the Cu-12.5Ni-5Sn alloy are improved by addition of trace amounts of Fe. The lamellar precipitates of Cu-12.5Ni-5Sn-xFe alloys are more and finer compared to those of Cu-12.5Ni-5Sn alloy. Fe can facilitate the aging process and strengthen the effect of aging-hardening.

Paraffin (PA) as a phase change material (PCM) has become one of the research hotspots for battery thermal management systems owing to its high latent heat, low cost, simple structure, and other me...

The dielectric properties and electromagnetic wave absorbing performance of granular polysilicon have important influences on microwave smelting efficiency. In this study, the dielectric parameters...

The performance of asymmetric supercapacitors (ASCs) is limited by the poorly matched electrochemical kinetics of available electrode materials, which generally results in reduced energy density and inadequate voltage utilization. Herein, a porous conductive graphene aerogel (GA) scaffold was decorated with copper cobalt selenide ((CuCo)Se2) or iron selenide (FeSe2) to construct positive and negative electrodes, respectively. The (CuCo)Se2/GA and FeSe2/GA electrodes exhibited high specific capacitances of 672 and 940 F g−1, respectively, at 1 A g−1. The capacitance contributions from the Co3+/Co2+ and Fe3+/Fe2+ redox couple for the positive and negative electrodes were determined to elucidate the energy storage mechanism. Furthermore, the kinetics study of the two electrodes was performed, revealing b values ranging between 0.7 and 1 at various scan rates and demonstrating that the surface-controlled processes played the dominant role, leading to fast charge storage capability for both electrodes. Fabrication of an ASC device with a configuration of (CuCo)Se2/GA//FeSe2/GA resulted in a voltage of 1.6 V, a high energy density of 39 W h kg−1, and a power density of 702 W kg−1. The excellent electrochemical performances of the (CuCo)Se2/GA and FeSe2/GA electrodes demonstrate their potential applications in energy storage devices.

The evolution of the electronic structure and optical transition upon n-doping of poly(9,9-dioctylfluorene) (PFO) films is elucidated with photoelectron spectroscopy, optical absorption, density functional theory (DFT), and time-dependent DFT (TD-DFT) calculations. Optical absorption measurements extending into near infrared show two low-energy absorption features at low doping ratios and an additional peak at a higher energy of similar to 2.2 eV that disappears with increasing doping ratios. A gap state (i.e., polaronic state) close to the Fermi level and a significantly destabilized highest valence band appear in the experimentally measured ultraviolet photoelectron spectra. These experimental results are interpreted by the TD-DFT calculations, which show that the lower energy peaks originate from the excitation from polaronic states to the conduction band, while the higher energy peak mainly originates from the destabilized valence band to conduction band transitions and only appears at low doping ratios (c(red) Funding Agencies|Knut and Alice Wallenberg Foundation project "Tail of the Sun"; Swedish Foundation for Strategic ResearchSwedish Foundation for Strategic Research [SE13-0060]; Swedish Research CouncilSwedish Research CouncilEuropean Commission [2016-05498, 2016-05990]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]

Natural rubber (NR) was reinforced in situ with nano CaCO3 that had been modified with methacrylic acid (MAA)(M-CaCO3). The structures and properties of the resulting composites were studied using attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR), scanning electron microscopy(SEM), and Mooney viscometer and mechanical tests. The results show that when NR is physically blended with CaCO3 and MAA, (Ca2+)-(−OOC) is formed in situ. When dicumyl peroxide (DCP) is added, the (Ca2+)-(−OOC) self-homopolymerizes, and during the curing process poly-(Ca2+)-(−OOC) is formed and grafts to the molecular chains of the NR via carbon-carbon double bonds. The NR/M-CaCO3 composites formed have close interfacial interaction and are well dispersed. Compared with the NR composites reinforced with unmodified nano CaCO3, the NR/M-CaCO3 composites have very different cure characteristics, rheological behavior, and mechanical properties, and these characteristics and properties show a significant relationship with the loading of M-CaCO3.

Developing dopant-free hole transporting materials (HTMs) is of vital importance for addressing the notorious stability issue of perovskite solar cells (PSCs). However, efficient dopant-free HTMs are scarce. Herein, we improve the performance of dopant-free HTMs featuring with a quinoxaline core via rational π-extension. Upon incorporating rotatable or chemically fixed thienyl substitutes on the pyrazine ring, the resulting molecular HTMs TQ3 and TQ4 show completely different molecular arrangement as well as charge transporting capabilities. Comparing with TQ3, the coplanar π-extended quinoxaline based TQ4 endows enriched intermolecular interactions and stronger π-π stacking, thus achieving a higher hole mobility of 2.08×10-4 cm2 V-1 s-1 . It also shows matched energy levels and high thermal stability for application in PSCs. Planar n-i-p structured PSCs employing dopant-free TQ4 as HTM exhibits power conversion efficiency (PCE) over 21 % with excellent long-term stability.

Temperature uniformity of lithium-ion batteries and maintaining the temperature within the range for efficient operation are addressed. First, Liquid cold plates are placed on the sides of a prismatic battery, and fins made of aluminum alloy or graphite sheets are applied between battery cells to improve the heat transfer performance. Then a simulation model is built with 70 battery cells and 6 liquid cold plates, and the performance is analyzed according to the flow rate, liquid temperature, and discharge rate. Finally, the results show that temperature differences are mainly caused by the liquid cold plates. The fin surface determines the equivalent thermal conductivity of the battery. The graphite sheets have heterogeneous thermal conductivity, which help improve temperature uniformity and reduce the temperature gradient. With lower density than the aluminum alloy, they offer a lower gravimetric power density for the same heat transfer capacity. In addition to the equivalent thermal conductivity, the temperature difference between the cooling liquid and battery surface is an important parameter for temperature uniformity. Optimizing the fin thickness is found to be an effective way to reduce the temperature difference between the liquid and battery during cooling and improve the temperature uniformity.

Interface engineering is a powerful tool to improve the performance of polymer solar cells (PSCs), and zinc oxide (ZnO) is a significant interfacial material for PSCs. However, ZnO is easy to agglo...

Chemical-looping combustion (CLC) is one of the ways to achieve carbon capture. As an oxygen carrier (OC), CaSO4 is a potential candidate due to high oxygen capacity and low price. However, it is l...

Highlights 3D carbon frameworks (3DCFs) constructed by interconnected nanocages show a high specific surface area, hierarchical porosity, and conductive network.The deoxidization process removed most of surface oxygen-containing groups in 3DCFs that leads to fast ion diffusion kinetics, good electric conductivity, and limited side reactions.The deoxidized 3DCFs exhibit an ultrafast charge/discharge rate as electrodes for SCs with high energy-power density in both aqueous and ionic liquids electrolytes. Electronic supplementary material The online version of this article (10.1007/s40820-020-00535-w) contains supplementary material, which is available to authorized users., Carbon-based electric double layer capacitors (EDLCs) hold tremendous potentials due to their high-power performance and excellent cycle stability. However, the practical use of EDLCs is limited by the low energy density in aqueous electrolyte and sluggish diffusion kinetics in organic or/and ionic liquids electrolyte. Herein, 3D carbon frameworks (3DCFs) constructed by interconnected nanocages (10–20 nm) with an ultrathin wall of ca. 2 nm have been fabricated, which possess high specific surface area, hierarchical porosity and good conductive network. After deoxidization, the deoxidized 3DCF (3DCF-DO) exhibits a record low IR drop of 0.064 V at 100 A g−1 and ultrafast charge/discharge rate up to 10 V s−1. The related device can be charged up to 77.4% of its maximum capacitance in 0.65 s at 100 A g−1 in 6 M KOH. It has been found that the 3DCF-DO has a great affinity to EMIMBF4, resulting in a high specific capacitance of 174 F g−1 at 1 A g−1, and a high energy density of 34 Wh kg−1 at an ultrahigh power density of 150 kW kg−1 at 4 V after a fast charge in 1.11 s. This work provides a facile fabrication of novel 3D carbon frameworks for supercapacitors with ultrafast charge/discharge rate and high energy-power density. Electronic supplementary material The online version of this article (10.1007/s40820-020-00535-w) contains supplementary material, which is available to authorized users.

Nanocarbon materials have become a class of ideal supports for surface molecularly imprinted materials because of their low density, high strength, environment-friendliness, controllable structure and modifiable surface. Thus, nanocarbon-based surface molecularly imprinted polymer adsorbents (C-SMIPs) have achieved satisfactory performance for the removal and enrichment of organic compound pollutants in liquids. This review summarizes C-SMIPs based on various nanocarbon materials for the treatment of ecological environmental pollutants in water during the last five years. The structural characteristics and adsorption features of these C-SMIPshave been comprehensively and systematically analyzed and compared. It is found that the low limit of adsorption capacity is usually decided by the carbon support while the upper limit depends more on the imprinted layer. Specifically, C-SMIPs based on porous carbon nanospheres or graphene oxide usually have large adsorption capacities. It can also be inferred that the essence of C-SMIP adsorption towards target molecules is physical adsorption at the solid-liquid interfaces, the chemical-like adsorption found in the literature is caused by an extremely strong interaction between active sites and the adsorbate by multiple non-covalent bonds like ionic bonds, hydrogen bonds, electrostatic interactions, and van der Waals forces, which settles the long-standing controversy on the nature of adsorption for C-SMIPs. Moreover, analysis and discussion of the literature provide some theoretical and practical evidence for support optimization, imprinting method amelioration, and adsorption parameter selection, which may promote the development and applications of C-SMIPs.

In this paper, a theoretical model is proposed to analyze the friction effect on the rolling contact fatigue (RCF) life of the angular contact ball bearing (ACBB). Firstly, the quasi-static model without race control hypothesis is introduced to study the load characteristics of the ACBB under different loading conditions. Then, the friction coefficient is quantitatively calculated by analyzing the relation between the gyroscopic torque and the sphere-race contact load. The effects of the axial load, radial load, torque load and rotating speeds on the friction coefficient, the maximum value of the sub-surface von Mises stress (SSVS) and the maximum peak-peak value of the sub-surface shear stress (SSSS) are subsequently investigated. The results show that they can significantly affect the friction coefficient and further influence the stress field beneath the contact surface. Further studies illustrate that the friction coefficient cannot affect the maximum peak-peak value of the SSSS but can change the distribution of the SSVS field. The relative RCF life of the sphere-race contact is calculated and the published studies confirm the accuracy of the calculation.

Micro/nano carbon materials, including activated carbon fibers, carbon nanotubes, graphene, carbon dots and carbon aerogels, have a low production cost, excellent biocompatibility and physicochemical and mechanical properties when used as antibacterial materials and carriers for giving wound dressings a strong bactericidal activity and improved wound healing ability. Here, highly innovative antibacterial agents and antibacterial dressings based on these micro/nano carbon materials, that provide new alternatives to treat infected wounds are reviewed. The current problems for their use in antibacterial dressings are discussed, possible solutions are proposed, and prospects are considered.

Controlling carbon emissions is an effective way to mitigate the greenhouse effect. According to the primary energy consumption of China, chemical looping combustion (CLC) using coal as the fuel ha...

Dye-sensitized solar cells (DSSCs) based on CuII/I bipyridyl or phenanthroline complexes as redox shuttles have achieved very high open-circuit voltages (VOC , more than 1 V). However, their short-circuit photocurrent density (JSC ) has remained modest. Increasing the JSC is expected to extend the spectral response of sensitizers to the red or NIR region while maintaining efficient electron injection in the mesoscopic TiO2 film and fast regeneration by the CuI complex. Herein, we report two new D-A-π-A-featured sensitizers termed HY63 and HY64, which employ benzothiadiazole (BT) or phenanthrene-fused-quinoxaline (PFQ), respectively, as the auxiliary electron-withdrawing acceptor moiety. Despite their very similar energy levels and absorption onsets, HY64-based DSSCs outperform their HY63 counterparts, achieving a power conversion efficiency (PCE) of 12.5 %. PFQ is superior to BT in reducing charge recombination resulting in the near-quantitative collection of photogenerated charge carriers.

The self-lubricating braided composite used in oscillating bearing was tested and evaluated under the extreme operating conditions. The Kevlar/PTFE braided composite was investigated on an oscillatory high load (> 30 MPa) and high frequency (> 2 Hz) tester with oscillating frequency ranging from 2.5 to 10 Hz and load from 30 to 50 MPa. Effects of the oscillating frequency and load on the friction coefficient and wear loss were obtained. Results show that the friction coefficient is mainly affected by oscillating frequency under higher loads. It firstly decreases with frequency and later is toward dynamic stability and fluctuates regionally with varying load. Friction surface and wear debris were analyzed under varied load and oscillating frequency using scanning electron microscope. Effects of the oscillating frequency and load on the friction coefficient and wear loss of the Kevlar/PTFE braided composite under high load condition were discussed. It is obtained that the friction surface is mainly damaged due to high frequency rather than high load. This study could provide a basis for performance matching and selection of composite under varied operating conditions.