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Novel SiO2-LiBr microcapsules for water-retaining pavement were prepared and firstly characterized by scanning electron microscope (SEM), particle size analysis, and Fourier transform infrared spectroscopy (FT-IR). The water vapor sorption and desorption of the formulated microcapsules was then experimentally studied using dynamic vapor sorption (DVS), with the results fitted to three kinds of adsorption kinetics models. In addition, the specific surface area (SSA) was also calculated based on BET theory; and the thermal performance was investigated by laser flash analysis (LFA). Experimental results show a change of 103% in mass of the microcapsule sample under 90% relative humidity (RH) at 30 °C after water vapor sorption. The fitting of results indicates that the adsorption process is mainly governed by the intra-particle diffusion mechanism, followed by the pseudo-first-order adsorption process. In comparison with most conventional pavement materials, it is found that the SSA of the formulated microcapsules is much larger while the thermal conductivity is lower. The unique properties of the formulated SiO2-LiBr microcapsules have significant potential to take the edge off the urban heat island effect and reduce rutting when applied to water-retaining pavement materials.

The key to develop high specific energy rechargeable batteries is development of new electrode materials. The existing electrode materials still have many problems: the shuttle effect and poor conductivity of the sulfur cathode, the inevitable volume expansion of the silicon anode and the lithium dendrite of the lithium metal anode that cause short circuits, etc. Nanofibers, as active electrical materials, conductive additives and electrode bodies, can play multiple roles in electrode design. More interestingly, nanofibers can be functionalized to obtain better controllable properties (i.e., electrolyte affinity, pore size distribution and surface electronic structure), thereby further enhancing electrochemical performance. In this article, the latest research progress in electrode design based on nanofibers is reviewed, including processing methods, structure, morphology and electrochemical performance. The key problems affecting the electrochemical performance of the electrode are also discussed, such as the preparation process, atomic structure, electrical conductivity, surface area and pore distribution of nanofibers, to provide reference points for nanofibers in excellent electrode design.

With the wide application of laser technology in laser processing and photoelectric detection, the measurement and display of the laser beam polarization has become an extremely important prerequisite. In this paper, we realize the laser polarization measurement tool based on the virtual instrument LabVIEW software platform. The set-up is designated to measure the Stokes parameters for an arbitrarily polarized beam, using the rotating waveplate method provided by the stepper motor, drive circuit, photodetector, and computer processing of the digitized electrical signal in the PCI expansion card. The Poincare sphere is used for the interpretation of the state of polarization (SOP) and degree of polarization (DOP). The working wavelength range is declared to be 400 – 1100 nm, the accuracy of DOP, azimuth measurement, and ellipticity are ±2%, 0.4°, and 0.4°, respectively.

The microencapsulation of volatile phase change materials is an important and challenging area for low-temperature thermal energy storage. Our previous studies have effectively addressed the challenge of long-term volatile core retention and also indicated that the quality of the obtained poly(urea-formaldehyde) microcapsules is highly affected by various process parameters, including reaction temperature, initial pH, reaction time, and homogenization speed. In this paper, the Taguchi orthogonal array has been employed to optimise controllable process parameters to identify the most synergistic combination, in order to maximise the payload, yield, and encapsulation efficiency. The Taguchi signal-to-noise ratio results substantiated that the most efficient combination of parameters was 3 h reaction time, pH 3.5, 55 °C reaction temperature, and 1200 rpm homogenization speed. With this combination of parameters, microcapsules with superbly high payload of 95.2%, as well as a yield of 30.5% and encapsulation efficiency of 71.1% were amalgamated. In addition, Analysis of Variance (ANOVA) was also utilised to demonstrate the mean response magnitudes (% contribution) of each of the four controllable process parameters, in terms of contribution for the payload, yield, and encapsulation efficiency. Overall, it was indicated that the temperature is the most influential parameter at 83.1% contribution, followed by pH at 6.8%, reaction time at 5.2%, and homogenization speed at 4.9%. Such findings in this work postulate the fundamental insights into maximising the output of the formulation conditions, which in turn is aimed to minimise the time and cost of production of the microcapsules.

A well-designed Co–Mo–P active site allows electron transport between Co and MoP, which will reduce the absorption free energy of the intermediates and improve the electrocatalytic activity of the hybrid.

The yolk–shell structure, realized by various synthesis methods, exhibits unique morphology and structural properties, which is currently undergoing a transition from material production technology to energy storage applications. To design an anode for lithium ion batteries (LIBs), a buffer space is designedly built between the Sb2Se3 nanorod yolk and the mesoporous carbon shell to obtain a novel yolk–shell structure (i.e., Sb2Se3@void@C). The confined void space is created by using a sacrificial template (such as silica) and the mesoporous carbon shell is obtained from the pyrolysis of phenolic resin, which effectively improves the electrical conductivity and structural stability of Sb2Se3 anode materials for LIB. Both the void space in the yolk–shell structure and the mesoporous carbon shell can efficiently buffer the volume expansion during the repeated discharge–charge processes, and further maintain the structural integrity. Besides, the permeable mesoporous carbon shell facilitates the electrolyte infiltration into the void space to ensure enough contact area between the Sb2Se3 and electrolyte, which benefits the shortening of the diffusion paths of Li+ ions. As a result, the Sb2Se3@void@C anode exhibits a high reversible specific capacity of 404.8 mA h g−1 at a rate of 1.0 A g−1 for at least 200 cycles, and maintains an average capacity of 594.7 at a rate of 3.0 A g−1. To further establish the detailed lithium storage behavior, in situ XRD is conducted to reveal the conversion reaction and alloying/dealloying reaction mechanisms. This research sheds light on yolk–shell structure designs with various morphologies to improve the electrochemical performance of energy storage materials.

Solar thermochemical CO2-to-fuel conversion via two-step redox cycles is a promising strategy to solve climate change and energy storage challenges simultaneously. However, ideal thermochemical materials possessing moderate operation temperature, high yield, good stability, and rapid kinetics operating under isothermal and near-isothermal conditions are still missing. Here, we propose Sr-doped SmMnO3 for moderate-temperature near-isothermal CO2-to-fuel conversions. A record-high isothermal cycle CO yield (376.1 μmol g−1) at no more than 1300 °C is reported based on Sm0.6Sr0.4MnO3. No obvious decay is observed during 14 cycles although grain sizes have increased to some extent. The weakened Mn–O bond induced by Sr doping helps to create more oxygen vacancies, and thus contributes to enhanced yield of both O2 and CO. The oxidation reaction is fast with a CO yield of 58.6 μmol g−1 in 15 minutes, which is 5.6 times as high as that of CeO2 under the same cycling conditions between 1300 °C and 1000 °C. Detailed kinetics for the oxidation step is unveiled based on the Sestak–Berggren model. In addition, SmxSr1−xMnO3 can capture full-spectrum solar energy with a solar absorptance of more than 86.6% in stark contrast to 13.5% for CeO2, making the required concentration ratio to drive reactions decrease by 33.4%. This work provides new materials for high yield and stable thermochemical CO2-to-fuel conversion under moderate-temperature near-isothermal conditions, and paves the way for the development of CO2 splitting techniques directly driven by low-concentration solar energy with high efficiencies.

The instability of weak surrounding rock around shallow buried tunnels induced by rainfall is a challenge for tunnel engineering and threatens construction safety. To reveal the influence of rainfall on the rock surrounding a tunnel, the results of experiments on the failure of surrounding rock under different rainfall intensities and durations using a self-developed test system are presented. First, the stress and seepage behaviors of the surrounding rock under rainfall were analysed, and the results showed that the stress increased while the pore water pressure decreased as the rainfall intensity decreased. It was more difficult to maintain vault collapse as rainfall intensity increased, and the particle erosion in the model intensified as the rainfall duration increased. The change in pore water pressure was greater than the change in stress, but the stress and pore water pressures influenced each other during rainfall. The influence of rainfall on the rock at the top of the tunnel was greater than that at the two sides of the tunnel because the seepage channels at the top of the tunnel were more developed and collapsed more easily due to smaller stresses. According to the phenomena of the surrounding rock observed during the test, the evolution of progressive failure under rainfall was roughly divided into eight stages: stability, water drop, continuous water flow, partial collapse, mud and water mixture, vault collapse, throughgoing collapse, and massive water and mud gushing. Furthermore, the final failure pattern of the surrounding rock consists of an excavation disturbance zone, vault damage zone and collapse failure zone. This research helps to reveal the progressive failure of surrounding rock around tunnels under rainfall conditions and can be used as a reference for designing disaster prevention strategies in practical engineering.

Herein, a uniformly distributed SnS2/Co3S4 heterostructure nanosheet array was grown on carbon cloth (CC) fibers by a simple solvothermal method and an oil bath method. When the hierarchical SnS2/Co3S4@CC nanoarray composite is used as a binder-free anode for sodium-ion batteries, its charge and discharge capacity is stabilized at 910.1 mA h g−1 at a current density of 0.5 A g−1 after 100 cycles. Even under a high current density of 2 A g−1, after 760 long-term cycles, the reversible capacity is stable at 637.2 mA h g−1, and still has excellent cycle stability with capacity retention of 87.3%. This excellent performance can be attributed to the reasonable design of the arrayed-electrode structure and the in situ growth of Co3S4 nanoparticles on the heterointerface of matrix SnS2 nanosheets: the well-defined array structure can shorten the diffusion path of Na+ ions and effectively alleviates volume expansion under long-cycle performance; the hierarchical heterostructure of SnS2/Co3S4 nanosheets can expand the interface contact area, provide more active sites and effectively enhance the electrochemical kinetics for sodium storage. The excellent electrochemical performance brought by the rational design of the heterogeneous nanostructure arrays provides new possibilities for the practical application of energy storage in the future.

We study a continuous-wave sum-frequency blue laser operating at 484 nm. The laser elaborated is based on the intracavity pumping technology. A 912 nm laser produced by an end-pumped Nd:GdVO4 crystal, using an 808 nm fiber-coupled laser diode, is employed to pump an Yb:YAG crystal in the cavity to achieve the simultaneous oscillations in 912 and 1030 nm lasers. An intracavity sum-frequency achieved in a type-I phase-matched BIBO crystal is used to obtain the 484 nm blue laser output. In our experiment, we apply a linear coaxial laser resonator structure. As a result, we obtain a sumfrequency blue laser output of 317 mW at a pump power of 25 W. The slope efficiency of the designed laser is 2.8%, and the beam quality factors are 1.34 in the X direction and 1.36 in the Y direction, respectively, with the power fluctuations about 3.8% within four hours.

Bionic electronic synapses with weight-modulation properties are promising alternative candidates when compared with traditional CMOS based neuromorphic hardware when building at-scale neural networks for efficient neuromorphic computing. In this Letter, due to the partial polarisation switching of multi-domain properties in polycrystalline Zr-doped HfO2 (HZO) ferroelectric materials, a capacitor-based bionic synapse was proposed, which showed multi-level capacitance modulation characteristics. By switching the voltage-controlled polarisation, the capacitance was gradually modulated via the variation of net polarisation vectors in the HZO layer. The potentiation and depression properties can be achieved with better linearity, symmetry and multiple states. This Letter laid the groundwork for realising the high-density integration neuromorphic computing system by using ferroelectric capacitors as the bionic synapse.

A coupled approach between the conventional computational fluid dynamics platform COMSOL and an in-house-developed direct numerical simulation code DigiDiss is presented to study the dissolution kinetics of an irregular-shaped particle in a stirred cuvette. The complex flow dynamics from COMSOL were imported into DigiDiss as an initial flow condition. A digitised 3D particle structure scanned and reconstructed by X-ray micro-tomography was used in the dissolution simulation. A quantitative assessment of the simulation results was made using as a reference experimental data and a theoretical calculation based on the shrinking spherical model with different flow velocity profiles near the particle. The comprehensive agreement demonstrates the coherence of the simulation method in reproducing the experimental behaviour and is seen as a step closer towards developing a computer software design aide to help with formulation development.

2 μm/3 μm laser has been extensively applied to the fields of medical treatment, communication and detection. In this paper, the genetic algorithm is innovatively used to solve the fiber power transmission equation, which improves the accuracy of simulation results. According to the simulation results, a dual-wavelength Er3+:ZBLAN fiber laser based on composite Fabry-Perot (F-P) cavity was designed and constructed. A stable continuous dual-wavelength output was obtained with a pump power of 50 W. The center wavelengths were 2.79 μm and 1.59 μm, respectively, the maximum output powers were 8.19 W and 2.8 W, respectively, the slope efficiencies were 17.7% and 7.17%, respectively, and the stability of the wavelengths in 2 h were 4.6% and 3.1%, respectively.

Hollow carbon spheres (HCSs) have attracted great attention for their unique structure, but they perform unsatisfactory rate capacity for lack of mesopore. Here, we propose a novel strategy for fabricating the HCSs with macro-meso-microporous hierarchical pore structure, without etching and alkali activation. Our results show that HCSs can deliver a high gravimetric energy density of 6.2 Wh·kg−1 at the power density of 25 W·kg−1, as well as the energy density reaches up to 3.6 Wh·kg−1 at a high power density of 2.2 kW·kg−1. Moreover, assembled into micro-supercapacitor, HCSs perform a high areal capacitance of 15.4 mF·cm−2 at 0.2 mA·cm−2. Such excellent electrochemical performances of HCSs should be ascribed to the well-balanced pore distribution, which have been revealed by the electrochemical impedance spectroscopy and equivalent series resistance. It is believed that such advanced hollow carbonaceous materials are not only suitable for supercapacitors, but also be expected to apply for Li–S battery, sensor and drug delivery.

Retarding filed analyzers (RFAs) measure the ion velocity distribution in edge plasmas, leading to an estimate of the ion temperature and space potential through curve fitting. This paper describes...

This paper discusses the problem of the Takagi-Sugeno (T-S) filter design form for a three level inverter drive system. A traditional filter always defines the noise in the infinite frequency domain, which results in low filtering accuracy. When the frequency of ranges of noises is known in advance, we can design the fuzzy filter in the finite-frequency domain where the fuzzy filter can estimate the rotor flux. The proposed fuzzy filter can get a better noise-attenuation performance. A three-level inverter drive system is designed and modulated by the space vector pulse width modulation (SVPWM) method. Noise sources with different frequencies are injected into the model to verify the effectiveness of the proposed method and then compared to simulations and experiment.

In this study, FeOx and CoOx thin films were successively and uniformly coated on high-surface-area carbon nanotubes by plasma-enhanced atomic layer deposition, which formed a heterojunction of the two oxides. As an electrocatalyst in the oxygen evolution reaction (OER), CoOx/FeOx/CNTs showed excellent electrocatalytic performance in terms of catalytic activity and stability. The overpotential of CoOx/FeOx/CNTs in OER was only 308 mV at 10 mA cm−2, which was lower than those of the pure oxides: CoOx/CNTs (392 mV) and FeOx/CNTs (406 mV). The as-prepared electrocatalyst also displayed better stability than the reference RuO2 material, with almost no attenuation of current density in contrast to the 10% loss seen with RuO2. The OER performance of CoOx/FeOx/CNTs was superior to those of its oxide components due to the formation of heterojunction, which led to a smoother reaction path and a lower overpotential for OER compared to pure oxides, as supported by the density-functional theory (DFT) calculations. These results provide a new direction for the preparation of electrocatalysts for metal–air batteries and water splitting reactions.

A dual-wavelength laser operating at 912 nm/1030 nm for the first time using a compact intracavity cascade pumping structure is set up The laser system model was designed and built for testing. The proposed system employs a coaxial linear cavity structure and uses a fiber-coupled 808 nm laser diode (LD) end-pumped Nd:GdVO4 crystal to obtain a 912 nm laser, which then pumped Yb:YAG crystal directly in the cavity to produce a 1030 nm laser. When the LD pump power at 808 nm is 25 W, a 0.97 W laser at 912 nm and a 1.33 W laser at 1030 nm are obtained, respectively. The corresponding optical to optical conversion efficiency is 9.2%. The beam quality factors M2 of 912 nm and 1030 nm lasers at maximum output power is measured to be 1.19 and 1.23.

Aqueous Zn-ion batteries with economical ZnSO4 solution as the electrolyte suffer from a tremendous tendency of dendrite formation under mildly acidic conditions; moreover, utilization of Zn(CF3SO3)2 delivers superior performance, but is expensive. Herein, we optimize the ZnSO4 electrolyte by inducing 50 μL of 10 M sulfuric acid in 10 mL electrolyte, which can achieve long cycle life (1000 h at 0.1 mA cm−2, 300 h at 1 mA cm−2 and 250 h at 10 mA cm−2) when the Zn foil is protected by three metallic oxides deposited by atomic layer deposition (ALD). The nucleation behaviour of the (002) facet has proved to play a critical role in the reversible lifespan. The Al2O3 layer would restrict the stripping procedure, leading to the highest overpotential, while the TiO2 layer and Fe2O3 layer tended to strip all orientations but the (002) facet. Al2O3@Zn demonstrated a preference for a compact hillock-like (101) orientation texture in the deposition procedure, while TiO2@Zn and Fe2O3@Zn were favourable to obtain a smooth terrace texture. Additionally, symmetric cells with Fe2O3@Zn expressed the lowest overpotential (31.64 mV) and minimal voltage hysteresis (23.6 mV) at 1 mA cm−2. A Zn-MnO2 battery with Fe2O3@Zn also displayed superior capacity, which could reach 280 mA h g−1 at a current density of 1 A g−1. The diffusion coefficient of Zn2+ discloses that among the three ALD layers, full cells with Fe2O3@Zn are the most favourable for diffusion of Zn2+ in acidic electrolyte.

Carbon capture is widely recognised as an essential strategy to meet global goals for climate protection. Although various CO2 capture technologies including absorption, adsorption and membrane exist, they are not yet mature for post-combustion power plants mainly due to high energy penalty. Hence researchers are concentrating on developing non-aqueous solvents like ionic liquids, CO2-binding organic liquids, nanoparticle hybrid materials and microencapsulated sorbents to minimize the energy consumption for carbon capture. This research aims to develop a novel and efficient approach by encapsulating sorbents to capture CO2 in a cold environment. The conventional emulsion technique was selected for the microcapsule formulation by using 2-amino-2-methyl-1-propanol (AMP) as the core sorbent and silicon dioxide as the shell. This paper reports the findings on the formulated microcapsules including key formulation parameters, microstructure, size distribution and thermal cycling stability. Furthermore, the effects of microcapsule quality and absorption temperature on the CO2 loading capacity of the microcapsules were investigated using a self-developed pressure decay method. The preliminary results have shown that the AMP microcapsules are promising to replace conventional sorbents.

Highly efficient, stable, and metal-free supramolecular photocatalysts for H2 production are uncommon and of significant interest. In this study, a donor-acceptor (D-A) cyanocarbazole-based supramolecule (2CzPN) is assembled by intermolecular C≡N⋅⋅⋅H-Ar H-bonding interactions to form an efficient, stable, and metal-free photocatalyst for H2 evolution. The catalyst affords an H2 production rate of 91.8 μmol h-1 (20 mg of samples, λ>420 nm) and a corresponding apparent quantum efficiency of 7.5 % at 420 nm. The photon-generated carrier separation of the 2CzPN supramolecule, which is higher than that of the analogous polymer, can be attributed to the strong D-A characteristics and high crystallinity. This study offers the first experimental evidence of visible-light H2 evolution among D-A cyanocarbazole-based supramolecules and it enriches the variety of supramolecular photocatalysts. This stable and effective metal-free 2CzPN supramolecular photocatalyst has obvious advantages among very few supramolecular photocatalysts for H2 production.

The influence of the processing conditions on the interfacial and electrical properties of the high-k/SiGe gate stacks based on ozone oxidation is investigated. Detailed analyses of the relationship between the interface chemical structures and the corresponding electrical properties, as a function of oxidation time, reveal that the change in the distribution of the Ge atoms is the dominant factor to achieve superior electrical properties. In addition, the increase in the ratio of Si 4+ to Si 3+ of the oxide interlayer can help decrease the interface trap densities. These results provide us an important passivation route for the high-k/SiGe interface based on ozone oxidation, which is to explore an oxidation method that can realize an ultrathin interlayer including as much Si 4+ component as possible over a long oxidation time.

Thermal energy storage is essential whenever there is a mismatch between the supply and consumption of energy. When the air conditioning system is applied in transport, a great challenge occurred due to frequent fluctuations of cooling load which causes comfort degradation and even healthy concern. In this study, we evaluate charging performance including charging time, transient charging rate, overall energetic and exegetic efficiency of the designed device under different operating conditions. Evolutions of PCM temperature with processing time both in the axial and radial directions are also investigated. What’s more, the dynamic exergy efficiency is studied for the first time to assess the optimal charging depth and charging time. The experimental results show that the charging time can be reduced by 49% and 28% by dropping the charging temperature from 15 to 11 °C and increasing the inlet air velocity from 0.70 to 1.20 m/s. The designed energy storage device has flexible charging rates with the maximum value of 1.3 kJ/s, high thermal efficiencies at 87% and overall exergy efficiencies up to 70%. Both the drop of the inlet air temperature and the rise of the inlet air velocity contribute to the energy efficiency. The analysis of dynamic exergy efficiency shows that the maximum exergy efficiency can reach around 90% with the optimal charging time varying from 10 to 52 min. The corresponding optimal charging depth varies between 46% and 58% under the studied conditions. These findings could provide guidelines for the design and optimization of PCM energy storage device specifically when it is used in the transport field.

Molybdenum disulfide (MoS2) exhibits additional reversible capacity beyond their theoretical value is promising candidates for electrodes of lithium ion batteries (LIBs). However, the sluggish kinetics, low conductivity and self-aggregating of MoS2 nanosheets hinder the practical application. Herein, ultra small few layer MoS2 combined with carbon hybrids of macro-micro-mesoporous structure (MoS2/MmC) is prepared via a simple and scalable liquid-solid-gas three-phase interface self-assembly process. When employed as anode for lithium ion batteries, such a clever structure possesses superior performance: exhibits discharge capacity of 938 mAh g−1 at current density of 200 mA g−1 following 100 cycles, and reveals reversible capacity of 843 mAh g−1 at current density of 2 A g−1 after 1000 cycles. The excellent performance is attributed to the rational design of electrode structure: ultra small few layer MoS2 nanosheets offer abundant active sites, while the 3D porous architectures are in favor of enhancing the mass-transportation and alleviating the volume expansion. These structural features greatly enhance surface reaction kinetics and facilitate the charge transport. Furthermore, Ex-situ XRD, FESEM are used to confirm the phase transformation of MoS2/MmC and verify the structure stability during the cycling. It is believed that our work opens up a new possible route for the industrial production of MoS2 based anode materials.

Liquid Air Energy Storage (LAES) stands out among other large-scale energy storage technologies in terms of high energy density, no geographical constraints, low maintenance costs, etc. However, the LAES has a relatively lower round trip efficiency, 50–60%, which is a big disadvantage. One of the main reasons is the lower liquid air yield, ∼70%, which is far from 100% due to the lack of cold energy during air liquefaction. Thus, in this paper, cold energy released during liquified natural gas (LNG) regasification is recovered and stored with pressurized propane, which is used to help air liquefaction in the LAES (denoted as LAES-LNG-CS). The LNG regasification process works independently of the LAES thanks to cold storage. Effects of various working conditions on the LAES-LNG-CS system are studied and three operation periods (off-peak, peak and full hours) of the LNG regasification process are considered. Comparisons are made between the LAES-LNG-CS and standalone LAES systems. The results show that the LAES-LNG-CS system could achieve a liquid air yield up to ∼89% and the power consumption per unit mass of liquid air is reduced by ∼32%, compared with the standalone LAES system. What’s more, the system exergy efficiency of the standalone LAES is improved by ∼28% as the air charging pressure is at 8 MPa under studied conditions. Year-round performance study indicates that the round trip efficiency of the LAES-LNG-CS is in the range of 78–89%. Therefore, the proposed LAES-LNG-CS offers a good option for the future development of the LAES system.

Polyetheretherketone (PEEK) is considered a potential orthopedic/dental material because of its excellent mechanical and chemical properties (e.g., similar elastic modulus to that of human bone). However, the poor bacteriostasis and anti-inflammatory and osseointegrative properties of bioinert PEEK impede its clinical application. We previously developed a facile and versatile surface modification method using dexamethasone plus minocycline-loaded liposomes (Dex/Mino liposomes) bonded by a mussel-inspired polydopamine coating, which effectively modulated cell inflammatory response and discouraged bacterial colonization in vitro. Herein, we report the application of this multifunctional surface modification method to improve bioinert PEEK, aimed at further studying the in vitro osteogenesis and in vivo properties of Dex/Mino liposome-modified PEEK to prevent bacterial contamination, attenuate the inflammatory response, and enhance ossification for physiologic osseointegration. Our study established that the Dex/Mino liposome-modified PEEK surface presented favorable stability and cytocompatibility. Compared with bare PEEK, improved osteogenic differentiation of human mesenchymal stem cells under both osteoinductive and osteoconductive conditions was found on the functionalized surface due to the liposomal Dex releasing. In vivo bacteriostasis assay confirmed that Mino released from the functionalized surface provided an effective antibacterial effect. Moreover, the subcutaneous foreign body reaction and beagle femur implantation models corroborated the enhanced anti-inflammatory and osteointegrative properties of the functionalized PEEK. Our findings indicate that the developed Dex/Mino liposome-modified PEEK with enhanced antibacterial, anti-inflammatory, and osseointegrative capacity has great potential as an orthopedic/dental implant material for clinical application.

Compressed air energy storage (CAES) is one of the most promising large capacity energy storage technologies and this technology which was used only for demand side management, it has not attained the status of an economic model due to its poor round-trip efficiency. However, in the emerging renewable power scenario, this technology has received a new interest among the scientists. In this paper, a comprehensive thermodynamic analysis is performed for conventional and modified configurations that enhances the round-trip efficiency appreciably. The results reveal that when the compressed air is kept at isothermal temperature at atmospheric condition, the mass of air stored in the tank will be high which will reduce the size of the storage tank appreciably for the given capacity. Further, the possibility of generating cool energy along with power generation during the expansion of compressed air from the atmospheric temperature is also addressed. Though this configuration yields a poor round-trip power efficiency, if the heat of compression and cool energy generated during expansion are utilized for other applications, then the overall polygeneration efficiency is very high. However, if the objective is to maximize the round-trip power efficiency then the compressed air in the storage tank to be heated by the stored heat along with the external heat source. The main conclusions drawn from this work will be of great help by providing guidelines for the future development of a high-efficiency Isothermal CAES (ICAES) system for enhanced power generation/combined with the concept of polygeneration.

A form stable NaCl-Al2O3 (50–50 wt-%) composite material for high temperature thermal energy storage was fabricated by cold sintering process, a process recently applied to the densification of ceramics at low temperature 300°C under uniaxial pressure in the presence of small amount of transient liquid. The fabricated composite achieved as high as 98.65% of the theoretical density. The NaCl-Al2O3 composite also retained the chloride salt without leakage after 30 heating-cooling cycles between 750°C–850°C together with a holding period of 24 h at 850°C. X-ray diffraction measurements indicated congruent solubility of the alumina in chloride salt, excellent compatibility of NaCl with Al2O3, and chemical stability at high temperature. Structural analysis by scanning electron microscope also showed limited grain growth, high density, uniform NaCl distribution and clear faceted composite structure without inter-diffusion. The latent heat storage density of 252.5 J/g was obtained from simultaneous thermal analysis. Fracture strength test showed high sintered strength around 5 GPa after 50 min. The composite was found to have fair mass losses due to volatilization. Overall, cold sintering process has the potential to be an efficient, safe and cost-effective strategy for the fabrication of high temperature thermal energy storage materials.

Well-dispersion of fillers in polymers is crucial for the preparation of mixed matrix membranes(MMMs). In this paper, COF-LZU1 particles were in-situ prepared in poly(ether-block-amide) membranes for the first time, and the as-obtained MMMs exhibited higher n-butanol/water sorption selectivity and pervaporation selectivity in comparison with that of MMMs prepared by conventional blending methods. The effects of reactants concentrations, growth temperature and solvents on property and pervaporation performance of MMMs were investigated. For the benzene-1,3,5-tricarbaldehyde (TFB) concentration of 2.0 mmol L−1, growth temperature of 70 °C, TFB to p-phenylenediamine molar ratio of 1:1.5, and solvent of n-butanol, the MMMs showed maximum separation factor (22.2) (increased by 139% in comparison with that of pristine membranes) and peameation flux of 611 g m−2 h−1, demonstrating great prospect for the recovery of n-butanol.

Nanosecond and sub-nanosecond ultrashort pulse have good applications in medical cosmetology, microstructure machining, scientific research, etc. Using stimulated Brillouin scattering(SBS) to compress the pulse width of ten nanoseconds to one nanosecond or even picosecond which is a technical way that is economical and easy to implement. This article uses a compact single-cell structure device to pass a Nd:YAG laser-pulse with 8.05ns and 145mJ through FC-40. An ultrashort pulse with 1.35ns and 94.5mJ was obtained. The pulse width after compression was measured within 4 h, and the pulse width stability was better than 5%.

Submicron PAF-56 particles with narrow size-distribution were prepared by bottom-up method for the first time, and incorporated in polydimethylsiloxane (PDMS) membranes for pervaporation of 5% n-butanol solution. The effects of PAF-56 loading on the hydrophilicity, swelling degree, partition coefficient and pervaporation performance of the mixed matrix membranes (MMMs) were studied. It was found that, the PAF-56/PDMS MMMs displayed n-butanol sorption-selectivity, and the permeation flux and separation factor increased with the decreased PAF-56 particles size at the same loading, demonstrating size-effects of PAF-56 particles. With the increased PAF-56 loading, the permeation flux and separation factor exhibited maximum values at 2–2.5% loading. For MMMs with PAF-56 size of 0.83 μm and 2.5 wt% loading, the separation factor and permeation fluxes were 48.4 and 1906 g m−2 h−1 (increased by 183% and 66% in comparison with that of pristine PDMS membrane), indicating great potential in recovery of n-butanol.

The development of high-performance adsorbents for water purification is of utmost importance. Herein, we report the construction of a 3D graphene hybrid aerogel integrated with hollow carbon spheres via a two-step synthetic strategy. The structure and morphology of the hollow carbon spheres/graphene aerogels (HCSs/GAs) were characterized using BET, XRD, FTIR, Raman, XPS, and FESEM. The HCSs/GAs monoliths with high surface area (356.1 m2 g−1) were utilized as an effective adsorbent for the removal of methyl orange (MO) and rhodamine B (RhB) dyes, organic solvents and oils from aqueous solutions. The HCSs/GAs demonstrated remarkably broad-spectrum adsorption performance with a high capacity for MO (344.1 mg g−1) and RhB (441.5 mg g−1), and up to 58–108 times its own weight for oils/organic solvents. Furthermore, the HCSs/GAs showed a rapid adsorbing ratio and superior recycling stability for oils/organic solvents. The adsorption kinetics of the HCSs/GAs were investigated and were well-fitted by the pseudo-second-order kinetics model. The high performance of the HCSs/GAs is related to its interconnected 3D hierarchical porous framework, high surface area and large pore volume. Therefore, the HCSs/GAs are believed to be a promising adsorbent for wastewater treatment.

The development of more efficient and reliable absorption/adsorption refrigeration for air conditioners (ACs) and chillers is of great interest due to the increasing demand of these cooling devices...

Cobalt sulfide coupled with carbon materials attracts tremendous interest as a promising anode for Li-ion storage. In this paper, hollow Co3S4/C nanoparticles (NPs) with a uniform size of 30 nm homogeneously anchored on nitrogen-doped carbon nanofibers (denoted as Co3S4/CNF) are prepared by electrospinning method, followed by carbonization and sulfuration process. The free-standing Co3S4/CNF composites are straightly acted as binder- and current collector-free anode for lithium-ion battery, which demonstrate a high reversible capacity of 742 mAh·g−1 at 200 mA·g−1 after 200 cycles and 436 mAh·g−1 at 1 A·g−1 after 500 cycles, respectively. Such superior lithium storage performance of the Co3S4/CNF composites can be ascribed to the synergetic effect of the composites structure, which can effectively facilitate the electron and lithium ion diffusion, restrain the volumetric variation and keep the structure intact.

Microencapsulated phase change material (MPCM) slurry has proven to have potential in elevating the overall performance of a photovoltaic/thermal (PV/T) module as a working fluid. In order to make full use of the superiority of MPCM slurry and further improve energy and exergy efficiencies of the PV/T module, the effects of MPCM concentration and melting temperature under a wide inlet fluid velocity range were explored based on a three-dimensional numerical model of coupled heat transfer in this study. The results show that both the energy and exergy efficiencies increased with the concentration. A lower melting temperature resulted in higher energy efficiency, whereas a higher melting temperature is helpful for exergy efficiency improvement. The slurry with an excessively low melting temperature (e.g. 27 °C) even led to lower exergy efficiency than pure water. The melting temperature needs to be precisely tailored to make a compromise between energy and exergy efficiencies. In comparison with pure water, the improvement in energy efficiency provided by the slurry was further enhanced at a lower inlet velocity, while the improvement in exergy efficiency was optimized by adjusting the inlet velocity to a certain value. The maximum improvement in energy efficiency provided by the slurry was 8.3%, whilst that in exergy efficiency was 3.23% in this work. From the above, the superiority of MPCM slurry can be further promoted by selecting suitable material properties and operating parameters. The authors would like to acknowledge the financial support of the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom (Grant Nos. EP/N000714/1 and EP/N021142/1), National Natural Science Foundation of China (Grant Nos. 51606135 and 51776142) and Natural Science Foundation of Hubei Province (Grant No. 2016CFB156).

Low freeze point paraffin-based phase change materials (PCMs) for thermal energy storage often have very high vapor pressure, rendering it extremely challenging to encapsulate. This work reports our success in fabricating amino resin microcapsules with low freeze point PCMs cargos. Our findings challenge the emulsifier selection criteria proposed a decade ago, and enable better understanding of the role of emulsifiers in the one-step encapsulation process without precondensate synthesis. A facile, low cost, efficient and efficacious screening method utilizing a fluorophore is reported here for fast examination of core retention without resorting to more complex or unnecessary quantification techniques. This method is transferable to other encapsulation methods or materials as a qualitative analysis tool. We report two new emulsifiers, i.e. xanthan gum and methylcellulose, which contribute to successful encapsulation of volatile cargos via the one-step in situ polymerization route. The concentration of xanthan gum affects not only the capsule size, but also shell thickness and surface roughness. Most importantly, we have demonstrated with methylcellulose that carboxyl or anhydride moieties in emulsifiers are not essential for the one-step process, contrary to the literature. Capsules produced with methylcellulose also demonstrate superior thermal cycling fatigue resistance.

This paper concerns the heat transfer behaviour of Composite Phase Change Material (CPCM) modules made of a eutectic carbonate salt of NaLiCO3 (phase change material, PCM), MgO (ceramic skeleton material, CSM) and graphite flakes (thermal conductivity enhancement material, TCEM). The CPCM has a melting point around 500 °C and is suitable for medium and high temperature thermal energy storage applications including peak shaving of power grids, effective use of curtailed wind energy, and concentrated solar power generation. Disk-like CPCM modules were fabricated for the work. The effects of TCEM loading and surface cooling conditions on the heat transfer were experimentally investigated and analysed. The results showed that the use of TCEM not only significantly enhanced heat transfer of the CPCM modules, but also reduced the temperature difference and hence the thermal resistance between heater surface and CPCM module surface, leading to a significant extent of enhancement of overall heat transfer. Temperature measurements of a flat surface of the CPCM modules as well as that within the modules showed a non-uniform temperature distribution perpendicular to heat transfer direction, suggesting the effect of CPCM microstructure on heat transfer. This microstructural effect was further investigated using a scanning electron microscope with energy dispersive spectrometry. The results indicated salt migration, particle breakage and particle redistribution in the interior of the CPCM modules during thermal cycling, leading to a more homogenous distribution of ingredients and more uniform heat transfer within CPCM modules.

Phase change materials (PCMs) are generally integrated into matrix materials to form shape-stabilized composite heat storage materials (HSMs) used for high temperature thermal energy storage applications. The conventional fabrication of composite HSMs is prevalently implemented at quite high temperatures, which is energy-intensive and narrows down the range of applicable PCMs because of thermal decomposition. Therefore, this paper establishes a novel fabrication approach to accomplish highly dense matrix to encapsulate PCMs at extremely low temperatures, based on the recently developed cold sintering process. The feasibility of the proposed approach was demonstrated by a case study of NaNO3/Ca(OH)2 composite HSMs. It was observed that the Ca(OH)2 matrix formed dense microstructure with obvious sintered boundaries and successfully encapsulated NaNO3 as PCM. The HSMs maintained stable macroscopic shape after hundreds of thermal cycles, and exhibited an energy storage efficiency of 59.48%, little leakage of PCM, and good thermal stability. Mechanical tests indicated that the HSMs possessed excellent mechanical properties when the sintering pressure is over 220 MPa. The discharging time of stored heat was presented through infrared thermography, and the heat storage capacity measured for the composite HSMs was over four times as high as those of typical solid storage materials of sensible heat, which demonstrated their excellent heat storage performances. The HSMs can be used in the form of packed bed or parallel channel with multi-layered heat storage, which is beneficial for efficiently utilizing solar heat and improving the performance of current energy storage system. This study therefore provides a novel route for energy-saving and low-carbon fabrication of shape-stabilized composite HSMs.

In this paper, EG of different concentration was added in water to form PCM with different freezing point. Then, 0.0625%, 0.125%, 0.25% and 0.5% MCNT was dispersed in to each EG-water basefluids respectively. The latent heat are 160.0, 141.0, 102.0 and 85.5 J/g and melting point are -12.2, -15.7, -22.1 and -25.4 oC for 15%~30% EG-water basefluids. We found that adding MCNT has very little influence on the latent heat and melting point because the total amount of MCNT is very small. Also, we noticed that thermal conductivity will increase with increasing amount of MCNT concentration in EG-water basefluids. An interesting observation is that the enhancement of thermal conductivity was much greater in solid state samples than liquid state samples. For example, in 0.5% MCNT sample, the enhancement of thermal conductivity in solid state was observed over twice higher than that in liquid state.

Liquid air energy storage (LAES) is a novel proven technology that can increase flexibility of the power network, obtaining revenue through energy price arbitrage. To assess the economic potential of a variety of energy storage options, this study develops a cost research framework for LAES, which is also applicable to other energy storage technologies. For the calculation of Levelized Cost of Storage (LCOS), it is essential to evaluate the electricity purchasing cost and the total electricity generated. However, they are often estimated by simply assuming an average electricity price and an annual operating cycle in the previous studies. In this paper, a price arbitrage algorithm is developed, according to which decisions are made at each time step whether to charge, discharge or stand by. Thus, the electricity purchasing cost as well as the amount of electricity generated by the storage unit is determined and the LCOS of the energy storage system is calculated. Results show that the LCOS for a 25MW/125MWh LAES system is in the range 191-590 £/MWh, depending on different round-trip efficiencies and different costs set in three scenarios. If the round-trip efficiency is assumed to be 60%, the LCOS would in the range 191-294 £/MWh under the three scenarios.

Silicon anode suffers from poor intrinsic conductivity and dramatic volume change during discharge/charge process, which hinders its commercialization for high energy density lithium-ion batteries. To address these challenges, silicon-sodium alginate-polyaniline composites are rationally designed and synthesized via in-situ polymerization. A hydrogen bond self-healing process occurs during lithiation and delithiation to accommodate the strong volumetric modification, so that the composites perform excellent electrochemical performance, with a capacity of 1099.5 mAh·g−1 after 200 cycles at the current density of 1.0 A·g−1. In view of the density functional theory calculations, the synergy effect of sodium alginate and polyaniline enhances the hydrogen bonding of the silicon and polymers, increases the electron transport capability, and results in excellent electrical, mechanical integrity and conductivity of the electrodes. Our work not only provides a facile procedure to prepare unique conducting three dimensional network structured composites as a commercial anode but also reveals the mechanism that the silicon nanoparticles avoids electrode pulverization via hydrogen bonding self-healing process.

Battery thermal management is of great significance for increasing the thermal safety and prolonging the service life of the electric vehicle battery pack. In this paper, the thermal property of pouch Lithium-ion battery module cooled by PCMs (Phase Change Materials) was investigated. The three-dimensional thermal models of battery modules consisted of different thickness batteries were established to study the effects of space between adjacent batteries, melting point and thermal conductivity of PCMs on cooling performance. The results showed that the Tmax (maximum temperature) and ΔTmax (maximum temperature difference) declined when space between modules and thermal conductivity of PCMs increased. And the decline became more obviously with the increasing melting point of PCMs. Tmax increased and ΔTmax declined as the melting point of PCMs increased. On the basis of the Tmax of battery module meeting the temperature requirements, improving the space between adjacent batteries, melting point and thermal conductivity of PCM properly contributed to enhance the conformity of temperature filed. The conclusion would contribute to the design of battery thermal management system based on PCMs.

The rapid increase in application of intermittent renewable energy generation has stimulated the development of energy storage system to guarantee a stable supply in electricity grid. As a large-scale storage technology, Liquid Air Energy Storage (LAES) technology has attracted many attractions in recent years due to it offers many unique advantages including high energy density, mature technologies based and geographical-constraint free. However, current LAES has relatively low round trip efficiency (less than 60%) and still needs improvement. In the LAES, the recovered cold energy from the liquid air is insufficient to cool the compressed air to the lowest temperature with the shortage of ~18% and liquid air yield does not achieve the maximum in the charging process; external free cold sources would be needed to further increase the liquid air yield, and the round trip efficiency could easily break through 60%. This paper proposes an innovative LAES system integrated with LNG regasification process, the objectives in this established work are to improve the product yield of liquid air and enhance the overall roundtrip efficiency. Sensibility analysis and exergy efficiency analysis of charging process and discharging process at LAES are discussed. Meanwhile, the comparisons of system performance are made between traditional LAES system and LAES with LNG regasification system (LAES-LNG) at same operating parameters. Through the LAES-LNG system, more liquid air is generated. Results show that relatively higher round trip efficiency could be obtained, with 15-35% enhancement compared with the current LAES. Also, liquid air yield obtains a significant improvement to 0.87.

The standby battery for outdoor base station could not function properly at cold environment for a long time. In order to improve its performance and lengthen its life time, it was necessary to heat the battery and keep warm. This dissertation presented the heating and heat preservation method of 48 V Lead-acid battery pack for base station based on the heating plate and phase change materials at cold environment. Then, the thermal management performances of this battery pack were simulated. The results showed that the uniformity of battery temperature field was increased and the heat preservation process was lengthened effectively. And the pack kept good working condition after continuous heating and heat preservation progress. The method was simple and practicable, and it could be used on the thermal management of lithium ion battery because of its good applicability

Herein, an advanced technique of plasma-enhanced atomic layer deposition is applied to in-situ adjust the intrinsic crystal structure and chemical composition of cobalt oxides by nitrogen-doping. The homogeneous N-CoOx thinfilm is conformally deposited on high-surface-area carbon nanotubes which maintains the one-dimensional structures. The N-CoOx/carbon nanotubes electrocatalyst displays remarkable bifunctional electrocatalytic activity and stability towards the oxygen reduction reaction and oxygen evolution reaction. The onset potential for oxygen reduction reaction is 0.9 V, which is about 80 mV positively shifted compared to the undoped sample while the oxygen evolution reaction performance is also improved by reducing the overpotential of 35 mV after nitrogen doping. Moreover, the limiting current density of N-CoOx/carbon nanotubes electrocatalyst is comparable to the benchmarking Pt/C while the former one exhibits better stability which is only 5% loss of current after operation for 10000 s and for the latter one is 11%. The improved electrochemical performance is affected by the introduction of N-dopant and the results provide a direction for designing and constructing other metal oxides as bifunctional electrocatalysts for air batteries and water splitting reactions.

A intracavity cascading pumped dual-wavelength output Nd:YAG/Yb:YAG laser is demonstrated for the first time. The system adopts a coaxial composite cavity structure, and using an all-solid-state Nd:YAG laser operating at 946 nm as intracavity pump source, a 1160 mW 946 nm laser and a 43 mW 1030 nm laser were obtained with 1.39 W absorbed pump power. The fluctuation of the output power was better than 5% in the given 30 min. The corresponding beam quality factors M2 are 1.25 and 1.27.

As a typical cold storage media working at sub-zero temperature, NaCl-water solution as a phase change material (PCM) with -21 oC melting point has been selected in this study. 0.0625 vol.%-0.5 vol.% multi-wall carbon nanotube (MCNT) was dispersed in the NaCl-water basefluid via ultra-sonicating to make nano-suspension. The viscosity of MCNT-NaCl-water was measured and the experimental results fitted well with the modified Krieger-Dougherty (K-D) model. The structure of MCNT cluster was derived from the fitting of viscosity data, showing that the lower the temperature, the larger the cluster size could be. Benefited from the MCNT cluster parameter, the thermal conductivity of MCNT-NaCl-water was predicted by modified Hamilton-Crosser (H-C) model, in which the MCNT cluster was considered as a whole part with its equivalent thermal conductivity. In addition, thermal conductivity experiment was also conducted to compare the measured value with the calculated value. The results indicated that the traditional H-C model underestimates the measured thermal conductivity by a large margin while the approach proposed in this paper shows good accuracy. Moreover, it is also found that MCNT will improve the thermal conductivity more significantly at low temperature than at high temperature.

Thermal energy storage (TES) has a crucial role to play in conserving and efficiently utilising energy, dealing with mismatch between demand and supply, and enhancing the performance and reliability of our current energy systems. A competitive TES technology requires a number of scientific and technological challenges to be addressed including TES materials, TES components and devices, and integration of TES devices with energy networks and associated dynamic optimization. This paper concerns mainly about TES materials challenges with a specific focus on using shape stable composite phase change materials (CPCMs) for medium and high temperature application. The paper first briefly reviews the state-of-the-art development of materials research for thermal energy storage. The focus is then on CPCMs for medium to high temperatures applications, covering materials screening, formulation based on molecular modelling validated at a different length scale through experiments, formulation based on chemical and physical compatibility, and manufacture of material modules via innovative use of conventional powder technology. The properties of the materials and materials modules are characterised and analysed with an aim to establish property-structure relationships. This includes a particularly interesting aspect of the motion of PCM and nanoscale objects with the PCMs for heat transfer enhancement during thermal cycling, which explains the mechanisms of the encapsulation of PCMs in the composite.

EG-water based MCNT nano-suspensions were prepared by two-step method. Both experimental work and theoretical analysis were carried out to investigate the rheological property of prepared samples at different volume fraction and temperatures. The results showed that the experimental viscosity value could be matched well with the modified K-D model considering effective volume fraction of aggregations. In addition, this work exhibited an interesting trend of the behaviour of the viscosity vs shear rate curve when temperature is dropping down. A particle aggregation transformation mechanism were proposed to reveal the relationship between MCNT aggregation conditions and temperature, furthermore to explain the variety of shear behaviour of nano-suspensions.

A general concept of converting capsules into sensors is reported. Such simple conversion enables instantaneous nondestructive analysis for applications such as controlled release and energy storage among others. Converted capsule sensors are responsive in emission colors to varying core cargos via the incorporation of a solvatochromic fluorophore under excitation. Such cargo-responsive self-sensing abilities facilitate their application in capsule-level analysis such as cargo retention-leakage detection and release implications, as well as defect identification. The versatile concept is shown as an auxiliary tool in thermal energy storage to visualize phase transition, exhibiting promising potentials in application-level characterization.