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Ultrabroad spectral absorption is required for semiconductor photocatalysts utilized for solar-to-chemical energy conversion. The light response range can be extended by element doping, but the photocatalytic performance is generally not enhanced correspondingly. Here we present a solid alkali activation strategy to synthesize near-infrared (NIR) light-activated carbon-doped polymeric carbon nitride (A-cPCN) by combining the copolymerization of melamine and 1,3,5-trimesic acid. The prepared A-cPCN is highly crystalline with a narrowed bandgap and enhanced efficiency in the separation of photogenerated electrons and holes. Under irradiation with NIR light (780 nm ≥ λ ≥ 700 nm), A-cPCN shows an excellent photocatalytic activity for H2 generation from water with rate of 165 µmol g−1 h−1, and the photo-redox activity for H2O2 production (109 µmol g−1 h−1) from H2O and O2, whereas no observed photocatalytic activity over pure PCN. The NIR photocatalytic activity is due to carbon doping, which leads to the formation of an interband level, and the alkali activation that achieved shrinking the transfer distance of photocarriers. The current synergistic strategy may open insights to fabricate other carbon-nitrogen-based photocatalysts for enhanced solar energy capture and conversion.

The applications of salts-based phase change materials (PCMs) are greatly restricted by their corrosion to containers and low thermal conductivity. To address these issues, a modified diatomite-based porous ceramic (MDPC) was prepared to shape-stabilize KNO3 salt in this paper. Particularly, effects of graphite content on the pore structure of diatomite-based porous ceramic (DPC) and MDPC on the thermophysical properties of shape-stabilized KNO3 were investigated. The results showed that 30 wt% graphite increased apparent porosity of DPC up to 67.21% and enlarged average pore diameter from 0.71 to 3.58 μm, while weakened its compressive strength from 19.12 to 5.51 MPa. The MDPC effectively prevented leakage of molten KNO3 to avoid its corrosion problem, and possessed an excellent chemical compatibility with KNO3 salt. Additionally, the MDPC hardly changed phase transition temperature of shape-stabilized KNO3, while increased latent heat of composites from 51.70 to 60.21 J/g due to its higher apparent porosity. The MDPC was also shown to enhance thermal conductivity of shape-stabilized KNO3 from 1.16 to 1.52 W/(m·K) at 25 °C, which was attributed to that the MDPC with a larger pore size was more easily infiltrated by molten salt, contributing to a lower apparent porosity of composites. Compared with pure KNO3, thermal conductivity and thermal stability of shape-stabilized KNO3 were seen to be significantly improved by 238% and 60 °C, respectively. This work therefore solved two key challenges for the application of KNO3 salt, and proposed an effective way to improve thermophysical properties of such heat storage material.

The droplet/wall interaction in the gas channel (GC) of proton exchange membrane fuel cells (PEMFCs) has significant influence on water management, which may affect the performance and durability of the cell. In this paper, a coupled level-set and volume-of-fluid (CLSVOF) method is used to simulate the dynamic behaviours of a micro-droplet impacting on a vertical wall in the GC. The effects of impact velocity (expressed by the Weber number, We), and impact angle on the spreading dynamics are evaluated. Next, the critical conditions for the transition from spreading to rebound are further discussed. For 0

It is important and urgent to overcome the intermittent nature of solar energy as a green substitute for fossil-based electricity. Concentrated solar power plants with thermochemical energy storage...

Simultaneous recording of action potentials (APs) and neurotransmitter release is highly desirable in living neurons since it provides a complete framework of the physiological and pathological statuses of nerve cells. In this work, we proposed an approach coupling ultra-thin microelectrode array (MEA) with total internal reflection fluorescence microscopy (TIRFM), which served as a powerful platform to visualize both APs and vesicular exocytosis in a neuronal circuit model formed by neuron-like PC12 cells. Taking advantages of fluorescent false neurotransmitter (FFN), the transient neurotransmitter transport down an axon could be visualized with high spatial and temporal resolution. The real-time recording of APs burst and neurotransmitter release induced by hypoxia with MEA/TIRFM platform reveals the relevance of electrical and chemical activities in the neuronal model. The combination of the optical and electrical techniques enables mapping of neuron connectivity in an entire neuronal circuit, which may ultimately lead to deeper understanding of nervous system.

Hydrogenation/deuteration of carbon chloride (C−Cl) bonds is of high significance but remains a remarkable challenge in synthetic chemistry, especially using safe and inexpensive hydrogen donors. In this article, a visible-light-photocatalytic watersplitting hydrogenation technology (WSHT) is proposed to in-situ generate active H-species (i.e., Had) for controllable hydrogenation of aryl chlorides instead of using flammable H2. When applying heavy water-splitting systems, we could selectively install deuterium at the C−Cl position of aryl chlorides under mild conditions for the sustainable synthesis of high-valued added deuterated chemicals. Sub-micrometer Pd nanosheets (Pd NSs) decorated crystallined polymeric carbon nitrides (CPCN) is developed as the bifunctional photocatalyst, whereas Pd NSs not only serve as a cocatalyst of CPCN to generate and stabilize H (D)-species but also play a significant role in the sequential activation and hydrogenation/deuteration of C−Cl bonds. This article highlights a photocatalytic-WSHT for controllable hydrogenation/deuteration of low-cost aryl chlorides, providing a promising way for the photosynthesis of high-valued added chemicals instead of the hydrogen evolution.

A novel versatile locked nucleic acid modified molecular beacon probe (LNA-MB) was developed for imaging intracellular precursor miRNAs (pre-miRNAs) and disturbing Dicer-mediated cleavage process. The target recognition reaction between the smart probe and pre-miRNA can not only induce the conformational changes of probe and block the Dicer cleavage site, but also inhibit the cleavage process, and then achieve down-regulation of miRNA expression. Simultaneously, the target recognition reaction broke the fluorescence resonance energy transfer (FRET) between fluorophore donor FAM and acceptor TAMRA, which were labelled on the LNA-MB probe, further induced the relevant change of fluorescence signal, and then achieved imaging analysis of pre-miRNA and inhibition events in situ. Both in vitro and in single living cell studies showed that the versatile probes exhibited a remarkable performance in targeting with pre-miRNA-21, and nearly 65% downregulation of mature miRNA-21 was achieved with 100 nM probes. All investigations demonstrate that the proposed strategy represents a promising alternative for regulating and inhibiting endogenous disease-associated RNAs, then further for achieving therapeutic outcomes in personalized treatments.

In this study, a novel high temperature two-phase closed flat heat pipe receiver is proposed and investigated experimentally. In order to simulate the transient startup from frozen state, a transient analysis code for the novel flat heat pipe receiver has been developed. Closed-form analytical solutions for the temperature distribution along the heat pipe length are obtained and experimental tests are undertaken. These closed-form analytical solutions are in good agreement with the experimental data. The theoretical and experimental studies prove that the flat heat pipe receiver with sodium as working fluid has a well startup performance. Experiments were carried out to investigate the temperature uniformity of FHPR under the normal conditions. It is found that the FHPR has well feature of uniformity and stability through startup process experiments with constant heat flux. This research provides guidance for the research and development of flat heat pipe solar receiver, and has important significance for broadening its application in the field of heat utilization of solar energy at high temperature.

Various design configurations of semi-T-shaped dual-channel micro-reactors were numerically examined for their laminar mass transport performance in heterogeneous catalytic combustion of methane and air. One single-channel and five dual-channel configurations (i.e., parallel, divergent, convergent, zig-zag, and curved configurations) were investigated with a two-dimensional computational fluid dynamics model. These innovative design configuration were compared in terms of CH4 utilization, pressure drop, CO/CO2 ratio, catalyst utilization, and a performance index at various Reynolds numbers. Dual-channel micro-reactors were found to enhance mass transport due to the well mixed flow and the increased reaction contact area. By suitably modifying the dual-channel layout angle and shape, recirculation zones can be formed within the reactor which increase CH4 utilization. However, the improved conversion rate is achieved at the cost of high pressure drop. The parallel dual-channel design provides the highest conversion per unit pressure drop over the range of the Reynolds numbers studied. For Reynolds numbers of 20 and 40, compared to the single-channel micro-reactor, divergent, convergent and curved channel designs yield higher conversion per unit pumping power. However, further increase of Reynolds number (i.e., 60, 80, and 100) deteriorates their performance due to the significantly increased pressure drop and shorter residence time.

In this paper, an innovative longitudinal triangular fin was proposed to improve the solidification performance of shell and tube latent heat thermal energy storage (LHTES) device. At first, the solidification behaviors (solid fraction, temperature distribution and solidification time) of two different layouts of innovative fins (Fin-B, Fin-C) were compared with the traditional rectangular fin (Fin-A). Then, the dynamic temperature response of the fins with superior performance were analyzed. In addition, the influences of the fin geometrical parameters, initial temperature and fin materials on the solidification performance were studied and discussed. The results showed that the innovative longitudinal triangular fins can significantly improve the solidification performance of PCM in LHTES, and the Fin-C had better heat transfer efficiency and superior solidification performance among the three types of fins. The solidification time of Fin-C-Ⅰ decreased 38.30% significantly compared with the traditional rectangular Fin-A. Generally, the solidification time decreased by decreasing the initial temperature, or increasing the thermal conductivity and the fin heights. However, the effect of the bottom width of triangular fin on the solidification performance can be neglected. To achieve a faster cooling rate, the recommended temperature difference between the inner wall and PCM was over 20 K.

Filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) has gained significant importance as a contender for the fifth generation mobile communication system and also meets the application requirements of the Internet of things. The peak-to-average power ratio (PAPR) of the FBMC-OQAM is very high due to using a same prototype filter for each subcarrier and the addition of different subcarriers at the transmitter. Therefore, a novel randomly assigning prototype filter (RAPF) method is proposed to reduce PAPR in FBMC-OQAM system. Based on the proposed RAPF method, the authors analyse the performances of both PAPR and bit error rate (BER) in the FBMC-OQAM system. Simulation results show that the proposed RAPF method helps to significantly reduce PAPR of FBMC-OQAM system. Meanwhile, compared with conventional FBMC-OQAM system, the proposed RAPF-FBMC-OQAM scheme has almost the same BER performance in the additive white Gaussian noise channel but is descended slightly only in the high signal-to-noise ratio region of the frequency selective fading channel.

In the present work, the equilibrium phase behaviors and thermal characteristics (phase diagrams, enthalpies, melting/freezing temperatures) of the binary systems dodecane-tetradedcane (C12H26-C14H30) and tridecane-pentadecane (C13H28-C15H32) were experimentally investigated to employ the potential PCMs for cryogenic applications. In addition, the phase diagrams were theoretically obtained by using both the ideal and non-ideal thermodynamic models. Results show that the compositions of eutectic points appear at 18 wt% C14 for the C12-C14 system and 10 wt% C15 for the C13-C15 system. The specific eutectic compositions of these two systems have satisfied enthalpies (158.0 J/g for C12-C14 and 143.1 J/g for C13-C15 in the melting process), slight supercooling (0.3 °C for C12-C14 and 0.4 °C for C13-C15), minor hysteresis (3.9 °C for C12-C14 and 2.2 °C for C13-C15) and superior thermal stability. Therefore, they are very attractive as the candidate PCMs in cryogenic energy storage systems. Moreover, the melting temperatures calculated by the theoretical models agree well with the experimental data. Especially for the non-ideal solubility model, the mean relative deviations are only 4% for the C12-C14 system and 8% for the C13-C15 system, respectively.

In this study, the phase diagrams for the binary systems of n-C11H24–n-C14H30, n-C12H26–n-C13H28, n-C12H26–n-C14H30, and n-C13H28–n-C15H32 were experimentally investigated to employ potential phase...

The calcium looping process is one of the most prospective candidates for thermochemical energy storage system owing to its high energy density, widespread availability and low cost. This paper aims to explore the effect of sensible heat on storage efficiency in the system of thermochemical energy storage based on calcium looping process. Three storage efficiencies in the charging process, discharging process, and total system are defined to quantify the role of sensible heat. The obtained results indicate that the maximum storage efficiencies in the charging process, discharging process, and total system are limited by the amount of sensible heat. Their values can be increased by 45.1%, 32.1%, and 61.59% when the sensible heat is taken full advantage in the charging process, discharging process, and total system, as compared to those without sensible heat. In addition, a sensitivity analysis on the amount of sensible heat is also performed, which demonstrates the amount of sensible heat is determined by different operation conditions. A positive effect is observed on the amount of sensible heat from several dominant parameters including reactor size, reaction temperature, molar flow of calcium carbonate and split ratio, except for carbonation pressure and carbon dioxide storage pressure. Besides, the optimal amount of sensible heat is in the range of 15–40% carbon dioxide percentage of the gas phase under the discharging pressure from 3 to 7 bar. These valuable results can deepen our understanding of the importance of heat recovery in the systems of thermochemical energy storage. More importantly, some meaningful descriptors are established to efficiently assess storage efficiencies for all gas-solid systems of thermochemical energy storage with heat recovery.

This study presents the numerical and experimental investigations of air/water direct contact heat and mass transfer in the humidifier. The mathematical model of humidifier is developed based on the Multiphase-Eulerian model. The regression equation for Merkel number utilized in the numerical model was proposed on the basis of experimental results. According to the numerical simulation results, the error between the numerical and experimental results is within 12%. The distributions of air temperature, the mass fraction of vapour in the air and total pressure have been studied to reveal the heat and mass transfer characteristics in the humidifier. And, the distributions of the relative humidity at different water inlet temperature and air-and-water mass flow ratio are investigated. It is found that the evaporation rate of the humidifier increases with the increase in the air mass flow rate, water inlet temperature and water mass flow rate. Comparing with the previous theoretical calculation results based on the Poppe model, the numerical results are closer to the experimental results. This study has important significance on the development of humidification-dehumidification desalination technology.

Most channel estimation techniques for orthogonal frequency division multiplexing system are not directly applicable to filter bank multi-carrier with offset quadrature amplitude modulation (FBMC-OQAM) system because of the imaginary interference of FBMC-OQAM system. Thus, a novel support vector regression (SVR) algorithm for fading channel estimation in FBMC-OQAM system is proposed. We propose a nonlinear complex SVR algorithm (NCSVR) adapted to two auxiliary pilots (AP)-based FBMC-OQAM signal, namely as AP-NCSVR. The practicality of our method is proved by simulation results obtained for Jakes fading model and vehicular A model. Simulation results reveal the accuracy of the proposed AP-NCSVR algorithm to estimate channel frequency response coefficients and show that the bit error rate performance of the proposed AP-NCSVR algorithm is better than the conventional interpolation method for Jakes fading model and vehicular A model.

Metal ion synergistically enhanced chemotherapy is a promising strategy for cancer treatment. However, targeting delivery of ions toward cancer cells remains challenging for decades. Herein, we developed a novel folic acid-nanogel (termed as FA-nanogel) with alkane chains as diffusion barriers for targeted transmembrane delivery of calcium ions into cancer cells. With the aid of hydrophobic diffusion barriers, the FA-nanogel showed a reduced and sustained speed for release of calcium ions, significantly prolonging the ion effect. Moreover, a pH-sensitive injectable hydrogel-loaded FA-nanogel and chemotherapeutic drug 5-fluorouracil (5-Fu) was synthesized for investigating the synergistic effect of nanogel on chemotherapy. Both in vitro and in vivo experiments confirmed that the intracellular calcium ions were continuously increased because of the targeted delivery ability and ion sustained release ability of the smart FA-nanogel, and the tumor growth was effectively inhibited by the ion synergistic chemotherapy. This study not only provides a powerful nanoplatform for sustained transmembrane delivery of ions into malignant cells but also creates better conditions for improving the therapeutic efficacy of chemotherapy.

Breast cancer develops from local tissue but is characterized by a distinct metastatic pattern involving regional lymph nodes and distant organs, which is the primary cause of high mortality in breast cancer patients. Herein, optimal docking nanoparticles (NPs) composed of a laurate-functionalized Pt(IV) prodrug (Pt(lau)), human serum albumin (HSA), and lecithin were predicted by computational modeling, prepared by nanoprecipitation, and validated by fluorescence spectroscopy. As macrophages have been reported to be preferentially recruited by breast cancer, Rex, the exosome spontaneously secreted by murine RAW 264.7 cells, was isolated to encapsulate the NPs. This high-performance delivery system, called NPs/Rex, possessed the desired physicochemical properties, enhanced colloidal stability, and redox-triggered release profile. Investigations of cytodynamics proved that NPs/Rex was internalized through multiple pathways, avoided entrapment by bilayers, and successfully platinized nucleic acids after bioreduction in the cytosol. Intracellular activation of Pt(lau) was confirmed by observing the characteristic effects of cisplatin on cell proliferation and the cell cycle following treatment with NPs/Rex. During in vivo application, the bioinspired Rex coating endowed docking NPs with prolonged blood circulation, smart organ tropism, and enhanced biocompatibility, as well as robust platinum (Pt) chemotherapy for breast cancer cells in orthotopic tumors of fat pads and metastatic nodules of lungs. Therefore, this favorable nanoplatform might provide valuable insight into the derivatization and development of Pt anticancer drugs used currently in the clinic.

With the popularization of Internet applications and the rapid development of e-commerce, online shopping has become a widespread and important pattern of consumption. Online user comments are an important data asset on e-commerce sites and have a great potential value for online users and merchants. However, accurate and effective extraction of the characteristics of products and users’ sentiment evaluation from a tremendous amount of comments is a significant challenge. Based on the concept of the LinLog energy model, this paper proposes an online review attribute-sentiment pair correlation model that evaluates user comments. After preprocessing the comment data of mobile phones and constructing an attribute dictionary, the proposed model conducts a clustering analysis of attributes and sentiment pairs to gain accurate assessment of attributes in order to explore potential information from user comments. Experiments conducted on one real-world dataset with comprehensive measurements verify the efficacy of the proposed model.

At present, centrifugal granulation has become the most promising method for waste heat recovery of molten slag. This paper investigates the effects of rotary disk configurations on particles characteristics with molten aluminum as the working medium. Four types of rotary disks and two kinds of particles characteristics which included particles size distribution and particles mean size were studied. It can be seen that the main particles sizes are populated in the range of 2.0~4.0mm for all disk configurations. Due to the special surface structure, the particles produced by curved-block disk and arc-edge disk configurations are more concentrated compared to other two types of disks. Besides, the results shown that the mean size of particles generated by curved-block disk is smaller. All the conclusions will be helpful for future development of the high-temperature molten slag dry granulation systems.

This numerical study investigates the effects of effective compression ratio in a gasoline and biodiesel fueled reactivity-controlled compression ignition (RCCI) engine. Simulations were conducted via coupled KIVA4-CHEMKIN code. A multi-component reaction mechanism was used to mimic the combustion process of gasoline and biodiesel. The effective compression ratios were kept at 13.71, 14.19, 14.62, 15.02 and 15.37 by varying either intake valve closing timing or stroke lengths. The combustion characteristics and NO emission were compared under different cases. The results reveal that increasing effective compression ratio would contribute to higher peak pressure, more released energy and more NO emissions.

In this paper, the electricity consumption model and pressure drop model of humidification-dehumidification (HDH) system is developed. An experimental study is carried out to investigate the effects of operating parameters on the pressure drop of HDH system. The pressure drops in humidifier, dehumidifier and the total pressure drop increase with the increase of air and solution mass flow rate. The values of undetermined coefficient in the pressure drop model are obtained based on the experimental data. Meanwhile, the validation of the pressure drop model is varied though experiment. On this basis, the optimization model for minimum specific total energy consumption (STEC) is proposed. The optimization results show that the value of optimized STEC increase with the increase of evaporation rate requirements. The value of air mass flow rate (mg) should be as small as possible. The adjustment of solution mass flow rate (ml) and solution inlet temperature in humidifier (Tlhi) is a priority. The minimum value of optimized STEC is 822.676 kJ/kg.

Numerical studies on molten slag droplets solidification behaviors in humid air were carried out by using the hybrid evaporation and solidification models. The numerical model was firstly validated by the experimental data in the literatures, and then solidification time, temperature distribution, and movement of phase change interface during the solidification process were analyzed. The effects of humidity ratio (content of atomized water), air inlet temperature and velocity, and droplet diameter on solidification behaviors of molten slag were discussed. Finally, a correlation for predicting the solidification time was proposed. The results show that, generally, the solidification time is decreasing by increasing the air inlet velocity and humidity ratio, or decreasing the droplet diameter and air inlet temperature. The solidification rates represent a trend of gradual decline during the solidification process due to the ever-increasing thickness of the solid slag region, and they are normally higher at the upwind side but relatively lower at the leeward side, resulting in an off-center solidification process of a slag droplet. The humidity ratio has significant effect on the cooling air temperature distributions, steeper temperature gradient is observed thanks to the evaporation process of the atomized water. The present work suggests that the operational conditions are: the humidity ratio within the range of 10%∼20%, the air inlet velocity is 1.0 m/s and the air inlet temperature is 303 K, respectively.

In this study, small punch tests are conducted at various displacement rates (0.005–0.5 mm/min) to investigate the mechanical behaviour and strain rate sensitivity of commercial pure titanium TA2. The experimental results show that the yield load Py and the maximum load Pmax depend strongly on the displacement rate. An exponential function is established to describe the relationship between the material properties and the displacement rate. In order to describe the deformation characteristics of the specimen in the small punch tests at different strain rates, the Johnson–Cook constitutive model is applied in the finite element simulation. The influence of the constitutive parameters on the deformation behaviour is also analysed. The results indicate that the elastic bending region and plastic bending region are mainly affected by parameter A, whereas parameter B dominates the membrane stretching region and the plastic instability region of the curve. An improved inverse algorithm, combining the advance-and-retreat method with the golden section search method, is proposed. Based on characteristic analysis of the parameters, the one-dimensional and two-dimensional identification methods are used to identify the constitutive parameters from the load–displacement curve. Thus, the mechanical properties of materials can be calculated by inversion of the constitutive parameters.

CaCO3/CaO thermochemical energy storage (TCES) system is one of the promising technologies to overcome mismatch between solar energy supplies and variable electricity demands mainly benefiting from its high energy density, superior reversibility and low cost. This TCES system is divided into three processes, energy charging, energy storage, and energy discharging. The discharging process is the most important due to the involvement of CO2 in the conversion from CaO to CaCO3 for power generation. In this paper, a simplified discharging process is proposed and the mathematic models are developed based on mass and energy balances. Theoretical investigation is carried out to explore the effect of different parameters (gas solid ratio, solid inventory in the carbonator, and carbonator pressure) on discharging performance, which is determined by expansion work of turbine and CaO conversion. The results indicate that the gas solid ratio is the most critical parameter in regard to expansion work of turbine, followed by carbonator pressure, while the effect of solid inventory in the carbonator is little. On the other hand, solid inventory is the most significant among three parameters for CaO conversion, and the effect of carbonator pressure can be ignored.

Microencapsulation of phase change material (PCM) has received great attention as a promising candidate for latent heat thermal energy storage application. In this study, we reported a successful s...

The low-temperature creep deformation characteristics and primary creep behaviour of TA2 were analysed by the small punch creep (SPC) test in this paper. Uniaxial creep and SPC tests were conducted to estimate the temperature and load influences on the creep deformation. At room temperature and 373 K, an increase in the creep load and temperature caused a rapid increase in the creep deflection, exhibiting a greater primary creep deformation. Considering the non-linear deformation process, a modified membrane stretch model was introduced and a deformation analysis was performed. The creep deformation evolution process of a SPC test specimen was discussed. An apparent decline was observed in the equivalent creep stress and uniform thickness reduction was found. The material characteristics and stress reduction caused by the non-linear deformation were believed to be the cause of the primary creep behaviour of TA2. The results showed that SPC characteristic differs from that of the uniaxial creep test. To simplify the creep curve, a modified power relation between the creep deflection and time was established. Based on the constant strain rate test results, consideration of the strain rate sensitivity was applied to rationalise the low-temperature creep behaviour of TA2 in the uniaxial and multiaxial creep tests. Finally, a modified creep analysis model for the SPC test was proposed to predict the low-temperature creep deformation.

As phase change thermal storage material, sodium acetate trihydrate (CH3COONa·3H2O) exhibits large thermal capacity and holds tremendous promise. However, main problems of undercooling of solidification and phase stratification constrained its application in energy storage. Thus, present work prepared a new composite phase change thermal storage material of sodium acetate trihydrate mixed with nucleating agent and thickening agent. The initial research results showed that addition of an appropriate proportion of nucleating agent tetrasodium pyrophosphate decahydrate led to a good restrain to the undercooling of CH3COONa·3H2O. A certain amount of thickening agent polyacrylamide could also avoid the phenomenon of phase stratification and maintain the heat storage capacity of samples. Meanwhile, the additions little affected the melting point and would not decrease the enthalpy of fusion of sodium acetate trihydrate as established from Differential Scanning Calorimetry study, which indicated that this novel composite material possessed excellent and stable performance suitable for its application for thermal energy storage systems.

Filter-bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) has been considered as an alternative scheme to orthogonal frequency division multiplexing (OFDM). However, the traditional channel estimation techniques of the OFDM cannot be directly applied to the FBMC-OQAM system because of the real-field orthogonality of the FBMC-OQAM signals. Although traditional channel estimation techniques, such as least square (LS) and minimum mean square error (MMSE), are widely applied to the FBMC-OQAM system via canceling the intrinsic imaginary interference from adjacent data symbols, the LS algorithm is subject to noise enhancement and it results in large mean square error (MSE), while the mmse algorithm needs to know the statistical information of channel in advance. Due to sparsity of the wireless channel, channel estimation is investigated as a compressive sensing (CS) problem. In this paper, we first introduce the coding method to cancel intrinsic imaginary interference for the FBMC-OQAM system. Then, a novel sparse adaptive subspace pursuit (SASP) method is proposed to improve the accuracy of LS channel estimation. Finally, we develop two distinctive algorithms, namely, auxiliary pilot (AP) SASP and coding-SASP, to estimate channel frequency respond (CFR) in the FBMC-OQAM system. The simulation results show that the AP-SASP and coding-SASP algorithms can offer a low complexity and fewer measurements compared with conventional orthogonal matching pursuit (OMP) and regularized OMP (ROMP) methods. Moreover, the proposed AP-SASP and coding-SASP algorithms have a better bit error ratio (BER) performance than the conventional OMP and ROMP methods for FBMC system in the doubly selective channels.

Objective: To study the association between post-traumatic stress disorder (PTSD) and serotonin transporter promoter (5-HTTLPR) gene polymorphism in Han children in Hainan; to explore the genetic mechanism of PTSD in children. Methods: 50 patients with post-traumatic stress disorder and healthy children in Han nationality in Hainan were selected. Detection of 5-HTTLPR gene polymorphism by polymerase chain reaction (PCR) and amplified fragment length polymorphism, the genotype and allele frequencies were analyzed using a case-control association analysis method. Results: There were 4, 14 and 32 cases of LL, SL and SS in the post-traumatic stress disorder group of Hainan Han children, and 13, 20 and 17 cases in the control group. From the perspective of gene frequency, the L gene of post-traumatic stress disorder appeared 22.0%, and S appeared 78.0%. In the control group, L appeared 46.0%, and S appeared 54.0%. There were significant differences in genotype and gene frequency (P < 0.01). Conclusion: The 5-HTTLPR gene polymorphism in Hainan Han children may be associated with post-traumatic stress disorder.

With the merits of relatively high frequency response and large displacement, piezoelectric compliant mechanisms have been widely used in recent decades. In this paper, we share our recent investigation results on enhancing the dynamic bandwidth and flow rate of flexure-amplified piezoelectric flow control valves by employing compliant mechanisms. We have developed a rhombus-type compliant mechanism, which can actuate two small sliding spools by one group of piezo-stacks. Compared with the traditional nozzle flapper servo valve, it can effectively overcome internal leakage and oil contamination. The experimental results show that the step response time is 8.2ms and the bandwidth is about 100Hz.

This paper proposes an improved micro quartz crystal microbalance (micro-QCM) with high resonance frequency and high quality factor. By designing a composite inverted-mesa and convex structure, the energy trapping effect, resonant frequency and mechanical strength of the piezoelectric quartz crystal resonator are enhanced. The coupling of vibration modes is also reduced with the increase of quality factor. The electro-mechanical behaviors of the presented micro-QCM are simulated with the commercially finite element software package COMSOL. By analyzing the influence of electrode size, diameter and thickness of convex, the geometric parameters are optimized with the multi-physics field coupling simulation. Moreover, the presented micro-QCM has a smaller power consumption and higher mass sensitivity.

The internal state information of lithium-ion batteries, such as lithium-plating, state of charge, etc., which can be reflected by the internal structure of the battery and its mechanical properties. During the battery charging process, the Young’s modulus, density and porosity of the internal electrode materials will change. Ultrasonic non-destructive testing can be used to characterize the internal state of the battery and obtain the relationship between wave propagation information and internal state. This study describes in detail the reflection/transmission characteristics of ultrasound in lithium-ion batteries. Based on the working principle of lithium-ion battery, the porosity in the electrode of the lithium-ion battery is considered by Biot theory, and the reflection/transmission coefficient of the single cell is solved by the the transfer matrix method. As the thickness of the lithium plating layer increases, the angle spectrum and the frequency spectrum show regular movement, which makes it possible to further characterize the thickness of the lithium plating layer. The results obtained by the finite element simulation are highly consistent with the theoretical calculation method, which further verifies the feasibility of the method.

The combination of antiangiogenesis and chemotherapy regimens with cancer immunotherapy has the potential to synergistically boost antitumor immunity. Herein, we report the construction of two bioresponsive nanoparticles, namely, Podo-NP and CbP-NP, comprising prodrugs of podophyllotoxin (Podo) and carboplatin, respectively. Sequential treatment with esterase-responsive Podo-NP, redox-sensitive CbP-NP, and a CD40 agonist promotes antitumor T cell response. Podo-NP suppresses angiogenesis by preventing proliferation and migration of endothelial cells, sprouting of neovessels, formation of tubules, and stabilization of newly formed vessels. Vascular endothelial growth factor blockade and endostatin stimulation normalize tortuous tumor vasculatures to allow efficient infiltration of effector immune cells. Subsequent treatment with CbP-NP arrests the cell-division cycle and elicits the apoptosis of tumor cells. CD40 agonist activates antigen-presenting cells to process the released tumor-associated antigens from dying tumor cells, thus reversing immunosuppressive tumor microenvironments. Sequential delivery of antiangiogenic and chemotherapeutic agents with bioresponsive NPs activates tumor microenvironments and synergizes with CD40 agonist to regress transplanted tumors and inhibit disseminated tumors in a lung cancer mouse model.

Code retrieval is to find the code snippet from a large corpus of source code repositories that highly matches the query of natural language description. Recent work mainly uses natural language processing techniques to process both query texts (i.e., human natural language) and code snippets (i.e., machine programming language), however neglecting the deep structured features of query texts and source codes, both of which contain rich semantic information. In this paper, we propose an end-to-end deep graph matching and searching (DGMS) model based on graph neural networks for the task of semantic code retrieval. To this end, we first represent both natural language query texts and programming language code snippets with the unified graph-structured data, and then use the proposed graph matching and searching model to retrieve the best matching code snippet. In particular, DGMS not only captures more structural information for individual query texts or code snippets but also learns the fine-grained similarity between them by cross-attention based semantic matching operations. We evaluate the proposed DGMS model on two public code retrieval datasets with two representative programming languages (i.e., Java and Python). Experiment results demonstrate that DGMS significantly outperforms state-of-the-art baseline models by a large margin on both datasets. Moreover, our extensive ablation studies systematically investigate and illustrate the impact of each part of DGMS., Accepted by ACM Transactions on Knowledge Discovery from Data (ACM TKDD)

Cancer immunotherapy, particularly the inhibition of immune checkpoints with neutralizing antibodies, has revolutionized the treatment of some cancer patients. However, immune checkpoint blockade has not provided survival benefits to most patients with colorectal and ovarian cancers. Here this work reports the design of acid-sensitive core-shell nanoscale coordination polymer particles (NCP) comprising a carboplatin prodrug and an siRNA against PD-L1 (siPD-L1) in the core and digitoxin on the shell for tri-modality cancer therapy. Upon cellular uptake, NCP particles rapidly burst in acidic organelles to release carboplatin for apoptosis, digitoxin for inducing immunogenicity, and siPD-L1 for PD-L1 knockdown. With long blood circulation and high tumor accumulation, NCP particles efficiently suppress the growth and metastasis of syngeneic cancers through reactivating innate and adaptive immune responses. NCP particles thus provide a promising platform to synergistically combine chemotherapy and immunotherapy for the treatment of advanced and aggressive cancers.

Photocatalytic water splitting technology (PWST) enables the direct use of water as appealing "liquid hydrogen source" for transfer hydrogenation reactions. Currently, the development of PWST-based transfer hydrogenations is still in an embryonic stage. Previous reports generally centered on the rational utilization of the in situ generated H-source (electrons) for hydrogenations, in which photogenerated holes were quenched by sacrificial reagents. Herein, the fully-utilization of the liquid H-source and holes during water splitting is presented for photo-reductive N -alkylation of nitro-aromatic compounds. In this integrate system, H-species in situ generated from water splitting were designed for nitroarenes reduction to produce amines, while alkanols were oxidized by holes for cascade alkylating of anilines as well as the generated secondary amines. More than 50 examples achieved with a broad range scope validate the universal applicability of this mild and sustainable coupling approach. The synthetic utility of this protocol was further demonstrated by the synthesis of existing pharmaceuticals via selective N -alkylation of amines. This strategy based on the sustainable water splitting technology highlights a significant and promising route for selective synthesis of valuable N -alkylated fine chemicals and pharmaceuticals from nitroarenes and amines with water and alkanols.

Photothermal nanotheranostics, especially in the near infrared II (NIR-II) region, exhibits a great potential in precision and personalized medicine, owing to high tissue penetration of NIR-II light. NIR-II-photothermal nanoplatforms with high biocompatibility as well as high photothermal effect are urgently needed but rarely reported so far. Te nanomaterials possess high absorbance to NIR-II light but also exhibit high cytotoxicity, impeding their biomedical applications. In this work, the controllable incorporation of biocompatible Se into the lattice of Te nanostructures is proposed to intrinsically tune their inherent cytotoxicity and enhance their biocompatibility, developing TeSex nano-alloys as a new kind of theranostic nanoplatform. We have uncovered that the cytotoxicity of Te nanomaterials primarily derives from irreversible oxidation stress and intracellular imbalance of organization and energy, and can be eliminated by incorporating a moderate proportion of Se (x = 0.43). We have also discovered that the as-prepared TeSex nano-alloys have extraordinarily high NIR-II-photothermal conversion efficiency (77.2%), 64Cu coordination and computed tomography contrast capabilities, enabling high-efficacy multimodal photothermal/photoacoustic/positron emission tomography/computed tomography imaging-guided NIR-II-photothermal therapy of cancer. The proposed nano-alloying strategy provides a new route to improve the biocompatibility of biomedical nanoplatforms and endow them with versatile theranostic functions., A nano-alloying strategy is proposed to completely eliminate the toxicity of Te nanomaterials and simultaneously endow them with versatile theranostic functions by Se incorporation, realizing safe, precise and high-efficacy cancer treatment by multimodal PT/PA/CT/PET imaging-guided NIR-II-photothermal therapy.

Metal-assisted deoxyribozyme catalysis (DNAzyme) has been a general platform for constructing highly sensitive and selective detection sensors of metal ions. However, the "always on" mode of the traditional DNAzyme sensors greatly limits their application in the visual analysis of endogenous metal ions in a complex physiological microenvironment. To overcome this obstacle, a smart acid-switchable DNAzyme nanodevice is designed to control the DNAzyme activity in living cells and achieve simultaneous visualization of metal ions (Zn

Rotary disk centrifugal granulation is one of the most promising methods for molten slag recovery with lower power consumption, compact and coupling with a variety of waste heat devices easily. In this paper, high temperature analogue experiments were performed by four types of disks with molten aluminum as the working fluid. The particles characteristics which include particles size distribution, particles mean size and fiber mass fraction were studied. The results show that the majority of the particles size is populated in the range of 2.0 mm∼4.0 mm for all the ω and Q. Both theoretic and experimental analyses indicate that the ω has more impact on particles size than Q. The particles produced by curved-block disk and arc-edge disk configurations are more concentrated than the other two types of disks. Besides, the mean size of particles generated by curved-block disk is smaller. A simple correlation of dm for four types of disks is proposed, which agrees well with the experimental data (R2 = 0.9172). Meanwhile, when the Q is relative low, a lower ω can contribute to the reduction of produced fiber. The main conclusions drawn from this work will be helpful for future development of the high-temperature molten slag dry granulation systems. Keywords: Rotary disk, Molten slag, Ligament, Disk configuration, Particle size, Fiber fraction

Thermal energy storage can provide cost-effective benefits for different commercial fields because it allows heat recycling for use, such as in concentrated solar power plants or metallurgical and steel plants. Compared to traditional sensible and latent energy storage, thermochemical energy storage (TCES) offers a greater possibility for stable and efficient energy generation owing to high energy storage densities, long-term storage without heat loss, etc. The aim of this review was to provide a comprehensive insight into the current state of the art of research on several typical TCES systems at high operation temperatures (673–1273 K). These systems include hydride, metal oxide and organic systems. Each system is discussed in regard to two aspects: cycle life and heat storage performance. A concrete analysis of the current research and development provided in this review exposes that the main challenges of the aforementioned TCES systems rely on robust cycling stability of materials, reliable energy charging and discharging reactors, and a high-efficiency system for widespread commercialization. To bring the TCES system to market, more intensive studies about enhancement of cycle life from micro perspective, charging-discharging behavior in the reactors and development of system integration are still required.

This study presents a combined flat plate heat receiver (FPHR) for a solar power tower plant. Four flat plate heat pipes (FPHPs) as heat transfer units are homogeneously enclosed in a cavity of 150° constituting the combined FPHR. The start-up characteristics of the FPHP were experimentally investigated and quantitatively analysed. In addition, the isothermal performance, heat transfer performance, stability under severe working conditions, and effect of non-condensable gas on the thermal characteristics were experimentally investigated. The results show that the heat transfer limits are not encountered during the start-up process and the FPHP heated on one-side surface could successfully start up. The continuum flow regime established in the FPHP results in a good isothermal characteristic and makes the output power to synchronously respond to the input power without delay under a heat flux fluctuation condition. It is also found that the FPHP possesses potential to inhibit the hotspots under non-uniform heating condition. Besides, the accumulated non-condensable gas would lead to the reduction of the heat transfer performance. The main conclusions drawn from this work will be helpful for further development of the heat receivers used in solar power tower systems.

In this study, thermomagnetic convection in a porous cavity filled with paramagnetic fluid under a magnetic quadrupole field is studied using lattice Boltzmann method (LBM), and the corresponding entropy generation is analyzed. The horizontal walls of the porous enclosure are adiabatic, and the temperatures of the vertical walls are different. The effects of Darcy number (Da), porosity (e), and magnetic force number (γ) on the heat transfer, fluid flow, and entropy generation characteristics are investigated. The results show that, as the magnetic force number increases, the flow is strengthened. The local Nusselt numbers (Nuloc) increase and the average Bejan number (Beave) decreases under the non-gravitational condition. Nuloc change a little along the hot wall due to the lower value of Darcy number and higher values of Darcy number lead to higher buoyancy forces, Nuloc change significantly under the gravitational or non-gravitational condition. Moreover, the average Nusselt number (Nuave) and total entropy generation (Stotal) slightly decrease at first and thereafter increase when the magnetic force dominates the entire domain under the gravitational condition. It is also observed that, when e0 = e1 = 0.5, γ > 10, the average Nusselt number (Nuave) is significantly higher than in the other cases. Furthermore, the average Nusselt number (Nuave) reaches its minimum value when e0 = e1 = 0.5, γ = 4.

Most of the peak-to-average power ration (PAPR) reduction techniques, such as partial transmit sequence (PTS) algorithm and selective mapping algorithm, for conventional OFDM systems are not directly applied to filter bank multi-carrier with offset quadrature amplitude modulation (FBMC-OQAM) systems because of the overlapping structure of FBMC-OQAM signals. Furthermore, the complexity of the existing algorithms based on PTS is very high for the FBMC-OQAM systems. In this letter, we propose a low-complexity PTS based on hybrid processing algorithm (H-PTS) to reduce the PAPR values of FBMC-OQAM systems. Firstly, the proposed algorithm processes phase factors of the PTS by double-layer search. As a result, the complexity of searching the optimal phase factors is simplified. Moreover, an efficient algorithm of estimating the PAPR values of the FBMC-OQAM signals is employed to further reduce computational complexity. Simulation results show that, compared with the conventional PTS algorithm and segmental PTS algorithm, the proposed H-PTS algorithm could achieve a better PAPR reduction as well as lower computational complexity.

In this study, mechanical behaviours and deformation characteristics of Incoloy800H were investigated experimentally and analytically by small punch test at various temperatures. First, parameter sensitivity analysis was performed in order to estimate the influence of anisotropy, geometric dimensions, and temperature on material strengths. Then, the mechanical properties of Incoloy800H were investigated. A relatively simple yet reasonable relation between mechanical properties and specimen thickness was obtained. A new prediction model based on the deformation energy was established. Meanwhile, the inverse prediction model based on golden section search algorithm was proposed to estimate the yield strength and constitutive parameters on the basis of iterative calculations. On the other hand, a small punch deformation model was discussed. The hardness, strain, and stress triaxiality were analysed in order to estimate the evolution of plastic damage and deformation character. Finally, an economic, accurate mechanical behaviour evaluation system of Incoloy800H was established on the basis of the small punch test.

Experiment and finite element analysis were performed in this study to estimate the deformation characteristics of small punch creep test. Considering the disadvantage of the traditional model owing to numerous unknown parameters, ductility exhaustion model was introduced and used to estimate the damage and multiaxial creep evolution process. The results show that the evolution trends of creep deflection and strain with three stages are similar. During deformation, apparent damage localization is observed. The maximum strain and damage also occurred in the necking region due to the stress concentration. Thus, a critical damage value is proposed for service-exposed Cr5Mo in this study. In the primary creep stage, a tensile deformation is observed at the lower surface and a compression deformation is observed at the upper surface. Subsequently, the stress triaxiality tends to be constant in the second creep stage. Thus, steady creep parameters of small punch test can be used to replace traditional creep results in the creep properties analysis of in-service components. Finally, the multiaxial creep and damage evolution characteristics of the small punch creep specimen are obtained.

Reduced graphene oxide (RGO) and three-dimensional graphene networks (3DGNs) are adopted to improve the performance of thermal interface materials (TIMs). Therein, the 3DGNs provide a fast transport network for phonons, while the RGO plays as a bridge to enhance the phonon transport ability at the interface between the filler and matrix. The types of surface functional groups of the RGO are found to exert a remarkable influence on the resulting thermal performance; the carboxyl groups are found in the optimal selection to promote the transport process at the interface area because a strong chemical bond will form between the graphene basal plane and epoxy resin (ER) through this kind of group. The resulting thermal conductivity reaches 6.7 Wm−1 K−1 after optimizing the mass fraction and morphology of the filler, which is 3250% higher than that of the pristine ER. Moreover, the mechanical properties of these as-prepared TIMs are also detected, and the specimens by using the RGO(OOH) filler display the better performances.

The effects of laser shock processing (LSP) on stress corrosion cracking (SCC) behavior of AISI 304 stainless steel have been investigated using slow strain rate tests (SSRT) in acid chloride solution. Modifications of surface microstructure are characterized by scanning electron microscopy (SEM) and transmission electron microscope (TEM). Results show that LSP generate deformation twins and refined microstructures in the surface layer of AISI 304 stainless steel. Results of SSRT tests reveal that significant improvements in stress corrosion cracking (SCC) resistance are observed in acid chloride solution. These improvements have been attributed to surface microstructure changes and compressive residual stress induced by LSP. The results confirm that the application of LSP is of a practical option to improve SCC resistance of AISI 304 stainless steel.

The identification technique of output-only modal parameters is proposed for the large wind turbine tower under emergency stop. Compared with the response of regular operating conditions, the immediate tower structural response under emergency stop much more resembles a state of free vibration, which is more appropriate for the modal identification of the wind turbine tower. The vibration response is measured in the nacelle, which is easy to perform in the field modal test. The variational mode decomposition (VMD) is applied to decompose the vibration response into several band-limited intrinsic mode functions. The free responses of decomposed functions are extracted by applying the random decrement technique (RDT). Finally, the modal damping ratio and natural frequency are identified from each free modal response by using the Hilbert transform method. Simulations and a 1.5 MW wind turbine field modal test results verify the effectiveness of the proposed identification method. The main modal parameters of wind turbine, including weak modes, are effectively extracted by using output-only vibration responses under emergency stop. The modal parameter identification method is provided for the large wind turbine structure under the engineering condition.

The purpose of this study is to identify common properties, as well as specific features of Boom Clay with regard to its response to thermo-hydro-mechanical (THM) loading through laboratory experiments, particularly at temperatures significant for radioactive waste disposal . Triaxial shearing tests at various temperatures and various effective confining pressures were performed on Boom Clay samples under undrained conditions. Test results clearly show that under the same hydro-mechanical conditions, an increase in temperature can cause a decrease of shear strength of Boom Clay. This weakening in shear strength was further interpreted as the reduction in cohesion and elastic modulus , and also the pore pressure build-up due to temperature elevation. However, the temperature effect on the friction angle is not clear. The results obtained confirm the effect of the overconsolidation ratio (OCR) on the thermal volume changes (contraction or dilation). The laboratory test results presented here give additional information to gain more insight into the thermal influence of heat emitting wastes on the behavior of clay, to validate and calibrate models.