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High-performance magnetic graphene aerogels nanocomposites with low density and enhanced microwave absorption properties have been developed firstly by a two-step strategy combining hydrothermal reaction and in situ pyrolysis. TEM images indicate that ultra-fine Ni nanocrystals with a relatively uniform size of 8 nm are anchored to the graphene nanosheets. Meanwhile, the resulting magnetic graphene aerogels possess superparamagnetism. The GA@Ni hybrids of paraffin mixed with an ultra-low filling content (

Three-dimensional (3D) superlight (bulk density 0.027 g cm−3) N-doped magnetic graphene foams-supported Ni nanoparticles (MGF@Ni) have been constructed through in-situ simultaneous deposition of Ni on graphene sheets. The minimum reflection loss can reach −58.7 dB at 13.9 GHz and maximum effective absorption bandwidth (EAB) exceeding −10 dB is up to 5.8 GHz with a thickness of 2.3 mm. Interestingly, The 3D superlight N-doped MGF@Ni composites exhibit much better microwave absorption (MA) properties and corrosion resistance than that of 2D hybrids structure. After treatment in hydrochloric acid for one month, the MGF@Ni still keeps excellent MA performance, indicating MGF@Ni can be used as an efficient MA material in moisture environment. Results show that the enhanced MA properties originate from the special porous structures and synergistic loss mechanisms. Thus, our study indicate that the 3D porous graphene-based composites could be a potential candidate for lightweight and corrosion-resistant microwave absorption materials.

Understanding surface dynamics during epitaxial film growth is key to growing high-quality materials with controllable properties. X-ray photon correlation spectroscopy (XPCS) using coherent X-rays opens new opportunities for in situ observation of atomic-scale fluctuation dynamics during crystal growth. Here, we present XPCS measurements of two-dimensional island dynamics during homoepitaxial growth in the layer-by-layer mode. Analysis of the results using two-time correlations reveals a new phenomenon—a memory effect in the arrangement of islands formed on successive crystal layers. Simulations indicate that this persistence in the island arrangements arises from communication between islands on different layers via adatoms. With the worldwide advent of new coherent X-ray sources, the experimental and analysis methods pioneered here will enable broad application of XPCS to observe atomic-scale processes on surfaces. In situ measurements based on coherent X-ray spectroscopy are performed during the epitaxial growth of gallium nitride films, revealing a memory effect in the arrangement of islands formed on successive crystal layers.

Superior corrosion-resistant magnetic graphene foams decorated by Fe3O4 (MGF@Fe3O4) have been constructed through in-situ simultaneous deposition of ferrous ion (Fe2+) induced graphene oxide (GO). Their chemical composition, micro structure and properties were investigated in detail by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and vector network analyzer. These 3D porous MGF@Fe3O4 exhibit much better electromagnetic wave (EMW) absorption properties and corrosion resistance than 2D hybrid materials of magnetic metal particles and graphene sheets. The tunable EMW absorption performance can be easily implemented by tailoring their micro structure. Their minimum reflection loss (RLmin) value reaches −64.4 dB at 10.8 GHz and maximum effective absorption bandwidth (EAB) is up to 6.0 GHz from 12 GHz to 18 GHz with a matching thickness of 2.4 mm. After treatment in hydrochloric acid for 70 days, the acid-treated MGF@Fe3O4 still keeps excellent EMW absorption performance with their decrease of saturation magnetization lower than 16%.

High-performance, lightweight, and broadband microwave absorption materials have drawn significant research focus. Graphene aerogels may give us inspiration for the design of highly efficient synergistic microwave absorption materials due to their low density and adjustable dielectric properties along with tunable porosity, providing abundant active sites for supporting functional magnetic components. Herein, we report a facile chemical reduction-assembly route, followed by in situ thermal decomposition for the fabrication of super-hydrophobic magnetic graphene aerogels. Owing to the improved attenuation characteristic and the synergistic effect, the fabricated magnetic graphene aerogels exhibited greatly enhanced microwave absorption performance. The hybrids with only 4.25 wt% of functional fillers reached a minimum reflection loss value of −51.6 dB at 14.6 GHz with an absorber thickness of 2.4 mm and a maximum effective absorption bandwidth (EAB, below −10 dB) of 6.5 GHz. Compared with other reported graphene-based absorbers, such high-performance synergistic microwave absorbers that are super-hydrophobic and lightweight with low filler loading may rapidly increase the research interest for future practical applications.

Aldehyde dehydrogenase 2 (ALDH2) is a key enzyme for metabolism of reactive aldehydes, but its role during liver ischemia-reperfusion injury (IRI) remains unclear. In the present study, we investigated the effects of the ALDH2 activator, Alda-1, in liver IRI and elucidated the underlying mechanisms. Mice were pretreated with Alda-1 and subjected to a 90 min hepatic 70% ischemia model, and liver tissues or serum samples were collected at indicated time points after reperfusion. We demonstrated that Alda-1 pretreatment had a hepatoprotective role in liver IRI as evidenced by decreased liver necrotic areas, serum ALT/AST levels, and liver inflammatory responses. Mechanistically, Alda-1 treatment enhanced ALDH2 activity and subsequently reduced the accumulation of reactive aldehydes and toxic protein adducts, which result in decreased hepatocyte apoptosis and mitochondrial dysfunction. We further demonstrated that Alda-1 treatment could activate AMPK and autophagy and that AMPK activation was required for Alda-1-mediated autophagy enhancement. These findings collectively indicate that Alda-1-mediated ALDH2 activation could be a promising strategy to improve liver IRI by clearance of reactive aldehydes and enhancement of autophagy.

SiOx has emerged as an important alternative to silicon as the high capacity anode host to store lithium due to its smaller volume change upon lithiation. However, conventional synthesis methods generally require harsh reaction conditions, making its production in industrial scale much challenging. Herein, a safe, economical and scalable approach is developed for SiOx using highly abundant natural silica as starting material via a magnesio-mechanochemical reduction process induced by ball-milling. The as-prepared SiOx is intrinsically porous and comprised of mixed nano clusters of SiO2 and Si. Upon lithiation, SiO2 nano domains convert into lithium silicates and Li2O, which help to absorb Si volume expansion and participate in the formation of a stable solid electrolyte interface. Such synergistic effect leads to exceptional cycling stability up to 2000 cycles with 71.3% capacity retention under 4 A g−1. After blending with graphite, a high areal capacity of 2.64 mAh cm−2 demonstrates stable cycling of 89.7% retention over 200 cycles with an high initial Coulombic efficiency of 82.3%, implying the feasibility for practical applications. Structural and compositional characterizations reveal the involved chemistry and evolution mechanism of the formed solid electrolyte interface upon cycling, providing guidelines of designing future silicon-based materials for future Li-ion batteries.

Two-dimensional (2D) gallium nitride (GaN) has attracted a lot of attention due to its promising applications in photoelectric nano-devices. Most previous research studies have focused on polar c-plane 2D structures. Here, by employing first principles calculations, we systematically investigate the structural and electronic properties of non-polar m-plane GaN with different numbers of atomic layers. The results show a layer-dependent structure transition and electronic band variation for m-plane GaN. It is found that the monolayer keeps a planar hexagonal structure due to sp2 hybridization, whereas the multilayers are formed by stacking of buckled hexagonal monolayers with unsaturated coordination number at the surface sublayer and bulk-like inner layers. These discrepancies in the structure further induce an indirect to direct transition of the band gap type when the layer number reaches twelve. By carefully examining the relationship between the structure and electronic bandgap, we find that the indirect bandgap comes from the unsaturated surface with a planar like structure. On surface modification, saturation of the surface dangling bonds results in an indirect to direct band gap transition.

Donor-derived cell-free DNA (dd-cfDNA) has been of major interest recently as a non-invasive marker of graft injury, but has not yet been extensively tested in children. From May to September in 2019, a total of 76 pediatric patients receiving a liver graft were enrolled and there were 27 patients excluded. Ultimately plasma samples and matched liver specimens from 49 patients were successfully collected whenever rejection was suspected clinically. Dd-cfDNA were analyzed and then compared to biopsy. Of these, 11 (22.4%) patients were found to have rejection by biopsy. Dd-cfDNA levels were higher among patients with rejection compared to those with no rejection. In subgroup analysis, dd-cfDNA% among patients with rejection differed from those with EBV/CMV infection and DILI patients. Similarly, observations were available concerning dd-cfDNA (cp/mL). The AUC for dd-cfDNA% and dd-cfDNA (cp/mL) were 0.878, 0.841, respectively, both of which were higher than conventional LFTs. For rejection, dd-cfDNA% ≥ 28.7% yielded a sensitivity of 72.7%, specificity 94.7% and dd-cfDNA (cp/mL) ≥ 2076 cp/mL, yielded a sensitivity of 81.8%, specificity 81.9%. Of note, the dd-cfDNA distribution was significantly different between whole liver and LLS transplantation. In the setting of pediatric LTx, dd-cfDNA appears to be a sensitive biomarker indicating the presence of rejection.International Clinical Trails Registry Platform: ChiCTR1900022406.

Road traffic state prediction is a challenging task for urban traffic control and guidance due to the complicated spatial dependencies on the roadway network and the time-varying traffic flow data. In this work, a novel traffic flow prediction method named the graph convolutional recurrent neural network (GCRNN) is proposed to tackle this challenge. First, we address the problem on a graph and build the model with graph embedding techniques. Second, the proposed model employs the GCN model to learn the interactions of the roadways to capture the spatial dependence and uses the long short-term memory (LSTM) neural network (NN) to learn dynamic changes of traffic data to capture temporal dependence. An experiment is conducted on a Hangzhou transportation network with several typical intersections under the Sydney coordinated adaptive traffic system (SCATS), the results of which indicate that our model yields excellent performance in terms of different prediction error measures.

Accurate prediction traffic flow is one of the most critical works of the intelligent transport system (ITS). Accurate prediction results can provide better conditions for traffic guidance, management, and control. However, many existing traffic flow prediction methods are not particularly satisfactory in practical applications. In this paper, the stack auto-encoder (SAE) and long short-term memory network (LSTM) are combined for traffic flow prediction, in which SAE is used to obtain spatial features, while LSTM extracts temporal features of traffic flow. Then, the features from SAE and LSTM are combined to predict the traffic flow state. The real-time traffic flow data from Beijing is used to evaluate the performance of the proposed method. Experimental results show that the performance of the proposed method is better than some well-known prediction models.

Miscut surfaces of layered crystals can exhibit a stair-like sequence of terraces having periodic variation in their atomic structure. For hexagonal close-packed and related crystal structures with an {\alpha}{\beta}{\alpha}{\beta} stacking sequence, there have been long-standing questions regarding how the differences in adatom attachment kinetics at the steps separating the terraces affect the fractional coverage of {\alpha} vs. {\beta} termination during crystal growth. To demonstrate how surface X-ray scattering can help address these questions, we develop a general theory for the intensity distributions along crystal truncation rods (CTRs) for miscut surfaces with a combination of two terminations. We consider half-unit-cell-height steps, and variation of the coverages of the terraces above each step. Example calculations are presented for the GaN (0001) surface with various reconstructions. These show which CTR positions are most sensitive to the fractional coverage of the two terminations. We compare the CTR profiles for exactly oriented surfaces to those for vicinal surfaces having a small miscut angle, and investigate the circumstances under which the CTR profile for an exactly oriented surface is equal to the sum of the intensities of the corresponding family of CTRs for a miscut surface., Comment: 15 pages, 15 figures, Supplemental with 9 tables specifying coordinates of the 9 reconstructions examined. v2 has edits for clarity, addition of supplemental. (arXiv admin note: substantial text overlap with arXiv:2007.05083)

With the quick development of mobile Internet and communication technology, the use of Global Position System (GPS)-enabled devices is rapidly increasing, which facilitates the collection of huge volumes of movement data in the form of trajectories. Trajectory data contain a lot of commuters’ travel information, which offer convenience for researchers to study traffic problems and to mine urban commuters’ travel information. In this paper, we represent an urban commuters’ origin–destination (OD) hybrid prediction method based on big GPS data, which considers the temporal and spatial dependencies of OD volume data simultaneously. The regional division was performed based on a simple grid map, and the data for each grid can be obtained. Based on the grids, the OD pairs can be constructed and the network topology of OD pairs can be established. A graph convolutional network and a long short-term memory deep learning method were introduced to capture the temporal and spatial dependencies, respectively. In addition, an attention mechanism was used to learn the weights of input data. The numerical experiment was performed based on the GPS data in Chengdu, China, and some comparisons were made. The results demonstrated that the proposed hybrid OD prediction method was significant and the accuracy was reasonable.

The electrical transport properties of β-Ga

Background: Epidemiological studies have shown direct associations between type 2 diabetes and the risk of cancers. Accumulating evidence indicates that metformin is profoundly implicated in preventing tumor development. However, the exact mechanism underlying the anti-tumor effects of metformin in hepatocellular carcinoma (HCC) is still not clear. Methods: In this study, we investigated the effects of metformin on a mouse hepatocellular carcinoma (HCC) model and interleukin-22 (IL-22)-associated carcinogenesis in vitro. Results: We found that metformin significantly suppressed the incidence and tumor burden of HCC in the diethyl-nitrosamine (DEN)-induced HCC mouse model. As expected, expression of IL-22, an important factor involved in HCC progression, was markedly reduced by metformin. Treatment of HCC cells with metformin inhibited IL-22 induced cell proliferation, migration and invasion, and promoted cell apoptosis. Furthermore, ectopic expression of IL-22 makes HCC more aggressive whereas metformin largely compromised it in vitro and in vivo. Mechanistically, the whole transcriptome analysis and functional analysis revealed that Hippo signaling pathway was involved in the anti-tumor ability of metformin. Consistent with this, metformin directly activated Mst1/2, phosphorylated YAP1 in vitro. After blocking Hippo pathway by XMU-MP-1, the inhibitor of MST1/2, the inhibitory effects by metformin were dramatically attenuated as shown by in vitro study. Conclusions: Collectively, our findings illuminate a new regulatory mechanism, metformin activates Hippo signaling pathway to regulate IL-22 mediated HCC progression and provide new insights into its tumor-suppressive roles.

Lithium (Li) metal offers the highest projected energy density as a battery anode, however its extremely high reactivity induces dendrite growth and dead Li formation during repeated charge/discharge processes, resulting in both poor reversibility and catastrophic failure. Approaches reported to date often seek to suppress dendrites formation at the expense of energy density. Here, a strategy that resolves the above conflict and achieves a dendrite-free and long-term reversible Li metal anode is reported. A self-organized core-shell composite anode, comprising an outer sheath of lithiated liquid metal (Li

Lithium metal (Li) is appealing anode material that provides the highest capacity and the lowest electrochemical potential to lithium battery. However, the easy formation of lithium dendrites during the charge/discharge process largely hinders its application. Reported approaches to suppressing the dendrites formation often scarify the energy density of the battery. We report here an energy-enhancing strategy to achieve dendrite-free and long-term stable Li anode. A self-organized core-shell composite anode, comprising of an outer shell of lithiation liquid metal (LixLMy) and an inner layer of Li, is developed. The composite anode (LixLMy) processes high electrical and ionic conductivity, isolates Li from the electrolyte, and inhibits the growth of Li dendrites. Full cells made of composite anodes and commercially available NCM622 cathodes show ultrahigh energy density of 1500 Wh L–1 (483 Wh kg–1), and a high capacity retention per cycle of 99.95% over more than 500 cycles.

Burton-Cabrera-Frank (BCF) theory has proven to be a versatile framework to relate surface morphology and dynamics during crystal growth to the underlying mechanisms of adatom diffusion and attachment at steps. For an important class of crystal surfaces, including the basal planes of hexagonal close-packed and related systems, the steps in a sequence on a vicinal surface can exhibit properties that alternate from step to step. Here we develop BCF theory for such surfaces, relating observables such as alternating terrace widths as a function of growth conditions to the kinetic coefficients for adatom attachment at steps. We include the effects of step transparency and step-step repulsion. A general solution is obtained for the dynamics of the terrace widths, assuming quasi-steady-state adatom distributions on the terraces. An explicit simplified analytical solution is obtained under widely applicable approximations. From this we obtain expressions for the full-steady-state terrace fraction as a function of growth rate. Fits of the theoretical predictions to recent experimental determinations of the steady-state and dynamics of terrace fractions on GaN (0001) surfaces during organo-metallic vapor phase epitaxy give values of the kinetic coefficients for this system. In Appendices, we also connect a model for diffusion between kinks on steps to the model for diffusion between steps on terraces, which quantitatively relates step transparency to the kinetics of atom attachment at kinks, and consider limiting cases of diffusion-limited, attachment-limited, and mixed kinetics., Comment: 22 pages, 11 fig, 5 tables, 3 appendices, and Supplemental. For clarity, arXiv:2007.05083 was split into two distinct papers focusing on separate subtopics. This paper focuses on developing BCF theory in presence of non-identical step-edges. The other paper arXiv:2010.06166, on the scattering experiments whose interpretations required the extensions to BCF

Popcorn-like α-Fe2O3/3D graphene sponge (α-F/3DGS) composites have been successfully fabricated by a novel and facile two-step synthetic route combining template-assisted preparation and co-precipitation method for microwave absorption application. The results show that the popcorn-like α-Fe2O3 nanoparticles with an average diameter about 150–200 nm are uniformly encapsulated into the 3DGS exhibiting a porous microstructure with plenty of wrinkles. The composite displays the optimum microwave absorption properties with the minimum reflection loss (RLmin) of − 55.7 dB and the maximum effective microwave absorption bandwidth up to 4.42 GHz (12.30–16.72 GHz) when the thicknesses are merely 1.4 and 1.7 mm, respectively, exhibiting greatly enhanced microwave absorption properties compared to those of some 2D graphene-based microwave absorbing materials. The excellent microwave absorption properties are attributed to the synergistic effect between dielectric loss and magnetic loss mechanism and improvement for the impedance matching behavior. This study paves a way for designing and fabricating lightweight and high performance microwave absorption materials based on 3D graphene composites.

Silicon is a promising candidate for negative electrodes due to its high theoretical specific capacity (~ 3579 mA h g−1) and low lithiation potential (~ 0.40 V vs. Li). However, its practical applications in battery have been inhibited by the large volume change (~ 400%) induced by Li+-insertion into Si lattices. Here, we attempt to resolve this issue at a fundamental level, and report for the first time a novel liquid metal (LM)-mediated spontaneous repairing conductive-additive-free Si anode for Li-ion battery. The fluidity of LM ensures the eternal contact between Si and the conducting-network during its repeated electrochemical reactions. The as-prepared nano-composite of LM/Si leads to superior performances as characterized by high capacity utilization (2300 mA h g−1 at 500 mA g−1), long-term stability (968 mA h g−1 after 1500 charge-discharge cycles at 8 A g−1 with 81.3% retention), high rate capability (360 mA h g−1 at 20 A g−1, equivalence of 55 C, or full charge/discharge in 65 s), and, in particular, an extra-ordinarily high initial coulombic efficiency (95.92%), which is not only the highest reported for Si to the best of our knowledge, but also higher than the mature graphitic carbon anodes. The unique approach described in this work not only resolves the basic stress challenges faced by the promising but often problematic alloy-type materials; in broader context it also provides a universal inspiration to all electrode materials whose electric properties suffer from extreme mechanic upheavals induced by the electrochemical strains during the cell reactions.

The real-time and accurate prediction of road traffic states is the basis of information service for road traffic participants. An algorithm based on kernel K-nearest neighbors (kernel-KNN) is pres...

Two novel n ≈ 1 oligomeric bismaleimide monomers containing phthalide cardo and cyano groups (PCBMI and MCBMI) were designed and synthesized. The chemical structures of the monomers were confirmed from proton nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. Both BMIs exhibit good solubility in common organic solvents, enabling easy solution processing. Thermal curing behaviors of the monomers were investigated by differential scanning calorimetry, displaying broad exothermic peaks and large thermal processing windows. Furthermore, PCBMI/carbon fiber composites were prepared, with their thermal stability and mechanical properties investigated. Thermogravimetric analysis and test of interlaminar shear strength indicated that the thermal polymerization of cyano groups improved the heat resistance of BMI resins and enhanced the interfacial adhesion at higher temperature.

Carbon coated 50 nm Si NPs using alkali lignin (AL) or alkali lignin-derived azo polymer (AL-azo-NO2) as the low cost carbon precursors were synthesized. The Si@C composites were facilely prepared by evaporating solvent THF of the Si NPs/carbon precursor dispersion solutions followed by carbonization in nitrogen. The resulting Si@C composites showed a vesical-like morphology with integrated carbon coating on Si NPs. When used as the anode materials for Li-ion batteries, the nitrogen-doped carbon coated Si NPs (Si@C-AL-azo-NO2) stemmed from the use of AL-azo-NO2 showed superior electrochemical performance. As the results, Si@C-AL-azo-NO2 exhibited a high reversible specific capacity of 882 mAh/g at a current of 200 mA/g over 150 cycles and a high coulombic efficiency (99%), paving the way for promising application of lignin in high performance Si@C anode materials for Li-ion batteries.

In this work, poly (methyl vinyl ether-alt-maleic anhydride) abbreviated as P(MVE-MA) is employed as an ecofriendly electrolyte additive for stabilizing the interface of high-voltage layered Li-rich oxides (LLROs) without sacrificing performance. By the addition of 1 wt.% P(MVE-MA), the capacity retention of the Li-rich oxides at 250 mA g−1 for 300 cycles in the voltage range of 2.5–4.6 V is significantly improved from 38.6% to 77.2%, and the retained specific discharge capacity is as high as 159 mAh g−1. It is also found that the voltage decay and resistance increase during cycling are both suppressed noticeably because that the addition of P(MVE-MA) suppresses electrolyte degradation. Based on various characterizations, P(MVE-MA) mainly has two functions: one is to decrease the H2O and HF contents in the electrolyte due to the hygroscopic property of anhydride; and the other is to form thin and stable polymer cathode electrolyte interphase (CEI) on LLROs because of its strong adhesive ability to the cathode. Therefore, the side reactions and structural degradation of LLROs are mitigated distinctly, improving the electrochemical performance of LLROs. Considering its effective and ecofriendly performance for high-voltage LLROs, P(MVE-MA) is believed to be positive for other high-voltage cathode materials.

// Li-Feng Huang 1, * , Ping Wan 1, * , Dong-Wei Xu 1, * , Seogsong Jeong 1 , Ming-Xuan Feng 1 , Jian-Jun Zhang 1 and Qiang Xia 1 1 Department of Hepatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China * These authors have contributed equally to this work Correspondence to: Qiang Xia, email: xiaqiang@shsmu.edu.cn Keywords: nomogram; liver transplantation; hepatocellular carcinoma; prognosis; pulmonary metastasis Received: June 09, 2017 Accepted: September 21, 2017 Published: December 19, 2017 ABSTRACT A novel prognostic nomogram predicting post-transplant pulmonary metastasis was established with a primary cohort of 308 HCC patients who received liver transplantation between 2007 and 2011 at Ren Ji Hospital. The C-indexes for predicting pulmonary metastasis was 0.85. The calibration curves fitted well between the predicted and actual outcomes. The decision curve analysis indicated that our nomogram was the optimal decision-making strategy for PM prediction compared to Milan, University of California San Franscisco, and up-to-seven criteria. These results were further validated by data from 103 patients who underwent liver transplantation between 2011 and 2012 at the same institution. In conclusion, our nomogram could be used as an effective tool to predict PM after liver transplantation.

In this study, we report a simple and efficient two-step method consisting of water-in-oil (W/O) emulsion technique and subsequent annealing process for synthesizing the hollow reduced graphene oxide microspheres embedded with Ni nanoparticles (Air@rGO€Ni). The microspheres showed good electromagnetic properties because of the coexistence of magnetic loss and dielectric loss to microwaves. The minimum reflection loss (RLmin) value of Air@rGO€Ni microsphere reaches up to − 59.7 dB at 11.6 GHz with a thickness of 2.7 mm and an absorption bandwidth (lower than − 10 dB) is 4.8 GHz (9.4–14.2 GHz). Their resistance to chemical corrosion is amazingly, after treatment in hydrochloric acid for 5 days, the saturation magnetization (Ms) values of Air@rGO€Ni microsphere has fallen only six percentage points. More interestingly, we can easily controll the microwave absorbing properties of the microspheres by changing the ratio of the two components in the composites. The unique 3D structure and excellent electromagnetic match at the corresponding resonance peaks for dielectric and magnetic loss play an important role in improving microwave absorption property. Our study provides a good potential method for preparation of lightweight microwave absorbing materials.

Layered Li-rich oxides (LLROs) attract much attention due to their high capacities. However, the electrolyte decomposition and interfacial reactions especially driven by the catalysis effect of high-valance transition metal ions under high voltage cause severe performance recession, hindering their practical applications. Lithium fluoride (LiF) is an effective component in both cathode electrolyte interphase (CEI) and solid electrolyte interphase (SEI) films. In this work, lithium 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonimide (LiHFDF) is employed as a novel electrolyte additive for generating LiF-abundant interphase on LLRO. With the addition of LiHFDF, the capacity retention and Coulombic efficiency of the LLRO are improved noticeably. In addition, the interfacial side reactions and voltage decay issues are mitigated. Transmission electron microscopy and X-ray photoelectron spectroscopy measurements confirm that a compact and thin CEI film with more LiF is formed on the cathode surface for the cell using LiHFDF, which is beneficial for the enhancement of the electrochemical performance. Moreover, differential scanning calorimetry (DSC) investigations reveal that the LLRO electrode with LiHFDF has improved safety compared to that with the blank electrolyte. This work provides an effective LiF-generating electrolyte additive for high-voltage LLROs, which is believed to be positive for other high-voltage cathode materials.

Rational design of microstructure and components provides an effective method to address the challenge of developing advanced microwave absorption (MA) materials. In this work, combining the preparation of the precursors (SiO2@RF) for the deposition of Fe-glycerate (Fe-G) nanosheets and in situ pyrolysis process, followed by removal of the SiO2 template, the bird-nest-patterned C@Fe3O4 (BN-HDCF) composites with hollow dual-shell structure are rationally constructed to obtain superior MA performance. The results demonstrate that the eddy effect is suppressed by lamellar Fe3O4 shell, which benefits the entrance of electromagnetic waves (EMWs) and the cavity and groove of bowl like carbon core could boost the attenuation of EMWs. Importantly, due to the integration of the synergistic effects and the multiple polarization loss as well as the improved impedance matching, the as-prepared BN-HDCF composites demonstrate excellent MA performance in view of both minimum reflection loss (RLmin, −80 dB) and effective absorption bandwidth (EAB, below −10 dB, 6.1 GHz) with a thickness of 2.23 mm, covering the full X band with a thickness of 3.1 mm. Such impressive MA performance lights the way to the fabrication of the hierarchical structure of advanced absorbents.

Matrimony vine-like α-Fe2O3/reduced graphene oxide have been prepared by a facile method, followed by transformation into Fe3O4/reduced graphene oxide through annealing at 500 °C with the particle size and morphology significantly unchanged. By changing the mass ratio of iron oxide, the hybrids display optimal electromagnetic wave absorption performance. The maximum reflection loss value of α-Fe2O3/reduced graphene oxide is −46.6 dB at 5.6 GHz with a thickness of 4.0 mm and the highest effective absorption bandwidth reaches 4.9 GHz at the thickness of 1.8 mm. Interestingly, after annealing treatment, the hybrids in which α-Fe2O3 were converted into Fe3O4 exhibit an effective absorption bandwidth of 4.6 GHz and the maximum reflection loss value reaches −42.8 dB at 13.3 GHz with the thickness of only 1.8 mm, indicating Fe3O4/reduced graphene oxide can be used as an efficient electromagnetic wave absorbing material in high temperature and moisture environment, where Fe3O4 will be oxidized into α-Fe2O3. Results show the enhancement of electromagnetic wave absorption performance originates from synergistic effects of dielectric loss and magnetic loss. Our study provides a potential method for preparing environmental resistance electromagnetic wave absorbing materials.

The realization of road traffic prediction not only provides real-time and effective information for travelers, but also helps them select the optimal route to reduce travel time. Road traffic prediction offers traffic guidance for travelers and relieves traffic jams. In this paper, a real-time road traffic state prediction based on autoregressive integrated moving average (ARIMA) and the Kalman filter is proposed. First, an ARIMA model of road traffic data in a time series is built on the basis of historical road traffic data. Second, this ARIMA model is combined with the Kalman filter to construct a road traffic state prediction algorithm, which can acquire the state, measurement, and updating equations of the Kalman filter. Third, the optimal parameters of the algorithm are discussed on the basis of historical road traffic data. Finally, four road segments in Beijing are adopted for case studies. Experimental results show that the real-time road traffic state prediction based on ARIMA and the Kalman filter is feasible and can achieve high accuracy.

The accurate measurement of road traffic states can provide decision making for travelers and traffic managers. In this paper, an algorithm based on Kernel k-nearest neighbors (Kernel-KNN) matching of regional traffic attractors is presented to estimate road traffic states. First, the road traffic running states are divided into several different modes. The concept of the regional traffic attractors of the target link is put forward for effective matching. The representative road traffic state data are extracted to establish the reference sequences of road traffic running characteristics (RSRTRC). Then the sequence of regional traffic attractors is selected and its kernel function is constructed, with which the regional traffic attractors can be mapped into a high dimensional feature space. The reference and current sequences of regional traffic attractors are extracted and the Euclidean distances in the feature space between them are obtained. Finally, the road traffic states are estimated from weighted averages of the selected k road traffic states, which correspond to the k smallest Euclidean distances. Several typical links in Beijing are adopted for case studies. The final results of the experiments are presented, which prove that this road traffic state measurement approach based on Kernel-KNN matching of regional traffic attractors is feasible and can achieve a high accuracy.

Real-time and effective traffic flow prediction has become an important part of intelligent traffic system. It not only helps individuals plan optimal routes, but also benefits transportation managers in making reasonable traffic guidance. An attention-based long short-term memory (ALSTM) network is proposed and applied to predict traffic flow, which considers the temporal correlation and effects of information at each time point. First, a long short-term memory (LSTM) layer is used to capture the features from raw data. Second, the attention mechanism based on the softmax function is utilized to score for attention weights of traffic flow at different time instants. Finally, a regression layer is set at the top of the model for traffic flow prediction. The experiments results show that the proposed ALSTM method for traffic volume prediction is better than traditional models. Moreover, the visualization of attention weights can help us understand the prediction process.

Oxidative stress and inflammation are the most important pathogenic events in the development and progression of liver diseases. Nuclear erythroid 2-related factor 2 (Nrf2) is the master regulator of the cellular protection via induction of anti-inflammatory, antioxidant, and cyto-protective genes expression. Multiple studies have shown that activation or suppression of this transcriptional factor significantly affect progression of liver diseases. Comprehensive understanding the roles of Nrf2 activation/expression and the outcomes of its activators/inhibitors are indispensable for defining the mechanisms and therapeutic strategies against liver diseases. In this current review, we discussed recent advances in the function and principal mechanisms by regulating Nrf2 in liver diseases, including acute liver failure, hepatic ischemia–reperfusion injury (IRI), alcoholic liver disease (ALD), viral hepatitis, non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and hepatocellular carcinoma (HCC).

The thermoelectric properties of monolayer Tl 2 O are studied using first-principles calculations with all involved electrical and thermal transport properties calculated in the parameter-free frameworks. It is found that monolayer Tl 2 O possesses remarkably high thermoelectric figure of merit, z T, due to its ultralow lattice thermal conductivity and fairly good power factor. The room temperature z T can be as high as 1.4 and 1.2 for n- and p-type systems, respectively, whereas the maximum z T values can reach up to 5.3 and 4.2 as the temperature increases to 800 K. In addition, it is clarified that the mobilities of monolayer Tl 2 O are orders of magnitude smaller than previous estimation from simplified semiempirical models. The room temperature electron and hole mobilities are only about 56 and 11 cm 2 V − 1 s − 1, respectively, due to the heavy effective mass along with strong polar optical phonons coupling scattering. Nonetheless, the intrinsically ultrahigh z T from entire first-principles calculations stimulate that the further experimental verification and exploration for practical application are worthwhile.

Liver transplantation (LT) has been accepted as an effective therapy for hepatocellular carcinoma (HCC). The Milan criteria (MC) are widely used across the world to select LT candidates in HCC patients. However, the MC may be too strict because a substantial subset of patients who have HCC exceed the MC and who would benefit from LT may be unnecessarily excluded from the waiting list. In recent years, many extended criteria beyond the MC were raised, which were proved to be able to yield similar outcomes compared with those patients meeting the MC. Because the simple use of tumor size and number was insufficient to indicate HCC biological features and to predict the risk of tumor recurrence, some biological markers such as Alpha-fetoprotein, Des-Gamma-carboxy prothrombin and the neutrophil-to-lymphocyte ratio were useful in selecting LT candidates in HCC patients beyond the MC. For patients with advanced HCC, downstaging therapy is an effective way to reduce the tumor stage to fulfill the MC by using liver-directed therapy such as transarterial chemoembolization, radiofrequency ablation and percutaneous ethanol injection. This article reviews the recent advances in LT for HCC beyond the MC.

Lithium (Li) metal offers the highest projected energy density as a battery anode, however its extremely high reactivity induces dendrite growth and dead Li formation during repeated charge/discharge processes, resulting in both poor reversibility and catastrophic failure. Approaches reported to date often seek to suppress dendrites formation at the expense of energy density. Here, a strategy that resolves the above conflict and achieves a dendrite-free and long-term reversible Li metal anode is reported. A self-organized core-shell composite anode, comprising an outer sheath of lithiated liquid metal (Lix LMy ) and an inner layer of Li metal, is developed, which posesses high electrical and ionic conductivity, and physically separates Li from the electrolyte. The introduction of Lix LMy not only prevents dendrite formation, but also eliminates the use of copper as an inert substrate. Full cells made of such composite anodes and commercially available LiNi0.6 Co0.2 Mn0.2 O2 (NCM622 ) cathodes deliver ultrahigh energy density of 1500 Wh L-1 and 483 Wh kg-1 . The high capacity can be maintained for more than 500 cycles, with fading rate of less than 0.05% per cycle. Pairing with LiNi0.8 Co0.1 Mn0.1 O2 (NCM811 ) further raises the energy density to 1732 Wh L-1 and 514 Wh kg-1 .

The electrical transport properties of β-Ga2O3 are studied by first-principles calculations. The calculated intrinsic electron Hall mobilities agree well with experiments, with intrinsic Hall factor decreasing monotonically from 1.54 at 100 K to 1.14 at 800 K. The anisotropy of electron mobility is weak due to the almost isotropic electron effective mass, which also results in nearly isotropic Seebeck coefficient and electronic contribution to the thermal conductivity. The mode analysis of phonon scattering reveals that the optical phonon scattering is almost entirely determined by the long-range polar interactions, whereas the acoustic phonon scattering also plays an important role especially at low temperatures. The intrinsic electron mobility is significantly overestimated even above room temperature by only considering the polar optical phonon scattering, in contrast to previous predictions from fitting of phenomenological models.

Traffic state estimation is a crucial elemental function in Intelligent Transportation Systems (ITS). However, the collected traffic state data are often incomplete in the real world. In this paper, a novel deep learning framework is proposed to use information from adjacent links to estimate road traffic states. First, the representation of the road network is realized based on graph embedding (GE). Second, with this representation information, the generative adversarial network (GAN) is applied to generate the road traffic state information in real-time. Finally, two typical road networks in Caltrans District 7 and Seattle area are adopted as cases study. Experimental results indicate that the estimated road traffic state data of the detectors have higher accuracy than the data estimated by other models.

In polar compounds, Frohlich interaction plays an important role in electrical transport, and it is highly dependent on the dimensionality. In two-dimensional (2D) materials, Frohlich interaction cannot be correctly described by the analytical model available for bulk materials, which prevents the employment of the state-of-the-art first-principles calculation of electrical transport based on maximally localized Wannier functions interpolation. Recently, an approximate 2D Frohlich model with screened dielectric properties is proposed. Selecting the strong polar material of monolayer InSe, we examine the accuracy of this 2D Frohlich model by comparing the electron mobility calculated using this model with that based on direct density functional perturbation theory calculations of 2D Frohlich interaction. It is found that the 2D Frohlich model can guarantee fairly good results with an advantage of tremendously reduced computational consumption. Using this model, the modulation of the electron mobility of monolayer InSe by the dielectric environment is studied. The electron mobility can be drastically enhanced by coating high-dielectric materials, with room-temperature mobility improved from about 100 c m 2 V − 1 s − 1 to about 500 c m 2 V − 1 s − 1, due to the strong suppression of Frohlich scattering.

Grafting modification is an effective means to improve the interfacial bonding properties of fibre composites. In this study, a series of grafted poly(p-phenylene benzobisoxazole)-polyurethane (PBO-PU) fibres were fabricated using online continuous air plasma treatment. The resulting PBO-PU fibres were characterised using attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy. The results of interlaminar shear strength (ILSS) tests show that all the PBO-PU fibre reinforced epoxy resin composites exhibited superior interfacial adhesion properties compared with the untreated composites, and the ILSS reached 48.0 MPa, indicating an improvement of 99.49 %. Our findings demonstrate that plasma grafting provides the possibility to realise industrial production of PBO/epoxy composites exhibiting high interlaminar shear strengths.

The poor adhesion between polybenzoxazole (PBO) fibre and resin can lead to limitations in the composites formed for practical applications. Air atmospheric dielectric barrier discharge was applied to graft multi-carboxyl polyurethane (C-PU) designed and synthesised by introducing polar functional groups on the PBO fibre surface to enhance interfacial bonding. The effects of power density and C-PU concentration on the composites formed, as well as the surface ageing time of post-grafted fibres, were studied. The surface chemical composition and morphologies of the grafted PBO fibre were characterised by X-ray photoelectron spectroscopy, attenuated total reflection Fourier transformed infrared spectroscopy, and scanning electron microscopy. Mechanical performance testing showed that the interlaminar shear strength of the PBO/BMI composites is significantly improved and that the fibre surface activity can be maintained for up to 15 days. More importantly, the transition temperature of the as-prepared C-PU graft matched with the curing temperature of the BMI resin.