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The method proposed in this letter for synthetic aperture radar (SAR) image classification has two main stages. In the first stage, a convolutional neural network (CNN) is trained for normal SAR image classification task. After training, the sample features can be obtained by extracting the output of middle layer in the forward propagation process of CNN. In the second stage, an end-to-end metric network is trained to measure the relations between sample features. The method proposed in this letter is tested with some of the larger targets in OpenSARShip data set which is collected from Sentinel-1 satellite, and it is also tested with the MSTAR data set which is created by the U.S. Air Force Laboratory. The experimental results show that our method can get a higher recognition accuracy than normal CNN structure.

The objective of this work is to propose a machine-learning assisted multi-objective optimization protocol to design and optimize alkali–surfactant–polymer flooding processes in the presence of multiple technical and economic objective functions. Several universal multi-layer neural networks are trained, and they act as universal surrogate models of high-fidelity numerical simulator to evaluate the objective functions involved in the optimization workflow. The HLD-NAC equation is employed to model the microemulsion phase behavior of the crude oil/brine/surfactant system with the presence of alkali agents. The validity of the expert systems is confirmed via extensive blind testing applications with error margins of 9%, which includes the predictions of fluid production and pressure responses. A multi-objective optimization workflow is structured by coupling the expert systems with particle swarm optimizer, which employs Pareto optimum theory to carry comprehensive ASP injection assessments considering various technical and economic objective functions. Moreover, the proposed workflow enables the decision makers to comprehend the project risks by taking the inherent uncertainties from crude oil market into accounts. The robustness of the optimization protocol is verified by introducing a synthetic field case study, which validates the competence of optimizing ASP injection design considering project net present value as an objective function. A series of Pareto front solutions are generated when more objective functions such as chemical efficacies and water cut reductions are included. Subsequently, the workflow evaluates the project economic uncertainties from the fluctuation of oil price, which helps the decision makers investigate the project risks from technical and economic perspectives.

Modulating the surface electronic properties of the 2D MXenes is of significant importance to boost their hydrogen evolution reaction (HER) activity. Herein, a series of transition metal adatoms are employed to tune the surface electronic properties of Cr-based MXenes with oxygen function group for realizing impressive HER performance. The Results show that the charge of surface oxygen atoms, which is affected by both the host metal atoms and the adsorbed transition metal atoms, play critical role in the adsorption strength of hydrogen. The optimal performance is achieved by depositing Cr atom on the Cr2TiC2O2 MXene, which results in the adsorption free energy of hydrogen very close to zero (0.03 eV). Systematic electronic structure analyses confirm that the charge transfer from the adsorbed transition metals to the neighboring surface oxygen atoms could tune the orbital occupancy of oxygen and their adsorption strength to hydrogen atom and therefore the HER activity. These findings and concepts may be useful for the design of advanced MXene-based HER catalysts.

Gate reliability and its degradation mechanism were studied for the normally off high-electron-mobility transistors (HEMTs) with regrown p-GaN gate and AlN/SiN x stack passivation. Through comparing the forward leakage current in two designed structures, the conduction mechanism is determined to be Fowler-Nordheim tunneling whose current is independent of temperature when the Pd/p-GaN Schottky junction is under high electric field. Even for the regrown p-GaN gates, this Schottky junction fails at first, resulting in an abrupt increase in gate current. The maximum gate operation voltage with a failure rate of 1% for 10-year lifetime is estimated to be about 6.87 and 6.07 V at room temperature by adopting power law and exponential law as extrapolation fitting, respectively. Degradation process monitoring reveals that the net acceptor concentration $N_{\mathrm {A}}$ extracted through $C$ – $V$ fitting presents an apparent decreasing trend from $3.8\times 10^{19}$ to $1.1\times 10^{19}$ cm−3 with the stress time increased from 30 to 2600 s. This is assumed to be related with the defects generation in the Schottky depletion region under high tunneling current and high electric field. These analyses show the feasibility of the normally off HEMTs with a regrown p-GaN gate and AlN/SiN x stack passivation for practical applications, giving directions for further improving the gate breakdown voltage and lifetime.

In this study, 84 scenes Sentinel-1A satellite datasets from October 2016 to September 2019 were used to analyze surface deformation in East Dongting Lake, China, by employing the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) method. The data are divided into two seasons, i.e., the flood and dry seasons. It was suggested that the surface deformation is related to the distribution of the river network and water flow activities. During the dry season, the water flow is active along the internal river, scouring the surrounding soil. During the flood season, the water flow basically occurs around the external drainage network. By qualitatively comparing surface deformation and precipitation changes as well as changes in soil erosion, it is found that the deformation was highly related to soil erosion and seasonal precipitation. The precipitation in the flood period is heavy than that in the dry season. Therefore, the runoff with amount silt will scour the soil in the passing area, resulting obvious surface deformation. During the dry period, surface deformation is smaller due to the less precipitation.

Multi-component porous Si-SiOx (pSi) consisting of Si, SiO and SiO2 was formed by the pretreatment of SiO at 950 °C for 3 h in an inert atmosphere (He) using a disproportionation reaction. Hybrids of pSi and carbon nanofibers (pSi-CNFs) with a core-shell structure were prepared by catalytic chemical vapor deposition (CVD) using Fe-Ni species as the catalyst and a mixture of CO/H2/C2H4 (volumetric ratio 3:1:1) as the reactant for 0.5, 1 and 2 h, and were characterized by SEM, TEM, EDS, XRD, Raman spectroscopy and XPS. Results indicate that the pSi-CNF particle sizes are 5−20 μ m with the diameters of the CNFs being 5−40 nm. The CNFs are uniformly coated on the surface of the pSi to form a core-shell structure. Electrochemical performance testing shows that the reversible capacity of the pSi-CNF (0.5 h) remains at 1 411 mAh.g−1 and the capacity retention is 74% after 100 cycles at a current density of 0.2 A.g−1. The reversible capacity remains at 735 mAh.g−1 at a current density of 1 A g−1 after 300 cycles with a capacity retention of 86%. In the pSi, Si and SiO provide the electrochemical reversible capacity. The core-shell structure with the CNF coating effectively improves the conductivity of the composites, and also inhibits the volume expansion of silicon to maintain the integrity of the core shell structure.

Nanoparticle-stabilized foam has aroused people’s attention due to its wide applications in oil fields. Understanding the dynamic surface properties of nanoparticles and their retention in reservoi...

Solid-state electrolytes (SSEs) have attracted considerable attention as an alternative for liquid electrolytes to improve safety and durability. Sodium Super Ionic CONductor (NASICON)-type SSEs, typically Na3Zr2Si2PO12, have shown great promise because of their high ionic conductivity and low thermal expansivity. Doping La into the NASICON structure can further elevate the ionic conductivity by an order of magnitude to several mS/cm. However, the underlying mechanism of ionic transportation enhancement has not yet been fully disclosed. Herein, we fabricate a series of Na3+xLaxZr2-xSi2PO12 (0 ≤ x ≤ 0.5) SSEs. The electronic and local structures of constituent elements are studied via synchrotron-based X-ray absorption spectroscopy, and the ionic dynamics and Na-ion conduction mechanism are investigated by solid-state nuclear magnetic resonance spectroscopy. The results prove that La3+ ions exist in the form of phosphate impurities such as Na3La(PO4)2 instead of occupying the Zr4+ site. As a result, the increased Si/P ratio in the NASICON phase, accompanied by an increase in the sodium ion occupancy, makes a major contribution to the enhancement of ionic conductivity. The spin-lattice relaxation time study confirms the accelerated Na+ motions in the altered NASICON phase. Modifications on the Si/P composition can be a promising strategy to enhance the ionic conductivity of NASICON.

It has been proven that the future of energy demands for human society is related to clean energy sources such as solar energy. On the other hand, fuel cell technology converts the chemical energy of a fuel into electrical energy. Meanwhile, the polygeneration system based on (semi) renewable energy can be a viable alternative to conventional fuel-based systems. However, examining their performance for widespread implementation requires further and powerful studies. The aim of the present work is to evaluate the performance of the polygeneration energy system to produce electricity, heat, hydrogen and cool. The novel hybrid power system consists of the 10 kWel phosphoric acid fuel cell, linear Fresnel solar reflector (LFR), Organic Rankine Cycle (ORC) and Stirling engine (SE). In the novel energy conversion process proposed, the fuel cell generates electricity and heat, and its waste heat is used to generate additional electricity in the SE. The fuel and oxidant required by the fuel cell are supplied by an electrolyzer that is powered by an ORC system. A solar thermal collector provides the duty required by the evaporator of ORC system. The effect of key parameters such as current density, solar radiation and flow rate of hydrogen on the system energy and exergy performance is also investigated. To evaluate the performance of the LFR system the climatic conditions of Tehran (in Iran) and Beijing (in China) are considered. Results revealed that, the SE and ORC system separately generates 1.48 and 26.54 kW of electricity, respectively. Furthermore, the electrolyzer consumes 23.36 kW of electric power and 3.64 kW of cooling is produced by the chiller. In addition, the energy efficiency and total exergy destruction of the proposed system are 71.32 % and 57.94 kW, respectively.

Cathode interface instability is a significant obstacle for the practical application of sulfide-based all-solid-state lithium-ion batteries (ASSLIBs). However, the origin of cathode interface degradation is lack of comprehensive understanding. In this paper, X-ray characterizations combined with electrochemical analysis are adopted to investigate the underlying degradation mechanism at cathode interface. The results indicate that residual lithium compounds on the surface of Ni-rich LiNi0.8Mn0.1Co0.1O2 (NMC811) are the main reason that triggering the oxidation of sulfide solid-state electrolytes (SSEs), therefore inducing severe side-reactions at cathode interface and structural degradation of NMC811. The degradation of the cathode interface can be significantly suppressed when the cathode surface is cleaned. As a result, the surface cleaned NMC811 without coating demonstrates significantly improved electrochemical performance in both Li5.5PS4.5Cl1.5 (LPSCl) and Li10GeP2S12 (LGPS) based ASSLIBs, proving the universal application of this strategy.

Assessing the impacts of future land use scenarios on ecosystem services can provide theoretical basis and reference for sustainable land use management. This study combined scenario analysis and quantitative assessment to monitor land use and ecosystem services in the intensive agricultural area of Qixia city, North China under three different scenarios, i.e. natural development, farmland and orchard to forest and farmland to forest and orchard, by using the GeoSoS-FLUS and the InVEST models. The integrated land use change impact index (ILUCII) and the single land use change impact index (SLUCII) were proposed to quantitatively depict the impact of different land use change scenarios on ecosystem services. The results demonstrated that: (1) Under the three land use scenarios, forest, farmland and orchard show different change patterns. Slope influences the soil and water conservation services, land use in greater than 15° slope section occupied more soil and water conservation services than 12–15° section and less than 12° section. In the same slope section, forest had the most soil and water conservation services compared with orchard and farmland. (2) The effects of different land use conversion on soil conservation services per study grid (90*90 m) in less than 12° slope section showed an order of farmland-forest > orchard-forest > farmland-orchard. In more than 12° slope section, the order is farmland-forest > farmland-orchard > orchard-forest. The effects of land use conversion on water conservation services per grid is farmland - forest > orchard - forest > farmland-orchard. (3) The total ILUCII on ecosystem services found that farmland and orchard to forest scenario (16517.54) > farmland to forest and orchard scenario (13074.12) > natural development scenario (−4975.02). The mean ILUCII on ecosystem services showed that farmland to forest and orchard scenario (0.63) > farmland and orchard to forest scenario (0.53) > natural development scenario (−0.11). The mean SLUCII on ecosystem services found that greater than 15° farmland to forest (0.89) > 12–15°farmland to orchard (0.49) > greater than 15°orchard to forest (0.34).

To reveal the underlying relationships between Chinese medicine (CM) syndromes and ultrafiltration (UF) in the treatment of heart failure based on a metabonomic approach. Seventeen acute decompensated heart failure (ADHF) patients were enrolled, and their CM syndromes before and after UF were collected. In addition, their venous plasma collected before and after UF was used for liquid chromatographmass spectrometer-based metabonomic analysis. Both reversed phase liquid chromatography and hydrophilic interaction liquid chromatography were used to analyze the plasma samples. Partial least-squares to latent structure-discriminant analyses were used for data analysis. An obvious difference was observed pre- and post-treatment. A total of 17 potential biomarkers associating with alterd syndromes with UF including hypoxanthine, 1-methylhistidine, phytosphingosine, O-decanoyl-R-carnitine, etc. were screened out, showing a significant change after UF. The major adjusted metabolic pathways were purine metabolism, histidine metabolism, leucine and isoleucine metabolism, arginine and proline metabolism, carnitine shuttle, sphingolipid metabolism and phospholipid metabolism. Metabonomic approach is a useful tool to identify potential biomarkers of altered syndromes link to UF and could provide a theoretical basis for further research on the therapeutic mechanism of UF combined with CM.

Nanomaterials, as carriers of small molecular drugs, have been a focal point in recent years. In this work, a carbazolyl functionalized metal-organic framework, UiO-67-CDC, was successfully synthesized employing the ligand 9H-carbazole-2,7-dicarboxylic acid (9H-2,7-CDC). Postsynthetic approaches targeted the cationization and replacement of the Lewis base carbazole site with two methyl groups, resulting in the positively charged skeleton, which has proven to be a promising carrier for the anticancer drug 5-fluorouracil (5-Fu). The prepared cationic framework UiO-67-CDC-(CH3)2 showed moderately high surface area, hierarchical pore structures, and positive surface characteristics, which effectively and selectivity encapsulated the electron-rich 5-Fu molecules through electrostatic attraction, with a relatively high loading of up to 56.5% (wt%). The drug delivery in simulated blood environment (pH = 7.4) exhibited a more effective release, demonstrating a physiological pH-responsive sustained release. Significantly, the electron-deficient Zr-MOF itself, as a kind of high-sensitivity fluorescence detector, has a unique fluorescence "turn-on" effect with 5-Fu. These results pave the way towards designing surface-engineered MOF materials of interest in drug delivery and fluorescent sensing applications.

Single-atom catalysts (SACs) have attracted much interest for electrochemical CO2 reduction because of their high metal utilization and excellent catalytic activity. However, the practical applications of SACs were restricted by the low production yield. Herein, we developed a facile synthetic strategy for fabricating metal-nitrogen-carbon nanotube (M-N-CNT, M = Ni, Co, Cu, Fe, Mn, Zn, Pt, or Ru) SACs at scale (>1 g) by direct pyrolysis of metal cations, phenanthroline and CNTs at high temperature. The pyrolysis leads to forming coordinated Ni-N active sites anchored on CNTs. The prepared Ni-N-CNT catalyst with a remarkable Ni loading of 2 wt% determined by ICP exhibits the highest activity for CO2-to-CO conversion with a high faradaic efficiency of 94% and excellent stability. Aberration-corrected high-angle annular dark-field transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray absorption spectroscopy confirm the presence of isolated Ni single atoms in Ni-N-CNT, which act as the active centers for CO2 electroreduction while the CNT support offers fast pathways for electron and mass transports. This work laid foundations for future practical applications in CO2 electroreduction, oxygen reduction reactions, water splitting and nitrogen reduction and beyond.

BaSO4 nanoparticles as important functional materials have attracted considerable research interests, due to their X-rays barrier and absorption properties. However, most of BaSO4 nanoparticles prepared by traditional technology are nanopowders with broad size distribution and poor dispersibility, which may greatly limit their applications. To the best of our knowledge, the synthesis of transparent BaSO4 nanodispersions was rarely reported. Here, we firstly present a novel and efficient method to prepare transparent and stable BaSO4 nanodispersions with a relatively small particle size around 10 to 17 nm using a precipitation method in a rotating packed bed (RPB), followed by a modification treatment using stearic acid. Compared with the BaSO4 prepared in a traditional stirred tank, the product prepared using an RPB has much smaller particle size and narrower size distribution. More importantly, by using RPB, the reaction time can be significantly decreased from 20 min to 18 s. Furthermore, the transparent BaSO4-polyvinyl butyral nanocomposite films with good X-ray shielding performance can be easily fabricated. We believe that the stable BaSO4 nanodispersions may have a wide range of applications for transparent composite materials and coatings with X-ray shielding performance for future research.

Emerging scientific workflows running at extreme scale are composed of multiple applications that interact and exchange data at runtime. While staging-based approaches, e.g. in-situ/in-transit processing, are promising, dynamic behaviors (e.g. data volumes and distributions) in coupled applications and varying resource constraints at runtime make the efficient use of these techniques challenging. Addressing these challenges requires fundamental changes in the way that workflows are executed at runtime. Specifically, it is required to monitor the operating environment and running applications, and then adapt and tune the application behaviors and resource allocations at runtime while meeting the data management requirements and constraints. In this paper, we propose a policy-based autonomic data management (ADM) approach that can adaptively respond at runtime to dynamic data management requirements. We first formulate the schematic abstraction of this ADM approach including its conceptual model and system elements. Then, we explore the realization of ADM runtime and demonstrate how to achieve adaptations in a cross-layer manner with pre-defined autonomic policies. We also prototype our ADM approach and evaluate its performance on the Intrepid IBM-BlueGene and Titan Cray-XK7 systems using Chombo-based AMR applications and a visualization application. The experimental results demonstrate its effectiveness in meeting user defined objectives and accelerating overall scientific discovery.

The development of high-performance sulfide electrolyte-based all-solid-state lithium-ion batteries (ASSLIBs) has been inhibited by problematic ionic transport and side reactions at the cathode interface, and their success is dependent on the functionalized interface upon charging and discharging. Despite recent progresses, it has proven challenging to design a favorable interface that can suppress the side reactions and enable smooth motion of Li+ ions. Herein, a favorable Zr-based cathode interface is elaborately manipulated by the atomic layer deposition (ALD) for sulfide-based ASSLIBs. Flexile control over the Li sub-cycle during the preparation process is demonstrated to be crucial for achieving a robust cathode interface with a desirable Li+ ionic conductivity. The ASSLIBs equipped with this functional interface exhibit excellent cycling stability and rate capability at room temperature (RT). Various electrochemical and spectroscopic characterizations reveal that the ionic conductive interface can significantly limit side reactions and induce a low polarization of the (de)intercalation toward cathode materials. The interfacial manipulation regarding ionic conductivity and structure realized by ALD provides a new strategy to achieve high-performance ASSLIBs.

Li–O2 battery is a promising rechargeable battery candidate due to its ultrahigh theoretical energy density. However, safety issues and poor cycling stability of Li–O2 batteries caused by the forma...

This present work is the first investigation on the laser welding of the novel hot-stamped steel with 2000MPa (HSS2000). Softening was present in mixed-grain HAZ and tempered zone, due to martensite transformation, precipitated carbons and partial recovery of martensite lath. Tensile strength of welded joint was ∼1500 MPa, 80% of base metal, due to the presence of soften zone. However, the softening cannot be eliminated with decreasing laser heat input but it did not influence the tensile strength of welded joints. Thus, the laser welding of HSS2000 is acceptable in the heat input range of 67∼86 J/mm because the tensile strength can reach 1500 MPa, which is superior to other ultra-high strength steels at present. HSS2000 has a potential application in the automotive manufactures in the future.

Global or quasi-global digital elevation model (DEM) datasets provide three-dimensional information on terrain surface, and they have been extremely useful in geoscience research and applications. However, the wide application of DEMs is constrained by differences in the means of observation and processing, and in the resolution of global public DEM datasets. An adaptive regularization variation model based on sparse representation is proposed to generate a high-quality DEM by fusing multi-source DEMs. First, since the sparse representation method has a powerful capability to reconstruct information based on a small amount of information, prior terrain information is extracted from the 90-m TanDEM-X DEM (TDM90) with unprecedented global accuracy using a so-called sparse representation. In this step, an intermediate DEM (termed STDM30) is first extracted from TDM90 that preserves maximum terrain details, thereby preventing the degradation of the DEM accuracy induced by resampling. Then, the designed regularization framework based on terrain slope can constrain the DEM spatial information during fusing multiple datasets. STDM30 is combined with the ALOS Global Digital Surface Model “ALOS World 3D 30 m” (AW3D30) and the 1 arc-second Shuttle Radar Topography Mission Digital Elevation Model (SRTM1) through the designed adaptive regularization variation model to generate a high-accuracy DEM product with a resolution of 30 m. The results of the proposed method were verified by a model-to-model comparison in South Dakota as well as by validation against GPS benchmarks in Southern California. The RMSE, MAE, and SD of the fused DEM are all lower than those of the existing public DEMs, especially in terms of removing topographic noise and refining terrain details. The GPS validation showed that the fused DEM has an RMSE of 3.04 m, with the highest absolute accuracy among the four studied DEMs, and its errors are almost equal to the normal distribution. These experimental results confirm that the multi-scale and multi-source DEM fusion strategy combining sparse representation and an adaptive regularization variation model can utilize existing public datasets and effectively improve the quality of global DEM products.

In the fifth generation (5G) networks, isolated logical slices are formed by the same infrastructure, and spectrum resource. In the coverage regions of the sharing access points (APs), device to device (D2D) communication can occur among different slices, i.e., one mobile terminal (MT) acts as a D2D relay for another MT serving by a different slice. Since the slices, and the MTs are selfish who will not help others voluntarily, this paper proposes a two-layered incentive scheme to stimulate cooperation. To achieve this, two resource allocating problems of the proposed incentive scheme are formulated which introducing the slices,’ and the MTs’ cooperative activities, thus more resources will be allocated to the cooperative slices, and MTs as reward. Since the slices,’ and the MTs’ instantaneous resource allocations can not be obtained by the two optimal problems, the incentive scheduling algorithms of the slices, and the MTs are designed. Finally, we define the isolation indexes to evaluate slice isolation when carrying out cooperation. By simulating, it is proved that the proposed incentive scheme can stimulate cooperation efficiently, since the throughputs of the cooperative slices, and MTs are both improved. And the proposed incentive scheme is helpful for the slices, and the MTs to meet the statistical service quality requirements, and brings the bad effect to the instantaneous service quality requirements.

Multitasking evolutionary algorithm (MTEA), which solves multiple optimization tasks simultaneously in a single run, has received considerable attention in the community of evolutionary computation, and several algorithms have been proposed in the literature. Unfortunately, knowledge transfer between constituent tasks may cause negative effect on algorithm performance, especially when the optimal solutions of all tasks are in different locations of the unified search space. To address this issue, an effective variable transformation strategy and the corresponding inverse transformation are proposed in multitasking optimization scenario. After using variable transformation strategy, the estimated optimal solutions of all tasks are both near the center point of the unified search space. More importantly, this strategy can enhance the task similarity, and then the effectiveness of knowledge transfer will probably be positive in this case, which can help us to improve the algorithm performance. Keeping this in mind, a multitasking evolutionary algorithm (named MTDE-VT) is realized as an instance by embedding the proposed variable transformation strategy into multitasking differential evolution. In MTDE-VT, the individuals in the original population are first transformed into new locations by the variable transformation strategy. Once the offspring is generated in the transformed unified search space, it must be transformed back to the original unified search space. The statistical analysis of experimental results on some multitasking optimization benchmark problems illustrates the superiority of the proposed MTDE-VT algorithm in terms of solution accuracy and robustness. Furthermore, the basic principle and the good parameter combination are also provided based on massive simulated data.

The setting of the alarm threshold is critical for photovoltaic (PV) fault diagnosis systems. In practice the prior knowledge is generally used to set the alarm threshold with a fixed value. However, the output of a PV array varies with the external environment, and the distribution of the array electrical parameters has obvious volatility and nonlinearity. Therefore, it is difficult to judge the abnormal state of the PV system under all working conditions by setting the alarm threshold to a fixed value. To solve this problem, this paper proposes a new method for setting the alarm threshold of a PV array output. In this paper, the dynamic variation of the PV array output under different environmental conditions is analyzed, quantile method is adopted to set the threshold of the PV array output, and the dynamic threshold is used to realize the abnormal state judgment of the PV array. Finally, the effectiveness of the proposed method is demonstrated by experimental verification in the actual PV system. The proposed method is simple in calculation and can adapt to dynamic changes in the PV output, which provides a new method for the threshold setting of PV system fault diagnosis systems.

In recent years, the water quality of lakes has been deteriorating, and the water eutrophication phenomenon is particularly serious. Therefore, it is of great significance to evaluate the water eutrophication of lakes accurately to achieve water protection management. Numerous mechanistic or data-driven methods have been proposed to perform evaluations of the water eutrophication status. However, issues with these methods must still be solved, such as the use of unreasonable thresholds for the water eutrophication levels based on arbitrary numerical values and inaccurate threshold intervals in the water eutrophication evaluation criteria. To solve these problems, an integrated water eutrophication evaluation algorithm is proposed in this study. An evaluation model based on a multidimensional trapezoidal cloud model is first established, where numerical intervals are employed to characterize the thresholds of different water eutrophication levels instead of arbitrary numerical values. The Atanassov’s interval-value intuition language numbers are introduced to identify the model parameters, which are calculated based on the data of a specific lake rather than relying on inaccurate classification threshold intervals. Finally, the water quality data of Qionghai were used to validate the proposed method. Experimental results showed that this method can provide a more accurate and reasonable evaluation of water eutrophication compared with other methods.

This article investigates a low carbon-oriented berth allocation and quay crane assignment problem considering vessels’ uncertain arrival time and loading/unloading workload for vessels. A two-stag...

Highly efficient electrically injected light source on exact Si(100) has been the bottleneck of Si photonics for decades. InGaN-based laser with a direct bandgap may serve as an efficient on-chip l...

It has been reported that the biological functions of enzymes could be altered when they are encapsulated in metal-organic frameworks (MOFs) due to the interactions between them. Herein, we probed the interactions of catalase in solid and hollow ZIF-8 microcrystals. The solid sample with confined catalase is prepared through a reported method, and the hollow sample is generated by hollowing the MOF crystals, sealing freestanding enzymes in the central cavities of hollow ZIF-8. During the hollowing process, the samples were monitored by small-angle X-ray scattering (SAXS) spectroscopy, electron microscopy, powder X-ray diffraction (PXRD), and nitrogen sorption. The interfacial interactions of the two samples were studied by infrared (IR) and fluorescence spectroscopy. IR study shows that freestanding catalase has less chemical interaction with ZIF-8 than confined catalase, and a fluorescence study indicates that the freestanding catalase has lower structural confinement. We have then carried out the hydrogen peroxide degradation activities of catalase at different stages and revealed that the freestanding catalase in hollow ZIF-8 has higher activity.

In order to deal with the problem of low precision and ignoring the influence of some factors on the growth system of cyanobacteria, this paper considers the effects of light, water temperature and other influencing factors to analyze cyanobacteria growth system. The time stochastic differential equation of cyanobacteria growth with double nutrient cycling is established. The numerical analysis and the intelligent evolutionary algorithm are used to optimize the steady parameters in the time stochastic differential equation of cyanobacteria growth. The light, water temperature and other factors is used to build time series modeling. The time stochastic parameters and the prediction of cyanobacteria biomass is realized. The bifurcation theory and the central manifold theory were used to analyze the nonlinear dynamics of cyanobacteria growth with double nutrient cycling system, so that the conditions of cyanobacteria bloom and prediction of cyanobacteria blooms are achieved. Compared with the existing research, the method proposed in this paper not only determines the conditions of cyanobacteria bloom, but also improves the accuracy of water bloom prediction, and provides an effective reference for environmental protection departments.

Summary Considerable research has been focused on the development of rate-transient-analysis (RTA) models to estimate the reserves of gas/condensate reservoirs. Currently, broadly deployed RTA tools rely on multiphase pseudopressure concepts to enable multiphase production-data analysis. In any multiphase pseudopressure calculation, the determination of the saturation/pressure (So/p) relationship plays a vital role because it directly influences the ability of multiphase RTA methods to reliably forecast original gas in place (OGIP). In this work, we present a thermodynamics-based So/p model that provides a better understanding of the phase behavior for the boundary-dominated gas/condensate reservoirs. The proposed So/p model is derived from the thermodynamic nature of extended black-oil formulations. A noniterative flash-calculation protocol is used to establish the So/p path in the condensate-buildup region. The developed method can be coupled with RTA tools and services for the calculation of multiphase pseudopressure. In this work, we present case studies of three gas/condensate reservoirs with different types of fluids. Two RTA multiphase analysis models are used to scrutinize the production data using the newly proposed So/p relationship, and results are compared with the use of a traditional steady-state method coupled with constant-volume-depletion (CVD) data. Results of the case studies show that RTA models that use the proposed So/p consistently yield more accurate OGIP estimation. Thus, this work presents a practical approach to remove commonly used yet potentially faulty assumptions in multiphase RTA applications for liquid-rich gas/condensate reservoirs.

All-solid-state lithium sulfur batteries (ASSLSBs) are considered promising candidates for next-generation energy-storage systems due to their enhanced safety and high theoretical energy density. However, usually both solid-state electrolyte (SSE) and conductive carbon need to be incorporated into the cathode composite to provide Li+/electron pathways, leading to the reduced energy density and inevitable SSE decomposition. Moreover, the real electrochemical behavior of S or Li2S cathodes can not be reflected due to the partially overlapped redox reaction of SSE. Herein, a series of unique P4S10+n cathodes for high-performance ASSLSBs that totally do not need any extra SSE additives are reported. Synchrotron-based X-ray absorption near edge structure coupled with other analyses confirmed that ionic conductive Li3PS4 together with Li4P2S6 components can be electrochemically self-generated during lithiation process and partially maintained to provide fast Li+ transport pathways within the cathode layer. This is further evidenced by a 30–43-fold higher reversible capacity for P4S10+n/C cathodes compared to a S/C cathode. Bulk-type ASSLSBs based on the P4S34/C cathode show a highly reversible capacity of 883 ​mAh g−1 and stable cycling performance over 180 cycles with a high active material content of 70 ​wt%. The present study provides a promising approach for generating ionic conductive components from the electrode itself to facilitate Li+ migration within electrodes in ASSLSBs.

Deformation monitoring of a converter station of an electrical power transmission system will help to prevent potential damages to power facilities and properties. Corner reflector InSAR (CRInSAR) enables local deformation measurements in low coherence areas like construction-engineering projects. However, the accuracy of CRInSAR will be degraded by the phase unwrapping errors, especially when the deformation is large or dominated by nonlinear component. This letter reports a study that employs CRInSAR technique to monitor the deformations of ten CRs installed in Xiangtan converter station, China, with seven TerraSAR-X Spotlight images. A two-step phase unwrapping tactics is proposed based on the least squares ambiguity decorrelation adjustment (LAMBDA) algorithm to focus on estimating nonlinear deformation without being affected by unwrapping errors. The results reveal that the two-step LAMBDA algorithm can achieve an accuracy of less than 2 mm for CRInSAR deformation monitoring regardless of small- or large-scale deformations, as validated by the trigonometric leveling measurements.

DNA hypermethylation is an epigenetic modification that plays a critical role in the oncogenesis of myelodysplastic syndromes (MDS). Aberrant DNA methylation represses the transcription of promotors of tumor suppressor genes, inducing gene silencing. Realgar (α-As4S4) is a traditional medicine used for the treatment of various diseases in the ancient time. Realgar was reported to have efficacy for acute promyelocytic leukemia (APL). It has been demonstrated that realgar could efficiently reduce DNA hypermethylation of MDS. This review discusses the mechanisms of realgar on inhibiting DNA hypermethylation of MDS, as well as the species and metabolisms of arsenic in vivo.

To this day, the petroleum industry is still searching for alternative ways to improve the recovery of hydrocarbon from the reservoir. The residual oil blotches may consist of about 30%–40% or more of a volume fraction. Seismic stimulation has great potential for IOR (improved oil recovery), because of its advantages on low cost, high effectivity, and environment-friendly as they introduce no formation damage, etc. The investigation and application of seismic stimulation have been launched for over 70 years. In this study, a literature review on the mechanism for IOR, including laboratory and theoretical modeling work, and oilfield application, is present here. Firstly, four different manners of vibration are introduced, and the seismic vibration with 1 Hz–100 Hz (frequency) and 1 μm–100 μm (amplitude) is the commonly used; Secondly, the mechanisms of IOR by seismic stimulation are summarized as: effect on capillary pressure, pore deformation, relative permeability, thermal and degassing effects, however, further tests and understanding of the mechanisms are necessary. Thirdly, the reviews of experimental research and mathematical modeling based on the published literature are made. Especially, the mathematical modeling of seismic vibration for the real reservoir development (such as non-Darcy flow, low permeability reservoirs, the coupling of non-Newtonian fluid, etc.) is still insufficient. Finally, some successful oilfield applications (in Russia, North America, and China) and prospects are proposed in this work. It will be more efficient to stimulate the reservoirs if the seismic wave is at the formation's resonant frequency. In our work, we don't expect to provide an exhaustive review of the work presented. On the contrary, we hope that our work can provide an introduction for other researchers to get a brief understanding of the seismic stimulation technology and possible results under which conditions the seismic stimulation works well.

All-solid-state lithium-ion batteries (ASSLIBs) are expected as safe and high-performance alternatives to replace the conventional liquid-based lithium-ion batteries. However, the incompatible interface between the most cathode materials and sulfide-based solid electrolytes is still challenging the stable delivery of electrochemical performance for ASSLIBs. Herein, a dual-functional Li3PO4 (LPO) modification is designed for Ni-rich layered oxide cathodes in sulfide-based ASSLIBs to realize the high performance. The modified cathode demonstrates a significantly improved initial capacity of 170.6 ​mAh g-1 at 0.1C, better rate capability, and reduced polarization compared to the bare cathode. More importantly, a stable long-term cycling is achieved with a low capacity degradation rate of 0.22 ​mAh g-1 per cycle for 300 cycles at 0.2C. The detailed surface chemical and structural evolutions are studied via X-ray absorption near edge spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The results indicate that the LPO modification not only significantly suppresses the side-reactions with sulfide electrolyte but also helps to alleviate the deterioration of the microstructural cracks during the electrochemical reactions. This work provides an ideal and controllable interfacial design for realizing high performance sulfide-based ASSLIBs, which is readily applicable to other solid-state battery systems.

Laser welding of Al-Si coated press-hardened steel (PHS) was still a challenging due to the formation of δ-ferrite in the fusion zone. However, it was ambiguous on the δ-ferrite evolution during post-weld heat treatment (PWHT). In this study, Al-Si coated PHS was welded by laser fiber and then heat-treated at various temperatures (650 °C, 950 °C and 1050 °C), and the microstructure evolution was investigated by in situ-observation. Mechanical properties and formability of welded joints was analyzed. The results showed that δ-ferrite did not go through phase transformation during PWHT regardless of any temperature, but with a grain boundary flatted and movement. The presence of coarse δ-ferrite after PWHT was the responsible for the decreasing of tensile strength and formability of welded joints. The initiation crack was easy to generate in the phase interface between δ-ferrite and martensite to form a local brittle fracture zone finally. This study results provides a new theoretical criterion for the properties improvement on the laser welding of PHS without removing Al-Si coating.

Solid polymer electrolytes (SPEs)-based all-solid-state lithium batteries (ASSLBs) with high-safety and high-performance have been regarded as promising next-generation energy storage devices. A fly in the ointment is that the cycling life is significantly limited by the Li dendrite growth. To tackle the Li dendrite issue, a selective Li deposition strategy is proposed, for the first time, to suppress Li dendrite formation via the rational design of a patterned Li anode. Through a facile and low-cost template-press method, the Li anode was divided into numerous square Li with deep grooves around 100 ​μm. Benefiting from the focused current density in the grooves, the Li preferentially deposits in the grooves instead of on the surface, thus suppressing the Li dendrite formation during the Li plating/stripping process. With this in mind, both cycling life of the assembled Li–Li symmetric cells and Li–LiFePO4 (LFP) full cells is prolonged for over 5 times. The Li–Li symmetric cells assembled with the patterned Li exhibit excellent cycling stability for 800/400 ​h ​at 0.1/0.2 ​mA ​cm−2. More importantly, the 3–4 ​mg ​cm−2 LFP-loaded patterned Li/PEO/LFP cell achieves high capacity retention of 91.3% within 100 cycles at 0.5C, while different degrees of short-circuits occurred for the bare Li/PEO/LFP cells.

Ni foils with various thickness were used as interlayer to achieve the laser tailored welding of 22MnB5 press-hardened steel (PHS) with Al-Si coating. The effect of Ni content on the microstructure, hardness and strength were studied. The results showed that Ni reduced the content of solidified primary δ phase in the fusion zone, and promoted the transformation from δ phase into γ phase. δ ferrite was absent with the Ni content of 4.7–19.5 wt.%. In addition, the fusion zone was in γ phase region during post-weld heat treatment at 950℃ because Ni can reduce the Ac3 temperature (the temperature at all ferrite was transformed into austenite). The microstructure of fusion zone after post-weld heat treatment was lath martensite with the Ni content of 4.7–11.2 wt.%. The average hardness was similar to base metal, and the tensile strength of welded joint was increased by ∼22% of as-received joint. Ni was effective to suppress the formation of δ ferrite in Al-rich fusion zone, which is potential to achieve the laser welding of PHS with Al-Si coating.

Due to the limited resources of water quality sensor networks, how to design a routing protocol which can prolong the network life cycle is one of a research hotspots. In this paper, according to the event level and the node energy of the sensor networks, the nodes’ types are defined, which can help to determine the cluster node. Then, an event driven routing protocol (EDRP) is proposed, which considers the event information and the remaining energy of the whole network. Simulation results show that, compared with distributed energy-efficient clustering algorithm, EDRP can reduce the overall energy consumption of the network by 138–172%, based on different kinds of events. Besides, EDRP can effectively prolong the life cycle and greatly increase the amount of data transmission of the network.

This paper investigates the effects of propanol isomers enrichment on natural gas TFR engine via experiment and simulation. The results indicate that the reforming effect of TFR cylinder with n-propanol enrichment is the best, followed by that with iso-propanol, and with that of the natural gas being the worst. The impact of negative effect due to lack of fire was the most significant on the reforming effects with n-propanol enrichment, less on those with iso-propanol, and the least on those with natural gas. According to the kinetics analysis, the rate of H2 formation depends on the rates of H, O, OH, and HO2 formation. The n-propanol had the fastest production rate for H, O, OH, and HO2 radicals in the early stage of combustion, compared with iso-propanol and methane. The performance analysis of the normal cylinder shows that n-propanol enriched normal cylinders produced the lowest fuel consumption.

Sulfide-based solid-state electrolytes (SSEs) are considered a key part in the realization of high-performance all solid-state lithium-ion batteries (ASSLIBs). However, the incompatibility between ...

Efficient and stable electrocatalysts for oxygen reduction reaction and free-standing electrode structure were developed to reduce the use of polymer binder in the cathode of metal-air battery. Con...

Superoxide-based Na-O2 batteries have been considered as one of the most promising candidates for next-generation energy storage systems due to their high theoretical energy density and energy effi...

All-solid-state Li metal batteries (ASSLMBs) have attracted significant attention because of their high energy density and improved safety. However, the poor stability at the Li anode/solid-state e...

Critical factors that govern the composition and morphology of discharge products are largely unknown for Na-O2 battery. Here we report a reversible ORR and OER process in a sodium-oxygen battery o...

This study uses a port-injection spark-ignition four-cylinder natural gas engine to achieve TFR (Thermochemical fuel reforming) mode. To study the effects of fuel reactivity on combustion, reforming process, emissions and fuel economy, chemicals including n-heptane, PRF50 and isooctane are respectively used as enriched fuel. The results show that the higher the reactivity of the enriched fuel, the better the combustion and cycle stability of the reforming cylinder. However, n-heptane enrichment with high reactivity has the problem of knocking at large equivalence ratio. The enrichment limit of PRF50 is the highest, which combines the properties of n-heptane and isooctane. The H2 production abilities of three enriched fuels are similar, but that of isooctane is slightly lower under large equivalence ratios. In terms of fuel economy, the three perform similarly at small equivalence ratios. Whereas it’s lower with isooctane enrichment at large equivalence ratios, which is at the expense of increased NOx emission.

Line drawing with colorization is a popular art format and tool for architectural illustration. The goal of this research is toward generating a high-quality and natural-looking colorization based on an architectural line drawing. This paper presents a new Generative Adversarial Network (GAN)-based method, named ArchGANs, including ArchColGAN and ArchShdGAN. ArchColGAN is a GAN-based line-feature-aware network for stylized colorization generation. ArchShdGAN is a lighting effects generation network, from which the building depiction in 3D can benefit. In particular, ArchColGAN is able to maintain the important line features and the correlation property of building parts as well as reduce the uneven colorization caused by sparse lines. Moreover, we proposed a color enhancement method to further improve ArchColGAN. Besides the single line drawing images, we also extend our method to handle line drawing image sequences and achieve rotation animation. Experiments and studies demonstrate the effectiveness and usefulness of our proposed method for colorization prototyping.

Lignocellulose, as the most abundant type of inedible biomass, is considered as a promising renewable feedstock for making fuels, chemicals, and materials. However, its complex structure makes most of current biorefinery processes suffer from low resource utilization rates, high energy consumption or ill-defined market orientation of the obtained products. Here, we propose and evaluate the EXA (Ethanol, Xylose, Adhesive) biorefinery strategy based on current xylose industry. This process integrates four conversion and separation stages to consecutively produce ethanol, xylose, and adhesive with total carbon utilization of 79.6%. The key innovation is the establishment of an easy-to-operate process for direct production of high-quality adhesive from a lignin-rich liquid fraction that makes the overall process significantly more sustainable. Techno-economic analysis (TEA) shows that the revenue of proposed EXA process increases more than 110 times compares with the current process and life cycle assessment (LCA) demonstrates a much lower CO2 footprint from an environmental burden per unit of revenue perspective.

In this article, Li2MnO3 was successfully prepared by a facile one-step high-energy mechanical activation method free from sintering. XRD, SEM, and TEM techniques were employed to analyse the mater...

As a family of important inorganic layered materials, layered double hydroxides (LDHs) have attracted considerable attentions owing to their potential applications in wide areas. Generally, the size, shape, uniformity and dispersity of LDHs have great effects on their application properties. Herein, we report an efficient approach to prepare surfactant-free transparent dispersions of monodispersed CO32- intercalated MgAl-LDH nanoparticles using a high-gravity-assisted intensified co-precipitation method in a rotating packed bed (RPB) reactor, followed by hydrothermal treatment. After a rapid co-precipitation in the RPB reactor, monodispersed MgAl-LDH nanoparticles with an average particle size of about 31 nm can be obtained. As compared to that in a stirred tank reactor (STR), the product from the RPB has much smaller particle size, narrower size distribution and higher optical transparency. More importantly, the reaction time can be significantly reduced from 20 min to 20 s, realizing an efficient contin...