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While there have been multiple recent reports in the literature focusing on the effects of magnetic field on the phase transformation behaviors, the research conducted with an ultra-high magnetic field greater than 20 T is still preliminary. In the current study, the structure evolution of Co-B alloys are experimentally studied with undercooling. The effects of a 25 T magnetic field on the solidification behavior and the subsequent solid-state phase transformation behavior have been investigated. The 25 T magnetic field is confirmed to have little effect on the homogeneous nucleation, but have some influence on the heterogeneous nucleation of Co3B and Co23B6 phases by modifying the wetting angle θ. The decomposition of Co23B6 phase in the subsequent cooling process can be effectively suppressed by applying the 25 T magnetic field. The present work might be helpful for not only theoretically understanding the influence of ultra-high magnetic field on the phase transformation behaviors but a potential technology of field-manipulation of magnetic materials.

Container on Barge (COB) facilitates intermodal transportation by transporting shipping containers on barge tows. COB has seen rapid expansion globally over the past 20 years, providing a cost-efficient, environmentally friendly, and congestion-reducing mode of container transportation. European countries have led COB transportation in both study and application over the past two decades. However, increasing interest is observed in both the USA and Asia. In this literature review and comparative analysis, 135 COB-focused peer-reviewed articles are reviewed and analyzed to systematically describe the development and current status of COB transportation research. The relevant literature is analyzed to reveal publication rates and titles, geographical regions of interest, research questions, applied methodologies, advantages of COB transportation, and key success factors. The aim of our effort is to provide information on various aspects of COB development among different regions in the world and to summarize the existing literature to support and guide future COB development.

The rapid development of wearable, highly integrated, and flexible electronics has stimulated great demand for on-chip and miniaturized energy storage devices. By virtue of their high power density and long cycle life, micro-supercapacitors (MSCs), especially those with interdigital structures, have attracted considerable attention. In recent years, tremendous theoretical and experimental explorations have been carried out on the structures and electrode materials of MSCs, aiming to obtain better mechanical and electrochemical properties. The high-performance MSCs can be used in many fields, such as energy storage and medical assistant examination. Here, this review focuses on the recent progress of advanced MSCs in fabrication strategies, structural design, electrode materials design and function, and integrated applications, where typical examples are highlighted and analyzed. Furthermore, the current challenges and future development directions of advanced MSCs are also discussed.

Weak water stability of soil is one of the prime causes of soil erosion and slope damage. To understand the improvement on the water stability of sand by a soluble organic polymer (polyurethane, PU), we have conducted a series of water-stability and turbidity tests to evaluate the effects of different polymer content, densities, and immersion times. The mechanism of the improvements is investigated based on scanning electron and digital microscopes. Our results reveal that the polymer can effectively improve the water stability of sand, where the water-stability coefficient enhanced from zero to 100. The turbidity of the water after oscillation was determined, and its value reduced from 84.5 to 10 and kept stable, which further proved the PU improvement on the water stability of sand. The results can be considered as the reference for construction and management of riverbanks and drainage ditches.

Surface roughening of hollow glass microspheres (HGMs) is a necessary step determining their adhesion ability with the following electroless plated metallization coating. In this paper, a new KF roughening and alkali washing strategy was proposed to replace HF roughening as a surface pretreatment for the following electroless plating metallization. In order to remove the byproduct of K2SiF6 from the roughening reaction of KF with HGMs, NaOH washing and KOH washing were conducted, the former of which was found to dissolve K2SiF6 effectively. The effects of KF roughening temperature, alkali concentration and HGMs loading on the recovery ratio, phase composition, surface morphology and performance of HGMs were investigated, through which such a pretreating strategy was found to not only decrease the damage ratio of HGMs compared to that by HF roughening, but also render the metallized HGMs a competitive absorbing ability for the electromagnetic wave in X-band and Ku-band. Finally, the related surface treatment and electroless plating mechanism were discussed. This paper illustrates successfully a new pretreatment strategy for development of lightweight HGMs-supported functional materials.

Natural sisal fiber is an environment-friendly and efficient material for soil reinforcement. Many studies have reported that the shear strength of soil has been improved by the addition of fiber. However, the mechanical properties of sand can be more effectively improved by the incorporation of water-based polymer and sisal fiber. An extensive laboratory testing program was conducted to determine the effect of water-based polyurethane and sisal fiber reinforcement on sand. Laboratory tests included sieve analysis, X-ray diffraction, conventional triaxial compression, and scanning electron microscopy (SEM) tests. The effects of polymer content (PC), fiber content (FC), fiber length (FL), and sample dry density (ρ) are thoroughly investigated. The results indicate that the increases of PC, FC, and ρ all improve the mechanical properties of sand. For FL, this improvement in shear strength was maintained to FLs of up to 18 mm. Beyond 18 mm, the shear strength decreased with further increase in FL. The mixing of polymer and fiber changes the failure mode from shear faulting to ductile flow. This indicates that the ductility of sand is improved. From the SEM images we found that sisal fibers, binding with colloidal materials formed by polymer, fill the sand voids and join the sand particles. This demonstrates that mixing of fiber and polymer can enhance the bonding of sand particles.

Pedestrian detection is an important task for human-robot interaction and autonomous driving applications. Most previous pedestrian detection methods rely on data collected from three-dimensional (3D) Light Detection and Ranging (LiDAR) sensors in addition to camera imagery, which can be expensive to deploy. In this letter, we propose a novel Pedestrian Planar LiDAR Pose Network (PPLP Net) based on two-dimensional (2D) LiDAR data and monocular camera imagery, which offers a far more affordable solution to the oriented pedestrian detection problem. The proposed PPLP Net consists of three sub-networks: an orientation detection network (OrientNet), a Region Proposal Network (RPN), and a PredictorNet. The OrientNet leverages state-of-the-art neural-network-based 2D pedestrian detection algorithms, including Mask R-CNN and ResNet, to detect the Bird's Eye View (BEV) orientation of each pedestrian. The RPN transfers 2D LiDAR point clouds into occupancy grid map and uses a frustum-based matching strategy for estimating non-oriented 3D pedestrian bounding boxes. Outputs from both OrientNet and RPN are passed through the PredictorNet for a final regression. The overall outputs of our proposed network are 3D bounding box locations and orientation values for all pedestrians in the scene. We present oriented pedestrian detection results on two datasets, the CMU Panoptic Dataset and a newly collected FCAV M-Air Pedestrian (FMP) Dataset, and show that our proposed PPLP network based on 2D LiDAR and monocular camera achieves similar or better performance to previous state-of-the-art 3D-LiDAR-based pedestrian detection methods in both indoor and outdoor environments.

Vegetation has good application in slope stabilization, but its beneficial effects on reinforcing topsoil are generally limited by the soil properties it was cultivated in. This study aims at evaluating the strength improvements of sand-root composite by treating with polyurethane polymer and hence investigating the mechanism of polymer-root-soil interactions. Vegetation roots were selected and mixed with dry sand and polymer solution to prepare remolded specimens. A series of experimental tests were then performed at different percentages of root content (0, 0.4, 0.8, 1.2, and 1.6 % by weight of dry sand) and polymer content (1, 2, and 4% by weight of dry sand) to evaluate the shear parameters and unconfined compressive strength (UCS). The combined mechanism was studied by scanning electron microscopy (SEM) images. The results showed that the strengthening effect has greater efficiency with higher polymer content. Through varying contents of vegetation root, it was found that low root content induced an undesirable weakening effect on the strength of the treated soil. However, this situation was somewhat improved with the increase in root content. The good flexibility of polymers not only promote the capacity of soil to energy absorption, but also impart good ductility to soil. The presence of polymers greatly strengthens soil stability due to its special network structure, by which the improved shear resistance at the root-soil interface provides sufficient anchorage effect for the tensile strength of roots to be fully mobilized. Overall, the synergistic effect of root reinforcement and polymer treatment has the potential for its use in soil stabilization.

A considerable number of engineering hazards are caused by loose internal structure of sands. Thus, many researchers have explored a variety of reinforcement methods. A new reinforcement technique was experimentally evaluated in this study. In particular, a hybrid method with a combination of fiber and polymer was studied. Three different types of fibers (sisal, polypropylene, and palm) in combination with varying concentrations of polymers were experimented to improve the internal structure and strength of sand samples reconstituted at different densities. Through a series of laboratory tests, the compressive and tensile strength variations of different combinations were obtained, and the interaction between fibers and polymer inside the sand was evaluated by scanning electron microscopy (SEM). The experimental results show that the tensile and compressive strength of the reinforced sand increases with the increase of the polymer concentration, sample density, and different fiber combinations. This provides some references for future practical engineering applications.

In heterogeneous ultra-dense networks (HUDNs), load balancing is always considered by offloading users from the macro base station (MBS) tier to the small base station (SBS) tier, to alleviate the data traffic of the MBS tier, while it causes a serious problem that the offloaded users will suffer strong interference from the MBS tier, and hence the signal-to-interference ratio (SIR) is in low region for the offloaded users. In order to improve the performance of these offloaded users, an interference mitigation scheme based on resource partitioning is employed in the literature. Specifically, a fraction of resource blocks (RBs) is reserved for the offloaded users, and then the SIRs of these users will be enhanced because there is only interference from the SBS tier. In summary, the combination of offloading and resource partitioning is called joint offloading and resource partitioning scheme, which has been investigated in the HUDNs built on the 2D space, while it has rarely been deliberated in 3D HUDNs that are used to model the scenario of high-rise buildings. Moreover, a two-tier 3D HUDN is proposed in this paper, and the MBS and SBS tiers are modeled as two independent Poisson point processes. Then, the SIR and rate meta distributions, which are used to characterize the fraction of users that achieve a desired link reliability given SIR or rate thresholds, are formulated for the proposed 3D HUDN. Lastly, numerical results show that with the usage of the joint offloading and resource partitioning scheme, the performance of the proposed 3D HUND can be significantly improved.

Ultrafiltration (UF) technology is considered an efficient water treatment method. In recent years, researchers have been committed to enhancing the treatment efficiency of UF and alleviating membrane fouling. An effective method is to achieve this is through the use of coagulation as a pre-treatment to UF; however, during a long term operation, membrane fouling can occur due to the residual organic matters and the generation of microorganisms. In this study, we combine coagulation and ozonation as a pre-treatment of UF and compare four types of pre-treatment: coagulation, ozonation, coagulation followed by ozonation (C–O) and ozonation followed by coagulation (O–C). Results showed that ozonation alone did not perform well. Both combinations of coagulation and ozonation enhanced the organic matter removal efficiency, although membrane fouling was lowest following the C–O pre-treatment as the microbial load was reduced. While a slight increase in the yield of disinfection by-products was observed with the addition of ozonation, the concentration remained below the Chinese standard for tap water quality (100 μg/L).

Na0.44MnO2 has drawn great attention as a promising cathode material for sodium-ion batteries (SIBs) owing to its unique tunnel-type structure that allows facile Na+ insertion/extraction. We here report the controllable preparation of Na0.44MnO2 nanowires (NMO NWs) through electrospinning and annealing processes and their SIB cathode application to boost the ionic diffusion dynamics and cyclic stability. The well-shaped NMO NWs with diameters of 50–200 nm effectively favour the easy access to electrolyte, facilitate the electrons/Na+ ions transportation, and retard the active materials fracture/pulverization upon prolonged cycling. Consequently, fascinating electrochemical performance in terms of high-rate capability (120.4 mAh g−1 at 0.1C; 31.7 mAh g−1 at 50C) and unprecedentedly long cycling life (89% capacity retention after 3300 cycles) is achieved. Furthermore, the underlying Na-ion storage mechanism and migration kinetics have been pioneeringly elucidated by a combination study of ex-situ structure/valence analyses and first-principles computations. The pseudocapacitive behaviour of NMO NWs electrode is also identified to benefit the high-rate performance. Finally, a pouch-type sodium-ion full battery assembled by the NMO NWs cathode and hard carbon nanofibers anode delivers an admirable energy density of 165.3 Wh kg−1 and an outstanding capacity retention of 88.57% over 200 cycles, showing great prospects.

This letter concentrates on the spectrum sensing (SS) problem for noncircular (NC) signal in multiantenna cognitive radio networks. A novel detection method called NC local average variance (NC-LAV) is developed to exploit the NC characteristic of the primary signals for SS. The distribution of the NC-LAV statistic in the absence of primary user is first derived. Then, based on the derived distribution, we present an asymptotic threshold determination of the proposed NC-LAV method. Compared to the peer methods, the proposed NC-LAV method exhibits much lower complexity. Meanwhile, the simulation results reveal that the proposed method achieves better performance than several state-of-the-art methods.

The membrane fouling is a challenge for the application of ultrafiltration, one of which the cake layer is the main influencing factor. However, the pros and cons of cake layer generated in the coagulation-ultrafiltration (C-UF) process needs to be explored. This study was carried out to investigate that the effect of a cake layer on the membrane fouling behavior with three Al species coagulants for different effluents. The results indicated that the fouling mechanisms of cake layer under different effluents conditions were diverse due to the particle characteristics. The Al hydrolysis that accompanied by the interaction between Al species coagulants and the –OH/-COOH functional groups of humic acid were conducted, and the effluents of Ala presented lighter membrane fouling. Meanwhile, the components mainly trapped by the membrane were soluble microbial products, protein, polypeptides and amino acid-like materials during C-UF process, because of the decrease in the proportion of fluorescence response. For the less/compact cake layer (system 2), the average of the external and internal membrane resistances were about 25 × 1010 m−1 and 21 × 1010 m−1, respectively, which caused severe membrane fouling. It was concluded that the poriferous/loose cake layer could effectively alleviate membrane fouling by re-adsorbing some organic matters.

This study focuses on the shear-strength properties of polyurethane polymer–treated sand stored at different temperatures. The triaxial test was performed at unconsolidated and undrained co...

Accurate detection of infrared small target in complex scenes plays a vital role in many practical applications. In the infrared patch-tensor (IPT) model, small target detection is regarded as a convex optimization problem of tensor robust principal component analysis (TRPCA), which separates low tubal rank and sparse tensors. Tensor singular value thresholding is employd as the proximal operation of tensor nuclear norm to estimate the low-rank background components. Considering the defect that the local structural weights in the Reweighted IPT shrink excessively small targets, an effective local prior map is used to better mine target and background information. The local prior and sparse enhancement weight are combined to obtain the final adaptive weight. Alternating direction method of multipliers (ADMM) is utilized to solve the model. Extensive experiments of infrared sequence images based on ground background prove that our algorithm has significant advantages in real-time and detection capability compared with state-of-the-arts.

The weight of motor is related to torque in exoskeleton. Designers need to install the motor on the exoskeleton. The weight and moment of inertia of the exoskeleton will change when the motor type is changed. For the purpose of determine the motor type, this paper developed a MATLAB Graphical User Interface (GUI) to complete forward kinematics solution, dynamic analysis through program writing and data interaction. The forward kinematics is solved by Denavit-Hartenberg (DH) parameters method, the dynamics is solved by Lagrange equation. General kinematics can be decomposed into multiple polynomials by Taylor series. Input polynomial coefficients into GUI to obtain motor torque curve data. The designer can then determine the motor power by the product of torque and rotational speed.

Being a promising candidate technology for the fifth-generation cellular systems, the ultra-dense network (UDN) is capable of improving the system throughput by deploying more small cells (SCs) in the existing macro-cells (MCs). In most cases, base stations (BSs) from both the MCs tier and SCs tier are modeled as two independent homogeneous Poisson point processes (PPPs) or other point processes derived from a PPP. In the previous works, the area spectral efficiency (ASE) and energy efficiency (EE) are evaluated from a typical user's perspective, and this method works well in single-user scenarios. However, there are multiple users sharing spectral resources in practical cellular systems, and the above-mentioned method cannot work in these scenarios. Therefore, we investigate the ASE and EE from the perspective of a typical BS. Analytical results show that the ASE increases with the increasing SCs density, which means that deploying more SCs in the MCs coverage area is a feasible way to enhance the system throughput. However, the energy consumption of the entire network is increasing as the SCs density increases. Therefore, we employ the firefly algorithm to jointly optimize the ASE and EE for the two-tier heterogeneous UDN. Finally, the optimal system parameters can be found under two fixed weights for the ASE and EE, respectively.

The effect of strong static magnetic field (SSMF) on the microstructure and phase transformation temperature of Co38Ni33Al29 ferromagnetic shape memory alloy during heat treatment has been studied. Results indicate that the microstructure and phase transformation temperature are significantly affected by the external SSMF. With the increasing magnetic field intensity, the volume fraction of γ phase decreased from 13.2 to 5.1%, the morphologies of γ phase evolved from rods to discrete stripes, and a clear alignment of γ phase was observed. In addition, the transformation temperatures are also elevated as the magnetic field intensity increases. The martensitic transformation temperature (MS) and the Curie point (TC) rose by 13 K and 10 K respectively when 4 T SSMF was applied. Moreover, the coercivity (HC) dramatically reduced to 11.7 Oe at 4 T magnetic field. Magnetic domains formed in β phase and they became ordered with the enhancing intensities of magnetic field.

This study investigated membrane fouling in a coagulation/ultrafiltration (C-UF) process by comparing the floc properties and humic acid (HA) removal efficiency of three hydrous Al(III) species (Ala, Alb, and Alc). The results indicated that the coagulation and membrane mechanisms were different for all three Al species because of the differences in floc properties. The HA removal efficiency increased with increasing Al dosage until an equilibrium was reached at the optimal dosage of 6 mg L−1. In addition, membrane fouling gradually decreased as the Al dosages increased. Regardless of coagulant type, the OH and COOH functional groups of HA reacted with the Al species. Both external and internal membrane fouling were strongly dependent on the porosity of the cake layer and on the size distribution of the floc particulates, respectively. The pore area of the cake layer formed by the Ala-coagulated effluent was large because of the strong charge neutralization. Moreover, Ala generated large and loose flocs with a porous cake layer that mitigated external fouling. However, the internal fouling with the Alc coagulant was significant because the concentration of residual aggregates in the membrane pores was high.

We analyze the mechanism of creating bubbles under asymmetric information through literature review. Our hypothesis is that information asymmetry will lead to herd behavior and then herd behavior will create bubbles. We find papers and evidences to support our hypothesis. However, after those literature reviews, we consummated our hypothesis and gave a conclusion. Our conclusion is the information asymmetry which can lead to herd behavior and there is a transaction phase. Herd behavior can create bubbles only when shocks come into the market. The bubble will enhance the herd behavior and then further create bubbles. In the first part of our hypothesis, we find three types of papers to support information asymmetry which can lead to herd behavior, which are theoretical model, mathematical model and experiment. It is similar in the second part of our hypothesis, which is herd behavior that can create bubbles.

Hierarchical urchin-like Fe 3 O 4 porous particles with 3D graphene modification (U-Fe 3 O 4 @RGO) are synthesized via cationic surfactant induced self-assembly of γ-FeOOH particles and graphene oxide (GO) sheets, followed by a calcination treatment. Fe 3 O 4 porous particles are tightly encapsulated by 3D graphene frameworks, which greatly improves the overall electrical conductivity and structural stability of the hybrids. With the help of synergistic effects between U-Fe 3 O 4 and graphene frameworks, U-Fe 3 O 4 @RGO anode demonstrates high reversible capacity, excellent cycling stability (2292 mA h g −1 specific capacity after 500 cycles at 0.5 A g −1 ) and outstanding rate capability (439 mA h g −1 specific capacity at 10 A g −1 ).

The Pb electrode is the most efficient and selective catalyst in reducing CO2 into HCOOH; however, the reaction mechanism remains elusive. Herein, we have investigated the mechanism of CO2 electroreduction to HCOOH on the Pb(111) surface using density functional theory calculations. We find that the effects of solvation and cations lead to different active intermediates for CO2 electroreduction (HCOO in gas-phase condition, both HCOO and COOH in solvent condition, and COOH in cation solution). In particular, the size and hydrophilic/hydrophobic nature of the cations are found to significantly affect the reaction selectivity and efficiency of CO2 electroreduction at different overpotentials. These findings rationalize several experimental observations and contribute to a thorough understanding of CO2 electroreduction.

Swine manure wastewater was treated in an anaerobic membrane bioreactor (AnMBR) that combined a continuous stirred tank reactor (CSTR) and a hollow-fiber ultrafiltration membrane, and the feasibility of ammonia and phosphorus recovery in the permeate was investigated. The AnMBR system was operated steadily with a high mixed liquor suspended solids (MLSS) concentration of 32.32 ± 6.24 g/L for 120 days, achieving an average methane yield of 280 mL/gVSadded and total chemical oxygen demand removal efficiency of 96%. The methane yield of the AnMBR is 83% higher than that of the single CSTR. The membrane fouling mechanism was examined, and MLSS and the polysaccharide contents of the extracellular polymeric substances were found to be the direct causes of membrane fouling. The effects of the permeation/relaxation rate and physical, chemical cleaning on membrane fouling were assessed for membrane fouling control, and results showed that a decrease in the permeation/relaxation rate together with chemical cleaning effectively reduced membrane fouling. In addition, a crystallization process was used for ammonia and phosphorus recovery from the permeate, and pH 9 was the optimal condition for struvite formation. The study has an instructive significance to the industrial applications of AnMBRs in treating high strength wastewater with nutrient recovery.

This study systematically determined the optimal dosage ratio and the viscosity (η) of co-coagulants, polyaluminum chloride (PAC) and poly dimethyldiallylammonium chloride (PDMDAAC), on coagulation performance and membrane fouling in a hybrid coagulation-ultrafiltration (C-UF) process for natural organic matter (NOM) removal. Floc characteristics—including floc size, fractal dimension, strength and re-growth ability—were studied with respect to coagulant-dosing operations. Membrane fouling was evaluated in association with assessment of NOM removal performance by the hybrid process. The best coagulation performance was achieved when PAC and PDMDAAC were dosed with 1.0 mg/L and 0.1 mg/L, respectively. The addition of PDMDAAC could enhance the NOM removal efficiency, especially at low PAC dosages. Co-coagulants PAC/PDMDAAC (ηPDMDAAC = 2.18 dL/g) resulted in formation of the largest flocs with the smallest Df under all shear conditions, while the flocs formed by PAC/PDMDAAC (ηPDMDAAC = 1.86 dL/g) had higher recovery abilities. The results from ultrafiltration experiments indicated that coagulation using PAC/PDMDAAC with a viscosity range from 0.99 dL/g to 1.86 dL/g can significantly reduce membrane fouling, leading to increasing water fluxes from 0.1170 to 0.4906 in the ultrafiltration process.

The effects of the composite flocculant, polyaluminium chloride and poly dimethyldiallylammonium chloride (PACl-PDMDAAC) in comparison with PACl on coagulation efficiencies and membrane fouling in coagulation-ultrafiltration (C-UF) process were analysed, which was conducted in the conditions of different basicity (B) values and the presence of Mg2+. Results showed that PACl-PDMDAAC enhanced the ability of charge neutralization and absorption bridging, and improved the coagulation efficiency. When B value was 1.5, the flocculant hydrolyzed to form more Alb morphology and effectively removed HA molecules. The presence of Mg2+ could improve the coagulation performance through bridging ability. The results of the ultrafiltration test showed that the flux reduction for PACl was 70%, while the flux reduction for PACl-PDMDAAC was 60% in C-UF process. PACl-PDMDAAC could effectively reduce membrane fouling mainly by reducing strongly attached cake/gel layer. When B value was 1.5, the Alb content of the flocculant was higher and the ability of adsorption charge neutralization was strong, resulting in forming a stable cake layer. Therefore, the membrane fouling was the lightest. In addition, the presence of Mg2+ in raw water reduced the membrane fouling.

This study focused on investigating the effects of polypropylene fiber on the liquefaction resistance of saturated sand. We performed a battery of tests with a state-of-the-art ring shear apparatus on fiber-reinforced saturated sand, considering the influences of fiber content and sand density. Two different shearing methods named shear-torque-controlled (STC) and cyclic-torque-controlled (CTC) were considered for carrying out the tests. An energy approach was chosen to evaluate the results, and the fiber reinforcement mechanisms were analyzed. Our test results showed that in STC tests, the shear strength and shearing time of saturated sand increased proportionally to an increase of fiber content and sand density. The cycles required for liquefaction in CTC tests also increase with an increase in sand density and fiber content. The presence of fibers clearly increases the shear energy required for liquefaction. The shear energy increases with an increase in sand density and fiber content. Greater total shear energy is required in specimens with a higher density or larger fiber content. Fiber reinforcement in sand has acted as a spatial network in interlocking soil grains, thereby resulting in the necessity of more energy for overcoming the resistance during the shearing process. After performing the shearing test, the unreinforced specimen with loose structure collapsed totally, and the one with a dense structure collapsed partially, while fiber reinforcement specimens still maintained structural stability.

As renewable and environment-friendly materials, coir and sisal natural fibers can be used in soil reinforcement with minimum cost and other benefits. In this study, we focused on their improvements of unconfined compressive properties of polymer treated sand. In total, 36 groups of unconfined compressive strength tests, combined with X-ray diffraction and scanning electron microscope investigations were performed. We had studied the effects of polymer and fiber contents, and fiber types on the reinforcement effectiveness. The results showed that both coir and sisal fiber can improve the mechanical properties and microstructure of treated sand. In terms of strength properties, sisal fiber inclusion was better than coir fiber, while both have a similar reinforcement benefit on soil ductile behaviors. The strength and compressive energy increased with an increment in polymer and fiber content. The reinforced sand can have up to 1 MPa compressive strength and 140 kPa compressive energy for coir fiber inclusion, while 1.2 MPa and 170 kPa, respectively, for sisal fiber. The axial stress-strain characteristics and failure patterns were also improved, and the brittle index decreased toward zero, which suggests an increasing ductile. The polymer membrane enwrapping and bonding sand grains, and the network structure built by fiber crossing and overlapping among sand grains, as well as the interfacial attachment conferred by polymer between sand grains and fiber, all contributed to the reinforcement of treated sand.

The significant criterion for evaluating the merits of a new type of high molecular polymer lies in its engineering properties and eco-friendliness. The focus of this study was to determine the effects of preparation conditions on the viscosity of the polyvinyl acetate (PVAc) emulsion, including reaction temperature (Tr), initiator concentration (CAPS), monomer concentration (CVA), pH value, and degree of dilution (Ddi). Based on the results of a series of laboratory tests, the range of viscosity value of PVAc was obtained under different conditions, and one set of viscosity values out of these was applied to soil reinforcement tests. Meanwhile, based on the test results, the engineering properties of PVAc solution were evaluated using strength and moisture retention tests, and the reinforcement mechanism was analyzed using scanning electron microscopy (SEM). In addition, it was proven through a vegetation growth test that the PVAc was eco-friendly.

Aggregation-induced emission (AIE) is currently receiving intense interest because of its important implications in photophysics. The structure-property relationship decipherment of AIE luminogens is of crucial importance for the fundamental understanding and application exploration. In this research, a series of novel luminogens based on phosphindole oxide (PIO), including a peculiar one with a folded conformation and apparent through-space conjugation, were synthesized and studied as models to elucidate the AIE mechanism. The significant impacts of steric, conjugation and electronic effects on the AIE property are presented based on the results of crystallography analysis, optical spectra measurements and theoretical computation. Non-doped yellow organic light-emitting diodes were fabricated with the new PIO-based luminogens, and they exhibited high brightness, good electroluminescence efficiencies and low efficiency roll-off.

The penetration of solar energy continues to rise and becomes a central piece of the global energy mix. Thus, considering ways for more efficiently operated power systems to accommodate significant amounts of such a variable resource will be increasingly important. Improvements in solar forecasting methods and techniques will clearly be relevant. In addition to season and irradiation angle, the most important factor of influencing solar energy output is the effect of cloud movement on solar irradiation shadow on solar plate. This paper briefly analyzes the advantages and disadvantages of various moving target algorithms, and compares the typical feature matching algorithm (block motion estimation algorithm) and optical flow algorithm (CLG algorithm) against the collected cloud movement image sequence. The result shows that optical flow algorithm (CLG algorithm) is applied to cloud movement image. The calculation is very fast, with an accuracy above 96%. A comparison with CLG algorithm shows that direction and speed accuracy of block motion estimation algorithm based on hexagonal search pattern is 0.79 and 0.47, respectively.

BCB is emerging as an attractive bonding adhesive for wafer bonding in 3-D integration. Although the bonding strength of BCB is satisfactory with the assist of adhesion promoter, it is found that BCB suffers from interface delamination in harsh chemical or thermal conditions. This paper proposes, at chemical bond level, that the mechanism of interface delamination in KOH solution is attributed to the decomposition of Si O Si bonds at the interface between substrates and AP3000 adhesion promoter as a result of hydrolysis. Silicon dioxide and silicon nitride films with various densities of Si H and Si N bonds are prepared, and the bond densities are measured using infrared spectroscopy. The corresponding interface delamination rates of these films and BCB in KOH solution are measured, and the relations between the bond densities and the delamination rates are obtained for silicon dioxide and silicon nitride. It shows that the delamination rates decrease with the increase in the densities of Si O Si. These results demonstrate that the decomposition of Si O Si in KOH is the main reason for BCB delamination, and increase in the density of Si O Si improves the bonding strength.

Thiolate-protected gold nanoclusters, Aum (SR)n , have potential applications in many fields due to their high stability and remarkable electronic properties. However, the controlling factors in determining the stability and HOMO-LUMO gap of Aum (SR)n remain controversial, despite decades of work on the topic. Through DFT calculations, including nonlocal many-body dispersion (MBD) interactions, the geometric and electronic properties of Aum (SR)n clusters are investigated. Calculations demonstrate that the MBD interactions are essential for correctly describing the geometry and energy of the clusters. Greater anisotropic polarization and more atoms distributed in the shell of the clusters lead to more pronounced MBD interactions and higher stability of the clusters. Furthermore, the HOMO-LUMO gap of the clusters strongly depends on the gold core. These results provide critical clues for understanding and designing Aum (SR)n clusters.

Epichlorohydrin-dimethylamine (DAM-ECH) copolymer was acquired by polycondensation of hazardous reagents: epichlorohydrin (analytical reagent, A.R.) and dimethylamine (A.R.) with ethanediamine (A.R.) as cross-linker. Its coagulation and membrane performance as coagulation aid of polyferric chloride (PFC) was evaluated by comparing with other two cationic coagulation aids: poly dimethyl diallyl ammonium chloride (PDMDAAC) and polyacrylamide (PAM) in humic acid-kaolin (HA-Kaolin) simulated water treatment. Firstly, optimum dosages of PFC&DAM-ECH, PFC&PDMDAAC and PFC&PAM were identified according to their coagulation performance. Then their impacts (under optimum dosages) on membrane fouling of regenerated cellulose (RC) ultra-membrane disc in coagulation-ultrafiltration (C-UF) process were reviewed. Results revealed that small addition of DAM-ECH was the effective on turbidity and DOC removal polymer. Furthermore, in the following ultra-filtration process, external membrane fouling resistance was demonstrated to be the dominant portion of the total membrane fouling resistance under all circumstances. Meanwhile, the internal membrane fouling resistance was determined by residual of micro-particles(1) that cannot be intercepted by cake layer or ultrafiltration membrane.

In this paper, simplified mechanical models for the design of the top wind girder of large storage tanks adopted in the codes SH3046 and API650 were presented to show their differences regarding the wind load magnitude and action zone. Finite element models for the tanks were built to study the strengthening effects of the bottom constraints. It is found that for a large storage tank with a small ratio of height to diameter, the strengthening effects of the bottom constraints are significant and should not be ignored. If based on two-dimensional models without considering the strengthening effects of the bottom constraints, the strength design of the top wind girder according to the present codes of SH3046 or API650 is too conservative.

Due to the loose packing of natural sand, great efforts have been intended to achieve its stabilization and prevent associated engineering failures. As a new soil reinforcement technique, the combined treatment using chemical stabilization and fiber reinforcement has drawn increasing attentions. The focus of this study is to investigate the effect of short fiber types (including polypropylene, basalt and glass fibers) on the mechanical performance of polyurethane (PU) polymer treated sand. Unconfined compressive and tensile tests were performed and analyzed to infer the degree of strength enhancement with different types of fiber reinforcements. Also, intrinsic mechanism and variation in the microstructure were studied by scanning electron microscopy (SEM). The results showed that the strength properties and brittle behaviors were improved greatly by fiber incorporation in comparison with only polymer reinforcement. With same content, polypropylene fiber imparted greater strength to the treated soil due to its well flexible structure and strength properties as compared to other fibers. As observed, 0.8% polypropylene fiber addition led to an increment in compressive and tensile strength by 108.07% and 295.42% respectively, while with same content basalt fiber imparted 63.91% and 147.06%, and fiberglass imparted 47.92% and 253.08% respectively. Additionally, the change in stress-strain curves and failure mode and enhanced value of brittleness index (about 2 to 4 times) indicated increasing ductility. The presence of polymer provided cementation the soil matrix, which also led to great bond strength in grains contacts and fiber-grains contacts. The fibers exhibited stretching and breakage rather than sliding through the soil during failure, which was commonly observed in monofilament polypropylene fiber reinforcement. Soil mechanical properties were also influenced by dry density. As observed, the strength properties got better with increasing dry density while the brittleness became worse, due to enhanced interfacial friction at fiber-sand and sand-sand interface. It was observed that the soil reinforcement with polymer and fiber displayed high strength and modulus for its efficient use being influenced by softness, strength properties, density and size of different fiber types.

Carbon-based hole-transporting material (HTM)-free CsPbBr3 perovskite solar cells (PSCs) provide new opportunities for promoting the commercial application of PSCs because of the low cost, simple preparation process and excellent stability under various extreme conditions. One of the remaining problems for inorganic CsPbBr3 PSCs is the low power conversion efficiency (PCE) due to the large energy level difference and inefficient hole extraction at CsPbBr3/carbon interface. Herein, polyaniline/graphite (PANi/G) composites are incorporated into carbon electrode to tailor work function and to improve hole-selectivity of back electrode for enhanced energy level alignment and interfacial hole extraction, leading to a remarkably reduced energy loss and charge recombination. The HTM-free CsPbBr3 PSC based on carbon-PANi/G electrode achieves a PCE of 8.87%, which is increased by 43.8% in comparison with 6.17% for the control device. Moreover, the unencapsulated device shows excellent long-term moisture tolerance with the initial PCE maintaining 93.5% even exposure to air atmosphere with 80% RH at 25 °C over 50 days. The successful improvement of energy level alignment and charge extraction in device by directly incorporating PANi/G composites into carbon electrode offers a promising strategy in developing low-cost and efficient HTM-free PSCs.

Hierarchical N-doped porous carbon has been prepared by assembling N-doped graphene quantum dots (N-GQDs) onto a carbonized metal-organic framework (cMOF-5) and used as an electrode material for supercapacitors. In this hierarchical composite structure, cMOF-5 provides an effective cubic porous framework with a large specific surface area and good electrical conductivity, while N-GQDs play an important role in enhancing the pseudocapacitive activity and improving the surface wettability of the electrode. Therefore, the N-GQD/cMOF-5 composite electrode material exhibits an outstanding specific capacitance of 780 F g-1 at 10 mV s-1 in a three-electrode system. Moreover, the composite electrode assembled in symmetric supercapacitors also displays a high specific capacitance of 294.1 F g-1 at 0.5 A g-1, excellent rate capacity and remarkable cycling stability with 94.1% of the initial capacitance retained after 5000 cycles at 5 A g-1. When used as the positive electrode, the N-GQD/cMOF-5//AC asymmetric supercapacitor exhibits an energy density of 14.4 W h kg-1 at a power density of 400.6 W kg-1, while the capacitance retention after 5000 cycles reaches 90.1%. The current N-GQD/cMOF-5 composite electrode paves a feasible avenue to improve the capacitive performances of supercapacitors by constructing heteroatom-doped, hierarchically porous carbon architectures.

To operate with limited sensor horizons in unpredictable environments, autonomous robots use a receding-horizon strategy to plan trajectories, wherein they execute a short plan while creating the next plan. However, creating safe, dynamically-feasible trajectories in real time is challenging; and, planners must ensure persistent feasibility, meaning a new trajectory is always available before the previous one has finished executing. Existing approaches make a tradeoff between model complexity and planning speed, which can require sacrificing guarantees of safety and dynamic feasibility. This work presents the Reachability-based Trajectory Design (RTD) method for trajectory planning. RTD begins with an offline Forward Reachable Set (FRS) computation of a robot's motion when tracking parameterized trajectories; the FRS provably bounds tracking error. At runtime, the FRS is used to map obstacles to parameterized trajectories, allowing RTD to select a safe trajectory at every planning iteration. RTD prescribes an obstacle representation to ensure that obstacle constraints can be created and evaluated in real time while maintaining safety. Persistent feasibility is achieved by prescribing a minimum sensor horizon and a minimum duration for the planned trajectories. A system decomposition approach is used to improve the tractability of computing the FRS, allowing RTD to create more complex plans at runtime. RTD is compared in simulation with Rapidly-Exploring Random Trees and Nonlinear Model-Predictive Control. RTD is also demonstrated in randomly-crafted environments on two hardware platforms: a differential-drive Segway, and a car-like Rover. The proposed method is safe and persistently feasible across thousands of simulations and dozens of real-world hardware demos., The first two authors contributed equally to this work

Flexible supercapacitors have shown enormous potential for portable electronic devices. Herein, hierarchical 3D all-carbon electrode materials are prepared by assembling N-doped graphene quantum dots (N-GQDs) on carbonized MOF materials (cZIF-8) interweaved with carbon nanotubes (CNTs) for flexible all-solid-state supercapacitors. In this ternary electrode, cZIF-8 provides a large accessible surface area, CNTs act as the electrical conductive network, and N-GQDs serve as highly pseudocapactive materials. Due to the synergistic effect and hierarchical assembly of these components, N-GQD@cZIF-8/CNT electrodes exhibit a high specific capacitance of 540 F g-1 at 0.5 A g-1 in a 1 m H2 SO4 electrolyte and excellent cycle stability with 90.9% capacity retention over 8000 cycles. The assembled supercapacitor possesses an energy density of 18.75 Wh kg-1 with a power density of 108.7 W kg-1 . Meanwhile, three supercapacitors connected in series can power light-emitting diodes for 20 min. All-solid-state N-GQD@cZIF-8/CNT flexible supercapacitor exhibits an energy density of 14 Wh kg-1 with a power density of 89.3 W kg-1 , while the capacitance retention after 5000 cycles reaches 82%. This work provides an effective way to construct novel electrode materials with high energy storage density as well as good cycling performance and power density for high-performance energy storage devices via the rational design.

Strong static magnetic field (SSMF) is a unique way to regulate the microstructure and improve the properties of materials. FeCoNi(AlSi)0.2 alloy is a novel class of soft magnetic materials (SMMs) designed based on high-entropy alloy (HEA) concepts. In this study, a strong static magnetic field is introduced to tune the microstructure, mechanical, electrical and magnetic properties of FeCoNi(AlSi)0.2 high-entropy alloy. Results indicate that, with the increasing magnetic field intensity, the Vickers hardness and the saturation magnetization (Ms) increase firstly, and then decrease and reach the maximum at 5T, while the yield strength, the residual magnetization (Mr) and the coercivity (Hc) take the opposite trend. The resistivity values (ρ) are found to be enhanced by the increasing magnetic field intensity. The main reasons for the magnetic field on the above effects are interpreted by microstructure evolution (phase species and volume fraction), atomic-level structure and defects (vacancy and dislocation density).

In this study, a novel polysaccharide (PCPs) was obtained from bamboo shoots (Chimonobambusa quadrangularis) processing by-products through the ultrasonic-assisted extraction (UAE) and Sephadex G-100 size-exclusion chromatography purification. By using a Box-Behnken design (BBD) to optimize the parameters for extracting the crude PCPs with UAE, the maximum yield of crude PCPs (8.76%) was obtained under the optimal extraction conditions as follows: ratio of water to raw material 20.2mL/g, extraction temperature 49°C, ultrasonic power 240W, and extraction time 40min. Structurally, PCPs was identified as hetero-polysaccharides, which was composed of Man, Rha, GlcA, GalA, Glc, Gal, Xyl, and Ara in a molecular ratio of 1.00:2.05:2.28:2.36:15.76:49.06:16.70:39.86. The molecular weight distribution analysis showed that PCPs had three components with molecular weights of 136.1, 29.7 and 8.3kD, respectively. The glycosidic linkage analysis showed that PCPs contained 1→or 1→6 glycosidic linkages (35.1%), 1→2 or 1→4 glycosidic linkages (14.8%), and 1→3 glycosidic linkages (50.1%). conformations. The obtained results revealed that PCPs with a semi-crystalline structure exhibited important functional properties including the repose angle, swelling index (SC), water retention capacity (WRC), and oil retention capacity (ORC). The viscoelastic property of PCPs system exhibited a gel-like behavior with storage modulus G' always being higher than loss modulus G″. PCPs displayed excellent thermal stability as assessed by rheology and TGA/DSC. Furthermore, PCPs exhibited good chemical antioxidant activities in DPPH, ABTS and hydroxyl radical scavenging abilities, and metal chelating activity.

The use of robots has been proposed as promising human assistants in accomplishing tasks that are otherwise too tough or dangerous to be executed by human alone. As robots in different forms have their differentiating strengths, a system that uses a combination of these robots can be more robust and resilient in achieving its mission. For example, UAVs can be used to quickly explore an unknown environment while ground robots can be used to navigate through the environment, clearing obstacles and potential dangers for human to enter. In this work, we design a unifying framework to allow human to control and accomplish an exploration mission using heterogeneous robot types. A prototype system is implemented using the Google Tango to control an UAV and a wheeled robot for the human to perform environment mapping. Preliminary experiments have been carried out to study the feasibility of the system.

Effects of ozonation and powdered activated carbon on removal of dissolved organic matter (DOM) and disinfection by-product (DBP) in reservoir water were intensively investigated in this study. Both the formation of carbonaceous DBP (C-DBP) and nitrogenous DBP (N-DBP) as well as their speciation were analyzed. Results exhibited that the addition of powdered activated carbon (PAC) greatly improved the removal of aromatic protein. Trihalomethanes (THMs) and haloacetonitriles (HANs) were the dominant species in C-DBP and N-DBP. The integrated coagulation and PAC processes could remove more than 70% of THMs and 93% of HANs precursors, while only 10.5 and 45% of capture were achieved by the single coagulation. The added ozone lowered the yields of HANs but synchronously increased the more toxic bromine-containing THMs from 78.5 to 128.1 μg/L. Kinetics parameters for THM formation indicated that the precursor creating the THMs fast could be easily removed by both the coagulation and PAC adsorption.

We have demonstrated a high power and high efficiency thulium-doped silica fiber laser using a cascade tandem pumping method. A 1915nm Tm-doped fiber laser was used as a pump source for another Tm-doped fiber laser with the output power of 63W at 1980nm, corresponding to the slope efficiency of ~80%, which is the highest power to our best knowledge. And the 3dB bandwidth was 0.24nm. The 1915nm Tm-doped fiber laser was pumped by 793nm diode laser and the slope efficiency was 51%. The preform of double cladding Tm-doped fiber for the tandem pumped fiber laser was manufactured by MCVD with using the vapor-solution hybrid doping method. The fiber has a ~25μm diameter, 0.098 NA(numerical aperture) core and 400μm diameter, 0.46 NA inner cladding. In the tandem pumped fiber laser, the resonant cavity consist of a high reflection FBG at 1980nm, flat fiber end and the homemade Tm-doped silica fiber. The optimal active fiber length was presented and it is found that when the length of homemade Tm-doped silica fiber was 7m, the efficiency was the highest. The influence of Tm concentration and ratio of Tm ion and Al ion on the efficiency was also explored. And it is found that the thulium-doped silica fiber with lower Tm concentration and higher Tm:Al ratio had lower optical efficiency. Meanwhile, the optimal fiber length became shorter.

Adding acid control of the circulating water in thermal power plants is one of the important measures of water quality regulation. It is a very complex industry control process, which has the characteristics including nonlinear with description difficulty, pure lag(delay), large inertia, time-varying, etc. For the adding acid control system in thermal power plants, normal PID control can not achieve ideal control effect. On this basis, a new fuzzy PID control strategy based on expert system is put forward in this paper. The simulation experiment is carried out with MATLAB. The results demonstrate that in adding acid control system of circulating water with hysteretic and nonlinear characteristics, the expert fuzzy PID control proposed in this paper can greatly improve the dynamic performance of system which has strong adaptability and robustness, and better control effect is obtained as a result.

Two kinds of aluminum-based coagulants and epichlorohydrin-dimethylamine (DAM-ECH) were used in the treatment of humic acid-kaolin simulated water by coagulation-ultrafiltration (C-UF) hybrid process. Coagulation performance, floc characteristics, including floc size, compact degree, and strength were investigated in this study. Ultrafiltration experiments were conducted by a dead-end batch unit to implement the resistance analyses to explore the membrane fouling mechanisms. Results showed that DAM-ECH aid significantly increased the UV254 and DOC removal efficiencies and contributed to the formation of larger and stronger flocs with a looser structure. Aluminum chloride (Al) gave rise to better coagulation performance with DAM-ECH compared with poly aluminum chloride (PACl). The consequences of ultrafiltration experiments showed that DAM-ECH aid could reduce the membrane fouling mainly by decreasing the cake layer resistance. The flux reductions for PACl, Al/DAM-ECH (dosing both Al and DAM-ECH) and PACl/DAM-ECH (dosing both PACl and DAM-ECH) were 62%, 56% and 44%, respectively. Results of this study would be beneficial for the application of PACl/DAM-ECH and Al/DAM-ECH composite coagulants in water treatment processes.

Ultra-filtration technology has been increasingly used in drinking water treatment due to improvements in membrane performance and lowering of costs. However, membrane fouling is the main limitation in the application of ultra-filtration technology. In this study, we investigated the impact of four different pre-treatments: Coagulation, adsorption, coagulation followed by adsorption (C-A), and simultaneous coagulation and adsorption (C+A), on membrane fouling and natural organic matter removal efficiency. The results showed that adsorption process required a large amount of adsorbent and formed a dense cake layer on the membrane surface leading to severe membrane fouling. Compared to adsorption alone, the coagulation and C-A processes decreased the transmembrane pressure by 4.9 kPa. It was due to less accumulation of particles on the membrane surface. As for water quality, the C-A ultra-filtration process achieved the highest removal efficiencies of natural organic matter and disinfection by-product precursors. Therefore, the addition of adsorbent after coagulation is a potentially important approach for alleviating ultra-filtration membrane fouling and enhancing treatment performance.

In modern manufacturing industries, machines are connected and shared within the manufacturing network. Thus, IoT (Internet of Things) and information technologies are widely applied in the smart factory, among which RFID (Radio Frequency Identification) devices are the most important elements to collect real time data and track important objects. With the continuously developing and widely applications of RFID technology, huge amount of RFID data would be generated during manufacturing processes. In this paper, an intelligent factory framework based on RFID is proposed and massive RFID data is produced. Then the unique characteristics of RFID data in intelligent factory are analyzed, and an algorithm of mining frequent patterns based on Apriori is designed to mine the frequent path knowledge. The algorithm is helpful for the production planning and task scheduling of intelligent factory.

The mechanical properties of sandy soil can be effectively improved by the incorporation of water-based polymer and glass fibers. In order to study the reinforcement effects of a type of water-based organic polymer and fiber glass on sand, three strength tests (unconfined compression test, direct shear test and tensile test) and scanning electron microscopy were carried out. A series of polymer content, fiber content and dry density were selected for the tests. The results revealed that the composite reinforcement of water-based organic polymer and fiber glass can improve the strength. With an increase in polymer content and fiber content, the unconfined compression strength, the cohesion, and the tensile strength increase. The internal friction angles maintain a relatively stable state. All three strength properties increase with an increase in dry density. The results can be considered as the reference for sand reinforced engineering.