Search

The pricing and reverse logistics network design problem in remanufacturing has attracted considerable attention in recent years due to increasingly serious environmental problems. In this study, we consider a pricing and reverse logistics network design problem with price-dependent return quality uncertainty. To handle the high uncertainty in return quality, we propose a distributionally robust risk-averse model to safeguard the profits of investors in extreme situations. We propose a Benders decomposition approach to solve the proposed model. It is enhanced through valid inequalities, local branching, in-out variant methods and scenario-based aggregated cuts. Computational experiments demonstrate that the distributionally robust model can effectively hedge against high uncertainty and that the enhanced Benders decomposition methods significantly outperform their classical counterparts and the off-the-shelf solver Gurobi. Lastly, managerial insights are explored, and future research directions are outlined.

The precooled turbine engine is applied to overcome the limitation of Mach number due to high temperature inlet air. This paper aims to investigate the effect of water injection cooling on the high-temperature intake air. Then, the theory evaluation and Eulerian-Lagrangian multiphase flow method are conducted to explore the thermodynamic process and resistance characteristics of the pre-cooling section built-in even spray apparatus with a drag reduction. Results show that larger amount of the injection flow rate at higher Mach number will deteriorate total pressure loss and flow field uniformity. Evaporation cooling can decrease flow loss by 9.4%–60.7%. Within 27 ms, total-temperature drop is in 14–144 K range with a low total-pressure drop coefficient of 0.56%–1.29%. Especially, mass flow will increase by 1.15%–18.50%. Thus, water injection cooling is conducive to a higher acceleration, as well as for improving the thermodynamics characteristics of inlet air for a turbine engine at a high Mach number.

Overlap and grouping functions as two kinds of special continuous, commutative aggregation functions have wide applications in image processing and classification. Modularity conditions between the class of overlap (grouping) functions satisfying O ( 1 , e ) = e ( G ( 0 , e ) = e ) and special classes of uninorms, and those of another special class of overlap (grouping) functions over nullnorms have been studied in [49] . In this paper we extend these results to any overlap (grouping) function. Moreover, we study the modularity conditions between overlap (grouping) functions and uni-nullnorms (null-uninorms), which are the generalization of uninorms (nullnorms).

Indium Tin Oxide (ITO) films were prepared, at room temperature, on a fluorphlogopite substrate using magnetron sputtering technology. At various temperatures of 500 °C, 600 °C, 700 °C, 800 °C, and 900 °C, the samples were (had) annealed for 2 h (a 2-h duration). The results showed improvement in the crystalline performance of ITO film at selected annealing temperatures, with a significant reduction in resistivity at 800 °C. The lowest resistivity is 4.08 × 10−4 Ω-cm, which is nearly an order of magnitude lower than the unannealed sample. All samples have an average light transmittance above 85% in the visible light range (400–800 nm), and with increasing annealing temperature, the average light transmittance tends to decrease. Besides, at the sensitive wavelength of 550 nm, the light transmittance is as high as 93.74%. The sheet resistance testing of the sample was through the number of bending times, which revealed that with the increase of the number of bending, the sheet resistance increases. However, after 1200 bending times, the change rate of the sheet resistance remains below 5%. Thus, the ITO film prepared on the flexible fluorphlogopite substrate revealed excellent optical and electrical properties, good flexibility, and improved stability after high-temperature annealing, which guarantees successful application in flexible electronic devices.

Based on a laser locked to the cesium Fg = 4 → Fe = 5 closed transition, we present the results of an investigation of nonlinear magneto-optical rotation (NMOR) using an uncoated buffer-gas-free cesium cell at room temperature under a near zero magnetic field, which has a reversal rotation signal and optimum rotation slope of − 46 rad/mT. Meanwhile, a magnetometer which has a simple structure and is available for cardiac magnetic measurement is reported. The magnetometer has a sensitivity of 0.3 pT/Hz1/2, which is limited by the photon-shot noise. Using a model for the interactions of atoms and linearly polarized light with arbitrary intensity that we built, we analyze the influence of the laser intensity on the linear dichroism of polarized atoms and the slope of the NMOR. The result of our theoretical analysis agrees with the experimental data. We also demonstrate that the intensity relative to zero slope is much less than the saturation intensity of the transition, because the rotation derives from the superposition of alignment precessions of Fg = 4 → Fe = 4,5 transitions and because the Fe = 5 state has a greater gyromagnetic ratio and total quantum number than Fg = 4 state does.

Based on investigation of rural buildings in china, there are more than 20% of the masonry structures constructed in 1970s. Thus, the old blue bricks (OBB) and old red bricks (ORB), which demolished from the typical brick masonry structures was built in 1970s, was chosen in the test. During demolishing the OBB and ORB, the original mortar was destroyed. Thus, the 1:7.8 cement mortar was chosen instead of original mortars and the 1:5 cement mortar was chosen as the reinforcement mortar. In order to know the performant of the reinforcement methods, there are three-level test plan was put forward in the study. Firstly, the mechanical properties of OBB and ORB and mortars was tested; Secondly, the experiment tested the shear strength of the reinforced and unreinforced masonry specimens along mortar joints; Thirdly, there are four walls (OBB reinforced wall and unreinforced wall, ORB reinforced wall and unreinforced wall) have been made for the pseudo-static tests. This research conducted physical performance tests on masonry bricks, masonry components, and masonry walls of typical masonry structures. Through experiments, the shear capacity of the masonry structure reinforced by high-strength mortar and steel bars can be obtained.

Customer satisfaction is a prevalent issue amongst manufacturing enterprises. Multi-agent scheduling models aim to optimise the given criteria for improving customer satisfaction by fulfilling the ...

With the wide application of natural gas, in order to increase the sustainability of buried utility tunnel and prevent the explosion of the gas pipeline cabin from threatening process safety, the performance of the partition wall (slab) of the cabin against gas explosion should be investigated. This paper presents the protective effect of unbonded prestressed ultra-high performance reinforced concrete slab (UPUHPRCS) against gas explosion in buried utility tunnel. There were four scenarios in the experiment, among which the variables were the length of tunnel (12,000 mm and 20,000 mm) and gas concentration (7.5 % and 9.5 %). The normal strength reinforced concrete slab (NSRCS) and ultra-high performance reinforced concrete slab (UHPRCS) were tested as reference specimens, and the simple supported steel slab fixed by stacking sandbags was compared with the concrete slab fully constrained on the tunnel. The overpressure curves caused by gas explosions in the tunnel, the damage of each concrete slab and the change of deflections were obtained through the tests. The results indicated that with the increase of the length of the buried utility tunnel, the power of gas explosion will further increase, and the UPUHPRCS, as the partition wall of the gas pipeline independent cabin in the buried utility tunnel, will play an excellent role in against gas explosion. Moreover, the gas explosion may have little effect on the circular section pipeline in the independent cabin.

This paper presents a novel medical image registration algorithm named total variation constrained graph-regularization for non-negative matrix factorization (TV-GNMF). The method utilizes non-negative matrix factorization by total variation constraint and graph regularization. The main contributions of our work are the following. First, total variation is incorporated into NMF to control the diffusion speed. The purpose is to denoise in smooth regions and preserve features or details of the data in edge regions by using a diffusion coefficient based on gradient information. Second, we add graph regularization into NMF to reveal intrinsic geometry and structure information of features to enhance the discrimination power. Third, the multiplicative update rules and proof of convergence of the TV-GNMF algorithm are given. Experiments conducted on datasets show that the proposed TV-GNMF method outperforms other state-of-the-art algorithms.

The ride quality of the railway vehicle is not only affected by the wheel-rail contact geometry but also by the yaw damper. In order to explore this variation law, an equivalent parameter model of the yaw damper was established based on the internal characteristics of the yaw damper, which is both accurate and efficient. Then, considering the influence of wheel wear and wheel-rail contact geometry, ride quality of the railway vehicle under different parameters of yaw damper and wheel-rail contact parameters was analysed. The results show that the wheel-rail contact points are scattered on the wheel profile after the wheel wears out, and the equivalent conicity also tends to increase with the increasing operating mileage. The distribution of ride quality space is sensitive to the change of equivalent conicity. In the low equivalent conicity area, the expansion rate of excellent ride quality space is faster. In the high equivalent conicity area, the expansion rate of qualified ride quality space is faster. Appropriate additional stiffness which is oil stiffness in parallel with structural damping in the equivalent parameter model of the yaw damper can improve the vehicle ride quality. The lateral ride quality is influenced obviously with the condition of the damping of the yaw damper being less than 440 kN·s·m−1. Properly reducing the joint stiffness of the yaw damper could reduce the influence of characteristic parameters of the yaw damper and equivalent conicity of the wheel-rail contact on vehicle lateral ride quality. The optimized characteristic parameters of the yaw damper are used in the actual vehicle test, and the ride quality is effectively improved.

Closed-loop supply chains (CLSCs) have received considerable attention because of various economic and regulatory factors. A CLSC is characterized by more complicated network structures and higher uncertainties compared to traditional supply chain networks. Therefore, reliable CLSCs are being increasingly emphasized in academic circles due to the vast impacts of disruptions such as natural disasters and terrorist attacks. This paper studies a reliable location-inventory problem in a CLSC considering the mutual effects between failures of forward and reverse distribution centers (DCs) when they are co-located. The disruption probability of a co-located forward DC is different from that of a standalone forward DC, i.e., probabilistic disruptions are dependent on facility type. The problem is formulated as a nonconvex mixed-integer programming problem. A decomposition approach based on the outer approximation (DOA) algorithm is proposed to address the resulting model. The algorithm alternately solves relaxed master problems (mixed-integer linear programs, MILPs) and two nonlinear programming (NLPs) problems. Extensive numerical experiments are conducted to evaluate the performance of the proposed solution approach, after which managerial insights are explored.

The conventional troubleshooting methods for high-speed railway on-board equipment, with over-reliance on personnel experience, is characterized by one-sidedness and low efficiency. In the process of high-speed train operation, numerous text-based on-board logs are recorded by on-board computers. Machine learning methods can help technicians make a correct judgment of fault types using the on-board log reasonably. Therefore, a fault classification model of on-board equipment based on attention capsule networks is proposed. This paper presents an empirical exploration of the application of a capsule network with dynamic routing in fault classification. A capsule network can encode the internal spatial part-whole relationship between various entities to identify the fault types. As the importance of each word in the on-board log and the dependencies between them have a significant impact on fault classification, an attention mechanism is incorporated into the capsule network to distill important information. Considering the imbalanced distribution of normal data and fault data in the on-board log, the focal loss function is introduced into the model to adjust the imbalanced data. The experiments are conducted on the on-board log of a railway bureau and compared with other baseline models. The experimental results demonstrate that our model outperforms the compared baseline methods, proving the superiority and competitiveness of our model.

Based on the ReaxFF-lg reaction force field, the thermodynamic and kinetic quantities of LLM-105 decomposition at different shock waves were analysed. The equation of state, bulk modulus and pressu...

Incense is an indispensable material with religion and life in Asia. It is also a bridge of cultural expression and inheritance. Because the operating environment concentration of dust generated during the production process is considerable, most of the research pertaining to the hazard of incense factories has investigated air pollution, such as PM2.5, PM10, and VOCs. However, the production of incense causes dust dispersion, high temperature from ovens, and static electricity generated by friction. It can all possibly lead a dust explosion. To prevent and alleviate hazard from re-occurring, we used sandalwood dust at an incense factory in Taiwan, measured the effect of moisture content on the explosion parameters under normal conditions by 20-L apparatus, and used the oven to diminish its moisture content to 0%, 10.0%, and 15.0% as a control group to analyze the explosion characteristics at the different moisture contents, such as maximum explosion pressure and explosion limit. The results showed that the minimum ignition energy of dry dust was 30 mJ. Beyond doubt, incense factories face potential explosion hazards. The above results could be evaluated by the most dangerous range to avoid incense dust in this range at the workplace, lessening hazards caused by a dust explosion. The effect of moisture content on the suppression of the dust explosion was explored.

This paper considers the problem of estimating the motion parameters of a low-observable high-speed maneuvering target with high-order motions, where the target’s complex motions will result in the range migration (RM) and Doppler frequency migration (DFM) effects within the observation time interval, which will significantly affect the radar performance. Based on the Hough transform (HT) and the polynomial Chirplet transform (PCT), a novel method for the motion parameter estimation, which we coin as HPCT, is proposed in this paper. It first employs the trajectory feature extracted from the image of range profiles by the HT to correct the first-order RM and resolve the Doppler ambiguity. Then, it compensates the residual range curvature and the DFM with the motion parameters estimated from the time-frequency ridge, which is extracted from the highly concentrated time-frequency representation (TFR) generated by the PCT. After that, the energy of radar returns can be coherently integrated along the target’s moving trajectory. In addition, we evaluate the parameter estimation performance, integration performance and computational cost of the proposed method via theoretical analysis or numerical experiments. The results show that in terms of the anti-noise ability, cross-term interference avoidance, measurement accuracy and computational complexity, the HPCT is superior to some common methods for the motion parameter estimation. Finally, we extend it to the scenario of multiple targets with different motion orders.

A semi-empirical model was proposed to estimate the apparent viscosity of gas-fluidized suspensions. This new model was derived by assuming that a suspension consisted of the bubble phase and the emulsion phase. A set of experimental measurements were also conducted to verify the validity of the proposed model as well as the models in the literature. The results indicated that none of the tested literature models provided satisfactory predictions for the fluidized gas-solid suspension over the mentioned target particle volume fraction range. The estimation using the newly proposed model generally well agreed with the experimental apparent viscosity values of the gas-solid suspensions composed of gas-fluidized Geldart Group A or B particles, as most of the estimated values situated within the ±25% error bars. The proposed model is of special significance as it provides a quick estimation method of the apparent viscosity of a gas-solid suspension flow in the engineering calculation.

Developing organic dyes with di-/multi-anchors has aroused increasing attention in recent years due to these dyes had many advantages in comparison with the analogues of single acceptor. Herein, four (D–π–A)-L2-(A–π–D–π–A)2 dyes (TQ1−2, OQ1−2) along with a reference D−(π–A)2 dye (TD), comprising phenothiazine/phenoxazine as a donor, thiophene as a π space, cyanoacetic acid as an acceptor and saturated n-hexyl/n-dodecyl as a flexible linker have been prepared and characterized. The correlative between the variation of structure and the optical, electrochemical properties in addition to photovoltaic performances of the dyes have been explored. Besides, the ultraviolet–visible spectra in solution and on the TiO2 film, cyclic voltammetry, photocurrent-voltage scan, incident photon-to-current conversion efficiency and electrochemical impedance spectroscopic of the presented dyes have been investigated. Compared with the reference dye TD, TQ1−2 and OQ1−2 exhibit higher molar extinction coefficient, broader and stronger incident photon-to-current conversion efficiency response spectrum, and higher density of light-absorbing units adsorbed on the TiO2 surface. Among the cells based on the pristine dyes, the relatively high photocurrent of OQ1-2 by comparison with the counterparts of TQ1−2 is attributed to the incorporation of phenoxazine donor into the (A–π–D–π–A)2 units. An increase open-circuit voltage of TQ2 and OQ2 compared to TQ1 and OQ1 is ascribed to the higher charge recombination resistance and the longer electron lifetime in their cells. Consequently, a maximum power conversion efficiency of 6.77% is attained by the TQ2-based cells with iodide/triiodide electrolyte under the illumination of 100 mW cm−2.

Visual-Inertial Odometry (VIO) fuses measurements from camera and Inertial Measurement Unit (IMU) to achieve accumulative performance that is better than using individual sensors. Hybrid VIO is an extended Kalman filter-based solution which augments features with long tracking length into the state vector of Multi-State Constraint Kalman Filter (MSCKF). In this paper, a novel hybrid VIO is proposed, which focuses on utilizing low-cost sensors while also considering both the computational efficiency and positioning precision. The proposed algorithm introduces several novel contributions. Firstly, by deducing an analytical error transition equation, one-dimensional inverse depth parametrization is utilized to parametrize the augmented feature state. This modification is shown to significantly improve the computational efficiency and numerical robustness, as a result achieving higher precision. Secondly, for better handling of the static scene, a novel closed-form Zero velocity UPdaTe (ZUPT) method is proposed. ZUPT is modeled as a measurement update for the filter rather than forbidding propagation roughly, which has the advantage of correcting the overall state through correlation in the filter covariance matrix. Furthermore, online spatial and temporal calibration is also incorporated. Experiments are conducted on both public dataset and real data. The results demonstrate the effectiveness of the proposed solution by showing that its performance is better than the baseline and the state-of-the-art algorithms in terms of both efficiency and precision. A related software is open-sourced to benefit the community.① https://github.com/PetWorm/LARVIO①

This study applied vacuum-impregnated casting thin sections, fluorescence slices, scanning electron microscopy (SEM), pressure-controlled mercury porosimetry (PCP), rate-controlled mercury porosimetry (RCP), X-ray diffraction of clay minerals, overburden pressure, and conventional physical property strategies to determine the microscopic characteristics of the Chang 6 member, a typical tight sandstone reservoir in the Jingbian oilfield in the Ordos Basin, China. We also analyzed the controlling effects of pore structure on reservoir quality and oiliness. The results showed that the pore types of the Chang 6 sandstone reservoir can be divided into four categories: residual intergranular pores, dissolution pores, intercrystalline pores between clay minerals, and microfractures. The pore size of the Chang 6 sandstone reservoir ranged from 20 to 50 μm. We employed PCP and RCP strategies to characterize the pore structure of the Chang 6 reservoir. The pore radius was less than 2 μm, and on average, the throat radius was less than 0.3 μm. The reservoir physical properties were affected by diagenesis, particularly compaction, and the average porosity failure rate was 56.3%. Cementation made the reservoir more compact, dissolution improved the physical properties of the reservoir locally, and fracturing effectively improved the reservoir seepage ability; however, its influence on porosity was limited. The pore structure controlled the quality of the reservoir. The physical properties of the reservoir were closely related to the oil-bearing properties. The lower limits of porosity and permeability of industrial oil flow in the reservoir were 7.5% and 0.15 mD, respectively. These results provide an additional resource for the exploration and development of tight oil in the Ordos Basin.

The grinding strategies for worn rails have a significant influence on the service life and maintenance cost of railways. Current grinding strategies, grinding the worn rails to their original profiles, leads to excessive amount of material removed and reduction of rail service life. Based on Non-Uniform Rational B-Spline theory (NURBS), which contributes to the control of curve smoothness, a rail profile reconstruction method was established considering the geometrical characteristics of the rail profile. The design of economical grinding rail profile can be achieved by using optimization method, which regards the amount of material removed and derailment coefficient as objectives, aiming at reducing rail wear. A new rail profile can be designed by integration of Archard wear model, FE contact model and vehicle-track coupling dynamic model. The result indicated that the wear of left and right rail is reduced by 29.26% and 31.06% compared with original CN60 profile, respectively. With the new rail profile, the dynamic performance is improved, and the contact stress, fatigue index and the amount of material removed is reduced. This optimized rail grinding profile contributes to the reduction of rail wear and guarantees the safety of train operation.

Recently, market has witnessed a tremendous growth in E-commerce sales, which bring tons of opportunities as well as challenges. Warehouses have to handle unique characteristics of customer orders in the era of E-commerce which consists of small order scales, large items count, unexpected irregular order arrival patterns, seasonality demand peeks, and high service level expectations. Warehouses are adopting wave-picking as an effective policy composed of item-batching, load-assignment and picker-routing problems. In this research, principle combination of load-assignment and picker-routing problems is studied. A mixed integer mathematical model is established based on features of a wave-picking warehouse. In order to conquer the complexity caused by routing decision of the proposed problem, a set of effective modified Estimation Distribution Algorithms is developed. The set of proposed algorithms is proved to have stable gaps (1% on average and maximum less than 2%) compared with Cplex 12.8, while can be solved in much larger scale within quite short time (100 pickers and 350 items in each wave within less than 2 min).

Exploring the transformation mechanisms of sulfur during the superfine comminution plays a crucial role in constructing a coal macromolecular model and developing clean coal technologies. In this w...

Carbon monoxide (CO), as one of the major gaseous product in the oxy-fuel combustion boiler, is found to exert great influence on nitric oxide (NO)-char reactions. Unfortunately, the detailed mechanism of CO enhancement still remains obscure. In this work, starting from the armchair model with embedded nitrogen, we propose some updated mechanisms with details at the molecular level that can describe the role of CO through energetic and kinetic evaluations based on the combination of density functional theory (DFT), transition state theory (TST) and Chemkin calculations. The preferred pathways are identified with 54 intermediates and 68 transition states. The addition of CO to the surface carbyne site with C-down mode is the most favorable and triggers the low-temperature desorption of CO2 via C C bond dissociation due to its low barrier of approximately 40 kJ/mol. One important role of CO is to react with the surface oxygen atom in the species C(NO) to clean the surface. More specifically, the energy barrier for nitrogen exposure reduced from 311.8 kJ/mol to 243.4 kJ/mol if the aromatic armchair edge is clean, and further reduced to 211.8 kJ/mol with the existence of nearby carbine type site. In addition, N2 desorption, is sensitive to, and largely facilitated by, the presence of CO. The results are of great value to interpret various reported experimental phenomena, including but not limited to, the small effect of CO at high temperatures, the initial NO reduction temperature at char surface, and the important impact of CO on the reaction activation energy.

In this paper, we study the problem of precision matrix estimation when the dataset contains sensitive information. In the differential privacy framework, we develop a differentially private ridge estimator by perturbing the sample covariance matrix. Then we develop a differentially private graphical lasso estimator by using the alternating direction method of multipliers (ADMM) algorithm. Furthermore, we prove theoretical results showing that the differentially private ridge estimator for the precision matrix is consistent under fixed-dimension asymptotic, and establish a convergence rate of differentially private graphical lasso estimator in the Frobenius norm as both data dimension p and sample size n are allowed to grow. The empirical results that show the utility of the proposed methods are also provided.

An experimental study on the ignition of single coal particles at low oxygen concentrations ( $${X_{{{\rm{O}}_2}}} < 21\% $$ ) was conducted using a tube furnace. The surface temperature (Ts) and the center temperature (Tc) of the coal particles were obtained from the images taken by an infrared camera and thermocouples respectively. The ignition processes were recorded by a high-speed camera at different $${X_{{{\rm{O}}_2}}}$$ values and furnace temperatures Tw. Compared with literature experimental data obtained at a high $${X_{{{\rm{O}}_2}}}$$ value, the ignition delay time τi decreases more rapidly as $${X_{{{\rm{O}}_2}}}$$ increases at the low $${X_{{{\rm{O}}_2}}}$$ region. The responses of Ts and Tc to the variation of $${X_{{{\rm{O}}_2}}}$$ are different: Ts decreases while Tc remains nearly constant with increasing $${X_{{{\rm{O}}_2}}}$$ at a low $${X_{{{\rm{O}}_2}}}$$ value. In addition, τi is less sensitive to Tw while the ignition temperature Ti is more sensitive to Tw at a low $${X_{{{\rm{O}}_2}}}$$ value than in air. Observations of the position of flame front evolution illustrate that the ignition of a coal particle may change from a homogeneous mode to a heterogeneous or combined ignition mode as $${X_{{{\rm{O}}_2}}}$$ decreases. At a low $${X_{{{\rm{O}}_2}}}$$ value, buoyancy plays a more significant role in sweeping away the released volatiles during the ignition process.

This work reveals the role of hydrogen in the N2 desorption using DFT calculations at the B3LYP/6-31G(d) level of theory as implemented in Gaussian 16 programme. The addition of one hydrogen on the active site, exothermicity by ≈380 kJ/mol, favors the hydrogenation of nearby active sites (ΔE ≈ 480 kJ/mol) but inhibits the hydrogenation of itself (ΔE ≈ 220 kJ/mol). N1 exposure with the highest barrier of 232.0 kJ/mol is the rate-determining step. By paying attention to this step, the potential roles are clarified: (1) two hydrogen attached to the same site creating a highly hydrogenated environment retards the overall reaction; (2) the attachment of one hydrogen to C2 site inhibits the overall reaction; and (3) the addition of one hydrogen on C1 and C3 sites favors the overall reaction. The proposed mechanism will help to explain various reported findings on the gasification of the carbonaceous surface.

The chemical properties of coal extracts play a crucial role in understanding coal structure, constructing coal model, and developing clean coal technology. However, there is little knowledge about...

In this paper, we study the multinomial logistic regression with interactive effects. Our approach involves the implementation of the pliable lasso penalty which allows for estimating the main effe...

A one-dimensional transient single coal particle combustion model was proposed to investigate the characteristics of single coal particle combustion in both O2/N2 and O2/CO2 atmospheres under the fluidized bed combustion condition. The model accounted for the fuel devolatilization, moisture evaporation, heterogeneous reaction as well as homogeneous reactions integrated with the heat and mass transfer from the fluidized bed environment to the coal particle. This model was validated by comparing the model prediction with the experimental results in the literature, and a satisfactory agreement between modeling and experiments proved the reliability of the model. The modeling results demonstrated that the carbon conversion rate of a single coal particle (diameter 6 to 8 mm) under fluidized bed conditions (bed temperature 1088 K) in an O2/CO2 (30:70) atmosphere was promoted by the gasification reaction, which was considerably greater than that in the O2/N2 (30:70) atmosphere. In addition, the surface and center temperatures of the particle evolved similarly, no matter it is under the O2/N2 condition or the O2/CO2 condition. A further analysis indicated that similar trends of the temperature evolution under different atmospheres were caused by the fact that the strong heat transfer under the fluidized bed condition overwhelmingly dominated the temperature evolution rather than the heat release of the chemical reaction.

Challenges associated with low-drug-loading capacity, lack of active targeting of tumor cells and unspecific drug release of nanocarriers synchronously plague the success of cancer therapy. Herein, we constructed active-targeting, redox-activated polymeric micelles (HPGssML) self-assembled aptamer-decorated, amphiphilic biodegradable poly (benzyl malolactonate-co-ε-caprolactone) copolymer with disulfide linkage and π-conjugated moieties. HPGssML with a homogenous spherical shape and nanosized diameter (∼150 nm) formed a low critical micellar concentration (10−3 mg/mL), suggesting good stability of polymeric micelles. The anticancer drug, doxorubicin (DOX), can be efficiently loaded into the core of micelles with high-drug-loading content via strong π–π interaction, which was verified by a decrease in fluorescence intensity and redshift in UV adsorption of DOX in micelles. The redox sensitivity of polymeric micelles was confirmed by size change and in vitro drug release in a reducing environment. Confocal microscopy and flow cytometry assay demonstrated that conjugating aptamers could enhance specific uptake of HPGssML by cancer cells. An in vitro cytotoxicity study showed that the half-maximal inhibitory concentration (IC50) of DOX-loaded HPGssML was two times lower than that of the control group, demonstrating improved antitumor efficacy. Therefore, the multifunctional biodegradable polymeric micelles can be exploited as a desirable drug carrier for effective cancer treatment.

Purpose Cabazitaxel (CBZ) is a new taxane-based antitumor drug approved by the FDA for the treatment of prostate cancer, especially for patients with advanced prostate cancer for whom docetaxel is ineffective or causes aggravation. However, Tween 80 injection can cause serious allergic reactions, and CBZ itself has strong toxicity, adverse reactions, and poor tumor selectivity, which greatly limits its clinical applications. Therefore, the CBZ-loaded bovine serum albumin nanoparticles (CBZ-BSA-Gd-NPs) were developed to overcome the allergenic response of Tween 80 and realize the integration of diagnosis and treatment. Methods CBZ-BSA-Gd-NPs were prepared by the biomineralization method. The characterization, magnetic resonance imaging (MRI), safety, and antitumor activity of the nanoparticles were evaluated in vitro and in vivo. Results The prepared nanoparticles were uniform in size (166 nm), with good MRI performance and stability over 24 h. Compared with CBZ-Tween 80 injection, CBZ-BSA-Gd-NPs showed much lower hemolysis, similar tumor inhibition, and enhanced cellular uptake in vitro. The pharmacokinetic behavior of CBZ-BSA-Gd-NPs in rats showed that the retention time of the nanoparticles was prolonged, the clearance rate decreased, and the area under the drug-time curve increased. The distribution of CBZ-BSA-Gd-NPs in nude mice was characterized by UPLC-MS/MS and MRI, and the results showed that CBZ-BSA-Gd-NPs could effectively target tumor tissues with reduced distribution in the heart, liver, spleen, lungs, and kidneys compared with CBZ-Tween 80, which indicated that CBZ-BSA-Gd-NPs not only had a passive targeting effect on tumor tissue but also achieved the integration of diagnosis and treatment. In vivo, CBZ-BSA-Gd-NPs showed improved tumor inhibitory effect with a safer profile. Conclusion In summary, CBZ-BSA-Gd-NPs can serve as an effective therapeutic drug carrier to deliver CBZ into prostate cancer, and realize the integration of diagnosis and therapy.

The π–π stacking between molecules is one of the biggest obstacles preventing dye-sensitized solar cells (DSSCs) from achieving theoretical photovoltaic performance. By introducing rigid auxiliary groups on the donor, three unique self-inhibiting aggregation dyes ZS06, ZS07, and ZS08 were designed and synthesized. By comparing the absorption peaks of dyes in solution and on the TiO2 film, it can be concluded that the aggregation degree of these molecules is significantly weakened. In this study, the influence of different auxiliary groups on the main chain, including spatial structure, energy level, and light-harvesting ability, was investigated in detail. The results show that the advantage of this type of dye is that the auxiliary group has little effect on the light-harvesting ability of the molecule. By precisely regulating the shape and size of the auxiliary group, the best balance can be found between the loading amount and performance, thereby ensuring the maximum improvement of photovoltaic performance.

Biomass materials show great potential in replacing mineral carbon source to fabricate novel high-energy electrode materials. However, it is greatly challenging to prepare core-shell carbon hybrid materials with homogeneous dispersion and high tap density features from biomass since biomass-carbons often exhibit blocky structure. Herein, we facilely fabricate the core-shell microcubes of MnO@C (CCM, average size of ∼5 μm) composite with high tap density of 2.17 g cm−3 using natural agaric as raw materials through simple hydrothermal treatments and calcination process. And the formation mechanism of core-shell microcube structures is analysized by the phase separator theory. It is found that the high-tap-density CCM composite with the stable porous carbon shell (∼1 μm) greatly contributes to accommodate the volume change of MnO active material during lithiation/delithiation process and enable rapid electron/ion transport. As expected, the CCM electrode offers a superhigh volumetric capacity of 1628.7 mAh cm−3, the high reversible capacity (1147 mAh g−1 at 0.1 A g−1), outstanding rate performance (552 mAh g−1 at 2 A g−1) and cycling stability (802 mAh g−1 after 950 cycles at 1 A g−1). We believe that the facile and low-cost biomass-intervened strategy is feasible to fabricate practical core-shell structured metal oxide@carbon composites for efficient electrochemical energy storage.

Our previous work reported for the first time that antimony tin oxide (ATO) nanoparticles were prepared by using reduced graphene oxide aerogels (rGOA) three-dimensional network as scaffolds. In this study, we encapsulated the hybrid aerogels as a whole by conducting polyaniline (PANI) to investigate the effect of the introducing of PANI on microstructure and performance of rGOA/ATO-PANI hybrids. Characterization of the as-prepared samples were performed by scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy, ultraviolet visible near infrared spectroscopy (UV–VIS–NIR) and compressive stress. The electrochemical performances of hybrids were also investigated as well. The results showed that PANI was successfully grafted on rGOA/ATO and formed a compact film, which could further improve the conductivity of the hybrids and infrared absorption performance. The PANI had crystalline phases, and corresponding diffraction peaks were found in rGOA/ATO-PANI, which further indicated that PANI grafted on the surface of rGOA/ATO. The mechanical, electrochemical, infrared barriering performance of rGOA/ATO-PANI were improved as well.

The capacitive properties of asymmetric supercapacitors (ASCs) are inseparable from the development of anode and cathode materials, which usually required high accessible surface area and uniform p...

Since Aczel studied the distributive law between two operations, the distributive laws among different binary aggregation functions become an interesting and vast research field. This paper is mainly devoted to solving the distributivity equations between 2-uninorms and overlap(grouping) functions, which are two classes of special aggregation functions found to possess wide applications in image processing, decision making, classification and fuzzy detection problems. We obtain the sufficient and necessary conditions of the distributivity equations between five classes of basic 2-uninorms and overlap(grouping) functions.

The classification performance of model coal mill classifiers with different bottom incoming flow inlets was experimentally and numerically studied. The flow field adjacent to two neighboring impeller blades was measured using the particle image velocimetry technique. The results showed that the flow field adjacent to two neighboring blades with the swirling inlet was significantly different from that with the non-swirling inlet. With the swirling inlet, there was a vortex located between two neighboring blades, while with the non-swirling inlet, the vortex was attached to the blade tip. The vorticity of the vortex with the non-swirling inlet was much lower than that with the swirling inlet. The classifier with the non-swirling inlet demonstrated a larger cut size than that with the swirling inlet when the impeller was stationary (~ 0 r⋅min-1). As the impeller rotational speed increased, the cut size of the cases with non-swirling and swirling inlets both decreased, and the one with the non-swirling inlet decreased more dramatically. The values of the cut size of the two classifiers were close to each other at a high impeller rotational speed (≥ 120 r⋅min-1). The overall separation efficiency of the classifier with the non-swirling inlet was lower than that with the swirling inlet, and monotonically increased as the impeller rotational speed increased. With the swirling inlet, the overall separation efficiency first increased with the impeller rotational speed and then decreased when the rotational speed was above 120 r⋅min-1, and the variation trend of the separation efficiency was more moderate. As the initial particle concentration increased, the cut sizes of both swirling and non-swirling inlet cases decreased first and then barely changed. At a low initial particle concentration (

Optimizing the molecular structure to adjust the properties of photosensitizer is one of the crucial means to improve the power conversion efficiency of dye-sensitized solar cells (DSSCs). In this paper, four aromatic fused rings were selected as electron donor units to construct photosensitizers PBT–series. The effects of structural differences in the donor moiety on the photophysical and photochemical properties of the molecules were investigated in detail. The results show that the devices based on the dyes with triphenylene or fluoranthene as electron donor can yield higher short-circuit photocurrent densities (Jsc) and open-circuit voltages (Voc) than the devices based on the reference dyes with pyrene or phenanthrene as electron donor, and the power conversion efficiency (PCE) is increased by 37% and 23%, respectively. PBT–2 and PBT–4 sensitizers have better light absorption properties due to stronger intramolecular charge transfer (ICT) charge transitions, which helps to increase the photocurrent of devices, while they also exhibit significantly lower charge recombination rates. Eventually, PBT–2-based devices showed the best power conversion efficiency of 7.67% under the standard global AM 1.5 solar conditions.

In this paper, quantum chemistry computation (density functional theory) of multi-air-staged combustion was investigated in combination with experiment. It was found that the presence of oxygen in the combustion environment has a great influence on the surface chemistry of coal char. In the reaction pathway, the ring-opening reaction happens first, and is followed by NO adsorption. Afterwards, the ring-closure reaction takes place, leaving the nitrogen atom trapped in the inner char molecule. This reaction route effectively inhibits NO formation and achieves the aim of controlling NO emissions. In the staged combustion experiments, the consumption of O2/NO was accompanied by an increase in the CO2 concentration. The quantum chemistry computation successfully interprets the recent experimental trends displayed in multi-air-staged combustion.

Due to its sustainability, biomass materials shows great potential in replacing mineral carbon source to fabricate high-energy electrode materials, and efficient routes have been explored to synthesize and regulate biomass-derived carbonaceous materials with rational structures to enable their applications. Herein, a simple and recyclable molten-salt route is used to synthesize porous ultrathin biocarbon nanosheets from biomass (agaric). Due to the excellent adsorption ability of agaric for molten-salt ions, the interior and exterior of the agaric was fully exposed to the molten-salts, the fluidity and thermal motion of the high-temperature ionic solution promoted the complete exfoliation of biomass. The obtained superthin porous 2D carbon nanosheets provided more active sites and shortened the diffusion distance for lithium ion insertion/deinsertion, and formed a continuous conducting network for electron transport. Consequently, when used as the anodic material for lithium storage, the electrode displayed a higher specific capacity (∼795 mAh g−1 at 0.1 A g−1), outstanding rate performance (∼382 and ∼331 mAh g−1 at 5 and 10 A g−1), and superior cyclic stability (no capacity decay after 1000 cycles at 1 A g−1). Therefore, the preparation of sustainable biocarbon materials by the recyclable, molten-salt-assisted method described in this paper will enable the practical application of such materials in various energy storage devices.

Large eddy simulation (LES) has become a promising tool for pulverized coal combustion with the development of computational fluid dynamics (CFD) technologies in recent years. LES can better capture the unsteady features and turbulent structures of coal jet flame than Reynolds averaged Navier Stokes (RANS). The coal-fired power plants in China are now required to be operated in a wide load range and quickly respond to the electric grid. The boiler performance of variable loads should be evaluated in terms of flow, heat transfer, and combustion processes. In this paper, LES was applied to simulate a 660 MW ultra-supercritical boiler under BMCR (boiler maximum continue rate), 75%THA-100, and 50%THA-100 conditions. The predicted gas velocities agree well with the thermal calculation and the temperature error is less than 130 K. The simulation results show that the operation load has significant effects on the boiler performance. It is also proved that LES can provide guidance for the design and operation of advanced coal-fired boilers.

In this paper, we present a differential privacy version of convex and nonconvex sparse classification approach. Based on alternating direction method of multiplier (ADMM) algorithm, we transform the solving of sparse problem into the multistep iteration process. Then we add exponential noise to stable steps to achieve privacy protection. By the property of the post-processing holding of differential privacy, the proposed approach satisfies the ϵ − differential privacy even when the original problem is unstable. Furthermore, we present the theoretical privacy bound of the differential privacy classification algorithm. Specifically, the privacy bound of our algorithm is controlled by the algorithm iteration number, the privacy parameter, the parameter of loss function, ADMM pre-selected parameter, and the data size. Finally we apply our framework to logistic regression with L1 regularizer and logistic regression with L1/2 regularizer. Numerical studies demonstrate that our method is both effective and efficient which performs well in sensitive data analysis.

The incidence of skin cancer around the world is increasing year by year. However, early diagnosis and treatment can greatly improve the survival rate of patients. Skin lesion boundary segmentation is essential to accurately locate lesion areas in dermatoscopic images. It is true that accurate segmentation of skin lesions is still challenging dues to problems such as blurred borders, which requires an accurate and automatic skin lesion segmentation method. In this paper, we propose an end-to-end framework which can perform skin lesion segmentation automatically and efficiently, called the CSARM-CNN (Channel & Spatial Attention Residual Module) model. Each CSARM block of the model combines channel attention and spatial attention to form a new attention module to enhance segmentation results. The multi-scale input images are obtained by the spatial pyramid pooling. Finally, a weighted cross-entropy loss function is used at each side of the output layer to sum the total loss of the model. We evaluated in two published standard datasets, ISIC 2017 and PH2, and achieved competitive results in terms of specificity and accuracy, with 99.03% and 99.45% specificity, 94.96% and 95.23% accuracy, respectively.

Carbon materials are appealing as electrodes for electrochemical energy storage due to their high surface area and tunable pore structures. In this work, hierarchical porous carbon microcubes (PCM) are synthesized through in-built template method from renewable agaric. Cubic MnO@C composite is obtained by hydrothermal treatment of agaric and subsequent calcination with the presence of manganese source. The in-built MnO-template is sacrificed by acid etching to prepare PCM sample with high specific surface area of 1052 m2 g−1, rational pore size distribution, and self N-doped property. The refined architecture endows PCM sample with significantly improved performance including high specific capacitance, superior rate capability and long-term cyclic stability when employed as electrodes for both lithium-ion batteries and supercapacitors. We believe that this work proposes a new concept to construct carbon architecture with well-refined, hierarchical porous structure for electrochemical energy storage.

The subgrid-scale effects on particle motion were investigated in forced isotropic turbulence by DNS and prior-LES methods. In the DNS field, the importance of Kolmogorov scaling to preferential accumulation was validated by comparing the radial distribution functions under various particle Stokes numbers. The prior-LES fields were generated by filtering the DNS data. The subgrid-scale Stokes number (StSGS) is a useful tool for determining the effects of subgrid-scale eddies on particle motion. The subgrid-scale eddies tend to accumulate particles with StSGS 1 while has an adverse impact on the particles with StSGS

This paper focuses on investigating the finite-time projective synchronization of Caputo type fractional-order complex-valued neural networks with time delay (FOCVNNTD). Based on the properties of fractional calculus and various inequality techniques, by constructing suitable the Lyapunov function and designing two new types controllers, i.e., feedback controller and adaptive controller, two sufficient criteria are derived to ensure the projective finite-time synchronization between drive and response systems, and the synchronization time can effectively be estimated. Finally, two numerical examples are presented to verify the effectiveness and feasibility of the proposed results.

Viterbi algorithm (VA) on time frequency (TF) distribution is a highly performed instantaneous frequency (IF) estimator. However, inaccurate IFs may be tracked due to switch problem in VA when signal components are overlapped on the TF plane. In order to address the problem, this paper first assumes the IF linearity in the overlapped TF regions should not change much, then, a new penalty function describing the variation of IF linearity based on the linear least square fitting technique is developed, and finally, a novel algorithm composed of two IF estimates is introduced. In the first coarse IF estimation, original VA is applied to determine the TF overlapped regions. In the second fine IF estimation, a modified VA employing the new penalty function is applied in the overlapped regions, while the original VA still functions in the non-overlapped regions. Simulations indicate the proposed algorithm can effectively suppress the switch problem and thus can achieve accuracy improvement especially for non-monotonous IF curves compared to other VA-based estimators.

Using the indirect boundary element method (IBEM) and Biot's theory, surface displacement associated with the field scattered by a 3-D inclusion in a two-phase poroelastic half space under plane SV waves has been studied. According to single-layered potential theory, scattering waves are constructed by the introduction of uniform loads and fluid sources distributed over the surface of the half space and on the interface between the inclusion and the half space. The magnitudes of these loads and sources are obtained by establishing a boundary integral equation based on continuity boundary conditions. The accuracy of this method is verified by comparing the results of degradation with existing results of cavities in elastic media. The scattering of plane waves due to a 3-D inclusion is investigated from several aspects. Numerical results show that the dynamic coupling effect between the solid frame and pore water and the permeability condition of the poroelastic soil boundary result in a generally larger surface displacement amplitude for dry soil than poroelastic soil when the porosity is n = 0.3. By contrast, the surface displacement amplitude of poroelastic soil is larger than that of dry soil when the porosity is n = 0.36. As the depth of burial decreases and as the inclusion becomes wider and thicker, the scattering effect increases. The peak value of the displacement spectrum curve usually appears near the incident frequency η = 1.

Vapor permeation seems to be a more suitable separation process than pervaporation in bio-ethanol recovery from fermentation broth because of its non-direct contact trait. The unsatisfactory flux and selectivity of polymeric membranes limit their utilization in industrial application. Here, we tailored the physical and chemical structure of commercial available polyacrylonitrile (PAN) ultrafiltration membrane to serve in vapor permeation. The membrane porosity was reduced till dense enough for separation while preserving an ultra-high flux by hydrolyzing in alkali. The hydrophilicity/hydrophobicity was controlled by grafting fluoroalkyl chains to ensure an acceptable ethanol selectivity. The changes of physical structure and chemical property were systematically characterized by Fourier transform infrared-attenuated total reflectance (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), water contact angle and pure water permeance. Tested at 60 °C, the optimized membrane exhibited a high flux of ca. 10.5 kg m−2 h−1 and a permeate ethanol content similar to vapor-liquid equilibrium curve, which outstripped most polymeric membranes (applied in pervaporation or vapor permeation) in both flux and selectivity.

MILD combustion is featured with a uniform heat flux and low NOx emission, and is thus a promising technology for clean coal utilization. Establishing the theoretical criteria of coal combustion mo...