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It is well known that monolayer transition-metal dichalcogenides (MX$_2$, M = Mo, W and X = S, Se, Te) could exist in three common structures, i.e. 1$T$, 1$T'$, and 1$H$ phases. In order to reveal their possible phase transitions driven by biaxial strain, we use first-principles calculations to determine the energy landscapes associated with these three phases. Due to its intrinsic dynamical instability, the centrosymmetric 1$T$ phase is known to be metastable and will transform into the 1$T'$ phase where pairs of metal atoms pull together toward each other. Moreover, controlling the metallic 1$T'$ and semiconducting 1$H$ phases is of particular interest as this can introduce novel opportunities in a series of applications. When a biaxial strain is simultaneously compressed along the zigzag direction and stretched along the armchair direction，phase transitions from 1$H$ to 1$T'$ have occurred in MSe$_2$ and MoTe$_2$, but for MSe$_2$ the biaxial strain is much difficult to realize in experiments. For WTe$_2$, the 1$T'$ structure will transform into the 1$H$ form when a biaxial strain is just compressed along the armchair direction. The transitions between 1$H$ and 1$T'$ phases could be attributed to the changes of metal-chalcogen bonds along the armchair direction by analyzing the Crystal Orbital Hamilton Population. Only half M-X bonds along the armchair direction is the main factor, because their lengths are robust in 1$T'$ phase and decrease in 1$H$ form with the tensile strain applied along the armchair direction. Our findings provide a guideline for the phase engineering of transition-metal dichalcogenides with biaxial strain.

Nanoporous (NP) iron with large surface area is highly desired for wastewater degradation catalysis. However, it remains a challenge for the fabrication of NP-Fe because the conventional aqueous dealloying or liquid metal dealloying are not applicable. Herein, a novel and universal plasma-assisted electro-dealloying technique was utilized to fabricate NP-Fe. The NP-Fe demonstrates evenly distributed pore structure. The pore density can be tuned by the variation of the ratio of Fe and Zn in the precursor, and the average pore size can be tuned by the processing time. Owing to its large specific surface area, the NP-Fe shows excellent wastewater degradation performance, which is 26 times better than that of commercial zero-valent iron catalysts. This study provides a useful approach to fabricate NP active metals with enhanced catalytic performance.

We investigate the polarization-induced doping in the gradient variation of Al composition in the p-Al0.75Ga0.25N/Al x Ga1−x N hole injection layer (HIL) for deep ultraviolet light-emitting diodes (DUV-LEDs) with an ultra-thin p-GaN (4 nm) ohmic contact layer capable of emitting 277 nm. The experimental results show that the external quantum efficiency (EQE) and wall plug efficiency (WPE) of the structure graded from 0.75 to 0.55 in the HIL reach 5.49% and 5.04%, which are improved significantly by 182% and 209%, respectively, compared with the structure graded from 0.75 to 0.45, exhibiting a tremendous improvement. Both theoretical speculations and simulation results support that the larger the difference between 0.75 and x in the HIL, the higher the hole concentration that should be induced; thus, the DUV-LED has a higher internal quantum efficiency (IQE). Meanwhile, as the value of x decreases, the absorption of the DUV light emitted from the active region by the HIL is enhanced, reducing the light extraction efficiency (LEE). The IQE and LEE together affect the EQE performance of DUV-LEDs. To trade off the contradiction between the enhanced IQE and decreased LEE caused by the decrease in Al composition, the Al composition in the HIL was optimized through theoretical calculations and experiments.

Based on the assembly and inspection process of projectiles and rockets, this paper studies and analyzes the inspection link and content setting of welding and assembly on the projectile. Combined with the characteristics of the components, it proposes three aspects: inspection of the components, inspection before power-on screening, and pre-delivery inspection after final assembly. The research results of this paper can effectively verify the state of the projectiles and rockets after welding and assembly and improve the assembly quality of the productss.

The velocity of a particle detector in granular flow can be regarded as the combination of rolling and sliding velocities. The study of the contribution of rolling velocity and sliding velocity provides a new explanation to the relative motion between the detector and the local granular flow. In this study, a spherical detector using embedded inertial navigation technology is placed in the chute granular flow to study the movement of the detector relative to the granular flow. It is shown by particle image velocimetry (PIV) that the velocity of chute granular flow conforms to Silbert’s formula. And the velocity of the detector is greater than that of the granular flow around it. By decomposing the velocity into sliding and rolling velocity, it is indicated that the movement of the detector relative to the granular flow is mainly caused by rolling. The rolling detail shown by DEM simulation leads to two potential mechanisms based on the position and drive of the detector.

The first wall of the helium-cooled ceramic breeder test blanket module (TBM) will be subjected to charge exchange neutral from the mixed deuterium (D) and tritium (T) deuterium–tritium (D–T) mixture plasma irradiation. To understand the isotope effects on mixed plasma-driven permeation (PDP) through the TBM wall, which is typically made by reduced activation martensitic/ferritic steel (RAFM), mixed D and protium (H) PDP experiments for a Chinese RAFM CLF-1 have been performed. Permeation fluxes of H and D through ∼mm thick CLF-1 have been recorded at various sample temperatures and particle incident energies. The co-permeation of H and D is found to be diffusion-limited in the bulk and obeys classical mass effects of diffusion species. The H/D ratio of the permeation fluxes is found to be stable when changing sample temperature and is insensitive to ion incident energy. In addition, the mixed H can provide more channels for D recombination to reduce the D permeation.

Internet of Energy (IoE) is an advanced form of energy system development. From theoretical exploration to engineering practice, top-level design and scientific IoE system planning is critical for realizing IoE, and a crucial guarantee for the successful implementation of large-scale IoE projects. In this paper, we study the theoretical basis of IoE planning, analyze, and summarize the main planning methods of conventional energy systems and IoE development planning, and provide IoE planning approaches based on “grid-information-value.” Finally, we elaborate the planning direction, concepts, and key points at all levels of the energy grid, information support, and value creation.

Developing highly efficient and stable electrocatalysts for oxygen evolution reaction is of significant importance for applications in energy conversion and storage. Modulation of electronic structure of catalysts is critical for improving the performance of the resulting electrodes. Here, we report a facile way to engineer the electronic structure of Ni3FeS by coating a thin polyaniline (PANI) layer for improving electrocatalytic activity for overall water splitting. Experimental investigations unveil that the strong electronic interactions between the lone electron pairs of nitrogen in PANI and d orbitals of iron, nickel in Ni3FeS result in an electron-rich structure of Ni and Fe, and consequently optimize the adsorption and desorption processes to promote the OER activity. Remarkably, the resulting PANI/Ni3FeS electrode exhibited much enhanced OER performance with a low overpotential of 143 mV at a current density of 10 mA·cm−2 and good stability. Promisingly, coupled with the reported MoNi4/MoO2 electrode, the two-electrode electrolyzer achieved a current density of 10 mA·cm−2 with a relatively low potential of 1.55 V, and can generate oxygen and hydrogen bubbles steadily driven by a commercial dry battery, endowed the composite electrocatalyst with high potential for practical applications.

Due to the limitation of volume and weight, the missile body parameters of the micro tailless air-to-ground missile have a large range during flight, and the characteristics of the rolling channel are greatly different from those of conventional missiles, the stability control of the roll channel is greatly affected by the error of the actuator. Under the classic PID control, the HWIL simulation results show that the jitter of roll angle is obvious, and the anti-disturbance ability of the system is poor. Based on the classic PID, fuzzy control is introduced to optimize the design of rolling channel by using fuzzy online self-correcting PID control. The results of the hardware-in-the-loop simulation show that the jitter of roll angle is suppressed, which improves the characteristics of the roll channel and the control efficiency.

This paper, A model reference adaptive control method based Lyapunov stability theory is proposed, because it is difficult for the control of inclined channel of missile, due to large disturbance and the dramatic change of missile parameter during the flight. The core strategy is that the real system can be adjusted automatically and in real time to be consistent with the reference model as far as possible, when the output of the real system is different from that of the reference model, so that the real system can run in the best state, this control method can well adapt to the changes of control parameters and external environment. The rationality and validity of the method has been verified by mathematical simulation.

A key component of the differential diagnosis of isolated hyperbilirubinemia (HB) is distinguishing between hemolytic and non-hemolytic types. Routine hemolysis screening markers have unsatisfactory sensitivity and specificity. Erythrocyte (RBC) lifespan shortening, the gold standard marker of hemolysis, is seldomly measured due to the cumbersome and protracted nature of standard methods. A new Levitt’s CO breath test method may enable simple, rapid RBC lifespan measurement. In this pilot prospective diagnostic study, Levitt’s CO breath test was evaluated to discriminate hemolytic from non-hemolytic HB in adults. One hundred and thirty eligible non-smoking adult patients who were aged 18 or older, referred for chronic (>6 months) isolated HB or had a known diagnosis of isolated HB of a rare cause, were recruited, including 77 with non-hemolytic HB and 53 with hemolytic HB. ROC curve analysis was applied to determine the optimal cutoff for discriminating between hemolytic and non-hemolytic HB, and the performance was calculated. Results showed that the mean RBC lifespan in non-hemolytic HB (93 ± 26 d) was reduced (p = 0.001 vs. normal reference value of 126 d), but longer than that in hemolytic HB (36 ± 17 d; p = 0.001). RBC lifespans did not differ significantly between 26 patients with simple hemolytic HB (32 ± 14 d) and 27 patients with a Gilbert syndrome comorbidity (40 ± 18 d). ROC curve analysis revealed an optimal lifespan cutoff for discriminating between hemolytic and non-hemolytic HB of 60 d (AUC = 0.982), with a diagnostic accuracy of 95.4%, 94.3% sensitivity and 96.1% specificity respectively. These results indicate that Levitt’s CO breath test seems to be very sensitive and specific for detecting hemolysis in adult patients with chronic isolated HB, and could enable simple, rapid, and reliable differential diagnosis of isolated HB. A large-scale validation study of the method is warranted.

Measuring quasar distance through joint analysis of spectroastrometry and reverberation mapping observations is a new method for driving the development of cosmology. In this paper, we carry out detailed simulation and analysis to study the effect of four basic observational parameters (baseline length, exposure time, equivalent diameter and spectral resolution) on the data quality of differential phase curves (DPCs), and furthermore on the accuracy of distance measurement. In our simulation, we adopt an axisymmetrical disk model of a broad line region (BLR) to generate differential phase signals. We find that the differential phases and their Poisson errors could be amplified by extending the baseline, while the influence of optical path difference errors can be reduced during fitting the BLR model. Longer exposure time or larger equivalent diameter helps reduce the absolute Poisson error. Therefore, the relative error of DPCs could be reduced by increasing any of the above three parameters, then the accuracy of distance measurement could be improved. In contrast, the uncertainty of absolute angular distances (D A) could be improved with higher spectral resolution, although the relative error of DPCs would be amplified. We show how the uncertainty of distance measurement varies with the relative error of DPCs. For our specific set of model parameters, without considering more complicated structures and kinematics of BLRs in our simulation, it is found that the relative error of DPCs < 20% is a limit for accurate distance measurement. The relative error of DPCs has a lower limit (roughly 5%) and the uncertainty in distance measurement can be better than 2%.

An N-stage three-waveguide system is proposed to improve the robustness and the fidelity of the resonant tunneling passage. The analytic solutions to the tunneling dynamics at the output are derived. When the number of subsystems increases, tunneling efficiency approaches to 100% in a large range and resonant tunneling is robust against variations in the phase mismatch and peak tunneling rate.

Aiming at the problem that the equipment maintenance support system is difficult to describe with highly stylized mathematical model, a framework model of equipment maintenance support agent is constructed. The paper introduces the Agent modeling method, analyzes the structure and workflow of the equipment maintenance support system, and abstracts the Agent framework structure according to the equipment maintenance guarantee and the modeling characteristics of the Agent. The internal modules of each Agent are designed and the agents are designed. The task environment between them has been studied, and the designed structural model can provide reference for other similar studies.

The active control of internal transport barriers (ITBs) is an important issue to achieve high performance plasma in a fusion reactor. A critical challenge of ITB control is to increase the ITB position. The ITBs with internal kink modes (IKMs), such as fishbone (FB) instability and long-live mode (LLM) with mode number of m/n = 1/1 are frequently observed on HL-2A tokamak in neutral beam heated discharges. The correlation of FB instability/LLM with ITBs is analyzed in order to extend the ITB radius. It has been revealed that FB instability and LLM are often excited after the ITB formation. Therefore, FB instability and LLM play no role in triggering ITBs on HL-2A tokamak. On the other hand, they may slow down the outward radial expansion and then shrink the foot position of ITB, and damp the gradient growth of ion temperature and rotation velocity. Since the perturbation of LLM is weaker than that of FB instability, the shrinking effect of ITB foot and braking effect on gradient growth are slighter than those of FB instability. Compared with the LLM, FB instability routinely appears in plasmas with lower density, higher heating power and lower plasma current. In addition, large ITBs without IKMs are also discussed on HL-2A tokamak. The large ITB is the largest one, the FB ITB is the strongest one and the LLM ITB is the widest one in three ITBs, where the ‘large’, ‘strong’ and ‘wide’ qualifications correspond to ITB position ρ ITB, the normalized temperature gradient R/LT, and its width W/a. Therefore, the large ITB position may be obtained if the IKMs are effectively controlled in a tokamak.

We theoretically explore the manipulation of a temporal electron-spin splitter by a δ-potential in an embedded magnetic-electric-barrier microstructure (EMEBM), which is constructed by patterning a ferromagnetic stripe and a Schottky-metal stripe on the top and bottom of an InAs/Al x In1−x As heterostructure, respectively. Spin polarization of the dwell time remains, even though a δ-potential is inserted by atomic-layer doping. Both the magnitude and sign of the spin-polarized dwell time can be manipulated by changing the weight or position of the δ-potential. Thus, a structurally controllable temporal electron-spin splitter can be obtained for spintronics device applications.

Remanufacturing plays a significant effect on saving social resources, developing green economy and reducing enterprise cost. Aiming at a production scheduling problem in manufacturing/remanufacturing hybrid systems we investigated, a multi-objective optimal scheduling model is built. The goals of optimization are to minimize total equipment idle time, total delivery delay and total setup time which are consistent with actual needs of the enterprise. An improved NSGA-II is adopted to increase the population diversity and improve the search performance. The similarity degree S is employed to evaluate the diversity of population in this paper. Crossover and mutation operations are adjusted adaptively based on S. This algorithm is applied to an engine manufacturing enterprise compared with the original genetic algorithm. The analysis of experimental results shows that the way in this paper has certain superiority.

We describe simulations of lubrication by a hexadecane molecular lubricating film during the shearing process of a Cu-Zn alloy performed using the atomistic method. The results indicate that with increasing Zn contents, the interface slip between the alloy wall and the lubricating film first decreases and then increases, according to variations of the radius distribution function (RDF), while the interface slip reaches its lowest value of 0.12 during the shearing of CuZn30 alloy. We also discuss the relationship between interface roughness and the lubricating film. During film lubrication, the interface’s roughness effectively inhibits interfacial slip. For the convex contact model, the presence of the hexadecane lubricating film reduces the interfacial contact pressure from 11.9 GPa to 8.7 GPa and the friction coefficient from 0.81 to 0.52.

In order to reveal the influence of the viscosity of the transmission oil on the braking performance of the hydraulic retarder, the change law of the viscosity of the hydraulic retarder at different temperatures is analysed, and the influence of the viscosity of the working medium on its braking performance is analysed. The results show that: low-viscosity transmission oil can increase braking torque.

To gain a better understanding of the mechanism governing arc dynamics in 3D gliding arc discharge (GAD) plasma, the spatio-temporal evolution of GAD was investigated in a reverse vortex flow by a novel reactor with ring (powered electrode, PE) and truncated cone (ground electrode, GE) electrodes. A newly underlying mechanism governing arc evolution in 3D GAD was gained with combination of flow field simulation, synchronous electrical characteristics, intensified charge coupled device images and high-speed photos. The spatio-temporal analysis indicates that, being different from the well-known ignition–gliding–extinction mechanism occurring in traditional GAD, the PE arc root glides continuously in the 3D GAD, but the GE arc root features jumps from the end of the gliding path to the beginning of the next one. By means of the jumping, the arc auto-sheds the caudal part of the arc and a new arc tail is simultaneously generated, rather than rebuilding a new arc channel back to the shortest electrode gap. With this special behavior of caudal autotomy and regeneration, the main part of the arc remains for each jump. This new insight improves the understanding of the discharge mechanism governing arc evolution in 3D GAD and provides a reference for optimization design of gliding arc plasma in a vortex flow.

This paper takes 3 construction machinery as the research object, uses the portable emission measurer (PEMS) to test the emission in the actual operation of construction machinery. And analyzes the relationship between the operating characteristics of construction machinery and the characteristics of NOx emission and CO emission. The research results show that the NOx emission of construction machinery is positively correlated with power, and the NOx emission change rate is positively correlated with the mechanical power change rate. There is no obvious correlation between the CO emissions of construction machinery and power, and the change rate of CO emissions is positively correlated with the rate of mechanical power change.

Large-scale in situ observations are sorely lacking, leading to poor understanding of nationwide atmospheric turbulence over China. Nevertheless, high-resolution soundings have become available starting in 2011, providing a unique opportunity to investigate turbulence across China. Here, we calculated the mean turbulence dissipation rate (ϵ) from radiosonde measurements across China for the period 2011–2018 using Thorpe analysis. The atmospheric layers that had stronger turbulence indicated by larger ϵ generally came with larger Thorpe length but with smaller Brunt–Väisälä frequency. Overall, the clear-air ϵ in the free atmosphere exhibited large spatial variability with a ‘south-high north-low’ pattern. Large clear-air ϵ values were observed in both the lower stratosphere (LS) and upper troposphere (UT), especially over the Tibetan Plateau (TP) and its neighboring regions with complex terrain likely due to large-amplitude mountain waves. Particularly, less frequent but more intense clear-air turbulence was observed in both lower troposphere (LT) and UT over the TP, while more frequent, less intense clear-air turbulence was found in northern China. The all-sky turbulence considering the moist-saturation effects was much stronger in the troposphere, notably in southern China where convective clouds and precipitation oftentimes dominated. In the vertical direction, the altitude of peak clear-air ϵ in the troposphere was found to decrease poleward, broadly consistent with the meridional gradient of tropopause height in the Northern Hemisphere. A double-peak mode stood out for the profiles of clear-air ϵ at midlatitudes to the north of 30° N in winter: one peak was at altitudes of 15–18 km, and another at altitudes of 5–8 km. The strong shear instabilities around the westerly jet stream could account for the vertical bimodal structures. The seasonality of ϵ was also pronounced, reaching maxima in summer and minima in winter. Our results may help understand and avoid clear-air turbulence, as related to aviation safety among other issues.

Original packaging design of Western Hubei Tujia is a handmade household item of Tujia people, and it is also a packaging container used to store, protect, and transfer living materials. The original ecological packaging origin, modelling materials, patterns, and colours of the Tujia nationality in western Hubei were reconstructed and sorted out under the guidance of sustainable design principles, from the perspective of sustainable design exploration and sustainable design continuation. These local materials were combined, in order to examine and interpret the spiritual significance and material function of the handmade packaging container. The prospects of development brought by the integration of the original ecological packaging of the Tujia family and modern design are explored, so that it further injects new life and energy into sustainable designs. While reflecting the advantages of original ecological packaging shape, material and rich ethnic elements, it focuses on the continuation and innovation of sustainable design of the Tujia native food packaging, promotes the ecological concept, develops sustainable packaging, and provides a creative space for Tujia family packaging design ideas.

Investigation of aerosol effects on fog with long-term measurements has generally focused on fog occurrence frequency and intensity; here we examine the effects on fog lifetime, fog formation, and fog dissipation. From analysis of 52 years (1960–2011) of data collected at 404 stations in China, it is found that fog lifetime exhibits a clear increasing trend with time, and the increased lifetime is mainly attributable to delayed fog dissipation. Increased aerosol levels and global warming affect fog lifetime in opposite ways; increased aerosol levels serve to prolong fog lifetime by primarily delaying fog dissipation, whereas warming decreases fog lifetime by primarily delaying fog formation. The overall aerosol effect on fog lifetime in China is shown to predominate, especially in the highly polluted region of Eastern China. The observational findings are confirmed by a suite of WRF-Chem simulations that reveal the influences of both increased aerosol levels and temperatures through a complex chain of interactions among microphysical, dynamical, thermodynamic, and radiative processes.

The current economic and social development and changes in internal and external environments have brought severe challenges to the operation of power grid companies. By studying the input-output relationship of all factors in power grid companies, from the perspective of effectiveness, efficiency, and benefit, this paper constructs an input-output evaluation index system, introduces analytic hierarchy process and entropy method for weight calculation, uses weighted average method to construct input-output evaluation model, and conducts empirical research with relevant data and information in a certain area as an example. The research results can provide auxiliary decision-making support for the scientific and reasonable allocation of resources, and realize the clarity of input and output effects of power grid enterprises, scientific and rational investment arrangements, and lean business management.

The research on the potential purchase behavior of users can help merchants develop better marketing strategies. At present, many research methods of online purchasing behavior are based on simple rule prediction, and the prediction results are not satisfactory. We design a hybrid model of Gradient Boosting Decision Tree and logistic regression to accurately predict the purchase behavior of users, which combines the association characteristics between users and commodities. Firstly, clustering algorithm and association rules are used to solve the problem of data imbalance and mine more potential related features. This scheme not only improves the processing efficiency of large data, but also solves the problem of user cold start. Secondly, we construct a scalable tree enhancement system (XGBoost) to train the initial feature set, which is a strong classifier composed of several weak classifiers. A new training set combines the new features with the original features through feature reconstruction, and a hybrid machine learning system is constructed by logistic regression (LR) model. Finally, the LR model is trained by the new training set. Compared with the existing schemes, the integrated decision tree model can train more sample sets with less resources. The experimental results show that the accuracy of the hybrid model is better than single model, and the F1_score is higher.