At present, the transformation of energy structure is at a critical stage, and emerging renewable energy technologies and multienergy equipment have been widely used. How to improve the energy efficiency of integrated energy system and promote large-scale absorption of renewable energy is of great significance to the application forms of energy in the future. The development of new internet technology and sensor technology provides strong technical support for the optimal operation and coordinated control of IES. In recent years, the IES (...) is experiencing unprecedented changes, which has attracted great attention from academia and industry. In this paper, the optimal control and operation behavior of IES are reviewed. Firstly, the research status of IES in recent years is summarized. Then, the modeling methods of different equipment in IES are analyzed in detail. The optimal operation of user, regional, and cross-regional IES are taken as typical research objects and the research status of optimization problems and operation modes, energy management planning, and power market allocation are summarized and analyzed. Finally, the key scientific issues and related frontier technologies in the IES are concluded, and the future research directions are prospected. (shrink)

In this paper, a new chaotic system is proposed based on mixing three-dimensional Chen chaotic system with a chaotic tactics. This new system is proved to be chaotic under Wiggins’ chaos definition and can generate chaotic sequences with high complexity. Furthermore, we propose a new pseudorandom bit generator based on this new system. A coding algorithm is used to make the sequences uniform. Both statistical and security tests are provided to show the generated sequences are with good randomness and high (...) complexity to withstand attacks. (shrink)

Difference is a category of relationship lying between identity and non-identity, and equality and inequality. This concept is both the Confucian reflection of the real relationship between things in the world and the value ideal of Confucianism. The Confucian idea of difference, embodied in the view of human relationships, of world, and of nature, seeks to build a rational order based on difference, so as to reach a harmonious, united and ideal state. Confucians in the past dynasties continually interpreted difference (...) and raised it to the level of ontology, enriching the system of Confucianism. (shrink)

Human contact networks constitute a multitude of individuals and pairwise contacts among them. However, the dynamic nature, which generates the evolution of human contact networks, of contact patterns is unknown yet. Here, we analyse three empirical datasets and identify two crucial mechanisms of the evolution of temporal human contact networks, i.e., the activity state transition laws for an individual to be socially active and the contact establishment mechanism that active individuals adopt. We consider both of the two mechanisms to propose (...) a temporal network model, the so-called memory-driven model, of human contact networks. Then, we study the susceptible-infected spreading processes on empirical human contact networks as well as four corresponding temporal network models and compare the full prevalence time of SI processes with various infection rates on the networks. The full prevalence time of SI processes in the MD model is the same as that in real-world human contact networks. Moreover, we find that the individual activity state transition promotes the spreading process, while the contact establishment of active individuals suppresses the prevalence. Besides, we observe that individuals who establish social ties with a small exploring rate are still able to induce an endemic which prevails in the networks. The study offers new insights to predict and control the diffusion processes on networks. (shrink)

In this paper, we consider the effect of constant rate harvesting on the dynamics of a single-species model with a delay weak kernel. By a simple transformation, the single-species model is transformed into a two-dimensional system. The existence and the stability of possible equilibria under different conditions are carried out by analysing the two-dimensional system. We show that there exists a critical harvesting value such that the population goes extinct in finite time if the constant rate harvesting u is greater (...) than the critical value, and there exists a degenerate critical point or a saddle-node bifurcation when the constant rate harvesting u equals the critical value. When the constant rate harvesting u is less than the critical value, sufficient conditions about the existence of the Hopf bifurcation are derived by topological normal form for the Hopf bifurcation and calculating the first Lyapunov coefficient. The key results obtained in the present paper are illustrated using numerical simulations. These results indicate that it is important to select the appropriate constant rate harvesting u. (shrink)

The deviation of the conveyor belt is a common failure that affects the safe operation of the belt conveyor. In this paper, a deviation detection method of the belt conveyor based on inspection robot and deep learning is proposed to detect the deviation at its any position. Firstly, the inspection robot captures the image and the region of interest containing the conveyor belt edge and the exposed idler is extracted by the optimized MobileNet SSD. Secondly, Hough line transform algorithm is (...) used to detect the conveyor belt edge, and an elliptical arc detection algorithm based on template matching is proposed to detect the idler outer edge. Finally, a geometric correction algorithm based on homography transformation is proposed to correct the coordinates of the detected edge points, and the deviation degree of the conveyor belt is estimated based on the corrected coordinates. The experimental results show that the proposed method can detect the deviation of the conveyor belt continuously with an RMSE of 3.7 mm, an MAE of 4.4 mm, and an average time consumption of 135.5 ms. It improves the monitoring range, detection accuracy, reliability, robustness, and real-time performance of the deviation detection of the belt conveyor. (shrink)

Newly collected high-resolution acoustic data are used to describe the morphologies and sedimentary characteristics along the slopes of isolated carbonate platforms in the Xisha Archipelago. Base on multibeam bathymetric and seismic data, we identified seven types of morphological and depositional features around the platforms, including erosive grooves, mass transport deposits, gullies, confined channels, canyons, mounded sediments and marginal contourite depressions. The occurrence of erosive channelized features around the platforms indicate that gravity flow is a major sediment-export mechanism for the transportation (...) of excess neritic carbonates towards the slope. Marginal contourite depressions and mounded sediments are interpreted as bottom-current reworking products, suggesting an important role of bottom current and deep-water circulation of the South China Sea in shaping the slope morphology of the carbonate platforms. Furthermore, the bottom-current products tend to develop along the slopes of the carbonate platforms at the Xisha Uplift margin, in particular, erosional features formed by bottom current frequently occur in the southern side of the carbonate platforms. By comprehensive analysis of morphological and depositional features, we establish a facies model around the carbonate platforms to interpret different sedimentary transport processes, such as off-platform and along-slope sediment transport processes. These findings highlight a notable and complex relay-style channelized transport system consisting of grooves/gullies-channels-canyons, which has implications for linking neritic carbonate platforms into deep-sea basins. (shrink)

The Ordos Basin has abundant conventional and unconventional oil and gas resources. Focusing on shale oil in the Ordos Basin, we studied the distribution, depositional features, and resource potential of shales in the upper Triassic Yanchang Formation based on the Ordos Basin development and depocenter migration. During the late Triassic, the Ordos Basin was a large cratonic sedimentary basin that bordered to the Hexi Corridor to the west, the southern North China block to the east, the Qilian and western Qinling (...) orogenic zone to the south, and the foot of the Yin Mountains to the north. During deposition of the Yanchang Formation, its depocenter was not fixed. It migrated to the west before deposition of the Chang 7 oil layer and to the south after deposition of the Chang 7 oil layer. Controlled by the depocenter migration and relevant deep-lake facies, the Yanchang Formation mainly developed two sets of source rocks. The dark mudstone and shale in the Chang 9 oil layer is chiefly distributed in the south-central region of the basin, with thicknesses of 4–16 m and covers an area of approximately [Formula: see text]. The shales in the Chang 7 oil layer can be divided into two types, black oil shale and dark mudstone, and they are much thicker and more widespread than the dark mudstone in the Chang 9 oil layer. The black shale alone can be up to 60 m thick, and covers an area of more than [Formula: see text]. The shales in the Chang 7 and 9 oil layers were mainly formed in a deep-lake environment that produced high concentrations of organic matter and large hydrocarbon generation potential. According to preliminary estimates, the Chang 7 oil shale may contain [Formula: see text] of oil, thereby representing a huge resource potential with broad exploration prospectivity. (shrink)

Although the relationship between stressors and thriving at work has been established, the linkage between them is still in the early stages of theory development. This study proposed a two-path model, based on Lepine’s stressors-performance model, to analyze the effects of the stressors on the thriving at work. Two complementary mediating paths were proposed, i.e., affective strain and motivation, which were explained using affective events theory and expectancy theory, respectively. Based on the empirical data from 233 employees, the results show (...) that challenge stressors could enhance employees’ positive affect and self-efficacy, thus leading to thriving at work; on the contrary, hindrance stressors would result in negative influences. In addition, it is also found that the effect of affective path tend to be greater than that of motivation path, which could provide a practical guide for organizations to effectively apply stress management and to promote employees thriving at work. (shrink)

The Lower Silurian shale-gas formation in the south of Sichuan Basin represents strong VTI feature. Successful characterization of shale-gas formation requires handling the great influence of anisotropy in the seismic wave propagation. Seismic AVO inversion for VTI media using PP-waves only is a difficult issue because more than three parameters need to be estimated and such an inverse problem is highly ill-posed. We have applied an AVO inversion method for VTI media based on a modified approximation of the PP-wave reflection (...) coefficient. This approximation consists of only three model parameters: the acoustic impedance, shear modulus proportional to the anellipticity parameter, and the approximated horizontal P-wave velocity, which can be well-inverted and have great interpretation capability in shale-gas reservoir characterization. A statistical-rock-physics method was then applied to the inverted attributes for quantitative interpretation of shale-gas reservoir. Markov random field is combined with Bayesian rule to improve the continuity and accuracy of the interpretation results. Shales can be successfully discriminated from surrounding formations by using the attribute pair A-C, and the organic-rich gas-bearing shale can be successfully identified by using the attribute pair C-B. Comparison between the prediction results and well logs demonstrates the feasibility of the inversion and quantitative interpretation approaches. (shrink)

The Lower Silurian shale-gas formation in the south of the Sichuan Basin represents a strong transverse isotropy with vertical axis of symmetry feature. Successful characterization of shale-gas formation requires handling the great influence of anisotropy in the seismic wave propagation. Seismic amplitude variation with offset inversion for VTI media using PP-waves only is a difficult issue because more than three parameters need to be estimated and such an inverse problem is highly ill posed. We have applied an AVO inversion method (...) for VTI media based on a modified approximation of the PP-wave reflection coefficient. This approximation consists of only three model parameters: the acoustic impedance, shear modulus proportional to the anellipticity parameter, and the approximated horizontal P-wave velocity, which can be well-inverted and have great interpretation capability in shale-gas reservoir characterization. A statistical-rock-physics method was then applied to the inverted attributes for quantitative interpretation of the shale-gas reservoir. A Markov random field is combined with Bayesian rule to improve the continuity and accuracy of the interpretation results. Shales can be successfully discriminated from surrounding formations by using the attribute pair [Formula: see text]-[Formula: see text], and the organic-rich gas-bearing shale can be successfully identified by using the attribute pair [Formula: see text]-[Formula: see text]. Comparison between the prediction results and well logs demonstrates the feasibility of the inversion and quantitative interpretation approaches. (shrink)

In this paper, the orbital stability of solitary wave solutions for the generalized Gardner equation is investigated. Firstly, according to the theory of orbital stability of Grillakis-Shatah-Strauss, a general conclusion is given to determine the orbital stability of solitary wave solutions. Furthermore, on the basis of the two bell-shaped solitary wave solutions of the equation, the explicit expressions of the orbital stability discriminants are deduced to give the orbitally stable and instable intervals for the two solitary waves as the wave (...) velocity changing. Moreover, the influence caused by the interaction between two nonlinear terms is also discussed. From the conclusion, it can be seen that the influences caused by this interaction are apparently when 0shrink)