Similar to the influence on nilpotent residual of the totally permutability of subgroups,naturally,we can study their influence on σ-nilpotent residual when nilpotent groups are generalized to σ-nilpotent groups.The intersection of all normal subgroups N of G such that G/N is σ-nilpotent is called σ-nilpotent residual of G,and is denoted as G^{{\mathit{??}}_{\sigma }}. Let G=AB, where A and B are totally permutable subgroups of G,this paper gives some new conclusions that B normalises A^{{\mathit{??}}_{\sigma }} and centralises A^{{\mathit{??}}_{\sigma }} by using the concepts and theories of σ-nilpotent subgroups and σ-supersoluble subgroups,and by applying some properties and methods of complete Hall σ-set and finite group theory.

The purpose of this paper is to establish some new oscillation criteria for the second-order nonlinear neutral differential equations with damping terms which have the form [a(t){\left|z^{\text{'}}(t)\right|}^{\alpha -\mathrm{1}}{z}^{\text{'}}{(t)]}^{\text{'}}+b(t){\left|z^{\text{'}}(t)\right|}^{\alpha -\mathrm{1}}{z}^{\text{'}}(t)+q(t){\left|x(\sigma (t))\right|}^{\beta -\mathrm{1}}x(\sigma (t))=\mathrm{0}， where z(t)=x(t)+p(t)x(\tau (t)). Our theorems improve, extent and unify a number of related results reported in the literature. The wide application of the obtained criteria is illustrated via examples.

This paper addresses the problem of fuzzy-state-feedback-controller-based finite-time H_{\mathrm{\infty }} asynchronous control for a class of Markov jump systems under Takagi-Sugeno fuzzy rules. The hidden Markov model is employed to describe the asynchronization between the fuzzy controller and the original system. Firstly, by means of constructing Lyapunov function, a sufficient condition for H_{\mathrm{\infty }} finite-time boundedness of the closed-loop system is obtained by using finite-time boundedness and H_{\mathrm{\infty }} control theory. Then, the asynchronous fuzzy state feedback controller is designed, which ensures H_{\mathrm{\infty }} finite-time boundedness of the closed-loop system. Finally, a simulation result is demonstrated to verify the effectiveness of the proposed method.

Aiming at the optimization of multi-UAVs patrol path, a patrol model of multi-UAVs based on hybrid genetic algorithm is proposed. When constructing the patrol model, each UAV must start from the police station and return to the police station at the end of the patrol. The algorithm is designed by combining traditional genetic algorithm and hill-climbing algorithm. In order to achieve a better optimization effect, the roulette wheel method is employed to select the excellent individuals with higher probability when selecting individuals of the population. In the application of genetic algorithm, the rules of gene crossover and mutation adapted to path optimization are defined. The simulation results show that the proposed hybrid genetic algorithm is significantly better than the traditional genetic algorithm on the optimization effect.

The rotated flux method could be used to effectively eliminate the shock instability of the approximate Riemann solver and suppress the generation of non-physical phenomenon if the equations to be solved meet the rotational invariance. For the 2D ideal magnetohydrodynamics (MHD) and shallow water magnetohydrodynamics (SWMHD) equations, the rotation-like matrix of flux function was constructed, and the corresponding rotational invariance theorem was given with proof, which was then used to deal with the governing equations applying quasi-1D method to derive the semi-discrete rotated flux scheme. Combining entropy stable flux and anti-diffusive flux by a flux limiter, a new flux that can adaptively adjust the dissipation term was obtained. Numerical experiments show that the new scheme can accurately capture the structure of solution, has high resolution, strong robustness and can be easily extended to higher dimensions.

In the new era of fintech, digital technology is the core driving force of the future development of financial industry. With the new technology and the risk of financial fraud escalating, fraud detection based on digital technology has become a new research hot spot. Meantime the research direction of financial fraud detection technology has shifted from traditional methods of improving expert experience and optimizing machine learning models to exploring graph machine learning methods for social network. This article focuses on social network, based on the development process of network analysis, from different perspectives of detecting abnormal individuals, suspicious groups and unhealthy intermediaries, with different technical methods of digital financial fraud detection as the main line, the existing social-oriented relational network fraud identification methods are investigated, and the future research trends and directions of digital financial fraud detection technologies are highlighted.

Herein, a novel one pot synthesis of chiral δ-substituent caprolactam strategy which applies 1-substituent homoallylic amine as the starting material is reported. This method combines the enzymatic dynamic kinetic resolution (DKR) and ring cross metathesis. Moreover, the configuration of caprolactam can be controlled by using lipase and protease as the DKR catalyst. The enantiomeric excess value of obtained R- and S-caprolactam can reach up to 90% and 82%, the yield can also be above 82% and 70%.

Criminal activities of abducting and trafficking children take place continuously despite that they are repeatedly prohibited, which bring many negative effects to families and society. No wonder and combating criminal activities of abduction and trafficking of children is of great significance to the sustainable development of human society and the protection of national rights and interests. Taking the data of the "baobeihuijia" public welfare platform as a research sample, and using GIS and social network analysis methods, the temporal and spatial evolution and formation mechanism of China's child abduction and trafficking criminal activities were explored. The results show that: (1) Timing characteristics, from 1978 to 2020, China's child trafficking criminal activities showed an inverted "V" pattern of "high incidence in the middle of the time period and low incidence at both ends", which reached a peak in 1989 and gradually declined. (2) Topological characteristics, the overall scale of the network of child abduction and trafficking activities first increased and then decreased, the network structure became increasingly loose, the intensity and accessibility of contacts decreased, and the core provinces of the network shifted from eastern provinces such as Henan and Fujian to southwestern regions such as Sichuan and Guizhou, and the market for buyers and sellers was significantly differentiated. (3) Spatial structure, criminal activities were concentrated in the southeast half of the Hu Huanyong Line, and trafficking of boys happened more ferequently prefer in the south than in the north; On the other hand, the spatial distribution pattern of criminal activities shifted significantly, with the abducted were mostly from the southwest region, and likely to be sold to the central and eastern regions. The trafficking route followed a trend from "high incidence in several places" to "frequent nationwide" then gradually shranked, the phenomenon of cross-provincial and intra-provincial trafficking coexisted; The criminal network has formed four major criminal associations, led by the Yunnan-Guangdong-Guizhou-Hebei trafficking community, and their internal ties are close, showing the regional characteristics of coexistence of geographical proximity and leapfrogging. (4) Formation mechanism, network nodes, network connections, and network communities were the three levels that affected the situation of child trafficking activities, and each level advanced sequentially, and the level is affected by multiple factors, making it fluctuating, phased, and regional.

Driven by the national strategies of health China and the integrated development of the Yangtze River Delta region, the supply capacity of health care resources has become an important indicator of the equalization of regional public facilities, and public health emergencies such as the new coronavirus pneumonia epidemic have put forward higher requirements on the supply capacity of regional health care resources. In order to identify the development characteristics and influencing factors of health care resource supply capacity in Yangtze River Delta, this article constructs an analytical structure with temporal evolution, spatial differentiation and factor exploration, and adopts the methods of Thiel index, spatial autocorrelation and multi-scale geographically weighted regression to study the regional differences and influencing factors of healthcare resource supply capacity in 41 prefecture-level cities in Yangtze River Delta from 2001 to 2019. The results show that the health care resources in the Yangtze River Delta grew rapidly during the study period and the regional balance was improved; the overall pattern was consistent with the "Z" spatial structure of Yangtze River Delta; the factors affecting the health care resources supply cover social, economic and political dimensions, and there was spatial heterogeneity in the intensity of their effects. On this basis, it proposes strategies to promote the integrated development of medical services in Yangtze River Delta.

With the advantages of high efficiency and convenience, shared bikes are rapidly gaining popularity in China, and become an important connection mode for rail transit stations, but it also brings many problems which affect urban transportation and environment. Based on multi-source big data such as Xiamen shared bikes and urban space, this article analyzes the spatial and temporal characteristics of shared bikes travel by Python and GIS, and explores their riding characteristics and the effects concerning land use, urban environment and other aspects in the station area. Shared bikes have the characteristics of short spatial and temporal distance utilization, which provides an important support for the connecting traffic of urban subway stations. The connection and utilization of shared bikes around the station are affected by various urban factors, which also reflect the stages and differences of the station development. By analyzing the characteristics of shared bikes trips, rail transit stations can be classified into four types, and the develop strategies should be taken according to the difference of station types, to improve the urban slow traffic system, promote the development level of rail transit stations.

Commuting satisfaction is an important factor influencing residents' life quality and subjective well-being, and can be used to evaluate the advantages and disadvantages of urban policies and planning. In the past decade, commuting satisfaction has attracted the attention of disciplines in urban planning, geography, and transportation. However, a comprehensive review of the relevant literature is lacking. This paper summaries the methodology for measuring, surveying, and modeling commuting satisfaction. This is followed by a meta-analysis to quantify the effects of socio-economic attributes, commuting characteristics, travel attitudes, built environment, and life events on commuting satisfaction to improve the understanding of commuting satisfaction and its influencing factors and mechanisms. On this basis, it points out the shortcomings and future research directions of commuting satisfaction studies, and presents the implications of existing research findings for policy and planning.

In recent years, many places in China have begun to implement the policy of "Strong Provincial Capitals", which not only modifies the positioning of cities, but also affects the image of cities.In the era of Web2.0, image data has become an important carrier for the study of urban tourism image.Taking Fuzhou, the capital of Fujian province, as a case, and taking the implementation time of the "Strong Provincial Capital" policy as the cut-off point, this study collected the official generated content OGC and tourist generated content TGC from the internet before and after the implementation of the strategy respectively, and coded them according to the photo content with the help of Nvivo software.It compared the differences between the official tourism marketing organizations and the urban tourism image constructed by tourists in the two stages to explore the impact of the "Strong Provincial Capital" policy on OGC and TGC.The findings are as follows: before the implementation of "Strong Provincial Capital" strategy, OGC is good at shaping city tourism image with three categories of "close-up of architecture", "natural ecological landscape" and "overview of city and spot", which forms a triangular communication structure with these three as the core. On the other hand, TGC prefers to use the five categories of "natural ecological landscape", "close-up of character", "close-up of animal and plant", "close-up of architecture" and "close-up of road " to express the image of tourist cities which forms a cross scattered structure with "natural ecological landscape" as the center and the other four connected to it. After the implementation of the strategy of strengthening the provincial capital, OGC's communication mode did not change much, but paid more attention to the use of "artistic culture" and other categories to show the cultural heritage of Fuzhou, and the communication content is more diversified, the communication structure is more stable, which TGC tends to show the main role of human in conveying the image of urban tourism, and penetrates the category of "close-up of character" into other categories. Besides, OGC has a certain effect on TGC; "Strong Provincial Capital" strategy brings OGC clearer goal orientation; the strategy of "Strong Provincial Capitals" increases tourists' subjective consciousness as "people".

Nowadays, the applications of engineering-procurement-construction (EPC) general contracting mode in hydraulic engineering projects are increasing. And it will benefit EPC general contractor in value management by exploring the value-added mechanism. Firstly, this paper studies the value chain of hydraulic engineering, and identifies the value-added factors through literature research and expert interviews. Then the approach of questionnaire is applied to investigate the influence degree among each factor, and their centrality and cause degree are obtained by analysis method of DEMATEL. On the above basis, this paper divides the factors into 6 layers by adopting the analysis method of interpretative structural modeling (ISM), hence builds the value-added path of hydraulic engineering project with EPC general contracting mode. The result will provide the inspiration for EPC enterprises to formulate strategies in value management and further research.