Composition Analysis and Identification of Ancient Glass Products Based on L1 Regularization Logistic Regression

In view of the composition analysis and identification of ancient glass products, L1 regularization, K-Means cluster analysis, elbow rule and other methods were comprehensively used to build logical regression, cluster analysis, hyper-parameter test and other models, and SPSS, Python and other tools were used to obtain the classification rules of glass products under different fluxes, sub classification under different chemical compositions, hyper-parameter K value test and rationality analysis. Research can provide theoretical support for the protection and restoration of ancient glass relics.

Research on the influence of quadrupole deformation and continuum effects on the exotic properties of 15,17,19B with the complex momentum representation method

The properties of exotic nuclei are the focus of the present research.Two-neutron halo structures of neutron-rich17,19B were experimentally confirmed.We studied the formation mechanism of halo phenomena in17,19B using the complex momentum representation method applied to deformation and continuum coupling.By examining the evolution of the weakly bound and resonant levels near the Fermi surface,s–d orbital reversals and certain prolate deformations were observed.In addition,by analyzing the evolution of the occupation probabilities and density distributions occupied by valence neutrons,we found that the ground state of15B did not exhibit a halo and the ground states of17B and19B exhibited halos at 0.6≤β2≤0.7 and0.3≤β2≤0.7,respectively.The low-l components in the valence levels that are weakly bound or embedded in the continuous spectrum lead to halo formation.

Consensus model of social network group decision-making based on trust relationship among experts and expert reliability

Due to people’s increasing dependence on social networks,it is essential to develop a consensus model considering not only their own factors but also the interaction between people.Both external trust relationship among experts and the internal reliability of experts are important factors in decision-making.This paper focuses on improving the scientificity and effectiveness of decision-making and presents a consensus model combining trust relationship among experts and expert reliability in social network group decision-making(SN-GDM).A concept named matching degree is proposed to measure expert reliability.Meanwhile,linguistic information is applied to manage the imprecise and vague information.Matching degree is expressed by a 2-tuple linguistic model,and experts’preferences are measured by a probabilistic linguistic term set(PLTS).Subsequently,a hybrid weight is explored to weigh experts’importance in a group.Then a consensus measure is introduced and a feedback mechanism is developed to produce some personalized recommendations with higher group consensus.Finally,a comparative example is provided to prove the scientificity and effectiveness of the proposed consensus model.

Workability and Strength of Ceramsite Self-Compacting Concrete with Steel Slag Sand

This study focuses on the workability and compressive strength of ceramsite self-compacting concrete with fine aggregate partially substituted by steel slag sand(CSLSCC)to prevent the pollution of steel slag in the environment.The SF,J-ring,visual stability index,and sieve analysis tests are primarily employed in this research to investigate the workability of freshly mixed self-compacting concrete containing steel slag at various steel slag sand replacement rates.The experiment results indicate that CSLSCC with the 20%volume percentage of steel slag(VPS)performs better workability,higher strength,and higher specific strength.The 7-day compressive strength of CSLSCC with the 0.4 of the water-binder ratio(W/B),decreases with the increase of steel slag content,while the 28-day compressive strength increases significantly.The ceramsite self-compacting concrete with good comprehensive performance can be obtained when the substitution rate of steel slag sand for fine aggregate is less than 20%(volume percentage).

Risk measurement of international oil and gas projects based on the Value at Risk method

International oil and gas projects feature high capital-intensity, high risks and contract diversity. Therefore, in order to help decision makers make more reasonable decisions under uncertainty, it is necessary to measure the risks of international oil and gas projects. For this purpose, this paper constructs a probabilistic model that is based on the traditional economic evaluation model, and introduces value at risk(VaR) which is a valuable risk measure tool in finance, and applies Va R to measure the risks of royalty contracts, production share contracts and service contracts of an international oil and gas project. Besides, this paper compares the influences of different risk factors on the net present value(NPV) of the project by using the simulation results. The results indicate:(1) risks have great impacts on the project's NPV, therefore, if risks are overlooked, the decision may be wrong.(2) A simulation method is applied to simulate the stochastic distribution of risk factors in the probabilistic model. Therefore, the probability is related to the project's NPV, overcoming the inherent limitation of the traditional economic evaluation method.(3) VaR is a straightforward risk measure tool, and can be applied to evaluate the risks of international oil and gas projects. It is helpful for decision making.

The Research Framework Model of Rapid Assessment and Emergency Plan Selection for Urban Flood Disaster

Given that it is difficult to assess the harmfulness and make emergency response timely in the early stage when flood disasters happen in cities for that the data are complex and rapidly changing, this article constructs a rapid assessment model, namely Simple Simos Procedure and PROMTHEE II Model (SSPPM), to assess the severity of flood disaster occurring in cities at the early stage based on a view of the rapid flood disaster assessment. On this basis, the fuzzy VIKOR method is applied to choose a scientific emergency plan. This article aims to construct a research framework model, which can provide some practice implications to reduce the losses caused by flood disaster.

Mechanical behaviours of sandstone containing intersecting fissures under uniaxial compression

Predicting rock cracking is important for assessing the stability of underground engineering.The effects of the intersecting angle a and the distribution orientation angleβof intersecting fissures on the uniaxial compressive strength and the failure characteristics of sandstone containing intersecting fissures are investigated through laboratory experiments and two-dimensional particle flow code(PFC2D).The relationship between the mechanical properties of sandstone and the intersecting angle a and the distribution orientation angleβis analysed.Crack initiation forms and the final failure modes are then categorised and determined via empirical methods.In addition,the cracking processes of intersecting fissures with different a andβvalues are discussed.The results show that variations in the peak stress,peak strain,average modulus,and crack initiation stress of sandstone containing intersecting fissures show a“moth”shape in the space of the a-β-mechanical parameters.Two crack initiation forms are identified:inner tip cracking(usually accompanied by one outer tip cracking)and only outer tips cracking.Two failure modes are observed:(1)the main fracture planes are created at the inner tip and one outer tip,and(2)the main fracture planes are formed at the two outer tips.Two main crack evolution processes of sandstone containing intersecting fissures under uniaxial compression are found.Approaches for quickly determining the crack initiation form and the failure mode are proposed.The combination of the determination equations for the crack initiation form and the failure mode can be used to predict the crack evolution.The approach for determining the crack evolution processes is hence proposed with acceptable precision.

Medium and long-term thermal coal contract embedded reparations from the perspective of an evolutionary game

Coal-fired electricity enterprises are caught in the dilemma of relative fixed prices and rising costs under the scenario of decarbonization.Meanwhile,soaring market-oriented coal pricing results in coal enterprises’increasing defaults on thermal coal medium-and long-term contracts(MLC).To investigate the implementation of MLC at the micro-level,this study formalized the contractual behaviors of coal and coal-fired electricity enterprises based on the asymmetric evolutionary game.We formalized the evolving behaviors of both parties using replicator dynamics equations and proved that there were two evolutionary stabilization strategies(ESSs):compliance and coal enterprises’unilateral default.A multi-agent-based simulation was applied to verify the evolving process of ESSs and determine the critical values of MLC design by sensitive analysis.From the simulation results,coal-fired electricity enterprises do not stop generation under the current carbon quota allocation mechanism,even if carbon emission trading increases electricity generation costs.Coal enterprises choose to“default”when the market price of coal is higher than the contracted price by 18%.However,if the original reparation is increased by 5%,the compliance rate of the coal enterprises improves.Dynamic reparations embedded in the MLC improved enforcement during the contracting period.Moreover,the proposed policy implications have practical significance for enhancing the coordinated operation of coal-electricity energy supply chains.

Current Situation of College Students’ Entrepreneurship and Employment in the Countryside in the Context of Rural Revitalization

Focusing on the talent training in the strategy of revitalizing the countryside, this paper uses questionnaire survey, field survey, descriptive statistics, chi-square test and other methods to study the willingness of college students to "go to the countryside" to contribute to rural development after graduation, as well as the influencing factors. The results show that the willingness of college students to "go to the countryside" is negative after graduation, and engaging in rural education and returning to their hometown to start a business is the mainstream will of college students to "go to the countryside". The one-sidedness of the understanding of rural areas, less employment opportunities, low wages, poor infrastructure conditions and the views of the older generation are the important reasons that hinder college students from "going to the countryside". The good environment in rural areas and the guidance of policies are the biggest promoting factors for "going to the countryside". The willingness of rural college students to "go to the countryside" is significantly higher than that of urban college students. The freshman s willingness to "go to the countryside" is the most positive, and the graduate students willingness to "go to the countryside" is the most negative. The college students majoring in agriculture are most willing to support the development of rural areas, while the students of "medicine","literature" and "art" are most unwilling to "go to the countryside". Whether or not to participate in the "volunteer activities for the country people" has no impact on the willingness to "go to the countryside".

Understanding the Correlations between Social Attention and Topic Trends of Scientific Publications

Purpose： We propose and apply a simplified nowcasting model to understand the correlations between social attention and topic trends of scientific publications. Design/methodology/approach： First, topics are generated from the obesity corpus by using the latent Dirichlet allocation （LDA） algorithm and time series of keyword search trends in Google Trends are obtained. We then establish the structural time series model using data from January 2004 to December 2012, and evaluate the model using data from January 2013. We employ a state-space model to separate different non-regression components in an observational time series （i.e. the tendency and the seasonality） and apply the ＂spike and slab prior＂ and stepwise regression to analyze the correlations between the regression component and the social media attention. The two parts are combined using Markov-chain Monte Carlo sampling techniques to obtain our results. Findings： The results of our study show that （1） the number of publications on child obesity increases at a lower rate than that of diabetes publications; （2） the number of publication on a given topic may exhibit a relationship with the season or time of year; and （3） there exists a correlation between the number of publications on a given topic and its social media attention, i.e. the search frequency related to that topic as identified by Google Trends. We found that our model is also able to predict the number of publications related to a given topic.

Preparation and Characteristics of Cu/Al_2O_3/MgF_2/Au Tunnel Junction

The fabrication process of Cu/Al2O3/MgF2/Au double-barrier metal/insulator/metal junction （DMIMJ） was introduced, and more stable light emission from this junction was successfully observed. The light emission physical mechanism of the junction was discussed. Results show that light emission spectrum of this structure locates at wavelength of 250-700 nm with two peaks at around 460 nm and 640 nm, which moves towards shorter wavelength region in comparison with that of the Al/Al2O3/Au junction. The light emission efficiency of this junction ranges from 0.7×10^-5-2.0×10^-5, which is 1 to 2 orders higher than that of the single-barrier Al/Al2O3/Au junction. The improved properties of this structure should be due to the electrons resonant tunneling effect in the double-barrier.

Dielectric and Pyroelectric Characteristics of the Infrared Sensitive (Pb_(1-x)Sr_x)TiO_3 Ceramics

PST ferroelectric ceramics were fabricated successfully by a two-step method, i e first, PbTiO3 and SrTiO3 were sintered respectively, then mixed and sintered together. The process and characteristics of PST ferroelectric ceramics were introduced and researched. Their dielectric and pyroelectric characteristics are as follows dielectric constant 10^4 order, low dielectric loss （lower than 3.0% in the working frequency range of 1-1 000 kHz）, saturation polarization intensity 10^-1 C/m^2 order, and pyroelectric coefficient 10^-3 C/m^2·K order.

Bargaining strategy of oil companies in international oil and gas development Projects-Based on a bilateral bargaining model

Bargaining between the host country and oil companies is very common to international oil and gas development projects.The existence of information asymmetry gives the host country an endogenous bargaining advantage.Foreign oil companies might change their unfavorable negotiating position by changing the order of bidding and adjusting bidding strategies.This paper introduces both factors into a bilateral bargaining model to study the impact of information asymmetry and bidding order on the strategy and equilibrium returns of oil companies.According to the ownership of the right to bid first,two scenarios are designed for the model to compare the equilibrium returns of the host country and oil companies.The results show that:1)There is a first-mover advantage in the process of bilateral bidding,so oil companies better bid first;2)The information asymmetry will lead to a higher nominal income ratio of oil companies and a lower nominal income ratio of the host country,but it doesn’t affect the total income ratio at all.

Dynamics of a Delayed Predator-prey System with Stage Structure for Predator and Prey

In this paper, a predator-prey system with two discrete delays and stage structure for both the predator and the prey is investigated. The dynamical behaviors such as local stability and local Hopf bifurcation are analyzed by regarding the possible combinations of the two delays as bifurcating parameter. Some explicit formulae determining the direction of the Hopf bifurcation and the stability of the bifurcating periodic solutions are derived by using the normal form method and the center manifold theory. Finally~ numerical simulations are presented to support the theoreticM analysis.

Hopf Bifurcation of Delayed Predator-prey System with Reserve Area for Prey and in the Presence of Toxicity

A kind of three species delayed predator-prey system with reserve area for prey and in the presence of toxicity is proposed in this paper. Local stability of the coexistence equilibrium of the system and the existence of a Hopf bifurcation is established by choosing the time delay as the bifurcation parameter. Explicit formulas to determine the direction and stability of the Hopf bifurcation are obtained by means of the normal form theory and the center manifold theorem. Finally, we give a numerical example to illustrate the obtained results.

Light Emission Characteristics of Metal/Insulator/Metal and Metal/Insulator/Si Tunnel Junctions Mediated by Surface Plasmon-polaritons

The Au/Al2O3/Al metal/insulator/metal junction(MIMJ) and Au/SiO2/Si metal/insulator/Si junction(MISJ) have been constructed successfully. The light emission of these junctions was mediated by surface plasmon-polaritons(SPPs) under surface roughness. The light emission from MISJ was more uniform and stable than that from MIMJ. The light power of MISJ was about 2~3 orders higher than that of MIMJ. The light emission spectrum of MISJ was analyzed especially. In the spectrum, there was one main peak located at the wavelength of 610 nm^640 nm, which was mainly due to the couple of SPP with the surface roughness at the Au/air and Au/SiO2 interfaces. A weak peak located at the shorter wavelength region in the spectrum was also found, which was caused by the direct radiation of doped-Si plasma oscillation.

Analysis and evaluation of structural complexity of circular economy system＇s industrial chain

This paper examined the method to evaluate structural complexity of circular economy system＇s industrial chain, which applied entropy information and hierarchical metrics to produce complexity degrees according to the theory of complex system. We developed an evaluation model to make a general metrics for circular economy system of industrial chains. The development of the evaluation tree drew upon five factors to identify the structural complexity. The evaluation model generated unitive entropy information from six data definition （node, level of community, metabolic span, degree of node, number of relation and connectivity of node） according to the evaluation tree. The industrial chains of Tashan circular economy park of Datong Coal Mine Group and Gujiao circular economy park of Xishan Coal-Electricity Group were evaluated by the proposed method. The key factors stunted by the decline of structural complexity were identified and the unitive metrics of entropy information of the industrial chain was shown for realigning the circular economy systems.

Modeling of unsupervised knowledge graph of events based on mutual information among neighbor domains and sparse representation

Text event mining,as an indispensable method of text mining processing,has attracted the extensive attention of researchers.A modeling method for knowledge graph of events based on mutual information among neighbor domains and sparse representation is proposed in this paper,i.e.UKGE-MS.Specifically,UKGE-MS can improve the existing text mining technology's ability of understanding and discovering high-dimensional unmarked information,and solves the problems of traditional unsupervised feature selection methods,which only focus on selecting features from a global perspective and ignoring the impact of local connection of samples.Firstly,considering the influence of local information of samples in feature correlation evaluation,a feature clustering algorithm based on average neighborhood mutual information is proposed,and the feature clusters with certain event correlation are obtained;Secondly,an unsupervised feature selection method based on the high-order correlation of multi-dimensional statistical data is designed by combining the dimension reduction advantage of local linear embedding algorithm and the feature selection ability of sparse representation,so as to enhance the generalization ability of the selected feature items.Finally,the events knowledge graph is constructed by means of sparse representation and l1 norm.Extensive experiments are carried out on five real datasets and synthetic datasets,and the UKGE-MS are compared with five corresponding algorithms.The experimental results show that UKGE-MS is better than the traditional method in event clustering and feature selection,and has some advantages over other methods in text event recognition and discovery.