Social-Emotional Competency(SEC),regarded as a critical psychological resource for individuals to adapt to social environments,is an effective protective factor for students’mental health,impacting their future succe...Social-Emotional Competency(SEC),regarded as a critical psychological resource for individuals to adapt to social environments,is an effective protective factor for students’mental health,impacting their future success and well-being.Analyzing the impact of SEC on university students’mental health can offer valuable insights for nurturing talents with healthy psychological and physical development.Based on data from two large-scale surveys of Chinese university students,this study designed two comprehensive Multiple Mediation Models involving SEC,stress,coping strategies,and stress reaction to explore the pathway of emotion nurturing mentality.Study 1 utilized a parallel mediation model to examine the relationships between SEC,academic stress,interpersonal stress,and stress reactions.The results indicated that SEC negatively predicted academic stress,interpersonal stress,and stress reactions.Additionally,academic and interpersonal stress mediated the relationships between SEC and stress reactions in parallel.Extending these findings,Study 2 further investigated the role of coping strategies.By constructing a multiple-chain mediation model,it examined the predictive relationships among SEC,academic stress,interpersonal stress,three types of coping strategies,and stress reactions.The findings indicated that SEC negatively predicted stress,problemavoiding strategy,and stress reactions,while positively predicting problem-solving and assistant-seeking strategies.Furthermore,the two stress types and three coping strategies significantly mediated the relationship between SEC and stress reactions.This indicated that higher SEC was associated with reduced stress and more adaptive coping strategies and subsequently contributed to more favorable stress reactions.This research explored the impact of university students’SEC on mental health and its relational mechanisms,aiming to provide theoretical reference and practical insights for future efforts in cultivating SEC among university students to adjust academic and interpersonal stress,to enhance problem-solving and stress resistance capabilities,and to maintain their mental health.展开更多
Hydroisomerization of n-heptane is an efficient method for producing gasoline with a high octane number.The focus of this study was to find a highly efficient catalyst that could both promote the conversion of n-hepta...Hydroisomerization of n-heptane is an efficient method for producing gasoline with a high octane number.The focus of this study was to find a highly efficient catalyst that could both promote the conversion of n-heptane and inhibit the cracking side reaction.MIL-101(Cr)is a chromium-based metal-organic framework(MOF)with good hydrothermal stability,and exhibits a three-dimensional pore structure that is similar to that of zeolites.Using phosphomolybdic acid(PMA;H3PMo12O40·xH2O)can increase the number of Brønsted acid sites on MIL-101(Cr),which contributes to improving the catalytic performance during isomerization.In this study,0.4%Pt/PMA-MIL-101(Cr)catalyst was successfully crystallized at 220℃using a hydrothermal synthetic method.The results showed that the synthesized samples were mesoporousmicroporous composite materials with the typical octahedral structure,and the MIL-101(Cr)framework was not damaged following modification with PMA.It was found that 0.4%Pt30%PMA-MIL-101(Cr)exhibited the best performance for isomerization of n-heptane,with a conversion rate and selectivity at 260°C of 47.6%and 96.6%,respectively.After five hours of reaction,the conversion rate and selectivity of the catalyst remained above 38%and 80%,respectively.展开更多
Objectives:To explore the relationship between college students’self-esteem(SE)and their social phobia(SP),as well as the mediating role of fear of negative evaluation(FNE)and the moderating effect of perfectionism.M...Objectives:To explore the relationship between college students’self-esteem(SE)and their social phobia(SP),as well as the mediating role of fear of negative evaluation(FNE)and the moderating effect of perfectionism.Methods:A convenience sampling survey was carried out for 1020 college students from Shandong Province of China,utilizing measures of college students’self-esteem,fear of negative evaluation,perfectionism,and social phobia.Data analysis was performed using the SPSS PROCESS macro.Results:(1)college students’self-esteem significantly and negatively predicts their social phobia(β=−0.31,t=−10.10,p<0.001);(2)fear of negative evaluation partially mediates the relation between self-esteem and social phobia among college students,with the mediating effect accounting for 48.97%of the total effect(TE);(3)the mediating role of fear of negative evaluation is moderated by perfectionism(β=0.18,t=7.75,p<0.001),where higher levels of perfectionism strengthen the mediating effect of fear of negative evaluation.Conclusions:Perfectionism moderates the mediating effect that fear of negative evaluation plays,establishing a moderated mediating model.展开更多
This paper explores the adaptive iterative learning control method in the control of fractional order systems for the first time. An adaptive iterative learning control(AILC) scheme is presented for a class of commens...This paper explores the adaptive iterative learning control method in the control of fractional order systems for the first time. An adaptive iterative learning control(AILC) scheme is presented for a class of commensurate high-order uncertain nonlinear fractional order systems in the presence of disturbance.To facilitate the controller design, a sliding mode surface of tracking errors is designed by using sufficient conditions of linear fractional order systems. To relax the assumption of the identical initial condition in iterative learning control(ILC), a new boundary layer function is proposed by employing MittagLeffler function. The uncertainty in the system is compensated for by utilizing radial basis function neural network. Fractional order differential type updating laws and difference type learning law are designed to estimate unknown constant parameters and time-varying parameter, respectively. The hyperbolic tangent function and a convergent series sequence are used to design robust control term for neural network approximation error and bounded disturbance, simultaneously guaranteeing the learning convergence along iteration. The system output is proved to converge to a small neighborhood of the desired trajectory by constructing Lyapnov-like composite energy function(CEF)containing new integral type Lyapunov function, while keeping all the closed-loop signals bounded. Finally, a simulation example is presented to verify the effectiveness of the proposed approach.展开更多
For high corrosion resistance and extensively modified biodegradable Mg-based alloys and composites for bone implants,a new Mgbased matrix model prepared by powder metallurgy is discussed and developed.In this researc...For high corrosion resistance and extensively modified biodegradable Mg-based alloys and composites for bone implants,a new Mgbased matrix model prepared by powder metallurgy is discussed and developed.In this research,Mg-5 wt.%Zn alloys were selected as a case.And they were impacted by hot extrusion and aging treatments to construct microstructure with different characteristics.Their selfforming corrosion product layer in Ringer’s solution,biodegradable behavior and corrosion mechanism were minutely investigated by in vitro degradation,electrochemical corrosion and cytocompatibility.The results demonstrated the extruded Mg-5 wt.%Zn alloy aged for 96 h showed high corrosion resistance,good biocompatibility for L929 and excellent ability of maintaining sample integrity during the immersion.Significantly,the alloy showed fine-grain microstructure and uniform distributed hundred nano-sized second phases,which promoted the formation of the uniform and smooth corrosion product layer at the beginning of immersion.The corrosion product layer was more stable in chloride containing aqueous solution and could be directly formed and repaired quickly,which effectively protected the matrix from further corrosion.In addition,an ideal model of Mg-based matrix for bone tissue engineering was tried to presume and propose by discussing the causal relationship between microstructure and bio-corrosion process.展开更多
The solidification-precipitation behavior of Al-Mg-Si multicomponent alloys has long been an absorbing topic. Experiments were carried out to analyze the precipitation behaviors of Al-Mg-Si alloys under different heat...The solidification-precipitation behavior of Al-Mg-Si multicomponent alloys has long been an absorbing topic. Experiments were carried out to analyze the precipitation behaviors of Al-Mg-Si alloys under different heat treatments. All specimens were homogenized at 570 ℃ for 8 h, and then solution treated at 540 ℃ for 55 min. Subsequently, the specimens were age treated for different times at temperatures of 100 ℃, 150 ℃ and 180 ℃, respectively. The experimental results show that the occurrence of dispersed free zones (DFZ) is caused by the uneven distribution of dispersed phase. During the aging process, pre-β" phases form at the initial stage and an aging temperature of 100 ℃is too low to complete the transformation of pre-β" to β". At 150℃, the precipitation sequence is concluded as SSSS-pre-β"-pre-β"+β"-β"-β'-β. Moreover, changes in sizes and densities of the pre-β", β"and β' phases during the aging process has an important influence on the evolution of microhardness and electrical resistivity. The microhardness peak value of 150 ℃ is similar to that of 180 ℃, which is -141 HV. While, at 100℃, the microhardness increases slowly, and the attainable value is 127 HV up to 19 days. When the aging temperature is 100 ℃, the electrical resistivity has the highest average value. When the aging temperature exceeds 100 ℃, with the occurrence and growth of β"and β', the resistivity has a distinct decrease with prolonged aging time.展开更多
Fe-Cr-Ni heat resistant steels with different contents of Al and Si were cast in intermediate frequency induction furnace with non-oxidation method. With oxidation weight gain method, the oxidation resistance of test ...Fe-Cr-Ni heat resistant steels with different contents of Al and Si were cast in intermediate frequency induction furnace with non-oxidation method. With oxidation weight gain method, the oxidation resistance of test alloys was examined at 1 200 ℃ for 500 h. The effects of Al and Si on oxidation resistance were studied through analyses of X-ray diffraction (XRD) and scanning electron microscope (SEM). It is shown that the composition of oxide scales is a decisive factor for the oxidation resistance of heat resistant steels. The compounded scale composed of Cr203, α-Al2O3, SiO2 and Fe (Ni)Cr2O4, with flat and compact structure, fine and even grains, exhibits complete oxidation resistance at 1 200 ℃. Its oxidation weight gain rate is only 0.081 g/(m^2.h). By the criterion of standard Gibbs formation free energy, a model of nucleation and growth of the compounded scale was established. The formation of the compounded scale was the result of the competition of being oxidated and reduction among Al, Si, and the matrix metal elements of Fe, Cr and Ni. The protection of the compounded scale was analyzed from the perspectives of electrical conductivity and strength properties.展开更多
We study the photo-detachment interference patterns of a hydrogen negative ion in the magnetic field near different dielectric surfaces with a semi-classical open orbit theory. We give a clear physical picture describ...We study the photo-detachment interference patterns of a hydrogen negative ion in the magnetic field near different dielectric surfaces with a semi-classical open orbit theory. We give a clear physical picture describing the photo-detachment of H- in this case. The electron flux distributions are calculated at various dielectric surfaces with unchanged magnetic field strength. It is found that the electron flux distributions of H- are very different in a magnetic field near different dielectric surfaces, namely the dielectric surface has a great influence on the photo-detachment interference pattern of the negative ion. Therefore, the interference pattern in the detached-electron flux distribution can be controlled by changing the dielectric constant. We hope that our studies may guide the future experimental research in photo-detachment microscopy.展开更多
An investigation on electrochemical behavior of Mg-5%Pb alloy, Mg-6%Al alloy and Mg-6%Al-5%Pb alloy(mass fraction) in 3.5% Na Cl(mass fraction) solution was conducted using electrochemical measurements and corroded mo...An investigation on electrochemical behavior of Mg-5%Pb alloy, Mg-6%Al alloy and Mg-6%Al-5%Pb alloy(mass fraction) in 3.5% Na Cl(mass fraction) solution was conducted using electrochemical measurements and corroded morphology observation, in which solid solution and the as-aged state of each alloy were compared to discuss the influence mechanism of lead and aluminium on the electrochemical properties of alloys. The X-ray diffraction(XRD) analysis was performed to make microstructure characterization. The electrochemical results indicate that the corrosion of Mg-5%Pb alloy is predominated by homogeneous pitting and dissolution of PbCl_2 film due to Cl ions attack, while corrosion crevice propagates along grain boundaries in solid solution of Mg-6%Al alloy and the micro galvanic corrosion also plays vital role in Mg_(17)Al_(12) phase containing experimental alloys. The co-existence of lead and aluminium in magnesium alloy increases corrosion current density and electrochemical activity as well. The comparison between solid solution and the as-aged state demonstrates that Mg_2 Pb and Mg_(17)Al_(12) somewhat increase corrosion resistance but lighten anodic polarization by facilitating corrosion product flaking off.展开更多
The cap-and-offset regulation is a practical scheme to lessen carbon emissions.The retailer selling fresh products can adopt sustainable technologies to lessen greenhouse gas emissions.We aim to analyze the optimal jo...The cap-and-offset regulation is a practical scheme to lessen carbon emissions.The retailer selling fresh products can adopt sustainable technologies to lessen greenhouse gas emissions.We aim to analyze the optimal joint strategies on order quantity and sustainable technology investment when the retailer faces stochastic market demand and can only acquire the mean and variance of distribution information.We construct a distributionally robust optimization model and use the Karush-Kuhn-Tucker(KKT)conditions to solve the analytic formula of optimal solutions.By comparing the models with and without investing in sustainable technologies,we examine the effect of sustainable technologies on the operational management decisions of the retailer.Finally,some computational examples are applied to analyze the impact of critical factors on operational strategies,and some managerial insights are given based on the analysis results.展开更多
As a completely new residential distribution infrastructure,energy internet facilitates transactions of equipment,energy and services. However,there is security risk under all the facilities.This paper proposes an ele...As a completely new residential distribution infrastructure,energy internet facilitates transactions of equipment,energy and services. However,there is security risk under all the facilities.This paper proposes an electricity pricing model based on insurance from the perspective of maximizing the benefits of Energy Internet service providers by using the principal-agent theory. The consumer prepays the provider insurance premiums and signs a contract. The provider sets electricity price according to the premiums and therefore provides differentiated electric services for the consumer. Loss suffered by the consumer due to the power failure is compensated by the provider according to the contract. The equivalent model is presented and a necessary condition of the optimal strategy is obtained on the basis of Pontryagin's maximum principle. At last,a numerical example is presented,which illustrates the effectiveness of the proposed model.展开更多
According to the basic problem of industrial production, the paper presents a monocular camera and automatic annotation ranging scheme with a ruler. The scheme eliminates a series of complex operation steps frequently...According to the basic problem of industrial production, the paper presents a monocular camera and automatic annotation ranging scheme with a ruler. The scheme eliminates a series of complex operation steps frequently used for image location of the calibration, image correction, it has simple implementation and has successfully realized precise ranging by using digital image processing technology. From the beginning of the analysis of image edge detection, edge detection principle and some common edge detection operators, and proposes an improved multi-scale edge detection algorithm, then according to the particularity of the edge proposed new edge thinning algorithm, finally mark the target point through the feature extraction, calculate the final results of fault location.展开更多
This paper presents a fuzzy C- means clustering image segmentation algorithm based on particle swarm optimization, the method utilizes the strong search ability of particle swarm clustering search center. Because the ...This paper presents a fuzzy C- means clustering image segmentation algorithm based on particle swarm optimization, the method utilizes the strong search ability of particle swarm clustering search center. Because the search clustering center has small amount of calculation according to density, so it can greatly improve the calculation speed of fuzzy C- means algorithm. The experimental results show that, this method can make the fuzzy clustering to obviously improve the speed, so it can achieve fast image segmentation.展开更多
In this paper, we conduct research on the applications of case studies and role playing methods on the enterprise strategic management course teaching. Training is an important part of the enterprise human resources m...In this paper, we conduct research on the applications of case studies and role playing methods on the enterprise strategic management course teaching. Training is an important part of the enterprise human resources management. For enterprises is a kind of novel important human capital investment, as well as other capital investments, both benefits. Also be risky, because of the risks and benefits is coexistence, indivisible. To deal with the mentioned challenge, we combine the novel and state-of-the-art training methodology to maximize the effectiveness of the training process. In the article, we cast our new opinion together with the prospect for the future.展开更多
With the rapid development of the management science and technology, the management related course is becoming popular. In this research paper, we research on the enterprise strategic management course based on the pr...With the rapid development of the management science and technology, the management related course is becoming popular. In this research paper, we research on the enterprise strategic management course based on the problem oriented teaching methodology. We reviewed the latest strategic management recently developed various theories and academic point of view to from the theoretical level of modern enterprise strategy management pattern to generalize and summarize, thus to guide the strategic management of modern enterprises. Enterprise strategic management is to point to determine its mission according to the external environment and internal conditions set strategic goals of the enterprise. Through combing the development of the strategic management theory, grasp the context and the regularity of the evolution of enterprise strategic thinking and the development trend of enterprise strategic theory at home and abroad was discussed to promote the existing strategic management research provides some unique ideas and thoughts.展开更多
In this research article, we conduct research on the curriculum system for the project management majored entrepreneurial talent. The engineering management major construction and the oriented real estate industry, es...In this research article, we conduct research on the curriculum system for the project management majored entrepreneurial talent. The engineering management major construction and the oriented real estate industry, especially for the large and medium-sized backbone enterprises in civil engineering construction and the real estate enterprises train innovative, applied and compound of high-level engineering technology and the management talent. Entrepreneurship education student entrepreneurial ability is to make the students have successful entrepreneurial innovation ability, the development ability, organization and the core management ability, interpersonal communication and cooperation ability, comprehensive ability. Student entrepreneurial ability of high and low depends largely on the amount of corresponding knowledge in practice. Our research provides novel paradigm for the curriculum system construction and optimization for the universities.展开更多
This paper introduces realization method of kinematics analysis for the planar four bar mechanism based on the MFC. A mathematicat model is established by a simple and effective method, using the computer simulation t...This paper introduces realization method of kinematics analysis for the planar four bar mechanism based on the MFC. A mathematicat model is established by a simple and effective method, using the computer simulation technology can the dynamic demonstration mechanism taotion and automatic drawing trajectory curve of arbitrary point on the connecting rod, and can output various motion displacement, speed and acceleration diagram. The paper provides a simple way for motion analysis of planar four link.展开更多
Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the ...Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.展开更多
Objective: This study aimed to investigate the therapeutic effects of Xiaoyao San(XYS), a herbal medicine formula, on exercise capacity and liver mitochondrial metabolomics in a rat model of depression induced by chro...Objective: This study aimed to investigate the therapeutic effects of Xiaoyao San(XYS), a herbal medicine formula, on exercise capacity and liver mitochondrial metabolomics in a rat model of depression induced by chronic unpredictable mild stress(CUMS).Methods: A total of 24 male SD rats were randomly divided into four groups: control group(C), CUMS control group(M), Venlafaxine positive treatment group(V), and XYS treatment group(X). Depressive behaviour and exercise capacity of rats were assessed by body weight, sugar-water preference test, open field test, pole test, and rotarod test. The liver mitochondria metabolomics were analyzed by using liquid chromatography-mass spectrometry(LC-MS) method. TCMSP database and Gene Cards database were used to screen XYS for potential targets for depression, and GO and KEGG enrichment analyses were performed.Results: Compared with C group, rats in M group showed significantly lower body weight, sugar water preference rate, number of crossing and rearing in the open field test, climbing down time in the pole test,and retention time on the rotarod test(P < 0.01). The above behaviors and exercise capacity indices were significantly modulated in rats in V and X groups compared with M group(P < 0.05, 0.01). Compared with C group, a total of 18 different metabolites were changed in the liver mitochondria of rats in M group.Nine different metabolites and six metabolic pathways were regulated in the liver mitochondria of rats in X group compared with M group. The results of network pharmacology showed that 88 intersecting targets for depression and XYS were obtained, among which 15 key targets such as IL-1β, IL-6, and TNF were predicted to be the main differential targets for the treatment of depression. Additionally, a total of 1 553 GO signaling pathways and 181 KEGG signaling pathways were identified, and the main biological pathways were AGE-RAGE signaling pathway, HIF-1 signaling pathway, and calcium signaling pathway.Conclusion: XYS treatment could improve depressive symptoms, enhance exercise capacity, positively regulate the changes of mitochondrial metabolites and improve energy metabolism in the liver of depressed rats. These findings suggest that XYS exerts antidepressant effects through multi-target and multi-pathway.展开更多
For a class of discrete-time singular stochastic systems with multi-state delay,the stabilization problem of receding horizon control(RHC)is concerned.Due to the difficulty in solving the proposed optimization problem...For a class of discrete-time singular stochastic systems with multi-state delay,the stabilization problem of receding horizon control(RHC)is concerned.Due to the difficulty in solving the proposed optimization problem,the RHC stabilization for such systems has not been solved.By adopting the forward and backward equation technique,the optimization problem is solved completely.A sufficient and necessary condition for the optimization controller to have a unique solution is given when the regularization and pulse-free conditions are satisfied.Based on this controller,an RHC stabilization condition is derived,which is in the form of linear matrix inequality.It is proved that the singular stochastic system with multi-state delay is stable in the mean-square sense under appropriate assumptions when the terminal weighting matrix satisfies the given inequality.Numerical examples show that the proposed RHC method is effective in stabilizing singular stochastic systems with multi-state delay.展开更多
基金Shandong Soft Science Project—Shandong Higher Education Top-Notch Talent Cultivation in Basic Disciplines from the Perspective of Social Emotional Learning(Project Number:2023RKY05001).
文摘Social-Emotional Competency(SEC),regarded as a critical psychological resource for individuals to adapt to social environments,is an effective protective factor for students’mental health,impacting their future success and well-being.Analyzing the impact of SEC on university students’mental health can offer valuable insights for nurturing talents with healthy psychological and physical development.Based on data from two large-scale surveys of Chinese university students,this study designed two comprehensive Multiple Mediation Models involving SEC,stress,coping strategies,and stress reaction to explore the pathway of emotion nurturing mentality.Study 1 utilized a parallel mediation model to examine the relationships between SEC,academic stress,interpersonal stress,and stress reactions.The results indicated that SEC negatively predicted academic stress,interpersonal stress,and stress reactions.Additionally,academic and interpersonal stress mediated the relationships between SEC and stress reactions in parallel.Extending these findings,Study 2 further investigated the role of coping strategies.By constructing a multiple-chain mediation model,it examined the predictive relationships among SEC,academic stress,interpersonal stress,three types of coping strategies,and stress reactions.The findings indicated that SEC negatively predicted stress,problemavoiding strategy,and stress reactions,while positively predicting problem-solving and assistant-seeking strategies.Furthermore,the two stress types and three coping strategies significantly mediated the relationship between SEC and stress reactions.This indicated that higher SEC was associated with reduced stress and more adaptive coping strategies and subsequently contributed to more favorable stress reactions.This research explored the impact of university students’SEC on mental health and its relational mechanisms,aiming to provide theoretical reference and practical insights for future efforts in cultivating SEC among university students to adjust academic and interpersonal stress,to enhance problem-solving and stress resistance capabilities,and to maintain their mental health.
基金National Natural Science Foundation of China(Grant No.22272129).
文摘Hydroisomerization of n-heptane is an efficient method for producing gasoline with a high octane number.The focus of this study was to find a highly efficient catalyst that could both promote the conversion of n-heptane and inhibit the cracking side reaction.MIL-101(Cr)is a chromium-based metal-organic framework(MOF)with good hydrothermal stability,and exhibits a three-dimensional pore structure that is similar to that of zeolites.Using phosphomolybdic acid(PMA;H3PMo12O40·xH2O)can increase the number of Brønsted acid sites on MIL-101(Cr),which contributes to improving the catalytic performance during isomerization.In this study,0.4%Pt/PMA-MIL-101(Cr)catalyst was successfully crystallized at 220℃using a hydrothermal synthetic method.The results showed that the synthesized samples were mesoporousmicroporous composite materials with the typical octahedral structure,and the MIL-101(Cr)framework was not damaged following modification with PMA.It was found that 0.4%Pt30%PMA-MIL-101(Cr)exhibited the best performance for isomerization of n-heptane,with a conversion rate and selectivity at 260°C of 47.6%and 96.6%,respectively.After five hours of reaction,the conversion rate and selectivity of the catalyst remained above 38%and 80%,respectively.
基金the Key Special Project of the Shandong Provincial Federation of Social Sciences on Humanities and Social Sciences“Risk Assessment and Prevention Mechanisms of‘Social Phobias’Phenomenon among College Students from the Perspective of Healthy China”(No.2023-zkzd-030)Special Task Project of Humanities and Social Science Research of the Ministry of Education in 2023(Research on University Counselors)(No.23JDSZ3080).
文摘Objectives:To explore the relationship between college students’self-esteem(SE)and their social phobia(SP),as well as the mediating role of fear of negative evaluation(FNE)and the moderating effect of perfectionism.Methods:A convenience sampling survey was carried out for 1020 college students from Shandong Province of China,utilizing measures of college students’self-esteem,fear of negative evaluation,perfectionism,and social phobia.Data analysis was performed using the SPSS PROCESS macro.Results:(1)college students’self-esteem significantly and negatively predicts their social phobia(β=−0.31,t=−10.10,p<0.001);(2)fear of negative evaluation partially mediates the relation between self-esteem and social phobia among college students,with the mediating effect accounting for 48.97%of the total effect(TE);(3)the mediating role of fear of negative evaluation is moderated by perfectionism(β=0.18,t=7.75,p<0.001),where higher levels of perfectionism strengthen the mediating effect of fear of negative evaluation.Conclusions:Perfectionism moderates the mediating effect that fear of negative evaluation plays,establishing a moderated mediating model.
基金supported by the National Natural Science Foundation of China(60674090)Shandong Natural Science Foundation(ZR2017QF016)
文摘This paper explores the adaptive iterative learning control method in the control of fractional order systems for the first time. An adaptive iterative learning control(AILC) scheme is presented for a class of commensurate high-order uncertain nonlinear fractional order systems in the presence of disturbance.To facilitate the controller design, a sliding mode surface of tracking errors is designed by using sufficient conditions of linear fractional order systems. To relax the assumption of the identical initial condition in iterative learning control(ILC), a new boundary layer function is proposed by employing MittagLeffler function. The uncertainty in the system is compensated for by utilizing radial basis function neural network. Fractional order differential type updating laws and difference type learning law are designed to estimate unknown constant parameters and time-varying parameter, respectively. The hyperbolic tangent function and a convergent series sequence are used to design robust control term for neural network approximation error and bounded disturbance, simultaneously guaranteeing the learning convergence along iteration. The system output is proved to converge to a small neighborhood of the desired trajectory by constructing Lyapnov-like composite energy function(CEF)containing new integral type Lyapunov function, while keeping all the closed-loop signals bounded. Finally, a simulation example is presented to verify the effectiveness of the proposed approach.
基金The authors acknowledge the Project(81472058)sup-ported by the National Natural Science Foundation of Chinathe financial support of the 2015 ShanDong province project of outstanding subject talent group.the project(LSD-KB1806)+2 种基金supported by the foundation of National Key labo-ratory of Shock Wave and Detonation Physics and the project(11802284)supported by the National Natural Science Foun-dation of China.The project(2017GK2120)supported by the Key Research and Development Program of Hunan Province and the Natural Science Foundation of Hunan Province of China(2018JJ2506).
文摘For high corrosion resistance and extensively modified biodegradable Mg-based alloys and composites for bone implants,a new Mgbased matrix model prepared by powder metallurgy is discussed and developed.In this research,Mg-5 wt.%Zn alloys were selected as a case.And they were impacted by hot extrusion and aging treatments to construct microstructure with different characteristics.Their selfforming corrosion product layer in Ringer’s solution,biodegradable behavior and corrosion mechanism were minutely investigated by in vitro degradation,electrochemical corrosion and cytocompatibility.The results demonstrated the extruded Mg-5 wt.%Zn alloy aged for 96 h showed high corrosion resistance,good biocompatibility for L929 and excellent ability of maintaining sample integrity during the immersion.Significantly,the alloy showed fine-grain microstructure and uniform distributed hundred nano-sized second phases,which promoted the formation of the uniform and smooth corrosion product layer at the beginning of immersion.The corrosion product layer was more stable in chloride containing aqueous solution and could be directly formed and repaired quickly,which effectively protected the matrix from further corrosion.In addition,an ideal model of Mg-based matrix for bone tissue engineering was tried to presume and propose by discussing the causal relationship between microstructure and bio-corrosion process.
基金financially supported by the Natural Science Foundation of Shandong Province(ZR2016EMQ11)the Major Research and Development Program of Shandong Province(2017GGX20119),China
文摘The solidification-precipitation behavior of Al-Mg-Si multicomponent alloys has long been an absorbing topic. Experiments were carried out to analyze the precipitation behaviors of Al-Mg-Si alloys under different heat treatments. All specimens were homogenized at 570 ℃ for 8 h, and then solution treated at 540 ℃ for 55 min. Subsequently, the specimens were age treated for different times at temperatures of 100 ℃, 150 ℃ and 180 ℃, respectively. The experimental results show that the occurrence of dispersed free zones (DFZ) is caused by the uneven distribution of dispersed phase. During the aging process, pre-β" phases form at the initial stage and an aging temperature of 100 ℃is too low to complete the transformation of pre-β" to β". At 150℃, the precipitation sequence is concluded as SSSS-pre-β"-pre-β"+β"-β"-β'-β. Moreover, changes in sizes and densities of the pre-β", β"and β' phases during the aging process has an important influence on the evolution of microhardness and electrical resistivity. The microhardness peak value of 150 ℃ is similar to that of 180 ℃, which is -141 HV. While, at 100℃, the microhardness increases slowly, and the attainable value is 127 HV up to 19 days. When the aging temperature is 100 ℃, the electrical resistivity has the highest average value. When the aging temperature exceeds 100 ℃, with the occurrence and growth of β"and β', the resistivity has a distinct decrease with prolonged aging time.
基金Supported by Shandong Science and Technology Key Projects (No2007GG30003004)
文摘Fe-Cr-Ni heat resistant steels with different contents of Al and Si were cast in intermediate frequency induction furnace with non-oxidation method. With oxidation weight gain method, the oxidation resistance of test alloys was examined at 1 200 ℃ for 500 h. The effects of Al and Si on oxidation resistance were studied through analyses of X-ray diffraction (XRD) and scanning electron microscope (SEM). It is shown that the composition of oxide scales is a decisive factor for the oxidation resistance of heat resistant steels. The compounded scale composed of Cr203, α-Al2O3, SiO2 and Fe (Ni)Cr2O4, with flat and compact structure, fine and even grains, exhibits complete oxidation resistance at 1 200 ℃. Its oxidation weight gain rate is only 0.081 g/(m^2.h). By the criterion of standard Gibbs formation free energy, a model of nucleation and growth of the compounded scale was established. The formation of the compounded scale was the result of the competition of being oxidated and reduction among Al, Si, and the matrix metal elements of Fe, Cr and Ni. The protection of the compounded scale was analyzed from the perspectives of electrical conductivity and strength properties.
基金Project supported by the Natural Science Foundation for Youths of Shandong Province,China(Grant No.ZR2014AQ022)
文摘We study the photo-detachment interference patterns of a hydrogen negative ion in the magnetic field near different dielectric surfaces with a semi-classical open orbit theory. We give a clear physical picture describing the photo-detachment of H- in this case. The electron flux distributions are calculated at various dielectric surfaces with unchanged magnetic field strength. It is found that the electron flux distributions of H- are very different in a magnetic field near different dielectric surfaces, namely the dielectric surface has a great influence on the photo-detachment interference pattern of the negative ion. Therefore, the interference pattern in the detached-electron flux distribution can be controlled by changing the dielectric constant. We hope that our studies may guide the future experimental research in photo-detachment microscopy.
基金Project supported by 2015 Shandong Provincal Fund for Outstanding Talent Group,China
文摘An investigation on electrochemical behavior of Mg-5%Pb alloy, Mg-6%Al alloy and Mg-6%Al-5%Pb alloy(mass fraction) in 3.5% Na Cl(mass fraction) solution was conducted using electrochemical measurements and corroded morphology observation, in which solid solution and the as-aged state of each alloy were compared to discuss the influence mechanism of lead and aluminium on the electrochemical properties of alloys. The X-ray diffraction(XRD) analysis was performed to make microstructure characterization. The electrochemical results indicate that the corrosion of Mg-5%Pb alloy is predominated by homogeneous pitting and dissolution of PbCl_2 film due to Cl ions attack, while corrosion crevice propagates along grain boundaries in solid solution of Mg-6%Al alloy and the micro galvanic corrosion also plays vital role in Mg_(17)Al_(12) phase containing experimental alloys. The co-existence of lead and aluminium in magnesium alloy increases corrosion current density and electrochemical activity as well. The comparison between solid solution and the as-aged state demonstrates that Mg_2 Pb and Mg_(17)Al_(12) somewhat increase corrosion resistance but lighten anodic polarization by facilitating corrosion product flaking off.
基金supported by the National Natural Science Foundation of China (Grant No.71702087)the Youth Innovation Science and Technology Support Program of Shandong Province Higher Education (Grant No.2021RW024)the Special Funds for Taishan Scholars,Shandong (Grant No.tsqn202103063).
文摘The cap-and-offset regulation is a practical scheme to lessen carbon emissions.The retailer selling fresh products can adopt sustainable technologies to lessen greenhouse gas emissions.We aim to analyze the optimal joint strategies on order quantity and sustainable technology investment when the retailer faces stochastic market demand and can only acquire the mean and variance of distribution information.We construct a distributionally robust optimization model and use the Karush-Kuhn-Tucker(KKT)conditions to solve the analytic formula of optimal solutions.By comparing the models with and without investing in sustainable technologies,we examine the effect of sustainable technologies on the operational management decisions of the retailer.Finally,some computational examples are applied to analyze the impact of critical factors on operational strategies,and some managerial insights are given based on the analysis results.
基金Supported by the National Natural Science Foundation of China(No.61672494,61402437)the National High Technology Research and Development Program of China(No.2015AA016005)
文摘As a completely new residential distribution infrastructure,energy internet facilitates transactions of equipment,energy and services. However,there is security risk under all the facilities.This paper proposes an electricity pricing model based on insurance from the perspective of maximizing the benefits of Energy Internet service providers by using the principal-agent theory. The consumer prepays the provider insurance premiums and signs a contract. The provider sets electricity price according to the premiums and therefore provides differentiated electric services for the consumer. Loss suffered by the consumer due to the power failure is compensated by the provider according to the contract. The equivalent model is presented and a necessary condition of the optimal strategy is obtained on the basis of Pontryagin's maximum principle. At last,a numerical example is presented,which illustrates the effectiveness of the proposed model.
文摘According to the basic problem of industrial production, the paper presents a monocular camera and automatic annotation ranging scheme with a ruler. The scheme eliminates a series of complex operation steps frequently used for image location of the calibration, image correction, it has simple implementation and has successfully realized precise ranging by using digital image processing technology. From the beginning of the analysis of image edge detection, edge detection principle and some common edge detection operators, and proposes an improved multi-scale edge detection algorithm, then according to the particularity of the edge proposed new edge thinning algorithm, finally mark the target point through the feature extraction, calculate the final results of fault location.
文摘This paper presents a fuzzy C- means clustering image segmentation algorithm based on particle swarm optimization, the method utilizes the strong search ability of particle swarm clustering search center. Because the search clustering center has small amount of calculation according to density, so it can greatly improve the calculation speed of fuzzy C- means algorithm. The experimental results show that, this method can make the fuzzy clustering to obviously improve the speed, so it can achieve fast image segmentation.
文摘In this paper, we conduct research on the applications of case studies and role playing methods on the enterprise strategic management course teaching. Training is an important part of the enterprise human resources management. For enterprises is a kind of novel important human capital investment, as well as other capital investments, both benefits. Also be risky, because of the risks and benefits is coexistence, indivisible. To deal with the mentioned challenge, we combine the novel and state-of-the-art training methodology to maximize the effectiveness of the training process. In the article, we cast our new opinion together with the prospect for the future.
文摘With the rapid development of the management science and technology, the management related course is becoming popular. In this research paper, we research on the enterprise strategic management course based on the problem oriented teaching methodology. We reviewed the latest strategic management recently developed various theories and academic point of view to from the theoretical level of modern enterprise strategy management pattern to generalize and summarize, thus to guide the strategic management of modern enterprises. Enterprise strategic management is to point to determine its mission according to the external environment and internal conditions set strategic goals of the enterprise. Through combing the development of the strategic management theory, grasp the context and the regularity of the evolution of enterprise strategic thinking and the development trend of enterprise strategic theory at home and abroad was discussed to promote the existing strategic management research provides some unique ideas and thoughts.
文摘In this research article, we conduct research on the curriculum system for the project management majored entrepreneurial talent. The engineering management major construction and the oriented real estate industry, especially for the large and medium-sized backbone enterprises in civil engineering construction and the real estate enterprises train innovative, applied and compound of high-level engineering technology and the management talent. Entrepreneurship education student entrepreneurial ability is to make the students have successful entrepreneurial innovation ability, the development ability, organization and the core management ability, interpersonal communication and cooperation ability, comprehensive ability. Student entrepreneurial ability of high and low depends largely on the amount of corresponding knowledge in practice. Our research provides novel paradigm for the curriculum system construction and optimization for the universities.
文摘This paper introduces realization method of kinematics analysis for the planar four bar mechanism based on the MFC. A mathematicat model is established by a simple and effective method, using the computer simulation technology can the dynamic demonstration mechanism taotion and automatic drawing trajectory curve of arbitrary point on the connecting rod, and can output various motion displacement, speed and acceleration diagram. The paper provides a simple way for motion analysis of planar four link.
基金supported by the Longkou City Science and Technology Research and Development Plan(No.2020KJJH061).
文摘Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.
基金supported by the National Natural Science Foundation of China,China(No.82074147)the Project of Natural Science Research of the Shanxi Province,China(No.202103021224027).
文摘Objective: This study aimed to investigate the therapeutic effects of Xiaoyao San(XYS), a herbal medicine formula, on exercise capacity and liver mitochondrial metabolomics in a rat model of depression induced by chronic unpredictable mild stress(CUMS).Methods: A total of 24 male SD rats were randomly divided into four groups: control group(C), CUMS control group(M), Venlafaxine positive treatment group(V), and XYS treatment group(X). Depressive behaviour and exercise capacity of rats were assessed by body weight, sugar-water preference test, open field test, pole test, and rotarod test. The liver mitochondria metabolomics were analyzed by using liquid chromatography-mass spectrometry(LC-MS) method. TCMSP database and Gene Cards database were used to screen XYS for potential targets for depression, and GO and KEGG enrichment analyses were performed.Results: Compared with C group, rats in M group showed significantly lower body weight, sugar water preference rate, number of crossing and rearing in the open field test, climbing down time in the pole test,and retention time on the rotarod test(P < 0.01). The above behaviors and exercise capacity indices were significantly modulated in rats in V and X groups compared with M group(P < 0.05, 0.01). Compared with C group, a total of 18 different metabolites were changed in the liver mitochondria of rats in M group.Nine different metabolites and six metabolic pathways were regulated in the liver mitochondria of rats in X group compared with M group. The results of network pharmacology showed that 88 intersecting targets for depression and XYS were obtained, among which 15 key targets such as IL-1β, IL-6, and TNF were predicted to be the main differential targets for the treatment of depression. Additionally, a total of 1 553 GO signaling pathways and 181 KEGG signaling pathways were identified, and the main biological pathways were AGE-RAGE signaling pathway, HIF-1 signaling pathway, and calcium signaling pathway.Conclusion: XYS treatment could improve depressive symptoms, enhance exercise capacity, positively regulate the changes of mitochondrial metabolites and improve energy metabolism in the liver of depressed rats. These findings suggest that XYS exerts antidepressant effects through multi-target and multi-pathway.
基金the Natural Science Foundation of Shandong Province (No.ZR2020MF063)the National Natural Science Foundation of China (No.61873332)。
文摘For a class of discrete-time singular stochastic systems with multi-state delay,the stabilization problem of receding horizon control(RHC)is concerned.Due to the difficulty in solving the proposed optimization problem,the RHC stabilization for such systems has not been solved.By adopting the forward and backward equation technique,the optimization problem is solved completely.A sufficient and necessary condition for the optimization controller to have a unique solution is given when the regularization and pulse-free conditions are satisfied.Based on this controller,an RHC stabilization condition is derived,which is in the form of linear matrix inequality.It is proved that the singular stochastic system with multi-state delay is stable in the mean-square sense under appropriate assumptions when the terminal weighting matrix satisfies the given inequality.Numerical examples show that the proposed RHC method is effective in stabilizing singular stochastic systems with multi-state delay.