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Sensitivity analysis of the deterioration of concrete strength in marine environment to multiple corrosive ions

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Frontiers of Structural and Civil Engineering 2022年第2期16卷 175-190页

作者： Jinwei yao Jiankang CHEN Zhejiang Business Technology Institute Ningbo315012China Key Laboratory of Impact and Safety Engineering Ministry of EducationSchool of Mechanical Engineering and MechanicsNingbo UniversityNingbo315211China

The corrosion degradation behavior of concrete materials plays a crucial role in the change of its mechanical properties under multi-ion interaction in the marine *** this study,the variation in the macrophysical and mechanical properties of concrete with corrosion time is investigated,and the source of micro-corrosion products under different salt solutions in seawater are *** of the continuous hydration effect of concrete,the damage effects of various corrosive ions(Cl^(−),SO_(4)^(2−),and Mg^(2+),etc.)on the tensile and compressive strength of concrete are discussed based on measurement in different salt *** sensitivity analysis method for concrete strength is used to quantitatively analyze the sensitivity of concrete strength to the effects of each ion in a multi-salt solution without considering the influence of continued *** quantitative results indicate that the addition of Cl−can weaken the corrosion effect of SO_(4)^(2−) by about 20%,while the addition of Mg^(2+)or Mg^(2+)and Cl^(−)can strengthen it by 10%–20%during a 600-d corrosion process.

关键词： sensitivity analysis concrete strength corrosion deterioration multi-ion interaction marine environment

Periodic and chaotic dynamics of composite laminated piezoelectric rectangular plate with one-to-two internal resonance

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Science China(Technological Sciences) 2009年第3期52卷 731-742页

作者： ZHANG Wei yao ZhiGang yao MingHui College of Mechanical Engineering Beijing University of TechnologyBeijing 100124China

The bifurcations and chaotic dynamics of a simply supported symmetric cross-ply composite lami- nated piezoelectric rectangular plate are studied for the first time, which are simultaneously forced by the transverse, in-plane excitations and the excitation loaded by piezoelectric layers. Based on the Reddy’s third-order shear deformation plate theory, the nonlinear governing equations of motion for the composite laminated piezoelectric rectangular plate are derived by using the Hamilton’s principle. The Galerkin’s approach is used to discretize partial differential governing equations to a two-degree- of-freedom nonlinear system under combined the parametric and external excitations. The method of multiple scales is employed to obtain the four-dimensional averaged equation. Numerical method is utilized to find the periodic and chaotic responses of the composite laminated piezoelectric rectangular plate. The numerical results indicate the existence of the periodic and chaotic responses in the aver- aged equation. The influence of the transverse, in-plane and piezoelectric excitations on the bifurca- tions and chaotic behaviors of the composite laminated piezoelectric rectangular plate is investigated numerically.

关键词： composite laminated piezoelectric rectangular plate third-order shear deformation parametric excitation bifurcation chaos

Multi-pulse orbits dynamics of composite laminated piezoelectric rectangular plate

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Science China(Technological Sciences) 2011年第8期54卷 2064-2079页

作者： yao MingHui ZHANG Wei yao ZhiGang College of Mechanical Engineering Beijing University of Technology Beijing 100124 China

The multi-pulse orbits and chaotic dynamics of a simply supported laminated composite piezoelectric rectangular plate under combined parametric excitation and transverse excitation are studied in detail. It is assumed that different layers are perfectly bonded to each other with piezoelectric actuator patches embedded. The nonlinear equations of motion for the laminated composite piezoelectric rectangular plate are derived from von Karman-type equation and third-order shear deformation plate theory of Reddy. The two-degree-of-freedom dimensionless equations of motion are obtained by using the Galerkin approach to the partial differential governing equation of motion for the laminated composite piezoelectric rectangular plate. The four-dimensional averaged equation in the case of primary parametric resonance and 1:3 internal resonances is obtained by using the method of multiple scales. From the averaged equation, the theory of normal form is used to find the explicit formulas of normal form. Based on the normal form obtained, the energy phase method is utilized to analyze the multi-pulse global bifurcations and chaotic dynamics for the laminated composite piezoelectric rectangular plate. The analysis of the global dynamics indicates that there exist multi-pulse jumping orbits in the perturbed phase space of the averaged equation. Based on the averaged equation obtained, the chaotic motions and the Shilnikov type multi-pulse orbits of the laminated composite piezoelectric rectangular plate are also found by numerical simulation. The results obtained above mean the existence of the chaos in the Smale horseshoe sense for the simply supported laminated composite piezoelectric rectangular plate.

关键词： laminated composite piezoelectric rectangular plates multi-pulse orbit chaotic dynamics energy phase method

Sums of nine almost equal prime cubes

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Frontiers of Mathematics in China 2014年第5期9卷 1131-1140页

作者： Yanjun yao School of Mathematics Shandong University Jinan 250100 China

We prove that each sufficiently large odd integer N can be written as sum of the form N = p1^3 ＋p2^3 ＋... ＋p9^3 with [pj - （N/9）^1/31 ≤ N^（1/3）-θ, where pj, j = 1,2,...,9, are primes and θ = （1/51） -ε.

关键词： Waring-Goldbach problem circle method exponential sum overprimes in short intervals

Plant flowers transmit various bio-agents through air

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Science China Earth Sciences 2020年第10期63卷 1613-1621页

作者： Siyu XU Maosheng yao State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

Growing air pollution,known as"April snow",by fluffy catkins from plant flowering was frequently observed during the Spring time in *** efforts mainly focus on controlling catkin release,while their public health and environmental impacts are ***,using culturing,microscopic and sequence methods we found that the flying catkins carry a significant amount of bio-agents(bacteria,fungal,viruses,and pollens),e.g.,up to 6.33×10^4 bacterial and 7.46×10^5 fungal cells per *** pollens from plants were also found riding on the flying *** collected fluffy catkins,bacterial Paracoccus,Massilia,fungal Ophiocordyceps,Arthrocladiella,pollen Robina,Pickeringia,Pinus,and viral family Genomoviridae,to name a few,were found to be *** infection and allergic potentials,the detected microbial structures on the fluffy catkins were different from those of local air,varying from one location to *** not just white pollution,flying plant fluffy catkins were discovered here also acting as a cloud of biological agents,and further actions need to be taken urgently to understand and limit their environmental and ecological consequences.

关键词： Plant flowering Flying fluffy catkins Bio-agents Transmission Air pollution

Numerical investigation of non-uniform temperature fields for proppant and fluid phases in supercritical CO_(2)fracturing

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Particuology 2024年第7期90卷 149-163页

作者： Boyu Liu Jun yao Research Center of Multiphase Flow in Porous Media China University of Petroleum(East China)Qingdao 266000China

The non-uniform temperature distribution in supercritical CO_(2)(Sc-CO_(2))fracturing influences the density,viscosity,and volume expansion or shrinkage rate of Sc-CO_(2),impacting proppant *** study presents a coupled computational fluid dynamics-discrete element method and heat transfer model to examine the effects of proppant bed shape and the heat transfers of proppant-wall,proppant-fluid,and fluid-wall on the fluid and proppant temperature *** Sc-CO_(2)volume expansion is assessed under various temperature conditions by evaluating the volume-averaged Sc-CO_(2)*** factors,including proppant size,shape,thermal conductivity,concentration,temperature difference,and injection velocity,are carefully analyzed to elucidate their *** findings elucidate the existence of four distinct zones in the fluid temperature *** zone exhibits different magnitudes of temperature change under diverse conditions and undergoes dynamic transformations with the development of the proppant *** fluid-wall heat transfer and the fluid temperatures in Zones C and D are significantly subject to the fluid injection velocity(governing the heating duration),the temperature difference between fluid and formation(impacting the magnitude of heat flux),and the proppant bed shape(controlling the effective heating area).Additionally,the proppant-wall and proppant-fluid heat transfers determine the temperatures of both the proppant bed and the fluid within Zone B,showing a strong correlation with proppant thermal conductivity,proppant size,injection velocity,and temperature *** proposed coupled model provides valuable insights into the temperature distributions and flow behaviors of temperature-dependent fracturing fluids and proppants.

关键词： CFD-DEM Heat transfer Compressible fluid CO_(2)sequestration Proppant transport

Fresh-Keeping Decision and Coordination of Fresh Agricultural Product Supply Chain Considering Carbon Cap-and-Trade under Different Dominance

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 30-51页

作者： Yang Yang Guanxin yao China Institute for Agricultural Equipment Industrial Development Jiangsu UniversityZhenjiang212013China Jiangsu Modern Logistics Research Base Yangzhou UniversityYangzhou225009China

In the context of low carbon,this paper discussed the impact of the carbon cap-and-trade policy on the fresh-keeping decision-making of two-echelon fresh agricultural product supply chains under different dominance,and designed cost-sharing contracts to coordinate the supply chain of fresh agricultural products dominated by suppliers and retailers *** results showed that:dominance has no effect on the fresh-keeping decision and total revenue of fresh agricultural product supply chain,but it affects the internal income distribution,and dominance does not always bring more benefits;the implementation of carbon cap-and-trade reduces the fresh-keeping decision-making of fresh agricultural products supply chain and reduces the free-rider income of followers;the role of higher carbon trading price is twofold,which not only brings about the speculation of leading enterprises,but also promotes the application of low-carbon technologies;consumers’high preference for freshness,low-cost and high-efficiency low-carbon technology are all conducive to improving the fresh-keeping efforts and benefits of the supply chain;cost-sharing contracts can coordinate the supply chain of fresh agricultural products.

关键词： Dominant power carbon cap-and-trade policy fresh agricultural product supply chain fresh-keeping decision-making

Dynamic Event-Triggered Control of Continuous-Time Systems With Random Impulses

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IEEE/CAA Journal of Automatica Sinica 2023年第12期10卷 2292-2299页

作者： Meng yao Guoliang Wei the College of Science University of Shanghai for Science and TechnologyShanghai 200093China the Business School University of Shanghai for Science and TechnologyShanghai 200093China

In this paper,the networked control problem under event-triggered schemes is considered for a class of continuoustime linear systems with random *** order to save communication costs and lighten communication burden,a dynamic event-triggered scheme whose threshold parameter is dynamically adjusted by a given evolutionary rule,is employed to manage the transmission of data ***,the evolution of the threshold parameter only depends on the sampled measurement output,and hence eliminates the influence of impulsive signals on the event-triggered ***,with the help of a stochastic analysis method and Lyapunov theory,the existence conditions of desired controller gains are received to guarantee the corresponding input-to-state stability of the addressed ***,according to the semi-definite programming property,the desired controller gains are calculated by resorting to the solution of three linear matrix *** the end,the feasibility and validity of the developed control strategy are verified by a simulation example.

关键词： mechanism. desired hence

The role of forest culture in green construction and management of forest parks:merging knowledge-attitude-practice and theory of planned behavior

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Journal of Forestry Research 2023年第3期34卷 841-852页

作者： yao Xu Zhiguang Zhang College of Economics and Management Nanjing Forestry UniversityNanjing 210037People’s Republic of China System Engineering Institute for Environment and Development Nanjing Forestry UniversityNanjing 210037People’s Republic of China

As a cultural concept refl ecting the relationship between humans and forests,forest culture plays an active role in sustainable forest *** parks provide a wide range of ecosystem services essential for the sustainable development of society,and the relationships between forest culture,green construction and management of forest parks have practical signifi *** study aimed to understand the interaction and process of forest culture infl uencing green construction and management in forest parks with the models Knowledge-Attitude-Practice(KAP)and Theory of Planned Behavior(TPB)by proposing a theoretical *** hypotheses were tested using data collected from 193 forest park employees in Heilongjiang Province,*** results show that forest culture had a signifi cant infl uence on green construction and forest *** addition,subjective norm and perceived behavioral control directly impacted behavior in green construction and management of the forest park,whereas attitude did not have an *** norm had a direct eff ect on *** between constructs show that forest culture had an indirect eff ect on planning and construction,and on ecological and economic ***,it supported three of four hypotheses within the proposed model in determining the infl uence of forest culture on green construction and management.

关键词： Forest parks Forest culture Green construction and management Knowledge-attitudepractice Theory of planned behavior