Taking a concrete frame supporting space structure as the research object,we systematically studied its lateral-torsion coupling effect of reverse problems in consistent earthquake excitation.Firstly,based on its reve...Taking a concrete frame supporting space structure as the research object,we systematically studied its lateral-torsion coupling effect of reverse problems in consistent earthquake excitation.Firstly,based on its reverse forms and features,we put forward a mechanical analysis model(flexibility layer model) and a calculation method using the response spectrum method and the weighted average method,and verified their validity and feasibility using case analysis.The result shows that the translation displacement change trend of the space structure is basically the same whether reverse exists in the supporting structure or not,but the supporting structure torsion has an effect on the displacement with a relative increase of 10%.展开更多
Sensitive and selective detection of Hg（II） contamination is of great importance with concern of public health. Herein, we successfully fabricated monolayer MoS2 （S-MoS2） decorated Cu7S4-Au （Cu7S4-Au@S-MoS2） nan...Sensitive and selective detection of Hg（II） contamination is of great importance with concern of public health. Herein, we successfully fabricated monolayer MoS2 （S-MoS2） decorated Cu7S4-Au （Cu7S4-Au@S-MoS2） nanocomposite modified electrode for the sensitive and selective detection of Hg（II） via anodic stripping voltammetric technique. Due to the excellent electrocatalytic reduction performance arisen from the abundant active edge sites of small monolayer MoS2 and good affinity of Au toward Hg, the current method displayed high sensitivity （LOD = 190 nmol L-l） and enhanced selectivity. As control, nanostructures including Cu7S4-Au, Cu7S4@S-MoS2 and Cu7S4-Au@M-MoS2 （M： multilayer） were also investigated, but showed low re- sponse to Hg（Ⅱ）, suggesting that both Au domains and active edge sites of monolayer MoS2 have crucial synergistic effects on the high-performance for recognition of Hg（Ⅱ）. Moreover, the developed method displays satisfied performance for the detection of Hg（Ⅱ） in real samples, which indicates its potentials in practical applications.展开更多
For the stochastic structure with stochastic excitation, an advanced stratified line sampling (SLS) method is presented to obtain the cumulative distribution function (CDF) of the structural response and its sensitivi...For the stochastic structure with stochastic excitation, an advanced stratified line sampling (SLS) method is presented to obtain the cumulative distribution function (CDF) of the structural response and its sensitivity. The advanced stratified line sampling method introduces a set of middle failure subsets firstly. And for each subset, the conventional line sampling can be used to obtain the corresponding value of the response's CDF. At the same time, the sensitivity estimations of each failure subset can also be computed by modifying the important direction and corresponding reliability coefficients. The properties of CDF sensitivity are proved while the performance function is linear with normal random variables. After two simple examples are used to demonstrate the properties of CDF sensitivity and the feasibility of the presented method, the method employed to analyze the CDF and corresponding sensitivity of root bending moment (RBM) responses for the stochastic BAH is wing with gust excitation to a square-edged gust and to a Dryden gust. The results show that the parameters of the second and the fifth order modals exert more influence on the CDF of response than the other ones, and the presented SLS method can more significantly reduce the computational cost compared with Monte Carlo simulation (MCS).展开更多
In this paper, we consider a sex-structured predator prey model with strongly coupled nonlinear reaction diffusion. Using the Lyapunov functional and Leray Schauder degree theory, the existence and stability of both h...In this paper, we consider a sex-structured predator prey model with strongly coupled nonlinear reaction diffusion. Using the Lyapunov functional and Leray Schauder degree theory, the existence and stability of both homogenous and heterogenous steady-states are investigated. Our results demonstrate that the unique homogenous steady-state is locally asymptotically stable for the associated ODE system and PDE system with self-diffusion. With the presence of the cross-diffusion, the homogeneous equilibrium is destabilized, and a heterogenous steady-state emerges as a consequence. In addition, the conditions guaranteeing the emergence of Turing patterns are derived.展开更多
基金Funded by the Research on Damage Mechanism of the Spatial Dome-Reinforced Concrete Structures and Reduce Vibration System in West Area (No. 51068019)
文摘Taking a concrete frame supporting space structure as the research object,we systematically studied its lateral-torsion coupling effect of reverse problems in consistent earthquake excitation.Firstly,based on its reverse forms and features,we put forward a mechanical analysis model(flexibility layer model) and a calculation method using the response spectrum method and the weighted average method,and verified their validity and feasibility using case analysis.The result shows that the translation displacement change trend of the space structure is basically the same whether reverse exists in the supporting structure or not,but the supporting structure torsion has an effect on the displacement with a relative increase of 10%.
基金supported by the National Natural Science Foundation of China(21475007 and 21675009)the Fundamental Research Funds for Central Universities(buctrc201507 and buctrc201608)the support from the "Public Hatching Platform for Recruited Talents of BUCT"
文摘Sensitive and selective detection of Hg（II） contamination is of great importance with concern of public health. Herein, we successfully fabricated monolayer MoS2 （S-MoS2） decorated Cu7S4-Au （Cu7S4-Au@S-MoS2） nanocomposite modified electrode for the sensitive and selective detection of Hg（II） via anodic stripping voltammetric technique. Due to the excellent electrocatalytic reduction performance arisen from the abundant active edge sites of small monolayer MoS2 and good affinity of Au toward Hg, the current method displayed high sensitivity （LOD = 190 nmol L-l） and enhanced selectivity. As control, nanostructures including Cu7S4-Au, Cu7S4@S-MoS2 and Cu7S4-Au@M-MoS2 （M： multilayer） were also investigated, but showed low re- sponse to Hg（Ⅱ）, suggesting that both Au domains and active edge sites of monolayer MoS2 have crucial synergistic effects on the high-performance for recognition of Hg（Ⅱ）. Moreover, the developed method displays satisfied performance for the detection of Hg（Ⅱ） in real samples, which indicates its potentials in practical applications.
基金the National Nature Science Foundation of China (Grant No. 51175425)the Aviation Science Foundation (Grant No. 2011ZA53015)+1 种基金the Aerospace Science and Technology Innovative Foundation (Grant No. 2011200093)the Nature Science Basic Research Fund of Shaanxi Province (Grant No. 2012JQ1015)
文摘For the stochastic structure with stochastic excitation, an advanced stratified line sampling (SLS) method is presented to obtain the cumulative distribution function (CDF) of the structural response and its sensitivity. The advanced stratified line sampling method introduces a set of middle failure subsets firstly. And for each subset, the conventional line sampling can be used to obtain the corresponding value of the response's CDF. At the same time, the sensitivity estimations of each failure subset can also be computed by modifying the important direction and corresponding reliability coefficients. The properties of CDF sensitivity are proved while the performance function is linear with normal random variables. After two simple examples are used to demonstrate the properties of CDF sensitivity and the feasibility of the presented method, the method employed to analyze the CDF and corresponding sensitivity of root bending moment (RBM) responses for the stochastic BAH is wing with gust excitation to a square-edged gust and to a Dryden gust. The results show that the parameters of the second and the fifth order modals exert more influence on the CDF of response than the other ones, and the presented SLS method can more significantly reduce the computational cost compared with Monte Carlo simulation (MCS).
文摘In this paper, we consider a sex-structured predator prey model with strongly coupled nonlinear reaction diffusion. Using the Lyapunov functional and Leray Schauder degree theory, the existence and stability of both homogenous and heterogenous steady-states are investigated. Our results demonstrate that the unique homogenous steady-state is locally asymptotically stable for the associated ODE system and PDE system with self-diffusion. With the presence of the cross-diffusion, the homogeneous equilibrium is destabilized, and a heterogenous steady-state emerges as a consequence. In addition, the conditions guaranteeing the emergence of Turing patterns are derived.
