Static and Dynamic Analysis of Lasing Action from Single and Coupled Photonic Crystal Nanocavity Lasers

The single and coupled photonic crystal nanocavity lasers are fabricated in the InGaAsP material system and their static and dynamic features are compared. The coupled-cavity lasers show a larger lasing e^ciency and generate an output power higher than the single-cavity lasers, results that are consistent with the theoretical results obtained by rate equations. In dynamic regime, the single-cavity lasers produce pulses as short as 113 ps, while the coupled-cavity lasers show a significantly longer lasing duration. These results indicate that the photonic crystal laser is a promising candidate for the light source in high-speed photonic integrated circuit.

Cellular Automata-based Chloride Ion Diffusion Simulation of Concrete Bridges under Multi-factor Coupling Actions

In order to accurately simulate the diffusion of chloride ion in the existing concrete bridge and acquire the precise chloride ion concentration at given time, a cellular automata （CA）-based model is proposed. The process of chloride ion diffusion is analyzed by the CA-based method and a nonlinear solution of the Fick＇s second law is obtained. Considering the impact of various factors such as stress states, temporal and spatial variability of diffusion parameters and water-cement ratio on the process of chloride ion diffusion, the model of chloride ion diffusion under multi-factor coupling actions is presented. A chloride ion penetrating experiment reported in the literature is used to prove the effectiveness and reasonability of the present method, and a T-type beam is taken as an illustrative example to analyze the process of chloride ion diffusion in practical application. The results indicate that CA-based method can simulate the diffusion of chloride ion in the concrete structures with acceptable precision.

Coupling action of rainfall and vehicle loads impact on the stability of loess slopes based on the iso-water content layer

To clarify the changes in slope stability of loess slopes under the coupling action of rainfall and vehicle loads.Experiments with different water contents under different environmental conditions were carried out indoors,and the relationship function between water content and shear strength parameters was obtained;based on Geostudio,an equivalent layered calculation model of water content-strength parameters of loess slope was established,the variation law of soil sample matrix suction with volumetric water content was measured by volumetric pressure plate tester.Finally,by using a combination of finite element analysis of saturated/unsatu-rated seepage and limit equilibrium analysis of slope stability,the SLOPE/W module in the modeling software GeoStudio is used to calculate and analyze the effects of vehicle loads,rainfall intensity,rainfall duration,and other working conditions on the stability of loess slopes,respectively.The results show that when the lane is in the middle of the slope,the vehicle load parameters have little effect on the uphill stability,but have a greater impact on the downhill;With the increase in rainfall,the change curves of the slope safety coefficient gradually overlap when the vehicle loads are four-axis,five-axis,and six-axis.This shows that when studying the change of slope safety factor under the dual influence of vehicle loads and rainfall,rainfall is the main cause of slope stability;The change rate of slope safety factor increases gradually with the increase of rainfall,and the change trends of the upper,lower and overall parts of the slope are similar.

ORA59 and EIN3 interaction couples jasmonate-ethylene synergistic action to antagonistic salicylic acid regulation of PDF expression

Hormonal crosstalk is central for tailoring plant responses to the nature of challenges encountered. The role of antagonism between the two major defense hormones, salicylic acid （SA） and jasmonic acid （JA）, and modulation of this interplay by ethylene （ET） in favor of JA signaling pathway in plant stress responses is well recognized, but the underlying mechanism is not fully understood. Here, we show the opposing function of two transcription factors, ethylene insensitive3 （EIN3） and EIN3-Like1 （EIL1）, in SA-mediated suppression and JA- mediated activation of PLANT DEFENSINI.2 （PDFI.2）. This functional duality is mediated via their effect on protein, not transcript levels of the PDF1.2 transcriptional activator octadecanoid-responsive Arabidopsis59 （ORA59）. Specifically, JA induces ORA59 protein levels independently of EIN3/EIL1, whereas SA reduces the protein levels dependently of EIN3/EIL1. Co-infiltration assays revealed nuclear co-localization of ORA59 and EIN3, and split- luciferase together with yeast-two-hybrid assays established their physical interaction. The functional ramification of the physical interaction is EIN3-dependent degradation of ORA59 by the 26S proteasome. These findings allude to SA-responsive reduction of ORA59 levels mediated by EIN3 binding to and targeting of ORA59 for degrada4tion, thus nominating ORA59 pool as a coordination node for the antagonistic function of ET/JA and SA.

Performance Degradation of the Repeated Recycled Aggregate Concrete with 70% Replacement of Three-generation Recycled Coarse Aggregate

The feasibility of using different generations recycled coarse aggregate（RCA） on structural concrete was fully evaluated by studying the performance of the recycled coarse aggregates and their corresponding concretes, the different generations of RCA were recycled by following the repeated mode of ‘concrete-waste concrete-coarse aggregate-concrete＇. Moreover, the focus was on ‘three generations＇ of repeated RCAs, the RCA was produced by crushing and regenerating the artificial accelerated degraded concrete, the process was designed to follow the nature degradation of the concrete with a coupling action of accelerated carbonation and bending load. The properties of x-generation（x=1, 2 or 3） of repeated RCA were systematically investigated and the compressive and splitting tensile strengths of relating structural concretes（with 70% replacement of x-generation of RCA） were studied accordingly. The results show a competent compressive and splitting tensile strength of 30 MPa at 28 th day of structural concretes with all generations of repeated RAC. And the gradual degraded performance of the repeated RCAs was observed with an increased numbers of repetition（1〉2〉3 generations）, the overall performances of all repeated RCAs fulfill the Class Ⅲ according to Chinese Standards GB25177-2010. Our gained insight demonstrates a feasibility of using at least 3 generations of repeated RCA for the production of normal structural concrete.

Study of Vertical Seismic Response of Concrete Self-Anchored Suspension Bridges

Based on the variational prineiple of incomplete generalized potential energy with large deflection, the vertical nonlinear vibrational differential equation of self-anchored suspension bridge is presented by taking the effect of coupling of flexural and axial action into consideration. The linear vertical equation is obtained by omitting the nonlinear term, and the pseudo excitation method(PEM). Taking the self-anchored concrete suspension bridge over Lanqi Songhua river for an example, the expected peak responses of main beam, towers and cables are calculated. And the seismic spatial effects on vertical seismic response of self-anchored suspension bridges are discussed.

Chloride ion transport performance in slag mortar under fatigue loading

The transport performance of chloride ion in slag cement mortar was investigated experimentally. In the self-designed experiment, fatigue loading was coupled simultaneously with ion transportation process, the diffusion law of chloride ion was obtained by titration and the AE (acoustic emission) technique was employed to detect the real-time damage distribution in the mortar specimen. The results for fatigue stress levels of 0.3, 0.4 and 0.5 and slag contents of 0, 10%, 30% and 50% showed that fatigue loading accelerated the diffusion of chloride ion in mortar and the acceleration effect increased with the increase in stress levels. Slag addition was found to improve anti-chloride ion erosion performance effectively with the best substitution level at 30%, because the inhibition effect of slag on chloride ion diffusion diminished when the slag content exceeded 30%. The comparative experiments indicated that dynamic load has a significant effect on the transport performance of chloride ion in slag cement mortar.

Adaptive Backstepping Sliding Mode Trajectory Tracking Control for a Quad-rotor

A quad-rotor aircraft is an under-actuated,strongly coupled nonlinear system with parameter uncertainty and un-modeled disturbance.In order to make the aircraft track the desired trajectory,a nested double-loops control system is adopted in this paper.A position error proportional-derivative(PD) controller is designed as the outer-loop controller based on the coupling action between rotational and translational movement,and an adaptive backstepping sliding mode control algorithm is used to stabilize the attitude.Finally,both the numerical simulation and prototype experiment are utilized to demonstrate the effectiveness of the proposed control system.