Cascading Delays for the High-Speed Rail Network Under Different Emergencies:A Double Layer Network Approach

High-speed rail(HSR) has formed a networked operational scale in China. Any internal or external disturbance may deviate trains’ operation from the planned schedules, resulting in primary delays or even cascading delays on a network scale. Studying the delay propagation mechanism could help to improve the timetable resilience in the planning stage and realize cooperative rescheduling for dispatchers. To quickly and effectively predict the spatial-temporal range of cascading delays, this paper proposes a max-plus algebra based delay propagation model considering trains’ operation strategy and the systems’ constraints. A double-layer network based breadth-first search algorithm based on the constraint network and the timetable network is further proposed to solve the delay propagation process for different kinds of emergencies. The proposed model could deal with the delay propagation problem when emergencies occur in sections or stations and is suitable for static emergencies and dynamic emergencies. Case studies show that the proposed algorithm can significantly improve the computational efficiency of the large-scale HSR network. Moreover, the real operational data of China HSR is adopted to verify the proposed model, and the results show that the cascading delays can be timely and accurately inferred, and the delay propagation characteristics under three kinds of emergencies are unfolded.

Delayed response to the photovoltaic performance in a double quantum dots photocell with spatially correlated fluctuation

A viable strategy for enhancing photovoltaic performance is to comprehend the underlying quantum physical regime of charge transfer in a double quantum dots(DQD) photocell. This work explored the photovoltaic performance dependent spatially correlated fluctuation in a DQD photocell. The effects of spatially correlated fluctuation on charge transfer and output photovoltaic efficiency were explored in a proposed DQD photocell model. The results revealed that the charge transport process and the time to peak photovoltaic efficiency were both significantly delayed by the spatially correlated fluctuation, while the anti-spatially correlated fluctuation reduced the output peak photovoltaic efficiency. Further results revealed that the delayed response could be suppressed by gap difference and tunneling coefficient within two dots. Subsequent investigation demonstrated that the delayed response was caused by the spatial correlation fluctuation slowing the generative process of noise-induced coherence, which had previously been proven to improve the quantum photovoltaic performance in quantum photocells. And the reduced photovoltaic properties were verified by the damaged noise-induced coherence owing to the anti-spatial correlation fluctuation and a hotter thermal ambient environment. The discovery of delayed response generated by the spatially correlated fluctuations will deepen the understanding of quantum features of electron transfer, as well as promises to take our understanding even further concerning quantum techniques for high efficiency DQD solar cells.

Minimally invasive treatment of forearm double fracture in adult using Acumed forearm intramedullary nail: A case report

BACKGROUND Currently,open reduction internal fixation is the conventional surgical method for treatment of double ulna and radius fracture.However,open reduction is associated with a high risk of complications.This case of forearm double fracture involved a patient treated using an Acumed intramedullary nail.The patient experienced good follow-up outcomes.The Acumed forearm intramedullary nail enables early functional exercise and hastens healing of the fracture.Few studies have reported on the use of this approach for the treatment of fractures.CASE SUMMARY A 23-year-old male patient was admitted to hospital after 5 h of pain,swelling,and limited activity of left forearm caused by a careless fall.Physical examination showed stable basic vital signs,swelling of the left forearm,and severe pain when pressing on the injured part of the forearm.Further,friction was felt at the broken end of the bone;the skin was not punctured.Movement of the left hand was normal,and the left radial artery pulse was normal.Three-dimensional computed tomography examination showed an ulna fracture of the left forearm and comminuted fracture of the radius.The fracture was located in the upper third of the radius,with significant displacement on the fracture side.Clinical diagnosis further confirmed the left radius comminuted fracture and ulna fracture.After analyzing the fracture pattern,age,and other patient characteristics,we chose an Acumed nail for treatment and achieved good follow-up outcomes.CONCLUSION Acumed forearm intramedullary nail for fixation of ulna and radius fracture reduced complication risk and resulted in good follow-up outcomes.

PERIOD-DOUBLING BIFURCATION FOR A DELAY-DIFFERENTIAL EQUATION RELATED TO OPTICAL BISTABILITY

The bifurcation of a periodic solution for a delay differential equation related to optical bistability has been discussed analytically.Using the theory of retarded functional differential equations,we have proved that it follows precisely the period-doubling route.

Application of Correlated Double Sampling in Space TDICCD Camera

As a sampling technique for CCD output video signal, the correlated double sampling(CDS) technique is described as well as the filtering effects of the CDS technique on the output noise of CCD including the reset noise of CCD, the white noise of output amplifier and 1/f noise. From real application of CDS device——TH7982A, it is concluded that the output signal-to-noise ratio of 50dB for CCD signal can be obtained.

Study on Congestion and Bursting in Small-World Networks with Time Delay from the Viewpoint of Nonlinear Dynamics

The small-world network model represented by a set of evolution equations with time delay is used to investigate the nonlinear dynamics of networks,and the nature of instability phenomena in traffic,namely,congestion and bursting in the networks,are studied and explained from bifurcation analysis.Then,the governing equation in the vector field is further reduced into a map,and the ensuing period-doubling bifurcation,sequence of perioddoubling bifurcation and period-3 are studied intuitively.The existence of chaos is verified numerically.In particular,the influences of time delay on the nonlinear dynamics are presented.The results show that there are a rich variety of nonlinear dynamics related to the intermittency of the traffic flows in the system,and the results can gain a fundamental understanding of the instability in the networks,and the time delay can be used as a key parameter in the control of the systems.

Stability analysis of the active control system with time delay using IHB method

In this paper, the incremental harmonic balance method is employed to solve the periodic solution that a vibration active control system with double time delays generates, and the stability analysis of which is achieved by the Poincare theorem. The system stability regions can be obtained in view of time delay and feedback gain, the variation of which is also studied. It turns out that along with the increase of time delay, the active control system is not always from stable to unstable, and the system can be from stable to unstable state, whereas the system can be from unstable to stable state. The extent that the two times delays impact to the relative magnitude of the two feedback gains. the condition of the well-matched feedback gains. control strategy of time-delayed feedback.

An analytical method for studying double Hopf bifurcations induced by two delays in nonlinear differential systems

An analytical method is introduced to investigate double Hopf bifurcations induced by two delays qualitatively and quantitatively.As an illustrative example,the clear procedure is demonstrated to study delay-induced weak resonant double Hopf bifurcation in a nonlinear system with multiple delays.When two delays are close to double Hopf bifurcation point,all solutions derived from the bifurcation are classified qualitatively and expressed explicitly.Numerical simulations are a good agreement with our theoretical analysis,and also already work in references.The results show that our work in this paper proposes a simple and valid method for investigating delay-induced double Hopf bifurcations.The important feature of our work is that the explicit expression of periodic solutions is easy to be obtained by solving algebraic equations.

The stability and Hopf bifurcation for an HIV model with saturated infection rate and double delays

An HIV infection model with saturated infection rate and double delays is investigated. First, the existence of the infection-free equilibrium E0, the immune-exhausted equilibrium E1 and the infected equilibrium E2 with immunity in different conditions is shown. By analyzing the characteristic equation, we study the locally asymptotical stability of the trivial equilibrium, and the existence of Hopf bifurcations when two delays are used as the bifurcation parameter. Furthermore, we apply the Nyquist criterion to estimate the length of delay for which stability continues to hold. Then with suitable Lyapunov function and LaSalle＇s invariance principle, the global stability of the three equilibriums is obtained. Finally, numerical simulations are presented to illustrate the main mathematical results.

基于自校正的大时延模拟源高精度实现技术

针对基于异步双存储技术的大时延模拟源精度难以提升的问题,提出了一种实时校正方法。自校正充分利用异步双存储的粗细两级存储延时模式,在细延时阶段完成时延闭环测量,在粗延时阶段完成时延修正。自校正通过模拟源系统内部闲余的数字资源实现,以低消耗、低成本,同时不影响模拟源正常工作,实现了高精度时延模拟。深入研究了异步双存储延时技术,提出了自校正原理,介绍了自校正的具体实现方法,通过比对实验验证了自校正技术对于精度的提升切实可行。

Microscopic Dynamics of Nonsequential Double Ionization by Elliptically Polarized Few-Cycle Laser Pulses

With the classical ensemble model, we investigate nonsequential double ionization （NSDI） of xenon atoms using 780 nm, 0.25 PW/cm2 elliptically polarized few-cycle laser pulses. The momentum distribution of correlated electron along the long axis o~ the laser polarization plane shows an obvious V-like structure locating at the third quadrant, and the momentum along the short axis of the laser polarization plane are mainly distributed in the second and fourth quadrants. Moreover, we demonstrate that the Coulomb repulsion interaction plays a decisive role to the above results. By back analyzing the class/ca/ trajectories of NSDI, we find that there are two kinds of recollision trajectories mainly contribute to NSDI, and the different microscopic dynamics for the two kinds of trajectories are clearly explored.

双BD600延时器在新直播系统中的应用

本文首先阐述了BD600延时器的工作原理、基本功能等。其次,介绍了BD600在传统系统当中的应用及会产生的问题。最后,介绍了双BD600在新系统当中的应用。

Simple Double Hetero[5]helicenes Realize Highly Efficient and Narrowband Circularly Polarized Organic Light-Emitting Diodes

Helicene-based emitters with unique inherent circularly polarized luminescence(CPL)are promising yet remain a formidable challenge for highly efficient circularly polarized organic light-emitting diodes(CP-OLEDs),ascribed to their tough synthesis,low emission efficiency,and easy racemization in the thermal deposition process.Herein,a pair of helicenebased enantiomers,namely(P)-helicene-BN and(M)-helicene-BN,were developed,which merge helical chirality and the B/N/S inserted polycyclic aromatic framework to concurrently feature CPL and narrow thermally activated delayed fluorescence(TADF)characteristics.Benefiting from the excellent thermal/photophysical/chiroptical properties,the narrowband green CP-OLEDs based on enantiomers achieved maximum external quantum efficiencies(EQE_(max))of up to 31.5%,and dissymmetry factor(|g_(EL)|)of 2.2×10^(−3).This work reveals the great potential of helicene-based emitters in CP-OLEDs.

Bifurcation analysis in a predator-prey model for the effect of delay in prey

In this paper, we study dynamics in a predator-prey model with delay, in which predator can be infected, with particular attention focused on nonresonant double Hopf bifurca- tion. By using center manifold reduction methods, we obtain the equivalent normal forms near a double Hopf critical point in this system. Moreover, bifurcations are classified in a two-dimensional parameter space near the critical point. Numerical simulations are presented to demonstrate the applicability of the theoretical results.