Clarification of underneath capacity loss for O3-type Ni, co free layered cathodes at high voltage for sodium ion batteries

Earth abundant O3-type NaFe_(0.5)Mn_(0.5)O_(2)layered oxide is regarded as one of the most promising cathodes for sodium ion batteries due to its low cost and high energy density.However,its poor structural stability and cycle life strongly impede the practical application.Herein,the dynamic phase evolution as well as charge compensation mechanism of O3-type NaFe_(0.5)Mn_(0.5)O_(2)cathode during sodiation/desodiation are revealed by a systemic study with operando X-ray diffraction and X-ray absorption spectroscopy,high resolution neutron powder diffraction and neutron pair distribution functions.The layered structure experiences a phase transition of O3→P3→OP2→ramsdellite during the desodiation,and a new O3’phase is observed at the end of the discharge state(1.5 V).The density functional theory(DFT)calculations and nPDF results suggest that depletion of Na^(+)ions induces the movement of Fe into Na layer resulting the formation of an inert ramsdellite phase thus causing the loss of capacity and structural integrity.Meanwhile,the operando XAS clarified the voltage regions for active Mn^(3+)/Mn^(4+)and Fe^(3+)/Fe^(4+)redox couples.This work points out the universal underneath problem for Fe-based layered oxide cathodes when cycled at high voltage and highlights the importance to suppress Fe migration regarding the design of high energy O3-type cathodes for sodium ion batteries.

Ziegler-Natta催化剂合成丙烯/1-丁烯共聚物

分别采用2种工业用Ziegler-Natta催化剂进行丙烯/1-丁烯淤浆共聚合研究,结果发现内给电子体结构对共聚合活性、共聚物组成、序列分布和产物相对分子质量都具有一定影响。通过调节反应物中丙烯/1-丁烯比例,分别合成了相对分子质量较高(重均相对分子质量30万～50万)和相对分子质量较低(重均相对分子质量10万～15万)且组成递变的2组丙丁共聚物。2组共聚物的结晶性能、热性能、拉伸性能和光学性能都随共聚物组成和序列分布的变化有所差异。

Robust stability and H-infinity control for uncertain discrete-time Markovian jump singular systems

The robust stability and stabilization, and H-infinity control problems for discrete-time Markovian jump singular systems with parameter uncertainties are discussed. Based on the restricted system equivalent （r.s.e.） transformation and by introducing new state vectors, the singular system is transformed into a discrete-time Markovian jump standard linear system, and the linear matrix inequality （LMI） conditions for the discrete-time Markovian jump singular systems to be regular, causal, stochastically stable, and stochastically stable with 7- disturbance attenuation are obtained, respectively. With these conditions, the robust state feedback stochastic stabilization problem and H-infinity control problem are solved, and the LMI conditions are obtained. A numerical example illustrates the effectiveness of the method given in the oaoer.

Robust D-Stability Test of LTI General Fractional Order Control Systems

This work deals with the robust D-stability test of linear time-invariant(LTI) general fractional order control systems in a closed loop where the system and/or the controller may be of fractional order. The concept of general implies that the characteristic equation of the LTI closed loop control system may be of both commensurate and non-commensurate orders, both the coefficients and the orders of the characteristic equation may be nonlinear functions of uncertain parameters, and the coefficients may be complex numbers. Some new specific areas for the roots of the characteristic equation are found so that they reduce the computational burden of testing the robust D-stability. Based on the value set of the characteristic equation, a necessary and sufficient condition for testing the robust D-stability of these systems is derived. Moreover, in the case that the coefficients are linear functions of the uncertain parameters and the orders do not have any uncertainties, the condition is adjusted for further computational burden reduction. Various numerical examples are given to illustrate the merits of the achieved theorems.

A Combined Alignment Method for Strapdown Inertial Navigation System on Stationary Base

Owing to the weak observability of the azimuth misalignment angle,alignment accuracy and time are always the contradictory issues in the initial alignment process of Strapdown Inertial Navigation System(SINS),which requires a compromise between them.In this paper,a combined alignment mechanism is proposed to construct an observable and controllable system model,which can effectively achieve higher azimuth alignment accuracy during the fixed time period.First,the Reduced Order Kalman Filter(ROKF)alignment algorithm was utilized to calculate the misalignment angles in parallel with the classical gyrocompass alignment algorithm.Then,the misalignment angles calculated by the gyrocompass alignment method were used to formulate the augmented measurement model with zero velocity models.Finally,the zero velocity model of the ROKF method was switched into the augmented measurement model when the azimuth misalignment angle of the gyrocompass alignment method was close to steady situation.The combined alignment method was analyzed reasonably by the observability and the mathematical deduction.The comparison results of the numerical simulation and the experimental data test showed that the combined method had good performance in terms of estimation accuracy and consistency of the alignment results.

The Influence of Monetary Policy and Fiscal Policy on the Rural Residents' Consumption

This paper conducts an empirical analysis of influence of fiscal expenditure supporting agriculture monetary supply on rural residents' s consumption by adopting a vector auto-regression model,based on the data from 1978 to 2011.The study indicated that:in the short term,fiscal policy is the Granger reason of rural residents' consumption,monetary policy is not the Granger reason of rural residents' consumption;in the long term,the comprehensive function of fiscal policy and monetary policy has a great influence on the of rural residents' consumption.Under the background of Economic Transition and Urbanization,Expanding Domestic Demand is the slogan.We should coordinate fiscal policy and monetary policy to promote the rural residents' consumption.

The Collaborative Relationship among Industrialization,Urbanization,Informatization and Agricultural Modernization and the Path of Synchronous Development in China: An Analysis Based on the Data during 1978-2011

The synchronous development of industrialization,urbanization,agricultural modernization and informatization is the basic trend and future requirements of China's economic and social development. By using the relevant data of 1978- 2011,and establishing the VAR model,we find that in the short term,industrialization is the Granger cause of urbanization; urbanization is the Granger cause of industrialization,informatization,and agricultural modernization; agricultural modernization is the Granger cause of industrialization,informatization and urbanization; informatization is the Granger reason of industrialization,urbanization and agricultural modernization. In the long run,there are long-term and stable relations among them,and at the same time,their changes affect the structure of each other,and there are pulling effect among them.

EXISTENCE AND UNIQUENESS AND STABILITY OF SOLUTIONS FOR STOCHASTIC IMPULSIVE SYSTEMS

This paper studies the existence, uniqueness, and stability of solutions for stochastic impulsive systems. By employing Lyapunov-like functions, some sufficient conditions of the global existence, uniqueness, and stability of solutions for stochastic impulsive systems are established. Furthermore, the results are specialized to the case of linear stochastic impulsive systems. Finally, some examples are given to illustrate the applications of our theory.

Strong Coupling of Magnetism and Lattice Induces Near-Zero Thermal Expansion over Broad Temperature Windows in ErFe10V2−xMox Compounds

Alloys with low thermal expansion could overcome thermal stress issues under temperature-fluctuated conditions and possess important application prospects,while they are restricted to finite chemical components and temperature windows.In this study,we report a novel class of near-zero thermal expansion(near ZTE)alloys,ErFe_(10)V_(2−x)Mo_(x),over a wide temperature range(120–440 K).Neutron diffraction and magnetic measurements demonstrated that the ErFe_(10)V_(2−x)Mo_(x)compounds exhibited complex ferrimagnetic(FIM)structures below Curie temperature(TC).The near-ZTE behaviors were closely related to the itinerant Fe 3d moments in the collinear FIM states,as well as the geometric[−Fe−Fe−]linkages.Further,X-ray absorption near-edge structure(XANES)spectra revealed that the nonmagnetic substitution changed the electronic valence states of Fe atoms,which,in turn,changed Fe 3d moments and TC,hence,regulating the thermal expansion behaviors.Our work provides an insight into chemical modifications of thermal expansion in magnetic intermetallic compounds.

Recent results on stochastic hybrid dynamical systems

This paper addresses stochastic hybrid systems,particularly switched and impulsive systems.The systems under consideration are linear and non-linear continuous with/without time delay,and with/without external force.The importance of using such systems and the discrepancies between hybrid and non-hybrid systems are presented.The objective of this paper is to survey recent developments on some of the important qualitative properties such as stability,stabilisation,input-to-state stability and state estimation along with the challenges that might arise when taking hybridness into account.These properties are mainly developed by using the direct method of Lyapunov or Lyapunov-Razumikhin if time delay is taken into account.Several examples with simulations are presented to further clarify the results introduced in this paper.