Transient transition behaviors of fractional-order simplest chaotic circuit with bi-stable locally-active memristor and its ARM-based implementation

This paper proposes a fractional-order simplest chaotic system using a bi-stable locally-active memristor.The characteristics of the memristor and transient transition behaviors of the proposed system are analyzed,and this circuit is implemented digitally using ARM-based MCU.Firstly,the mathematical model of the memristor is designed,which is nonvolatile,locally-active and bi-stable.Secondly,the asymptotical stability of the fractional-order memristive chaotic system is investigated and some sufficient conditions of the stability are obtained.Thirdly,complex dynamics of the novel system are analyzed using phase diagram,Lyapunov exponential spectrum,bifurcation diagram,basin of attractor,and coexisting bifurcation,coexisting attractors are observed.All of these results indicate that this simple system contains the abundant dynamic characteristics.Moreover,transient transition behaviors of the system are analyzed,and it is found that the behaviors of transient chaotic and transient period transition alternately occur.Finally,the hardware implementation of the fractional-order bi-stable locally-active memristive chaotic system using ARM-based STM32F750 is carried out to verify the numerical simulation results.

Anomalous Magneto-Transport Behavior in Transition Metal Pentatelluride HfTe5

There is a long-standing confusion concerning the physical origin of the anomalous resistivity peak in transition metal pentatelluride HfTe5. Several mechanisms, such as the formation of charge density wave or polaron, have been proposed, but so far no conclusive evidence has been presented. In this work, we investigate the unusual temperature dependence of magneto-transport properties in HfTe5. It is found that a three-dimensional topological Dirac semimetal state emerges only at around Tp （at which the resistivity shows a pronounced peak）, as manifested by a large negative magnetoresistance. This accidental Dirac semimetal state mediates the topological quantum phase transition between the two distinct weak and strong topological insulator phases in HfTe5. Our work not only provides the first evidence of a temperature-induced critical topological phase transition inHfTe5 but also gives a reasonable explanation on the long-lasting question.

Multistability and coexisting transient chaos in a simple memcapacitive system

The self-excited attractors and hidden attractors in a memcapacitive system which has three elements are studied in this paper.The critical parameter of stable and unstable states is calculated by identifying the eigenvalues of Jacobian matrix.Besides,complex dynamical behaviors are investigated in the system,such as coexisting attractors,hidden attractors,coexisting bifurcation modes,intermittent chaos,and multistability.From the theoretical analyses and numerical simulations,it is found that there are four different kinds of transient transition behaviors in the memcapacitive system.Finally,field programmable gate array(FPGA)is used to implement the proposed chaotic system.

Effects of Molecular Weight on the Crystallization and Melting Behaviors of Poly(L-lactide)

In this study, a series of monodispersed poly（L-lactide）（PLLA） were synthesized by the ring-opening polymerization with Schiff base aluminum catalyst, and the effects of the number-average molecular weight（Mn） on the crystallization and melting behaviors of PLLA were investigated by differential scanning calorimetry（DSC） and wide-angle X-ray diffraction（WAXD）. The total crystallization rate of PLLA was Mn-dependent, which reached the maximum value for PLLA with Mn of 18.6 kg/mol. In addition, when Mn of PLLA was 18.6 kg/mol, the melting enthalpy（ΔHm） showed a maximum value（87.1 J/g）, which was the highest reported value till now. The critical temperature for change of crystal formation from ？-form to ？-form crystals increased in the isothermal crystallization process with Mn increasing. In the reheating procedure, high-Mn PLLA demonstrated a small exothermal peak prior to the dominant melting peak, corresponding to crystal transition from ？- to ？-form, but low-Mn PLLA didn＇t show the peak of crystal transition. These different crystallization and melting behaviors were attributed to the different chain mobility of PLLA with different Mn.

Behavioral Consistency Checking between Requirements and Implementations

Checking if the implementations conform to the requirement models is challenging. Most existing techniques for consistency checking either focus on requirement models（e.g., requirements consistency checking）, or on the implementations（e.g., code-based testing） only. In this paper we propose an approach to checking behavioral consistency of implementations against requirement models directly to overcome these limitations. Our approach extracts two behavioral models represented by Labelled Transition Systems（LTS） from requirement models and implementations respectively, and checks the behavioral consistency between these two models based on behavioral simulation relation of LTS. The checking results of our approach provide evidence for behavioral inconsistency as well as inconsistent localization. A research prototype called BCCH and a case study are presented to give initial validation of this approach.

Solids behavior in dilute zone of a CFB riser under turbulent conditions

The behavior of the solid phase in the upper zone of a circulating fluidized bed riser was studied using a phase Doppler anemometer. Glass particles of mean diameter 107μm and superficial gas velocities UE covering the turbulent and the beginning of the fast fluidization regime were investigated. Three static bed heights were tested. Ascending and descending particles were found co-existing under all oper ating conditions tested, and at all measurement locations. Superficial gas velocity proved/happened to have a larger effect on descending particles at the wall and on ascending particles in the central region. Transversal particle velocities in both directions （toward the center and toward the wall） behaved rela- tively equivalently, with only slight difference observed at the wall. However, observation of the number of particles moving in either transversal direction showed a change in bed structure when increasing Ug. Furthermore, a balance was constantly observed between the core zone and the annulus zone where the mutual mass transfer between these two zones occurred continuously. Transition from a slow to a fast particle motion was accompanied by a transition to high levels of velocity fluctuations, and was found corresponding to the appearance of significant solid particle flow rate.

Transcriptional identification of differentially expressed genes associated with division of labor in Apis cerana cerana

Workers of Apis cerana cerana undergo an in-hive nursing to outdoor foraging transition,but the genes underlying this age-related transition remain largely unknown.Here,we sequenced the head transcriptomes of its 7-day-old normal nurses,18-and 22-day-old normal foragers,7-day-old precocious foragers and 22-day-old over-aged nurses to unravel the genes associated with this transition.Mapping of the sequence reads to Apis mellifera genome showed that the three types of foragers had a greater percentage of reads from annotated exons and intergenic regions,whereas the two types of nurses had a greater percentage of reads from introns.Pair-and group-wise comparisons of the five transcriptomes revealed 59 uniquely expressed genes(18 in nurses and 41 in foragers)and 14 nurse-and 15 forager-upregulated genes.The uniquely expressed genes are usually low-abundance long noncoding RNAs,transcription factors,transcription coactivators,RNA-binding proteins,kinases or phosphatases that are involved in signaling and/or regulation,whereas the nurse-or forager-upregulated genes are often high-abundance downstream genes that directly perform the tasks of nurses or foragers.Taken together,these results suggest that the nurse-forager transition is coordinated by a social signal-triggered epigenetic shift from introns to exons/intergenic regions and the resulting transcriptional shift between the nurse-and forager-associated genes.