摘要：In this paper, a new four-dimensional autonomous hyperchaotic system is designed for generating complex chaotic signals. In the design, its parameters are selected according to the requirements for chaos and hyperchaos. The hyperchaotic nature is verified theoretically by using the bifurcation analysis and demonstrated experimentally by the implementation of an analogue electronic circuit. Moreover, the Field Programmable Gate Array （FPGA） technology is applied to implementing a continuous system in a digital form by using a chip of Altera Cyclone II EP2C35F484C8. The digital sequence generated from the FPGA device is observed in our experimental setup.

摘要：To generate complex pseudo-noise （PN） sequences for chaos-based communications, this article presents a novel switched hyperchaotic model, which is constructed based on a modified Chen system by introducing a dynamical controller. The system consists of two different hyperchaotic subsystems and can change its behavior randomly via a switching function. Basic dynamical behaviors of the hyperchaotic system are further investigated. Furthermore, the switched system is confirmed by its positive Lyapunov exponents and laboratory measurements by an electronic circuit.

摘要：Hydrogen,regarded as a promising energy carrier to alleviate the current energy crisis,can be generated from hydrogen evolution reaction(HER),whereas its efficiency is impeded by the activity of ***,effective strategies,such as strain and interfacial engineering,are imposed to tune the catalysis performance of novel two-dimensional(2D)phosphorus carbide(PC)layers using first-principle *** findings show that P site in pristine monolayer PC(ML-PC)exhibits higher HER performance than C ***,constructing bilayer PC sheet(BL-PC)can change the coordinate configuration of P atom to form 3-coordination-P atom(3-co-P)and 4-coordination-P atom(4-co-P),and the original activity of 3-co-P site is higher than the 4-co-P *** an external compressive strain is applied,the activity of the 4-co-P site is enhanced whereas the external strain can barely affect that of 3-co-P ***,the graphene substrate enhances the overall activity of the BL-PC because the graphene substrate optimizes the?GH*value of 4-co-P site,although it can barely affect the HER activity of 3-co-P site and *** desirable properties render 2 D PC-based material promising candidates for HER catalysts and shed light on the wide utilization in electrocatalysis.

摘要：The 60-GHz traveling-wave tube （TWT） prevails nowadays as the amplifier for the satellite communication and electronic countermeasures. The folded waveguide （FW） is a promising all-metal slow-wave structure （SWS） for the 60-GHz TWT with advantages of robust performance, fine heat dissipation, considerable power and bandwidth. A novel FW periodically loaded with rectangular grooves is analyzed for the purpose of gaining higher power and gain. The rf characteristics are investigated by numerical simulation, and the nonlinear large- signal performance of such a TWT is analyzed by a 3I） particle-in-cell code MAGIC. Compared with normal circuits, relatively higher continuous-wave power （40-56 W） and similar bandwidth （5 GHz） are predicted by simulation. Meanwhile, the designed operation voltage is 10.5 kV, which keeps the low-voltage advantage of the popular helix TWT competitor. The novel FW will favor the design of a broadband and high-power 60-GHz TWT

摘要：The hybrid CMOS molecular （CMOL） circuit, which combines complementary metal-oxide- semiconductor （CMOS） components with nanoscale wires and switches, can exhibit significantly improved performance. In CMOL circuits, the nanodevices, which are called cells, should be placed appropriately and are connected by nanowires. The cells should be connected such that they follow the shortest path. This paper presents an efficient method of cell allocation in CMOL circuits with the hybrid CMOS/nanodevice structure; the method is based on a cultural algorithm with chaotic behavior. The optimal model of cell allocation is derived, and the coding of an individual represent- ing a cell allocation is described. Then the cultural algorithm with chaotic behavior is designed to solve the optimal model. The cultural algorithm consists of a population space, a belief space, and a protocol that describes how knowledge is exchanged between the population and belief spaces. In this paper, the evolutionary processes of the population space employ a genetic algorithm in which three populations undergo parallel evolution. The evolutionary processes of the belief space use a chaotic ant colony algorithm. Extensive experiments on cell allocation in benchmark circuits showed that a low area usage can be obtained using the proposed method, and the computation time can be reduced greatly compared to that of a conventional genetic algorithm.

摘要：Biophysical restrictions regulate protein diffusion,nucleus deformation,and cell migration,which are all universal and important processes for cells to perform their biological ***,current technologies addressing these multiscale questions are extremely ***,through two-photon polymerization(TPP),we present the precise,low-cost,and multiscale microstructures(micro-fences)as a versatile investigating *** nanometer-scale printing resolution and multiscale scanning capacity,TPP is capable of generating micro-fences with sizes of 0.5-1000μ*** micro-fences are utilized as biophysical restrictions to determine the fluidity of supported lipid bilayers(SLB),to investigate the restricted diffusion of Src family kinase protein Lck on SLB,and also to reveal the mechanical bending of cell nucleus and T cell climbing *** together,the proposed versatile and low-cost micro-fences have great potential in probing the restricted dynamics of molecules,organelles,and cells to understand the basics of physical biology.

摘要：Left-hand materials have drawn increasing attention from many disciplines and found widespread application, especially in microwave engineering. A sandwiched metamaterial consisting of multi-nested square-split-ring resonators on the top side and a set of wires on the back side is proposed. Scattering parameters are retrieved by high-frequency structure simulator(HFSS) software based on the finite element method. Effects of square-split-ring number on the left-hand characteristics containing negative values of permittivity, permeability, and refractive index have been intensively investigated. Simulated results show that obvious resonant left-hand characteristics could be observed within 8-18 GHz, and the resonant frequency counts are inclined to be in direct proportion to the square-split-ring number over 8-18 GHz. Besides, the proposed sandwiched metamaterial with three square-split-ring resonators and three wires presents the widest frequency band of left-hand characteristics in a range of 8-18 GHz. Further, electromagnetic field distributions demonstrated that the induced magnetic dipole dominates the resonant absorption. The multi-peak resonance characteristics of square-split-ring resonant structure are considered to be a promising candidate for selective-frequency absorption or modulation toward microwave frequency band.

摘要：The BaF2 （barium fluoride） spectrometer is one of the experiment facilities at the CSNS-WNS（White Neutron Source at China Spallation Neutron Source）, currently under construction. It is designed to precisely measure the（n, γ） cross section, with 92 crystal elements and complete 4π steradian coverage. In order to improve the precision of measurement, in this paper, a new precise digitization and readout method is proposed. Waveform digitizing with 1 GSps sampling rate and 12-bit resolution is used to precisely capture the detector signal. To solve the problem of massive data readout and processing, the readout electronics is designed as a distributed architecture with 4 PXIe crates. The digitized signal is concentrated to the PXIe crate controller through a PCIe bus on the backplane and transmitted to the data acquisition system over gigabit Ethernet in parallel. Besides, the clock and trigger can be fanned out synchronously to every electronic channel over a high-precision distribution network. Test results show that the prototype of the readout electronics can achieve good performance and meet the requirements of the CSNS-WNS BaF2 spectrometer.

摘要：The ever-decreasing size of transistors requires effectively electrostatic control over ultra-thin semiconductor *** design of the gate configuration can fully persevere the intrinsic property of two-dimensional(2 D)*** we design and demonstrate a 2 D Mo S_(2) transistor with omega-shaped gate,in which the local gate coupling is enhanced by the non-planar *** omega-shaped non-planar transistors exhibit a high current of 0.89 A/lm and transconductance of32.7 l S/*** high performance and desirable current saturation promise the construction of robust logic *** inverters show a voltage gain of 26.6 and an ideal total margin nearly 89%.We also assemble NOT-AND(NAND)gate on an individual Mo S_(2) flake,and the constructed NAND gate demonstrates the universal functionality of the transistors as *** work provides an alternative strategy to fully take the advantages of 2 D materials for high-performance field-effect transistors.

摘要：Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device *** retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT)and the interface electronic *** film growth of C8-BTBT molecules is diversified depending on the substrate-molecule and molecule-molecule *** atomic smooth substrates C8-BTBT film grows in layer-by-layer mode while on coarse substrate it grows in islands *** initial molecular layer at dielectric,semiconductor and conductive substrates displays slight different lattice *** initial molecule orientation depends on the substrate and will gradually change to standing up configuration as in bulk phase.C8-BTBT behaves as electron donor when contacting with dielectric and stable conductive *** usually induces a dipole layer pointing to C8-BTBT and an upward bend bending in C8-BTBT side toward the *** it is air stable,C8-BTBT is chemically reactive with some transition metals and *** orientation change from lying down to standing up in the film usually leads to decrease of ionization *** article provides insights to the interface physical and chemical processes and suggestions for optimal design and fabrication of C8-BTBT based devices.