Fast ground-state cooling of mechanical resonator with time-dependent optical cavities

We propose a feasible scheme to cool down a mechanical resonator (MR) in a three-mirror cavity optomechanical system with controllable external optical drives. Under the Born-Oppenheimer (BO) approximation, the whole dynamics of the mechanical resonator and cavities is reduced to that of a time-dependent harmonic oscillator, whose effective frequency can be controlled through the optical driving fields. The fast cooling of the MR can be realized by controlling the amplitude of the optical drives. Significantly, we further show that the ground-state cooling may be achieved via the three-mirror cavity optomechanical system without the resolved sideband condition.Comment: Some references including our previous works on cooling of mechanical resonators are added, and some typos are corrected in this new version. Comments are welcom

Perfect Function Transfer in two- and three- dimensions without initialization

We find analytic models that can perfectly transfer, without state initializati$ or remote collaboration, arbitrary functions in two- and three-dimensional interacting bosonic and fermionic networks. We elaborate on a possible implementation of state transfer through bosonic or fermionic atoms trapped in optical lattices. A significant finding is that the state of a spin qubit can be perfectly transferred through a fermionic system. Families of Hamiltonians, both linear and nonlinear, are described which are related to the linear Boson model and that enable the perfect transfer of arbitrary functions. This includes entangled states such as decoherence-free subsystems enabling noise protection of the transferred state.Comment: 4 pages, no figur

Water Dancer II-a: a Non-tethered Telecontrollable Water Strider Robot

Water Strider Robot (WSR) is a kind of bio‐ inspired micro robot that can stand and move on water surface via surface tension. In this paper, a design method is presented with algorithms for designing driving leg. Structure, control system and software of the robot are also discussed in details. A prototype Water Dancer II‐a that is driven with two electric motors is presented as successfully tested in lab. The proposed WSR is tele‐controlled with infrared signals and has the capability of turning and speed regulation with features of light tiny volume and low power consumption. Experimental results are reported and discussed to show practical feasibility of the presented WSR prototype. The new results in the paper are related also to the WSR prototype design with a robot body of less than 30 x 30 mm size and with ten leg rods of 90 mm length and 0.2 diameter that are able to provide lifting force for a water walk of the 6.0 grams robot at a forward speed of 20 cm/s or angular velocity of 9 degree/s with two micro DC motors (RoomFlight 4 x 8 mm, 28 Ohm)

Identification of the Flow Resistance Coefficient and Validation of a Building Air Conditioning System

The fundamental parameter that characterizes the hydraulic state of a water pipeline and largely determines the efficiency of the water-transport process is the hydraulic resistance coefficient (HRC). The actual values of the HRC may be different from the theoretical values because of the complexity of the actual situation. A novel method-multi-goal optimization (MGO) strategy-for HRC estimation in building air conditioning systems is described in this paper. First, the basic principle of the approach is presented. Then the strategy is validated using a numerical example

Finding sands in the eyes: vulnerabilities discovery in IoT with EUFuzzer on human machine interface

In supervisory control and data acquisition (SCADA) systems or the Internet of Things (IoT), human machine interface (HMI) performs the function of data acquisition and control, providing the operators with a view of the whole plant and access to monitoring and interacting with the system. The compromise of HMI will result in lost of view (LoV), which means the state of the whole system is invisible to operators. The worst case is that adversaries can manipulate control commands through HMI to damage the physical plant. HMI often relies on poorly understood proprietary protocols, which are time-sensitive, and usually keeps a persistent connection for hours even days. All these factors together make the vulnerability mining of HMI a tough job. In this paper, we present EUFuzzer, a novel fuzzing tool to assist testers in HMI vulnerability discovery. EUFuzzer first identifies packet fields of the specific protocol and classifies all fields into four types, then using a relatively high efficiency fuzzing method to test HMI. The experimental results show that EUFuzzer is capable of identifying packet fields and revealing bugs. EUFuzzer also successfully triggers flaws of actual proprietary SCADA protocol implementation on HMI, which the SCADA software vendor has confirmed that four were zero-day vulnerabilities and has taken measures to patch up

Cloning and characterization of a putative transcription factor induced by abiotic stress in Zea mays

bZIP transcription factors have been reported to play important roles in plant responses to abiotic stresses. Here, we reported the cloning and characterization of a putative bZIP transcription factor (ZmbZIP17) from maize inbred line Han21, which is up-regulated by drought treatment. The open reading frame sequence of ZmbZIP17 was obtained by using 5’RACE and RT-PCR. Sequence analysis showed that ZmbZIP17 encodes a polypeptide of 563 amino acids with predicted molecular mass of59.8 kDa and pI of 5.6. Southern blot analysis showed that ZmbZIP17 exists as a single copy gene in maize genome. Subcellular localization of ZmbZIP17 was identified in nucleus. The results of real-time PCR analysis indicated that ZmbZIP17 was up-regulated by drought, heat, ABA and NaCl stressimmediately, which suggested that ZmbZIP17 is an early stage responsive gene to various abiotic stresses. The result also showed that ZmbZIP17 expressed much higher in leaves than in other organs in maize seedlings

Research on temperature field and microstructure distribution of cross wedge rolling based on square billet

With the deepening and popularization of the cross wedge rolling process, the requirements for the cross wedge rolling blanks have become wider and wider. Relying only on the traditional round blanks will restrict the promotion of the cross wedge rolling process to a certain extent. The emergence of the square billet is a breakthrough in the selection of raw materials, but related research is relatively scarce. Therefore, this paper conducts a finite element simulation for the rolling process of the square billet. Four characteristic points are taken on the longitudinal section of the billet to track the temperature change. Research on the law of field changes. At the same time, the change of the grain size and dynamic recrystallization percentage of the rolled piece during the rolling process is studied. Simulation and experiment are combined to obtain the change rule of the average grain size of the characteristic points of the longitudinal section of the billet with time