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Quantum steering plays a crucial role in quantum communication and one-way quantum computation. Here, we study quantum steering between two magnon modes in a cavity-magnonics system by applying a two-photon drive field to the microwave cavity. The two magnon modes are entangled and the one-way steering can be implemented when the four-wave mixing is triggered. Different from most schemes that use the dissipation of the system to control quantum steering, in our scheme the one-way steering can be modulated on demand by adjusting the coherent coupling ratio between the two magnons and the cavity, which provides a flexible and feasible way in experiments. We also reveal that the directionality of quantum steering is related to the mode populations, i.e., the mode with a larger population dominants the steering. Our study has high manipulability and may provide a promising platform for one-way quantum computing and communications based on macroscopic entanglement state.

For solid-state spin systems, the collective spin motion in a single crystal embodies multiple magnetostatic modes. Recently, it was found that the cross-Kerr interaction between the higher-order magnetostatic mode and the Kittel mode introduces a new operable degree of freedom. In this work, we propose a scheme to entangle two magnon modes via the cross-Kerr nonlinearity when the bias field is inhomogeneous and the system is driven. Quantum entanglement persists at the steady state, as demonstrated by numerical results using experimentally feasible parameters. Furthermore, we also demonstrate that entangled states can survive better in the system where self-Kerr and cross-Kerr nonlinearities coexist. Our work provides insights and guidance for designing experiments to observe entanglement between different degrees of freedom within a single ferrimagnetic crystal. Additionally, it may stimulate potential applications in quantum information processing using spintronic devices., 10 pages, 4 figures

Uniform helix angle tools cannot effectively suppress the chatter in the high machining process. Consequently, cutters with non-uniform helix and pitch angles are more and more common in various mi...

Quantum entanglement is a key element for quantum information that can be generated in a double-cavity magnomechanical system that consists of two microwave cavities, a magnon mode, and a vibrational mode. The magnon mode, which describes a collective excitation of spins, is excited by a strong microwave field. In this system, cavity photons and magnons are coupled via magnetic dipole interaction. The magnons and phonons interact via magnetostrictive interaction, while the two microwave cavities can be connected by a superconducting transmission line. By changing the external driving fields on the two cavities to break the symmetry of spatial inversion, we propose a scheme for asymmetric transmission and entanglement. With the use of current experimental parameters for numerical simulation, we believe our results may reveal a new strategy to build quantum resources for noise-tolerant quantum processors and realize chiral networks.

As a key factor, the accuracy of the instantaneous undeformed thickness model determines the force-predicting precision and further affects workpiece machining precision in the micro-milling process. The runout with five parameters affects the machining process more significantly compared with macro-milling. Furthermore, modern industry uses cutters with non-uniform pitch and helix angles more and more common for their excellent properties. In this article, an instantaneous undeformed thickness model is presented regarding cutter runout, variable pitch, and helix angles in the micro-milling process. The cutter edge with the cutter runout effect is modeled. Then, the intersecting ellipse between the plane vertical to the spindle axis and the cutter surface which is a cylinder can be gained. Based on this, the points, which are used to remove the material, on the ellipse as well as cutter edges are calculated. The true trochoid trajectory for each cutting point along the tool path is built. Finally, the instantaneous undeformed thickness values are computed using a numerical algorithm. In addition, this article analyzes runout parameters’ effects on the instantaneous undeformed thickness values. After that, helix and pitch angles’ effects on the instantaneous undeformed thickness are studied. Ultimately, the last section verifies the correctness and validity of the instantaneous undeformed thickness model based on the experiment conducted in the literature.

The effect of Cr content and cooling rate on the microstructure of Al-Mn alloy was studied using well resistance furnace melting, and the alloy was analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experimental results showed that adding Cr could significantly improve the morphology of the primary phase in the Al-2.5Mn alloy. Without Cr, the primary phase in the alloy was thick, needle-like, and strip-like structure. After adding 0.2wt%-0.5wt% Cr, the primary phase in the upper part of the alloy was gradually fined and reached the best effect at 0.35wt% Cr. When the content of Cr was 0.5wt%, the microstructure of the primary phase in the upper part began to coarsen. The bottom of the alloy was a large bulk phase, but still much finer than that without adding Cr. XRD and SEM analysis showed that the precipitation phase at the bottom was mainly Al85Mn7Cr8, while the fine microstructure at the top was Al6Mn and Al3Mn. The results of the cooling rate experiments showed that the primary phase of Al-2.5Mn-0.35Cr was further refined, and the eu-tectic microstructure was partly achieved, under air-cooling condition. And when the cooling method was iron die-cooling, the microstructure of the Al-2.5Mn-0.35Cr alloy was changed into a eutectic microstructure.

This article describes the bistable behavior of squeezed and entangled states induced by the magnon self-nonlinear Kerr effect.

We show how to implement stationary one-way quantum steering with strong entanglement in a cavity magnonic system that consists of two magnon modes and a microwave cavity. The cavity is driven by a squeezed vacuum field generated by a flux-driven Josephson parameter amplifier and coupled to two Kittel modes via magnetic dipole interaction. We find that the steering directivity only depends on the ratio of two coupling rates (i.e., the ratio of coherent information exchange frequencies) and is barely affected by the dissipation of the system. Meanwhile, the entanglement and steering can be significantly enhanced due to the squeezed vacuum field and thus are more robust against thermal noises. This provides an active method to manipulate the steering directivity instead of adding asymmetric losses or noises to subsystems at the cost of reducing steerability.

We propose a scheme that can generate tunable magnomechanically induced amplification in a double-cavity parity-time-(PT -) symmetric-like magnomechanical system under a strong control and weak probe field. The system consists of a ferromagnetic-material yttrium iron garnet (YIG) sphere placed in a passive microwave cavity which is connected with another active cavity. We reveal that ideally induced amplification of the microwave probe signal may reach the maximum value 1000000 when cavity-cavity, cavity-magnon and magnomechanical coupling strengths are nonzero simultaneously. The phenomenon might have potential applications in the field of quantum information processing and quantum optical devices. Besides, we also find the phenomena of slow-light propagation. In this case, group speed delay of the light can achieve 0.000035s, which can enhance some nonlinear effect. Moreover, due to the relatively flat dispersion curve, the proposal may be applied to sensitive optical switches, which plays an important role in storing photons and quantum optical chips., 6 pages,6 figures

We present a method to enhance steady-state bipartite and tripartite entanglement in a cavity-optomagnonics system by utilizing the Kerr nonlinearity originating from the magnetocrystalline anisotropy. The system comprises two microwave cavities and a magnon and represents the collective motion of several spins in a macroscopic ferrimagnet. We prove that Kerr nonlinearity is reliable for the enhancement of entanglement and produces a small frequency shift in the optimal detuning. Our system is more robust against the environment-induced decoherence than traditional optomechanical systems. Finally, we briefly analyze the validity of the system and demonstrate its feasibility for detecting the generated entanglement.

We present a scheme to implement a steady optical-photon-and-magnon entanglement in a hybrid optomagnonics-mechanical system by adiabatical elimination of the auxiliary microwave (MW) cavity and effective laser cooling of a delocalized Bogoliubov mode. The system consists of a magnon, an optical and a MW cavities, and a mechanical vibrator. To achieve a direct entangling interaction between the magnon and the optical photon, we drive the optical cavity and magnon at the red and blue sideband associated with the mechanical resonator, respectively. In particular, by eliminating the MW cavity and optimizing the relative ratio of effect couplings, rather than merely increasing their magnitudes, we achieve a strong entanglement between optical photons and magnons.

Vibration-based damage detection using the 2D modal curvature has become a research focus. However, the traditional methods based on modal curvature lack the sensitivity to direction of the damage. To address this problem, a directional 2D Morlet wavelet modal curvature is proposed in this paper. The directional wavelet modal curvatures show the following merits: robust to noise interference and sensitive to direction of damage. By the numerical simulation, the efficiency of the proposed method is demonstrated in the plate-like structure.

In Lamb wave-based structural health monitoring, amplitude damage imaging is commonly used because the defects feature can be easily amplified by summing all the response signals together. However, the grating and side lobes affect the imaging quality and blind areas further restrict the inspection area. Considering that the existing phase-based imaging algorithms are either unfit for dispersive Lamb wave or strict to many requirements to guarantee better performance, inspired by the absence of phase information in focusing phased array, a novel focusing phase imaging (FPI) method for Lamb wave phased array is developed. The main contribution of the paper is introducing the phase information to focusing phased array. By applying the inverse-dispersion effect to the excitation signals and the superposition operation, the energy can be focused at every inspection point. The phase damage index is constructed by directly measuring the degree of consistency and alignment of the instantaneous phases. The experiments for the circular and linear array under various excitation signals with multiple defects verify that the FPI is effective for both surface damage and through-hole damage. The proposed algorithm is superior for its ability in energy focusing for defects, the capability in suppression of grating and side lobes, strong anti-disturbance ability from boundary reflection, the nonexistence of imaging blind area, and its adaptability for various excitation parameters and array layout.

Precisely controlled dimensions of heterostructured ZnO nanorod arrays were grown on micropatterned Au films supported by Si substrate using chemical vapor deposition (CVD). The field emission properties were attributed to pointed nanorods, thickness of catalyst, preferential growth, density, morphology of ZnO and Molybdenum (Mo) decorated ZnO nanorod arrays (Mo/ZnO). The selective restrained heterostructure approach resulted in excellent control over periodicity, location and density of ZnO nanorod arrays. Overall, field emission properties of bare ZnO nanorod arrays showed a low turn-on field of ~4.7 V/μm and a high field enhancement factor (β) ~1686 to 7.3 V/μm and (β) ~807 for Mo/ZnO. It was also found that the field emission properties were significantly influenced by densely decorated Mo nanoparticles on as-grown ZnO nanorod arrays.

During the dressing process of diamond wheel using laser/ultrasonic-vibration combined dressing method, the removal mode of the local materials on the surface of wheel with the use of laser’s heating effect transits from brittle fracture to plastic flow, so that the wear of diamond dresser can be reduced and the dressing efficiency and surface dressing quality can be improved. Using ANSYS analysis software, the three-dimensional units were used and the nonlinearity of the material’s thermophysical properties was taken into account, and thereby, the finite element model of the temperature field of the diamond wheel heated by the laser during the dressing process was constructed. Then, the distributions of the temperature field on the surface and section of the wheel under different technological parameter were acquired. Moreover, the temperature distribution of the dressed wheel under actual working conditions was measured using infrared temperature measurement method. The results indicate that, under the same working conditions, the simulation results using finite element model fit well with the measured values, i.e., the finite element model has important guiding significance to the selection of technological parameters in dressing.

Usually, generating parts with complex surfaces, especially three-dimensional (3D) curved-surface blades, involves difficult designing, complicated manufacturing processes, and low production efficiency. In this study, by integrating 3D curved-surface modeling and the rapid prototyping functions of the pro/E software platform with computer-aided design, layered manufacturing, and material curing technologies, an improved process was realized. The once-challenging fabrication of irregular curved-surface blades was transformed into a simple technique of making planes. By selectively curing the raw material, as demonstrated in this study, complex surfaces can be manufactured rapidly, thus shortening research and development stages of new products, reducing costs, and endowing manufacturers with an improved capacity to research and develop products with greater competence and accuracy .

Strong earthquake motion observations have gathered much useful data for the seismic-resistant design of civil engineering structures, and for developing earthquake prevention technology. The performance of Chinese strong motion network has been evaluated from recent earthquakes in Chinese Mainland. To follow the new requirement of the earthquake mitigation plan, some new practice of strong motion observations are described, including rapid urban ShakeMap, earthquake early warning system.

Through the research on the structure and properties of different soft start device applied to long distance and large capacity belt conveyor. Analysis and comparison of technical characteristics of some used soft start of this kind of belt conveyor, and then get the reasonable way of soft start. In order to provide optimization scheme of application of belt conveyor in long distance and large capacity in the actual production for enterprise.

With the rapid development of 3D CAD technology, 3D assembly process is playing an important role in the on-site assembly. A closed-loop control method and three-dimensional site visualization technology site is presented. The methodology takes into account CAD design stage, assembly process design, site assembly and site inspection. The method includes three key technologies: the verification process technology of three-dimensional assembly process, optimization and process simulation techniques of site assembly, closed-loop control technology of assembly process quality inspection. Finally, the method and technology has applied in the actual assembly, and achieved good results.

There are a lot of faults in making complex surface parts (especially 3D curved blade) as designing difficultly, processing complexly, low production efficiency and so on. In this paper, it integrates the computer aided design and manufacturing, layered manufacturing and increase material molding technology. They are based on the pro/E 3d surface modeling and rapid prototype technology. The technology can put the blades of irregular surface processing into simple graphic processing. We can make complex plane quickly, make the development cycle of new products shorter and reduce the development cost by selected material curing. Thus it can make the enterprise have higher product development capacity and market competitiveness.

Based on the status of diagnosis of engineering mechanical fault, the service platform was set up. It could detect the condition of engineering mechanical equipment at any time by the communication technology ZigBee and GPRS and analyses the development tendency of equipment in order to diagnose the fault of engineering mechanical equipment and sustain it.

t is quite constrained for us to use some other input devices to communicate with computers. In this paper, we integrate human-computer interaction technologies with handwritten Chinese character recognition strategies using depth image information provided by Kinect sensor to realize an unconstrained handwritten character recognition system, which only uses our hand as input device. We predefine several hand gestures as instructions, and for the recognition of these hand gestures, we calculate the contour and fingertips of the hand used for writing using depth image taken by Kinect. By mimicking the functionalities of the computer mouse only using our hands, we can write freely in the air and get the original character image. After Gaussian blurring and normalization, we adopt some classic handwritten character recognition schemes to accomplish the recognition task. Experiments show that the system gives a good result.

The purpose of this paper is to simulate the residual field of laser brazing by FEM of ANSYS. The 2-D coupled field element is elected to create finite element model. The brazing experiments have been done by means of 45steel which is the matrix and Ni-Cr solder and the residual stress of the diamond wheel has been measured by Raman method. The results of measure show that the maximum stress value is less strength of diamond. The residual stress distribution is basically identical between the results of simulation and experiment. According to this paper, it is possible to decrease the costs of study by selecting reasonable processing parameters on laser brazing.

Two vanillin derivatives have been designed and synthesized and their biological activities were also evaluated for antimicrobial activity. Their chemical structures are characterized by single crystal X-ray diffraction studies, 1H NMR, MS, and elemental analysis. Structural stabilization of them followed by intramolecular as well as intermolecular H-bonds makes these molecules as perfect examples in molecular recognition with self-complementary donor and acceptor units within a single molecule. Docking simulations have been performed to position compounds into the FtsZ active site to determine their probable binding model. Compound 3a shows the most potent biological activity, which may be a promising antimicrobial leading compound for the further research.

The performances of automobiles rely on the engine in high extent, plus connecting rods are the main part of the engine, whose work environment is poorer and pressure is complex. In order to decrease the inertial force and add the span life of the engine, the weight of connecting rods is as litter as possible. Conventional design method is mainly dependent on experience. By means of soft ware of ANSYS, connecting rods are optimized when the structure of connecting rod is simplified, such as big end hole being a whole and taking no account of the interaction between bearing and bush. 45steel is chosen as a material and it must meet tensile strength, lower yield strength, impact toughness, and so on. The new connecting rod can save the material, compared with the conventional connecting rods.