Micromachined membrane particle filters

We report here several particle membrane filters (8 x 8 mm^2) with circular, hexagonal and rectangular through holes. By varying hole dimensions from 6 to 12 pm, opening factors from 4 to 45 % are achieved. In order to improve the filter robustness, a composite silicon nitride/Parylene membrane technology is developed. More importantly, fluid dynamic performance of the filters is also studied by both experiments and numerical simulations. It is found that the gaseous flow through the filters depends strongly on opening factors, and the measured pressure drops are much lower than that from numerical simulation using the Navier-Stokes equation. Interestingly, surface velocity slip can only account for a minor part of the discrepancy. This suggests that a very interesting topic for micro fluid mechanics research is identified

Compliance adaptation of an intrinsically soft ankle rehabilitation robot driven by pneumatic muscles

Pneumatic muscles (PMs)-driven robots become more and more popular in medical and rehabilitation field as the actuators are intrinsically complaint and thus are safer for patients than traditional rigid robots. This paper proposes a new compliance adaptation method of a soft ankle rehabilitation robot that is driven by four pneumatic muscles enabling three rotational movement degrees of freedom (DoFs). The stiffness of a PM is dominated by the nominal pressure. It is possible to control the robot joint compliance independently of the robot movement in task space. The controller is designed in joint space to regulate the compliance property of the soft robot by tuning the stiffness of each active link. Experiments in actual environment were conducted to verify the control scheme and results show that the robot compliance can be adjusted when provided changing nominal pressures and the robot assistance output can be regulated, which provides a feasible solution to implement the patient-cooperative training strategy

Conduction mechanisms of epitaxial EuTiO3 thin films

To investigate leakage current density versus electric field characteristics, epitaxial EuTiO3 thin films were deposited on (001) SrTiO3 substrates by pulsed laser deposition and were post-annealed in a reducing atmosphere. This investigation found that conduction mechanisms are strongly related to temperature and voltage polarity. It was determined that from 50 to 150 K the dominant conduction mechanism was a space-charge-limited current under both negative and positive biases. From 200 to 300 K, the conduction mechanism shows Schottky emission and Fowler-Nordheim tunneling behaviors for the negative and positive biases, respectively. This work demonstrates that Eu3+ is one source of leakage current in EuTiO3 thin films.Comment: 17 pages,4 figures, conferenc

Pseudospin symmetry in supersymmetric quantum mechanics: Schr\"odinger equations

The origin of pseudospin symmetry (PSS) and its breaking mechanism are explored by combining supersymmetry (SUSY) quantum mechanics, perturbation theory, and the similarity renormalization group (SRG) method. The Schr\"odinger equation is taken as an example, corresponding to the lowest-order approximation in transforming a Dirac equation into a diagonal form by using the SRG. It is shown that while the spin-symmetry-conserving term appears in the single-particle Hamiltonian $H$, the PSS-conserving term appears naturally in its SUSY partner Hamiltonian $\tilde{H}$. The eigenstates of Hamiltonians $H$ and $\tilde{H}$ are exactly one-to-one identical except for the so-called intruder states. In such a way, the origin of PSS deeply hidden in $H$ can be traced in its SUSY partner Hamiltonian $\tilde{H}$. The perturbative nature of PSS in the present potential without spin-orbit term is demonstrated by the perturbation calculations, and the PSS-breaking term can be regarded as a very small perturbation on the exact PSS limits. A general tendency that the pseudospin-orbit splittings become smaller with increasing single-particle energies can also be interpreted in an explicit way.Comment: 31 pages, 11 figures, 2 table

Courtyard sound field characteristics by bell sounds in Han Chinese Buddhist temples

The acoustic environments of Han Chinese Buddhist temples have long played an important role in the development of Buddhism. This study explored the effects of layouts and spatial elements of Han Chinese Buddhist temples on courtyard sound fields. First, sound fields of three traditional Han Chinese courtyards were measured, and results were compared with sound field simulations to determine the appropriate acoustic and software parameter setting for ancient building materials in the context of sound field simulation. Next, a sound field model for standard forms of Han Chinese Buddhist temples was built and analysed. Results indicate that in traditional Buddhist temples, spatial elements—such as the height and sound absorption coefficient of temple courtyard walls, position of courtyard partition walls, and the position and height of bell towers—could significantly affect the sound pressure level (SPL), reverberation time (RT), and musical clarity (C80) of each courtyard. However, enclosure materials, such as those used in roofs, on the ground, and in windows of Han Chinese Buddhist temples, had relatively small effects on temple courtyard sound fields

Candidate MKiD nucleus 106Rh in triaxial relativistic mean-field approach with time-odd fields

The configuration-fixed constrained triaxial relativistic mean-field approach is extended by including time-odd fields and applied to study the candidate multiple chiral doublets (MKiD) nucleus 106Rh. The energy contribution from time-odd fields and microscopical evaluation of center-of-mass correction as well as the modification of triaxial deformation parameters beta, gamma due to the time-odd fields are investigated. The contributions of the time-odd fields to the total energy are 0.1-0.3 MeV and they modify slightly the gamma values. However, the previously predicted multiple chiral doublets still exist.Comment: 9 pages, 3 figures, accepted for publication as a Brief Report in Physical Review

Right-sided invasive metastatic thymoma of the heart

Cardiac tumours may display diverse symptoms through potential involvement of any structure of the heart. We describe a case of a highly malignant thymoma with involvement of different cardiac structures with important haemodynamic compromise. With the high sensitivity of transthoracic echocardiography for detection of intracardiac masses, computed tomography and magnetic resonance add essential structural preoperative information on the tumour and surrounding tissue as vessels, pleura, lung and mediastinum

IEEE Access Special Section Editorial: Biologically Inspired Image Processing Challenges and Future Directions

Human kind is exposed to large amounts of data. According to statistics, more than 80% of information received by humans comes from the visual system. Therefore, image information processing is not only an important research topic but also a challenging task. The unique information processing mechanism of the human visual system provides it with fast, accurate, and efficient image processing capabilities. At present, many advanced image analysis and processing techniques have been widely used in image communication, geographic information systems, medical image analysis, and virtual reality. However, there is still a large gap between these technologies and the human visual system. Therefore, building an image system research mechanism based on the biological vision system is an attractive but difficult target. Although it is a challenge, it can also be considered as an opportunity which utilizes biologically inspired ideas. Meanwhile, through the integration of neural biology, biological perception mechanisms, and computer science and mathematical science, related research can bridge biological vision and computer vision. Finally, the biologically inspired image analysis and processing system is expected to be built on the basis of further consideration of the learning mechanism of the human brain

Carbon inequality and economic development across the Belt and Road regions

Given the aim of maintaining global warming below 2 °C, carbon emission reduction has become a global top priority. Since the Belt and Road Initiative has increasing influence on manufacturing-oriented developing countries, more attention should be paid to carbon emission reduction in these regions. This study conducts a comprehensive analysis by analyzing the carbon inequality and regional development and compares the carbon emissions driven by final demand among countries in and outside the Belt and Road area from 1990 to 2015. It is found that the majority of the Belt and Road regions achieved a rapid GDP growth rate with increasing carbon emissions, in which the investment-driven type demonstrated a significant growth. In contrast, the developed countries outside the Belt and Road area maintained their economic growth while decreasing the carbon emissions owed to the declining of investment-driven emissions; however the consumption-driven emissions stably remained a relatively high level. Our results showed that the inequality of carbon emission within Belt and Road regions is lower than the global average, while the inequality of the investment-driven emissions showed an obviously increasing trend. By discussing the carbon inequality and regional development, rational and feasible strategies for countries and regions within and outside the Belt and Road area are essential, and different types of strategies such as low-carbon technologies transfers and overseas financial cooperation are suggested for regional carbon emission reduction and sustainable regional development under the Belt and Road Initiative