ABSTRACT
This article introduces a spatial angle measuring device based on ensemble diamond nitrogen-vacancy (NV) center optical detection magnetic resonance (ODMR). This device realizes solid-state all-optical wide-field vector magnetic field measurements for solving the angles of magnetic components in space. The system uses diamond NV center magnetic microscope imaging to obtain magnetic vector distribution and calculates the spatial angles of magnetic components based on the magnetic vector distribution. Utilizing magnetism for angle measuring enables non-contact measuring, reduces the impact on the object being measured, and ensures measurement precision and accuracy. Finally, the accuracy of the system is verified by comparing the measurement results with the set values of the angle displacement platform. The results show that the measurement error of the yaw angle of the system is 1°, and the pitch angle and roll angle are 1.5°. The experimental results are in good agreement with the expected results.
ABSTRACT
The wide-field (2.42 mm × 1.36 mm, resolution: 5.04â µm) tomography imaging of double circuits is performed using nitrogen-vacancy (NV) center ensembles in a diamond. The magnetic-field distribution on the surface of the circuit produced by the lower layer is obtained. Vector magnetic superposition is used to separate the magnetic-field distribution produced by the lower layer from the magnetic-field distribution produced by two layers. An inversion model is used to perform the tomography imaging of the magnetic-field distribution on the lower layer surface. Compared with the measurements of the upper layer, the difference in the maximum magnetic-field intensity of inversion is approximately 0.4%, and the difference in the magnetic-field distribution of inversion is approximately 8%, where the depth of the lower layer is 0.32 mm. Simulations are conducted to prove the reliability of the imaging. These results provide a simple and highly accurate reference for the detection and fault diagnosis of multilayer and integrated circuits.
ABSTRACT
Radiation with high-efficiency, large-bandwidth, and uniform magnetic field radiation antennas in a large field of view are the key to achieving high-precision wide-field imaging. This paper presents a hollow Ω-type antenna design for diamond nitrogen-vacancy (NV) ensemble color center imaging. The uniformity of the antenna reaches 94% in a 4.4 × 4.4 mm2 area. Compared with a straight copper antenna, the radiation efficiency of the proposed antenna is 71.8% higher, and the bandwidth is improved by 11.82 times, demonstrating the effectiveness of the hollow Ω-type antenna.
ABSTRACT
We present an efficient and faithful hyperentanglement purification protocol (hyper-EPP) for three-photon system in mixed hyperentangled Greenberger-Horne-Zeilinger states with bit-flip errors in both spatial-mode and polarization degrees of freedom (DOFs), resorting to the fidelity-robust quantum gates and hyperentanglement link. Our high-efficiency hyper-EPP comes from two aspects. One is to pump the higher-fidelity hyperentanglement from different three-photon systems into the same three-photon system with fidelity-robust swap gates, the other is to reproduce some hyperentangled three-photon systems from hyperentangled two-photon subsystems based on hyperentanglement link. Moreover, as the infidelity originating from imperfect single-photon scattering can be heralded as a failure by triggering a detector, our hyper-EPP operates faithfully with the present quantum circuits. Furthermore, our hyper-EPP can be directly extended to purify multiple photon systems entangled in one DOF or hyperentangled in multiple DOFs.
ABSTRACT
The two or more degrees of freedoms (DOFs) of photon systems are very useful in hyperparallel photonic quantum computing to accomplish more quantum logic gate operations with less resource, and depress photonic dissipation noise in quantum information processing. We present some flexible and adjustable schemes for hybrid hyper-controlled-not (hyper-CNOT) gates assisted by low-Q cavities, on the two-photon systems in both the spatial-mode and the polarization DOFs. These hybrid spatial-polarization hyper-CNOT gates consume less quantum resource and are more robust against photonic dissipation noise, compared with the integration of two cascaded CNOT gates in one DOF. Besides, simultaneous counter-propagation of two photons economize extremely the operation time in the whole process of our schemes. Moreover, these quantum logic gates are more feasible for fast quantum operations in the weak-coupling region of the low-Q cavities with current experimental technology, which are much different from strong-coupling cases of the high-Q ones.
ABSTRACT
Presenting with common mental health difficulties, particularly depression and anxiety, there is also preliminary evidence that mindfulness-based interventions (MBIs) including mindfulness-based cognitive therapy (MBCT), mindfulness-based stress reduction (MBSR) and integrated mindfulness yoga practices may also be effective in reducing common mental health difficulties during pregnancy. We systematically reviewed and synthesized the current literature on the effectiveness of MBIs in reducing severity of perinatal anxiety and depression. Databases including PubMed, Cochrane Library, IndMED and PsychoInfo were searched for relevant studies. Manual searches were conducted in relevant articles and Google Scholar. Seventeen cohorts representing 18 studies were included. Pre-post effect sizes were reported for both treatment and control groups. Seven randomized controlled trials (RCTs), two non-randomized controlled trials and nine treatment evaluations were included. Maternal participation in an MBI was associated with reductions in perinatal anxiety of moderate to large magnitude. Results for the effect of MBIs on depression were less consistent, with pre-post treatment reductions of moderate magnitude, but no significant differences in depression scores when MBI was compared with a control group. There was some evidence that MBIs were associated with increased mindfulness. Risk of bias in studies was variable. Our review offers preliminary evidence for the effectiveness of MBIs in reducing perinatal anxiety, with more equivocal findings with regard to perinatal depressive symptoms. Further methodologically rigorous evaluation using RCTs and longer follow-up periods are recommended.
ABSTRACT
AIMS/HYPOTHESIS: Adult beta cells have a diminished ability to proliferate. Phosphatase and tensin homologue (PTEN) is a lipid phosphatase that antagonises the function of the mitogenic phosphatidylinositol 3-kinase (PI3K) pathway. The objective of this study was to understand the role of PTEN and PI3K signalling in the maintenance of beta cells postnatally. METHODS: We developed a Pten (lox/lox); Rosa26 (lacZ); RIP-CreER (+) model that permitted us to induce Pten deletion by treatment with tamoxifen in mature animals. We evaluated islet mass and function as well as beta cell proliferation in 3- and 12-month-old mice treated with tamoxifen (Pten deleted) vs mice treated with vehicle (Pten control). RESULTS: Deletion of Pten in juvenile (3-month-old) beta cells significantly induced their proliferation and increased islet mass. The expansion of islet mass occurred concomitantly with the enhanced ability of the Pten-deleted mice to maintain euglycaemia in response to streptozotocin treatment. In older mice (>12 months of age), deletion of Pten similarly increased islet mass and beta cell proliferation. This novel finding suggests that PTEN-regulated mechanisms may override the age-onset diminished ability of beta cells to respond to mitogenic stimulation. We also found that proteins regulating G1/S cell-cycle transition, such as cyclin D1, cyclin D2, p27 and p16, were altered when PTEN was lost, suggesting that they may play a role in PTEN/PI3K-regulated beta cell proliferation in adult tissue. CONCLUSIONS/INTERPRETATION: The signals regulated by the PTEN/PI3K pathway are important for postnatal maintenance of beta cells and regulation of their proliferation in adult tissues.
