Joint measurement of multiple noncommuting parameters

Although quantum metrology allows us to make precision measurements beyond the standard quantum limit, it mostly works on the measurement of only one observable due to the Heisenberg uncertainty relation on the measurement precision of noncommuting observables for one system. In this paper, we study the schemes of joint measurement of multiple observables which do not commute with each other using the quantum entanglement between two systems. We focus on analyzing the performance of a SU(1,1) nonlinear interferometer on fulfilling the task of joint measurement. The results show that the information encoded in multiple noncommuting observables on an optical field can be simultaneously measured with a signal-to-noise ratio higher than the standard quantum limit, and the ultimate limit of each observable is still the Heisenberg limit. Moreover, we find a resource conservation rule for the joint measurement

Quantum enhanced joint measurement of two conjugate observables with an SU(1, 1) interferometer

We jointly measure the phase and amplitude modulation of an optical field with the newly developed SU(1,1) interferometer. We simultaneously achieve a signal-to-noise ratio improvement of 1.1 and 1 dB over the standard quantum limit in amplitude and phase measurement

Dynamic characteristics of aero-engine’s rotor under large maneuvering flight

In view of the large maneuvering overload of the rotor system in Unmanned Aerial Vehicle (UAV), the dynamic characteristics of rotor system under large maneuvering overload conditions were analyzed in this paper. The finite element model of rotor system under large maneuvering overload was first established by Timoshenko beam element theory and finite element method. The motion differential equations of the rotor system were derived by Lagrange equation, and the additional damping matrix, stiffness matrix and excitation force were obtained. Critical speeds and unbalance response were calculated by characteristic equation method and Newmark-β numerical integration method respectively. The calculation results showed that the additional damping and stiffness leaded the critical speeds of the rotor system to change under large maneuvering flight, and the additional excitation force resulted in a certain static displacement of the whirling orbits

Optimum quantum resource distribution for phase measurement and quantum information tapping in a dual-beam SU(1,1) interferometer

Quantum entanglement is a resource in quantum metrology that can be distributed to two conjugate physical quantities for the enhancement of their measurement sensitivity. This is demonstrated in the joint measurement of phase and amplitude modulation signals in quantum dense metrology schemes. We can also devote all the quantum resource to phase measurement only, leading to the optimum sensitivity enhancement. In this paper, we experimentally implement a dual-beam sensing scheme in an SU(1,1) interferometer for the optimum quantum enhancement of phase measurement sensitivity. We demonstrate a 3.9-dB improvement in signal-to-noise ratio over the optimum classical method, and this is 3-dB better than the traditional single-beam scheme. Furthermore, such as cheme also realizes a quantum optical tap of quantum entangled fields and has the full advantages of an SU(1,1) interferometer, such as detection loss tolerance, making it more suitable for practical applications in quantum metrology and quantum information

Use of anchorchip-time-of-flight spectrometry technology to screen tumor biomarker proteins in serum for small cell lung cancer

<p>Abstract</p> <p>Background</p> <p>The purpose of this study is to discover potential biomarkers in serum for the detection of small cell lung cancer (SCLC).</p> <p>Methods</p> <p>74 serum samples including 30 from SCLC patients and 44 from healthy controls were analyzed using ClinProt system combined with matrix-assisted laser desorption/ionization time-of-flight masss spectrometry (MALDI-TOF-MS). ClinProt software and genetic algorithm analysis selected a panel of serum markers that most efficiently predicted which patients had SCLC.</p> <p>Results</p> <p>The diagnostic pattern combined with 5 potential biomarkers could differentiate SCLC patients from healthy persons, with a sensitivity of 90%, specificity of 97.73%. Remarkably, 88.89% of stage I/II patients were accurately assigned to SCLC.</p> <p>Conclusions</p> <p>Anchorchip-time-of-flight spectrometry technology will provide a highly accurate approach for discovering new biomarkers for the detection of SCLC.</p

Research on the dynamic characteristics of the squeeze film damper of a certain aero-engine

Numerical methods were conducted to simulate the characteristics of SFD under different clearance, eccentricity and precession angular velocity and verified by bidirectional excitation experiments, which is comparatively leading initiative in characteristic measurement of SFD. In addition, finite difference method was introduced to derive Reynolds equation and SOR method to obtain the distribution of oil film, the convergence was also mathematical proof. The results indicate the rotor system keep large vibration state for a long time due to the increasing of actual critical speed of system, which result from the oil film stiffness increases nonlinear excessively with the increase of eccentricity; clearance make a great influence on SFD, especially SFD with large radial size should be kept within 2 ‰

Glechoma longituba (Lamiaceae) alleviates apoptosis in calcium oxalate-induced oxidative stress in kidney proximal tubule epithelial cell line, HK-2

Purpose: To investigate the effects of Glechoma longituba on calcium oxalate (CaOx)-induced stress in HK-2 cells as a possible treatment strategy for nephrolithiasis (kidney stones).Methods: Human kidney HK-2 cells were treated with CaOx and Glechoma longituba at different concentrations. The levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), and malondialdehyde (MDA) were measured. Cell apoptosis and viability were assessed by flow cytometry and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, respectively, while apoptosis-related proteins were determined using western blotting. The levels of the nuclear factorerythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NADPH-quinone-oxidoreductase 1 (NQO-1) genes were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). Using lentivirus, Nrf2 was knocked down in HK-2 cells, and this was confirmed by both qRT-PCR and western blotting. Scramble and si-Nrf2 transfected HK-2 cells were treated with CaOx and Glechoma longituba, and ROS levels and apoptosis were also assessed.Results: CaOx significantly increased the levels of ROS, LDH and MDA, while Glechoma longituba pretreatment attenuated these elevations in a dose-dependent manner. CaOx treatment increased cell apoptosis and decreased cell viability (p &lt; 0.05), while Glechoma longituba pre-treatment abolished these effects in a dose-dependent manner. Glechoma longituba pre-treatment significantly upregulated the expressions of Nrf2, HO-1 and NQO-1 (p &lt; 0.05). In HK-2 cells, Si-Nrf-2 attenuated the effects of Glechoma longituba pre-treatment on cell oxidative stress and apoptosis induced by CaOx.Conclusion: Glechoma longituba pre-treatment attenuates cell apoptosis and oxidative stress induced by CaOx via Nrf2/HO-1 signalling pathway. Thus, the plant is a potential source of agents for the treatment of nephrolithiasis.Keywords: Glechoma longituba, Nephrolithiasis, Nuclear factor-erythroid 2-related factor 2, Oxidative stress, Apoptosi