The design of a new fiber optic sensor for measuring linear velocity with pico meter/second sensitivity based on Weak-value amplification

We put forward a new fiber optic sensor for measuring linear velocity with picometer/second sensitivity with Weak-value amplification based on generalized Sagnac effect [Phys. Rev. Lett.\textbf{93}, 143901(2004)].The generalized Sagnac effect was first introduced by Yao et al, which included the Sagnac effect of rotation as a special case and suggested a new fiber optic sensor for measuring linear motion with nanoscale sensitivity. By using a different scheme to perform the Sagnac interferometer with the probe in momentum space, we have demonstrated the new weak measure protocol to detect the linear velocity by amplifying the phase shift of the generalized Sagnac effect. Given the maximum incident intensity of the initial spectrum, the detection limit of the intensity of the spectrometer, we can theoretically give the appropriate pre-selection, post-selection, and other optical structures before the experiment. Our numerical results show our scheme with Weak-value amplification is effective and feasible to detect linear velocity with picometer/second sensitivity which is three orders of magnitude smaller than the result $\nu$=4.8 $\times$ $10^{-9}$ m/s obtained by generalized Sagnac effect with same fiber length.Comment: 3 figures; 9 pages. arXiv admin note: substantial text overlap with arXiv:2105.1363

nonlocal quark condensate from Dyson-Schwinger Equation and its contributions to the gluon vacuum polarization based on OPE approach

The operator-product expansion(OPE) could be employed to obtain the lowest-order, nonlocal quark scalar condensate component of gluon vacuum polarization. In particular, nonlocal quark scalar condensate can be calculated by solving Dyson-Schwinger Equation(DSE) of QCD. Then, field-theoretic aspects of the gluon vacuum polarization and nonperturbative gluon propagator will be considered in the Landau gauge of the Lorentz gauge fixing. The gluon propagator we obtained is finite in the infrared domain where the single gluon mass $m_g$ can be determined. Our results of the ratio $m_{g}/\Lambda_{QCD}$ the range of that from 1.33 to 1.39 agree with previous determinations for this ratio. Besides, the analytic structure of the gluon propagators from the OPE's result is explored. Our numerical analysis of the gluon' Schwinger function finds clear evidence of the positivity violations in the gluon propagator. In addition, a new method for obtaining the chemical potential dependence of the gluon vacuum polarization and the dressed gluon propagator is developed.Comment: 9 pages, 14 figures

A potential third-generation gravitational-wave detector based on autocorrelative weak-value amplification

Reducing noises and enhancing signal-to-noise ratios (SNRs) have become critical for designing third-generation gravitational-wave (GW) detectors with a GW strain of less than $10^{-23}$/$\rm \sqrt{Hz}$. In this paper, we propose a potential third-generation GW detector based on autocorrelative weak-value amplification (AWVA) for GW detection with a strain of $h_g =$ $4 \times 10^{-25}$/$\rm \sqrt{Hz}$. In our scheme, a GW event induces a phase difference $\Delta \phi$ by passing through an 11-bounce delay line, 10-km arm-length, zero-area Sagnac interferometer illuminated with a 1064-nm laser. Subsequently, $\Delta \phi$ is amplified as the parameter of post-selection by choosing the appropriate pre-selected state and coupling strength in AWVA. In particular, we theoretically investigate the AWVA measurements for GW detection within the frequency band of 200 Hz $\leq$ $f_g$ $\leq$ 800 Hz, considering Gaussian noises with negative-decibel SNRs. The peak response of the AWVA sensitivity $\kappa(f_g)$ occurs at frequency $f_{g, max}$ = 500 Hz, which falls within the frequency band of interest of the current third-generation GW detectors. Our simulation results indicate that AWVA can demonstrate a measurable sensitivity of $\Theta(f_g)$ within the frequency band of interest. Moreover, the robustness of WVA shows promising potential in mitigating the effects of Gaussian noises.Comment: 21 pages, 6 figure

Chiral Separation of D,L-Mandelic Acid Using An Enantioselective Membrane Formed by Polycondensation of β-Cyclodextrin with 1,6-Diisocyanatohexane on A Polysulfone Membrane

An enantioselective composite membrane was prepared by polycondensation between β-cyclodextrin (β-CD) on a polysulfone support (PS) and a heptane solution of 1,6-diisocyanatohexane (1,6-DCH). The flux and permselective properties of the composite membrane were studied using an aqueous solution of D,L-mandelic acid as the feed solution. The influences of a number of parameters, such as the air-drying time of the β-CD solution on PS, the time of polymerization, the operating pressure and the feed concentration of the racemate, were studied. Chemical characterization was carried out using Fourier transform infrared spectroscopy and the top surface/cross-section was analyzed by scanning electron microscopy. The results showed that when using the enantioselective composite membrane for the optical resolution of the D,L-mandelic acid racemic mixture, an enantiomeric excess of over 85% could be obtained. The paper thus details, for the first time, how a poly(β-CD crosslinked with 1,6-DCH)/PS composite membrane can be used as an optical resolution membrane material to isolate the optical isomers of D,L-mandelic acid

Cloning and Expression Analysis of a PISTILLATA Homologous Gene from Pineapple (Ananas comosus L. Merr)

PISTILLATA (PI)-like genes are crucial regulators of flowering in angiosperms. A homologue of PI, designated as AcPI (Genbank accession number HQ717796), was isolated from pineapple cultivar Comte de Paris by reverse transcriptase polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The cDNA sequence of AcPI is 907 bp in length and contains an open reading frame of 594 bp, which encodes a protein of 197 amino acids. The molecular weight was 2.29 kDa and the isoelectric point was 9.28. The alignment showed that AcPI had a high identity with CsPIC2 (78.6%), AoPI (77.4%), OrcPI (75.7%) and HPI2 (72.4%). Quantitative real-time polymerase chain reaction (qRT-PCR) analyses in different tissues showed that the expression pattern of AcPI was different from the B-class genes in eudicots. AcPI was expressed in all the tissues investigated. The expression level was very low in fruit stems, bracts, leaves and sepals, high in petals and carpels, and moderate in apical meristems, flesh and stamens. The qRT-PCR analyses in different stages indicated that the expression of AcPI reached the highest level at 40 days after flower inducement, when the multiple fruit and floral organs were forming. It proved the important role of AcPI in floral organs and fruit development. The 35S::AcPI transgenic Arabidopsis plants flowered earlier and had more inflorescences or branches than wild type plants

Geostatistical mapping and quantitative source apportionment of potentially toxic elements in top- and sub-soils: A case of suburban area in Beijing, China

Abstract The risk assessment and source identification for potentially toxic elements (PTEs) in soils, particularly agricultural soils from megacities, are significant for environmental protection and pollution control. In this study, an intensive sampling (4127 topsoil samples and 994 subsoil samples) was conducted in the Shunyi District, Beijing, which is a suburban area with extensive cropland cover and has been impacted by the megacity over several decades. Concentrations and distributions of 8 PTEs, including V, Cr, Ni, As, Cd, Zn, Pb and Hg, were determined, and their possible sources were quantitatively assessed by principal component analysis (PCA), redundancy analysis (RDA), positive matrix factorization (PMF) analysis, and anthropogenic contribution ratio method. Among 8 PTEs, Zn, V and Cr exhibited significantly high concentrations in soils, with means of 68.29, 68.19 and 52.13 mg/kg, respectively, followed by Pb (23.84 mg/kg), Ni (22.91 mg/kg), As (8.30 mg/kg), Cd (0.15 mg/kg) and Hg (0.05 mg/kg). RDA and PCA demonstrated that the rock weathering was a significant source of V, Cr, Ni and As, and the local emissions and atmospheric deposition respectively contributed most of Cd, Zn and Pb, and of Hg in soils. This source category was confirmed the spatial variations of anthropogenic contribution ratios to individual PTEs. PMF results showed that the local emissions contributed 96.3% of Cd, 44.4% of Zn and 32.0% of Pb in soils, and the atmospheric source carrying urban pollutants amounted to 78.7–80.2% of Hg. In this case, several effective analysis methods have been successfully applied to quantify the impact of a megacity to PTEs in suburban soils. These results improve understanding of the contamination status of PTEs in suburban soils from Beijing megacity, and provide basis for policymaker regarding environmental protection and pollution control

catena-Poly[[[tetra­aqua­neodymium(III)]-di-μ-isonicotinato] chloride]

In the title complex, {[Nd(C6H4NO2)2(H2O)4]Cl}n, the NdIII cation is located on a twofold rotation axis and coordinated by four isonicotiniate anions and four water mol­ecules in a distorted square-anti­prismatic geometry. The carboxyl­ate groups of the isonicotinate anions bridge the NdIII cations, forming polymeric chains running along the c axis. The Cl− anion is located on a twofold rotation axis and is linked to the polymeric chains via O—H⋯Cl hydrogen bonding. Inter­molecular O—H⋯O and O—H⋯N hydrogen bonds are also present in the crystal structure

Auto-correlative weak-value amplification under strong noise background

In the general optical metro-logical protocols based on the weak-value amplification(WVA) approach, it is beneficial to choose the pre-selected state and the post-selected one to be nearly orthogonal for improving the sensitivity. However, the orthogonality of the post-selection decreases the probability of detecting photons and makes the weak measurement difficult, especially when there is strong noise background and the pointer is drowned in noise. In this article, we investigate a modified weak measurement protocol with a temporal pointer, namely, the auto-correlative weak-value amplification (AWVA) approach. We find it can significantly improve the precision of optical metrology under Gaussian white noise, especially with a negative signal-to-noise ratio. With the AWVA approach, a small longitudinal time delay (tiny phase shift) $\tau$ of a Gaussian pulse is measured by implementing two auto-correlative weak measurements. The small quantities are obtained by measuring the auto-correlation coefficient of the pulses instead of fitting the shift of the mean value of the probe. Simulation results show that the AWVA approach outperforms the standard WVA technique in the time domain, remarkably increasing the precision of weak measurement under strong noise background.Comment: 15 pages, 10 figure

Fibrosis progression in interferon treatment-naive Chinese plasma donors with chronic hepatitis C for 20 years: a cohort study

SummaryObjectivesTo evaluate the progression of fibrosis and factors influencing this in interferon (IFN) treatment-naive Chinese plasma donors infected with hepatitis C virus (HCV) for approximately 20 years.MethodsFrom July 2010 to June 2011, we investigated 122 IFN treatment-naive chronic hepatitis C (CHC) patients infected by plasma donation in 1992–1995. Liver fibrosis stage and inflammation grade were evaluated by Metavir and Scheuer scoring systems, respectively.ResultsOne hundred and twenty patients underwent liver biopsy. Liver biopsy was not performed in one patient with cirrhosis due to ascites, and another patient was excluded because of an invalid biopsy specimen. Cirrhosis was observed in three patients (fibrosis stage F4 in two patients revealed by biopsy, and one patient with ascites confirmed by physical and Doppler ultrasound examination). Fibrosis stages F1 and F2 were present in 55 and 50 patients, respectively. The severity of liver inflammation was independently related to moderate to severe fibrosis (F ≥2). Older age and male sex showed an increasing tendency for more severe fibrosis (F3/F4) in the present cohort.ConclusionsBased on histopathology results, the progression of fibrosis in patients with CHC infected by repeated plasma donation is slow after HCV infection of approximately 20 years. Liver inflammation is closely related to the development of moderate to severe liver fibrosis