Enhanced super-Heisenberg scaling precision by nonlinear coupling and postselection

In quantum precision metrology, the famous result of Heisenberg limit scaling as $1/N$ (with $N$ the number of probes) can be surpassed by considering nonlinear coupling measurement. In this work, we consider the most practice-relevant quadratic nonlinear coupling and show that the metrological precision can be enhanced from the $1/N^{\frac{3}{2}}$ super-Heisenberg scaling to $1/N^2$, by simply employing a pre- and post-selection (PPS) technique, but not using any expensive quantum resources such as quantum entangled state of probes.Comment: 6 pages, 4 figure

Measurement and Simulation Study on Effective Drainage Radius of Borehole Along Coal Seam

A measurement study was conducted for the effective drainage radius of borehole along coal seam #9 of the Kaiyuan Coal Mine using the gas pressure method and gas flow method. The measurement results show that the effective drainage radius of borehole along coal seam #9 was 0.75 m, 27 days after drainage, and 1.5 m, 92 days after drainage. Experimental schemes were designed for the entire evolution of the stress in the coal mass around the borehole, and an experimental study on methane seepage in the coal mass around borehole was conducted. Fitting functions for the permeability of the coal sample and its vertical stress were obtained by fitting the experimental data. Based on the vertical stress–permeability functional relationship of coal masses around borehole, a numerical calculation model for methane seepage from coal masses around borehole was established, and the influences of drainage time, initial gas pressure, borehole diameter, and drainage negative pressure on the effective drainage radius of borehole were investigated. The numerical simulation results show that with the increase in initial gas pressure and borehole diameter, the effective drainage radius of borehole increases continuously but its increase amplitude decreases constantly. With the increase in drainage negative pressure, the effective drainage radius of borehole increases linearly but the increase amplitude is relatively small. The layout parameters of borehole along coal seam #9 of the Kaiyuan Coal Mine were optimized based on the numerical calculation results, and the reasonable drainage time, reasonable borehole diameter, and reasonable drainage negative pressure are 180 days, 120 mm, and 15 kPa, respectively, for the borehole along coal seam #9

Quantum-coherence-free precision metrology by means of difference-signal amplification

The novel weak-value-amplification (WVA) scheme of precision metrology is deeply rooted in the quantum nature of destructive interference between the pre- and post-selection states. And, an alternative version, termed as joint WVA (JWVA), which employs the difference-signal from the post-selection accepted and rejected results, has been found possible to achieve even better sensitivity (two orders of magnitude higher) under some technical limitations (e.g. misalignment errors). In this work, after erasing the quantum coherence, we analyze the difference-signal amplification (DSA) technique, which serves as a classical counterpart of the JWVA, and show that similar amplification effect can be achieved. We obtain a simple expression for the amplified signal, carry out characterization of precision, and point out the optimal working regime. We also discuss how to implement the post-selection of a classical mixed state. The proposed classical DSA technique holds similar technical advantages of the JWVA and may find interesting applications in practice.Comment: 7pages, 5 figures. arXiv admin note: text overlap with arXiv:2207.0366

Topological structures of energy flow: Poynting vector skyrmions

Topological properties of energy flow of light are fundamentally interesting and have rich practical applications in optical manipulations. Here, skyrmion-like structures formed by Poynting vectors are unveiled in the focal region of a pair of counter-propagating cylindrical vector vortex beams in free space. A N\'eel-Bloch-N\'eel skyrmion type transformation of Poynting vectors is observed along the light propagating direction within a volume with subwavelength feature sizes. The corresponding skyrmion type can be determined by the phase singularities of the individual components of the coherently superposed electromagnetic field in the focal region. This work reveals a new family member of optical skyrmions and may introduce novel physical phenomena associated with light scattering and optical force

Intelligent prediction method for roof gas drainage roadway layout

The roof gas drainage roadway, with its advantages of large flow and continuous extraction, is widely used in the gas control of high gas or outburst mine working faces. How to determine the reasonable arrangement position of the roof roadway to efficiently extract the pressure-relief gas in the goaf is key to ensuring the effect of gas control on the working face. Therefore, through a deep analysis of the arrangement principles of the roof gas drainage roadway and the main controlling factors of its arrangement position, an intelligent prediction method for the arrangement position of the roof gas drainage roadway based on the GA–BP neural network model is proposed. The prediction indicators of the GA–BP neural network model were determined using the grey correlation analysis method, and an intelligent prediction system for the arrangement position of the roof gas drainage roadway was designed and developed. The research results show: ① The mining thickness, burial depth, overlying rock structure, coal seam dip angle, and dip length of the working face are the main controlling factors for the arrangement position of the roof gas drainage roadway, and their weight values are ranked as: mining thickness > burial depth > overlying rock structure > coal seam dip angle > dip length; ② With the increase of genetic generations, the fitness of the GA–BP neural network continuously decreases, and when the genetic generation is 60, its fitness change is basically stable, indicating that the initial weight and bias of the GA–BP neural network are good; ③ Under the premise of the current training sample data set, the relative error of the prediction result of the arrangement position of the roof gas drainage roadway based on the GA–BP neural network model and the actual working condition value is only 0.43%～11.27%, which is within an acceptable range. This research can provide a certain reference for the precise design of the arrangement of the roof gas drainage roadway

Influence of coal seam bedding on the effect of fracturing coal and enhancing permeability by microwave

As a typical structural weak surface, bedding is ubiquitous in coal seams. The relative mechanical properties between coal seam bedding and coal matrix are the key to determining the effect of enhancing permeability by microwave in coal seams with bedding development. To this end, a self-developed microwave irradiation (MI) test device was used to carry out microwave fracturing coal experiments on coal samples with an angle of 0°, 30°, 45°, 60° and 90° between the bedding plane and the loading direction. The evolution characteristics of microscopic pore structure and microscopic cracks of coal samples with different bedding directions were explored, and the influence of bedding structure on the number, scale, and connectivity of coal pores and fractures under MI was revealed. The gas permeability characteristics of coal in different bedding directions before and after MI were compared and analyzed. The variation law of coal permeability under the influence of coal seam bedding and fracturing coal by microwave was clarified, and the influence mechanism of coal seam bedding on fracturing coal and enhancing permeability by microwave was revealed. The results show that the coal seam bedding has a significant effect on the effect of fracturing coal and enhancing permeability by microwave. The larger the angle between the bedding plane and the loading direction, the greater the reduction of the bound pores and the growth of the connected fractures of the coal under MI. Compared with the original coal samples, the order of magnitude difference between the permeability of coal samples in different bedding directions after MI is effectively reduced, and the permeability anisotropy is obviously weakened. The development of meso-cracks in coal under MI has a significant bedding effect. The specific evolution process is first to expand the original cracks along the bedding plane, followed by the initiation of new cracks along the bedding plane, and finally to expand the cracks intersecting with the bedding plane. The difference of dielectric loss and heat transfer properties between coal matrix and bedding plane makes the thermal stress distribution of coal subject to the bedding plane. When the bedding plane is perpendicular or parallel to the loading direction, the coal body is dominated by tensile failure. When the bedding plane is oblique to the loading direction, the coal body is dominated by shear slip failure

Identification of LncRNA Linc00513 Containing Lupus-Associated Genetic Variants as a Novel Regulator of Interferon Signaling Pathway

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by augmented type I interferon signaling. High-throughput technologies have identified plenty of SLE susceptibility single-nucleotide polymorphisms (SNPs) yet the exact roles of most of them are still unknown. Functional studies are principally focused on SNPs in the coding regions, with limited attention paid to the SNPs in non-coding regions. Long non-coding RNAs (lncRNAs) are important players in shaping the immune response and show relationship to autoimmune diseases. In order to reveal the role of SNPs located near SLE related lncRNAs, we performed a transcriptome profiling of SLE patients and identified linc00513 as a significantly over expressed lncRNA containing functional SLE susceptibility loci in the promoter region. The risk-associated G allele of rs205764 and A allele of rs547311 enhanced linc00513 promoter activity and related to increased expression of linc00513 in SLE. We also identified linc00513 to be a novel positive regulator of type I interferon pathway by promoting the phosphorylation of STAT1 and STAT2. Elevated linc00513 expression positively correlated with IFN score in SLE patients. Linc00513 expression was higher in active disease patients than those inactive ones. In conclusion, our data identify two functional promoter variants of linc00513 that contribute to increased level of linc00513 and confer susceptibility on SLE. The study provides new insights into the genetics of SLE and extends the role of lncRNAs in the pathogenesis of SLE

Maintenance Chemotherapy With Chinese Herb Medicine Formulas vs. With Placebo in Patients With Advanced Non-small Cell Lung Cancer After First-Line Chemotherapy: A Multicenter, Randomized, Double-Blind Trial

Background: Chinese Herb Medicine Formulas (CHMF) was reported to improve the quality of life (QoL) in advanced NSCLC patients. The present study was designed to investigate whether maintenance chemotherapy plus CHMF in patients would improve QoL and progression-free survival (PFS).Methods: Seventy-one patients were enrolled from 8 medical centers in China, and were randomly assigned to a maintenance chemotherapy plus CHMF group (n = 35) or a maintenance chemotherapy plus placebo group (n = 36). The outcome measures included PFS, Karnofsky performance status (KPS) scores, QoL (assessed with the lung cancer symptom scale (LCSS) questionnaire), and adverse events (AEs).Results: Patients in the CHMF group showed significant improvements in median PFS (HR = 0.55, 95% CI 0.28–0.88, P = 0.019), KPS scores (P = 0.047), fatigue (cycle [C] 3: P = 0.03), interference with daily activities (C3: P = 0.04) and dyspnea (C2: P = 0.03) compared with patients in the placebo group. Compared with the placebo group, the incidence of AEs decreased in the CHMF group, including loss of appetite (C2: P = 0.011, C4: P = 0.004) and dry mouth (C4: P = 0.011).Conclusion: The essential finding of our study is that maintenance chemotherapy combined with CHMF may prolong PFS, relieve symptoms, improve QoL and alleviate the side effects

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe