Prediction for the surface settlement of double-track subway tunnels for shallow buried loess based on peck formula

In the process of constructing double-track subway tunnels in shallow buried loess areas, the interaction of double-track tunnels is significantly influenced by the net distance and the cross-section size, which is challenging to control the surface settlement. Therefore, the surface settlement prediction is essential while constructing double-track subway tunnels in shallow buried loess areas. The paper analyzed the surface settlement law of shallow buried double-track tunnels in loess areas through theoretical research and numerical simulation. The research results show that with the decrease of the net distance, the surface settlement superimposed curve was double V shape -W shape - single V shape. When the superimposed curve is double V shape and W shape, the Peck formula was used to calculate the surface settlement curve of the single-track tunnel, then superimposed to obtain the final surface settlement curve. When the superimposed surface settlement curve was V shape, based on the Peck formula, the formula for predicting the surface settlement suitable for symmetry and asymmetry was established. The net distance ratio and the area ratio were defined, and considering the tunnel’s interaction, the value and position of the maximum were corrected. Then numerical tests were carried out 16 times with different net distance ratios and area ratios, to determine the parameters of increments and position offsets of the maximum regarding the net distance ratio and the area ratio. Finally, two engineering were conducted for verifying the rationality and applicability exhibited by the prediction formula. The prediction formula served for predicting the surface settlement of double-track subway tunnels in shallow buried loess areas. Which can reduce construction risks and assure the safety of buildings above the ground

Stairs-climbing Capacity of a W-Shaped Track Robot

Stairs-climbing capacity is an important index for obstacle-overcoming performance for coal mine rescue robot. For studying on stairs-climbing capacity of the coal mine rescue robot with W-shaped track suspensions, theoretical analysis, kinematics simulations and tests on real stairs have been carried out. According to sizes of normal stairs in reality, there are two climbing situations: (1) the first track section and the third track section climb the nosings of the two adjacent steps or two septal steps successively, (2) the front and rear tracks climb two nosings simultaneously. There are two critical states: (1) the first and third track section just touch the nosing of two interval steps, (2) the first and third track section barely touches the nosings of the adjacent steps. According to the two states, equation sets which describe the relationship between tread depth and riser height are deduced. According to the physical dimensions of the robot, the relation curves are drawn corresponding to the equation sets. Conditions of the two climbing situations are obtained. The stairs-climbing are simulated on RecurDyn, and tests on a simulated staircase test platform in laboratory and on real stairs in and outside the building are carried out. The simulation and tests results are in accordance with the theoretical analysis. Research in this paper is conducive to optimizing the shape and size of the W-shaped track suspension according to the parameters of the stairs, and also contributes to guiding the application of the robot with a W-shaped track moving mechanisms

Comparative Studies on Functional Foods and Health Foods in China

With the rapid development of the economy and society and the increasing improvement of people’s living standards, people have gained a scientific understanding of the sub-health state of the body. Many foods with functional claims such as supplementing dietary nutrients, maintaining or improving the body’s health status and reducing the risk of disease have emerged on the market. At the same time, as the country has introduced new policies, laws and regulations such as the “Healthy China 2030” plan to support the development of the health industry, the objective need for food functional claims has become increasingly apparent. But our current laws and regulations do not clearly definite the concept of functional foods and its requirements, so the directions of research, production and sale, market recognition and market regulation of functional foods are unclear. In particular, functional foods cannot be discriminated from health foods, which have a legal definition. In the long term, this will not only fail to promote scientific and technological innovations in ordinary foods, but also hinder the healthy development of the health food industry. In this paper, information concerning the definition and requirements of functional foods is collected and sorted out from government official documents, websites, academic journals, and other authoritative media, and the current focuses of research on functional foods in China and abroad are compared by visual analysis of high-frequency keywords. Moreover, this paper differentiates between the requirements for functional foods and those for health foods, and it suggests that top-level design be made for refined classification of functional foods on the market and puts forward suggestions on how to better connect each category with the current system

Analysis and Radiometric Calibration for Backscatter Intensity of Hyperspectral LiDAR Caused by Incident Angle Effect

Hyperspectral LiDAR (HSL) is a new remote sensing detection method with high spatial and spectral information detection ability. In the process of laser scanning, the laser echo intensity is affected by many factors. Therefore, it is necessary to calibrate the backscatter intensity data of HSL. Laser incidence angle is one of the important factors that affect the backscatter intensity of the target. This paper studied the radiometric calibration method of incidence angle effect for HSL. The reflectance of natural surfaces can be simulated as a combination of specular reflection and diffuse reflection. The linear combination of the Lambertian model and Beckmann model provides a comprehensive theory that can be applied to various surface conditions, from glossy to rough surfaces. Therefore, an adaptive threshold radiometric calibration method (Lambertian-Beckmann model) is proposed to solve the problem caused by the incident angle effect. The relationship between backscatter intensity and incident angle of HSL is studied by combining theory with experiments, and the model successfully quantifies the difference between diffuse and specular reflectance coefficients. Compared with the Lambertian model, the proposed model has higher calibration accuracy, and the average improvement rate to the samples in this study was 22.67%. Compared with the results before calibration with the incidence angle of less than 70 degrees, the average improvement rate of the Lambertian-Beckmann model was 62.26%. Moreover, we also found that the green leaves have an obvious specular reflection effect near 650-720 nm, which might be related to the inner microstructure of chlorophyll. The Lambertian-Beckmann model was more helpful to the calibration of leaves in the visible wavelength range. This is a meaningful and a breakthrough exploration for HSL.Peer reviewe

Incidence, persistence, and clearance of anogenital human papillomavirus among men who have sex with men in Taiwan: a community cohort study

BackgroundMen who have sex with men (MSM) have an increased risk of human papillomavirus (HPV) infection. This study aimed to assess the incidence, persistence, and clearance of anogenital HPV infections among MSM and the correlates in a 3-year community cohort study.MethodsFrom 2015 to 2019, MSM were recruited and followed up at 6, 12, 24, and 36 months in Taiwan. Questionnaires and anogenital swabs were collected at baseline and each follow-up visit. Thirty-seven HPV genotypes were tested and genotyped using the linear array HPV genotyping test. The incidence, persistence, and clearance rates of anogenital HPV infection and 95% confidence intervals (CIs) were estimated through Poisson regression. Correlates of the incidence and clearance rates were examined using a generalized estimating equations (GEE) model.ResultsA total of 201 MSM were retained in the cohort study with a median age of 27 years (interquartile range [IQR]: 24–32) at baseline. The incidence, persistence, and clearance rates of any anal HPV infection among MSM were 43.6 (95% CI: 33.7–55.6), 23.4 (17.7–30.2), and 58.3 (45.1–74.1) per 1,000 person months (pms), respectively. The incidence, persistence, and clearance rates of any penile HPV infection among MSM were 26.8 (20.1–34.9), 13.4 (8.0–20.9), and 51.5 (37.8–68.5) pms, respectively. MSM who did not consistently use a condom in receptive sex (adjusted odds ratio [AOR]: 2.06, 95% CIs: 1.14–3.72) were more likely to acquire any anal HPV infection. Age at recruitment (1.05, 1.01–1.09) was positively associated with any penile HPV incidence. MSM with over one sex partner in receptive anal sex (0.53, 0.30–0.94) were less likely to clear any anal HPV infection. MSM who were unemployed/students (0.55, 0.30–0.98) were less likely to clear any penile HPV infection.ConclusionHigh incidence and low clearance of anogenital HPV infection among MSM in the study serve as a reminder that this population needs to be targeted for HPV vaccination. It is essential for MSM to scale up HPV screening and adhere to safe sex

(Re)constructing school readiness from Chinese young children's perspectives

This interim report presents the ongoing progress of a collaborative project between the Centre for Teacher and Early Years Education (CTEY), UCL Institute of Education and the Faculty of Education, Beijing Normal University (BNU), which aims to (re)construct school readiness from Chinese children's perspectives. In this report, we first set out the context and rationale for carrying out this project (see Section 1). Then, we introduce the overarching research questions of this project, followed by a detailed account of the research design and the instruments for conducting research with young children (see Section 2). Subsequently, we report the pilot study we have conducted and present the preliminary findings (see Section 3). Finally, we outline the first round of fieldwork that has been carried out in seven early years settings of different backgrounds in Beijing (see Section 4), together with a timetable illustrating the next steps and upcoming milestones of this research project (see Section 5)

A Multidimensional Analytical Comparison of Remicade and the Biosimilar Remsima

In April 2016, the Food and Drug Administration approved the first biosimilar monoclonal antibody (mAb) – Inflectra/Remsima (Celltrion) based off the original product Remicade (infliximab, Janssen). Biosimilars promise significant cost savings for patients, but the unavoidable differences between innovator and copycat biologics raise questions regarding product interchangeability. In this study, Remicade and Remsima were examined by native mass spectrometry, ion mobility and quantitative peptide mapping. The levels of oxidation, deamidation and mutation of individual amino acids were remarkably similar. We found different levels of C-terminal truncation, soluble protein aggregates and glycation that all likely have a limited clinical impact. Importantly, we identified over 25 glycoforms for each product and observed glycoform population differences, with afucosylated glycans accounting for 19.7% of Remicade and 13,2% of Remsima glycoforms, which translated into a 2-fold reduction in FcγRIIIa binding for Remsima. While this difference was acknowledged in Remsima regulatory filings, our glycoform analysis and receptor binding results appear to be somewhat different from the published values, likely due to methodological differences between laboratories and improved glycoform identification by our laboratory using a peptide map-based method. Our mass spectrometry based analysis provides rapid and robust analytical information vital for biosimilar development. We have demonstrated the utility of our multiple attribute monitoring workflow using the model mAbs Remicade and Remsima, and have provided a template for analysis of future mAb biosimilars