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As a common optical element material, aluminum alloy has been widely used because of its high reflectivity, easy lightweight design and other advantages. However, due to the soft texture and large plasticity of aluminum alloy, the surface is prone to mechanical damage during processing. In order to improve the surface quality and processing efficiency, this paper designs a new type of solid flexible bonnet tool to polish aluminum alloy optical elements. Then the finite element analysis method is used to compare the performance of several bonnet tools. Finally, the aluminum alloy polishing experiment is carried out, and the material removal mechanism and the factors affecting the polishing surface quality are analysed. The results show that the new solid flexible bonnet tool has good deformation stability, good fit with the workpiece, and can achieve high efficiency and precision polishing of aluminum alloy optical elements. According to the pressure distribution in the contact area, the abrasive particles in the sliding state are divided into three removal modes: micro-cutting, micro-plowing and micro-rubbing. At the same time, the hard particles in aluminum alloy have an important influence on the surface morphology after polishing. Due to the strong plasticity and viscosity of aluminum alloy, the abrasive dust is easy to adhere to the surface of the workpiece, reducing the surface roughness.

•Describes resistance of M. lepraeto rifampicin (pooled incidence = 11% [95% CI, 7% to 15%]).•Patients who had leprosy relapse were twofold more resistant than new patients.•Nonresponsive and intractable cases of leprosy were more than four times as resistant as new cases.•The pooled incidence varies globally, with the Western Pacific having a greater degree of resistance.•Mutations in codon 456 are common in the Americas, whereas mutations in codon 531 are detected in the Western Pacific.

•Dapsone resistance is closely related to leprosy relapse and long-term drug use.•Dapsone monotherapy is one of important reason for drug resistance in relapsed cases.•Differences in drug resistance in different populations and different regions of the world.

Reduced tillage practices present a tool that could sustainably intensify agriculture. The existing literature, however, lacks a consensus on how and when reduced tillage practices should get implemented. We reanalyzed here an extensive dataset comparing how regular tillage practices (i.e., conventional tillage) impacted yield of eight crops compared to stopping tillage altogether (i.e., no-tillage practice). We observed that aridity and fertilization favored no tillage over conventional tillage whereas conventional tillage performed better under high fertility settings. We further show that the responses are consistent across the crops. Our reanalysis complements the original and fills a gap in the literature questioning the conditions under which reducing tillage presents a viable alternative to common tillage practices.

The experimental study on flow characteristics of the turbulent falling film flowing along a vertical Perspex plate was carried out using ultrasonic Doppler velocimetry (UDV, a non-intrusive technique) at 1.85 × 104≤ Reynolds number of the liquid film (Rel) ≤ 3.69 × 104. The instantaneous velocity of the turbulent falling film at different Relwas measured to investigate the velocity distribution, fluctuation range, turbulence intensity, and the flow behavior in falling films. The results showed that the increase of Relreduced the length of the development region and accelerated turbulent falling films to a steady flow state. There were mainly two reasons for the change of the velocity gradient in films: the amplitude of interfacial waves and the collision of the liquid that has different velocity directions. When the falling films were away from the inlet, the mass transfer within falling films may be dominated by the lateral movement rather than Rel.

Annual variations of interstellar scintillation can be modelled to constrain parameters of the ionized interstellar medium. If a pulsar is in a binary system, then investigating the orbital parameters is possible through analysis of the orbital variation of scintillation. In observations carried out from 2011 to 2020 by the European Pulsar Timing Array radio telescopes, PSRs J0613–0200 and J0636+5128 show strong annual variations in their scintillation velocity, while the former additionally exhibits an orbital fluctuation. Bayesian theory and Markov-chain-Monte-Carlo methods are used to interpret these periodic variations. We assume a thin and anisotropic scattering screen model, and discuss the mildly and extremely anisotropic scattering cases. PSR J0613–0200 is best described by mildly anisotropic scattering, while PSR J0636+5128 exhibits extremely anisotropic scattering. We measure the distance, velocity, and degree of anisotropy of the scattering screen for our two pulsars, finding that scattering screen distances from Earth for PSRs J0613–0200 and J0636+5128 are 316−20+28pc and 262−38+96pc, respectively. The positions of these scattering screens are coincident with the shell of the Local Bubble towards both pulsars. These associations add to the growing evidence of the Local Bubble shell as a dominant region of scattering along many sightlines.

Abstract

Abstract

Colorectal cancer (CRC) is one of the most common malignant tumors in the digestive tract in humans. The development of colorectal cancer is composed of multiple stages, starting with benign adenomatous polyps in the inner wall of the large intestine and rectum, and then gradually developing. Then it developed into advanced adenomas carcinoma in situ and invasive carcinoma. Represents the distant metastasis of the most advanced development. The purpose of this review is to novel routine screening and diagnostic methods (e.g., Endoscopy and CT colonoscopy, SEPT9 methylation assay, Fecal test) and find reliable molecular markers for early diagnosis of CRC.