Cleaning of two mirrors in the first mirror unit using radiofrequency capacitively coupled plasma

First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the influence of simultaneous cleaning of two mirrors on mirror cleaning efficiency and uniformity,experiments involving single-mirror cleaning and dual-mirror cleaning were conducted using RF capacitively coupled plasma in the laboratory.For the test and simultaneous cleaning of two mirrors,the FM and second mirror(SM),both measuring 110 mm×80 mm,were placed inside the first mirror unit(FMU).They were composed of 16 mirror samples,each with a dimension of 27.5 mm×20 mm.These mirror samples consist of a titanium-zirconium-molybdenum alloy substrate,a 500 nm Mo intermediate layer and a 30 nm Al_(2)O_(3) surface coating as a proxy for Be impurities.The cleaning of a single first mirror(SFM)and the simultaneous cleaning of the FM and SM(DFM and DSM)lasted for 9 h using Ar plasma at a pressure of 1 Pa.The total reflectivity of mirror samples on the DSM did not fully recover and varied with location,with a self-bias of−140 V.With a self-bias of−300 V,the total reflectivity of mirror samples on the SFM and DFM was fully recovered.The energy dispersive spectrometer results demonstrated that the Al_(2)O_(3) coating had been completely removed from these mirror samples.However,the mass loss of each mirror sample on the SFM and DFM before and after cleaning varied depending on its location,with higher mass loss observed for mirror samples located in the corners and lower loss for those in the center.Compared with SM cleaning,the simultaneous cleaning of two mirrors reduced the difference between the highest and lowest mass loss.Furthermore,this mass loss for the mirror samples of the DFM facing the DSM was increased.This indicated that mirror samples cleaned face to face in the FMU simultaneously could influence each other,highlighting the need for special attention in future studies.

RETRACTED:A Numerical Study on the Charging Voltage of the Lunar Surface

Short Retraction Notice? This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's?Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused. Please see the?article page?for more details. The full retraction notice in PDF is preceding the original paper which is marked "RETRACTED".

基于Rotterdam CT评分评估的颅脑损伤术中控制性减压的临床应用价值

目的观察控制性减压技术治疗以鹿特丹(Rotterdam)CT评分为评估基础的不同程度颅脑损伤(TBI)的临床效果。方法选取湖南省脑科医院神经外科自2019年9月至2022年9月收治的TBI后严重颅高压需行去骨瓣减压手术的患者100例,采用随机数字表法将患者分为试验组(控制性减压)和对照组(快速减压),每组50例。所有患者术前行Rotterdam CT评分辅助评估,术后3个月随访,比较2组患者术中各Rotterdam CT分值区间一过性脑膨出发生率及预后情况。结果试验组Rotterdam CT 4~6分的脑膨出发生率低于对照组,差异有统计学意义(P<0.05)。随访3个月,40例患者预后良好,其中试验组27例,对照组13例,试验组预后良好率高于对照组,差异有统计学意义(P<0.05)。试验组各Rotterdam CT分值段(5~6分)GOS评分均高于对照组,差异有统计学意义(P<0.05)。结论严重颅脑损伤患者术中脑膨出的发生与术前高颅压状态有关,对颅内压失代偿需去骨瓣患者采用分阶段、分步骤的控制减压操作,可明显降低围术期并发症的发生率,改善预后。

Geometrical transition properties of vortex cavitation and associated flow-choking characteristics in poppet valves

Poppet valves have become increasingly significant in ensuring precise digital flow rate and pressure control in hydraulic systems,necessitating a more profound understanding of the geometrical properties of cavitation in them,as well as associated flow-choking conditions.Through a comparative analysis with experimentally observed cavity images,we found that large eddy simulation(LES)turbulence modeling effectively replicates the geometrical properties of cavitation in these valves.The analysis demonstrated that cavitation is generated from vortices that result from the interaction between the notch contracta flow and the surrounding fluid structure.Variations in the internal or external vena contracta conditions result in fixed or discrete cavities,and the length-to-diameter ratio serves as a measure of the transition between internal and external vena contracta flow properties.This study establishes a threshold length-to-diameter ratio of approximately 2 for the tested poppet valves.More specifically,in notch structures with a smaller valve opening,longer sealing length,and smaller throttling angle(corresponding to a larger length-to-diameter ratio),the liquid-to-vapor transfer process is more evident than that in the reverse direction.A long-standing vapor cavity becomes fixed inside the notch,leading to a more pronounced flow-choking phenomenon.In contrast,for structures with a smaller length-to-diameter ratio,the cavitation process for discrete vapor cavities is more complete,ensuring fluid flow continuity and significantly reducing the occurrence of the flow-choking phenomenon.

How the U.S.presidential election impacts global health:governance,funding,and beyond

The United States plays a crucial role in shaping global health through its policy decisions and engagements.Histori-cally,bipartisan support underpinned U.S.involvement in multilateral and bilateral global health initiatives in advanc-ing its national health,security interests,and foreign policy.However,recent decades have witnessed increased politicization and polarization of global health and fluctuating stances between Republican and Democratic admin-istrations.This commentary speculates the potential implications of the 2024 presidential election on global health,focusing on how ideological differences between parties and previous administrative actions might affect U.S.’s strategies in addressing key global health issues,including governance,funding allocation,sexual and reproductive health policies,responses to humanitarian crises,and efforts to combat climate change.The election may be a critical juncture that could determine whether the U.S.global health strategies will continue to reflect the globalist and lib-eral policies typically associated with recent Democratic administrations or shift back to the isolationist tendencies observed during Trump’s presidency.The outcome will significantly determine the direction of U.S.global health policy and its broader implications for global health equity and security.The conclusions emphasize the necessity of maintaining strong international cooperation and commitment to health as a global public good.

Intelligent construction technology of railway engineering in China

Intelligent construction technology has been widely used in the field of railway engineering.This work first analyzes the connotation,function,and characteristics of intelligent construction of railway engineering(ICRE)and establishes its system structure from three dimensions,namely,life cycle,layers of management,and intelligent function,to deeply understand the development situation of intelligent railway construction in China.Second,seven key technical support systems of ICRE,which include building information modeling(BIM)standard system for China’s railway sector,technology management platform and life cycle management based on BIM-hGIS(geography information system),ubiquitous intelligent perception system,intelligent Intemet-of-Things(IoT)communication system based on mobile interconnection,construction management platform based on cloud computing and big data,unmanned operation system based on artificial intelligence,intelligent machinery and robot,and intelligent operation and maintenance system based on BIM and PHM(prediction and health management),are established.Third,ICRE is divided into three development stages:primary(perception),intermediate(substitution),and advanced(intelligence).The evaluation index system of each stage is provided from the aspects of technology and function.Finally,this work summarizes and analyzes the application situation of ICRE in the entire railway sector of China,represented by Beijing-Zhangjiakou and Beijing-Xiong’an high-speed railways.Result shows that the technical support systems of the ICRE have emerged in China and are still in the process of deepening basic technology research and preliminary application.In the future,the ICRE of China’s railway sector will develop toward a higher stage.

Vitamin D receptor (VDR) mediates the quiescence of activated hepatic stellate cells (aHSCs) by regulating M2 macrophage exosomal smooth muscle cell-associated protein 5 (SMAP-5)

An effective therapeutic regimen for hepatic fibrosis requires a deep understanding of the pathogenesis mechanism.Hepatic fibrosis is characterized by activated hepatic stellate cells(aHSCs)with an excessive production of extracellular matrix.Although promoted activation of HSCs by M2 macrophages has been demonstrated,the molecular mechanism involved remains ambiguous.Herein,we propose that the vitamin D receptor(VDR)involved in macrophage polarization may regulate the communication between macrophages and HSCs by changing the functions of exosomes.We confirm that activating the VDR can inhibit the effect of M2 macrophages on HSC activation.The exosomes derived from M2 macrophages can promote HSC activation,while stimulating VDR alters the protein profiles and reverses their roles in M2 macrophage exosomes.Smooth muscle cell-associated protein 5(SMAP-5)was found to be the key effector protein in promoting HSC activation by regulating autophagy flux.Building on these results,we show that a combined treatment of a VDR agonist and a macrophage-targeted exosomal secretion inhibitor achieves an excellent anti-hepatic fibrosis effect.In this study,we aim to elucidate the association between VDR and macrophages in HSC activation.The results contribute to our understanding of the pathogenesis mechanism of hepatic fibrosis,and provide potential therapeutic targets for its treatment.

The Multiple Modification Road of Li-Rich Manganese-Based Cathode Materials

Li-rich manganese-based cathode materials(LR) are considered as excellent cathode materials for a new generation of lithium-ion batteries causes their outstanding electrochemical performance, friendly price, and environmental friendliness. But defects such as rapid voltage decay and loss of lattice oxygen limit their applications. The electrochemical performance of LR has to be improved by means of modification. The previous single modification methods like element doping, surface coating, structure design, etc. can only optimize the electrochemical performance of LR from one aspect. Recently, multiple modifications,which can combine the advantages of multiple modifications, have been favored by researchers. Here, we comprehensively review the recent progress of multiple modification of LR based on the combination of different modification means. The review and summary of the multiple modification of LR will play a guiding role in its development in the future.