Fabry–Prot resonance coupling associated exceptional points in a composite grating structure

The exceptional point（EP） is a significant and attractive phenomenon in an open quantum system. The scattering properties of light are similar to those in the open quantum system, which makes it possible to achieve EP in the optic system. Here we investigate the EP in a Fabry–P′erot（F–P） resonant coupling structure. The coupling between different types of F–P resonances leads to a near zero reflection, which results in a degeneration of eigenstates and thus the appearing of EP. Furthermore, the multi-wavelength EPs and unidirectional invisibility can be achieved which may be used in integrated photonics systems.

Orchestrating Network Functions in Software-Defined Networks

Software.defined networking(SDN) enables third.part companies to participate in the network function innovations. A number of instances for one network function will inevitably co.exist in the network. Although some orchestration architecture has been proposed to chain network functions, rare works are focused on how to optimize this process. In this paper, we propose an optimized model for network function orchestration, function combination model(FCM). Our main contributions are as following. First, network functions are featured with a new abstraction, and are open to external providers. And FCM identifies network functions using unique type, and organizes their instances distributed over the network with the appropriate way. Second, with the specialized demands, we can combine function instances under the global network views, and formulate it into the problem of Boolean linear program(BLP). A simulated annealing algorithm is designed to approach optimal solution for this BLP. Finally, the numerical experiment demonstrates that our model can create outstanding composite schemas efficiently.

Survey on the Application of Deep Reinforcement Learning in Image Processing

feature representations from a large amount of data,and use reinforcement learning to learn the best strategy to complete the task.Through the combination of deep learning and reinforcement learning,end-to-end input and output can be achieved,and substantial breakthroughs have been made in many planning and decision-making systems with infinite states,such as games,in particular,AlphaGo,robotics,natural language processing,dialogue systems,machine translation,and computer vision.In this paper we have summarized the main techniques of deep reinforcement learning and its applications in image processing.

Memory effect evaluation based on transmission matrix calculation

The memory effect is a type of auto correlation observed in linear systems, which is widely used to control scattered light through thin scattering layers.We show that there exists a strong correlation among the optimized phase distributions of adjacent focal points in focusing through scattering media.The numeric simulation and experiment indicate that within the memory effect, the phase difference between the two adjacent focal points shows an optical phase fringe pattern, and the closer the adjacent focal points are, the wider the fringe pattern will be, corresponding to the tilting of a plane wave phase added onto the acquired optical phase distribution at the focal point.This effect can be utilized for achieving optimal phase distributions of focal point scanning without optical phase evaluation via the experiment, which has great potential application in imaging through the scattering medium.

Epidemiological and clinical characteristics of 35 children with COVID-19 in Beijing,China

Importance:Within the coronavirus disease 2019(COVID-19)global pandemic,more attention is warranted for whether this new infectious disease has unique manifestations in children.Objective:To retrospectively determine the epidemiological and clinical characteristics of 35 children with COVID-19 in Beijing,China.Methods:We collected data for 35 children diagnosed with COVID-19 who were admitted to Beijing Ditan Hospital from January 2020 to June 2020,and analyzed their epidemiological characteristics,clinical manifestations,laboratory examinations,chest imaging findings,treatments,and outcomes.Results:The children comprised 18 boys(51.4%)and 17 girls(48.6%)aged 6 months to 15 years.All patients had clear epidemiological history,with family clusters accounting for 28 cases(80.0%)and clear tracing of exposure to high epidemic areas in the remaining 7 cases(20.0%).Four(11.4%)patients were classified as asymptomatic,17(48.6%)as acute upper respiratory infection,and 14(40.0%)as mild pneumonia,with no severe or critical cases.Clinical manifestations were mild,including fever in 18(51.4%),cough in 14(40.0%),and nausea and diarrhea in 7(20.0%)patients.White blood cell count was mostly normal(26 cases,74.3%)or decreased(7 cases,20.0%);lymphocyte percentage was increased in 24(68.7%);neutrophil percentage was decreased in 25(71.4%);alanine aminotransferase was increased in 3(8.6%);and serum potassium was decreased in 4(11.4%).Time to negative viral nucleic acid testing was 2-42 days(mean:14.0±9.4 days).Chest imaging examination revealed that 20 patients(57.1%)had different forms of lung inflammation.Treatment was mainly isolation and nutritional support.Eleven patients were treated with interferon atomization inhalation.No patients required oxygen therapy.All 35 children were cured and discharged.Length of hospital stay was 9-54 days(mean:25.4±13.8 days).During regular follow-up after discharge,5 children showed positivity again in the viral nucleic acid test and were re-hospitalized for observation and treatment.The mean length of re-hospitalization stay was 10.8 days.Interpretation:Children with COVID-19 mainly become infected within their family,and children of all ages are generally susceptible.The disease in children is mostly mild and the prognosis is good.Nucleic acid tests in some patients become positive again after discharge,suggesting that it is of great significance to carry out centralized isolation medical observations and active nucleic acid tests in close contacts for early detection of patients and routine epidemic prevention and control.

2018-2022年四川省甘孜藏区棘球蚴病监测结果分析

目的调查2018-2022年四川甘孜藏区棘球蚴病流行状况,为优化棘球蚴病的防控对策提供科学参考。方法采用影像学和血清学检测方法筛查甘孜藏区2018-2022年人群棘球蚴感染情况;通过解剖目检、PCR和测序法检测疑似染疫的牲畜(牛羊)和啮齿动物脏器;采用酶联免疫吸附试验检测犬科动物粪便中的棘球绦虫抗原,分析不同时间和区县棘球蚴病流行状况。结果甘孜藏区2018-2022年人群棘球蚴病总患病率为0.028%,且呈逐年下降趋势(χ^(2)_(趋势)=328.133,P<0.01);牲畜总感染率为3.44%,呈下降趋势(χ^(2)_(趋势)=325.295,P<0.01);啮齿类动物总感染率为2.96%,呈下降趋势(χ^(2)_(趋势)=257.235,P<0.01);犬科动物粪便中棘球绦虫抗原阳性率为1.40%,呈下降趋势(χ^(2)_(趋势)=899.060,P<0.01)。2022年与2018年相比,各区县(东路、南路和北路区县)中人群棘球蚴病患病率、牲畜棘球蚴感染率、啮齿动物棘球蚴感染率和犬科动物粪便中棘球绦虫抗原阳性检出率均显著降低,且均以北路区县降低最明显。截至2022年,不同区县人群棘球蚴病患病率和犬科动物粪便中棘球绦虫抗原阳性率均显著不同(χ^(2)=12.595,263.144,均P<0.01),以东路区县最高(分别为0.022%和1.71%);不同区县牲畜和啮齿动物棘球蚴感染率显著不同(χ^(2)=28.406,24.829,均P<0.01),以北路区县最高(分别为2.91%和2.75%)。结论2018-2022年甘孜藏区棘球蚴病流行总体呈下降趋势,但不同区县人群、牲畜、啮齿动物和犬科动物中棘球蚴病的流行程度不同,提示需关注不同区县棘球蚴病传播动力学因素,秉承“OneHealth”理念控制传染源和切断传播途径,防止棘球蚴病流行。

On the localised corrosion of carbon steel induced by the in-situ local damage of porous corrosion products

The effect of in-situ local damage of uniform porous corrosion products on the localised corrosion of carbon steel is investigated using the wire beam electrode technique(WBE)combined with morphology characterisation and electrochemical tests.The WBE measurements demonstrate that the localised corrosion is enhanced by the in-situ local removal of porous corrosion products,supported by the morphology characterisation and electrochemical tests.The enhanced localised corrosion does not originate from the damaged wire in WBE where the corrosion products are removed but from the other undamaged wires,which is reported for the first time.A mechanism is proposed that the intensive anodic polarisation effect of the damaged wire on the undamaged wires could account for the enhanced localised corrosion,which is due to the protective corrosion products newly formed on the damaged surface and the increase in the potential of damaged wire.

A reined global-local approach for evaluation of singular stress ield based on scaled boundary inite element method

A reined global-local approach based on the scaled boundary inite element method（SBFEM） is proposed to improve the accuracy of predicted singular stress ield. The proposed approach is carried out in conjunction with two steps. First, the entire structure is analyzed by employing an arbitrary numerical method. Then, the interested region, which contains stress singularity, is re-solved using the SBFEM by placing the scaling center right at the singular stress point with the boundary conditions evaluated from the irst step imposed along the whole boundary including the side-faces. Beneiting from the semi-analytical nature of the SBFEM, the singular stress ield can be predicted accurately without highly reined meshes. It provides the FEM or other numerical methods with a rather simple and convenient way to improve the accuracy of stress analysis. Numerical examples validate the effectiveness of the proposed approach in dealing with various kinds of problems.

Interpretation of the National Action Plan for Eliminating Hepatitis C as a Public Health Threat(2021–2030)

Summary Hepatitis C virus(HCV)infection is a major public health problem in China.In 2016,the World Health Organization(WHO)proposed a goal to eliminate viral hepatitis as a public health threat by 2030,and in 2018,the National Health Commission of China launched Hepatitis C Elimination Action by 2030.Hepatitis C control and prevention has made significant progress in China in recent years.To implement the“Healthy China 2030”plan and the Healthy China Initiative(2019–2030),and to contribute to the global target of eliminating viral hepatitis as a public health threat by 2030,the National Health Commission of China and eight other government departments jointly issued the National Action Plan for Eliminating Hepatitis C as a Public Health Threat(2021–2030)(hereinafter referred to as the“National Plan”)in 2021.The National Plan has an overarching goal and 15 specific targets that cover health education,comprehensive prevention interventions,testing and treatment,and capacity building.The National Plan introduces key tasks and strategies of“five strengthenings,one expanding,and one implementation,”i.e.,strengthening health education,comprehensive prevention,referral and treatment,drug supply,and information management;expanding testing;and implementing relevant medical insurance policies.The National Plan also proposes key guaranteeing measures of“four intensifications and one mobilization,”i.e.,intensification of organizational leadership,capacity building,scientific research and international cooperation,and supervision and fulfillment;mobilization of social participation.The National Plan is an important component of the Healthy China initiative,adhering to the integration of treatment and prevention and deepening the“integration of medical treatment,medical insurance,and medicine supplies.”In this review,we describe the National Plan and discuss its challenges and prospects.

Supervised Analysis of Hepatitis C Virus RNA-Positive Case Reporting in County-Level Hospitals--China,2013−2018

What is already known on this topic?To understand the status of the diagnosis and reporting of hepatitis C and standardize the reporting of hepatitis C cases in county-level hospitals,we conducted the first supervised analysis of hepatitis C cases in county-level hospitals in China from 2013 to 2018,covering all provincial-level administrative divisions(PLADs)except Tibet.What is added by this report?Through 6 years of supervision,we have obtained key data such as the nucleic acid detection rate and positive rate of hepatitis C virus(HCV)antibody positive cases in our county-level hospitals,the report rate and accuracy of HCV RNA positive cases,and standardized and improved the hepatitis C case reporting in countylevel hospitals to improve data quality and provide data support for the judgment and estimation of hepatitis C in China.What are the implications for public health practice?By strengthening the management and supervision of hepatitis C case reporting,the reporting rate and accuracy of HCV RNA positive cases in county-level hospitals in China had been greatly improved.By combining the number of HCV antibody tests and the number of viral nucleic acid tests in medical institutions around the country,it was possible to effectively assess the current status of hepatitis C in China and to provide a scientific basis for the development of hepatitis C prevention and treatment measures.

特殊桁架式钢框架连接节点的滞回性能分析

1994年美国北岭地震、1995年日本阪神地震的灾害调查发现传统抗弯钢框架结构的梁柱连接节点出现了大量的脆性破坏,导致具有良好延性行为的抗弯钢框架结构变形能力未能得到充分发挥,结构整体抗震性能较差。因此,梁柱连接节点性能的优劣成为决定抗弯钢框架结构抗震性能好坏的关键因素。为适应公共建筑跨度大的特点,国内外一些大型公共建筑(如医院、商场、体育场馆等)逐渐采用特殊桁架式钢框架结构(简称STMF)。STMF结构具有抗侧刚度大、水平承载力高、耗能性能优良等优点,具有广阔的应用前景。但钢桁架与钢柱之间的连接节点易于断裂,特别是腹杆、弦杆与钢柱的连接焊缝处极易脆断,导致STMF结构的延性及变形能力较差。目前,国内外学者对STMF连接节点的研究仍相对较少,不利于STMF结构的工程推广应用。为明晰STMF连接节点的滞回性能,以STMF结构的边柱节点作为研究对象,通过有限元方法分析了STMF连接节点的受力特征,明晰了相关设计参数对其滞回性能的影响,为其工程应用提供参考。首先,设计了STMF连接节点的BASE试件,利用CAD程序建立其三维几何模型,使用Hypermesh程序对其进行了网格划分,采用ABAQUS程序建立了微观有限元模型并进行了滞回性能分析。其次,在BASE试件的基础上,衍生设计了3个系列STMF连接节点,重点考察了弦杆截面、桁架高度、端斜腹杆截面等主要因素对其滞回性能、抗弯承载力、变形能力、屈服模式、应力分布的影响。分析发现:STMF连接节点中桁架下弦杆的Mises应力水平相对较高,端节间的下弦杆在弹塑性阶段易出现整体失稳,加载后期还会出现局部失稳;随着弦杆截面的增加,STMF连接节点的抗弯承载力、初始转动刚度、耗能能力均呈增大趋势,但对STMF连接节点滞回曲线的形状影响较小;随着桁架高度的增加,STMF连接节点的抗弯承载力、初始转动刚度均呈显著增加趋势,其耗能能力略呈增大趋势但破坏模式并未显著改变;在桁架端部斜腹杆未屈曲的前提下,改变端斜腹杆截面对STMF连接节点的滞回性能、抗弯承载力、节点转动刚度、耗能能力影响不明显,其受力模式和应力分布并未发生显著改变。