7055铝合金中低比例动态再结晶的模拟

研究7055铝合金在温度为390~470°C和应变速率为0.01~1 s^(−1)条件下热变形和动态再结晶行为。电子背散射衍射(EBSD)表征结果表明,7055铝合金在热变形下动态再结晶含量较低,动态再结晶含量为1%~13%。为了模拟低比例动态再结晶问题,对JMAK动态再结晶模型进行修正。应用修正的模型,结合商业有限元软件DEFORM-3D,对7055铝合金的热压缩过程进行数值模拟,模拟得到的动态再结晶比例和晶粒尺寸的平均绝对相对误差(AARE)分别为13.7%和6.3%,与实验结果吻合良好。为了进一步证实该模型的有效性,采用该方法对7055铝合金工业化热轧过程进行模拟,模拟结果表明热轧板的动态再结晶分布不均匀,与实验观察结果一致。

雷珠单抗联合玻璃体切割术治疗DR合并新生血管性青光眼

目的:探究雷珠单抗联合玻璃体切割术治疗DR合并新生血管性青光眼(NVG)的临床效果。方法:选取2016-01/2018-02我院眼科收治的DR合并NVG患者198例,根据治疗方案不同分为观察组(103例)和对照组(95例),观察组采用术前注射雷珠单抗联合玻璃体切割术治疗,对照组单纯采用玻璃体切割术治疗,玻璃体切割术后10~15dⅡ期实施Ahmed房水引流阀植入。观察两组治疗后眼压、BCVA、VEGF等指标变化情况。结果:观察组的玻璃体切割术的手术时间、新生血管出血次数、电凝次数均低于对照组(P<0.001)。观察组在玻璃体切割术后1wk和Ⅱ期Ahmed房水引流阀植入术后1moBCVA、眼压均低于对照组(P<0.001)。观察组Ⅱ期Ahmed房水引流阀植入术前VEGF和术后1mo视网膜黄斑中心凹厚度均低于对照组(P<0.001)。观察组总并发发生率低于对照组(10.7%vs28.4%,P<0.05)。结论:雷珠单抗联合玻璃体切割术治疗DR合并NVG的疗效显著,且使Ⅱ期Ahmed房水引流阀植入手术难度下降,对患者视力、眼压水平恢复较好。

Solar cycle prediction using a long short-term memory deep learning model

In this paper,we propose a long short-term memory(LSTM)deep learning model to deal with the smoothed monthly sunspot number(SSN),aiming to address the problem whereby the prediction results of the existing sunspot prediction methods are not uniform and have large deviations.Our method optimizes the number of hidden nodes and batch sizes of the LSTM network structures to 19 and 20,respectively.The best length of time series and the value of the timesteps were then determined for the network training,and one-step and multi-step predictions for Cycle 22 to Cycle 24 were made using the well-established network.The results showed that the maximum root-mean-square error(RMSE)of the one-step prediction model was6.12 and the minimum was only 2.45.The maximum amplitude prediction error of the multi-step prediction was 17.2%and the minimum was only 3.0%.Finally,the next solar cycles(Cycle 25)peak amplitude was predicted to occur around 2023,with a peak value of about 114.3.The accuracy of this prediction method is better than that of the other commonly used methods,and the method has high applicability.

Numerical investigation on threading dislocation bending with InAs/GaAs quantum dots

The threading dislocations(TDs)in GaAs/Si epitaxial layers due to the lattice mismatch seriously degrade the performance of the lasers grown on silicon.The insertion of InAs quantum dots(QDs)acting as dislocation filters is a pretty good alternative to solving this problem.In this paper,a finite element method(FEM)is proposed to calculate the critical condition for InAs/GaAs QDs bending TDs into interfacial misfit dislocations(MDs).Making a comparison of elastic strain energy between the two isolated systems,a reasonable result is obtained.The effect of the cap layer thickness and the base width of QDs on TD bending are studied,and the results show that the bending area ratio of single QD(the bending area divided by the area of the QD base)is evidently affected by the two factors.Moreover,we present a method to evaluate the bending capability of single-layer QDs and multi-layer QDs.For the QD with 24-nm base width and 5-nm cap layer thickness,taking the QD density of 10^(11) cm^(-2) into account,the bending area ratio of single-layer QDs(the area of bending TD divided by the area of QD layer)is about 38.71%.With inserting five-layer InAs QDs,the TD density decreases by 91.35%.The results offer the guidelines for designing the QD dislocation filters and provide an important step towards realizing the photonic integration circuits on silicon.

Epidemiology, clinical characteristics, and treatment of severe fever with thrombocytopenia syndrome

Severe fever with thrombocytopenia syndrome(SFTS)is an emerging tick-borne infectious disease caused by a novel phlebovirus(SFTS virus,SFTSV)in the family Phenuiviridae of the order Bunyavirales.The disease causes a wide spectrum of clinical signs and symptoms,ranging from mild febrile disease accompanied by thrombocy-topenia and/or leukocytopenia to hemorrhagic fever,encephalitis,multiple organ failure,and death.SFTS was first identified in China and was subsequently reported in South Korea and Japan.The case-fatality rate ranges from 2.7%to 45.7%.Older age has been consistently shown to be the most important predictor of adverse disease outcomes.Older age exacerbates disease mainly through dysregulation of host immune cells and uncontrolled inflammatory responses.Tick-to-human transmission is the primary route of human infection with SFTSV,and Haemaphysalis longicornis is the primary tick vector of SFTSV.Despite its high case-fatality rate,vaccines and an-tiviral therapies for SFTS are not currently available.The therapeutic efficacies of several antiviral agents against SFTSV are currently being evaluated.Ribavirin was initially identified as a potential antiviral therapy for SFTS but was subsequently found to inefficiently improve disease outcomes,especially among patients with high viral loads.Favipiravir(T705)decreased both time to clinical improvement and mortality when administered early in patients with low viral loads.Anti-inflammatory agents including corticosteroids have been proposed to play therapeutic roles.However,the efficacy of other therapeutic modalities,such as convalescent plasma,is not yet clear.

3D Object Tracking with Adaptively Weighted Local Bundles

The 3D object tracking from a monocular RGB image is a challenging task.Although popular color and edgebased methods have been well studied,they are only applicable to certain cases and new solutions to the challenges in real environment must be developed.In this paper,we propose a robust 3D object tracking method with adaptively weighted local bundles called AWLB tracker to handle more complicated cases.Each bundle represents a local region containing a set of local features.To alleviate the negative effect of the features in low-confidence regions,the bundles are adaptively weighted using a spatially-variant weighting function based on the confidence values of the involved energy terms.Therefore,in each frame,the weights of the energy items in each bundle are adapted to different situations and different regions of the same frame.Experiments show that the proposed method can improve the overall accuracy in challenging cases.We then verify the effectiveness of the proposed confidence-based adaptive weighting method using ablation studies and show that the proposed method overperforms the existing single-feature methods and multi-feature methods without adaptive weighting.