模块化连续手语识别算法及技术综述

手语是听障人士和其他人之间重要的沟通方式,但许多普通人看不懂手语,导致听障人士和普通人交流障碍.随着深度学习网络在连续手语识别方向的应用,算法大模型为复杂难懂的连续手语动作翻译成通俗易懂的文本语句提供了技术基础.但是连续手语识别仍然面临着冗余帧过多,空间特征提取和时间特征提取网络不平衡,手语语序与文本语序不匹配等诸多问题.因此,研究准确率高、耗时少、场景通用性高的连续手语识别算法成为计算机视觉领域的热点问题之一.本文首先分析单模态和多模态的连续手语识别框架,并重点阐述关键帧提取、特征提取、序列学习3个模块在连续手语识别中的作用,以及模块中所用网络的优势与不足,然后总结连续手语数据集以及识别结果的评价指标,最后阐述连续手语识别算法的难点并展望其未来的发展方向.

Anthropogenic Influence on Decadal Changes in Concurrent Hot and Dry Events over China around the Mid-1990s

The frequency and duration of observed concurrent hot and dry events(HDEs) over China during the growing season(April–September) exhibit significant decadal changes across the mid-1990s. These changes are characterized by increases in HDE frequency and duration over most of China, with relatively large increases over southeastern China(SEC), northern China(NC), and northeastern China(NEC). The frequency of HDEs averaged over China in the present day(PD,1994–2011) is double that in the early period(EP, 1964–81);the duration of HDEs increases by 60%. Climate experiments with the Met Office Unified Model(MetUM-GOML2) are used to estimate the contributions of anthropogenic forcing to HDE decadal changes over China. Anthropogenic forcing changes can explain 60%–70% of the observed decadal changes,suggesting an important anthropogenic influence on HDE changes over China across the mid-1990s. Single-forcing experiments indicate that the increase in greenhouse gas(GHG) concentrations dominates the simulated decadal changes,increasing the frequency and duration of HDEs throughout China. The change in anthropogenic aerosol(AA) emissions significantly decreases the frequency and duration of HDEs over SEC and NC, but the magnitude of the decrease is much smaller than the increase induced by GHGs. The changes in HDEs in response to anthropogenic forcing are mainly due to the response of climatological mean surface air temperatures. The contributions from changes in variability and changes in climatological mean soil moisture and evapotranspiration are relatively small. The physical processes associated with the response of HDEs to GHG and AA changes are also revealed.

基于深度学习的颅面点云生成模型

针对实际应用中对初始头骨数据完整性要求高、重建复原时间长、扩展性和实用性不强等问题,论文设计提出一种基于深度学习的形状修补以及形状学习颅面点云复原模型。模型通过使用补全自编码器(Repair AutoEncoder,rAE)从缺失的头骨点云数据中复原完整头骨点云,并通过形状生成自编码器(Generation AutoEncoder,gAE)来生成初始头骨所对应的头面部点云。实验表明该模型补全生成的头骨点云和学习生成的头部点云的复原精度能很好地支撑对头部模型的三维重建。论文提出的深度学习方法与传统方法相比较能够由不完整的头骨数据,快速、逼真和准确地重构三维头部形状,在经典颅面复原任务如:出土残缺古人类头骨补全、面貌复原、刑事案件侦破等任务中展现出良好的稳定性与可扩展性。

Assessment of the effectiveness of weight-adjusted antibiotic administration,for reduced duration,in surgical prophylaxis of primary hip and knee arthroplasty

BACKGROUND Prophylactic antibiotics have significantly led to a reduction in the risk of postoperative surgical site infections(SSI)in orthopaedic surgery.The aim of using antibiotics for this purpose is to achieve serum and tissue drug levels that exceed,for the duration of the operation,the minimum inhibitory concentration of the likely organisms that are encountered.Prophylactic antibiotics reduce the rate of SSIs in lower limb arthroplasty from between 4%and 8%to between 1%and 3%.Controversy,however,still surrounds the optimal frequency and dosing of antibiotic administration.AIM To evaluate the impact of introduction of a weight-adjusted antibiotic prophylaxis regime,combined with a reduction in the duration of administration of post-operative antibiotics on SSI incidence during the 2 years following primary elective total hip and knee arthroplasty METHODS Following ethical approval,patients undergoing primary total hip arthroplasty(THA)/total knee arthroplasty(TKA)with the old regime(OR)of a preoperative dose[cefazolin 2 g intravenously(IV)],and two subsequent doses(2 h and 8 h),were compared to those after a change to a new regime(NR)of a weight-adjusted preoperative dose(cefazolin 2 g IV for patients<120 kg;cefazolin 3g IV for patients>120 kg)and a post-operative dose at 2 h.The primary outcome in both groups was SSI rates during the 2 years post-operatively.RESULTS A total of n=1273 operations(THA n=534,TKA n=739)were performed in n=1264 patients.There was no statistically significant difference in the rate of deep(OR 0.74%(5/675)vs NR 0.50%(3/598);fishers exact test P=0.72),nor superficial SSIs(OR 2.07%(14/675)vs NR 1.50%(9/598);chi-squared test P=0.44)at 2 years postoperatively.With propensity score weighting and an interrupted time series analysis,there was also no difference in SSI rates between both groups[RR 0.88(95%CI 0.61 to 1.30)P=0.46].CONCLUSION A weight-adjusted regime,with a reduction in number of post-operative doses had no adverse impact on SSI incidence in this population.

Safety of tranexamic acid in surgically treated isolated spine trauma

BACKGROUND Tranexamic acid(TXA),a synthetic antifibrinolytic drug,effectively reduces blood loss by inhibiting plasmin-induced fibrin breakdown.This is the first study in the United Kingdom to investigate the effectiveness of TXA in the surgical management of isolated spine trauma.AIM To assess the safety of TXA in isolated spine trauma.The primary and secondary outcomes are to assess the rate of thromboembolic events and to evaluate blood loss and the incidence of blood transfusion,respectively.METHODS This prospective observational study included patients aged≥17 years with isolated spine trauma requiring surgical intervention over a 6-month period at two major trauma centers in the United Kingdom.RESULTS We identified 67 patients:26(39%)and 41(61%)received and did not receive TXA,respectively.Both groups were matched in terms of age,gender,American Society of Anesthesiologists grade,and mechanism of injury.A higher proportion of patients who received TXA had a subaxial cervical spine injury classification or thoracolumbar injury classification score>4(74%vs 56%).All patients in the TXA group underwent an open approach with a mean of 5 spinal levels involved and an average operative time of 203 min,compared with 24 patients(58%)in the non TXA group who underwent an open approach with an average of 3 spinal levels involved and a mean operative time of 159 min.Among patients who received TXA,blood loss was<150 and 150–300 mL in 8(31%)and 15(58%)patients,respectively.There were no cases of thromboembolic events in any patient who received TXA.CONCLUSION Our study demonstrated that TXA is safe for isolated spine trauma.It is challenging to determine whether TXA effectively reduces blood loss because most surgeons prefer TXA for open or multilevel cases.Further,larger studies are necessary to explore the rate,dosage,and mode of administration of TXA.

Mesh representation matters:investigating the influence of different mesh features on perceptual and spatial fidelity of deep 3D morphable models

Background Deep 3D morphable models(deep 3DMMs)play an essential role in computer vision.They are used in facial synthesis,compression,reconstruction and animation,avatar creation,virtual try-on,facial recognition systems and medical imaging.These applications require high spatial and perceptual quality of synthesised meshes.Despite their significance,these models have not been compared with different mesh representations and evaluated jointly with point-wise distance and perceptual metrics.Methods We compare the influence of different mesh representation features to various deep 3DMMs on spatial and perceptual fidelity of the reconstructed meshes.This paper proves the hypothesis that building deep 3DMMs from meshes represented with global representations leads to lower spatial reconstruction error measured with L_(1) and L_(2) norm metrics and underperforms on perceptual metrics.In contrast,using differential mesh representations which describe differential surface properties yields lower perceptual FMPD and DAME and higher spatial fidelity error.The influence of mesh feature normalisation and standardisation is also compared and analysed from perceptual and spatial fidelity perspectives.Results The results presented in this paper provide guidance in selecting mesh representations to build deep 3DMMs accordingly to spatial and perceptual quality objectives and propose combinations of mesh representations and deep 3DMMs which improve either perceptual or spatial fidelity of existing methods.

Digital Twins for Wastewater Treatment:A Technical Review

The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domains,and key technologies.More specifically,we investigate the transformative potential of digital twins for the wastewater treatment engineering sector.Our discussion highlights the application of digital twins to wastewater treatment plants(WWTPs)and sewage networks,hardware(i.e.,facilities and pipes,sensors for water quality and activated sludge,hydrodynamics,and power consumption),and software(i.e.,knowledge-based and data-driven models,mechanistic models,hybrid twins,control methods,and the Internet of Things).Furthermore,two cases are provided,followed by an assessment of current challenges in and perspectives on the application of digital twins in WWTPs.This review serves as an essential primer for wastewater engineers navigating the digital paradigm shift.

Locally Enhanced Flow and Electric Fields Through a Tip Effect for Efficient Flow‑Electrode Capacitive Deionization

Low-electrode capacitive deionization(FCDI)is an emerging desalination technology with great potential for removal and/or recycling ions from a range of waters.However,it still suffers from inefficient charge transfer and ion transport kinetics due to weak turbulence and low electric intensity in flow electrodes,both restricted by the current collectors.Herein,a new tip-array current collector(designated as T-CC)was developed to replace the conventional planar current collectors,which intensifies both the charge transfer and ion transport significantly.The effects of tip arrays on flow and electric fields were studied by both computational simulations and electrochemical impedance spectroscopy,which revealed the reduction of ion transport barrier,charge transport barrier and internal resistance.With the voltage increased from 1.0 to 1.5 and 2.0 V,the T-CC-based FCDI system(T-FCDI)exhibited average salt removal rates(ASRR)of 0.18,0.50,and 0.89μmol cm^(-2) min^(-1),respectively,which are 1.82,2.65,and 2.48 folds higher than that of the conventional serpentine current collectors,and 1.48,1.67,and 1.49 folds higher than that of the planar current collectors.Meanwhile,with the solid content in flow electrodes increased from 1 to 5 wt%,the ASRR for T-FCDI increased from 0.29 to 0.50μmol cm^(-2) min^(-1),which are 1.70 and 1.67 folds higher than that of the planar current collectors.Additionally,a salt removal efficiency of 99.89%was achieved with T-FCDI and the charge efficiency remained above 95%after 24 h of operation,thus showing its superior long-term stability.

西奥多·费舍尔与1900年前后的德语区城市建筑艺术理论

本文通过梳理著名建筑师西奥多·费舍尔所处的时代与理论背景,分析1900年前后德语区城市建筑艺术理论的意涵变化与发展,结合对费舍尔城市建筑理论及实践探索的考察,揭示这一时期德语区城市建筑法则与城市建筑艺术理论的高度关联性,及其对城市建设的影响。

The Representation of Soil Moisture−Atmosphere Feedbacks across the Tibetan Plateau in CMIP6

Thermal processes on the Tibetan Plateau(TP)influence atmospheric conditions on regional and global scales.Given this,previous work has shown that soil moisture−driven surface flux variations feed back onto the atmosphere.Whilst soil moisture is a source of atmospheric predictability,no study has evaluated soil moisture−atmosphere coupling on the TP in general circulation models(GCMs).In this study,we use several analysis techniques to assess soil moisture−atmosphere coupling in CMIP6 simulations including:instantaneous coupling indices;analysis of flux and atmospheric behaviour during dry spells;and a quantification of the preference for convection over drier soils.Through these metrics we partition feedbacks into their atmospheric and terrestrial components.Consistent with previous global studies,we conclude substantial inter-model differences in the representation of soil moisture−atmosphere coupling,and that most models underestimate such feedbacks.Focusing on dry spell analysis,most models underestimate increased sensible heat during periods of rainfall deficiency.For example,the model-mean bias in anomalous sensible heat flux is 10 W m−2(≈25%)smaller compared to observations.Deficient dry-spell sensible heat fluxes lead to a weaker atmospheric response.We also find that most GCMs fail to capture the negative feedback between soil moisture and deep convection.The poor simulation of feedbacks in CMIP6 experiments suggests that forecast models also struggle to exploit soil moisture−driven predictability.To improve the representation of land−atmosphere feedbacks requires developments in not only atmospheric modelling,but also surface processes,as we find weak relationships between rainfall biases and coupling indexes.

Machine Learning Driven Latency Optimization for Internet of Things Applications in Edge Computing

Emerging Internet of Things(IoT)applications require faster execution time and response time to achieve optimal performance.However,most IoT devices have limited or no computing capability to achieve such stringent application requirements.To this end,computation offloading in edge computing has been used for IoT systems to achieve the desired performance.Nevertheless,randomly offloading applications to any available edge without considering their resource demands,inter-application dependencies and edge resource availability may eventually result in execution delay and performance degradation.We introduce Edge-IoT,a machine learning-enabled orchestration framework in this paper,which utilizes the states of edge resources and application resource requirements to facilitate a resource-aware offloading scheme for minimizing the average latency.We further propose a variant bin-packing optimization model that co-locates applications firmly on edge resources to fully utilize available resources.Extensive experiments show the effectiveness and resource efficiency of the proposed approach.

Effects of sampling frequency on node mobility prediction in dynamic networks: A spectral view

The field of mobility prediction has been widely investigated in the recent past,especially the reduction of the coverage radius of cellular networks,which led to an increase in hand-over events.Changing the cell coverage very frequently,for example,may lead to service disruptions if a predictive approach is not deployed in the system.Although several works examined mobility prediction in the new-generation mobile networks,all of these studies focused on studying the time features of mobility traces,and the spectral content of historical mobility patterns was not considered for prediction purposes as yet.In the present study,we propose a new approach to mobility prediction by analyzing the effects of a proper mobility sampling frequency.The proposed approach lies in the mobility analysis in the frequency domain,to extract hidden features of the mobility process.Thus,we proposed a new methodology to determine the spectral content of mobility traces(considered as signals)and,thus,the appropriate sampling frequency,which can provide numerous advantages.We considered several types of mobility models(e.g.pedestrian,urban,and vehicular),containing important details in the time and frequency domains.Several simulation campaigns were performed to observe and analyze the characteristics of mobility from real traces and to evaluate the effects of sampling frequency on the spectral content.

Mutual Self‑Regulation of d‑Electrons of Single Atoms and Adjacent Nanoparticles for Bifunctional Oxygen Electrocatalysis and Rechargeable Zinc‑Air Batteries

Rechargeable zinc-air batteries(ZABs)are a promising energy conversion device,which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction(ORR)and oxygen evolution reactions(OER).Herein,we fabricate a range of bifunctional M-N-C(metal-nitrogen-carbon)catalysts containing M-Nx coordination sites and M/MxC nanoparticles(M=Co,Fe,and Cu)using a new class ofγ-cyclodextrin(CD)based metal-organic framework as the precursor.With the two types of active sites interacting with each other in the catalysts,the obtained Fe@C-FeNC and Co@C-CoNC display superior alkaline ORR activity in terms of low half-wave(E1/2)potential(~0.917 and 0.906 V,respectively),which are higher than Cu@C-CuNC(~0.829 V)and the commercial Pt/C(~0.861 V).As a bifunctional electrocatalyst,the Co@C-CoNC exhibits the best performance,showing a bifunctional ORR/OER overpotential(ΔE)of~0.732 V,which is much lower than that of Fe@C-FeNC(~0.831 V)and Cu@C-CuNC(~1.411 V),as well as most of the robust bifunctional electrocatalysts reported to date.Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER,resulting in an enhanced bifunctional electrocatalytic performance.The Co@C-CoNC-based rechargeable ZAB exhibited a maximum power density of 162.80 mW cm^(−2) at 270.30 mA cm^(−2),higher than the combination of commercial Pt/C+RuO2(~158.90 mW cm^(−2) at 265.80 mA cm^(−2))catalysts.During the galvanostatic discharge at 10 mA cm^(−2),the ZAB delivered an almost stable discharge voltage of 1.2 V for~140 h,signifying the virtue of excellent bifunctional ORR/OER electrocatalytic activity.

A Study on Factors Influencing Cost Overrun in High-rise Building Construction across India

Cost overrun is a common problem in construction projects worldwide.Most Indian construction projects,particularly those involving high-rise buildings,have had severe cost overruns.For managers,architects,engineers,and contractors,completing building projects within the specified cost budget has become the most important and hard assignment.Since it is common for high-rise building projects to go over budget,the aim of this study is to find out the causes of cost overruns and provide effective measures.The study found 70 cost overrun factors based on a comprehensive literature review and expert opinions.A Google form questionnaire was distributed to 150 construction professionals across India.After following up,101 of the 150 responses were received.A five-point Likert scale was used and the acquired data was analyzed and ranked using the Relative Importance Index(RII)technique.According to the findings of RII,the top ten critical factors influencing cost overruns were frequent change orders during construction by the owner,delay in construction,escalation of material prices,market inflation or deflation,rework,frequent changes in design,inaccurate evaluation of the project timeline,unforeseen ground condition,inaccurate quantity take-off,and delay in progressive payment by the owner.Spearman’s rank correlation test revealed that there is a very significant relationship between the rankings of factors provided by the owner,the consultant,and the contractor.In addition,a factor analysis tool in the SPSS software was also used to categorize the seventy factors into sixteen core components.The top ten critical factors were presented to subject matter experts,and their suggestions were being compiled.These results are expected to help construction professionals minimize cost overruns,improve cost control measures,and initiate future research.

Seismic loss assessment of RC high-rise buildings designed according to Eurocode 8

A probabilistic seismic loss assessment of RC high-rise(RCHR)buildings designed according to Eurocode 8 and located in the Southern Euro-Mediterranean zone is presented herein.The loss assessment methodology is based on a comprehensive simulation approach which takes into account ground motion(GM)uncertainty,and the random effects in seismic demand,as well as in predicting the damage states(DSs).The methodology is implemented on three RCHR buildings of 20-story,30-story and 40-story with a core wall structural system.The loss functions described by a cumulative lognormal probability distribution are obtained for two intensity levels for a large set of simulations(NLTHAs)based on 60 GM records with a wide range of magnitude(M),distance to source(R)and different site soil conditions(SS).The losses expressed in percent of building replacement cost for RCHR buildings are obtained.In the estimation of losses,both structural(S)and nonstructural(NS)damage for four DSs are considered.The effect of different GM characteristics(M,R and SS)on the obtained losses are investigated.Finally,the estimated performance of the RCHR buildings are checked to ensure that they fulfill limit state requirements according to Eurocode 8.

葡萄铁蛋白基因Ferritin的鉴定、克隆及其在果实发育不同时期对氨基酸铁复合肥喷施的响应

【目的】铁蛋白Ferritin在植物生长发育过程中发挥重要作用,其在果树中的生物学功能尚未见报道。克隆葡萄Ferritin家族基因并揭示其在果实发育不同时期的表达模式及其对叶面喷施氨基酸-铁(Fe)复合肥处理的响应差异,可为研究果树铁素营养与代谢的分子机制提供理论依据。【方法】通过同源克隆法从‘马瑟兰’中克隆Ferritin家族基因,利用生物信息学手段分析葡萄Ferritin及其编码蛋白的详细特征;设置叶面喷施氨基酸-Fe复合肥处理,利用荧光实时定量PCR技术分析Ferritin在葡萄果实发育不同时期的表达特征及其对叶面喷施处理的差异响应。【结果】在葡萄基因组中检索并克隆获得4个Ferritin家族基因,命名为VvFer1—VvFer4,分布于第6、8和13号三条染色体上,均含有7个长度不一的内含子,且主要定位于叶绿体和细胞核。本文所选16种植物Ferritin蛋白序列的一致性高达61.48%,系统发育树分析表明同一属的Ferritin同源蛋白如十字花科的拟南芥和芜菁,茄科的烟草和马铃薯,豆科的大豆、落花生和鹰嘴豆,大戟科的橡胶树、木薯和蓖麻,蔷薇科的苹果、桃和草莓,遗传进化关系较近,葡萄VvFer3和茄科同源蛋白遗传关系最近。葡萄VvFer基因在五年生‘马瑟兰’果实发育不同时期、不同组织中的表达水平差异较大,其中,VvFer3在不同组织中的表达量均最高,最大值出现在硬核期至成熟期的果实中,其次是VvFer2和VvFer4。‘马瑟兰’葡萄发育不同时期果实中的Fe含量略有差异,从幼果期开始逐渐增加,并在转色期果实中达到最高值,从转色期到成熟期略有下降,但仍高于幼果期和硬核期果实中的Fe含量,叶面喷施处理显著提高了成熟期果实中的Fe含量、乌头酸酶ACO(aconitase)、硝酸还原酶NIR(nitrite reductase)和琥珀酸脱氢酶SDH(succinate dehydrogenase)的酶活性。VvFer2—4在转录水平易受叶面喷施铁肥的诱导而显著增强,且与葡萄组织/器官分布和果实发育的不同时期密切相关,VvFer2在葡萄发育整个周期仅在果实中对叶面喷施铁肥处理比较敏感,VvFer3在所有组织中仅从幼果期至转色期对叶面喷施铁肥有响应,VvFer4在葡萄发育整个周期的韧皮部和叶片中持续受叶面喷施铁肥的诱导,而在果实中仅从幼果期至转色期对叶面喷施铁肥有响应;VvFer1在本文所选组织中的表达量相对较低,但很均匀,且在转录水平对叶面喷施铁肥没有响应。【结论】从葡萄中克隆并鉴定了4个铁蛋白基因Ferritin,其在葡萄发育不同时期、不同组织中的表达水平差异较大,并在转录水平易受叶面喷施铁肥的诱导;VvFer3在葡萄所有组织中的整体表达量最高(特别是果实中最为突出),且在幼果期至转色期易受铁肥叶面喷施的调控。

Advances and challenges of gastrostomy insertion in children

When oral feeding cannot provide adequate nutritional support to children,enteral tube feeding becomes a necessity.The overall aim is to ultimately promote appropriate growth,improve the patient’s quality of life and increase carer satisfaction.Nasogastric tube feeding is considered appropriate on a short-term basis.Alternatively,gastrostomy feeding offers a more convenient and safer feeding option especially as it does not require frequent replacements,and carries a lower risk of complications.Gastrostomy tube feeding should be considered when nasogastric tube feeding is required for more than 2-3 wk as per the ESPEN guidelines on artificial enteral nutrition.Several techniques can be used to insert gastrostomies in children including endoscopic,image guided and surgical gastrostomy insertion whether open or laparoscopic.Each technique has its own advantages and disadvantages.The timing of gastrostomy insertion,device choice and method of insertion is dependent on the local expertise,patient requirements and family preference,and should be individualized with a multidisciplinary team approach.We aim to review gastrostomy insertion in children including indications,contraindications,history of gastrostomy,insertion techniques and complications.

基于图像的深度学习降雨强度估计方法

城市洪水是世界性的重大问题,造成巨大的经济损失,严重威胁公共安全。减轻其影响的一种有希望的方法是开发实时洪水风险管理系统;然而,由于缺乏高时空降雨数据,构建这样一个系统通常具有挑战性。虽然一些方法(即地面降雨站或雷达和卫星技术)可用于测量和(或)预测降雨强度,但使用这些方法很难获得具有理想时空分辨率的准确降雨数据。本文提出了一种基于图像的深度学习模型来估计具有高时空分辨率的城市降雨强度。进一步来说,一种称为基于图像的降雨卷积神经网络(image-based rainfall CNN,irCNN)模型是使用从现有密集传感器(即智能手机或交通摄像头)收集的降雨图像及其相应的测量降雨强度值开发的。随后使用经过训练的irCNN模型根据传感器的降雨图像有效地估计降雨强度。分别利用合成降雨数据和真实降雨图像来探索irCNN在理论和实际模拟降雨强度方面的准确性。结果表明,irCNN模型提供的降雨量估计值的平均绝对百分比误差在13.5%~21.9%之间,超过了文献中其他最先进的建模技术的性能。更重要的是,所提出的irCNN的主要特点是它在有效获取高时空城市降雨数据方面成本较低。irCNN模型为估算城市降雨强度提供了一种有前景的替代方案,可以极大地促进城市实时洪水风险管理的发展。

Achieving high ductility and strength in magnesium alloy through cryogenic-hot forming

Magnesium alloys are the lightest structural alloys and have attracted substantial research attention in the past two decades. However, their mechanical properties, including ductility and strength, are limited after forming due to the formation of coarse grains and strong texture. This study proposes and proves a new cryogenic-hot forming process concept. Cryogenic deformation is imposed before the hot deformation. The effect of the cryogenic step has been compared with a conventional direct hot deformation process. The mechanical properties, microstructure,and texture of both the novel and conventional process routes have been compared. The cryogenic-hot deformed sample exhibits the highest ductility and fracture strength(ultimate tensile strength: 321 MPa, ductility: 21%) due to effective grain refinement and texture weakening by cryogenically formed twin-twin interaction induced recrystallisation. The proposed cryogenic-hot forming process can be a potential innovative manufacturing method for producing high-performance magnesium components.

基于Internet的远程音乐教育模式的探讨

本文简要地介绍了远程音乐教育的优越性和基本特点，并就其结构模式及其 功能、教学方式和远程音乐考试系统作了较具体的阐述。