冷轧薄宽带钢局部型中浪瓢曲变形行为研究

针对薄宽带钢冷轧过程中易发多发的局部型中浪瓢曲缺陷,引入非均匀载荷宽度、弹性约束系数及平均张应力建立了屈曲变形的解析计算模型。应用能量最低原理对屈曲变形区域进行搜索求解,得到了局部型中浪屈曲临界条件(包括临界应力、屈曲波长和屈曲波宽),获得了其与非均匀载荷宽度、弹性约束系数、平均张应力的关系,并发现平均张应力是产生局部型中浪的重要影响因素。应用样条有限元方法对局部型中浪进行数值仿真分析,验证了屈曲解析计算方法的正确性。在实验轧机上进行了轧制研究,通过轧制获得了局部型中浪屈曲模态,对实验结果分析得到了相对应的屈曲临界条件,与解析法和样条有限元法结果基本吻合,证明了样条有限元计算方法与解析计算方法的正确性及其工程应用价值。     

INFLUENCE OF DAMPING MODELS ON DYNAMIC ANALYSES OF A BASE-ISOLATED COMPOSITE STRUCTURE UNDER EARTHQUAKES AND ENVIRONMENTAL VIBRATIONS

Structural design simultaneously governed by earthquakes and environmental vibrations has received a lot of attention in recent years.Base-isolated composite structures are typically used in the above-mentioned structural design.The corresponding analysis involves validating structural safety under earthquakes and human comfort under environmental vibrations through a time-history analysis.Thus,a reasonable damping model is essential.In this work,the representatives of viscous damping model and rate-independent damping model,namely the Rayleigh damping model and uniform damping model,were adopted to investigate the influence of damping models on the time-history analysis of such structural designs.The energy dissipation characteristics of the above-mentioned damping models were illustrated via a dynamic test of recycled aggregate concrete specimens.A case study was performed on a base-isolated steelconcrete composite structure.The dynamic responses under the excitation of earthquakes and environmental vibrations were compared using different damping models.The uniform damping model was found to be more flexible than the Rayleigh damping model in dealing with excitations with different frequency components.The uniform damping model is both theoretically advantageous and easy to use,demonstrating its potential in dynamic analysis of structures designed simultaneously governed by earthquakes and environmental vibrations.     

A VIBRATION RECOGNITION METHOD BASED ON DEEP LEARNING AND SIGNAL PROCESSING

Effective vibration recognition can improve the performance of vibration control and structural damage detection and is in high demand for signal processing and advanced classification.Signal-processing methods can extract the potent time-frequency-domain characteristics of signals;however,the performance of conventional characteristics-based classification needs to be improved.Widely used deep learning algorithms(e.g.,convolutional neural networks(CNNs))can conduct classification by extracting high-dimensional data features,with outstanding performance.Hence,combining the advantages of signal processing and deep-learning algorithms can significantly enhance vibration recognition performance.A novel vibration recognition method based on signal processing and deep neural networks is proposed herein.First,environmental vibration signals are collected;then,signal processing is conducted to obtain the coefficient matrices of the time-frequency-domain characteristics using three typical algorithms:the wavelet transform,Hilbert-Huang transform,and Mel frequency cepstral coefficient extraction method.Subsequently,CNNs,long short-term memory(LSTM)networks,and combined deep CNN-LSTM networks are trained for vibration recognition,according to the time-frequencydomain characteristics.Finally,the performance of the trained deep neural networks is evaluated and validated.The results confirm the effectiveness of the proposed vibration recognition method combining signal preprocessing and deep learning.     

有限宽度和椭圆孔形状对缺口层合板强度预测的影响

本文采用有限元方法对正交各向异性材料含有不同椭圆孔形状的有限宽度板作了分析,给出了有限宽度和椭圆孔形状对应力集中因子K₁和孔边应力分布σ_y(x,0)的影响公式。数值结果表明:正交各向异性板的有限宽度和椭圆孔形状对K_r和σ_y(x,0)的影响均与各向同性材料不同,所以有限宽度和椭圆孔形状将对缺口层合板强度的预测产生影响。      

复合材料加筋板的动力分析

本文构造了九自由度三角形拟协调罚函数复合材料板单元与六自由度复合材料梁单元,考虑了剪切变形与转动惯量的影响。用这两种单元对复合材料加筋板的自由振动、阻尼特性和瞬态响应问题进行了研究,给出一些有益结果。      

数字3D电影最新动向

全球数字3D电影领域的领头羊Real D公司于10月17日与欧洲投资商Terra Firma公司旗下在泛西欧拥有1600块银幕的Odeon院线以及UCI院线签署协议,将于未来2年中在英国、爱尔兰、德国、奥地利以及葡萄牙合作安装500块数字3D银幕.     

第十二届中国建筑企业高峰论坛在绍兴市举行王治安主持会议并致辞

<正>本刊讯2014年12月23日,由中国建设报社、浙江省住房和城乡建设厅、绍兴市人民政府主办的第十二届中国建筑企业高峰论坛在绍兴市举行。来自全国各地的建筑行业主管部门、行业协会负责人,专家学者及企业代表等300余人齐聚一堂,围绕"创新融合,开放共赢"主题,共同分享了一场建筑行业思想盛宴。中国建设报社党委书记杜久才、社长翟建和中国建筑装饰协会会长李秉仁、中国土木工程协会副理事长刘     

9.3大阅兵:高标准让军魂荡气回肠

<正>阅兵是展示辉煌的时刻,而为这一辉煌采取的所有的标准,不啻也是宝贵的财富,应当成为践行标准的榜样……这个月最令人难忘、最引人自豪、最提振国威的事情,当属"9.3"大阅兵,它有着以往没有的多重的亮点:首次以纪念抗日战争暨世界反法西斯战争胜利为阅兵主题,彰显维护和平是全世界人民共同的愿望。首次邀请外国军队代表参加分列式,体现纪念大会的国际性。首次组织抗战老兵包括国民党老兵参加,体现了对历史的尊重,体现全民族抗战的特色。首次编组英模部队方队受阅,展示中国共产党在抗战中定海     

车类影视广告拍摄——光线表现篇

汽车能满足人们生活、娱乐、工作的各种需求,为生活添加乐趣.商务车、房车、越野车或轿车,不管是驰骋还是安静地停放,都具有他们独特的气质,外型、轮廓、结构、颜色、车漆的纹理及其光泽度各有特点.拍摄广告就是要把汽车的这些独到之处提炼、表达出来,在观赏者印象中建立一个全方位的立体形象,激发消费者的购买愿望,这里就必须用到一个非凡的摄影手段--光线.     

CIG前驱膜叠层方式对CIGS膜成分和结构的影响

采用中频交流磁控溅射方法制备了三种不同叠层方式的CuInGa（CIG）前驱膜。采用固态法硒化,获得了CIGS吸收层。采用SEM和XRD观察和分析了薄膜的成分、组织结构和表面形貌。着重分析不同叠层方式的CIG前驱膜对CIGs吸收层薄膜成分、晶体结构的影响。结果表明,三种叠层方式的前驱膜都可以获得成分均匀、结构一致的CIGS吸收层薄膜。Ga可以有效抑制In2Se挥发相生成,保持成分的稳定性。以CuGa（top）／CuIn（bottom）形式的前驱膜有利于形成紧密晶粒排列的CIGS。     

Control of vertical phase separation in high performance non-fullerene organic solar cell by introducing oscillating stratification preprocessing

Non-fullerene organic solar cell(NFOSC)has attracted tremendous attention due to their great potential for commercial applications.To improve its power conversion efficiency(PCE),generally,sequential solution deposition(SSD)methods have been employed to construct the graded vertical phase separation(VPS)of the bulk-heterojunction(BHJ)active layer for efficient exciton separation and charge transition.However,a variety of orthogonal solvents used in the SSD may lead to the unpredicted change in the BHJ morphology and introduce additional defects inside the BHJ bulk thus complicate the fabrication process.Here,a simple oscillating stratification preprocessing(OSP)is developed to facilitate the formation of graded VPS among the BHJ layer.As a result,a significant improvement is obtained in PCE from 10.96%to 12.03%,which is the highest value reported among PBDB-T:ITIC based NFOSC.     

High power and stable P-doped yolk-shell structured Si@C anode simultaneously enhancing conductivity and Li+diffusion kinetics

Silicon is a low price and high capacity ancxje material for lithium-ion batteries.The yolk-shell structure can effectively accommodate Si expansion to improve stability.However,the limited rate performance of Si anodes can't meet people's growing demand for high power density.Herein,the phosphorus-doped yolk-shell Si@C materials(P-doped Si@C)were prepared through carbon coating on P-doped Si/SiO_xmatrix to obtain high power and stable devices.Therefore,the as-prepared P-doped Si@C electrodes delivered a rapid increase in Coulombic efficiency from 74.4%to 99.6%after only 6 cycles,high capacity retention of-95%over 800 cycles at 4 A·g^-1,and great rate capability(510 mAh·g^-1at 35 A·g^-1).As a result,P-doped Si@C anodes paired with commercial activated carbon and LiFePO₄cathode to assemble lithium-ion capacitor(high power density of?61,080 W·kg^-1at 20 A·g^-1)and lithium-ion full cell(good rate performance with 68.3 mAh·g^-1at 5 C),respectively.This work can provide an effective way tofurther improve power density and stability for energy storage devices.     

让七十多年前的影片《迷途的羔羊》重返银幕

中国电影资料馆珍藏着大量早期影片,其中许多具有珍贵的保存价值.1936年由蔡楚生编导、任光谱曲的<迷途的羔羊>是我国第一部以流浪儿童为题材的影片,也是我国儿童影片中的第一部有声片.此片在思想和艺术上都取得了突破,尤其是以童谣形式演唱的主题歌<月光光歌>感人至深,充分发挥了音乐的魅力,增强了整部影片的感染力.影片公映后,深受广大观众的欢迎和电影工作者的赞扬.七十多年过去了,当我们准备再次让它同观众见面时,却发现能够最真实、最原始记录影音效果的原底、声底片却出现了许多问题,给复制工作带来了空前的难度,这是我们从事资料影片复制工作三十多年来从未遇到过的难题.主要有以下几方面问题:     

Regulating Zn Deposition via an Artificial Solid–Electrolyte Interface with Aligned Dipoles for Long Life Zn Anode

Aqueous zinc ion batteries show prospects for next-generation renewable energy storage devices.However,the practical applications have been limited by the issues derived from Zn anode.As one of serious problems,Zn dendrite growth caused from the uncontrollable Zn deposition is unfavorable.Herein,with the aim to regulate Zn deposition,an artificial solid–electrolyte interface is subtly engineered with a perovskite type material,BaTiO3,which can be polarized,and its polarization could be switched under the external electric field.Resulting from the aligned dipole in BaTiO3 layer,zinc ions could move in order during cycling process.Regulated Zn migration at the anode/electrolyte interface contributes to the even Zn stripping/plating and confined Zn dendrite growth.As a result,the reversible Zn plating/stripping processes for over 2000 h have been achieved at 1 mA cm^?2 with capacity of 1 mAh cm?2.Furthermore,this anode endowing the electric dipoles shows enhanced cycling stability for aqueous Zn-MnO2 batteries.The battery can deliver nearly 100%Coulombic efficiency at 2 Ag^?1 after 300 cycles.     

Low-Temperature Growing Anatase TiO2/SnO2 Multi-dimensional Heterojunctions at MXene Conductive Network for High-Efficient Perovskite Solar Cells

A multi-dimensional conductive heterojunction structure,composited by TiO2,SnO2,and Ti3C2TX MXene,is facilely designed and applied as electron transport layer in efficient and stable planar perovskite solar cells.Based on an oxygen vacancy scramble effect,the zero-dimensional anatase TiO2 quantum dots,surrounding on two-dimensional conductive Ti3C2TX sheets,are in situ rooted on three-dimensional SnO2 nanoparticles,constructing nanoscale TiO2/SnO2 heterojunctions.The fabrication is implemented in a controlled lowtemperature anneal method in air and then in N2 atmospheres.With the optimal MXene content,the optical property,the crystallinity of perovskite layer,and internal interfaces are all facilitated,contributing more amount of carrier with effective and rapid transferring in device.The champion power conversion efficiency of resultant perovskite solar cells achieves 19.14%,yet that of counterpart is just 16.83%.In addition,it can also maintain almost 85%of its initial performance for more than 45 days in 30–40%humidity air;comparatively,the counterpart declines to just below 75%of its initial performance.     

浅谈油品中水分存在的危害性及检测中注意事项

水分是指存在于石油产品中的水含量,主要开采原有的炼制时存在的,水进入冰点会升高,低温下油路堵塞,高温下腐蚀设备,会起氧化反映.     

车类影视广告的摄制——运动器材表现篇

汽车在中国发展成为大众能接受的商品,时间不算很长,所以在最初的时期,车类影视广告中自然是以展示车的外形、颜色、类别这些最为基本的属性为主.     

2.47 GPa grade ultra-strong 15Co-12Ni secondary hardening steel with superior ductility and fracture toughness

This study investigated the effect of multi-step heat treatment on the microstructure, mechanical properties and fracture behavior of thick 15 Co-12 Ni secondary hardening steel. As-quenched sample was found to have elongated prior austenite grain(PAG) and coarse lenticular martensitic structure. On the other hand, heat-treated sample was observed to have fine lenticular martensitic structure due to fine PAG size and a lot of nano-sized carbides. Also, after heat treatment, nano-scale reverted austenite film was formed at the martensite interfaces. The heat-treated sample showed 2.47 GPa superior tensile strength and superior elongation of about 12 %. The high strength was mainly due to fine block size and high number density of nano-sized carbides. The average value of plane strain fracture toughness(KIC) was 29.3 MPa m1/2, which indicated a good fracture toughness even with the high tensile strength. The tensile fracture surface was observed to have ductile fracture mode(cup-and-cone) and the formation of about ~1 μm ultra-fine dimples. In addition to this, nano-sized carbides were observed within the dimples.The findings suggested that the nano-sized carbide had a positive effect not only on the strength but also on the ductility of the alloy. The fractured surface after toughness test, also showed ductile fracture mode with a lot of dimples. Based on the above results, correlation among microstructural evolution,deformation and fracture mechanisms along the heat-treatment was also discussed.     

中国标准化杂志社编委会会议暨2015年会召开

<正>4月8日,中国标准化杂志社编委会会议暨2015年年会在北京汉能控股集团召开,中国标准化协会理事长、中国标准化杂志社编委会名誉顾问纪正昆,中国标准化研究院院长、编委会主任马林聪,国家质检总局新闻办里新,国家标准委办公室主任邓志勇等出席会议并讲话,来自中国标准化杂志社编委会和理事会成员等70多人出席了此次会议,会议由马林聪院长主持。中国标准化协会理事长纪正昆对杂志社编委会提出明确要求,他说:我们现在遇到了一个非常难得的发展机遇,杂     

热力公司锅炉附属仪表使用及检定情况

目前在新疆的供热公司大多存在着麻痹思想,对锅炉的附属仪表均不够重视,因此导致的安全隐患几乎都没有意识到.