Design and FPGA verification of a novel reliable real-time data transfer system

Considering the increasing use of information technology with established standards, such as TCP/IP and XML in modem industrial automation, we present a high cost performance solution with FPGA （field programmable gate array） implementation of a novel reliable real-time data transfer system based on EPA （Ethemet for plant automation） protocol and IEEE 1588 standard. This combination can provide more predictable and real-time communication between automation equipments and precise synchronization between devices. The designed EPA system has been verified on Xilinx Spartan3 XC3S1500 and it consumed 75% of the total slices. The experimental results show that the novel industrial control system achieves high synchronization precision and provides a 1.59-ps standard deviation between the master device and the slave ones. Such a real-time data transfer system is an excellent candidate for automation equipments which require precise synchronization based on Ethemet at a comparatively low price.

Fast and Balanced Charge Transport Enabled by Solution-Processed Metal Oxide Layers for Efficient and Stable Inverted Perovskite Solar Cells

Metal oxide charge transport materials are preferable for realizing long-term stable and potentially low-cost perovskite solar cells(PSCs).However,due to some technical difficulties(e.g.,intricate fabrication protocols,high-temperature heating process,incompatible solvents,etc.),it is still challenging to achieve efficient and reliable all-metal-oxide-based devices.Here,we developed efficient inverted PSCs(IPSCs)based on solution-processed nickel oxide(NiO_(x))and tin oxide(SnO_(2))nanoparticles,working as hole and electron transport materials respectively,enabling a fast and balanced charge transfer for photogenerated charge carriers.Through further understanding and optimizing the perovskite/metal oxide interfaces,we have realized an outstanding power conversion efficiency(PCE)of 23.5%(the bandgap of the perovskite is 1.62 eV),which is the highest efficiency among IPSCs based on all-metal-oxide charge transport materials.Thanks to these stable metal oxides and improved interface properties,ambient stability(retaining 95%of initial PCE after 1 month),thermal stability(retaining 80%of initial PCE after 2 weeks)and light stability(retaining 90%of initial PCE after 1000 hours aging)of resultant devices are enhanced significantly.In addition,owing to the low-temperature fabrication procedures of the entire device,we have obtained a PCE of over 21%for flexible IPSCs with enhanced operational stability.

Real-time 3-D space numerical shake prediction for earthquake early warning

In earthquake early warning systems, real-time shake prediction through wave propagation simulation is a promising approach. Compared with traditional methods, it does not suffer from the inaccurate estimation of source parameters. For computation efficiency, wave direction is assumed to propagate on the 2-D surface of the earth in these methods. In fact, since the seismic wave propagates in the 3-D sphere of the earth, the 2-D space modeling of wave direction results in inaccurate wave estimation. In this paper, we propose a 3-D space numerical shake pre- diction method, which simulates the wave propagation in 3-D space using radiative transfer theory, and incorporate data assimilation technique to estimate the distribution of wave energy. 2011 Tohoku earthquake is studied as an example to show the validity of the proposed model. 2-D space model and 3-D space model are compared in this article, and the prediction results show that numerical shake prediction based on 3-D space model can estimate the real-time ground motion precisely, and overprediction is alleviated when using 3-D space model.

Real-time tracking of deformable objects based on MOK algorithm

The traditional oriented FAST and rotated BRIEF（ORB） algorithm has problems of instability and repetition of keypoints and it does not possess scale invariance. In order to deal with these drawbacks, a modified ORB（MORB） algorithm is proposed. In order to improve the precision of matching and tracking, this paper puts forward an MOK algorithm that fuses MORB and Kanade-Lucas-Tomasi（KLT）. By using Kalman, the object＇s state in the next frame is predicted in order to reduce the size of search window and improve the real-time performance of object tracking. The experimental results show that the MOK algorithm can accurately track objects with deformation or with background clutters, exhibiting higher robustness and accuracy on diverse datasets. Also, the MOK algorithm has a good real-time performance with the average frame rate reaching 90.8 fps.

Real-time numerical shake prediction and updating for earthquake early warning

Ground motion prediction is important for earthquake early warning systems, because the region＇s peak ground motion indicates the potential disaster. In order to predict the peak ground motion quickly and pre- cisely with limited station wave records, we propose a real- time numerical shake prediction and updating method. Our method first predicts the ground motion based on the ground motion prediction equation after P waves detection of several stations, denoted as the initial prediction. In order to correct the prediction error of the initial prediction, an updating scheme based on real-time simulation of wave propagation is designed. Data assimilation technique is incorporated to predict the distribution of seismic wave energy precisely. Radiative transfer theory and Monte Carlo simulation are used for modeling wave propagation in 2-D space, and the peak ground motion is calculated as quickly as possible. Our method has potential to predict shakemap, making the potential disaster be predicted before the real disaster happens. 2008 Ms8.0 Wenchuan earthquake is studied as an example to show the validity of the proposed method.

Characterization and Synthesis through Fast Phase-Transfer of Oil-Soluble Double-Coordinated Tea-Polyphenols Arsenic

Fast phase-transferring was adopted in ethanol solution at the condition of n (oil-soluble tea pol-yphenol): N (As3﹢) = 2:1, 4:1, 6:1, pH = 4.0, temperature 40°C - 45°C, action period of 15 h to compose the target, of which the productivity was 59%, UV was 267.50, 218.00, 220.50 nm, FTIR was 6291, 34158.6, 2850.2, 1708.2;1457.3;1370.4, 1224.2, 1144.0, 760.5 cm﹣1, fluorescence value λmax = 257, 591.1, 593.7, 590.3, 591.0, 591.5, XRD λ/nm is 3.6974, 4.186, 12.0762, 15.4747, 1H-NMRδ = 0.782, 1.193, 1.483 - 1.586, 1.959 - 2.184, 2.479, 3.116, 3.970 - 3.981, 5.231 - 5.753, 6.537 - 7.300. Finally it was ascertained through XRD as double-coordinated polycrystal compound.

钠液面高度对氩气空间耦合传热特性影响的实验研究

锥顶盖作为快堆主容器重要的压力边界之一,其结构的完整性对快堆的安全运行至关重要。锥顶盖结构完整性与其温度载荷密切相关,而温度载荷受氩气空间自然对流与辐射耦合传热特性影响显著,有必要开展深入研究。基于钠液面上部氩气空间传热特性实验台架,开展了氩气空间传热特性实验研究,测量了锥顶盖、氩气空间和主泵支承的温度分布,阐明钠液面高度对传热特性的影响。实验结果表明,随着钠液面高度的增加,锥顶盖和氩气空间的温度随之升高,而且在高钠温时现象更加明显。此外,钠液面高度对主泵支承的温度分布和周向温差影响微弱。通过开展氩气空间钠液面高度对传热规律的影响研究,可为建立实验装置与原型反应堆之间的温度映射关系提供参考。

池式钠冷快堆复杂空间内流动与传热特性三维数值模拟研究综述

钠冷快堆是第四代先进核能系统的重要堆型之一。池式钠冷快堆安全裕量大,但结构较为复杂,其堆内一回路循环流动呈多尺度、复杂空间、多路径、三维流动等特点,给池式钠冷快堆计算与实验带来一定困难。近年来,计算流体力学(CFD)的快速发展为解决上述问题提供了重要技术路径,本文对池式钠冷快堆复杂空间内流动与传热特性三维数值模拟研究进行综述。对于全堆一体化整体计算,获取池式钠冷快堆典型对称/非对称工况下的三维温度场分布及关键热工参数瞬态变化,评价其余热排出能力;对于局部部件或区域精细化计算,获取局部三维流动与传热特征参数,也为全堆一体化计算提供关键输入。相关研究为池式钠冷快堆安全稳定运行及设计优化提供重要支撑。

热辐射特征参数对快堆锥形顶盖空间换热特性影响的研究

池式钠冷快堆的钠池内充满高温液态钠,其上方覆盖有氩气,高温液态钠主要通过辐射换热及对流换热的方式向快堆主容器上部结构及氩气空间传递热量,其换热特性及其影响因素十分复杂。辐射发射率及液态钠蒸发形成的气溶胶层对主容器上部结构的热工水力特性会造成一定影响。因此,为保证主容器上部结构在不同温度载荷下的安全性与稳定性,十分必要获取不同辐射发射率及不同气溶胶层分布下的温度分布。本研究建立大型池式钠冷快堆主容器上部锥形顶盖空间(以下简称“锥顶盖”)数值计算模型,开展数值模拟计算,得到不同发射率及气溶胶层厚度影响下锥顶盖的温度场。研究结果表明,发射率越高,锥顶盖斜肩及氩气空间温度越高;当气溶胶层存在于靠近钠液面的高度范围时(0~0.2 m),增加其厚度可使氩气空间局部温度升高,但对锥顶盖斜肩温度影响有限。发射率增高53%,则辐射换热量增加31.47%,格拉晓夫数(Gr)减少19.29%,辐射换热效果增强,自然对流效果减弱;气溶胶层高度由0增加到0~0.1 m时,对辐射换热量的吸收增加22.68%,格拉晓夫数(Gr)减少19.29%,气溶胶层高度由0~0.1 m增加到0~0.2 m时,透过气溶胶层的辐射换热量减少了0.04%,格拉晓夫数(Gr)增加了0.9%,辐射换热效果减弱,自然对流效果加强。

无监督域适应迁移学习在旋转机械故障诊断中的应用

故障诊断在旋转机械领域具有重要的意义,而深度学习和迁移学习的发展为提高故障诊断的准确性和鲁棒性提供了新的途径。针对旋转机械故障诊断问题,提出了一种基于深度对抗神经网络(domain-adversarial neural network, DANN)和多核最大平均差异(multiple kernel maximum mean discrepancy, MK-MMD)的无监督域适应迁移学习方法。首先,收集了源工况和目标工况下的振动信号数据并通过快速傅里叶变换(fast Fourier transform, FFT)转化为频域信号。然后,构建了一个ResNeXt-50特征提取器,并使用DANN和MK-MMD方法进行特征映射和域适应,从而实现源工况到目标工况的迁移学习。试验结果表明,该方法能提高对故障特征的识别精度,且在不同工况下的迁移试验中具有更好的鲁棒性。

The fast method and convergence analysis of the fractional magnetohydrodynamic coupled flow and heat transfer model for the generalized second-grade fluid

In this paper,we first establish a new fractional magnetohydrodynamic(MHD)coupled flow and heat transfer model for a generalized second-grade fluid.This coupled model consists of a fractional momentum equation and a heat conduction equation with a generalized form of Fourier law.The second-order fractional backward difference formula is applied to the temporal discretization and the Legendre spectral method is used for the spatial discretization.The fully discrete scheme is proved to be stable and convergent with an accuracy of O(τ^(2)+N-r),whereτis the time step-size and N is the polynomial degree.To reduce the memory requirements and computational cost,a fast method is developed,which is based on a globally uniform approximation of the trapezoidal rule for integrals on the real line.The strict convergence of the numerical scheme with this fast method is proved.We present the results of several numerical experiments to verify the effectiveness of the proposed method.Finally,we simulate the unsteady fractional MHD flow and heat transfer of the generalized second-grade fluid through a porous medium.The effects of the relevant parameters on the velocity and temperature are presented and analyzed in detail.

基于迁移学习的快速多边响应法

针对基于多边响应的快速时域仿真计算中,需要通过瞬态仿真得到所有边沿响应的时间花费问题,提出了基于迁移学习的多响应预测方法。首先,根据非线性链路的响应特点,将拖尾响应划为线性区和非线性区分别处理,以减少所需测量的响应长度;其次,以“0电平”响应作为源域数据构建预训练模型网络;然后,利用预训练模型的网络参数训练其他三种响应的迁移学习模型;最后,将所有非线性区响应绘制在一个单位间隔内,并将线性区的积累电压扩充至眼图轮廓。实验结果表明,该方法能以更少的响应数据,更全面且准确预测其余响应,从而提高快速多边响应法的计算速率。

一种汽车撞击作用下桥上列车运行安全快速评估方法研究

针对跨线铁路桥梁遭遇汽车撞击后可能诱发的桥上列车运行安全问题,选取一座在役32 m跨度T形截面简支梁桥为工程背景,采用敲击试验和数值模拟相结合的方法,提出了一种基于传递函数的快速评估方法。该方法通过力锤敲击试验,采集敲击力时程和敲击作用下桥梁关键位置动力响应时程。将敲击力作为输入变量,以桥梁动力响应作为输出变量,求出桥梁结构的传递函数。将汽车撞击力时程进行快速傅里叶变换,与传递函数进行复数点乘,对其结果进行傅里叶逆变换,得到汽车撞击的桥梁动力响应时程。通过与有限元模型计算结果进行对比,验证了基于传递函数的快速计算方法的适用性。在工程领域内,该方法避免了大量重复性的有限元计算以及破坏性试验,可以快速推导出桥梁遭遇汽车撞击后动力响应,并实现对桥上列车运行安全的快速评估。

快堆堆芯三操作头模型出口冷却剂温度振荡流固传递特性实验研究

来自堆芯不同通道的冷却剂存在温度差异,当其在堆芯上腔室混合后将产生流体温度振荡,从而会引发周围固体结构的温度振荡。长时间的温度振荡会导致结构的高周疲劳破坏,影响快堆安全运行。针对温度振荡的研究,多为流体的温度振荡,对于流固热耦合的研究相对较少。本文通过数值模拟计算,确定了三组操作头组合三叶梅花导流筒的实验装置,以水代替钠作为工质开展了堆芯出口温度振荡实验研究,并获得了温度振荡从流体到固体的传递特性。结果表明:流体在冷热操作头交界区域温度振荡比较强烈,在近操作头处冷热流体产生剧烈温度振荡,向中心测量柱底壁面逐渐衰减;固体温度振荡主要发生在壁面附近比较薄的区域,在40 K温差和0.3 m/s流速工况下,温度振荡传递到固体内2.5 mm处几乎消失;基于实验结果,修正了已有的温度振荡衰减经验公式,预测精度在±5.7%以内。

南水北调中线渠首前馈控制方案快速计算分析

明渠调水工程中为适时适量的满足下游用水需求,需要提前制定控制方案。前馈控制方案的设计往往较为复杂,且影响因素众多,调度人员难以快速做出决策。基于蓄量补偿法对南水北调中线工程刁河节制闸至十二里河节制闸段作前馈控制,基于蓄量补偿计算结果,分析了初始流量、分水流量与前馈控制时间的关系,构建了单、双变量的前馈控制时间快速计算公式。探究了不同因素对蓄量补偿控制下游水位偏差的影响,得到初始流量、分水流量与下游水位最大偏差之间的函数关系式。针对工程运行中的极端工况,原蓄量补偿控制的下游水位偏差过大的问题,采用二次蓄量补偿规则对渠池进行前馈控制,有效减小了下游水位偏差。

液态金属快堆螺旋管蒸汽发生器一、二次侧耦合传热数值研究

螺旋管蒸汽发生器是液态金属快堆中能量传递的核心设备,其运行的稳定性、安全性对核电站的运行有至关重要的影响。为此,本文构建了液态金属快堆螺旋管蒸汽发生器一次侧、二次侧耦合传热的三维数值模型,分别基于经济合作与发展组织核能署(The Organisation for Economic Co-operation and Development,OECD/NEA)物性手册和美国国家标准与技术研究院(National Institute of Standards and Technology,NIST)数据库建立液态金属和水-水蒸气变物性计算关联式,采用Lee相变模型计算二次侧水-水蒸气蒸发过程中两相间的质量传递。基于实验数据,分别对本文模型一次侧传热以及二次侧传热的计算可靠性进行了验证。最后以铅铋快堆为例,研究了不同一次侧进口参数下蒸汽发生器一、二次侧之间的耦合传热特性,并与传统水冷堆进行了对比。结果表明:在同等条件下,相比于传统水冷堆,一次侧采用铅铋液态金属时,一、二次侧之间的壁面热流密度明显提升,热流密度峰值可达1439.97 kW·m^(-2),比水冷堆相应数值提升5~6倍,这导致二次侧管内气相蒸发过程明显加剧,体积含气率急剧上升;同时,一、二次侧之间的沿程热流密度分布更加不均匀,沿程热流密度分布相对偏差值比水冷堆相应数值增大3~4倍。随着一次侧进口铅铋温度从350℃增大到450℃,一、二次侧之间的壁面热流密度随之增大,对应的热流密度峰值从950.7 kW·m^(-2)增大到1439.97 kW·m^(-2),提升约1.5倍,同时一、二次侧之间的沿程热流密度分布更加不均匀,不均匀度增大20%。

铅-超临界二氧化碳换热器耦合流动传热特性研究

为探究螺旋盘管式主换热器内的耦合流动传热机理,基于等长度分段模型,构建了以液态铅和超临界二氧化碳为工质的螺旋盘管式主换热器原型及模化比例样件的理论设计方法,并利用相似性原理完成了主换热器小比例样件设计。以主换热器小比例样件为研究对象,通过SST k-ω湍流模型数值分析了液态铅和超临界二氧化碳在螺旋盘管换热器内的流动传热特性。计算结果表明:螺旋盘管换热器内耦合流动传热性能主要受壳侧质量流量、管侧质量流量和壳侧工质入口温度影响;管侧超临界二氧化碳质量流量对螺旋盘管换热器内耦合流动传热性能的影响最为显著,在超临界二氧化碳质量流量增加52.4%的条件下,螺旋管的平均表面换热系数增大了21.2%;在壳侧液态铅的质量流量和入口温度分别增大94.6%、20 K的情况下,螺旋管内的表面传热系数分别增大了5.5%、3.3%。该研究可为螺旋盘管式换热器的工况选择和高效设计提供理论指导。

Molecular cloning and mRNA expression analysis of myosin heavy chain(MyHC)from fast skeletal muscle of grass carp,Ctenopharyngodon idella

The myosin heavy chain(MyHC)is one of the major structural and contracting proteins of muscle.We have isolated the cDNA clone encoding MyHC of the grass carp,Ctenopharyngodon idella. The sequence comprises 5 934 bp,including a 5 814 bp open reading frame encoding an amino acid sequence of 1 937 residues.The deduced amino acid sequence showed 69%homology to rabbit fast skeletal MyHC and 73%–76%homology to the MyHCs from the mandarin fish,walleye pollack,white croaker,chum salmon,and carp.The putative sequences of subfragment-1 and the light meromyosin region showed 61.4%–80%homology to the corresponding regions of other fish MyHCs.The tissue-specific and developmental stage-specific expressions of the MyHC gene were analyzed by quantitative real-time PCR.The MyHC gene showed the highest expression in the muscles compared with the kidney,spleen and intestine.Developmentally,there was a gradual increase in MyHC mRNA expression from the neural formation stage to the tail bud stage.The highest expression was detected in hatching larva.Our work on the MyHC gene from the grass carp has provided useful information for fish molecular biology and fish genomics.

快堆钠池传热流动计算程序 FASTOR-3D 的校验计算

为研究快堆钠池内的流动和传热，采用质量、动量、能量守恒方程和空隙率方法，建立了快堆钠池内三维流动和传热的数学模型，并利用ＳＩＭＰＬＥ计算方法编制了计算程序ＦＡＳ－ＴＯＲ－３Ｄ．由于钠池的结构非常复杂，任何一点的设计变动可能改变池内的传热特性，给整个快堆带来巨大的影响．选用了１０个比较有代表性的算例，从不同的侧面验证了ＦＡＳＴＯＲ－３Ｄ．计算结果表明，ＦＡＳＴＯＲ－３Ｄ的计算基础是正确的．对于复杂区域的三维流动和传热还有待于全真模型实验的进一步验证．

Establishment and Application of UFC-ACC Heat Transfer Coefficient Model

Based on medium plate runout table ultra-fast cooling( UFC)-accelerated cooling equipment( ACC) system,a heat transfer coefficient model was constructed. Firstly,according to the measured data,heat transfer coefficients under different roll speed and water volume were calculated by using an inverse heat conduction method. Secondly,a monofactorial heat transfer coefficient calculation formula was obtained. Finally,the heat transfer coefficient model based on medium plate runout table UFC-ACC system was constructed by intercept function,slope function,interaction influence function and linear or nonlinear influencing factors. The precision of these models was validated by comparing model prediction value with measured data,and the results were in good agreement with practical needs,and the average deviation was less than 5%.