矢量语音传感器微阵列

人工智能的普及促进了语音交互技术的发展,语音传感器阵列作为智能语音交互的硬件前端,成为语音交互领域的前沿研究方向.矢量语音传声器自有的偶极子指向性、零点深度以及阵列体积小便于集成的特点特别符合语音交互技术对硬件设备的要求.基于此,通过采用两组矢量敏感单元"共点正交"形成矢量微阵列实现声源空间锐化波束指向,其不受瑞利限与空间采样率限制,与传统空间离散分布的声压麦克风阵列有着本质区别,是矢量微阵列的核心优势所在.矢量微阵列传声器弥补了现有双麦阵列的不足,具有更为广阔的应用前景,作为智能语音交互的硬件前端,对推动智能语音交互领域的发展具有重要意义.     

基于蜻蜓翅脉结构的连续碳纤维增强树脂基复合材料仿生设计与增材制造

以具有轻质高强优异性能的蜻蜓翅脉结构为设计灵感，在分析翅脉网格结构抗冲击原理的基础上，设计了传统和仿生两类对比结构。采用熔融挤出3D打印机成功制备了具有不同结构的连续碳纤维增强聚乳酸复合材料试样，并对不同结构复合材料试样的拉伸性能和抗冲击性能进行了测试和对比分析。研究分析结果表明：由于拉伸力方向上的连续碳纤维含量相对较少，限制了仿生结构复合材料抗拉强度的提高，但仿生结构的平均抗拉强度为传统结构的1.18倍；当仿生结构复合材料试样受到冲击力时，其内部六边形结构的连接角度会发生变化，从而极大消耗冲击能量，同时具有六边形网格结构的连续碳纤维可以有效阻碍裂纹的扩展，因此仿生结构的平均冲击韧性可以达到传统结构的2.46倍；仿生蜻蜓翅脉结构可以显著提高增材制造复合材料的综合力学性能，且对于抗冲击性能的提高具体突出效果。连续碳纤维增强树脂基复合材料的有效可行的仿生蜻蜓翅脉结构设计和增材制造，可极大扩展其在高冲击载荷领域中的相应应用。     

Decreased CD10-positive granulocytes for the differential diagnosis of myelodysplastic syndrome

Myelodysplastic syndromes (MDS) are highly heterogeneous myeloid neoplasms, and a large number of patients are difficult to diagnose and classify by blood and bone marrow examination. As a surface marker of granulocyte, studies have shown CD10 can be used to define the degree of granulocyte maturation in MDS patients. However, whether it can be used for differential diagnosis of MDS and other hematological diseases remains inconclusive. To explore the value of CD10 for differential diagnosis of MDS, 60 newly diagnosed MDS, 20 aplastic anemia (AA) patients, and 35 iron-deficient anemia (IDA) patients were selected for this study. Bone marrow (BM) specimens were processed for surface marker analysis and labeled with pre-conjugated monoclonal antibodies. Stained cells were detected by flow cytometry. Our results indicated that CD10-positive granulocytes were significantly decreased in BM of MDS patients than AA and IDA patients, and the level of CD10-positive mature granulocytes was not associated with the clinical stages of malignancy. Receiver operating characteristic (ROC) areas under the curve (AUC) of CD10-positive granulocytes was 0.86 and 0.85, respectively, in MDS patients than the IDA group and AA group with good specificity and sensitivity. Further, CD10-positive granulocytes were increased after effective treatment. In conclusion, we found the decrease in CD10-positive granulocytes has a differential diagnostic value of MDS.     

300M超高强钢在中性盐雾环境中的腐蚀行为及机制

摘要：为了研究300M超高强钢在中性盐雾环境中的腐蚀行为及腐蚀机制，采用失重法，宏观、微观腐蚀形貌分析，三维表面轮廓分析及电化学分析的研究方法，来表征腐蚀实验现象并进行分析。结果表明：300M超高强钢在中性盐雾环境中的腐蚀产物为FeOOH、Fe2O3、Fe(OH)3和Fe3O4；腐蚀速率随着腐蚀时间逐渐降低，腐蚀后期（72h）腐蚀速率降低50%；腐蚀初期以点蚀为主，点蚀坑通过横向扩展，逐渐发展为后期的均匀腐蚀，腐蚀表面形貌呈沟壑状；外腐蚀层对基体的保护能力很弱，Cr元素在锈层靠近基体的一侧偏聚使内腐蚀层具有一定的抗腐蚀性。     

Adaptive backstepping repetitive learning control design for nonlinear discrete‐time systems with periodic uncertainties

This paper addresses a tracking problem for uncertain nonlinear discrete‐time systems in which the uncertainties, including parametric uncertainty and external disturbance, are periodic with known periodicity. Repetitive learning control (RLC) is an effective tool to deal with periodic unknown components. By using the backstepping procedures, an adaptive RLC law with periodic parameter estimation is designed. The overparameterization problem is overcome by postponing the parameter estimation to the last backstepping step, which could not be easily solved in robust adaptive control. It is shown that the proposed adaptive RLC law without overparameterization can guarantee the perfect tracking and boundedness of the states of the whole closed‐loop systems in presence of periodic uncertainties. In addition, the effectiveness of the developed controller is demonstrated by an implementation example on a single‐link flexible‐joint robot. Copyright © 2014 John Wiley & Sons, Ltd.     

P-doped CoSe2 nanoparticles embedded in 3D honeycomb-like carbon network for long cycle-life Na-ion batteries

We report for the first time a Na-ion battery anode material composed of P-doped CoSe2 nanoparticles(P-CoSe2)with the size of 5-20 nm that are uniformly embed in a 3D porous honeycomb-like carbon network.High rate capability and cycling stability are achieved simultaneously.The honeycomb-like carbon network is rationally designed to support high electrical conductivity,rapid Na-ion diffusion as well as the accommodation of the volume expansion from the active P-CoSe2 nanoparticles.In particular,heteroatom P-doping within CoSe2 introduces stronger P-Co bonds and additional P-Se bonds that signif-icantly improve the structure stability of P-CoSe2 for highly stable sodiation/desodiation over long-term cycling.P-doping also improves the electrical conductivity of the CoSe2 nanoparticles,leading to highly elevated electrochemical kinetics to deliver high specific capacities at high current densities.Benefiting from the unique nanostructure and atomic-level P-doping,the P-CoSe2(2∶1)/C anode delivers an excel-lent cycle stability with a specific capacity of 206.9 mA h g-1 achieved at 2000 mA g-1 after 1000 cycles.In addition,this material can be synthesized using a facile pyrolysis and selenization/phosphorization approach.This study provides new opportunities of heteroatom doping as an effective method to improve the cycling stability of Na-ion anode materials.     

Attitude dynamics of coupled spacecraft undergoing fuel transfer

Multibody System Dynamics - This paper represents an explicit analytical solution for attitude dynamics of spacecraft combination during on-orbit refueling. Due to the fuel transfer from the...     

Wearing prediction of stellite alloys based on opposite degree algorithm

In order to predict the wearing of stellite alloys,the related methods of rare metals data processing were discussed. The method of opposite degree(OD) algorithm was put forward to predict the wearing of stellite alloys.OD algorithm is based on prior numerical data, posterior numerical data and the opposite degree between numerical forecast data. To compare the performance of predicted results based on different algorithms, the back propagation(BP) and radial basis function(RBF) neural network methods were introduced. Predicted results show that the relative error of OD algorithm is smaller than those of BP and RBF neural network methods. OD algorithm is an effective method to predict the wearing of stellite alloys and it can be applied in practice.     

关于水电站建设工程保险

介绍了国内外水电站工程建设中应投保的主要保险险种及其理赔情况。通过对国内外的水电站保险状况对比,及对工程保险实例的论述,指出了我国水电站建设工程保险的现状,通过实施保险来减轻和转移水电站工程的风险和损失。