Statistical inference on restricted partially linear additive errors-in-variables models

As a useful extension of partially linear models and additive models, partially linear additive model has been paid considerable attention in recent years. This paper considers statistical inference for the semiparametric model when the covariates in the linear part are measured with additive error. To test hypothesis on the parametric component, we propose a novel test statistic based on the difference between the corrected residual sums of squares under the null and alternative hypotheses, and show that its limiting distribution is that of a weighted sum of independent standard? $\chi_{1}^{2}$ . We also develop an adjusted test statistic, which has an asymptotically standard chi-squared distribution. Some simulation studies are conducted to illustrate our approaches.     

基于多阶段工作转移矩阵的串行耦合设计任务分配策略

针对串行耦合设计任务的团队分配因涉及任务的返工而导致分配策略相当复杂这一问题,引入多阶段工作转移矩阵,将任务间的耦合关系以返工量的形式量化,并根据团队分配衍生矩阵建立串行耦合设计任务分配的数学模型,简化了串行耦合设计任务的分配过程。利用遗传算法求解该模型,获得了不同设计需求下产品开发任务的最佳任务分配方案。以某电动汽车开发项目为例,验证了该模型的可行性和有效性。     

Preparation and friction properties of PBT/MMT composites

Poly(butylene terephthalate)/clay composites were prepared by direct melt compounding. Two structures were formed as confirmed by XRD and transmission electron microscopy. The presence of MMT layers does not change the crystal structure and the degree of crystallinity of PBT matrix. The tribological behaviors of neat PBT and PBT/clay composites were studied by the means of a pin‐on‐disk apparatus. It was found that the intercalation of organoclay could help reduce the friction coefficient and the specific wear rate of PBT, while the addition of natural clay was harmful to the friction coefficient and wear resistance of the polymer matrix. The different tribological behaviors of the composites are due to their different morphologies and the difference in the interfacial adhesion between the matrix and the clay platelets. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

The friction and wear properties of clay filled PA66

Polyamide 66(PA66)/clay nanocomposites were prepared by direct melt compounding. The mechanical and tribological properties were evaluated. It was found that addition of clay into PA66 increased the bending strength and microhardness of PA66. And also, the incorporation of clay can reduce the friction coefficient of PA66. The nanocomposites which have the mass fraction less than 5% show less wear rate compared with neat PA66. High fraction of clay can cause severe agglomerated abrasives. The differences in the friction and wear behaviors of PA66 and PA66/clay nanocomposites are attributed to the differences in their surface morphologies, transfer film characteristic. The agglomerated abrasives on the worn surface contribute to the increase of wear rate of nanocomposites of higher mass fraction clay. The friction and wear behaviors of PA66 and its nanocomposites under high temperature exhibit similar tendency with those under 25°C. POLYM. ENG. SCI., 48:203–209, 2008. © 2007 Society of Plastics Engineers     

Flexible visible-infrared metamaterials and their applications in highly sensitive chemical and biological sensing

Flexible electronic and photonic devices have been demonstrated in the past decade, with significant promise in low-cost, light-weighted, transparent, biocompatible, and portable devices for a wide range of applications. Herein, we demonstrate a flexible metamaterial (Metaflex)-based photonic device operating in the visible-IR regime, which shows potential applications in high sensitivity strain, biological and chemical sensing. The metamaterial structure, consisting of split ring resonators (SRRs) of 30 nm thick Au or Ag, has been fabricated on poly(ethylene naphthalate) substrates with the least line width of ～30 nm by electron beam lithography. The absorption resonances can be tuned from middle IR to visible range. The Ag U-shaped SRRs metamaterials exhibit an electric resonance of ～542 nm and a magnetic resonance of ～756 nm. Both the electric and magnetic resonance modes show highly sensitive responses to out-of-plane bending strain, surrounding dielectric media, and surface chemical environment. Due to the electric and magnetic field coupling, the magnetic response gives a sensitivity as high as 436 nm/RIU. Our Metaflex devices show superior responses with a shift of magnetic resonance of 4.5 nm/nM for nonspecific bovine serum albumin protein binding and 65 nm for a self-assembled monolayer of 2-naphthalenethiol, respectively, suggesting considerable promise in flexible and transparent photonic devices for chemical and biological sensing.     

文家沟巨型岩质滑坡高速远程运移特征分析

文家沟滑坡是汶川地震诱发的巨型高速远程岩质滑坡,其运移特征尚不明确.在现场调查的基础上,结合遥感解译,进一步深入研究其运移特征.分析得出,滑体自滑源区差异性启动,途经斜坡区铲刮坡表岩土体,随后以滑行、飞行等方式进入沟谷区,沿沟铲刮两岸坡体继续下行,与岸坡发生了5次明显的冲撞,逐步解体碎屑化,于第3次冲撞后开始大规模减速堆积,最终于沟口区停积.结果表明,地形是滑体运移堆积的主控因素,滑体的解体碎屑化和冲撞山体时的爬高、抛摔、越顶现象以及冲击气浪的形成等是高速行程的具体表现,碰撞是导致全程解体碎屑化的主要途径.     

Twinning‐, Polytypism‐, and Polarity‐Induced Morphological Modulation in Nonplanar Nanostructures with van der Waals Epitaxy

Twinning, polytypism, and polarity are important aspects in nanostructural growth since their presence can affect various properties of the as‐grown products. The morphology of nanostructures grown via van der Waals epitaxy is shown to be strongly influenced by the twinning density and the presence of polytypism within the nanostructures, while the growth direction is driven by the compound polarity. With ZnTe as the model material, vertically aligned nanorods are successfully produced with variable cross‐section and branched crystals (tripods and tetrapods) on only a single type of substrate. Van der Waals epitaxy contributes by relaxing the lattice‐mismatch requirements for epitaxial growth and by enabling a variety of crystal planes in the initial stages of the growth to be interfaced to the substrate, regardless of the polarity of the epitaxial material. These results may provide more flexibility in tuning rationally the morphology of epitaxial nanostructures into other shapes with higher complexity by routine adjustment of growth environment.     

低比例甲醇汽油在通用小型汽油机中的试验研究

在ST188通用小型汽油机未做调整的情况下,试验研究了燃用低比例甲醇汽油(M10和M20)对发动机性能的影响.试验结果表明,通用小型汽油机燃用甲醇汽油后,随甲醇含量的增加动力性呈下降趋势;与93#标准汽油相比,甲醇汽油虽然油耗率有所上升,但能耗率相当;比较甲醇汽油与汽油的常规排放物发现,甲醇汽油对CO的降低有明显作用,对HC的排放有升高作用,对NOx的排放有所增加,但增加幅度不大.     

轿车自动无级变速器的试验研究及其试验装置的开发

燃油经济性和较少的有害气体排放和日益增大的舒适性等要求是现代汽车十分重要的研究课题,ＣＶＴ已经从理论上回答现代汽车设计所需迫切解决的很多问题,其主要优点是改善了汽车性能,燃油消耗和排污。     

Exploration on ecological regulation of the reservoirs

Reservoir regulation process in the Yangtze River Basin is mainly divided into two types of flood regulation and initiating benefit regulation. The present reservoir management system and operation mode are mainly fro dealing with or coordinating of flood control and benefit initiation as well as benefit distribution among various beneficial functions. From the view point of river eco-system protection, the current regulation mode has two kinds of problems: firstly, most of the reservoir regulation plans do not consider eco-system protection at downstream of dams and needs of environment protection in reservoir areas; secondly, integrated regulation or management of water resources is ignored. It is very necessary to improve reservoir regulation mode, bearing problems faced by regulation of the Three Gorges Reservoir and issues related to cascade development and regulation in Tuojiang and Minjiang River Basins in mind. In accordance with the concept of scientific development, and the philosophy of “ensuring a healthy Yangtze River and promoting the harmony between human and water”, taking flood control, benefit initiation and eco-system as a whole, this paper put forward the basic consideration to improve reservoir regulation as follows: on the basis of requirements of eco-system protection at downstream of dams and needs of environment protection in reservoir areas, we should bring the functions of reservoir such as flood control and benefit initiation into full play, control the negative influence to the eco-system at downstream of dams and the environment in reservoir areas in an endurable scope, and restore the eco-system and the environment step by step. This paper put forward the relevant regulation process aiming at the idiographic problems such as protection of eco-system at downstream of dams and environment in reservoir areas, protection of aquatic wildlife species and fish species, regulation of sediment and protection of wetland.