Efficiently Testing Sparse <Emphasis Type="Italic">GF</Emphasis>(2) Polynomials

We give the first algorithm that is both query-efficient and time-efficient for testing whether an unknown function f:{0,1} ⁿ →{−1,1} is an s-sparse GF(2) polynomial versus ε-far from every such polynomial. Our algorithm makes poly(s,1/ε) black-box queries to f and runs in time n⋅poly(s,1/ε). The only previous algorithm for this testing problem (Diakonikolas et al. in Proceedings of the 48th Annual Symposium on Foundations of Computer Science, FOCS, pp. 549–558, 2007) used poly(s,1/ε) queries, but had running time exponential in s and super-polynomial in 1/ε.     

Research and Implementation of Task Management Model in Product Development Process Management

The implementation of product development process management (PDPM) is an effective means of developing products with higher quality in shorter lead time. It is argued in this paper that product, data, person and activity are basic factors in PDPM With detailed analysis of these basic factors and their relations in product developmed process, all product development activities are considered as tasks and the management of product development process is regarded as the management of task execution A task decomposition based product development model is proposed with methods of constructing task relation matrix from layer model and constraint model resulted from task decomposition. An algorithm for constructing directed task graph is given and is used in the management of tasks. Finally, the usage and limitation of the proposed PDPM model is given with further work proposed.     

3D-QSAR and molecular docking studies of selective agonists for the thyroid hormone receptor beta

Three-dimensional quantitative structure-activity relationship (3D-QSAR) models were developed using comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) on a series of agonists of thyroid hormone receptor beta (TRbeta), which may lead to safe therapies for non-thyroid disorders while avoiding the cardiac side effects. The reasonable q(2) (cross-validated) values 0.600 and 0.616 and non-cross-validated r(2) values of 0.974 and 0.974 were obtained for CoMFA and CoMSIA models for the training set compounds, respectively. The predictive ability of two models was validated using a test set of 12 molecules which gave predictive correlation coefficients (r(pred)(2)) of 0.688 and 0.674, respectively. The Lamarckian Genetic Algorithm (LGA) of AutoDock 4.0 was employed to explore the binding mode of the compound at the active site of TRbeta. The results not only lead to a better understanding of interactions between these agonists and the thyroid hormone receptor beta but also can provide us some useful information about the influence of structures on the activity which will be very useful for designing some new agonist with desired activity.     

Effect of pre-existing substructures on the fatigue properties of pure aluminium

Pure aluminium was thermomechanically treated (cold rolled to 80% reduction of thickness and annealed at 200° C for various lengths of time) in order to obtain different kinds of substructures. These aluminium specimens were then fatigued with a stress amplitude of 9×10³ psi or 90% of their ultimate tensile strength. The substructures of the specimens before and after fatigue were compared with each other and were then correlated to their fatigue property. The size and shape of substructure introduced by fatigue depend on the pre-existing substructure formed by thermomechanical treatment. The sub-boundaries of the fatigued specimen are not as well-defined as the pre-existing subgrain. The substructure size of the fatigued specimen increases initially with annealing time and then reaches a saturation value (2.32 m) when the annealing time is longer than 2 h. A peak value of fatigue life against the annealing time was found if the stress amplitude of fatigue is 90% of the ultimate tensile strength. The peak value also occurs at an annealing time of 2 h. The reason why the specimen annealed for 2 h possesses the optimum fatigue and property is discussed in terms of the substructures before and after fatigue.     

催化重整装置紧急停车系统

介绍固定床半再生催化重整装置紧急停车系统的组成、原理及工作过程，给出调试和维护要点。     

基于VB6.0的汽车点火线圈测试系统软件设计

VB因其简单易学，功能强大而倍受测控软件开发人员的青睐。本文针对作者在开发点火线圈测试台软件的过程中遇到的重点、难点问题—串口通讯、端口读写、数据库操作等，介绍了用Visual BasiC 6．0实现的方法。     

Characterization of (Y,Gd) BxV1-xO4-x:Eu Phosphor Prepared by Coprecipitation Reaction

White body-color (Y, Gd)BxV1- xO4-x :Eu3 phosphors were prepared by coprecipitation reaction. Under VUV excitation at 147 nm, the red emission colorimetric purity of (Y, Gd)BxV1- xO4-x :Eu3 phosphor is much better than that of commercial PDP (plasma display panels) phosphor (Y, Gd)BO3:Eu3 . But its relative emission intensity is only about 90% of the commercial phosphor.     

Study on Adsorption of Rare Earth Elements by Kaolinite

Rareearthelements (REEs)werewidelyappliedtotracingthesourcesofmaterialsandtostudyingtheirevolutionprocessesinmanyfieldsofearthscienceinconsiderationoftheirsimilarityandsystematicdiffer enceinchemicalproperties .Furthermore ,lanthanidesarebothimportantprod…     

Air oxidation behavior of nitrogen ion implanted zircaloy-4 at 500 °C

Journal of Materials Science -