自适应防漏堵漏钻井液技术研究

针对钻井液漏失地层非均质性强及漏失通道尺寸难以准确预知等问题,提出了自适应防漏堵漏钻井液技术。该技术无须明确预知漏失地层孔喉直径,能自适应封堵岩石表面较大范围的孔喉,对较宽孔径分布的漏层具有很好的封堵作用,封堵速度快,封堵层浅,适合于油层防漏、堵漏。室内评价表明,自适应防漏堵漏钻井液能在一定范围内对不同孔径分布的漏层产生良好的封堵作用。封堵率达到90%以上,封堵带压力强度大于9MPa,封堵厚度小于1cm,切片后渗透率恢复率达90%以上。现场应用证明,自适应防漏堵漏钻井液能有效提高地层的承压能力,并且有良好的防漏及堵漏效果。     

Effects of level of cooperative choice by the other player on choices in a prisoner's dilemma game: Part I.

In a Prisoner's Dilemma type game, Ss (male and female students) were asked to make repeated choice between 2 alternatives, R and B, where R is presumably the cooperative and B the competitive choice. While believing that they were playing persons of the same sex, Ss actually played a simulated partner who, for ? of the group, chose 83% random R and, for the other ?, 83% random B for 30 trials. Thereafter for 60 trials, the simulated partner chose according to a strategy of 83% matching, 17% mismatching the choices of S. The purpose of this procedure was to determine the effects of initial level of simulated cooperation on S's own level of cooperation. The results failed to demonstrate that the level of simulated cooperation employed functioned to determine choice by S. Ss had been stratified according to a test of character which failed to predict choice. However, a 2nd scoring formula employed on this test did significantly distinguish the amount of R choice emitted by S and deserves further examination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduction of NRRO in ball bearings for HDD spindle motors

In this paper, it is theoretically and experimentally analyzed that the non-repetitive run-out (NRRO) of a ball bearing is caused by geometrical errors of the inner and outer races and the balls, and the number of balls.

The results are summarized as follows:

(1) As for the geometrical errors of the inner and outer races, it is possible to reduce the NRRO to be less than 1 nm by choosing 12 or 18 number of balls, even if the inner and outer races have a harmonic undulation of less than the 11th order.

(2) The NRRO of a ball bearing with 12 balls is very small even if the geometrical errors of ball bearing parts are large. It was confirmed that 12 was an optimal number of balls for ball bearings used for HDD spindle motors.

     

Avoiding game‐tree pathology in 2‐player adversarial search

Adversarial search, or game‐tree search, is a technique for analyzing an adversarial game to determine what moves a player should make in order to win a game. Until recently, lookahead pathology (in which deeper game‐tree search results in worse play) has been thought to be quite rare. We provide an analysis that shows that every game should have some sections that are locally pathological, assuming that both players can potentially win the game. We also modify the minimax algorithm to recognize local pathologies in arbitrary games and cut off search accordingly (shallower search is more effective than deeper search when local pathologies occur). We show experimentally that our modified search procedure avoids local pathologies and consequently provides improved performance, in terms of decision accuracy, when compared with the minimax algorithm. In addition, we provide an experimental evaluation on the African game of Kalah, which shows the improved performances of our suggested error‐minimizing minimax algorithm when there is a large degree of pathology.     

A NOVEL ROUTE FOR MAKING COERCIVE NdFeB POWDER——HDD PROCESS

NdFeB coercive powder can be obtained directely by hydrogen treated ahoy ingots,The magnetic properties of the powder are comparable with that made by rapidsolidifiedprocess.An appreciable coercivity created during hydrogen treatment is closely relatedto the refined crystal grains.     

硬盘驱动器（HDD）用磁性材料

简要介绍了迅猛发展的计算机硬盘驱动器（ＨＤＤ）用的新型磁性材料。它们分别是磁头材料,磁记录材料,永磁材料以及磁流体材料。同时叙述了这些材料在硬盘驱动器中的作用以及未来发展的前景。     

硬盘播放机的运输包装设计研究

由于硬盘播放机运输距离较远,为减少运输成本,以某款硬盘播放机的运输包装为研究对象,在保障运输过程中产品不破损的条件下,以40英尺的货柜为运输单元,提出了3种包装设计方案,从产品保护性、缓冲性能、经济性、环保性结合客户意见,对3个方案进行了评估,选择了最终的方案。根据选择的方案制作了包装样品,在环境试验和运输包装测试的基础上,进一步修改和优化了设计方案,使产品装载量提高了5%,经厂方鉴定后已投入工业实际应用。     

用于工程勘察的水平定向钻探技术探讨

在工程勘察中采用水平定向钻探技术,可以高效地解决一些垂直钻孔无法解决的问题。论文概述了水平定向钻探技术在非开挖铺设管线、油气钻井、地质勘探等领域的技术现状,认为在工程勘察领域的应用前景广阔。分析了应用水平定向钻探进行工程勘察在适用能力、勘察速度、勘察精度等方面具有的优势,提出水平定向钻探适用于深埋隧道等水平线状工程、既有建筑加固工程、考古发掘探测等领域的勘察。最后对应用于工程勘察的水平定向钻探技术需要研发的重点方向提出了建议,包括超长孔钻进技术、轨迹控制技术、连续取心技术、综合测试技术等。     

On the distributed stable full information H∞ minimax problem

We study the distributed parameter suboptimal full information H^∞ problem for a stable well-posed linear system with control u, disturbance w, state x, and output y. Here u, w, and y are L²-signals on (0,∞) with values in the Hilbert spaces U, W, and Y, and the state x is a continuous function of time with values in the Hilbert space H. The problem is to determine if there exists a (dynamic) γ-suboptimal feedforward compensator, i.e., a compensator 𝒰 such that the choice u = 𝒰w makes the norm of the input/output map from w to y less than a given constant γ. A sufficient condition for the existence of a γ-suboptimal compensator is that an appropriately extended input/output map of the system has a (J,S)-inner–outer factorization of a special type, and if the control and disturbance spaces are finite-dimensional and the system has an L¹ impulse response, then this condition is also necessary. Moreover, in this case there exists a central state feedback/feedforward controller, which can be used to give a simple parameterization of the set of all γ-suboptimal compensators. Our proof use a game theory approach. © 1998 John Wiley & Sons, Ltd.     

Analysis of Collaborative Brain Computer Interface (BCI) Based Personalized GUI for Differently Abled

Brain-Computer Interfaces (BCI) use Electroencephalography (EEG) signals recorded from the brain scalp, which enable a communication between the human and the outside world. The present study helps the patients who are people locked-in to manage their needs such as accessing of web url’s, sending/receiving sms to/from mobile device, personalized music player, personalized movie player, wheelchair control and home appliances control. In the proposed system, the user needs are designed as a button in the form of a matrix, in which the main panel of rows and columns button is flashed in 3 sec intervals. Subjects were asked to choose the desired task/need from the main panel of the GUI by blinking their eyes twice. The double eye blink signals extracted by using the bio-sensor of NeuroSky’s mind wave device with portable EEG sensors are used as the command signal. Each task is designed and implemented using a Matlab tool. The developed Personalized GUI application collaborated with the EEG device accesses the user’s need. Once the system identifies the desired option through the input control signal, the appropriate algorithm is called and performed. The users can also locate the next required option within the matrix. Therefore, users can easily navigate through the GUI Model. A list of personalized music, movies, books and web URL’s are preloaded in the database. Hence, it could be suitable to assist disabled people to improve their quality of life. Analysis of variance (ANOVA) is also carried out to find out the significant signals influencing a user’s need in order to improve the motion characteristics of the brain computer interface based system.