弱双曲流形的逼近

弱双曲流形是一类包含中心流形作为其特例的不变流形.本文讨论了它的逼近问题,不仅给出了计算其逼近的方法,还估计了使得这一逼近有效的它的局部性半径. 同时给出了一个具体实例来展示这些计算和估计.     

现代机构精度分配理论的发展方向和关键

本文分析、探讨了机构精度分配理论和方法的组成和发展概况及其发展方向,在此基础上指出了发展现代机构精度分配理论问题的关键及其前景。     

Dishing and nitride erosion of STI-CMP for different integration schemes

In this paper, we investigate the effects of integration schemes on the STI-CMP performance of two polishers, as well as the influence of consumables and process parameters. The experiment was based on both the blanket-oxide wafers and the patterned wafers processed using 0.18 μm technology. The polishing capability was evaluated, based on the results collected using metrology tools such as Opti-probe, Tencor profiler; atomic force microscope (AFM), and x-ray-scanning electron microscopy (X-SEM) analysis.     

以学生为主体的混合式个性化教学模式在分析化学课程中的探索与思考

In order to solve the issues of traditional teaching methods in the undergraduate basic theory course, the blended learning mode was put forward by taking analytical chemistry as an example. With concept of student-centered, personalized teaching, together with assistant means, was introduced to achieve the breakthrough in solving the problems. We hope to reinforce the adaptability and targeting of the course teaching.     

非晶态(Fe1-xWx)84.5B15.5合金的低温电阻率反常

研究了(Fe_1-xW_x)_84.5B_15.5(x=0—0.1)非晶态合金的电阻率ρ与温度T(4.2—300K)的关系。实验结果表明,在所研究浓度区域内均出现电阻率与温度关系的极小值,电阻率极小值的温度T_min在x=0.06时出现峰值。用x=0.02—0.1浓度区域内,当Tmin时,又出现了电阻率与温度关系的极大值,电阻率极大值的温度T_max在26—35K之间。低温电阻率反常现象与类Kondo效应及局域磁矩之间RKKY相互作用有关。 关键词：     

Two New O-terpenoidal Coumarins, Excavacoumarin A and B from Clausena excavata

Cla!tsenaexcavataBurm.f(Rutaceae)isabushwidelydistributedinYunnan,China.Leavesandbarksofthisplanthavebeenusedasfolkrnedicineforthetreatmentofdysentery,enteritis,andurethrainfection1.ClalISenaspeciesareknowntobetherichsourcesofcarbazolealkaloidsandcoumarins=-j.TheconstituentsofCexcavalacollectedinXishuangbannahavebeenstudied'andthispaperdescribestheisolationandstructureelucidationoftwonewO-terpenoidalcoumarins,excavacoumarinA(2)andexcavacoumarinB(3),andthel3CNMRspectraldataassignmentsfora…     

A New Technique to Determine Horizontal and Vertical Permeabilities from the Time-Delayed Response of a Vertical Interference Test

To determine the permeabilities from a vertical interference test, earlier investigators proposed correlations or type curves based on point source solutions or partially penetrated well solutions. However, it is impossible for these correlations or type curves to cover all possible scenarios in the real world. In more recent years, people use regression analysis to simultaneously match the pressure responses at the source interval and the observation point. With regression analysis, we face the problem of non-unique solutions. Sometimes, estimated permeability could be outside a reasonable range when analyzing noisy data from real tests. In this paper, a new technique is presented to estimate horizontal and vertical permeabilities from the time-delayed response in a wireline vertical interference test. In a vertical test, a pressure drawdown test period is followed by a pressure buildup test period. Because of the delay in response, the pressure at the observation probe continues to drop for some time while the pressure at the source interval is being built up. The maximum pressure drop at the observation probe with regard to the maximum pressure drop in the source interval is time-delayed. Using this time delay and the maximum pressure drop at the observation probe, vertical and horizontal permeabilities can be estimated. A novel numerical scheme is used. The new technique is compared with the previous methods, and it shows its superiority in accuracy. In addition, it can be used in different test configurations. Application issues in real testing conditions are discussed. Finally, two field tests are analyzed using this technique, while an earlier effort to analyze the tests using a conventional method was not successful due to poor data quality.     

模糊控制技术中一种特殊的高维插值法

本文介绍一种在模糊控制技术中高维插值方法的应用。这种方法可以由有限数据或经验规则，通过高维插获完整的全值表，从而克服了过去去多因素，多目标，非线性的复杂被控系统由于经验规则远远不足，无法得到完整的控制规则表听困难。为进一步设计模糊模糊控制器提供了可行的基础。     

Parlay Gateway体系结构的多视点研究

基于“4 1”多视点模型描述了ParlayGateway体系结构的全貌。逻辑视点模型清晰地描述了ParlayGateway的概念模型,分析了该逻辑功能实体涉及的主要角色及其逻辑功能;将面向对象、构件化、低耦合的思想用于开发视点模型,展示了它的标准接口功能、协议适配功能等主要内容;在进程、物理视点模型中,描述了它的并发、冗余、安全、一致性等各种非功能属性,部署视图模型专门讨论网关和网络实体的连接问题;在场景视图中,将多个视点的研究有机地结合起来,全面展示了SCF注册、AS发现、Framework认证、第三方应用执行的整个过程。     

超冷费米气体研究的新进展

近几年,人们在超冷费米气体的实验和理论研究方面取得了一系列激动人心的进展,比如分子玻色—爱因斯坦凝聚的成功实现和BCS-BEC渡越过程的大量研究。在本文中,我们对超冷费米气体中的这些进展进行了介绍,并讨论了今后几年的发展趋势。