Preparation and characterization of r.f.-sputtered multilayered TiN---Au films

TiN---Au films with multiple intermediate layers deposited by r.f. sputtering are suggested as a solution to the problem of adhesion of gold films to TiN coatings. Their optical and mechanical properties are investigated and compared with those of conventional electroplated gold films. Various analysis techniques have been used: Auger electron spectroscopy to determine the composition profiles, the direct tensile test for adhesion characteristics, optical rub test for scratch characteristics, salt spray test for corrosion characteristics and the selected ordinate method to identify the color of resultant films. It is shown that poor adhesion of gold films of TiN coatings can be overcome. Resultant multilayered TiN---Au films show the same color as that of commercially available electroplated gold films and their reflectivity reaches 98% of that of gold films over the wavelength range studied. For further applications, electrical properties of multilayered TiN---Au have also been studied. The sheet resistance of these TiN---Au films on n-Si and p-Si is in the range 0.54ω/□–6.12ω/□. Thus these multilayered structures may be used as durable contacts for microelectronic applications.     

Bioeffects of Low Energy Ion-Beam Implantation and Vacuum Treatment on M1 Arabidopsis Thaliana

Vacuum treatment and ion-beam bombardment are two major processes in the low energy ion-beam implantation. To accurately study the contributions of these two major factors to the bioeffects separately, the M1 generation variation of Arabidopsis thaliana with ion-beam implantation and vacuum treatment were compared through a series of key plant development parameters including morphological observation, biochemical assay and RAPD （random amplified polymorphic DNA） analysis. The results showed that ion-beam implantation had obvious effect on almost all of these parameters, and the vacuum treatment had some impacts on several morphological parameters such as the bolting time and the length of the primary stem. Taking the results together, the indication is that vacuum treatment has some slight contributions to the bioeffects of ion-beam implantation while ion-beam bombardment itself is the major creator of the bioeffects.     

The nature and role of incoherent interphase interfaces in diffusional solid-solid phase transformations

In this article, some views on the nature of incoherent interphase interfaces, and their role in the nucleation and growth processes governing the evolution of microstructure in solid-state diffusional transformations (reconstructive transformations), are explored. It is argued that essentially incoherent interfaces can be involved in the initiation and propagation of polymorphic transformations and massive transformations as well as in various precipitation phenomena in metallic and ceramic systems. Similar views have already been advanced earlier in connection with studies of massive transformations. Faceting along the interphase interface during nucleation and growth can derive from thermodynamic, kinetic, and crystallographic factors independent of the bicrystallography of the conjugate phases. This idiomorphic behavior can be relevant to both intergranular and intragranular phase formation. The concept of one-dimensional (1-D) commensuration of phases through plane edge-to-edge/row matching is an interesting extension of the classic ideas of coherency and bicrystallography and potentially important in characterizing the behavior of certain types of boundaries. However, the general importance of these geometrical relations in real and reciprocal space will depend on the depth of the energy wells in orientation space associated with these special boundaries. This article is based on a presentation made in the “Hume-Rothery Symposium on Structure and Diffusional Growth Mechanisms of Irrational Interphase Boundaries,” which occurred during the TMS Winter meeting, March 15–17, 2004, in Charlotte, NC, under the auspices of the TMS Alloy Phases Committee and the co-sponsorship of the TMS-ASM Phase Transformations Committee.     

An efficient implementation of SELF, a dynamically-typed object-oriented language based on prototypes

We have developed and implemented techniques that double the performance of dynamically-typed object-oriented languages. Our SELF implementation runs twice as fast as the fastest Smalltalk implementation, despite SELF's lack of classes and explicit variables.To compensate for the absence of classes, our system uses implementation-levelmaps to transparently group objects cloned from the same prototype, providing data type information and eliminating the apparent space overhead for prototype-based systems. To compensate for dynamic typing, user-defined control structures, and the lack of explicit variables, our system dynamically compilesmultiple versions of a source method, eachcustomized according to its receiver's map. Within each version the type of the receiver is fixed, and thus the compiler can statically bind andinline all messages sent toself.Message splitting andtype prediction extract and preserve even more static type information, allowing the compiler to inline many other messages. Inlining dramatically improves performance and eliminates the need to hard-wire low-level methods such as+, ==, andifTrue:.Despite inlining and other optimizations, our system still supports interactive programming environments. The system traverses internal dependency lists to invalidate all compiled methods affected by a programming change. The debugger reconstructs inlined stack frames from compiler-generated debugging information, making inlining invisible to the SELF programmer.This work has been generously supported by National Science Foundation Presidential Young Investigator Grant #CCR-8657631, and by IBM, Texas Instruments, NCR, Tandem Computers, Apple Computer, and Sun Microsystems.This paper was originally published inOOPSLA '89 Conference Proceedings (SIGPLAN Notices, 25, 10 (1989) 49–70).     

Edge-to-edge matching in thin films

A peculiar type of preferential orientation was recently observed in polycrystalline films that are formed by a solid-state reaction on a single crystal substrate. This texture, for which the term axiotaxy was proposed, is characterized by the preferred alignment of a low-index plane in the film to a low-index plane with the same d-spacing in the substrate. The alignment of lattice planes with nearly identical d-spacings across the interface results in a periodic structure along one direction in the plane of the interface. As a consequence of the constraint that a set of planes in the film is preferentially parallel to a set of planes in the substrate, the texture manifests itself as an off-normal fiber texture. This article is based on a presentation made in the “Hume-Rothery Symposium on Structure and Diffusional Grwoth Mechanisms of Irrational Interphase Boundaries,” which occurred during the TMS Winter meeting, March 15–17, 2004, in Charlotte, NC, under the auspices of the TMS Alloy Phases Committee and the co-sponsorship of the TMS-ASM Phase Transformations Committee.     

振动筛合金篦条磨损机理及抗磨损技术

分析了山西焦化股份有限公司振动筛合金篦条磨损情况，对合金篦条磨损机理进行了研究，提出控制磨蚀和提高材料耐磨洼的方法。     

Layered Video and Differentiated Coding for Adaptive QoS in Mixed Wired-Satellite Networks

Mobile networks are becoming nothing but a way to allow ubiquitous access to multimedia services. To allow efficient use of resources, new systems provide flexible bandwidth and different error protection techniques to match channel behavior. As the backbone network is increasingly becoming based on packet techniques and in particular on IP and related transport protocols, end to end service quality must be analyzed considering both the fixed and the mobile part. Source scalability may help in coping with a mixed and heterogeneous environment. In this work we present some results of a transmission chain comprising a scalable MPEG-2 coder, an IP network and a radio access exploiting the availability of satellites. It is shown that for a given target rate, differentiated coding can be exploited to achieve decodability and good quality at a channel SNR much lower that single layer streams. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于排队理论的渠道容量设计

在设计一个新的灌溉配水系统时，渠道容量是一个不易确定的参数，因为农场用户提出供水的时间和水量通常是不确定的，取决于季节、气候、农作物种类等因素。渠道容量对灌溉投资和服务质量有重要的影响。提出运用排队理论确定渠道容量的大小。依据该理论，服务系统需提供的容量取决于将要达到的服务水平，以及顾客到达时间和服务时间的平均密度和分布规律。将灌溉渠道容量比作排队系统的服务能力。研究了指数分配和非指数分配模型及10个连续的灌溉周期。计算实例显示，同传统的Clement方程相比，该方法的结果相当可信。     

埋地管道三层PE外覆盖层及其检测方法研究

文章介绍了埋地管道三层PE外覆盖层系统的构造参数和性能特点,论述了两种用于埋地钢质管道外覆盖层状况检测的方法,一种是多频管中电流法,另一种是DCVG/CIPS组合检测技术。分别介绍了两种方法的工作原理、操作方法和设备,并结合工程实例进行了说明。这些方法和设备可分别或同时用于管道不开挖检测防腐层破损点的位置以及漏点大小。     

大庆油田三类油层聚合物驱注入速度研究

注入速度是影响聚合物驱开发效果的重要指标,而由于假设条件的局限性,数值模拟方法无法体现聚合物溶液弹性对注入速度的影响。为了确定大庆油田三类油层合理注入速度,通过不同注入速度条件下的天然岩心驱油试验,对水驱和聚合物驱驱油效率进行了研究,结果表明,聚合物驱驱油效率提高值随驱替速度的变化可由二次多项式来表示。依据此关系式,由势的叠加理论得到的流体在油层中的渗流速度的基础上,建立了该类油层合理注入速度模型,并给出大庆油田三类油层在100 m注采井距下的合理注入速度为0.288 PV年/,该方法对现场开发方案编制有重要指导意义。