自动机床刀具的自动保护

介绍用单片机与逻辑控制电路自动测量和控制刀具的切削温度和切削力，从而保证刀具在切削加工中长久正常地工作，以达到提高刀具寿命、减少刀具消耗的目的。     

An Introduction to Using XML for the Management of Laboratory Data

Extensible Markup Language (XML) and the XML Path Language (XPath) are introduced with software examples demonstrating how one can use them to write laboratory data management programs. Topics explored include XML document creation, manipulation, and searching. Programming examples make use of the Microsoft® XML Parser library and the Visual Basic programming language. The problem of managing microplate screening data is used as an illustration. Source code for all examples can be downloaded from http://www.labprogrammer.net.     

Connectivity Infrastructure and Components for POCT Environments - Overall Infrastructure

Connectivity infrastructure, hardware and software components for point-of-care testing (POCT) environments at medium-to-large sized hospitals with expected number of POCT instruments in the order of hundreds or thousands are described. The instruments include both network-ready and non-network-ready devices. The latter are connected to the network by means of a hardware-based Instrument Network Adapter. Instrument messages are converted to standardized form and, depending on message content, are routed and delivered to appropriate destinations by a software-based Message Routing System consisting of a Message Router and a Delivery Agent. Target information systems consist of departmental and central information systems.     

Integrated Mobility and QoS Control in Cellular Wireless ATM Networks

This paper presents a traversed pathtracking-based technique for integrated mobility andquality-of-service (QoS) management of connections incellular wireless ATM networks. Simulation andanalytical results for probabilities of connectionBlocking, Dropping, and Unsuccessful Connections aredetermined. A distributed operating system-basedarchitecture for implementation of integrated mobilityand QoS control is then proposed. The objective is totreat mobility as a network impairment triggeredactivity which is to be handled via QoS management.Depending on the speed of the mobile unit and thecategory of service being used, the QoS of a connectionmay or may not vary continuously during a session. Theresults presented here consider coexistence of constantbit-rate and nonreal-time variable bitrate ATM connections over a single session.     

Control of the Underactuated Inertia Wheel Inverted Pendulum for Stable Limit Cycle Generation

This paper deals with a control approach dedicated to stable limit cycle generation for underactuated mechanical systems. The proposed approach is based on partial nonlinear feedback linearization and dynamic control for optimal periodic reference trajectories tracking. The computation of the reference trajectories is performed in order to optimize the behavior of the whole dynamics of the system and especially its zero dynamics at the end of each cycle. Simulation results as well as experiments show the performance and the efficiency of the proposed control scheme.     

Coupled effect of heat input and beam oscillation on mechanical properties of alloy 718 electron beam weldments

Abstract

Autogenous full penetration electron beam welds were made on alloy 718 with and without beam oscillation technique. Weldments were subjected to two types of post-weld heat treatments: direct aging (DA) and solution treatment at 980°C followed by aging (STA). When the welds were prepared using different heat inputs in the welding processes with and without beam oscillation, the influence of beam oscillation could not be studied in isolation but the coupled effect of heat input and beam oscillation was studied. Laves particles were finer in size and lower in amount in unoscillated welds compared with those in beam oscillated welds subjected to DA condition. δ phase needles were observed around Laves particles in the welds subjected to STA condition. The amount of Laves particles was less and that of δ phase was more in unoscillated welds compared with those in beam oscillated welds subjected to STA condition. Unoscillated weldments exhibited longer fatigue lives compared with beam oscillated weldments in both DA and STA conditions owing to less amount of Laves in the former. Weldments in STA condition had longer lives compared with those in DA condition. The role of δ phase needles in fatigue life could not be identified.     

Development of hybrid hydraulic–electric power units for field and service robots

Energetic autonomy of a hydraulic-based mobile robot requires a power source capable of both hydraulic and electrical power generation. The hydraulic power is used for locomotion, and the electric power is used for the control computer, sensors and other peripherals. In addition, the power source must be lightweight and quiet. This study presents several designs of internal combustion engine-based power units. Each power unit is evaluated with a Ragone plot which shows its performance over a wide range of operation times. Several hydraulic–electric power units (HEPUs) were built and successfully demonstrated on the Berkeley lower extremity exoskeleton (BLEEX). The best-performing design of the HEPUs, based upon the Ragone plot analysis, is described in detail. This HEPU produces constant pressure hydraulic power and constant voltage electric power. The pressure and voltage are controlled on board the power unit by a computer. A novel characteristic of this power unit is its cooling system in which hydraulic fluid is used to cool the engine cylinders. The prototype power unit weighs 27 kg and produces 2.3 kW (3.0 hp) hydraulic power at 6.9 MPa (1000 p.s.i.) and 220 W of electric power at 15 V DC.     

Evaluation,degradation and life assessment of coatings for land based combustion turbines

Abstract

Use of metallic and thermal barrier coatings to protect hot section blades and vanes of combustion turbines for power generation has been common practice for the past three and one decades respectively. Because these coatings must be optimised with respect to both different forms of corrosion and modes of operation (base load versus peak load), their performance may be machine specific. Industrial end users generally do not have detailed knowledge of the failure mechanisms of the coatings and the basis for selecting coatings to suit specific requirements, topics the present review seeks to address. The evolution of protective coatings, coating failure mechanisms and a methodology for selecting machine specific coatings are described. The methodology, which can be used to rank and optimise coating systems and to predict the remaining life of coatings, forms the basis of a computer code known as COATLIFE. The ingredients of this methodology, i.e. degradation modelling and thermomechanical fatigue life prediction, are reviewed.     

A Fully Automated Process Using a Magnetic Particle Based Kit for Removal of Dye Terminators from Sequencing Reactions

Prolinx,® Inc. of Bothell, WA has developed the RapXtract™ 384 Dye Terminator Removal Kit for full automation of DNA sequencing reaction purification. The RapXtract product line is based upon proprietary superparamagnetic particle technology that eliminates the need for centrifugation, vacuum filtration, or modified primers to achieve purification of sequencing reactions. The kit described here is pre-dispensed in a 384-well microtiter plate and run on the TECAN GENESIS Workstation 150 (Tecan U.S. Inc., Research Triangle Park, NC). This system enables rapid purification of up to 384 sequencing reactions in a single run.As the completion of the Human Genome Project nears, it is imperative for biotechnology and pharmaceutical companies to increase throughput of DNA sequencing in order to be competitive in the drug discovery and validation process. The “race to market” requires a shift from standard DNA sequencing processes-including DNA sequencing reaction purification-towards complete walk-away automation for all steps.Existing sequencing reaction purification methods (Table 1) require considerable resources including: plastic and other laboratory consumables; specialized equipment, such as high-speed centrifuges or vacuum filtration apparatus; and labor-intensive protocols requiring large amounts of technician time. As a result, walk-away automation of standard purification methods is difficult and expensive.     

Mobile Agent-Based Management in the INSERT Project

This paper describes work carried out atUniversity College London to evaluate the use of MobileAgents (MA), written in Java, in network and systemmanagement. The work draws on experience fromconventional management systems based on ISO CommonManagement Information Protocol (CMIP) andInternet Simple Network ManagementProtocol (SNMP). These systems make use of theconcept of a Managed Object (MO). The paper describes the way in which the MOconcept has been translated into a form suitable forMA-based management and how the features of the Javalanguage may be used to express management information and to implement MOs. A platform has beenimplemented which allows MOs to be instantiated,controlled and stored. The platform also allows the easyproduction of MAs, their launching into the system and their subsequent management. Details of theplatform implementation are given and an initialassessment of performance is presented.