CAS-OB在Q345qC生产中的试用情况

主要介绍了CAS-OB工艺处理Q345qC的试用情况，并对经CAS-OB工艺与LF炉工艺处理的产品质量进行了比较。结果表明，采用CAS—OB工艺处理的产品质量良好、性能稳定。     

Micro-image analysis in the diffusion-bonded zone of Fe3Al/Q235 carbon steel dissimilar materials

The chemical composition of the second phase precipitation in the vacuum diffusion-bonded zone of Fe₃Al intermetallic compound and Q235 carbon steel was analysed by means of electron probe microanalyser (EPMA). The relative content of the second phase precipitation and grain size was evaluated through a micro-image analyser. The percentage of Fe and Al content in the diffusion zone was measured by EPMA. The results indicated that the relative content of the second phase precipitation rich in carbon and chromium at the Fe₃Al/Q235 interface was much higher. With the transition from Fe₃Al intermetallic compound to Q235 carbon steel across Fe₃Al/Q235 interface, the grain diameter decreased from 250 μm, to 112 μm, Al atom content decreased from 27% to 15%, while Fe atom content increased from 76% to 96%.     

Linking sportfishing trip attributes,participation decisions,and regional economic impacts in Lower and Central Cook Inlet,Alaska

Forecasts of the regional economic impacts of changes in the demand for recreation occasioned by regulatory changes, changes in the quality of the recreation experience, or changes in average trip costs require a model that links changes in these trip attributes to individual participation decisions and population participation rates. The probability that an individual will take a particular recreational trip is described using a nonlinear random effects probit model based on variable trip attributes and individual economic and demographic characteristics. These conditional individual probabilities are transformed into predictions of changes in total recreation demand using a simulation-based sample enumeration method. The regional impacts associated with ensuing changes in primary and secondary expenditure patterns are elucidated with a stand-alone recreation-sector module linked to a regionally adjusted zip code-level input-output model. Because the participation model allows for non-constant marginal utility, primary and secondary impacts exhibit nonlinear responses to variations in trip attributes. The modeling approach is demonstrated in an application to the saltwater sport fisheries for Pacific halibut and salmon in Lower and Central Cook Inlet, Alaska. Received: February 2001/Accepted: December 2001     

Price rigidity in the downstream petroleum industry in New Zealand: where does it happen?

This paper examines the pricing behaviour of the downstream petroleum product market in New Zealand using multivariate error correction models. The unique feature of these models is the use of actual weekly wholesale and retail prices of diesel and unleaded petrol to measure the relative rigidity of domestic prices. The results suggest that price adjustments in domestic markets in response to price changes in world crude oil markets and refined product markets are very weak. Domestic wholesale prices appear to be the key variable in determining retail prices. Lack of competition in the wholesale sector is found to be the main reason for weak price adjustments.     

Exact learning of DNF formulas using DNF hypotheses

We show the following: (a) For any ε>0, log^(3+ε)n-term DNF cannot be polynomial-query learned with membership and strongly proper equivalence queries. (b) For sufficiently large t, t-term DNF formulas cannot be polynomial-query learned with membership and equivalence queries that use t^1+ε-term DNF formulas as hypotheses, for some ε<1 (c) Read-thrice DNF formulas are not polynomial-query learnable with membership and proper equivalence queries. (d) logn-term DNF formulas can be polynomial-query learned with membership and proper equivalence queries. (This complements a result of Bshouty, Goldman, Hancock, and Matar that -term DNF can be so learned in polynomial time.)Versions of (a)-(c) were known previously, but the previous versions applied to polynomial-time learning and used complexity theoretic assumptions. In contrast, (a)-(c) apply to polynomial-query learning, imply the results for polynomial-time learning, and do not use any complexity-theoretic assumptions.     

高性能低温烧结NiCuZn材料ZL500的开发

介绍了一种应用于MHz下的高磁导率(μi=500)、高Q值(在1MHz下超过120)、低烧结温度(880℃)NiCuZn材料的开发。研究表明,引入适量的CuO并掺杂适量的V2O5和Co2O3可以促进晶粒的生长,从而降低烧结温度,并且可以获得高Q值;通过对原材料的选择,严格控制主配方和制备工艺获得了优良的材料性能。     

EP1C6Q在水轮机组转速测量中的应用

状态监测系统在工业现场控制中已受到越来越多的重视。文章结合在开发基于现场总线技术的状态监测系统中遇到的实际问题，提出了一种采用现场可编程门阵列(FPGA)器件EP1C6Q设计的水轮机组转速测量系统的实现方案，并给出了详细的电路组成结构。最后就方案实现过程中遇到的问题提出了一些应注意的事项。     

三维成像雷达高度计成像模拟研究

根据三维成像雷达高度计系统（CIALT,China Imaging Altimeter)的成像基本原理建立了一个模拟系统,用来获得原始数据并进行成像处理。在该模拟系统基础上,给出了对各种目标的模拟成像结果,并针对系统参数选择、窗函数选择以及聚焦深度和距离弯曲等因素对成像的影响进行了深入的讨论。最后,介绍了三维成像的初步结果。     

Effect of strain rate on high temperature mechanical properties of Q460 continuous cast slab

Gleeble 3500 thermal simulation testing machine and metallographic method were used to test the high temperature mechanical properties of construction steel Q460 continuous cast slab at different strain rates, and the high temperature strength, hot ductility and final room temperature microstructure of Q460 continuous cast slab at different strain rates in the range of 600℃ to 1200℃ were obtained. The results show that when Q460 continuous cast slab is performed at a higher strain rate (10s-1), the reduction of area increases with the increase of the tensile temperature without obvious high temperature brittle zone. But when the strain rate is (10-3s-1), the curves of the reduction of area has two brittle regions. The first one is located at 1100℃ to the melting point temperature, and the second is near 700℃. In general, the reduction of area of this steel grade is greater than 65%, indicating that construction steel Q460 continuous cast slab has good high temperature hot ductility. In addition, under the same strain rate, the tensile strength of Q460 continuous cast slab decreases with the increase of tensile temperature, while the elongation increases with the increase of tensile temperature.     

基于802.1x协议及IP认证实现多重认证技术研究

首先介绍了IEEE802.1x协议的体系结构,指出了802.1x协议在实际应用中的局限性,提出了基于802.1x协议及IP认证实现多重认证的设计方案和具体实现方法,并将本认证方式与802.1x认证方式在各方面作了比较,充分阐述了本认证方式的优越性。