中碳V-N微合金钢热变形行为

用Gleeble-1500热模拟试验机对中碳V-N微合金钢在不同变形温度(900~1050℃)及不同变形速率(0.005~30 s-1)的奥氏体区热变形行为进行研究。通过建立真应力-真应变曲线、动态再结晶图、功率耗散效率因子(η)图和应变速率敏感因子(m)图综合分析其热变形行为。结果表明,试验钢在1050℃、1 s-1变形条件下发生了动态再结晶,其真应力-真应变曲线、动态再结晶图、m图等方法得出的结果相互吻合。其中η图与m图差异很小,但由于应变速率敏感因子具有合理的物理意义,因此建议利用m图分析材料的热变形行为和选取最佳热变形工艺参数。     

首钢京唐1~#高炉TRT工艺优化及生产实践

首钢京唐公司建设1#5500 m3高炉中,采用了纯干式全流量并联透平机主体工艺流程,在主体设备中自主集成透平机三级可调静叶、入口调速阀、高炉减压阀组联合工艺控制顶压的核心技术。工程设计提出了大型化、露天化、集约型设计理念,实现了新一代钢铁流程自主集成、国际一流的工程目标。     

武钢7.63m焦炉技术改进

阐述武钢7.63 m焦炉投产后配煤、热工及地面协调系统存在的难题,介绍在预粉碎工艺、降低炉顶空间温度、完善地面协调系统等方面的技术改进。     

Complement of 99mTc-octreotide scintimammography to mammography in evaluating breast cancers

In this paper,the 99mTc-octreotide scintimammography as a useful complementary technique of mammography was evaluated in diagnosing breast cancers.The 45 breast lesions were consecutively detected by mammography,and 99mTc-octreotide scintimammography,and both combination technique on the basis of self-examination,physical examination.Clinical diagnosis was confirmed by histopathologic analysis.Radioactivity uptake ratios for tumor vs normal breast tissues (T/NT) were calculated using regions of interest.In the breast cancer groups and the benign lesion groups,the average uptake ratios of the 99mTc-octreotide were 1.63±0.19 and 1.09±0.13,respectively,and t was 9.638 (P0.001).Based on sensitivity,specificity,accuracy,positive predicting value,and negative predicting value,99mTc-octreotide scintimammography was 87%,79%,84%,90%,and 73%,the mammography was 65%,64%,64%,80%,and 45%,and both combination was 95%,100%,97%,100% and 92%,respectively.This showed that the 99mTc-octreotide scintimammography was more useful than mammography in the evaluating suspected breast cancers,and the combination technique can accurately discriminate lesions.     

不同合金成分对无镍白铜颜色及性能的研究

从分析当前实际生产和生活,并结合各元素对铜基合金的作用,论证了Mn、Zn、Al元素对合金组织性能及颜色的影响,利用正交试验确定了合金的最佳成分。结果表明,该合金具有较好的性能,生产成本低廉,具有良好的经济和社会效益。     

Near-infrared photoluminescence of V-doped GaN

The visible and infrared luminescence of vanadium-doped GaN (GaN:V) grown by metalorganic vapour phase epitaxy technique (MOVPE) on SiN-treated sapphire substrate were examined. Growth process was in-situ monitored by laser reflectometry. At room temperature and in the visible spectral range, photoluminescence (PL) shows a strong blue emission band. At 10 K, the near-infrared PL spectra exhibit several emissions dominated by a zero-phonon line (ZPL) at 0.821 eV with a full-width at half-maximum (FWHM) of 8.8 meV. Other peaks emerge in the low- and high-energy side of ZPL, which can be assigned to the fine structure of the charge state or the satellite lines. By increasing the temperature, the peaks’ intensities decrease and disappear above 150 K. The red-shift and the FWHM of the 0.821 eV line increase versus temperature, indicating a high contribution of the photonic Raman processes. This emission was assigned to be a vanadium intracenter emission.     

一种非线性最大长度伪随机序列发生器的设计

伪随机序列在众多领域得到应用,研究伪随机序列的产生具有重要意义.基于m序列,首次提出采用特征函数构造非线性最大长度移位寄存器反馈函数.运用这种方法,构造了一类非线性反馈函数.根据该类反馈函数,设计了非线性伪随机序列发生器,并在FPGA(EPF10K)上得到实现.结果表明,该序列发生器生成的伪随机序列,周期长度,平衡特性、游程特性与m序列相同,非线性度较之得到提高,是难得的序列.     

新疆地区密点麻蜥不同亚种及其不同部位总磷脂含量的比较

本实验以密点麻蜥不同亚种(库氏亚种、叶城亚种)及其断尾体与尾巴为研究对象,主要用紫外-可见分光光度计对密点麻蜥不同亚种及其不同部位总磷脂进行了分析.结果显示:叶城亚种体内磷脂的含量高于库氏亚种磷脂的含量,叶城亚种尾巴中磷脂的含量明显高于叶城亚种断尾体中磷脂的含量,库氏亚种断尾体与库氏亚种尾巴中磷脂含量相差不大.     

改进的并行ORTHOMIN（m）算法

通过利用ORTHOMIN（m）算法的固有性质,消除ORTHOMIN（m）算法的内积计算数据相关性,给出了一种改进的ORTHOMIN（m） （IORTHOMIN（m））算法。同ORTHOMIN（m）算法对比,IORTHOMIN（m）算法与ORTHOMIN（m）算法有相同的收敛性,在基于MPI的分布式存储并行机群上进行并行计算时,同步开销次数减少为ORTHOMIN（m）算法的一半。数值计算结果与理论分析表明改进的IORTHOMIN（m）算法的性能要优于ORTHOMIN（m）算法。     

A simple model for estimating monthly mean daily sums of solar irradiation and its local distribution

This paper deals with linear correlations between solar irradiation sums and sunshine duration for mapping global, diffuse and direct irradiation. All values represent long-term averages of monthly mean daily sums. The first part of this paper describes a set of fourteen correlation equations based on an earlier study. The constants of all correlations depend on a common numerical triple that describes the climatic conditions. The constants, correlation coefficients and the triple are determined and discussed with reference to the example of two stations in the Federal Republic of Germany. In the second part, a general method for generating solar irradiation maps is proposed and applied for the state of North-Rhine Westphalia (FRG). The distribution of global and diffuse irradiation in terms of yearly averages is shown and discussed. © 1997 John Wiley & Sons, Ltd.