现代高炉炉底炉缸结构

对高炉炉底、炉缸结构的主要设计趋势进行了阐述,并重点对炭砖炉底、炉缸结构的主要特点进行了讨论。认为德国SGL开发的各种不同高炉用炭砖和石墨砖,如普通炭砖、微孔炭砖、半石墨砖、微孔半石墨砖、石墨砖和低铁石墨砖等,可以适应和满足炉底、炉缸结构的设计和生产要求。     

高炉炉缸耐火材料抗渣侵蚀性及挂渣性

 对高炉炉缸用炭砖及刚玉砖的抗渣侵蚀性及挂渣性进行了研究。在1 500 ℃高温条件下进行试验,探究现场高炉渣对炭砖及刚玉砖的侵蚀机理,通过SEM-EDS及XRD等手段分析侵蚀界面的微观组织结构和物相组成,并提出炭砖及刚玉砖挂渣理论。试验结果表明,高炉渣与刚玉砖在侵蚀界面发生反应,反应生成的镁铝尖晶石及刚玉砖中的Al2O3、SiC等高熔点物质阻碍高炉渣对刚玉砖的进一步侵蚀;高炉渣在炭砖表面未生成高熔点物质,炭砖因与高炉渣黏结点少而导致高炉渣对炭砖黏结强度差,从而形成炭砖表面渣皮周期性脱落。     

长寿高炉使用真正的微孔炭砖的必要性

 针对目前出现的高炉炉缸烧穿和短寿的情况,对其中一些高炉用的炭砖进行了解剖分析。结果发现：高炉炉缸烧穿和短寿的最主要原因是所用的炭砖质量太差。进口热压小炭砖是全部或部分采用电极石墨为原料生产的炭砖,而且不是微孔炭砖。某些高炉所采用的国产微孔炭砖和半石墨炭砖均为假冒伪劣产品。这些炭砖的生产工艺和技术已倒退到用普煅无烟煤生产普通炭砖的水平,而且由于加入大量电极石墨,使用效果还不如普通炭砖。为扭转高炉出现短寿的被动局面,建议采用岩相检验方法鉴别真假微孔炭砖,保证使用炭砖的高炉长寿。     

高炉长寿用炭素耐火材料研究进展

对我国近年来高炉长寿用炭素耐火材料的研究与应用状况进行了综述,简要介绍了半石墨炭砖、石墨炭砖、微孔炭砖、超微孔炭砖、微孔模压炭砖及炭素捣打料的研究工作和发展现状,并明确了超微孔炭砖的发展目标。     

延长高炉寿命的组合砖设计

1 前言 目前我国各级高炉使用的砖型只有单一的楔形砖和直形砖。由于单块砖四周是平滑的面,用它们砌成的砖环实是各为一体的并合环,砌成的内衬稳定性差,当砌体某一局部砖衬因故受损时,将导致相邻砖衬也随之塌落。基于楔形砖和直形砖存在的问题,笔者设计出了12种新型组合砖,它们具有如下特点:砖体的一侧或两侧设有形状相同的凹槽与凸台,凸台的外部较接近砖体的部分大,砌成的砖衬能相互咬合,砌成的砖环近乎一个带链的圆环整体。当砌体某一局部砖衬因故受损时,由于相邻的砖衬是相互咬合的,不会随之塌落。用这种组合砖砌筑的高炉内衬的稳定性强,有利于延长高炉寿命。     

高炉热风炉悬链线拱顶砖计算软件开发

本文介绍了高炉热风炉悬链线拱顶砖多段圆弧拟合计算新方法,用计算机语言编程计算砖的尺寸,砖的层教,每层砖的类型、数量,每层砖组合误差等,并用C#编写界面.提高热风炉拱顶砖计算精度,减少了设计计算时间,便于使用.     

我国高炉用炭砖现状及评述

对比分析了国内高炉使用自焙炭砖、半石墨炭砖、微孔炭砖和超微孔炭砖与国外同类产品的质量,得出我国自产的微孔炭砖和超微孔炭砖质量已达到国外同类型炭砖水平.提出高炉选择炭砖时不应该过于看重导热系数单一指标,应该选择<1μm孔容积比、导热系数、耐压强度、透气度、抗铁水熔蚀指数、氧化率、抗碱性等综合指标,严格按照行业标准对炭砖质量进行综合评价.     

国内外高炉炭砖的现状及发展

对国内高炉用半石墨炭砖、微孔炭砖和模压炭砖与国外同类产品的质量进行对比分析,找出我国高炉炭砖的长处及与国际先进水平的差距,并对高炉炭砖的发展趋势进行了一些探讨。半石墨炭砖应当进一步提高抗铁水溶蚀性、提高导热系数、改进抗碱性、改进微气孔指标。高炉微孔炭砖的发展方向是提高导热系数和进一步提高微气孔指标,开发超微孔炭砖。     

一块楔形砖半径变化量及楔形砖间尺寸关系的研究与应用

一、一块直形砖半径增大量研究成果的应用楔形砖与直形砖配合砌筑的砖环中,砖量配比的计算有很多种方法,例如: K_直=2π△R/a=2π(R-R_0)/a (1) 式中 K直——与楔形砖配砌的直形砖的块数; a——一块直形砖的加入尺寸,包括砖缝厚度; △R——加入K_直块直形砖砖环的半径增大量,△R=R-R_0; R——所计算砖环的弯曲外半径;     

锌浸出渣挥发窑内衬砖的选择和实践

分析总结了葫芦岛锌厂锌浸出渣挥发窑内衬砖损坏机理及原因 ,提出了内衬砖的选用原则 ,并对普通烧结镁砖、直接结合镁铬砖、铝铬砖、镁铬铝砖等几种常用内衬砖的性能指标及实际应用情况进行了对比 ,介绍了镁铬铝砖实际应用情况     

Sulfur distribution in bacteriorhodopsin from multiple wavelength anomalous diffraction near the sulfur K-edge with synchrotron x-ray radiation

Estimates of variance components for test day records in an animal model that considered multiple traits over multiple lactations were calculated using REML methodology. Test day records were classified into 11 periods within first and later lactations. Missing ancestors in the relationship matrix were classified in genetic groups. Data were collected from Costa Rican dairy farms. Estimates of components for total and additive genetic variance were clearly heterogeneous during the lactation. Heritabilities for traits in later parities were slightly higher than those for traits in first parity. Heritabilities were highest for records of midlactation. Phenotypic and genetic correlations for adjacent test days were close to 1. Phenotypic correlations were lower than genetic correlations. Heterogeneity of variances during the lactation suggests the adequacy of the multiple-trait test day model to describe milk yield during the lactation. When missing ancestors were allocated to a single base population instead of genetic groups, the estimates of residual variance were lower, and the estimates of genetic variance and genetic correlations were higher. When standardized records were used instead of actual test day records, the estimates of residual and total variance were lower, and the estimates of genetic variance were higher. Consequently, estimates of heritability and genetic correlations were also higher. Use of standardized data obtained by interpolation procedures is not advised for estimation of genetic variance components in a test day model.     

Optic neuritis caused by contact with lead compounds

The reliability and validity of the Uzgiris and Hunt (1975) scales of sensorimotor development were examined with severely and profoundly retarded children. The subjects were 63 severely or profoundly retarded children between 42 and 126 months of age. Thirty of the subjects were living in residential facilities, and 33 were living at home and attending day schools. All of the subjects were assessed on all six scales of the Uzgiris and Hunt instrument. Interexaminer and test-retest reliabilities were computed. Scalogram analyses were also computed for all but the Schemes scale. The findings were that the scales were reliable and, as theorized by Piaget, ordinal with the present sample. These findings were interpreted as indicating that these scales could be used reliably and validly with severely and profoundly retarded children. This was discussed in terms of the present and potential uses of these scales.     

Effects of ionizing radiation on incisor development of the prenatal mouse

The effects of 100 rad of X-irradiation of incisor development in CD1 mice were studied. 24 pregnant mice were irradiated on the 12th day post coitum and sacrificed from the 14th through the 20th gestational days. The 191 irradiated fetuses were smaller than those not irradiated, their crania and necks were malformed and their lower extremities were poorly developed. The developing incisors of the irradiated animals were retarded, the pulpal vessels were enlarged and the vessels walls did not maintain their structural integrity. The cells of the future pulp were necrotic, and the basement membranes appeared hyalinized. Ameloblasts and odontoblasts were abnormal in morphology and the formation of dental hard tissue was inhibited in places. Complete absence of incisor tooth germ was noted in three of the fetuses.     

A clinical study of Thai patients with spondyloarthropathy

Eighty-eight Thai patients (61 males and 27 females) with spondyloarthropathy (SpA) were studied. Their mean age and mean duration of the disease were 25.97 and 3.34 years respectively. In 16 cases the disease first appeared before the age of 16 or had juvenile onset. Eleven cases were ankylosing spondylitis (AS), 9 were juvenile AS (JAS), 20 were Reiter's syndrome (RS), 4 were juvenile RS, 14 were psoriatic arthritis (PsA), 27 were undifferentiated SpA (uSpA), and 3 were juvenile uSpA. Peripheral arthritis, especially oligoarthritis of the lower extremity joints, was the most common form of arthritis in all groups, except for PsA, where polyarthritis was common. Back pain and bilateral sacroiliitis were commonly seen in JAS and AS. Enthesopathy was not uncommon. Extra-articular manifestations were more common in RS patients. Acute inflammatory eye diseases were seen in 45 per cent of AS and 66 per cent of RS cases. In general, the clinical features of Thai patients with SpA were similar to those reported in other countries in Asia and the west.     

Taking care of the elderly: the unmentioned abuses

A total of 10,427 diarrhoeal stool specimens were cultured for Vibrio cholerae between 1992 and 1997. The isolation rates were 2%, 2.6%, 6.7%, 7.08%, 0.9% and 2.6% in the years from 1992 to 1997 respectively. Till 1992, Vibrio cholerae 01 ogawa was the predominant strain. In 1993, 81.3% of the isolates were of 0139 Bengal strain and the rest were V. cholerae 01. From 1994 to 1997, V. cholerae 01 ogawa was the predominant strain and there were no isolation of 0139 strain. The predominant phage type in 1992 and 1993 were T2 and T27 thereafter. Most Vibrio cholerae strains were sensitive to tetracycline, gentamycin, netromycin, norfloxacin and furazolidine. Strains were resistant to cotrimaxozole till 1996, but were 100% sensitive in 1997. Strains were sensitive to chloramphenicol till 1993 but acquired resistance thereafter.     

Root canals in two-rooted maxillary second molars

The aim of this study was to register the root canal number, root canal position, and root canal cross-section in human two-rooted, permanent maxillary second molars. One hundred and fifty-nine such teeth extracted in Denmark were cross-sectioned at the mid-root level and apically in accordance with precise guidelines. The observations were made in a stereomicroscope, corresponding to the above-mentioned section levels. At mid-root there were two canals present in 11% of the teeth examined; the canals were located mesially and distofacially, mesiofacially and distally, or facially and lingually. Three canals positioned mesiofacially, distofacially, and lingually were observed in 89% of the teeth. At the same level 62% of the canal cross-sections were noncircular, some being, for instance, C-shaped, whereas 38% of the cross-sections were circular. Apically, two canals were found, representing 19% of the teeth, with the canal position as at mid-root; 81% of the teeth were three-canaled with the same canal position as at mid-root. At the apical level 60% of the canal cross-sections were noncircular, whereas 40% of the cross-sections were circular.     

Within-child associations between family income and externalizing and internalizing problems.

Within-child associations between family income and child externalizing and internalizing problems were examined using longitudinal data from the NICHD Study of Early Child Care and Youth Development (2004a, 2004b; N = 1,132). Variations in income effects were estimated as a function of whether families were poor, whether mothers were partnered, and the number of hours mothers and their partners were employed. On average, children had fewer externalizing problems during times when their families' incomes were relatively high than during times when their families' incomes were relatively low; the estimated benefits of increased income were greatest for children who were chronically poor. For both externalizing and internalizing problems, income was most strongly associated with problems when chronically poor children's mothers were partnered and employed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mammographic screening of the health district 38, hospital of Gardone Val Trompia (Brescia - Lombardy). Results of the first 2 rounds

The authors report the results of the first two rounds of a mammographic screening program by the Health District of Gardone Val Trompia (Brescia) including women 50 to 69 years old. 9,650 women were invited for round one and 6,415 (66.5%) attended; 9,656 were invited for round two and 6,552 (67.8%) attended. Fifty-four cancers were found in round one (detection rate: 8.4/1000): 11.1% of them were in situ carcinomas, 63% were T1 and 24.1% were T2 lesions, or higher. In round two, 32 lesions were detected (detection rate: 4.9/1000): 15.6% of them were in situ carcinomas, 78.1% were T1 and 3.2% were T2 lesions. In the positive cases axillary lymph nodes involvement was observed in 24.1% of cases in round one and was unknown in 27.8%, but the figures decreased to 6.2% and 9.4%, respectively, in round two. Effectiveness indicators were always observed.     

In vitro application of testosterone potentiates gonadotropin-releasing hormone-stimulated gonadotropin-II secretion from cultured goldfish pituitary cells

This report describes the methods used in conducting a long-term follow-up study and the factors associated with the successful location of subjects. In 1987-91, we selected, from among the women who were born in 1959-66 as members of the Philadelphia and Providence cohorts of the Collaborative Perinatal Project (CPP), 391 who were preterm at birth, 413 who were small-for-gestational age (SGA) and 978 who were term and appropriately grown; 1314 were from Philadelphia and 468 from Providence. Tracing was accomplished using original CPP records, telephone directories, voter registration and driver's licence records, birth certificate files and credit bureaux. A total of 61% of the women were located, 55% at Philadelphia and 77% at Providence. After adjustment, the odds ratio for ease of location, compared with women who were term and appropriately grown, was 0.85 [95% CI 0.66-1.11] for women who were preterm and 1.02 [0.78-1.34] for women who were SGA. In Philadelphia, African-American women were more likely than white women to be located, but in Providence, African-American women were less likely than white women to be located. Women whose own mothers were older at the time of their birth were more likely to be located, as were those who had more siblings followed in the CPP. Compared with women who did not complete their original CPP examinations at ages 4 and 7 years, those whose original CPP follow-up was more complete were more likely to be located. These findings demonstrate that long-term follow up in a US urban setting can be accomplished, and that successful location was not associated with birth status.     

Human versus computerized evaluations of polygraph data in a laboratory setting.

Computer algorithms that process physiological reactions to polygraph test questions and assess the probability that the questions were answered truthfully were evaluated with data obtained in two mock crime experiments. One half of the subjects in each experiment were guilty of committing a mock theft, and one half were innocent. Data from 100 subjects in one experiment (standardization sample) were used to develop a discriminant function of electrodermal, cardiovascular, and respiration measures. The distributions of discriminant scores were used to derive Bayesian assessments of the probability of truthfulness. Data from 48 subjects in another experiment were used to cross validate the computer model (validation sample). Dichotomous computer classifications of subjects in the standardization sample were 93% correct. Blind numerical evaluations of the same data by an expert interpreter were 89% correct. On cross-validation, computer outcomes were 94% correct, and numerical evaluations were 92% correct. There were no significant differences between computer and human evaluations. The findings suggest that computer techniques may be developed for applied settings and would perform at least as well as expert human interpreters. (PsycINFO Database Record (c) 2010 APA, all rights reserved)