磁性耐磨材料在烧结球团生产中应用的探讨

磁性耐磨材料的抗磨原理是在自身与含铁物料之间形成一层“保护膜”，从而避免材料的磨损。济钢烧结厂采用磁性材料作成品矿仓内衬，不仅村板寿命延长，而且烧结转运过程中的减粒现象减轻，取得了较好效果。     

邯钢烧结杯试验装置简介

邯钢科技开发部重建的烧结试验装置检测仪表齐全，数据处理先进，具有较好的整体性能，是一套较理想的烧结试验装置。简要介绍了这套装置的特点和功能。     

罗泊河铁矿粉的烧结杯试验

罗泊河矿粉烧结性能欠佳，粒度组成呈两头大中间小分布。4种不同粒度组成的烧结杯试验结果表明：增加中间粒级，减少细粒级比例，可获得较好的烧结指标。     

烧结工艺对低Co超细晶硬质合金性能的影响

低Co超细晶硬质合金具有比常规的超细晶硬质合金更高的硬度、耐磨性、红硬性,在精密机械、加工刀具、特种耐磨材料及零件、拉拔模具等领域有其独特的优势和广泛的应用。本文以超细WC粉和球形Co粉为原料,采用真空烧结或低压烧结制备低Co超细晶硬质合金。采用低压烧结技术可成功制备出硬度为2110 HV30,矫顽力为55.7 kA/m,抗弯强度为2 250 MPa的低Co超细晶硬质合金。采用SEM、金相显微镜、维氏硬度计、矫顽磁力仪、材料实验机等研究烧结工艺对合金显微组织和物理机械性能的影响。结果表明:提高烧结温度或采用低压烧结,可以使低Co超细晶硬质合金中的孔隙度减少,强度提高。低压烧结制备的合金晶粒度大于真空烧结制备的合金晶粒度,但是采用真空烧结制备的合金中易出现WC晶粒异常长大现象。     

配加桃冲粉矿的烧结生产

介绍了桃冲粉矿的特性,分析了用桃粉取代海南粉或姑粉时。烧结生产的技术经济指标变化。实践证明,桃粉有较好的烧结性能。     

纳米硬质合金烧结技术进展

介绍了用于纳米硬质合金烧结的压力烧结、场辅助烧结、微波烧结、二步烧结等新技术，在评价各种烧结方法的基础上，以实验依据充分论证了普通真空烧结在纳米硬质合金制备中的可行性。     

烧结强化剂及其在重钢生产中的应用

重钢烧结厂通过近三年的实验研究，对目前国内兴起的铁矿烧结强化剂进行了广泛的试用和筛选，找到适合自己使用的产品。在进一步通过工业试验之后，将烧结强化剂应用于生产中，并取得了较好的效果。     

强化烧结过程的途径浅议

介绍了国内外强化烧结过程的新技术：低温烧结、球团烧结、褐铁矿烧结、特高品位精矿烧结，以及国内强化烧结过程的主要技术措施：同碱诬烧结、厚料层烧结、改善原料条件、低温烧结、小球团烧结等。根据湘钢烧结厂强化烧结过程已采取的措施，分析了所存在的问题，并据此提出了完善强化烧结过程应采取的措施。     

凌钢小球团烧结生产实践

凌钢通过对现有烧结系统进行小球团烧结改造，使烧结矿的技术经济指标有了不同程度的改善，取得了较好的效果。     

用褐铁矿作烧结铺底料的研究

为解决不加铺底料烧结的弊端，研究了用褐铁矿作烧结铺底料。研究结果表明：用梧桐沟褐铁矿作烧结铺底料可以取得较好的烧结生产指标，烧结后梧桐沟褐铁矿的烧失降至0．48％，TFe提高到63％；转鼓指数降至80％；可以利用烧结过程产生的热量使结晶水充分脱除，并使碳酸盐充分分解。     

Differential induction of systemic resistance in Arabidopsis by biocontrol bacteria

Selected nonpathogenic, root-colonizing bacteria are able to elicit induced systemic resistance (ISR) in plants. To elucidate the molecular mechanisms underlying this type of systemic resistance, an Arabidopsis-based model system was developed in which Pseudomonas syringae pv. tomato and Fusarium oxysporum f. sp. raphani were used as challenging pathogens. In Arabidopsis thaliana ecotypes Columbia and Landsberg erecta, colonization of the rhizosphere by P. fluorescens strain WCS417r induced systemic resistance against both pathogens. In contrast, ecotype RLD did not respond to WCS417r treatment, whereas all three ecotypes expressed systemic acquired resistance upon treatment with salicylic acid (SA). P. fluorescens strain WCS374r, previously shown to induce ISR in radish, did not elicit ISR in Arabidopsis. The opposite was found for P. putida strain WCS358r, which induced ISR in Arabidopsis but not in radish. These results demonstrate that rhizosphere pseudomonads are differentially active in eliciting ISR in related plant species. The outer membrane lipopolysaccharide (LPS) of WCS417r is the main ISR-inducing determinant in radish and carnation, and LPS-containing cell walls also elicit ISR in Arabidopsis. However, mutant WCS417rOA-, lacking the O-antigenic side chain of the LPS, induced levels of protection similar to those induced by wild-type WCS417r. This indicates that ISR-inducing bacteria produce more than a single factor that trigger ISR in Arabidopsis. Furthermore, WCS417r and WCS358r induced protection in both wild-type Arabidopsis and SA-nonaccumulating NahG plants without activating pathogenesis-related gene expression. This suggests that elicitation of an SA-independent signaling pathway is a characteristic feature of ISR-inducing biocontrol bacteria.     

Pulsus paradoxus: an objective measure of severity in croup

We used a noninvasive monitor of arterial pressure to determine the utility of pulsus paradoxus (PP) as an objective severity measure in croup. We performed a prospective, blinded comparison of PP in children with croup versus healthy control subjects, analyzed the relationship between PP and Westley croup score (WCS), and observed the effect of racemic epinephrine (RE) on PP and WCS in a subgroup of patients with severe croup. The PP and WCS were measured at presentation and in severe patients after treatment with RE. Mean PP was 6.1 +/- 1.8 (SD) mm Hg (n = 29) in control subjects compared with a mean of 17.8 +/- 11.2 (SD) mm Hg (n = 28) in patients with croup (p < 0.00001). There was significant concordance between baseline WCS and PP (Spearman's rho: 0.68; p = 0.0001). The mean decrease in PP after RE was 7.5 +/- 11.8 (SD) mm Hg (p = 0.05; n = 12). The magnitude of decrease in PP after RE has significant concordance with the concurrent decrease in WCS (Spearman's rho: 0.73; p < 0.007). PP is elevated in children with croup, and the magnitude of elevation correlates with severity as measured by the WCS. PP may have utility as a research tool to objectively measure the severity of upper airway obstruction in croup.     

The technetium white cell scan as an initial imaging investigation for evaluating suspected childhood inflammatory bowel disease

BACKGROUND: The technetium white cell scan (WCS) may be a useful investigation for patients with inflammatory bowel disease (IBD). In a retrospective study we assessed the use of the WCS as an initial imaging investigation in evaluating children with suspected IBD. METHODS: Over a 3-year period, 60 WCS were performed on 55 patients (25 boys, median age 12.1 years, age range 1.5-18 years) with known or suspected IBD. There were two clinical groups: those with previously diagnosed IBD (histologically and radiologically) and in clinical relapse (13 patients), and newly presenting patients with suspected IBD (42 patients). RESULTS: Eighteen scans were performed on the 13 patients presenting with relapse. Seventeen were positive and one patient, subsequently shown to have an inactive stricture, had a negative scan. Seven of the 42 newly presenting patients had abnormal scans, confirmed to be due to IBD by a combination of histology and barium examinations. Of the remaining 35 scans, three were abnormal and 32 were normal. None of these patients were subsequently proven to have IBD. These results show that in detecting active IBD, a positive WCS has a 100% sensitivity (24/24) and a 91% specificity (32/35) in the diagnosis of IBD. CONCLUSIONS: Our results show that the WCS is very useful as an initial imaging investigation in evaluating patients with suspected IBD to select patients for further investigation.     

Use of the Work Components Study with new college-level employees.

Reports data based on 869 male and 344 female new college-level employees which show the reliability and structure of the Work Components Study (WCS). A comparison of those persons who remain with the company with those who leave at the company's initiative and with those who leave of their own initiative shows few differences in their orientations toward work as measured by the WCS. However, when the company's rating of how many years it will take the new hires to reach the 3rd level of management was taken as a criterion, it was found that those who score highest on WCS Score 3, Competitiveness desirability, highest on the School and College Abilities Test verbal ability score, and highest on a personality measure of responsibility are those perceived by the company as moving ahead fastest. These results suggest that it is not the "organization man" type who is likely to be promoted, but the man perceived to be highly competitive, intelligent, and responsible. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A high glycemic index starch diet affects lipid storage-related enzymes in normal and to a lesser extent in diabetic rats

The of this study was to evaluate the chronic effects of a high (waxy corn) vs. a low (mung beans) glycemic index starch diet on the lipogenic enzymes, fatty acid synthase (FAS) and lipoprotein lipase (LPL). Normal and diabetic (streptozotocin-injected on d 2 of life) male Sprague-Dawley rats consumed a diet containing 575 g/kg carbohydrates either as waxy cornstarch (WCS) or as mung bean starch (MBS). After 3 wk, neither body weights nor relative epididymal fat pad weights differed. In diabetic rats, the WCS diet induced high basal plasma insulin levels. Plasma triglycerides were not significantly affected by diet in either normal or diabetic rats. Adipose tissue and liver LPL activities were not modified by the type of starch in the diet. In normal rats, FAS activity and gene expression in epididymal adipose tissue but not in liver were greater in rats consuming the WCS diet than in those consuming MBS. To evaluate the implication of insulin in this regulation, two genes regulated by insulin [GLUT4 and phosphoenolpyruvate carboxykinase (PEPCK)] were also studied. The high glycemic index WCS diet compared with the low glycemic index MBS diet resulted in lower hepatic PEPCK mRNA in both normal and diabetic rats. Normal, but not diabetic rats fed WCS had greater GLUT4 gene expression in adipocytes than did those fed MBS. We conclude that the total replacement of 575 g/kg low glycemic index starch by a high glycemic index starch for 3 wk caused the following in normal rats: 1) high FAS activity and mRNA in adipose tissue but not in liver and 2) high GLUT4 gene expression in adipose tissue. In both normal and diabetic rats this same diet resulted in lower hepatic PEPCK mRNA. Therefore, high glycemic index starch diet is implicated in stimulating FAS activity and lipogenesis and might have undesirable long-term metabolic effects.     

A novel signaling pathway controlling induced systemic resistance in Arabidopsis

Plants have the ability to acquire an enhanced level of resistance to pathogen attack after being exposed to specific biotic stimuli. In Arabidopsis, nonpathogenic, root-colonizing Pseudomonas fluorescens bacteria trigger an induced systemic resistance (ISR) response against infection by the bacterial leaf pathogen P. syringae pv tomato. In contrast to classic, pathogen-induced systemic acquired resistance (SAR), this rhizobacteria-mediated ISR response is independent of salicylic acid accumulation and pathogenesis-related gene activation. Using the jasmonate response mutant jar1, the ethylene response mutant etr1, and the SAR regulatory mutant npr1, we demonstrate that signal transduction leading to P. fluorescens WCS417r-mediated ISR requires responsiveness to jasmonate and ethylene and is dependent on NPR1. Similar to P. fluorescens WCS417r, methyl jasmonate and the ethylene precursor 1-aminocyclopropane-1-carboxylate were effective in inducing resistance against P. s. tomato in salicylic acid-nonaccumulating NahG plants. Moreover, methyl jasmonate-induced protection was blocked in jar1, etr1, and npr1 plants, whereas 1-aminocyclopropane-1-carboxylate-induced protection was affected in etr1 and npr1 plants but not in jar1 plants. Hence, we postulate that rhizobacteria-mediated ISR follows a novel signaling pathway in which components from the jasmonate and ethylene response are engaged successively to trigger a defense reaction that, like SAR, is regulated by NPR1. We provide evidence that the processes downstream of NPR1 in the ISR pathway are divergent from those in the SAR pathway, indicating that NPR1 differentially regulates defense responses, depending on the signals that are elicited during induction of resistance.     

SYP增效剂用于褐铁矿烧结的试验研究

根据昆钢红河钢铁有限公司烧结以褐铁矿为主的原料特点，结合生产实践提出了添加SYP增效剂烧结的技术思路。在实验室烧结杯试验取得初步效果的基础上，组织了工业性试验，验证了SYP增效剂改善烧结生产技术经济指标的作用。SYP增效剂的使用，在一定程度上解决了褐铁矿烧结强度差、返矿量大的问题，为拓宽资源利用，降低成本奠定了良好的基础。     

金属粉末激光烧结过程中搭接率敏感性分析

依据金属粉末直接激光烧结(DMLS)的实际烧结过程,以304不锈钢粉作为烧结材料,利用Ansys有限元软件,对其烧结成形温度场进行了数值模拟。首先对多道烧结过程中温度场的变化规律进行了分析,进而分析不同搭接率对温度场的影响,得出搭接率对烧结效果的敏感性。结果表明:搭接率过低会导致相邻烧结道之间存在未烧结粉末区域;搭接率过高又会造成温度过量集中,热量积累严重。针对所研究的304不锈钢粉,搭接率在26%~33%之间时,烧结效果较好。     

烧结工序能耗精细化管理及其软件开发

基于现有烧结生产存在的能耗高、能效水平低、能源管理粗放化等问题,通过理论计算结合烧结厂生产实际,建立一套烧结工序能耗计算分析模型,并且实现该模型的软件化。实例分析表明,该软件系统能够较为准确地计算出烧结厂各种能源的消耗,实现烧结工序能耗的精细化管理,进而帮助烧结厂更好地掌握烧结系统的整体用能情况、主要耗能问题以及节能潜力所在,对烧结工序能效评估工作具有较高的实用价值。     

喜迎我国烧结行业的大发展

本文从我国13年来烧结行业产量大幅提高、质量和主要技术经济指标得到改善、烧结机不断大型化、工艺技术装备和自动化水平的提高以及环境保护有了新的起色等方面叙述了其发展的进程。特别是1998年大中型烧结机的面积首次超过小型烧结机的面积，成为我国烧结机向大型化发展的一个转折点。文章还分析了烧结行业大发展的条件、优势及烧结法的利与弊，从而得出结论，在今后一个相当长的时期内，高碱度烧结矿仍然是我国高炉的主要含铁原料。