天钢Q345R钢板质量调查及改进

对天津钢铁集团有限公司Q345R钢板产品用户反馈信息进行分析,发现Q345R钢板存在的主要质量问题是分层及凹坑。针对这两个质量问题进行研究与分析,制定出了从降低钢中硫化物夹杂和去除表面氧化铁皮两个主要方面进行工艺改进的措施。实施后,天钢Q345R钢板的质量得以稳定,性能得到了提高,满足了用户的使用需求。     

压力容器用钢板Q345R延伸率不合格原因分析

针对Q345R锅炉与压力容器用钢板断后伸长率不合格的问题,利用直读光谱仪、金相显微镜、扫描电镜等设备对Q345R断后伸长率不合格试样进行了化学成分、金相组织、断口形貌等方面的检测分析。分析结果表明,钢中的硫化锰夹杂物、贝氏体组织和带状组织是造成Q345R钢板断后伸长率不合格的主要原因。通过提高铸坯炼钢冶金质量、降低锰和硫元素含量、减轻成分偏析、采用合理的控轧控冷工艺、减少异常组织产生等措施,使得Q345R钢板的断后伸长率明显提高。     

Q345R钢板探伤不合格原因分析及控制

针对14～22 mm厚度Q345R钢板出现的探伤合格率下降情况,采取Z向拉伸检测和扫描电镜分析对探伤不合格钢板进行研究,结果显示中心偏析、偏析处MnS夹杂和裂纹等内部缺陷是造成Q345R钢板探伤不合格的主要原因.分析了影响Q345R探伤合格率的主要因素.通过采取低过热度浇铸、降低硫含量、增加铸坯堆垛缓冷时间等措施有效地提高了Q345R探伤合格率.     

压力容器用Q345R钢板正火和正火轧制工艺对比研究

针对压力容器用Q345R钢板在正火和正火轧制两种工艺条件下的微观组织和力学性能进行对比研究,结果表明:正火轧制工艺生产钢板可以获得与正火工艺生产钢板相近似的性能,满足相关标准要求。两种工艺生产的钢板经再次正火后抗拉强度略微降低,但冲击韧性均得到改善。可采用正火轧制代替轧后正火的方式生产Q345R钢板。     

Q345R钢板低延伸率分析与控制

采用金相显微镜、扫描电镜和能谱仪对低延伸率的Q345R钢板的显微组织、夹杂物及断口形貌进行检测,分析了造成Q345R钢板断后延伸率不合格的原因,并提出了相应的控制措施。结果表明,钢板心部存在高硬度脆性相贝氏体和长条状硫化物夹杂聚集是导致钢板延伸率不合格的主要原因。通过优化生产工艺参数,改善钢板原始铸坯心部的成分偏析,可以使Q345R钢板延伸率合格比例得到明显提升。     

压力容器用中厚板Q345R探伤不合格原因分析

针对Q345R钢板探伤不合格问题,从生产过程、金相检验、扫描电镜检测等方面进行分析,结果表明钢中的夹杂物、中心裂纹是造成探伤不合格的主要原因。通过优化相关的生产工艺,可以避免探伤不合格现象的产生,对提高Q345R钢板探伤合格率起到关键作用。     

提高Q345B钢板屈服强度的TMCP工艺实践

利用临钢中板厂新建的控冷设备,结合目前存在的Q345B钢板屈服强度不合格率较高的现象,进行了Q345B钢板的TMCP工艺试验.通过本次试验,给出了在现有生产条件下生产Q345B钢板的精轧开轧温度、待温厚度、碳当量的范围,提高了Q345B钢板的合格率.     

200mm厚度压力容器用钢Q345R的研发

本文叙述了200mm 厚度Q345R特厚压力容器用钢板的研制开发过程。通过添加适量微合金元素V、Nb、Ti,采用低过热度浇注,高温低速大压下工艺等一些列工艺及措施,使得生产出来的钢板力学性能优良、内部质量良好。     

Q345R(HIC)钢板抗HIC性能不合格的原因分析及对策

通过低倍检验、金相显微镜、扫描电镜和断口分析等手段,对Q345R(HIC)钢板抗HIC性能不合格的原因进行研究分析,探讨了压力容器钢板抗HIC性能的关键影响因素,从改善钢板偏析、夹杂物变性和提高钢板止裂性能3个方面采取工艺措施,最终提高了Q345R(HIC)钢板的抗HIC性能。     

硫氢比与钢板探伤合格率关系调研

通过对重庆钢铁股份有限公司生产的低合金钢Q345R硫氢比与钢板探伤合格率关系的综合分析,得出随着硫氢比的提高、钢板探伤合格率呈上升趋势的基本结论。     

火焰原子吸收光谱法测定合金结构钢中铬、锰

利用火焰原子吸收光谱法测定合金结构钢中铬、锰,此方法快速、准确、灵敏度高、精密性好,方法简便,并充分反应了现代仪器的高科技分析手段。合金结构钢使用较为广泛,因此利用原于吸收光谱法测定铬、锰,能迅速有效的达到检测目地的需要。本方法改变了以往化学法操作时间长、步骤多、消耗试剂多的弊病,解决了高氯酸氧化铬对人体的危害及对环境的严重污染。通过对各项做条件试验,优选了最佳仪器测试条件。对干扰元素铁、镍抑制铬的吸收,采用硫酸钠做干扰消除剂,彻底消除了干扰,测定数据稳定可靠。经过对标准样品的测定,重复性好,误差小,回收率达到99～102%,效果令人满意。     

Measuring students' connectedness to school, teachers, and family: Validation of three scales.

Connectedness to school, teachers, and family are all significant protective factors in adolescents' lives, yet the measurement of each varies considerably. This article describes the measurement properties of three composite scales of adolescent connectedness, adapted from the Add Health study and the California Healthy Kids Survey. These composite scales are created by either summing or taking the mean of all individual items, measured on an ordinal scale. This approach fails to account for the ordinal, non-normal nature of the data. Using a covariance approach, this article describes the measurement properties of the latent constructs of connectedness to school, teachers, and family and the contribution of each of the items used to compile the relevant composite score. The outcomes of this study will provide researchers and practitioners with information about the validity, reliability, and overall usefulness of each of the measures of adolescents' perception of their connectedness to school, teachers, and family. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Leaching Behavior of Lead, Chromium (III), and Zinc in Cement/Metal Oxides Systems

This paper reports the study of the leaching behavior of cement/metal oxides mixtures containing lead, chromium (III) and zinc oxides. A fractional factorial design of experiments (24?1) was carried out considering four factors, the concentration of ZnO, Cr2O3, PbO, and Fe2O3 in the formulations. Iron oxide was also included in the experimental design as it is usually the main constituent of industrial wastes from thermal processes, where lead, chromium and zinc oxides are also found. After 56 days of curing, samples were subjected to the Acid Neutralization Capacity Test and the concentrations of Cr, Zn, and Pb were determined in the leachate at different pH after filtering. The output variables for the analysis of the experimental data were the concentration of metals at initial pH (in water), at pH 9, 7, and 4, and the acid neutralization capacity of the samples at pH 9. The analysis of the results indicates that the immobilization of Zn and Pb in Portland cement is poor; these metals behave as their amphoteric hydroxides. However, the leaching of Cr (III) is in the range found in the control sample, indicating that the stabilization of Cr (III) is successful.     

Reservoir Bank Deformation Modeling: Application to Grangent Reservoir

Within inshore or fluvial environments, submerged fine matter mud banks are characterized by a high water content, a great spatial variability, and a strong deformability. The study of their instabilities induced by the variation of hydraulic stress requires a coupled modeling of sliding, erosion, and deposition mechanisms. In order to predict the impact of dam reservoir emptying on the stability of immersed upstream slopes, the method of approach to the problem proposed here combines theoretical developments, numerical modeling, site observations, and measurements. First, the theoretically achieved sliding criterion is compared with unstable mud height measurements. For more accuracy in the representation of the natural events, the sliding criterion is then integrated within a numerical code which couples the computation of hydrodynamic conditions, the erosion, and deposition of mud and the banks sliding. Finally, the results of the combination of all these mechanisms are compared with the variations in the bathymetric profiles obtained on the experimental site.     

银含量对方铅矿浮选的影响及其机理研究进展

为了阐明银含量对方铅矿浮选的影响,提高含银方铅矿中伴生银的综合回收效率,通过全面梳理前人研究成果,对含银方铅矿的资源状况、工艺流程和药剂制度进行了总结。首先,从不同维度和层面（从试验到模拟、从宏观到微观）综述了银含量对方铅矿的影响,其中包括银含量对方铅矿浮选行为及表面接触角的影响。然后,评述了前人利用红外光谱、微热动力学、电化学和量子化学等分析方法开展的有关银含量对方铅矿浮选行为影响机理的研究进展,上述分析方法相互验证,均证实银矿物对方铅矿的浮选有促进作用,且银含量与促进程度呈正相关。最后,针对含银方铅矿今后研究方向和银铅锌矿资源开发,提出科学、合理的建议,如：在现场生产中应尽量避免使用石灰调浆,如必须使用时,应控制好石灰用量,从而减少伴生银的损失。     

Le premier vocabulaire de sciences cognitives en langue fran?aise.

Reviews the book, Vocabulaire de sciences cognitives by O. Houdé, D. Kayser, O. Koenig, J. Proust, and F. Rastier (1998). The Vocabulaire de sciences cognitives contains 130 alphabetically ordered entries, each entry corresponding to a different word or expression used in cognitive science. The entries are treated from the point of view of each of the five main disciplines contributing to cognitive science: artificial intelligence, neuroscience, linguistics, philosophy, and psychology. The texts concerning a given entry form distinct sections labeled with the name of the discipline concerned. Numerous cross-references to related entries are given. Overall, the Vocabulaire contains about 200 different texts, a third of which have been authored by the members of the editorial board, each of whom is specialized in one of the disciplines mentioned; the remaining texts were written by 54 other authors from these various fields. Of the 130 entries, only 2 very pivotal terms in cognitive science (FUNCTION and REPRESENTATION) receive complete multidisciplinary treatment; 15 entries referring mostly to major cognitive functions (e.g., LANGUAGE, LEARNING, MEMORY, PERCEPTION, REASONING) are covered by three or four disciplines, and 31 others receive a bidisciplinary treatment. Analysis of the 144 pairs of disciplines found in these 48 entries shows the neighborhood among disciplines to be fairly evenly distributed except in the case of psychology and neuroscience, whose greater conceptual proximity is explained by the fact that most neuroscience texts have been written by neuropsychologists. The contributions of the various disciplines were reviewed by one specialist and by at least one nonspecialist. Although predictably more critical, the specialists did not identify many serious problems or errors. However, the reviewers expressed some reservations concerning the choice of the terms deemed worth of an entry, the limited number of disciplines contributing to some entries, the variable length and nature of the texts, as well as the exaggerated place sometimes given to secondary research. If the Vocabulaire de sciences cognitives does not constitute a monumental achievement, it is nonetheless an impressive piece of work, especially considering the breadth and state of the domain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impressions of psychotherapists' offices.

For counseling settings, research suggests that softness, personalization, and order might affect the experience and the perceived expertness, trustworthiness, and social attractiveness of the therapist. This article discusses exploratory studies on college students' perception of the counseling office environment and whether the likely client experience was associated with the softness/personalization and order of the office. As stimuli, the studies used 30 color photographs of psychotherapists' offices viewed from the client's perspective. After obtaining ratings of the characteristics of each office, we obtained ratings from different groups of students of the quality of care and comfort expected in each office (Study 1) and how qualified, bold, and friendly the therapist in the office would be (Study 2). Additional studies examined the likelihood of choosing a therapist based on the office, and the first thought or feeling that came to mind about the office, the therapist, and the patient experience. There were strong correlations in response between groups (by whether they had experienced therapy; their level in school; their gender; and their major, location, and school size). The quality of care, comfort, therapist boldness, qualifications of the therapist, and the likelihood that one would choose a therapist based on the office improved with increases in the office's softness/personalization and order. Friendliness improved with increases in softness/personalization. The office choices, open-ended responses, and reported reasons for the ratings confirmed the importance of softness (comfort) and order. Research should test longer term exposure and behavior. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

基体分离-电感耦合等离子体原子发射光谱法测定高纯钼中9种元素

利用电感耦合等离子体原子发射光谱法(ICP-AES)测定高纯钼样品中杂质元素含量时,由于钼元素具有丰富的谱线,因此钼基体对待测元素干扰较大。为了消除钼基体对待测元素的干扰,实验使用过氧化氢溶解样品,过量硝酸沉淀分离钼基体作为样品前处理步骤,建立了基体分离-电感耦合等离子体原子发射光谱法测定高纯钼中钙、铬、铜、钴、镁、镍、锌、镉和锰的方法。使用4mL过氧化氢溶解样品,10mL硝酸沉淀钼基体,钼的沉淀效率大于99%,沉淀后,各待测元素背景等效浓度均有下降,且回收率都高于85%,随沉淀损失较少。使用高纯钼基体沉淀分离的方法配制校准曲线,各待测元素校准曲线线性相关系数均大于0.9997;方法中各元素的定量限为0.20~2.03μg/g。实验方法用于测定高纯钼样品中钙、铬、铜、钴、镁、镍、锌、镉和锰,结果的相对标准偏差(RSD,n=5)为2.0%~4.8%,测定结果与电感耦合等离子体质谱法(ICP-MS)结果一致。     

Stability of I-Walls in New Orleans during Hurricane Katrina

Failures of I-walls during Hurricane Katrina were responsible for many breaches in the flood protection system in New Orleans. Six breaches were examined in detail by Task Group 7 of the Interagency Performance Evaluation Taskforce. Four of these failures and breaches, which occurred before the water levels reached the top of the wall, were not caused by overtopping erosion. The failure of the I-wall at the 17th Street Canal resulted from shear through the weak foundation clay. The south failure of the London Avenue I-wall was caused by subsurface erosion, which carried massive amounts of sand inland, and removed support for the wall, leading to catastrophic instability. At the north breach on London Avenue, the failure was caused by high pore pressures, combined with a lower friction angle in the loose sand, which resulted in gross instability of the I-wall under the water pressure load from the storm surge. Looking back, with the benefit of 20-20 hindsight, these stability and erosion failures can be explained in terms of modern soil mechanics, exploration techniques, laboratory test procedures, and analysis methods. An important factor in all of the cases investigated was development of a gap behind the wall as the water rose against the wall and caused it to deflect. Formation of the gap increased the load on the wall, because the water pressures in the gap were higher than the earth pressures that had acted on the wall before the gap formed. Where the foundation soil was clay, formation of a gap eliminated the shearing resistance of the soil on the flood side of the wall, because the slip surface stopped at the gap. Where the foundation soil was sand, formation of the gap opened a direct hydraulic connection between the water in the canal and the sand beneath the levee. This hydraulic short circuit made seepage conditions worse, and erosion due to underseepage more likely. It also increased the uplift pressures on the base of the levee and marsh layer landward of the levee, reducing stability. Because gap formation has such important effects on I-wall stability, and because gaps behind I-walls were found in many locations after the storm surge receded, the presence of the gap should always be assumed in I-wall design studies.     

高炉喷吹兰炭的最佳配比

 为探究高炉喷吹兰炭的最佳配比,使用TG-DTG热分析技术研究了百善无烟煤、神华烟煤和兰炭组成混煤的燃烧特性。结果表明,混煤中兰炭配比量增加可以降低煤粉的着火温度与燃尽温度,缩短燃烧时间,提高综合燃烧特性指数,改善混煤燃烧性;升温速率增大,混煤反应速率峰值升高,综合燃烧特性指数升高,混煤燃烧性得到优化。使用KAS等转化率法分析了不同混煤方案的燃烧过程动力学,当兰炭配比量由0增加至40%时,活化能分别为115.25、113.03、112.22、108.20 和104.53 kJ/mol,兰炭的加入可以降低混煤的表观活化能。