Application of the Schommers method for constructing a hybrid pair potential

An algorithm is developed to construct an effective pair potential that can reproduce several characteristics of a system during a molecular dynamics simulation. This algorithm is based on the Schommers method and the Belashchenko method of potential hybridization and is used to construct an effective pair potential for liquid iron near the melting temperature. The constructed potential well reproduces the pair correlation function of liquid iron in an NPT ensemble with zero pressure in a barostat and provides good agreement for the atomic density and the linear thermal expansion coefficient.     

An Outlier Identification and Judgment Method for an Improved Neural‐Network BOF Forecasting Model

Due to the lack of simple and effective data filtering method for multi‐variable and numerous samples in BOF endpoint forecasting model, a method of outlier identification and judgment was introduced and applied to data screens for improving BOF endpoint forecasting model. The outside values as potential outliers are calculated using the method of five‐number summary which is a robust estimation of the population parameter, and then the potential outliers are judged with the clustering method. By comparing the exceptional data from clustering analysis with the outside values from the five‐number summary, the intersection of these two groups is regarded as the final outliers to be deleted; in addition, the exceptional data but not outside values are regarded as final exceptional data to be further analyzed; and the outside values but not exceptional data are regarded as final outliers to be deleted too. Finally, to verify the data selection, an improved BP‐based neural network model is used to predict the end‐point carbon content and temperature. By using this data pretreatment method, the absolute values of the mean and maximum training residuals of endpoint carbon and temperature decreased by 26.7%, 41% and 17.3%, 34.5% respectively; and those of the prediction decreased by 10%, 44.9% and 9.4%, 22.9% respectively. It is shown that the proposed method improves effectively the neural network model for BOF endpoint forecasting.     

The role of persuasive arguments in changing affirmative action attitudes and expressed behavior in higher education.

The research reported in this article examined the conditions under which persuasive arguments are most effective in changing university students' attitudes and expressed behavior with respect to affirmative action (AA). The conceptual framework was a model that integrated the theory of reasoned action and the elaboration likelihood model of persuasion. Studies 1 and 2 established effective manipulations of positive-negative AA information, and peripheral-central routes of processing. Study 3 implemented these techniques, and a path analysis was carried out testing the differential effects of valence of information processed via different routes on AA evaluative beliefs, attitudes, intention, and expressed behavior. Results indicated that positive AA messages processed centrally (i.e., for meaning) resulted in significantly more positive evaluative beliefs. Modifications to the original model resulted in a final model with excellent fit to the data that supported the mediating role of intention in the AA attitude-behavior relationship, as predicted by the theory of reasoned action. The findings highlight potential benefits of interventions for improving support for AA policies, provided that positive information is processed at a central, evaluative level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Leading by example: The case of leader OCB.

The importance of leading by personal example or role modeling for effective leadership has been recognized in many leadership theories. However, leaders' ability to influence group behavior through exemplary behavior has received little attention in empirical work. This study explores leading by example through theoretical development and empirical testing of a moderated mediation model of the potential effects of leader organizational citizenship behavior (OCB). This model suggests that a leader's OCB may promote group OCB directly and indirectly by enhancing the group's belief that OCB is worthy. It also specifies the moderators of the direct and indirect effects of leader OCB on group OCB. Data from 683 members of 67 intact work groups, 67 group managers, and their supervisors support the hypothesized model. The theoretical and practical implications of these findings are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

专家控制技术在锌湿法冶炼技术中的应用

针对锌湿法冶炼生产过程自动化控制系统中的实际问题,介绍了专家控制技术在生产过程控制的作用。把模型的优化控制方 法和专家控制系统技术 相结合,能对复杂的生产过程进行有效的实时控制和集中监视,减轻工人劳动强度和提高劳动生产率。     

基于强度理论的岩石损伤弹塑性模型

根据单轴受力特性曲线唯象地考察岩石材料损伤演化,定义弹性应变表示的一维损伤变量及其本构模型,利用双剪强度理论将其推广至三维模型.塑性是潜在破坏面的摩擦滑移,在传统塑性理论的框架中,建立了基于摩尔-库仑强度理论与潜在滑移面摩擦软-硬化特性的各向异性损伤弹塑性本构关系.结果表明,计算的损伤演化与CT观测结果符合很好,用本文的弹塑性模型反映损伤材料的力学特性是可行的.     

铜闪速冶炼冰铜品位在线控制数学模型应用

闪速炉在线控制数学模型结构简述,分析当前铜闪速冶炼主要采用前馈-反馈来推定冰铜品位方法的原理,给出前反馈触发条件和计算方法。该理论成果通过在金隆公司的实践应用,效果良好,对保障铜闪速炉稳定生产有非常重要的作用。     

Disopyramide phosphate: electrophysiological and inotropic effects in isolated cat papillary muscles and comparison with quinidine (author's transl)

The effects of 4-diisopropylamino-2-phenyl-2-(2-pyridyl)-butyramide monophosphate (disopyramide phosphate; D; 10(-6)--10(-4) M) on transmembrane resting potential, action potential, effective refractory period and twitch tension were simultaneously studied in electrically driven (frequency 1 Hz) papillary muscles isolated from the right ventricles of cats. The experiments were performed at 35degrees C with intracellular glass microelectrodes. Quinidine sulfate (10(-6)--10(-4) M) was used for comparison. D increased the duration of the action potential during phase 3 (90% repolarization) in a concentration-dependent manner. The effective refractory period was prolonged by nearly the same extent whereas the maximal rate of rise of the action potential was reduced. The overshoot was slightly decreased only at 10(-4) M. Resting potential and plateau phase of the action potential were not affected by D. The effects of D on the electrical events were accompanied by concomitant decreases in twitch tension. The effects of quinidine were essentially similar to those obtained with D. It is concluded that the effects of D on dV/dtmax and effective refractory period observed in cat papillary muscle may account for the clinically observed efficacy of D to overcome ventricular arrhythmias. The results suggest also that the mechanism of the ventricular effects of D is similar to that of quinidine.     

A novel anti-inflammatory drug, SDZ ASM 981, for the topical and oral treatment of skin diseases: in vivo pharmacology

There is a need for safe and effective therapies for inflammatory skin diseases. Current topical and systemic treatment of psoriasis is effective but suffers from side-effects or is inconvenient. The therapeutic armamentarium for atopic dermatitis is very limited and far from satisfactory. In vivo preclinical data are presented for SDZ ASM 981, a novel ascomycin macrolactam derivative with high anti-inflammatory activity. Anti-inflammatory activity was observed in mouse, rat and pig models of allergic contact dermatitis. In the pig model, topical SDZ ASM 981 was as effective as the ultrapotent corticosteroid clobetasol-17-propionate, and when compared with a series of commercial topical corticosteroid preparations, 0.1% SDZ ASM 981 had equivalent efficacy to clobetasol-17-propionate (0.05%), the most potent product on the market. Unlike the corticosteroid, however, SDZ ASM 981 did not cause skin atrophy in pigs. SDZ ASM 981 potently inhibited allergic contact dermatitis in mice and rats when given systemically, and oral treatment was more effective than cyclosporin A in rats. Furthermore, SDZ ASM 981 has a low potential for affecting systemic immune responses, as demonstrated in rat models of localized graft vs. host reaction and allogeneic kidney transplantation. Preclinical results suggest that SDZ ASM 981 has the potential to be a well-tolerated and effective drug for topical as well as oral treatment of inflammatory skin diseases.     

Effects of contraction-excitation feedback on electrophysiology and arrhythmogenesis in rabbits with experimental left ventricular hypertrophy

OBJECTIVE: The aim was to investigate the influence of contraction-excitation feedback on myocardial electrophysiology and arrhythmia susceptibility in the setting of experimental left ventricular hypertrophy. METHODS: New Zealand White rabbits with perinephritis hypertension were used. With the hearts perfused in vitro, left ventricular monophasic action potential duration and local effective refractory periods were determined at three sites, namely the anterior, apical, and posterior wall, together with ventricular tachycardia inducibility and ventricular fibrillation threshold under different loading conditions. RESULTS: The left ventricular dry weight to body weight ratio was increased by 31% in the hypertrophied group (3.863 x 10(-4), v 2.955 x 10(-4) in the controls). Left ventricular hypertrophy was associated with prolongation of action potential duration when the left ventricle was not loaded and under normal loading conditions. Changing from unloaded Langendorff to baseline working heart perfusion resulted in a consistent decrease in action potential duration and effective refractory period at all left ventricular sites in both hypertrophied and control hearts. Subsequent manipulations of myocardial loading resulted in decreases in action potential duration and effective refractory period in both groups of hearts. Ventricular tachycardia could not be induced in any heart in Langendorff mode. Under different increased loading conditions, a total of four hypertrophied hearts (44%) became inducible, while control hearts remained non-inducible. The ventricular fibrillation threshold under conditions of increased load tended to be lower in the hypertrophied hearts than the control hearts; in the setting of increased preload the hypertrophied group showed significantly increased vulnerability to ventricular fibrillation (median threshold currents 35 mA v > 100 mA, p < 0.05). CONCLUSIONS: Left ventricular hypertrophy is associated with a prolongation of action potential duration and effective refractory period and an increased arrhythmia susceptibility in the setting of increased myocardial loading. There were no marked differences between the groups in the magnitude of the changes in action potential duration, effective refractory period, or dispersion of repolarisation and refractoriness resulting from manipulations of myocardial loading that could have been implicated in the increased arrhythmia susceptibility of the hypertrophied hearts during changes in load.     

方坯连铸凝固传热的复合数值模拟

根据连铸机特点和铸流场特性，在拉坯方向上将整个铸流长度划分为上部计算域和下部计算域。对于铸坯温度场的数值模拟，上部计算域充分耦合钢液对流对传热的影响，采用了三维稳态流动传热耦合模型；下部计算域则将铸流场对传热的影响考虑为有效导热系数，并忽略拉坯方向上的传热效果，采用了二维非稳态有效导热系数模型。计算过程和结果表明，采用此复合模拟方法保证了数值模拟的准确性并降低了仿真程序的计算成本。     

板坯连铸二次冷却模型控制系统的研究与开发

以国内某厂老连铸机的改造为研究背景,开发了板坯连铸二次冷却模型控制系统,即在基本水表的基础上,建立通过线性插值计算配水量的二次冷却控制模型,并引入切片生命周期法计算铸流的动态速度,通过为动态速度和静态速度设定不同权重,实现二次冷却动静态混合控制。系统建立了基于事件消息驱动的连铸生产跟踪方法,为连铸全过程二次冷却模型自动控制奠定了基础。系统投入运行后生产自动化程度大幅度提高,铸坯质量也控制在有效范围内。     

黄金选矿数字孪生技术应用探索

随着工业互联网、大数据、人工智能等新一代信息技术与矿业领域传统工艺技术的不断融合发展,选矿流程数字化、智能化成为行业发展趋势.数字孪生技术与选矿工艺相结合建立数字仿真平台,将提升设备改进、流程优化、智能控制等在选矿全生产周期的应用效果.介绍了数字孪生技术在流程工业应用中的发展历史及趋势,以及不同数字化模型在黄金选矿流程...     

不同桩体材料复合地基承载及变形性状对比试验研究

通过室内模型试验,实测得到碎石桩、夯实水泥土桩和CFG桩复合地基桩土荷载分担比、桩土应力比和桩间土深层变形,并对三类不同桩体材料复合地基的承载及变形性状进行了对比分析.认为碎石桩复合地基和夯实水泥土桩复合地基均存在有效桩长或有效复合土层厚度;碎石桩桩长超过有效桩长,对提高复合地基承载力和压缩模量、减小变形效果不明显,除一些特别情况如为处理可液化地基外,设计桩长可适当超过有效桩长,但不宜过长;夯实水泥土桩复合地基的有效桩长与桩身强度相关性显著,应以桩身强度控制进行夯实水泥土桩桩体设计,使按桩身强度确定的单桩承载力大于或等于由桩周土及桩端土的抗力所提供的单桩承载力;CFG桩复合地基桩身强度高,桩体自身压缩性小,可全桩长发挥侧阻作用,当桩端落在好的持力层时,能很好地发挥端阻,提高承载力,减小变形,设计时应优先选择好的桩端持力层进行设计.

     

Making students' evaluations of teaching effectiveness effective: The critical issues of validity, bias, and utility.

This article reviews research indicating that, under appropriate conditions, students' evaluations of teaching (SETs) are (a) multidimensional; (b) reliable and stable; (c) primarily a function of the instructor who teaches a course rather than the course that is taught; (d) relatively valid against a variety of indicators of effective teaching; (e) relatively unaffected by a variety of variables hypothesized as potential biases (e.g., grading leniency, class size, workload, prior subject interest); and (f) useful in improving teaching effectiveness when SETS are coupled with appropriate consultation. The authors recommend rejecting a narrow criterion-related approach to validity and adopting a broad construct-validation approach, recognizing that effective teaching and SETs that reflect teaching effectiveness are multidimensional; no single criterion of effective teaching is sufficient; and tentative interpretations of relations with validity criteria and potential biases should be evaluated critically in different contexts, in relation to multiple criteria of effective teaching, theory, and existing knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A music-based HIV prevention intervention for urban adolescents.

Objective: This research examines the process of conducting and evaluating a music-based HIV prevention intervention among urban adolescents, and is informed by the information, motivation, behavioral skills (IMB) model. Design: Musically talented opinion leaders were recruited to write, record, and distribute HIV prevention themed music to their peers to increase HIV prevention motivation, behavioral skills, and behaviors. In this 3-month field experiment, participants were 306 students enrolled in health classes at each of three large multiracial urban high schools (one treatment school; two control schools). Main Outcome Measures: Measures of HIV prevention information, motivation, behavioral skills, and behaviors, both pre- and postintervention. Results and Conclusion: Results indicate that the intervention influenced several aspects of HIV prevention motivation, behavioral skills, and condom use and HIV testing behaviors. This research demonstrates that the incorporation of music into HIV prevention interventions for adolescents has the potential to be effective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of Storm-Water Management Design Criteria to Maintain Geomorphic Stability in Kansas City Metropolitan Area Streams

Fifty-three years of historical precipitation data were applied to the U.S. Environmental Protection Agency Storm Water Management Model (SWMM) to conduct hydrologic and hydraulic simulations, generating continuous stream flow hydrographs in the receiving stream channels. On-site BMP and regional detention criteria were selected to allow postdevelopment replication of predevelopment peak flow frequency exceedance curves and the critical portions of shear stress duration curves. Instream continuous stage data generated by SWMM were used to examine erosion potential through the use of an erosion potential index. Coarse stream bed material were found to be less sensitive to changes in erosion potential due to urbanization, and extended detention ponds designed for flood control and water quality treatment were effective in reducing erosion potential. These controls were less effective in reducing erosion potential of fine loam bed material, indicating reductions of runoff volumes are required to minimize increases in channel erosion. Findings indicate that regional analysis based on local hydrologic and geomorphic characteristics are necessary to identify appropriate storm-water control requirements.     

特钢返回钢优化利用及可利用资源的开发

特钢制造过程中产生的金属损耗,可用按工序测算的模式,建立回收和循环返回使用机制.根据钢种特性,对资源细分,实施精细化管理,匹配合理的使用工艺.无形损耗同样有很大的回收和循环使用潜能.回收特钢产品用户的加工废钢,有待建立有效网络体系.     

铁促进黄铜矿浸出的研究进展

综述了铁促进黄铜矿浸出机理及影响因素的研究状况,指出铁是一种有效的助浸剂,其作用效果与氧化还原电位、铁离子浓度、pH以及介质类型等因素有关.     

利用OpenGL对岩体三维模型进行切剖面方法研究

通过对三维图形的一般切割技术的介绍,提出了直接利用OpenGL高级技术进行三维模型的剖面绘制过程。利用OpenGL的高级绘图功能,对岩体三维模型的切割剖面的方法作了详细的介绍。最后对某露天矿的三维模型进行剖切,生成一系列剖面图形,从而验证了此方法是有效的和可行的。