有机锗的研究现状和发展趋势

主要介绍了有机锗的活性,总结了有机锗的作用及其机理,并对它的应用也做了简要的说明.同时根据它的研究现状对其发展趋势作了分析.     

烦恼 快乐 艺术——池莉“人生三部曲”解读

池莉的"人生三部曲"--<烦恼人生>、<不谈爱情>、<太阳出世>诉尽了普普通通的市民烦恼,小说中主人公被柴米油盐、吃喝拉撒、老婆孩子等琐事所烦着,从而构成他们的"烦恼人生".然而池莉通过自己的艺术创作,以积极的人生态度,又让读者体会到生活本身的快乐,"烦恼人生"中包含着"快乐人生".     

废水处理站自动控制系统的应用

介绍了邯钢冷轧废水站的配套项目废水处理站的自动控制系统,主要从自控设备组成、网络控制系统等方面论述了控制功能的实现,该系统的应用为ERP的数据采集提供了很好的保证,提高了电气控制的集成度和可靠性,简化了控制环节,提高了生产效率.     

杂质对Ti-55.8%Ni SMA低周弯曲疲劳性能的影响

真空感应熔炼时采用高纯氧化物坩埚及石墨坩埚, 保持其他控制参数不变, 得到名义成分为Ti-55.8%Ni的TiNi形状记忆合金铸锭, 经完全相同的加工工艺制备成Φ 1.5 mm的TiNi合金丝材. 用自制试验装置对所得TiNi合金丝材的室温低周弯曲疲劳性能进行评价. 研究发现, 使用氧化物坩埚熔炼所得材料的低周弯曲疲劳性能较使用石墨坩埚得到的材料有显著提高. 杂质成分分析及SEM形貌观察显示合金中第二相夹杂物有所减少, 这是其性能得到改善的主要原因. 采用随机安排对比试验结果的t检验方法可以判断, 氧化物坩埚使用中期所得到TiNi合金的疲劳性能较好. 认为坩埚的连续使用次数过多坩埚材料性能的恶化是造成周期疲劳变坏的主要原因.     

从软件开发项目看管理中的沟通

用任何方法或形式,在两个或两个以上的主体(如人或电脑)传递、交换或分享任何种类的信息的任何过程,就叫做沟通.要完成一个项目,需要具备各种才能和素质的人,由此产生了对组织或团队的需求,因此组织的成员都必须与他人共事.而沟通则是实现"共事"的必要条件.没有沟通就无法传达任务,组员不明确任务就无法工作.沟通要定位清晰,采取恰当的沟通渠道和方式,要以尊重他人为前提进行沟通交流,了解他人的性格个性,多倾听,鼓励,提高交谈技巧,表达要清晰.恰当的、及时主动的沟通能够避免软件项目开发中不必要的失误.     

基于可持续发展的企业组织结构创新研究

21世纪的中国要实现经济的发展,更要实现经济的可持续发展.作为支撑国家经济支柱的企业同样如此.当代企业应该以什么方式发展,才能与可持续发展的命题相一致,这是一个重要的课题.本文从企业可持续发展的内涵着手,分析了我国企业组织实现可持续发展所面临的问题,提出了几点基于组织创新的企业可持续发展的对策.     

电炉电极降耗机理及工艺研究

石墨电极是电炉炼钢和钢包精炼炉的主要加热部件,但电极消耗也是在炼钢过程中所不可避免的消耗材料.电极消耗成本是电弧炉炼钢的主要成本之一.针对近年来电弧炉炼钢居高不下的电极消耗量,相关领域的冶金炼钢专家对此做了深入分析研究,并取得了很好的效果,降低了电极的消耗.然而与国外先进炼钢生产水平的电极消耗相比仍有相当的差距.为此,针对这一现状对电炉电极消耗机理及国内外研究现状做了综合性的分析研究,旨在为电弧炉电极研究专家及工作人员的系统研究做详细的总结陈述,以便于电极的研究与生产.     

赤泥絮凝分离机理的研究进展

合成高分子絮凝剂在赤泥絮凝分离中有重要的应用,首先介绍了稀释矿浆的性质及絮凝剂的作用形式,然后对各种絮凝剂在氧化铝赤泥沉降分离中絮凝机理的研究现状进行了综述,并提出了氧化铝工业用絮凝剂的发展方向.     

黄金价格和石油价格的联动分析

黄金和石油的价格波动在大多数时候呈正向联动关系,虽然没有严格的数字比例关系,但是其波动趋势往往相同.这主要是因为影响黄金价格和石油价格波动的因素中,有一部分影响因素是相同的,如美元汇率、通货膨胀、主要石油生产国(特别是石油输出国组织)对黄金的运作以及国际上的重大政治事件.当这些相同的影响因素事件发生,特别是对国际市场产生重大影响时,石油价格和黄金价格的走势通常趋向一个方向;但是,出于各种各样的原因,也产生了数次背离.     

浓缩-沉淀法制备铟锡氧化物(ITO)微米棒状粉末的试验研究

文章利用新颖的浓缩析出加煅烧工艺、制备了微米级ITO棒状粉末.借助X射线衍射(XRD)对棒状粉末进行了相结构研究;利用扫描电镜(SEM)对棒状粉末形貌进行了相关的表征;用能量分散谱仪(EDS)以及化学分析方法对粉末的化学成分进行了分析;利用热分析仪(TG-DTA,TG-DTG)对粉末的受热行为进行了相关的表征.结果表明:绝大部分ITO棒的直径位于2～9 μm,而且约95%的棒的长径比大于6;ITO棒中的Sn含量主要富集于表面,而且由棒的表面向核心区逐渐递减,这与Sn的引入方式有关;In(OH)3棒中应该存在含In的硝酸盐或亚硝酸盐;In(OH)3强烈的脱水发生在260～280 ℃,随后在更高的温度下形成ITO固溶体.     

Addition of Cobalt to Lead Anodes Used for Oxygen Evolution—A Literature Review

A review of the literature dealing with the effect of cobalt on lead-based anodes for oxygen evolution during electrolysis of sulfuric acid solutions verifies that the presence of cobalt at the anode–electrolyte interface, either as constituent of the anode material or as ions in the electrolyte, catalyzes the evolution of oxygen and reduces the corrosion of the anodes and the contamination by lead of metal cathodes produced during electrowinning. However, due to harmful effects of cobalt ions on the cathodic reaction in some processes, these benefits are limited to the electrowinning of copper. Efforts to develop a way of introducing cobalt at the anode–electrolyte interface without interfering with the cathodic reactions are reviewed in this paper. The use of lead–cobalt alloy anodes has had limited success due to issues arising from the low solubility of cobalt in lead, segregation during casting of the alloys, and nonuniform distribution of cobalt which affects the integrity of the anodes. This has been overcome in part lately by inclusion of cobalt into only the surface layer of a lead or lead alloy substrate, by thermal treatment of a cobalt salt to form a catalytic cobalt oxide surface species, or by electrodeposition of composite lead–cobalt oxide anodes. The last approach in particular has been actively investigated by several groups, but to our knowledge it is yet to find application in the industry. The review also critically examines the likely reaction mechanisms involved.     

A review of effects of silver,lead, sulfide and carbonaceous matter on gold cyanidation and mechanistic interpretation

Despite the wealth of published data on the beneficial or detrimental effects of silver, lead, sulfide, and carbonaceous matter on the rate of gold cyanidation at an anode or by dissolved oxygen, the lack of comparative studies on relative effects has hampered rationalisation of the role of these activators or passivators of gold. In the present study, the published rate data per unit surface area of gold, silver, and gold–silver alloys based on electrochemical or chemical dissolution of rotating discs or foils of constant surface area in aerated cyanide solutions at ambient temperatures are analysed on the basis of the Levich equation. The current status of the reaction mechanism is also reviewed and updated on the basis of species distribution and potential–pH diagrams, stoichiometric factors, and interim chemical species of gold(I), silver(I), and lead(II). The anodic peak potentials of reported voltammograms closely follow the potential–pH lines of Au(I)/Au(0) and Pb(II)/Pb(0) couples. Despite the formation of stable complexes between lead(II), nitrate, and hydroxide ions, the total calculated soluble lead(II) in alkaline solutions of pH range 10–11 saturated with lead hydroxide is shown to be < 0.1 g/m³. A comparison of the reported diffusion coefficients of cyanide ions and dissolved oxygen with the values based on the Levich plots of reported rates reveals the rate-controlling stoichiometric M/CN or M/O₂ molar ratios. The difference between some of these ratios and the generally accepted ratios of M/CN = 1/2 and M/O₂ = 1/0.5 or 1/0.25 based on the formation of M(CN)₂⁻, H₂O₂ or OH⁻ in the overall cyanidation reaction is attributed to the oxidation of cyanide to cyanate and passivation due to the formation of gold hydroxides/oxides. The alloyed or dissolved silver and lead eliminate passivation due to the involvement of mixed hydroxo–cyano complexes of silver and lead ions in the surface reaction. Gold dissolution by oxygen in cyanide-rich solutions is limited by oxygen diffusion, but enhanced by the presence of a low concentration of sodium sulfide due to the involvement of hydrosulfide ion in the surface reaction. However, excess lead or sulfide retards gold cyanidation due to surface blockage by metallic lead, lead hydroxide, or due to passivation by Au₂S/S. Even low concentrations of hydrosulfide passivate gold–silver alloys due to the formation of Ag₂S. This can be eliminated by adding stoichiometric quantities of lead(II) to precipitate sulfide as PbS. Large stoichiometric ratios of O₂/M for the cyanidation of graphite coated gold appears to be a result of the enhanced oxidation of cyanide by oxygen or hydrogen peroxide, leading to a cyanide deficiency at the surface and passivation of gold by hydroxide/oxide. The presence of excess cyanide or lead(II) does not override this effect.     

Sham reasoning, Humpty Dumpty, and the burden of proof.

Slife and Reber ask of psychologists that they recognize their prejudice against theism and the incompatibility between theistic and naturalistic worldviews. Yet, the subtext of their article is that theism and naturalism are equally valid and that psychology’s secularism is a mistake. Given that theism is not beyond reason, the only sufficient ground for charging psychologists with prejudice is if (i) theism has survived serious attempts at conceptual and empirical test, and (ii) psychology ignores or disguises this fact. So, the grounds for believing in the reality of a supernatural existent are highly relevant to the authors’ allegation. However, their concept of God affords no such grounds. They disavow the logic involved in the ordinary meaning of the term “incompatible” and they ignore a crucial distinction between conditions of existence and qualities of things or processes. The consequence is that either God is this-worldly, and there is no ontological basis to Slife and Reber’s incompatibility thesis, or God’s mode of existence is quite different from the mode of existence of ordinary things and all the problems of dualism follow. Either way, their charge of prejudice is without foundation. The burden of proof rests with the defender of theism and, for now, psychology’s secularism can be considered a mark of the discipline’s (sometimes questionable) rationality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failure Resistance of Historic Stone Bridge Structure of Charles Bridge. II: Susceptibility to Floods

The paper is a follow-up to the first part devoted to an analogical problem investigated with a view to the degradation of the stone structure due to the effects of nonstress load, and it deals with the probability problem of the bridge structure collapse under the effect of an extreme flood wave. The paper presents the results of the numerical analysis of the response of the historic stone bridge structure of Charles Bridge of the 14th century to the flood wave effect simulated by angular rotation, subsidence, and shifting in the footing bottom of a bridge pier. Special focus is on the effect of interventions into the stone bridge structure dating back to the last major overhaul of 1967–1975, particularly, on the effect of the reinforced concrete slab (tie plate) connecting the opposite bridge breast walls increasing the rigidity of the breast walls and their structurally efficient connection to the vaults of the bridge arches. The numerical analyses performed point out the prevailing negative effects of the implemented interventions in terms of structural rigidity of the stone bridge structure exposed to the effect of a flood wave.     

Reliability-Based Design for External Stability of Mechanically Stabilized Earth Walls

A two-phase approach was used to develop a reliability-based design (RBD) method for external stability of mechanically stabilized earth (MSE) walls. In the first phase, a parametric study was conducted using Monte Carlo simulation to identify parameters that affect the probability of external failure of MSE walls. Three modes of failure were considered: sliding, overturning, and bearing capacity. External stability was assessed by treating the reinforced soil as a rigid mass using the same procedures employed for conventional gravity-type wall systems. Results from the parametric study indicate that the mean and coefficient of variation of the backfill friction angle are significant for sliding, the mean and coefficient of variation of the friction angle of the backfill and coefficient of variation of the unit weight of the backfill are significant for overturning, and the mean and coefficient of variation of the friction angle of the foundation soil and the mean of the backfill friction angle are significant for bearing capacity. In the second phase, a series of additional simulations was conducted where the significant parameters identified in the parametric study were varied over a broad range. Results of these simulations were used to develop a set of RBD charts for external stability of MSE walls. A comparison indicates that similar reinforcement lengths are obtained using RBD and conventional methods and that the inherent probability of external failure in conventional deterministic design is ? 0.001. This probability of external failure is similar to inherent probability of failure reported by other investigators for similar geotechnical structures.     

Response Surface Models to Detect and Localize Distributed Cracks in a Complex Continuum

Linear response surface (RS) models are used to represent the relationship between samples of response time histories measured by sensors placed across a structure. Different structural states of a general time-variant system are considered for short intervals capturing a linearized model of each state. Within this framework, the error associated with each RS model is sensitive to a modification of the structural state. A method that relates the changes of the statistical characterization of the error to the occurrence of a structural modification is developed for damage detection. The localization of damage is then pursued by identifying the largest discrepancies resulting from the comparison between the statistics of the sum of the squares of the error obtained at each sensor location. The generality of the method is shown by applying it to the experimental data of a realistic structure, which is representative of a continuous body affected by distributed cracking.     

New Orleans Levee System Performance during Hurricane Katrina: London Avenue and Orleans Canal South

Hurricane Katrina was one of the worst natural disasters in U.S. history. The effects of the hurricane were particularly devastating in the city of New Orleans. Most of the damage was due to the failure of the levee system that surrounds the city to protect it from flooding. This paper presents the results of centrifuge models conducted at Rensselaer Polytechnic Institute and the U.S. Army Corps of Engineers simulating the behavior of the levees at London Avenue North and South that failed during Hurricane Katrina. Those levees failed without being overtopped by the storm surge. Also included are the results of a centrifuge model of one levee section at Orleans Canal South, which did not fail during the hurricane. The key factor of the failure mechanism of the London Avenue levees was the formation of a gap between the flooded side of the levee and the sheetpile. This gap triggered a reduction of the strength at the foundation of the protected side of the levee. The results are fully consistent with field observations.     

铜,砷矿物类型对金氰化浸出的影响及如何提高其浸出率的探讨

本文引用了某些理论研究的成果，考察了含铜，含砷矿物在氰化溶液中的行为和对金氰化浸出的影响的规律，找出金浸出率与各种有害矿物含量的相关关系，为制定难选金工艺方案时参考。并结合小型试验和工业实践，对矿石性质作深入了研究，同时其浸出工艺条件也进行了最佳选择和应用，为提高金的浸出率进行了讨论。     

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)     

Social psychoanalytic research and the twenty-first-century family: Comment on Wallerstein and Lewis (2007).

Seligman regards Wallerstein and Lewis' paper (see record 2007-10890-004) as an exemplary piece of social-developmental psychoanalytic research, finding it accessible, activist and empirical. He admires Wallerstein and Lewis' careful attention to the influence of social reality on the development of the internal worlds of both children and adults, following a psychoanalytic tradition which has been neglected recently. Since actual family configurations are changing so rapidly in the current American situation, analysts should develop new theoretical and research approaches that reflect these changing realities. Seligman highlights two specific implications of such adaptive shifts: the de-centering of the Oedipus complex as the standard form of psychosocial-family organization of the personality, and increased attention to the role of sibling relationships in development. He calls for more analytic clinical research efforts that will apply the substantial potentials of social-psychoanalytic research in service of the varying groups of children who are suffering in the midst of the array of psychosocial strains in the contemporary culture. (PsycINFO Database Record (c) 2010 APA, all rights reserved)