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1.
介绍了Access数据库的特点和优点,在采购管理中应用的意义.使用Access编写了<供应仓储管理系统>,论述了该系统的设计思想、程序结构及应用效果.该系统的应用,减轻了工作人员劳动强度、提高了工作效率、确保了物资及时供应、减少了资金的占压.  相似文献   

2.
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.  相似文献   

3.
介绍了天钢1~#TRT顶压控制系统,对现有的顶压控制系统进行了分析,在原有差压调节模式的基础上增加了顶压调节模式,将实际操作改为差压调节与顶压调节两种互选模式,提高了系统的发电效率;对旁通阀组的控制进行了优化,优化后极大地提高了系统的安全性,保证了炉顶压力的稳定,延长了设备的使用寿命,产生了较高的经济效益。  相似文献   

4.
分析了20 t桥式抓斗起重吊车常见故障及原因,采取了相应的解决措施,从根本上杜绝了吊车的常见故障、节约了备件、降低了生产成本、减轻了维修人员劳动强度及提高了企业的经济效益.  相似文献   

5.
济钢中厚板厂3500线粗轧机改造主传动系统采用ACS6000SD变频驱动系统,系统的整流侧和逆变侧采用了对称结构,降低了维护难度;采用了IGCT技术,保证了系统的性能响应;使用了DTC技术,提高了系统的鲁棒性。这种交直交系统做到了对电网的最少谐波运行,既减少了对电网的污染,又省去了无功补偿系统的投资。  相似文献   

6.
有机锗的研究现状和发展趋势   总被引:3,自引:2,他引:1  
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.  相似文献   

7.
2012年1月9日,"智能巡点检仪开发与应用"项目通过了由首钢总公司组织的验收评估。该项目研发的设备智能巡点检仪使用可靠、运行稳定,各项功能和技术指标均达到设计要求,实现了与四级信息化系统的紧密集成和数据共享,提高了数据准确性和人力资源效率;优化了业务流程、加快了信息传递、深化了资源共享,有效减少了设备故障停机时间,提高了设备技术管理水平。  相似文献   

8.
从转炉耐材的损害机理入手,分析了耐材的损耗机理,探讨了炉渣的优化机制,对炉渣的组成及渣料的使用进行优化,对溅渣的工艺进行了改进,实现了转炉护炉的提升,延长了转炉的使用寿命,降低了耐材的损耗,降低了转炉工序的成本。  相似文献   

9.
贺礼泰 《中国钨业》2003,18(4):15-19
概要介绍了樟东坑矿区的主要地质特征,在前人工作的基础上,对矿床的基本特征(尤其是矿脉的变化特征)进行了分析、探讨和总结;利用这些特性及其变化规律,采用一些新的探矿方法不但找到了一些隐伏盲矿,增加了地质储量,延长了矿山的服务年限,而且降低了探矿费用,减少了采矿的盲目性,节约了成本,增加了经济效益。  相似文献   

10.
马坤  郭瑞兴  张晓冬 《冶金设备》2010,(3):64-66,80
简单描述了目前国内芯棒生产的现状,提出了芯棒表面镀铬装置存在的问题,介绍了赛瑞公司自主研发的芯棒镀铬装置的设计背景,阐述了芯棒镀铬装置的基本结构及设备特点,解决了现存的一些问题。  相似文献   

11.
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.  相似文献   

12.
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/O= 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.  相似文献   

13.
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)  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
李远荣 《黄金》1994,15(11):37-42
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。  相似文献   

19.
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)  相似文献   

20.
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)  相似文献   

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