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1.
大型顶吹平炉投产以来,由于降碳速度快,因而造渣困难,脱硫能力差,长期不能冶炼硅钢。针对上述问题,对造渣工艺进行改革,获得成功,不仅降低了消耗,提高了质量,缩短了熔炼时间,而且也满足了用户对硅钢的要求,同时,取得了较大的经济效益。  相似文献   

2.
通过大量的调查研究,查清了电磁站内渗漏水的缺陷,提出了解决方案和具体操作方法,改变了原定的搬迁方案,不仅彻底地消除了缺陷,还节约了大修费,缩短了工期,为生产创了可观的效益。  相似文献   

3.
承钢“八五”期间坚持“科技是第一生产力”的思想,紧紧依靠技术进步,狠抓节能降耗,增产增收,投资7亿余元用于科技进步的项目,实现了高炉喷吹煤粉,连铸,连轧,热电联产等工艺技术并已取得了显著的经济效益,经济技术指标水平明显提高,有力地促进了企业的发展,提高了市场竞争的能力,保证了经济效益的提高,为“九五”的进一步发展奠定了基础。  相似文献   

4.
本文介绍10t“0”型龙门吊通过静定车架结构代替传统的超静定结构的改进,其造型美观,受力合理,降低了精度要求,节省了大量的材料,降低了成本,使制造工艺更加方便,大大降低了金属结构的自重,改善了起重机的运行状态,延长了驱动车轮的寿命,故障率低,维修费用少。  相似文献   

5.
热电厂煤气加压站经过系统优化改造后,设备运行可靠,操作方便,满足了生产工艺要求,实现了变频调速,消除了煤气的泄漏现象,达到了节电,节油,节约维修费用的目的,经济效益可观。  相似文献   

6.
铝-钪(2%)合金的制备   总被引:4,自引:0,他引:4  
传统的生产铝钪合金的方法,成本高,条件复杂,不利于工业生产,我们对金属热还原制取A1—Sc合金进行了研究,简化了生产条件,降低了对原料的要求,缩短了工艺流程,降低了生产铝钪合金的成本,开拓了铝钪合金的应用市场。  相似文献   

7.
本文叙述了国内先进的煤气净化工艺和氨、硫回收装置,净化了焦炉煤气,减少了环境污染,改善了硫铵质量,增加了硫磺新产品,提高了生产管理水平,确保了安全生产。  相似文献   

8.
湖北丹江哆嗦业公司三期技改工程供电整流系统采用了较多的新技术,新设备,新工艺,在该前提下,对运行参数进行详细研究,达到合理利用电能的目的,同时采用全面质量管理工作的方法,成功地改善了电流的稳定性,减少了设备停运率,为安全生产提供了有力的保障,达到了节能降耗的目的,取得了一定的经济效益。  相似文献   

9.
基于问题原型的采矿方法选择专家系统的研究   总被引:1,自引:1,他引:0  
杨洪军  黄士芳 《黄金》1997,18(10):19-22
本文针对矿山的实际需要,以矿山工作人员应用对象,在充分分析矿块回采问题的基础上,提出了三种问题原型,建立了领域问题的知识库,编制了推理机,用户接口,解释,知识库管理等程序模块,形成了采矿专家系统的框架,为进一步开发奠定了基础。  相似文献   

10.
混合轻稀土萃取分离工艺优化研究   总被引:1,自引:0,他引:1  
针对现行稀土萃取分离工艺存在的问题,对混合轻稀土萃取分离工艺进行了系统的优化研究,以模糊分组新工艺取代了传统分离工艺,并对模糊分组新工艺与传统分离工艺的技术经济指标进行了全面的比较,结果表明,模糊分组新工艺,分离效果好,大幅度降低了酸,碱消耗,减少了有机相和稀土的存槽量,既降低了生产成本,又节省了充槽费。  相似文献   

11.
锰铁合金、锰硅合金、金属锰中铅、砷、钛、铜、镍、钙、镁、铝的含量决定了产品质量,以往常采用化学法或原子吸收光谱法进行测定,但存在准确度较差或测定速度不能满足要求等问题。为了实现上述元素的准确、快速测定,建立了采用电感耦合等离子体原子发射光谱法(ICP-AES)测定锰铁合金、锰硅合金和金属锰中微量铅、砷、钛、铜、镍、钙、镁、铝的方法。实验以硝酸、盐酸、氢氟酸、高氯酸分解样品,并使硅与氢氟酸反应生成四氟化硅挥发除去,试液中剩余共存元素主要有铁、锰等。实验结果表明,铁不干扰测定,通过在标准溶液系列中进行锰基体匹配消除锰基体效应的影响。以2mL高氯酸和6mL盐酸混合酸(8%)作为分析介质,可以达到最佳分析效果。在各元素校准曲线线性范围内,线性相关系数在0.9992~0.9999之间;方法中各元素的检出限在0.0001~0.0040μg/mL。实验方法用于测定锰铁合金、锰硅合金、金属锰中铅、砷、钛、铜、镍、钙、镁、铝,结果的相对标准偏差(RSD,n=11)在2.2%~9.4%;回收率在95%~105%;选择7个实验室进行了验证试验,各实验室间结果基本一致;按照实验方法测定了4个标准样品(材字-32、YSB C 28618、YSB C 26605)中铅、砷、钛、铜、镍、钙、镁、铝,结果与认定值相吻合。  相似文献   

12.
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)  相似文献   

13.
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.  相似文献   

14.
15.
Understanding the hydraulics of flow in a compound channel with vegetated floodplains is very important for determining the stage-discharge curve and for supporting the management of fluvial processes. In this paper, the flow patterns over different types of vegetation, such as tree, shrub, and grass, are described, based on an experimental study. For vegetation on the floodplain, the authors choose plastic grass, duck feathers, and plastic straws as model grass, shrubs, and trees, respectively. A 3D acoustic Doppler velocimeter was used to measure the local flow velocities for different types of vegetation on the floodplain, and the total discharge and flume slope were measured independently. In the cases of nonvegetated floodplains, all measured streamwise velocity distributions followed the logarithmic distribution, but for vegetated floodplains, they followed an S-shaped profile, exhibiting three zones. For all cases, the fluctuating velocity followed a normal distribution. The influence of different types of vegetation on the distributions of the secondary currents, turbulence intensities, and Reynolds shear stresses were also analyzed.  相似文献   

16.
This paper identifies and analyzes the open-policy trend of the Chinese construction industry, which is characterized by trade liberalization, the underlying principle of the World Trade Organization (WTO). Compared to the construction industries in the United States, Japan, and the U.K., the construction industry in China is less developed in its legal framework, industrial structure, technological level, and international market share. To develop a competitive construction industry, the Chinese construction industry needs not only to accommodate appropriate international practice, but also to adapt and adopt it according to the market environment in China. A model to enhance the performance of the Chinese construction industry is proposed. The model consists of six modules: defining government’s role, opening up the construction market and establishing a competitive mechanism, promoting design institutes’ services and empowering professional bodies, encouraging technological innovations, upgrading employees’ educational level, and adopting multiprocurement routes. Recognizing China’s recent accession to the WTO and the attendant boost to its economy and industry development, the paper gives a timely evaluation of the post-WTO Chinese construction industry and proposes a model for its development. The model may serve the needs of academics, Chinese construction policymakers, construction enterprises, design institutes, and foreign contractors.  相似文献   

17.
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.  相似文献   

18.
In this paper, the results of the standard percussion cup test, the penetration cone test, and the laboratory vane test performed on organic sediments and kaolin are discussed. First, the relationship between the water content and the cone penetration depth is explored. Second, the relationship between the shear strength, using the laboratory vane apparatus, and the water content is investigated. Finally, the relationship between the shear strength and the penetration depth of the cone, at different levels of water content, is explored.  相似文献   

19.
火焰原子吸收光谱法测定合金结构钢中铬、锰   总被引:1,自引:0,他引:1  
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。  相似文献   

20.
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   

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