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1.
《铁合金》2008,39(2):5
从近年的情况看,由于经济的快速发展,我国已经成为世界上最主要的矿产和金属的消费国之一。有人认为,到2020年我国铁矿石的消费将占到世界的35.7l%,而消费比例超过20%的矿产由高到低有:煤、锡、锌、铅、氧化铝、铝、铅、铜等。近年来,中国矿产品产量的迅速提高并不能满足国内高涨的需求。根据中国矿业联合会的研究,到2020年中国所需的45种主要矿产可以基本划分为:可以保证、基本保证、短缺、严重短缺四类;可以保证的矿产共24种:煤、天然气、钨、钼、银、稀土、菱镁矿、萤石、耐火黏土、磷、重晶石、水泥灰岩、玻璃硅质原料、石膏、高岭土、石材、硅藻土、钠盐、芒硝、膨润土、石墨、石棉、滑石、硅灰石。基本保证的矿产两种:钛、硫。  相似文献   

2.
依据山西省90年代完成的1:20万区域化探扫面成果,本文系统的统计了山西省Ag、As、Au、B、Ba、Bt、Bi、Cd、Co、Cr、Cu、F、Hg、La、Li、Mn、Mo、Nb、Ni、P、Pb、Sb、Sr、Th、Ti、U、V、W、Y、Zn、Zr、SiO_2、Al_2O_3、Fe_2O_3、MgO、CaO、Na_2O、K_2O等38元素的平均含量及其在不同地质单元中的平均含量、标准差、变异系数和浓集系数。并以Cu元素为例总结了元素的分布特征。  相似文献   

3.
近年来,阴极溶出伏安法得到很快的发展。本文共收集了52篇参考文献,对于用此法所测定的铝、钒、铬、锰、铁、钴、镍、铜、锌、锗、砷、硒、钼、锝、镉、铟、锑、铈、钨、金、铊、碲、铅、镨、铀、镧、硫、氯、溴、碘、氰离子、硫氰离子、硫酸根和—些有机化合物作了简单的论述。  相似文献   

4.
1999年一季度我国铜、铝、铅、锌、锡、镍六种基本有色金属及其制品的外贸结构虽无大的、根本性的变化,出口创汇的顺序是铝、铜、锌、锡、铅、镍;进口用汇顺序仍是铜、铝、锌、镍、锡、铅。  相似文献   

5.
目前,我厂使用的标准样品有:碳素钢、低合金钢、高锰钢、镍铬不锈钢、高温耐热钢、硼钢、铬钨钢、滚动轴承钢、高硅铝合金、生铁、铬钼铜合金、铸铁、稀土球墨铸铁、高铬铸铁、合金铸铁、中低碳素锰铁、中低炭素铬铁、硅铁、钛铁、烧结矿、高炉渣、锰矿、电炉渣、石灰石、萤石、硅砖、铬镁砖、镁砂、焦炭、煤等系列标准样品。在配合分析使用时,如何尽快的选择随心所需的标准样品,一度成为难题。现在能非常方便、快速、准确的找到。我们的做法如下:(1)建立台帐:新购回标准样品按不同系列分类,每瓶有新编序号,对标准样品的原编号、产地、…  相似文献   

6.
《太钢科技》2004,(4):69-71,13
《太钢科技》是太原钢铁(集团)有限公司根据党和国家的政策、法令创办的,经山西省新闻出版局批准备案的科学技术刊物。主要刊登太钢矿山、耐火、焦化、炼铁、炼钢、连铸、轧钢、锻造、理化检验、能源、机械、土建、计控、自动化、环保、安全、教育和医学等专业以及科研、工艺质量攻关、产品开发、技术开发和技术管理等方面的试验研究、科技成果、技术总结、综合评述和经验介绍等。  相似文献   

7.
正唐山唐钢气体有限公司是由河北钢铁股份有限公司与中国气体工业投资控股有限公司共同投资创立的河北省第一家中外合资气体生产企业,注册资本7.78亿元,下设多家子分公司唐钢气体是集各类气体生产、运输、销售服务为一体的大型专业化气体公司主要生产和销售氧、氮、氦、氩、氢、二氧化碳、医用氧、车用天然气产品,并提供生产、销售、使用相关的技术咨询服务和运输,进行气体生产设备的研制。同时,从事氢、一氧化碳、硫化氢、甲烷、乙烷、丙烷、正丁烷、乙炔、丙烯、丙二烯、溶解乙炔、氯乙炔、环氧乙烷、硅烷、氯甲烷、氧、空气、氮、氦、氖、氩、氪、氙、一氧化二氮、二氧化碳、六氟化硫、氨、磷烷、一  相似文献   

8.
本刊是中国有色金属工业总公司主办的科技刊物,主要报道稀有金属(钛、钨、钼、稀土、锂、铍、铷、铯、锆、铪、钒、铌、钽、镓、铟、铊、锗、硒、碲、铼等)在选矿、冶炼、分析测试方面,稀有金属、有色金属材料科学与工程以及半导体材料的制备、测试等方面的科研、生产和应用成果。内容力求与国内科研、生产紧密结合,  相似文献   

9.
《太钢科技》2009,(4):53-55
《太钢科技》是太原钢铁(集团)有限公司根据党和国家的政策、法令创办的,经山西省新闻出版局批准备案的科学技术刊物。主要刊登太钢矿山、耐火、焦化、炼铁、炼钢、连铸、轧钢、锻造、理化检验、能源、机械、土建、计控、自动化、环保、安全等专业以及科研、工艺质量攻关、产品开发、技术开发和技术管理等方面的试验研究、科技成果、技术总结、综合评述和经验介绍等。  相似文献   

10.
《太钢科技》2009,(2):57-59
《太钢科技》是太原钢铁(集团)有限公司根据党和国家的政策、法令创办的,经山西省新闻出版局批准备案的科学技术刊物。主要刊登太钢矿山、耐火、焦化、炼铁、炼钢、连铸、轧钢、锻造、理化检验、能源、机械、土建、计控、自动化、环保、安全等专业以及科研、工艺质量攻关、产品开发、技术开发和技术管理等方面的试验研究、科技成果、技术总结、综合评述和经验介绍等。  相似文献   

11.
Within-child associations between family income and child externalizing and internalizing problems were examined using longitudinal data from the NICHD Study of Early Child Care and Youth Development (2004a, 2004b; N = 1,132). Variations in income effects were estimated as a function of whether families were poor, whether mothers were partnered, and the number of hours mothers and their partners were employed. On average, children had fewer externalizing problems during times when their families' incomes were relatively high than during times when their families' incomes were relatively low; the estimated benefits of increased income were greatest for children who were chronically poor. For both externalizing and internalizing problems, income was most strongly associated with problems when chronically poor children's mothers were partnered and employed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

12.
Data on adolescents' after-school experiences and their susceptibility to peer pressure were derived from surveys administered to a heterogeneous sample of 865 adolescents in Grades 5–9. Consistent with the findings of previous studies, the results show that Ss who reported home after school were not significantly different from those who were supervised by their parents at home during after-school hours. However, when a 2nd sample of latchkey children (n?=?594) was studied to include greater variation in after-school experiences, Ss who were more removed from adult supervision were found to be more susceptible to peer pressure to engage in antisocial activity. Ss who were home alone were less susceptible to peer pressure than are those who were at a friend's house after school, and those who were at a friend's house, in turn, were less susceptible than were those who describe themselves as "hanging out." Moreover, latchkey Ss whose parents knew their whereabouts and those who had been raised authoritatively were less susceptible to peer influence than were their peers, even if their afternoons were spent in contexts in which adult supervision was lax and susceptibility to peer pressure was generally high. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
通过2种途径将熔体快淬法制得的FeCuNbSiB非晶薄带制成环状粘结磁体。一是将非晶薄带进行晶化处理,再将晶化后的薄带粉碎成不同粒度的粉末,然后与粘结剂相混合制成粘结磁体。二是将非晶薄带直接粉碎成不同粒度的粉末,再将此粉末进行晶化处理,将晶化后的磁粉与粘结剂相混合制成粘结磁体。分析了磁粉粒度和模压压力对粘结磁体性能的影响。并对两种粘结磁体的性能进行比较。结果表明,第一种方法制备的粘结磁体的性能优于第二种。  相似文献   

14.
Flexural behavior and serviceability performance of 24 full-scale concrete beams reinforced with carbon-, glass-, and aramid-fiber-reinforced-polymer (FRP) bars are investigated. The beams were 3,300?mm long with a rectangular cross section of 200?mm in width and 300?mm in depth. Sixteen beams were reinforced with carbon-FRP bars, four beams were reinforced with glass-FRP bars, two beams were reinforced with aramid-FRP bars, and two were reinforced with steel, serving as control specimens. Two types of FRP bars with different surface textures were considered: sand-coated bars and ribbed-deformed bars. The beams were tested to failure in four-point bending over a clear span of 2,750?mm. The test results are reported in terms of deflection, crack-width, strains in concrete and reinforcement, flexural capacity, and mode of failure. The experimental results were compared to the available design codes.  相似文献   

15.
In this paper, efficiency and effectiveness of carbon fiber-reinforced polymers (CFRP) in upgrading the shear strength and ductility of seismically deficient beam-column joints have been studied. For this purpose, four reinforced concrete interior beam-column sub-assemblages were constructed with nonoptimal design parameters (inadequate joint shear strength with no transverse reinforcement) representing preseismic code design construction practice of joints and encompassing the vast majority of existing beam-column connections. Out of these four, two specimens were used as baseline specimens (control specimens) and the other two were strengthened with CFRP sheets under two different schemes (strengthened specimens). In the first scheme, CFRP sheets were epoxy bonded to the joint, beams, and part of the column regions. In the second scheme, however, sheets were epoxy bonded to the joint region only but they were effectively prevented against any possible debonding through mechanical anchorages. All four subassemblages were subjected to cyclic lateral load histories so as to provide the equivalent of severe earthquake damage. Further, the damaged control specimens were repaired after filling the cracks through epoxy and wrapping them with CFRP sheets under the same two above-mentioned schemes. These repaired specimens were subjected to the similar cyclic lateral load history and their response histories were obtained. Hence, a total of six specimens were tested: two control; two strengthened; and two repaired. Response histories of control, repaired, and strengthened specimens were then compared. The results were compared through hysteretic loops, load-displacement envelopes, column profiles (maximum horizontal displacements of column along its height), joint shear distortion, ductility, and stiffness degradation. The comparison shows that CFRP sheets improve the shear resistance of the joint and increase its ductility. Results of two chosen schemes of strengthening were also compared and the importance of beam upgrading was highlighted.  相似文献   

16.
通过辉光放电质谱法(GDMS)测定了高温合金中的C,Mg,Al,P,S,Ti,V,Cr,Mn,Fe,Co,Cu,Nb,Mo,W共15种元素。对辉光放电参数如电流、电压、预溅射时间进行了优化;对高温合金中的质谱干扰进行了分析并详细叙述了各分析元素的干扰情况。选择丰度大且不受干扰或干扰少的同位素用于分析,大多数元素测定结果很好。对于仍存在干扰的元素通过数学校正的方法进行质谱干扰校正。建立干扰校正公式,成功地消除了62Ni2+和36Ar12C+对31P+和48Ti+的质谱干扰。在优化的实验条件下,建立工作曲线。  相似文献   

17.
In this paper, efficiency and effectiveness of carbon fiber reinforced polymers (CFRPs) in upgrading the shear strength and ductility of seismically deficient corner or knee reinforced concrete beam-column joints have been studied. For this purpose, four as-built corner/knee joints were constructed with no transverse reinforcement, representing extreme case of preseismic code design construction practice of joints and encompassing many existing beam-column corner joints. Out of these four as-built specimens, two specimens were used as baseline specimens (control specimens) and other two were strengthened with CFRP sheets under two different schemes (strengthened specimens). In the first scheme, CFRP sheets were epoxy bonded to joint, beams, and part of the column regions. In the second scheme, however, sheets were epoxy bonded to joint region only but they were effectively prevented against any possible debonding through mechanical anchorages. All these four subassemblages were subjected to cyclic lateral load histories to simulate loading due to earthquake and provide the equivalent of severe earthquake damage. The damaged control specimens were then repaired by filling their cracks through epoxy and externally bonding them with CFRP sheets under the same above two schemes. These repaired specimens were subjected to the similar cyclic lateral load history and their response histories were obtained. Response histories of control, repaired, and strengthened specimens were then compared. The results were compared through hysteretic loops, load-displacement envelopes, column profiles, ductility, and stiffness degradation. The comparison shows that CFRP sheets are very effective in improving shear resistance and deformation capacity of the corner beam-column joints and delaying their stiffness degradation. Shear capacities of control, repaired, and strengthened specimens were also predicted using writers’ published formulation. The predicted shear capacities were in a good agreement with the experimental values.  相似文献   

18.
系统汇集了20世纪70年代以来我国使用X射线荧光光谱(XRF)分析技术进行铁矿石分析的文献共计101篇,其中熔融制样法文献78篇,粉末压片法文献11篇,能量色散仪器分析及野外现场应用文献12篇。首先介绍了铁矿石分析的基础条件:包括专著、标准物质、标准方法和综合性评述论文;然后采用表格方式对文献要点进行了介绍, 按熔融法、粉末压片法、能量色散多元素分析方法进行了重点评介;最后讨论了铁矿石分析中常遇到的粒度、矿物效应,制样方法选择和内标的应用等实际问题。对XRF在铁矿石分析中的某些重要问题进行了探讨,并对XRF分析铁矿石的应用前景作了展望。文献表明:XRF技术已经成为铁矿石主、次量元素分析最重要的分析方法之一。全篇引文151篇。  相似文献   

19.
微波消化技术在铁矿石分析中的应用研究   总被引:4,自引:1,他引:4       下载免费PDF全文
通过微波高压密封法对沉积物样品的消解,采用正交试验设计法系统地研究了微波消解中如试剂种类、压力控制和消解程序等影响因素,确定了最佳消解条件。用微波高压密封法对不同矿源和形态的铁矿石样品进行消解,方法快速、简单,测定结果准确度高,相对标准偏差小于0.15%。本法亦可用于其他矿石样品和环境样品的消解。  相似文献   

20.
系统汇集了20世纪70年代以来我国使用X射线荧光光谱(XRF)分析技术进行铁矿石分析的文献共计101篇,其中熔融制样法文献78篇,粉末压片法文献11篇,能量色散仪器分析及野外现场应用文献12篇。首先介绍了铁矿石分析的基础条件:包括专著、标准物质、标准方法和综合性评述论文;然后采用表格方式对文献要点进行了介绍, 按熔融法、粉末压片法、能量色散多元素分析方法进行了重点评介;最后讨论了铁矿石分析中常遇到的粒度、矿物效应,制样方法选择和内标的应用等实际问题。对XRF在铁矿石分析中的某些重要问题进行了探讨,并对XRF分析铁矿石的应用前景作了展望。文献表明:XRF技术已经成为铁矿石主、次量元素分析最重要的分析方法之一。全篇引文151篇。  相似文献   

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