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超细及纳米WC-Co复合粉的低成本短流程制备及应用 总被引:2,自引:0,他引:2
综述了在超细及纳米WC-Co粉末的制备研究方面国内外的相关研究进展,系统介绍了北京工业大学硬质合金研究组在研究开发超细及纳米WC-Co复合粉的原位反应合成技术、超细及纳米复合粉在金属陶瓷防护涂层及烧结硬质合金块体材料中的应用等方面开展的系列工作和取得的研究结果。以合成的WC-Co复合粉为原料,制备的超细结构硬质合金涂层、超细晶及纳米晶硬质合金块体材料均具有优良的综合性能。 相似文献
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制备纳米/超细晶WC-Co类硬质合金的两大关键因素是优质纳米/超细晶WC-Co复合粉末的制备和烧结过程中晶粒长大过程的控制。从纳米/超细晶WC-Co复合粉末的制备技术和纳米/超细晶硬质合金的烧结技术两方面,综合评述了近年来国内外的研究进展,并展望了纳米/超细晶硬质合金的发展前景和今后研究开发的重点。 相似文献
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介绍了超细WC-Co硬质合金的磁性能和金相,对它们之间的关系和作用进行了比较分析,认为磁性能和金相是超细WC-Co硬质合金质量控制的重要检测方法。 相似文献
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以原位还原所得超细WC-6%Co复合粉为原料,研究了热压烧结制备硬质合金材料的工艺过程,并分析了材料的物理性能及力学性能。结果表明:将平均粒径约300nm的超细WC-Co复合粉在热压炉中于1 370℃烧结1.5h,可得到平均晶粒度为600nm、相对密度99%且具有良好综合力学性能的亚微米WC-Co硬质合金。 相似文献
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中国超细晶粒WC-Co硬质合金研究进展 总被引:10,自引:1,他引:10
概述了我国超细晶粒WC-Co硬质合金的研究开发现状与进展。我国在制备超细晶粒硬质合金主要粉末原料的批量化生产技术及烧结过程中抑制WC晶粒长大等关键技术方面已取得重要进展,可制备出超细和纳米晶粒硬质合金,获得优异性能。在此基础上推动我国超细晶粒硬质合金向产业化发展的基础条件已趋于成熟。对超细晶粒硬质合金工业化技术开发的重点方向提出了建议。 相似文献
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超细晶粒硬质合金的研究与应用 总被引:8,自引:0,他引:8
硬质合金是目前最重要的刀具材料之一,本文着重介绍和分析了超细品粒WC-Co硬质合金研究中的几个热点领域:超细WC粉末制备,晶粒长大控制,烧结技术以及超细品硬质合金的应用。 相似文献
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纳米硬质合金的研究进展 总被引:5,自引:0,他引:5
概述了纳米晶WC-Co硬质合金的研究开发现状与进展。重点介绍了纳米硬质合金粉末常用的制备方法和烧结技术。同时,对我国超细晶粒硬质合金工业化技术开发的重点方向提出了具体看法。 相似文献
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In this article, personalization is defined as diverse forms of recognizing the other as a unique, responsive, inviolable, and valued subject, all of which are contingent upon community. The processes of personalization are depicted further in terms of (a) the dialectic of recognition and negation, (b) personal and impersonal epistemologies, (c) intentionality and fact, and (d) asymmetrical and mutual recognition. Good enough parenting may be understood in terms of varied forms of personalization, which contribute to psychosocial achievements--psyche-soma integration, sense of going on being or cohesion, self-continuity, sense of aliveness and being real, the capacity to make use of social reality, self-reflection, and emotional regulation. These forms of personalization are supported by the community's web of symbols--symbols that facilitate and represent recognition and appearance of the other as a unique subject. Given the relation between personalization and community, transference is reconceptualized as the patient's history of personalizing, impersonalizing, and/or depersonalizing interactions, as well as his or her desire for and fear of personalization and fellowship. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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以调查区的严格管控区土壤为研究对象,挑选了酸模、龙葵、月季、金盏菊、万寿菊、油牡丹、凤仙花7种植物进行了大田试验,考察超积累植物对土壤中Cd、Pb富集的影响。结果表明,不同植物体内或同种植物体内各部位重金属的含量存在较大差异;酸模、金盏菊、龙葵、月季地上部分重金属含量明显高于地下部分,说明重金属在这几种植物的茎叶里积累较多。金盏菊、凤仙花、万寿菊、龙葵对Cd的富集较强,有利于修复Cd污染的土壤。除凤仙花外,其他6种植物对Cd的转运系数均大于1,对Cd的转移能力由强到弱的顺序依次为酸模、金盏菊,龙葵、油牡丹、月季、万寿菊。就单株而言,积累生物量从大到小依次是酸模、金盏菊、万寿菊、月季;就每亩而言,积累生物量从大到小依次是金盏菊、酸模、月季、万寿菊。综合植物对重金属的富集系数、植物自身的转运系数、整株生物量以及植物的经济价值等考量,万寿菊、金盏菊、月季在修复土壤重金属污染的同时还可兼顾提升经济效益,酸模作为有效降低Cd、Pb含量的重金属修复植物,可推广应用于碱性耕地的重金属污染修复。综上所述,从植物对重金属的富集系数、植物自身的转运系数、整株生物量以及植物的经济价值等综合考量,万寿菊、金盏菊、月季作为修复土壤重金属污染的同时兼顾提升经济,酸模作为有效降低Cd、Pb含量的重金属修复植物,可推广应用于碱性耕地的重金属污染修复。 相似文献
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Management of Fluid Mud in Estuaries, Bays, and Lakes. II: Measurement, Modeling, and Management 总被引:2,自引:0,他引:2
William H. McAnally Allen Teeter David Schoellhamer Carl Friedrichs Douglas Hamilton Earl Hayter Parmeshwar Shrestha Hugo Rodriguez Alexandru Sheremet Robert Kirby 《Canadian Metallurgical Quarterly》2007,133(1):23-38
Techniques for measurement, modeling, and management of fluid mud are available, but research is needed to improve them. Fluid mud can be difficult to detect, measure, or sample, which has led to new instruments and new ways of using existing instruments. Multifrequency acoustic fathometers sense neither density nor viscosity and are, therefore, unreliable in measuring fluid mud. Nuclear density probes, towed sleds, seismic, and drop probes equipped with density meters offer the potential for accurate measurements. Numerical modeling of fluid mud requires solving governing equations for flow velocity, density, pressure, salinity, water surface, plus sediment submodels. A number of such models exist in one-, two-, and three-dimensional form, but they rely on empirical relationships that require substantial site-specific validation to observations. Management of fluid mud techniques can be classified as those that accomplish: Source control, formation control, and removal. Nautical depth, a fourth category, defines the channel bottom as a specific fluid mud density or alternative parameter as safe for navigation. Source control includes watershed management measures to keep fine sediment out of waterways and in-water measures such as structures and traps. Formation control methods include streamlined channels and structures plus other measures to reduce flocculation and structures that train currents. Removal methods include the traditional dredging and transport of dredged material plus agitation that contributes to formation control and/or nautical depth. Conditioning of fluid mud by dredging and aerating offers the possibility of improved navigability. Two examples—the Atchafalaya Bar Channel and Savannah Harbor—illustrate the use of measurements and management of fluid mud. 相似文献
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针对碳酸盐、砷和铜含量高的“三高”金矿选矿回收难度较大的问题,采用原矿焙烧脱碳除砷—NH4Cl“闪速”浸钙—(NH4)2SO4浸镁铜—非氰浸剂药剂(swust-1)浸金工艺流程综合回收矿石中有价元素。研究结果表明:当焙烧温度为950 ℃、焙烧时间为2 h、矿浆浓度为30%、-0.074 mm粒级含量为70%、NH4Cl浓度为3.0 mol/L和浸出时间为10 min时,矿石中Ca2+、Mg2+和Cu2+浸出率分别为82.88%、20.12%和16.75%;在(NH4)2SO4浓度为2.5 mol/L、矿浆浓度为30%和浸出温度为50 ℃的条件下,经过“两段”浸出,Mg2+和Cu2+浸出效果较好。经过“焙烧—浸钙镁铜”后,金的浸出率也大大提高。通过上述工艺流程处理后,钙、镁、铜和金的总浸出率分别可达96.18%、95.16%、80.51%和78.86%,提高了高碱性含铜金矿中有价元素浸出率和综合经济价值。 相似文献
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The effects of B and Ce on the removal of inclusions, microstructures, and properties of Cu-Fe-P alloys were studied. Certain impurity elements and the microstructures, mechanical properties, and conductivity of four experimental alloys, Cu-0.22Fe-0.06P, Cu-0.22Fe-0.06P-0.05Ce, Cu-0.22Fe-0.06P-0.02B, and Cu-0.22Fe-0.06P-0.05Ce-0. 02B ( %, mass fraction), were tested and analyzed. Results show that on one hand, B and Ce have a remarkable function of removing S, Pb, and Bi from copper alloys ; on the other hand, the recrystallization temperature of the Cu-Fe-P alloy is considerably increased by adding trace B and Ce, resulting in the combined strengthening effect of precipitation hardening and cold work hardening after cold working and aging, while the negative effect of B and Ce on conductivity is slight. Therefore, a good combination of high strength and conductivity is achieved. 相似文献
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高炉炼铁的物理本质是铁素物质流在碳素能量流的驱动和作用下,按照设计的流程网络和运行程序,经过一系列复杂物理化学冶金反应过程,将铁矿石转变/转化为液态生铁的过程。碳素不仅是铁矿石还原过程的能量驱动源,也是生成铁水的重要非金属合金元素。面向全球“碳达峰”“碳中和”的发展形势,传统高炉必须在已有工艺技术的基础上进行改进、优化和创新,努力实现低碳化、高效化、绿色化、智能化等多重目标。提出了未来高炉在实现高效低碳的同时,必须从功能设计、装备设计和流程设计入手,遵循节能减排、低碳绿色新的发展理念,通过工艺优化、结构优化和技术开发,使传统高炉更加适应于炉料结构和燃料结构的变革,减少焦炭消耗和对其依赖,在碳素能量输入降低的条件下,形成新的耗散结构体系,进而实现高炉低碳高效炼铁的工程演进和技术发展。 相似文献
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加压浸出作为一种高效的湿法冶金手段,迄今为止已在铜、锌、镍、钴等重金属行业,以及铀、钼、黄金和铂族等稀贵金属行业得到推广应用。总结了重有色金属铜、铅、锌、镍、钴行业和冶炼过程副产物加压浸出技术研究和工业化应用现状,包括复杂硫化铜矿、铜钴矿、硫化砷渣、黑铜泥、铜阳极泥、白烟尘和铜钴冶炼转炉渣加压浸出,复杂硫化锌矿、锌浸出渣、赤铁矿除铁、镓锗富集物、铜渣等加压浸出,硫化镍矿、红土镍矿、白合金、铜渣和钴冰铜加压浸出等。最后,对加压浸出技术在重有色金属行业未来发展趋势进行了展望。 相似文献
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It is clear that psychological aggression is both common in workplaces and harmful to individuals and organizations. An emerging line of research examines organizational responses to allegations of bullying and mobbing. As a result, some researchers now identify processes for detecting, correcting, and preventing bullying and mobbing. Strategies to improve the quality of working life such as surveillance, policy development, training, coaching, and the development of selection, performance management, and reward systems that set standards for collaborative and supportive behavior at work are all necessary to move organizations toward eliminating tolerance of bullying and mobbing. Consulting psychologists have the expertise to provide such interventions because of their in-depth understanding of personality, testing, and assessment, and the application of these concepts to selection, coaching, and performance management. The consulting psychologist brings an attention to human factors that humanize the workplace. The author reviews research on bullying and mobbing, adds practitioner insights based on 13 years of practice in this area, and discusses interventions applied in practice settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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在“碳达峰”、“碳中和”的目标背景下,绿色低碳、清洁高效成为资源开采的新要求,也对科学开采这一复杂系统问题的研究提出了新的方向。阐述了矿产资源开采理念的发展演化,综述了近年来国内外在科学开采方面的研究现状,构建了安全、高效、绿色、低碳、经济、科学管理“六位一体”的科学开采体系,丰富了科学开采的内涵和框架。从复杂科学问题的判断标准、科学开采体系的特征两方面进行推断,得出科学开采属于复杂问题,承载科学开采复杂问题的系统是复杂系统。以复杂科学的思路研究科学开采的复杂性,构建科学开采复杂系统模型,从顶层设计、中层连接和底层基础3个层次思考了实现科学开采的新途径,为实现矿产资源的科学开采提供了新的发展方向。 相似文献
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Reviews the books The art of being, by Erich Fromm (1992); Basic writings, by Martin Heidegger (1993); History of the concept of time: Prolegomena, by Martin Heidegger (1992); Complexity: Life at the edge of chaos, by Roger Lewin (1992); The future of an illusion: Film, feminism, and psychoanalysis, by Constance Penley (1989); Human inquiry: A sourcebook of new paradigm research, by Peter Reason and John Rowan (1990); Reading Heidegger: Commemorations, edited by John Sallis (1993); and Truth and existence, by Jean-Paul Sartre (1992). Brief synopses of each book are presented, rather than full reviews. In The art of being, Fromm presents his synthesis of spiritual teachings from Zen to existentialism, as well as a synopsis of his earlier critiques of consumer capitalism. Basic writings is a collection of essays, lectures, and sections from Heidegger's major works. Of special interest to psychologists interested in Heidegger's methodology is the re-translation of the introduction to Being and Time. In History of the concept of time: Prolegomena, Heidegger elaborates the methodological and foundational connection of his work to Brentano, Dilthey, and Husserl, thus providing for the first time an authoritative understanding of the relationship of his uniquely hermeneutic phenomenology to the ideas of his predecessors. In Complexity: Life a the edge of chaos, Roger Lewin discusses the search for the set of rules that underly complexity theory and the "grand unification" of the life sciences. The future of an illusion: Film, feminism, and psychoanalysis, by Constance Penley, is a collection of essays on the sexual politics of representation. In Human inquiry: A sourcebook of new paradigm research, Reason and Rowan cover the philosophy, methodology, practice, and prospects of what the editors call "new paradigm research": alternative approaches to human science research that are both collaborative and experiential. Reading Heidegger: Commemorations is a richly provocative book of essays by an impressive list of 23 Heidegger scholars around the world. This text celebrates, reconsiders, and sometimes pokes fun at one of the most controversial and most important thinkers of our century. Finally, written in response to Heidegger's The essence of truth, Jean-Paul Sartre's Truth and existence provides a bridge between Sartre's Being and nothingness and his Critique of dialectical reason. It is a philosophical as well as psychological study of epistemology, based on his phenomenological ontology, that becomes a work on morality. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献