株洲力洲硬质合金有限公司DMF压力烧结炉投入大批量生产

株洲力洲硬质合金有限公司作为一家专业生产拉丝模产品的高科技民营企业，致力于走“科技领先”发展之路，投入巨资购置DMF压力烧结炉，率先成为拉丝模产品采用DMF压力烧结炉生产的厂家。公司经过一年的攻关试验，拉丝模产品性能明显提高，抗弯强度比真空烧结提高30％以上。金相孔隙明显降低。采用DMF压力烧结炉生产的拉丝模产品自今年投放市场以来，     

我国硬质合金烧结设备的发展

介绍了我国烧结技术各个发展阶段的典型烧结设备的结构、技术特性,使用的优点和缺点,以及硬质合金烧结炉的发展方向。     

ZYS50/50/130低压真空烧结炉控制系统研究

本文概要地介绍了ZYS50／50／130低压真空烧结炉的组成结构、主要工艺过程，并详细地介绍了低压真空烧结炉的控制系统设计以及该设备在硬质合金生产中的应用。     

真空连续烧结炉在钢结硬质合金生产中的应用

株洲硬质合金厂于1970年研制成功了一台大型的真空连续烧结炉,1971年正式投入钢结硬质合金生产,至今已使用十几年.实践证明,该设备设计合理,操作方便,节约能源,能连续烧结多种牌号、不同规格的产品:生产效率较高,有显著的经济效益,为钢结合金的生产和发展创造了条件.本文就是作者在株洲硬质合金厂工作期间参与该设备的调试、试生产和生产情况的简要总结.一、真空连续烧结炉的基本结构1.基本结构真空连续烧结炉由炉体、两个Φ380毫米电动真空闸阀、装舟室、卸舟室、机械推舟装置、抽真空系统和电控系统构成,见图1.炉体的断面结构见图2.现将其主要的基本结构简述如下.(1)炉体主要由炉壳、三带炉管、炉头联接部件、炉尾联接部件、筑炉耐火材料、发热元件(钼丝)、测温观察装置等构成.炉壳采用夹套通水冷却,内层用不锈钢板,外层用普通优质钢板制作.炉管由三带刚     

几种新型的硬质合金生产设备及其应用效果

介绍了硬质合金生产用可倾式球磨机、真空蒸汽干燥柜、卧式排胶妒与卧式真空烧结炉等设备的特点及其应用效果。     

湘潭新大粉末冶金设备制造有限公司的一体化真空烧结炉

简要介绍了湘潭新大粉末冶金设备制造有限公司研制的一体化真空烧结炉的炉子结构、脱蜡系统、工艺气体的引入系统、设备的控制系统以及炉子性能的鉴定结果。     

新型烧结炉

美国宾州大学安装了一台KYK Oxynon连续烧结炉，能加热到2200℃。这种炉子不使用真空或氢气，而是在减低氧分压的条件下烧结和钎焊金属与合金。特别适于烧结与钎焊含高蒸汽压元素（铬，锰等）的材料。现已进行了不锈钢、硬质合金、铌、钼、钨、钛、含锰钎焊料、氮化硅及氧化铝等的烧结与钎焊试验。     

硬质合金真空烧结

本文讨论了硬质合金真空烧结的工艺制度原则及真空烧结炉的现状和发展。     

双室多功能硬质合金烧结炉

双室多功能真空烧结炉的冷室用于烧结后制品的快冷、气淬或油淬;热室用于压坯的脱脂、成份调整和烧结。设备造价不高。产品质量好。     

硬质合金/碳钢复合轧辊的可行性初探

为了寻找一种替代传统整体硬质合金轧辊的新型复合轧辊,以期在不影响轧辊使用性能的基础上,节省宝贵的W、Co资源,降低生产成本,对采用硬质合金/碳钢复合轧辊的可行性进行初步探索,并从材料的物理力学性能与微观组织结构两方面对WC-Co硬质合金与碳钢连接区域进行深入解析.结果表明,通过对铁基粉末与硬质合金混合料粉末的合理搭配、采用特殊装料方式、用传统模压成形方法压制毛坯、施行热等静压烧结或加压烧结,所制备的WC-Co硬质合金/碳钢烧结复合体材料,结合区强度可达1 600 MPa,并通过Fe、Co原子互扩散形成了良好的冶金结合,从制备工艺方面初步证明以硬质合金/碳钢复合轧辊替代硬质合金轧辊是可行的.     

Comparative pharmacokinetics and glucodynamics of two human insulin mixtures. 70/30 and 50/50 insulin mixtures

OBJECTIVE: To compare and contrast the pharmacokinetics and glucodynamics of two insulin mixtures, one of 50% NPH human insulin and 50% Regular human insulin (50/50) and one of 70% NPH human insulin and 30% Regular human insulin (70/30), in healthy male volunteers after subcutaneous administrations of 0.3 U/kg. RESEARCH DESIGN AND METHODS: We administered single doses of 50/50 and 70/30 insulins to 18 volunteers in a randomized crossover fashion. All subjects received 0.3 U/kg of each mixture separated by at least 7 days. Each dose was given after an overnight fast and during a glucose clamp to maintain a euglycemic state. We measured serum insulin and C-peptide concentrations through frequent blood sampling after each treatment. Pharmacokinetic measurements were calculated from insulin data corrected for C-peptide, including maximum insulin concentration (Cmax), time to maximum insulin concentration (tmax), terminal rate constant (beta), area under the curve from 0 to infinity (AUCinfinity0), and mean residence time (MRT). Pharmacodynamic measurements were summarized from C-peptide concentrations (minimum C-peptide concentration [Cmin], time to minimum C-peptide concentration [tmin], area between the C-peptide baseline and the C-peptide suppression curve [AOCc], absolute maximal difference from baseline [Sdiff] and glucose clamp measurements. The glucose clamp measurements included maximum infusion rates (Rmax) and time to Rmax (TRmax) from glucose infusion rate (GIR) documentation, as well as cumulative glucose infused during the first 4 h ((0)4Gtot) and total glucose infused (Gtot) during the study. RESULTS: For the pharmacokinetic assessment, statistically greater values of insulin Cmax and beta were found for the 50/50 mixture, whereas the 70/30 mixture had a greater MRT. Statistical differences were also detected in glucodynamics, with greater values of Rmax and (0)4Gtot found with the 50/50 mixture. Notably, differences were not detected for insulin AUCinfinity0 and Gtot values. CONCLUSIONS: Higher insulin concentrations and a greater initial response were present with the 50/50 mixture, but the two mixtures had equivalent bioavailability and cumulative effects. These results support use of the 50/50 mixture in situations where greater initial glucose control is required.     

50kg／m钢轨轨腰分层缺陷的研究

通过低倍金相和扫描电镜观察及能谱分析，得出５０ｋｇ／ｍ钢轨轨腰分层缺陷是由于钢锭头部缩孔降到钢锭本体截口以下，硅酸盐杂物破坏钢轨轨腰金属连续性造成的，采用５０ｋｇ／ｍ钢轨的钢锭模小保温帽改为大保温帽，基本消除了这种缺陷。     

Microstructural study of Ti50Pd50 and Ti50Ni50−xPdx alloys produced by combustion synthesis

The microstructure of the Ti-Ni-Pd ternary shape memory alloys (SMAs) produced by combustion synthesis was studied by scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDAX) and X-ray diffraction methods. It was found that, apart from the parent phase, Ti₅₀Ni_50-xPd_x, there also exists a second phase with the stoichiometry of (Ni_1−y, Pd_y,)Ti₂. Higher palladium and lower nickel contents were found in the parent Ti-Ni-Pd phase compared with the theoretical, ideal solution values. Lower palladium and higher nickel contents were found in the second (Ni_1−y,Pd_y)Ti₂ phase. These discrepancies were explained in that palladium has a greater affinity for titanium than for nickel. The X-ray diffraction data show that the structure of the parent phase is orthorhombic (B19), and the orthorhombic unit cell contracts with in-creasing nickel content. This paper is based on a presentation made in the symposium “Reaction Synthesis of Materials” presented during the TMS Annual Meeting, New Orleans, LA, February 17-21, 1991, under the auspices of the TMS Powder Metallurgy Committee.     

50%

摩根士丹利、煤林和麦格理银行等金融机构预测,2008年度铁矿石长期合同价格将上涨50%,这是目前媒体上所能看到的涨幅的最高预测。摩根大通则认为2008年铁矿石价格将上涨30%,而 JP 摩根的预期涨幅为25%～30%。与金融机构和各利益相关方的百家争鸣相反,身处漩涡中心的各方谈判     

50 kg/m钢轨踏面掉块缺陷分析

 50 kg/m钢轨在使用一段时间后踏面出现掉块缺陷。采用光学显微镜、图像仪和低倍检验等方法对钢轨踏面掉块缺陷产生的机理进行了分析和研究。结果表明,掉块缺陷的形成是由于钢轨滚动接触疲劳伤损所致。改善轮轨接触方式,减少钢轨踏面的轮轨接触应力,可以减缓曲线钢轨踏面压溃、剥离裂纹和浅层状剥离掉块伤损的出现,通过对钢轨进行及时的预防性打磨,是预防和减轻滚动接触疲劳伤损的最有效方法。     

B-50/GAP-43-induced formation of filopodia depends on Rho-GTPase

In the present study we show that expression of the neural PKC-substrate B-50 (growth-associated protein [GAP-43]) in Rat-1 fibroblasts induced the formation of filopodial extensions during spreading. This morphological change was accompanied by an enhanced formation of peripheral actin filaments and by accumulation of vinculin immunoreactivity in filopodial focal adhesions, colocalizing with B-50. In time lapse experiments, the B-50-induced filopodial extensions were shown to stay in close contact with the substratum and appeared remarkably stable, resulting in a delayed lamellar spreading of the fibroblasts. The morphogenetic effects of the B-50 protein were entirely dependent on the integrity of the two N-terminal cysteines involved in membrane association (C3C4), but were not significantly affected by mutations of the PKC-phosphorylation site (S41) or deletion of the C terminus (177-226). Cotransfection of B-50 with dominant negative Cdc42 or Rac did not prevent B-50-induced formation of filopodial cells, whereas this process could be completely blocked by cotransfection with dominant negative Rho or Clostridium botulinum C3-transferase. Conversely, constitutively active Rho induced a similar filopodial phenotype as B-50. We therefore propose that the induction of surface extensions by B-50 in spreading Rat-1 fibroblasts depends on Rho-guanosine triphosphatase function.     

Hydrogen Gorsky effect in amorphous Cu50 Ti50

A previous investigation for the short range diffusion of hydrogen in amorphous Cu₅₀ Ti₅₀ suggests that there exist six representative atomic structures for the small clusters of the tetrahedra, where a short range jump of a hydrogen atom takes place with the activation energies E₀,E₁…,E₅(E₀>E₁>… E₅). In the present work, the long range connectivity of these hydrogen sites with various E_m(m = 0 to 5) in amorphous Cu₅₀ Ti₅₀ is investigated in the hydrogen concentration range below 15 at.% by means of the hydrogen Gorsky effect (HGE) measurements. HGE is always observed to be composed of two constituents, HGE-1 and 2. HGE-1 is surmised to be HGE through the whole thickness of a specimen, and HGE-2 to be HGE in some local-regions with the effective diffusion length of several μm reflecting a distribution of internal stress in a specimen. The activation energy for HGE-1, E_G⁽¹⁾, is always found at around E₁ or in between E₀ and E₂, suggesting that there is no long range diffusion path spanning only the sites with lower E₃ to E₅. E_G⁽²⁾ for HGE-2 is slightly higher than E_G⁽¹⁾. These results are discussed in the light of the site percolation.