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K   总被引:9,自引:0,他引:9  
《天津冶金》2008,(2):31
Kal—Do(卡尔多法):在倾斜(于垂直方向)转炉中吹炼高磷生铁,转炉沿自己的对称轴旋转,顶吹氧。  相似文献   

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Keratin expression in cultured malignant melanoma cells has been studied only rarely. Moreover, no studies have reported of universality of keratin expression in human malignant melanoma cells. In this study, therefore, we analyzed keratin expression in eight cell lines. Using a low-salt aqueous solution without high salt and Triton X-100, as a washing buffer for keratin extraction, followed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and immunological analysis, we demonstrated keratin expression in all eight human malignant melanoma cell lines. The keratin polypeptide expressions common to all melanoma cells were K1, K5, K10 and K14. In addition, K8, K13, K17 and K18, respectively, were detected in individual cells. A measure of keratin expression universality in malignant melanoma cells may have implications regarding their invasive and metastatic behaviors, co-expressed with vimentin.  相似文献   

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Equilibrium oxygen pressures of the univariant ternary coexistences hematite + spinel + alumina, alloy + wustite + spinel, and alloy + spinel + alumina were determined at temperatures in the range 1123 to 1423 K using solid state electrochemical cells. The compositions of alloys and oxide phases of this Fe-Al-0 system that equilibrated with one another at 1273, 1423, and 1573 K were determined. These results and those from the literature are used to determine stabilities of the ternary oxide phases as a function of oxygen pressure and composition by constructing equilibrium oxygen pressure diagrams at 1073, 1173, and 1273 K. Formerly with McMaster University  相似文献   

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爱普生黑白喷墨打印机K100/K200上市伊始,就凭借其速度快、成本低和健康环保的优良特性,受到医疗行业用户的广泛欢迎,成为各医疗用户的打印"新宠"。日前,K100/K200黑白喷墨打印机赢得陕西省某县人民医院采购大单,助力医疗信息化,为广大患者提供更快捷和更环保的贴心服务。  相似文献   

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The concentration of vitamin K was determined in the liver of different strains of rats, and in male and female warfarin-resistant rats by feeding 3H-vitamin K in a purified diet. In each case, the level of vitamin K in the liver correlated approximately with the amount of vitamin K fed. The results indicate that differences in the requirement for vitamin K between the sexes and between strains of rats are due principally to different required concentrations of vitamin K in liver and not to differences in absorption or turnover of the vitamin. The results of the determination of vitamin K epoxide levels in male and female warfarin-resistant rats, and other data, suggest that the amount of vitamin K required in liver may be in part due to differences in the activity of the enzyme, vitamin K epoxide reductase.  相似文献   

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The cyclic stress-strain response and the low cycle fatigue life of conventionally heat treated Inconel 718 were studied. Fully reversed strain-controlled tests were performed at room temperature and at 823 K. Optical and electron microscopy were used to study the development of deformation and cracking during cycling. A power-law relationship between life-time and plastic strain amplitude was obtained. A substantial decrease in fatigue life occurred as the temperature was increased from 298 to 823 K and as the cycling frequency was lowered from 3 cyclesJmin to 0.3 cyclesJmin at 823 K. At 298 K, for all the strain amplitudes investigated, an initial rapid hardening was followed by softening, while at 823 K only softening occurred. Electron microscopy showed that the precipitates were sheared in the course of cyclic straining and that plastic deformation proceeded by the propagation of planar bands. These bands were identified as twins. Twinning was found to be more abundant at elevated temperatures than at room temperature, especially at lower frequencies. Cracking was generally initiated along the interfaces between these twin bands and the matrix but, at elevated temperatures and low strain rates, intercrystalline cracking took place, as well. The influence of particles shearing and twinning on the cyclic stress-strain response of the material are discussed. The importance of planar deformation and twinning on intergranular cracking is emphasized. Formerly with Centre des Matériaux  相似文献   

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Insecticide resistance often is blamed for failures of insecticides to control cat fleas, Ctenocephalides felis (Bouché). Yet the genetics and adaptive advantage of resistance traits remain unexamined. Lethal doses of insecticides that kill 50% of the population fluctuate 7-fold within a cat flea strain. Many reports of flea resistance may be attributable to variable mortality from effects of solvents, substrates, humidities, temperatures, colonization, and ages of fleas. Resistance ratios (ratios of lethal doses of a resistant to a susceptible strain) are < 690-fold in fleas; lower than many other arthropods. This, plus strain variability, hinders resistance detection. Relationships between resistance levels, control failures, and health threats are unclear. Insensitive acetylcholinesterase, knockdown recovery, glutathione transferase conjugation, and mixed function oxidase/cytochrome P450 are demonstrated resistance mechanisms in cat fleas. Ecological genetics of resistance in cat fleas probably involves flea transfer among hosts, host movements, refugia, founder effects, and mortality from abiotic factors. Understanding cat flea resistance requires population monitoring before, during, and after insecticide treatments using conventional and rapid molecular bioassays. Sustained insecticide release devices such as flea collars and long-lived insecticide residues for premises possibly contribute to the development of resistance. New systemic and topical insecticides, especially when given prophylactically, may act similarly. Eliminating insecticides prevents insecticide resistance but necessitates application of biorational tactics incorporating mechanical, environmental, and cultural controls. Using high temperatures, low humidities, host grooming and such tactics as decreasing doses, increasing action thresholds, rotating insecticides, and leaving spatial and temporal refugia may suppress cat flea resistance.  相似文献   

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