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WC对Cu/WC_P复合材料性能及组织的影响 总被引:8,自引:0,他引:8
通过WC含量对WC/Cu复合材料性能的影响,确定了冷压-烧结法制备Cu/WC材料的适宜WC含量为10vol%左右。并就WC对该材料组织和再结晶行为的影响进行了有益的探讨。 相似文献
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AM Luciani S Di Capua L Guidoni R Ragona A Rosi V Viti 《Canadian Metallurgical Quarterly》1996,41(3):509-521
NMR relaxation times T1 and T2 of agarose and Fricke agarose gels have been measured in the range 17-51 MHz. The analysis of the spin echo curves indicates a multiexponential behaviour, characterized by three components, at all the examined frequencies. The relative T2 values, ranging from a few to a hundred milliseconds, can be attributed to different species of water molecules present in the gel. Two of these components are characterized by relaxation rates R2a and R2b, more sensitive than R1 to gamma irradiation, the sensitivity S being S(R1) = 0.066 s-1 Gy-1, S(R2a) = 0.088 s-1 Gy-1, S(R2b) = 0.17 s-1 Gy-1. The three T2 values decrease as a function of frequency, but no gain in dose sensitivity is obtained by changing the working frequency in the examined range. The relaxivity of agarose gels containing ferrous or ferric ions has also been measured and found to be different from those of the corresponding solutions in the absence of agarose. Thus it was possible to estimate the irradiation yield from three independent parameters, R1, R2a and R2b. No effect of the dose rate or of the source energy has been observed for any of these parameters. 相似文献
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G Barbaro G Barbarini W Calderon B Grisorio P Alcini G Di Lorenzo 《Canadian Metallurgical Quarterly》1996,111(5):1169-1177
BACKGROUNDS & AIMS: Contrasting opinions exist about the pharmacological treatment of esophageal candidiasis in patients with acquired immunodeficiency syndrome (AIDS). The aim of this study was to assess the long-term efficacy of fluconazole and itraconazole treatment. METHODS: This study evaluated 2213 human immunodeficiency virus-positive patients at first episode of esophageal candidiasis diagnosed by endoscopy; 1105 received fluconazole and 1108 received itraconazole. The endoscopic and clinical response to treatment was assessed periodically until the end of the follow-up period (1 year). RESULTS: At week 2, endoscopic cure occurred in 81.2% of patients treated with fluconazole and in 65.6% of patients treated with itraconazole (P < 0.001). Clinical cure was observed in 81.5% of patients treated with fluconazole and in 75.2% of patients treated with itraconazole (P < 0.001). At the end of the follow-up period, endoscopic and clinical cure were observed in 96% of patients treated with fluconazole and in 95.6% of patients treated with itraconazole (P = 0.788), with similar differences by intention-to-treat analysis (93.6% vs. 93.3%; P = 0.853). Treatment failure was observed in 22.3% of fluconazole-treated patients and in 26.6% of itraconazole-treated patients (P = 0.022). CONCLUSIONS: Fluconazole and itraconazole are provided with good long-term therapeutic efficacy in the treatment of Candida esophagitis in patients with AIDS. Fluconazole is associated with a higher rate of cure than itraconazole in short-term treatment. 相似文献
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重馏分油加氢脱氮反应动力学模型的研究 总被引:10,自引:1,他引:9
简要地介绍了一些典型的模型氮化物的HDN反应规律。根据胜利VGO在3722B催化剂上的大量HDN实验数据,提出了如下的HDN基本反应动力学方程:dCNdt=-k1+K*CNCNPH2为了扩大上式的应用范围,详细分析了各种因素(如原料油种类和馏程及H2S等)对HDN的影响,并开发了相应的经验关联式,从而得到了一个较完整的馏分油HDN反应动力学模型。验证实验表明,该模型是成功的。 相似文献
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A novel, heat-resistant and Pronase-sensitive, inhibitor of eukaryotic DNA topoisomerase I has been purified from Xenopus laevis ovaries. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the most purified fraction revealed three bands with apparent molecular masses of 25, 28.5, and 33.5 kDa. The 25- and 33.5-kDa peptides recovered from an SDS-PAGE gel inhibited X. laevis DNA topoisomerase I. The purified inhibitor was specific to DNA topoisomerase I and did not inhibit other DNA enzymes tested. The inhibitor blocked the catalytic activity of DNA topoisomerase I by interacting with the enzyme, rather than by competing for binding sites on substrate DNA. Binding of DNA topoisomerase I to substrate DNA was blocked by the inhibitor, as was the cleavage reaction catalyzed by DNA topoisomerase I. Inhibition of DNA topoisomerase I was relieved by divalent cations Ca2+, Mg2+, or Mn2+. 相似文献
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冲击飞片式无起爆药电雷管试产质量分析 总被引:1,自引:0,他引:1
文中介绍了冲击飞片式无起爆药瞬发电雷管试产的产品质量情况,有关数据表明,它是一种技术工艺比较成熟的雷管换代产品,但废品牢相对较高,需要进一步研究合适的工艺参数来加以控制。 相似文献
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