添加物对Fe_2O_3超微粒的稳定作用

粒子的尺寸直接关系着气敏元件性能的好坏．为了防止Ｆｅ２Ｏ３超微粒在气敏元件烧结过程中长大，我们在纯Ｆｅ２Ｏ３中掺入５ｍｏｌ％碱土金属离子，利用ＸＲＤ和ＴＥＭ系统研究了掺杂物对Ｆｅ２Ｏ３超微粒子的稳定作用，并对由掺杂引起的Ｆｅ２Ｏ３电学性质的变化作了初步探讨．     

等离子喷焊铜基自熔性合金的研制

为了克服铜铁异种材料喷焊过程中易产生焊缝裂纹和基体裂纹的倾向,研制开发了一种Cu-Ni-Sn自熔性合金粉末材料.通过对Cu-Ni-Sn粉末材料的化学成分的设计,喷焊层的组织显微结构及抗腐蚀性能的综合分析,认为该材料等离子喷焊工艺性能良好,焊层耐腐蚀效果十分明显.在生产实际中应用等离子喷焊制备Cu-Ni-Sn焊层,能明显提高粉末材料的熔敷率和性能,并且改善劳动工作环境.该合金性能优于传统材料,值得推广.     

钨铜化合物氢还原制备钨铜复合粉研究

通过对钨铜化合物氢还原过程进行热力学分析,找到了制备均匀细颗粒钨铜复合粉的热力学途径--彻底快速除去还原系统中的水分.设计了封闭还原系统,用此系统进行氢气热还原,不仅使氢气得到充分利用,而且容易判断反应终点.通过系统内的特殊装置除水,降低了还原温度,在600℃下还原得到了混合均匀的钨铜复合粉.系统能彻底快速除去反应生成的水分,使反应物的湿度大大降低,确保得到细颗粒的钨铜复合粉,其平均粒径小于80nm.     

The Effect of Formulation on Radioiodide Thyroid Uptake in the Hyperthyroid Cat

This investigation was designed to compare in vitro dissolution profiles from sodium iodide capsules with radioiodide thyroid uptake in hyperthyroid cats using sodium iodide capsules prepared with a formulation exhibiting a complete release of radioiodide (I-123) in vitro and a formulation with an incomplete release of radioiodide. In vitro dissolution profiles for I-123 sodium iodide capsules with two different formulations were determined using the USP XXIII dissolution test. The two formulations studied in vitro were sodium phosphate dibasic powder with 1% magnesium stearate and calcium phosphate dibasic powder with 3% magnesium stearate. By 20 min after initiation of the dissolution test, over 95% of the I-123 was released from capsules of sodium phosphate dibasic powder. The capsules of calcium phosphate dibasic powder reached 75% at 65 min, with no further release occurring thereafter. There was a statistically significant difference in the dissolution profiles of the two formulations. The thyroid uptake of I-123 from capsules exhibiting complete release and incomplete release of radioiodide was determined in hyperthyroid cats. At 4 hr, the mean percentage thyroid uptake value for sodium phosphate dibasic powder with 1% magnesium stearate (complete release formulation) was 12.0% compared to 9.4% for calcium phosphate dibasic powder with 3% magnesium stearate (incomplete release formulation); at 24 hr, the values were 34.4% compared to 23.7%. The data suggest that the incomplete dissolution profile observed in vitro may correlate with a reduction in the bioavailability of the radioiodide in vivo. However, using the Wilcoxon signed rank test, statistically significant differences did not occur between the complete release formulation and incomplete release formulation at either 4 hr or 24 hr (p >. 05). The results of the in vivo study with five hyperthyroid cats were not conclusive due to the variability in response between individual cats.     

应用水化硅酸盐纳米粉体制备块体材料

以磨细生石灰和硅质原料的混合物为前驱物,采用动态水热合成方法制备了水化硅酸盐纳米粉体.借助SEM、TEM及氮吸附等测试方法,分析了制得的水化硅酸盐粉体的形貌、粒径和比表面积.将制得的水化硅酸盐纳米粉体压制成块状固体.采用正交设计方法研究了成型压力、水泥掺量、纤维掺量、聚合物掺量等因素对块体材料力学性能的影响.结果表明:由该粉体压制成的块体材料立即具有强度和耐水性,且表观密度低;成型压力是影响其力学性能最显著的因素.     

高能球磨制备TiB_2/TiC纳米复合粉体

研究了通过高能球磨制备ＴｉＢ２／ＴｉＣ纳米复合粉体的反应过程和机理,对粉体的显微结构进行了表征．实验结果表明,采用金属 Ｔｉ和 Ｂ４Ｃ为原料,在球磨过程中, ＴｉＣ先于 ＴｉＢ２形成．球磨５ｈ后Ｔｉ与Ｂ４Ｃ反应生成ＴｉＢ２和ＴｉＣ,在随后的长时间高能球磨过程中ＴｉＢ２和ＴｉＣ两相保持稳定．球磨 ３０ｈ后,直径约 ８ｎｍ的 ＴｉＣ纳米粒子分布在 １００～２００ ｎｍ的 ＴｉＢ２粒子中,形成均匀分布的纳米ＴｉＢ２／ＴｉＣ复合粉体．     

自动送粉激光熔覆装置及工艺研究

研制了一种工作稳定性好、粉末流量连续可调的自动送粉装置。经A_3钢表面激光熔覆WF-150不锈钢合金粉末的研究表明,所获得的激光熔覆层均匀连续、无宏观气孔和裂纹,粉末利用率高达94％。     

70%稻瘟灵可湿性粉剂的研制

制备了国内外文献未见报道的70%稻瘟灵可湿性粉剂(WP),对该剂型的配方组成、加工工艺、贮存稳定性进行了研究,并对其各项性能进行了测试,确定了优惠配方。实验结果表明,该产品的各项指标均符合可湿性粉剂标准的要求,悬浮率在90%以上,润湿时间在1min以内,在40±2℃下贮存60天后的分解率小于5%。     

粉状饲料混合制粒机的设计

针对粉状混合饲料的生产和运输、储藏中存在的问题,设计了融搅拌混合和颗粒成型为一体的饲料生产机械.介绍了整机的结构和工作原理,对饲料的混合室、搅拌器、螺旋输送挤压器、颗粒成型机构的主要结构特点及相应参数进行了分析与计算.     

The influence of temporary hydrogenation on ECAP formability and low cycle fatigue life of CP titanium

It is generally believed that thermo-hydrogen processing has a beneficial effect on tensile ductility and fatigue properties of titanium. This study was concerned with investigating whether this also applies to titanium of commercial purity (CP) with an ultrafine-grained structure obtained by equal-channel angular pressing (ECAP). It was shown that despite the possibility to manipulate the microstructure of titanium the thermo-hydrogen processing offers, temporary hydrogenation was not able to improve ductility and low cycle fatigue life of CP titanium over the levels achievable by straight ECAP.