排序方式: 共有11条查询结果,搜索用时 15 毫秒
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研究了以氯化钴为原料,通过比较选择了价格相对低廉的碳酸氢铵代替草酸作沉淀剂制备前驱体,考察了反应温度、反应时间、氯化钴的浓度、碳酸氢铵溶液加料速度等因素对产品粒度大小的影响,从而得出最佳沉淀反应条件.在最佳反应条件下,制得的氧化钴产品平均粒径为200~300 nm,各项性能指标达到了Y级氧化钴国家标准的要求. 相似文献
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纳米材料由于具有比表面大,熔点低等特性,在材料科学方面意义深远,文章就纳米材料的制备及特点做了系统的阐述,并展望了其未来的应用前景。 相似文献
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羟基喜树碱壳聚糖纳米冻干粉的制备及表征 总被引:1,自引:0,他引:1
为研究制备载羟基喜树碱的叶酸-壳聚糖纳米冻干粉的制备方法,以羟基喜树碱、叶酸、壳聚糖、三聚磷酸钠为原料,以葡萄糖和甘露醇为保护剂,应用真空冷冻干燥技术,制备了载羟基喜树碱的叶酸-壳聚糖纳米粒冻干粉。以冻干粉外观及在水中再分散性为指标,分别考察了冻干保护剂的种类、体积分数、用量及加入方式对冻干的影响。并利用扫描电镜及透射电镜对冻干粉的微观形态进行观察。结果表明,甘露醇作为冻干保护剂优于葡萄糖。当甘露醇体积分数为8%,与纳米粒水分散体系体积比为1∶1时,所制备的冻干粉呈颜色均一、外表光滑、致密松脆的完整的饼状,且在水中再分散迅速,无任何悬浮物,成均一乳状胶体。在扫描电镜下观察冻干粉呈花瓣形,再分散后于透射电镜下观察,纳米粒子呈规则球形,大小均匀,平均粒径约200 nm左右。该工艺所制备得冻干粉针剂有望成为羟基喜树碱的新剂型。 相似文献
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Shannon Lydia Spruit 《Journal of Risk Research》2017,20(3):326-346
Workers who develop and use nanoparticles are on the front line of exposure to the purported risks of nanoparticles. Employers have a legal duty to protect their employees against any work-related harm. However, it is difficult to perform the required risk assessment and management when dealing with uncertainty. Risk ethicists have therefore argued for using the precautionary principle to guide such decisions on uncertain risks. In this paper, I argue that if we want to make use of innovative products, such as nanomaterials, but lack the knowledge and shared standards for choosing between protective measures, the precautionary principle is underdetermined. For the use of nanoparticles in working environments, there are several guidelines that suggest different precautionary strategies for dealing with their purported risks, but choosing between these guidelines proves difficult in the absence of a clear, scientific, decision principle. I therefore explore the ethics of care to develop a complementary decision criterion for the precautionary principle. From this perspective, the caring qualities of working relationships are key in comparing precautions with each other. I propose three conditions for assessing risk management strategies based on (1) the existence of a mutual concern for employee health and safety, (2) the connectedness and continuity of the relationships between employer and employee, and (3) the responsiveness of employers to employee needs. Using these criteria will support choosing between precautions, by shifting attention from the acceptability of imposing a risk to creating a social context in which the imposition of the residual risks can be considered acceptable. 相似文献
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GROUCHKO Michael KAMYSHNY Alexander MIHAILESCU Cristina Florentina ANGHEL Dan Florin MAGDASSI Shlomo 王晓芳编译 《中国印刷物资商情》2011,(4):75-78
目前,尚没有金属油墨可以在室温下只通过印刷步骤便形成导电图案的技术。例如使用纳米金属油墨在塑料电子产品上印制导电图案,必须进行额外的烧结处理,通常是通过加热至高温来实现。在烧结过程中,形成图案的纳米粒子(NPs)发生团聚以形成连续的导电层。近年来,发展了很多新型的烧结工艺,如微波、激光烧结,脉冲氙气、电子或化学烧结以及等离子烧结等,但是这些方法通常需要高成本的设备以及复杂的预处理或后处理工艺。因此,对于油墨而言,尚需研究的课题是,印制后无须额外烧结工艺即可获得高导电率。 相似文献
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D. Raju S. Bathini S. Badilescu R. J. Ouellette A. Ghosh 《Enterprise Information Systems》2020,14(4):532-541
ABSTRACTA novel method for the detection of exosomes in body fluids and cell cultures has been developed. The method is an optical method, based on LSPR of silver nanoparticles. The method was extended to a microfluidic environment, amenable to be integrated in a sensor network. However, for clinical applications, their isolation, detection and quantification methods in bio-fluids are challenging. Herein, we present a simple label-free technique to capture and detect EVs, by using a synthetic peptide, called Vn96. To quantify EVs, a LSPR detection technique was used. This work is an attempt to adapt a biosensing method to the future requirements of Industry 4.0. 相似文献
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丁香苦苷 PLGA 纳米粒的体外释放研究 总被引:1,自引:0,他引:1
为研究丁香苦苷PLGA纳米粒( SYR-NP)的体外释药规律,采用动态透析技术考察SYR-NP体外释药性能,并用高效液相测定SYR-NP和SYR溶液的含量,以累积释药百分率进行不同模型的拟合.SYR-NP的体外释放规律基本符合Higuchi方程的释药模型,拟合的释药动力学方程为 Q=0.1281+0.0189t1/2(r=0.9568).相比于药物溶液,SYR-NP具有良好的缓释的作用. 相似文献
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