排序方式: 共有46条查询结果,搜索用时 15 毫秒
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在机械制造过程中,对大型工件进行退火处理都有一定难度,而对结构紧凑、不同组件又有不同的性能要求的大件进行退火处理更加困难,如何克服对主件处理时不影响其它组件的性能呢?本文采用陶瓷电加热器进行局部热处理的方法,较好地解决这一难题,具有普遍的借鉴意义。 相似文献
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本文以自制的二氧化硅微球为对象,以带氨基官能团的APTES硅烷为硅烷化试剂,对比研究了气相蒸发法和液相浸渍法两种不同方法对二氧化硅微球进行硅烷化修饰的差异,为二氧化硅微球表面硅烷化的反应控制提供了实验基础和理论依据。 相似文献
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王珊 《咸阳师范专科学校学报》2008,(6):30-32
以甲醛作为交联剂,通过悬浮交联法制备出单分散性壳聚糖微球。利用空壳状壳聚糖微球具有比表面大的特点,结合其表面氨基易于配位的特点,通过扫描电镜及红外光谱仪等仪器对其吸附Pb^2+的前后结构进行了表征,并对其吸附Pb^2+的初步条件进行了探索。研究了Pb^2+初始浓度,pH值,壳聚糖用量,时间对饱和吸附量影响。实验发现在室温下,pH=4.8时,此时吸附容量约为283 mg(Pb^2+)/g(CS)。吸附达到平衡大约需要45min。结果表明:此微球具有很强的吸附能力,而且平衡时间快,是一类很值得开发的新型吸附分离材料。 相似文献
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本文建立了热残余应力分析的数学模型,采用数值方法对陶瓷涂层材料的热残余应力进行了分析,得出了金属基底的弹性性能、过渡层的厚度和陶瓷涂层的孔隙率对热残余应力的影响,为含FGM的陶瓷涂层材料的优化提供了一种理论分析方法。 相似文献
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朱洪龙 《咸阳师范学院学报》2007,22(6):47-49
研究了用于ZrO2陶瓷微球成型的方法——内胶凝工艺,系统探讨了工艺温度、原材料的浓度以及干燥和煅烧条件对工艺及微球形貌的影响。确定了ZrO2陶瓷微球成型的最佳工艺参数,氧氯化锆原料的浓度为1.6mol/L,固化剂六次甲基四胺和尿素与金属离子的摩尔比值为0.68与0.57;成型温度控制在90℃。通过添加稳定剂Y2O3,微球具有TZP材料的结构特征。 相似文献
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采用反相悬浮聚合法合成了聚丙烯酰胺(PAM)高分子微凝胶,以其为模板,在室温条件下,以硒代硫酸钠(Na2SeSO3)作为硒源,制备得到了Se-PAM无机-有机复合微球材料,利用扫描电子显微镜(SEM)、X射线衍射(XRD)等手段对复合微球的形貌、无机物硒晶形结构等进行了表征。 相似文献
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Duriya FONGMOON Surathat PONGNIKORN Aphiruk CHAISENA Sitthichai IAMSAARD 《Journal of Zhejiang University. Science. B》2014,15(1):75-83
Background: Lung cancer ranks as the fifth largest of all cancer cases in Thailand. However, it is the first leading cancer in the northern part of Thailand (data from 2003-2007). There are several predisposing causes that lead to lung cancer and one important inducement is particulate matters (PMs). Lampang Province in Thailand is famous for the ceramic industry, where there are over 200 ceramic industrial factories. PMs are produced during the ceramic manufacturing process and spread throughout all of the working areas. It is very possible that workers could directly inhale PM-contaminated air during working hours. Objective: This study focuses on the toxic effects of PMs collected from ceramic factories on genes and lungs of rats. Methods: PMs collected from six ceramic factories in Lampang Province were extracted using dimethyl sulfoxide (DMSO). The inductively coupled plasma mass spec- trometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) were used to analyze the chemical elements at lower and higher concentrations, respectively. Then, the toxicity of PMs on the genes was ex- amined by the Ames test, and subsequently, the effect of PMs on DNA was examined by quantifying the amount of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Finally, the toxicity of the PMs on rat's lungs was examined by histology. Results: As chemical elements of lower concentrations, cadmium, chromium, nickel, copper, and lead were detected by ICP-MS. As chemical elements of higher concentrations, manganese, magnesium, zinc, iron, potassium, calcium, and sodium were detected by ICP-OES. No mutagenicity in Salmone/la typhimurium was found in the PM extracts from all six factories by utilizing the Ames test. In the histological study, the reduction in spaces of alveolar ducts and sacs, and terminal bronchioles, the thickening of interstitial connective tissues were noted by PM extracts in high amounts (100 and 350 pg). Female rats were more sensitive to PM extracts than males in terms of their pulmonary damages. Conclusions: PMs were not mutagenic to S. typhimurium but can damage the lung tissue of rats. 相似文献