排序方式： 共有4条查询结果，搜索用时 15 毫秒
1
1.
Preparation and Characterization of M-Type Barium Ferrite Fibers via Aqueous Sol-Gel Process 总被引：1，自引：0，他引：1
BaFe12O19 fibers was prepared via an aqueous sol-gel process using Fe(OH)(HCOO)2 synthesized in laboratory and Ba(CH3COO)2 as the original materials and citrate as the chelate. The rheological behaviour of spinnable sol was characterized on rheometer, and the development of gel fibers to barium ferrite fibers was studied by IR, TG and XRD. Morphology observation of the fibers was given on SEM, and the diameter of the obtained fibers was between 5 and 10 μm corresponding to different additives. The additives affected the surface tension of the precursor sol which had close relation to the microstructure of fibers. Sucrose and hydroxyethylic cellulose could improve the surface tension while diethanolamine and hexadecylamine reduce that of the precursor sol. And using diethanolamine or hexadecylamine as an additive, well-structured BaFe12O19 fibers could be obtained. 相似文献
2.
山清水秀的贵州是一个多民族省份,除汉族外,世居的少数民族有十六个,人口约1200多万,占全省总人口35%.其中有苗族、布依族、侗族、水族、彝族、仡佬族、回族、土家族等人口已超过了十万,还有散布在省内各地的人口较少一些的壮族、瑶族、畲族、毛南族、白族、蒙古族、满族、羌族等.…… 相似文献
3.
侗族分布在贵州、湖南、广西毗邻地区,大部分在贵州境内玉屏、黎平等地,一提到侗族,最著名的也许就是侗族大歌和侗家风雨楼了,其实侗家的民族节日也很有意思.各地的侗族大多要过春节,时间也是正月初一.有些地方在十月底或十一月初择日过侗年.四月八日或六月六日为祭牛节,节日时是不可以使用牛的.此外,还有抢花炮的花炮节,吃新米的吃新节,停止生产活动,以及各姓氏自己过的姓氏节及赶歌会、姑娘节、斗牛节等.这之中最好玩的莫过于花炮节.…… 相似文献
4.
Diesel particulate filter （DPF） is an important factor which influences the sound from exhaust system of an engine. In order to underst and the propagation law of sound wave and predictthe insertion loss in DPF, based on the general aero-dynamic equations and Darcy＇s law, an acoustic property calculation model of DPF is constructed. Propagation and attenuation characteristics of the forward and backward propagating acoustic waves in the close and open pipe of the filter are investigated. The theoretical model is combined with experiment to investigate sound attenuation property of DPF. The insertion loss obtained from the experiment is compared with that computed for a DPF. The results from the experiment and theoretical calculation agree well. 相似文献
1