新疆库尔勒土壤模拟溶液中X70钢的缝隙腐蚀

以新疆库尔勒土壤模拟溶液为腐蚀介质(0.06 M Cl- 0.009 M SO2-4 0.001 7 M HCO3-),在阴极极化条件下,采用楔型缝隙模型研究了具有剥离涂层缺陷X70钢的缝隙腐蚀.楔型缝隙的一端封闭,另一开口端延伸到溶池(100 mm×100 mm×100 mm)的模拟溶液中.楔型缝隙的尺寸为深100 mm,宽45 mm,开口尺寸0.15～0.45 mm.将6条X70钢电极试样安装到缝隙中用以测定缝口不同距离处的局部电流密度、极化电位并监测试样的腐蚀状况.安装在缝隙上盖测量孔中的H 离子探头用于测量缝内的pH值.采用-0.85,-1.0和-1.15 V(相对于CSE)的阴极极化电位分别对缝口尺寸(δ)为 0.15,0.30和 0.45 mm的楔型缝隙进行阴极极化.试验结果表明,随着极化时间的延长,缝内局部电流密度和极化电位变得更为均匀,随着缝口控电位的降低以及缝口尺寸的增加,缝内的局部电流密度和pH值增加.缝口控电位相同时,从缝口到缝底的pH值先增加,然后达到一个较稳定的状态.缝口控电位越低以及缝口尺寸越大,pH值越易于达到稳定状态,且pH值开始增加的速率越小.     

Electrochemical corrosion behavior of carbon steel with bulk coating holidays

With epoxy coal tar as the coating material, the electrochemical corrosion behavior of Q235 with different kinds of bulk coating holidays has been investigated with EIS （Electrochemical Impedance Spectroscopy） in a 3.5vo1% NaCI aqueous solution. The area ratio of bulk coating holiday to total coating area of steel is 4.91%. The experimental results showed that at free corrosion potential, the corrosion of carbon steel with disbonded coating holiday is heavier than that with broken holiday and disbonded ＆ broken holiday with time; Moreover, the effectiveness of Cathodic Protection （CP） of carbon steel with broken holiday is better than that with disbonded holiday and disbonded ＆ broken holiday on CP potential -850 mV （vs CSE）. Further analysis indicated that the two main reasons for corrosion are electrolyte solution slowly penetrating the coating, and crevice corrosion at steel/coating interface near holidays. The ratio of impedance amplitude （Z） of different frequency to minimum frequency is defined as K value. The change rate of K with frequency is related to the type of coating holiday.     

铝合金宽温快速阳极化与阴极电泳的配套性

以传统硫酸阳极化为基础加入其他酸类及硫酸盐等物质，使阳极化温度范围扩大，时间缩短，得到了铝合金硫酸宽温快速阳极化配方及工艺，研究了阴极电泳涂装与硫酸宽温快速阳极化相配套的工艺参数，探讨了铝合金阴极电泳前表面处理对漆膜性能的影响，得到了硫酸宽温快速阳极化与阴极电泳涂装相配套的较佳配方和工艺，所得涂层的附着力及耐蚀性等性能达到了国家标准．     

Ni-SiC复合镀层的热稳定性和耐蚀性

用电沉积方法在钢上获得Ni SiC复合镀层 ,研究了Ni SiC复合镀层在 85 0℃的热稳定性及通过极化曲线的测定 ,对钢基体、Ni层、Ni SiC层耐蚀性进行比较 .结果表明 ,SiC在 85 0℃加热保温半小时时SiC不分解 ,Ni SiC复合镀层的耐蚀性最好 ,Ni镀层次之 ,钢基体最差 .     

Preparation and characteristic of self-regulation water-transmitting coating fiber

Common clay, Kaolin and Bentonite were used as additives to prepare water-transmitting coating fiber, respectively, and the water-transmitting characteristic of coating fiber was studied. Different water-transmitting coating fibers were prepared by coating fiber using coating material with different mass proportions of additives to adhesive. And the coating materials were made from three kinds of inorganic clays as additives respectively and polyvinyl alcohol (PVA) as adhesive. Furthermore, the surface morphology and water-transmitting capacity of coating fiber were studied by SEM, Perkin Elmer Diamond S II thermal multi-analyzer and instrument for quick measurement moisture M30. The experimental results indicate that water-transmitting coating fibers made from three kinds of clays all have water-transmitting capacity. The surface of water-transmitting coating fiber prepared by common clay T is continuous and compact, and the water-transmitting effect is better than coating fibers made from other clays. Funded by the National High Technology Research and Development Program of China (2001AA322100), the Ministry of Education of Republic of China (106086), and the Cooperation and Merger Found of Beijing (ZH114140537)     

碳钢高温抗氧化涂料涂层的研究

用以氧化物为主要原料制成的醇基快干型涂料,涂敷于碳钢块上,点火块干使其固化形成涂层,防止碳饮氧化烧损.并采用失重法,对45#和T 10碳钢涂涂料的试样与裸样在高温下氧化失重进行了对比实验,分析了涂料对降低氧化烧损的影响以及涂料层的主要性能。实验表明,该涂料所形成的涂层在碳钢的加热过程中,与基体结合紧密,抗氧化性能以及耐热震性能较好,减少了碳钢高温氧化烧损,使碳钢在相同的加热温度和时间下,(如45#在6小时内100℃下),氧化烧损量由2.4~4.2g降低为0.8~2.5g,氧化速度由5.310×10-5g/mm2.h降低为3.885×1-0 5/mm2.h.     

圆极化天线特性参数测量方法

提出了一种利用线极化源天线测量圆极化天线特性参数的新方法．基于椭圆极化波的分解理论,建立了测量方法的数学模型,用线极化源天线进行两次正交的测量即可得到圆极化天线的方向图、轴比、增益等特性信息,并研制了实际的测试系统．利用该测试系统对圆极化天线进行实际测试,证明了该方法具有实用性强、自动化程度高、测量精度高等特点．     

Improved oxidation resistance of chemical vapor reaction SiC coating modified with silica for carbon/carbon composites

To protect carbon/carbon (C/C) composites from oxidation, a SiC coating modified with SiO2 was prepared by a complex technology. The inner SiC coating with thickness varying from 150 to 300 μm was initially coated by chemical vapor reaction (CVR): a simple and cheap technique to prepare the SiC coating via siliconizing the substrate that was exposed to the mixed vapor (Si and SiO2) at high temperatures (1 923?2 273 K). Then the as-prepared coating was processed by a dipping and drying procedure with tetraet...     

碳棒电极示波极谱法测定氨苄青霉素

采用碳棒电极示波极谱阴极溶出法，测定了氨苄青霉素及其胶囊的含量。氨苄青霉素在０．３ｍｏｌ／Ｌ盐酸及１％甲醛的底液中，于－０．６５Ｖ（ｖｓ，ＳＣＥ）处有一灵敏的阴极溶出二阶导数峰。氨苄青霉素的浓度在２．０μｇ／ｍＬ～４０．０μｇ／ｍＬ范围内与峰电流（Ｉｐ″）呈良好的线性关系，回收率为９２％～１０６％，方法简单可靠。     

低偏振相关损耗多重体光栅CWDM设计

多重体全息光栅可当作一种粗波分复用器使用.用严格耦合波分析算法对多重体全息光栅的衍射效率进行理论分析,计算并分析光栅厚度及布拉格角度对该复用器的偏振相关损耗的影响.数值结果表明,通过优化光栅厚度和布拉格角度,在无明显增加附加损耗的前提下,可获得一种低偏振相关损耗的复用器.实验制作了一个波长间隔为20 nm的8通道粗波分复用器,其测量结果与模拟计算结果吻合.     

Subgrains and boron distribution of low carbon bainitic steels

The structure variation of deformed austenite during the relaxation stage after deformation at various temperatures in an Nb-B ultra low carbon bainitic steel and Fe-Ni alloy was studied by the thermo-simulation. Optical microscope and TEM were applied to analyze the microstructure after RPC （Relaxation-precipitation-controlling phase transformation technique） and the evolution of dislocation configuration. The particle tracking autoradiography （PTA） technique, revealing the distribution of boron, was employed to show the change of boron segregation after different relaxation times. The results indicate that during the relaxation stage the recovery occurs in the deformed austenite, the dislocations rearrange and subgrains form. During the subsequent cooling the boron will segregate at the boundaries of subgrains.