共查询到20条相似文献,搜索用时 46 毫秒
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探讨了株化集团在企业管理及改革等方面的经验。该公司为适应市场经济的变革制订了科学的发展规划、思路和目标;确定了目标管理实施方案和各项制度;强化销售工作和质量管理,加大科技投入,加强科技创新活动;理顺各种关系,做好各项有关工作,使企业的经济效益和对社会的贡献逐年增大。 相似文献
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双噁唑啉化合物是一种重要的有机反应中间体.酚醛树脂具有优良的耐热性、电绝缘性、耐化学腐蚀性,所以在工业中得到广泛的应用,然而通用酚醛树脂也有自身的缺点,如固化过程中有小分子释放出,固化时形成微孔结构,降低了固化物的性能;苯并噁嗪树脂是一种新型的酚醛树脂,虽然固化时无小分子放出,然而存在固化温度高、固化诱导期和固化时间长,尤其是交联密度太低的缺点.这些缺点限制了通用酚醛树脂和苯并噁嗪树脂的应用.用双噁唑啉改性通用酚醛树脂或苯并噁嗪树脂得到的聚醚酰胺树脂有良好的耐热性、电绝缘性、低吸水性、优良的工艺性能. 相似文献
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以自行合成的环氧基倍半硅氧烷(POSS)为改性剂,分别对环氧树脂139S/六氢苯酐和环氧树脂BE 188EL/六氢苯酐进行改性,制备环氧树脂/POSS杂化材料。力学性能分析结果表明,两种杂化材料的冲击强度和弯曲强度都有明显的提高,冲击强度分别提高了57.45 %和32.26 %,弯曲强度分别提高了9.23 %和5.07 %。热性能分析结果表明,两种杂化材料在高温时的热残留量都有所提高,分别提高了50.19 %和20.16 %。两种杂化材料的热膨胀系数也得到了降低,即热稳定性得到了提高。 相似文献
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淀粉接枝丙烯酰胺-丙烯酸(盐)三元共聚反应研究 总被引:2,自引:0,他引:2
以过硫酸盐、过硫酸盐-尿素复合物、过硫酸盐-尿素-催化剂复合物为引发剂,引发反相乳液中的淀粉接枝乙烯基单体的聚合反应,研究了引发过程温度、pH、引发剂浓度、引发剂组成、共聚单体的种类等因素对单体转化率、接枝率和产品特性黏度的影响.E-N络合物作为氧化还原体系引发催化剂可以使引发温度降低至30℃.以丙烯酰胺、丙烯酸、丙烯酸盐为聚合单体,合成出具有不同电荷分布、电荷密度的系列淀粉接枝共聚物.在保持固含量为30%的情况下,当淀粉与单体质量比为12时,接枝效率最好.研究单体的比例发现,丙烯酰胺与丙烯酸盐的比例为73时接枝效率最好. 相似文献
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以三甲基膦(TMP)为前体对ZSM-5分子筛进行磷改性,以提升其水热稳定性,然后再分别通过等体积浸渍法引入Ga2O3或ZnO,制备得到磷和金属氧化物复合改性的ZSM-5分子筛。利用X射线衍射(XRD)、固体核磁(MAS NMR)、氨程序升温脱附(NH3-TPD)以及吡啶吸附傅里叶变换红外光谱(Py-FTIR)等表征手段系统地研究了磷和金属氧化物复合改性对ZSM-5分子筛的物化性质、P和Al相互作用以及酸性的影响。并以正十四烷裂解为探针反应,研究磷和金属氧化物复合改性对ZSM-5分子筛催化裂解性能的影响。研究结果表明以三甲基膦为前体对ZSM-5分子筛改性,再引入金属氧化物的复合改性方式制备的催化裂解催化剂不仅具有较高的酸性保留度,具有较高的催化裂解活性,也同时保留了金属氧化物中心的脱氢作用,从而提升了C2=~C4=收率及选择性,同时降低了积炭的生成。 相似文献
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碳钢水冷器广泛应用于炼油化工装置,受循环冷却水的影响,长期运行过程中易出现腐蚀、结垢问题导致停车检修,造成巨大经济损失。介绍了腐蚀机理和影响腐蚀的因素,着重分析了水冷器不同腐蚀结垢的类型,并提出了防治措施。 相似文献
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This study investigated the adsorption of calcium and gypsum on scheelite and fluorite using micro-flotation, X-ray photoelectron spectroscopy, scanning electron microscope with energy-dispersive spectrometer, and zeta potential measurements. Micro-flotation showed scheelite recovery is more sensitive to calcium, and gypsum shows stronger inhibition than calcium. Stick-shape precipitates as sulfate-bearing are only found on fluorite surface in gypsum solution. Change law of the zeta potentials of scheelite and fluorite in gypsum solution is obviously different from that in calcium solution. Therefore, we concluded that gypsum would make the separation of scheelite from fluorite more difficult than calcium. 相似文献
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以聚丙烯酰胺,聚乙二醇为载体制备了固定化L-天门冬酰胺酶。对固定化酶载体材料——凝胶的溶胀比、机械强度及其影响因素进行了研究。结果表明,单体及交联剂浓度是影响凝胶性能的重要因素,聚乙二醇作为稀释剂能有效控制聚合速率,提高凝胶的溶涨性能和韧性。此外考察了酶负载量、pH值和温度等因素对固定化酶活性的影响。实验结果还表明分批反应6次或存储42天后,固定化酶仍保持较高的活力。 相似文献
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基于Ethernet网络化仪器的设计与实现 总被引:7,自引:2,他引:5
首先通过分析网络化仪器特点,利用386EX、网络接口芯片以及相关外围接口电路实现网络化仪器的硬件架构;软件上,精简并整合了TCP/IP协议族。最后给出实验结果,实验结果表明系统能完成客户方的请求,进行数据采集、传输和信息发布。 相似文献
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1 买方市场是赊销现象的主要社会经济原因我国从经济转型过程中,社会生产力迅速发展,许多商品从供不应求转变为供大于求。在供大于求的现实情况下,竞争的压力往往迫使许多企业会采用各种促销手段,向买方提供优惠的交易条件,以求开拓市场,增加销售收入。赊销就是行之有效的促销手段。 相似文献
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Gizem Ceylan Türkoğlu Berrak Buket Avcı Gökhan Erkan Ceyda Özen Şerife Tozan Rüzgar Alper Akkaya 《Coloration Technology》2023,139(2):136-146
This research investigated the effect of various proteolytic enzymatic pretreatment on morphological and chemical features and the dyeability properties of wool fibres. Scoured merino wool fibres are treated with protease, papain, trypsin, and pepsin in specified conditions. Each enzyme activity measurement was provided by appropriate methods such as Bradford, BAPNA (N-benzoyl-1-arginine-p-nitroanilide), and BSA (Bovine Serum Albumin). Enzymatic processes were carried out for 24 h in the incubator set at 40°C, 100 rpm, and specified pH with 1 mg/ml enzyme concentration. Whiteness index (Stensby) and yellowness index (ASTM D 1925) were examined after enzymatic pretreatment. Pepsin and trypsin-treated wool fibres showed the highest whiteness index as 61.3 and 61.1, respectively whilst untreated wool fibres had 52.2. Fourier-transform infrared (FTIR) analysis revealed the increase in the intensity of amide-related bands and hydroxyl bands after enzymatic treatment. Scanning electron microscopy (SEM) photomicrographs manifested the cuticle layer is partially removed in enzyme-treated fibres. Elemental identification was provided by SEM–energy-dispersive X-ray spectroscopy (EDX). It appears that the sulphur bonds decreased after the treatment and the pepsin-treated fibres have fewer bonds of all. To examine the damage to the structure, photomicrographs were taken using fluorescence and light microscopes. The alkali solubility test (ASTM D1283) was also conducted to compare different enzyme types. Wool fibres were dyed in 2.0% concentration with reactive dyestuff. Dyeability and colorimetric features of fibres were measured by a spectrophotometer. The washing fastness test showed that all the samples have good results and the colour change after washing was better in enzyme-treated samples (grade 5) compared to untreated wool fibres (grade 4–5). 相似文献
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It will be shown that it is possible to predict the walking behavior of humans on extraterrestrial bodies – i.e. under different gravitational forces – by applying techniques from dimensional analysis to measurements obtained in a stationary terrestrial laboratory. These terrestrial experiments allow us to generate artificial data about extraterrestrial walking and are, therefore, of great importance for space travel as well as for extraterrestrial physiology. What at first glance appears to be an interesting application of dimensional analysis and model theory, proves in retrospect to be an elegant means for gaining important insights for space technology. 相似文献