共查询到20条相似文献,搜索用时 78 毫秒
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根据化学专业人才培养的要求,为使化工基础这门唯一的技术基础课程的实验内容和实验手段跟上现代科技发展的步伐,我们总结了近几年来化工基础实验教学中的一些经验,对实验教学内容和教学方法进行了改进和充实,对实验设备及实验手段进行了改造、更新,就如何提高学生的动手操作能力和科研意识,增强他们综合运用基本理论及适应社会发展的能力,提出笔者的一点见解。 相似文献
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建设创新型国家是我们中华民族的历史责任。“自主创新、重点突破、支撑发展、引领未来”的16字方针应当成为我们未来创新活动的指南。建设创新型国家把自主创新放在首位,并提出了引领未来的高标准要求。钢铁科技创新必须突出重点,抓住创新成果产业化这个关键,支撑起行业和国民经济的发展。 相似文献
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Solid solutions of diphosphates of zinc and copper and of zinc and cobalt were synthesized from mixtures of pure diphosphates at temperatures up to 1000°C. Their X-ray diffractometry patterns varied continuously from one end member to the other. Solid solutions of orthophosphates of composition Zn3−x Cox(PO4 )2, with x = 0.4–1.6, were formed at temperatures up to 950°C; all exhibited the structure of γ-Zn3 (PO4 )2. Solid solutions of orthophosphates of composition Zn3−x Cux (PO4 )2 exhibited more-complex behavior. At 1000°C and copper contents of 20–80 mol%, a phase that is related to Cu3 (PO4 )2, termed here the "ε-phase," predominated. At 850°–950°C and in the region from 20 mol% to ∼33 mol% of copper, the solid solutions (the "η-phase") adopted the structure of graftonite. At 800°–900°C and 10–15 mol% of copper, the solid solutions exhibited a new structure (the "δ-phase"), which we found to be related to the mineral sarcopside. At temperatures 950°C, the solutions that contained 5–15 mol% of copper (the "β-phase") had the structure of β-Zn3 (PO4 )2, whereas at 800°–850°C, solutions with 5 mol% of copper (the "-phase") exhibited the structure of γ-Zn3 (PO4 )2. Attempts to synthesize Cu+ ZnPO4 and Cu+ Cu2+ Zn3 (PO4 )3 were unsuccessful. 相似文献
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相比已经完善丰富的开采和勘探技术,油气的运输以及储存却仍然存在不足之处。我国对能源安全提出更加严格要求的同时,对区域经济的发展规划也有足够重视。因此,保障油气管道的安全则成为了我国能源安全战略的重中之重。在阐释油气管道现阶段在储运安全保障技术发展状况的基础上,分析了现存的问题及解决问题的手段,并指出未来可能使用的目标策略,为今后研究者提供一定程度上的借鉴经验。 相似文献
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膜的污染和劣化及其防治对策 总被引:25,自引:0,他引:25
较为系统地介绍了膜污染和劣化的定义和特点,因膜污染和劣化而造成的膜性能变化,以及如何预防、减少或清除膜污染和劣化的一些通用方法。 相似文献
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The composition and solubility properties of eight ammonium and potassium orthophosphites and hypophosphites were determined to evaluate the potential of these classes of materials for increasing the plant nutrient content of liquid fertilizers. Phase relationships for the systems (NH4)2O-P2O3-H2O, K2O-P2O3-H2O, (NH4)2O-P2O-H2O, and K2O-P2O-H2O were determined along with the crystallographic properties (X-ray and optical) of the solid phases. Toxicity and phosphite response was tested in greenhouse experiments for the compounds. 相似文献
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Tetraalkynylated and Tetraalkenylated Benzenes and Pyridines: Synthesis and Photophysical Properties
Peter Ehlers Ani Hakobyan Antje Neubauer Stefan Lochbrunner Peter Langer 《Advanced Synthesis \u0026amp; Catalysis》2013,355(9):1849-1858
Tetra(arylalkynyl)pyridines and tetra(arylalkenyl)pyridines and their benzene analogues were prepared by palladium‐catalyzed cross‐coupling reactions from the commercially available chlorinated substrates in good to excellent yields. The photophysical properties of selected compounds were investigated and compared to each other. Very good fluorescence quantum yields were observed, especially for the pyridine derivatives. 相似文献
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填料-橡胶的化学和物理作用及补强ⅡN330,SiO2,n-SiO2和n-SiO2/KH-846与NR 总被引:1,自引:0,他引:1
研究了填料-橡胶的相互作用。发现N330-NR间的相互作用。n-SiO2(粒径:15nm)/KH-846-NR间的相互作用,都是化学作用占优势(>80%),化学作用对补强的贡献率都大于90%;无偶联剂KH-846时,n-SiO2和SiO2(粒径:15.8nm)与NR都无化学作用,只有物理交联,由于隔离作用,都降低硫化体系与橡胶相互作用的化学交联密度,但n-SiO2的物理交联密度是SiO2的2.6倍,对补强的贡献是SiO2的1.9倍,也是n-SiO2/KH-846体系的61%。 相似文献
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绿色火炸药及相关技术的发展与应用 总被引:12,自引:1,他引:11
综述了绿色火炸药及其生产工艺、销毁以及回收利用方面具有“绿色”特征的改进和应用研究成果。绿色火炸药包括洁净固体推进剂、无铅双基推进剂、TPE发射药、无毒发射药、无铅点火药和起爆药。绿色制造技术包括N2O5作硝化剂的含能硝基化合物化学合成,过硝酸盐作硝化剂、微生物作催化剂的生物合成技术,连续化柔性制造技术,基于双螺杆混合成型火炸药生产技术,火炸药生产中挥发性污染物的安全消除技术和纳米复合含能材料的Sol-Gel制备技术。绿色销毁和回收利用技术包括销毁产品的熔盐氧化技术、摧毁含含能化合物废水的光催化技术以及火炸药的回收再利用(R^3)技术。评述了上述火炸药及相关技术的最新状况和发展方向,附参考文献25篇。 相似文献
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Michael P. Badart Emma M. Barnes Andrew P. Cording Selena C. L. Gilmer Ian D. Billinghurst Veera V. Shivaji R. Edupuganti Prof. Guillaume Lessene Abigail R. Bland Rebekah L. Bower Zohaib Rana Scott A. Ferguson Helen K. Opel Reading Prof. Gregory M. Cook Prof. Rhonda J. Rosengren Prof. Kurt L. Krause Dr. Allan B. Gamble Prof. John C. Ashton Dr. Bill C. Hawkins 《ChemMedChem》2021,16(8):1308-1315
A second-generation enantiospecific synthesis of spiroleucettadine is described. The original reported antibacterial activity was not observed when the experiment was repeated on the synthetic samples; however, significant anti-proliferative activity was uncovered for both enantiomers of spiroleucettadine. Comparison of the optical rotational data and ORD-CD spectra of both enantiomers and the reported spectrum from the natural source have not provided a definitive answer regarding the absolute stereochemistry of naturally occurring spiroleucettadine. Efforts then focussed on alteration at the C-4 and C-5 positions of the slightly more active (−)-spiroleucettadine. Ten analogues were synthesised, with three analogues found to possess similar anti-proliferative profiles to spiroleucettadine against the H522 lung cancer cell line. 相似文献