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101.
Qing Liu Lin Wang Zhuoheng Zhou Qiuquan Wang Lijuan Yan Bo Zhang 《Electrophoresis》2014,35(6):836-839
CEC is a high performance electrodriving liquid phase separation technique. It does not need complex and sophisticated high pressure instrumentation for nanoflow driving. This is attractive for parallel multicolumn analysis. To this end, high throughput methods for column preparation are needed to support the use of multiple columns. In this study, we directly used CEC mobile phase solution as the packing solvent, and realized rapid preparation of capillary columns based on a single particle fritting technology. The method presented high preparation throughput compared with other reported methods based on various fritting technologies. The single particle fritting approach promoted column preparation throughput to 1 column/h, including all the fritting, packing and conditioning steps. The rapidly prepared columns showed consistently high efficiency of up to 150 000 plates per meter, and usefulness in reversed phase CEC of neutral, charged and biomolecules. With standard peptides as the sample, excellent long term reproducibility (better than 0.8%RSD, ten days, for retention times) was observed. 相似文献
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采用完全液相法制备了不同Si/Al摩尔比的浆状一步法二甲醚合成催化荆,在搅拌式反应釜中对其催化性能进行了评价.通过XRD,NH3-TPD-MS,H2-TPR和XPS等方法表征了催化剂的体相结构和表面性质.结果表明,完全液相法制备的CuZnSiAl催化剂在反应前其活性组分Cu主要以低价态存在,Cu晶粒大小是影响其活性的主... 相似文献
103.
1,1-二(2,4,6-三硝基苯甲酰胺基)-2,2-硝基乙烯的合成 总被引:1,自引:0,他引:1
以1,1-二氨基-2,2-二硝基乙烯(FOX-7)和2,4,6-三硝基苯甲酰氯(TNBC)为原料反应合成得到了1,1-二(2,4,6-三硝基苯甲酰胺基)-2,2-二硝基乙烯,并通过单因素试验和正交试验方法,分别探讨了反应介质、缚酸剂、反应温度和反应时间等对产物产率的影响,得到适宜的工艺条件为:FOX-7与TNBC物质的量的比1∶2.4,以四氢呋喃(THF)为反应介质,N,N-二甲基甲酰胺(DMF)为缚酸剂,反应温度0℃,反应时间48 h,产率可达94%.采用紫外可见光谱(UV-Vis)、核磁共振氢谱(1H NMR)、核磁共振碳谱(13C NMR)、红外光谱(FT-IR)、质谱(MS)及元素分析等对产物的结构进行了表征.利用差热分析仪对产物热稳定性进行了研究,结果表明,产物在空气中分解峰值温度为167℃,理论计算爆速为7.434km· s-1,爆压为23.67 GPa. 相似文献
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This study proposed a novel technology, which uses exposed technology with ultraviolet light‐emitting‐diode (UV‐LED) arrays and the polydimethylsiloxane (PDMS) magnetic flexible soft mold imprint technology, to develop exposed equipments with UV‐LED arrays. This study used magnetic soft mold imprint technology to replicate the structure of microlens, providing a more effective alternative for imprint technology and application. The measurement results showed that PDMS with magnetic iron powder can precisely cast mold to replicate the structures of microlens. Electromagnetic plates were used to control even imprinting with magnetic force, in order to fill the mold of micro‐structure of the photo‐resist. Magnetic iron powder was added to PDMS to produce composite material, which can effectively avoid the transformation of pure PDMS during soft mold imprinting, and increase mechanical strength. Magnetic PDMS soft mold is easy to make, and the casting time is short, so that costs can be effectively reduced. Also with advantages of less free energy on its surface, and unlikely to adhere to the photo‐resist during imprinting, it can be combined with electromagnetic plates evenly to control the magnetic soft mold. This imprinting technology is a big advantage to the production process of micro‐structures during imprinting. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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为延长稀有气体卤化物准分子激光器工作气体使用寿命,在原有供气设备基础上增加了工作气体实时补给技术.该技术采用FPGA控制系统将逐步提高放电电压、补充卤素气体和更换部分混合气体等操作有效组合起来.随着激光脉冲能量的下降,逐步提高放电电压;当放电电压达到最大值时,开始补充卤素气体,并恢复放电电压;当补充卤素气体效果不明显时,更换部分混合工作气体.将该技术应用于医用型ArF准分子激光器中进行实验研究,结果表明:在没有使用工作气体实时补给技术的情况下,激光器累计工作14.38 h后,输出单脉冲激光能量下降了17.2%;采用工作气体实时补给技术后,激光器输出能量下降速率明显降低,累计工作14.38 h,其单脉冲能量下降率能控制在3%范围内.因此,采用该技术可延长激光器工作气体的使用寿命、提高输出激光能量稳定性、减少停机次数并降低运行成本. 相似文献
110.
Ghizlane Choukrani Jimena Álvarez Freile Natasha Ustyanovska Avtenyuk Wei Wan Kerstin Zimmermann Edwin Bremer Lars Dähne 《Particle & Particle Systems Characterization》2021,38(7):2100012
Nanoparticles may limit off-tumor/on-target ubiquitous activation of signaling by protein-based drugs. However, many challenges still exist in the design of a nanoparticle for protein delivery. In this study, conditions to establish vaterite nanoparticles as a pH-sensitive drug delivery system (DDS) for encapsulated protein drugs are comprehensively evaluated. Low coprecipitation pH of vaterite and protein prevents protein denaturation and yields high loading efficiency. Unprotected vaterite recrystallizes in aqueous solutions within 3 h to calcite and releases the loaded protein completely, but surface-modified particles with carboxyl groups containing polymers prove stable for more than 5 months. Notably, modification of vaterite with sulfonated polymers increases the loading of cationic proteins by a multiple. A system is developed for vaterite exposure to (pH) conditions under body-like-flow rates, with the dissolution of vaterite and simultaneous release of active proteins at tumor microenvironmental pH reaching up to 80% and only 20% at physiological pH within 2 h. Importantly, the immunomodulatory protein tumor necrosis factor preserves its native structure and fully retains functional activity in vitro after release from the particles. In conclusion, the studies described here provide a framework for the development of vaterite-based DDS as a carrier for bioactive protein-based therapeutics. 相似文献