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排序方式: 共有88条查询结果,搜索用时 359 毫秒
1.
Yan B Collins N Wheatley J Irving M Leopold K Chan C Shornikov A Fang L Lee A Stock M Zhao J 《Journal of combinatorial chemistry》2004,6(2):255-261
We have developed a high-throughput purification system to purify combinatorial libraries at a 50-100-mg scale with a throughput of 250 samples/instrument/day. We applied an accelerated retention window method to shorten the purification time and targeted one fraction per injection to simplify data tracking, lower QC workload, and simplify the postpurification processing. First, we determined the accurate retention time and peak height for all compounds using an eight-channel parallel LC/UV/MS system, and calculated the specific preparative HPLC conditions for individual compounds. The preparative HPLC conditions include the compound-specific gradient segment for individual compounds with a fixed gradient slope and the compound-specific UV or ELSD threshold for triggering a fraction collection device. A unique solvent composition or solvent strength was programmed for each compound in the preparative HPLC in order to elute all compounds at the same target time. Considering the possible deviation of the predicted retention time, a 1-min window around the target time was set to collect peaks above a threshold based on UV or ELSD detection. Dual column preparative instruments were used to maximize throughput. We have purified more than 500 000 druglike compounds using this system in the past 3 years. We report various components of this high-throughput purification system and some of our purification results. 相似文献
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Deng Xi Wu Liling Deng Yunmeng Huang Siqi Sun Mengtian Wang Xiaowu Liu Qiong Li Ming Li Zhi 《Journal of Sol-Gel Science and Technology》2021,100(3):477-488
Journal of Sol-Gel Science and Technology - This work presents a facile synthesis approach of methyltriethoxysilane (MTES) based aerogels using pure water as the only solvent, and the effects of... 相似文献
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实验以潮州工夫茶文化为背景,在工夫茶传统冲泡工艺的基础上,采用茶汤抗氧化活性为评判指标,探讨工夫茶冲泡工艺的优化条件.实验内容包括文献调研、实验方案设计、实验操作、数据处理及小论文撰写等一系列学习任务.实践教学结果表明,将传统茶文化融入实验教学中,易于激发学生的学习兴趣,传递文化基因;引导学生从文化生活源头提出问题,运用科学方法分析问题、解决问题,利于学生熟悉科学过程,养成正确的科学思维习惯;同时,实践活动中学生会触及到多个学科领域、多重实验操作技能训练,可以全面提升学生的综合素养,达成课程育人目标. 相似文献
6.
The phase transitions in Pd40Ni10Cu30P20 bulk metallic glass (BMG) have been studied under high pressure and high temperature (HP & HT) by X-ray diffraction measurements with synchrotron radiation source. We found that the BMG underwent a phase transitions of amorphous-crystalline-amorphous at 10 GPa upon heating. The parallel experiments were carried out at 7 GPa, while we did not observe the amorphous-crystalline-amorphous transitions by increasing temperature. Quenching the melted BMG at 7 GPa, it was found that the phase crystallized from the melt differed from the primary phase crystallized from the starting amorphous solid upon heating, suggesting there existed a distinct mechanism in two cases. 相似文献
7.
Liling Sun Arthur L. Ruoff Chang-Sheng Zha 《Journal of Physics and Chemistry of Solids》2006,67(12):2603-2608
Optical properties of solid methane (CH4) were studied at high pressure and room temperature using a diamond anvil cell. Reflectivity and transmission measurements were used to measure the refractive index to 288 GPa. Fabry-Perot interferometery was used to measure the sample thickness to 172 GPa. This data was fitted to the derived expression of thickness vs. pressure that was then used to calculate the thickness to 288 GPa. This in turn was combined with optical absorption experiments to obtain the absorption coefficient and hence the extinction coefficient k*. From combined reflection and absorption experiments the refractive index n=ns+ik* was obtained. The index of refraction and the ratio of molar refraction to molar volume showed a large increase between 208 and 288 GPa. This behavior indicated that a phase transformation of insulator-semiconductor might have occurred in solid CH4 by 288 GPa. 相似文献
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采用原子吸收光谱法,测定了肾病综合症、过敏性紫癜患儿血清和尿中铅含量,均高于近期国内外报道允许正常值,给临床治疗和诊断提供了一个新的研究途径。 相似文献
9.
Qiong Liu Jingjun Lin Hui Cheng Liling Wei Fuxian Wang 《Angewandte Chemie (International ed. in English)》2023,62(13):e202218720
Photocatalytic conversion of CO2 is of great interest but it often suffers sluggish oxidation half reaction and undesired by-products. Here, we report for the first the simultaneous co-photocatalytic CO2 reduction and ethanol oxidation towards one identical value-added CH3CHO product on a rubidium and potassium co-modified carbon nitride (CN-KRb). The CN-KRb offers a record photocatalytic activity of 1212.3 μmol h−1g−1 with a high selectivity of 93.3 % for CH3CHO production, outperforming all the state-of-art CO2 photocatalysts. It is disclosed that the introduced Rb boosts the *OHCCHO fromation and facilitates the CH3CHO desorption, while K promotes ethanol adsorption and activation. Moreover, the H+ stemming from ethanol oxidation is confirmed to participate in the CO2 reduction process, endowing near ideal overall atomic economy. This work provides a new strategy for effective use of the photoexcited electron and hole for high selective and sustainable conversion of CO2 paired with oxidation reaction into identical product. 相似文献
10.
Recent results on conversion from graphite to diamond by aid of non-metallic catalysts are reviewed. The current status of
experimental advances is presented and typical examples from relevant literature are provided for understanding the mechanism
of the graphite-diamond conversion by aid of these non-metallic catalysts. Furthermore, a tendency of graphite-diamond transformation
assisted by carbonates, sulfates or phosphorus under high pressure and high temperature has been investigated by calculating
the activation energy and transformation probability of the carbon atoms over a potential barrier. It was found that the activation
energy is highly sensitive to the catalyst chosen. The probability sequence of graphite-diamond transformation with these
catalysts was put forward.
Project supported by the National Natural Science Foundation of China (Grant No. 19674970). 相似文献