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101.
Jiahui Xian Suisheng Li Hui Su Peisen Liao Shihan Wang Runan Xiang Yawei Zhang Prof. Qinghua Liu Prof. Guangqin Li 《Angewandte Chemie (International ed. in English)》2023,62(30):e202306726
The conversion of industrial exhaust gases of nitrogen oxides into high-value products is significantly meaningful for global environment and human health. And green synthesis of amino acids is vital for biomedical research and sustainable development of mankind. Herein, we demonstrate an innovative approach for converting nitric oxide (NO) to a series of α-amino acids (over 13 kinds) through electrosynthesis with α-keto acids over self-standing carbon fiber membrane with CoFe alloy. The essential leucine exhibits a high yield of 115.4 μmol h−1 corresponding a Faradaic efficiency of 32.4 %, and gram yield of products can be obtained within 24 hours in lab as well as an ultra-long stability (>240 h) of the membrane catalyst, which could convert NO into NH2OH rapidly attacking α-keto acid and subsequent hydrogenation to form amino acid. In addition, this method is also suitable for other nitrogen sources including gaseous NO2 or liquidus NO3− and NO2−. Therefore, this work not only presents promising prospects for converting nitrogen oxides from exhaust gas and nitrate-laden waste water into high-value products, but also has significant implications for synthetizing amino acids in biomedical and catalytic science. 相似文献
102.
103.
A new cycloartane glycoside was isolated from the dried aerial parts of Camptosorus sibiricus Rupr. By means of chemical and spectroscopic methods (IR, 1D and 2D NMR, ESI-MS), the structure was established as 3beta, 7beta, 24beta, 25, 30-pentahydroxycycloartane-3-O-beta-D-glucopyranoside-24-O-beta-D-glucopyranosyl(1 --> 2)-D-glucopyranoside (1). 相似文献
104.
105.
设计了一种基于马赫-曾德(M-Z)光纤干涉滤波器的可调谐多波长掺铥环形光纤激光器,M-Z光纤滤波器由两个3 d B耦合器级联构成,通过光纤耦合器接入环形腔中,并利用Sagnac光纤反射镜实现反射式滤波。实验利用一个发射功率为250 m W的1573 nm光纤激光器作为泵浦源,通过一个1570/2000 nm波分复用器(WDM)注入一段4 m长单模掺铥光纤(TDF)中获得2μm波段光增益。环形腔内加入偏振控制器(PC)调节腔内损耗,实现了2μm波段可调谐多波长输出,观测到最多3个波长激光。 相似文献
106.
导航定位中针对双频码相组合法(MW)无法探测L1和L2载波同一历元发生相同周跳,以及周跳探测后不能实现频率间周跳分离的情况,提出了一种联合多普勒及MW组合法的周跳探测改进方法。利用多普勒积分可对单频点进行周跳检测和修复的特性,将传统MW组合法与多普勒积分法相结合,建立改进模型,从而计算并分离出L1和L2载波相位产生的周跳。用实测数据进行验证和分析,对比了3种不同情况下改进方法的检测效果,实验表明新算法能精确探测和分离出L1和L2载波相位中的周跳组合,可以准确探测周跳发生位置及周跳数值,并且能够探测和修复1周以上的周跳,有效提高了MW组合算法探测与修复周跳的准确性和可靠性。 相似文献
107.
保偏光纤对入射的线偏振光具有偏振保持能力,用白光干涉系统可实现准分布式应力、温度和位置传感。超辐射发光二极管(SLD)当驱动电流较小时,光谱服从高斯分布;随着驱动电流增加,中心波长向短波方向漂移,光谱畸变,可用两个高斯函数相加拟合。本文详细分析了SLD光源在不同驱动电流下的谱型分布及拟合曲线,并在保偏光纤应力传感系统中进行了实验,实验结果表明随着光源输出功率增加,在耦合点两侧对称分布着伪耦合点。当光源功率为15 mW时,伪耦合点的耦合强度比力致耦合点的耦合强度约小15 dB。 相似文献
108.
Ping Yin Xian‐Yang Chen Chong‐De Li Xin‐Quan Xin 《International journal of quantum chemistry》2001,82(6):293-298
Ab initio calculations have been carried out to study the structures and relative stabilities of the planar eight‐membered ring B4N4H4 and its isoelectronic species C8H4 at the HF/6‐31G*, MP2/6‐31G*, MP2/6‐311G**, and MP4SDQ/6‐31G* levels. The analyses of Milliken population, vibration frequencies, π‐molecular orbital components, and orbital energy levels were used to evaluate the relative stabilities of these two similar systems. The homodesmotic reactions were also taken to be a useful index of relative stability for X4Y4H4 (XY=CC, BN) and gave the resonance energies with MP4SDQ/6‐31G* of C8H4 (?37.2 kcal/mol) < B4N4H4 (?29.2 kcal/mol). Furthermore, we calculated the thermodynamic functions of these reactions to discuss the influence of temperature. It is concluded that B4N4H4 may exist in theory and could be a little more stable than C8H4. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 82: 293–298, 2001 相似文献
109.
Yan Taihong Zhen Weifang Ye Guoan Zhang Yu Xian Liang Di Ying Bian Xiaoyan 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(1):293-299
Dihydroxyurea (DHU) was synthesized using tri-associated solid phosgene [bis(trichloromethyl) carbonate] dissolved in dioxane and hydroxylamine hydrochloride dissolved in potassium acetate solution.
The reduction of Pu(IV) by DHU was investigated using UV-Vis spectrophotometry. The reduction back-extraction behavior of
Pu(IV) in 30% tri-butyl phosphate/kerosene was firstly investigated under conditions of various temperature, various DHU and
HNO3 concentrations and various phase contact times. The results showed that Pu(IV) in the organic phase can be stripped rapidly
to the aqueous phase by DHU. Simulating the 1B contactor of the PUREX process using a 0.1 M DHU in 0.36M nitric acid solution
as the stripping agent, the separation factors of uranium/plutonium can reach 2.1·104. This indicates that DHU is a promising salt free agent for uranium/plutonium separation. 相似文献
110.