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71.
72.
针对星模拟器与星敏感器观星的色温不匹配对星敏感器光信号定标精度产生的影响,设计了一种基于LED的多色温多星等单星模拟器,采用该系统模拟特定色温的星光用于星敏感器光信号定标,大幅降低了色温非匹配带来的定标误差。从理论上分析了色温非匹配影响星敏感器光信号的定标精度的机理;根据设计指标确定了星模拟器的设计方案,主要解决了光源的选型、多色温多星等单星模拟器驱动和控制系统、色温星等匹配算法、多色温多星等单星模拟器软件设计四项关键技术问题;对多色温多星等单星模拟器进行了标定和性能测试:0等星4000K和3等星7000 K星光的光谱匹配误差分别为4.87%和7.83%,星等等级分别为0.03和2.93;光源稳定后,多色温多星等单星模拟器的平行光管出口Φ100 mm口径内的照度非均匀度为6.5%,均满足设计指标。 相似文献
73.
Single Crystal to Single Crystal (SC‐to‐SC) Transformation from a Nonporous to Porous Metal–Organic Framework and Its Application Potential in Gas Adsorption and Suzuki Coupling Reaction through Postmodification 下载免费PDF全文
Dr. Rupam Sen Debraj Saha Dr. Subratanath Koner Dr. Paula Brandão Dr. Zhi Lin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(15):5962-5971
A new amino‐functionalized strontium–carboxylate‐based metal–organic framework (MOF) has been synthesized that undergoes single crystal to single crystal (SC‐to‐SC) transformation upon desolvation. Both structures have been characterized by single‐crystal X‐ray analysis. The desolvated structure shows an interesting 3D porous structure with pendent ?NH2 groups inside the pore wall, whereas the solvated compound possesses a nonporous structure with DMF molecules on the metal centers. The amino group was postmodified through Schiff base condensation by pyridine‐2‐carboxaldehyde and palladium was anchored on that site. The modified framework has been utilized for the Suzuki cross‐coupling reaction. The compound shows high activity towards the C?C cross‐coupling reaction with good yields and turnover frequencies. Gas adsorption studies showed that the desolvated compound had permanent porosity and was microporous in nature with a BET surface area of 2052 m2 g?1. The material also possesses good CO2 (8 wt %) and H2 (1.87 wt %) adsorption capabilities. 相似文献
74.
Wu Shang-Zhuo Yu Qiang Li Yue-Hua Cui Guang-Hua 《Research on Chemical Intermediates》2021,47(2):835-851
Research on Chemical Intermediates - Combination of three aromatic carboxylic acids (5-nitroisophthalic acid (H2nip), 2,6-naphthalenedicarboxylic acid (H2ndc), tetrabromoterephthalic acid (H2tbta))... 相似文献
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76.
采用旋涂的方法在基底材料表面原位生长BiOX(X=C1、Br、I)薄膜材料.样品的晶体结构和光学性质等通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)、紫外可见漫反射光谱(UV-Vis)进行了表征.结果表明旋涂法制备的BiOX薄膜是纯净的,无其他杂质,均匀性好.通过对BiOX薄膜材料的光催化性能和瞬态表面光电压技术(TPV)进行了研究,发现卤素掺杂的BiOBr0.48I052具有较好的光催化性能.其结果表明催化性能提高的原因可能是BiOBr0.48I0.52薄膜在光照下可以产生更强的光生载流子并具有更长的光生载流子寿命. 相似文献
77.
Hongxing Jia Prof. Guilin Zhuang Qiang Huang Jinyi Wang Yayu Wu Shengsheng Cui Prof. Shangfeng Yang Prof. Pingwu Du 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(10):2159-2163
Bottom-up synthesis of π-extended macrocyclic carbon rings is promising for constructing length- and diameter-specific carbon nanotubes (CNTs). However, it is still a great challenge to realize size-controllable giant carbon macrocycles. Herein, a tunable synthesis of curved nanographene-based giant π-extended macrocyclic rings (CHBC[n]s; n=8, 6, 4), as finite models of armchair CNTs, is reported. Among them, CHBC[8] contains 336 all-carbon atoms and is the largest cyclic conjugated molecular CNT segment ever reported. CHBC[n]s were systematically characterized by various spectroscopic methods and applied in photoelectrochemical cells for the first time. This revealed that the proton chemical shifts, fluorescence, and electronic and photoelectrical properties of CHBC[n]s are highly dependent on the macrocycle diameter. The tunable bottom-up synthesis of giant macrocyclic rings could pave the way towards large π-extended diameter- and chirality-specific CNT segments. 相似文献
78.
Hang Liu Juan Zhang Prof. Xinxin Xu Prof. Qiang Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(19):4403-4409
Capacitive deionization is a promising technique in sea water desalination. Compared with common electrodes, mixed capacitive-deionization electrodes exhibit better performance in sea water desalination because they integrate pseudocapacitance and electric double-layer capacitance in one system. Herein, a 3D binder-free mixed capacitive-deionization electrode was fabricated by direct electrodeposition of SiW12O404− and polyaniline on a 3D exfoliated graphite carrier. In this electrode, SiW12O404−/polyaniline composite particles with a size of about 100–120 nm are dispersed homogenously on the 3D exfoliated graphite carrier. Its specific capacitance reaches 352 F g−1 at 1 A g−1. With increasing current from 1 to 20 A g−1, the specific capacitance only decays by 32 %. When employed in sea water desalination, the performance of this mixed capacitive-deionization electrode is also excellent. At 1.2 V, the salt adsorption capacity of this mixed electrode reaches 23.1 mg g−1 with a salt adsorption rate of 1.38 mg g−1 min−1 in 500 mg L−1 NaCl. The performance of this electrode is well retained after 30 cycles. The excellent sea water desalination performance originates from the synergistic effect between SiW12O404− and polyaniline. This work has developed polyoxometalate as a new material for capacitive-deionization electrodes. 相似文献
79.
Wenxiang Liu Lele Lu Qiang Li Boyuan Wu Ruizhe Zhang Wei Shi Peng Cheng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(53):12206-12211
Photocatalytic hydrogen evolution by water splitting is highly important for the application of hydrogen energy and the replacement of fossil fuel by solar energy, which needs the development of efficient catalysts with long-term catalytic stability under light irradiation in aqueous solution. Herein, Zn0.5Cd0.5S solid solution was synthesized by a metal–organic framework-templated strategy and then loaded with MoS2 by a hydrothermal method to fabricate a MoS2/Zn0.5Cd0.5S heterojunction for photocatalytic hydrogen evolution. The composition of MoS2/Zn0.5Cd0.5S was fine-tuned to obtain the optimized 5 wt % MoS2/Zn0.5Cd0.5S heterojunction, which showed a superior hydrogen evolution rate of 23.80 mmol h−1 g−1 and steady photocatalytic stability over 25 h. The photocatalytic performance is due to the appropriate composition and the formation of an intimate interface between MoS2 and Zn0.5Cd0.5S, which endows the photocatalyst with high light-harvesting ability and effective separation of photogenerated carriers. 相似文献
80.
Shuang Dong Ziqin Jiang Zhen Liu Ling Chen Qiang Zhang Youli Tian Amir Sohail Muhammad Idrees Khan Hua Xiao Xiaoping Liu Yuxing Wang Honggen Li Hanyu Wu Weiwen Liu Chengxi Cao 《Electrophoresis》2020,41(16-17):1529-1538
As an effective separation tool, free-flow electrophoresis has not been used for purification of low-abundance protein in complex sample matrix. Herein, lysozyme in complex egg white matrix was chosen as the model protein for demonstrating the purification of low-content peptide via an FFE coupled with gel fitration chromatography (GFC). The crude lysozyme in egg while was first separated via free-flow zone electrophoresis (FFZE). After that, the fractions with lysozyme activity were condensed via lyophilization. Thereafter, the condensed fractions were further purified via a GFC of Sephadex G50. In all of the experiments, a special poly(acrylamide- co-acrylic acid) (P(AM-co-AA)) gel electrophoresis and a mass spectrometry were used for identification of lysozyme. The conditions of FFZE were optimized as follows: 130 μL/min sample flow rate, 4.9 mL/min background buffer of 20 mM pH 5.5 Tris-Acetic acid, 350 V, and 14 °C as well as 2 mg/mL protein content of crude sample. It was found that the purified lysozyme had the purity of 80% and high activity as compared with its crude sample with only 1.4% content and undetectable activity. The recoveries in the first and second separative steps were 65% and 82%, respectively, and the total recovery was about 53.3%. The reasons of low recovery might be induced by diffusion of lysozyme out off P(AM-co-AA) gel and co-removing of high-abundance egg ovalbumin. All these results indicated FFE could be used as alternative tool for purification of target solute with low abundance. 相似文献