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41.
Shengyun Zhu Yongnan Zheng Yi Zuo Dongmei Zhou Daqing Yuan Anli Li Zhiqiang Wang Xiao Duan Meng Liu Yong Li 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(3):615-621
The perturbed angular correlation (PAC) and positron annihilation spectroscopy (PAS) that use nuclear probes to characterize
the micro-structure of materials are briefly described. Three examples are given to show their partial applications. The first
example is the study of radiation damage in Si irradiated by fast neutrons of 1.45·1020 cm−2 and 178W heavy ions of 5·1011 cm−2, respectively. The PAC and PAS measurements all show that the monovacancy-oxygen complexes and divacancies and divacancy-oxygen
complexes were produced by the irradiations, and quadrivacancies and quadrivacancy-oxygen complexes were formed during thermal
annealing. The second one illustrates the investigation of high T
c
superconductivity for YBaCuO. The PAS experiment found the charge transfer during the superconducting trasition. The PAC
measurement suggested a transition of two-to one-dimensional Cu-O-Cu chain structure at the superconducting trasition temperature
T
c
, which favors the charge transfer from the CuO layer to the CuO chain in YBaCuO. The third one is for investigating the hydrogen
behavior in Pd0.75Ag0.25-H
x
as functions of temperature from 77 K to RT and hydrogen concentration (x) from 0 to 35 at.%. The PAC and PAS results exhibit that hydrogen atoms are congregated into the hydrogen bubbles and the
hydrogen bubbles grow with the increasing of the hydrogen concentration in Pd0.75Ag0.25-H
x
. These examples demonstrate that the PAC and PAS techniques are very sensitive and powerful tools in materials science, which
can well investigate phenomena in materials on atomic scale. 相似文献
42.
A separation method for O6‐benzylguanine (O6‐BG) and 8‐oxo‐O6‐benzylguanine (8‐oxo‐O6‐BG) is developed by using MEKC. This study includes the optimization of separation and incubation parameters for both off‐line and on‐line procedures. The BGE consisted of 25 mM sodium phosphate buffer‐methanol (70:30, v/v), apparent pH 7.4, in which SDS and methyl‐β‐cyclodextrin were dissolved yielding final concentrations of 50 and 15 mM, respectively. Separations were performed at 15 kV using an untreated fused‐silica capillary (40 cm length, effective length is 30 cm) with the detection wavelength at 195 nm. The capillary was kept at 15°C. Good performances were demonstrated for the repeatability and linearity. The LOQ was determined to be 14 μM for 8‐oxo‐O6‐BG (S/N = 10). The accuracy values showed a bias of +7.9% for 50 μM and –7.0% for 100 μM. Premix and transverse diffusion of laminar flow profiles (TDLFP) methods were used for on‐line mixing and reaction of the substrate O6‐BG with aldehyde oxidase. Both procedures were successful in mixing as well as subsequent separation of the substrate and the metabolite, while the repeatability of TDLFP (14.7% (n = 3)) was much better than the premix technique. 相似文献
43.
Dongmei Zhou Yongnan Zheng K. Matsuta M. Mihara M. Fukuda D. Nishimura J. Komurasaki D. Ishikawa R. Matsumiya T. Nagatomo T. Izumikawa S. Takahashi H. Hirano T. Ohtsubo S. Momota Y. Nojiri A. Kitagawa M. Kanazawa M. Torikoshi S. Sato T. Minamisono J. R. Alonso G. F. Krebs T. J. M. Symons Daqing Yuan Yi Zuo Ping Fan T. Suzuki Xizhen Zhang Shengyun Zhu 《Hyperfine Interactions》2007,180(1-3):37-42
The magnetic moment of 28P (I π = 3?+?, T1/2 = 270.3 ms) in the ground state has been measured by the $\upbeta $ -nuclear magnetic resonance method for the first time. The measured magnetic moment of $\vert \upmu (^{28}$ P)∣ = 0.309(9) $\upmu _{{\rm N}}$ is well reproduced by the shell model value of +0.306 $\upmu _{{\rm N} }$ . The shell model calculation also yields a proton density distribution with a long tail. The present results provide a strong confirmation of the configuration of the 2s 1/2 proton which should lead to the proton halo. 相似文献
44.
The endoplasmic reticulum (ER) is the site for maturation of proteins destined for the secretory pathway. Failure in maturation leads to production of misfolded proteins that are eliminated through the ER-associated degradation (ERAD) pathway. ERAD is a complex process that includes misfolded protein recognition, retrotranslocation to the cytosol, ubiquitination and proteasomal degradation. gp78 is an E3 ubiquitin ligase that integrates these ERAD steps by nucleating a unique degradation machine, which uses the p97/VCP-Npl4 complex for retrotranslocation instead of the wellknown p97/VCP-Ufd1-Npl4 complex. A growing list of substrates have been identified for gp78, which highlights the importance of gp78-mediated ERAD in essential physiological pathways and pathological processes. 相似文献
45.
Dr. Yannan Liu Yiyue Lu Dr. Arafat Hossain Khan Dr. Gang Wang Yong Wang Dr. Ahiud Morag Dr. Zhiyong Wang Dr. Guangbo Chen Dr. Shengyun Huang Dr. Naisa Chandrasekhar Dr. Davood Sabaghi Dongqi Li Dr. Panpan Zhang Prof. Dongling Ma Prof. Eike Brunner Dr. Minghao Yu Prof. Xinliang Feng 《Angewandte Chemie (International ed. in English)》2023,62(30):e202306091
Emerging rechargeable aluminium batteries (RABs) offer a sustainable option for next-generation energy storage technologies with low cost and exemplary safety. However, the development of RABs is restricted by the limited availability of high-performance cathode materials. Herein, we report two polyimide two-dimensional covalent organic frameworks (2D-COFs) cathodes with redox-bipolar capability in RAB. The optimal 2D-COF electrode achieves a high specific capacity of 132 mAh g−1. Notably, the electrode presents long-term cycling stability (with a negligible ≈0.0007 % capacity decay per cycle), outperforming early reported organic RAB cathodes. 2D-COFs integrate n-type imide and p-type triazine active centres into the periodic porous polymer skeleton. With multiple characterizations, we elucidate the unique Faradaic reaction of the 2D-COF electrode, which involves AlCl2+ and AlCl4− dual-ions as charge carriers. This work paves the avenue toward novel organic cathodes in RABs. 相似文献