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41.
Assumpta C Nwanya Daniel Obi Rose U. Osuji R. Bucher Malik Maaza Fabian I. Ezema 《Journal of Solid State Electrochemistry》2017,21(9):2567-2576
We used a simple chemical synthesis route to deposit nanorod-like cobalt oxide thin films on different substrates such as stainless steel (ss), indium tin oxide (ITO), and microscopic glass slides. The morphology of the films show that the films were uniformly spread having a nanorod-like structure with the length of the nanorods shortened on ss substrates. The electrochemical properties of the films deposited at different time intervals were studied using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The film deposited after 20 cycles on ss gave the highest specific capacity of 67.6 mAh g?1 and volumetric capacity of 123 mAh cm?3 at a scan rate 5 mV s?1 in comparison to 62.0 mAh g?1 and 113 mAh cm?3 obtained, respectively, for its counterpart on ITO. The film electrode deposited after 20 cycles on ITO gave the best rate capability and excellent cyclability with no depreciation after 2000 charge–discharge cycles. 相似文献
42.
We consider closed manifolds that admit a metric locally isometric to a product of symmetric planes. For such manifolds, we prove that the Euler characteristic is an obstruction to the existence of flat structures, confirming an old conjecture proved by Milnor in dimension 2. In particular, the Chern conjecture follows in these cases. The proof goes via a new sharp Milnor–Wood inequality for Riemannian manifolds that are locally a product of hyperbolic planes. Furthermore, we analyze the possible flat vector bundles over such manifolds. Over closed Hilbert–Blumenthal modular varieties, we show that there are finitely many flat structures with nonzero Euler number and none of them corresponds to the tangent bundle. Some of the main results were announced in [M. Bucher, T. Gelander, Milnor–Wood inequalities for manifolds locally isometric to a product of hyperbolic planes, C. R. Acad. Sci. Paris Ser. I 346 (2008) 661–666]. 相似文献
43.
Nonlinear Dynamics - Described is a closed-loop control scheme capable of stabilizing a parametrically excited nonlinear structure in several vibration modes. By setting the relative phase between... 相似文献
44.
Christian H. Bucher Julia C. Berkmann Lisa-Marie Burkhardt Carolin Paschke Claudia Schlundt Annemarie Lang Angelique Wolter Alexandra Damerau Sven Geissler Hans-Dieter Volk Georg N. Duda Katharina Schmidt-Bleek 《Experimental & molecular medicine》2022,54(8):1262
With increasing age, the risk of bone fractures increases while regenerative capacity decreases. This variation in healing potential appears to be linked to adaptive immunity, but the underlying mechanism is still unknown. This study sheds light on immunoaging/inflammaging, which impacts regenerative processes in aging individuals. In an aged preclinical model system, different levels of immunoaging were analyzed to identify key factors that connect immunoaged/inflammaged conditions with bone formation after long bone fracture. Immunological facets, progenitor cells, the microbiome, and confounders were monitored locally at the injury site and systemically in relation to healing outcomes in 12-month-old mice with distinct individual levels of immunoaging. Bone tissue formation during healing was delayed in the immunoaged group and could be associated with significant changes in cytokine levels. A prolonged and amplified pro-inflammatory reaction was caused by upregulated immune cell activation markers, increased chemokine receptor availability and a lack of inhibitory signaling. In immunoaged mice, interleukin-22 was identified as a core cell signaling protein that played a central role in delayed healing. Therapeutic neutralization of IL-22 reversed this specific immunoaging-related disturbed healing. Immunoaging was found to be an influencing factor of decreased regenerative capacity in aged individuals. Furthermore, a novel therapeutic strategy of neutralizing IL-22 may successfully rejuvenate healing in individuals with advanced immune experiences.Subject terms: Trauma, Mechanisms of disease, Interleukins, Osteoimmunology 相似文献
45.
Rudolf v. Bucher 《Monatshefte für Chemie / Chemical Monthly》1893,14(1):598-611
Ohne Zusammenfassung 相似文献
46.
47.
J. Karpinski S. Rusiecki E. Kaldis B. Bucher E. Jilek 《Physica C: Superconductivity and its Applications》1989,160(5-6):449-457
The P-T-x phase diagram of the pseudobinary system (Y-Ba-Cu-O)-O2 has been further investigated in the oxygen pressure range between 1 and 3000 bar. The stability ranges of the phases YBa2Cu4O8 (124), YBa2Cu3.5O7.5−x (123.5) and YBa2Cu3O7−x (123) have been determined. Long duration experiments showed that the 123 phase is not stable at least down to 7 bar≤P≤20 bar oxygen and 900°C. It is not clear whether at lower pressures and temperatures the 123 phase is thermodynamically stable or metastable due to low reaction rates. In the presence of excess CuO, the 124 is the stable phase. The melting of 124 pellets at PO2=2800 bar shows that even at this pressure the 124 compound melts incongruently. Using the phase diagram data we could change the Tc of 123.5 from 16 to 70 K by varying systematically the nonstoichiometry. Due to a narrow homogeneity range the Tc of 124 remained constant but is different for powder pellets (81 K) and for crystals (70 K), probably due to the influence of the flux. Single crystals of both 124 and 123.5 with dimensions up to 4 mm were grown from the flux under high oxygen pressure. 相似文献
48.
M. Saad H. Riazi E. Bucher M. C. Lux-Steiner 《Applied Physics A: Materials Science & Processing》1996,62(2):181-185
Heterojunctions, such as ZnO/CdS/CuGaSe2, were fabricated for photovoltaic applications. Optimization of device structures based on monocrystalline CuGaSe2 led to the highest-to-date power conversion efficiencies for CuGaSe2 solar cells. At room temperature under 100 mW/cm2 AM1.5 illumination a maximum cell efficiency of 9.7% was achieved, given by an open-circuit voltage of 946 mV, a short circuit current density of 15.5 mA/cm2, and a fill factor of 66.5%. Preparation and performance of the optimum device are described. Current voltage characteristics dependent on illumination intensity and temperature, spectral response and electron-beam-induced current measurements were performed to determine the device parameters as well as to analyse the current transport and loss mechanisms. Tunneling, assisted by defect levels in the CdS layer, seems to play a major role. High injection effects are observed at forward bias ofV > 0.5 V or an illumination level ofP > 10 mW/cm2. Under such conditions, as well as at low temperatures, the non-zero series resistance comes into play. Effects of the shunt resistance, however, are negligible in all cases. 相似文献
49.
50.
M. Landolt F. Meter P. Zürcher H. Oesterreicher K. Ensslen J. Hoenigschmid E. Bucher 《Solid State Communications》1979,32(11):1009-1011
The spin polarization of photoelectrons from ErFe2 was found to go from near zero to ~ ? 20% upon exposure to 1000 L H2. Exposure to 1000 L O2 yielded zero spin polarization. We conclude that no hydrogen or oxygen induced surface segregation occurs at room temperature in ErFe2 (unlike LaNi5 or FeTi). It is indicated that hydrogen itself causes activation of the ErFe2 surface for hydrogenation. 相似文献