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91.
根据 HL-2M 装置物理实验加热的需求,完成了总功率为 8MW 的电子回旋共振加热及电流驱动
(ECRH/ECCD)系统设计,开展了波源、传输及天线等关键部件研制。8MW ECRH/ECCD 系统,由 8 套 105GHz/
1MW/3s 波源系统、8 条内径为 63.5mm 的真空传输线及三套极向实时可控的发射天线构成。目前,已完成
ECRH/ECCD 系统关键部件研制及其相关的桌面与高功率性能测试。测试结果表明,微波源回旋管输出微波功率
达到1MW/3s,在真空度为 10‒2Pa 的过模波纹圆波导传输线中能低耗稳定传输,发射天线极向全量程角度转动响
应时间在 50ms 以内。 相似文献
92.
Casper de Lichtenberg Christopher J. Kim Petko Chernev Richard J. Debus Johannes Messinger 《Chemical science》2021,12(38):12763
The molecular oxygen we breathe is produced from water-derived oxygen species bound to the Mn4CaO5 cluster in photosystem II (PSII). Present research points to the central oxo-bridge O5 as the ‘slow exchanging substrate water (Ws)’, while, in the S2 state, the terminal water ligands W2 and W3 are both discussed as the ‘fast exchanging substrate water (Wf)’. A critical point for the assignment of Wf is whether or not its exchange with bulk water is limited by barriers in the channels leading to the Mn4CaO5 cluster. In this study, we measured the rates of H216O/H218O substrate water exchange in the S2 and S3 states of PSII core complexes from wild-type (WT) Synechocystis sp. PCC 6803, and from two mutants, D1-D61A and D1-E189Q, that are expected to alter water access via the Cl1/O4 channels and the O1 channel, respectively. We found that the exchange rates of Wf and Ws were unaffected by the E189Q mutation (O1 channel), but strongly perturbed by the D61A mutation (Cl1/O4 channel). It is concluded that all channels have restrictions limiting the isotopic equilibration of the inner water pool near the Mn4CaO5 cluster, and that D61 participates in one such barrier. In the D61A mutant this barrier is lowered so that Wf exchange occurs more rapidly. This finding removes the main argument against Ca-bound W3 as fast substrate water in the S2 state, namely the indifference of the rate of Wf exchange towards Ca/Sr substitution.Access to the oxygen-evolving complex in photosynthesis is restricted by specific barriers in the channels connecting the Mn4CaO5 catalyst with bulk water. Together with other recent data, this finding allows assigning the two substrate waters. 相似文献
93.
Tau neutrinos favored over sterile neutrinos in atmospheric muon neutrino oscillations 总被引:1,自引:0,他引:1
Fukuda S Fukuda Y Ishitsuka M Kajita T Kameda J Kaneyuki K Kobayashi K Koshio Y Miura M Moriyama S Nakahata M Nakayama S Obayashi Y Okada A Okumura K Sakurai N Shiozawa M Suzuki Y Takeuchi H Takeuchi Y Toshito T Totsuka Y Yamada S Earl M Habig A Kearns E Messier MD Scholberg K Stone JL Sulak LR Walter CW Goldhaber M Barszczak T Casper D Gajewski W Kropp WR Mine S Price LR Smy M Sobel HW Vagins MR Ganezer KS Keig WE Ellsworth RW Tasaka S Kibayashi A Learned JG Matsuno S Takemori D 《Physical review letters》2000,85(19):3999-4003
The previously published atmospheric neutrino data did not distinguish whether muon neutrinos were oscillating into tau neutrinos or sterile neutrinos, as both hypotheses fit the data. Using data recorded in 1100 live days of the Super-Kamiokande detector, we use three complementary data samples to study the difference in zenith angle distribution due to neutral currents and matter effects. We find no evidence favoring sterile neutrinos, and reject the hypothesis at the 99% confidence level. On the other hand, we find that oscillation between muon and tau neutrinos suffices to explain all the results in hand. 相似文献
94.
Larissa A. Casper Dr. Michael Linseis Dr. Serhiy Demeshko Dr. Mykhailo Azarkh Prof. Malte Drescher Prof. Rainer F. Winter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(42):10854-10868
Three new electrochromic ferrocenyl triarylmethylium dyes with fluorenylium ( 1 a +, 1 b +) or thioxanthylium ( 1 c +) residues were selected in order to keep the intrinsic differences of redox potentials for ferrocene oxidation and triarylmethylium reduction small and to trigger valence tautomerism (VT). UV/Vis/NIR and quantitative EPR spectroscopy identified paramagnetic diradical isomers 1 a ..+– 1 c ..+ alongside diamagnetic forms 1 a +– 1 c +, which renders these complexes magnetochemical switches. The diradical forms 1 a ..+– 1 c ..+ as well as the one-electron-reduced triarylmethyl forms of the complexes were found to dimerize in solution. For radical 1 a ., dimerization occurs on the timescale of cyclic voltammetry; this allowed us to determine the kinetics and equilibrium constant for this process by digital simulation. Mößbauer spectroscopy indicated that 1 a + and 1 b + retain VT even in the solid state. UV/Vis/NIR spectro-electrochemistry revealed the poly-electrochromic behaviour of these complexes by establishing the distinctly different electronic absorption profiles of the corresponding oxidized and reduced forms. 相似文献
95.
Yamamoto S Zalipska J Aliu E Andringa S Aoki S Argyriades J Asakura K Ashie R Berghaus F Berns H Bhang H Blondel A Borghi S Bouchez J Burguet-Castell J Casper D Catala J Cavata C Cervera A Chen SM Cho KO Choi JH Dore U Espinal X Fechner M Fernandez E Fukuda Y Gomez-Cadenas J Gran R Hara T Hasegawa M Hasegawa T Hayashi K Hayato Y Helmer RL Hiraide K Hosaka J Ichikawa AK Iinuma M Ikeda A Inagaki T Ishida T Ishihara K Ishii T Ishitsuka M Itow Y Iwashita T Jang HI Jeon EJ Jeong IS Joo KK Jover G 《Physical review letters》2006,96(18):181801
We performed an improved search for nu(mu) --> nu(e) oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2 x 10(19) protons on target. No evidence for a nu(e) appearance signal was found, and we set bounds on the nu(mu) --> nu(e) oscillation parameters. At Deltam(2)=2.8 x 10(-3) eV(2), the best-fit value of the K2Knu(mu) disappearance analysis, we set an upper limit of sin(2)2theta(mue) < 0.13 at a 90% confidence level. 相似文献
96.
Larissa A. Casper Steffen Oßwald Patrick Anders Lisa-Catherine Rosenbaum Rainer F. Winter 《无机化学与普通化学杂志》2020,646(13):712-725
We have prepared and studied extremely electron-poor, deeply colored dicationic 1,1'-bis(diarylmethylium)-substituted ferrocenes [(η5-C5H4-CAr2)2Fe]2+ with various aryl substituents as their [B{C6H3(CF3)2-3,5}4]– salts. Due to the strong acceptor substitution, the redox potential for the ferrocene-based oxidation of the anisyl- or 2-methylanisyl-substituted congeners 1b2+ and 1c2+ is close to or even surpasses that of the second oxidation of parent ferrocene, i.e. the Cp2Fe+/2+ couple. The strongly Lewis-acidic character of these complexes is manifest through strong interactions with donor solvents, which lead to a significant reduction of the intensities of the charge-transfer bands in their electronic spectra and to solvatochromism. The reduced forms of the complexes tend to dimerize or oligomerize as revealed by EPR spectroscopy. Direduced 1b selectively reacts with molecular oxygen to form a peroxo-bis(diarylmethyl)[4]ferrocenophane, which was also characterized by X-ray crystallography. 相似文献
97.
98.
Regulation related to capital requirements is an important issue in the banking sector. In this regard, one of the indices used to measure how susceptible a bank is to failure, is the capital adequacy ratio (CAR). We consider two types of such ratios, viz. non‐risk‐based (NRBCARs) and risk‐based (RBCARs) CARs. According to the US Federal Deposit Insurance Corporation (FDIC), we can further categorize NRBCARs into leverage and equity capital ratios and RBCARs into Basel II and Tier 1 ratios. In general, these indices are calculated by dividing a measure of bank capital by an indicator of the level of bank risk. Our primary objective is to construct continuous‐time stochastic models for the dynamics of each of the aforementioned ratios with the main achievement being the modelling of the Basel II capital adequacy ratio (Basel II CAR). This ratio is obtained by dividing the bank's eligible regulatory capital (ERC) by its risk‐weighted assets (RWAs) from credit, market and operational risk. Mainly, our discussions conform to the qualitative and quantitative standards prescribed by the Basel II Capital Accord. Also, we find that our models are consistent with data from FDIC‐insured institutions. Finally, we demonstrate how our main results may be applied in the banking sector. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
99.
100.
Ming Li Casper Hoeck Dr. Sanne Schoffelen Dr. Charlotte H. Gotfredsen Prof. Morten Meldal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(21):7206-7214
The identification of pairs of small peptides that recognize each other in water exclusively through electrostatic interactions is reported. The target peptide and a structure‐biased combinatorial ligand library consisting of ≈78 125 compounds were synthesized on different sized beads. Peptide–peptide interactions could conveniently be observed by clustering of the small, fluorescently labeled target beads on the surface of larger ligand‐containing beads. Sequences of isolated hits were determined by MS/MS. The interactions of the complex showing the highest affinity were investigated by a novel single‐bead binding assay and by 2D NMR spectroscopy. Molecular dynamics (MD) studies revealed a putative mode of interaction for this unusual electrostatic binding event. High binding specificity occurred through a combination of topological matching and electrostatic and hydrogen‐bond complementarities. From MD simulations binding also seemed to involve three tightly bound water molecules in the interface between the binding partners. Binding constants in the submicromolar range, useful for biomolecular adhesion and in nanostructure design, were measured. 相似文献