1. 选择题：What is the capital of South Africa?A. Cape Town B. Pretoria C. Johannesburg D. Bloemfontein 2. 选择题：What is the opposite of ‘easy’?A. Simple B. Difficult C. Hard D. Challenging 3. 选择题：What is the capital of Chile?A. Santiago B. Valparaiso C. Concepcion D. ...
argon- Argon is the name for the element with atomic number 18 and is represented by the symbol Ar. It is a member of the noble gases group. aromatic compound- an organic molecule that contains a benzene ring. Arrhenius acid- species that dissociates in water to form protons or hydrogen ...
blisters formed during subsequent heating, probably related to micrometeoroid impact, which induced the release of trapped solar wind gas species. This is consistent with steady and continual solar wind irradiation through time, while micrometeoroid bombardment occurs sporadically. ...
Nuclear magnetic resonance (NMR) spectroscopy confirms the identity of the σ-methane complex and shows that the four protons of the metal-bound methane are in rapid exchange with each other. The methane ligand has a characteristically shielded 1H NMR resonance (δ –2.16), and the highly ...
At the cathode, the protons are reduced to hydrogen (Eq. (2)). (1)H2,lowp⟶2H++2e− (2)2H++2e−⟶H2,highp Through the applied electrical driving force, the pressure of hydrogen is increased towards the cathode side. The potential compression relationship is governed by the Nernst...
Excitation functions for the production of 174W from 195Pt have been calculated and folded with the proton and neutron fluence spectra. Incident particles from ca. 100 MeV. on significantly contribute to tungsten production. In total, the contribution of protons and neutrons to the production of ...
6) where the two protons on the thiophene ring make up the I-spins and the natural abundant carbonyl-13C spin (abundance ∼2%) is the S-spin. The compound was purchased from Sigma-Aldrich and used without further purification in a 0.4 M solution in DMSO-d6, degassed by N2-bubbling ...
(IMPT) system. IMPT systems enable spatial control of circumscribed beams of protons that may have a variable energy and/or intensity. IMPT takes advantage of the charged-particle Bragg peak—as noted, the characteristic peak of dose at the end of particles' delivery range—combined with the ...
Protons H-1 and H-2, associated with the p-xylylene linkers, exhibit (Fig. 4d) downfield shifts (Δδ = 0.18 and 0.14 ppm for H-1 and H-2, respectively). In the 1H NMR spectra (Supplementary Fig. 33) of 3Me-HBC⊂TPACage6+ and 3F-HBC⊂TPACage6+, a new set of ...
Exploration of efficient water oxidation catalysts (WOCs) is the primary challenge in conversion of renewable energy into fuels. Here we report a molecularly well-defined heterogeneous WOC with Aza-fused, π-conjugated, microporous polymer (Aza-CMP) coor