P C-H Cheng

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Quasiparticle dynamics of FeSe single crystals revealed by dual-color transient reflectivity measurements (ΔR/R) provides unprecedented information on Fe-based superconductors. The amplitude of the fast component in ΔR/R clearly gives a competing scenario between spin fluctuations and superconductivity. Together with the transport measurements, the(More)
1,3,5,7,9-Pentakis(4-methoxyphenylthio)corannulene (3), 1,3,5,7,9-pentakis(2-naphthylthio)corannulene (4), and 1,3,6,8-tetrakis(4-methoxyphenylthio)corannulene (5b) have been synthesized by chlorination of corannulene with ICl in CH(2)Cl(2) at 25 degrees C and subsequent nucleophilic aromatic substitution with the appropriate sodium thiophenolate in DMEU at(More)
During our routine calibration of a Varian Clinac-20 linear accelerator, the absorbed dose for a fixed monitor unit (mu) was found to decrease with increasing dose rate. Between dose rates of 100 and 500 mu/min, there was up to 20% difference in absorbed dose for a 20-MeV electron beam. The cause of this problem was a failure in the electronics circuit of(More)
The study investigated the effects of chunking and perceptual patterns that guide the drawings of Rey complex figure. Ten adult participants (M age=22.2 yr., SD=4.1) reproduced a single stimulus in four drawing modes including delayed recall, tracing, copying, and immediate recall across 10 sessions producing a total of 400 trials. It was hypothesized that(More)
A spectrophotometric method used to test for paraquat in 160 confiscated marijuana samples is described. Twenty of these samples (12.5 per cent) tested positive for paraquat. Nine confiscated hash oil samples tested negative. The identification of paraquat was proven by isolation, chromatography, and spectral methods. The cannabinoids in paraquat positive(More)
The multinuclear metal-ligand supramolecular synthon R-C≡C⊃Ag(n) (R = alkyl, cycloalkyl; n = 3, 4, 5) has been employed to construct two high-nuclearity silver ethynide cluster compounds, [Cl(6)Ag(8)@Ag(30)((t)BuC≡C)(20)(ClO(4))(12)]·Et(2)O (1) and [Cl(6)Ag(8)@Ag(30)(chxC≡C)(20)(ClO(4))(10)](ClO(4))(2)·1.5Et(2)O (chx = cyclohexyl) (2), that bear the same(More)
Both photogeneration and quenching of singlet oxygen by monomeric and aggregated (dimeric and oligomeric) molecules of bacteriochlorophyll (BChl) d have been studied in solution and in chlorosomes isolated from the green photosynthetic bacterium Chlorobium vibrioforme f. thiosulfatophilum. The yield of singlet-oxygen photogeneration by pigment dimers was(More)
Stable ten-component sandwich compounds have been characterized in which four lithium ions reside between two tetraanions derived from corannulene or its alkyl-substituted derivatives and four additional lithium ions decorate the exterior. In tetrahydrofuran solution, the four lithium ions inside the sandwich can exchange environments with the four external(More)
Using the AAPM Task Group 21 protocol, photon and electron doses were compared in polystyrene and acrylic phantoms. The ionization chambers used were a Farmer graphite chamber, a PTW acrylic chamber, a homemade polystyrene chamber, and an Exradin air-equivalent chamber, all being of cylindrical type. A Memorial parallel-plate polystyrene chamber was also(More)
Surface functionalization of polyoxometalate anions with silver(I) tert-butylethynide in an organic solution medium has been achieved for the first time using an acid-induced facile approach. The generated neutral hybrid monomeric complexes [Ag(40)(C[triple bond]C(t)Bu)(22)(CF(3)COO)(12)(V(10)O(28))].4CH(3)OH (1) and [Ag(40)(C[triple(More)
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