Electrodeposited polythiophene films provide reproducible samples for laser desorption ion trap mass spectrometry studies

Electrodeposited polythiophene films can provide consistent laser desorption signal levels for over 20,000 laser shots on one position of a probe tip in an ion trap. A similar lack of signal decay was observed for multiple positions on the same film. The consistency and longevity of the ion signal resulting from laser desorption of a polythiophene film are much greater than those typically obtained from simple solution residue samples. Uniform, electrodeposited polythiophene films can provide a great reduction in the uncertainty of ion production that has previously been associated with ion trapping studies utilizing laser desorption.     

An Organizational Model of Integrated Budgeting for Short-Run Operations and Long-Run Investments

In managerial finance, the short run usually refers to multiperiod models which involve operating plans and cash flow analysis. Long-run models are for capital investment or capital budgeting. Their essential link is the emphasis on cash flow and budgets. This relation is explored with an integrated model and its decompositions by budgets. The decomposition yields subunit models for the short run and long run which are related to earlier models, but yields insight into the organizational use of budgets for coordination and control. To obtain relative efficiency measures on two alternatives organizational budgeting mechanisms, a simulation was performed and analyzed.     

Kinetics of fluorescence decay of SO2 excited in the 2662–3273 Å region

The kinetics of fluorescence decay of SO₂ excited in the 2975–3273 Å region was studied using a powerful, frequency doubled, tunable dye laser system. The existence of two emitting species, first observed by Brus and McDonald, was confirmed. The collision-free lifetimes of the long-lived (L) species ranged from 100 to 300 μsec and the short-lived (S) species from 17 to 43 μsec over the wavelength range employed. The magnitude of the bimolecular quenching rate constant for the L state was a function of the excitation energy; the data show that about 1 kcal/mol of internal energy is lost per collision of the SO₂(L) species excited in the range of 2998–3107 Å. Studies of the relative initial fluorescence intensity of the S to that of the L state (I_S°/I_L°) were made in experiments which extended to 0.11 mtorr. The pressure dependence of the I_S°/I_L° ratio for experiments at 3107, 3211, and 3225 Åproved that the S and L states do not decay independently. Either efficient bimolecular S → L conversion occurs or bimolecular S ? L interconversion of both states is important. These data coupled with spectroscopic studies of Hamada and Merer and Shaw and coworkers favor the designation of the S and L states as SO₂(¹A₂) and SO₂(¹B₁), respectively. However, if the assignment is correct, then the band origin of the ¹B₁ state must be at a somewhat longer wavelength, λ> 3273 Å than tentative spectroscopic assignments suggest. Bimolecular quenching rate constants for the L and S components with various atmospheric gases were determined in 3130- and 2662-Å studies.     

Surface chemistry and electrical properties of germanium nanowires

Germanium nanowires (GeNWs) with p- and n-dopants were synthesized by chemical vapor deposition (CVD) and were used to construct complementary field-effect transistors (FETs). Electrical transport and X-ray photoelectron spectroscopy (XPS) data are correlated to glean the effects of Ge surface chemistry to the electrical characteristics of GeNWs. Large hysteresis due to water molecules strongly bound to GeO(2) on GeNWs is revealed. Different oxidation behavior and hysteresis characteristics and opposite band bending due to Fermi level pinning by interface states between Ge and surface oxides are observed for p- and n-type GeNWs. Vacuum annealing above 400 degrees C is used to remove surface oxides and eliminate hysteresis in GeNW FETs. High-kappa dielectric HfO(2) films grown on clean GeNW surfaces by atomic layer deposition (ALD) using an alkylamide precursor is effective in serving as the first layer of surface passivation. Lastly, the depletion length along the radial direction of nanowires is evaluated. The result suggests that surface effects could be dominant over the "bulk" properties of small diameter wires.     

Nitramines with Varying Sensitivities: Functionalized Dipyrazolyl‐ N‐nitromethanamines as Energetic Materials

1,3‐Dichloro‐2‐nitro‐2‐azapropane is an excellent precursor to dense energetic functionalized dipyrazolyl‐N‐nitromethanamines. This new family of energetic compounds was fully characterized by using ¹H, ¹³C, and ¹⁵N NMR and IR spectroscopy, differential scanning calorimetry, elemental analysis, and impact sensitivity tests. Additionally, single‐crystal X‐ray structuring was done for 3 and 5? CH₃CN, which gave insight into structural characteristics. The experimentally determined densities of 2 – 9 fall between 1.69 and 1.90 g cm^?3. Heats of formation and detonation properties were calculated by using Gaussian 03 and EXPLO5 programs, respectively. The influence of different energetic moieties on the structural and energetic properties was established theoretically.     

Energetic N‐Trinitroethyl‐Substituted Mono‐, Di‐, and Triaminotetrazoles

A series of dense energetic N‐trinitroethyl‐substituted mono‐, bis‐, and tri‐5‐aminotetrazoles were obtained by reacting primary amines with in situ generated cyanogen azide, followed by the trinitroethyl functionalization that involves a condensation of a hydroxymethyl intermediate (prepared by a reaction with formaldehyde) with trinitromethane. These compounds were fully characterized by using multinuclear NMR spectroscopy, IR, elemental analysis, differential scanning calorimetry (DSC), and, in one case with 9 , with single‐crystal XRD analysis. The heats of formation for all compounds were calculated with Gaussian 03 and then combined with experimental densities to determine the detonation pressures (P) and velocities (D_v) of the energetic materials. Interestingly, most of them exhibited high density, good thermal stability, acceptable oxygen balance, positive heat of formation, low impact sensitivity, and excellent detonation properties, which highlighted their practical application potentials as a fascinating class of highly energetic materials.     

Energetic N,N′‐Ethylene‐Bridged Bis(nitropyrazoles): Diversified Functionalities and Properties

A new class of N,N′‐ethylene‐bridged bis(nitropyrazoles) was synthesized and fully characterized. The highly efficient formation of the N,N′‐ethylene bridge was accomplished using dibromoethane and ammonium or potassium pyrazolate. Further functional‐group transformations of diaminobis(pyrazole) and dichlorobis(pyrazole) gave rise to diversified derivatives, including dinitramino‐, diazido‐ and hexanitrobis(pyrazole). Single‐crystal X‐ray diffractions were obtained for hexanitro and diazido derivatives to illustrate the structural characteristics. Heats of formation and detonation performance were calculated by using Gaussian 03 and EXPLO5 v6.01 programs, respectively. Because of the different functionalized groups, the impact and friction sensitivities of these new compounds range from insensitive to sensitive. Among them, the hexanitro derivative displays the most promising overall energetic properties (density (ρ)=1.84 g cm^?3; decomposition temperature (T_d)=250 °C; detonation pressure (P)=34.1 GPa; detonation velocity (v_D)=8759 m s^?1; impact sensitivity (IS)=25 J; friction sensitivity (FS)=160 N), which is competitive with those of 1,3,5‐trinitrotriazacyclohexane (ρ=1.80 g cm^?3; T_d=205 °C; P=35.0 GPa; v_D=8762 m s^?1; IS=7 J; FS=120 N).