No abstract

We report a new simplified synthetic procedure for commercial manufacture of ternary single-source precursors (SSPs). This new synthetic process has been successfully implemented to fabricate known SSPs on bulk scale and the first liquid SSPs to the semiconductors CuInSe(2) and AgIn(x)S(y). Single crystal X-ray determination reveals the first unsolvated ternary AgInS SSP. SSPs prepared via this new route have successfully been used in a spray assisted chemical vapor deposition (CVD) process to deposit polycrystalline thin films, and for preparing ternary nanocrystallites.

Although developmental psychologists frequently assume that parents change their child-rearing practices as their children develop, there is little research on this topic and virtually none involving parents of adolescents and a longitudinal, repeated-measures design. We examined changes in mothers' reported practices over time in regard to independence and control, expression of positive and negative affect, and disciplinary practices using items from the Child-Rearing Practices Report (CRPR). The CRPR was administered to the same mothers 5 times over an 8-year time period (from when their children were aged 7 or 8 years until they were 15-16 years old). A substantial degree of stability in behaviors and values was noted, even over the 8-year period. In addition, some practices increased or decreased with age, with most of the changes being consistent with prior theorizing and research, as well as commonsense notions related to child rearing.

No abstract

Field experiments were conducted during 1992 and 1993 at Kalispell and Moccasin, MT, to determine the influence of application timing on the efficacy of reduced rate postemergence applications of imazamethabenz and diclofop in spring barley. Herbicides were applied at their respective 1 × and ½ × use rates at either 1, 2, or 3 weeks after crop emergence (WAE). While excellent wild oat control was sometimes achieved with reduced rates, there was no consistent relationship between wild oat growth stage and the level of control at either site regardless of the herbicide or rate applied. This response suggests that efficacy is governed not only by wild oat growth stage, but also by weed demographics and environmental considerations. Barley yield and adjusted gross return values were highest at Kalispell when imazamethabenz treatments were applied at 1 WAE, regardless of the level of wild oat control. Adjusted gross return values were similar for the 1 × and ½ × imazamethabenz treatments. Yields and adjusted gross returns with diclofop treatments were more related to the level of wild oat control at Kalispell, with the 1 × diclofop treatments providing the greatest yields and adjusted gross return values. The level of wild oat control at Moccasin had minimal effect on barley yield and adjusted gross returns, with both values being comparable to the nontreated check.

Nuclear magnetic resonance spectra for each of the interstitials within centered [(Zr6Z)Cl i 12Cl a 6 - n L n ] m - clusters (Z = Be, B, C, N, Mn, and Co; L = Cl-, AlCl4 -, CH3CN, and/or PPh3; n = 0−6) are reported. For C- and Mn-centered clusters, chemical shifts for both solids and solutions have been measured. Chemical shifts for B-centered clusters were measured in solution. Chemical shifts for Be-, N-, and Co-centered clusters were measured in the solid state. Interstitial carbide resonances for all 10 axially substituted species ({[(Zr6C)Cl12](CH3CN) n Cl6 - n } n -4, n = 0−6) have been located; their chemical shifts range from 457.7 ppm for {[(Zr6C)Cl12]Cl6}4- to 480.1 ppm for {[(Zr6C)Cl12](CH3CN)6}2+. 11B chemical shifts for boride-centered clusters ({[(Zr6B)Cl12](CH3CN) n Cl6 - n } n -5, n = 0−5) range from 185 to 193.8 ppm. 11B and 13C data reveal the axially bound chlorides to be substitutionally inert. Chemical shifts for 55Mn-centered clusters range from 5359 ppm (isotropic) for solid RbZr6Cl14Mn to 5618 ppm for [(Zr6Mn)Cl12Cl6]5- in a Cl--rich molten salt. These are the most deshielded manganese compounds presently known. Solid-state 9Be for K3Zr6Cl15Be, 15N for Zr6Cl15N, and 59Co for Zr6Cl15Co reveal chemical shifts of 77.1, 271, and 4082 ppm, respectively (the 9Be data is not corrected for the second-order quadrupolar contribution). A discussion of the origin of large paramagnetic shielding contributions to the chemical shifts of the interstitial atoms is given.

Although developmental psychologists frequently assume that parents change their child-rearing practices as their children develop, there is little research on this topic and virtually none involving parents of adolescents and a longitudinal, repeated-measures design. We examined changes in mothers' reported practices over time in regard to independence and control, expression of positive and negative affect, and disciplinary practices using items from the Child-Rearing Practices Report (CRPR). The CRPR was administered to the same mothers 5 times over an 8-year time period (from when their children were aged 7 or 8 years until they were 15-16 years old). A substantial degree of stability in behaviors and values was noted, even over the 8-year period. In addition, some practices increased or decreased with age, with most of the changes being consistent with prior theorizing and research, as well as commonsense notions related to child rearing.

The development of thin-film solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution for fabricating solar arrays with high specific power (W kg À1). The use of a polycrystalline chalcopyrite absorber layer for thin-film solar cells is considered as the next generation in photovoltaic devices. At NASA GRC we have focused on the development of new single-source precursors (SSPs) and their utility to deposit the chalcopyrite semiconducting layer (CIS) onto flexible substrates for solar-cell fabrication. The syntheses and thermal modulation of SSPs via molecular engineering are described. Thin-film fabrication studies demonstrate that the SSPs can be used in a spray chemical vapor deposition process for depositing CIS at reduced temperatures, and result in electrical properties that are suitable for photovoltaic devices.