Reporting computational experiments in mathematical programming

This paper presents a set of recommended standards for the presentation of computational experiments in mathematical programming.The authors are members of the Committee on Algorithms of the Mathematical Programming Society.     

Synthesis and structure of [CpFe(CO){(Ph2P)2NlNMe2}] [I]-CH2Cl2

C₃₂H₃₁FeIN₂OP₂-[CH₂Cl₂],1, monoclinicP2₁/c,a=14.134(3),b=9.496(3),c=26.272(6) Å,=90.92(2)°,Z=4,D _c=1.49 g cm^–3,R=0.044,R _w=0.048, GOF=0.84. Interaction of the hydrazinophosphine Me₂NN(PPh₂)₂ with cyclopentdienyliron dicarbonyl iodide in THF yields compound1 as the sole phosphorous containing species (by³¹P{¹H} NMR). The structure of1 was inferred on the basis of spectroscopic data and solubility characteristics and confirmed via X-ray diffraction.     

Reaction of group 13 sulfido cubanes with dimethylzirconocene

The reaction of Cp₂ZrMe₂ with the aluminum- and gallium-sulfido cubane compounds [( ¹ Bu)M(₃-S)]₄ (M = Al, Ga), has been followed by NMR spectroscopy. Cleavage of the M₄S₄ core occurs resulting in abstraction of a monomeric ( ¹ Bu)M(S) moiety and yielding Cp₂Zr(-S)(-Me)Al( ¹ Bu)Me (1) and [Cp₂Zr(/gm-S)]₂,[Ga( ¹ Bu)Me₂]₂ (3), respectively. The remaining ( ¹ Bu)₃M₃S₃ fragment reacts further with Cp₂ZrMe₂ to give [(Cp₂Zr)M₃(₃-S)₃ ( ¹ Bu)₃Me₂], M = Al (2), Ga (4). The molecular structure of [(Cp₂Zr)Ga₃,(₃-S)₃('Bu)₃Me₂] (4) has been confirmed by X-ray crystallography. All these compounds subsequently decompose to [Cp₂Zr(-S)]₂ and M( ¹ Bu)Me₂. The structure of compound 3 is discussed with respect to the decreased propensity of gallium, as compared to aluminum, to form 3-center 2-electron bridging bonds. Crystal data for [(Cp₂Zr)Ga₃(₃-S)₃( ¹ Bu)₃Me₂] (4): monoclinic, P2₁/n,a = 10.585(2),b = 17.970(4),c = 16.418(3) A, = 101.00(3)°, R = 0.0402, R _w = 0.0402.     

Interactions of speaking condition and auditory feedback on vowel production in postlingually deaf adults with cochlear implants

This study investigates the effects of speaking condition and auditory feedback on vowel production by postlingually deafened adults. Thirteen cochlear implant users produced repetitions of nine American English vowels prior to implantation, and at one month and one year after implantation. There were three speaking conditions (clear, normal, and fast), and two feedback conditions after implantation (implant processor turned on and off). Ten normal-hearing controls were also recorded once. Vowel contrasts in the formant space (expressed in mels) were larger in the clear than in the fast condition, both for controls and for implant users at all three time samples. Implant users also produced differences in duration between clear and fast conditions that were in the range of those obtained from the controls. In agreement with prior work, the implant users had contrast values lower than did the controls. The implant users' contrasts were larger with hearing on than off and improved from one month to one year postimplant. Because the controls and implant users responded similarly to a change in speaking condition, it is inferred that auditory feedback, although demonstrably important for maintaining normative values of vowel contrasts, is not needed to maintain the distinctiveness of those contrasts in different speaking conditions.