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Creator | Title | Description | Subject | Date |
101 |
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Davidson, Diane W. | Species diversity and community organization in desert seed-eating ants | Patterns of species diversity and community organization in desert seed-eating ants were studied in 10 habitats on a longitudinal gradient of increasing rainfall extending from southeastern California, through southern Arizona, and into southwestern New Mexico. Local communities of harvester ants... | Ants; Arizona; California; Communities; Competition; Desert Granivores; Diversity; Insects; New Mexico; Novomessor; Pheidole; Pogonomyrmex; Resource allocation; Veromessor. | 1977 |
102 |
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Capecchi, Mario R. | Isolation of a suppressible nonsense mutant in mammalian cells | An HGPRT- cell line derived from mouse L cells has been shown to have the following properties: it is CRM'; the defective HGPRT molecules are altered in the carboxyterminal peptide; the mutant cells regain HGPRT activity when ochre-suppressor tRNA is microinjected into them, but not when amber... | HGPRT cell line; HGPRT activity; Ochre nonsense mutation; Mouse L cells; Mammalian cells | 1977 |
103 |
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Gesteland, Raymond F. | Cell-free synthesis of herpes simplex virus proteins | Polyribosomes isolated from herpes simplex virus type I (HSV-1)-infected cells have been used to program a eucaryotic cell-free translation system. At least 10 HSV-specific polypeptides, with apparent molecular weights of 25,000 to 160,000, are synthesized by wild-type HSV-infected polyribosomes. Po... | Viral Proteins; Herpes Simplex; Peptide Biosynthesis; Thymidine Kinase | 1977 |
104 |
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Ailion, David Charles | NMR in lithium metal: thermal mixing | We present a calculation of the thermal mixing rate t~ 1 between nuclear Zeeman and dipolar reservoirs in the presence of large rf fields. We applied this calculation to slow-motion diffusion in lithium metal. In particular, we measured the rotating frame spin-lattice relaxation time Tl p as a funct... | NMR; Nuclear magnetic resonance; Lattices; Relaxation time | 1977 |
105 |
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Boll, Steven F. | Noise suppression methods for robust speech processing (1 Oct. 1976 - 31 March 1977) | To develop robust speech processes, based upon the integration of digital noise suppression methods and narrow band speech analysis-synthesis methods, capable of realizing practical, real time methods for effectively processing speech recorded in practical operating environments. | Digital noise suppression | 1977 |
106 |
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Ailion, David Charles | New NMR techniques to study diffusion in multispin crystals | We present a new NMR method for studying slow diffusion in multispin systems. With this method we can vary the effect of a particular spin species' motion relative to the others, thus enabling us to separate and identify the component motions. We present a new pulse sequence for measuring T1L', a ge... | NMR; Nuclear magnetic resonance; Crystals; Nuclear-spin species; Diffusion; Molecular rotations | 1977 |
107 |
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Ailion, David Charles | Nuclear magnetic resonance in LiF: a single nuclear-dipolar-spin temperature in crystals with more than one spin species | In a crystal containing more than one species of nuclear spin in a large dc magnetic field, the secular dipolar interactions between all spins, unlike as well as like, form a single reservoir described by a single spin temperature. We demonstrated this concept with experiments on LiF. In particula... | Spin species; Spin-lattice relaxation; NMR; Nuclear magnetic resonance | 1977 |
108 |
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Miller, Joel Steven | Photoemission of ferrocene, decamethylferrocene, and decamethylferrocene-bis(7,7,8,8-tetracyano-p-quinodimethane) | We present the first vacuum ultraviolet photoemission measurements of condensed ferrocene, decamethylferrocene, and the highly conductive charge transfer complex decamethylferrocene-7,7,8,8-tetracyano-p-quinodimethane, at photon energies from 7.7 to 21.2 eV. We compare the electronic spectra of thes... | Energy; Transfer; TCNQ | 1977 |
109 |
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Seger, Jon | Numerical method for estimating coefficients of relationship in a langur troop | The average coefficient of relationship ( r ij) among the members of a social group is expected to influence the evolution of any trait that affects the average fitness of group members other than the bearer of the trait. It is usually impossible to write a general expression for r ij , because it... | Mating; Reproduction; Trait | 1977 |
110 |
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Ailion, David Charles | NMR relaxation study of molecular motions between unequal potential wells in solid trans, trans- muconodinitrile | We report observations of extremely unusual proton NMR relaxation rates in solid trans, transmuconodinitrile (TMD, N=C-CH = CH-CH = CH-C = N). In particular we measured, over the temperature range 77-423 °K, proton dipolar relaxation times Tw and spin lattice relaxation times Tt (at 24 and 58 MH... | NMR; Nuclear magnetic resonance; Lattices; Relaxation time | 1977 |
111 |
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Armentrout, Peter B. | Endothermic reactions of uranium ions with N2, D2, and CD4 | The assessment of new technology for isotope separation has revived an interest in the spectroscopy, properties, and reactions of uranium and its compounds. Newer methods which have been demonstrated include the use of lasers to selectively excite a particular uranium isotope with subsequent chemic... | Uranium ions; Nitrogen | 1977 |
112 |
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Davidson, Diane W. | Foraging ecology and community organization in desert seed-eating ants | Granivorous ants in the southwestern deserts of the United States are characterized by species-specific colony foraging behaviors that determine their efficiencies at utilizing seeds from different density distributions. Workers search for food either in groups or as individuals, and these feedin... | Ants; Arizona; California; Coexistence; Communities; Density specialization; Desert granivores; Foraging strategies; Insects; New Mexico; Resource partitioning | 1977 |
113 |
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Vardeny, Zeev Valentine | Raman-scattering study of pressure-induced phase transitions in CuI | The pressure-induced phase transitions: zinc-blende (ZB) --* rhombohedral -> tetragonal in Cul were studied by Raman scattering. The rhombohedral primitive cell is presented as a slightly distorted ZB unit cell that is twice as long as the primitive cell in the [111] direction. By folding back the Z... | Raman-scattering; Pressure cell; Phase transitions | 1977-01 |
114 |
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Sokolsky, Pierre | Single-pion production in neutrino and antineutrino reactions | We have studied the neutral-current reactions vµN→vµN'rr0 and vµN→vµN'π0 and compared them to the charged-current reactions vµN→ µ-N"π0 and vµN → µ+N"π0 . We have measured the ratios R0' =(vµN- vµN'π0)/2σ(vµN→µ+N''π0) and R0' = O(vµN→vµN'π0)/2σ(vµN(vuN→u+N"π) to... | | 1977-01 |
115 |
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Mattis, Daniel C. | Electron states in random alloys with short-range order | We present an accurate and economical iterative method of calculating the energy levels of a disordered or partly ordered random alloy. Results presented for one- and three-dimensional simple cubic lattices compare favorably with exact calculations. We also present the systematic effects of partia... | Random alloys; Density of state | 1977-04 |
116 |
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Miller, Joel Steven | Photoelectron spectra of transition-metal carbonyl complexes: comparison with the spectra of adsorbed CO | The uv and x-ray photoelectron spectra of carbon monoxide and transition-metal (TM) carbonyl complexes have been studied. The systematic changes in these spectra were recorded as the number of metal atoms in the complexes was increased and as the bonding configuration of the CO changed. The observat... | TM carbonyl complexes; electron binding energies; metal atoms | 1978 |
117 |
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Miller, Joel Steven | Photoelectron spectra of transition-metal carbonyl complexes: comparison with the spectra of adsorbed CO | The uv and x-ray photoelectron spectra of carbon monoxide and transition-metal (TM) carbonyl complexes have been studied. The systematic changes in these spectra were recorded as the number of metal atoms in the complexes was increased and as the bonding configuration of the CO changed. The observat... | TM carbonyl complexes; electron binding energies; metal atoms | 1978 |
118 |
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Symko, Orest George | Magnetic anisotropy of Zn-Cr alloys at very low temperatures | The temperature dependent magnetization of Zn-Cr single crystals was measured from 2K down to 10 mK using a SQUID magnetometer. A large anisotropy is observed for the magnetization along the parallel and perpendicular axes of the crystal. For low concentrations impurity-impurity reactions do not do... | Magnetic anisotropy; Zn-Cr alloys; Temperature dependent magnetization | 1978 |
119 |
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Ailion, David Charles | NMR methods for identifying and studying diffusion of different spin species in heteronuclear systems | We introduce a new dipolar relaxation lime TU)' which characterizes the spin-lattice relaxation of secular dipolar interactions in the presence of a large rf field. Measurements of T]D' are particularly useful for studying slow atomic motions in muitispin systems, since such measurements enable us ... | NMR; Nuclear magnetic resonance; Nuclear-spin species; Diffusion; Molecular rotations | 1978 |
120 |
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Miller, Joel Steven; Epstein, Arthur J. | Proton spin-lattice and spin-spin relaxation times of (N(CH3)3)H)(I)(TCNQ) | Proton spin-lattice T(1) and spin-spin T(2) relaxation times are reported for (N(CH(3))(3)H)(I)(TCNQ) in the temperature range 150 to 5OOK. The overall relaxation process of the system can be described by contributions from rotation of the N(CH3)3H+ group about its symmetry axis, tumbling of that g... | Transition; Reorientation; Conductivity | 1978 |
121 |
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Davidson, Diane W. | Size variability in the worker caste of a social insect (veromessor pergandei mayr) as a function of the competitive environment | Worker size polymorphism in colonies of Veromessor pergandei, a granivorous desert ant, is inversely related to the intensity of interspecific competition in the habitat for seven ant communities in the deserts of southern California and southern Arizona. Seed size preferences are positively corr... | Ants; Arizona; California; Coexistence; Communities; Density specialization; Desert granivores; Foraging strategies; Resource partitioning; Size | 1978 |
122 |
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DeTar, Carleton | Hadronic deformation energy. I. Quark-antiquark separation | The MIT bag model for hadrons is treated in the static cavity approximation in three dimensions with a definite quark number. The energy of the system is computed to second order in the gluon coupling. A constrained variational method is described which permits the calculation of the energy as a f... | Bag models; Quark bag; Deformation energy; Antiquarks; Gluon coupling; Quark energies; Gluon energies | 1978-01 |
123 |
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DeTar, Carleton | Hadronic deformation energy. II. Two-nucleon interaction | The MIT bag model for hadrons is treated in the static cavity approximation. The adiabatic deformation of a six-quark hadron with quantum numbers of the deuteron is studied in a configuration which permits the separation of two triplets with quantum numbers of the neutron and proton. The energy of... | Bag models; Quark bag; Deformation energy; Gluon coupling; Two-nucleon problem; Nucleons; Self-energy | 1978-01 |
124 |
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Mattis, Daniel C. | Solution of multiple scattering by finite iteration | We propose an iterative nonlinear solution to the general potential scattering problem in quantum mechanics. It is illustrated by the case of N2 localized scatterers of arbitrary strengths Vj located at arbitrary points Rj in an infinite lattice, for which we obtain the complete set of bound and sca... | Bound states; Eigenstates | 1978-01 |
125 |
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Vardeny, Zeev Valentine | Specific heats and lattice dynamics of cuprous halides | The specific heats Cp(T) of CuCl, CuBr, and Cul were measured by the adiabatic calorimetric technique. The corresponding Debye temperature for each crystal is given and a comparison between the results is drawn. The room-temperature phonon dispersion relations for these cystals are fitted by a nine... | Cuprous halides; CuBr; CuCl; CuI | 1978-10 |