Hagler A T and S Lifson 1974. Energy Functions for Peptides and Proteins. II. The Amide Hydrogen Bond and Calculation of Amide Crystal Properties. Journal of the American Chemical Society 96 5327-5335.  [c.267]

A. E. Lipkin and V. A. Smirnov, Khim. Geterotsikl. Soedinenii. 3, 571 (1968) Chem. Abstr., 69, 96555,  [c.325]

V. A. Smirnov and A. E. Lipkin, Khim. Geterotsikl. Soedinenii, 7, 1369 (1971) Chem. Abstr., 76, 46129.  [c.332]

A. E. Lipkin and V. A. Smirnov, Khim. Geterotsikl. Soedinenii, 3, 571 (1968), Chem. Abstr., 69, 96555.  [c.559]

S. Lifson and A. Warshel,/ Chem. Phjs. 49, 5116 (1968) A. Warshel and S. Lifson, Chem. Phjs. Tett. 4, 255 (1969) A. Warshel and S. Lifson,/  [c.170]

L. M. Leviason, Electronic Ceramics, Marcel Dekker, New York, 1988.  [c.211]

E. G. Lufkin and co-workers, Intern. Med. 117, 1 (1992).  [c.247]

LVSEM low-voltage scanning electron microscope MTF modulation transfer function  [c.1623]

Cambridge Instruments builds the first commercial SEM 1968 Crewe and colleagues introduce the PEG as electron beam source 1968 Crewe and colleagues build the first STEM prototype 1995 Zach proves the concept of a corrected LVSEM  [c.1624]

Modem EMs use electromagnetic lenses, shift devices and spectrometers. However, electrostatic devices have always been used as electron beam accelerators and are increasingly being used for other tasks, e.g. as the objective lens (LVSEM, [10]).  [c.1630]

SEM with low acceleration voltage (1-10 kV) (LVSEM) can be applied without metal coating of the sample, e.g. for quality control purposes in semiconductor industries, or to image ceramics, polymers or dry biological samples. The energy of the beam electrons (the acceleration voltage) should be selected so that charge neutrality is approached, i.e. the amount of energy that enters the sample also leaves the sample in the fomi of SE and BSE. Modem SEM instmments, equipped with FEGs provide an adequate spot size, although tire spot size increases with decreasing acceleration voltage. The recent implementation of a cathode lens system [47] with very low aberration coefficients will allow the surfaces of non-metal coated samples at beam energies of only a few electronvolts to be imaged without sacrificing spot size. New contrast mechanisms and new experimental possibilities can be expected.  [c.1642]

The first corrected electron-optical SEM was developed by Zach [10]. Eor low-voltage SEM (LVSEM, down to 500 eV electron energy instead of the conventional energies of up to 30 keV) the spot size is extremely large without aberration correction. Combining and correction and a electrostatic objective lens, Zach showed that a substantial improvement in spot size and resolution is possible. The achievable resolution in a LVSEM is now of the order of 1-2 mn. More recently, Krivanek and colleagues succeeded in building a corrected STEM [53,M].  [c.1643]

Lipkin N, Lefebvre R and Moiseyev N 1992 Resonances by complex nonsimilarity transformations of the Hamiltonian Phys. Rev. A 45 4553  [c.2327]

Gortschakov G, Loffhagen D and Winkler R 1998 The homogeneity of a stabilized discharge-pumped XeCI laser Appl. Phys B 66 313-22  [c.2813]

M. Levitt and Shneior Lifson. Refinement of protein conformation using a macromolecular energy minimization procedure. J. Mol. Biol., 46 269-279, 1969.  [c.93]

I lagler A T, E Huler and S Lifson 1977. Energy Functions for Peptides and Proteins. I. Derivation of a Consistent Force Field Including the Hydrogen Bond from Amide Crystals. Journal of the American Chemical Society 96 5319-5327.  [c.267]

V. A. Smirnov, A. E. Lipkin, and T. B. Ryskina, Khim. Farm. Zh., 24 (1972). Chem. Abstr, 77, 109860.  [c.333]

The accuracy of molecular mechanics and that of molecular dynamics simulations share an inexorable dependence on the rigor of the force field used to elaborate the properties of interest. This aspect of molecular modeling can easily fill a volume by itself. The topic of force field development, or force field parameterization, although primarily a mathematical fitting process, represents a rigorous and highly subjective aspect of the discipline (68). A perspective behind this high degree of rigor has been summarized (69). Briefly put, the different schools of thought regarding the development of force fields arose principally from the initial objectives of the developers. For example, in the late 1960s through the 1970s, the AUinger school targeted the computation of the stmcture and energetics of small organic and medicinal compounds (68,70,71). These efforts involved an incremental development of the force field, building up from hydrocarbons and adding new functional groups after certain performance criteria were met, eg, reproduction of experimental stmctures, conformational energies, rotational barriers, and heats of formation. Unlike the consistent force field approach of Lifson and co-workers (59,62—63,65), the early AUinger force fields treated a dozen or more functional groups simultaneously, and were not derived by an analytical least squares fit to aU the data (61). However, because the focus of Lifson was the analysis and prediction of the properties of hydrocarbons or peptides, it was not surprising that a consistent force field was possible. The number of variables to be optimized concurrentiy to permit calculation of aU the stmcture elements, conformational energies, and vibrational spectra concurrentiy was, and stiU is, a massive quantity. However, the calculation for a limited number of functional groups could be accompHshed, albeit slowly. If the goal is to reproduce and predict vibrational spectra, the full second derivative force  [c.164]

Chem. Phjs. 53, 582 (1970) A. T. Hagler and S. Lifson,Cjstallogr. Sect. B 30, 619 (1974) A. T. Hagler, E. Huler, and S. Lifson,/ Am. Chem. Soc. 96, 5319 (1974) A. Warshel andM. Levitt, Nature 253, 694 (1975). M. Levitt and A. Warshel,/ Mol Biol 106, 421 (1976) M. Levitt and A. Warshel, / Am. Chem. Soc. 100, 2607 (1978).  [c.170]

A. T. Hagler, L. Leiserowitz, and M. Tuval,/ Am. Chem. Soc. 98, 4600 (1976) S. Lifson, A. T. Hagler, and P. Dauber, / Am. Chem. Soc. 101, 5111 (1979).  [c.170]

J. I. Goldstein, D. E. Newbury, P. Echlin, D. C. Joy, C. Eiori, and E. Lifshin, ScanningTlectron Microscopy and A-Tay Microanalysis, Plenum Press, New York, 1981.  [c.288]

Analytical Methods" in ECT3rd ed., VoL 2, pp. 586—683, by E. Lifshin and E. A. WiUiams, General Electric Co.  [c.409]

Analytical Methods" in ECT3rd ed., Vol 2, pp. 586—683, by E. Lifshin and E. A. WiUiams, General Electric Co.  [c.549]

Another microbial polysaccharide-based emulsifier is Hposan, produced by the yeast Candida lipolytica when grown on hydrocarbons (223). Liposan is apparentiy induced by certain water-immiscible hydrocarbons. It is composed of approximately 83% polysaccharide and 17% protein (224). The polysaccharide portion consists of D-glucose, D-galactose, 2-amino-2-deoxy-D-galactose, and D-galacturonic acid. The presence of fatty acyl groups has not been demonstrated the protein portion may confer some hydrophobic properties on the complex.  [c.298]

See pages that mention the term Luvican : [c.255]    [c.1970]    [c.3021]    [c.3031]    [c.322]    [c.748]    [c.749]    [c.167]    [c.173]    [c.248]    [c.249]    [c.256]    [c.439]    [c.291]    [c.291]    [c.291]    [c.175]    [c.352]    [c.186]    [c.103]    [c.492]    [c.534]    [c.569]    [c.170]    [c.542]    [c.565]    [c.298]   
Plastics materials (1999) -- [ c.472 , c.473 ]