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排序方式: 共有106条查询结果,搜索用时 15 毫秒
21.
Gary Lindstrom 《BIT Numerical Mathematics》1973,13(1):50-70
Techniques for language extension are of interest today as a means for language design experimentation without language proliferation. Attention thus far has been focused on methods for data structure definition and manipulation. The problem of program control extensibility has been recognized by workers in the field but less thoroughly treated. This paper outlines an approach to control extensibility applicable on the source language level to appropriate programming languages.Using the recursive language LISP as an example, extensions are defined that provide call by name function parameters, generator functions (as in IPL-V), non-deterministic functions, and general coroutines. LISP facilitates this exercise by features including dynamic scope of variables, source programs manipulatable as data, simplicity of program state representations, and control over context of function evaluation. The results of this paper suggest criteria for evaluating base languages in extensible programming systems, as well as a possible insight into formal program analysis. 相似文献
22.
The analyzing powers iT11, T20, T21 and T22 have been measured for the reaction 3He(d, p)4He at laboratory energies of 344, 465 and 727 keV. A polarized deuteron beam was used with quantization axis oriented perpendicular to and at 54.7° to the incident beam direction. With semi-conductor proton detectors in two perpendicular planes all four analyzing powers could be determined. The beam polarization was determined using the 3H(d, n)4He reaction at a mean energy of 130 keV. The uncertainty in this analyzing power and the effect on the results is discussed. The analyzing powers have been fitted to a Legendre polynomial expansion to four or five terms and the resulting coefficients tabulated. The results indicate that d-waves contribute to the reaction only through the entrance channel and their contribution falls off both above and below the resonance at 430 keV. 相似文献
23.
Jonathan M. Borwein Scott B. Lindstrom Brailey Sims Anna Schneider Matthew P. Skerritt 《Set-Valued and Variational Analysis》2018,26(2):385-403
We expand upon previous work that examined the behavior of the iterated Douglas-Rachford method for a line and a circle by considering two generalizations:that of a line and an ellipse and that of a line together with a p-sphere. With computer assistance we discover a beautiful geometry that illustrates phenomena which may affect the behavior of the iterates by slowing or inhibiting convergence for feasible cases. We prove local convergence near feasible points, and—seeking a better understanding of the behavior—we employ parallelization in order to study behavior graphically. Motivated by the computer-assisted discoveries, we prove a result about behavior of the method in infeasible cases. 相似文献
24.
Burachik Regina S. Dao Minh N. Lindstrom Scott B. 《Journal of Optimization Theory and Applications》2021,189(3):744-771
Journal of Optimization Theory and Applications - We study the implications of a well-known metric inequality condition on sets to the applicability of standard necessary optimality conditions for... 相似文献
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26.
R. L. Paul R. M. Lindstrom C. Brocker E. A. Mackey 《Journal of Radioanalytical and Nuclear Chemistry》2008,278(3):697-701
A new instrument for cold neutron prompt gamma-ray activation analysis (CNPGAA) is being designed and constructed at the NIST
Center for Neutron Research (NCNR). The new instrument is expected to have lower gamma-ray and neutron background and better
detection limits for most elements than the current cold neutron PGAA instrument. Other advantages over the current facility
will include the ability to analyze larger samples and greater overall measurement capability due to the addition of scanning
stages, cryostats, and sample changers. 相似文献
27.
V. V. Litvinov A. A. Klechko J. L. Lindstrom V. P. Markevich L. I. Murin 《Journal of Applied Spectroscopy》2000,67(5):904-909
The vibrational absorption bands associated with some types of double thermal donors (TD) in Ge enriched with the oxygen isotopes 16O and 18O have been identified. The thermal donors were formed during heat treatment of Ge:O crystals at 300 and 350°C. Absorption spectra were measured at room temperature and at 10 K. The formation of the thermal donors was accompanied by the appearance of three absorption bands, which in the Ge:16O spectra at room temperature are located at 600, 740, and 780 cm–1. In low-temperature measurements, the bands at 600 and 780 cm–1 exhibited splitting into series of narrow lines (up to 9) associated with some types of thermal donors (TD1–TD9). The absorption spectra measured at 10 K after different cooling conditions display bistability of the first four types of thermal donors (TD1–TD4). In the samples cooled by illumination with light in the region of frequencies of the fundamental absorption of Ge, pairs of lines are observed that belong to the bistable thermal donors in the helium-like configuration of double donors (DD). After cooling the samples in the dark, these pairs of lines are replaced by three new bands, which belong to local vibrational modes of bistable thermal donors in the low-energy neutral configuration. Based on the isotopic shift of the local vibrational modes of the thermal donors in Ge:16O and Ge:18O, a rigorous proof of the oxygen atoms entering into the composition of thermal donors is obtained. 相似文献
28.
29.
Beavis D Bennett MJ Carroll JB Chiba J Chikanian A Crawford H Cronqvist M Dardenne Y Debbe R Doke T Engelage J Greiner L Hallman TJ Hayano RS Heckman HH Kashiwagi T Kikuchi J Kumar S Kuo C Lindstrom PJ Mitchell JW Nagamiya S Nagle JL Pope JK Stankus P Tanaka KH Welsh RC Zhan W 《Physical review letters》1995,75(17):3078-3081
30.
Harry L. Welles Jr. Michael J. Kustek Richard E. Lindstrom 《Journal of solution chemistry》1975,4(5):391-398
The apparent molal volumes of sodium chloride, sodium bromide, potassium chloride, and potassium bromide were determined for each salt at 2.000m in 8.000m urea-in-water solvent systems at 25°C. In each instance, the volumes were larger than those observed for the same salts in pure water. The volume changes on mixing the six pairs of these salts were measured at a constant ionic strength of 2m in the same urea-water solvent. The results of this test suggest that Young's rule applies equally well in urea-water solvent systems as it does in pure water. 相似文献