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41.
Dr. Antonio Caballero Laura Swan Dr. Fabiola Zapata Prof. Paul D. Beer 《Angewandte Chemie (International ed. in English)》2014,53(44):11854-11858
The first example of utilizing halogen‐bonding anion recognition to facilitate molecular motion in an interlocked structure is described. A halogen‐bonding and hydrogen‐bonding bistable rotaxane is prepared and demonstrated to undergo shuttling of the macrocycle component from the hydrogen‐bonding station to the halogen‐bonding station upon iodide recognition. In contrast, chloride‐anion binding reinforces the macrocycle to reside at the hydrogen‐bonding station. 相似文献
42.
Polubarinova-Kochina's analytical differential equation methodis used to determine the pseudo-steady-state solution to problemsinvolving the freezing (solidification) of wedges of liquidwhich are initially at their fusion temperature. In particular,we consider four distinct problems for wedges which are: freezingwith the same constant boundary temperature, freezing with thesame constant boundary heat fluxes, freezing with distinct constantboundary temperatures and freezing with distinct constant fluxesat the boundaries. For the last two problems, a Heun's differentialequation with an unknown singularity is derived, which in bothcases admits a particularly elegant simple solution for thespecial case when the wedge angle is . The moving boundariesobtained are shown pictorially. 相似文献
43.
ER Badman GE Patterson JM Wells RE Santini RG Cooks 《Journal of mass spectrometry : JMS》1999,34(8):889-894
Dual-detector differential non-destructive Fourier transform detection in a quadrupole ion trap is shown to improve signal intensity and reduce noise compared with spectra recorded using a single detector. A larger area detector in each end-cap electrode is machined to fit its hyperbolic shape and so minimize field imperfections on the z-axis. Argon, acetophenone and bromobenzene spectra were recorded to allow a comparison between single- and dual-detector (differential) modes of detection and to demonstrate the improvement achieved with differential detection. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
44.
Alves GA Amato S Anjos JC Appel JA Astorga J Bernard T Bracker SB Cremaldi LM Darling CL Dixon RL Errede D Gay C Green DR Jedicke R Karchin PE Kwan S Lueking LJ de Mello Neto JR Metheny J Milburn RH de Miranda JM da Motta Filho H Napier A Passmore D Rafatian A dos Reis AC Ross WR Santoro AF Sheaff M Souza MH Spalding WJ Stoughton C Streetman ME Summers DJ Takach SF Wallace A Wu Z 《Physical review letters》1994,72(6):812-815
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Tommy J. Mccord David R. Smith Janet K. Swan Anna M. Goebel Donald E. Thornton Criss C. Yakshe Alvie L. Davis 《Journal of heterocyclic chemistry》1979,16(6):1249-1252
Methyl 5-chloro- and 5,7-dichloro-2,1-benzisoxazole-3-carboxylates have been synthesized by treatment of o-nitromandelic and 5-chloro-2-nitroamandelic methyl esters, respectively, with thionyl chloride under appropriate reaction conditions. The structural assignments of both heterocyclic products were based on elemental and spectral analyses, and their conversion to the corresponding 5-chloro- and 5,7-dichloro substituted 2,1-benzisoxazole-3-carboxylic acids and isatins. Methyl α-chloro-o-nitrophenylacetate and o-nitrophenylcarbomethoxymethinyl sulfite were also obtained from reactions of methyl o-nitromandelate and thionyl chloride. A possible reaction mechanism involving two consecutive nucleophilic substitutions of methyl o-nitromandelate with thionyl chloride was proposed to account for the formation of methyl 5-chloro-2,1-benzisoxazole-3-carboxylate. 相似文献
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Repeated interview surveys were made in suburban residential areas of London. At six selected sites, four sets of interviews were conducted at different times of year and at a further two sites two sets of interviews were conducted during summer months. At all sites traffic noise levels were measured over 24 hours at each interview phase with a microphone 1 m from the dwelling facade at first floor level. Seasonal weather data were also collected. In the course of the repeated interviews the initial sample of 364 respondents was reduced to 222. The questionnaire included two types of noise nuisance scale, questions bearing on the typicality of road traffic conditions, and on the opening and closing of windows. The results confirm others already reported but in addition, show that if annoyance scores are averaged over repeated occasions a highly significant increase in reliability is obtained, and the proportion of score variance accounted for by noise increases significantly. No evidence was found of seasonal changes in traffic noise levels and annoyance scores did not vary significantly despite significant differences in the proportion of windows open at different times of the year. 相似文献
50.
The purpose of this paper is to discuss and if possible to dispel the industrialist's misunderstanding of operational research. The author lists some of the varied ideas held by industrialists of operational research including several which are contradictory, as for example (a) That operational research is new and revolutionary; and (b) That operational research proves nothing new and has always been practised without being so named.A number of suggestions are then made and developed, which should lead to a better understanding. These include, clearer definitions of operational research and a better adaptation of the specialized literature to the needs of industrial management, with particular emphasis on the publication of real rather than synthetic case histories. Headings of sections are: 相似文献
- 1The attitude of industrialists.
- 2The exact nature of operational research.
- 3Problems, criteria, models.
- 4The practice of operational research in business.