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201.
T Briggs 《The Journal of organic chemistry》1970,35(5):1431-1434
202.
The EEC Commission is currently developing a system of environmental classification and mapping as an aid to regional planning in Europe. This paper describes the proposed system and discusses the method and its objectives in relation to experience gained in applying the proposals in South Yorkshire. It is argued that although the objectives of the project are laudable, the approach which has been adopted may be unrealistic due to deficiencies in the available data, lack of knowledge about the environmental systems under consideration, and some conceptual and technical shortcomings in the proposed model. 相似文献
203.
204.
Smith EF Rutten FJ Villar-Garcia IJ Briggs D Licence P 《Langmuir : the ACS journal of surfaces and colloids》2006,22(22):9386-9392
Ultra-high-vacuum (UHV)-based techniques can offer the scientist a tremendous amount of information about samples of interest. However, until recently the range of samples that could be routinely investigated using unmodified instrumentation was limited to solid samples and frozen solutions. In this paper we report the investigation of low-vapor-pressure, liquid samples using both X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. We demonstrate the suitability of UHV techniques in the investigation of a range of room-temperature ionic liquids, offering the opportunity to measure high-quality solution-phase spectra using unmodified instrumentation. 相似文献
205.
Watt AA Sambrook MR Porfyrakis K Lovett BW El Mkami H Smith GM Briggs GA 《Chemical communications (Cambridge, England)》2006,(18):1944-1946
In this communication we demonstrate a directly-bonded crystalline fullerene superlattice and show that the incorporation of spin-active N@C60 endohedral fullerenes is readily achieved to give an atomic-molecular hybrid spin-active superlattice material. 相似文献
206.
In this paper, we study the numbers D
n,k
which are defined as the number of permutations σ of the symmetric group S
n
such that σ has no cycles of length j for j ≤ k. In the case k = 1, D
n,1 is simply the number of derangements of an n-element set. As such, we shall call the numbers D
n,k
generalized derangement numbers. Garsia and Remmel [4] defined some natural q-analogues of D
n,1, denoted by D
n,1(q), which give rise to natural q-analogues of the two classical recursions of the number of derangements. The method of Garsia and Remmel can be easily extended
to give natural p, q-analogues D
n,1(p, q) which satisfy natural p, q-analogues of the two classical recursions for the number of derangements. In [4], Garsia and Remmel also suggested an approach
to define q-analogues of the numbers D
n,k
. In this paper, we show that their ideas can be extended to give a p, q-analogue of the generalized derangements numbers. Again there are two classical recursions for eneralized derangement numbers.
However, the p, q-analogues of the two classical recursions are not as straightforward when k ≥ 2.
Partially supported by NSF grant DMS 0400507. 相似文献
207.
Rebecca L. Greenaway Valentina Santolini Angeles Pulido Marc A. Little Ben M. Alston Michael E. Briggs Graeme M. Day Andrew I. Cooper Kim E. Jelfs 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(45):16421-16427
We describe the a priori computational prediction and realization of multi‐component cage pots, starting with molecular predictions based on candidate precursors through to crystal structure prediction and synthesis using robotic screening. The molecules were formed by the social self‐sorting of a tri‐topic aldehyde with both a tri‐topic amine and di‐topic amine, without using orthogonal reactivity or precursors of the same topicity. Crystal structure prediction suggested a rich polymorphic landscape, where there was an overall preference for chiral recognition to form heterochiral rather than homochiral packings, with heterochiral pairs being more likely to pack window‐to‐window to form two‐component capsules. These crystal packing preferences were then observed in experimental crystal structures. 相似文献
208.
Jamie Fairbrother Adam N. Letchford Keith Briggs 《Computational Optimization and Applications》2018,69(3):653-676
In the k -partition problem (k-PP), one is given an edge-weighted undirected graph, and one must partition the node set into at most k subsets, in order to minimise (or maximise) the total weight of the edges that have their end-nodes in the same subset. Various hierarchical variants of this problem have been studied in the context of data mining. We consider a ‘two-level’ variant that arises in mobile wireless communications. We show that an exact algorithm based on intelligent preprocessing, cutting planes and symmetry-breaking is capable of solving small- and medium-size instances to proven optimality, and providing strong lower bounds for larger instances. 相似文献
209.
We present a novel scheme for performing a conditional phase gate between two spin qubits in adjacent semiconductor quantum dots through delocalized single exciton states, formed through the interdot F?rster interaction. We consider two resonant quantum dots, each containing a single excess conduction band electron whose spin embodies the qubit. We demonstrate that both the two-qubit gate and arbitrary single-qubit rotations may be realized to a high fidelity with current semiconductor and laser technology. 相似文献
210.
Chemical reactions inside single-walled carbon nano test-tubes 总被引:3,自引:0,他引:3
Britz DA Khlobystov AN Porfyrakis K Ardavan A Briggs GA 《Chemical communications (Cambridge, England)》2005,(1):37-39
We report the application of SWNTs as templates for forming covalent polymeric chains from C(60)O reacting inside SWNTs; the resulting peapod polymer topology is different from the bulk polymer in that it is linear and unbranched. 相似文献