In this paper we discuss farthest-point problems in which a set or sequence S of n points in the plane is given in advance and can be preprocessed to answer various queries efficiently. First, we give a data structure that can be used to compute the point farthest from a query line segment in O(log2n) time. Our data structure needs O(nlogn) space and preprocessing time. To the best of our knowledge no solution to this problem has been suggested yet. Second, we show how to use this data structure to obtain an output-sensitive query-based algorithm for polygonal path simplification. Both results are based on a series of data structures for fundamental farthest-point queries that can be reduced to each other. 相似文献
We report the first successful deposition of triacetate-pullulan polysaccharide thin films by matrix assisted pulsed laser evaporation. We used a KrF* excimer laser source (λ = 248 nm, τ ≈ 20 ns) operated at a repetition rate of 10 Hz. We demonstrated by FTIR that our thin films are composed of triacetate-pullulan maintaining its chemical structure and functionality. The dependence on incident laser fluence of the induced surface morphology is analysed. 相似文献
This work discusses the synthesis and the fragmentation patterns for 2-(p-acetylaminosulfonamido)-2-thiono-(5,5-dimethyl-1,3,2-dioxaphosphorinane)(1) and for the p-acetylaminosulfonylamides of O,O-diethylthiophosphoric acid (2), O,O-diphenylthiophosphoric acid (3), dimethylaminocyclohexylthiophosphoric acid (4), and diethylaminophenylthiophosphoric acid (5). A thionamidic-thiolimidic structure was attributed to compounds 1-5, consistent with their IR and NMR spectra. EI mass spectra at 70 eV, high resolution (HR) mass measurements and metastable ion spectra were used to elucidate the fragmentation processes and to determine the kinetic energy release values associated with the metastable ion dissociations. HR accurate mass measurements were used to confirm the compositions of the more abundant ions. 相似文献
A new kinetic approach to flowing chemical system is introduced, based on the elimination of reaction extents attached to linearly dependent reactions. The method is applied to analyze the propagation of acoustic waves in a reacting chemical mixture.
In the present work, we explore the possibility to deposit polyaniline–silicon dioxide (PAni–SiO2) and polythiophene–silicon dioxide (PTh–SiO2) nanocomposites through a plasma polymerization route. The films were generated by spraying of mixtures of nano-sized silica particles dispersed in the liquid monomer into a plasma stream of the DC-plasma discharge reactor. The silica in the resulted polymer matrix changes the conduction mechanisms varying from ohmic to ballistic and traps inducing the space charged limited currents (SCLC). The silica modifies the morphology and composition of the deposited films. 相似文献
A new compound, CePdGa6, and its isostructural analog, LaPdGa6 have been synthesized by flux growth and characterized by single-crystal X-ray diffraction. The compounds adopt a tetragonal structure with P4/mmm space group, Z=1. The lattice parameters for CePdGa6 are and and and for LaPdGa6. Magnetic and thermal measurement have revealed that CePdGa6 is a heavy-fermion with the specific heat coefficient and Ce f moments order antiferromagnetically along c-axis at . Reconfiguration of spin occurs at to induce a ferromagnetic component only in the a-b plane. This strong anisotropy in the magnetism might be related to its unique layered structure. 相似文献
Abstract In quasi-homeotropic oriented liquid crystal cells, obtained by oblique SiO deposition on glass and surfactant added to the nematic, a continuous tilt angle versus temperature change followed by an abrupt surface transition was observed. At room temperature, the sign of the tilt angle measured from the normal to the surface depends on the SiO deposition angle. A model for the temperature dependence of the tilt angle is proposed. 相似文献
A high-precision exact-matching quadruple isotope dilution method (ID4MS) was employed for the quantitation of nitrate in an air-dried spinach powder Certified Reference Material (CRM). The analyte was extracted in hot water following addition of 15NO\({}_{3}^{-}\) internal standard. The blend was then treated with sulfamic acid to remove nitrite and with triethyloxonium tetrafluoroborate to promote aqueous conversion of nitrate into volatile EtONO2. The derivative was analyzed by headspace GC–MS with 3-min elution time. The method performance was validated with a series of tests which demonstrated adequate selectivity and ruggedness. This method supported the development of novel SPIN-1 CRM giving a modest contribution to its uncertainty (uchar = 0.85%). With respect to previous attempts, the SPIN-1 was proven stable, homogeneous (uhom = 0.44%), and suitable for spinach monitoring under EU regulations. On dried basis, the nitrate content of SPIN-1 was found to be 22.53 ± 0.43 mg/g (Uc = 1.9%, k = 2). The material was also used in an inter-laboratory study where four laboratories employed a total of ten measurement methods.