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1.
A novel Ni2+ optode was prepared by covalent immobilization of thionine, 3,7-diamine-5-phenothiazoniom thionineacetate, in a transparent agarose membrane. Influences of various experimental parameters on Ni2+ sensing, including the reaction time, the solution pH and the concentration of reagents were investigated. Under the optimized conditions, a linear response was obtained for Ni2+ concentrations ranging from 1.00 × 10−10 to 1.00 × 10−7 mol l−1 with an R2 value of 0.9985. The detection limit (3σ) of the method for Ni2+ was 9.30 × 10−11 mol l−1. The influence of several potentially interfering ions such as Ag+, Hg2+, Cd2+, Zn2+, Pb2+, Cu2+, Mn2+, Co3+, Cr3+, Al3+ and Fe3+ on the determination of Ni2+ was studied and no significant interference was observed. The membrane showed a good durability and short response time with no evidence of reagent leaching. The membrane was successfully applied for the determination of Ni2+ in environmental water samples.  相似文献   

2.
Ca (or Sr)TiO3:Eu3+, M (Li+ or Na+ or K+) and CaTiO3:Pr3+, M (Li+ or Na+ or Ag+ or K+ or Gd3+ or La3+) powders were prepared by combustion synthesis method and the samples were further heated to ~1000 °C to improve the crystallinity. The structure and morphology of materials were examined by X-ray diffraction (XRD) and a scanning electron microscopy (SEM). The morphologies of SrTiO3:Eu3+, CaTiO3:Eu3+ or CaTiO3:Pr3+ powders co-doped with other metal ions were very similar. Small and coagulated particles of nearly cubical shapes with small size distribution having smooth and regular surface were formed. Photo-luminescence spectra of CaTiO3:Pr3+ and co-doped either with Li+, Na+, K+, Ag+, La3+ or Gd3+ ions showed red emissions at 613 nm due to the 1D2  3H4 transition of Pr3+. The variation of intensity of emission peak with different co-doping follows the order: K+ > Ag+ > Na+ > Li+ > La3+ > Gd3+. The characteristic emissions of CaTiO3:Eu3+ lattices had strong emission at 614 and 620 nm for 5D0  7F2 with other weak transitions observed at 580, 592, 654, 705 nm for 5D0  7Fn transitions where n = 0, 1, 3, 4 respectively in all host lattices. Photoluminescence intensity in SrTiO3:Eu3+ is more than CaTiO3:Eu3+ lattices. A remarkable increase of photoluminescence intensity (in 5D0  7F2 transition) was observed if co-doped with Li+ ions in CaTiO3:Eu3+ and SrTiO3:Eu3+.  相似文献   

3.
《Calphad》2005,29(3):163-211
Predicting and characterizing the crystal structure of materials is a key problem in materials research and development. We report the results of ab initio LDA/GGA computations for the following systems: AgAu, AgCd, AgMg, AgMo1, AgNa, AgNb1, AgPd, AgRh1, AgRu1, AgTc1, AgTi, AgY, AgZr, AlSc, AuCd, AuMo1, AuNb, AuPd, AuPt1, AuRh1, AuRu1, AuSc, AuTc1, AuTi, AuY, AuZr, CdMo1, CdNb1, CdPd, CdPt, CdRh, CdRu1, CdTc1, CdTi, CdY, CdZr, CrMg1, MoNb, MoPd, MoPt, MoRh, MoRu, MoTc1, MoTi, MoY 1, MoZr, NbPd, NbPt, NbRh, NbRu, NbTc, NbY 1, NbZr1, PdPt, PdRh1, PdRu1, PdTc, PdTi, PdY, PdZr, PtRh, PtRu, PtY, PtTc, PtTi, PtZr, RhRu, RhTc, RhTi, RhY, RhZr, RuTi, RuTc, RuY, RuZr, TcTi, TcY, TcZr, TiZr1, Y Zr1 (1= systems in which the ab initio method predicts that no compounds are stable). A detailed comparison to experimental data confirms the high accuracy with which ab initio methods can predict ground states.  相似文献   

4.
Based on the method of (n,k)-universal sets, we present a deterministic parameterized algorithm for the weighted rd-matching problem with time complexity O(4(r−1)k+o(k)), improving the previous best upper bound O(4rk+o(k)). In particular, the algorithm applied to the unweighted 3d-matching problem results in a deterministic algorithm with time O(16k+o(k)), improving the previous best result O(21.26k). For the weighted r-set packing problem, we present a deterministic parameterized algorithm with time complexity O(2(2r−1)k+o(k)), improving the previous best result O(22rk+o(k)). The algorithm, when applied to the unweighted 3-set packing problem, has running time O(32k+o(k)), improving the previous best result O(43.62k+o(k)). Moreover, for the weighted r-set packing and weighted rd-matching problems, we give a kernel of size O(kr), which is the first kernelization algorithm for the problems on weighted versions.  相似文献   

5.
A strategy for dual sensing of Na+ and K+ ions using Prussian blue nanotubes via selective inter/deintercalation of K+ ion and competitive inhibition by Na+ ion, is reported. The analytical signal is derived from the cyclic voltammetry cathodic peak position Epc of Prussian blue nanotubes. Na+ and K+ levels in a sample solution can be determined conveniently using one Prussian blue nanotubes sensor. In addition, this versatile method can be applied for the analysis of single type of either Na+ or K+ ions. The dual-ion sensor response towards Na+ and K+ can be described using a model based on the competitive inhibition effects of Na+ on K+ inter/deintercalation in Prussian blue nanotubes. Successful application of the Prussian blue nanotubes sensor for Na+ and K+ determination is demonstrated in artificial saliva.  相似文献   

6.
Abstract— This paper discusses the properties of sputtered multicomponent amorphous dielectrics based on mixtures of high‐κ and high‐bandgap materials and their integration in oxide TFTs, with processing temperatures not exceeding 150°C. Even if Ta2O5 films are already amorphous, multicomponent materials such as Ta2O5—SiO2 and Ta2O5—Al2O3 allow an increase in the bandgap and the smoothness of the films, reducing their leakage current and improving (in the case of Ta2O5—SiO2) the dielectric/semiconductor interface properties when these dielectrics are integrated in TFTs. For HfO2‐ based dielectrics, the advantages of multicomponent materials are even clearer: while HfO2 films present a polycrystalline structure and a rough surface, HfO2—SiO2 films exhibit an amorphous structure and a very smooth surface. The integration of the multicomponent dielectrics in GIZO TFTs allows remarkable performance, comparable with that of GIZO TFTs using SiO2 deposited at 400°C by PECVD. For instance, with Ta2O5—SiO2 as the dielectric layer, field‐effect mobility of 35 cm2/(V‐sec), close to 0 V turn‐on voltage, an on/off ratio higher than 106, a subthreshold slope of 0.24 V/dec, and a small/recoverable threshold voltage shifts under constant current (ID= 10 μA) stress during 24 hours are achieved. Initial results with multilayers of SiO2/HfO2—SiO2/SiO2 are also shown, allowing a lower leakage current with lower thickness and excellent device performance.  相似文献   

7.
The image template matching problem is one of the fundamental problems of and has many practical applications in image processing, pattern recognition, and computer vision. It is a useful operation for filtering, edge detection, image registration, and object detection [13]. In this paper, we first design twoO[(M2/p2)log logM] andO[(M2/p2)+(M/p)log logp] time parallel image template matching algorithms on a 3-D processor array with a reconfigurable bus system usingp2N2processors with each processor containingO(1) andO(M/p) restricted memory for 1 ≤pMN, respectively, for anN×Ndigital image and anM×Mtemplate. By increasing the number of processors, these two proposed algorithms can be run inO(M2/p2) time for speeding up the time complexity usingp2M1/cN2andp2+1/cN2processors, respectively, wherecis a constant andc≥1. Furthermore, anO(1) time can be also obtained from these two proposed algorithms by usingM2+1/cN2processors. These results improve the best known bounds and achieve both optimal and optimal speed-up in their time and processor complexities.  相似文献   

8.
Abstract— Photostimulated luminescent (PSL) materials are currently used for digital storage and display in radiography. The phosphor BaFBr:Eu2+ doped with Al3+ is shown to have a very high PSL intensity, and the peak of the PSL spectrum shifts to a longer wavelength. Compared with BaFBr:Eu2+ doped with Ca2+, Sr2+, or Mg2+, BaAlFBr:Eu2+ is better suited to the stimulated light wavelength emitted by a semiconductor laser. The red‐shift mechanism is considered to be a FAcenter for BaFBr:Eu2+ doped with Ca2+, Sr2+, or Mg2+ and a FZ1 center for BaFBr:Eu2+ doped with Al3+.  相似文献   

9.
An efficient algorithm for determining the linear complexity and the minimal polynomial of a binary sequence with period 2 n p m is proposed and proved, where 2 is a primitive root modulop 2. The new algorithm generalizes the algorithm for computing the linear complexity of a binary sequence with period 2 n and the algorithm for computing the linear complexity of a binary sequence with periodp n , where 2 is a primitive root modulop 2.  相似文献   

10.
We present the R 2 D 2 redundancy detector. R 2 D 2 identifies redundant code fragments in large software systems written in Lisp. For each pair of code fragments, R 2 D 2 uses a combination of techniques ranging from syntax-based analysis to semantics-based analysis, that detects positive and negative evidences regarding the redundancy of the analyzed code fragments. These evidences are combined according to a well-defined model and sufficiently redundant fragments are reported to the user. R 2 D 2 explores several techniques and heuristics to operate within reasonable time and space bounds and is designed to be extensible.  相似文献   

11.
We present the Monte Carlo generator RacoonWW that computes cross sections to all processes e+e→4f and e+e→4 and calculates the complete electroweak radiative corrections to e+e→WW→4f in the electroweak Standard Model in double-pole approximation. The calculation of the tree-level processes e+e→4f and e+e→4 is based on the full matrix elements for massless (polarized) fermions. When calculating radiative corrections to e+e→WW→4f, the complete virtual doubly-resonant electroweak corrections are included, i.e. the factorizable and non-factorizable virtual corrections in double-pole approximation, and the real corrections are based on the full matrix elements for e+e→4. The matching of soft and collinear singularities between virtual and real corrections is done alternatively in two different ways, namely by using a subtraction method or by applying phase-space slicing. Higher-order initial-state photon radiation and naive QCD corrections are taken into account. RacoonWW also provides anomalous triple gauge-boson couplings for all processes e+e→4f and anomalous quartic gauge-boson couplings for all processes e+e→4.  相似文献   

12.
This paper presents an improved impossible differential cryptanalysis of SAFER ciphers, which uses the miss-in-the-middle technique developed by Biham et al. We analyze 3.75-round SAFER SK-64,1 using 245 chosen plaintexts, 238 bytes memory and 242 half round computations. Furthermore, the new impossible differential attack on 3.75-round SAFER+/128 uses 278 chosen plaintexts, 275 half round computations and 268 bytes memory. And attack on 3.75-round SAFER++/128 uses 278 data, 266 time, and 262 memory.  相似文献   

13.
In this study, we present the first evaluation of the MODIS (Moderate Resolution Imaging Spectroradiometer) annual net primary production (NPP) for Turkey’s forest ecosystems using field measurements. Due to lack of country scale field measurements (i.e. flux tower for forest ecosystems), tree DBH (diameter at breast height) data set provided by Ministry of Forest and Water Affairs (MFWA) of Turkey is used to calculate NPP of Turkey’s forest ecosystems. The lack of a reliable NPP data set leads the researchers to use global NPP models such as MODIS annual NPP product. The MODIS MOD17A3 product of vegetation NPP is one of the most highly used data sources for studies of global carbon cycle. However, it is still necessary to test its predictions in multiple biomes, especially for heterogeneous areas in terms of its accuracy and potential bias. Here, we studied a new approach to evaluate coarse scale NPP estimates from the MODIS NPP-MOD17A3 data product, using 2008–2013 field measurements of tree growth throughout Turkey. Three different methods were used to calculate field NPP, including standardized growth coefficients (ministry coefficients [MC]), growth coefficients from North America (Jenkins coefficients [JC]), and annual expected increment (AEI). The average NPP values for all the country is calculated as 2.06 kgC m–1/5 years (0.412 kgC m2 year1) (SD = 1.15 kgC m1/5 years) from MOD17A3, 0.90 kgC m1/5 years (0.18 kgC m2 year1) (SD = 0.57 kgC m1/5 years) with MC, 0.63 kgC m1/5 years (0.126 kgC m2 year1) (SD = 0.37 kgC m1/5 years) with JC and 0.58 kgC m2 year1 (SD = 0.29 kgC m1/5 years) with AEI for the studied plots. We found that the MODIS NPP product has a clear relation with both the NPP estimates obtained by using MC (R2 = 0.34, root mean square error (RMSE) = 1.51 kgC m1/5 years) and JC (R2 = 0.32, RMSE = 1.73 kgC m1/5 years). In addition to that, the relation between MOD17A3 product and AEI-derived NPP is relatively strong (R2 = 0.48, RMSE = 0.26 kgC m2 year1). We discuss possible reasons for these trade-offs among different methods. This study lays out a new approach to validate coarse scale MODIS product using field data directly, including for highly heterogeneous areas.  相似文献   

14.
现有的对于Piccolo算法的安全性分析结果中,除Biclique分析外,以低于穷举搜索的复杂度最长仅攻击至14轮Piccolo-80和18轮Piccolo-128算法.通过分析Piccolo算法密钥扩展的信息泄漏规律,结合算法等效结构,利用相关密钥-不可能差分分析方法,基于分割攻击思想,分别给出了15轮Piccolo-80和21轮Piccolo-128含前向白化密钥的攻击结果.当选择相关密钥量为28时,攻击所需的数据复杂度分别为258.6和262.3,存储复杂度分别为260.6和264.3,计算复杂度分别为278和282.5;在选择相关密钥量为24时,攻击所需的数据复杂度均为262.6和262.3,存储复杂度分别为264.6和264.3,计算复杂度分别为277.93和2124.45.分析结果表明,仅含前向白化密钥的15轮Piccolo-80算法和21轮Piccolo-128算法在相关密钥-不可能差分攻击下是不安全的.  相似文献   

15.
Abstract— Understanding the mechanism of blue‐light emission in Eu‐doped BAM phosphor as well as its sensitive degradation is required because this is a very important material in fluorescent lamps and plasma‐display panels. In this study, both theoretical and experimental investigations on the host emissions in BaMgAl10O17 and SrMgAl10O17 were performed. Host emissions from BaMgAl10O17 and SrMgAl10O17 by photoluminescence and thermoluminescence spectra were observed. Photoluminescence spectra suggested that the host emission from SrMgAl10O17 was easily quenched by thermal vibrations. The thermoluminescence spectra showed the existence of shallow and deep defect levels in BaMgAl10O17 and SrMgAl10O17 phosphors. It was shown that SrMgAl10O17 and its conduction plane could undergo degradation during irradiation of vacuum‐ultra‐violet (VUV) lights based on the calculated energy of formation of an oxygen vacancy. Moreover, the structural defects, such as oxygen vacancies, would cause localizing levels in the upper level in the valence band and in theconduction band. The results suggest the contribution of the host emission to the energy transfer to the Eu atoms would not be significant and the oxygen vacancies would act as the traps for excited carriers.  相似文献   

16.
The nonlinear Klein-Gordon equation describes a variety of physical phenomena such as dislocations, ferroelectric and ferromagnetic domain walls, DNA dynamics, and Josephson junctions. We derive approximate expressions for the dispersion relation of the nonlinear Klein-Gordon equation in the case of strong nonlinearities using a method based on the tension spline function and finite difference approximations. The resulting spline difference schemes are analyzed for local truncation error, stability and convergence. It has been shown that by suitably choosing the parameters, we can obtain two schemes of O(k2+k2h2+h2) and O(k2+k2h2+h4). In the end, some numerical examples are provided to demonstrate the effectiveness of the proposed schemes.  相似文献   

17.
This paper first introduces the basic notions of overall systems with logical relations, their subsystems, structure representation graphs, sets of H-structures and G-structures with logical relations S H L and S G L, immediate refinement and aggregate with logical relations, structure-graph mappings rV L, rG L, etc., and the notions of inclusiveness with logical relations, upper bounding and lower bounding with logical relations. Then it proves the sufficient conditions under which representation graphs R L form a lattice. By defining the least upper bound and largest lower bound of (RL, ) and recommending a lemma on distributivity, this paper proves the sufficient conditions under which G-structures with logical relations form Boolean lattices. Finally after defining the M-structures and C-structures with logical relations, i.e. M-structures and C-structures, this paper proposes the sufficient conditions for the uniqueness of C-structures in G-structure equivalence classes, and proves that the C L-structure is the least refined GL-structure in equivalence class S G L/r G L.  相似文献   

18.
We applied density functional calculations to study the circular redox reaction mechanism of N2O with CO catalyzed by fullerometallic cations C60Fe+ and C70Fe+. The on-top sites of six-membered rings (η6) of fullerene cages are the most preferred binding sites for Fe+ cation, and the hexagon to pentagon migration of Fe+ is unlikely under ambient thermodynamic conditions. The initial ion/molecule reaction, N2O rearrangement and N2 abstraction on the considered fullerometallic cations are easier than those on the bare Fe+ cation in the gas phase. Generally, our results indicate that fullerometallic ions, C60Fe+ and C70Fe+, are more favorable substrates for redox reaction of N2O with CO in comparison to the other previously studied carbon nanostructures such as graphene and nanotubes.  相似文献   

19.
Imposing constraints is an effective means to incorporate biological knowledge into alignment procedures. As in the PROSITE database, functional sites of proteins can be effectively described as regular expressions. In an alignment of protein sequences it is natural to expect that functional motifs should be aligned together. Due to this motivation, Arslan introduced the regular expression constrained sequence alignment problem and proposed an algorithm which, if implemented naïvely, can take time and space up to O(2|Σ|4|V|n2) and O(2|Σ|4|V|n), respectively, where Σ is the alphabet, n is the sequence length, and V is the set of states in an automaton equivalent to the input regular expression. In this paper we propose a more efficient algorithm solving this problem which takes O(3|V|n2) time and O(2|V|n) space in the worst case. If |V|=O(logn) we propose another algorithm with time complexity O(2|V|log|V|n2). The time complexity of our algorithms is independent of Σ, which is desirable in protein applications where the formulation of this problem originates; a factor of 2|Σ|=400 in the time complexity of the previously proposed algorithm would significantly affect the efficiency in practice.  相似文献   

20.
《Computers & Geosciences》2006,32(9):1479-1498
A Visual Basic program for flexible, interactive processing of ion-microprobe data acquired for quantitative trace element, 26Al–26Mg, 53Mn–53Cr, 60Fe–60Ni and U–Th–Pb geochronology applications is described. Default but editable run-tables enable software identification of secondary ion species analyzed and for characterization of the standard used. Counts obtained for each species may be displayed in plots against analysis time and edited interactively. Count outliers can be automatically identified via a set of editable count-rejection criteria and displayed for assessment. Standard analyses are distinguished from Unknowns by matching of the analysis label with a string specified in the Set-up dialog, and processed separately. A generalized routine writes background-corrected count rates, ratios and uncertainties, plus weighted means and uncertainties for Standards and Unknowns, to a spreadsheet that may be saved as a text-delimited file. Specialized routines process trace-element concentration, 26Al–26Mg, 53Mn–53Cr, 60Fe–60Ni, and Th–U disequilibrium analysis types, and U–Th–Pb isotopic data obtained for zircon, titanite, perovskite, monazite, xenotime and baddeleyite. Correction to measured Pb-isotopic, Pb/U and Pb/Th ratios for the presence of common Pb may be made using measured 204Pb counts, or the 207Pb or 208Pb counts following subtraction from these of the radiogenic component. Common-Pb corrections may be made automatically, using a (user-specified) common-Pb isotopic composition appropriate for that on the sample surface, or for that incorporated within the mineral at the time of its crystallization, depending on whether the 204Pb count rate determined for the Unknown is substantially higher than the average 204Pb count rate for all session standards. Pb/U inter-element fractionation corrections are determined using an interactive loge–loge plot of common-Pb corrected 206Pb/238U ratios against any nominated fractionation-sensitive species pair (commonly 238U16O+/238U+) for session standards. Also displayed with this plot are calculated Pb/U and Pb/Th calibration line regression slopes, y-intercepts, calibration uncertainties, standard 204Pb- and 208Pb-corrected 207Pb/206Pb dates and other parameters useful for assessment of the calibration-line data. Calibrated data for Unknowns may be automatically grouped according to calculated date and displayed in color on interactive Wetherill Concordia, Tera–Wasserburg Concordia, Linearized Gaussian (“Probability Paper”) and Gaussian-summation probability density diagrams.  相似文献   

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