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Seamen usually select popular routes according to navigational and hydrographical characteristics when passing through a strait with congested traffic. In order to minimise the possibility of collisions, Principal Fairways (PFs) are commonly used by sailors. It is essential to delineate PFs quantitatively and objectively for designing or refining routing measures. In this paper, a space use method found in habitat evaluation of wildlife is applied to extract PFs of ship passages through a strait. Compared with existing methods, the proposed method helps to identify cumulative activity patterns for ship groups derived from mass ship trajectories, and provides a clearer interpretation of shifting space-use patterns within strait corridors. Moreover, it gives a better insight for directional and seasonal factor for PFs in straits. Finally, this novel method is used to extract PFs in western Taiwan Strait and its adjacent sea. The results indicate that the proposed method is helpful to identify gaps between current ship routing system plan and cumulative activity patterns recognised by real ship trajectories.

In the photosynthetic green sulfur bacterium Chlorobaculum tepidum, the baseplate mediates excitation energy transfer from the light-harvesting chlorosome to the Fenna-Matthews-Olson (FMO) complex and subsequently toward the reaction center (RC). Literature data suggest that the baseplate is a 2D lattice of BChl a-CsmA dimers. However, recently, it has been proposed, using 2D electronic spectroscopy (2DES) at 77 K, that at least four excitonically coupled BChl a are in close contact within the baseplate structure [ Dostál , J. ; et al., J. Phys. Chem. Lett. 2014 , 5 , 1743 ]. This finding is tested via hole burning (HB) spectroscopy (5 K). Our results indicate that the four excitonic states identified by 2DES likely correspond to contamination of the baseplate with the FMO antenna and possibly the RC. In contrast, HB reveals a different excitonic structure of the baseplate chromophores, where excitation is transferred to a localized trap state near 818 nm via exciton hopping, which leads to emission near 826 nm.

This paper investigates the existence and uniqueness of weak solutions to a periodic boundary value problem for a system of nonlinear wave equations with spatially dependent coefficients. Priori estimates of weak solutions are also established for the periodic boundary value problem. The arguments rely on spectral properties of the corresponding wave operator and a global inverse function theorem. The results presented in this paper extend the ones known in the literature in that eigenvalues of nonlinear perturbing terms appeared in the system of nonlinear wave equations can be chosen from the spectrum of the underlying wave operator.

This paper aims at revisiting estimates for domains of invertibility of diffeomorphisms. In contrast to previous results, we establish the estimates without the assumption of the underlying function being a diffeomorphism from its domain onto its range, and show that the arguments can be easily exploited to derive an analogous result in the framework of finite-dimensional spaces. Furthermore, the established results provide more estimates of the balls on which diffeomorphisms take place. In addition, we use these results to derive several variants of global inverse function theorem, which extend the known ones. The results presented in the paper are also applied to validate the existence of solutions for nonlinear equations.

Wetlands are an important part of the global soil organic carbon pool and microorganisms play a pivotal role in carbon exchange between soils and atmosphere. Most wetland carbon studies have focused on boreal freshwater wetlands, especially peatlands. Less attention has been paid on the estuarine wetlands where variation in tide salinity can highly affect microbiology and carbon sequestration ability of the wetland soils. In this study, two representative estuarine wetlands in the Yangtze River estuary were chosen to determine the possible differences in microbial communities and activities between coastal (high salinity) and riparian (low salinity) zones of both wetlands. Over a 4-year period, the mean soil respiration of the coastal zones was significantly lower (P

Estuarine wetlands undergoing rapid succession have high organic carbon accumulation rates due to their high primary productivity. A previous study indicated that organic carbon storage in soil differed among successional stages of the Chongming Dongtan tidal wetland due to differences in soil microbial respiration (SMR) and plant biomass. To investigate the mechanisms underlying the differences in SMR, variability in microbial and physicochemical characteristics of soil from different successional stages was studied. Bacterial community composition varied among the successional stages. Some dominant and site-specific bacteria inhabiting the tidal flat may have influenced SMR and soil carbon storage capability. Uncultured members of the Cytophagales and Pseudomonas genera, which include efficient degraders of complex organic compounds, were found primarily in the high tidal flat where the highest SMR and relatively low soil organic carbon storage were observed. Soil environment factors such as particle size, salinity, and total nitrogen (TN) may have affected microbial community composition, in particular the dominant bacterial species, and hence, SMR. The relatively small particle size, low salinity, and high TN in the high tidal flat provided suitable conditions for chemoorganotrophic bacteria such as Cytophagales and Pseudomonas species, which are specialized in the degradation of organic matter.

This work focuses on the low-temperature (5 K) photochemical (transient) hole-burned (HB) spectra within the P870 absorption band, and their theoretical analysis, for the (M)L214G mutant of the photosynthetic Rhodobacter sphaeroides bacterial reaction center (bRC). To provide insight into system-bath interactions of the bacteriochlorophyll a (BChl a) special pair, i.e., P870, in the mutated bRC, the optical line shape function for the P870 band is calculated numerically. On the basis of the modeling studies, we demonstrate that (M)L214G mutation leads to a heterogeneous population of bRCs with modified (increased) total electron-phonon coupling strength of the special pair BChl a and larger inhomogeneous broadening. Specifically, we show that after mutation in the (M)L214G bRC a large fraction (∼50%) of the bacteriopheophytin (HA) chromophores shifts red and the 800 nm absorption band broadens, while the remaining fraction of HA cofactors retains nearly the same site energy as HA in the wild-type bRC. Modeling using these two subpopulations allowed for fits of the absorption and nonresonant (transient) HB spectra of the mutant bRC in the charge neutral, oxidized, and charge-separated states using the Frenkel exciton Hamiltonian, providing new insight into the mutant's complex electronic structure. Although the average (M)L214G mutant quantum efficiency of P(+)QA(-) state formation seems to be altered in comparison with the wild-type bRC, the average electron transfer time (measured via resonant transient HB spectra within the P870 band) was not affected. Thus, mutation in the vicinity of the electron acceptor (HA) does not tune the charge separation dynamics. Finally, quenching of the (M)L214G mutant excited states by P(+) is addressed by persistent HB spectra burned within the B band in chemically oxidized samples.

We focus on problems with elucidation of site energies ( E n0) for photosynthetic complexes (PSCs) in order to raise some genuine concern regarding the conflicting estimations propagating in the literature. As an example, we provide a stern assessment of the site energies extracted from fits to optical spectra of the widely studied CP47 antenna complex of photosystem II from spinach, though many general comments apply to other PSCs as well. Correct values of E n0 for chlorophyll (Chl) a in CP47 are essential for understanding its excitonic structure, population dynamics, and excitation energy pathway(s). To demonstrate this, we present a case study where simultaneous fits of multiple spectra (absorption, emission, circular dichroism, and nonresonant hole-burned spectra) show that several sets of parameters can fit the spectra very well. Importantly, we show that variable emission maxima (690-695 nm) and sample-dependent bleaching in nonresonant hole-burning spectra reported in literature could be explained, assuming that many previously studied CP47 samples were a mixture of intact and destabilized proteins. It appears that the destabilized subpopulation of CP47 complexes could feature a weakened hydrogen bond between the 13 1 -keto group of Chl29 and the PsbH protein subunit, though other possibilities cannot be entirely excluded, as discussed in this work. Possible implications of our findings are briefly discussed.

In this paper, we use continuation technique to obtain estimates on the domain of invertibility for a diffeomorphism. We then apply these estimates to implicit function theorems. Our estimates are more feasible and sharper than those known in the literature.

The exotic species Spartina alterniflora has recently rapidly expanded in the Chongming Dongtan Nature Reserve. As a result, many technologies to control this organism have been developed. To clarify the effects of S. alterniflora invasion as well as the controlling technologies on the organic carbon reservation capability of the Chongming Dongtan Wetland, variations in soil microbial respiration (SMR) after S. alterniflora invasion and the implementation of different controlling technologies in Chongming Dongtan were analyzed, and their influencing mechanisms were studied by analyzing the soil and plant litter characteristics. The results showed that the SMR of S. alterniflora rhizosphere was 1.87 times ( P = 0.000 Phragmites communis rhizosphere, but that their annual organic matter input was almost identical. These findings implied that the organic carbon reservation capability of the S. alterniflora wetland was lower than that of the native P. communis wetland. S. alterniflora stalks more easily decayed into soil than P. communis stalks due to their lower lignin content and C/N ratio. This resulted in increased soil organic carbon (SOC) and TN content in soil of the S. alterniflora rhizosphere, which likely promoted microbial activities, thereby accelerating SMR and organic carbon output. In addition, three artificial measures for controlling the spread of S. alterniflora were found to generally improve the soil microbial activities, thereby increasing organic carbon output when compared to the control. However, when compared to other measures, the effects of mowing plus tillage and waterlogging (MTW) on soil microbial activities and SMR were relatively low owing to restriction by waterlogging. Overall, MTW was a relatively low carbon method for control of the spread of S. alterniflora .

International audience; This paper is concerned with the numerical solution of optimal control problems subject to mixed control-state constraints with differential-algebraic equations. The necessary conditions arising from a local minimum principle are transformed into an equivalent nonsmooth equation in appropriate Banach spaces. We then develop a parametric smoothing Newton method for solving this nonsmooth equation. The global and local convergence is proposed under suitable settings. Numerical examples are presented to demonstrate the efficiency of our global smoothing technique.

We investigate effective Newton-type methods for solving piecewise linear systems. We prove that under certain relaxed conditions the proposed Newton-type methods converge monotonically and have a finite termination property. Moreover, we give some conclusions on the existence of solution for the piecewise linear systems.

The semi-local convergence of a Newton-type method used to solve nonlinear equations in a Banach space is studied. We also give, as two important applications, convergence analyses of two classes of two-point Newton-type methods including a method mentioned in [5] and the midpoint method studied in [1,2,12]. Recently, interest has been shown in such methods [3,4].

Ostrowski provided the sharp sufficient condition ρ ( F ′ ( x ∗ ) ) 1 for x ∗ to be an attraction point, for a nonlinear mapping differentiable at a fixed point x ∗ [1] . This result provides no estimate for the size of the attraction ball. Recently, Catinas [2] provided such an estimate in terms of ‖ F ′ ( x ∗ ) ‖ 1 in a Holder continuity setting. We show that the results by Catinas remain valid in a weaker setting by simply replacing the Holder by the center-Holder continuity assumption. The radius of convergence of Picard’s iteration is extended, which allows a wider choice of initial guesses. Moreover the estimates of the distances ‖ x 0 − x ∗ ‖ are more precise, which lead to the computation of fewer iterates to achieve a desired accuracy. We also provide examples where our results apply, whereas those by Catinas [2] do not, or where our results are better.

In this paper, some existence and uniqueness results for generalized solutions to a periodic-Dirichlet problem for semilinear wave equations are given, using a global inverse function theorem. These results extend those known in the literature.

This paper presents some variants of the inexact Newton method for solving systems of nonlinear equations defined by locally Lipschitzian functions. These methods use variants of Newton's iteration in association with Krylov subspace methods for solving the Jacobian linear systems. Global convergence of the proposed algorithms is established under a nonmonotonic backtracking strategy. The local convergence based on the assumptions of semismoothness and BD-regularity at the solution is characterized, and the way to choose an inexact forcing sequence that preserves the rapid convergence of the proposed methods is also indicated. Numerical examples are given to show the practical viability of these approaches. Copyright © 2009 John Wiley & Sons, Ltd.

In this study we are concerned with the local convergence of a Newton-type method introduced by us [I.K. Argyros and D. Chen, On the midpoint iterative method for solving nonlinear equations in Banach spaces, Appl. Math. Lett. 5 (1992), pp. 7–9.] for approximating a solution of a nonlinear equation in a Banach space setting. This method has also been studied by Homeier [H.H.H. Homeier, A modified Newton method for rootfinding with cubic convergence, J. Comput. Appl. Math. 157 (2003), pp. 227–230.] and Ozban [A.Y. Ozban, Some new variants of Newton's method, Appl. Math. Lett. 17 (2004), pp. 677–682.] in real or complex space. The benefits of using this method over other methods using the same information have been explained in [I.K. Argyros, Computational theory of iterative methods, in Studies in Computational Mathematics, Vol. 15, C.K. Chui and L. Wuytack, eds., Elsevier Science Inc., New York, USA, 2007.; I.K. Argyros and D. Chen, On the midpoint iterative method for solving nonlinear equations in Banac...

In this paper, by employing a non-variational version of a max–min principle, new results on existence and uniqueness of generalized solution to the boundary value problem of higher order elliptic partial differential equations at resonance are given.

A class of sufficient conditions are obtained for the existence and uniqueness of solutions to the boundary value problems of semi-linear elliptic partial differential equations, using a global inverse function theorem.

A class of sufficient conditions are obtained for the existence of a unique 2 π -periodic solution of even order differential equations, employing an initial value problem.

We report measurements of the magnetic tuning and broadening of single rotational lines in the (1,0) band of the F4Δ-X4Δ transition of FeH. Since the Zeeman effect of FeH in the lowest rotational levels of the ground X4Δ state has been measured previously, the present measurements provide information on g-factors for two upper state rotational levels. The Zeeman splitting in the Q(7/2) line of the (1,0) band of the F4Δ7/2-X4Δ7/2 transition was successfully modeled using a phenomenological approach. The observation of Zeeman broadening in the corresponding R(7/2) line has also made it possible to extract an approximate g-factor for the J = 9/2 level of the F4Δ7/2(v = 1) vibronic state. The g-factors determined have been used to predict spectral patterns for numerous rotational lines in the F4Δ7/2-X4Δ7/2 system; these are compared with observed features in the sunspot umbral spectrum.

In this paper, inexact Gauss---Newton methods for nonlinear least squares problems are studied. Under the hypothesis that derivative satisfies some kinds of weak Lipschitz conditions, the local convergence properties of inexact Gauss---Newton and inexact Gauss---Newton like methods for nonlinear problems are established with the modified relative residual control. The obtained results can provide an estimate of convergence ball for inexact Gauss---Newton methods.

A class of pre-symmetric minimal residual method to solve large-scale system of linear algebraic equations with indefinite symmetrizable coefficient matrix is presented in this paper, briefly called as PSMINRES method. The PSMINRES method is established by first transforming the non-symmetric system of equations into symmetric system of equations by the pre-symmetric technique, and then utilizing the minimal residual (MINRES) method to solve the symmetric system of equations and getting a new approximation to the original system of linear equations. Theoretical analysis and numerical computations show that the pre-symmetric technique is feasible and behaviors of the PSMINRES are superior to some Krylov subspace methods, which are usual adopted for solving general non-symmetric linear systems, such as CGS, GMRES, etc.

In this paper, under the hypothesis that derivative satisfies some kinds of weak Lipschitz condition, the radius estimates of the convergence balls of secant type methods for operator equations are established in Banach space. Some applications and numerical experiments are also given.

An improved regula falsi iterative formula for solving nonlinear equations is proposed in this paper. This method is effective and promising with its third-order convergence of both the sequences of diameters and iterative points sequence.

A class of regularized conjugate gradient methods is presented for solving large-scale sparse system of linear equations of which the coefficient matrix is an ill-conditioned skew-symmetric indefinite matrix. The convergence is proved and the possible choices of the parameters involved in the new methods are discussed in detail. Preliminary numerical computations show that the numerical behaviors of the new methods are superior to those of some standard Krylov subspace methods, such as CGNE, CGS, GMRES etc.

In this study, a modification of the classical Secant method for solving nonlinear, univariate and unconstrained optimization problems based on the development of the cubic approximation is presented. The iteration formula including an approximation of the third derivative of f(x) by using the Taylor series expansion is derived. The performance of the new method is analyzed in terms of the number of iterations in comparison with the Secant methods using six test functions.

This paper presents a new class of exponential iteration methods with global convergence for finding a simple root x^* of a nonlinear equation f(x)=0 in the interval [a,b]. The new methods are shown to be quadratically convergent. Both the sequences of diameters {b"n-a"n} and the iterative sequence {x"n-x^*} are quadratically convergent to zero. The theoretical analysis and numerical experiments show that new exponential iterative formulae are effective and comparable to those of the well-known Newton and Steffensen methods.

This paper employs two new iterative methods accelerating convergence after using the classical regula falsi methods, such that both the sequence of diameters { ( b n - a n ) } n = 1 ∞ and the sequence of iteration { ( x n - x ∗ ) } n = 1 ∞ produced by the new methods quadratically converge to zero. The numerical experiments show that new methods are effective and comparable to some well-known methods.

In this paper, we obtain some new bounds for Perron root of a nonnegative matrix, which are expressed by easily calculated function in element of matrix. These new results generalize and improve the bounds of G. Frobenius [1] and H. Minc [2], and also extend the known results by Liu [6].

A class of regula falsi iterative formulae for solving nonlinear equations is proposed in this paper. Those methods are shown to be quadratic convergence. Both the sequences of diameters and iterative points sequence are quadratically convergent to zero. The numerical experiments show that new methods are effective and comparable to well-known methods.

This study describes new recombinant water-soluble chlorophyll (Chl)-binding proteins (WSCP) from Lepidium virginicum (LvWSCP). This complex binds four Chls (i.e. two dimers of Chls) per protein tetramer. We show that absorption, emission, hole-burned (HB) spectra and the shape of the zero-phonon hole (ZPH) action spectrum are consistent with the presence of uncorrelated excitation energy transfer between two Chl dimers. Thus, there is no need to include slow protein relaxation within the lowest excited state (as suggested in a previous analysis of cauliflower WSCP [Schmitt, F.-J. et al. (2008) J. Phys. Chem. B, 112, 13951; Pieper, J. et al. (2011) J. Phys. Chem. B, 115, 4053]) in order to explain the large shift observed between the maxima of the ZPH action and emission spectra. Experimental evidence is provided which shows that electron exchange between lowest energy Chls and the protein may occur, i.e. electrons can be trapped at low temperature by nearby aromatic amino acids. The latter explains the shape of nonresonant HB spectra (i.e. the absence of antihole), demonstrating that the hole-burning process in LvWSCP is largely photochemical in nature, though a small contribution from nonphotochemical hole burning (in resonant holes) is also observed.

In this paper, we study the convergence of Gauss–Newton's like method for nonlinear least squares problems. Under the hypothesis that derivative satisfies some kind of weak Lipschitz condition, we obtain the sharp estimates of the radii of convergence ball of Gauss–Newton's like method and the uniqueness ball of the solution.

Some new iterative formulae having three-order convergence are discussed in this paper. The theoretical analysis and numerical experiments show that new iterative formulae are effective and comparable to well-known method of Newton and Stefensen method.

A class of exponential iterative formulae having quadratic convergence is discussed in this paper. The theoretical analysis and numerical experiments show that new exponential iterative formulae are effective and comparable to well-known method of Newton.

Under weak Lipschitz condition, local convergence properties of inexact Newton methods and Newton-like methods for systems of nonlinear equations are established in an arbitrary vector norm. Processes with modified relative residual control are considered; the results easily provide an estimate of convergence ball for inexact methods. For a special case, the results are affine invariant. Some applications are given.

We present some sufficient and necessary conditions for convergent splitting of a non-Hermitian indefinite matrix. Some sufficient conditions to determinate a matrix with a (strongly) dominant symmetric part for a class of boundary value problem are also obtained. These results are applicable to identify the convergence of iterative methods for solving large sparse systems of linear equations.

Emission spectra of the A 2 Π 3/2 – X 2 Σ + (0, 1), (0, 0), and (1, 0) bands and the B 2 Σ + – X 2 Σ + (0, 1), (0, 0), (1, 0), (2, 0), and (3, 1) bands of ScS have been recorded in the 10 000–13 500 cm −1 region at a resolution of 0.05 cm −1 using a Fourier transform (FT) spectrometer. The A 2 Π r – X 2 Σ + (1, 0) band as well as the B 2 Σ + – X 2 Σ + (0, 0) and (1, 0) bands have been recorded at high resolution (±0.001 cm −1 ) by laser excitation spectroscopy using a supersonic molecular beam source. The FT spectral features range up to N = 148, while those recorded with the laser cover the “low- N ” regions. The lines recorded with the laser exhibit splittings due to the 45 Sc ( I = 7/2) magnetic hyperfine interactions, which are large (∼6.65 GHz) in the X 2 Σ + state and much smaller in the B 2 Σ + and A 2 Π states. The energy levels were modeled using a traditional ‘effective’ Hamiltonian approach, and improved spectroscopic constants were extracted and compared with previous determinations and theoretical predictions.

A class of modified regula falsi iterative formulae for solving nonlinear equations is presented in this paper. This method is shown to be quadratically convergent for the sequence of diameters and the sequence of iterative points. The numerical experiments show that new method is effective and comparable to well-known methods.

In this paper, a non-variational version of a max–min principle is extended, and some unique existence results for the periodic boundary value problem of the higher order nonconservative systems with resonance u ( 2 k ) ( t ) + ∑ j = 1 k A j u ( 2 j − 1 ) ( t ) + ( − 1 ) k − 1 ∇ G ( u , t ) = e ( t ) are obtained.

Doppler-free two-photon excitation spectra and the Zeeman effects for the 1021401 and 1011401 bands, whose vibrational excess energies are 3412 and 2492 cm−1, respectively, of the S1 1B2u ← S0 1A1g...

In this paper, we study the convergence of Gauss–Newton’s method for nonlinear least squares problems. Under the hypothesis that derivative satisfies some kinds of weak Lipschitz condition, we obtain the exact estimates of the radii of convergence ball of Gauss–Newton’s method and the uniqueness ball of the solution. New results can be used to determinate approximation zero of Gauss–Newton’s method.

The high resolution molecular beam laser-induced fluorescence (LIF) spectrum of the (0, 0) band of the [17.6]7.5– X 1 8.5 system of holmium monoxide, HoO, has been recorded field free and in the presence of a variable static electric field. The rotational constant, B 0 , and magnetic hyperfine structure constant, h , for the v = 0 levels of the [17.6]7.5 and X 1 8.5 states were obtained by assigning and fitting the field-free spectral features. The Stark shifts and splittings in the LIF spectra were analyzed to produce values for the magnitude of the permanent electric dipole moments, | μ |, of 3.96(6) and 4.80(5) D for [17.6]7.5, v = 0 and X 1 8.5, v = 0, respectively.