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851.
852.
In this paper we consider the formally symmetric differential expressionM [.] of any order (odd or even) ≥ 2. We characterise the dimension of the quotient spaceD(T
max)/D(T
min) associated withM[.] in terms of the behaviour of the determinants det [[f
rgs](∞)] where 1 ≤n ≤ (order of the expression +1); here [fg](∞) = lim [fg](x), where [fg](x) is the sesquilinear form in f andg associated withM. These results generalise the well-known theorem thatM is in the limit-point case at ∞ if and only if [fg](∞) = 0 for everyf, g ε the maximal domain Δ associated withM. 相似文献
853.
The large hadron collider (LHC) under construction at CERN will deliver ion beams up to centre of mass energies of the order
of 5.5 TeV per nucleon, in case of lead. If compared to the available facilities for the study of nucleus-nucleus collisions
(SpS and RHIC), this represents a huge step forward in terms of both volume and energy density that can be attained in nuclear
interactions. ALICE (a large ion collider experiment) is the only detector specifically designed for the physics of nuclear
collisions at LHC, even though it can also study high cross-section processes occurring in proton-proton collisions. The main
goal of the experiment is to observe and study the phase transition from hadronic matter to deconfined partonic matter (quark
gluon plasma —QGP). ALICE is conceived as a general-purpose detector and will address most of the phenomena related to the
QGP formation at LHC energies: for this purpose, a large fraction of the hadrons, leptons and photons produced in each interaction
will be measured and identified. 相似文献
854.
The natural abundance 13C magnetic resonance spectra of reduced proaporphines are reported, with complete assignments based on peak multiplicity and empirical calculations of chemical shifts. The chemical shift values of C-8, C-12 and C-7 are found to be strongly diagnostic of the spiro carbon configuration. 相似文献
855.
LIPOSOMAL DELIVERY OF A PHOTOSENSITIZER, BENZOPORPHYRIN DERIVATIVE MONOACID RING A (BPD), TO TUMOR TISSUE IN A MOUSE TUMOR MODEL 总被引:4,自引:0,他引:4
Anna M. Richter Elizabeth Waterfield Ashok K. Jain Alice J. Canaan Beth A. Allison Julia G. Levy 《Photochemistry and photobiology》1993,57(S1):1000-1006
Abstract— Biodistribution studies were carried out on 14 C-labeled benzoporphyrin derivative monoacid ring A (BPD), which had been formulated as a unilamellar liposome or taken from a stock solution in dimethyl sulfoxide diluted into phosphate-buffered saline immediately before intravenous injection into DBA/2 mice. By and large the general distribution of BPD to various organs and tissues was comparable for both formulations. It was noted, however, that liposomal material appeared to enter tissues more rapidly and to be cleared more rapidly, as demonstrated by shorter half-lives for a number of tissues including skin, lung and fat, and generally lower levels in most tissues 24 h following administration. Accumulation in tumor tissue was slightly higher with liposomal BPD, and clearance rates for this tissue were equivalent (half-lives 16.1 h for liposomal BPD and 16.9 h for aqueous BPD). When the two preparations were tested in a bioassay in tumor-bearing mice, photodynamic therapy (PDT) with liposomal BPD proved to be superior to the aqueous preparation when PDT was administered 3 h following intravenous administration of BPD. Plasma distribution studies in vitro demonstrated that 91.1 ± 0.3% of the liposomal BPD distributed to the lipoprotein fraction within the first hour of mixing, whereas only 49.1 ± 2.6% of nonliposomal BPD was associated with lipoprotein under the same conditions. Furthermore, while lipoprotein-associated liposomal BPD distributed evenly between all three types of lipoprotein (high, low and very low density), a majority of nonliposomal BPD associated with the high-density lipoprotein fraction. 相似文献
856.
In this article our concern is with the third Painlevé equation
d2 y /d x 2 = (1/ y )(d y /d x )2 − (1/ x )(d y /d x ) + ( αy 2 + β )/ x + γy 3 + δ / y
where α, β, γ, and δ are arbitrary constants. It is well known that this equation admits a variety of types of solution and here we classify and characterize many of these. Depending on the values of the parameters the third Painlevé equation can admit solutions that may be either expressed as the ratio of two polynomials in either x or x1/3 or related to certain Bessel functions. It is thought that all exact solutions of (1) can be categorized into one or other of these hierarchies. We show how, given a few initial solutions, it is possible to use the underlying structures of these hierarchies to obtain many other solutions. In addition, we show how this knowledge concerning the continuous third Painlevé equation (1) can be adapted and used to derive exact solutions of a suitable discretized counterpart of (1). Both the continuous and discrete solutions we find are of potential importance as it is known that the third Painlevé equation has a large number of physically significant applications. 相似文献
d
where α, β, γ, and δ are arbitrary constants. It is well known that this equation admits a variety of types of solution and here we classify and characterize many of these. Depending on the values of the parameters the third Painlevé equation can admit solutions that may be either expressed as the ratio of two polynomials in either x or x
857.
Experiments conducted at very small scales are increasingly being used to study the morphodynamics of sediment beds under
the action of flowing water. For such microscale experiments, we propose a measurement approach aimed at jointly mapping the
evolving bed topography and distribution of water depth. The proposed measurement system includes a single color camera, a
red stripe laser and green fluorescent dye. The stripe laser is scanned back and forth over the experimental surface, while
the fluorescent dye is mixed with the flowing water, allowing both the bed topography and water depth to be reconstructed
from color images. We present the steps needed for image calibration and processing, including simple models of light refraction
and attenuation. The methods are verified using a surface of known geometry, then demonstrated for a challenging groundwater
channelization experiment. For this application, co-registered maps of bed topography and water depth are obtained at millimetric
resolution for an experimental domain of 650 mm by 650 mm, at a rate of one pair of maps per minute (experimental time). The
methods are found to yield accurate results and vividly depict the evolution of a self-formed channel network. 相似文献
858.
Alice Chung-Phillips 《Journal of computational chemistry》1989,10(5):733-747
Several general procedures for the derivation and analysis of a Fourier-series expansion V(?) over computed torsional energies E(?i) are formulated. STO-3G energy values in n-butane, 1-chloropropane, and 1,2-dichloroethane are used as test data for deriving V(?) with the numerical methods of interpolation and least squares. The accuracy of each derived V(?) is assessed on the basis of calculated conformational properties, mean and rms deviations, and an error curve, V(?)–V(?)ref, where V(?)ref represents a reference set of E(?i). Results indicate that given the same number of expansion terms, interpolation and least squares yield functions of comparable accuracy; however, interpolation is a more efficient procedure for monitoring the accuracy of a function in regions of interest. In cases where there are too few input energies to achieve the desired accuracy, energy derivatives can be employed effectively for expanding the input set. In designing special-purpose functions, the error curve can be used meaningfully as a guide; an example for producing functions that are especially well behaved in regions for gauche conformations is provided. The present study continues to add systematics and rigor to the fitting of an internal rotation potential function from energy data. 相似文献
859.
860.
Gary S. Sayler Alice Layton Curtis Lajoie John Bowman Mike Tschantz James T. Fleming 《Applied biochemistry and biotechnology》1995,54(1-3):277-290
A variety of modern biotechnical approaches are available to assist in optimizing and controlling bioremediation processes.
These approaches are broad-ranging, and may include genetic engineering to improve biodegradative performance, maintenance
of the environment, and process monitoring and control. In addition to direct genetic engineering strategies, molecular diagnostic
and monitoring technology using DNA gene probing methods and new quantitative mRNA analytical procedures allows direct analysis
of degradative capacity, activity, and response underin situ conditions. Applications of these molecular approaches in process developments for trichloroethylene (TCE), polychlorinated
biphenyls (PCB), and polynuclear aromatic hydrocarbons (PAH) bio-oxidation in soils, aquifer sediments, and ground-water treatment
reactors have been demonstrated. Molecular genetic technologies permit not only the development of new processes for bioremediation,
but also new process monitoring, control strategies, and molecular optimization paradigms that take full advantage of vast
and diverse abilities of microorganisms to destroy problem chemicals. 相似文献