1,928 research outputs found
On the r-matrix structure of the hyperbolic BC(n) Sutherland model
Working in a symplectic reduction framework, we construct a dynamical
r-matrix for the classical hyperbolic BC(n) Sutherland model with three
independent coupling constants. We also examine the Lax representation of the
dynamics and its equivalence with the Hamiltonian equation of motion.Comment: 20 page
Seismic Response and Liquefaction Analysis by an Approximate Method
Presented is a simplified procedure for performing the dynamic effective stress analysis. An equivalent linear method is applied to the procedure. It is assumed, in this method, that the variations of the shear modulus and damping factor due to strain level and effective stress are independent one another. That is, firstly the total stress analysis is done in order to obtain the effective strain. Then the effective stress analysis is carried out and the moduli are varied due to the variation of the effective stress only. The accuracy of the result is checked by comparing it with that of nonlinear solution
Critical enhancement of thermopower in a chemically tuned polar semimetal MoTe
Ferroelectrics with spontaneous electric polarization play an essential role
in today's device engineering, such as capacitors and memories. Their physical
properties are further enriched by suppressing the long-range polar order, as
is exemplified by quantum paraelectrics with giant piezoelectric and dielectric
responses at low temperatures. Likewise in metals, a polar lattice distortion
has been theoretically predicted to give rise to various unusual physical
properties. So far, however, a "ferroelectric"-like transition in metals has
seldom been controlled and hence its possible impacts on transport phenomena
remain unexplored. Here we report the discovery of anomalous enhancement of
thermopower near the critical region between the polar and nonpolar metallic
phases in 1T'-MoNbTe with a chemically tunable polar
transition. It is unveiled from the first-principles calculations and
magnetotransport measurements that charge transport with strongly
energy-dependent scattering rate critically evolves towards the boundary to the
nonpolar phase, resulting in large cryogenic thermopower. Such a significant
influence of the structural instability on transport phenomena might arise from
the fluctuating or heterogeneous polar metallic states, which would pave a
novel route to improving thermoelectric efficiency.Comment: 26 pages, 4 figure
Onset of scrambling as a dynamical transition in tunable-range quantum circuits
In a fast scrambling many-body quantum system, information is spread and
entanglement is built up on a timescale that grows logarithmically with the
system size. This is of fundamental interest in understanding the dynamics of
many-body systems, as well as in efficiently producing entangled resource
states and error-correcting codes. In this work, we identify a dynamical
transition marking the onset of scrambling in quantum circuits with different
levels of long-range connectivity. In particular, we show that as a function of
the interaction range for circuits of different structures, the tripartite
mutual information exhibits a scaling collapse around a critical point between
two clearly defined regimes of different dynamical behaviour. We study this
transition analytically in a related long-range Brownian circuit model and show
how the transition can be mapped onto the statistical mechanics of a long-range
Ising model in a particular region of parameter space. This mapping predicts
mean-field critical exponents , which are consistent with the
critical exponents extracted from Clifford circuit numerics. In addition to
systems with conventional power-law interactions, we identify the same
phenomenon in deterministic, sparse circuits that can be realised in
experiments with neutral atom arrays.Comment: 19 pages, 9 figure
Spatial Graphs with Local Knots
It is shown that for any locally knotted edge of a 3-connected graph in
, there is a ball that contains all of the local knots of that edge and is
unique up to an isotopy setwise fixing the graph. This result is applied to the
study of topological symmetry groups of graphs embedded in .Comment: 20 pages, 3 figures; in v. 2 the proof of Theorem 1 has been
clarified, and other minor revisions have been mad
mu-Crystallin as an intracellular 3,5,3 '-triiodothyronine holder in vivo
ArticleMOLECULAR ENDOCRINOLOGY. 21(4): 885-894 (2007)journal articl
Reconstructions of C60 on the Ag(111)1x1 Surface
We report the scanning tunneling microscope (STM) study of the C60 adsorption on the Ag(111)1x1 surface. The well-ordered C60 monolayer with good quality was obtained by briefly annealing the multilayer C60 at approximately 300°C. It is concluded that the (2√3)x(2√3)R30° reconstruction is energetically the most stable phase, while two other phases, hex-a and hex-b phases, are also observed, rotated by approximately 12.5 ± 1.5° and 47.5 ± 1.5° with respect to the stable (2√3)x(2√3)R30° phase. It is suggested that some specific stable adsorption sites are responsible for the pinning and growth of these hex-a and hex-b phases. Orientational ordering is also documented based on the observed high resolution structures
Pharmacokinetics and tumor dynamics of the nanoparticle IT-101 from PET imaging and tumor histological measurements
IT-101, a cyclodextrin polymer-based nanoparticle containing camptothecin, is in clinical development for the treatment of cancer. Multiorgan pharmacokinetics and accumulation in tumor tissue of IT-101 is investigated by using PET. IT-101 is modified through the attachment of a 1,4,7,10-tetraazacyclododecane-1,4,7-Tris-acetic acid ligand to bind ^(64)Cu^(2+). This modification does not affect the particle size and minimally affects the surface charge of the resulting nanoparticles. PET data from ^(64)Cu-labeled IT-101 are used to quantify the in vivo biodistribution in mice bearing Neuro2A s.c. tumors. The ^(64)Cu-labeled IT-101 displays a biphasic plasma elimination. Approximately 8% of the injected dose is rapidly cleared as a low-molecular-weight fraction through the kidneys. The remaining material circulates in plasma with a terminal half-life of 13.3 h. Steadily increasing concentrations, up to 11% injected dose per cm^3, are observed in the tumor over 24 h, higher than any other tissue at that time. A 3-compartment model is used to determine vascular permeability and nanoparticle retention in tumors, and is able to accurately represent the experimental data. The calculated tumor vascular permeability indicates that the majority of nanoparticles stay intact in circulation and do not disassemble into individual polymer strands. A key assumption to modeling the tumor dynamics is that there is a “sink” for the nanoparticles within the tumor. Histological measurements using confocal microscopy show that IT-101 localizes within tumor cells and provides the sink in the tumor for the nanoparticles
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Effect of daily versus weekly home fortification with multiple micronutrient powder on haemoglobin concentration of young children in a rural area, Lao People's Democratic Republic: A randomised trial
Abstract Background Multiple micronutrient deficiencies, in particular iron deficiency anaemia (IDA) is a severe public health problem in Lao People's Democratic Republic (Lao PDR). Because of the practical difficulties encountered in improving the nutritional adequacy of traditional complementary foods and the limitations associated with the use of liquid iron supplementation for the treatment and prevention of IDA in infants and young children, recently, home-fortification with multivitamins and minerals sprinkles was recommended. This study aims to compare the effect of twice weekly versus daily supplementation with multivitamins and minerals powder (MMP) on anaemia prevalence, haemoglobin concentration, and growth in infants and young children in a rural community in Lao PDR. Methods A randomized trial was conducted in six rural communities. Children aged 6 to 52 months (n = 336) were randomly assigned to a control group (n = 110) or to one of two intervention groups receiving either two sachets per week (n = 115) or a daily sachet (n = 111) of MMP for 24 weeks; 331 children completed the study. A finger prick of blood was taken at baseline, at week 12, and again at week 24 to determine haemoglobin concentration. Anthropometric measurements were taken every 4 weeks. The McNemar test was used to assess within group differences at three time points in the study subjects with anaemia and one-way ANOVA was used to assess changes in mean haemoglobin concentration in the treatment groups. Results MMP supplementation resulted in significant improvements in haemoglobin concentration and in the reduction of anaemia prevalence in the two treatment groups compared with the control group (p <0.001). The severely to moderately anaemic children (Hb <100 g/L) on daily supplementation recovered faster than those on twice weekly supplementation. MMP was well accepted and compliance was high in both treatment groups. Overall, the improvement in the weight for age Z-score was very small and not statistically significant across the three study groups. Conclusions MMP supplementation had positive effects in reduction of anaemia prevalence and in improving haemoglobin concentration. For severely to moderately anaemic children, daily MMP supplementation was more effective in improving haemoglobin concentration and reducing anaemia prevalence. A longer intervention period is probably needed to have a positive effect on growth.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Investigation of the crystallization process of CSD-ErBCO on IBAD-substrate via DSD approach
REBaCuO (REBCO, RE: rare earth, such as Y and Gd) compounds have been extensively studied as a superconducting layer in coated conductors. Although ErBCO potentially has better superconducting properties than YBCO and GdBCO, little research has been made on it, especially in chemical solution deposition (CSD). In this work, ErBCO films were deposited on IBAD (ion-beam-assisted-deposition) substrates by CSD with low-fluorine solutions. The crystallization process was optimized to achieve the highest self-field critical current density (J) at 77 K. Commonly, for the investigation of a CSD process involving numerous process factors, one factor is changed keeping the others constant, requiring much time and cost. For more efficient investigation, this study adopted a novel design-of-experiment technique, definitive screening design (DSD), for the first time in CSD process. Two different types of solutions containing Er-propionate or Er-acetate were used to make two types of samples, Er-P and Er-A, respectively. Within the investigated range, we found that crystallization temperature, dew point, and oxygen partial pressure play a key role in Er-P, while the former two factors are significant for Er-A. DSD revealed these significant factors among six process factors with only 14 trials. Moreover, the DSD approach allowed us to create models that predict J accurately. These models revealed the optimum conditions giving the highest J values of 3.6 MA/cm for Er-P and 3.0 MA/cm for Er-A. These results indicate that DSD is an attractive approach to optimize CSD process
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