Search Results - (Author, Cooperation:W. Mao)

2018-03-09

BMJ Publishing Group

0017-5749

1468-3288

Medicine

2016-04-30

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2018-01-04

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

2018-10-16

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

2018-10-16

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

1077-3118

AIP Digital Archive

Physics

A series of new intramolecular charge transfer compounds with absorption bands in shorter wavelengths have been synthesized. Bright visible light emits from the crystals of these new compounds under infrared pulsed laser pumping. The spectral and pump density dependent properties demonstrate that some of the emissions are up-conversion fluorescence due to two photon absorption. The fluorescent yields of one- and two-photon absorption are in the same order at high pump density. This work demonstrates that these new intramolecular charge transfer crystals are good candidates for nonlinear optical materials. © 1995 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Up to now, in most of the research work done on the effect of hydrogen on a Schottky barrier, the hydrogen was introduced into the semiconductor before metal deposition. This letter reports that hydrogen can be effectively introduced into the Schottky barriers (SBs) of Au/n-GaAs and Ti/n-GaAs by plasma hydrogen treatment (PHT) after metal deposition on 〈100〉 oriented n-GaAs substrates. The Schottky barrier height (SBH) of a SB containing hydrogen shows the zero/reverse bias annealing (ZBA/RBA) effect. ZBA makes the SBH decrease and RBA makes it increase. The variations in the SBHs are reversible. In order to obtain obvious ZBA/RBA effects, selection of the temperature for plasma hydrogen treatment is important, and it is indicated that 100 °C for Au/n-GaAs and 150 °C for Ti/n-GaAs are suitable temperatures. It is concluded from the analysis of experimental results that only the hydrogen located at or near the metal-semiconductor interface, rather than the hydrogen in the bulk of either the semiconductor or the metal, is responsible for the ZBA/RBA effect on SBH.

Electronic Resource

1365-246X

Blackwell Publishing Journal Backfiles 1879-2005

Geosciences

We have developed an algorithm which can, given an initial trial solution, determine simultaneously earthquake-source mechanism, hypocentre and source-time function from the inversion of broad-band waveform data of local and near-regional events (epicentral distances less than 10°).The forward modelling of the seismic ground motion is computed for frequencies up to 10 Hz by multimodal summation in layered anelastic media. The non-linear damped least-squares technique is used to minimize the difference between the theoretical and the observed seismograms in the time domain. The use of a weighting matrix and variable damping factor in each iteration avoids the problem of the ill-conditioned matrix inverse and guarantees the stability of the inverse solution. To reduce the influence of the earth model error on the inversion, for each source-receiver path the most appropriate layered earth model can be used.The algorithm has been tested against synthetic data to investigate the inversion convergence and the dependence of the solution on the fact that the assumed earth model is never equal to the true one. The synthetic tests indicate that if the earth model(s) is (are) adequate, the inversion converges rapidly to the ‘true’ solution. The sensitivity of the method to the starting model is found to be frequency dependent. The initial location can be in error by approximately the P- or S-wave wavelength and the initial source mechanism parameters can differ considerably from ‘true’model. The focal depth and source-time function depend strongly on the crustal model.Subsequently, the algorithm has been successfully applied to two events: a near-regional and a local event. The first is the 1974 March 22 event which occured in Albania, was recorded at Bari and Trieste LP stations (like WWSSN), and has been analysed using two differnt structural models based upon surface-wave dispersion measurements. The second is the Friuli event of 1987 December 27, which was recorded at five digital SP local stations, and has been analysed using a local crustal model obtained from the inversion of P- and S-wave arrival times.

Electronic Resource

1365-246X

Blackwell Publishing Journal Backfiles 1879-2005

Geosciences

The calculation of loading tides on a stratified viscoelastic self-gravitating half-space is studied. The advantages of using this model instead of the spherical model are that the crustal and upper mantle local structure can be better modelled in the near-field problems. Moreover the loss-of-precision problems caused by the cummation of high-order Love number terms can be avoided in the computation. It can be easily applied to the ocean tide and crust and upper mantle local structure inversion.The equations of motion are solved and the various Green's functions of loading tides are calculated by the solutions of the equations of motion satisfying the surface mass-load boundary conditions (stresses and perturbing potential). The results show that the effects of self-gravitation are negligible for the evaluation of loading tides for displacements, tilt and strains. However the perturbing density field contribution to the gravity Green's function is more than 30 per cent for distances greater than 3 km from the load.Following Zschau's work (1978) we give a new expression for calculating the energy dissipation for the high-order spherical harmonic contribution of the ocean loading tides.

Electronic Resource

1365-2133

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1365-2133

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background  Epidermolytic palmoplantar keratoderma (EPPK) is an autosomal dominant inherited skin disorder characterized by diffuse yellow thickening of the skin of the palms and soles, sharply bordered with erythematous margins. Histologically and ultrastructurally, EPPK presents cytolysis of keratinocytes and abnormal aggregation of tonofilaments in the suprabasal layers of the epidermis. To date, 15 different mutations of the keratin 9 gene (KRT9) have been demonstrated to cause most cases of EPPK.Objectives  To identify the KRT9 mutation in a large Chinese family with EPPK.Methods  Denaturing high-performance liquid chromatography (DHPLC), DNA sequencing and allele-specific polymerase chain reaction (AS-PCR) were used to screen exon 1 of the KRT9 gene for sequence variations.Results  The DHPLC elution profiles of the DNA fragments amplified from the affected samples differed from those obtained from unaffected individuals, indicating that a sequence variation existed within the analysed fragment of KRT9. DNA sequencing revealed a novel insertion–deletion mutation in the exon 1 of KRT9, 497delAinsGGCT, resulting in the change of tyrosine166 to tryptophan and leucine (Y166delinsWL). AS-PCR confirmed the mutation was not a common polymorphism.Conclusions  The results suggest the molecular basis of EPPK in this Chinese family and provide further evidence that mutations in the helix initiation motif of keratin 9 underlie Chinese EPPK.

Electronic Resource

0300-9629

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Electronic Resource

0300-9629

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Electronic Resource

0168-583X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

1436-5057

68Q25 ; 68R05 ; Bin packing ; approximation algorithms ; best-k-fit algorithm ; worst-case performance bound

Springer Online Journal Archives 1860-2000

Computer Science

deZusammenfassung Das Bin-Packing-Problem besteht darin, eine Liste von reellen Zahlen aus (0, 1], in Kästen (“bins”) der Kapazität 1 zu verpacken. SeiA(L) die Zahl der Kästen, die benötigt wird, wenn der ApproximationsalgorithmusA auf die ListeL angewandt wird undOPT(L) die Minimalzahl der für das Packen vonL benötigten Kästen. Sei weiterR ∞[A] der Grenzwert des VerhältnissesA(L)/OPT(L) für OPT(L)→∞ im ungünstigsten Fall. Für Best-k-Fit (kurzBkF,k≥1) zeigen wir in diesem Beitrag, daßR ∞[BkF]=1.7+3/10k.

Abstract The bin packing problem is to pack a list of reals in (0, 1] into unit-capacity bins using the minimum number of bins. LetR ∞[A] be the limiting worst value for the ratioA(L)/OPT(L) asOPT(L) goes to ∞, whereA(L) denotes the number of bins used when the approximation algorithmA is applied to the listL, andOPT(L) denotes the minimum number of bins needed to packL. For Best-k-Fit (BkF for short,k≥1), we prove in this paper thatR ∞[BkF]=1.7+3/10k.

Electronic Resource

1573-0581

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Abstract To estimate the loading correction, the convolution integral of tidal height with gravity Green's function is usually adopted. Therefore, two kinds of error sources should be discussed, i.e. errors produced by different earth models and errors due to the inaccuracy of the cotidal maps. Thus, the effect of different earth models on tidal correction was estimated by using different loading Love numbers and gravity Green function obtained on the basis of two different earth models, G-B and 1066 model. We also calculated the error caused by Schwidersky's cotidal map, by assuming the error of average tidal height to be 5 cm in 1°×1° grids, but yet the effect coming from the errors of local cotidal maps had not been taken into consideration in this work. In carrying out this calculation, the results of tidal height errors in adjacent ocean around station, harmonic coefficient errors in open ocean and a truncation error are discussed respectively.

Electronic Resource

1420-9136

Tilt ; strain ; seismicity

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Abstract Tilt and strainmeter data collected in the Friuli seismic area between 1977 and 1985 have been analyzed to study the stress-strain field and/or the elastic parameter variations in the area after the strong 1976 seismic event. We concentrated on three different frequency bands, respectively linked with the tidal waves, the seasonal effect and the secular one. The results from the first two bands point at an increase of the local rigidity modulus. Relevant stresses induced by the seasonal groundwater level variations have been found, thus supporting the hypothesis that they can act as triggering effects. The secular trend reveals significant tectonic stress modifications. It appears that the post-seismic tectonic stresses faded during 1981–1983, and were followed by a new loading phase.

Electronic Resource

1420-9136

Seismic velocity ; hypocenter location ; Friuli

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Abstract A layeredP- andS-wave velocity model is obtained for the Friuli seismic area using the arrival time data ofP- andS-waves from local earthquakes. A damped least-squares method is applied in the inversion. The data used are 994P-wave arrival times for 177 events which have epicenters in the region covered by the Friuli seismic network operated by Osservatorio Geofisico sperimentale (OGS) di Trieste, which are jointly inverted for the earthquake hypocenters andP-wave velocity model. TheS-wave velocity model is estimated on the basis of 978S-wave arrival times and the hypocenters obtained from theP-wave arrival time inversion. We also applied an approach thatP- andS-wave arrival time data are jointly used in the inversion (Roecker, 1982). The results show thatS-wave velocity structures obtained from the two methods are quite consistent, butP-wave velocity structures have obvious differences. This is apparent becauseP-waves are more sensitive to the hypocentral location thanS-waves, and the reading errors ofS-wave arrival times, which are much larger than those ofP-waves, bring large location errors in the joint inversion ofP- andS-wave arrival time. The synthetic data tests indicated that when the reading errors ofS-wave arrivals are larger than four times that ofP-wave arrivals, the method proposed in this paper seems more valid thanP- andS-wave data joint inversion. Most of the relocated events occurred in the depth range between 7 and 11 km, just above the biggest jump in velocity. This jump might be related to the detachment line hypothesized byCarulli et al. (1982). From the invertedP- andS-wave velocities, we obtain an average value 1.82 forV p /V s in the first 16 km depth.

Electronic Resource

1615-6102

Brefeldin A ; Endoplasmic reticulum ; Filamentous fungi ; Golgi ; Microtubules ; Nocodazole

Springer Online Journal Archives 1860-2000

Biology

Summary The effects of nocodazole and brefeldin A (BFA) on the growth of dikaryotic hyphae inSchizophyllum commune corresponded with the development of abnormal structures in the apical region of treated hyphae. Microtubules (MTs) were totally depolymerized after 1 h nocodazole treatment, which correlated with strong branch formation in the apical cells. One reason for branching could be the shift in the position of apical vesicles from the center to the side of the tip, observed in some nocodazole-treated hyphae. After 2 h growth in the presence of nocodazole the apical cells had malformed or swollen tips, or tips of normal shape but containing only a few apical vesicles. After 0.5 h treatment with BFA, almost all the leading hyphae had swollen apical parts in which the endoplasmic reticulum (ER) formed an interconnected network and perturbed Golgi particles were found. The orientation of MTs in the BFA-treated hyphae often followed that of the interconnected ER network, which suggested an association between MTs and ER. The results of the experiments with nocodazole suggest that, in filamentous homobasidiomycetes the subtle organization of cytoplasm necessary for the polar growth at the apex is maintained only in the presence of an intact MT cytoskeleton. The BFA experiments indicated that the secretion pathway inS. commune is sensitive to BFA. In addition rapid change in apical morphology in the BFA-treated hyphae emphasizes the importance of correct orientation of components of the secretory pathway for normal apical growth to continue.

Electronic Resource

1573-157X

Roermond ; source inversion ; regionalstructure

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Abstract The Mw = 5.4 Roermond earthquake of April 13, 1992, is used as a 'test' earthquake for the development of source inversion methods at a regional scale in Europe. We combine structural modelling of the European continent (Du et al., 1997) with two source inversion methods derived from Sileny et al. (1992), and Mao et al. (1994). We show that following this strategy, it is possible to fully analyze the inverse problem of the hypocentral relocation, source mechanism and rupture history. We define and discuss our methodology on the basis of the inverse problem and of the associated tools. The results of our application to the Roermond earthquake are discussed in the light of other previously published solutions. Such an approach appears to offer a promising tool for the global description of seismic sources in regions well studied from the structural point of view, through waveform inversion of a few regional records.

Electronic Resource