Search Results - (Author, Cooperation:Q. Cao)

2018-12-20

Institute of Physics (IOP)

1755-1307

1755-1315

Geography

Geosciences

Physics

2015-10-03

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2018-12-11

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2011-11-19

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; *Biodiversity ; Carbon Dioxide ; Carbon Isotopes ; China ; *Ecosystem ; *Extinction, Biological ; Fires ; *Fossils ; Geologic Sediments ; Invertebrates/classification ; Isotopes ; Lead ; Mass Spectrometry ; Methane ; Oceans and Seas ; Plants/classification ; Radioisotope Dilution Technique ; Radiometric Dating ; Seawater/chemistry ; Time ; Uranium ; Vertebrates/classification

2011-05-28

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2011-01-06

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Amino Acid Sequence ; Calcium-Calmodulin-Dependent Protein Kinases/metabolism ; Cloning, Molecular ; Evolution, Molecular ; Gene Duplication ; Genes, Plant ; Glomeromycota/physiology ; Lipopolysaccharides/*metabolism ; Molecular Sequence Data ; Mycorrhizae/*physiology ; Nitrogen Fixation ; Phylogeny ; Plant Proteins/genetics/*metabolism ; Plant Root Nodulation ; Protein Kinases/genetics/*metabolism ; RNA Interference ; Root Nodules, Plant/microbiology/physiology ; Signal Transduction ; Sinorhizobium/*physiology ; *Symbiosis ; Ulmaceae/genetics/*microbiology/*physiology

1089-7550

AIP Digital Archive

Physics

Pr(Fe0.6Co0.4)2 ribbons were prepared by melt spinning with different wheel speeds from 35 to 45 m/s. Their structure, magnetic properties, and thermal stability are investigated. At a wheel speed of 35 m/s, the ribbon consists of a mixture of Pr(Fe,Co)2 cubic Laves phase and some noncubic phases. An almost Pr(Fe,Co)2 nanocrystalline single phase with a Curie temperature of 305 °C is obtained at a wheel speed of 40 m/s. Except for Pr(FeCo)2 phase a small amount of amorphous phase is observed with increasing wheel speeds to 45 m/s. Pr(Fe,Co)2 phase becomes unstable and decomposes above 770 °C. The resin-bonded Pr(Fe,Co)2 nanocrystalline phase which is obtained at a wheel speed of 40 m/s combines high magnetostriction (λ(parallel)−λ⊥=140 ppm), with significant coercivity, iHc=5 kOe. © 2000 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

A series of polycrystalline bulk (La1−xSmx)2/3Sr1/3MnO3 samples over a wide composition range (x=0,0.1,0.33,...,1) was prepared by solid-phase reaction sintering technique. The x-ray diffraction pattern indicates that all the samples have an orthorhombically distorted perovskite structure. A large linear magnetostriction with a value up to −180×10−6 was observed at the temperature of 77 K under the maximum magnetic field of 1.5 T. The linear magnetostriction and magnetoresistance effect of our samples has similar dependence on the Sm content x. At room temperature, the sample with a Curie temperature of 320 K, and a Sm content of x=0.33, shows both maximum linear magnetostriction value of −40×10−6 and a maximum magnetoresistance value of −12%. © 1999 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The microstructure and Giant Magnetoresistance (GMR) in Co–Cu and Co–Ni–Cu alloy granular films prepared by dc magnetron sputtering technique was discussed. The microstructure of Co–Ni–Cu alloy granular films observed by XRD, SEM, and HRTEM examinations showed even microscopic tissue in which nanoparticles of Co–Ni were well-distributed, much different than that of Co–Cu alloy granular films in which full-grown microparticles of Co were embedded in Cu matrix. By Magnetic Hysteresis Measurement and Neel's superparamagnetism theory, the mean size of the Co–Ni particles in Co–Ni–Cu alloy granular films was estimated to be 2 to 4 nm, much smaller than that in Co–Cu alloy granular films. These results indicated that owing to the existence of Ni in Co–Ni–Cu alloy granular films the phase segregation was not a nucleation and growth process as that of Co–Cu alloy granular films but due to spinodal decomposition which was reported for the first time in granular films. It was also found that when samples dropped from room temperature to low temperature, the GMR boomed in Co–Ni–Cu alloy granular films, on the contrary to the behavior of Co–Cu alloy granular films. This fact meant that the Co–Ni–Cu alloy granular films with proper Ni content might have no response to the temperature change. Furthermore, the GMR as a function of magnetic density in Co–Ni–Cu alloy granular films is of much better linearity than that in Co–Cu alloy granular films. © 1996 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Electronic Resource

1077-3118

AIP Digital Archive

Physics

A series of bulk polycrystalline La1−xAgxMnO3 samples with x ranging nominally from 0 to 0.5 were prepared by conventional solid-state reaction processing in air. X-ray diffraction patterns show that the samples contain a single perovskite phase when x≤0.25, and are composed of two phases (a magnetic perovskite phase and a nonmagnetic Ag-rich phase) for x〉0.25. It is found that, in this series of polycrystalline samples, maximum magnetoresistance occurs for x=0.30, i.e., for a composite of the two phases whose magnetoresistance ratio is about 25.5% at room temperature. The enhancement of the magnetoresistance effect in such an inhomogeneous granular system can be attributed to the spin-dependent scattering of electrons at the interface of the two phases. © 2000 American Institute of Physics.

Electronic Resource

0888-7543

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

0925-4005

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electrical Engineering, Measurement and Control Technology

Electronic Resource

0167-2738

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0040-4039

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0040-4039

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Fig. 1 Isolation of DHIOBur from DOI by ion-exchange chromatography on a DEAE-Sephadex A-25 column (1 x 25 cm). 50 mg of sample were applied to the column, eluted using 50 ml of the initial 0.05 MTris buffer, pH 7.6, with 40% isopropanol and then eluted through a salt gradient (from 200 ml ...

Electronic Resource

1432-1971

Key words: Amplatzer septal occluder — Atrial septal defect — Three-dimensional echocardiography

Springer Online Journal Archives 1860-2000

Medicine

Abstract. Atrial septal defect (ASD) size measurement is of paramount importance for the successful deployment of a transcatheter septal occluder. The stretched balloon diameter (SBD) has long been regarded as the gold standard for selection of the size of any device. Three-dimensional (3-D) transesophageal echocardiography (TEE) can visualize the overall structure of the atrial septum, therefore rendering an accurate size of the ASD. In this study we aimed to validate the accuracy of ASD size measurement by 3-D TEE and to elucidate the reason for the difference between balloon sizing and 3-D measurement. Forty-one consecutive patients were enrolled in this protocol for ASD device closure using the Amplatzer septal occluder. Thirty-nine patients were diagnosed by 2-D transthoracic echocardiography as secundum ASD and 2 patients were diagnosed as patent foramen ovale. Two measurements of the balloon size were sequentially obtained by 2-D TEE after the balloon was fully inflated in the left atrium. First, no residual shunt across the septum could be seen while the balloon was pulled back against the septum. This measurement was called the balloon occlusive diameter (BOD). Second, with balloon deflation, a slight deformity of the balloon was seen just prior to its popping through the septum. This measurement was called the stretched balloon diameter (SBD). Three-dimensional TEE was performed in all patients at the beginning of the procedure before device deployment and within 15 minutes after device release. Three-dimensional TEE provided superior views of the ASDs, showing the spatial relationship between the ASD and the neighboring structures. For maximal ASD size measurement, balloon sizing was larger than 3-D TEE examination, whereas 2-D was smaller than the other two methods. The best correlation was found between 3-D TEE measurements and the BOD (r= 0.98, p 〈 0.0001). Three-dimensional TEE provides en face view of ASD; thus, it can accurately measure the size of ASD. Three-dimensional TEE measurement of ASD can be used instead of balloon sizing for the selection of transcatheter ASD occluder size.

Electronic Resource

1572-8897

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Mathematics

Abstract A second-order method is developed for the numerical solution of the initial-value problems $$u' \equiv du/dt = f_1 \left( {u,v} \right)$$ , $$t 〉 0$$ , $$u\left( 0 \right) = U^0 $$ and $$v' \equiv dv/dt = f_2 \left( {u,v} \right)$$ , $$t 〉 0$$ , $$v\left( 0 \right) = V^0 $$ , in which the functions $$f_1 \left( {u,v} \right) = B + u^2 v - \left( {A + 1} \right)u$$ and $$f_2 \left( {u,v} \right) = Au - u^2 v$$ , where A and B are positive real constants, are the reaction terms arising from the mathematical modelling of chemical systems such as in enzymatic reactions and plasma and laser physics in multiple coupling between modes. The method is based on three first-order methods for solving u and v, respectively. In addition to being second-order accurate in space and time, the method is seen to converge to the correct fixed point ( $$U^ * = B$$ , V* = A/B) provided $$1 - A + B^2 \geqslant 0$$ . The approach adopted is extended to solve a class of non-linear reaction–diffusion equations in two-space dimensions known as the “Brusselator” system. The algorithm is implemented in parallel using two processors, each solving a linear algebraic system as opposed to solving non-linear systems, which is often required when integrating non-linear partial differential equations (PDEs).

Electronic Resource

1573-2703

computational methods ; KP/GKP equation ; solitary waves ; stability analysis ; phase error.

Springer Online Journal Archives 1860-2000

Mathematics

Technology

Abstract Computational methods based on a linearized implicit scheme and a predictor-corrector method are proposed for the solution of the Kadomtsev–Petviashvili (KP) equation and its generalized from (GKP). The methods developed for the KP equation are applied with minor modifications to the generalized case. An inportant advantage to be gained from the use of the linearized implicit method over the predictor-corrector method which is conditionally stable, is the ability to vary the mesh length, and thereby reducing the computational time. The methods are analysed with respect to stability criteria. Numerical results portraying a single line-soliton solution and the interaction of two-line solitons are reported for the KP equation. Moreover, a lump-like soliton (a solitary wave which decays to zero in all space dimensions) and the interaction of two lump solitons are reported for the KP equation.

Electronic Resource