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排序方式: 共有123条查询结果,搜索用时 15 毫秒
81.
82.
We use a quality-based approach to assess contributing institutions and authors in international business (IB) research. Specifically, we use Google Scholar citations of individual articles to weigh the number of IB research articles in core IB and other non-IB elite journals. Our approach mitigates concerns about the quality difference among articles across different journals and within individual journals. We find evidence to suggest that IB research in the European and Asia-Pacific regions exhibits an upward trend over the 1995–2011 period. With respect to institutional research quality, we document that an IB program with faculty members working with their peers in foreign countries and the presence of a doctoral program can enhance an institution’s research quality. Prolific authors are very mobile and typically have global experience.  相似文献   
83.
Crystal chemistry and subsolidus phase equilibrium studies of the Ba-Nd-Cu-O system near the CuO and Nd2O3 corners have been carried cut at 950°C in air. Two solid-solution series have been identified in the Ba-Nd-Cu-O system. The first series involves the high- T c superconductor phase, and has the formula Ba2–xNd1+xCu3O6+z, where × < ≅ 0.7. At the ideal compound stoichiometry of Ba2NdCu3O6+z, the transformation from the high- T c orthorhombic to tetragonal phase occurs at 550°–575°C in air. This temperature varies as a function of composition, and at x ≅ 0.2 to 0.3 it occurs at 950°C. The second solid solution is the non-superconducting "brown phase" represented by Ba2+2x-Nd4–2xCu2–xO10–2z 0 ≤ x ≤ 0.1. Preliminary phase diagrams of the BaO–Nd2O3 and Nd2O3–CuOx systems are also presented. Standard X-ray diffraction patterns of BaNd2–CuO5 and (Nd1.9Ca0.1)CuO4–z are provided.  相似文献   
84.
Multisite recording represents a suitable condition to study microphysiology and network interactions in the central nervous system and, therefore, to understand brain functions. Several different materials and array configurations have been proposed for the development of new probes utilized to record brain activity from experimental animal models. We describe new multisite silicon probes that broaden the currently available application base for neuroscientists. The array arrangement of the probes recording sites was extended to increase their spatial resolution. Probes were integrated with a newly developed electronic hardware and novel software for advanced real-time processing and analysis. The new system, based on 32- and 64-electrode silicon probes, proved very valuable to record field potentials and single unit activity from the olfactory-limbic cortex of the in vitro isolated guinea-pig brain preparation and to acutely record unit activity at multiple sites from the cerebellar cortex in vivo. The potential advantages of the new system in comparison to the currently available technology are discussed.  相似文献   
85.
An international project was successfully completed which involved two major undertakings: (1) a round-robin to demonstrate the viability of the selected standard and (2) the certification of the lattice parameters of the SRM 1990, a Standard Reference Material® for single crystal diffractometer alignment. This SRM is a set of ≈3500 units of Cr-doped Al2O3, or ruby spheres [(0.420.011 mole fraction % Cr (expanded uncertainty)]. The round-robin consisted of determination of lattice parameters of a pair of crystals: the ruby sphere as a standard, and a zeolite reference to serve as an unknown. Fifty pairs of crystals were dispatched from Hauptman-Woodward Medical Research Institute to volunteers in x-ray laboratories world-wide. A total of 45 sets of data was received from 32 laboratories. The mean unit cell parameters of the ruby spheres was found to be a=4.7608 ű0.0062 Å, and c=12.9979 ű0.020 Å (95 % intervals of the laboratory means). The source of errors of outlier data was identified. The SRM project involved the certification of lattice parameters using four well-aligned single crystal diffractometers at (Bell Laboratories) Lucent Technologies and at NRC of Canada (39 ruby spheres), the quantification of the Cr content using a combined microprobe and SEM/EDS technique, and the evaluation of the mosaicity of the ruby spheres using a double-crystal spectrometry method. A confirmation of the lattice parameters was also conducted using a Guinier-Hägg camera. Systematic corrections of thermal expansion and refraction corrections were applied. These rubies are rhombohedral, with space group R3¯c. The certified mean unit cell parameters are a=4.76080±0.00029 Å, and c=12.99568 ű0.00087 Å (expanded uncertainty). These certified lattice parameters fall well within the results of those obtained from the international round-robin study. The Guinier-Hägg transmission measurements on five samples of powdered rubies (a=4.7610 ű0.0013 Å, and c = 12.9954 ű0.0034 Å) agreed well with the values obtained from the single crystal spheres.  相似文献   
86.
87.
This letter investigates simultaneous and proportional estimation of force in 2 degree-of-freedoms (DoFs) from intramuscular electromyography (EMG). Intramuscular EMG signals from three able-bodied subjects were recorded along with isometric forces in multiple DoF from the right arm. The association between five EMG features and force profiles was modeled using an artificial neural network. Correlation coefficients between the measured and the estimated forces were 0.85 ± 0.056 and 0.88?± 0.05 without and with post processing, respectively. The results showed that force can be estimated in 2 DoFs with high accuracy and that the degree of performance depended on the force function (task) to be estimated.  相似文献   
88.
The superconducting properties of a solid-solution region in the Ba-Y-Gd-Cu-O system were investigated as a function of composition. Phase relations, the peritectic decomposition temperature, the superconducting onset temperature ( T c), and the transport current density ( J c) were measured. The highest T c and J c are observed along the line between the stoichiometric Ba2YCu3O6+ x and Ba2GdCu3O6+ x compositions.  相似文献   
89.
90.
cADPR is a second messenger that releases Ca2+ from intracellular stores via the ryanodine receptor. Over more than 15 years, it has been controversially discussed whether cADPR also contributes to the activation of the nucleotide-gated cation channel TRPM2. While some groups have observed activation of TRPM2 by cADPR alone or in synergy with ADPR, sometimes only at 37 °C, others have argued that this is due to the contamination of cADPR by ADPR. The identification of a novel nucleotide-binding site in the N-terminus of TRPM2 that binds ADPR in a horseshoe-like conformation resembling cADPR as well as the cADPR antagonist 8-Br-cADPR, and another report that demonstrates activation of TRPM2 by binding of cADPR to the NUDT9H domain raised the question again and led us to revisit the topic. Here we show that (i) the N-terminal MHR1/2 domain and the C-terminal NUDT9H domain are required for activation of human TRPM2 by ADPR and 2′-deoxy-ADPR (2dADPR), (ii) that pure cADPR does not activate TRPM2 under a variety of conditions that have previously been shown to result in channel activation, (iii) the cADPR antagonist 8-Br-cADPR also inhibits activation of TRPM2 by ADPR, and (iv) cADPR does not bind to the MHR1/2 domain of TRPM2 while ADPR does.  相似文献   
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