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排序方式: 共有3499条查询结果,搜索用时 15 毫秒
971.
972.
Hill Clara E.; Zack Jason S.; Wonnell Teresa L.; Hoffman Mary Ann; Rochlen Aaron B.; Goldberg Julie L.; Nakayama Emilie Y.; Heaton Kristin J.; Kelley Frances A.; Eiche Keith; Tomlinson Merideth J.; Hess Shirley 《Canadian Metallurgical Quarterly》2000,47(1):90
The authors tested whether a focus on dreams added something specific to the therapy process beyond the structure of a 3-stage approach. Fourteen distressed clients with troubling dreams and recent loss of a loved one participated in brief structured therapy focused on dreams or loss. After therapy, clients in both conditions reported being satisfied with therapy, having lowered impact of the loss, gaining new insights about themselves, and having made changes. In addition, clients in the dream condition rated the process of therapy higher, became involved in the therapeutic process more quickly, gained more understanding of their dreams, liked the structure of therapy more, and kept fewer secrets from their therapists than clients in the loss condition. In contrast, clients in the loss condition gained more insight about the effects of the past and their loss and liked therapist guidance more than clients in the dream condition. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
973.
The wireless Internet: promises and challenges 总被引:1,自引:0,他引:1
In the 1980s, the PC migrated from the hobbyist's den to the corporate desktop, a huge development in information technology. Ten years later, that honor fell to the Internet and wireless telephones, which until now have followed separate paths. The author predicts that this decade will see the convergence of wireless communications and the Internet. Although the commercial impact of wireless communications has thus far been limited to cellular telephones, the business and technical communities anticipate rapid growth in wireless data services. Almost daily, some prominent company announces plans for a “wireless e-commerce” enhancement to its business. The author examines the outlook for wireless data. Specifically, he considers the utility of wireless data services and why they have not been widely adopted until now. He also looks at the technology trends promoting wireless Internet convergence, and the obstacles preventing their implementation. As computing becomes increasingly mobile, the limitations of third-generation cellular telephony and the wireless applications protocol become increasingly apparent. The author asserts that only a new approach can make the Internet truly wireless 相似文献
974.
Margarida M. Silva Torbjörn Wigren Teresa Mendonça 《International Journal of Adaptive Control and Signal Processing》2014,28(12):1357-1371
This paper presents a modeling and identification strategy for the depth of anesthesia using the propofol and remifentanil rates as the system inputs, and the bispectral index and state entropy measurements as the systems outputs. The standard model used for this purpose has twenty two patient‐dependent parameters. This high number of parameters, the little input excitation, and the small amount of output data make classical system identification approaches unsuccessful. To overcome these issues, the new model presented in this paper has six parameters, thereby meeting the parsimony principle of system identification. An extended Kalman filter algorithm is also developed and applied to real data. The good fitting results, combined with noise suppression and a recursive update of the model parameters, are promising for the design of the depth of anesthesia controllers to be used in real time platforms. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
975.
Ioannis G. Theodorou Mary P. Ryan Teresa D. Tetley Alexandra E. Porter 《International journal of molecular sciences》2014,15(12):23936-23974
Demand for silver engineered nanomaterials (ENMs) is increasing rapidly in optoelectronic and in health and medical applications due to their antibacterial, thermal, electrical conductive, and other properties. The continued commercial up-scaling of ENM production and application needs to be accompanied by an understanding of the occupational health, public safety and environmental implications of these materials. There have been numerous in vitro studies and some in vivo studies of ENM toxicity but their results are frequently inconclusive. Some of the variability between studies has arisen due to a lack of consistency between experimental models, since small differences between test materials can markedly alter their behaviour. In addition, the propensity for the physicochemistry of silver ENMs to alter, sometimes quite radically, depending on the environment they encounter, can profoundly alter their bioreactivity. Consequently, it is important to accurately characterise the materials before use, at the point of exposure and at the nanomaterial-tissue, or “nanobio”, interface, to be able to appreciate their environmental impact. This paper reviews current literature on the pulmonary effects of silver nanomaterials. We focus our review on describing whether, and by which mechanisms, the chemistry and structure of these materials can be linked to their bioreactivity in the respiratory system. In particular, the mechanisms by which the physicochemical properties (e.g., aggregation state, morphology and chemistry) of silver nanomaterials change in various biological milieu (i.e., relevant proteins, lipids and other molecules, and biofluids, such as lung surfactant) and affect subsequent interactions with and within cells will be discussed, in the context not only of what is measured but also of what can be visualized. 相似文献
976.
Javier A. Arcibar‐Orozco Dimitrios A. Giannakoudakis Teresa J. Bandosz 《Advanced Materials Interfaces》2015,2(16)
Dimethyl chlorophosphate (DMCP) is a surrogate of G‐series organophosphate nerve agents. The destruction of DMCP over copper hydroxyl nitrate (CuON) and copper hydroxyl nitrate/graphite oxide composite (CuONGO) is studied. The extent of interactions between DMCP and the adsorbent surface is monitored by Fourier transform infrared spectroscopy in a total attenuated reflectance mode at several predetermined time exposures. Thermal analysis/mass spectrometry is also used to determine the reactive adsorption process. Here, a gradual replacement of NO3− groups by Cl− and/or CO3− indicating the mineralization of DMCP to form CuCl2 and CuCO3 is shown. Even though more DMCP is reactively adsorbed on CuON, its decomposition is faster on CuONGO. Detected NO2, which is formed as an intermediate, causes the conversion of an unevaporated DMCP liquid to H3PO4, as supported by MS results. This mineralization of DMCP happens via an indirect contact with the catalyst. Thus, CuON and CuONGO are considered as highly powerful media for the decontamination of chlorophosphate‐based nerve agents. 相似文献
977.
Agus EL Young DT Lingard JJ Smalley RJ Tate JE Goodman PS Tomlin AS 《The Science of the total environment》2007,386(1-3):65-82
Measurements of urban particle number concentrations and size distributions in the range 5-1000 nm were taken at elevated (roof-level) and roadside sampling sites on Narborough Road in Leicester, UK, along with simultaneous measurements of traffic, NO(x), CO and 1,3-butadiene concentrations and meteorological parameters. A fitting program was used to determine the characteristics of up to five modal groups present in the particle size distributions. All particle modal concentrations peaked during the morning and evening rush hours. Additional events associated with the smallest mode, that were not observed to be connected to primary emissions, were also present suggesting that this mode consisted of newly formed secondary particles. These events included peaks in concentration which coincided with peaks in solar radiation, and lower concentrations of the larger modes. Investigation into the relationships between traffic flow and occupancy indicated three flow regimes; free-flow, unstable and congested. During free-flow conditions, positive linear relationships existed between traffic flow and particle modal number concentrations. However, during unstable and congested periods, this relationship was shown to break-down. Similar trends were observed for concentrations of the gas phase pollutants NO(x), CO and 1,3-butadiene. Strong linear relationships existed between NO(x), CO, 1,3-butadiene concentrations, nucleation and Aitken mode concentrations at both sampling locations, indicating a local traffic related emission source. At the roadside, both nucleation and Aitken mode are best represented by a decreasing exponential function with wind speed, whereas at the roof-level this relationship only occurred for Aitken mode particles. The differing relationships at the two sampling locations are most likely due to a combination of meteorological factors and distance from the local emission source. 相似文献
978.
Ullate LG Godoy G Martínez O Sánchez T 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2006,53(10):1944-1954
Two-dimensional (2-D) arrays of squared matrix have maximum periodicity in their main directions; consequently, they require half wavelength (lambda/2), interelement spacing to avoid grating lobes. This condition gives rise to well-known problems derived from the huge number of array elements and from their small size. In contrast, 2-D arrays with curvilinear configuration produce lower grating lobes and, therefore, allow the element size to be increased beyond lambda/2. Using larger elements, these arrays have the advantage of reducing the number of elements and of increasing the signal-to-noise ratio (SNR). In this paper, the beamforming properties of segmented annular phased arrays are theoretically analyzed and compared with the equivalent squared matrix array. In the first part, point-like elements are considered in order to facilitate the field analysis with respect to the array structure. Afterward, the effect of the element size on the steered beam properties also is presented. In the examples, it is shown that the segmented annular array has notably lower grating lobes than the equivalent squared matrix array and that it is possible to design segmented annular arrays with interelement distance higher than lambda whose beam characteristics are perfectly valid for volumetric imaging applications. 相似文献
979.
Yonte T Sánchez-Soto LL 《Journal of the Optical Society of America. A, Optics, image science, and vision》2006,23(12):3223-3228
We characterize the reflectance peak near the Brewster angle for both an interface between two dielectric media and a single slab. To approach this problem analytically, we approximate the reflectance by a first-order diagonal Padé. In this way, we calculate the width and the skewness of the peak, and we show that although they present a well-resolved maximum they are otherwise not so markedly dependent on the refractive index. As an application of interest, we derive simple expressions for the precision of the Abelès Brewster-angle method. 相似文献
980.
Gonzalez MT Wu S Huber R van der Molen SJ Schönenberger C Calame M 《Nano letters》2006,6(10):2238-2242
We propose an objective and robust method to extract the electrical conductance of single molecules connected to metal electrodes from a set of measured conductance data. Our method roots in the physics of tunneling and is tested on octanedithiol using mechanically controllable break junctions. The single molecule conductance values can be deduced without the need for data selection. 相似文献