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181.
The chemical vapor deposition of copper and copper alloys 总被引:1,自引:0,他引:1
The chemical vapor deposition of copper and copper alloys for very large scale integrated interconnects is described using a series of Lewis base stabilized copper (I) 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato (hfac) complexes. When the Lewis base is dimethyl-1,5-cyclooctadiene, high-purity copper metal is deposited at substrate temperatures from 150 to 250 °C. The deposition rate becomes mass-transport limited at the higher substrate temperatures, but excellent filling of sub-micron vias (3:1 aspect ratio) was achieved. The deposition of copper-tin alloys can also be achieved when vinyl trialkyltin is used as the Lewis base. At 180 °C, a carbon-free copper film, containing 0.6 at.%Sn, is deposited. A very strong substrate temperature dependence towards film purity was observed and results from thermal decomposition of the tin-containing ligand. These preliminary results demonstrate the utility of using single-source, mixed-metal precursors for copper alloy formation. 相似文献
182.
Graph models for investigating behavior of mobile users in an environment with several access areas, such as cells in cellular networks, Bluetooth clusters in devices controlling ad hoc networks, or similar configurations, are presented in the paper. Based on these models, distributions of a number of communication links in different access areas are derived. 相似文献
183.
T Baldewicz K Goodkin DJ Feaster NT Blaney M Kumar A Kumar G Shor-Posner M Baum 《Canadian Metallurgical Quarterly》1998,60(3):297-308
OBJECTIVE: Previous research has demonstrated that a theoretical model including measures of life stressors, social support, and coping style significantly predicts psychological distress. This study tested plasma pyridoxine (vitamin B6) deficiency status as a predictor of overall psychological distress and specific mood states in this model, controlling for HIV-1 serostatus. METHOD: Subjects included HIV-1+ (N = 76) and HIV-1- (N = 58) recently bereaved homosexual men. At baseline, subjects completed a battery of psychosocial questionnaires, together with a physical examination and venipuncture. The Profile of Mood States (POMS) provided measures of overall psychological distress as well as specific mood states. Pyridoxine deficiency status (a categorical measure of deficient vs. adequate status) was determined with a bioassay of erythrocyte aspartate aminotransferase activity. RESULTS: Pyridoxine deficiency was a significant predictor of increased overall psychological distress in this model, controlling for life stressors, social support, coping style, and HIV-1 serostatus. In post hoc analyses of specific mood state effects, pyridoxine deficiency status was significantly associated with increases in depressed, fatigued, and confused mood levels, but not with those of anxiety, anger, or vigor. DISCUSSION: These findings suggest that adequate pyridoxine status may be necessary to avert psychological distress in the setting of bereavement. Inasmuch as pyridoxine is a cofactor for 5-hydroxytryptophan decarboxylase--an enzyme in the biosynthesis pathway of serotonin--serotonin level in the brain is implicated as the mediating factor. 相似文献
184.
A randomised-controlled trial compared outcomes for women recently diagnosed with breast cancer who either received support and information from a multidisciplinary team or used a shared decision-making programme on an interactive video disk (IVD) system. Using the IVD did not have a significant effect on the decisions women made about treatment, yet it was evaluated positively by those who used it. The results suggest that the role of clinical staff is more significant than the form of information provided. Potential benefits for the IVD were apparent such as standardising the information received by patients, promoting evidence-based practice and providing a measure for quality assurance. 相似文献
185.
Mass spectral analysis of gaseous effluents from glow discharge polymerization of propylene confirms the formation of molecular propyne as an intermediate in the polymerization reaction. Observation of oligomeric species of mass number 138 or higher at the lowest monomer feed rate of the study indicates that a certain fraction of polymerization occurs in the gas phase. 相似文献
186.
An overview of some of the issues and problems related to psychological research on AIDS and human immunodeficiency virus (HIV) infection is presented. Behavioral, cognitive, psychobiological, and neuropsychological issues are examined in relation to the development of a scientific research agenda on AIDS. The role of psychobiological variables in the etiology, treatment, and prevention of infection and disease are reviewed as they pertain to the fight against AIDS. The relation between AIDS and basic scientific processes is bidirectional in that AIDS may provide important insight into various basic processes and these same processes may also yield information useful to efforts to halt the spread of the disease. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
187.
A particularly simple geometry is considered in which an inhomogeneous and anisotropic lens is specified for the transitioning of plane waves between media of different permittivities. The permittivities of the regions outside of the lens can be constant, but the permittivity of the lens region depends on position. Results are presented for a plane wave in the second medium propagating normally to the assumed plane boundary of that medium. The results for the case of normal incidence are then generalized to the case of nonnormal incidence. The conditions of transit time conservation and impedance matching are related to the Brewster angle 相似文献
188.
We present an iterative soft-output decoding algorithm for serially concatenated coding systems. It has better performance than the conventional noniterative decoding algorithm. When applied together with an outer convolutional code to the dicode channel with partial response (1 — D), we obtain an additional coding gain of about 1 dB at a bit-error rate of 10-4 after two iterations. This new algorithm can also be applied advantageously to satellite communication and fading channels. 相似文献
189.
190.
SR Johnston BP Haynes NP Sacks JA McKinna LJ Griggs M Jarman M Baum IE Smith M Dowsett 《Canadian Metallurgical Quarterly》1993,28(3):241-250
Chronic in utero methamphetamine treatment, throughout gestation in rats, resulted in alterations in both behavior and brain monoamine function in the adult offspring. The higher dose of methamphetamine (10 mg/kg/b.i.d.) caused a significant decrease in square crossing and rearing in an open field, as well as a regional increase of serotonin and dopamine uptake sites. In contrast, the lower dose of in utero methamphetamine (2 mg/kg/b.i.d.) resulted in a significant decrease in regional densities of serotonin and dopamine uptake sites, and only decreased rearing behavior. Across treatment groups, there were significant correlations between open-field square crossing activity and the number of uptake sites in specific brain areas. Other measured behaviors, such as the neonate righting reflex and the adult Morris water maze performance, were unaffected by either in utero drug regimen. These results are discussed in terms of the known neurotoxicity of amphetamines and the ability of the immature nervous system to compensate for fetal exposure to methamphetamine. 相似文献