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排序方式: 共有412条查询结果,搜索用时 15 毫秒
41.
Tronick E. Z.; Messinger D. S.; Weinberg M. K.; Lester B. M.; LaGasse L.; Seifer R.; Bauer C. R.; Shankaran S.; Bada H.; Wright L. L.; Poole K.; Liu J. 《Canadian Metallurgical Quarterly》2005,41(5):711
Prenatal cocaine and opiate exposure are thought to subtly compromise social and emotional development. The authors observed a large sample of 236 cocaine-exposed and 459 nonexposed infants (49 were opiate exposed and 646 nonexposed) with their mothers in the face-to-face still-face paradigm. Infant and maternal behaviors were microanalytically coded. No opiate-exposure effects were detected. However, mothers of cocaine-exposed infants showed more negative engagement than other mothers. The cocaine-exposed dyads also showed higher overall levels of mismatched engagement states than other dyads, including more negative engagement when the infants were in states of neutral engagement. Infants exposed to heavier levels of cocaine showed more passive-withdrawn negative engagement and engaged in more negative affective matching with their mothers than other infants. Although effect sizes were small, cocaine exposure, especially heavy cocaine exposure, was associated with subtly negative interchanges, which may have a cumulative impact on infants' later development and their relationships with their mothers. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
42.
Damjanovic D. Bolla H.K. Singh R. Poole K.F. Senter H.F. Narayan J. 《Semiconductor Manufacturing, IEEE Transactions on》2005,18(1):55-62
We show that UV/VUV-enhanced rapid thermal processing (RTP) in combination with single-wafer processing using a single tool for the fabrication of metal gate/high-/spl kappa/ dielectric gate stacks not only improves overall device performance, but also leads to a significant reduction in process variation at the front end of the CMOS process flow for the sub-90-nm technology node. The gate stacks were fabricated under various UV/VUV conditions. Gate stacks processed under UV/VUV radiation during all processing steps displayed low leakage currents of the order of 10/sup -11/ A/cm/sup 2/. It is shown that the Al-Al/sub 2/O/sub 3/-Si gate stacks processed under UV/VUV conditions also display the lowest variations both in mean leakage current and mean capacitance, as compared to devices where UV/VUV was not used for all the processing steps. Therefore, it can be see that reliance on successive corrective iterations common to automatic process control or standard design simulation can be reduced significantly. As a result, UV/VUV-enhanced RTP has the potential to reduce the effect of process variations on overall device performance, thereby making the overall process more cost effective and time efficient and therefore improving yield and device reliability. 相似文献
43.
Wide-band Fabry-Perot-like filters in optical fiber 总被引:6,自引:0,他引:6
Town G.E. Sugden K. Williams J.A.R. Bennion I. Poole S.B. 《Photonics Technology Letters, IEEE》1995,7(1):78-80
We report the fabrication and characterization of wide-band Fabry-Perot-like resonators in optical fiber. Using Bragg gratings with variable detuning, resonators that operate ever a wavelength span in excess of 140 nm have been produced, with free spectral ranges between 0.09 nm and 11.27 nm. Numerical and experimental results for two typical resonators are presented, showing good agreement between the two 相似文献
44.
45.
S. L. Ahlstrom D. I. Bradley S. N. Fisher A. M. Guénault E. A. Guise R. P. Haley S. Holt O. Kolosov P. V. E. McClintock G. R. Pickett M. Poole R. Schanen V. Tsepelin A. J. Woods 《Journal of Low Temperature Physics》2014,175(5-6):725-738
We describe the development of a two-dimensional quasiparticle detector for use in visualising quantum turbulence in superfluid $^3$ He-B at ultra-low temperatures. The detector consists of a $5 \times 5$ matrix of pixels, each a 1 mm diameter hole in a copper block containing a miniature quartz tuning fork. The damping on each fork provides a measure of the local quasiparticle flux. The detector is illuminated by a beam of ballistic quasiparticles generated from a nearby black-body radiator. A comparison of the damping on the different forks provides a measure of the cross-sectional profile of the beam. Further, we generate a tangle of vortices (quantum turbulence) in the path of the beam using a vibrating wire resonator. The vortices cast a shadow onto the face of the detector due to the Andreev reflection of quasiparticles in the beam. This allows us to image the vortices and to investigate their dynamics. Here we give details of the design and construction of the detector and show some preliminary results for one row of pixels which demonstrates its successful application to measuring quasiparticle beams and quantum turbulence. 相似文献
46.
Several studies have indicated that degradation of ultrahigh-molecular-weight polyethylene following gamma irradiation in air adversely affects the mechanical properties of the material; however, it is not known how this subsequently affects its wear rate. Wear studies have therefore been performed on three groups of ultrahigh-molecular-weight polyethylene; unirradiated material, recently irradiated material (aged for 2 months), and aged irradiated material (aged for 5 years). The aging took place in sterile packaging on the shelf. The wear studies were carried out on a tri-pin-on-disk wear tester, with a pin from each type of material being studied in each test. In each test the wear rate of the nonirradiated material was slightly lower than the 2-month-aged, irradiated material. The 5-year-aged, irradiated material had the highest wear rate, and this was significantly greater than that of the unirradiated material (P < .05). 相似文献
47.
K Honda E Sbisà A Tullo PA Papeo C Saccone S Poole M Pignatelli RR Mitry S Ding A Isla A Davies NA Habib 《Canadian Metallurgical Quarterly》1998,77(5):776-782
Forty-two patients with hepatocellular carcinoma (HCC) were resected and their tumours were analysed for p53 mutations by GC-clamped denaturing gradient gel electrophoresis (DGGE), single-strand conformation polymorphism (SSCP) and gene sequencing. All the exons have been analysed in this study. Eight of 12 HCCs with cirrhosis due to viral hepatitis and the two patients with sarcomatoid changes displayed p53 mutations. In contrast, no mutation was observed in the fibrolamellar variant (n = 9), non-cirrhotics (n = 13) and alcoholic cirrhosis (n = 6). The mutations observed were in exons 5-8. Two mutations were observed in codons 136 and 213 as well as a T insertion between residues 156 and 157 (exon 5) and these are reported for the first time in HCC. Likewise, the silent mutation polymorphism in codon 213 was noticed in 3 of the 42 patients. Survival analysis of these patients after surgery showed the mean and median survival in patients with wild-type p53 to be 60 and 43 months respectively. In the group with p53 mutations, the mean and median survival was 15 and 12 months. The difference was statistically significant (P= 0.003). 相似文献
48.
Renal disease is a disease closely associated with aging. Although kidney disease can occur at any age, the prevalence and severity of renal disease is far more prominent in the elderly. As the geriatric population continues to grow, nurses can anticipate treating significant numbers of elderly people with renal disease. Research suggests that with early dietary intervention the progression of renal disease can be altered. Therefore, knowledge of the characteristics and goals of diet therapy are necessary to provide effective client education and promote compliance. 相似文献
49.
GM Tozer VE Prise R Motterlini BA Poole J Wilson DJ Chaplin 《Canadian Metallurgical Quarterly》1998,42(4):849-853
The present study was undertaken to analyse the loss of heterozygosity (LOH) of the three genes, BRCA1, BRCA2 and ATM, and their correlation to clinicopathological parameters in sporadic breast cancer. We studied 59 sets of invasive ductal carcinoma, compared to matched normal control DNA. Microsatellite markers intragenic to BRCA1 (D17S1323, D17S1322, D17S855), BRCA2 (D13S1699, D13S1701, D13S1695) and ATM (D11S2179) were simultaneously used. In addition, one marker telomeric to BRCA2 (D13S1694) and four markers flanking ATM were analysed (D11S1816, D11S1819, D11S1294, D11S1818). Thirty-one per cent of the informative cases showed loss of heterozygosity for the BRCA1 gene, 22.8% for BRCA2 gene and 40% for ATM. LOH of BRCA1 correlated with high grade tumors (p=0.0005) and negative hormone receptors (p=0.01). LOH of ATM correlated with higher grade (p=0.03) and a younger age at diagnosis (p=0.03) in our set of tumors. No correlations were detected between BRCA2 LOH and any of the analysed clinicopathological parameters. However, a correlation was detected between allelic loss of the D13S1694 marker, telomeric to BRCA2, and larger tumor sizes and negative estrogen receptors, favoring the hypothesis of the presence of another putative tumor suppressor gene, telomeric to BRCA2, in the 13q12-q14 region. Only 11 tumors had LOH at more than one of the three genes, most of them (6/11) associated LOH of BRCA1 and ATM. One tumor only combined loss of the three genes BRCA1, BRCA2 and ATM. 相似文献
50.
The Harris semiconductor manufacturing systems organization has released a new environment for performing complex analyses of semiconductor manufacturing processes and IC products in its facilities worldwide. This innovative analysis toolset has increased the productivity of engineers by providing a method for complex manufacturing data reduction without the need for exhaustive training. The interactive, forms-based interface utility has also provided significant reductions in the time required to isolate parameters and identify relationships that significantly influence manufacturing yields. With little knowledge of data structures, query languages, or the underlying statistical analysis software, users of the system can access data in a variety of Harris worldwide locations and generate complex ad-hoc queries that result in statistics, histograms, box plots, and scatter plots. The more sophisticated user can enjoy the benefits of an open system. The foundation of the system is the internally developed, Unix-based manufacturing and engineering data base (MEDB). MEDB is a fully automated system for collecting and loading in-line manufacturing parameters, sample probe, wafer probe, and package test data from a variety of equipment platforms. The system is comprised of Harris proprietary database management software wrapped around the commercially available INGRES relational database product 相似文献