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121.
Joseph J. Niemela 《Journal of Low Temperature Physics》1997,109(5-6):709-732
Liquid Helium II drops, of diameter 1 mm or less, are charged with positive helium ions and subsequently levitated by static
electric fields. Stable levitation was achieved for drops of order 100–150 micrometers in diameter. The suspended drops could
be translated to arbitrary positions within the levitator using additional superimposed DC electric fields, and also could
be made to oscillate stably about their average positions by means of an applied time-varying electric field. A weak corona
discharge was used to produce the necessary ions for levitation. A novel superfluid film flow device, developed for the controlled
deployment of large charged drops, is described. Also discussed is an adjustable electric fountain that requires only a field
emission tip operating at modest potentials, and works in both Helium I and Helium II. 相似文献
122.
利用生产实践数据,分析了铁水中Si+Ti含理对炼铁焦比、产量、生铁S以及提钒时的钒回收率、钒渣品位、白灰消耗等工序指标的影响,提出了适合于承钢铁水的Si+Ti含量。 相似文献
123.
Joseph W. Burley 《乙烯基与添加剂工艺杂志》1996,2(4):282-286
Both the European and USA markets for liquid mixed metal stabilizers have moved or are moving to cadmium-free products. Self-lubricating products now dominate demanding areas such as calendering and extrusion in the European marketplace while the USA market has produced higher efficiency products by other means. In both markets, the use of organic costabilizers has played a major role in the formulation of cadmium-free products. The merits of self-lubricating technology and a new class of patented pyrrolidines are discussed here. 相似文献
124.
Lee Y.-H. Yau L.D. Hansen E. Chau R. Sabi B. Hossaini S. Asakawa B. 《Electron Devices, IEEE Transactions on》1993,40(1):163-168
It is shown that while gate oxides containing thermal/LPCVD composite oxide have lower defect densities than gates using only thermal oxides, they are more susceptible to hot-carrier degradation. The hot-carrier-induced degradation of composite oxides is worse in p-channel MOSFETs than in n-channel MOSFETs. This sensitivity of p-channel MOSFETs is caused by higher electron trapping levels in LPCVD oxides. For 150-Å gate technology, the hot-carrier-degradation resistance of thermal/LPCVD composite gate oxides with a 70-Å or thicker thermal oxide layer approaches that of high-quality pure thermal oxide 相似文献
125.
126.
AG Heriot D Kumar V Thomas M Young J Pilcher AE Joseph 《Canadian Metallurgical Quarterly》1998,85(12):1713-1715
BACKGROUND: The use of fine-needle aspiration cytology (FNAC) in the diagnosis of colonic lesions was investigated. METHODS: Some 22 patients (median age 71 years) with a colonic lesion identified on abdominal ultrasonography underwent ultrasonographically-guided FNAC using a 21-G needle. The sample was checked immediately by a cytopathologist for adequacy. RESULTS: Eighteen patients had colonic carcinoma; aspiration cytology detected malignant epithelial cells consistent with colonic carcinoma in 17 patients and severely dysplastic cells in one patient. The sensitivity and specificity of ultrasonographically-guided FNAC in the diagnosis of colonic carcinoma was 94 and 100 per cent respectively. The remaining four patients had a diagnosis of ileocaecal tuberculosis, ileocaecal Crohn's disease, and metastatic adenocarcinoma in the liver with no identifiable primary (two patients). One demonstrated granulomata, grew acid-fast bacilli and the patient was treated for tuberculosis. One had inflammatory cells and the patient was found to have Crohn's disease on histology. The remaining two patients had confirmed metastatic adenocarcinoma in the liver on aspiration cytology but suspected colonic lesions were found to be benign on cytological examination and no primary lesion was subsequently demonstrated. There were no complications of FNAC and patients complained of minimal discomfort. There has been no evidence of tumour recurrence with a median follow-up of 12 (range 1-25) months. CONCLUSION: Ultrasonographically-guided FNAC is a valid method for the diagnosis of colonic tumours. 相似文献
127.
BACKGROUND: Hepatocellular carcinoma (HCC) over 10 cm in diameter at the time of diagnosis continues to account for a number of patients undergoing hepatic resection. This study evaluated the clinicopathological features and outcome following surgery for large HCC. METHODS: Forty patients with a large HCC (greater than 10 cm) (group 1) resected between 1991 and 1996 were studied retrospectively. They were compared with 245 patients who had smaller HCCs (10 cm or less) (group 2). RESULTS: No patient in group 1 had hepatitis C infection compared with 22.9 per cent in group 2 (P=0.001). Patients in group 1 were significantly younger, had higher alpha-fetoprotein levels (16750 versus 1864 ng/ml; P < 0.001), better liver function, a higher incidence of multiple tumours (27 of 40 versus 42.0 per cent; P=0.003) and venous invasion (35 of 40 versus 52.2 per cent; P < 0.001), and underwent more major resections (37 of 40 versus 26.5 per cent; P < 0.001) than those in group 2. Morbidity and mortality rates and hospital stay were comparable in the two groups. For group 1, the 1-, 3- and 5-year disease-free survival rates were 42, 30 and 28 per cent respectively. Multiple tumours, venous invasion and impaired liver function were factors associated with recurrence. CONCLUSION: Large HCC had specific clinicopathological features. In selected patients, resection is safe and offers the chance of long-term disease-free survival. 相似文献
128.
膜淤塞对微滤的油水分离性能的影响 总被引:5,自引:0,他引:5
本文报道了用微滤分离乳化含油废水的研究,利用微滤过程中膜淤塞的特点,显著地提高了油水的分离效率,同时维持较高的水透过率。文章讨论了油水分离的机理,并根据实验结果提出流体中适当的油粒粒径分布,是获得较好分离效果的重要条件。本研究表明了在一定下,可以用水透过率较高、操作成本降低的微滤取代超滤。 相似文献
129.
130.
Lavine Howard; Huff Joseph W.; Wagner Stephen H.; Sweeney Donna 《Canadian Metallurgical Quarterly》1998,75(2):359
In 3 experiments, the authors assessed whether attitude strength moderates the susceptibility of attitudes to item context effects in surveys. In Experiment 1, respondents completed multiple measures of attitude strength. Three weeks later, respondents participated in a context experiment. Results revealed that respondents with weak attitudes exhibited significantly larger context effect for 1 of 2 issues. In Experiment 2, the results of Experiment 1 were conceptually replicated by use of measures of interattitudinal embeddedness to assess attitude strength. In Experiment 3, significant strength-moderated context effects were found when attitude strength was assessed in a multi-item, multidimensional manner but not when it was assessed with a single item. Discussion focuses on measurement and theoretical issues related to the moderation and mediation of context effects in attitude surveys. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献