共查询到20条相似文献,搜索用时 62 毫秒
1.
针对杭钢1号高炉深死铁层的情况,建立了二维非稳态包括凝固潜热的炉缸、炉底传热数学模型,运用大型软件Ansys模拟计算了炉缸、炉底温度场,并根据现场实测温度建立了侵蚀模型。结果表明深死铁层设计有效地避免了炉缸、炉底异常侵蚀,有利于高炉长寿。 相似文献
2.
针对某钢厂1号高炉深死铁层的情况,建立了二维非稳态包括凝固潜热的炉缸、炉底传热数学模型,运用大型软件Ansys模拟计算了炉缸、炉底温度场,并根据现场实测温度建立了侵蚀模型,结果表明深死铁层设计有效的避免了炉缸、炉底异常侵蚀,有利于高炉长寿。 相似文献
3.
4.
石横特钢3号高炉开炉仅1年后炉缸炉底电偶温度急剧升高,为了对其侵蚀进行及时准确地监测,在原有50个测温点的基础上新增了45个测点,并根据炉缸炉底侵蚀机理研究对新增测点的位置参数进行了优化设计,进一步开发了包含凝固潜热和诊断知识库的三维非稳态侵蚀在线监测系统,实现了对炉缸炉底侵蚀内型、温度场、渣铁壳变化的在线计算,得知炉缸侧壁相同高度的圆周方向上侵蚀不规则,不同高度越靠近炉缸炉底交界侵蚀越严重,炉缸砖衬最薄剩余厚度为734mm,其原因可能是入炉碱金属负荷过高使得炉内焦炭劣化严重、炉缸中心焦堆透液性恶化,进而导致高温铁水在拐角处形成环流;由于隔热法炉底的缺点,炉底陶瓷垫整体侵蚀较严重,最薄剩余厚度为138mm。 相似文献
5.
采用有限元法求解高炉炉缸炉底侵蚀模型,利用边界单元变形方式模拟侵蚀边界,采用最小二乘法将参考点温度计算值与实际测量值的离差平方和最小值作为优化判据,修正侵蚀边界的方向及幅度,从而快速逼近实际侵蚀线位置。该模型用于推定高炉炉缸炉底1 150℃等温线的位置和形状,以便了解和分析高炉炉缸炉底侵蚀情况。模型应用结果表明,采用有限元法计算高炉炉缸炉底温度场分布,具有计算速度快、计算结果精确可靠等优点。 相似文献
6.
高炉炉缸炉底侵蚀模型的开发及应用 总被引:1,自引:0,他引:1
用有限元法建立了高炉炉缸炉底侵蚀推测二维模型,可在线提供高炉炉缸炉底温度场及侵蚀线图,为高炉安全生产,实现高炉长寿和炉缸炉底的结构参数优化设计提供了依据。 相似文献
7.
8.
9.
为了分析投产初期高炉炉缸炉底的温度分布情况,以经典传热模型为基础,采用有限元计算技术,建立了昆钢新区2 500 m~3高炉炉缸炉底侵蚀模型。本模型以高炉开炉初期温度为基础,绘制出炉缸炉底温度场分布曲线,模型计算值与热电偶实测值相比,误差在-6.52%~+7.69%的范围内,表明模型计算较为准确。根据模型计算结果,提出了加长风口小套长度、提高鼓风动能和加大死铁层厚度等工作建议,为制定高炉合理的操作维护方针和完善高炉长寿设计提供重要参考。 相似文献
10.
11.
12.
Two studies investigated the role of expressive vocal behavior (specifically, speech rate and loudness) in fear and anxiety and in sadness and depression. In the 1st study, participants spoke about personally experienced fear and anxiety-arousing and neutral events using 3 different voice styles: fast and loud, normal, and slow and soft. In the 2nd study, participants spoke about personally experienced sad or depressing and neutral events using the same 3 voice styles. In both studies, the participants' highest levels of subjective affective and cardiovascular (CV) arousal occurred when they spoke about the emotional events in a mood-congruent voice style: fast and loud in the case of fear and anxiety, and slow and soft in the case of sadness or depression. Mood-incongruent voice styles canceled the heightened levels of CV arousal normally associated with these negative emotions. The voice-style manipulation had no significant effect on the participants' levels of CV arousal during the neutral discussions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
13.
Despite the use of multimodal therapy, higher-grade glioma is still uniformly fatal in the adult population. There is a considerable difference between the length of survival in each given patient, even within the same tumor type and malignancy grade group, suggesting that there are factors that might differentially influence outcome. To identify such factors, 107 patients with anaplastic or malignant glioma were retrospectively investigated. Clinical parameters and paraclinical data on the p53, mdm2, and EGFR genes at the DNA or protein level were evaluated by univariate analysis and Cox proportional hazards regression modeling. Kaplan-Meier survival estimation demonstrated that immunohistochemical positivity for mdm2 protein in patients with anaplastic astrocytoma or with glioblastoma multiforme was associated with a shorter survival time (p = 0.02). P53 gene mutations and immunopositivity for the epidermal growth factor receptor (EGFR) protein were not significantly related to poor prognosis. The Cox proportional hazards model revealed immunohistochemical positivity for p53, mdm2, or for both of them, the presence of postoperative irradiation, and the extent of surgical resection of tumor to be variables significantly associated with prolonged survival. EGFR overexpression, age over 60 years, and Karnofsky performance score below 40 points did not significantly shorten survival time. In conclusion, the present study identified immunohistochemically detected mdm2-protein overexpression as a statistically significant negative prognostic parameter in patients bearing anaplastic or malignant glioma. Association analysis of variables revealed a possible correlation between mdm2 and p53, which is also consistent with the biological interaction mode of both proteins in vivo. 相似文献
14.
BACKGROUND: As aging research increasingly reflects an effort to dissociate true time-driven changes from those that can be improved, sexuality in later life remains largely unexplored. Several problems are evident. There is a lack of normative data, a lack of a conceptual framework relating to the biology, psychology, and sociology of sex, and an attitudinal resistance that obscures the entire topic. METHODS: We conducted a three-part instructional series on major topics involved with sexuality and aging. We surveyed our group of attendees (n 158, average age 68 for males, 65 for females) before and after the series. RESULTS: A remarkably robust sex life was evidenced by both the men and the women, even until advanced old age. Yet, a substantially decreased involvement was reported from 10 years earlier. Despite current activities, people of both sexes wished they were participating even more than they currently were. Impotency was identified as the major negative feature for the men; relationship problems were for the women. A questionnaire 6 months after the series reported improved sexual attitudes, but no change in sexual activities from the earlier survey. CONCLUSION: Sexuality is a major quality-of-life issue which persists into old age. Our study showed that the usual sexual practices reported by our group were not considered by them to be ideal. The intervention of this instructional series provided improved sexual attitudes but not performance. Additional studies are encouraged. 相似文献
15.
M Engelhardt I Reuter J Freiwald T B?hme A Halbsguth 《Canadian Metallurgical Quarterly》1997,26(9):755-759
Spondylolysis and spondylolisthesis occur predominantly in the lower lumbar spine. Besides congenital defects such as predisposition of spondylolysis the correlation between competitive sports activities and an increased incidence of spondylolysis is proved. In early stages, complete healing can be achieved by conservative treatment (abstinence from sports activities for 3 months, orthesis). Persistence of pain, neurologic symptoms and progression of vertebral slipping are indications for operative treatment (reconstruction of the isthmus, dorso-ventral spondylodesis). The exercise tolerance depends on the extent of instability, progression of vertebral slipping and clinical symptoms. The limits of exercise tolerance vary among the individual athletes and require the decision of the physician. Backstroke swimming, abdominal and back muscle strengthening exercises, and types of sport involving smooth movements are advisable. Sports education in school is possible without restriction in patients with stable spondylolysis and in those with spondylolisthesis without unfavourable concomitant factors. 相似文献
16.
OBJECTIVE: To test the validity of Benjamin Franklin's maxim "early to bed and early to rise makes a man healthy, wealthy, and wise." DESIGN: Cross sectional analysis of sleeping patterns in a nationally representative group of elderly people, and longitudinal investigation of mortality. SETTING: Eight areas in Britain (five in England, two in Scotland, and one in Wales). SUBJECTS: 1229 men and women aged 65 and over who in 1973-4 had taken part in a survey funded by the Department of Health and Social Security and for whom data on sleeping patterns, health, socioeconomic circumstances, and cognitive function had been recorded. MAIN OUTCOME MEASURES: Self reported income, access to a car, standard of accommodation, performance on a test of cognitive function, state of health and mortality during 23 years of follow up. RESULTS: 356 people (29%) were defined as larks (to bed before 11 pm and up before 8 am) and 318 (26%) were defined as owls (to bed at or after 11 pm and up at or after 8 am). There was no indication that larks were richer than those with other sleeping patterns. On the contrary, owls had the largest mean income and were more likely to have access to a car. There was also no evidence that larks were superior to those with other sleeping patterns with regard to their cognitive performance or their state of health. Both larks and owls had a slightly reduced risk of death compared with the rest of the study sample, but this was accounted for by the fact that they spent less time in bed at night. In the study sample as a whole, longer periods of time in bed were associated with increased mortality. After adjustment for age, sex, the presence of illness, and other risk factors, people who spent 12 or more hours in bed had a relative risk of death of 1.7 (1.2 to 2.5) compared with those who were in bed for 9 hours. The lowest risk occurred in people who spent 8 hours in bed (adjusted relative risk 0.8; 0.7 to 1.0). CONCLUSION: These findings do not support Franklin's claim. A "late to bed and late to rise" lifestyle does not seem to lead to socioeconomic, cognitive, or health disadvantage, but a longer time spent in bed may be associated with increased mortality. 相似文献
17.
Mechanical allodynia (MA) following hand injury is a well-documented clinical problem. The purpose of this pilot study was to examine the relationship between hand MA and the upper limb tension test (ULTT). The ULTT mechanically stresses the neural structures from the C5/6/7 neural foramina to the median nerve distally. This study examined 29 subjects with unilateral hand MA before and after a 2-week neural self-mobilization programme. There was a significant difference between the subjects' affected and unaffected sides when tested using the ULTT, both in reproduction of symptoms and in reduced range of motion of the ULTT. Following the self-mobilization program, there was an improvement in the range of the ULTT, and subjects reported a reduction in their symptoms. Complete recovery was not obtained in all cases. The results of this study suggest that the ULTT is a useful tool both in assessment and treatment of subjects with hand MA. 相似文献
18.
刘印华 《有色冶金设计与研究》2006,27(2):47-50
根据深云立交桥梁的检测结果,对该桥目前的整体状况、工作状态,及其使用情况做出综合评价,对桥的病害原因进行了分析,并提出合理的加固方案。 相似文献
19.
20.
贺冬梅 《湖南冶金职业技术学院学报》2009,9(4):46-48
劳伦斯小说《儿子与情人》一个鲜明的语言特色就是标准英语和当地方言频繁的语码转换。莫瑞尔用方言来对抗妻子,而妻子坚持用标准英语,偶尔也用方言来讽刺、挖苦丈夫。语码转换反映了劳伦斯男女二元对立的哲学思想。 相似文献