起止回收CO体积分数影响转炉烟气能量回收的规律分析

转炉炼钢工序转炉烟气显热、潜热回收是"负能炼钢"的核心.以某钢厂300 t顶底复吹转炉为例,建立了转炉烟气中CO、O2体积分数随吹炼时间变化的特征模型,分析了起止回收CO体积分数对转炉煤气回收量及热值、蒸汽极限回收量的影响规律.结果表明,当起止回收CO体积分数增加±1％,转炉煤气回收量减少±0.50 m3/t,热值增加±22.3 kJ/m3,蒸汽极限回收量增加±1.77 kg/t.最后从转炉煤气回收、转炉烟气高温显热回收、转炉吹炼初末期低热值煤气回收利用三个角度分析了提升转炉烟气余热余能回收利用率的途径.     

转炉高温烟气喷吹煤粉回收煤气工业试验研究

针对目前转炉煤气低热值和回收率低的问题,提出以中国宝武武钢集团鄂城钢铁有限责任公司35 t转炉煤气回收系统为研究对象来探究制备高品质转炉煤气的新工艺。通过对比不同煤粉喷吹进入转炉汽化冷却烟道内的反应效果,来研究喷吹量对转炉煤气回收质与量的影响。结果表明:在煤气回收期,喷吹煤粉时,煤气中O_2和CO_2含量降低,CO、H2含量和煤气回收总量增加,煤气热值提高。当煤粉喷吹速率为30 kg/min时,转炉煤气中O_2和CO_2体积分数分别降低63.92%和41.19%,CO和H2体积分数分别提高20.09%、240.18%,煤气回收时间增加11.40%。因此,新工艺具有提高转炉煤气回收质和量的优点。     

转炉炼钢节能的技术问题

转炉煤气回收首先要保证回收煤气中CO含量,不应降低CO含量来增加煤气回收量。转炉的设备大型化和高生产率是提高转炉炼钢热效率的关键。降低铁水比和少渣炼钢可以有效地减少能耗。优化转炉供氧技术,实现高效吹氧是合理用氧的重要内容。改进转炉钢厂的仪表对节能有重要意义。     

转炉煤气自动回收系统的研究与应用

分析了转炉煤气自动化回收系统和控制要求,认为煤气回收必须以CO和O2含量为基础条件,来确定回收时机。从西林钢铁集团有限责任公司转炉应用角度讨论了基于PLC的全自动煤气回收系统,介绍了系统构成,详述了烟气净化、成分分析、罩口微差压自动调节、风机高低速自动调节、回收放散无扰切换等控制功能。实践证明,该自动控制系统的使用,实现了转炉煤气资源再生,保证煤气质量、减少煤气燃放、确保安全运行,达到环境保护与能源综合利用的要求。     

一种转炉煤气回收气氛在线分析系统的应用介绍

本文对转炉煤气回收气氛在线分析系统的应用进行了介绍,该系统能够实时在线地分析检测转炉烟气当中的CO、O的成分含量,为煤气安全回收提供了保证,并且维护量小,可靠性高,可以长期稳定工作。     

转炉煤气回收及综合利用

应用炉口微差压技术，将RD阀的开度与吹炼规律结合起来，减少了外溢烟气量和吸人空气量，增加了回收时间。提高了所回收转炉煤气的质量。回收煤气φ（CO）达65％以上，最高达85％，实现了自动回收转炉煤气；制订了50000m^3转炉煤气柜验收标准；结合转炉煤气的特性，分析研究其组成成分及热值，开发了用户。标准状况下煤气回收量达到吨钢96m^3，最高为102m^3。     

提高转炉煤气回收与利用的措施

转炉煤气含CO约为60％～80％,平均热值约为8．8MJ／m3,是钢铁企业重要的二次能源,转炉煤气回收占整个转炉工序能源回收的80％～90％,提高转炉煤气回收与利用的水平,是实现负能炼钢的重要手段。我国钢铁企业转炉煤气回收利用与国外先进水平相比还有差距,     

提高转炉煤气回收能力的技术应用

安钢第二炼轧厂目前拥有三套转炉干法除尘系统,是目前国内较为先进的集蒸汽余热回收、转炉煤气回收、转炉粗灰回炉、转炉细灰收集和颗粒物超低排放全过程控制的冶金环保系统。为了提高转炉干法除尘系统的煤气回收能力,除了设定CO含量最低回收条件和最大风机转速外,还介绍了如何判断和处理若干常见的回收故障问题。     

转炉煤气回收规律及其影响因素研究

分析了转炉炉气成分和发生量随冶炼时间的变化规律 ,研究了转炉煤气回收量与影响因素之间的关系 ,给出了理想工况下的吨钢转炉煤气最大回收量。结果表明 ,铁水比提高1 % ,吨钢煤气回收量提高 1 0 89m3 /t;供氧强度提高 1m3 /(t·min) ,煤气回收量增加1 1 95 5m3 /t;若将煤气回收限制性条件放宽至CO≥ 3 5 %且O2 <1 % ,吨钢回收量提高1 5 2m3 /t;在理想工况下 ,转炉煤气最大回收量为 1 2 8 83m3 /t。     

钢铁冶炼新技术讲座之七 转炉炼钢新技术(四)

5煤气回收与负能炼钢5.1技术原理氧气转炉炼钢的基本化学反应是碳、硅、元素在氧化反应中放热。[C]+[O]→CO↑[Si]+[O]→SiO2氧化反应生成大量CO燃气;燃气温度(物理热)平均为1500℃￣1600℃,燃气热值(化学潜热)平均为2100kCal/Nm3,煤气波动在7￣115Nm3/t。见表1。表1转炉煤气成分、热值和回收气体量回收煤气成分/%煤气热值回收煤气量CO CO2N2H2O2kCal/Nm3/Nm3/t67.7￣71.214.4￣1513.3￣15.80.9￣1.20.1208￣218997￣115采用煤气回收装置回收转炉烟气的化学潜热;采用余热锅炉回收烟气的物理显热。当炉气回收的总热量大于炼钢厂生…     

Voices of fear and anxiety and sadness and depression: The effects of speech rate and loudness on fear and anxiety and sadness and depression.

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)     

Synthesis and analysis of mixed chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans and assessment of formation and occurrence of the fluorinated and chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans

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.     

Sexuality and aging--usual and successful

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.     

Spondylolysis and spondylolisthesis and sports

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.     

Larks and owls and health, wealth, and wisdom

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.     

Craniometaphyseal and craniodiaphyseal dysplasia, head and neck manifestations and management

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.     

深云立交桥梁检测及加固改造

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。     

关于摩尔浓度及其与硬度转换关系问题的讨论

众所周知，国际单位制物质的量采用摩尔(mol)表示，近几年出版的给排水专业书籍，为了与国际单位制接轨，逐渐将摩尔的使用频率不断提高，被给排水技术人员广泛应用的新版给排水设计手册，将表示物质浓度的单位“当量／升”或“毫克当量／升”．改为mol／l或mmol／l，虽然编者对其基本单元定义作了说明，但在实际运用上仍会出现误解，     

《儿子与情人》的语码转换与男女二元对立

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。