渣铁成分对铁水含砷量的影响

在实验室对炉渣碱度、铁水初始硫含量和温度对铁水含砷的影响进行研究。结果表明,在试验条件下,铁水含砷量随着二元碱度的增大而增高;碱度超过1.16之后生铁中砷含量变化减缓,改变碱度对生铁砷含量影响已不明显;增大炉渣碱度有利于炉渣脱砷,但不宜过大。随着生铁中初始硫含量的增加,铁水中砷含量也随之增加,说明炉渣脱砷率下降。所以,在相同条件下生铁含硫高则含砷也高,在实际生产中应尽量降低[S],控制生铁含硫在一定意义上也就控制了砷含量。在1 400~1 550℃温度范围内,炉渣脱砷率随温度的升高而降低;温度超过1 475℃后,脱砷率降低幅度变得更显著。     

炼铁工序铁素流的系统动力学分析

运用系统动力学原理,采用因果关系和存量流量分析方法,在相对宏观的层面构建了钢铁生产流程炼铁工序的铁素流动态模型。仿真结果准确,验证了所建炼铁工序系统动力学模型的正确性并分析了不同返回情况下高炉铁素、铁水铁素流和损失铁素流的动态特性。计算结果表明:从物料投入高炉到铁水稳定输出时段,铁水铁素流随时间的增加而不断增大,然后逐渐趋于稳定,且铁水铁素流在炼铁初始时段增加速度最快;高炉铁素和损失铁素流均与本单元铁素流返回率呈正相关,且不随上游铁素流返回率的变化而改变;铁水铁素流与上游铁素流返回率、本单元铁素流返回率均呈负相关;上游铁素流返回率的增大会使铁水铁素流减小至新的稳定输出状态;本单元铁素流返回率的增大会使铁水铁素流先减小,然后逐渐增大至新的稳定输出状态。     

苏打脱磷剂冲罐法铁水脱磷

 为研究铁水冲罐法对铁水预处理脱磷效果的影响,向放有一定量苏打的铁水罐中倒入铁水进行铁水脱磷工业试验研究。考察了铁水中Si、Ti浓度、铁水温度以及苏打添加量对脱磷率的影响,并比较了钙系脱磷剂与苏打的脱磷效果。结果表明：铁水中低的硅、钛浓度、低温以及适当的苏打消耗量有助于脱磷;与钙系脱磷剂只有一定的脱磷能力相比,苏打有较强的脱磷和脱硫能力;同时考察了氧气对苏打脱磷效果的影响,向铁水表面喷吹氧气可以减少铁水温降,为铁水的二次预处理提供温降空间,采用苏打铁水二次脱磷后,得到了w［P］＜0.010%的铁水;还考察了苏打脱磷过程中w［Cr］、w［V］和w［C］的变化,铁水中铬浓度几乎不变,钒几乎全部被氧化进入渣中,而碳浓度大约减小了0.2%(质量分数,下同)。     

铁水"三脱"的工艺特点及对转炉冶炼的影响

对宝钢铁水“三脱”工艺的处理效果进行了简介。宝钢的铁水“三脱”工艺可以将铁水的磷硫含量控制在很低的水平,但“三脱”工艺的粉剂单耗和处理温度降偏高,对影响脱磷效果和温降的因素进行了分析。采用“三脱”铁水,转炉可以实现少渣冶炼,并可以采用锰矿还原工艺,降低工艺成本。铁水的“三脱”对宝钢的纯净钢生产提供了技术保障,宝钢目前已具备了大批量生产纯净钢的能力。     

SiO2-TiO2-CaO-MgO-FeO-MnO渣系与脱钛过程铁水中Ti-Si平衡热力学模型

 为降低铁水中钛含量,采用烧结矿或球团矿进行铁水包脱钛预处理。基于共存理论,采用Matlab编程软件,建立了铁水包脱钛典型渣系SiO2-TiO2-CaO-MgO-FeO-MnO中TiO2活度计算模型。结果表明,随着MgO、FeO、MnO摩尔分数和炉渣碱度的增大,脱钛渣中TiO2活度下降;随着TiO2摩尔分数的增大,TiO2活度提高。脱钛终点铁水中的钛含量与硅含量呈线性关系,其斜率受温度、铁水成分以及炉渣中SiO2和TiO2活度的影响。计算结果与试验结果及实际生产数据十分吻合。     

含钒钛铁水/半钢预脱硫温降计算与分析

为了分析含钒钛铁水/半钢预脱硫过程中影响温降的因素,根据物料平衡和热量平衡原理,建立了铁水/半钢预脱硫温度预报模型。根据脱硫前铁水/半钢温度,通过调节脱硫剂喷吹量、载气流量和喷吹时间等参数,较好地控制了脱硫后的铁水/半钢的温度。工业试验表明,当精度为±5 ℃时,模型温度预报的合格率达85%。进一步根据该模型探讨了脱硫剂、载气、炉衬、炉渣等因素对温降的影响规律,发现脱硫剂镁是造成铁水预脱硫温降大于半钢的主要原因,并给出了减小含钒钛铁水预脱硫过程温降的有效方法。     

液渣成分和硅酸二钙颗粒含量对铁水预处理非均相脱磷剂脱磷能力的影响简

 高磷铁水预处理脱磷的难题是脱磷剂用量太大、温降太多，急需研究脱磷能力强的脱磷剂。含有固体颗粒和液渣的非均相脱磷剂比仅含液渣的均相脱磷剂的脱磷能力强很多。为此，针对磷的质量分数为0. 5%的高磷铁水，应用FactSageTM热力学软件优选出脱磷能力强的3种液渣，添加不同数量的硅酸二钙颗粒配制非均相脱磷剂试样，脱磷剂和熔铁在1560℃下反应6h，测定熔铁中的平衡磷含量，用以评价其脱磷能力，然后在1400℃下进行了铁水脱磷预处理试验。研究结果表明，随着硅酸二钙颗粒含量的增加，非均相脱磷剂的脱磷能力明显改善；采用非均相脱磷剂有助于减少渣量和控制反应器内衬的侵蚀；采用非均相脱磷剂对铁水脱磷，仍然需要控制较高的渣铁界面FetO浓度。     

基于LM算法BP神经网络的高炉-转炉界面铁水温度预报模型

通过研究高炉-转炉界面铁水运输过程温度的主要影响因素,确定了影响高炉-转炉界面铁水运输过程温度的参数,建立了基于Levenberg-Marquardt (LM)算法BP神经网络的高炉-转炉界面铁水温度及铁水过程温降的预报模型.用沙钢100包铁水数据进行模型训练,50包铁水数据进行现场预报,结果表明:在高炉-转炉界面“一包到底”模式下,当绝对误差| X |≤20℃时,铁水温度命中率为94％,铁水温降命中率为78％;当绝对误差|X|≤40℃时,铁水温度命中率为100％,铁水温降命中率为92％,该预报模型能够满足现场实际生产需求,对炼钢生产有很好的指导意义.     

铁水包预处理脱钛理论分析与试验研究

为降低铁水的钛含量,采用烧结矿或铁精粉进行铁水包脱钛预处理.采用500 kg中频感应炉对铁水脱钛进行了试验研究,并对脱钛过程热力学进行了分析.结果表明,相同温度下,烧结矿脱钛表观平衡常数明显大于铁精粉脱钛表观平衡常数.脱钛过程前4 min平均脱钛速率最大,可达0.033 ％/min,16～20 min阶段平均脱钛速率为0.000 7％/min.20 min内,脱钛率可达57.19％～71.20％.脱钛剂中氧利用率的计算结果表明,终渣中剩余氧量占脱钛剂供氧量的4.8％～9.3％,脱钛氧利用率平均为12.28％,低于脱硅氧利用率(43.34％)和脱碳氧利用率(20.18％).另外,试验结果表明,炉渣碱度增大,脱钛率提高.因此,为降低铁水钛含量,应适当提高脱钛渣碱度.     

用CaO Fe2O3基熔剂进行铁水预处理脱磷

 在实验室小型实验炉内，采用CaO Fe2O3基粉状脱磷剂，进行了铁水预处理脱磷的实验。主要研究了铁水中原始硅含量、钙氧比、熔剂含量和助熔剂含量等因素对铁水脱磷率的影响。结果表明，较低的铁水硅含量、合适的钙氧比、适量的CaF2和Al2O3含量能提高铁水预处理脱磷率。     

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。