双线电渣炉电极“冻结”机理及“防冻”研究

对双线电渣炉自耗电极“冻结”现象做了生产观察、实验，分析了“冻结”机理，找出了主要影响因素，提出“理想状态”重熔和“准理想状态”重熔措施，彻底克服了电极“冻结”总理２，经两年多生产证明措施切实可行。     

离心式煤气鼓风机“飞动”现象及避免措施

离心式鼓风机出现“飞动”是企业生产中需要努力避免的运行状态，本文简要分析了风机的运行特性和“飞动”现象，并根据其出现“飞动”的原因，提出了风机在日常运行、开停和倒换过程中避免出现了“飞动”的措施和公司现有规程的修改意见。     

“电渣重熔专刊”征稿启事

正电渣冶金在高品质特种合金和高端装备制造用材料领域发挥着重要作用。不仅如此,电渣冶金技术还推广至资源回收领域。电渣冶金装备及工艺对产品质量有重要影响。近年来,在电渣冶金领域诞生了电渣连铸、导电结晶器、电渣液态浇注、加压/保护气氛电渣重熔等一系列新技术。同时,在电渣重熔渣系优化、电渣重熔过程合金成分控制、电渣重熔产品内部质量及表面质量控制、电渣重熔过程数值模拟等方面产生了一大批优秀成果。电渣冶金在特殊钢和合金的生产中越来越受到重视。     

提高不锈钢重熔锭底部表面质量的工艺探索

我公司的锻件产品人多采用“电炉+电渣重熔”生产钢锭的工艺路线,生产不锈钢重熔锭时,底部常产生夹渣和渣沟,这一问题困扰我们多年.本文介绍了这一问题的解决过程,希望能对我们技术人员提供一些借鉴.     

北方户外露天水管防冻计算

介绍了北方地区户外水管在保温与不保温状态下的冻结时间计算,通过计算列出了DN15~DN250不同管径水管,在保温与不保温状态下的冻结时间,并提出了一些相应的防冻措施。     

工艺参数对电渣重熔锭质量和电耗的影响

针对热作模具钢电渣重熔锭生产过程中存在的质量不稳定、电耗大、成品率不高的问题,分析了电渣重熔过程中几个重要技术参数对电渣重熔钢质量和电耗的影响.通过试验和生产实践,提出了工艺改进措施并取得了良好的效果.     

水电钢电渣重熔过程中Al元素烧损研究

根据电渣重熔生产过程中Al元素烧损机理,归纳了影响Al元素烧损的三大因素,并通过采取增加保护性气氛、控制自耗电极埋入深度、向重熔渣池加入金属铝的措施,有效减少了 Al元素的烧损,并科学地制定了水电钢电渣重熔母材Al元素含量标准.     

MnS形态对超高强度钢韧性的影响

 利用扫描电镜和能谱分析等检测手段研究了2种不同冶炼工艺生产的G50钢中夹杂物类型和尺寸分布。结果表明：随MnS复合夹杂物中钙含量的降低,MnS变形程度逐渐加重,纵横比随之增大。“电弧炉+VOD+真空自耗重熔”冶炼钢的韧性(冲击韧性和断裂韧性)明显得到改善。由于“电弧炉+VOD+真空自耗重熔”冶炼钢中夹杂物的钙含量均较高,纵横比小于“真空感应炉熔炼+真空自耗重熔”冶炼钢,因而有利于改善G50超高强度钢的韧性。     

“爆炸法”处理高炉炉缸冻结事故

山东张店钢铁厂４＾＃１００ｍ＾３高炉炉役后期由于冷却设备漏水和操作不当等发生炉缸冻结事故，采用“爆炸法”处理炉缸冻结，并配合有效的上、下部调剂，仅２ｄ就恢复了正常炉状，效果良好。     

消除Cr20Ni80合金“蜂窝状气泡”的试验研究

高电阻电热合金Cr20Ni80合金,采用非真空感应炉和电渣重熔双联工艺生产时,电渣锭出现气孔,锻造时产生严重裂口,未能加工成材。查其原因,在非真空感应炉生产浇注的电极棒中有较严重的“蜂窝状气泡”。经研究分析和计算,确定是由于液态合金中含氮量较高,浇注后,随着温度的下降,氮的溶解度降低,部分氮析出的缘     

Predicting Frost Heave Using FROST Model with Centrifuge Models

The FROST numerical model was used to predict frost heave developing in centrifuge soil models. When uncalibrated predictions of heave using Gardner's coefficients were selected from accompanying FROST documentation based on soil grain size, the predictions were not good. However, when the parameters were calibrated to surface heave developing in one set of models of heave in silt, numerical predictions for other freezing conditions in the same silt showed very good matches to centrifuge model data of heave. These close matches occurred not only in heave development patterns but also in statistical distributions when variations of input soil parameters were considered. The same good fit after a similar calibration exercise was not found in either heave developments or statistical distributions in the case of silty clay, which develops heave following a different pattern. Predicted ultimate depths of frost penetration were considerably less than measured penetrations, and final water contents (frozen and unfrozen) predicted after freezing were reasonably close to centrifuge model results. A sensitivity analysis of seven input soil parameters required for the FROST model was conducted using the Monte Carlo simulation technique to assess the response of the FROST model to their random variation. Based on this analysis, the FROST model was found to be most sensitive to those parameters characterizing movement and retention of water, especially the Gardner's coefficients for unsaturated conditions. These parameters are also the most difficult to measure reliably, and therefore back calculation of these values is common. Data obtained from centrifuge models of soil freezing can therefore provide an attractive design calibration and research tool.     

Effect of three conditions of administration on "trait" and "state" measures of anxiety.

Administered a battery of test anxiety scales and 2 physiological measures to 25 undergraduates under 3 differing sets of demand characteristics in order to determine the effect of situational aspects on anxiety scale scores. Measures of academic performances were also obtained. The hypothesis that specific demand characteristics would differentially influence Ss' scoring on "trait" and "state" anxiety scales was supported, but no support for a hypothesized relationship between the operation of demand characteristics and systematic changes in the correlations between the anxiety scales and academic performance was found. Implications of findings for the construction and use of anxiety scales were discussed. (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"黑粉"对PM镍基粉末高温合金组织性能的影响

研究了用等离子旋转电极(PREP)工艺生产的镍基高温合金粉末中发现的"黑粉"及其对PM合金中形成原始颗粒边界(PPB)等异常组织,并在力学试验中造成颗粒间断裂和对性能的影响.分析了"黑粉"形成的原因,提出了控制和防止出现"黑粉"的可行性措施.     

Diameter of the mammalian porin channel in open and "closed" states: direct measurement at the single channel level in planar lipid bilayer

Porin isolated from bovine skeletal muscle was reconstitute in planar lipid bilayers under voltage clamp conditions. A set of non-electrolytes were used as molecular probes for determining the pore diameter. The maximal diameter of the open channel was estimated to be 3.02 +/- 0.26 nm. As observed for other porin channels, a large transmembrane potential drove the channel into a "closed" state. The channel transition to the low conductance (closed) state was followed by a decrease in the maximal diameter of the channel to 2.4 +/- 0.08 nm.     

磁翻转机构“点头”现象的解决

磁翻转机构是某钢厂型材自动码垛过程中重要的设备,主要用于等边角钢、工字钢、槽钢的反向码垛工序。该自动码垛机投产使用后不久,磁翻转机构在反向码垛下降过程中,翻转电磁铁频繁出现"点头"现象,且有劣化趋势。该现象对设备造成了严重冲击,影响了自动码垛机的有效使用。在不影响生产节凑的前提下,通过调节PLC程序,降低磁翻转机构每次速度的变化率,使其达到平稳过渡,解决了磁翻转机构"点头"现象,取得良好效果。     

Further evidence for differences between non-selective and BZ-1 (omega 1) selective, benzodiazepine receptor ligands in murine models of "state" and "trait" anxiety

The behavioural effects of several BZ (omega) receptor ligands were compared in mice using the light/dark choice task, an animal model of "state" anxiety, and the free-exploration test, which has been proposed as an experimental model of "trait" anxiety. The drugs used included non-selective full (alprazolam, clorazepate, chlordiazepoxide and diazepam), partial agonists (bretazenil, imidazenil and Ro 19-8022) and BZ-1 (omega 1) selective receptor ligands (abecarnil, CL 218,872 and zolpidem). In the light/dark choice task, non-selective full agonists elicited clear anxiolytic-like effects increasing time spent in the lit box and simultaneously reducing attempts at entry into the illuminated cage followed by withdrawal responses, a measure of risk assessment. With the exception of abecarnil, both non-selective partial agonists and BZ-1 (omega 1) selective receptor ligands displayed reduced efficacy compared to the full agonists as they decreased risk assessment responses without altering time in the lit box. In addition, the weak anxiolytic-like actions displayed by selective BZ-1 (omega 1) agents were evident only at doses which reduced locomotor activity, indicating that this effect may be non-specific. In the free-exploration test, non-selective BZ (omega) receptor agonists markedly increased the percentage of time spent in the novel compartment and reduced the number of attempts to enter whereas selective BZ-1 (omega 1) receptor ligands displayed a weaker neophobia-reducing effect as they reduced risk assessment responses only. As was the case in the light/dark choice task, this latter effect was observed at locomotor depressant doses. These findings indicate that while both full and partial BZ (omega) receptor agonists are equally effective against "trait" anxiety, full agonists may be superior in reducing "state" anxiety. In addition, the lack of specific effects of selective BZ-1 (omega 1) receptor ligands in reducing both types of anxiety suggests that the BZ-1 (omega 1) receptor subtype cannot be considered as the primary target mediating the anxiolytic action of drugs interacting with the GABAA benzodiazepine receptor complex.     

The function of the musculo-venous "pump" of the foot in varicose veins

The functional state of foot musculo-venous "pump" was studied with the help of distal and retrograde phlebography. rheovasography and phlebotonometry in 148 patients with varicose disease. The authors suggested that in the base of its dysfunction lies the foot deep vein ectasis and the varicose insufficiency of communicating veins connected with them.     

"Acquired" congenital diaphragmatic hernia

"Acquired" congenital diaphragmatic hernia (ACDH), has been defined as delayed or late appearance of a congenital diaphragmatic hernia after a documented time periol of postnatal life with no evidence of herniation. Three new cases are presented. This diagnosis has been characterized on the basis of a review of these cases and 14 additional patients from the literature. A classification based upon timing of herniation and state of pulmonary development is presented.     

实施“三三○”安全管理方法的探讨

本文从总结泗洲选矿厂的安全生产实践出发,介绍了“三三○”系统安全管理方法,运用“安全本质”的理论,阐述了安全管理运用方法,对企业生产现场安全管理工作有一定参考意义。     

浅析国有矿山企业党群系统的绩效考核

本文从国有矿山企业的实际出发,结合长期矿山工作经验,引入绩效管理,对国有矿山企业党群系统的绩效考核进行探讨,意在完善矿山企业长期以来党群系统考核模糊状态。