钢坯表面发纹的探讨

对优质中碳钢坯表面出现的发纹缺陷及危害进行研究 ;借助磁力探伤与显微观察等方法 ,对发纹的形貌和氧化物进行分析 .找出钢坯表面发纹形成的原因 ,揭示钢坯表面发纹生成与钢中残铝量的关系 ;提出适当控制钢中的残铝量可降低钢坯表面发纹的形成 .     

无发纹合金结构钢的研制

根据舍金结构钢发纹产生机理,从炉料选择、冶炼、加工及热处理等方面进行工艺试验,对产生发纹的各影响因素进行了探讨,总结出控制舍金结构钢塔形检验发纹的有效途径.     

高锰钢板表面横向发纹缺陷成因分析及改进措施

高锰钢板的发纹缺陷产生在钢板次表面,具有隐蔽性。针对用户在使用钢板过程中曾多次发生冷折开裂情况,对不同厚度钢板次表面发纹缺陷及其钢板的生产工艺执行情况进行分析,并结合缺陷检验鉴定结果,确定发纹缺陷的产生与钢坯质量、加热工艺、轧制工艺及轧后冷却等有关。按实际工况提出了一系列改进措施,并应用于实践,发纹缺陷得到了有效控制,取得了较好的效果。     

20g钢板断口发纹缺陷的研究

介绍了20g钢板断口发纹缺陷产生的原因和对使用性能的影响。通过试验,证明减少钢中硫含量或对MnS进行形态控制是减少发纹的根本措施,并为正确评价断口上的发纹和合理使用钢材提供了理论依据。     

LZ50车轴“发纹”缺陷分析及控制措施

本文研究了LZ50车轴“发纹”产生的机理,分析了钢中氧化铝类夹杂、铝、氮的质量分数等因素与发纹的关系,提出了具体的控制措施。     

有关钢材发纹、分层、偏析和脱碳的标准规定

在钢材检验实践中，深感钢材标准中有关发纹、分层、偏析和脱碳的有些规定不尽合理，在此提出与同行探讨。１发纹发纹是一种破坏金属连续性的缺陷，它直接影响钢材的顶锻性能、疲劳强度，当暴露至表面时还会引起淬火开裂。它是气泡、疏松和非金属夹杂物在热变形加工中沿加...     

钢材塔形发纹酸浸检验方法国标（草案）与YB47—64对比试验

用同一试样，分别按“国际草案”与ＹＢ４７－６４进行塔形发纹检验对比试验，结果表明按“国标草案”规定的塔形阶梯表面积比ＹＢ４７－６４增大，发纹出现概率也增大，尤以第一阶梯发纹出现较多，这主要多为皮下缺陷所致。     

45钢活塞杆表面发纹产生原因

用45钢圆钢生产工程机械高压油缸用活塞杆时,发现2支活塞杆电镀后存在发纹缺陷.对缺陷样进行了化学成分、金相组织、扫描电镜和能谱等分析,认为机加工中的表面划伤和原材料中的夹杂物是产生发纹的原因.     

不锈钢发纹的研究与对策

对电弧炉冶炼１Ｃｒ１８Ｎｉ９Ｔｉ不锈钢发纹产生的原因调查研究，讨论了影响发纹产生的因素，提出强化精炼后操作，出钢浇注过程氩气保护以及配合适的保护渣等改善不锈钢质量的措施。     

合金圆钢表面裂纹探讨

本文主要对因折叠、划伤和旋带状发纹引起的圆钢表面裂纹进行探讨、分析研究。     

Efficacy of etodolac for the treatment of osteoarthritis of the hip joints in dogs

STUDY OBJECTIVE: To arrive at a consensus on the priorities for future research in emergency medical services for children. METHODS: A consensus group was convened using the Rand-UCLA Consensus Process. The group took part in a 3-phase process. Round 1 involved reviewing a compendium of relevant research articles and answering a mailed questionnaire. Panel members were asked to prioritize topics on the basis of the 1993 Institute of Medicine Report on Emergency Medical Services for Children. Participants were asked to rate each topic based on the significance of the research, and whether the topic would (1) improve general knowledge, (2) change behavior, (3) improve health, (4) decrease the cost of care, or (5) change public policy. A 4-point Likert scale was used. Participants were also asked if the research would require a multicenter study and if the research were feasible. Round 2 of the study involved a meeting of the panel, where the results of Round 1 were discussed and the topics were reprioritized. The topics were given a rank order and a final ranking was done in Round 3. RESULTS: The panel considered a list of 32 topics; these were combined and reworded to give them more precise meaning. Several new topics were also added. Fifteen topics were given a rank order and placed within the 7 broad categories of the Institute of Medicine report. Clinical aspects of emergency care, systems organization, configuration, and operation and injury prevention were given high priority rankings. The first 5 topics were very close in point-rank order. CONCLUSION: The panel was able to develop a list of important topics for future research in emergency medical services for children that can be used by foundations, governmental agencies, and others in setting a research agenda for such services.     

Behavior of Ellipsoids of Two Sizes

The influence of particle shape on granular material response is examined by using the discrete element method. Triaxial drained and undrained tests were performed on specimens of ellipsoids of two sizes. The triaxial test boundary conditions were simulated with a recently developed boundary mechanism. Different loading paths including axial compression, axial extension, lateral compression, and true extension were employed. The specimens were composed of 1,170 ellipsoids having two types of particles. The specimen is made up of 50% by weight of Type I particles that have an aspect ratio of 1.2. The aspect ratio of the Type II particles varies between 1.5 and 2. The specimens were consolidated isotropically before shearing. Comparing with the behavior of specimens of mono-size particles, a higher friction angle and a more complex particle shape effect were observed. The friction angles from the drained tests (axial extension, true extension, and lateral compression tests) were similar and the values are higher than that of the axial compression test. All simulated results are in good agreement with laboratory observation of sands.     

Effects of Consolidation History on Critical State of Sand

A series of drained biaxial compression tests were conducted on two sands to determine the effects of consolidation history on their critical states. Specimens of each sand were consolidated along at least two separate paths in void ratio-effective stress space, creating several unique consolidation histories. Because the sands were dilative, strains localized during shearing and the evolution to critical state occurred only within the shear band. Digital images were obtained through a plexiglass sidewall throughout each test. Digital image correlation techniques were used to quantify the displacements within the band, and a linear regression technique was used to formulate a displacement function from which strains were computed. The critical state was achieved within the shear band in each test, but the critical state line was found to depend on the initial state and subsequent consolidation history of the sand specimens.     

Application of Numerical Simulation Technique to Casting Process of Valve Block

 The numerical simulation technique was applied to the casting process of a valve type part. The mold filling and solidification stages of the casting were numerically analyzed. The filling behavior, solidification sequence, and thermal stress distribution were reproduced and the possible defects, such as cold shut and shrinkage, were predicted. Based on the simulation result, the double gating system was replaced by a single gating system. Meanwhile, the chills were used to regulate the solidification sequence of casting. To eliminate the cracks in the casting, the sand core was converted into a canulate one. By modifying the original process, the defects were eliminated and the casting with good quality was obtained.     

The application of the modified method of determination of aldosterone in plasma

Concentrations of triglycerides, free fatty acids (FFA) and glycerol were measured in umbilical venous blood from 99 infants with a birth weight of between 1100-2700 g and a gestational age of 27-41 weeks. Thirty infants were small for gestational age (SGA), 58 were appropriate (AGA) and 11 were of uncertain gestational age. In AGA infants with a gestational age of less than or equal to 35 weeks. FFA values were lower than in those with a gestational age of less than 35 weeks; otherwise concentrations of triglycerides, FFA and glycerol were independent of birth weight and gestational age in AGA infants. In SGA infants, higher FFA values were found compared with both AGA and term infants of normal birth weight. Triglyceride values were higher in SGA than in AGA infants. In SGA infants, a significant positive correlation was found between gestational age and concentrations of both FFA and triglycerides. No differences in FFA, glycerol and triglyceride concentrations were seen between asphyxiated and non-asphyxiated AGA infants.     

Conditioned reactions of the neurons of the dorsal region of the hippocampus to a combination of sound and extracellular polarization

Neuronal responses were recorded in the dorsal part of the rabbit hippocampus to a, aperiodical (45 units) and b, periodical (25 units) presentations of combinations of a sound and a DC pulse (anode, 0,1-2,0 na) acting through the recording microelectrode. In the group (a) identified conditioned responses to a former indifferent acoustic stimulus were elaborated in 22% of the neurones. More than a half of them produced differentiation and extinction. Differences were revealed between conditioned reactions and responses in pseudoconditioning tests. In the group (b) 30% of units elaborated a conditioned reaction to time. Activation type reactions were predominant. They appeared when the stimuli were omitted, and sometimes they emerged in 12 or more successive omissions.     

The effects of mild frustration on the expression of prejudiced attitudes.

"The present study was designed to test the proposition that frustration may increase the expression of prejudice. Sixty-four S's were given a series of attitude scales, following which all were exposed to a relatively mild, experimentally induced frustration. Immediately thereafter, alternate forms of the attitude scale were administered. Significant increases were found… [and] the results were interpreted as an instance of 'targeting' of a minority group within the general framework of the scapegoat phenomenon." 23 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Process demands of rejection mechanisms of recognition memory.

A surge of research has been conducted to examine memory editing mechanisms that help distinguish accurate from inaccurate memories. In the present experiment, the authors examined the ability of participants to use novelty detection, recollection rejection, and plausibility judgments to reject lures presented on a recognition memory test. Participants studied a list of word pairs that were arranged in a category relationship (both words from the same category) or an unrelated relationship (both words from different categories) under full or divided attention. At test, participants were given a yes/no recognition test in which they were to respond after seeing the test items for 400 ms or 2,800 ms. Some of the test items were rearranged word pairs that were consistent with the study relationship, whereas others were inconsistent with the study relationship. The results demonstrate that the participants required full attention at study to use novelty detection, recollection rejection, and plausibility judgments to reject lures. Moreover, the results indicate that a long response deadline at test was needed for participants to use both recollection rejection and plausibility judgments to reject lures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of laparoscopy in the management of impalpable testes

Both diagnostic and operative laparoscopy were used in the management of 68 impalpable testes. Twenty-three were either vanishing or atrophied, and were associated with a precarious blood supply. Two were found in the groin, 12 in the inguinal canal, and 32 at variable distances from the internal ring; of these, 2 were in a patient with persistent müllerian duct syndrome. Two atrophied abdominal testes were removed laparoscopically, 3 patients underwent a two-stage Fowler-Stephens procedure, and 28 underwent one-stage, laparoscopically assisted orchidopexy. An algorithm for surgical management of the impalpable testis based on laparoscopic findings is proposed.     

Relationship of the Guttman components of attitude intensity and personal involvement.

"A random sample of 388 residents of a central Pennsylvania community were surveyed regarding their attitudes toward a local company. Guttman scaling techniques were applied, and a six-item scale of 'general attitude' resulted, with a reproducibility of .88… . those respondents most involved in their attitudes toward the company were on the average the most and least favorable in their attitudes. There was a very significant, although not extremely high, positive relationship between the intensity of the attitudes expressed and personal involvement in the attitudes toward the company." These findings were contrary to a theory by Guttman (see 29: 2325). (PsycINFO Database Record (c) 2010 APA, all rights reserved)