铝合金管材6061自由弯曲成形工艺仿真及优化

金属管材是工业领域中结构承重、输送气体和液体的重要部件。自由弯管成形技术有助于实现管件生产的高精度、高性能、高效率和数字化，其精度控制理论和成形技术的研究具有重要的工业应用价值。本文选择直径 30 mm 壁厚 2.0 mm 的铝合金管材6061为仿真优化对象，通过相关基础实验获得材料的基本力学数据，用于仿真模型参数的表征。同时，结合管材压弯实验验证本构模型成形预测的有效性。在完成仿真模型表征和验证的基础上，对铝合金管材的自由弯曲成形过程进行仿真模拟，分析对比了影响自由弯曲成形的各工艺参数，确定了该工况下最优的移动模与管材间隙大小、摩擦系数和进给速度等。该研究有助于优化管材空间自由弯曲成形工艺，具有一定的工业应用价值。      

TA34钛合金波纹管成形研究

采用恒应变速率拉伸方法研究了普通退火态(M态)和等温退火态(HT态)TA34钛合金管坯的冷成形性能，结果表明：M态TA34钛合金管坯的强度更高，最大应变硬化率更低，冷成形性能更好，更适用于波纹管的成形。采用有限元模拟的方法对DN85波纹管的成形参数进行仿真计算，得到最佳鼓波压力、成形压力和最大波深系数等成形参数。根据仿真模拟结果进行DN85波纹管成形工艺的探索，HT态管坯在波深系数1.162时即出现开裂，M态管坯在波深系数1.165、1.169、1.178时均未出现表面质量缺陷。以M态TA34钛合金管坯为坯料，选择合适的波纹管成形工艺参数可以制备出质量优良的TA34钛合金波纹管。     

大口径方管滚模成形工艺的仿真分析

针对滚模成形大口径方形管成形工艺,采用有限元仿真软件ANSYS/DYNA对拉拔、推挤和滚轧进行仿真和比较分析,揭示各工艺过程的变形特点和作用力变化规律,为优选成型工艺参数提供了基础。     

车门外板用钢冲压开裂分析与仿真工艺优化

针对车门外板用钢由DC04替换成DC01引起的冲压起皱及开裂问题，分析了两种材料力学性能和成形极限的差异，并利用成形仿真软件开展了适用于鞍钢产品的车门外板成形工艺研究。结果表明，塑性应变比r值和双拉变形区极限应变的降低会导致材料的成形能力变差，使材料与模具的匹配设计难度大幅增加。仿真模型预测准确，且通过灵活设计拉延筋及阻力系数，有效控制了冲压缺陷，显著提高产品的订货量及应用稳定性。     

油泵齿轮轴精锻成形工艺研究及缺陷分析

针对油泵齿轮轴特殊形状设计了齿轮轴精锻模具.通过有限元仿真和精锻实验研究了齿轮轴成形过程和金属流动规律.分析了对油泵齿轮轴精锻工艺中产生齿形角隅填充不满缺陷的原因:角隅填充是成形终了时成形载荷陡增的主要原因之一,由于齿轮轴精锻模具结构的特殊性,其强度无法满足齿形角隅填充所需高成形载荷的需要.基于角隅填充状况,提出了齿形端面斜面分流和环形槽分流,并对传统精锻工艺和两种分流锻造工艺进行了有限元仿真.分析结果表明两种分流方法均能有效减小齿形角隅填充时金属流动阻力,保证齿形良好填充,降低成形载荷,并且斜面分流优于环形槽分流.锻造实验验证了有限元仿真的准确性.      

基于DEFORM软件的U型梁激光拼焊件热成形仿真分析

采用DEFORM软件对U型梁激光拼焊件进行计算机仿真,拼焊材料为热成形钢800HS与1500HS,研究热成形过程中温度场、相组成的变化过程,并对保压、模具间隙、冷却能力等热成形主要工艺参数对热成形效果的影响予以讨论,获得了全工序的温度场、相组成的变化规律,给出了热成形主要工艺参数对热成形效果的影响,其中模具间隙是决定热成形淬火性能的关键因素,冷却水道是保障连续模淬的关键措施。经实际生产验证,仿真分析符合性较好,对激光拼焊件热成形实际生产具有一定的指导意义。     

钛合金板材多道次高温拉深有限元仿真及实验研究

钛及钛合金金属材料的特点是塑性差,变形抗力大,拉深成形困难。针对TA15钛合金深筒件,提出了一种多道次高温拉深成形方法。通过有限元仿真研究了压边力、各道次拉深深度等工艺参数对成形性的影响。最后经实验得到了TA15钛合金筒形件,总长180 mm,孔径24 mm。实验证明了仿真计算的准确性和工艺设计的可靠性,最终产品满足实际生产要求。     

超高强梁零件筋槽的辊冲成形工艺分析

辊冲成形工艺为一种新型成形工艺,该工艺兼具辊压和冲压特点,特别适合超高强、尤其是超高强变截面梁类零件的生产。筋槽是汽车零部件中常见的局部形状,在各类纵梁、加强梁等零件上用于装配定位、避让和加强刚度。针对筋槽的辊冲成形,选取了平底筋槽和圆底筋槽两类典型的筋槽形状,基于ABAQUS软件平台,建立了筋槽辊冲成形仿真分析模型,并对不同尺寸筋槽的辊冲成形进行了对比分析,结果表明,当筋槽圆角半径增大时,辊冲成形过程最大Mises应力、最大应变和最大减薄率均减小;采用辊冲成形工艺,两类筋槽安全成形的最小圆角半径分别为8mm和4mm。     

复合式滑板成形工艺对强度性质的影响

应用热弹性力学理论和有限元法对滑板在股役期间的实际应力情况进行计算，通过对滑板砖一次成形工艺和二次成形工艺的应力分析比较得中论：在外部材料能够满足性能要求和前提下，与一次成形工艺比较，二次成形工艺理能发挥材料特性，提高滑板的抗热震性和耐用性。     

超高强度钢防撞梁热成形改冷冲压工艺设计及优化

安装在车门内的防撞梁是提高轿车侧碰撞安全性的关键部件,国外高安全性轿车都用超高强度钢板制造防撞梁,但超高强度钢板成形困难,普遍采用成本高的加热成形方法.笔者绍了采用有限元分析软件Dynaform对某高级进口型轿车超高强度钢防撞梁热成形改冷冲压工过程进行模拟仿真,并优化成形工艺,主要研究了温度对超高强度板内部组织变化起的作用.通模拟和实际对比研究工艺补充面对零件成形及回弹的影响,并设置凸顶得到了优化的工艺型面,同类相关高强度钢零件的生产起到了指导作用.     

钢铁工业加热炉先进控制技术及其发展

对国内外加热炉温度控制技术的理论研究情况进行了较详细的分析，对目前加热炉控制方法中存在的问题了较为深入的探讨，指出了加热炉集成控制技术中存在的不足，同时，本文总结了温度控制技术在工程实际中的应用情况，最后对我国加热炉温度控制技术发展趋势进行了讨论。     

Propensity score techniques and the assessment of measured covariate balance to test causal associations in psychological research.

There is considerable interest in using propensity score (PS) statistical techniques to address questions of causal inference in psychological research. Many PS techniques exist, yet few guidelines are available to aid applied researchers in their understanding, use, and evaluation. In this study, the authors give an overview of available techniques for PS estimation and PS application. They also provide a way to help compare PS techniques, using the resulting measured covariate balance as the criterion for selecting between techniques. The empirical example for this study involves the potential causal relationship linking early-onset cannabis problems and subsequent negative mental health outcomes and uses data from a prospective cohort study. PS techniques are described and evaluated on the basis of their ability to balance the distributions of measured potentially confounding covariates for individuals with and without early-onset cannabis problems. This article identifies the PS techniques that yield good statistical balance of the chosen measured covariates within the context of this particular research question and cohort. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

钢包炉精炼控制技术的发展与展望

概述了钢包炉精炼控制技术的国内外发展状况，对LF炉控制技术的应用现状及其发展过程进行了详细阐述，并对LF炉主要环节的控制技术提出了今后的发展方向。     

Improvement of result coherence in clinical enzymology: multicenter study of gamma-glutamyltransferase, alkaline phosphatase and amylase activities

We report here on the results of a multicenter study of three enzyme activities (gamma-glutamyltransferase, alkaline phosphatase and amylase). For each activity, measurements were performed in two laboratories on different series of patients' specimens under routine conditions, at 30 and 37 degrees C, with techniques frequently used in France and with the IFCC reference method, when it exists. For each technique, precision was acceptable, but results differed considerably according to the technique used. The study also showed that for different techniques it is not possible to use a single transformation factor for activities between 30 and 37 degrees C. Patients' results determined by two techniques often showed a constant relationship. Groups of techniques that determined the same catalytic activity in patients' specimens were identified, whereas other techniques did not have this property. Several preparations, including reference materials produced by the Community Bureau of Reference (European Community, Brussels) and ten commercial secondary materials were tested for similar behaviour as compared to patients' samples. Results show the commutability of reference materials within a group of techniques indicating that they can be used as calibrators. This was seldom the case for the commercial secondary materials and we did not find any such material suitable for calibration of the three enzymatic activities. The present study demonstrates that with defined techniques and validated calibrators it is possible to reduce considerably differences between results obtained with different techniques at different temperatures and in different laboratories.     

The use of play therapy with adolescents in high school.

Describes appropriate play therapy techniques for use with adolescents In a high school setting and provides specific case examples of the use of a variety of creative, expressive play therapy techniques that can help emotional development. The review of the literature on using play therapy techniques with children and adolescents included in the article provides support for the appropriateness of using creative techniques with adolescents and provides evidence of the need for current information on this topic. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement of absolute lung volumes by imaging techniques

In this paper, the techniques available for estimating total lung capacities from standard chest radiographs in children and infants as well as adults are reviewed. These techniques include manual measurements using ellipsoid and planimetry techniques as well as computerized systems. Techniques are also available for making radiographic lung volume measurements from portable chest radiographs. There are inadequate data in the literature to support recommending one specific technique over another. Though measurements of lung volumes by radiographic, plethysmographic, gas dilution or washout techniques result in remarkably similar mean results when groups of normal subjects are tested, in patients with disease, the results of these different basic measurement techniques can differ significantly. Computed tomographic and magnetic resonance techniques can also be used to measure absolute lung volumes and offer the theoretical advantages that the results in individual subjects are less affected by variances of thoracic shape than are measurements made using conventional chest radiographs.     

大型钢结构工业厂房施工测量技术

结合大型钢结构工业厂房的结构特点和施工要求，介绍韶钢大转炉工程主厂房柱基施工测量及钢结构安装测量的技术和方法，如柱基施工采用建筑方格网放样法等等．本施工测量技术具有测量精度高、方法简捷、实用性强等特点．     

The application of temporal correlation techniques in psychology.

"Definitions and computation procedures for various temporal correlation techniques are presented. These techniques include serial correlations for discrete data and correlation functions for continuous data. Specifically described are autocorrelations for temporal relatedness within one series of data, and crosscorrelations for such relatedness between two series. These techniques are appropriate for discovery of both cyclical and noncyclical temporal phenomena. Various applications of temporal correlation techniques within psychology are described." 29 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)