隔膜室盖强度的接触有限元分析

运用ANSYS软件对隔膜泵中的隔膜室盖进行接触有限元分析。建立隔膜腔、隔膜室盖以及联接螺栓的接触有限元模型,详细讨论载荷与边界条件的处理方法,应用ANSYS软件的螺栓预紧功能模拟隔膜腔和隔膜室盖的螺栓联接,对隔膜室盖强度的接触有限元法进行计算,得到隔膜室盖接近实际的应力。     

隔膜室盖联接螺栓预紧力的有限元分析

以隔膜泵液力端隔膜腔与隔膜室盖的联接螺栓为研究对象,通过预紧力单元法模拟螺栓预紧力的加载方法,采用有限元软件ANSYS分析预紧力单独作用与预紧力及外载荷同时作用的情况,并进行隔膜室螺栓的接触分析,得出分析隔膜泵螺栓联接能力、预紧效果及失效原因的理论依据。分析结论对料浆输送主要设备隔膜泵联接螺栓的设计制造、安装调试与维护检修具有参考意义。     

高炉炉顶放散阀的改造

1　问题分析济南钢铁集团总公司 (简称济钢 )高炉的炉顶煤气放散阀结构如图 1所示。它是一种采用刚性金属密封结构的煤气放散阀 ,阀盖与阀座球面接触面处堆焊有耐磨硬质合金层 ,经研磨加工成球面接触 ;阀盖 1与曲杆 2通过销子 3联接 ,煤气放散阀由地面上的卷扬机或油缸牵引钢丝绳 5来打开 ,靠平衡重关闭。该结构煤气放散阀在零件加工制造完毕、阀盖与阀座研磨后安装过程中出现了阀盖与阀座球面不同心、阀盖与阀座密封不严的情况。其原因是在零部件的加工制造过程中存在误差 ,同时安装过程中也会出现误差 ,而阀盖相对曲杆只能沿销子 3在垂直…     

球磨机进料器与中空轴联接螺栓断裂原因分析

球磨机进料器与中空轴联接螺栓断裂原因是进料器与中空轴之间间隙过大 ,密封锥面受矿浆冲蚀而被破坏。根据生产实际 ,找到了取出断裂螺栓的方法 ,缩短了检修时间 ,并提出了预防中空轴进浆的措施。     

热风阀联接装置的改造

高炉热风阀联接装置由原来60条M27×120螺栓联接改造为5根丝杆联接。     

球磨机进料器与中空轴承接螺栓断裂原因分析

球磨机进料器与中空轴联接螺栓断裂进料器与中空轴之间间隙过大，密封锥面受矿浆冲蚀而被破坏，根据生产实际，找到了取出断裂螺栓的方法，缩短了检修时间，并提出了预防中空轴进浆的措施     

解决轧钢机减速机箱体接合面漏油的办法

我厂550轧机主传动减速机箱体接合面处的长期漏油问题一直未得到彻底解决,经过分析认为:主要由于箱体接合面的加工精度未达到图纸要求;轧钢时的强大冲击负荷使联接螺栓松动破坏了该处的密封;密封设计不够完善以及箱内形成正压等原因造成。 在运转时,箱体内油温升高,空气膨胀,另外从油管带进一部分空气,在箱体顶部虽有1～2个出气孔,但常由于堵塞或出气不畅,很难使箱内与箱外的气压保持平衡,往往使箱内形成正压。这种正压现象可从轴承座上盖的测温孔和联接螺栓孔中冒出润滑油得到证实。     

球磨机端盖的内孔修理

我矿选矿车间使用的MQG2700×3600球磨机,进料端盖与进料口间原设计采用12根M30螺栓联接。由于其强度不足,在给料器的冲击负荷作用下     

基于Solidworks螺栓联接中螺纹各牙的受载分析

通过Solidworks对普通螺纹联接中螺纹各螺牙的受载分析,得出了在螺栓联接中螺纹各牙的受载情况,并对标准结构的螺纹联接所存在的问题进行了系统的研究.     

ZD80减速器的设计

在ＺＤ８０减速器的设计中，对减速器箱盖采用了焊接结构，大齿轮采用组合结构；轴承采用刮油润滑方式，对于单向运转的减速器，装配型式可改为双端输入输出；在确定减速器配置方式时，应使承受最大作用力的轴承座上盖螺栓不承受拉力。     

Testing for Localized Stimulus Enhancement and Object Movement Reenactment in Pig-Tailed Macaques (Macaca nemestrina) and Young Children (Homo sapiens).

Four puzzle boxes were used to investigate localized stimulus enhancement and object movement reenactment (OMR) in 13 pig-tailed macaques (Macaca nemestrina) and 30 human infants (Homo sapiens). Participants received contrasting demonstrations on each box. A circular lid was gripped by its rim or handle and swiveled to the left or right. A flap door was pushed or flipped. A sliding lid was pushed to the left or right. A pin bolt was demonstrated being pushed down, or the participants were left to solve the puzzle for themselves. Despite the fact that the monkeys watched the demonstrations about 60% of the time, only a weak OMR effect was found on the sliding lid. In contrast, the children watched significantly more, and there was clear evidence of socially mediated learning on all of the boxes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

数值模拟在锚杆支护技术中的应用

介绍国内外锚杆支护的应用现状,阐述数值模拟技术在锚杆支护机理,锚杆支护参数的选择,锚杆支护设计及工艺中的应用,说明数值模拟技术在锚杆支护应用中的可行性,同时指出应用中所存在的一些问题.     

复合螺栓搓丝模板成型控制系统研究

针对复合螺栓搓丝模板的成型特点,引入闭环控制系统对液压缸的位移、压力进行实时动态调节,首先设定位移、压力值,其次对传感器采集的数值与设定值比较,二者的偏差经PID算法调节后送入比例放大器调节比例阀的开度,以控制液压缸的动作,最后利用CAN总线将传感器采集的实时数据传输至触摸屏,实现位移、压力等数据的实时显示。通过现场调试及生产应用,实现了复合螺栓搓丝模板表面在同一水平面上,用该模板加工而成的复合螺栓的螺纹牙底在同一圆柱面上,复合螺栓具有较好的可旋合性与防松可靠性。     

Do asian elephants (Elephas maximus) apply causal reasoning to tool-use tasks?

Two experiments addressed contradictory claims about causal reasoning in elephants. In Experiment 1, 4 Asian elephants (Elephas maximus) were pretrained to remove a lid from the top of a bucket and retrieve a food reward. Subsequently, in the first 5 critical trials, when the lid was placed alongside the bucket and no longer obstructed access to the reward, each elephant continued to remove the lid before retrieving the reward. Experiment 2, which involved 11 additional elephants and variations of the original design, yielded similarly counterintuitive observations. Although the results are open to alternative interpretations, they appear more consistent with associative learning than with causal reasoning. Future applications of Fabrean methodologies (J. H. Fabre, 1915) to animal cognition are proposed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Fornix reconstruction in ocular pemphigoid with Goretex surgical membrane

After separation of symblepharons in ocular pemphigoid, transplantation of nasal or bucal mucosa is recommended to prevent recurrent lid fusion; however, it is not always successful. BACKGROUND: An 86-year-old patient was referred to our eye clinic because of trichiasis in ocular pemphigoid. In the right eye, the only functional eye, fusion of the lower lid and the globe was present. There was severe trichiasis with multiple lesions of the cornea and beginning neovascularization. The left eye showed complete fusion of the lid fissure and neovascularization of the cornea. To prevent the right eye from suffering the fate of the left, we tried to find a simple surgical method that could easily be performed on the multimorbid patient. METHOD: Under parabulbar anesthesia we separated the lower lid from the globe until free passive motility of the lower lid was achieved. A cut-to-size piece of Gore-Tex surgical membrane was prepared and fixated with resorbable u-sutures on the inner lid. The membrane was left in place for 4 weeks until suture lysis. A silicone tube, which was transitorily fixed to the outer lower lid, had an additional ectropionizing effect. Three months later, lower-lid ectropion surgery was performed, combined with tarsectomy to obtain a long-term effect. RESULT: Six months later the lower-lid fornix had stabilized, and the lid and globe had good motility. The corneal lesions had healed. CONCLUSION: The use of 0.1 mm membrane prevents penetration of cell because of the microstructure. Similar to the "bare sclera" technique, which is used in selected cases in strabismus or pterygium surgery, the inner lid and sclera were epithelialized separately from the remaining conjunctiva. The surgical membrane prevented recurrence of the symblepharon. We think the presented technique is an easy, quick method of preventing recurrence of lid fusion after separation of symblepharons.     

高应力破裂岩体锚网支护机理及应用

本文通过对树脂锚杆作用机理进行研究，建立树脂锚杆的力学模型，发现树脂锚杆的锚固力与围岩性质、树脂锚固剂、锚杆杆体和围岩应力等因素有关；同时分析了锚网支护与围岩共同作用机理，并应用FLAC对锚网支护机理进行研究，发现锚网支护与围岩形成压缩拱，依靠压缩拱来抵抗围岩应力，进而维护巷道围岩的稳定。通过在红透山铜矿进行现场试验，锚网支护能够维护高应力破裂岩体围岩的稳定，在同类矿山中具有推广应用价值。     

Partial purification of protein farnesyl cysteine carboxyl methyltransferase from bovine brain

Asian upper and lower eyelids are typically characterized by a fuller appearance than the lids of whites. Inferior extension of preaponeurotic fat and brow fat into the Asian upper lid explain the upper lid fullness and its difference from the upper lid of whites. Analogous structures in the Asian lower lid may exist to explain its full appearance. High-resolution magnetic resonance imaging (MRI) of 24 normal Asian and white lower lids was performed to evaluate differences in Asian and white lower lid anatomy. Magnetic resonance images revealed two major differences. First, the orbital fat projected further anteriorly with respect to the orbital rim in all Asian lower lids studied. No analogy with the upper lid exists for this difference. Second, the orbital fat extended further superiorly, to the inferior border of tarsus, in those Asian lower lids that did not have well defined creases. This was analogous to the preaponeurotic fat location of the Asian upper lid and different from the white lower lid. The suborbicularis oculi fat in the lower lid, the analogous structure of the brow fat pad in the upper lid, was not different in location in Asian and white lower lids. Therefore, the Asian lower lid appearance is explained by the difference in orbital fat location, which is only partly analogous to the anatomical differences between the Asian and white upper lids.     

Nutritional management of acute diarrhea

PURPOSE: To study whether lid suturing can induce axial myopia and explore whether trans-scleral cryotherapy can affect ocular growth in piglets or not. METHODS: A total of fourteen 2- to 3-week-old piglets were studied. Three groups were included: lid suture, cryotherapy, and both lid suture/cryotherapy groups. The lid suturing group (N = 6) was given lid suturing to produce visual deprivation. The cryotherapy group (N = 4) received trans-scleral cryotherapy 360 degrees to encircle anterior to the equator. Both treatment groups (N = 4) received both cryotherapy and lid suturing. The cycloplegic refraction, corneal power, biometric axial length, and intraocular pressure (IOP) were measured before the experiments and 4 months later. RESULTS: Mild axial myopia was induced in five lid-sutured eyes of the lid suturing group. The ocular refraction and eye size of cryotherapy eyes were not different from the control eyes in the cryotherapy group. More myopia was found in all four piglets that received both cryotherapy and lid suturing. CONCLUSIONS: Lid suturing can induce axial myopia; however, cryotherapy did not affect normal eye growth and did not prevent the development of lid suturing myopia in piglets.     

排气门阀座成形模结构分析

简要分析发动机排气门阀座结构形状及工况特性，介绍阀座成形模拟计算特点，及其在生产实践中应用的实例，这种成形模是结构能满足并保证排气门阀座的批量生产及使用要求。