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61.
详细了介绍了锦州石化公司体育馆及附属设施钢架结构的防火及防火涂料涂装;讨论了钢架结构的防火,并且制定涂层的设计方案、施工工艺及质量验收标准等。  相似文献   
62.
利用抽余碳五馏份制备TAME   总被引:4,自引:0,他引:4  
探索了以抽余C5为原料经与甲醇醚化制TAME的过程。试验表明,在国产催化剂D54型大孔阳离子交换树脂存在下,在反应温度60℃、LHSV2.4h-1、甲醇/异戊烯物质的量比1.00、反应压力0.2MPa的条件下,抽余C5中的异戊烯可与甲醇反应生成醚,异戊烯的转化率达63.26%,TAME的选择性可达99.61%。  相似文献   
63.
条形药包爆炸应力场试验研究   总被引:2,自引:0,他引:2  
应用动态光弹性模型试验方法研究了条形药包的爆炸应力场分布特性。研究结果表明:起爆方式和位置影响着条形药包爆炸应力场的分布形态,并首次成功地记录了条形药包瞬间爆炸应力场的动光弹条纹,得到了理想成力场的分布形式。  相似文献   
64.
The influence of 0.1-0.6 at.-%RE additions (RE= La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb) on themechanical properties of Pd was studied. All above RE additions increased not only the strengthproperties at ambient temperature but also the tensile strength, creep rupture time and activation en-ergy at high temperatures, simultaneously increased the elongation of Pd. In the range of dilute con-centration, the strength properties of Pd-RE alloy enhanced linearly with RE concentration. Whenthe strength properties of Pd-RE alloys were normalized at 0.1 at.-%RE, it was found that light REelements had stronger effect on the properties of Pd than heavy RE, whereas Eu, Yb, Ce had anoma-lous effect. In all Pd-RF alloys, Pd-Eu alloy had the highest strength properties, successively Pd-Yband Pd-Ce alloy. The effect mechanisms of RE in alloy, such as purifying impurities, increasingrecrystallization temperature, refining grain size. expanding crystal lattice, increasing dislocation den-sity and decreasing stacking fault energy, forming stable RE oxidation by internal oxidation, and soon, were observed. They were strengthening sensitive factors. The influence of the factors onstrength properties and elongation of Pd was discussed.  相似文献   
65.
本文采用有限元与边界元耦合方法对上与结构物进行共同作用的分析.其中上部结构采用有限元子结构法,地基上考虑为横观各向同性特性,应用边界元法,通过基础界面上位移连续、面力平衡的条件进行耦合分析.编制了相应的计算程序,对某高层空间剪力培与地基的共同作用进行了计算,与有限元法和实测结果进行了对比分析,得到了满意的结果.说明:有限元和边界元的耦合方法能充分发挥两者的优越性,不失为共同作用分析的一种有效途径.  相似文献   
66.
67.
The computation of incompressible three-dimensional viscous flow is discussed. A new physically consistent method is presented for the reconstruction for velocity fluxes which arise from the mass and momentum balance discrete equations. This closure method for fluxes allows the use of a cell-centered grid in which velocity and pressure unknowns share the same location, while circumventing the occurrence of spurious pressure modes. The method is validated on several benchmark problems which include steady laminar flow predictions on a two-dimensional cartesian (lid driven 2D cavity) or curvilinear grid (circular cylinder problem at Re = 40), unsteady three-dimensional laminar flow predictions on a cartesian grid (parallelopipedic lid driven cavity) and unsteady two-dimensional turbulent flow predictions on a curvilinear grid (vortex shedding past a square cylinder at Re = 22,000).  相似文献   
68.
Although progesterone and estrogens are essential to maintain human pregnancy after implantation, the localization of their specific receptors in different uterine cell types during pregnancy has not been investigated. We studied uteri (n = 40) obtained during the first 3 months of pregnancy (n = 21) and in late pregnancy (n = 9) as well as from women 5-14 weeks pregnant (n = 10) who had received the antiprogestagen RU 38486 (Roussel-UCLAF) to induce cervical dilation. Frozen tissues were processed for indirect immunocytochemical staining with specific monoclonal antibodies against estrogen receptors (ER; Abbott Laboratories) and progesterone receptors (PR; Li 417). Specific staining for steroid receptors was only detected in the nucleus. In the endometrium, PR staining remained fairly constant throughout pregnancy, whereas ER staining was initially weak and then undetectable. PR was widely expressed in stromal cells and in spiral arterial wall cells, whereas ER was expressed in scattered stromal cells and arterial cells. Both PR and ER were absent from glandular epithelium, contrasting with the secretory activity during the first trimester. Spiral arteries of the endometrium and myometrial smooth muscle cells showed intense PR and moderate ER staining in early pregnancy. The progesterone antagonist RU 38486 (mifepristone), given in early pregnancy at a dose of 200 mg, caused a marked increase in ER staining and a smaller increase in PR staining in stromal cells, whereas the glandular epithelium remained negative for both ER and PR (except for one and two specimens, respectively). We conclude the following. 1) Stromal cells retain PR despite the high progesterone levels during pregnancy, in keeping with the role of progesterone in stromal decidualization. The absence of PR from the secretory glandular epithelium suggests a paracrine link between decidualized stromal cells and epithelial cells. 2) Significant PR down-regulation by progesterone during pregnancy occurs only in epithelial cells of the endometrium. 3) In contrast, the absence or low level of ER staining in the various cell types of the endometrium during gestation concurs with the known effect (down-regulation) of steroid hormones on ER mRNA or protein levels. The increase in ER in human decidua after RU 38486 treatment indicates that the main cause of the low ER levels is progesterone secretion. 4) The intense PR staining in smooth muscle cells of spiral arteries during early pregnancy suggests that progesterone is essential for modulating blood flow during pregnancy.  相似文献   
69.
邓建辉  张昆吾 《钢铁钒钛》1998,19(3):26-29,40
以高碳低锰碳素热轧钢轨为热处理原料轨,采用双频电感应加热、压缩空气欠速淬火热处理技术研制的PD275kg/m热处理钢轨,硬化层深度≥15mm、组织为细珠光体;力学性能:σ0.2815 ̄980MPa、σb1185 ̄1340MPa、δ510% ̄15%,常温冲击韧性aK14 ̄33J/cm^2,断裂韧性KIc平均值45.5MPa·m^1/2。具有强度高,塑韧性好的综合性能。使用性能优良,寿命比同曲线的U7  相似文献   
70.
The copolymer from D ,L -lactide and poly(tetramethyene ether glycol) (PTMG) was prepared in bulk with an isotributyl aluminum–water–phosphoric acid complex catalyst as the initiator and characterized by H-NMR, GPC, and DSC. The effects of the temperature and the amount of PTMG on the polymerization rate and the molecular weight of copolymers were studied. The behavior of the degradation and delivery rate of Levonorgestrel microspheres in vitro was observed. The results show that the degradation and the delivery rate can be controlled by adjusting the molar rate of hydrophilic and hydrophobic segments of the copolymer © 1995 John Wiley & Sons, Inc.  相似文献   
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