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41.
HDI和IC封装用高性能覆铜板的开发 总被引:1,自引:1,他引:0
重点介绍开发HDI和IC封装用高性能覆铜板的紧迫性、工艺路线及初步成果。 相似文献
42.
《塞维利亚的理发师》是罗西尼创作的第17部歌剧, 当时罗西尼年仅23岁,只用短短的13天就完成该剧音乐的创作!1816年2月20日,该剧在罗马雅典剧场举行首演时,场内竟然嘘声四起,叫骂声、口哨声、跺地板声更是此起彼伏,甚至有人跳上舞台,把男主角的吉他摔断,将死猫扔到台上。 相似文献
43.
本文针对一往复式氢气压缩机管道振动十分强烈的情况,分析了管系的结构自振频率、气柱固有频率和气流脉动,采取了改变管系结构频率和气柱固有频率的减振措施,经实践证明获得了较为理想的减振效果。 相似文献
44.
E Messou SV Sangaré R Josseran C Le Corre J Guélain 《Canadian Metallurgical Quarterly》1997,90(1):44-47
BACKGROUND: Gastric sucrose permeability is a noninvasive marker that reliably increases in association with gastrointestinal injury due to use of nonsteroidal antiinflammatory drugs. Despite the effect of Helicobacter pylori infection on the gastric mucosa, in a previous study we were unable to demonstrate that H. pylori infection was associated with abnormal gastric sucrose permeability. Our goal in this study was to explore further whether H. pylori infection changed gastric permeability; therefore, we evaluated the effect of treatment of H. pylori infection on gastric permeability to sucrose and the relation of sucrose permeability to density of polymorphonuclear leukocytes. MATERIALS AND METHODS: Five hundred milliliters of a solution containing 100 gm of sucrose was ingested by the subject at bedtime. Overnight urine was collected and assayed for sucrose by high-performance liquid chromatography. Sucrose permeability was assessed both before and approximately 4 weeks after anti-H. pylori therapy. RESULTS: Seventeen asymptomatic H. pylori-infected volunteers participated; 8 were cured. Sucrose permeability was in the range commonly found in normal controls both before and after anti-H. pylori therapy (mean excretion, 76.3 mg; range, 13-171 mg). Gastric sucrose permeability correlated with the density of polymorphonulcear cell infiltration of the mucosa. Cure of the H. pylori infection was associated with a small but significant decrease in sucrose permeability (98.8 +/- 18 mg to 51.7 +/- 9.8 mg (p = .01). Sucrose permeability was greater in those with a high density of mucosal polymorphonuclear cells compared to those with lower scores (119.5 +/- 4 vs 71.4 +/- 13 for those with scores > or = 5 compared to scores < or = 4; p = .023). Failed therapy resulted in an increase in the mucosal density of polymorphonuclear infiltration and sucrose permeability (56.4 +/- 13 mg-99.7 +/- 19 mg pretreatment vs posttreatment, respectively; p = .031). CONCLUSION: H. pylori gastritis causes a small but measurable increase in gastric permeability to sucrose that may reflect epithelial transmigration of neutrophils. 相似文献
45.
46.
设计并研制了一种用于压缩式致冷设备的电子式定温域多功能控制装置。它除具有控温范围宽、精度高、控温参数易调等优点外,还实现了低成本的温度显示、半自动除霜控制、加电延时保护、过欠压保护等功能。全部采用无触点控制方式,有良好的性能/价格比。 相似文献
47.
运放滞回比较电路在差动式温度控制中的应用研究 总被引:1,自引:0,他引:1
从差动式温度控制的角度研究了两种由集成运算放大器构成的滞回比较器(基型和交叉耦合型)的传输特性,发现它们均能用作闭环差动式控温单元,并都具有在温度设置点转换速度快、抗干扰能力强、控制单元设计简单等优点。分析和比较了这两种控温单元的控制参数的调节性能和参数的稳定性,获知后者的预置温度(Th或TL)和差动温度范围(△T)的设置值均能各自独立地调节,且系统的Th,TL,△T的实际值几乎仅决定于设置电路本身,因而显得更为优越。文中还讨论了应用中的有关问题,并给出了相关的应用实例。 相似文献
48.
The purpose of this study is to examine the interface between financial strain, informal received economic support, informal anticipated financial support, and psychological distress in later life. Data provided by a large probability sample of older adults in the People's Republic of China reveal that the relationship between financial difficulty and psychological distress is stronger for older adults who receive more economic assistance. However, the results involving anticipated support are in the opposite direction. More specifically, the association between financial problems and psychological distress is lower for older adults who believe that others stand ready to help in the future should the need arise. A detailed theoretical rationale is developed to explain these results. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
49.
冷轧形变量对钛板材再结晶织构形成的影响 总被引:1,自引:0,他引:1
采用三维晶体学取向分布函数(CODF)分析法研究了工业纯钛板材不同冷轧形变量对织构形成的影响。结果表明,冷轧形变量为50-70%时,再结晶退火后形成了(2118)(0110)和(1018)(1210)的部分纤维织构,而在30%较低或86%较高的形变量冷轧时,形成典型的轧制织构(2115)(0110)和再结晶织构(1013)(1210)型式。 相似文献
50.
A method for modeling and analyzing vias the multilayered integrated circuits is presented. The model is based on microwave network theory. The whole via structure is divided into cascaded subnetworks, including a vertical via passing through different layers and transitions from the microstrip line and/or striplines to the vertical via. The parameters of each subnetwork are obtained from electromagnetic field analysis. Numerical results in the frequency domain and the time domain are presented. Validation of the model has been carried out by both measurements and finite-difference-time-domain (FDTD) modeling. The results show good agreement with the measurements in the frequency range for which the components of the experimental model are within specification. The time domain simulation results also agree well with the FDTD results 相似文献