Search | Engineering

订阅投稿

首页学术期刊学术焦点学术视频工程成就工程前沿联系我们 English

资源类型

期刊论文 4

年份

2019 1

2008 1

2007 1

2006 1

关键词

GH位移 1

光子静质量 1

消失波 1

物理光学 1

负折射率 1

负波速 1

展开︾

检索范围：

排序：展示方式：

Effects of parenteral nutrition with and without GH on the GH/IGF-1 axis after hepatectomy in hepatocellular

CAO Jie, LUO Shimin, LIANG Lijian, LAI Jiaming, CHEN Shanming

《医学前沿（英文）》 2007年第1卷第3期页码 287-293 doi: 10.1007/s11684-007-0055-x

摘要： Postoperative hepatic insulin-like growth factor-1 (IGF-1) production may be severely disturbed in patients with liver cirrhosis. Complex alterations in the GH/IGF-1 axis are thought to play an important role in the protein catabolism that complicates major surgical procedures. The aim of this study was to explore the effects of parenteral nutrition (PN) with and without growth hormone (GH) on the GH/IGF-1 axis after hepatectomy for hepatocellular carcinoma (HCC) with cirrhosis and evaluate the potential roles of recombinant human GH (rhGH) therapy. Twenty-four patients with HCC with cirrhosis who underwent hepatectomy were randomly divided into two groups: a PN group ( = 12) and an rhGH+PN group ( = 12). Liver function, serum GH, IGF-1 and IGFBP-3 were measured before the operation and at postoperative days (POD) 1 and 6. Insulin-like growth factor-1 and IGFBP-3 mRNA in the liver tissue was detected by RT-PCR. The liver Ki67 immunohistochemistry staining was studied. At the same time, 12 patients with cholelithiasis or liver hemangioma who underwent operation served as normal control group. On POD 6, serum prealbumin, GH, IGF-1, IGFBP-3, hepatic IGF-1 mRNA, IGFBP-3 mRNA and liver Ki67 LI were higher in the rhGH+PN group than in the PN group. There was no significant difference in the 6- and 12-month tumor-free survival rate and the median tumor-free survival time between the PN group and the rhGH+PN group (〉0.05). These data indicate that rhGH+PN could ameliorate the changes in the GH/IGF-1 axis after hepatectomy for HCC in the setting of cirrhosis.

关键词： control function production surgical Complex

HTML PDF 收藏

Creep-fatigue crack growth behavior in GH4169 superalloy

Dianyin HU, Xiyuan WANG, Jianxing MAO, Rongqiao WANG

《机械工程前沿（英文）》 2019年第14卷第3期页码 369-376 doi: 10.1007/s11465-018-0489-7

摘要： This study aims to examine the crack growth behavior of turbine disc GH4169 superalloy under creep-fatigue loading. Crack growth experiments were performed on compact tension specimens using trapezoidal waveform with dwell time at the maximum load at 650 °C. The crack growth rate of GH4169 superalloy significantly increased with dwell time. The grain boundaries oxidize during the dwell process, thereby inducing an intergranular creep-fatigue fracture mode. In addition, testing data under the same dwell time showed scattering at the crack growth rate. Consequently, a modified model based on the Saxena equation was proposed by introducing a distribution factor for the crack growth rate. Microstructural observation confirmed that the small grain size and high volume fraction of the d phase led to a fast creep-fatigue crack growth rate at 650 °C, thus indicating that two factors, namely, fine grain and presence of the d phase at the grain boundary, increased the amount of weakened interface at high temperature, in which intergranular cracks may form and propagate.

关键词： crack growth rate creep-fatigue GH4169 superalloy CT specimen dwell time

HTML PDF 收藏

物理光学的若干进展

黄志洵

《中国工程科学》 2006年第8卷第2期页码 18-29

摘要：

就物理光学方面的一系列理论和实验研究，如Goos-Hänchen位移、FTIR现象、负折射率、太赫超光速实验、光子静质量测量等做了评述和讨论。指出近年来的研究显示了消失波现象的重要性，例如消失波可造成超光速传播，且常有新方法和新测量结果；介绍了物理光学在相关领域的技术创新和应用实例；讨论了光子有静止质量的可能性及光频标准和光频测量的历史和新的进展。

关键词：物理光学负波速负折射率 GH位移消失波光子静质量

HTML PDF 收藏

Grindability of high-temperature alloy with ceramic alumina wheels

ZHANG Hongxia, CHEN Wuyi, CHEN Zhitong

《机械工程前沿（英文）》 2008年第3卷第2期页码 139-145 doi: 10.1007/s11465-008-0040-3

摘要： The grindability of high-temperature alloy by using ceramic alumina wheels is studied on the basis of extensive analysis of the grinding force, grinding temperature, surface roughness and topography of ground surfaces, residual stress, hardness distribution of surface layer, and morphology of the surface layer from a metallographic point of view. The grinding burn mechanism of high-temperature alloy is unveiled and the feasible grinding parameters to avoid burning are analyzed. Some conclusions are obtained as follows. Increasing the grinding depth or the wheel velocity makes grinding temperature and residual tensile stress of the surface rise, which deteriorates the surface topography. Appropriate liner velocity of the wheel is 18–22 m/s and the depth of grinding should not exceed 0.02 mm in grinding GH2132 alloy with ceramic alumina wheels to assure the surface quality. When increases enough to cause grinding burn, the strengthening effect of particles ′ in base decrease and the micro-hardness of the surface is obviously lower than that of the base material, which deteriorates the mechanical properties and heat resistance of GH2132 alloy. Results provide a theoretical and experimental basis for technical optimization in the grinding of high-temperature alloy with high efficiency and high quality.

关键词： metallographic topography grinding GH2132 resistance decrease