Density of crystalline lens and cornea in different trimesters of pregnancy

PurposeTo evaluate topographic measurements of the anterior segment and densitometric measurements of the cornea and lens by Pentacam HR in different trimesters of pregnancy.MethodsThis prospective study included 150 healthy pregnant women in their first, second, or third trimester (Groups 1, 2 and 3, respectively) and 54 non-pregnant healthy women (Group 0). Topographic measurements, including central corneal thickness (CCT), corneal volume (CV), anterior chamber depth (ACD), corneal densitometry (CD) and lens densitometry (LD), were done with the Pentacam HR (Oculus, Wetzlar, Germany). The measurement results of the healthy pregnant women and non-pregnant healthy women were compared.ResultsCD values were found in Group 1 to be 13.19, in Group 2 to be 13.16, in Group 3 to be 13.17 and in Group 0 to be 13.22 (p = 0.811). The mean Group 1, Group 2, Group 3 and Group 0 LD-horizontal was 5.40 ± 0.5, 5.47 ± 0.38, 5.53 ± 0.44, 5.36 ± 0.43, respectively. The mean Group 1, Group 2, Group 3 and Group 0 LD-vertical was 5.6 ± 0.43, 5.66 ± 0.32, 5.71 ± 0.40 and 5.5 ± 0.44, respectively. Area LD values were higher in the advanced trimester period, and the only statistically significant difference was between Group 3 and Group 0 (p = 0.025). The difference between three-dimensional (3D) and peak LD values was not statistically significant between the groups (p = 0.89 and p = 0.91, respectively).DiscussionThe Pentacam HR seems to be an important option for the evaluation of LD, CD and topographic measurements of the anterior segment in pregnancy. In the present study, CD and LD, including LD-horizontal, LD-vertical, peak and 3D values, were not significantly different between pregnant women and non-pregnant women.     

Effect of Co on the microstructure evolution of modified HR3C austenitic heat-resistant steels during long-term ageing

The modified HR3C austenitic heat-resistant steels were aged at 650°C and 700°C for up to 3000 h. The effect of Co on microstructure evolution during long-term ageing was investigated using scanning electron microscope and transmission electron microscope. The experimental results showed that a large amount of σ phase precipitated within the grain during long-term ageing. The growth and coarsening of the σ phase were greatly influenced by the temperature. The variation of micro-hardness can be well understood in terms of volume fraction of the σ phase. The activation energy of forming σ phase was calculated by the Johnson–Mehl–Avrami equation and Arrhenius equation. It was found that Co addition can suppress the precipitation of the σ phase. The related mechanism of Co effect is discussed.     

大厚度20HR钢焊接性及焊接热影响区韧性研究

对大厚度20HR钢的焊接性及焊接热影响区(HAZ)韧性进行了试验研究,为核电设备焊接工艺的制定提供了依据。     

高温长时服役HR3C钢焊接接头的组织与性能

采用金相显微镜、扫描电镜、X射线衍射仪以及拉伸和弯曲试验研究了高温服役4.2万小时超超临界机组用HR3C钢焊接接头的微观组织和力学性能。研究结果表明,高温长时服役后HR3C钢焊缝金属中形成了大量条状和颗粒状M₂₃C₆析出相,焊接热影响区奥氏体晶粒长大,在晶界附近形成了板状M₂₃C₆相。拉伸和弯曲试验结果表明HR3C钢焊接接头高温服役后表现出明显的时效脆化倾向。     

SAP系统在供电企业人力资源管理中的应用

人力资源管理模块（SAPHR）在浙江省电力公司各市县单位的上线运行,解决了以前因为管理和业务不规范造成的数据重复、反复填报等问题,实现了与其他业务系统的集成和对人力资源的统一规划、合理调配,提高了企业的经济效益,使供电企业的信息化管理提升到了一个新的水平。介绍了HR模块在供电企业组织管理,人事管理和薪资管理等方面的应用以及管理的提升。     

700℃时效过程中HR100合金的碳化物析出行为

对经700℃时效不同时间后的镍基HR100合金中的析出相进行了定性与定量分析,研究了HR100合金中的碳化物在长期时效过程中的析出行为。结果表明,HR100合金中的M_6C型碳化物为亚稳相。在长期时效过程中,随着合金元素的扩散,HR100合金中的M_6C会逐渐转化为M_(12)C。而且在700℃时效1万h过程中,HR100合金中的碳化物的析出行为主要分3个阶段:快速析出与M_6C→M_(12)C转化阶段,相对稳定阶段,M_(12)C和M23C6进一步析出、长大阶段。另外,对不同类型碳化物中的合金元素配比在长期时效过程中的变化进行了分析,发现在(M_6C+M_(12)C)的粗化过程中,Cr元素和Mo元素起主要作用;而在M_(23)C_6的粗化过程中,Cr元素起主要作用。     

人松弛素H2类似物在毕赤酵母中的高效表达及其活性

目的利用毕赤酵母表达系统高效分泌表达人松弛素H2类似物(Human relaxin-2 analogue,HR2),并检测其生物活性。方法通过密码子优化合成HR2基因,构建重组表达质粒pPICZαA-HR2,转化毕赤酵母菌GS115,甲醇诱导表达,并对表达产物进行Tricine-SDS-PAGE和Western blot分析。表达产物经超滤和柱层析纯化后,切除人工C肽,检测其生物活性。结果经双酶切鉴定和测序证实,重组表达质粒pPICZαA-HR2构建正确;Tricine-SDS-PAGE分析显示,表达的重组蛋白相对分子质量约6 500,表达量占菌体总蛋白的47.6%,为451μg/ml,且为分泌表达;Western blot分析显示,重组蛋白具有良好的反应原性;纯化的重组蛋白纯度达96%;经检测C肽切除的重组HR2对THP-1细胞具有刺激活性。结论成功在毕赤酵母GS115中高效分泌表达了重组松弛素H2类似物,并具有一定的生物活性。     

A review on the clad failure studies

In this paper, an attempt has been made to systematically organize the research investigations conducted on clad tube failure, so far. Before presenting the review on the clad failure studies, an introduction to different clad materials has been added, in which the effect of alloying elements on the material properties have been presented. The literature on clad failure has been broadly categorized under the headings LOCA and RIA. The failure mechanisms like creep, corrosion and pellet-clad interaction have been discussed in details. Each subsection of the review has been provided with summary table, in which the studies are arranged in the chronological order. A small section on acceptance criteria for ECCS has also been included. The last section of the review has been dedicated to the core-degradation phenomena.     

哈尔乌素露天煤矿提高459HR电铲效率的措施

根据哈尔乌素露天煤矿生产的实际情况,针对495HR电铲达不到设计的生产能力的状况,探讨了如何提高495HR电铲效率的措施。     

电站锅炉用HR3C新型奥氏体耐热钢的激光焊接

超(超)临界电站锅炉用新型铁素体、奥氏体耐热钢对传统焊接技术提出了挑战.激光焊接技术作为一种可靠高效的先进焊接方法,为此类钢的焊接提供了经济可行的解决办法.采用窄间隙激光填丝焊接技术,研究了10 mm厚HR3C新型奥氏体耐热钢管的激光焊接性,并对接头显微组织及高温持久强度进行了分析.试验采用3 500 W Slab CO2激光器,填充焊丝为T-HR3C.结果表明,通过优化激光焊接工艺参数,可以获得X射线探伤和渗透检验合格的焊接接头;焊缝具有明显的沿中心对称形态,以细小的柱状晶为主,混夹着少量细小的等轴晶;热影响区晶粒没有明显长大,焊缝与母材的显微硬度相当,没有明显的软化区;焊态下的激光焊接接头高温持久强度较固溶处理的热丝TIG焊接头有明显提高.