FATIGUE CRACK GROWTH BEHAVIOR of 0Cr18Ni9 STAINLESS STEEL AT HIGH TEMPERATURES

研究奥氏体不锈钢0Cr18nI9在高温(550℃)下的疲劳裂纹扩展规律。测试采用标准CT(COMPACT TEnSIOn)试样,最大载荷范围为6.5 kn~14 kn,应力比为0.1(室温)和0.05(550℃)。裂纹扩展过程通过QuESTAr长焦距显微镜直接观测,同时采用COd(CrACk OPEnIng dISPlACEMEnT)规记录加载线位移。由于在高温条件下,测试终止时试样的裂纹前缘呈明显弧形,故此给出实测表面处裂纹长度有效值的修正方法。对高温疲劳裂纹扩展问题,采用应力强度因子范围Δk作为裂纹扩展驱动力参数,同时考虑高Δk和低Δk值对裂纹扩展规律的影响,得到0Cr18nI9不锈钢在550℃下的疲劳裂纹扩展规律表征模型,给出裂纹扩展率的上限结果。For austenitic stainless steel 0Cr18Ni9,fatigue crack grow law are studied at 550 ℃.The crack growth tests adopt the standard compact tension(CT) specimens.The applied maximum loads are from 6.5 kN to 14 kN and the stress ratios are 0.1(at room temperature) and 0.05(at 550 ℃).The crack growth length is directly measured by QUESTAR long focus microscope system and the load-line displacement is simultaneously recorded by using crack opening displacement(COD) gauge.Because of the good ductility of 0Cr18Ni9 at high temperatures,the crack front curves on fracture surface of the specimens are complex.In order to get an effective crack size,a modified method for crack length inspected on the surface is proposed.The stress intensity factor range ΔK is used as the driving force parameter of fatigue crack growth.Considering the high ΔK and the low ΔK effects on the fatigue crack growth law,the fatigue crack growth law is obtained for stainless steel 0Cr18Ni9 at room and high temperatures and the upper bound to the crack growth rate is given.国家自然科学基金(50605039);福建省新世纪优秀人才支持计划资助项目---

Reliability and validity of the Chinese version of Family Hardiness Index

目的测评中文版家庭坚韧性量表的信度和效度。方法取得原作者对量表的翻译和使用的授权,组成翻译小组对量表进行翻译,选取30名入院患儿的父母进行预调查,对语言表述调适,采用中文版家庭坚韧性量表对330名住院患儿父母进行调查,评价其内部一致性、重测信度、内容效度、结构效度。结果中文版家庭坚韧性量表的CrOnbACH'Sα系数为0.803,折半信度系数为0.738,各条目内容效度和量表总体内容效度指数均为1,结构效度3个公因子的累积贡献率为61.25%。结论中文版家庭坚韧性量表的信度和效度高,有可操作性,可作为家庭坚韧性的测量工具。Objective To validate the reliability and validity of the Chinese version Family Hardiness Index( FHI).Methods On base of obtaining authorized translation and use of the scale's original author,a translation team was set up to translate the FHI.Thirty hospitalized children's parents were asked to participate in the preliminary investigation,language adjustment was done.Totally,330 parents of hospitalized children were investigated by FHI of Chinese version.Then,the Cronbach's alpha coefficient,test-retest reliability,content validity and construct validity were then tested.Results The Cronbach's alpha coefficient of the Chinese version FHI was 0.803,the split-half reliability was 0.738,the content validity I-CVI was 1,S-CVI was 1,and the three common factors' accumulating contribution rate was 61.25%.Conclusion The Chinese version FHI has good reliability and validity,and has high operability.It can be used as a valid tool for the measurement of family hardiness

Optimization of separation methods and culture system of chicken embryonic stem cells in vitro

背景:胚胎干细胞是从动物早期胚胎的内细胞团或原始生殖细胞分离出来的具有发育全能性的一种未分化的无限增殖细胞系。而鸡胚胎干细胞则是从X期鸡胚的胚盘分离而来。目的:优化鸡胚胎干细胞分离方法和离体培养体系。方法:采用滤纸纸环-发环的方法从X期鸡胚分离胚盘细胞,并采用STO细胞作为饲养层和大鼠肝细胞(brl)条件培养基(CM)+细胞因子作为离体培养体系对分离的胚盘细胞进行培养。结果与结论:滤纸纸环-发环法获得的完整胚盘率为75%~85%,克隆形成率约为50%。brl-CM+饲养层培养体系,鸡胚胎干细胞可传至7代,而brl-CM+饲养层+细胞因子培养体系,鸡胚胎干细胞可传至25代。分离到的鸡胚胎干细胞,经碱性磷酸酶染色、SSEA-1染色鉴定,表明鸡胚胎干细胞处于未分化状态。提示,实验不仅优化了鸡胚胎的分离方法,获得完整且杂质少的胚盘,而且进一步优化了鸡胚胎干细胞体外培养体系。BACKGROUND:Embryonic stem cells are undifferentiated permanent cell line derived from inner cell mass cells and primordial germ cells of animal's early embryos.Chicken embryonic stem cells are derived from the blastodermal of a X-stage embryo.OBJECTIVE:To optim the separation method and in vitro cultural system of chicken embryonic stem cells.METHODS:The X-stage chicken embryos were isolated by using a small square of ?lter paper with a hole punched in the center,and the blastodermal cells were isolated by using the hair loop.STO cells were used to make feeder layer;at the same time,BRL-CM and cytokine were also used for chicken embryonic stem cells in vitro cultural system.RESULTS AND CONCLUSION:The filter paper loop and the hair loop could obtain complete the blastoderm,and the successful percentage was 75%-85%.The colony formation rate was about 50%.After culture in the BRL-CM + feeder layer + cytokine culture system,the passage of CES cells is the seventh generation;BRL-CM + feeder layer + cytokines,cultured chicken embryonic stem cells could passage to the 25th generation.Isolated chicken embryonic stem cells were in an undifferentiated state detected by alkaline phosphatase staining and SSEA-1 staining.The findings indicate that this experiment not only optimized the isolation method of chicken embryonic stem cells to obtain complete and pure embryos,but also further improved the in vitro culture system of chicken embryonic stem cells.国家973项目(2009CB941600)资助;国家自然科学基金项目(31072101)资助---

海洋管理经济刺激手段性质剖析

文章对我国已经和即将实施的几种主要海洋管理经济刺激手段的概念、内涵、外延及其经济性质进行了剖析,并探讨了这些经济刺激手段间及他们与行政事业收费间的区别和联系。理清海洋管理的经济刺激手段的性质,对完善我国海洋管理,利用经济刺激手段来提高海洋资源的利用效率、保护我们赖以生存的海洋资源与环境的安全性和完整性具有重要意义。海洋工程和溢油污染生态补偿/赔偿关键技术研究示范(#201105006

A New Approach to Object Verification Based on Bayesian Theory

提出了一种验证图像中候选目标的新方案.综合目标的先验知识,将目标验证转化为给定候选目标的条件下,图像特征观察集合的条件概率问题.同时,提取图像的短线段特征,利用短线段特征的观察,给出了一种目标验证方法排除复杂场景图像中虚假建筑物目标.在自然图像集上进行的实验表明,所提出的方法能有效排除虚假目标,满足处理自然图像的要求.A novel framework of object verification is proposed.Integrating by the prior knowledge of object,object verification is turned into a conditional probability of a set of observable cues available conditioned upon an object hypothesis.Then features of short line segments are extracted,and a new algorithm which verifies objects of building in complex scenes is presented using observation of line segments,.Tests on natural image sets showed that the proposed algorithm could effectively eliminate false objects,and satisfy the request of processing natural images on time performance.国家自然科学基金资助项目(60175008);; 国家创新研究群体资助项目(60024301);; 厦门大学“985”二期信息创新平台项

畜禽草耦合模式初探

草原牧鸡推动畜-禽-草耦合,成为一种新型草地利用方式,在生物灭蝗、土壤培肥和牧民增收等方面发挥良好作用,大范围推广有可能实现退化草地生态和生产功能的双提升.农区散养鸡由来已久,方法简单,易于掌握,能否照搬到草原牧区?这种方式会对草地生态系统有何影响?尚不清楚.为此,本研究通过开展以农区散养鸡方式牧鸡(MJ)和围封(CK)对比实验,探索以农区散养鸡方式开展牧鸡的可行性.结果表明,MJ样地内鸡群的空间分布符合依赖密度的聚集分布幂法则模型.随距离鸡舍由近及远,鸡的密度显著降低,从4000只/hm~2(R<R60 m).植物群落受MJ、距离和MJ×距离影响显著.距离鸡栖息地20 m以内,MJ对植被的破坏严重,群落高度、盖度和地上生物量均显著低于CK.20~60 m范围内,得益于MJ的养分添加效应,其物种丰富度、盖度和地上生物量均显著高于CK,MJ当年的升高幅度分别为110.0%,54.7%和43.2%,MJ第二年的升高幅度与第一年相当;而当距离大于60 m时,MJ对植被无显著影响.MJ会造成鸡群的不均匀分布和近栖息地附近植被的严重破坏,不宜在畜禽草耦合模式中应用.实际生产过程中牧鸡应尽量做到密度适中和均匀分布,充分发挥其养分添加效应,促进植被的生长与恢复

高温培养条件下爪哇伪枝藻的生理特性和超微结构特征

荒漠生物结皮广泛分布于干旱区环境,高温是影响生物结皮中藻类生存的重要环境因子。在实验室培养条件下,以生物结皮形成和发育中的重要优势种爪哇伪枝藻(Scytonema javanicum Born et Flah)为材料,研究高温胁迫对伪枝藻生理生化特性和细胞结构的影响。设置了25℃(对照)、35℃、40℃和45℃等不同高温处理,测定了短期(6h)和长期(15d)高温条件下,S.javanicum的光合活性、光合色素、多糖含量和丙二醛含量以及细胞超微结构的变化。结果表明,S.javanicum最大光化学量子产量Fv/Fm和PSII有效光化学量子产量ΦPSII在35℃下表现出最大值。40℃高温明显抑制藻体叶绿素a合成,35℃处理促进了叶绿素a合成(高于对照值),而40℃处理明显促进了藻体类胡萝卜素合成,高于对照处理和35℃处理。随温度升高,S.javanicum丙二醛、胞内可溶性糖和胞外多糖含量呈现出逐渐增大的趋势。透射电镜切片显示,40℃高温明显破坏了藻体细胞超微结构,如原生质体出现絮状形态和空泡化,35℃处理则有利于细胞形态结构的保持和稳定。以上结果初步证实了S.javanicum能够较好地耐受适当的高温(35℃)。研究对于了解S.javanicum对高温环境的耐受程度及对高温的适应性具有一定的理论意义,并对利用荒漠蓝藻治理荒漠化具有实际指导价值

近1200 a来黄河下游梁山泊沉积记录的环境变迁

利用梁山泊670 cm柱状岩芯沉积物,基于精确的AMS-14C年代测定,通过高分辨率的粒度、磁化率、总有机碳、 C/N比值等环境代用指标的综合分析,并结合历史文献记载,初步揭示了1200 a来黄河下游地区平原湖泊沉积特征及环境演化历史.结果表明,梁山泊环境演化大致分为5个阶段: 790 940 AD期间,为低湖面的沼泽沉积环境,气候冷干; 940 1215 AD期间,屡次受到黄河决溢洪水影响,湖盆扩张,湖泊水位上升,为梁山泊极盛期,气候暖湿; 1215 1310 AD期间,黄河夺淮入黄海,湖区淤积严重,湖泊萎缩减小; 1310 1470 AD期间,再次受到黄河决溢洪水影响,水位上升,面积扩张,但逊于极盛期; 1470 AD至现代,黄河河道进一步南移,远离梁山泊,湖盆淤积抬高,梁山泊最终消失,直到1855 AD,黄河第6次大改道北移,湖泊再次受到黄河洪水影响,由于前期受到泥沙淤积抬高,该地区仅作为黄河泥沙承载区.在气候变化大背景下,黄河改道决溢是梁山泊演化的主因.</p