X60管线钢焊接过热区裂纹萌生和扩展特征的研究

本文通过程序控制的热模拟方法获得Ｘ６０管线钢焊接过热区组织，在对冲击载荷下裂纹萌生和扩展阶段的能量特征的分析中，发现Ｘ６０过热区在不同服役温度下具有四种典型的断裂类型。采用断口形态和裂纹行这跟踪观察的实验方法，观察了过热区在裂纹萌生和扩展阶段的力学特征和组织特征。在上述实验结果的基础上，采用塑性滑移线场理论，提出了Ｘ６０过热区在不同服役温度下的断裂机理。

A METHOD OF INITIAL VORTEX RELOCATION AND NUMERICAL SIMULATION EXPERIMENTS ON TROPICAL CYCLONE TRACK

Using the technique of smooth filtering and cylindrical filtering,the initial vortex circulation and large-scale environmental field were separated from the background field.Then the separated initial vortex circulation was translated and reinserted in the location where it was observed.This led to the determination of a method of initial vortex relocation.For seven tropical cyclones at 23 points of measurement time in the years of 2006 and 2007,two schemes,either directly adding a tropical cyclone bogus model in the background or adding it after the relocation of the initial vortex in the background field,were employed.Simulation experiments were compared.The results showed that the mean errors of the simulated tropical cyclone tracks at 24 and 48 hours were both smaller with the scheme of adding tropical cyclone bogus model after the relocation of the initial vortex in the background field.The relocation method of the initial vortex decreases the error caused by the deviation of the initial tropical cyclone location in tropical cyclone models.The relocation method is conducive to improving the track forecast of tropical cyclone models and has a good perspective for operational application.

DIAGNOSIS AND IDENTIFICATION OF DYNAMIC CORRELATION FACTORS BETWEEN WEST-PACIFIC SUBTROPICAL HIGH AND EAST ASIA MONSOON SYSTEM INDEXES

Based on the daily reanalysis data of NCEP / NCAR and by using the method of phase space reconstruction, the point conditional probability density of the subtropical high ridge index are determined and then used, together with their power spectra, to seek the correlation between them and individual monsoon-affecting factors and their power spectra. Through diagnosis, six indexes are discovered that have the most important effects on the subtropical high index. The results of the diagnosis indicate that the technique can identify the factors which are dynamically correlated. It can offer the basis in determining and choosing dynamic conceptual factors.

Preliminary Assessment of the Common Land Model Coupled with the IAP Dynamic Global Vegetation Model

The Common Land Model(CoLM) was coupled with the IAP Dynamic Global Vegetation Model(IAPDGVM), and the performance of this combined CoLMIAP model was evaluated. Offline simulations using both the original Common Land Model(CoLM-LPJ) and CoLM-IAP were conducted. The CoLM-IAP coupled model showed a significant improvement over CoLMLPJ, as the deciduous tree distribution decreased over temperate and boreal regions, while the distribution of evergreen trees increased over the tropics. Some biases in CoLM-LPJ were preserved, including the overestimation of evergreen trees in tropical savanna, the underestimation of boreal evergreen trees, and the absence of boreal shrubs. However, most of these biases did not exist in a further coupled simulation of IAP-DGVM with the Community Land Model(CLM), for which the parameters of IAP-DGVM were optimized. This implies that further improvement is needed to deal with the differences between CoLM and CLM in parameterizations of landbased physical and biochemical processes.

Responses of Earthworms to Organic Matter at Different Stages of Decomposition

This study was conducted to examine the responses of earthworms to soil organic matter and litter at different decomposition stages and their contributions in litter decomposition processes in southern subtropical areas of China. Two plantations were selected as the study sites: Site I was dominated by the exotic endogeic earthworm species Ocnerodrilus occidentalis; Site II was dominated by epigeic species Amynthas corticis. After the fallen litter and earthworms were removed or expelled, four treatments were set up as: reserving the top soil (0–5 cm, equal to H layer) (H), removing the top soil and adding fresh litter (Le), removing the top soil and adding semi-decomposed litter (Li), and a control with no top soil nor any litter (CK). Five randomized blocks that were enclosed with nylon nets on the top were set up in each site, and then the four treatments were arranged randomly in each block. After 2–3 months, earthworms were collected using the formalin method. The results showed that Ocnerodrilus occidentalis preferred Treatment H though it was found in Treatments Le and Li as well; Amynthas corticis preferred Treatment Li though sometimes it also appeared in Treatment H; and Amynthas sp., another epigeic species, was mainly present under Treatment Le and only appeared in Treatment H occasionally. These findings confirmed that earthworm species belonging to different ecological groups had different responses to organic matter at different decomposition stages. The impacts of earthworm communities dominated by O. occidentalis mainly appeared at the later periods of litter decomposition.

Making Use of the Eddy Currents Effect in the Examination of the Tribological Characteristics of Strip Rolling Mill Rolls

The key element in the proper performance of a rolling mill is the careful planning of the rolls operational conditions, since this factor constitutes the restricting element in the manufacturing process. In the article, a collection of operation and research steel strips hot-rolling mill information was presented, which was processed based on the advanced computer programmes for rolls grinders. The research outcomes were produced, presenting the application of eddy currents to detect materials flaws in metallurgical mill rolls.

热风卡腰炉附加煤粉节焦小结

遵照伟大领袖毛主席关于“人类总得不断地总结经验,有所发现,有所发明,有所创造,有所前进”的教导,在上级党组织和厂党支部正确领导下,通过批判刘少奇、林彪散布的“上智下愚”“爬行主义”反动谬论,排除王张江姚“四人帮”的干扰破坏,我厂铸造车间依靠工人群众,发扬自力更生、不断革命的精神,以革命推动生产发展,在省机械研究所指导下,在省、地铸造技术协作组协助下,我们对热风卡腰炉进行了一些技术革新,并进行了附加煤粉节省焦炭的试验生产,取得一定效果。现将改革的技术过程和我们的体会介绍如下:

“三通效应”对高温过热器管壁工作的影响及改进措施

针对阳逻电厂４号炉高温过热器超温爆管问题，分析与计算了进口等径三通对过热器管内蒸汽流量及壁温的影响，并提出了改进措施。

家有红鲤其乐无穷

我喜欢养鱼,养过金鱼,也养过热带鱼,几经比较选择,我现今养的却是当地农田里捞来的一种小鲤鱼——红鲤。这种小鲤鱼鳞衣绯红,也有粉红的、红白或红黑相同的,色彩斑斓,鲜丽晶莹,并不逊于一般的观赏鱼。这种红鲤还有许多优点,首先它生命力强。

Possible causes of the variation in fractal dimension of the perimeter during the tropical cyclone Dan motion

We calculated the fractal dimensions Db of the perimeter of tropical cyclone(TC)Dan based on the satellite GMS-5 infrared sensor images from 1800 UTC,1 October 1999 to 1200 UTC,9 October 1999.The fractal dimensions Db were used to characterize objectively the temporal change of TC complex structure.Our results show that the change of fractal dimension during TC Dan motion can be divided into three stages.The statistically significant difference does not exist either between Dm1 and DL or between Dm3 and DL,but it exists between Dm2 and DL,where Dmi denotes the mean value of Db in i-th stage(i=1,2 and3);DL denotes Lovejoy’s fractal dimension calculated based on satellite and radar data within the size range(1–1.2×106 km2),which is used as a"normal value"of the fractal dimension of the cumulus cloud perimeter for the global tropical region.TC Dan turns to the north from the west abruptly at the end of the second stage.The emergence of the second stage with high fractal dimensions may be viewed as a possible premonition for the track turning.Our results also show that there are two kinds of processes resulting in the translation from the first stage to the second stage.One is the interaction of TC circulation and an adjacent small scale convective cloud cluster,causing to the complexity increase of a local segment of the perimeter.The other includes the fragmentation of a strong convective area within the TC inner region,the self-organization of the small strong convective cloud clusters,the emergence,development,and merger of the small scale non-convective holes,and the formation of a gap of the perimeter,causing to the complexity increase of the whole TC perimeter.

Reducing the biases in shortwave cloud radiative forcing in tropical and subtropical regions from the perspective of boundary layer processes

Biases in shortwave cloud radiative forcing(SWCF), which cause overestimates in tropical regions and underestimates in subtropical marine stratocumulus regions, are common in many climate models. Here, two boundary layer processes are investigated in the atmospheric model GAMIL2, entrainment at the top of the boundary layer and longwave radiative cooling at the top of stratocumulus clouds, in order to reduce biases and reveal the mechanisms underlying these processes. Our results show that including the entrainment process in the model can reduce negative SWCF biases in most tropical regions but increases positive SWCF biases in subtropical marine stratocumulus regions. This occurs because entrainment reduces the low-level cloud fraction and its cloud liquid water content by suppressing the vertical turbulent diffusion in the boundary layer and decreasing the relative humidity when warm and dry free atmosphere is entrained in the boundary layer. Longwave radiative cooling at the top of stratocumulus clouds can enhance turbulent diffusion within the stratocumulus-topped boundary layer. When combined with the entrainment process, longwave radiative cooling reduces the positive SWCF biases in subtropical marine stratocumulus regions that are observed using the entrainment process alone. The incorporation of these two boundary layer processes improves the simulated SWCF in tropical and subtropical regions in GAMIL2.

Dynamic expression of the LAP family of genes during early development of Xenopus tropicalis

The leucine-rich repeats and PDZ (LAP) family of genes are crucial for the maintenance of cell polarity as well as for epithelial homeostasis and tumor suppression in both vertebrates and invertebrates.Four members of this gene family are known:densin,erbin,scribble and lano.Here,we identified the four members of the LAP gene family in Xenopus tropicalis and studied their expression patterns during embryonic development.The Xenopus LAP proteins show a conserved domain structure that is similar to their homologs in other vertebrates.In Xenopus embryos,these genes were detected in animal cap cells at the early gastrula stage.At later stages of development,they were widely expressed in epithelial tissues that are highly polar in nature,including the neural epithelia,optic and otic vesicles,and in the pronephros.These data suggest that the roles of the Xenopus LAP genes in the control of cell polarity and morphogenesis are conserved during early development.Erbin and lano show similar expression patterns in the developing head,suggesting potential functional interactions between the two molecules in vivo.