锚链钢弯环内侧开裂分析原因

对锚链钢弯环的原材料和车削后热处理材料及开裂的弯环进行低倍、组织、断口检验，结果表明弯环开裂是由车削后的热处理工艺和焊接工艺控制不当造成的。     

钛合金大型环件热辗扩成形应力-应变场演变规律的尺寸效应(英文)

基于可靠的钛合金大型环件热辗扩成形过程热力耦合三维有限元模型,研究并对比了不同尺寸环件的应力应变场演变规律。结果表明:对于不同尺寸环件的成形过程,当γ(整个成形过程的当量每转进给量分配比)减小时,成形结束时的Mises应力峰值可能从环件的驱动辊侧咬入点转移至芯辊侧咬入点,而等效塑性应变峰值有从环件外表面向内表面转移的可能性;当L(整个成形过程的当量变形区长度)增大时,成形结束时的Mises应力峰值可能出现在中间层。成形结束时Mises应力峰值和等效塑性应变峰值的位置是以上两方面综合作用的结果。在成形环件的变形区,环件表层金属处于三向压缩应力状态,中间层金属处于一向压缩、两向拉伸或者两向压缩、一向拉伸应力状态;整个环件处于一向压缩、两向拉伸应变状态。     

双环永磁轴承径向偏移承载能力的研究

在分析永磁轴承基本结构的基础上,提出了双环永磁轴承的结构,并进一步分析了该轴承的工作原理和径向偏移承载能力,推导了径向磁吸力、轴承间隙、剩磁之间的关系,经仿真其结果表明:大部分磁力线形成闭合回路,最大限度地减少了磁力线的对外散发,保证了永磁环性能的稳定,延长了永磁环的使用寿命;径向磁吸力随轴承间隙的增大逐渐减小,随表面剩磁的增加而增大;轴承的径向刚度等于长度为半周长的线性模型的刚度。     

CZ9206自动车床改进

CZ9206自动车床工作时,由于推料头的自动调心功能差,容易造成推料头、V形支承和轴承等工装损坏;此外,当机床正常工作而料道中没有套圈时,也会出现以上损坏。针对上述情况,对推料头的结构进行了改进,增加了自动调心功能;对机床的电气控制系统进行了部分改进,增加了当料道中无套圈时机床的自我保护功能。以上改进措施效果良好,避免了工装的损坏,保证了生产的顺利进行,减少了废品,提高了经济效益。     

Optimized time‐gated generalized polarization imaging of Laurdan and di‐4‐ANEPPDHQ for membrane order image contrast enhancement

The membrane dyes Laurdan and di‐4‐ANEPPDHQ can be used to image membrane order due to a spectral blue‐shift in the fluorescence emission between the liquid‐ordered and liquid‐disordered phases. These images typically take the form of a normalized intensity ratio image known as a generalized polarization (GP) plot. Here, we exploit the known excited state photophysics and time‐resolved data acquisition via time‐correlated single‐photon counting (TCSPC) to demonstrate GP contrast enhancement for these two probes of 7 and 31%, respectively. This improvement in image contrast enhancement will be invaluable when studying the role of lipid rafts in fixed and live cell systems. Microsc. Res. Tech. 2010. © 2009 Wiley‐Liss, Inc.     

Effects of honed cylinder surface topography on the wear of piston-piston ring-cylinder assemblies under artificially increased dustiness conditions

This paper presents results of the measurement of the surface roughness and other physical properties of the outer layer of honed cylinders. The cylinders tested had various surface topographies as a result of honing by abrasive tools of differing design. The results of wear measurements of the cylinders and piston rings mating with them during automotive gasoline Polonez 1500 engine operation under artificially increased dustiness conditions are presented and analysed.     

Pooled versus separate measurements of tree-ring stable isotopes

δ¹³C and δ¹⁸O of tree rings contain time integrated information about the environmental conditions weighted by seasonal growth dynamics and are well established as sources of palaeoclimatic and ecophysiological data. Annually resolved isotope chronologies are frequently produced by pooling dated growth rings from several trees prior to the isotopic analyses. This procedure has the advantage of saving time and resources, but precludes from defining the isotopic error or statistical uncertainty related to the inter-tree variability. Up to now only a few studies have compared isotope series from pooled tree rings with isotopic measurements from individual trees. We tested whether or not the δ¹³C and the δ¹⁸O chronologies derived from pooled and from individual tree rings display significant differences at two locations from the Iberian Peninsula to assess advantages and constraints of both methodologies. The comparisons along the period 1900-2003 reveal a good agreement between pooled chronologies and the two mean master series which were created by averaging raw individual values (Mean) or by generating a mass calibrated mean (MassC). In most of the cases, pooled chronologies show high synchronicity with averaged individual samples at interannual scale but some differences also show up especially when comparing δ¹⁸O decadal to multi-decadal variations. Moreover, differences in the first order autocorrelation among individuals may be obscured by pooling strategies. The lack of replication of pooled chronologies prevents detection of a bias due to a higher mass contribution of one sample but uncertainties associated with the analytical process itself, as sample inhomogeneity, seems to account for the observed differences.     

传统古村落的保护与发展——以张家口市蔚县西古堡为例

我国古村落数量大,历史悠久,历史和艺术价值不容忽视,但当今社会快速发展,人们生活方式发生巨大变革,原始古村落难以满足现代人生活需求,古村落发展和保护面临许多现实问题,该文以张家口市西古堡为例,探讨古村落的保护和发展问题。     

Effect of oil degradation during frying on the color of fried, battered squid rings

Oil degradation caused by the number of fryings performed and the effect of oil degradation on the color of fried battered squid rings were studied. Spectrophotometric techniques with absorbance in the UV and visible ranges, and iodine, peroxide, and acid values were used to determine oil degradation. Determination of various CIELAB parameters in order to study the external color of the fried battered squid rings revealed no differences in color due to the number of fryings. A study of the color of the battered squid rings at various frying times and temperatures showed significant differences for both variables. Although there was some degradation in the oil after 20 fryings, appearing as a slight darkening, it did not affect the final color of the fried, battered squid rings.     

关于环的正则性

利用环的拟理想对环的正则性进行了刻画,主要得到了两个结果:①设R是左SPF-环.若R的每一个极大的左理想是拟理想,则R/J(R)是强正则环.②设环R的每一个极大的左理想是拟理想,则以下等价:R是强正则环;R是广义正则的SI环;每一个单左R-模是GP-内射的.