板型燃料组件内部温度场数值模拟

以板型燃料组件为研究对象，采用商用流体力学计算程序CFX5对板型燃料组件内部温度场进行数值模拟。数值计算结果表明：燃料组件不同流道的流速分布和温度分布均较均匀，单一流道的流速分布和温度分布也较均匀。燃料板所构成的各流道从外到内流速变化不太大，在中间流道内流速稍小一些，但差值很小；燃料组件单一流道内的流速在壁面附近快速减小，壁面上流速为0。燃料板和定位梳的温度最高，侧板温度与板间流体温度相近，侧板外侧的流体温度较低。     

温度、酸度对大曲酒产、质量的影响

本文从温度、酸度对大曲酒产、质量的影响，揭示大曲酒夏季＂掉排＂的主要原因为高温、高酸环境抑制了酿酒酵母的发酵，降低了酿酒酵母的发酵力，从而影响了大曲酒的产、质量。     

Stable Oxygen and Carbon Isotopic Compositions of Lates stappersii Otoliths from Lake Tanganyika,East Africa

In this study, we measured growth trends in oxygen and carbon isotopic ratios in whole sagittal otoliths from three adult centropomid fish (Lates stappersii) from each of three sub-basins of Lake Tanganyika, East Africa. Sampling density was 20 to 50 samples per otolith. Both δ¹⁸O and δ¹³C values increase with age. The δ¹⁸O data suggest that otoliths were precipitated near the expected equilibrium with the ambient environment (ca. +3.5‰) and support a migration pattern from surface waters during larval stages to deeper waters (40 to 80 m) for mature fish. Relatively high δ¹⁸O values in the southern sub-basin are consistent with cooler temperatures in the region during seasonal upwelling. The δ13C increase from otolith core to edge is large (up to 4‰) and is interpreted as due to ontogenetic changes in diet and contributions from a decrease in the proportion of respired CO₂ incorporated into otolith carbonate as metabolic rates of the fish dropped with maturity. The data seem to successfully reveal life strategy and migration patterns of L. stappersii, document regional differences in lake conditions, and provide a record of temperature within the water column during which the fish lived. Higher resolution studies and analyses of historical samples could be used to constrain modern and past growth patterns, and to reconstruct past temperature gradients and productivity patterns in the lake.     

The PET18 locus of Saccharomyces cerevisiae: a complex locus containing multiple genes

The basis of pleiotropy shown by the pet18 mutants of Saccharomyces cerevisiae (rho-0,KIL-0 and temperature sensitive growth) was examined by cloning the fragment which complements the defect in growth at 37 degrees C of the pet18 mutants. The cloned DNA could complement the defect in the maintenance of the killer plasmid but did not give the cell the ability to maintain mitochondrial DNA. Sequence analysis of the cloned DNA revealed the presence of four open reading frames, at least two of which are necessary for the complementation activity. By using the cloned DNA as a probe, we found that two independent pet18 mutants have a deletion covering the entire sequence contained in the probe. From these results we predict that the traits of the pet18 mutants that concern temperature sensitivity and killer of the pet18 mutants are controlled by a separate gene(s) from that which participates in the maintenance of mitochondrial DNA.     

Excel的常用函数在单元格中的粘贴要素

以十种函数为例,讨论了在EXCEL电子表格软件中的单元格里粘贴函数的应用要素,即参数的数量、参数的种类、参数之间的关系、函数的书写及粘贴过程等。例举少许易懂函数样例,有助于人们理解、发挥函数功能的强大作用,提高工作效率。     

吸入短寿命氡子体动物肺组织剂量与体重关系的探讨

本文介绍吸入短寿命氡子体的不同种动物肺组织吸收剂量与体重的关系。实验结果表明,吸收剂量随体重的增加而减小。     

Improvement of levitation characteristics in a magnetic bearing system using HTSC‐permanent magnet hybrid structure

Magnetic bearing using pinning force of a permanent magnet and a high‐temperature superconductor has been developed. Additional permanent magnet is introduced to increase the levitation force of the magnetic bearing. In this hybrid magnetic bearing system, levitation force is mainly given by the repulsive force of the permanent magnets, and stability for the lateral direction is given by pinning force of the superconductor. The experimental device is developed. A ring‐type superconductor and a bulk one are examined. Levitation characteristics of the hybrid magnetic bearing are measured. The bulk superconductor shows better characteristics of both levitation and lateral stability than the ring one. Levitation force of the hybrid system becomes about twice as large as that of the nonhybrid one. Although, the repulsive force of the permanent magnet decreases the lateral stability of the system, its influence becomes small by choosing an adequate position of the permanent magnets and the superconductor. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(1): 71–77, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10350     

溅渣护炉工艺探讨

从炉渣对炉衬和溅渣层的侵蚀机理入手,提出了兼顾冶金和溅渣双重效果的直接造渣工艺,探讨了终渣碱度、MgO、FeO含量等的调整范围,分析了溅渣操作中枪位、时间等的控制和炉底上涨的原因,以期更好地运用溅渣护炉技术。     

Surface Hardening of High-Strength Low Alloy Steels (HSLA) Dual-Phase Steels by Ball Burnishing Using Factorial Design

Burnishing is used increasingly as a finishing operation which gives additional advantages such as increased hardness, fatigue strength, and wear resistance. Experimental work based on 3⁴ factorial design was carried out to establish the effects of ball burnishing parameters on the surface hardness of high-strength low alloy steels (HSLA) dual-phase (DP) steel specimens. Statistical analysis of the results shows that the speed, feed, lubricant and ball diameter have significant effect on surface hardness.     

（Ba1-xSrx）（Zn1/3Nb2/3）O3微波介质陶瓷温度系数的异常

研究了（Ba1-xSrx）（Zn1/3Nb2/3）O3微波介质陶瓷温度系数的非线性变化以及异常的原因。根据CM公式，随着系统中Sr（Zn1/3Nb2/3）O3的增多，τc的异常是由于氧八面体的畸变导致的相转变（对称性降低）所造成的（晶体结构由无序立方相向有序赝立方相的连续变化）。相转变的发生相应影响了极化以及极化模式，这是造成τc异常的根本原因。