铁合金文摘THJ1829─1840

铁合金文摘ＴＨＪ１８２９─１８４０ＴＨＪ１８２９ＴＦ６４１．１ＴＦ６１５Ｃｒ－Ｓｉ－Ｃ系和Ｃｒ－Ｆｅ－Ｓｉ－Ｃ系中的液－固平衡［Ｌｉｑｕｉｄ－ＳｏｌｉｄＥｑｕｉｌｉｂｒｉａｉｎｔｈｅＣｒ－Ｓｉ－ＣａｎｄＣｒ－Ｆｅ－Ｓｉ－ＣＳｙｓｔｅｍｓ］，（Ｋ．Ｋｏ...     

熔融织构超导样品的交流磁化率特性

在外磁场Ｈ∥Ｃ的情况下，用交流磁化率方法对熔融织构样品ＧＢＣＯ进行了研究。当外加磁场较低（０～５×１０￣（－２）Ｔ）时，得到不同磁场下ＧＢＣＯ的交流磁化率实部与虚部随温度变化的系列曲线，并从虚部曲线中取出不同磁场时的峰值温度Ｔ＿ｍ（Ｈ），与各自零外场时的Ｔ＿ｍ（Ｏ）约化为ｔ＝Ｔ＿ｍ（Ｈ）／Ｔ＿ｍ（Ｏ），再作于ｔ－Ｈ平面上。发现ＧＢＣＯ的ｔ与Ｈ之间可用线性关系进行近似拟合，在较高的外加磁场（０～７Ｔ）下同样在ｔ－Ｈ平面内作出了ＧＢＣＯ的ｔ－Ｈ曲线，可用指数关系ｔ＝ＡＨ￣ｎ（ｎ＝２／３）进行拟合，类似于不可逆线行为。并对Ｔ＿ｍ－Ｈ曲线的行为及代表的意义作了讨论。     

选择性螯合滴定法测定铅含量

提出用ＡＤＴＣＰＡ作释放剂选择性螯合滴定法测定铅。加入过量ＥＤＴＡ（螯合Ｐｂ＾２＋和其他金属离子），剩余的ＥＤＴＡ用锌标准溶液，在ｐＨ５￣６时返滴定，以ＸＯ－ＭＴＢ－ＣＰＢ为混合指示剂。然后加入ＡＤＴＣＰＡ，分解Ｐｂ－ＥＤＴＡ螯合物，释放出的ＥＤＴＡ，再用锌标准溶液返滴定，终点变化额外敏锐。实验结果表明，几乎所有金属离子均不干扰。该法已应用于测定铅基合金镀层、Ｐｂ－Ｓｎ－Ｃｕ合金镀层和电镀溶液中的     

C,P对碳素钢冶炼影响浅析

本文通过统计数据分析了Ｃ、Ｐ对碳素钢冶炼的影响，得出冶炼碳素钢的氧化时间（Ｔ０）与脱Ｃ量（ＣＳ－Ｃｆ）的关系：Ｔ０＝［５２（Ｃｓ％－Ｃｆ％）＋９．６］ｍｉｎ，指出冶炼碳素钢的脱Ｃ量加以合理的控制，可实现高产、优质、低耗。     

搅拌磨机械化学法合成β—TCP粉末

利用搅拌磨的机械化学效应合成了超细β－ＴＣＰ粉末,研究了磨矿时间、热处理温度和反应时间对β－ＴＣＰ粉末性能的影响。结果表明,用机械化学法合成β－ＴＣＰ,工艺简单,周期短,粉末平均粒径小于０．５μｍ。同时探讨了机械化学法合成β－ＴＣＰ的机理。     

激光重熔预处理制备陶瓷涂层

在激光表面重溶预处理的ＴＣ４合金基材上预置涂敷ＣａＨＰＯ·２Ｈ２Ｏ－ＣａＣＯ３－Ｙ２Ｏ３混合粉末，再经激光熔覆处理制备了生物陶瓷复合涂层，研究了该生物陶瓷涂层的组织和性能。结果表明，采用激光表面重熔预处理作过渡层制备的生物陶瓷涂层的界面结构良好，表层为ＨＡ和β－ＴＣＰ组成的活性生物陶瓷复合涂层。     

化学气相沉积制备SiC涂层：I.热力学研究

对化学气相沉积（ＣＶＤ）法制备ＳｉＣ的热力学进行了系统研究，考察了Ｈ２－ＭＴＳ，Ａｒ－ＳｉＯ－Ｃ，Ｈ２－ＳｉＯ－ＣｘＨｙ，Ｈ２－ＳｉＨ４－ＣｘＨｙ等体系，着重研空了温度、压力、载气量和图对ＣＶＤ法制备ＳｉＣ的实验具有指导作用。     

二次炼钢钢水加热技术及应用

对国内外二次炼钢中所应用的钢水加热技术，如利用化不原理加热的ＲＨ－ＯＢ／ＰＢ，ＲＨ－ＫＴＢ，ＣＡＳ－ＯＢ，ＶＯＤ／ＶＯＨ，ＩＲ－ＵＴ等，利用电加热的ＬＦ，ＶＡＤ，直流电弧加热，感应加热，等离子体加热等；和其它如电渣加热，燃料－氧加热等技术及其实际应用效果作了较全面的介绍了，作者针对攀钢的实际情况提出了建议。     

添加剂及温度对Al_2O_3－C质耐火材料中SiC晶须形成的影响

通过实验研究了加入特殊硅，活性炭等及温度对Ａｌ２Ｏ３－Ｃ质耐火材料中ＳｉＣ晶须形成的影响。结果表明，加入特殊硅及活性炭可使ＳｉＣ晶须发育得更好，并且Ａｌ２Ｏ３－Ｃ质耐火材料中ＳｉＣ晶须形成的适宜温度应在１２００℃＜Ｔ＜１４００℃之间。     

锰对Cu—Zn—Al形状记忆合金的影响

研究了锰对Ｃｕ－Ａｎ－Ａｌ形状记忆合金的Ｔβ（α＋β／β）点、晶粒度、相变温度和形状恢复率的影响。研究结构表明Ｃｕ－Ａｎ－Ａｌ合金中添加少量锰，可以降低Ｔβ点、细化晶粒、降低相变温度、不影响形状恢复率，添加少量的锰是细化Ｃｕ－Ｚｎ－Ａｌ形状记忆合金粒的一种有效的新方法。     

On the Structure,Transformation and Deformation of Long-Period Stacking Ordered Phases in Mg-Y-Zn Alloys

Ternary Mg-Y-Zn alloys have attracted considerable attention due to their unique microstructures and promising mechanical properties. The microstructure of these alloys contains predominantly intermetallic phases of 18R and/or 14H long-period stacking ordered (LPSO) structures, depending on the alloy processing conditions. Such 18R and/or 14H structures or similar LPSO structures are also found in other magnesium alloys such as Mg-Gd-Zn, Mg-Gd-Y-Zn, Mg-Dy-Zn, Mg-Ho-Zn, Mg-Er-Zn, Mg-Y-Cu, Mg-Y-Ni, and Mg-Y-Co. In addition, LPSO structures such as 24R and 10H have also been reported, even though they are less frequently observed. This paper provides a review of the current status on the characterization of the structure, thermal stability, transformation, and deformation of the LPSO structures using high-angle annular dark-field scanning transmission electron microscopy and electron diffraction. Unsolved issues on the LPSO structures are also highlighted and discussed.     

Endocytotic formation of vesicles and other membranous structures induced by Ca2+ and axolemmal injury

Vesicles and/or other membranous structures that form after axolemmal damage have recently been shown to repair (seal) the axolemma of various nerve axons. To determine the origin of such membranous structures, (1) we internally dialyzed isolated intact squid giant axons (GAs) and showed that elevation of intracellular Ca2+ >100 microM produced membranous structures similar to those in axons transected in Ca2+-containing physiological saline; (2) we exposed GA axoplasm to Ca2+-containing salines and observed that membranous structures did not form after removing the axolemma and glial sheath but did form in severed GAs after >99% of their axoplasm was removed by internal perfusion; (3) we examined transected GAs and crayfish medial giant axons (MGAs) with time-lapse confocal fluorescence microscopy and showed that many injury-induced vesicles formed by endocytosis of the axolemma; (4) we examined the cut ends of GAs and MGAs with electron microscopy and showed that most membranous structures were single-walled at short (5-15 min) post-transection times, whereas more were double- and multi-walled and of probable glial origin after longer (30-150 min) post-transection times; and (5) we examined differential interference contrast and confocal images and showed that large and small lesions evoked similar injury responses in which barriers to dye diffusion formed amid an accumulation of vesicles and other membranous structures. These and other data suggest that Ca2+ inflow at large or small axolemmal lesions induces various membranous structures (including endocytotic vesicles) of glial or axonal origin to form, accumulate, and interact with each other, preformed vesicles, and/or the axolemma to repair the axolemmal damage.     

Histological comparison of morphea and lichen sclerosus et atrophicus

To clarify the role of the lens capsule in cataract formation, changes in the protein conformational structure of immature cataractous lens capsules from patients with systemic hypertension or glaucoma have been investigated, as compared to normal lens capsules. The protein secondary structure and composition of these capsular samples were determined using Fourier transform infrared microspectroscopy with second-derivative, deconvolution and curve-fitting methods. We found that the composition of both random coil and beta-type (beta-sheet and beta-turn) structures in the immature cataractous human lens capsules was increasingly induced by systemic hypertension or glaucoma, but alpha-helix content clearly decreased, leading to the alteration of protein conformational structures in lens capsules. A possible pathway of cataract formation exacerbated by systemic hypertension or glaucoma is discussed. According to the results, we propose that systemic hypertension or glaucoma induce changes in the protein conformational structures of the lens capsule, then cause alteration of membrane transport and permeability for ions, and finally increase intraocular pressure, resulting in the exacerbation of cataract formation. The effect on the conformational structure of cataractous human lens capsules is more pronounced for systemic hypertension than for glaucoma. The present study implies that systemic hypertension or glaucoma can exacerbate cataract formation in senile patients by modifying the protein secondary structures in the lens capsule.     

Immunochemical study of transforming growth factor-beta in the kidney of the rat and chicken

RATIONALE AND OBJECTIVES: Some septal structures have been observed in the areas of incomplete interlobar fissures (IIFs) in resected lungs. We describe the anatomy of IIFs with or without the presence of septal structures. METHODS: Twenty fused areas from 16 autopsy cases were examined histologically. Other septal structures outside the areas of IIFs also were examined. RESULTS: In 10 of the 20 fused areas, there was a mixture of septal structures with and without defects. In the remaining 10, there were no septal structures. The septal structures consisted of two inner layers from both lobes. Other septal structures examined were the same as ones observed in the IIFs. CONCLUSION: Linear shadows seen at interlobar fissures and on computed tomography scans do not necessarily depict the presence of complete interlobar fissures. The absence of linear shadows does not necessarily imply the absence of septal structures.     

Molecular dissection of radixin: distinct and interdependent functions of the amino- and carboxy-terminal domains

The ERM proteins--ezrin, radixin, and moesin--occur in particular cortical cytoskeletal structures. Several lines of evidence suggest that they interact with both cytoskeletal elements and plasma membrane components. Here we described the properties of full-length and truncated radixin polypeptides expressed in transfected cells. In stable transfectants, exogenous full-length radixin behaves much like endogenous ERM proteins, localizing to the same cortical structures. However, the presence of full-length radixin or its carboxy-terminal domain in cortical structures correlates with greatly diminished staining of endogenous moesin in those structures, suggesting that radixin and moesin compete for a limiting factor required for normal associations in the cell. The results also reveal distinct roles for the amino- and carboxy-terminal domains. At low levels relative to endogenous radixin, the carboxy-terminal polypeptide is associated with most of the correct cortical targets except cleavage furrows. In contrast, the amino-terminal polypeptide is diffusely localized throughout the cell. Low level expression of full-length radixin or either of the truncated polypeptides has no detectable effect on cell physiology. However, high level expression of the carboxy-terminal domain dramatically disrupts normal cytoskeletal structures and functions. At these high levels, the amino-terminal polypeptide does localize to cortical structures, but does not affect the cells. We conclude that the behavior of radixin in cells depends upon activities contributed by separate domains of the protein, but also requires modulating interactions between those domains.     

Etiological and clinical characteristics of infectious optic neuritis

Infection by the tapeworm Echinococcus granulosus in the intermediate host results in the development of a hydatid cyst which contains the protoscoleces within a fluid-filled cavity enclosed by the bilayered cyst membrane. N-glycans were enzymatically released from crude extracts of homogenates of hydatid cyst membranes and protoscoleces and their structures were defined by high sensitivity fast atom bombardment mass spectrometry in conjunction with sequential exoglycosidase digestions. The major N-glycans from the cyst membrane were found to be non-charged structures having complex-type antennae and core fucosylation. The antennae are either truncated at the first N-acetylglucosamine or are extended with beta-galactose to form N-acetyllactosamine (lacNAc). A significant proportion of the lacNAc backbones are capped by alpha-galactose. The resulting Gal alpha-Gal beta-terminal structures may account for the earlier observation that antibodies against the blood group P1 epitope recognise components of hydatid cyst extracts. The complex-type N-glycans identified in the protoscoleces extracts were the same as the neutral structures found in the cyst membrane but a small proportion of high mannose structures and truncated di- and trimannosyl core structures were also identified. Sialylated N-glycans were identified as minor constituents of the cyst membrane preparation but were not observed in protoscoleces extracts. Whether the sialylated glycans are host derived or endogenously synthesized by the parasite remains to be established. This is the first reported structural analysis of N-glycans from cestodes and provides new insights into protein glycosylation in helminths.     

Context-Dependent Reorganization of Spatial and Movement Representations by Simultaneously Recorded Hippocampal and Striatal Neurons During Performance of Allocentric and Egocentric Tasks.

Hippocampal and striatal place- and movement-correlated cell firing was recorded as rats performed place or response tasks in a familiar environment, and then after cue manipulation. In a familiar environment, place field properties did not differ across brain structures or task conditions. Movement correlates were stronger during place task performance only in hippocampal neurons. After cue manipulations, place- and movement-sensitive hippocampal and striatal neurons changed their correlate strength, regardless of behavioral strategy. Thus, for both structures, place-correlated cells may encode spatial context information, whereas movement-correlated cells may represent both egocentric movement and learned behavioral responses. The striking overall similarity between hippocampal and striatal neural responses to context manipulation (regardless of strategy) suggests that these structures operate continuously, and in parallel, during multiple forms of learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bank-Attached Vanes for Bank Erosion Control and Restoration of River Meanders

The effectiveness of a novel approach of using vanes, installed at a low angle and attached to the bank, for bank protection and for the restoration of river meanders has been investigated in a laboratory study. Experiments were carried out in a large-scale meandering mobile-bed channel with graded sediment. The bed topography, three-dimensional flow pattern, and turbulence characteristics in the meandering channel with or without structures are analyzed. When a single or an array of such vanes is installed, the scour hole at the base of the outer bank is infilled and the thalweg is relocated toward the center of the river. The structures induce a secondary flow cell near the outer bank which counteracts the main spiral flow in the bend. In contrast to common spurs and bendway weirs, large-scale horizontal vortices are not generated behind the structures. Vanes which grade to the bed from bankfull level at the bank show better performance than low level ones, whereas multiple structures show positive effects as far downstream as the crossover section.     

Molecular modeling of the octacoordinated tetracarbonato-Nd(III), [Nd(CO3)4], complex and its nonacoordinated fluoro- and aquo-adducts

Theoretical investigation on the structures of the octacoordinated [Nd(CO₃)₄]^5- and the nonacoordinated [Nd(CO₃)₄.OH₂]^5- complexes, using the SPARKLE parameters of the lanthanides within MOPAC, revealed that they possessed dodecahedral and square antiprismatic structures respectively with an average Nd-O distance of 0.249 nm. These structures and the Nd-O distances agreed well with those experimentally found in the crystal structures. Replacing the water molecule with a fluoride ion or a mondentatecarbonato ligand resulted in a nonacoordinated distorted square antiprismatic structures where the trans-carbonato groups were twisted. The corresponding decacoordinated structures with two fluoride ions or a bidentatecarbonato group, [Nd(CO3)₄·F₂]^7- and [Nd(CO₃)₅]^7-, were also investigated. In both cases considerable twisting of the transcarbonato groups was observed.     

Mechanism of short-term memory and repetition in conduction aphasia and related cognitive disorders: a neuropsychological, audiological and neuroimaging study

The minimal nitrogen cycle involves five reduction reactions and three oxidation reactions, each of which poses interesting problems in bioinorganic chemistry, energy transduction and protein structure/function relationships. Many of the major recent developments in this field have depended on the acquisition of protein crystal structures, including structures of enzymes with bound substrates or products and in protein-protein complexes. These enzymes include nitrogenase, nitrite reductases, hydroxylamine oxidoreductase and a fungal nitric oxide reductase.