具有晶间腐蚀抗力的铝合金及其制备方法

一种耐腐蚀的铝合金具有控制量的铁、锰、铬和钛，并且含有铜、硅、镍以及不超过杂质水平的锌。调整所述合金的化学组成，以使晶粒边界的电解电位与合金基体相匹配，从而降低晶间腐蚀。所述合金特别适合于采用挤压和钎焊技术制造热交换器中的管材。     

原子吸收分光光度法连续测定铝及其合金中的铜,铁,镁,锰,锌,铬,镍

连续测定铝及其合金中的铜，铁，镁，锰，锌，铬，镍诸元素分析方法未见报道。本文研究了在聚四氟乙烯烧杯中，用酸溶样，在同一份试验样中用原子吸收连续测定铜，铁等元素。方法简单，快速，准确度且能降低分析成本。     

矿石中铜钴镍铅锌镉的方波极谱测定

铜、钴、镍、铅、锌、镉极谱分析,难点在于钴和锌的测定。在多种底液中,钴和锌半波电位相当接近,不能连续测定。文献成功地分开了钴、锌和镍波。文献利用钴波的不可逆性,逆向电压扫描测定锌。有人以萃取—反萃取方式将铜、钴、镍和铅、锌、镉分成两组实施测定。 本工作试验了用萃取—反萃取法分离,极谱测定红土矿中铜、钴、镍、铅、锌、镉六元素。     

火焰原子吸收光谱法快速测定纯镍中铁铜镁锰锌

提出了运用火焰原子吸收光谱法快速测定纯镍中铁铜镁锰锌的含量，介绍了铁铜镁锰锌最佳测定条件及呈良好线性范围的浓度，在测定中对样品中的干扰因素进行了综合考虑。该方法具有很好的灵敏度和重现性，具有方法步骤简单、操作容易、干扰少等特点。测定样品铁铜镁锰锌含量的相对标准偏差均小于1．0％（n=10）。标准加入回收率均在97．0％～99．0％（n=6）范围内。适用于纯镍材料中铁铜镁锰锌的含量控制分析和系统分析。     

高镍阳极铜电解试验

随着国民经济的发展,国家要求我厂生产更多的电解铜,以满足工农业的需要,因此,必须进一步扩大铜料的来源。我们曾对一种呆滞多年的进口合金进行过试验(合金含铜60～63％、镍13～16％,其余为锌)。该铜料经火法除锌后,锌已基本符合     

含锰高强度低合金烧结钢(Ⅰ)——成分系列

锰是钢铁工业中重要的合金化元素.该文作者评述了含锰高强度低合金烧结钢的成分系列及性能,指出:锰作为烧结钢的重要合金元素,具有突出的强化效果,可以取代铜、镍、铬和钼等价格较贵的金属元素;含锰低合金烧结钢强度高,烧结尺寸变化可控,适用于制造承受中、高载荷的机械零件.     

ICP-OES测定土壤中锌、铜、铅、镉、锰、汞、砷、镍、铬、镁十种元素

本文土壤经过HCI-HNO_3-HF-HCO_4四酸消解,对土壤中锌、铜、铅、镉、锰、汞、砷、镍、铬、镁十种元素同时测定,讨论了溶液酸度控制、分析谱线的选择和元素干扰试验,同时对精密度和回收率等进行了试验,各元素的回收率为95%～105%之间,RSD%为0.79%～2.73%。该方法简便、快捷、准确稳定,能满足土壤中锌、铜、铅、镉、锰、汞、砷、镍、铬、镁的测定。     

电镀锌锰合金耐腐蚀钢板

日本钢管公司研究中心研制成功电镀锌锰合金耐腐蚀钢板。在试验过程中采用了锌和锰不同比例的电解液,电解液中含有柠檬酸,锌锰合金镀层量为20g/m~2。锌锰合金镀层钢板的耐腐蚀性能取决于锰的含量。锌锰合金中含锰量到20%,镀层过程     

超声辅助-王水提取法在测定土壤中重金属元素的应用

建立了超声辅助王水消解土壤样品的前处理方法,并结合电感耦合等离子体原子发射光谱法(ICP-AES)和电感耦合等离子体质谱法(ICP-MS)对土壤样品中铜、锌、镍、铁、锰、铅、砷、汞、铬、镉等10种元素进行测定。通过试验确定王水用量为5mL、超声水浴温度为80℃、超声提取时间为45min的超声提取条件。在优化的仪器条件下,按照实验方法测得的土壤样品中10种元素的校准曲线线性相关系数为0.9996~0.9999;各元素的检出限为0.0021~0.23mg/kg,各元素的测定下限为0.0070~0.78mg/kg。按照实验方法(超声王水提取-ICP-AES/ICP-MS)测定土壤样品中铜、锌、镍、铁、锰、铅、砷、汞、铬、镉,测定结果的相对标准偏差(RSD,n=6)为0.39%~7.8%;除铁、锰的提取值较小外,其他元素的测定结果与采用国标方法(GB 15618—1995、GB/T 22105.1—2008)得到的测定值基本一致;按照实验方法测定土壤标准物质GBW07404、GBW07406、GBW07407、GBW07427中铜、锌、镍、锰、铅、砷、汞、铬、镉,除了锰由于其在原土中主要以氧化物结合态存在,测定结果偏低以外,其他元素测定值与认定值相吻合。     

锌基合金的熔炼

一、前言锌基合金是以锌为基体,加入其他合金元素组成的二元或多元合金。按其性质与用途,可分为铸造锌合金,超塑性合金、模用合金、镀锌合金等。目前应用最广泛的为铸造锌合金,常用的有锌—铝系、锌—铝—铜系、锌—铝—镁系、锌—铝—铜—镁系。     

Development of New Combined Manufacturing Technologies ‐ Influence of the Cutting Process on Workpiece Properties

Properties of materials for high‐strength structure components are influenced by production processes. These influences can be augmented by a combination of two presently consecutively executed process steps. The presented work shows first results in the development of novel combined manufacturing technologies, which along with prospective tools use this effect to adjust the material properties locally, adapted to the requirements. The combination consists of a merging of the process steps ‘material separation’ (metal cutting) and ‘changing properties’ (rubbing, rolling) to one single process step. For this purpose novel combined tools have to be developed. For the estimation of the possibilities of properties changes by combined processes at first the influences of single processes have to be determined. This contribution presents results of a “material separation” process. The investigated material is the industrially important aluminium wrought alloy AI7075‐T6, the applied process is orthogonal turning, the process parameters varied are cutting speed and feed as well as the tool geometry. Cutting force and feed force are measured, and the process influences on surface and subsurface properties are determined.     

Acute effects of short-term feed deprivation and refeeding on circulating concentrations of metabolites, insulin-like growth factor I, insulin-like growth factor binding proteins, somatotropin, and thyroid hormones in adult geldings

Two studies were performed with Standardbred geldings 7 to 21 yr of age to determine the sequence of changes in blood plasma concentrations of some hormones and metabolites during feed deprivation for 48 h and for 12 h after refeeding. Plasma hormone and metabolite concentrations were determined with methods validated for horse plasma. Insulin-like growth factor binding proteins (IGFBP) were determined with radioligand analysis following SDS-PAGE electrophoresis. In both experiments, plasma concentrations of triiodothyronine and thyroxine decreased (P < .01) during feed deprivation and increased (P < .01) during refeeding. Plasma glucose and IGF-I either decreased or were not altered during feed deprivation. In contrast, plasma concentrations of NEFA and urea nitrogen increased (P < .01) during feed deprivation and decreased (P < .01) during the refeeding period. Plasma somatotropin (ST) increased (P < .01) approximately 80% at 24 to 36 h of feed deprivation, declined (P < .01) to control values at 48 h of feed deprivation, increased (P < .01) nearly three fold at 3 h after refeeding, and returned to control values by 6 h after refeeding. We identified five IGFBP, and their plasma concentrations were not significantly altered during feed deprivation or following refeeding. We conclude that metabolite availability during feed deprivation and following refeeding alters the secretion of thyroid hormones, ST, and possibly IGF-I, thereby maintaining homeostasis in horses.     

Experimental and Analytical Based Investigations on Machinability of High-Chrome White Cast Iron Using CBN Tools

High-chrome white cast iron (HCWCI) is one of the hardest metals used in the process and mining industries faces tough challenge in metal cutting. Focusing on this issue, influence of cutting parameters (e.g., cutting speed, depth of cut, feed rate) on machinability characteristics (e.g., cutting forces, surface roughness, material removal rate, machining power) of HCWCI has been investigated by experimentally and analytically using cubic boron nitride (CBN) cutting tools. Experimentation is carried out in conjunction with the Taguchi techniques and the influence of each cutting parameter of the process has been analyzed by analytical tools; analysis of variance, regression technique and artificial neural networks (ANNs). The study reveals depth of cut has the highest contribution on the cutting forces, and cutting speed on surface roughness and machining power. The confirmation test identifies both regression and ANN techniques are the most effective tools to evaluate machinability characteristics of HCWCI. Further, the CBN cutting tool exhibits excellent performance in machining of HCWCI.     

Machinability of the high-strength corrosion-resistant high-ductility austenitic steel 06Kh22AG15N8M2F

The machinability of the high-nitrogen corrosion-resistant austenitic steel 06Kh22AG15N8M2F during turning is studied. The specific features of the structure of the surface layers in steel workpieces after turning are revealed. The cutting conditions that provide the lowest wear of VK8 alloy cutting tools upon turning are found: the cutting speed is 21–74 m/min, the feed is 0.15–0.60 mm/rev, and the cutting depth is 0.15–0.75 mm. The presence of a large amount of Cr₂N-type chromium nitrides in the structure of the steel annealed at 800°C for 2 h and a high nitrogen content in the austenite of the steel quenched from 1100°C increase the wear of the cutting tools. As to turning of the forged steel, the wear resistance of the cutting tools upon turning of the 06Kh22AG15N8M2F steel is higher than that upon turning of 08Kh18N10T steel, in which deformation martensite forms (in surface layers) during turning.     

Estimation of genetic parameters for growth, feed consumption, and conformation traits for double-muscled Belgian blue bulls performance-tested in Belgium

For 1,442 Belgian Blue bulls performance-tested at the Centre de Sélection de la Race Blanc-Bleue Belge, nine traits were observed: height at withers at 7 mo, height at withers at 13 mo, weight at 7 mo, weight at 13 mo, average feed consumption of concentrates, average daily gain, average feed consumption of concentrates per average daily gain, average feed consumption of concentrates per mean metabolic weight, and price per kilogram of live weight. This price is based on muscle conformation and is therefore used as muscle conformation score. Restricted maximum likelihood with a derivative-free algorithm was used to estimate (co)variance components because there were different models and missing values per trait. Estimates of heritabilities were above .50 except for average feed consumption per average daily gain (.16) and average feed consumption per mean metabolic weight (.33). Estimates of genetic and phenotypic correlations between height at withers and weight traits were positive and moderate to high. Average daily gain showed a negative genetic correlation with weight at 7 mo (-.68) but had positive correlations with height at withers at 13 mo and weight at 13 mo (.22 and .43). Muscle conformation expressed as price per kilogram of live weight was related to low average feed consumption per average daily gain. Average feed consumption showed high correlations with weight at 7 mo and weight at 13 mo. Average feed consumption per average daily gain had a high negative genetic correlation with average daily gain (-.89).     

Wear resistance in ceramic silicon nitride cutting tools bearing continuous or discrete titanium nitride coatings

Measurements have been made on the wear resistance of ceramic cutters based on silicon nitride and bearing titanium nitride coating during the continuous machining of ShKh15 steel. The coatings were deposited by cathode sputtering. Use was made of continuous coatings and discrete ones in the form of ordered fragments. The continuous TiN coatings raise the wear resistance by a factor of 1.7, while the factor is 2.2 for the discrete TiN coatings. The performance of the tool is also improved in the case of the discrete coatings as the cutting speed and feed can be raised by comparison with tools with continuous coating.     

Experimental Determination of Cutting Forces and Surface Roughness when Turning 50CrV4 Steel (SAE 6150) and Modelling with the Artificial Neural Network Approach

In this experimental study, 50CrV4 (SAE 6150) steel parts were subjected to machining test using coated and uncoated carbide cutting tools through single point turning operation. The turning tests were performed at various cutting parameters (cutting speed, feed rate and depth of cut). In the light of these parameters, cutting forces and surface roughness values obtained were determined. A suitable cutting force measurement dynamometer was used for measuring the three cutting force components. The surface roughness values were also measured. The results of experiments were modelled with artificial neural network system. The relation between the cutting forces and surface roughness values was defined.     

Online tools for evaluating patient change: Statistical foundations, clinical applications, research relevance.

Purpose: To present Internet-based tools for evaluating whether meaningful change has occurred in individual patients across time. These tools were developed to make empirically based analyses of clinical change readily available to clinicians and clinical researchers. Method: Tools were developed on the basis of 4 statistical paradigms, including (a) the Reliable Change Index, (b) the Reliable Change Index with an adjustment for bias, (c) bivariate regression, and (d) multivariate regression. A library of measures that uses these platforms is described. Conclusions/Implications: Clinical indications and limitations for using these tools are explained. Clinical reasoning involved in using these tools is discussed and demonstrated with case illustrations. The clinical and research potential of these tools is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of cutting parameters on cutting force and surface roughness in milling alumina reinforced Al–6Zn–2Mg–2Cu composites

Abstract

This paper presents the effect of main cutting parameters on cutting force and surface roughness in machining of alumina reinforced Al–6Zn–2Mg–2Cu composites. The composites were produced using powder metallurgy route. After an application of annealing heat treatment to these composites, their microstructural and mechanical characterisations were carried out. Then, machining was performed using the face milling operation with three different cutting tools and at various cutting speeds and feed rates for comparison. Results show that both cutting force and surface roughness increased with increasing the feedrate significantly. Furthermore, the cutting speed practically did not affect the cutting force in milling operation.     

Indications for radical prostatectomy in localized cancer of the prostate

The exceptional character of the natural history of prostate cancer continues to feed the controversy about the indication of radical prostatectomy in localised prostatic cancer. However, the correlation between tumor volume and the risk of disease progression established by recent pathological studies seems to demonstrate an ideal indication for radical prostatectomy for a tumor volume between 0.5 and 4 cc. However the precise estimation of this tumor volume by current diagnostic tools is still insufficient. Nevertheless, recent publications show that radical prostatectomy, whose complications must not be overestimated, gives real chances of obtaining good local control of the disease, even for advanced localised cancers. This operation can be rationally proposed to people with a sufficiently long life expectancy.