Effect of Y for enhanced age hardening response and mechanical properties of Mg-Gd-Y-Zr alloys

In this study, compositional dependence of age hardening response and tensile properties were investigated for Mg-10G(d-x)Y-0.4Zr (x = 1, 3, 5 wt.%) alloys. With increasing Y content, the age hardening response of the alloys enhanced and tensile properties increased. The Mg-10Gd-5Y-0.4Zr alloy exhibited maximum tensile strength and yield strength at aged-peak hardness, and the values were 302 MPa and 289 MPa at room temperature, and 340 MPa and 267 MPa at 250 degrees C, respectively. The strong peak age hardening was attributed to the precipitation of prismatic beta' plates in a triangular arrangement. The cubic shaped beta phase was also observed at grain boundaries. The remarkable improvement in strength is associated with a uniform and high dense distribution of beta' and cubic shaped beta precipitate phases in Mg matrix. Elongation of Mg-10Gd-0.4Zr alloys decreased with increasing Y content, and the elongation of Mg-10Gd-5Y-0.4Zr alloy was less than 3% below 250 degrees C, whereas the alloys containing I wt.% and 3 wt.% Y exhibited higher elongation than 5% at room temperature.

三元共聚物P(EO-PO-AGE)-LiCLO_4络合物的离子电导

本文合成了聚(环氧乙烷-环氧丙烷-烯丙基缩水甘油醚,三元共聚物,P(EO-PO-AGE)。扭辨分析、DSC、X-射线衍射结果表明,三元共聚物的玻璃化转变温度较低(T_g=-74℃),无定形结构含量～98％,并确定了与LiClO_4组成为Li/O(mole)=0.25的结晶络合物存在。络合物电导行为的研究发现,络合物电导与盐浓度有关,在Li/O(mole)=0.05时具有较大值,室温下电导可达5×10~-5)scm~(-1)。

二甲氧基聚乙二醇增塑的P(EO-PO-AGE)-LiClO_4聚合物膜的离子电导

本文研究了二甲氧基聚乙二醇(PEGDME)对聚合物电解质膜的影响。结果表明,PEGDME增塑的(环氧乙烷-环氧丙烷-烯丙基缩水甘油醚)三元共聚物-LiClO_4络合物具有较低的玻璃化转变温度,室温导电率≥10~(-4)Scm~(-1),热稳定性及力学性能良好,在100℃下无相分离,室温下在干燥器中放置一年无蠕变。

Using otolith weight to predict the age of Pennahia macrocephalus in the mouth of the Beibu Gulf

The relation between otolith weight (OW) and the age of marine fish is studied. A total of 222 individuals of bighead white croaker, Pennahia macrocephalus were sampled seasonally in the mouth of the Beibu Gulf, the South China Sea, in 2007. Since there are no significant differences in sagittal OW between otolith in pairs (Pa parts per thousand yen0.05), the undamaged left sagittal otolith is used for age determination. The highest correlations among standard length, OW and fish ages are confirmed by linear, exponential and multinomial regression. Results show that sagittal OW overlaps only occasionally among age groups, and to individuals with similar standard length, the older and slower-growing fish has a heavier otolith because of the continued otolith material deposition. There are differences in sagittal OW among different age groups and significant positive linear relationship with age (P < 0.05). The age readings can be verified by plotting the sagittal OW versus the standard length for age groups, and the individuals with similar standard length but in different ages can be separated by sagittal OW frequency analysis. Mostly, the predicted ages using the regression between sagittal OW and ages are closed to the observed ages by counting annulus on scale. It indicates that the sagittal OW analysis is a useful technique for validating the accuracy of age determination by annuli counts, especially for individuals of similar size. Furthermore, the technique is applied for Pennahia macrocephalus with discussion in this paper.

ISOTOPIC CHARACTERISTICS AND AGE DATING OF THE PUMICE IN OKINAWA TROUGH

The data on the isotope compositions of rubidium, strontium and oxygen in the pumice of Okinawa Trough are reported for the first time. The ages of the pumice were successfully dated with the method of U-series disequilibrium. Then, the material source, crystallization evolution of magma and activity cycles of volcanos are explored. Isotopic data show that pumice magma was originally from the mantle, but had undergone a full crystallization differentiation and had been contaminated to a fair extent by crust-derived materials before the magma was erupted out of the sea floor. According to the dating results available so far, the earliest volcanic eruption in Okinawa Trough occurred about 70,000 a ago and the latest eruption was about 10,000 a B.P. During this period, there were three volcanic eruption cycles which were respectively corresponding to the middle Late Pleistocene, the late Late Pleistocene and the Early Holocene.

THE COMPOUND EYE AS AN INDICATOR OF AGE AND SHRINKAGE IN ANTARCTIC KRILL

Laboratory studies have shown that Antarctic krill (Euphausia superba) shrink if maintained in conditions of low food availability. Recent studies have also demonstrated that E. superba individuals may be shrinking in the field during winter. If krill shrink during the winter, conclusions reached by length-frequency analysis may be unreliable because smaller animals may not necessarily be younger animals. In this study, the correlation between the body-length and the crystalline cone number of the compound eye was examined. Samples collected in the late summer show an apparent linear relationship between crystalline cone number and body-length. From a laboratory population, it appears that when krill shrink the crystalline cone number remains relatively unchanged. If crystalline cone number is little affected by shrinking, then the crystalline cone number may be a more reliable indicator of age than body-length alone. The ratio of crystalline cone number to body-length offers a method for detecting the effect of shrinking in natural populations of krill. On the basis of the crystalline cone number count, it appears from a field collection in early spring that E. superba do shrink during winter.

企业经营风险决策的组织行为学研究

This thesis has investigated the risk preferences of the Chinese company managers in kinds of simulated decision situations and their perceptions of risk concerning types of business decisions. Four studies are conducted: Study I is utility analysis. 214 company managers and 46 middle - school headmasters have responded to Utility Measurement Survey. The results indicate: (1) The risk preferences of the managers vary in the different decision situations. In most of the situations, most of the managers are risk aversion; In few situations, they are risk-seeking. (2) In some of the decision situations, there are significant differences on risk preference between business managers and school headmasters, male managers and female managers, senior managers and junior managers, managers with high qualifications and managers with low qualifications, non-state-owned firms' managers and state-owned firms' managers, medium-small sized firms' managers and large-sized firms' managers. In the other situations there aren't significant differences between them. (3) In all of the decision situations, so significant differences on risk preference are found among managers with different marriage, experience, age and education. Study II is risky decision simulation. The Risky Decision Situations Simulation Survey is administered to 82 company managers. The result indicates that firm culture, business condition, survival limit and risk preference of the superior influence the managers' risk decision-making behavior. Study III is perceptions of business decision risks. 68 company managers have filled in Decision Cases Risk Perception Inventory. The results indicate: (1) Inaccurate market analysis and prediction, instable politics and the changes of economic policy are the more risky elements to strategy decision. (2) Erroneous market analysis and prediction, appearance of new technology and the changes of market demands are the more risky elements to investment decision. (3) Poor quality control, backward technology and too large stocks are the more risky elements to production decision. (4) Shortage of development fund, wrong choice in development project and limitation of the development ability are the more risky elements to new production development decision. (5) No payment of the foreign partner's capital, the changes of national relevant policy, difficulty in marketing, too high selling prices of foreign partner's equipments are the more risky elements to joint-venture decision. (6) Unfamilarity with oneself and misjudgement in qualification of oneself are the more risky elements to personnel decision. (7) Bad market of the product, defects in product quality and the changes of consumers demands are the more risky elements to marketing decision. (8) Wrong strategy and ambiguous goals are the more risky elements to public relation decision. (9) Violation of the law, ambiguous goals and poor creation are the more risky elements to advertisement decision. (10) Deterioration of diplomatic relations, unsuitable products for foreign consumers and unfamilarity with foreign market are the more risky elements to international business decision. Study IV is structured interview. 5 company managers have answered all questions of the Interview Questionnaire. The results indicate: (1) The managers think that risks are the possible unfavourable consequences of decisions; (2) The self-ratings of the managers coordinate with the results of utility measurement; (3) The managers admit that risks always accompany bussiness decision; (4) Individual difference is found among managers on risk perception. This thesis has also pointed out the important implications of the research and discussed several further questions.

Age-dependence of urinary normal and modified nucleosides in childhood as determined by reversed-phase high-performance liquid chromatography

Modified nucleosides have been characterized as tumor markers for a number of malignant diseases. In order to use these markers in children, the age-dependence of the nucleoside levels in healthy children has to be established and taken into account in diagnostic decisions. In this study, the levels of 12 normal and modified nucleosides in urine of 166 healthy children and adolescents with an age between 1 day and 19 years are determined by reversed-phase HPLC, and age-dependent reference ranges are defined. The urinary nucleoside concentrations are related to the creatinine concentrations, which allows the use of randomly collected urine samples. All nucleoside levels in urine of children decrease with age, most pronounced during the first 4 years of life, and the age-dependence of the reference values of the individual nucleosides can be approximated by a mathematical function y = b(0) + b(1) (1/x) with the regression coefficients b(0) and b(1), the nucleoside levels y and the age x between 1 year and 19 years. In the very young children, the shifts in the nucleoside concentrations are more differentiated. Starting with low levels on the first day of life, the concentrations of all studied nucleosides rise up to an age of 1-2 months, when they reach their absolute maximum for all age periods, and then decrease. (C) 2004 Elsevier B.V. All rights reserved.

A framework for the transformation of the creative industries in a digital age.

The creative industries sector faces a constantly changing context characterised by the speed of the development and deployment of digital information systems and Information Communications Technologies (ICT) on a global scale. This continuous digital disruption has had significant impact on the whole value chain of the sector: creation and production; discovery and distribution; and consumption of cultural goods and services. As a result, creative enterprises must evolve business and operational models and practices to be sustainable. Enterprises of all scales, type, and operational model are affected, and all sectors face ongoing digital disruption. Management consultancy practitioners and business strategy academics have called for new strategy development frameworks and toolkits, fit for a continuously changing world. This thesis investigates a novel approach to organisational change appropriate to the digital age, in the context of the creative sector in Scotland. A set of concepts, methods, tools, and processes to generate theoretical learning and practical knowing was created to support enterprises to digitally adapt through undertaking journeys of change and organisational development. The framework is called The AmbITion Approach. It was developed by blending participatory action research (PAR) methods and modern management consultancy, design, and creative practices. Empirical work also introduced to the framework Coghlan and Rashford’s change categories. These enabled the definition and description of the extent to which organisations developed: whether they experienced first order (change), second order (adaptation) or third order (transformation) change. Digital research tools for inquiry were tested by a pilot study, and then embedded in a longitudinal study over two years of twentyone participant organisations from Scotland’s creative sector. The author applied and investigated the novel approach in a national digital development programme for Scotland’s creative industries. The programme was designed and delivered by the author and ran nationally between 2012-14. Detailed grounded thematic analysis of the data corpus was undertaken, along with analysis of rich media case studies produced by the organisations about their change journeys. The results of studies on participants, and validation criteria applied to the results, demonstrated that the framework triggers second (adaptation) and third order change (transformation) in creative industry enterprises. The AmbITion Approach framework is suitable for the continuing landscape of digital disruption within the creative sector. The thesis contributes to practice the concepts, methods, tools, and processes of The AmbITion Approach, which have been empirically tested in the field, and validated as a new framework for business transformation in a digital age. The thesis contributes to knowledge a theoretical and conceptual framework with a specific set of constructs and criteria that define first, second, and third order change in creative enterprises, and a robust research and action framework for the analysis of the quality, validity and change achieved by action research based development programmes. The thesis additionally contributes to the practice of research, adding to our understanding of the value of PAR and design thinking approaches and creative practices as methods for change.