基于生命周期理论的陕西省装备制造业演化轨迹的研究

装备制造业所处的生命周期阶段对于陕西省的经济发展具有重要的影响.本文以陕西省近十年的统计年鉴数据为依据,采用增长率产业分类法对陕西省装备制造业的七大类所处生命周期阶段进行划分,得出金属制品业和仪器仪表及文化办公用设备制造业处于发展阶段,交通运输设备制造业处于成长阶段,专用设备制造业、通用设备制造业和电气机械及器材制造业处于成熟阶段,电子及通信设备制造业处于衰退阶段的结论.     

制造型企业客户关系管理战略模型的构建与应用

金融危机使我国制造型企业面临前所未有的挑战,制造型企业迫切需要寻求新的战略模式以获取竞争优势。结合平衡计分卡的基本思想,构建基于BSC的制造型企业客户关系管理战略模型,并在一个企业实际应用以验证模型的可行性和有效性。     

制造业绩效及其影响因素——基于全球视角的实证研究

对59个国家与地区在1990年和2002年的制造业绩效进行了评价,在此基础上分别以发达和发展中两类国家与地区为样本,通过多元回归分析,揭示两类样本中七类因素与制造业绩效的统计特征及其变化特点。实证结果表明,贸易、科技创新、能源环境、劳动力以及金融发展这五类因素对同类国家与地区间的制造业绩效差异具有较强的解释力;与1990年相比,发达国家与地区的制造业绩效同贸易、需求、能源环境、基础设施的相关性在增强,同金融发展、劳动力的相关性在下降;发展中国家与地区的制造业绩效则同各类因素的相关性呈现全面上升的态势。本文最后结合分析结果对中国制造业的发展提出了建议。     

Endogenous technical advance and the stochastic trend in output: A neoclassical approach

In the recent endogenous growth literature, the trend in output is stochastic, while investment in scientific knowledge is treated as analogous to a capital stock. This paper models both research and development (R&D) and disembodied technical advance using neo-classical equations, which specify the equilibrium stocks as a function of prices and output. The elasticity of R&D in the production function, estimated using factor shares, is time-varying and increasing. Returns to scale are increasing in all factors. The most important aspect of the model is that the equilibrium rate of technical advance is not cyclically invariant, but co-moves with output at business cycle frequencies. This allows the production function to behave as a stochastic trend. Growth accounting demonstrates that long-term variations in the rate of productivity growth have been associated mainly with low-frequency fluctuations in the rate of disembodied technical advance, with secondary effects from the stocks of R&D and physical capital. During the high productivity period 1948–1972, technical advance contributed 1.48 percentage points per year to output, with 0.98 accounted for by R&D. The productivity slowdown of the mid-1970s was accounted by a gradual decline in the effect of R&D, and a more abrupt collapse in disembodied technology. The subsequent productivity revival was associated with two accelerations in disembodied technical advance, the first beginning in the early 1980s, and the second in the mid-1990s. The production function is simulated in a small econometric model. Model simulations find that exogenous shocks to the inflation rate generate significant variations in growth by inducing fluctuations in disembodied technology.     

Antioxidant and lipid lowering activities of Indian black tea

Indian black tea; CTC leaf and dust, produced by Tata Tea Limited, Kolkata, (India) was studiedin vitro as potential scavenger of oxygen free radicals. Super oxide anions were generated in a system containing xanthine—xanthine oxidase (enzymic system) and by NADH- phenozine methosulphate (non enzymic system). Anions were assayed in terms of uric acid formation and reduction of nitroblue tetrazolium salt, which were shown to be suppressed by tea extracts. Extracts from both leaf and dust also inhibted the formation of hydroxyl radicalsin vitro in the enzymic system comprising hypoxanthine—Cu⁺²—sodium ascorbate and xanthine oxidase and in non enzymic system of deoxyribose—Cu⁺²—sodium ascorbate and H₂O₂ as well as the Cu⁺² induced lipid peroxidation in human low density lipoprotein. Feeding with black tea in normal rats for sixty days increased their antioxidant activity and their liver microsomes were shown to be protected against peroxidation of lipids as stimulated by metal ions with enzymic or non enzymic reactants. Furthermore feeding with tea extracts in normal as well as triton WR—1339 induced hyperlipidemic rats caused decrease in their plasma levels of total cholesterol, phospholipids and triglycerides. The antioxidant and lipid lowering activities of both extracts from CTC leaf and dust tea was comparable and may be due to the presence of natural products like catechin and others.     

基于区块链的制造企业信息共享文明模式研究

在既有的研究基础上,将区块链理念引入制造企业信息共享管理中,探求一种新的企业基础信息共享模式,试图解决目前典型制造企业基础信息共享模式中存在着跨部门信息协同一致难和相互信任难的核心问题。通过分析目前典型传统信息共享模式的缺陷,基于区块链技术的本质特征并解析信息共享文明,构建一种基于区块链的新型制造企业内部信息资源共享文明模式,并给出系统框架和运行流程。     

Assessing Model Similarity in Structural Equation Modeling

Two models can be nonequivalent, but fit very similarly across a wide range of data sets. These near-equivalent models, like equivalent models, should be considered rival explanations for results of a study if they represent plausible explanations for the phenomenon of interest. Prior to conducting a study, researchers should evaluate plausible models that are alternatives to those hypothesized to evaluate whether they are near-equivalent or equivalent and, in so doing, address the adequacy of the study’s methodology. To assess the extent to which alternative models for a study are empirically distinguishable, we propose 5 indexes that quantify the degree of similarity in fit between 2 models across a specified universe of data sets. These indexes compare either the maximum likelihood fit function values or the residual covariance matrices of models. Illustrations are provided to support interpretations of these similarity indexes.     

Explaining the substantial inter-domain and over-time correlations in student achievement: the importance of stable student attributes

Multi-domain and longitudinal studies of student achievement routinely find moderate to strong correlations across achievement domains and even stronger within-domain correlations over time. The purpose of this study is to examine the sources of these patterns analysing student achievement in 5 domains across Years 3, 5 and 7. The analysis is of longitudinal population data of over 22,000 students and utilizes fixed-effects models to incorporate stable general and domain-specific latent factors. These latent factors correspond to a general cognitive-ability-like factor and specific aptitudes in particular, or types of, subject areas. The preferred model incorporates both general and domain-specific latent factors with stronger effects for the general factor, although the domain-specific factors are particularly strong for spelling and numeracy. When taking into account general and domain-specific latent factors, the effects of student’s socioeconomic status (SES) and school SES are trivial.     

主应力轴旋转情况下土的各向异性理论研究进展

从理论方面,对国内外主应力轴旋转情况下土的各向异性研究进行了对比和总结,并提出了一些研究建议。指出在理论方面,应当对屈服面方程采用应力分量表示的模型在三维空间里进行屈服面性状的描述,同时考虑不同加载方向下屈服面的变化特性以及旋转硬化的问题,并应开展对加载方向变化时土体屈服面变化特性的实验研究及理论验证。