SrBPO5:Ce3 的光谱特性

运用高温固相法,在空气中合成了SrBPO5:Ce3 荧光体,通过研究SrBPO5:Ce3 的光谱特性,发现激发光谱随Ce3 的掺入量增加而红移,据此认为Ce3 在进入格位时有两种电荷补偿方式,发射光谱则随Ce3 的掺入量增加而增强.     

Role of Negative Emotion in Communication about CO2 Risks

This article describes how the effectiveness of risk communication is determined by the interaction between emotional and informative elements. An experiment is described that examined the role of negative emotion in communication about CO₂ risks. This experiment was based on the elaboration likelihood model and the related heuristic systematic model of attitude formation. The results indicated that inducing fear of CO₂ risks leads to systematic processing of information about energy conservation as a risk-reducing strategy. In turn, this results in more favorable attitudes toward energy conservation if strong arguments are provided. Individual differences in concern seem to have similar effects.     

On the incidence–prevalence relation and length‐biased sampling

For many diseases, logistic constraints render large incidence studies difficult to carry out. This becomes a drawback, particularly when a new study is needed each time the incidence rate is investigated in a new population. By carrying out a prevalent cohort study with follow‐up it is possible to estimate the incidence rate if it is constant. The authors derive the maximum likelihood estimator (MLE) of the overall incidence rate, λ, as well as age‐specific incidence rates, by exploiting the epidemiologic relationship, (prevalence odds) = (incidence rate) × (mean duration) (P/[1 ? P] = λ × µ). The authors establish the asymptotic distributions of the MLEs and provide approximate confidence intervals for the parameters. Moreover, the MLE of λ is asymptotically most efficient and is the natural estimator obtained by substituting the marginal maximum likelihood estimators for P and µ into P/[1 ? P] = λ × µ. Following‐up the subjects allows the authors to develop these widely applicable procedures. The authors apply their methods to data collected as part of the Canadian Study of Health and Ageing to estimate the incidence rate of dementia amongst elderly Canadians. The Canadian Journal of Statistics © 2009 Statistical Society of Canada     

科技英语疑问句的信息功能探析

句子的功能所实现的交际任务是传递信息。根据话语信息传递和语言交际功能理论原则,通过甄选科技英语相关例证作为分析语料,从英语的科技文体视角探析了疑问句在科技英语信息推进中的五大作用,同时指出了解这些相关作用的必要性。     

《水浒传》“灵官殿”小考——兼及《水浒传》成书时间问题

《水浒传》第十三回和第十四回都写到了刘唐醉卧灵官殿,这应是灵官信仰在民间较为普遍所致。有关灵官之名及其事迹、信仰的记载都大量出现于明永乐年间之后,因此,关于灵官殿的细节应视为推断《水浒传》成书时间的重要参考依据。     

Bayesian inference for dynamic social network data

We consider a continuous-time model for the evolution of social networks. A social network is here conceived as a (di-) graph on a set of vertices, representing actors, and the changes of interest are creation and disappearance over time of (arcs) edges in the graph. Hence we model a collection of random edge indicators that are not, in general, independent. We explicitly model the interdependencies between edge indicators that arise from interaction between social entities. A Markov chain is defined in terms of an embedded chain with holding times and transition probabilities. Data are observed at fixed points in time and hence we are not able to observe the embedded chain directly. Introducing a prior distribution for the parameters we may implement an MCMC algorithm for exploring the posterior distribution of the parameters by simulating the evolution of the embedded process between observations.     

内生增长理论下的循环经济研究

经济学一直是以研究稀缺资源为中心的,而现在的稀缺资源已从劳动和资本开始变为自然资源。而新古典经济学中的生产函数仍以资本和劳动为内生变量,而将自然资源作为外生变量,在此情景下,我们需要对新古典经济中的生产函数进行相应的修正,将自然资源外生变量内生化,将其作为生产函数中的内生变量来对生产函数进行重新研究。     

硅酸盐体系电解液组成对铝合金微弧氧化的影响

利用正交试验试验研究了硅酸盐体系的组成和组分浓度对6063铝合金微弧氧化陶瓷膜层的生长速度的影响.结果表明,既能够使陶瓷膜层快速生长,又能够保证膜层质量的电解液适宜配方为硅酸钠8 g/L、氢氧化钠2 g/L、钨酸钠1 g/L、EDTA二钠2 g/L;氢氧化钠浓度超过2.5 g/L时会产生局部烧蚀现象.     

12Cr1MoV钢动态断裂韧性的试验研究

采用Hopkinson压杆装置对试样冲击加载,完成了12Cr1MoV钢在不同温度冲击条件下动态断裂韧性的测试.实验获得了12Cr1MoV钢的KId-t曲线,该曲线具有明显的韧脆转变趋势,存在上平台区、韧脆转变过渡区及下平台区,材料的韧脆转变温度DBTT=-4.3℃.     

明代前期潮州海防及其历史影响(下)

明代潮州的海防格局,是在洪武朝30多年间逐步建立起来的。文章主要通过明代地方文献的分析,描述明初潮州海防系统建立的缘由、过程和制度变迁,探讨沿海卫所布局所反映的潮州地方社会情形,一个侧面反映明初中央王朝的政策在沿海边远地区推行的实况及地方社会的因应过程。文章也力图从当时社会的实际情况出发去理解海防体系建构过程的种种安排,并揭示这一过程对地方社会的长远影响。文章试图说明,就户籍和田土管理制度而言,明初潮州地方确实存在着行政和军事两大相互独立的系统,但与北方和西南沿边地区不同的是,东南沿海的“沿海卫所”和“内地卫所”可能并未因为这种管理体制的差别,而成为独立于府县之外“地理单位”。相反的,潮州沿海的各个守御千户所都与周围的乡村有密切的联系,成为理解小范围地域社会发展脉络不可或阙的重要因素。明初潮州海防另一影响深远的举措,是南澳岛的弃守。洪武初年曾将粤闽交界洋面南澳岛的居民纳入版图,但洪武、永乐年间“弃而不守”。南澳岛因而成为各国商人和各种海上活动力量聚集之区,从而变成有明一代闽粤海防的心腹大患,其影响直至清初实施迁界政策之后。文章也对这一举措的历史影响进行了讨论。