本振相位噪声对接收机性能的影响

针对工程中本振相位噪声对接收机的影响常难以估量的问题,提出利用等效相位白噪声谱密 度进行评估的方法。通过分析相位噪声的产生及其对剩余误码率和动态范围的影响机理,仿 真了不同相位噪声对误码率的影响程度。通过仿真结果可知：相位噪声对接收机性能具有重 要的影响,工程中应针对不同的应用场合要求合理的相位噪声指标。     

新型固相萃取材料在样品前处理技术中的应用研究进展

固相萃取是近年来发展比较迅速的样品前处理技术,固相萃取材料的选择是影响固相萃取效率的主要因素之一。本研究对近年来新型的固相萃取材料及其在样品前处理技术中的应用进行综述,并对其未来发展的方向进行了展望。     

Towards an understanding of international city break travel

This paper explores city break tourism and, in particular, the distinctive characteristics of this form of travel. The city break is examined and compared with other types of trips. The research follows a sequential mixed methods approach involving both a visitor survey and in‐depth interviews. The findings show the international city break trip to have a number of distinctive characteristics. These are summarised into five main areas (5 Ds) — duration, distance, date flexibility, discretionary nature and destination travel party. These distinguishing features provide a useful insight into one of the most important yet least examined travel segments in tourism research. Copyright © 2009 John Wiley & Sons, Ltd.     

分离富集环境水溶液中铅离子的离子印迹—固相萃取技术

以Pb(Ⅱ)为模板离子,壳聚糖为功能单体,硅胶为载体,γ-(2、3环氧丙氧)丙基三甲氧基硅烷(KH-560)为偶联剂,利用表面分子印迹技术和溶胶-凝胶法在稀醋酸溶液中制备了Pb(Ⅱ)离子印迹聚合物.采用傅立叶变换红外光谱法(FT-IR)对Pb(Ⅱ)离子印迹和非印迹聚合物的表面形貌和结构进行表征;并用电感耦合等离子体原子发射光谱法(ICP-AES)考察了吸附酸度、吸附剂用量、静置时间等对聚合物吸附性能的影响;研究了印迹聚合物在混合溶液中对Pb(Ⅱ)的选择性,比较了印迹和非印迹聚合物的吸附容量;在最佳吸附酸度为4.5时,0.3g吸附剂吸附5h达到平衡,Pb(Ⅱ)离子印迹聚合物对Pb(Ⅱ)离子具有较高的选择性,其饱和吸附容量是非印迹聚合物的2倍.     

习近平新时代流通发展观的核心思想及其演化脉络

作为习近平新时代中国特色社会主义经济思想重要组成部分的流通发展观,是中国流通现代化的思想指南和行动纲领,对于实现党的十九大提出的伟大战略目标具有重要的理论价值和现实意义。文章总结习近平新时代经济思想流通发展观的核心思想四大方面的内容,考察分析该理论体系形成过程中所经历的三个不同阶段,进一步梳理其形成的历史脉络,以便深刻理解和把握这一科学理论体系,指导中国流通现代化的伟大实践。     

Confirming the timing of phase-based costing in oncology studies: a case example in advanced melanoma

Aims: The utilization of healthcare services and costs among patients with cancer is often estimated by the phase of care: initial, interim, or terminal. Although their durations are often set arbitrarily, we sought to establish data-driven phases of care using joinpoint regression in an advanced melanoma population as a case example.

Methods: A retrospective claims database study was conducted to assess the costs of advanced melanoma from distant metastasis diagnosis to death during January 2010–September 2014. Joinpoint regression analysis was applied to identify the best-fitting points, where statistically significant changes in the trend of average monthly costs occurred. To identify the initial phase, average monthly costs were modeled from metastasis diagnosis to death; and were modeled backward from death to metastasis diagnosis for the terminal phase. Points of monthly cost trend inflection denoted ending and starting points. The months between represented the interim phase.

Results: A total of 1,671 patients with advanced melanoma who died met the eligibility criteria. Initial phase was identified as the 5-month period starting with diagnosis of metastasis, after which there was a sharp, significant decline in monthly cost trend (monthly percent change [MPC]?=?–13.0%; 95% CI?=?–16.9% to –8.8%). Terminal phase was defined as the 5-month period before death (MPC?=?–14.0%; 95% CI?=?–17.6% to –10.2%).

Limitations: The claims-based algorithm may under-estimate patients due to misclassifications, and may over-estimate terminal phase costs because hospital and emergency visits were used as a death proxy. Also, recently approved therapies were not included, which may under-estimate advanced melanoma costs.

Conclusions: In this advanced melanoma population, optimal duration of the initial and terminal phases of care was 5 months immediately after diagnosis of metastasis and before death, respectively. Joinpoint regression can be used to provide data-supported phase of cancer care durations, but should be combined with clinical judgement.     

股票资金流强弱指数的结构突变研究

以股票资金流强弱指数为研究对象,根据时间序列分析方法,运用修正的ICSS算法,基于上证A股2010年5月4日至2015年5月22日的日交易数据,得到上证A股的结构突变点,并对所得到的变点进行了实证分析和应用研究。结果表明：上证A股资金流强弱指数是平稳的非正态时间序列;上海股票市场具有波动聚集性,而且是政策市场;构建了股票资金流强弱指数判别法,用以便捷的对资金流强弱指数结构突变点进行分类。     

语境动态顺应论在外贸谈判中的应用探析

基于Verschueren的顺应理论,通过价格谈判、付款方式谈判、佣金谈判、发货谈判案例,对外贸谈判中的语境动态顺应这一话语现象进行分析,进一步揭示语境动态顺应的应用能更有效地突破谈判僵局达成交易,从而达到双赢谈判的目标。     

一种新的2CPFSK信号极化合成方法

针对低信噪比下连续相位调制信号的极化合成,提出了一种基于多符号检测技术的极 化合成新方法。通过把解调和极化合成作为一个整体进行处理,在基带上完成了通常在中频 上实现的极化合成过程,避免了连续相位调制信号在低信噪比下载波相位跟踪困难的问题。 仿真结果表明,该方法的合成效果与理论值之间的差距小于0.3 dB。     

The Stability of the Demand for Money in Monetary Unions: Some Empirical Evidence from WAEMU

Previous studies of the stability of the demand for money have been largely conducted in the context of individual countries. To the extent that these countries have control over their monetary policies, such an approach is well justified. However, for monetary unions, where the control over monetary policy is usually vested in a central or outside authority, it is more appropriate to examine the stability of the money demand for the union as a collective entity. This paper follows this approach with respect to a West African monetary union, the WAEMU, whose monetary policies are largely dictated by the French authorities. Using cointegration theory and CUSUM stability tests, we find evidence that the demand for broad money is stable in this union. Given the empirical results, the paper draws inferences regarding their implications for the formulation of optimal monetary policy for the WAEMU.