技术创新对高新技术产品贸易竞争力的影响

以新贸易理论为基础,探讨技术创新对中国高新技术产业产品贸易竞争力的影响,并进行实证分析,目的是通过分析中国高新技术产品贸易竞争力和技术创新状况,研究技术创新与高新技术产品贸易竞争力的互动关系,并对提升高新技术产品出口竞争力作进一步探讨。结果表明：中国高新技术产品R＆D投入产出率与贸易竞争力间存在长期均衡关系,而人力资本投入强度、新产品开发强度与贸易竞争力关联度不大。     

Box-Cox变换下联合均值与方差模型的极大似然估计

在提出Box-Cox变换下联合均值与方差模型的基础上,研究了该模型参数的估计问题.同时利用截面极大似然估计方法对变换参数λ进行估计,并对均值模型和方差模型的参数进行极大似然估计.通过随机模拟和实例研究,结果表明该模型和方法是有效和可行的.     

电磁导弹的波瓣特性

首次在球坐标系统下研究了电磁导弹有趣的波瓣特性。研究表明:当天线口径、距离一定时,电磁导弹的波瓣随波形参量减小而变窄;当天线口径、波形参量一定时,电磁导弹的波瓣随距离增加而变窄;当波形参量、距离一定时,电磁导弹的波瓣随天线口径增加而变宽;电磁导弹不存在副瓣;电磁导弹的能量在远轴时仍按球面波方式衰减。这些结论有助于理解电磁导弹的实质。     

非均匀平面波声场中质点运动的椭圆度

当均匀平面声波入射在液—固介质分界面上产生非均匀平面波时，场中质点将在其平衡位置附近作椭圆振动。计算表明：对于场中固体界面上的质点，当入射角比纵波临界角小得多时，其椭圆度近似为１，质点基本上作直线振动；当入射角比横波临界角大得多时，纵波场中质点运动的椭圆度接近于０，质点运动轨迹近于圆，而横波场中质点运动的椭圆度最小；当入射角在纵波临界角或横波临界角附近时，质点运动的椭圆度有较大的变化。文中指出固体粘滞系数对场中质点运动椭圆度的影响不大，且仅仅表现在临界角附近。在瑞利角入射下，界面法线方向上的固体质点，其运动的椭圆度呈周期性变化，当深度为瑞利波半波长整数倍时，椭圆度为１；当深度为瑞利波半波长的奇数倍时，椭圆度最小     

传统饮料热灌装系统的灌装控制改进和结构优化

第1代PET塑料瓶饮料热灌装机存在灌装控制系统简易、工艺不稳定、易发生料液渗漏的问题,使得产品质量不稳定,存在一定风险。笔者提出 一种基于传统热灌装系统的新控制系统和灌装通路优化方法：通过对灌装阀组设计增加新的卫生级气动控制模块,实现灌装工艺的时间变量控制;同时通过优化 分配器和排气管路结构,提高了灌装过程中排气通道的可靠性,消除了冷凝水回流对产品的污染。该改进方法实现了以少量的改造投入,有效提高了工艺稳定性 ,提高了产品的灌装质量。     

"人"在《金瓶梅》中

在古代文学作品中,《金瓶梅》对于人和人性的描写和思考达到了前所未有的高度。它写了人性的压抑、人性的觉醒、人性的扭曲,写出了人的兽性与理性的矛盾与统一。这也是《金瓶梅》在艺术上能塑造出一批真人、活人的重要保证。     

对"溺婴"的人口社会学分析

文章通过对溺婴行为的界定分析了溺婴的原因及产生的社会后果,并对如何抑制这种现象作了进一步的探讨。     

构建民族地区新型农村社会福利制度的思考

农村社会福利制度是社会保障制度中的最高层次,保障着农村居民的生活水平和生活质量随着生产力水平的提高而同步提高。本文通过对湖南省少数民族地区农村社会福利制度建设状况的调研,分析了少数民族地区农村社会福利制度建设存在的主要问题,提出了构建湖南省少数民族地区新型农村社会福利制度的思路。     

An International Pooled Analysis for Obtaining a Benchmark Dose for Environmental Lead Exposure in Children

Lead is a recognized neurotoxicant, but estimating effects at the lowest measurable levels is difficult. An international pooled analysis of data from seven cohort studies reported an inverse and supra‐linear relationship between blood lead concentrations and IQ scores in children. The lack of a clear threshold presents a challenge to the identification of an acceptable level of exposure. The benchmark dose (BMD) is defined as the dose that leads to a specific known loss. As an alternative to elusive thresholds, the BMD is being used increasingly by regulatory authorities. Using the pooled data, this article presents BMD results and applies different statistical techniques in the analysis of multistudy data. The calculations showed only a limited variation between studies in the steepness of the dose‐response functions. BMD results were quite robust to modeling assumptions with the best fitting models yielding lower confidence limits (BMDLs) of about 0.1–1.0 μ g/dL for the dose leading to a loss of one IQ point. We conclude that current allowable blood lead concentrations need to be lowered and further prevention efforts are needed to protect children from lead toxicity.     

A New Multicriteria Risk Mapping Approach Based on a Multiattribute Frontier Concept

Invasive species risk maps provide broad guidance on where to allocate resources for pest monitoring and regulation, but they often present individual risk components (such as climatic suitability, host abundance, or introduction potential) as independent entities. These independent risk components are integrated using various multicriteria analysis techniques that typically require prior knowledge of the risk components’ importance. Such information is often nonexistent for many invasive pests. This study proposes a new approach for building integrated risk maps using the principle of a multiattribute efficient frontier and analyzing the partial order of elements of a risk map as distributed in multidimensional criteria space. The integrated risks are estimated as subsequent multiattribute frontiers in dimensions of individual risk criteria. We demonstrate the approach with the example of Agrilus biguttatus Fabricius, a high‐risk pest that may threaten North American oak forests in the near future. Drawing on U.S. and Canadian data, we compare the performance of the multiattribute ranking against a multicriteria linear weighted averaging technique in the presence of uncertainties, using the concept of robustness from info‐gap decision theory. The results show major geographic hotspots where the consideration of tradeoffs between multiple risk components changes integrated risk rankings. Both methods delineate similar geographical regions of high and low risks. Overall, aggregation based on a delineation of multiattribute efficient frontiers can be a useful tool to prioritize risks for anticipated invasive pests, which usually have an extremely poor prior knowledge base.