增长曲线模型中回归系数的线性估计的可容许性

对增长曲线模型,当协差阵是降秩的,在矩阵损失函数下,本文分别给出了回归系数的线性估计在非齐次线性估计类和全体估计类中是可容许估计的条件.     

Boundary control of a linear distributed parameter bioprocess

This paper is concerned with boundary control of a linear distributed parameter bioprocess. Huang's result (Ann. Differential Equations 1(1) (1985) 43) on the spectrum determined growth assumption is applied to prove that the closed-loop system becomes exponentially stable under a certain condition with respect to the feedback gain. Moreover, it is shown that the decay rate of the open-loop system is given by letting the feedback gain tend to zero.     

Undesirable economic growth via agents’ self-protection against environmental degradation

Our model analyzes the effects of the interplay between environmental degradation and consumption choices on economic growth dynamics and on economic agents’ welfare. We show that if private goods can be consumed as substitutes for environmental goods, then economic growth may be fueled by environmental deterioration. In this context, undesirable economic growth may occur, characterized by an inverse correlation between aggregate capital accumulation and economic agents’ welfare.     

唐山城乡居民消费对经济增长影响差异化的实证分析

作为多年来经济总量位居河北省第一位的唐山市,这几年国民经济得到了飞速发展,消费需求总量的逐步扩大在一定程度上对经济增长的拉动起到了举足轻重的作用。本文建立了城乡居民消费水平与唐山经济增长关系的误差修正模型,研究表明唐山城乡居民消费对其经济增长有正向拉动作用,城镇居民消费的拉动作用比农村居民的要大。因而,采取措施缩小城乡居民消费的差距,统筹二者的发展,是唐山完成两个"率先"的目标、建成全面小康社会不得不面对的问题。     

我国省际人才集聚对经济增长的贡献测算

构建“人才集聚-人才资本-经济增长”(T-C-E)的人才经济价值转化链，测算人才集聚对区域经济增长的贡献。首先计算1990-2014年我国大陆31个省（市、自治区）的平均人才集聚度和人才资本水平；然后基于扩展的柯布-道格拉斯函数计算各地区人才资本对经济增长的贡献率，并采用聚类算法构建“人才集聚度-人才资本贡献率”矩阵进行分析。结果表明：我国省际区域的人才集聚水平存在较大差异，北京市人才集聚水平最高，其平均集聚度达到22.31%，青海省人才集聚度最低，其平均人才集聚度仅为0.51%；人才集聚水平不同，其区域的人才资本对经济增长的贡献存在显著差异，其中，北京等九个区域的人才资本贡献率超过35%，宁夏等八个区域的人才资本贡献率低于10%；总体而言，人才集聚水平较高的区域，其对经济增长的贡献也较高，但两者之间并不具有严格的正向关系。     

WTO与农民收入增长研究

本文通过定性分析和定量计算，找到影响农民收入增长的最重要因素；结合WTO《农业协议》及我国农业资源变化趋势和中国人口实际，提出逐步加大财政支农力度及区别对待；加强农业和农村经济发展的宏观调控，结合各地实际，分类指导；采取灵活的土地承包政策，实现土地规模经营，提高土地的产出率等一系列增加农民收入措施。     

Externalities, technological complementarities and sustained economic growth

Externalities as conventionally defined miss many of the spillovers that are both causes and consequences of the technological changes that underlie economic growth. We introduce a much wider concept called technological complementarities. New general purpose technologies (GPTs) rejuvenate the growth process by creating technological complementarities, which are adequately measured neither by total factor productivity (TFP) nor by externalities. There would be major gains from technological change even if the returns on capital invested in innovation never exceeded the returns on investing in existing technologies so that there were neither externalities nor positive changes in TFP.     

Potential production simulation and optimal nutrient management of two hybrid rice varieties in Jinhua,Zhejiang Province,China

Potential growth of two widely-grown hybrid rice varieties in the Jinhua district of Zhejiang Province, Shanyou63 for mid-rice and Xieyou46 for late rice, was simulated using a crop growth model of WOFOST. Parameters of the rice growth in WOFOST were calibrated through field experiments from 1999 to 2002 in Jinhua. The potential yield simulated with WOFOST was about 12 t/ha for Shanyou63 and 10 t/ha for Xieyou46, which are in good agreement with the highest recorded yield obtained in this area. Under farmers practice, current yield is about 7.5 t/ha for Shanyou63 and 6.5 t/ha for Xieyou46. There is a gap between the actual rice yield and the potential yield for these two hybrid rice varieties grown in this area. The attainable target yields were set to 70% to 75% of their potential yields for the two varieties. A recently developed software ＂Nutrient Decision Support System （NuDSS）＂ for irrigated rice was used to optimize nutrient management for these two rice varieties. According to NuDSS, the optimal fertilizer N requirement for the target yields was about 150 kg/ha for Shanyou63 and about 120 kg/ha for Xieyou46, which were only about 70% of the fertilizer N application under current farmers＇ practice. Comparing with farmers＇ practice, there is great potential to increase actual rice yields and to reduce fertilizer N use rates by improving rice crop management practice in Jinhua.     

关于营造我国农村新型合作组织良好成长环境的探讨

目前农村合作组织在我国之所以发展相对落后并且遭遇瓶颈,是多种环境因素共同作用的结果。它们既包含宏观的国家政策、体制、法律等方面的问题,也有组织本身的问题。只有主观上改变农民对农村新型合作组织的认识,客观上优化组织发展的外部环境,健全组织运行的内部机制,才能实现农村新型合作组织快速健康的成长。