长株潭"3+5"城市群产业目标结构研究

通过对长株潭"3+5"城市群产业结构现状与同等收入水平的国际"标准"产业目标,发现长株潭"3+5"城市群的产业结构现状与国际"标准"产业目标结构差距较大,国际"标准"产业目标结构不宜作为其产业调整的近期目标结构.最后,结合长株潭"3+5"城市群内各市的发展现状,制定了各市产业调整的近期目标结构.     

The multiple effects of carbon values on optimal rotation

Non-consumptive benefits which increase with crop age, like keeping carbon sequestered, lengthen optimal rotation compared with rotation for timber alone. High proposed carbon prices may extend rotation indefinitely. Carbon storage in wood products reduces this tendency. Biomass as an energy source displacing fossil fuels favours rotations near those of maximum biomass productivity. Use of sawn timber to displace structural materials with high embodied carbon favours somewhat longer rotations. Effects of rotation on soil carbon, and fossil carbon volatilised in harvesting operations, are further complications. Including all carbon effects results in optimal rotations somewhat longer than those based only on timber value, but shorter than those based on timber plus forest carbon. To include all factors intuitively is not possible: balanced appraisal needs economic calculations.     

高效液相色谱串联质谱法测定豆芽中4-氯苯氧乙酸、6-苄基腺嘌呤残留量的不确定度评定

目的:建立高效液相色谱串联质谱法测定豆芽中4-氯苯氧乙酸(4-CPA)、6-苄基腺嘌呤(6-BA)残留量的不确定度评定方法.方法:建立数学模型,分析实验过程中不确定度因素的主要来源.结果:豆芽中4-CPA含量为(9.06±0.86)μg·kg-1(k=2),6-BA含量为(9.41±0.88)μg·kg-1(k=2)....     

5G系统中基于解调参考信号的信道估计方法

5G系统使用解调参考信号(Demodulation Reference Signal,DMRS)用于下行信道估计,工程中通常采用插值法得到数据位置信道响应,考虑实际信道中噪声的影响,频域采用线性最小均方误差(Linear Minimum Mean Squared Error,LMMSE)插值算法。针对LMMSE需要获取信道先验统计特性以及存在矩阵求逆运算量大问题,利用信号时域内能量集中特点估计出信道均方根时延、信噪比和信道自相关矩阵,对于DMRS信号在频域上间隔较大、DMRS信号所在子载波相关性不强的问题,通过引入导频加密方法提升DMRS信号所在子载波间的相关性以提升信道估计性能,并通过滑动窗口插值方法进一步降低LMMSE算法求逆运算复杂度。仿真结果表明,所提算法均方误差和误码率总体均优于线性插值和基于矩阵奇异值分解的LMMSE算法,并与传统LMMSE算法相比性能极为接近,而且复杂度降低了99.85〖WT《Times New Roman》〗%〖WTBZ〗,适合实际工程应用。     

服务业中基于六西格玛管理的客户中心化流程的优化

本文通过分析服务业流程特点,为服务业提供实施六西格玛管理模式与框架,优化服务业流程,为服务业实施六西格玛管理提供参考。     

头孢妥仑酯侧链4-甲基-5-噻唑甲醛的合成

研究了头孢妥仑酯侧链4-甲基-5-噻唑甲醛的合成工艺,以丙酮和硫脲为原料,在碘催化下合成2-氨基-4-甲基噻唑,应用Vilsmeiar反应合成2-氨基-4-甲基-5-噻唑甲醛,再经重氮化脱除氨基,得到头孢妥仑酯的侧链,总收率达30%。     

基于FPGA的高速分裂基FFT算法实现

快速傅里叶变换(FFT)是离散傅里叶变换(DFT)的快速算法,而分裂基FFT算法是所有FFT算法中一种效率较高的一种算法,有着广泛的应用。在高速的系统要求下,文章选择分裂基FFT算法作为实现高速FFT处理器的基本算法。文中设计采用了并行处理、流水线技术等有效的实现方法,在Virtex-5 FPGA平台上有着很好的效果,并且满足了高速的系统要求。结果显示,系统延时只有13个周期,并且在资源利用上面有很高的效率。     

西部地区经济差异化分析——基于基尼系数的产业分解

随着西部经济的进一步发展,该区内部经济发展不平衡的问题也日渐凸显。文章在梳理西部省区经济差异发展状况和产业结构演变历程的基础上,运用基尼系数对西部12省区进行了产业分解。结果表明,二、三产业发展水平是西部经济差异化扩大的主要因素,而地理集中程度又是导致西部二、三产业发展水平差异化的主要因素。     

Accounting for Negative,Zero and Positive Willingness to Pay for Landscape Change in a National Park

In contingent valuation, despite the fact that many externalities manifest themselves as costs to some and benefits to others, most studies restrict willingness to pay to being non‐negative. In this paper, we investigate the impact of allowing for negative, zero and positive preferences for prospective changes in woodland cover in two UK national parks, the Lake District and the Trossachs. An extended spike model is used to accomplish this. The policy implications of not allowing for negative values in terms of aggregate benefits are also investigated, by comparing the extended spike model with a simple spike making use of only zero and positive bids, and a model which considers positive bids only. We find that ignoring negative values over‐states the aggregate benefits of a woodland planting project by up to 44%.     

Non‐Parametric Modelling of CO2 Emission Quota

Dutch glasshouse firms are facing the introduction of a system of tradable CO₂ emission quotas. This paper employs a non‐parametric method for modelling tradable CO₂ emissions of Dutch glasshouse firms. The method is capable of generating shifts in CO₂ emissions across the sample of firms. Moreover, changes in volumes of outputs produced and inputs used are computed. Results show that firms using a conventional heating technology will be net purchasers of CO₂ emissions, whereas firms using more advanced heating technologies will sell part of their emission quota.