A Comparative Study of the Performance of Public Water Rights Allocation in China

Pubic water rights allocation, in which water resources are allocated to users administratively as shared public property, is an effective and powerful policy for water resource management. Dozens of public water right allocation systems have been established in China since 1998 without any unified standard across the country. An indicator-based assessment approach, based on equity, efficiency and sustainability, is proposed in this study to evaluate the performance of public water rights allocation systems in China in a quantitative way. The approach was applied in 11 river basins of China in which water rights have been defined. The results show that the performance of the allocation systems depends on the spatial density and exploitation ratio of the water resources. The performance of allocated water rights systems is better in river basins with greater resource densities and smaller water exploitation ratios. This assessment approach is very useful for evaluating policy options for public water rights allocation with appropriate consideration of the local conditions of the river basins.     

Development of a compact filament-discharge multi-cusp H- ion source

A 14 MeV medical cyclotron with the external ion source has been designed and is being constructed at China Institute of Atomic Energy. The H(-) ion will be accelerated by this machine and the proton beam will be extracted by carbon strippers in dual opposite direction. The compact multi-cusp H(-) ion source has been developed for the cyclotron. The 79.5 mm long ion source is 48 mm in diameter, which is consisting of a special shape filament, ten columns of permanent magnets providing a multi-cusp field, and a three-electrode extraction system. So far, the 3 mA∕25 keV H(-) beam with an emittance of 0.3 π mm mrad has been obtained from the ion source. The paper gives the design details and the beam test results. Further experimental study is under way and an extracted beam of 5 mA is expected.     

Characterizing natural dissolved organic matter in a freshly submerged catchment (Three Gorges Dam, China) using UV absorption, fluorescence spectroscopy and PARAFAC

This study applied parallel factor analysis (PARAFAC) to fluorescence excitation-emission matrices (EEMs) of natural water samples in a freshly submerged catchment in the upper reach of Three Gorges Dam (China). Two fluorescent natural dissolved organic matter (NDOM) components (humic/fulvic-like) were uncovered and were positively correlated with selected water quality parameters, i.e. dissolved oxygen concentration, dissolved organic carbon concentration, dissolved Kjeldahl nitrogen concentration and total (dissolved plus particulate) phosphorus concentration, respectively. To other water quality parameters (i.e. total nitrogen, particulate nitrogen, particulate phosphorus, dissolved phosphorus, dissolved nitrate, pH, and chemical oxygen demand), either the two components did not show any correlation or only one component showed correlation. In particular, particulate N correlated significantly to the fulvic acid, but not to the humic acid. Meanwhile, two conventional spectroscopic indices i.e. specific UV absorbance at 254 nm (SUVA254) and fluorescence index (FI) indicated that the whole NDOM in the waters were low in aromaticity and predominantly derived from aquatic microbial processes. Given together, it concludes that N and P did not function equally in the NDOM production, and the two components were not derived from the same microbial processes. The EEMs-PARAFAC has proven to be of potential as an effective tool in investigation of the interlink between NDOM and nutrients which may be utilized as an indicator of water environment.     

黑龙江省水田发展北扩战略研究

从黑龙江省北部地区种植结构调整、农民增产增收以及为黑龙江省水田发展谋取新的增长空间出发,在黑河市爱辉区高寒高纬度水田种植试验取得成功的基础上,提出在第四、第五积温带进行水稻种植的条件完全具备,确定了水田北扩的范围为北纬48°~51°之间的黑河市6个县区、大兴安岭的呼玛三卡地区和伊春市的嘉荫县,并提出了水田北扩的初步设想。     

IEEE802.11p下删余卷积编码译码方法的研究

应用于智能交通系统的无线接入协议IEEE802.11p,其物理层卷积编码的码率可通过对(2,1,7)卷积编码器的删余来实现。讨论了删余位置的图案和算法,分析了在删余位置插入不同哑元时维特比译码后误码率的统计特性。仿真的同时比较了固定哑元下不同码率所引入的误比特率。     

基于FPGA的可配置FFT_IFFT处理器的设计与实现

设计实现了一种用于P2P移动无线通信手持终端产品。该设计采用优化的单碟形4路并行结构,兼容802.11g协议,可配置完成64点、256点、1 024点的FFT-IFFT处理器,设计以Xilinx公司的Virtex-2系列的XC22V500芯片为硬件平台。通过大量实际信号与数据的联合调试,表明了设计的正确性及实用性。     

基于无线的物联智能家居控制系统设计

提出一种基于无线的物联智能家居控制系统设计,该系统通过PXA270和nRF24L01模块实现无线采集、发送各项家居信息;通过GSM通信将烟雾、煤气、红外等传感器的异常报警信息以短信方式通知用户,并连接PXA270的PC实现实时远程监控。经过测试,该系统工作稳定,便于实际应用,市场前景广阔。     

基于增广矩阵束方法的平面天线阵列综合

针对平面阵列的稀布优化问题,提出了一种基于增广矩阵束方法的减少阵元数目、求解阵元位置和设计幅度激励的优化方法。首先对期望平面阵的方向图进行采样并由采样点数据构造增广矩阵,对此矩阵进行奇异值(SVD)分解,确定在误差允许范围内所需的最小阵元数目;然后基于广义特征值分解分别计算两组特征值,并根据类ESPRIT算法对特征值进行配对;最后在最小二乘准则条件下根据正确的特征值对求解平面阵列的阵元位置和激励。仿真结果表明该算法具有较高的计算效率和数值精度。     

基于模块化的大综合PLC实验平台的研究与设计

提出了一种基于模块化设计的柔性大综合PLC实验平台。该实验平台以PLC为核心,融合了单片机技术、无线测控技术、多种上位监控技术、基于以太网和电话网的远程控制技术、变频以及步进电机驱动等技术,可灵活组合不同功能模块完成基础性、综合性、开放性和设计性的几十种实验,为PLC大综合实验平台的设计进行了有益的探索。     

Structure and function of maladaptive cognitions in Pathological Internet Use among Chinese adolescents

This study empirically investigated the structure and function of maladaptive cognitions related to Pathological Internet Use (PIU) among Chinese adolescents. To explore the structure of maladaptive cognitions, this study validated a Chinese Adolescents’ Maladaptive Cognitions Scale (CAMCS) with two samples of adolescents (n1 = 293 and n2 = 609). The results of the exploratory factor analysis and confirmatory factor analysis revealed that CAMCS included three distinct factors, namely, “social comfort,” “distraction,” and “self-realization.” To examine the function of maladaptive cognitions, this study tested an updated cognitive-behavioral model in the third sample of 1059 adolescents. The results of structural equation model analyses verified both the direct effect of maladaptive cognitions on PIU and their mediating role in the relationships between distal factors (social anxiety and stressful life events) and PIU among Chinese adolescents. Theoretical and practical implications of these findings were discussed.