国内外能源转型比较与启示

当前全球能源转型正处于加速推进时期,各国转型进程呈现出一定的差异化特征。基于对能源转型发展方向的剖析,提出涵盖能源结构、能源效率、能源安全、能源价格4个维度的能源转型评价指标体系。在此基础上,对中国、美国、德国、法国、日本、韩国等主要国家能源转型情况进行对比分析,进而提出对中国能源转型的结论与启示。     

Opportunistic channel selection approach under collision probability constraint in cognitive radio systems

In this work, we consider a cognitive radio system with multiple primary channels and one secondary user, and then we introduce a channel-usage pattern model and some basic concepts in this system. Based on this system model and the basic concepts, we propose two opportunistic channel selection algorithms to optimize the throughput of the secondary user: minimum collision rate channel selection algorithm and minimum handoff rate channel selection algorithm. According to the two algorithms, we, respectively, present the channel selection scheme based on minimum collision rate algorithm (CSS-MCRA) and the channel selection scheme based on minimum handoff rate algorithm (CSS-MHRA) under the constraint that the collision probability is bounded below collision tolerable level. Theoretical analysis and simulation results both show that, on one hand, both CSS-MCRA scheme and CSS-MHRA can follow the constraint of collision tolerable level; on the other hand, the performance of CSS-MCRA scheme is better than that of CSS-MHRA scheme if handoff latency is zero or very low, while the performance of CSS-MHRA scheme is better than that of CSS-MCRA scheme if handoff latency is long enough.     

同频同时全双工数字自干扰抵消算法

同频同时全双工是第五代移动通信（5G）提出的核心概念之一,其关键技术为自干扰抵消。其中数字抵消具备灵活高效的优势,进一步提高其性能是降低全双工节点的成本、功耗和复杂度的重要途径。本文首先介绍了基本数字抵消算法——信道估计重构法的原理,然后从提高自适应性、提高自干扰信号还原准确性以及实现简化三个角度介绍了改进算法。最后,展望了全双工数字自干扰抵消算法未来的研究方向,为全双工架构和算法设计提供参考。     

Application Prospects of 1000-kV AC Transmission Technologies in China

The scale of 1000-kV AC transmission development, which relates to the strategy of the state＇s energy development, is mainly determined by the output scale of large pit-mouth power plants in northern China. The demonstration has shown the construction of large-sized pit-mouth power plants of aircooling type in Shanxi, Shaanxi and Inner Mongolia for sending bulk power to Central and East China is economically rational and overall beneficial to environmental protection.     

Uplink sum capacity evaluation of multi-user distributed antenna systems

This letter focuses on the simplified sum capacity evaluation for the uplink of a generalized multi-user distributed antenna system (DAS). Based on system scale-up, we derive a good approximation of the sum capacity by generalizing the results from random matrix theory. An iterative method is presented to calculate the unknown parameters in the approximation. The approximation is illustrated to be quite accurate and the iterative method is demonstrated to be quite efficient by Monte Carlo simulations.     

陕西汉阴县黄龙金矿成矿物质来源及成矿模式探讨

陕西省汉阴县黄龙金矿位于陕西石泉-旬阳金矿带整装勘查区中部,是区内重点调查的典型矿床之一,本次工作通过对黄龙金矿不同地质体的氢氧同位素、硫同位素、石英包裹体均一温度及稀土元素等方面的研究,以及成矿物理化学条件的分析,结合矿体地质特征,认为黄龙金矿床成矿物质是多源的,主要来源有3个方面:(1)中-下志留统梅子垭岩组;(2)煌斑岩脉;(3)早期剥离断层。通过对该矿床成矿物质来源及区内构造变形特征分析,建立了黄龙金矿岩浆热液叠加改造型金成矿模式图。为区内寻找同类型金矿床提供新的思路。     

Comparison of trends in the quantity and variety of Science Citation Index (SCI) literature on human pathogens between China and the United States

The proportion of pathogenic microorganisms in the microbial world is relatively small, while their threat to human health, economic development and social stability is severe. The quantity and variation of Science Citation Index (SCI) literature related to pathogenic microorganisms may reflect the level of relevant research and the degree of attention. Here we compared trends in the quantity and variety of SCI literature relating to certain important pathogenic microorganisms published by scientists from United States and China from 1996 to 2010 by searching the Science Citation Index database. The pathogenic microorganisms in this study comprise two categories of pathogens: Bacillus anthracis, Yersinia pestis, Francisella tularensis, Ebola virus, Burkholderia pseudomallei, which belong to biodefense-associated pathogens (BDAPs) and the human immunodeficiency virus (HIV), SARS coronavirus, hepatitis B virus (HBV), Mycobacterium tuberculosis, influenza virus, which belong to the commonly encountered health-threatening pathogens. Our results showed that the United States (US) published much more SCI literature on these pathogens than China. Furthermore, literature on BDAPs published by scientists from the US has increased sharply since 2002. However, the numbers of literature relating to CEHTPs from China has demonstrated a gradual increase from 1996 to 2010. Research into pathogenic microorganisms requires three balance to be achieved: investment in BDAP and CEHTP studies; basic and applied research; a faster pace of research into pathogens and fulfilling biosafety and biosecurity requirements.     

某型钢-混凝土结构大楼主要施工技术分析

湖南某大楼主要结构为型钢混凝土组合框架,工程中采用最佳的钢结构施工技术和措施,保证了大跨度后张法有粘结预应力楼盖框架梁和300t钢结构连廊整体提升施工质量,又提高了施工效率,使主体结构施工进度进行顺利,比原计划提前了2个月完成,具有很好的经济效益,为在同类工程提供很好的参考作用。