基于通用DSP的视频编码器量化算法研究

通过构造合适的量化矩阵,实现了快速量化;同时,对不同的视频编码块类型,采用不同的量化策略,避免了统一量化引起的图像质量下降。实验结果表明：不仅提高了编码器在DSP上的量化效率,而且明显改善了编码图像的主,客观质量。     

基于压缩感知的大规模多输入多输出空间共稀疏信道估计

针对频分复用双工方式的大规模多输入多输出（MASSIVE MIMO）系统在虚拟角域信道中估计精度较差的问题,提出一种基于门限的稀疏度自适应匹配追踪（BT-SAMP）算法。该算法融合了回溯正交匹配追踪（BAOMP）算法的原子选择特性和稀疏度自适应匹配追踪（SAMP）算法的自适应特性,将BAOMP算法的"添加原子"规则作为SAMP算法的原子选择预处理,通过合理的阈值添加固定的原子,然后延续SAMP算法的步长迭代自适应特性,寻找到信道矩阵近似系数最大,达到了提高SAMP算法估计精度、加快算法收敛的目的。仿真结果表明,在低信噪比（SNR）情况下,与SAMP算法相比,信道估计精度均有提高,特别是信噪比在0~10 dB时,其估计精度提升4 dB,算法的运行时间减少约61%。     

实用户外视频监控异常检测策略

树枝叶等植物的晃动是造成户外监控背景复杂性的主要因素。该文提出一种基于视频分析的运动对象检测策略，利用快慢双背射模型检测运动变化像素，并通过邻域像素的棚关性检测消除虚假运动对象。实验表明此算法对户外监控不但速度快而且检测效果理想，满足实用化要求。     

一种用户偏好的美学图像推荐方法

在众多的图像信息资源中快速、有效地寻找用户最喜欢的图像,提出了一种用户偏好的美学图像推荐方法,通过使用深度卷积神经网络提取图像的深层特征,并经过SVMrank后得到一个图像排序得分,同时使用手工标记的图像美学因素（如色调法、图像组合规则、清晰度以及简洁性）计算并得到图像的美学特征,得到一个美学得分,最后进行加权交叉验证得到一个令用户满意的推荐结果。通过实验表明该算法为一种有效的美学偏好推荐方法。     

2015年中国PM2.5浓度遥感估算与时空分布特征

以PM2.5污染物为主的大气污染对社会的可持续发展及人类健康带来了严峻的挑战,厘清我国PM2.5污染物的空间分布特征及演变规律,对于PM2.5污染物的区域联防联控具有重要的意义。基于MODIS卫星的气溶胶产品、气象基础数据以及PM2.5污染物实测站点监测数据,构建地理加权回归模型,对2015年中国PM2.5污染物浓度进行了模拟估算,对PM2.5污染物浓度的空间分异格局及季节演化特征进行分析。结果表明：①2015年全国PM2.5浓度整体表现出明显的空间地带性分异特征。北方PM2.5污染物浓度明显高于南方,中部明显高于东部与西部;②4个季度PM2.5浓度表现出明显的季节适应性演化特征。第四季度PM2.5污染最重,第三季度和第一季度次之,第二季度最低,最大值出现在第四季度（165 μg/m³）,最小值出现在第二季度（4.3 μg/m³）。③通过多因子构建的地理加权回归模型估算的PM2.5浓度具有较高的模拟精度,第一至第四季度的相对误差分别为10.2%、7.0%、9.3%和8.6%。     

Estimation and Spatial-temporal Distribution Characteristics of PM2.5 Concentration by Remote Sensing in China in 2015

Air pollution characterized by PM2.5 pollutants poses severe challenges to the sustainable development of society and human health. Therefore, it is of great significance to clarify the spatial-temporal distribution and evolution of PM2.5 pollutants in China for regional joint prevention and control of PM2.5 pollutants. Based on the MODIS satellite aerosol products, meteorological basic data and PM2.5 pollutant monitoring site monitoring data, a geographically weighted regression model was established to simulate and estimate PM2.5 pollutant concentration in China in 2015 on the basis of aerosol and meteorological data pre-processing. In addition, the spatial distribution pattern, the seasonal evolution characteristics of PM2.5 pollutant concentration were analyzed. The results showed that: (1) the PM2.5 concentration values in China in 2015 as a whole showed obvious spatial zonal differentiation characteristics. The concentration of pollutants in the north is significantly higher than that in the south, and the areas with high PM2.5 concentrations are mainly concentrated in the Beijing-Tianjin-Hebei region, the Jianghuai plain, the Sichuan basin, and the Takaramalkan desert. The area has a wide spatial distribution and significant continuity; (2) The PM2.5 concentration in the fourth quarter showed obvious seasonal adaptive evolution characteristics. The PM2.5 concentration changed significantly in the season. PM2.5 pollution was the heaviest in the fourth quarter, followed by the first quarter of the third quarter and the lowest in the second quarter. The maximum occurred in the fourth quarter (165 μg/m³). The minimum appeared in the second quarter (4.3 μg/m³). Seasonal changes in PM2.5 concentrations were influenced by meteorological factors and human social activities; and (3) The accuracy of the inversion of PM2.5_{concentration by a multi-factorial, geographically weighted regression model was higher, with relative errors in the four quarters being 10.2%, 7.0%, 9.3%, and 8.6%, respectively.}     

空调系统的VAV末端

概要介绍了空调系统ＶＡＶ末端的工作原理、产品特点、基本组合、部件结构、选型及设备使用方法,预测了ＶＡＶ末端在国内的发展前景。     

斜发沸石对氨氮废水吸附性能的实验研究

用江苏丹徒天然斜发沸石进行模拟氨氮废水的脱氮实验研究.结果表明,在氨氮溶液初始浓度为300mg/L、pH值为2.5～8.5时,天然斜发沸石对氨氮的吸附量较高,吸附等温线符合Freundlich方程,相关系数都在0.99以上,吸附动力学符合准二级吸附动力学模型,并以化学吸附为主;应用于畜禽废水处理中,氨氮去除率达85.6%.     

聚丙烯辐射效应的研究

本文研究了在不同温度下和不同介质存在时,γ射线对等规立构聚丙烯的性能与结构的影响。实验结果表明,聚丙烯的特性粘度随剂量的增加而减少,而且初始下降相当大。当在室温下空气中辐照时,聚丙烯的裂解稍占优势;真空中辐照时则能使聚丙烯的交联效率增加。若提高辐照温度,聚丙烯的凝胶点则向高剂量方向移动,在180℃下真空辐照的聚丙烯就不再产生凝胶了。X射线和红外光谱测定结果指出,聚丙烯的结晶度和等规度随辐照温度的增加而迅速下降。     

Biosynthesis of nanocrystal akaganéite from FeCl2 solution oxidized by Acidithiobacillus ferrooxidans cells

Akaganéite (beta-FeOOH) is a major iron oxyhydroxide component in some soils, marine concretions, and acid mine drainage environments. Recently, synthetic beta-FeOOH has been found to be a promising absorbent in the treatment of metal-contaminated water. It has been recognized in previous study that akaganéite could be formed via FeCl2 chemical oxidation under specific conditions. Here we report a novel and simple method for akaganéite bioformation from FeCl2 solution oxidized by Acidithiobacillus ferrooxidans LX5 cells at 28 degrees C. After acclimation in modified 9K medium containing 0.2 M chloride, Acidithiobacillus ferrooxidans cells had great potential for oxidization of Fe2+ as FeCl2 solution, and then resulted in the formation of precipitates. The resulting precipitates were identified by powder X-ray diffraction and transmission FT-IR analyses to be akaganéite. Scanning electron microscopy images showed the akaganéite was spindle-shaped, approximately 200 nm long with an axial ratio of about 5, and the spindles had a rough surface. X-ray energy-dispersive spectral analyses indicated the chemical formula of the crystalloid akaganéite could be expressed as Fe8O8(OH)7.1(Cl)0.9 with Fe/Cl molar ratio of 8.93. The biogenetic akaganéite had a specific surface area of about 100 m2 g(-1) determined by BET method.