智能空间中基于场景和本体的用户异常活动识别

基于传感器和本体的异常活动识别研究大多数认为,任何偏离日常活动的模型都是异常,却忽略场景因素。根据本体库中的ADL场景和四种已确定的异常活动,对异常活动进行更丰富的识别。经过试验验证,异常活动识别准确率有明显提高。     

水下爆炸的一些声学特性分析

为了验证水下爆炸所产生的声信号能否作为一种干扰源并用于鱼雷的水声干扰对抗,进行了高能炸药装药的水下爆炸试验及其测试.根据测试数据曲线分析了冲击波的传播和衰减、气泡脉动、持续时间、声压级以及功率谱.结果表明,水下爆炸作为一种强水声干扰源,可在反鱼雷干扰对抗中发挥重要作用.     

室内良好声环境实现的措施研究

噪声问题是众多城市环境问题中备受关注的问题之一。在人们需要安静休息的住宅、病人需要静养的医院、学生需要静心学习的教室等,都需要良好的声环境。而随着生产的发展和工业体系的完善,噪声污染也越来越严重。本文依据物理原理,对噪声进入室内的方式进行了分类,并对室内噪声声场分布进行分析,从而提出了一些降低室内噪声的可行性措施。     

Estimation of speed of sound of ionic liquids using surface tensions and densities: A volume based approach

The limited availability of experimental data and their quality have been preventing the development of predictive methods and Computer Aided Molecular Design (CAMD) of ionic liquids (ILs). Based on experimental speed of sound data collected from the literature, the inter-relationship of surface tension (σ), density (ρ), and speed of sound (u) has been examined for imidazolium based ILs containing hexafluorophosphate (PF₆), tetrafluoroborate (BF₄), bis(trifluoromethanesulphonyl) amide (NTf₂), methyl sulphate (MeSO₄), ethyl sulphate (EtSO₄), and trifluoromethanesulphonate (CF₃SO₃) anions, covering wide ranges of temperature, 278.15–343.15 K and speed of sound, 1129.0–1851.0 m s⁻¹. The speed of sound was correlated with a modified Auerbach's relation, by using surface tension and density data obtained from volume based predictive methods previously proposed by the authors. It is shown that a good agreement with literature data is obtained. For 133 data points of 14 ILs studied a mean percent deviation (MPD) of 1.96% with a maximum deviation inferior to 5% was observed. The correlations developed here can thus be used to evaluate the speeds of sound of new ionic liquids.     

Estimates of Internal Pressure and Molar Refraction of Imidazolium Based Ionic Liquids as a Function of Temperature

Estimates of the internal pressure (∂ U/∂ V) _T of the ionic liquids (ILs) 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF₄], 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF₆], and 1-methyl-3-octylimidazolium tetrafluoroborate [OMIM][BF₄] were made from experimentally determined densities and speeds of sound in the temperature range 283.15 to 343.15 K. Values (∂ U/∂ V) _T for all the ILs studied are higher than those of water and molecular organic liquids. We also measured the refractive indices n _D in the temperature range 288.15 to 343.15 K and estimated the molar refraction R _M. Refractive indices of ILs were also higher than those of normal organic liquids but were comparable to those of long hydrocarbon chain organic solvents.     

Azolo[5,1-<Emphasis Type="Italic">c</Emphasis>]-1,2,4-triazines as a new class of antiviral compounds

Synthetic methods, reactivity, and the properties of a new class of antiviral compounds, pyrazolo-, imidazo-, 1,2,4-triazolo[5,1-c]-1,2,4-triazinones, tetrazolo[5,1-b]-1,2,4-triazinones, and azoloannulated amino-1,2,4-triazines having structural similarity with biogenic purines and capable of mimicking them in metabolic processes are considered. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 967–995, May, 2008.     

音乐厅音质设计

音乐厅音质设计除了和其他有音质要求的建筑一样满足一些共同要求外,本文就其音质设计在体型设计、声扩散处理和演奏台设计等方面进行了探讨．体型设计将影响直达声、早期友射声和混响声在时间和空间上的分布．较宽频率范围的声扩散程度是音质优美的关键．演奏台则主要是为乐队各声部提供良好的平衡     

Hydrofracturing and episodic compaction of muddy rocks in sedimentary basin

Hydrofracturing has been found in a numbr of sedimentary bahs throughout the world, which pay an important role in the migration of hydrocarbon and compaction of deposits in overpressured impermeable muddy rock. The forming proceses of hydmfracture in the basin evolution has been simulated and the associated episodic compaction of deposits has been evaluated. The modelling results indicate that episodic compacting process in impermeable rocks induced by hydrofracturing is an important way of sediment compaction.     

用超声波声速法测定油品中含水率

基于流体中声波传播速度决定于流体性质,提出用超声波声速法测量油品含水率的方法。实测结果表明,油品中声波的传播速度与油品的温度和油品中的含水率成线性关系,只要测得油品的温度及油品中的声速,就可由声速的温度系数确定油品的含水率。     

基于压缩感知算法的传感器网络异常事件检测

为改善传感器网络异常事件检测效果,提出一种基于压缩感知算法的传感器网络异常事件检测模型.首先采集传感器网络状态信息,并采用压缩感知算法对信息进行采样和重构,在减少传感器网络异常事件检测信息的同时,删除一些无效信息;然后从重构后的传感器网络异常事件检测信息中提取特征,组成传感器网络异常事件检测的特征向量;最后采用极限学习机建立传感器网络异常事件检测模型,并进行传感器网络异常事件检测仿真实验,分析模型的性能.实验结果表明,压缩感知算法可加快传感器网络异常事件检测速度,且传感器网络异常事件检测率高于95%,明显高于其他传感器网络异常事件检测模型.