养老设施活动空间背景声源类型对情绪及活动的影响

情绪感知研究是声环境研究中的重 要内容。已有研究表明了不同声源与情绪感 知之间的关系,但在目前国内养老设施声环 境研究中,尚未将声源类型与情绪进行关联。 本文以呼和浩特及哈尔滨8处养老设施为对 象,在其活动空间播放鸟鸣声、流水声、钢 琴曲和中国民歌4种背景声源,收集有效问卷 177份,同时测量声压级,在此基础上分析不 同背景声源类型对于情绪及活动影响的差异 性。研究发现鸟鸣声具有最佳的提升愉悦情 绪和安静感受的效果,钢琴曲对觉醒情绪提 升最大,中国民歌对抵抗烦扰情绪最有效; 棋牌活动空间不适合增加背景声源,乒乓球活动空间更适合中国民歌,台球活动空间与鸟鸣声和钢琴曲的组合都对情绪具有积极影响,多 种声源都对改善静坐活动空间声环境有帮助等。     

城镇化进程中的能源供应体系变革研究

我国正处于城镇化加速发展阶段,能源需求还将合理增加,构建城镇化与能源供给协调发展的能源供应体系是实现低碳城镇化的首要任务.本文在分析城镇化发展对能源供应体系变革提出新要求的基础上,提出应从推进煤炭清洁高效利用、优化能源供应布局、大力发展分布式能源、发挥农村生物质资源优势等方面对城镇和农村能源供应体系变革采取新举措,为新型城镇化发展提供能源保障.     

建筑室内材料和物品VOCs、SVOCs 污染源散发机理及控制技术——推动室内装修环保控制模式新突破

正1研究意义随着我国新型城镇化进程的推进和建材行业的迅猛发展,室内环境保障面临着巨大挑战,众多的科研工作者为此开展了大量的工作。目前我国虽然在室内材料和物品污染物散发特性检测和控制方法研究领域取得了较大进展,但在污染物散发检测标准和散发标识体系方面与欧美发达国家相比仍存在较大差距。主要表现在:欧美国家最早通过颁布室内材料和物品标识体系(欧洲AgBB、CESAT、     

Inhalation intake fraction of pollutants from episodic indoor emissions

The intake fraction is the attributable pollutant mass inhaled by an exposed population per unit mass released from a source. In this paper, mathematical models are combined with empirical data to explore how intake fraction varies with governing parameters for episodic indoor pollutant releases, such as those from cleaning, cooking, or smoking. Broadly, the intake fraction depends on building-related factors (e.g., ventilation rate), occupant factors (e.g., occupancy), and pollutant dynamic factors (e.g., sorption). In the simple case of the episodic release of a nonreactive pollutant into a well-mixed indoor space with steady occupancy and constant ventilation and breathing rates, the intake fraction is the ratio of the occupants’ volumetric breathing rate to the building's ventilation flow rate. Factors such as incomplete mixing, time-varying occupancy, and sorptive interactions modify this basic relationship.     

一种未知信源数的高分辨DOA估计算法

众多性能优良的超分辨波达方向(DOA)估计算法通常需要预先判定信源数目,然而,现有的信源数估计算法在有限采样快拍条件下,估计性能随着信噪比的降低而下降,错误概率也相应增加,最终导致DOA估计失败。该文提出一种超分辨的DOA估计算法,此算法不需要预判信源个数和进行特征值分解,同时在时变环境中,针对快拍数较少的情况下,依然保持较高的角度分辨能力,可以被认为是综合了Capon法和MUSIC法的优点。通过对实验数据和实测数据的计算机仿真及性能分析可得,与传统算法相比较,该算法有很好的鲁棒性和可行性。     

基于多数据源和联合聚类的智能推荐

随着Internet的普及和电子商务的盛行,智能推荐系统也应运而生.协同推荐是目前公认为最好的一种推荐技术,但其存在着一些不足之处,如:稀疏性、可扩展性和冷启动问题.本文提出一种混合推荐技术来克服协同过滤的不足.首先,通过引入多个数据源对评价矩阵进行平滑填充来解决数据的稀疏性问题.其次,采用从用户和项目两方面进行联合聚类来提高系统的可扩展性和精度.实验结果证明,该方法在很大程度上较传统的协同过滤方法推荐精度高,且在线推荐的速度快.     

Toward an Ecological Civilization: China’s Progress as Documented by the Second National General Survey of Pollution Sources

The relationship between environmental quality and economic growth has been a hot topic for decades. After years of rapid industrialization and urbanization, China’s environmental challenges are approaching a turning point. Following the principles of ecological civilization construction, China is on its way to maintaining high-quality and green economic development. On 10 June 2020, the Chinese Government reported the key findings of the Second National General Survey of Pollution Sources (fiscal year 2017), which provides strong quantitative evidence of progress toward ecological civilization. In terms of our comparison between the two National General Surveys in 2007 and 2017, it was found that environmental pollution, measured in terms of many wastewater and air emission pollutant discharges, is decreasing despite the steady growth in economic activities—and at a noticeably fast pace. Other national and local governments can adopt some of China’s ecological civilization practices, within their own individual contexts.     

Occurrence of trace metals in foodstuffs and their health impact

BackgroundUnlike organic pollutants, heavy metals are not created nor are biodegradable materials. They naturally occur in earth crust and many of them reach the environment via anthropogenic activities, which belonged to mining, smelting, production of fertilizers, pesticide applications and others.Scope and approachDue to their water solubility and bioaccumulative tendency in different matrices of the environment, some heavy metals are extremely toxic even at low exposure levels and can be transported into the food chain.Key findings and conclusionsMany criteria are defined to identify heavy metals based on their specific gravity, weight and atomic number, chemical properties and their toxicity, therefore the heavy metals term is still very loose. Dietary exposure is a significant route for trace metals to the humans and constitutes about 90% of exposure. Long term exposure to metals via food consumption, drinking water or other occupational sources leads to serious problems, e.g., hepatotoxicity, kidney failure and neurotoxicity. Analysis of the current situation concluded that the concentrations of heavy metals declined over the years, but they are still hot spots suffering from domestic wastes, agrochemicals like pesticides, fertilizers and industrial wastes. Due to the contamination sources in those hot spots, levels of some metals exceeded the approved permissible limits and become sources of severe problems to humans. Almost comprehensive hazard assessment of these metals is missing due to insufficient data corresponding to body burden for groups potentially exposed to high concentration of metals and their concentrations in foodstuffs.     

Polar organic and inorganic markers in PM10 aerosols from an inland city of China — Seasonal trends and sources

Polar organic compounds and elements were quantified in PM₁₀ aerosols collected in urban and rural areas of Baoji, an inland city of China, during winter and spring 2008. Concentrations of biomass burning markers and high molecular weight n-alkanoic acids (HMW, > C_22:0) were heavily increased in winter. In contrast, sugars presented in higher levels in the spring, among which sucrose was the most abundant with an average of 219 ng m⁻³ in winter and 473 ng m⁻³ in spring respectively. This suggests enhanced biotic activity in the warm season, whereas no obvious trend was observed for sugar alcohols, concentrations of the three sugar alcohols in spring were only 0.94-2.3 times as those in winter, indicating a second pathway of their formation other than fungal spores in cold season. Major crustal elements (i.e., Fe, K, Mn and Ti) in PM₁₀ aerosols were also observed in larger concentrations in spring samples than those in winter due to an enhancement of coarse particles from soil minerals. By using principal component analysis (PCA) and positive matrix factorization (PMF), sources and their contributions to the PM components were also investigated in this study. Four factors were extracted with both models, and the sources represented by different factors were based on the highest loaded marker species as follows: factor 1, soil and road dust (Fe, Sr and Ti); factor 2, biomass burning (levoglucosan, galactosan and syringic acid); factor 3, microbial emissions (fructose and sucrose); and factor 4, fossil fuel combustion and fungal spores influence (Pb, Zn, arabitol and mannitol). The high correlation between PM₁₀ and factor 1 suggested that PM₁₀ pollution in Baoji was dominated by soil and dust re-suspension.     

Polybrominated diphenyl ethers and polychlorinated biphenyls in indoor dust in Durban,South Africa

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in indoor dust of three microenvironments in Durban, South Africa. The sum of eight PBDEs and three PCBs were quantified by gas chromatography with mass spectral detection. The mean concentrations of ∑_n = 8 PBDEs and ∑_n = 3 PCBs in 10 homes, 11 offices, and 13 university students’ computer laboratories were 1710, 1520, and 818 ng/g, and 891, 923, and 1880 ng/g for PBDEs and PCBs, respectively. The concentration of PCBs found in homes was independent (P = 0.0625) of building construction year. Similarly, no relationship was observed between PCB concentrations and floor type. The concentrations of PBDEs correlated (r = 0.60) with PCB concentrations in homes, thus assuming similar sources. The elevated concentrations of PBDEs and PCBs may have significant implications for human exposure.