松嫩平原土地利用变化对区域生态系统服务价值的影响研究

应用遥感和GIS技术,在获取松嫩平原三期土地利用动态数据的基础上,分析了该地区土地利用变化与成因及其所引起的生态价值的变化.结果表明,从1986年到2000年,松嫩平原草地、水域和湿地面积大量减少,耕地、城镇用地和未利用地面积在增加.该地区总生态价值从1986年的34 926.10×106美元减少到2000年的31 744.54×106美元,减少率为9.11%,净损失值为3 181.56 ×106美元.1995-2000年的5年时间里,生态系统服务价值降低的趋势得到一定程度的缓和.对生态价值变化的空间区域分析表明,黑龙江省部分生态价值损失不大,而吉林省部分,特别是吉林西部环境脆弱带生态价值损失较多.     

Variations in traffic-related polycyclic aromatic hydrocarbons in PM2.5 in Kanazawa, Japan, after the implementation of a new vehicle emission regulation

A three-year sampling campaign was conducted at a roadside air pollution monitoring station in the urban area of Kanazawa, Japan. Due to a new emission regulation, PAHs levels decreased over the sampling campaign, exhibiting values of 706 ± 413 pg/m³ in 2017, 559 ± 384 pg/m³ in 2018, and 473 ± 234 pg/m³ in 2019. In each year, similar seasonal variations in PAHs levels were observed, with higher levels observed in winter and lower levels in summer. Among the PAHs isomer ratios, we observed that the ratio of benzo[b]fluoranthene (BbF) and benzo[k]fluoranthene (BkF), [BbF]/([BbF] + [BkF]), and the ratio of indeno[1,2,3-cd]pyrene (IDP) and benzo[ghi]perylene (BgPe), [IDP]/([BgPe] + [IDP]), showed stability over the sampling campaign and were less affected by the new emission regulation, seasonal variations, and regional characteristics. When using the combined ratio ranges of 0.66 - 0.80 ([BbF]/([BbF] + [BkF]) and 0.26-0.49 ([IDP]/([BgPe] + [IDP]), traffic emissions were clearly distinguished from other PAHs emission sources. Principal component analysis (PCA) and positive matrix factorization (PMF) were also performed to further analyse the characteristics of traffic-related PAHs. Overall, this study affirmed the effectiveness of the new emission regulation in the reduction of PAHs emissions and provided a combined range for identifying PAHs traffic emission sources.     

Dust collection efficiency analysis in a two-dimensional circulating granular bed filter

Dust collection efficiency data were analyzed to determine better operating conditions for a two-dimensional circulating granular bed filter (CGBF). The dust collection efficiency in the granular bed was affected by the following operating parameters: the louver angle, the solids mass flow rate, and the particle size of the bed material. Experimental results showed that higher dust collection efficiency occurs when the solids mass flow rates were 20.34 +/- 0.24, 21.50 +/- 0.11, and 30.51 +/- 0.57 g/sec at louver angles of 45 degrees, 30 degrees, and 20 degrees, respectively. Optimal dust collection efficiency peaked with a louver angle of 30 degrees. Average particle sizes of bed material by sieve diameters (microm) of 795 microm had higher dust collection efficiency than the average collector particle size of 1500 microm. Dust collection efficiency is influenced by bed material attrition phenomenon, causing dust collection efficiency to decrease rapidly. The dust collection efficiency analysis not only found the system free of design defects but also assisted in the operation of the two-dimensional CGBF system.     

机械故障振动信号征兆提取方法

在机械状态监测与故障诊断中，故障征兆的提取是关键环节，本文将介绍几种效果较好的故障征兆提取方法。     

电选法回收利用废印刷线路板

废印刷线路板含有多种有价值的物质，随意丢弃或处理处置方法不当既污染环境，又造成资源流失。采用剪切式破碎和电力分选技术对废印刷线路板的机械分离进行了研究。结果表明，电选法可以实现废印刷线路板中金属和玻璃纤维、树脂的分离；在实验的粒径范围内（-14＋20目到-120＋200目分为5个粒径级别），金属主要集中在-20＋120目粒级范围内，且该粒级范围分选效果最好。     

分光光度法测定降水中微量过氧化氢

研究了一种测定降水中微量过氧化氢的方法。在0.4～1.5mol／L磷酸介质中，过氧化氢与钒（V）及2－（3，5-二溴-2-吡啶偶氮）－5-二乙氨基苯酚（3,5-diBr-PADAP）反应形成一种组成比为1：1：1的蓝色三元配合物，其最大吸收波长为598nm，表现摩尔吸光系数为5.6×104L·mol-1·cm-1。过氧化氮量在2×10-7～1．3×10－5mol／L时服从比耳定律。方法简便，选择性较高，用于降水中微量过氧化氢的直接测定，结果令人满意。     

A simple effective procedure for the determination of adenosine triphosphate in soils

A simple method for the extraction and determination of adenosine 5′-triphosphate (ATP) in soil is described. ATP was extracted by stirring with dimethyl sulphoxide (DMSO), followed by adding 0.01 M trisodium phosphate (Na₃PO₄) buffer solution for a further dispersion. The ATP content was quantitatively measured by luciferin-luciferase system employing a standard addition technique. The method was most efficient in comparison with 7 other extraction procedures. The recoveries of ATP in spiked soil were found to be approximately 100 %. ATP contents in 16 selected soils were in ranges of 0.76±0.05 – 7.79±0.83 μg/g (dry weight). A significant correlation between ATP amounts and biomasses in these soils was also observed.     

纳米TiO2光催化降解酸性粒子元青溶液的研究

对纳米 Ti O2 光催化氧化法降解酸性粒子元青溶液进行了试验研究。结果表明 ,反应符合一级反应 ,反应速率常数为2 .9× 10 - 3min- 1。确立的最佳工艺条件 :催化剂的用量为 4.0 g·L- 1 ,溶液的 p H为 6.3 8,空气的体积流量为 12 0 m L· min- 1 ,在此最佳工艺条件下 ,酸性粒子元青的降解率达到 92 .3 %。且测得反应的表现活化能 Ea为 -17.9k J· mol- 1 。     

Effective removal of antibiotic resistance genes and potential links with archaeal communities during vacuum-type composting and positive-pressure composting

As a major reservoir of antibiotics, animal manure contributes a lot to the augmented environmental pressure of antibiotic resistance genes (ARGs). This might be the first study to explore the effects of different ventilation types on the control of ARGs and to identify the relationships between archaeal communities and ARGs during the composting of dairy manure. Several ARGs were quantified via Real-time qPCR and microbial communities including bacteria and archaea were analyzed by High-throughput sequencing during vacuum-type composting (VTC) and positive-pressure composting (PPC). The total detected ARGs and class I integrase gene (intI1) under VTC were significantly lower than that under PPC during each stage of the composting (p < 0.001). The relative abundance of potential human pathogenic bacteria (HPB) which were identified based on sequencing information and correlation analysis decreased by 74.6% and 91.4% at the end of PPC and VTC, respectively. The composition of archaeal communities indicated that methane-producing archaea including Methanobrevibacter, Methanocorpusculum and Methanosphaera were dominant throughout the composting. Redundancy analysis suggested that Methanobrevibacter and Methanocorpusculum were positively correlated with all of the detected ARGs. Network analysis determined that the possible hosts of ARGs were different under VTC and PPC, and provided new sights about potential links between archaea and ARGs. Our results showed better performance of VTC in reducing ARGs and potential HPB and demonstrated that some archaea could also be influential hosts of ARGs, and caution the risks of archaea carrying ARGs.