固定源PM_(2.5)稀释采样器的研制

为研究固定源PM2.5的排放特征,研制开发了一套紧凑型稀释采样器,能模拟高温烟气排放到大气中的冷却、稀释、凝结等物理化学过程,采集固定源排放的一次PM2.5.稀释采样器主要的技术参数如下:稀释比在20∶1~50∶1范围内,在稀释器里的停留时间为10 s,稀释后的烟气温度和相对湿度分别小于42℃和50%,满足ISO 25597:2013的要求.稀释采样器的性能评价实验表明,稀释器气密性良好,稀释空气中颗粒物浓度低,气流混合均匀性良好,细颗粒在采样器内的损失小,表明稀释采样器可靠性高,适合于对固定源排放PM2.5的采集.     

多次进水-曝气的好氧颗粒污泥系统实验

选用SBR反应器R1和R2接种污水处理厂活性污泥,以生活污水为进水,分别采用一次进水-曝气策略和多次进水-曝气策略运行,对运行过程中粒径变化及处理效果进行研究.实验表明,运行56和39 d后R1和R2成功实现污泥颗粒化;稳定运行后R1和R2中出水COD、 TN和TP浓度(mg·L~(-1))分别为29.7、 13.7、 0.31和19.2、 8.1、 0.37,去除率分别为87.7%、 75.6%、 95.1%和90.1%、 85.6%、 94.2%,其中颗粒平均粒径达到740μm和791μm.结果表明,相同运行时间下,R2中的出水NO~-_3-N浓度和出水TP浓度低于R1.运行后期,R1和R2中DPAO占全部PAOs的比值由最初11.17%分别增至25.47%和34.08%.与一次进水-曝气策略相比,采用多次进水-曝气策略运行在启动初期系统内NO~-_3-N浓度较低,PAOs受到的冲击更小,DPAO富集情况更好,除磷性能更好,利于AGS的形成.     

基于多元统计分析的火灾灾后抢险物资配送模型研究

传统物资配送方法存在配送物资效率低、配送成本高等缺点,为了及时确定抢险物资应急救援路线,向火灾受灾点快速配送抢险物资,提出基于多元统计分析的火灾灾后抢险物资配送模型。建模时采用多元统计分析法分析火灾受灾点救援需求和配送路线连通随机性,以及救援出发点对受灾点的最大覆盖范围的限制,利用加权贝叶斯算法将物资配送多目标规划问题转变成单目标规划问题,建立抢险物资配送单目标规划模型;运用遗传算法对模型求解,并采用惩罚函数处理模型中的约束条件,实现物资在受灾点之间均衡分配。     

降尘规律研究--兰州城区降尘变化规律及多元自身回归预测

探讨了降尘的年变化、月变化.运用逐步回归筛选变量.采用主分量分析法,得出不同季节的主分量,揭示了降尘的规律,建立了多元自身回归预测方程.对城区降尘进了预测,并与实测作了验证和对比,取得较好效果.     

Analysis of factors affecting individual participation in carbon market

China will set up a national carbon emissions trading market by the end of 2017, which is initially open to individual investors from the initial market for business and institutional investors. In this article, the main influencing factors and mechanism of individual participation in carbon trading market are studied by establishing multiple linear regression model. The study found that age, education level, length of account opening time, and risk attitude are the main factors influencing the participation of individual investors. Environmental awareness and environmental impact are less affected; information transparency and transaction risk also have an impact on the degree of individual investor participation; investment experience does not affect the participation of individual investors in the carbon trading market.     

Geology-dependent impacts of forest conversion on stream fish diversity

Forest conversion is one of the greatest global threats to biodiversity, and land-use change and subsequent biodiversity declines sometimes occur over a variety of underlying geologies. However, how forest conversion and underlying geology interact to alter biodiversity is underappreciated, although spatial variability in geology is considered an integral part of sustaining ecosystems. We aimed to examine the effects of forest conversion to farmland, the underlying geology, and their interaction on the stream fishes’ diversity, evenness, and abundance in northeastern Japan. We disentangled complex pathways between abiotic and biotic factors with structural equation modeling. Species diversity of stream fishes was indirectly shaped by the interaction of land use and underlying geology. Diversity declined due to nutrient enrichment associated with farmlands, which was mainly the result of changes in evenness rather than by changes in species richness. This impact was strongest in streams with volcanic geology with coarse substrates probably because of the differential responses of abundant stream fishes to nutrient enrichment (i.e., dominance) and the high dependency of these fishes on large streambed materials during their life cycles. Our findings suggest that remediation of deforested or degraded forest landscapes would be more efficient if the interaction between land use and underlying geology was considered. For example, the negative impacts of farmland on evenness were larger in streams with volcanic geology than in other stream types, suggesting that riparian forest restoration along such streams would efficiently provide restoration benefits to stream fishes. Our results also suggest that land clearing around such streams should be avoided to conserve species evenness of stream fishes.     

应用超声空化效应多泡声致发光技术测量海水总有机碳(TOC)

超声化学是声学与化学相互交叉而发展起来的一门新兴学科, 它作为一种新颖的声化学技术正在日益受到人们的重视.超声化学主要是利用超声空化效应而进行的,本文对超声空化效应氧化降解有机物以及反应过程中的多泡声致发光机理进行了研究,就应用多泡声致发光技术来表征海水总有机碳(TOC)的可行性进行了分析,同时指出了应用超声空化效应-多泡声致发光技术测量海水总有机碳(TOC)的巨大潜力以及发展前景     

固含率和稀释率对餐厨垃圾水解酸化过程的影响研究

研究了餐厨垃圾分批厌氧消解过程中不同起始固含率（10％,12％和14％）和稀释率（0.25 d^－1和0.33 d^－1）对水解酸化过程pH值、垃圾消解、水解酸化液生产效率、脂肪酸组成和浓度等的影响。实验结果发现：以总固体去除率、单位质量垃圾累积COD溶出量（ACODm）和单位体积反应器累积COD溶出量（ACODv）等指标作为评价标准,起始固含率12％的体系具有较高的垃圾处理效率和反应器运行效率。与稀释率0.25 d^－1的体系相比,稀释率0.33 d^－1的体系在pH稳定性、总固体去除率和水解酸化液生产效率等方面具有明显的优势。所有体系中水解酸化产生的脂肪酸和醇均以乙酸、乙醇和丁酸为主,丙酸占总脂肪酸和醇的百分数在14.6％到17.1％之间,这种脂肪酸组成不会发生丙酸抑制,有利于后续产甲烷发酵的进行。     

Nutrient and Sediment Production,Watershed Characteristics,and Land Use in the Tahoe Basin,California‐Nevada1

Abstract: In efforts to control the degradation of water quality in Lake Tahoe, public agencies have monitored surface water discharge and concentrations of nitrogen, phosphorus, and suspended sediment in two separate sampling programs. The first program focuses on 20 watersheds varying in size from 162 to 14,000 ha, with continuous stream gaging and periodic sampling; the second focuses on small urbanized catchments, with automated sampling during runoff events. Using data from both programs, we addressed the questions (1) what are the fluxes and concentrations of nitrogen and phosphorus entering the lake from surface runoff; (2) how do the fluxes and concentrations vary in space and time; and (3) how are they related to land use and watershed characteristics? To answer these questions, we calculated discharge‐weighted average concentrations and annual fluxes and used multiple regression to relate those variable to a suite of GIS‐derived explanatory variables. The final selected regression models explain 47‐62% of the variance in constituent concentrations in the stormwater monitoring catchments, and 45‐72% of the variance in mean annual yields in the larger watersheds. The results emphasize the importance of impervious surface and residential density as factors in water quality degradation, and well‐developed soil as a factor in water quality maintenance.     

鸡、猪粪便源大肠杆菌对4种抗生素耐药性的比较

以琼脂稀释法对67株鸡源大肠杆菌及61株猪源大肠杆菌进行最低抑菌浓度(MIC)测定,并以SPSS分别进行卡方检验和Probit模型估算,分析不同来源大肠杆菌耐药差异显著性及不同抗生素的半数抑菌浓度(MIC50),以期对不同畜禽粪便来源的大肠杆菌耐药差异进行详细准确的探讨。结果显示,鸡源大肠杆菌对头孢噻肟、诺氟沙星、环丙沙星和四环素耐药率分别为98.51%、68.66%、56.72%和100%,猪源大肠杆菌对头孢噻肟耐药率为88.52%,对诺氟沙星、环丙沙星和四环素则100%耐药。除四环素,鸡源、猪源大肠杆菌对诺氟沙星、环丙沙星、头孢噻肟的耐受差异显著(P0.05),51%的鸡源大肠杆菌和89%的猪源大肠杆菌均呈4重耐药。SPSS分析结果表明,Probit模型估算结果优于当前MIC50常规计算方法,头孢噻肟、诺氟沙星、环丙沙星和四环素对鸡源大肠杆菌MIC50分别为40.031μg·m L~(-1)、40.020μg·m L~(-1)、2.683μg·m L~(-1)和101.418μg·m L~(-1),对猪源大肠杆菌MIC50分别为8.724μg·m L~(-1)、56.044μg·m L~(-1)、31.214μg·m L~(-1)和130.915μg·m L~(-1)。回归方程显示环丙沙星对鸡源大肠杆菌抑制作用最强;高于40.031μg·m L~(-1)时,诺氟沙星抗菌作用弱于头孢噻肟,低于120.23μg·m L~(-1)时,诺氟沙星抗菌作用强于四环素;头孢噻肟、环丙沙星、诺氟沙星和四环素对猪源大肠杆菌的抑菌作用则呈递减趋势。同时验证了诺氟沙星和环丙沙星属同种作用机制,基于Probit模型计算更简单、快速、直观。研究结果可为畜禽养殖中大肠杆菌的耐药差异监控提供一定的数据基础。