The Impact of Ethanol Fuel Blends on PM Emissions from a Light-Duty GDI Vehicle

This study explores the influence of ethanol on particulate matter (PM) emissions from gasoline direct injection (GDI) vehicles, a technology introduced to improve fuel economy and lower CO₂ emissions, but facing challenges to meet next-generation emissions standards. Because PM formation in GDI engines is sensitive to a number of operating parameters, two engine calibrations are examined to gauge the robustness of the results. As the ethanol level in gasoline increases from 0% to 20%, there is possibly a small (<20%) benefit in PM mass and particle number emissions, but this is within test variability. When the ethanol content increases to >30%, there is a statistically significant 30%–45% reduction in PM mass and number emissions observed for both engine calibrations. Particle size is unaffected by ethanol level. PM composition is primarily elemental carbon; the organic fraction increases from ～5% for E0 to 15% for E45 fuel. Engine-out hydrocarbon and NO_x emissions exhibit 10–20% decreases, consistent with oxygenated fuel additives. These results are discussed in the context of the changing commercial fuel and engine technology landscapes.

Copyright 2012 American Association for Aerosol Research     

Chemical Mass Closure and Chemical Characteristics of Ambient Ultrafine Particles and other PM Fractions

Ambient ultrafine particles (UPs or PM _0.1 ), PM _2.5 and PM ₁₀ were investigated at the roadside of Syuefu road in Hsinchu city and in the Syueshan highway tunnel in Taipei, Taiwan. A SMPS (TSI Model 3936), three Dichotomous samplers (Andersen Model SA-241), and three MOUDIs (MSP Model 110) were collocated to determine the PM number and mass concentrations simultaneously. The filter samples were further analyzed for organic carbon (OC), element carbon (EC), water-soluble ions, and trace elements. The OC artifact was studied and quantified using the quartz behind quartz (QBQ) method for all PM fractions. Taking into account the OC artifact, chemical mass closure (ratio of the reconstructed chemical mass to the gravimetrical mass) of PM _0.1 , PM _2.5 , and PM ₁₀ was then calculated and found to be good. The chemical analysis results of UPs at both sites showed that UPs in the present tunnel was mostly contributed from the vehicle emissions while UPs at the roadside was mainly influenced by urban sources.     

广州市天河区某小学PM2.5的化学组成分析

为了解广州市天河区某小学大气环境中细粒子(PM2.5)的污染水平和组分特征,采用便携式PM2.5采样器(MiniVol)在2010年3月25日~4月1日对该小学室外PM2.5浓度进行了监测,并通过离子色谱仪、碳分析仪、X射线荧光分析仪(XRF)分析PM2.5的化学组成。结果表明该采样点室外PM2.5浓度范围为25.1～145.9μg/m3,PM2.5的主要离子成分是SO42-、NO3-、NH4+,含碳组分浓度不高,S、K、Cl、Na、Al、Si、Fe、Mg、Ca、Zn等元素对PM2.5浓度有一定贡献。该采样点PM2.5主要来源于煤燃烧源、生物质燃烧源、海洋源、本地交通源、土壤尘和建筑尘。     

浅谈接近开关在化工生产中的应用

阐述了接近开关的特点及其分类,并叙述了电磁感应式、电容式接近开关的工作原理及其在化工生产中的几种应用,并且使用效果很好。     

浮法玻璃表面的理化特征

从浮法玻璃成形工艺的特点出发,论述了浮法玻璃表面渗锡以及渗锡分布特征,浮法玻璃表面化学成分的变化特征,浮法玻璃表面物理性质的变化特征。     

East versus West in the US: Chemical Characteristics of PM2.5 during the Winter of 1999

The chemical composition of PM_2.5 was investigated at four sites (Rubidoux, CA, Phoenix, AZ, Philadelphia, PA, and Research Triangle Park, NC) in January and February of 1999. Three samplers were used to determine both the overall mass and the chemical composition of the aerosol. Teflon filters were weighed for total mass. Ions were analyzed using ion chromatography. Elements were determined using X-ray fluorescence. Organic and elemental carbon were measured using a thermo-optical method. At all of the sites, reconstructed mass was observed to be greater than or equal to the measured mass. Good ionic balance was found for ammonium, nitrate, and sulfate at each of the sites. Overall, the chemical composition of the aerosol for each site was in good agreement with the expected composition based upon previous studies, with the exception of relatively high nitrate contribution to the total mass at Philadelphia. Good agreement was found between the predicted amount of sulfate by XRF analysis of sulfur and the sulfate measured by ion chromatography. As expected, sulfate was a more important contributor to the total mass at the East Coast sites. Nitrate contributed more to the total mass at the West Coast sites and was an important factor in the highest observed mass concentration at Rubidoux. Teflon filters appear to lose nitrate to a greater extent than heat-treated quartz fiber filters. Organic carbon was also found to be the largest part of the aerosol mass on minimum days for all sites and a significant portion of the mass on other days with 25-50% of the total mass at all of the sites. At three of the sites, organic carbon (OC) collected on denuded filters was less than that found on nondenuded samples, indicating an absorptive artifact on the quartz fiber filters. It was also found that the crustal component to PM_2.5 was highest at Phoenix. PM_2.5 was also found to contribute significantly to the PM₁₀ particle mass at all the sites.     

PM1.0 and PM2.5 Characteristics in the Roadside Environment of Hong Kong

Daily mass concentrations of PM _1.0 (particles less than 1.0 μm in diameter), PM _2.5 (particles less than 2.5 μm in diameter), organic carbon (OC), and elemental carbon (EC) were measured from January through May 2004 at a heavily trafficked sampling site in Hong Kong (PU). The average concentrations for PM _1.0 and PM _2.5 were 35.9 ± 12.4 μ g cm ^{? 3} and 52.3 ± 18.3 μ g cm ^{? 3} . Carbonaceous aerosols were the dominant species in fine particles, accounting for ～ 45.7% of PM _1.0 and ～ 44.4% of PM _2.5 . During the study period, seven fine-particle episodes occurred, due to the influence of long-range transport of air masses from mainland China. PM _1.0 and PM _2.5 responded in similar ways; i.e., with elevated mass and OC concentrations in those episode days. During the sampling period, PM _1.0 OC and EC generally behaved similarly to the carbonaceous aerosols in PM _2.5 , regardless of seasonal variations and influence by regional pollutions. The low and relatively constant OC/EC ratios in PM _1.0 and PM _2.5 indicated that vehicular emissions were major sources of carbonaceous aerosols. PM _1.0 and PM _2.5 had the same dominant sources of vehicular emissions in winter, while in spring PM _2.5 was more influenced by PM _{1 ? 2.5} (particles 1–2.5 μ m in diameter) that did not form from vehicle exhausts. Therefore, PM _1.0 was a better indicator for vehicular emissions at the Roadside Station.     

Influence of Some Herbicides on the Physical and Chemical Characteristics of Soybean Oil

The effect of some herbicides on the soybean oil quality and quantity has been studied. Herbicides caused a highly significant increase in soybean oil content. Statistical analysis showed that there was no and highly significant differences in acid value; unsaponifiables and saponification value and iodine value respectively of soybean oil extracted from plants subjected to various herbicides. The increase of herbicides application rates exhibited profound effects on the physical and chemical characters of soybean oil. The application of herbicides leads to the following changes on soybean oil fatty acids: decrease the concentrations of 13:0, 15:0, 18:0 and 20:0; increase the quantity of 16:0 and the appearance of 10:0, 11:0, UC15, 16:1 and 17:0 as new synthetically fatty acids. The total unsaturated to total saturated fatty acid ratios showed that cobex and linuron at low application rates caused desaturation some of 18:1 to form 18:2. On the contrary, these herbicides at high application rates exhibited the reverse effect.     

川芎中挥发性化学成分的研究

用超临界二氧化碳萃取和水蒸汽馏法提取川芎挥发油，并设置不同条件及贮存条件，将样品分成五组，用气相色谱-质谱联用仪对各样品的化学成分进行分离鉴定。共鉴定出45个成分，同时对不同条件的结果进行分析并对两种提取方法进行了比较。     

Chemical Characteristics of Fine Particles (PM1) from Xi'an,China

Daily mass concentrations of water-soluble inorganic (WS-i) ions, organic carbon (OC), and elemental carbon (EC) were determined for fine particulate matter (PM₁, particles < 1.0 μm in diameter) collected at Xi'an, China. The annual mean PM₁ mass concentration was 127.3 ± 62.1 μg m^–3: WS-i ions accounted for ～38% of the PM₁ mass; carbonaceous aerosol was ～30%; and an unidentified fraction, probably mostly mineral dust, was ～32%. WS-i ions and carbonaceous aerosol were the dominant species in winter and autumn, whereas the unidentified fraction had stronger influences in spring and summer. Ion balance calculations indicate that PM₁ was more acidic than PM_2.5 from the same site. PM₁ mass, sulfate and nitrate concentrations followed the order winter > spring > autumn > summer, but OC and EC levels were higher in autumn than spring. Annual mean OC and EC concentrations were 21.0 ± 12.0 μg m^?3 and 5.1 ± 2.7 μg m^–3 with high OC/EC ratios, presumably reflecting emissions from coal combustion and biomass burning. Secondary organic carbon, estimated from the minimum OC/EC ratios, comprised 28.9% of the OC. Positive matrix factorization (PMF) analysis indicates that secondary aerosol and combustion emissions were the major sources for PM₁.     

城市垃圾焚烧飞灰物化特性动态分析

以某一垃圾焚烧电厂2017年内不同时期产生的焚烧飞灰为研究对象,对其进行较系统性、动态的物化特性分析。结果表明:焚烧飞灰粉体白度约46、密度约1.88 g/cm~3、颗粒的粒径D50、D90分别约为25μm与76μm。粉体颗粒无固定的形态结构,其中可见针状结构、板片结构与方柱状颗粒。焚烧飞灰中存在氯化钾(KCl)、氯化钠(NaCl)、氧化钙(CaO)、碳酸钙(CaCO_3)等,其主体元素含量分布特征为钙(Ca)>氯(Cl)>钠(Na)>钾(K)>硅(Si)>锌(Zn),同时垃圾焚烧飞灰中含多种重金属元素,且重金属在所检样品中的量化顺序是铅(Pb)>铜(Cu)>铬(Cr)>镉(Cd)。本课题工作可为垃圾焚烧飞灰固废的多元化、绿色化、资源化的利用提供积极的技术支撑与理论指导。     

Cold Shock and Various Extenders Effects on Physical and Chemical Characteristics of Ram Sperms

The protective effect of egg yolk citrate, egg yolk skimmed milk, and egg yolk lactose extenders on the sperm cell against freezing injury was studied using Ossimi and Rahmani rams. Advanced motility, dead and coiled tail percentages of fresh spermatozoa did not differ significantly between the two breeds. Freezing caused a highly significant increase in dead and coiled tail percentages of spermatozoa diluted with various extenders. Unsaponifiable matter of fresh spermatozoa of both breeds contained various hydrocarbons and sterols with C 26, C 24 and cholesterol being the basic compounds. The unsaponifiables distribution could be used to characterize the spermatozoal origin. Changes in total sterols/total hydrocarbons ratios of the unsaponifiables were occurred after freezing of both breeds using the three extenders. Cholesterol content of fresh spermatozoa and the changes in physical properties of spermatozoa of both breeds indicated that the freezability of Ossimi semen was better than that of Rahmani. Also, the changes occurred in physical properties and total sterols/total hydrocarbons ratios showed that egg yolk lactose extender was better than egg yolk skimmed milk and egg yolk citrate extenders for sperm protection against freezing injury.     

七台河地区低热值煤矸石理化特性及燃烧特性分析

采集七台河市勃利县的低热值煤矸石样品进行理化特征分析,并且利用热重法分析了该地区不同粒径低热值煤矸石的着火及燃尽特性。结果表明,该地区煤矸石矿物组成以石英为主,对水体环境危害较大的有害物质氟化铍含量相对较高。化学成分主要为Si O₂和Al₂O₃,含量占比分别约为49.78%～66.75%和13.53%～21.06%,Fe₂O₃含量约为1.91%～3.07%,含硫量约为0.10%～0.18%,属于铝硅型低硫煤矸石。该地区低热值煤矸石的燃烧分为三个阶段。1mm以下煤矸石样品均是较易稳定着火的。随着煤矸石粒径增大,燃烧结束时样品残留量增加,燃尽时间增加,着火温度逐渐升高,达到最大燃烧速率时的温度也随之升高,而最大燃烧速率有所下降。     

化工实验室质量控制

实验室是化工行业发展的技术支撑,在化工行业发展中起着重要的作用。为了符合国内外技术标准要求,保证所提供的数据公正、准确和科学,这就要求加强实验室管理,对实验室所有活动进行有效的质量控制。概述了化工实验室质量控制的关键要素,包括内部质量控制和外部质量控制,并对内部质量控制进行了详细分析。     

北京2004年春季的一次沙尘天气物理化学特性分析

分析了2004年春季发生在北京的一次沙尘天气的物理化学特性.这次沙尘天气强度较小,沙尘过程矿物元素的粗细粒态比重接近,但粗粒态在沙尘初期的比重大于沙尘后期,也大于沙尘过后.各类污染物元素的粗细粒态比重差别较大.各类元素的直径大于16 μm的粒子所占的比重均很小.大气气溶胶的粒子谱不同于以往研究的其他沙尘暴过程.这次矿物元素的粗细粒态富集因子差别较小,但污染物元素的差别较大,而且污染物元素在沙尘期间和沙尘后有着显著的变化.这次沙尘天气来源于蒙古的西南部和内蒙的中西部.     

Effects of Soil Moisture,Physical, and Chemical Characteristics on Abiotic Nitric Oxide Production

The objective of this study was to examine the effect of soil water content, and other physical and chemical factors, on the abiotic component of nitric oxide (NO) production in laboratory studies using soils from agricultural fields in Minnesota, California, and Connecticut. In all soils, gross NO production decreased with increasing gravimetric water content (ϑ) in nitrite (NO₂⁻)-amended sterilized soils. The rate coefficient describing nitrous acid (HNO₂)-mediated NO production (k_p) also decreased with increasing ϑ in both gamma-irradiated and autoclaved soils. Significant correlations were found between ln k_p and several soil properties including: content of silt, clay, total carbon, total N, and extractable iron, and an estimate of the cation exchange capacity of the clay fraction. Multiple regression models incorporating these variables explained 85–93% of the variance in ln k_p. The relationships obtained suggest that the mechanism of abiotic NO production is primarily mediated at the soil solution–surface interface. These findings provide consistent evidence of a previously unrecognized mechanism by which soil water content can affect NO production by mediating a chemical process. Application of a dynamic process model indicated that the simulated variation in NO emissions as a consequence of this effect is comparable to the variation observed in previous studies of NO emissions. Comparison of soils from two different long-term tillage studies also indicated that reduced pH in no-till systems may lead to greater NO emissions for a given level of NO₂⁻ accumulation. Overall, these results suggest that current views of controls over N oxide gas emissions may need to be revised to include abiotic reactions, in addition to microbial and physical processes, as yet another category of factors that is highly sensitive to soil water content.     

Characterization of Physical and Chemical Defenses in the Hemlock Woolly Adelgid

The invasive hemlock woolly adelgid (Adelges tsugae Annand, Hemiptera: Sternorrhyncha: Adelgidae) causes significant mortality to eastern and Carolina hemlock (Tsuga canadensis Carrière and T. caroliniana Engelmann, respectively) throughout the eastern United States. Adelges tsugae produces vast quantities of a wax covering that surrounds most of the instars as well as the adult and eggs. Using direct probe EI mass spectrometry, this wax covering was characterized as a diketoester wax, 17-oxohexatriacontanyl 11-oxotriacontanoate, and accounted for ≈?42 % of A. tsugae total biomass. The presence of the anthraquinone, chrysophanol, and its precursor anthrone, chrysarobin, in A. tsugae has only been briefly described. Further study confirmed these compounds in all A. tsugae life stages. Additionally, several predatory beetles in use or under consideration as biological control agents for this species appear to ingest and excrete these compounds when feeding on A. tsugae. The production of both a physical and a chemical defense may represent a significant energy investment by A. tsugae.     

物理化学在化学工业中的应用

综述了物理化学在化学工业中的应用,着重阐述了热力学、动力学、电化学、离子液体、超临界流体在化学工业中的实际应用情况,并对该领域的研究发展方向进行了初步的探讨.     

育苗基质物理及化学性质的综述

从基质的粒径大小、容重、密度、孔隙度、保水性等方面总结阐述了基质物理性质方面的研究指标及研究进展;从有效成分,酸碱度、电导率、离子吸附与交换能力、盐基交换量、缓冲能力等方面阐述了基质的化学性质方面的研究指标及研究进展。且指出,利用农业废料开发新型基质,填补国内空缺,是未来我国基质开发研究的一个很重要的方向。