Source profiles of particulate organic matters emitted from cereal straw burnings

Cereal straw is one of the most abundant biomass burned in China but its contribution to fine particulates is not adequately understood. In this study, three main kinds of cereal straws were collected from five grain producing areas in China. Fine particulate matters （PMzs） from the cereal straws subjected to control burnings, both under smoldering and flaming status, were sampled by using a custom made dilution chamber and sampling system in the laboratory. Element carbon （EC） and organic carbon （OC） was analyzed. 141 compounds of organic matters were measured by gas chromatography-mass spectrum （GC-MS）. Source profiles of particulate organic matters emitted from cereal straw burnings were obtained. The results indicated that organic matters contribute a large fraction in fine particulate matters. Levoglucosan had the highest contributions with averagely 4.5% in mass of fine particulates and can be considered as the tracer of biomass burnings. Methyloxylated phenols from lignin degradation also had high concentrations in PM2.5, and contained approximately equal amounts of guaiacyl and syringyl compounds. 13-Sitostrol also made up relatively a large fraction of PMz5 compared with the other sterols （0.18%-0.63% of the total fine particle mass）. Normal alkanes, PAHs, fatty acids, as well as normal alkanols had relatively lower concentrations compared with the compounds mentioned above. Carbon preference index （CPI） of normal alkanes and alkanoic acids showed characteristics of biogenic fuel burnings. Burning status significantly influenced the formations of EC and PAHs. The differences between the emission profiles of straw and wood combustions were displayed by the fingerprint compounds, which may be used to identify the contributions between wood and straw burnings in source apportionment researches.

Changes of thromboxane and prostacyclin in the pathogenesis of multiple organ failure in severe burns

Fifty-seven severely burned patients were divided into 2 groups:16 withmultiple organ failure（MOF）,and 41 without MOF.It was found that the levelof thromboxane B2（TXB2）and the ratio between TXB2 and 6-keto-prostaglandinF1α(TBX2/6-keto-PGF1α)in plasma and in visceral tissues were increased and re-mained significantly high in the first 5～7 d postburn in patients with MOF but notso in those without MOF.The circulatory platelet aggregate ratio（CPAR）wasmarkedly decreased in the same period in MOF group.Myocardial enzymes（CPK,LDH,and GOT）were markedly increased in the first 3d and remainedsignificantly high within 7 d postburn.Degeneration,structural destruction,edema,hemorrhage and thrombosis were revealed in cardiac,pulmonary,renal andhepatic tissues succumbing to functional failure.Thirteen out of the 16 cases de-veloped MOF during the 3rd to 7th day posthurn and 11 died in that period.These findings substantiate that persistent increase of thromboxane andthromboxane/prostacyclin ratio is closely related to the origin and development ofMOF after burn injury.

Emission of Carbonaceous Species from Biomass Burning in the Traditional Rural Cooking Stove in Bangladesh

Characterization of carbonaceous species from the particulate matters (PM) after combustion of seven commonly used biomass species, albizia tree (Albizia julibrissin), dry leaves (mahogany tree), jackfruit tree (Artocarpus heterophyllus), rain tree (Samanea saman), mahogany tree (Swietenia mahogany), cow dung and mango tree (Mangifer aindica) was done. PM samples were collected on quartz fiber filters emitted from biomass burning in a typical rural cooking stove. PM loaded filters were characterized with scanning electron microscope (SEM) for surface morphology, fourier transform infrared (FTIR) to determine the functional group of organic compounds. Black carbon (BC) and brown carbon (BrC) concentrations were determined with Aethalometer. A TOC analyzer was used to determine the total organic carbon (TOC) present in the biomass samples. The surface morphology was almost similar for all biomass burning PM samples. The average concentrations of BC and BrC were 5.85 ± 4.40 and 13.0 ± 8.80 μg·m&#453, respectively. The emission factors of BC and BrC were 1.08 ± 0.89 and 2.35 ± 1.67 mg·g&#451, respectively. Concentration of BC was the highest in dry leaves and the lowest in mango tree. The emission factors of the determined biomass followed the sequence-dry leaves of mahogany > albizia tree > jackfruit tree > rain tree > cow dung > mahogany tree > mango tree. PM from mango tree had lower emissions compared to the other biomass species used in this study.

Successful treatment of severe burn patients with multiple organ dysfunction syndrome:A case report

Multiple organ dysfunction syndrome is the presence of altered organ function of two or more organ systems in acute ill patients with severe trauma,burn,shock and infection.In this case,the patient with burn area amounted to 95%and the third-degree burn was up to 90%.He underwent gastrointestinal tract,blood clotting,lung,brain,heart,liver dysfunction,and cardiac arrest for 30 minutes during the courses of treatment,and was discharged from the hospital after 108 days on the basis of comprehensive treatment and repeated skin grafting.

燃煤机组烟气挥发性有机物排放特征

为了解不同容量燃煤机组烟气挥发性有机物(VOCs)的排放特性和不同尾部空气污染物控制设备(APCDs)对VOCs的控制作用,在福建省国投云顶湄洲湾电力公司400 MW亚临界对冲燃烧机组和1 000 MW超超临界切圆燃烧机组进行在线法和离线法采样测试,获取烟气中甲烷、非甲烷总烃和其他VOCs的全流程浓度。结果表明,1 000 MW机组SCR前的非甲烷总烃质量浓度(24.66 mg/m^(3))低于400 MW机组(33.36 mg/m^(3))。由于1 000 MW机组负荷和炉膛温度高,且煤在切圆燃烧炉内比对冲燃烧停留时间长,故煤燃烧更彻底。两机组SCR系统均能脱除超过70%的非甲烷总烃,400 MW和1 000 MW机组的SCR脱除效果分别为88.43%和74.32%。而在静电除尘过程(ESP)中,高压静电场可能会导致飞灰释放部分VOCs,增加烟气VOCs浓度。经所有APCDs后,400 MW机组和1 000 MW机组的VOCs排放质量浓度分别为8.40和8.47 mg/m^(3),整体脱除率为73.98%和63.02%,几乎未检出甲烷。离线测试结果:印尼煤燃烧后VOCs主要为正己烷、苯系物和苯甲醛。各固体样品(如煤、灰、石膏)有机物浓度分析显示,VOCs种类与机组大小无明显关联。这些发现有助于深入理解燃煤电厂对空气质量影响及优化污染控制设备设计。燃煤电厂实际运营中需依具体情况优化污染控制设备,以达到最大脱除效果,也需考虑机组大小和运行效率,有效控制VOCs排放。

Influence of meteorological factors on open biomass burning at a background site in Northeast China

Biomass burning(BB)is a very important emission source that significantly adversely impacts regional air quality.BB produces a large number of primary organic aerosol(POA)and black carbon(BC).Besides,BB also provides many precursors for secondary organic aerosol(SOA)generation.In this work,the ratio of levoglucosan(LG)to organic carbon(OC)and the fire hotspots map was used to identify the open biomass burning(OBB)events,which occurred in two representative episodes,October 13 to November 30,2020,and April1 to April 30,2021.The ratio of organic aerosol(OA)to reconstructed PM_(2.5)concentration(PM_(2.5)^(*))increased with the increase of LG/OC.When LG/OC ratio is higher than 0.03,the highest OA/PM_(2.5)^(*)ratio can reach 80%,which means the contribution of OBB to OA is crucial.According to the ratio of LG to K^(+),LG to mannosan(MN)and the regional characteristics of Longfengshan,it can be determined that the crop residuals are the main fuel.The occurrence of OBB coincides with farmers’preferred choices,i.e.,burning biomass in“bright weather”.The“bright weather”refers to the meteorological conditions with high temperature,low humidity,and without rain.Meteorological factors indirectly affect regional biomass combustion pollution by influencing farmers’active choices.

火烧迹地恢复后不同稳定机制土壤有机碳库特征研究

以大兴安岭重度火烧迹地经过不同方式恢复的林分土壤为研究对象,采用物理-化学联合分组方法,研究未保护、物理保护、化学保护、生物化学保护、物理-化学保护和物理-生物化学保护有机碳组分含量特征及其与土壤总有机碳含量间的关系。结果表明,1)人工恢复的林分土壤总有机碳、未保护有机碳、物理保护有机碳、物理-化学保护有机碳、物理-生物化学保护有机碳和生物化学保护有机碳含量均显著高于自然恢复。化学保护有机碳含量在不同恢复方式下变化不显著。除化学保护有机碳和物理-化学保护有机碳外,其余各保护态有机碳均表现为上层土壤含量显著高于下层(P<0.05)。2)2种恢复方式下的土壤有机碳组分均以未保护有机碳占比最高,物理-化学保护有机碳占比最低。与天然恢复相比,人工恢复下的土壤物理保护有机碳含量占比显著提高2.80%~3.19%(P<0.05)。3)回归分析表明,除物理-化学保护有机碳和化学保护有机碳组分外,其余各保护态有机碳组分与总有机碳含量之间均呈极显著的正相关关系(P<0.001)。大兴安岭重度火烧迹地经过32 a的人工恢复,更利于土壤总有机碳积累,土壤未保护有机碳的积累更多。研究结果为该区域重度火烧迹地植被恢复提供科学依据。

无机建筑涂料的燃烧性能的分析和研究

论文测试了大量的无机建筑涂料的燃烧性能,对无机建筑涂料的高分子有机物含量和燃烧性能的参数不燃性、燃烧热值、单体燃烧试验进行统计研究,讨论了标准对无机建筑涂料的要求,可供无机建筑涂料的产品配方设计参考。

烧伤后肠道功能保护及治疗研究进展

大面积严重烧伤可导致皮肤、皮下组织严重损伤,引发全身炎症反应综合征甚至多器官功能衰竭等。肠道功能障碍是严重烧伤后多器官功能衰竭的始动因素,烧伤后肠道功能保护对防治全身炎症反应综合征及多器官功能衰竭至关重要。目前,烧伤后肠道功能障碍的发病机制尚未完全明确,临床治疗方法也不完善。因此,本文对近年来大面积烧伤后肠道功能保护及治疗的研究进展进行了综述,以期为临床治疗提供理论依据。

油气储运中油气回收技术的应用

在油品装车、装船过程中,大量的挥发性油气会进入大气,导致资源的浪费和周边环境的污染。为了解决这个难题,将对罐区现有设备与其他成熟的技术进行对比分析,阐述各项技术的优缺点及我公司现有设施的使用情况。

Seasonal characteristics and provenance of organic aerosols in the urban atmosphere of Liaocheng in the North China Plain:Significant effect of biomass burning

To better understand the seasonal characteristics of urban organic aerosol(OA)in the North China Plain(NCP),PM2.5 samples in the urban atmosphere of Liaocheng were collected and analyzed.The molecular distribution of the organic markers in the urban atmosphere of Liaocheng reveals that n-alkanes(39.3%)was the most abundant species all year round,followed by saccharides(28.2%),phthalic acids(Ph,20.8%),biogenic secondary organic aerosol(BSOA)tracers(9.4%),and polycyclic aromatic hydrocarbon(PAHs,2.3%).PM2.5,organic carbon(OC),elemental carbon(EC),and primary organic markers exhibit the highest concentrations in winter,due largely to the increased biomass burning and coal combustion for house heating in local and surrounding regions.However,the concentration and relative abundance of BSOA are significantly higher in summer than other seasons,induced by the more favorable meteoro-logical conditions that would promote the emissions of biogenic volatile organic compounds(BVOCs)and the secondary production of BSOA.The ratios of OC/EC and 3-methyl-1,2,3-butanetricarboxylic acid to cis-pinic acid plus cis-pinonic acid(MBTCA/(PA+PNA)are higher in the warm seasons than those in the cold seasons,indicating that the oxidation of OA is sensitive to air temperature.Compared to 2017,the concentration level of PAHs during wintertime decreased by 40.8%,confirming that the stringent regulation of coal burning is effective.The highest concentration of high molecular weight(HMW)n-alkanes and three anhydrosugars in winter,and the close correlation of levoglucosan with HMW n-al-kanes suggests that the impact of biomass burning was more significant in winter.The same seasonal characteristic of the ratios of high-/low-NO_(x) products with NO_(x) and the strong correlation of high-/low-NO_(x) products with levoglucosan indicate that the formation of isoprene SOA(SOA1)tracers was signif-icantly influenced by anthropogenic emissions.The molecular compositions,the distributions of fire spots,backward trajectories of air masses,and correlation analysis suggest that air pollution events in spring were primarily resulted from biomass burning and secondary oxidation,while pollution events in winter were largely driven by the increased combustion sources,and promoted aqueous secondary formation.Our results suggest that the reduction of biomass and coal combustion should be taken into account to improve the urban air quality in the NCP.

成批大面积烧伤患者的组织救治效果分析

目的 分析成批大面积烧伤患者的组织救治效果。方法 19批(79例)烧伤面积>30%的大面积烧伤患者,均接受补液等药物治疗、气管切开、创面治疗以及其他治疗。记录治疗结果,并比较治疗前后患者的生长因子[血管内皮生长因子(VEGF)、S100钙结合蛋白A9(S100A9)、碱性成纤维细胞生长因子(bFGF)]水平、疼痛因子[P物质(SP)、前列腺素E2(PGE2)、环氧化酶2(COX-2)]水平。结果 79例患者治愈69例,死亡10例,其中4例死于创面感染,2例死于重度吸入性损伤,1例死于后期气管切开的无名动脉出血,1例死于肾衰竭,1例死于继发性肺炎,1例死于导管败血症。治疗后,患者的VEGF(265.73±18.49)μg/L、S100A9(176.49±10.18)μg/L、bFGF(274.85±18.63)μg/L均高于治疗前的(110.54±7.63)、(80.53±3.12)、(101.52±7.24)μg/L,差异有统计学意义(P<0.05)。治疗后,患者的SP、PGE2、COX-2分别为(46.53±5.11)ng/ml、(124.39±10.67)pg/ml、(53.47±3.42)ng/ml,均低于治疗前的(75.29±10.24)ng/ml、(238.74±20.15)pg/ml、(126.79±10.82)ng/ml,差异有统计学意义(t=22.337、44.576、57.429,P=0.000、0.000、0.000<0.05)。结论 针对成批大面积烧伤患者实施组织救治的效果显著,有利于减轻疼痛程度,调节生长因子水平,临床可进一步推广应用。

湿法炼锌有机试剂净化除钴工艺技术优化研究

湿法炼锌试剂净化除钴工艺采用有机试剂进行除钴,生产中存在除钴效果差、有机分解物在湿法炼锌系统富集、锌电积烧板及熔铸化料困难等问题。本文针对上述问题进行了分析,提出了优化除钴工艺、新液质量、除锗工艺参数以及去除纳米硫化锌的思路。通过实施优化措施,有机试剂的使用量显著减少,有机物在系统中的富集也显著降低,净化新液中钴、镉等杂质得到进一步去除,系统稳定性更好,从根本上解决有机试剂分解的有机物对锌电积工艺的危害。

Characterization of Organic Aerosol at a Rural Site in the North China Plain Region:Sources,Volatility and Organonitrates

The North China Plain(NCP)is a region that experiences serious aerosol pollution.A number of studies have focused on aerosol pollution in urban areas in the NCP region;however,research on characterizing aerosols in rural NCP areas is comparatively limited.In this study,we deployed a TD-HR-AMS(thermodenuder high-resolution aerosol mass spectrometer)system at a rural site in the NCP region in summer 2013 to characterize the chemical compositions and volatility of submicron aerosols(PM_(1)).The average PM_(1)mass concentration was 51.2±48.0μg m^(−3) and organic aerosol(OA)contributed most(35.4%)to PM_(1).Positive matrix factorization(PMF)analysis of OA measurements identified four OA factors,including hydrocarbon-like OA(HOA,accounting for 18.4%),biomass burning OA(BBOA,29.4%),lessoxidized oxygenated OA(LO-OOA,30.8%)and more-oxidized oxygenated OA(MO-OOA,21.4%).The volatility sequence of the OA factors was HOA>BBOA>LO-OOA>MO-OOA,consistent with their oxygen-to-carbon(O:C)ratios.Additionally,the mean concentration of organonitrates(ON)was 1.48−3.39μg m−3,contributing 8.1%-19%of OA based on cross validation of two estimation methods with the high-resolution time-of-flight aerosol mass spectrometer(HRToF-AMS)measurement.Correlation analysis shows that ON were more correlated with BBOA and black carbon emitted from biomass burning but poorly correlated with LO-OOA.Also,volatility analysis for ON further confirmed that particulate ON formation might be closely associated with primary emissions in rural NCP areas.

Investigation over the recirculation influence on the combustion of micro organic dust particles

This paper investigates the role of recircnlation and non-unity Lewis number on the combustion of organic dust particles. Since recirculation effect is more noticeable in micro-combustors, it is necessary to propose a modeling approach of this phenomenon to better simulate the performance of micro-combustors. In this research, in order to model the combustion of organic dust particles, it is assumed that the dust particles va- porize first to yield a known chemical structure which is oxidized in the gas phase, and the chemical structure of this gaseous fuel is assumed methane. To study the flame structure and solve the governing equations, it is considered that the flame structure consists of three zones titled the preheat-vaporization zone, the narrow reaction zone and finally the post flame zone. The recirculation phenomenon is evaluated by entering the exhausted heat from the post flame zone into the preheat zone. The solution is based on the follow- ing approach. First, the governing equations in each zone are nondimensionalized. Then the needed boundary and matching conditions are applied in each zone. After that, these equations and the required boundary and matching conditions are simultaneously solved with the analytical model. Consequently, the remarkable effects of recirculation and non- unity Lewis number on the combustion characteristics of the organic dust particles such as burning velocity and temperature profiles for different particle radii are obtained. The results show reasonable agreement with published experimental data.

Correlation between Serum Neutrophil Gelatinase Associated Lipocalin and Burn Severity: A Pilot Study

The severity of an initial burn injury is critical for determining the treatment plan and prognosis of burn patients. Here, we measured serum neutrophil gelatinase-associated lipocalin (NGAL) levels to determine whether NGAL can be used as a biomarker for severity of burn injuries. A study of the demographic, clinical, and laboratory markers for various organ damage was performed at Bestian Burn Center (n = 10 healthy people, n = 31 patients). NGAL and organ damage marker levels were measured in 31 patients with severe burns within 2 - 3 days following their admission to the intensive care unit. Serum NGAL level of the expired patients was 788.5 (685.0 - 998.0) pg/mL, whereas that of the discharged patients was 421.2 (356.2 - 480.6) pg/mL, showing that the initial serum NGAL level can be used to estimate mortality. We also determined the correlation between serum NGAL level and the currently used severity markers (total body surface area burned and abbreviated burn severity index) and confirmed that serum NGAL level could be used as a severity marker. We also found that serum NGAL level was correlated with damage of organs such as the liver, kidney, heart, and respiratory organs in patients with severe burns.

Effect of wall temperature and random distribution of micro organic dust particles on their combustion parameters

The effect of wall temperature on the characteristics of random combustion of micro organic particles with recirculation was investigated. The effect of recirculating in micro-combustors is noticeable, hence it is necessary to present a model to describe the combustion process in these technologies. Recirculation phenomenon is evaluated by entering the exhausted heat from the post flam zone into the preheat zone. In this work, for modeling of random situation at the flame front, the source term in the equation of energy was modeled considering random situation for volatizing of particles in preheat zone. The comparison of obtained results from the proposed model by experimental data regards that the random model has a better agreement with experimental data than non-random model. Also, according to the results obtained by this model, wall temperature affects the amount of heat recirculation directly and higher values of wall temperature will lead to higher amounts of burning velocity and flame temperature.

Significance of biopterin induction in rats with postburn Staphylococcus aureus sepsis

Objective:It has been demonstrated that biopterin,an essential cofactor of nitric oxide synthase(NOS),plays an important role in the pathogenesis of endotoxin-induced shock,yet its biological significance ingram-positive sepsis remains unclear.In this study,we adopted a rat model of postburn Staphylococcus aureus (S.aureus) sepsis to observe the time course and tissue distribution of biopterin in postburn S.aureus infection,and toinvestigate its potential role in the pathogenesis of gram-positive sepsis...

计划烧除对云南松林土壤碳组分及碳库管理指数的影响

探讨计划烧除对土壤碳组分和土壤碳库的影响,为火干扰下森林生态系统可持续管理提供理论参考。以云南滇中地区多年周期性计划烧除云南松林为研究对象,以未实施计划烧除云南松林为对照,通过对比分析土壤有机碳(SOC)、微生物生物量碳(MBC)、易氧化有机碳(EOC)、可溶性有机碳(DOC)、颗粒有机碳(POC)含量在计划烧除后不同恢复时间(2021年1-12月)的动态特征,明确土壤有机碳及其组分与土壤理化性质的关系;并在此基础上通过计算碳库管理指数(CPMI),分析土壤碳库变化特征。结果表明,1)云南松林土壤有机碳及其组分含量随着土层深度增加而降低,计划烧除对表层(0~10 cm)土壤有机碳及其组分含量影响显著(P<0.05)。2)土壤有机碳及其组分平均含量在计划烧除后短期内(3月)均有所增加并高于对照,在6-12月计划烧除林地土壤有机碳及其组分平均含量均低于对照;在一个计划烧除周期内,土壤SOC、MBC、DOC、EOC、POC平均含量比对照分别低4.83%、12.95%、8.14%、11.69%和8.59%。3)在一个计划烧除周期内,计划烧除林地土壤CPMI平均值显著(P<0.05)降低7.02%。4)冗余分析结果表明,土壤粘粒、全氮、容重、pH是影响云南松林土壤有机碳及其组分含量的主要环境因子,全氮对计划烧除林地土壤有机碳及其组分含量变化解释度最高。计划烧除对土壤有机碳及其组分产生了重要影响,改变了土壤有机碳库和活性碳库,降低了土壤碳库质量以及稳定性。

大兴安岭重度火烧迹地植被恢复后土壤团聚体稳定性及有机碳特征

为探明植被恢复对大兴安岭重度火烧迹地土壤团聚体及有机碳的影响,以重度火烧迹地上种植的不同林龄(11、21、32 a)落叶松人工林作为研究对象,通过测定土壤团聚体各粒级百分含量及团聚体有机碳含量,开展土壤团聚体稳定性以及团聚体有机碳特征研究。结果表明,1)重度火烧迹地在种植落叶松后,不同林龄落叶松人工林土壤机械稳定性团聚体与水稳性团聚体均以大于0.25 mm粒级含量为主,占比分别为85.57%~89.42%和62.86%~83.19%。随着林龄的增加,落叶松人工林0~10 cm层土壤机械稳定性团聚体大于2 mm粒级含量显著下降,0.25~2 mm粒级含量显著上升,水稳性团聚体则表现为大于2 mm粒级显著减小,0.5~2 mm粒级含量显著上升的趋势(P<0.05)。2)32 a落叶松人工林土壤机械稳定性团聚体的平均重量直径(Mean weight diameter,MWD)和几何平均直径(Geometric mean diameter,GMD)均显著小于11 a,上层土壤水稳性团聚体的MWD与机械稳定性团聚体特征一致。水稳定性大团聚体含量(Water-stable macroaggregate content,W SA 0.25)随着恢复年限的增加逐渐上升,32 a生落叶松人工林团聚体破坏率(Percentage of aggregate destruction,PAD)显著减小。3)随着林龄的增加,落叶松人工林土壤团聚体有机碳含量增加,且上层增加较多。大团聚体(>0.25 mm粒级)的有机碳贡献率占主导地位。研究结果为大兴安岭重度火烧迹地植被恢复提供了科学依据。