Influence of agricultural biomass burning on aerosol size distribution and dry deposition in southeastern Brazil

The size distributed composition of ambient aerosols is used to explore seasonal differences in particle chemistry and to show that dry deposition fluxes of soluble species, including important plant nutrients, increase during periods of biomass (sugar cane trash) burning in S?o Paulo State, Brazil. Measurements were made at a single site centrally located in the State's sugar cane growing region but away from the immediate vicinity of burns, so that the airsampled was representative of the regional background. Calculation of ion equivalent balances showed that during burning periods smaller particles (Aitken and accumulation modes) were more acidic, containing higher concentrations of SO4(2-), oxalate, NO3-, HCOO-, CH3COO-, and CI-, but insufficient NH4+ and K+ to achieve neutrality. Larger particles showed an anion deficit due to the presence of unmeasured ions and comprised resuspended dusts modified by accumulation of nitrate, chloride, and organic anions. Increases of resuspended particles during the burning season were attributed to release of earlier deposits from the surfaces of burning vegetation as well as increased vehicle movement on unsurfaced roads. During winter months the relative contribution of combined emissions from road transport and industry diminished due to increased emissions from biomass combustion and other activities specifically associated with the harvest period. Positive increments in annual particulate dry deposition fluxes due to higher fluxes during the sugar cane harvest were 44.3% (NH4+), 42.1% (K+), 31.8% (Mg2+), 30.4% (HCOO-), 12.8% (CI-), 6.6% (CH3COO-), 5.2% (Ca2+), 3.8% (SO4(2-)), and 2.3% (NO3-). Na+ and oxalate fluxes were seasonally invariant. Annual aerosol dry deposition fluxes (kg ha(-1)) were 0.5 (Na+), 0.25 (NH4+), 0.39 (K+), 0.51 (Mg2+), 3.19 (Ca2+), 1.34 (Cl-), 4.47 (NO3-), 3.59 (SO4(2-)), 0.58 (oxalate), 0.71 (HCOO-), and 1.38 (CH3COO-). Contributions of this mechanism to combined aerosol dry deposition and precipitation scavenging (inorganic species, excluding gaseous dry deposition) were 31% (Na+), 8% (NH4+), 26% (K+), 63% (Mg2+), 66% (Ca2+), 32% (Cl-), 33% (NO3-), and 36% (SO4(2-)).     

Ion budgets and sediment-water interactions during the experimental acidification and recovery of Little Rock Lake, Wisconsin

Ion budgets for the two basins of experimentally acidified Little Rock Lake (Vilas County, WI, U.S.A.) indicate that Ca2+, Mg2+, and K+ were released from the bottom sediments to the water column during 1984-1994, and NH4+, NO3-, and SO4(2-) were removed for a net internal alkalinity generation (IAG). Sulfate removal contributed approximately 50% of the IAG in the reference basin, and cation production generated approximately 40%. In-lake processes in the reference basin removed approximately 38% of the sulfate input; 58% was lost to outflow, and 4% remained in the water column. As a result of acid additions that stimulated sulfate reduction and lower pH that enhanced ion exchange, sulfate removal and Ca2+ production were more important for IAG in the treatment basin. During 1984-1994, sulfate removal contributed about 61% of the IAG, and Ca2+ production contributed about half of the IAG from cation production. In the treatment basin, in-lake processes removed about 46% of the total input of sulfate (including acid additions); 36% was lost to outflow and 18% remained in the water column (representing approximately 25% of the added acid). In both basins of LRL, NH4+ consumption roughly balanced NO3- consumption, and net N transformations provided only 3-12% of the IAG. Overall, Na+ and Cl- were conservative in both basins during 1984-1994. Most ion budget components, including calculated internal reaction terms, showed fairly large interannual variations; e.g., ion inputs (dominated by atmospheric deposition) varied by a factor of about two. Over the 10-year period, ANC terms calculated from the budgets as the difference between base cation and acid anion terms agreed well with measured ANC terms for the budget components, indicating that the budgets accounted for all important IAG constituents.     

离子色谱双通道自动进样同时分析瓶装水中阴阳离子

建立了一种离子色谱双通道自动进样同时分析检测瓶装水中阴阳离子的方法。所测离子包括消毒副产物溴酸盐,常规阴离子F-、Cl-、NO2-、Br-、NO3-,SO4^2-以及常规阳离子Na＋、K＋、Mg^2＋、Ca^2＋。其中溴酸盐能够准确定量到5μg/L,远远低于国家标准中10μg／L的限量要求,完全可以满足检测需求。使用自动进样系统实现阴阳离子同时进样分析,简便快捷,无需变换系统,一次性完成阴阳离子分析测定。此方法用于实际样品的检测获得满意结果,可用于瓶装水的批量检测。     

添加抗氧化剂BHT对地沟油生物柴油离子含量的影响

生物柴油油品是保证柴油发动机正常运行的必要条件,本论文采用离子色谱法研究了添加抗氧化剂对生物柴油离子含量的影响。研究结果表明：添加抗氧化剂BHT对生物柴油离子含量产生影响,对不同离子影响的程度差别较大。抗氧化剂BHT添加量为2000 mg·kg-1时,生物柴油中Na+、NH4+、K+含量大幅度降低,其中钠离子的含量降低程度最大,高达84%,而Mg2+和Ca2+含量大幅度增加,钙离子的含量增加了136%;未检测出F-、Br-、PO43-等无机阴离子,而Cl-、NO3-和SO42-无机阴离子含量和甲酸、乙酸和丙酸有机酸根离子含量都在一定程度上降低,抗氧化剂BHT的添加对Cl-无机阴离子含量影响最大,其含量降低了14%,对甲酸根离子含量影响较大,其离子含量降低了10%。     

AMP脱氨酶的生化性质研究

主要从底物浓度、温度、pH和常见离子等方面对相对分子量56ku左右的腺苷酸脱氨酶的催化作用的影响因素进行研究。通过酶的催化实验,结果表明:原始底物质量浓度为2.78×10-2g/L、温度为37℃、pH为5.9时,AMP脱氨酶催化活性最好,IMP的转化速度最高为1.965×10-2mol/min。同时考察了Cu2+、Fe2+、Al3+、Mn2+、Na+、Mg2+、Zn2+等阳离子和SO42-、Cl-、NO3-、CO32-、H2PO4-、B4O72-、柠檬酸根、EDTA离子等阴离子对AMP脱氨酶催化能力的影响。结果表明:柠檬酸根离子和Mn2+对AMP脱氨酶有明显激活性影响,其他离子浓度超过0.01mol/L时对AMP脱氨酶一般有抑制性影响,AMP脱氨酶商品酶在常温干燥状态下稳定性很好,4℃存放的酶液半衰期为5.5d。     

Assessing the impact of animal waste lagoon seepage on the geochemistry of an underlying shallow aquifer

Evidence of seepage from animal waste holding lagoons at a dairy facility in the San Joaquin Valley of California is assessed in the context of a process geochemical model that addresses reactions associated with the formation of the lagoon water as well as reactions occurring upon the mixture of lagoon water with underlying aquifer material. Comparison of model results with observed concentrations of NH4+, K+, PO4(3-), dissolved inorganic carbon, pH, Ca2+, Mg2+, SO4(2-), Cl-, and dissolved Ar in lagoon water samples and groundwater samples suggests three key geochemical processes: (i) off-gassing of significant quantities of CO2 and CH4 during mineralization of manure in the lagoon water, (ii) ion exchange reactions that remove K+ and NH4+ from seepage water as it migrates into the underlying anaerobic aquifer material, and (iii) mineral precipitation reactions involving phosphate and carbonate minerals in the lagoon water in response to an increase in pH as well as in the underlying aquifer from elevated Ca2+ and Mg2+ levels generated by ion exchange. Substantial off-gassing from the lagoons is further indicated by dissolved argon concentrations in lagoon water samples that are below atmospheric equilibrium. As such, Ar may serve as a unique tracer for lagoon water seepage since under-saturated Ar concentrations in groundwater are unlikely to be influenced by any processes other than mechanical mixing.     

正交试验优化蔬菜中水溶态阳离子的离子色谱法提取工艺

目的：研究蔬菜中的Na+、NH4+、K+、Mg2+、Ca2+5 种阳离子的最佳提取工艺条件。方法：用正交试验优化提取工艺条件,并在优化条件下利用离子色谱仪同时测定蔬菜中Na+、NH4+、K+、Mg2+、Ca2+ 离子的含量。结果：影响5 种阳离子同时提取工艺的因素顺序为提取时间、提取功率、溶剂量,提取时间和提取功率对试验有显著性影响;最佳工艺条件为提取时间20min、提取功率160W、溶剂量25mL。对Na+、NH4+、K+、Mg2+、Ca2+5 种阳离子做加标回收实验,得平均加标回收率为89.2%、89.9%、82.7%、87.3%、84.2%。     

Effects of diet magnesium on acid-base status and calcium metabolism of dry cows fed acidogenic salts.

The objective was to study effects of dietary Mg on acid-base status and Ca metabolism of Holstein cows fed acidogenic diets with relatively high Ca concentrations. Eight nonlactating, nonpregnant Holstein cows were used in a switchback experiment with three 28-d periods. The normal Mg (.2%, dry basis) diet consisted of corn silage plus a concentrate mix supplemented with NH4Cl (126 g/d per cow) and (NH4)2SO4 (126 g/d per cow). The high Mg (.37%, dry basis) diet had MgSO4 substituted for an equivalent amount of S supplied by (NH4)2SO4 in the normal Mg diet. Cation-anion differences of the two diets were -302 (normal Mg) and -289 (high Mg) meq/kg of dietary DM. Compared with cows fed the normal Mg diet, those fed high Mg tended to have higher blood pH and plasma concentrations of total Ca but lower plasma concentrations of P and lower urinary excretion of ammonium and net acid. Cows fed the high Mg diet also tended to increase Mg excretion with a decrease in urinary excretion of Ca. Metabolic responses to intravenous infusion of Na2-EDTA were similar among cows fed either diet. Results indicate that increasing Mg intake of cows fed acidogenic salts was of no advantage with regard to Ca metabolism.     

25℃Na~+,K~+∥Cl~-,SO_4~(2-)-H_3BO_3-H_2O体系相平衡研究

实验测定了２５℃Ｎａ＋,Ｋ＋∥Ｃｌ－,ＳＯ２－４－Ｈ３ＢＯ３－Ｈ２Ｏ五元体系的溶解度并对所绘相图进行了分析,讨论了硼酸的分离及其对硫酸钠转化制硫酸钾的影响     

豆腐柴鲜叶凝胶形成因素的研究

对豆腐柴叶胶质形成因素进行了研究,结果表明:豆腐柴叶制备滤汁的鲜叶比水(w/v)为1:8～1:10;添加0.04%～0.08%Mg2+或Ca2+能形成强度适中的凝胶,K+、Na+、Cl-、CO32-无促胶凝作用;调整滤汁pH在4～5之间;温度因素对胶质胶凝性基本无作用。     

Study of compatibility between enzyme and textile auxiliaries with wool北大核心

The article studied the compatibility between alkaline proteinase, neutral protease and textile auxiliaries with the wool finished. We analyzed the nonionic-organic textile auxiliaries, ionic-organic textile auxiliaries and dyes by reduction and relative activity combination method. The results showed that the salt of Na+ , K+ , NH4+ , Mg 2+ , Ca2+ promoted the catalytic of enzyme when the concentration of the salt was lower, the nonionic-surfactants could promot the catalytic of enzyme. The salt of Cu2+ ,Fe3+, Mn0 4- , ionic-surfactants and dyes could evidently restraint the catalytic of alkaline proteinase, neutral protease. The salt of Na + , K+ , NH4+ , Mg 2+ , Ca2+ promoted more evidently the catalytic of neutral protease than alkaline proteinase. The ionic-surfactants and dyes restrainted more evidently the catalytic of alkaline proteinase than neutral protease. The studies might guide the application of protease for the wool textle industry on the theory.     

浓海水纳滤膜分离实验研究

采用美国海德能公司ESNA1-LF-4040纳滤膜,在不同温度、压力等操作条件下,对海水淡化浓海水进行了分离实验研究。实验结果表明:操作压力提高,膜通量增大的同时截留率也略有提高;料液温度上升,膜通量增大但截留率下降;在操作压力为1.4 MPa,料液温度为28℃时该纳滤膜对浓海水中一价离子(Na+、Cl-、K+)的截留率均小于15%,对二价离子(Ca2+、Mg2+、SO24-)的截留率均大于35%,其中对SO24-的截留率可达97%以上,从而为纳滤膜在浓海水中的综合利用提供了可行的工艺参数。     

蒜氨酸酶的分离纯化及其动力学特性

采用 (NH4 ) 2 SO4 盐析、SephadexG 2 0 0凝胶过滤和ConA Sepharose亲和层析方法对蒜氨酸酶进行了部分纯化 ,并研究了其酶动力学特性 ,结果表明其最适反应温度为 3 0℃ ,最适pH值为6 2 4,以蒜氨酸为底物 ,最大反应速度Vmax =1 2 0u/mg(蛋白质 ) ,米氏常数 Km =6 0 2× 1 0 - 3mol/L。文中同时研究了抑制与激活剂对蒜氨酸酶活性的影响     

The influence of acidic diets on the acid-base balance of dry cows and the effect of fertilization on the mineral content of grass.

To investigate the safety and practicality of an acidic concentrate in milk fever prevention, the pH, carbon dioxide, standard bicarbonate, and base excess of whole blood and the pH in the urine were measured in three treatment groups of dry cows after 14 and 21 d of feeding an acidogenic diet (experiment 1). The dietary cation-anion differences (DCAD) of cows on treatments 1 (n = 11), 2 (n = 13), and 3 (n = 12) were +2275, -262, and -1185 meq/d, respectively. No changes in any parameters were found from the beginning to the end of the experiment in cows on treatment 1. In cows on treatment 2, a significant reduction in urine pH was observed, and in cows on treatment 3 significant decreases in all parameters except blood pH were observed. Mineral analyses of grass samples from fields fertilized with N from NH4NO3, Ca(NO3)2, or (NH4)2SO4, with S from (NH4)2SO4, and with different amounts of K from KCl or K2SO4 and of Cl from KCl revealed DCAD ranging from -14 to +726 meq/kg of dry matter (experiment 2). Fertilization with Cl increased the chloride concentration in the crop and had the largest effect on DCAD. The results indicate that the use of acidic concentrates is not a health hazard for dry cows, at least not when the DCAD is greater than about -1200 meq/d or about -140 meq/kg of dry matter.     

2-year study of chemical composition of bulk deposition in a south China coastal city: comparison with east Asian cities

Using the emission strengths of the precursor gases, the nature of soil in China, the ventilation power and half value rainout region length, the nss-SO42-, NO3-, Ca2+, and NH4+ concentrations, and pH of rainwater at Hong Kong and other cities of China and Japan are compared and rationalized. The chemical composition of Hong Kong bulk deposition from 1998 to 2000 is taken from our collection and analysis of 156 daily samples. The volume-weighted average (VWA) pH is 4.2 over the whole study period. Nonsea salt- (nss-) sulfate is the most abundant species in the samples, and the pH mostly depended upon the concentrations of the major species nss-SO42, NO3-, Ca2+, and NH4+. All species concentrations show higher levels in the cold season (especially NO3- and Ca2+), which indicates the dominant dilution effects in the warm season due to heavy rainfall and the influence of the continental outflow of pollutants during the cold season. For Hong Kong bulk deposition, the VWA pH is slightly lower in the cold season, and there is a slight decrease in VWA pH over the period from 1994 to 2000. The impact of acid rain in Hong Kong is briefly discussed.     

Trace metal concentrations and water solubility in size-fractionated atmospheric particles and influence of road traffic

The abundance and the behavior of metals (Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Se, Ag, Cd, Sn, Ba, Pt, Hg, and Pb) and ions (Na+ K+ Mg2+ Ca2+, NH4+, Cl-, NO3-, SO4(2-), PO4(3-), and oxalate) in size-fractionated atmospheric particulate matter (PM) were studied in the U. K. and Ireland at four observation sites simulating extreme degrees of vehicular-traffic influence in the environment. Trace metals in urban PM showed distinct types of size-fractionated behavior depending on the particle sources from which they originate. In coarse PM (1.5 < Dp < 3.0 microm) the concentrations of copper, barium, and iron correlated closely across over 2 orders of magnitude in urban air, which is seen as evidence that major portions of transition metals (Cu, Ba, Fe, and Mn) are released through abrasive vehicular emissions, particularly the wear of brake linings. Further results are strongly indicative of a decoupling of coarse iron and calcium, the former arising predominantly from vehicles, the latter from soil resuspension. In fine PM (Dp < 0.5 microm), several combustion and secondary sources of particulates were identified, but these were much less unique in terms of elemental fingerprints. An analysis of the water solubility of trace metals yielded that solubility varies considerably with element and, to a lesser extent, with particle size. Notable differences were found to the elemental water solubilities determined in previous work, partially explained by differences in extraction procedures.     

西台吉乃尔盐湖卤水等温蒸发实验研究

文章依据K+、Na+、Mg2+∥Cl-、SO2-—H2O五元体系介稳相图,对青海西台吉乃尔盐湖井采卤水进行了等温蒸发实验研究及相图分析,确定盐湖井采卤水盐类结晶析出顺序和各阶段的分离点,为该盐湖卤水的综合开发利用提供了理论依据。     

镰刀霉菌(Fusarium sp)JN158紫色素的提取及理化性质

研究了由镰刀霉菌(Fusarium sp)JN158发酵所产紫色素的提取条件和理化性质,结果表明:该紫色素的提取溶剂为体积分数95%乙醇溶液;紫色素在酸性条件下对温度,光照,柠檬酸和苯甲酸钠有较好的稳定性;最大吸收波长为310 nm和510 am;对H2O2和Na2SO3敏感;蔗糖与葡萄糖有增色效果;金属离子Zn2+、...     

香椿叶中提取槲皮素的稳定性研究

研究了槲皮素溶液稳定性的影响因素。结果表明，槲皮素溶液在pH=6．59～7．90条件下比较稳定；在还原剂Na2SO3,NaS2O3中不稳定，而在氧化剂H2O2中较为稳定；碳水化合物对槲皮素溶液的稳定性没有明显的影响；金属离子K^＋、Ca^2＋、Na^＋、Al^3＋对槲皮素溶液具有稳定作用，Mg^2＋、Zn^2＋、Fe^3＋对槲皮素溶液的稳定性有不利的影响；高温、自然光照射对槲皮素具有降解作用。     

柴达木北部新盐带卤水水化学特征研究

通过对柴达木西部地区北部新盐带潜卤水的赋存特征、水化学成分、化学类型及相图研究,初步揭示了其水化学特征.研究表明,该潜卤水与柴达木盆地晶间卤水含量相比,Ca2＋、Na＋值较高,K＋、Cl-值接近,Mg2＋、HCO3-较低,SO24-偏低.总体而言,潜卤水的主要离子变化幅度不同,分布不均匀,TDS、Cl-和Na＋的Cv值较小,Mg2＋、Li＋、SO24-、NO3-、cO23-的Cv值较大,HCO3-、B2O3、K＋、Ca2＋成分介于二者之间,其水化学类型划分为硫酸镁亚型和氯化物型两类,二者分别在K＋、Na＋、Mg2＋∥Cl-、SO2--H2O五元体系相图和K＋、Na＋、Mg2 ＋//Cl--H2O四元体系相图中反映出不同的演化阶段.