321 resultados para CO_2
Resumo:
<正>一、引言煤与瓦斯(包括CO_2)突出是威胁煤矿井下安全生产的一个严重问题。我国煤的年产量居世界第三位。我国的能源结构以煤为主,今后相当长的时期内仍将如此。因此,煤与瓦斯突出问题是一个应该十分重视研究的课题。本文从力学角度对煤与瓦斯突出的机理,从数量级的比较和量纲上加以分析,以期引起力学工作者对这个重要问题的注意。鉴于问题复杂并且缺少可靠的现场实测数据,我们在此只能做些粗略的定性分析。我们认为煤与瓦斯突出的基本模型看来是清楚的。
Resumo:
本文对CH_4横向喷入超音速高温空气主流的二维流场进行了数值模拟,对CH_4-O_2的六方程反应模式进行了检验,借以对混合与燃烧过程的现象与机理加以研究,并与单方程反应模型及H_2横向喷射的情况进行了对比。得到了较为理想的结果。本文采用二维雷诺平均全N-S方程进行计算,采用热完全气体模型,用Baldwin-Lomax代数涡粘性湍流模型来模拟湍流效应。假定N_2不参加反应,CH_4-O_2反应机制选取六个基本反应,以及九个组元O、O_2、CH_3、CH_4、OH、CHO、CH_2O、CO和CO_2,应用空间二阶精度Harten-Yee隐式TVD格式,采用化学源项点隐的全隐方法数值求解。本文对多种超音速空气主流及边界条件的工部进行了数值模拟,并对其流场进行了分析。针对工作中出现的问题,提出了对下一步工作的展望。
Resumo:
The anionic tripod ligand NaLoMe (L_(oMe) - = [(η^5-C_5H_5)Co{P(O)(OCH_3)_2}_3]^-) reacts with RuO_4 in a biphasic reaction mixture of 1% H_2SO_4 and CCI_4 to afford [(L_(oMe) (HO)Ru^(IV) (µ-O)_2Ru ^(IV)(OH)(L_(oMe)] (1), which is treated with aqueous CF_3S0_3H to generate [(L_(oMe)(H_2O)Ru^(IV) (µ-O)_2R^(IV) (OH_2)(L_(oMe)][CF_3SO_3]_2 ([H_21][CF_3SO_3]_2). Addition of iodosobenzene to an acetonitrile solution of this salt yields [(L_(oMe)(O)Ru^v(µ-0)2Ru^v-(O)(_(LoMe)] (2). The dimer 1 can be reduced chemically or electrochemically to the Ru^(III)- Ru^(III) dimers [(L_(oMe)(H_20)Ru^(III) (µ-OH)_2Ru^(III) (OH_2)(L_(oMe)) ]^2+ and [(L_(oMe)) ^(III) (µ-0Hh(µ-0H2)Ru^(III) (L_(oMe)]^2+ which interconvert in aqueous media. Two electron processes dominate both the bulk chemistry and the electrochemistry of 1. Among these processes are the quasi-reversible Ru^(IV) - Ru^(IV)/Ru^(III)- Ru^(III) and Ru^(III)- Ru^(III)/ Ru^(II)- Ru^(II) reductions and a largely irreversible Ru^(V) - Ru^(V)/ Ru^(IV) - Ru^(IV)/oxidation. The dioxo dimer 2 oxidizes alcohols and aldehydes in organic media to afford 1 and the corresponding aldehydes and acids. Analogously, the Ru^(V) - Ru^(V)/ Ru^(IV)- Ru^(IV) redox wave mediates the electrooxidation of alcohols and aldehydes in aqueous buffer. In this system, substrates can be oxidized completely to CO_2. The kinetic behavior of these oxidations was examined by UV-vis and chronoamperometry, respectively, and the chemistry is typical of metal-oxo complexes, indicating that electronic coupling between two metal centers does not dramatically affect the metal-oxo chemistry. Dimer [H_21]^(2+) also reacts with alcohols, aldehydes, and triphenylphosphine in CH_3CN to afford Ru^(III)- Ru^(III) products including [(L_(oMe))CH_3CN) Ru^(III) (µ-OH)_2 Ru^(III) (NCCH_3)( L_(oMe))][CF_3SO_3]2 (characterized by X-ray crystallography) and the corresponding organic products. Reaction of 1 with formaldehyde in aqueous buffer quantitatively affords the triply bridged dimer [(L_(oMe)Ru^(III) (µ-OH)2- (µ-HCOO) Ru^(III) (L_(oMe)][CF_3SO_3] (characterized by X-ray crystallography). This reaction evidently proceeds by two parallel inner-sphere pathways, one of which is autocatalytic. Neither pathway exhibits a primary isotope effect suggesting the rate determining process could be the formation of an intermediate, perhaps a Ru^(IV) - Ru^(IV) formate adduct. The Ru^(III)- Ru^(III)formate adduct is easily oxidized to the Ru^(IV) - Ru^(IV) analog [(L_(oMe)Ru^(IV)(µ-OH)_2-(µ-HCOO) Ru^(IV) (L_(oMe)][CF_3SO_3], which, after isolation, reacts slowly with aqueous formaldehyde to generate free formate and the Ru^(III)- Ru^(III) formate adduct. These dimers function as catalysts for the electrooxidation of formaldehyde at low anodic potentials (+0.0 V versus SCE in aqueous buffer, pH 8.5) and enhance the activity of Nafion treated palladium/carbon heterogeneous fuel cell catalysts.
Resumo:
Cp*_2Sc-H reacts with H_2 and CO at -78°C to yield Cp*_2ScOCH_3. A stepwise reduction of CO to an alkoxide is observed when CO reacts with Cp*_2ScC_6H_4CH_3-p to give the η^2-acyl Cp*_2Sc(CO)C_6H_4CH_3-p, which then reacts with H_2 to produce Cp*_2ScOCH_2C_6H_4CH_3-p. Cp*_2ScCH_3 and Cp*_2ScH(THF) react with CO to give unchar- uncharacterizable products. Cp*_2ScH and Cp*_2ScCH_3 react with Cp_2MCO (M = Mo, W) to give scandoxycarbenes, Cp_2M=C(CH_3)OScCp*_2, while a wide variety of Cp*_2ScX (X = H, CH_3, N(CH_3)_2, CH_2CH_2C_6H_5) reacts with CpM(CO)_2 (M = Co, Rh) to yield similar carbene complexes. An x-ray crystal structure determination of Cp(CO)Co=C(CH_3)- OScCp*_2 revealed a µ^2: η^1, η^1 carbonyl interaction between the Co-CO and Sc.
CO_2 inserts cleanly into Sc-phenyl bonds at -78°C to produce a carboxylate complex, Cp*_2Sc(O_2C)C_6H_4CH_3-p. The structure of this compound was determined by x-ray crystallographic techniques.
Excess C_2H_2 reacts with Cp*_2ScR (R = H, alkyl, aryl, alkenyl, alkynyl, amide) at temperatures below -78°C to form the alkynyl species Cp*_2Sc-C≡C-H, which then reacts with the remaining acetylene to form polyacetylene. Cp*_2Sc-C≡C-H further reacts to yield Cp*_2sc-C≡C-ScCp*_2. This unusual C_2 bridged dimer was characterized by x-ray crystallography.
Attempts were made to model the C-N bond breaking step of hydrodenitrogenation by synthesizing Cp*_2TaH(η^2-H_2C=N(C_6H_4X)) and studying its rearrangement to Cp*_2Ta(=N(C_6H_4X))(CH_3). The 1,2 addition/elimination reactions of Cp*_2Ta(η^2- H_2C=N(CH_3)H and Cp*_2Ta(=X)H (X=O, S, NH, N(C_6H_5)) were investigated. Cp*_2Ta(=NH)H was found to react with D_2 to give Cp*_2Ta(=ND)H, implying a nonsymmetric amide-dihydride intermediate for the addition/elimination process. Cp*_2Ta(=S)H and H_2O equilibrate with Cp*_2Ta(=O)H and H_2S, which allowed determination of the difference in bond strengths for Ta=O and Ta=S. Ta=O was found to be approximately 41 kcals/mole stronger than Ta=S.
Resumo:
Secondary-ion mass spectrometry (SIMS), electron probe analysis (EPMA), analytical scanning electron microscopy (SEM) and infrared (IR) spectroscopy were used to determine the chemical composition and the mineralogy of sub-micrometer inclusions in cubic diamonds and in overgrowths (coats) on octahedral diamonds from Zaire, Botswana, and some unknown localities.
The inclusions are sub-micrometer in size. The typical diameter encountered during transmission electron microscope (TEM) examination was 0.1-0.5 µm. The micro-inclusions are sub-rounded and their shape is crystallographically controlled by the diamond. Normally they are not associated with cracks or dislocations and appear to be well isolated within the diamond matrix. The number density of inclusions is highly variable on any scale and may reach 10^(11) inclusions/cm^3 in the most densely populated zones. The total concentration of metal oxides in the diamonds varies between 20 and 1270 ppm (by weight).
SIMS analysis yields the average composition of about 100 inclusions contained in the sputtered volume. Comparison of analyses of different volumes of an individual diamond show roughly uniform composition (typically ±10% relative). The variation among the average compositions of different diamonds is somewhat greater (typically ±30%). Nevertheless, all diamonds exhibit similar characteristics, being rich in water, carbonate, SiO_2, and K_2O, and depleted in MgO. The composition of micro-inclusions in most diamonds vary within the following ranges: SiO_2, 30-53%; K_2O, 12-30%; CaO, 8-19%; FeO, 6-11%; Al_2O_3, 3-6%; MgO, 2-6%; TiO_2, 2-4%; Na_2O, 1-5%; P_2O_5, 1-4%; and Cl, 1-3%. In addition, BaO, 1-4%; SrO, 0.7-1.5%; La_2O_3, 0.1-0.3%; Ce_2O_3, 0.3-0.5%; smaller amounts of other rare-earth elements (REE), as well as Mn, Th, and U were also detected by instrumental neutron activation analysis (INAA). Mg/(Fe+Mg), 0.40-0.62 is low compared with other mantle derived phases; K/ AI ratios of 2-7 are very high, and the chondrite-normalized Ce/Eu ratios of 10-21 are also high, indicating extremely fractionated REE patterns.
SEM analyses indicate that individual inclusions within a single diamond are roughly of similar composition. The average composition of individual inclusions as measured with the SEM is similar to that measured by SIMS. Compositional variations revealed by the SEM are larger than those detected by SIMS and indicate a small variability in the composition of individual inclusions. No compositions of individual inclusions were determined that might correspond to mono-mineralic inclusions.
IR spectra of inclusion- bearing zones exhibit characteristic absorption due to: (1) pure diamonds, (2) nitrogen and hydrogen in the diamond matrix; and (3) mineral phases in the micro-inclusions. Nitrogen concentrations of 500-1100 ppm, typical of the micro-inclusion-bearing zones, are higher than the average nitrogen content of diamonds. Only type IaA centers were detected by IR. A yellow coloration may indicate small concentration of type IB centers.
The absorption due to the micro-inclusions in all diamonds produces similar spectra and indicates the presence of hydrated sheet silicates (most likely, Fe-rich clay minerals), carbonates (most likely calcite), and apatite. Small quantities of molecular CO_2 are also present in most diamonds. Water is probably associated with the silicates but the possibility of its presence as a fluid phase cannot be excluded. Characteristic lines of olivine, pyroxene and garnet were not detected and these phases cannot be significant components of the inclusions. Preliminary quantification of the IR data suggests that water and carbonate account for, on average, 20-40 wt% of the micro-inclusions.
The composition and mineralogy of the micro-inclusions are completely different from those of the more common, larger inclusions of the peridotitic or eclogitic assemblages. Their bulk composition resembles that of potassic magmas, such as kimberlites and lamproites, but is enriched in H_2O, CO_3, K_2O, and incompatible elements, and depleted in MgO.
It is suggested that the composition of the micro-inclusions represents a volatile-rich fluid or a melt trapped by the diamond during its growth. The high content of K, Na, P, and incompatible elements suggests that the trapped material found in the micro-inclusions may represent an effective metasomatizing agent. It may also be possible that fluids of similar composition are responsible for the extreme enrichment of incompatible elements documented in garnet and pyroxene inclusions in diamonds.
The origin of the fluid trapped in the micro-inclusions is still uncertain. It may have been formed by incipient melting of a highly metasomatized mantle rocks. More likely, it is the result of fractional crystallization of a potassic parental magma at depth. In either case, the micro-inclusions document the presence of highly potassic fluids or melts at depths corresponding to the diamond stability field in the upper mantle. The phases presently identified in the inclusions are believed to be the result of closed system reactions at lower pressures.
Resumo:
本论文为国家自然科学基金重大项目“中国陆地生态系统对全球变化的反应模式研究”的部分研究内容。 本文对C02正常浓度(350ppm)和C02倍增(700ppm)条件下,小麦(Triticum, aestivum)、半野生小麦(Triticum aestivum spp.tibeticumShao)、大麦(Hordeum vulgare)、野大麦(Hordeum brevisubulalum)、水稻(Oryza sativa,)、野生稻(Or7za sativa ssp.)、谷子(Setaria italica)、狗尾草(Setaria viridis)、高粱(Sorghum vulgare)、玉米(Zea mays)、旱雀麦(Bromus tectorum)、旱麦草(Eremopyrum triticeum)等12种禾本科植物幼苗的叶片厚度、叶肉细胞密度、维管束鞘细胞中的叶绿体数、叶肉细胞中的叶绿体数、表皮细胞密度、气孔密度、气孔指数、气孔长度、气孔阻抗及平均株高、鲜重、茎秆直径、根的直径、种子的萌发率及叶绿体超微结构等进行了比较研究。 结果表明,C02倍增使不同种类、不同测试项目反应不一。总体上看,CO2浓度倍增,使10种禾本科植物(野大麦、玉米外)的吐片厚度普遍增加。除个别种类外,C4种类的平均株高、鲜重、根直径倍增组比对照组减小;气孔平均密度增加,而C3种类则呈相反趋势o C4种类比C3种类的叶片气孔开度对C02倍增反应更为敏感。在高浓度C02条件下,C4种类的叶绿体超微结构变化较明显,淀粉粒显著增加。野生种类的表皮细胞密度,叶肉细胞密度,维管束鞘细胞中的叶绿体数及茎秆直径,C02倍增组比对照组减少,栽培种类则显著增加。气孔密度与气孔指数基本呈正相关;而气孔长度与气孔密度则大体上呈负相关。 文中对高浓度C02条件下,供试植物形态结构的变化和规律,及全球大气变化对未来农业可能产生的影响进行了讨论。
Resumo:
本文以复苏植物牛耳草Boea hygrometrica成熟植株的离体叶片为试材,对比非复苏植物烟叶唇苣苔Chirita heterotricha, 以光合作用在脱水-复水过程中的变化为切入点,从生理水平上探讨其脱水保护位点:应用mRNA差异显示技术,从分子水平上探讨其脱水保护机制。 光合放氧速率、快速荧光诱导动力学、慢速荧光诱导动力学、荧光发射光谱、荧光激发谱的结果表明,相对于烟叶唇柱苣苔,脱水对牛耳草净光合速率、PS II和PS I光化学活性、电子传递、光合磷酸化及CO_2固定的影响有一个共同的特点,即脱水时迅速降低,复水后恢复能力强。通过非变性绿胶的研究牛耳草叶片类囊体膜叶绿素-蛋白复合体在脱水-复水过程中保持高度稳定。色素含量分析表明牛耳草的叶绿素含量在脱水-复水过程中也相对稳定。这些特征可能是牛耳草叶片光合作用脱水保护机制的一部分。 SDS-PAGE和IEF电泳结果表明,牛耳草脱水复苏过程中蛋白质表达有差异,或增或减,并分别发现了一条(SDS-PAGE)和两条(IEF)在脱水过程中特异出现的蛋白质。 本文以银染法代替放射自显影用于mRNA差异显示,不但简化了实验步骤,缩短了实验周期,而且在不降低灵敏度的前提下避免了放射性危害,降低了实验成本。本文证明了mRNA差异银染显示法用于复苏植物牛耳草脱水-复水过程中基因表达变化的研究是可行的。 mRNA差异银染显示法揭示牛耳草耐脱水复苏机制涉及到基因表达的调控。脱水-复水过程中差异表达的基因有6种,其中脱水特异诱导表达的13个cDNA所相应的基因、脱水上调节的15个cDNA所相应的基因可能参与牛耳草叶片脱水保护机制,复水特异诱导的8个cDNA的所相应基因可能参与牛耳草复水后的修复机制。2个脱水特异诱导表达的cDNA片段进行了克隆和测序。
Resumo:
预测下世纪中叶,大气CO_2浓度将高到目前的两倍(即达到700μ1•1~(-1))。CO_2倍增对植物地上部的影响已经有了较多的研究,胆是由于方法学上的困难,至今关于倍增CO_2对植物根及根区微生物的研究仍是非常匮乏。本文应用国际上最新的根研究方法,以根系为中心,研究开顶式CO_2C熏蒸培养室中,CO_2倍增条件下根系与地上部,根系与根区微生物[共生的泡囊-丛枝菌根(VAM)真菌,非共生的土壤微生物]的关系。 1. CO_2倍增对根系的影响目前CO_2倍增对根系影响的研究多集中在根生物量的测定,或根/冠比值的测定,而善于其它参数如根长度则很少涉及,而根表面的反应目前还未见文献报道。本实验以幼苗期小麦“青323”(Triticum aestivum)、水稻“中作 29”(Oryza sativa)、大豆“科农4号”(Glycine max)、玉米“农大3138”(Zea mays)、甜高粱“M-81E”(Sorghum saccharatum)为材料,研究CO_2倍增对植物生物量的影响,发现CO_2倍增使C_3植物水稻、大豆的地上部、根系干重均显著增加,使小麦的根系干重显著增加,地上部无显著差异;C_4植物玉米和甜高粱的地上部和根系均没有显著反应。植物干重反应资料表明在光合产物的分配方面,C_3和C_4植物之间存在巨大的差异。 为了解根系获取土壤资源的能力的变化,我们对根系总长度和总表面积进行了分析。用样格交叉法研究根系长度的变化,结果显示,幼苗期的小麦、大豆的根系长度均被显著促进,尤其值得注意的是,尽管玉米根系干重没有显著改变,但是根长度已发生显著变化。同时应用研究根系表面积的最新方法-Na NO_2吸附法,研究发现幼苗期小麦、水稻和大豆的根系表面积在CO_2倍增条件下均显著增加,C_4植物玉米的根表面积亦有显著增加,但甜高粱的根表面积却没有显著反应,这说明即使在C_4植物类型中,根系表面积的反应在不同物种间仍存在很大差异。由于根长度和根表面积增幅大于根干重的增幅,所以推断在CO_2倍增条件下,植物根系细根比例增加,这有利于植物获取更多的养分。由于不同植物之间根系的反应不同,这将改变群落中原有的根系竞争关系,从而影响群落中物种的组成。 2. CO_2倍增对VAM真菌侵染强度和活力的影响本文应用NBT染色法,并结合浸染强度等级和活力等级标准,首次对CO_2倍增条件下,植物VAM真菌的侵染强度和活力的变化进行了检测。对比常规的酸性品红乳酸甘油法和NBT法,发现两者在显示侵染强度时元显著差异,但后者能同时用于侵染活力等级的研究。对幼苗期大豆以及不同生长期的小麦和玉米根系VAM真菌的侵染强度和活力进行观测,结果显示,倍增CO_2对大豆的侵染强度和活力均没有显著效应;使幼苗期玉米的侵染强度显著增加,但侵染活力无显著差异,但随生长期的推移,侵染强度所受的CO_2倍增效应逐渐减小,与14天苗龄(DAP)和35DAP相比,侵染活力在22DAP时所受效应最大;使10DAP小麦的VAM侵染强度和活力均显著增加,而且这种效应在30DAP小麦中的表现与10DAP小麦的相同。说明C_3、C_4植物中,菌根真菌对CO_2倍增反应不同,这也许是C_3、C_4植物对CO_2倍增反应不同的原因之一。倍增CO_2改善了VAM真菌的发育,所以较之于非菌根侵染植物,菌根侵染植物将因为CO_2倍增而获益更多,另一方面不同种植物中,VAM真菌的发育反应不同,这将使植物群落中,根系获取无机营养的竞争能力发生变化,最终影响植物群落的物种丰度和生物多样性以及群落的演替。 3. CO_2倍增对非共生土壤微生物的影响CO_2倍增使生长70天的小麦、垂柳(Salix babylonica)、藜(Chenopodium album)、繁穗苋(Amaranthus cruentus)品种“红苋K112”的地上部和根系的生物量增加。以这些植物所在土壤为材料,用氯仿熏蒸直接提取法研究土壤微生物生物量C(C_(mic))和生物量N(N_(mic))的变化,发现CO_2倍增尽管使各类型植物的C_4植物)土壤中C_(mic)的变化趋势不完全相同(小麦和藜所在土壤的C_(mic)下降,垂柳中C_(mic)升高,而在繁穗苋中无显著差异),但N_(mic)在各物种所在土壤中均有不同程度的上升,在繁穗苋中增幅最大。C_(mic):N_(mic)比值在4个物种所在土壤中均明显下降,这意味着CO_2倍增后在植物生长后期,土壤微生物活性提高,分解植物凋落物和土壤中其它有机质的能力加强,从而改善贫瘠土壤中有机质质量。 4.CO_2倍增对植物呼吸和光合作用及C素积累的影响 1)CO_2倍增对植物暗呼吸的影响:以杜仲(Eucommia ulmoides)、紫花苜蓿(Medicago sativa)和玉米等10种植物的离体成熟叶片或整株为材料,研究不同测定温度(15~35 ℃)下,CO_2倍增对植物暗呼吸的影响。结果表明:在较低温度(15 ℃、20 ℃)下,CO_2倍增对植物暗呼吸没有显著效应;在较高温度(30 ℃、35 ℃)时,多数被测植物的暗呼吸显著增强。由于植物在不同温度时它们的暗咱吸受CO_2倍增的促进幅度不同,这将导致不同地区(环境温度不同)的植物暗呼吸反应有差异,而且由于不同物种的暗呼吸增幅不同,综合光合效应,它们的生物量的反应也会不同。 2)CO_2倍增对整株植物的CO_2气体交换及植物C素积累的影响:利用自行设计的一套CO_2气体测定装置,首次尝试同步测定CO_2倍增条件下幼苗期小麦地下部和地上部的气体交换在昼夜24小时内的变化及C素的积累。发现CO_2倍增不仅使小麦地上部C素的积累增加,也使地下部释放的C素增加,但整株植物的C素收入仍高于对照两倍多,这从植物与环境的CO_2气体交换角度为CO_2倍增促进植物生物量的增加提供了依据。并首次提出:植物的整体性及植物所在的环境条件(主要是温度和光照强度)决定着植物暗呼吸对CO_2倍增的响应方式:被抑制或无效应。
Resumo:
在丝状蓝藻Anabaena sp.PCC7120细胞粗提液的碳酸酐酶(CA)分析中,发现了两种形式的CA活性.高CO_2下生长的细胞,在35μmol/L EZ(Ethoxyzolamide,碳酸酐酶的抑制剂)存在的情况下,CA总活性的85%左右被抑制,其半抑制浓度I_(50)为7.4μmol/L;随着EZ浓度的继续增加,CA活性在EZ浓度达到约150μmol/L处出现了第二个抑制峰,在250μmol/L处抑制程度达到最大,使CA总活性的15%被抑制,其半抑制浓度I_(50)为190μmol/L。在空气条件
Resumo:
随着全球环境恶化问题的日益加重,环境意识将越来越多地影响产品和生产过程的可接受性,并驱使下一代的经济发展。许多国家主动推广下世纪全球需求的绿色技术(“green”technologies)。如果削减CO_2 的国际协议达成,在能源生产方面的CO_2 有效利用将被提到很高的位置。本文分析“海洋种植能源”的潜力及可行性,为发展生物、能源与环境方面的交叉科学,抛砖引玉。
Resumo:
本文主要介绍了自GCPs分离技术建立以来,气孔生理研究中有关保卫细胞对K~+的吸收、释放机制;保卫细胞的能量供应、碳代谢及其调节;环境信号如光、CO_2、ABA等对GCPs的作用及其机制等方面取得的进展。
Resumo:
对硝基酚对栅藻光合放氧有明显抑制作用,半抑制浓度在16毫克/升左右;对硝基酚钠对栅藻光合放氧和CO_2同化的抑制作用十分一致,它们的半抑制浓度分别在54毫克/升和52毫克/升左右。实验室证明对硝基酚在水体中主要是由细菌分解,藻类起供氧作用。一旦藻类的光合放氧受到抑制,细菌对对硝基酚的好气性降解能力也消失。对硫磷和二乙基硫代磷酸钾对栅藻光合放氧无明显抑制作用。
Resumo:
<正> 一、材料和方法黑龙江水化学分析是1958年在黑河断面进行的。断面位置、分层分点、采样时间等都与浮游生物的断面采集相同,同时进行。表层采样用改良北原式采水器;底层采样用茹可夫斯基式采水器,用来分析气体的水样则取自缚在茹可夫斯基式采水器上的带出水管的玻瓶采水器中。测定项目共16项——pH、O_2、CO_2、硷度、溶解有机物耗氧量、PO_4~=、NO_3~-、NO_2~-、NH_4~+、Fe~(+++)、总铁量、SiO_2~=、Mg~(++)、总硬度、Cl~-和SO_4~=。最后四个分析项目(Mg~(+
Resumo:
本文分析了上吸式气化炉的气固流动特性及气化过程。分析了气化过程中三个主要反应过程,即热分解过程、CO_2的还原过程及炭的燃烧过程的反应速率、质量及其影响因素。文中还介绍了常规上吸式气化炉的优缺点并据此提出了改进的炉型,归纳了最佳运行条件及上吸式气化炉的设计要素。
Resumo:
一、前言现有的研究表明,硝酸盐可作为污水中有机物分解的有效氧化剂。借助具有硝酸盐还原作用的微生物(反硝化细菌等),在厌气条件下最终将有机物氧化为CO_2,同时将NO_3-还原为N_2。与以氧为氧源的好氧生化法比较,用硝酸盐做为氧源的生物分解过程有如下优越性。一是效率高,每公斤硝酸盐的氧化能力相当于2.86公斤O_2;第二,硝酸盐在水中溶