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431.
A method is presented by which it is possible to estimate the initial rate of chemical reactions when theexperimental conditions are varied according to a response surface design.The method is intended as acomplementary method for analysing data obtained from experiments in synthetic chemistry when theobjective is to optimize the yield of the reaction.Data obtained by simulations have been used to develop the method.From the simulated reactions itis shown that sequential analysis of the chemical yield of the reaction makes it possible to estimate modelswhich describe how the parameters of the response surface of the yield vary over time.The derivativesof these time functions of the response surface parameters can be used to define a rate function whichdescribes how the variations in the experimental conditions influence the rate of the reaction.It is shown how such rate functions can be used to afford reasonable estimates of the initial rates ofthe reaction.The initial reaction rates thus estimated can be used to determine the kinetic order of thereactants and also to provide estimates of the activation energy of the reaction.A thorough discussion of how canonical analysis of the rate function may assist in the elucidation ofreaction mechanisms is given.  相似文献   
432.
以天津汉沽盐场高镁卤水为研究对象,对其杂质形式、成色原因进行了系统分析。研究表明,卤水中的成色物质主要是大量的饱和脂类、羧酸类、醇醚类、胺类及不饱和的芳烃类、醛酮类、烯烃类等有机物质,经过氧化氢氧化-氢氧化锆吸附联合脱色工艺后,卤水色度及CODCr去除率分别可达99%和85%,镁离子的损失率可控制在1%以下,吸附剂氢氧化锆经脱附再生后可循环使用,大大降低了工艺运行成本。  相似文献   
433.
为研究常见地表污染源对地下水造成的影响,开展了某傍河区域的研究。在对傍河研究区开展野外调查、钻探取样分析等工作的基础上,从水化学角度对研究区地下水进行了系统分析,揭示了研究区内污染河水与地下水并没有明显的水力联系,深、浅含水层水力联系微弱;浅层地下水化学成分的形成以溶滤作用为主,并存在阳离子交换作用,易受到地表污染源及人为活动的影响;深层地下水化学成分的形成主要受到大区域水文地质环境演化的影响。  相似文献   
434.
This paper describes coal petrographic characteristics, sulfur abundance, distribution and isotopic signature in coals in the Wuda coalfield, Inner Mongolia, northern China. Petrographic studies suggest that depositional environment influences petrographic composition. The No. 9 and No. 10 coal seams, which are thought to have formed on a tidal delta plain, have high collodetrinite contents (up to 66.1%) indicating enhanced gelification and bacteria activity during coal accumulation, and also have the highest sulfur content (3.46% and 3.42%). Both organic and pyritic sulfur isotope values (−12.3‰ to 5.8‰ and −18.7‰ to 1.1‰, respectively) are variable and generally tend to be more negative in high-sulfur coals than those in low-sulfur coals in the Wuda coalfield. The negative sulfur isotope values indicate that a large portion of sulfur in the high-sulfur coals has a bacterial origin. Sulfur isotopic compositions and variations within the section were used to propose a model to explain the origin of sulfur in these coals. The presence of pyritized rod-like bacteria, cyanophyte's gelatinous sheaths and degraded algae organic matter suggests that bacteria, and perhaps algae, may play an important role in the formation of these high-sulfur coals.  相似文献   
435.
海洋沉积物中有机质早期成岩矿化路径及其相对贡献   总被引:4,自引:1,他引:4  
陆架边缘海沉积物是重要的生物地球化学反应器,海洋中90%以上的有机质沉积于此并在早期成岩作用过程中矿化.其矿化路径包括有氧呼吸、反硝化、锰氧化物还原、铁氧化物还原、SO4(-2)还原和CO2还原,并按生成自由能减少的顺序依次发生,构成理想的氧化还原序列.定量研究有机碳矿化路径及其对有机质矿化的相对贡献对揭示能量分配和碳...  相似文献   
436.
为了监测刈割+水淹+种植秋茄综合治理互花米草对土壤理化特征的影响,于治理前、治理1个月后、治理8个月后采集治理区和对照区(互花米草样地)土壤,测定土壤有机碳含量等理化指标。结果表明,整个治理过程中,互花米草治理区和对照区各土壤层pH值无显著性差异(P>0.05),治理过程未造成土壤pH值的变化;治理区表层土壤(0~10cm)土壤密度显著高于对照区,其他土层则无显著差异(P>0.05),治理过程导致表层土壤板结,土壤密度增大;此外,治理1个月后,治理区表层土壤(0~10cm)有机碳显著高于对照区(P<0.05),治理8个月后则显著低于对照区(P<0.05),治理措施导致土壤表层土壤有机碳含量先增加后降低。总之,刈割+水淹+种植秋茄综合治理互花米草对湿地表层土壤有机碳含量等产生一些影响。  相似文献   
437.
In different areas of the Western Desert of Egypt, the Abu Roash “G” Member exhibits either a reservoir or source affinity. Thus, thirteen cutting samples covering the Abu Roash “G” Member were selected from the Nest-1A well at Matruh Basin to investigate its hydrocarbon source potential. Palynological age dating of the section that is calibrated with foraminifera and ostracodes enabled a proper identification of the “G” Member. Detailed analysis of the vertical distribution of particulate organic matter of this member shows two palynofacies types. PF-1 reflects an outer middle shelf depositional environment of prevailed reducing (suboxic-anoxic) conditions for the organic-rich shales of the lower “G” Member (samples 1–8). While, PF-2 reflects a minor regression that resulted in deposition of another organic-rich shales of the upper “G” Member (samples 9–13) in an inner middle shelf setting under the same prevailing reducing (suboxic-anoxic) conditions.Organic geochemical analysis reveals good to very good potential of the “G” Member as a hydrocarbon source rock (1.8–2.41, avg. 2.15 total organic content wt %). It also shows good to very good petroleum potential (PP: 4.8–11 , avg. 8 mg HC/g rock). Pyrolsis and palynofacies analyses show kerogen type II for the lower “G” Member (samples 1–8), which is characterized by high Hydrogen index (HI: 396 and 329 mg HC/g TOC at depths 1500 and 1560 m) and very high dominance of oil-prone material (amorphous organic matter “AOM”, marine palynomorphs, and sporomorphs) and very rare occurrence of gas-prone material (brown phytoclasts). The upper “G” Member (samples 9–13) shows kerogen type II-III, which is characterized by a lower HI value of 213 mg HC/g TOC at depth 1340 m and it contains fewer amounts of gas-prone material and relatively lower AOM and marine palynomorphs in comparison to the upper “G” Member. Maturation parameters Tmax (430–433 °C), production index (PI: 0.1 mg HC/g rock), and thermal alteration index (TAI: 2+) indicate the lower “G” Member has already entered the early oil-window kitchen, and it is expected to produce oil. The upper “G” Member is expected to produce only oil with no gas shows, because it is marginally mature (Tmax 426 °C, PI 0.2, TAI 2). The source potential index (SPI: 5.3 t HC/m2) of the “G” Member shows it as currently generating moderate quantities of oil in the area of Nest-1A well.Consequently, the organic-rich shales of the “G” Member are suggested here as a promising, active oil source rock in that extreme northwestern part of the Western Desert of Egypt. However, for commercial oil recovery from the Abu Roash “G” Member, it is highly recommended to explore the depocentre of Matruh Basin at about 150 km east the Nest-1A well.  相似文献   
438.
表生地球化学研究十分广泛。表生地质地球化学的研究包括有表生地球化学过程中各种动力学模型的研究,微生物对各种元素地球化学循环的控制作用及机理研究,岩石风化过程中定量指标的研究与应用,稀土元素在表生作用过程中的地球化学行为及有机质在表生矿产特别是金属矿产成矿机制中的作用的研究。上述诸方面的研究近年来已取得了不少新的成果,对表生矿产的形成机制及合理地开发和利用作出了应有的贡献。  相似文献   
439.
试论中西地理思想的差异及中国古代地理学的特点   总被引:1,自引:0,他引:1  
中国古代有独持的地理学的理论与成就,西方科学家称之为“东方文化生态”。其中,”天人合一”的地理观;天、地、生、人各系统之间的整体、有机观体现了中国古代地理学的特点。深入发掘中国古代的地理学思想,对当今建立开放、复杂的地理巨系统有现实意义。  相似文献   
440.
Rate coefficients for the reactions of difunctional nitrates with atmospherically important OH radicals are not currently available in the literature. This study represents the first determination of rate coefficients for a number of C(3) and C(4) carbonyl nitrates and dinitrates with OH radicals in a 38 l glass reaction chamber at 1000 mbar total pressure of synthetic air by 298±2 K using a relative kinetic technique.The following rate coefficients (in units of 10-12 cm3 molecule-1 s-1) were obtained: 1,2-propandiol dinitrate, <0.31; 1,2-butandiol dinitrate, 1.70±0.32; 2,3-butandiol dinitrate, 1.07±0.26; -nitrooxyacetone, <0.43; 1-nitrooxy-2-butanone, 0.91±0.16; 3-nitrooxy-2-butanone, 1.27±0.14; 1,4-dinitrooxy-2-butene, 15.10±1.45; 3,4-dinitrooxy-1-butene, 10.10±0.50.The possible importance of reaction of OH as an atmospheric sink for the compounds compared to other loss processes is considered.  相似文献   
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