Optimal size,hydraulic retention time and volatile solids loading rate of biogas unit using water hyacinth

With a view to evaluate the effects of hydraulic retention time and volatile solids loading rate on methane production using water hyacinth, experiments were conducted in a 160 dm³ capacity, well-mixed continuous digestion unit at ambient temperature. The optimal design of biogas plant using water hyacinth was elucidated, to provide a unit giving a maximum methane yield of 0.16 nm³ kg^?1 volatile solids added, which was 60% greater than the conventional plant using cowdung. The calculations of optimal design factors were based on reactor size, hydraulic retention time and volatile solids loading rate; considerations were made of capital cost, running costs and operational revenue.     

Variations in Spectral Slope in Lake Taihu,a Large Subtropical Shallow Lake in China

Spectral slope (S), describing the exponential decrease of the absorption spectrum over a given wavelength range, is an important parameter in the study of of chromophoric dissolved organic matter (CDOM) dynamics, and also an essential input parameter in remote sensing models. Furthermore, S is often used as a proxy for CDOM composition, including the ratio of fulvic to humic acids and molecular weight. The relative broad range in S values reported in the literature can be explained by the different spectral ranges and fitting methods used. A single exponential model is used to fit the S values for 17 investigations involving 458 samples in Lake Taihu from January to October in 2004. The average S value was 15.18 ± 1.39 μm⁻¹ for the range of 280–500 nm, which fell within the range reported in the literature. The frequency distribution of S value basically obeyed a normal distribution. Significant differences in S values between summer and other seasons showed that phytoplankton degradation was one of the important sources of CDOM in summer, whereas CDOM mainly came from the river input in other seasons. Furthermore, the estimated S value decreased with increasing wavelength range used in regression. The maximum and minimum values derived from the regression were 17.89 ± 1.25 μm⁻¹ and 13.62 ± 2.11 μm⁻¹ for the wavelength ranges of 280–380 nm and 400–500 nm, respectively, a decrease of 23.9%. S values significantly decreased with the increase of CDOM absorption coefficients. CDOM absorption coefficients could be more appropriately estimated from exponential model introducing the variation of S with absorption coefficients, making them useful for a remote sensing bio-optical model of Lake Taihu. DOC-specific absorption coefficient a*(λ) and the parameter M describing molecular size of the humic molecules could also be used as a proxy for the sources and types of CDOM. A general relationship was found between S and a*(λ), and M values. S increased with the decrease of DOC-specific absorption coefficient and the increase of M corresponding to the decrease of molecular weight.     

轻质油中C1—C7轻烃的地球化学特征

作者对5个盆地18个轻质油样品作了C_1—C_7轻烃分析,检测出29种单体轻烃。通过轻烃组成特征研究,认识到石蜡指数(PI_1)和庚烷值(PI_2)作为成熟度的指标,不受沉积盆地类型影响;C_6,C_7烃类族组分受母质类型影响较大。陆相(含煤地层)有机质生成轻质芳烃(苯)的含量比海相有机质要高。新疆塔里木盆地沙参2井原油的轻烃分析资料表明,该井油源岩为海相沉积。     

蒸发油气污染的生物控制技术探讨

生物降解气态有机污染物的研究是近年来发展起来的大气污染控制新领域。通过介绍生物降解气态有机污染物的基本原理，探讨石油储运过程中的蒸发油气污染运用生物控制技术的可行性，提出需要解决的问题和研究的重点。     

Study on Dihydrated Praseodymium Acetylacetonate by Photoacoustic Spectra with Broad Wavelength Range

Photoacousticspectroscopy (PAS)hasbeenusedtonondestructivelyinvestigatealmostallkindsofsam ples,whetherthesampleiscrystalline ,powderorgel .PAspectr oscopyisacalorimetrictechniquewhichmeasurestheenergyabsorbedandsubsequentheatingofthesamplesduetoanonradiativerelaxationpro cess .ThereforePAScanbeusedtostudyopaque ,highlyreflectiveandscatteringsamples ,whicharedif ficulttostudybyconventionalspectroscopytech niques[1] .Withouttheneedofsamplepreparation ,PASavoidstheriskofsamplealteration ,pre…     

裂解碳五馏分分离中取代二萃单元的研究

针对目前裂解碳五馏分分离流程中第二萃取单元的诸多问题,提出采用选择性加氢除去炔烃后再进行精馏的方法代替二萃单元,得到聚合级异戊二烯产品。研究结果表明,工艺流程的改进部分是可行的,具有流程短、安全可靠、能耗低、生产成本低、环境污染少、简化溶剂回收单元等优点。     

镜质体反射率与砂岩孔隙度关系的研究与应用

利用有关孔隙度和有机质热成熟度的理论公式研究了二者之间的内在联系 ,建立起Ro与砂岩孔隙度之间的关系模型。用该模型对济阳坳陷沾化凹陷渤南洼陷沙河街组四段上亚段烃源层有机质的成熟度进行了估算 ,指出该烃源层有机质已达到成熟     

Formation of ordered microporous films with water as templates from poly(D,L‐lactic‐co‐glycolic acid) solution

Recently a method that uses water droplets at the air–solution interface as an ordered template was reported for the preparation of ordered micrometer‐size honeycomb structures. Here we show that the method can also be used for formation of honeycomb‐like porous films from random copolymers with certain hydrophilicity, besides those polymers with defined structures such as block copolymers, starlike homopolymers, amd amphiphilic polymers. This demonstrates that the stabilization of water droplets is the key factor for the regular structure. Also we indicate that size and structure of the films can be regulated by such variables as concentration and atmospheric humidity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1846–1850, 2003     

氰化浸出体系中金的溶剂萃取

本文评述了金的碱性氰化溶液溶剂萃取研究与开发工作的最新进展。包括改性胺，季铵盐，磷氧化物及胍类萃取剂等。