Effect of carbon source on growth and lipid accumulation in Chlorella sorokiniana GXNN01

Heterotrophic culture of microalgae to develop methods of increasing biomass productivity and storage lipids has brought new insight to commercial biodiesel production. To understand the relationship between heterotrophy and lipid production, the effects of carbon sources on the growth and lipid accumulation of Chlorella sorokiniana GXNN01 was studied. The alga exhibited an increased growth rate in response to the addition of carbon sources, which reached the stationary phase after 48 h at 30A degrees C. In addition, glucose and NaAc had a significant effect on the lipid accumulation during the early-stationary phase. Specifically, the lipid content was 0.237 +/- 0.026 g g(-1) cell dry weight and 0.272 +/- 0.041 g L-1 when glucose was used as the carbon source, whereas the lipid content reached 0.287 +/- 0.018 g g(-1) cell dry weight and 0.288 +/- 0.008 g L-1 when NaAc was used as the carbon source. The neutral lipid content was found to first decrease and then increase over time during the growth phase. A glucose concentration of 20 mmol L-1 gave the maximal lipid yield and the optimum harvest time was the early-stationary phase.

Effect of iron on growth and lipid accumulation in Chlorella vulgaris

The economic feasibility of algal mass culture for biodiesel production is enhanced by the increase in biomass productivity and storage lipids. Effect of iron on growth and lipid accumulation in marine microalgae Chlorella vulgaris were investigated. In experiment I, supplementing the growth media with chelated FeCl3 in the late growth phase increased the final cell density but did not induce lipid accumulation in cells. In experiment II, cells in the late-exponential growth phase were collected by centrifugation and re-inoculated into new media supplemented with five levels of Fe3+ concentration. Total lipid content in cultures supplemented with 1.2 x 10(-5) mol L-1 FeCl3 was up to 56.6% biomass by dry weight and was 3-7-fold that in other media supplemented with lower iron concentration. Moreover, a simple and rapid method determining the lipid accumulation in C. vulgaris with spectrofluorimetry was developed. (c) 2007 Elsevier Ltd. All rights reserved.

A nonlinear model for assessing multiple probabilistic risks: A case study in South five-island of Changdao National Nature Reserve in China

Several methods for estimating the potential impacts caused by multiple probabilistic risks have been suggested. These existing methods mostly rely on the weight sum algorithm to address the need for integrated risk assessment. This paper develops a nonlinear model to perform such an assessment. The joint probability algorithm has been applied to the model development. An application of the developed model in South five-island of Changdao National Nature Reserve, China, combining remote sensing data and a GIS technique, provides a reasonable risk assessment. Based on the case study, we discuss the feasibility of the model. We propose that the model has the potential for use in identifying the regional primary stressor, investigating the most vulnerable habitat, and assessing the integrated impact of multiple stressors. (C) 2006 Elsevier Ltd. All rights reserved.

Composition, Abundance, and Diversity of the Peracarida on Different Vegetation Types in the Qi'ao-Dan'gan Island Mangrove Nature Reserve on Qi'ao Island in the Pearl River Estuary, China

Chang-Fu Wang, Xian-Qiu Ren, and Run-Lin Xu (2010) Composition, abundance, and diversity of the Peracarida on different vegetation types in the Qi'ao-Dan'gan Island Mangrove Nature Reserve on Qi'ao Island in the Pearl River estuary, China. Zoological Studies 49(5): 608-615. Almost nothing is known about the Peracarida in the Pearl River estuary. This is the 1st report to study the composition, abundance, and diversity of the Peracarida in the Qi'ao-Dan'gan I. Mangrove Nature Reserve on Qi'ao I., in the Pearl River estuary, southern China. Bimonthly samplings were carried out in 3 representative vegetation types (mangrove arbor, emergent plants, and seaweed) for 2 yr. Using a Peterson grab, 1940 individuals (id.) were collected in total, including 11 species of 6 genera, 5 families, and 3 orders (Amphipoda, Isopoda, and Tanaidacean). Discapseudes mackiei Bamber 1997 was the dominant species with the highest density of 1,432 incl./m(2). The effect of temperature on the abundance of Peracarida was significant (p < 0.01), and the optimum temperature was 22-23 degrees C in both the mangrove arbor and seaweed. The results showed that the abundance of the Peracarida was higher in the mangrove arbor, while the diversity, especially Amphipoda diversity, was higher in the seaweed. In contrast, emergent plants provided no suitable habitats for the Peracarida. http://zoolstud.sinica.edu.tw/Journals/49.5/608.pdf

The Shandong mud wedge and post-glacial sediment accumulation in the Yellow Sea

Two well-defined deltaic sequences in the Bohai Sea and in the South Yellow Sea represent post-glacial accumulation of Yellow River-derived sediments. Another prominent depocenter on this epicontinental shelf, a pronounced clinoform in the North Yellow Sea, wraps around the northeastern and southeastern end of the Shandong Peninsula, extending into the South Yellow Sea. This Shandong mud wedge is 20 to 40 m thick and contains an estimated 300 km(3) of sediment. Radiocarbon dating, shallow seismic profiles, and regional sea-level history suggest that the mud wedge formed when the rate of post-glacial sea-level rise slackened and the summer monsoon intensified, at about 11 ka. Geomorphic configuration and mineralogical data indicate that present-day sediment deposited on the Shandong mud wedge comes not only from the Yellow River but also from coastal erosion and local rivers. Basin-wide circulation in the North Yellow Sea may transport and redistribute fine sediments into and out of the mud wedge.

Accumulation of petroleum hydrocarbons and heavy metals in clams (Ruditapes philippinarum) in Jiaozhou Bay, China

Accumulation and distributions of aliphatic and polyaromatic hydrocarbons (PAHs) and heavy metals were measured in tissues of the clam Ruditapes philippinarum collected from 5 sites in Jiaozhou Bay, Qingdao, China. The concentrations of total aliphatic hydrocarbon and PAHs ranged from 570 to 2 574 ng/gdw (gram dry weight) and from 276 to 939 ng/gdw, in the most and least polluted sites, respectively. The bio-accumulation of hydrocarbons and PAHs in the clams appeared to be selective. Aliphatic hydrocarbons were predominantly represented by short chain (< nC(23)) n-alkanes, suggesting that petroleum hydrocarbons were likely the major contamination source. The selective uptake of 3 and 4 ring PAHs, such as naphthalene, fluorene, phenanthrene, fluoranthene and pyrene, by the clams was probably related to the physiological and bio-kinetic processes that were energetically favorable for uptake of compounds with fewer rings. Accumulation of the metals Cd, Cu, Zn, Pb, Cr, Hg, and As in the clam tissues also showed high variability, ranging from 0.043 to 87 A mu g/gdw. Among the 7 detected metals, Zn, Cd, Cu, and As had a particularly high potential of accumulation in R. philippinarum. In general, a positive correlation was found between the tissue concentrations and sediment concentrations of hydrocarbons and of some metals. Our study suggests that moderate contamination with polyaromatic hydrocarbons, and low to moderate contamination with metals, currently exists for clam R. philippinarum in Jiaozhou Bay, in comparison with other regional studies. A long-term monitoring program is certainly needed for assessment of the potential ecological influence and toxicity of these contaminants of R. philippinarum in Jiaozhou Bay.

Influence of lanthanum on the accumulation of trace elements in chloroplasts of cucumber seedling leaves

Influence of La3+ on the accumulation of trace elements (Se-75, Co-56, Rb-83, V-48, (95)mTc, and Ga-67) in chloroplasts of cucumber seedling leaves was studied by a radioactive multitracer technique. At the same time, chloroplast contents of different concentrations of La3+ treatment were calculated. It was observed that chloroplast contents peaked at 0.02 mM La3+ treatment and that the uptake and distribution of these trace elements in chloroplasts of cucumber seedling leaves are different under different La3+, treatments. With the increase of lanthanum concentrations from 0.002 to 2 mM, the uptake percentages of Se-75, Co-56, and Rb-83 presented an obvious increase and then sharply decreased in contrast to the nonlanthanum treatment, whereas there appeared a sharp decrease and then restored control level in the uptake of V-48. The other two trace elements, namely Tc-95m and Ga-67, were accumulated only in the presence of 0.02 mM La3+. The results indicate that lanthanum treatments to growing the cucumber lead to the change of trace element uptake in the chloroplasts of leaves, which suggest that lanthanum might influence the accumulation of trace elements in chloroplasts of cucumber seedling leaves by regulation of various ion transport mechanisms, thus affecting the photosystem of leaves.

四川盆地构造控藏规律研究

Firstly, established sequence stratigraphy of Sinian System-Middle Triassic Series framework in Sichuan basin,be divided into 21 second-level sequence stratigraphy and 105 third-level sequence stratigraphy.From many aspects,discussed sequence stratigraphy characteristic. On the foundation of structure unconformity and fission track analysis, on the ground of An county-Shuinin county regional seismic section, using the positive evolution equilibrium principle technology, comprehensivly be mapped structure evolution of Sichuan basin. It can be divided into seven stages, that is :Pre-Sinian basement stage, cratonic depression basin(Z1-S)stage, cratonic rifted basin(D-T2)stage, passive continental margin(T3x1-3)stage, foreland basin(T3x4-6)stage, depression basin (Jurassic Period-Miocene Epoch) stage, formed basin (Holocene Epoch) stage. Analysis on structure evolution history,burial history,source rocks thermal evolution history, Maoba changxing formation gas pool forming process can be classified into four stages: ancient lithological oil pool stages in Indosinian-early Yanshanian period（T-J1-2）, ancient structure- lithological gas pool stages in middle Yanshanian period（J3-K1）, structure- lithological gas pool setting stages in last Yanshanian period（K2）, structure- lithological gas pool adjusting and transformation stages in Himalayan period（R-Q）. Maoba feixianguan formation gas pool forming process can be classified into two stages: second structure gas pool stages in last Yanshanian period（K2）,second structure gas pool physical adjusting and transformation stages in Himalayan period（R-Q）,and summarize reservoir formation model. On the base of newest exploration achievement and petroleum geologic comprehensive research , demonstrate how structure controls hydrocarbon accumulation. Structure controlling source rocks behaves structure controlling main source rocks’sedimentary facies, medium-large pools mainly located at center or margin of hydrocarbon generation. Structure controlling palaeo-karst reservoirs ,reef and beach facies reservoirs, fault and fracture reservoirs. Structure controlling palaeo-uplift, and palaeo-uplift controlling hydrocarbon migration, active reservoirs’forming, palaeo-structure traps forming. Structure controls distribution of mudstone and gypsolith, controls preservation. Structure controls hydrocarbon conducting, structure traps forming and hydrocarbon accumulation. Whether or no, Structure controls total process of basin forming-source rocks’generation- hydrocarbon accumulation. It is direct effect results of structure movements that large traps’ conditions, conducting migration conditions, high quality preservation. source rocks’condition and reservoirs’ condition are the indirect effect results. In the last analysis, “source rock controlling theory”, “high quality reservoir mainly controlling theory”, “palaeo-uplift controlling theory” and “current structure deciding theory” are structure controlling hydrocarbon accumulation. There are high variability and complex mechanisms in Sichuan basin , but the regional hydrocarbon accumulation conditions are very well, such as abundant source rocks, matching process of hydrocarbon accumulation and many exploration areas. By means of integrated analysis, put forward hydrocarbon exploration direction and large-middle targets of China Petroleum and Chemical Corporation .Thus, more and more hydrocarbon proved reserve and output in Sichuan basin will be contributed to China energy industry in a long future time.

冀东油田柳南地区新近系油藏剩余油形成及分布规律研究

This thesis is based on the research project of Study on the Geological Characteristics and Remaining Oil Distribution Law of Neogene Reservoirs in Liunan Area, which is one of the key research projects set by PetroChina Jidong Oilfield Company in 2006. The determination of remaining oil distribution and its saturation changes are the most important research contents for the development and production modification of oilfields in high water-cut phases. Liunan oilfield, located in Tangshan of Hebei Province geographically and in Gaoliu structural belt of Nanpu sag in Bohai Bay Basin structurally, is one of the earliest fields put into production of Jidong oilfield. Focusing on the development problems encountered during the production of the field, this thesis establishes the fine geological reservoir model through the study of reservoir properties such as fine beds correlation, sedimentary facies, micro structures, micro reservoir architecture, flow units and fluid properties. Using routine method of reservoir engineering and technology of reservoir numerical modeling, remaining oil distribution in the target beds of Liunan area is predicted successfully, while the controling factors of remaining oil distribution are illustrated, and the model of remaining oil distribution for fault-block structure reservoirs is established. Using staged-subdivision reservoir correlation and FZI study, the Strata in Liunan Area is subdivided step by step; oil sand body data-list is recompiled; diagram databases are established; plane and section configuration of monolayer sandstone body, and combination pattern of sandstone bodys are summarized. The study of multi-level staged subdivision for sedimentary micro-facies shows that the Lower member of Minghuazhen formation and the whole Guantao formation in Liunan Area belong to meandering river and braided river sedimentary facies respectively, including 8 micro facies such as after point bar, channel bar, channel, natural levee, crevasse splay, abandoned channel, flood plain and flood basin. Fine 3D geological modeling is performed through the application of advanced software and integration of geological, seismic logging and reservoir engineering data. High resolution numerical simulation is performed with a reserve fitting error less than 3%, an average pressure fitting fluctuation range lower than 2Mpa and an accumulate water cut fitting error less than 5%. In this way, the distribution law of the target reservoir in the study area is basically recognized. Eight major remaining oil distribution models are established after analysis of production status and production features in different blocks and different layers. In addition, fuzzy mathematics method is used to the integreted evaluation and prediction of abundant remaining oil accumulation area in major production beds and key sedimentary time units of the shallow strata in Liunan Area and corresponding modification comments are put forward. In summary, the establishment of fine reservoir geological model, reservoir numerical simulation and distribution prediction of remaining oil make a sound foundation for further stimulation of oilfield development performance.

吐合盆地鲁克沁构造带断块油藏形成机制及油藏预测

Lukeqin arc belt is a compound structure generated by multi-movements and composed of 6 sub-structural zones, which are connected by Huoyanshan Mountain. General characteristics of the arc belt are multi-patterns of structure, multi-phases for petroleum, multi-types of trap and multi-layers for reservoirs. As a part of the eastern Lukeqin arc belt located on the south of Taibei depression, Lukeqin structural zone behaves as a complex faulted-fold zone, in which the formation and distribution of hydrocarbons are controlled by structures. As the dominant source of dynamics for the second migration of hydrocarbon, structure stress field is closely related with the potentials of hydrodynamics. Results derived from the simulations of stress field by finite element method indicate that the northwest tending faults prefer seal to the northeast tending ones. The reason is that the northwest tending faults were squeezed more strongly than the northeast tending ones. Therefor, the northeast tending faults become always the paths for oil to migrate southeastward. Lukeqin structural zone is the main site for oil to concentration because it is surrounded by high stress. Situated on the front of the foreland basin of Turpan-Hami, Lukeqing arc belt is a dam to hold back the southward migrating oil from Shengbei depression. The axis line of Shenquan-Shengnan-Yanmuxi, Lukeqin and Yubei controls the migrating paths and concentrating process of oil and gas. Results derived from stress simulation and structure analyses indicate consistently that both Yubei and Lukeqin structural zones are the favorite areas for oil to migrate. The generally southward paths for oil to migrate out of Taibei depression can be two ways. One of them is from Taibei depression to Yubei structural zone and the other is from Taibei depression to Lukeqin structural zone. By the both ways, oil migrated upward along the faults and southeastward along the structural axis to concentrate in either Permian or Triassic system. The newly ascertained path for oil migration, which is accurately southeastward instead of coarsely southward, indicates the directions for further explorations on the compound Lukeqin block zone. Five kinds of seal models of fault are all found in Lukeqin block zone by studying the seal features of faults occurred in the zone. Having studied the fault seal and their controlling factors by fuzzy set method, the paper deems that the northwest tended faults are better than the northeast tended ones for oil to concentrate. The most important factors to decide the seal extent of faults in this zone are the characteristics of main stress and fluids instead of capillary pressure differences between the two sides of fault and smear mud factors. There exist seal differences not only between the faults of different time but also between the sections within a fault due to the variation of depths, strata and positions. The general distribution rules of reservoirs were dominated by the seal characteristics of a fault during the time reservoirs formed. While the current features of fault seal decide the conservation of reservoirs and heights of oil accumulations. Seal or not of a fault is not absolute because the essential for fault to seal is the distribution of permeability of fault zone. Therefor, the multi cyclical activities of faults create the space-time variation of seal features of the fault. Totally, the seal extent of the faults within the area is not as perfect as to accumulate ordinary crude. Crude oil can only be sealed when it becomes viscous. Process for crude oil to become viscous and viscous happened strongly because of the fault-fold movements. Shallowly burying and even revealing of the objective layers of the reservoirs made the crude oil to be thickened by water washing biologically degradation and oxidation degradation. The northwestward deepening during or after the reservoir formation of the structural zone provided the power for oil to migrate one or more times. The main reason for oil accumulation is the formation of Lukeqin block zone during Xishanyao stage, middle Jurassic Period, Early Yanshanian Movement. While the main reason for reservoir conservation is the placidity of Triassic blocks after the formation of reservoirs. Contrasting to former opinions, it is concluded that the reservoirs in Lukeqin zone, including viscous reservoirs, were formed by one time but not more times. So the author proposes the opinion that the reservoirs of viscous oil were formed by viscous oil migration under the conditions of aptitude sets of fault seals controlled by fluid and other factors. To grope the distribution rules outside Taibei depression and discuss the formation mechanism of Anjurassic reservoirs, it is necessary to study the dominate factors for the formation of reservoirs in Lukeqin structural zone such as structural stress, fault seals and thickening mechanism of crude oil. Also, the necessary studies are the key to break through the Taibei depression and Anjurassic systems. Therefor, they are significant for the future exploration and reserve increasing of hydrocarbon within the Turpan-Hami basin. The paper studied the distribution rules of block reservoirs and forecasted the favorable zones for further exploration in Turpan-Hami basin. Conclusions can be useful for not only the exploration in the area but also the theory consult in the adjacent areas.

黄骅坳陷大港探区油气资源潜力与资源结构预测

Facing the problems that Dagang region of Huanghua Depression has high exploration degree and its remaining resource potential and structure are not clear, the theory of Petroleum Accumulation System (PAS) is applied to divide and evaluate the oil/gas systems quantitatively. Then, the petroleum accumulation systems are taken as units to forecast and analyse the oil/gas resources and their structure using statistical methods of sampling analysis of discovery process model and generalized pareto distribution model. The exploration benefit of the unit is estimated using exploration simulation methods. On the basis of the above study, the resource potential of Huanghua Depression is discussed.Huanghua Depression can be diveded into four petroleum accumulation systems, i.e. North PAS5 Middle Qibei PAS, Middle Qinan PAS and South PAS. Each PAS can be diveded futher into several sub- PASs. Using the basic princple of Analytical Hierarchy Process, the method of quantitative evaluation of PAS is established. Then the elements and maturity of PAS are evaluated quantitatively.Taking migration and accumulation units and sub-PASs as prediction units, sampling analysis of discovery process model and generalized pareto distribution model are applied comparatively to forecast the resource structure of eight migration and accumulation units in six PASs of medium-high exploration degree. The results of these two methods are contrasted and analyzed. An examination of X2 data of these two models from exploration samples shows that generalized pareto distribution model is more effective than sampling analysis of discovery process model in Huanghua Depression. It is concluded that minimum and maximum size of reservoir and discovery sequence of reservoirs are the sensitive parameters of these two methods.Aiming at the difficult problem of forecast in low exploration degree, by analysis of relativity between resource parameters and their possible influential geological factors, forecast models for resource parameters were established by liner regressing. Then the resource structure is forecasted in PASs of low exploration degree.Based on the forecast results, beginning with the analysis of exploration history and benefit variation, the exploration benefit variation of the above PASs is fitted effectively using exploration simulation method. The single well exploration benefit of remaining oil resource is also forecasted reasonably.The results of resource forecast show that the total oil resources ofHuanghua Depression amount to 2.28 b illion ton. By the end o f 2 003, the accumulative total proved oil reserve is 0.90 billion ton and the remaining oil resources is 1.38 billion ton. The remaining oil resource is concentrated in Kongdian-Dengmingshi, Banqiao-Beidagang, Qidong-Yangerzhuang and Baidong-Qizhong sub-PASs.