Effects of cell density, light intensity and mixing on Undaria pinnatifida gametophyte activity in a photobioreactor

An on-line controlled 7 1 sterilizable photobioreactor was used for the optimisation of a culture of gametophytes of Undaria pinnatifida. The gametophytes, which had been stored for three years in a culture cabinet at 16 degreesC, could rapidly grow in the photobioreactor under controlled conditions. The rate of increase of dissolved oxygen and pH were used to monitor the photosynthetic activity. Optimal gametophytes density changed varying the light intensity. The optimal cell densities were 3.24 and 3.45 g FW l(-1) when the cultures were exposed to 61.7 and 82.3 muE m(-2) s(-1), respectively. The optimal cell density was higher under a high photon flux density (PFD) than under low PFD. On the other hand, the optimal light intensities were different for different cell density cultures. The light saturation point was higher at high cell density cultures than at low cell density cultures. The optimal rotational speed was 150 rpm for high cell density culture in the photobioreactor. (C) 2003 Elsevier B.V. All rights reserved.

Relative paleointensity of the geomagnetic field during the past 200 ka from the West Philippine Sea and its chronological significance

Our rock magnetic analysis of core Ph05 from the West Philippine Sea demonstrates that the core preserves a strong, stable remanent magnetization and meets the magnetic mineral criteria for relative paleointensity (RPI) analyses. The magnetic minerals in the sequence are dominated by pseudosingle-domain magnetite, and the concentration of magnetic minerals is at the same scale. Both the conventional normalizing method and the pseudo-Thellier method were used in conjunction with the examination of the rock magnetic properties and natural remanent magnetization. Susceptibility (chi), anhysteretic remnant magnetization (ARM) and saturation isothermal remnant magnetization (SIRM) were used as the natural remanent magnetization normalizer. However, coherence analysis indicated that only ARM is more suitable for paleointensity reconstruction. The age model of core is established based on oxygen isotope data and AMS(14)C data, which is consistent with the age model estimated from RPI records. The relative paleointensity data provide a continuous record of the intensity variation during the last 200 ka, which correlates well with the global references RPI stacks. Several prominent low paleointensity values are identified and are correlated to the main RPI minima in the SINT-200 record, suggesting that the sediments have recorded the real changes of geomagnetic field.

Low-amplitude BSRs and gas hydrate concentration on the northern margin of the South China Sea

The passive northern continental margin of the South China Sea is rich in gas hydrates, as inferred from the occurrence of bottom-simulating reflectors (BSR) and from well logging data at Ocean Drilling Program (ODP) drill sites. Nonetheless, BSRs on new 2D multichannel seismic reflection data from the area around the Dongsha Islands (the Dongsha Rise) are not ubiquitous. They are confined to complex diapiric structures and active fault zones located between the Dongsha Rise and the surrounding depressions, implying that gas hydrate occurrence is likewise limited to these areas. Most of the BSRs have low amplitude and are therefore not clearly recognizable. Acoustic impedance provides information on rock properties and has been used to estimate gas hydrate concentration. Gas hydrate-bearing sediments have acoustic impedance that is higher than that of the surrounding sediments devoid of hydrates. Based on well logging data, the relationship between acoustic impedance and porosity can be obtained by a linear regression, and the degree of gas hydrate saturation can be determined using Archie's equation. By applying these methods to multichannel seismic data and well logging data from the northern South China Sea, the gas hydrate concentration is found to be 3-25% of the pore space at ODP Site 1148 depending on sub-surface depth, and is estimated to be less than values of 5% estimated along seismic profile 0101. Our results suggest that saturation of gas hydrate in the northern South China Sea is higher than that estimated from well resistivity log data in the gas hydrate stability zone, but that free gas is scarce beneath this zone. It is probably the scarcity of free gas that is responsible for the low amplitudes of the BSRs.

海相碳酸盐－稀土元素共沉淀过程中的分异作用研究

本文主要运用稳定加液－反应系统对海水中方解石和文石形成时稀土元素的共沉淀现象进行了分析，研究了稀土元素在固-液体系中的迁移、转化和分配。进而在对其定量描述的前提下，研究了稀土元素共沉淀对各种反应条件的响应，并对共沉淀行为的机制进行了探讨。 本实验首先运用pH测试、高精度滴定分析等手段测定了实验中的一些基本参数，如[H+]、碱度和[Ca2+]，根据计算结果获得了各碳酸体系要素，并以此为基础建立了5℃、15℃和25℃及pCO2=0.003atm下海水中方解石或文石的沉淀动力学方程。实验结果表明： 1）在各条件下，方解石或文石的沉淀速率（R）和其在海水中过饱和度（Ω）存在很好的线性相关性，即海相碳酸盐的沉淀动力学方程可以通过下面的基本表达式来表示：LogR=k*Log(Ω-1)+b ； 2）过高的稀土元素浓度会对文石或方解石的沉淀产生抑制作用，进而对共沉淀过程中YREEs的分异和分馏产生一定的影响。相比方解石而言，文石的沉淀动力学过程承受稀土元素的干扰能力更强； 3）不同温度下得到的方解石或文石各自的沉淀动力学方程存在明显的差异，表明这一过程受热力学因素控制。相对于方解石而言，温度对文石的沉淀动力学的影响更为显著。 与前人研究不同的是，本实验中YREEs的浓度设定在非常低的范围内，从而避免了过高浓度YREEs对方解石或文石沉淀动力学过程的干扰。在最终的反应液中，各种实验条件非常接近自然环境。有关稀土元素的共沉淀行为主要得出以下定性或定量化结论： 1）YREEs在随方解石或文石的共沉淀过程中，均发生了强烈的分异作用。在方解石实验中，稀土元素的分异系数分布曲线呈凸状分布；而在文石实验中，稀土元素的分异系数随原子序数的增加逐渐减小，遵循镧系收缩的规律。总的来说，稀土元素，尤其轻稀土元素在文石中的分异作用要强于方解石。 2）无论是方解石还是文石，沉淀速率对YREEs的分异作用都有着明显的影响。在方解石中，YREEs的分异系数随沉淀速率的增加呈一致性递减趋势；而在文石中，其分异系数对文石沉淀速率有着截然不同的响应：轻稀土元素（La, Ce, Nd, Sm, Eu, Gd）的分异系数随文石沉淀速率的增加而下降，而重稀土元素（Ho, Y, Tm, Yb , Lu）的分异系数则随文石沉淀速率的增加呈上升趋势。 3）在方解石中YREEs的分异系数之间存在非常好的相互关系，表明这些元素是以成比例的方式参与共沉淀。整个谱系呈现中等强度的分馏，MREE相对于LREE和HREE要更为富集；在文石中由于沉淀速率的作用不同，只有Y、Ho、Yb、Lu等元素的分异系数之间有较好的相互关系。YREEs出现了差异性的强烈分馏，在新生成沉淀中轻稀土元素相对于重稀土元素强烈富集。 4）YREEs在溶液中和碳酸盐晶体表面的碳酸根配位形式对YREEs在共沉淀过程中的分异作用极为重要，YREEs在碳酸盐晶体表面的吸附是整个谱系发生分馏效应的关键环节。对于文石来讲，晶体中有效YREE离子和Ca离子半价大小之间的相近程度是其分馏效应的关键因素；而对于方解石来说，YREEs在方解石晶格中的安置就是其分馏效应的关键控制因子，但在晶格安置中起到关键作用的是YREEs和方解石中O原子之间离子键M-O的键长，而非离子半径。 5）综合YREEs在方解石中的分异作用和分馏效应，我们认为M2(CO3)3-CaCO3和MNa(CO3)2-CaCO3是最为可能的两种固体溶液形成模式。 最为重要的是，对比我们的实验结果与前人在灰岩、叠层石、微生物成因碳酸盐等方解石质载体中的研究成果，两者之间出现了非常好的一致性。我们认为方解石质载体将是重建古海水中稀土元素相关信息的重要工具。相比之下，文石质载体不适合作为类似的载体。

Changes in nitrogen and phosphorus and their effects on phytoplankton in the Bohai Sea

Systematic studies of the changes in dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) and their effects on phytoplankton over the last 30 years in the Bohai Sea are presented. The amount of sewage disposal, use of fertilizer and the Huanghe River runoff were found to have a significant influence on the DIN or DIP concentrations in the Bohai Sea over the last 30 years. Moreover, the changes in DIN and DIP resulted in changes in the limiting nutrients of phytoplankton in the Bohai Sea from nitrogen in the early 1980s to nitrogen-phosphorus in the late 1980s, and then to phosphorus after the 1990s. In addition, changes in nitrogen and phosphorus had a significant effect on the phytoplankton community structure. The half saturation constant (K (s)) was used to evaluate the effect of nutrients on the phytoplankton community structure in the Bohai Sea over the last 30 years. Cell abundance percentages of dominant phytoplankton species with high K (s) values for phosphorus and low K (s) values for nitrogen have decreased since the 1980s, while those of dominant phytoplankton species with low K (s) values for phosphorus and high K (s) values for nitrogen increased during this period.

Seasonal and interannual variation in water vapor and energy exchange over a typical steppe in Inner Mongolia, China

In this study, we conducted eddy covariance (EC) measurements of water vapor exchange over a typical steppe in a semi-arid area of the Inner Mongolia Plateau, China. Measurement sites were located within a 25-year-old enclosure with a relatively low leaf area index (similar to 1. 5 m(2) m(-2)) and dominated by Leymus chinensis. Energy balance closure was (H + LE) = 17.09 + 0.69 x (Rn - G) (W/m(2); r(2) = 0.95, n = 6596). Precipitation during the two growing seasons of the study period was similar to the long-term average. The peak evapotranspiration in 2004 was 4 mm d(-1), and 3.5 mm d(-1) in 2003. The maximum latent heat flux was higher than the sensible heat flux, and the sensible heat flux dominated the energy budget at midday during the entire growing season in 2003; latent heat flux was the main consumption component for net radiation during the 2004 growing season. During periods of frozen soil in 2003 and 2004, the sensible heat flux was the primary consumption component for net radiation. The soil heat flux component was similar in 2003 and 2004. The decoupling coefficient (between 0.5 and 0.1) indicates that evapotranspiration was strongly controlled by saturation water vapor pressure deficit (VPD) in this grassland. The results of this research suggest that energy exchange and evapotranspiration were controlled by the phenology of the vegetation and soil water content. In addition, the amount and frequency of rainfall significantly affect energy exchange and evapotranspiration upon the Inner Mongolia plateau. (c) 2007 Published by Elsevier B.V.

Blood-gas properties of plateau zokor (Myospalax baileyi)

Plateau zokor (Myospalax baileyi) is one of the blind subterranean mole rats that spend their life solely underground in scaled burrows. It is one of the special species of the Qinghai-Tibet plateau. In their burrows, oxygen is low and carbon dioxide is high and their contents fluctuate with the change of seasons, soil types, rain and depth of burrows. However, plateau zokors show successful adaptation to that extreme environment. In this study, their adapting mechanisms to the hypoxic hypercapnic environment were analyzed through the comparison of their blood-gas properties with that of pikas (Ochotona curzniae) and Sprague-Dawley rats. The results indicated that plateau zokors had higher red blood corpuscle counts (8.11 +/- 0.59 (10(12)/L)) and hemoglobin concentrations (147 +/- 9.85 g/L), but hematocrit (45.9 +/- 3.29%) and mean corpuscular volume (56.67 +/- 2.57 fL) were lower than the other rodents. Their arterial blood and venous blood pH were 7.46 +/- 0.07 and 7.27 +/- 0.07. Oxygen pressure in arterial blood of plateau zokors was about 1.5 times higher than that of pikas and rats, and it was 0.36 and 0.26 times in their venous blood. Partial pressure for carbon dioxide in arterial and venous blood of plateau zokors was 1.5-fold and 2.0-fold higher, respectively, than in rats and pikas. Oxygen saturation of plateau zokors was 5.7 and 9.3 times lower in venous blood than that of pikas and rats, respectively. As result, the difference of oxygen saturation in arterial blood to venous blood was 2- and 4.5-fold higher in plateau zokors as that of pikas and rats, respectively. In conclusion, plateau zokors had a high tolerance to pH changes in tissues, together with strong capabilities to obtain oxygen from their hypoxic-hypercapnic environment. (c) 2006 Published by Elsevier Inc.

Photosynthetic depression in relation to plant architecture in two alpine herbaceous species

The Qinghai-Tibet Plateau is characterized by extremely high radiation, which may induce down-regulation of photosynthesis in plants living in this alpine ecosystem. To clarify whether photoinhibition occurs in the alpine environment and to discern its underlying mechanisms, we examined photosynthetic gas exchange and fluorescence emission in response to the changes in photosynthetic photon flux density (PPFD) and leaf temperature under natural regimes for two herbaceous species: prostrate Saussurea superba and erect-leaved Saussurea katochaete from altitude 3250 m on the Qinghai-Tibet Plateau. S. superba intercepted a higher maximum PPFD and experienced much higher leaf temperature than the erect-leaved S. katochaete. S. superba exhibited a much higher light saturation point for photosynthesis than S. katochaete. Under controlled conditions, the former species had higher CO2 uptake rates and neither species showed obvious photosynthetic down-regulation at high PPFD. Under natural environmental conditions, however, apparent photoinhibition, indicated by reduced electron transport rate (ETR), was evident at high PPFD for both species. After a night frost, the photochemistry of S. katochaete was depressed markedly in the early morning and recovered by mid-day. After a frost-free night, it was high in the morning and low at noon due to high radiation. S. superba did not respond to the night frost in terms of daytime photochemical pattern. In both species, photochemical depression was aggravated by high leaf temperature and the erect species was more sensitive to high temperature. This study suggests that the high radiation on the Qinghai-Tibet Plateau is likely to induce rapidly reversible photoinhibition, which is related closely to plant architecture. Photochemistry in the prostrate species seems able to tolerate higher PPFD, without obvious suppression, than the erect species. (C) 2003 Elsevier Science B.V. All rights reserved.

动态参数模型确定SoC中异步FIFO深度的方法

针对超大规模集成电路和片上系统设计中确定异步FIFO浓度的问题,根据异步FIFO运行时的属性提出FIFO动态参数模型,该模型包括FIFO饱和度、写入端和读出端数据传输率及上溢/下溢频率。在该模型的基础之上,分析异步FIFO的深度与动态参数之间的关系,采用功能仿真方法确定片上系统中异步模块之间数据传输所需FIFO的深度。对典型实例的分析表明,采用这种方法能够在保证系统数据通信性能的前提下,获得最小的FIFO深度,优化系统资源的使用。

投资时间序列的混沌分维研究

以某市固定资产投资同比增长数据为根据 ,利用混沌动力学中的相空间重构技术、幅值谱分析、庞加莱截面等方法进行分析 ,并计算其关联分维 ,得出其饱和嵌入维数为 5、关联分维约为 1 7,初步确定某市固定资产投资增长过程具有混沌特性 ,有 5个因素影响着某市固定资产投资的同比增长幅度 ,其中 2个因素起决定作用·该法可用于复杂的经济系统的分析研究·

综合权值递推最小二乘法估计从UUV航行参数

根据主UUV观测系统测量的从UUV方位信息精度高、距离信息精度低的特点,将遗忘因子和位置权值构成的综合权值融入递推最小二乘算法(RLS)用于从UUV航行参数分析,避免采用EKF算法对观测噪声要求高的缺陷,克服数据饱和现象。同时对从UUV方位信息进行预处理以提高航行参数估计的收敛速度。仿真实验证明了方法的有效性。

储层评价目标驱动的地震叠前叠后综合反演方法研究

The exploration and development of natural gas in the north of Ordos basin have been one important part in China’s energy stratagem. Reservoir in upper Palaeozoic group is of lithological trap and its prediction is a crux in a series of works. Based on foregoing seismic reservoir prediction, seismic data are re-processed with some optical methods and pre-stack information is used in corresponding inversions. Through the application of diverse methods, a series of techniques for reservoir prediction come into being. Several results are achieved as flowing: 1. A set of log processing and interpretation methods is developed. Porosity, permeability and gas saturation models are rebuilt. 2. Based on the petro-physics analysis of reservoirs in upper Palaeozoic group, the equations about lithology, property, hydrocarbon and elastic parameters are established. 3. Forward modeling based on elastic wave theory is first applied in the study area and increases the resolution of modeling results. 4. A series of techniques such as pre-stack time migration and others are combined to improve the data quality. 5. Pre-stack seismic inversion is first employed in the north of Ordos Basin and brings the results of EI, P-impedance, S-impedance and other elastic parameters. 6. In post-stack inversion, logs indicating reservoir parameters are rebuilt and boost the resolution of lithology inversion. 7. Amplitude, coherence, frequency-discomposed amplitude, waveform and other sensitive attributes are extracted to describe sands distribution. Seismic modes standing for sands of P1x3, P1x2 are established. 8. Among 9 proposed wells, 8 wells encountered sands and became production wells. The output of DK13 amounts to 510,000 m3 per day. Keywords：the north of Ordos Basin, reservoir prediction, pre-stack inversion, post-stack inversion, seismic attributes．

辽东湾隐蔽油气藏地球物理识别技术研究

In China and world, more than half the recent basin discovered reserves involve lithologic hydrocarbon reservoir reserves. The major target for further hydrocarbon basin exploration is the subtle reservoir. The Liaodong Bay prospect is much important in Bohai Sea, which includes Liaoxi low uplift, Liaodong uplift, Liaoxi sag and Liaozhong sag. After dozens years’ exploration in Liaodong Bay, few unexplored big-and-middle-sized favorable structural traps are remained and most of the stock structure targets are bad for fragmentary. Thus seeking for new prospect area and making a breakthrough, have become the unique way to relieve the severe exploration condition in Liaodong Bay. Technique Route Based on the petrophysical property of target area, the seismic forward inference of typical subtle trap model is expanded with analysis of logging, seismic and geologic data. According to petrophysical characteristics and forward inference and research on seismic response of actual seismic data in target area, the optimization of geophysical technique is used in subtle trap identification and the geophysical identification technique system of subtle reservoir is formed. The Key Research ① Petrophysical Model The petrophysical parameter is the basic parameter for seismic wave simulation. The seismic response difference of rocks bearing different fluids is required. With the crossplot of log data, the influence of petrophysical parameters on rock elastic properties of target area is analyzed, such as porosity, shale index, fluid property and saturation. Based on the current research on Biot-Gassmann and Kuster-Toksoz model, the petrophysical parameter calculator program which can be used for fluid substitution is established. ② S-wave evaluation based on conventional log data The shear velocity is needed during forward inference of AVO or other elastic wave field. But most of the recent conventional log data is lack of shear wave. Thus according to the research on petrophysical model, the rock S-wave parameter can be evaluated from conventional log data with probability inverse method. ③ AVO forward modeling based on well data For 6 wells in JZ31-6 block and 9 wells in LD22-1 block, the AVO forward modeling recording is made by log curve. The classification of AVO characteristics in objective interval is made by the lithologic information. ④ The 2D parameter model building and forward modeling of subtle hydrocarbon trap in target area. According to the formation interpretation of ESS03D seismic area, the 2D parameter model building and seismic wave field forward modeling are carried on the given and predicted subtle hydrocarbon trap with log curve. ⑤ The lithology and fluid identification of subtle trap in target area After study the seismic response characteristics of lithology and fluid in given target area, the optimization of geophysical technique is used for lithology identification and fluid forecast. ⑥The geophysical identification technique system of subtle reservoir The Innovative Points of this Paper ① Based on laboratory measurement and petrophysical model theory, the rock S-wave parameter can be evaluated from conventional log data with probability inverse method. Then the fluid substitution method based on B-G and K-T theory is provided. ② The method and workflow for simulating seismic wave field property of subtle hydrocarbon trap are established based on the petrophysical model building and forward modeling of wave equation. ③ The description of subtle trap structural feature is launched. According to the different reflection of frequency wave field structural attribute, the fluid property of subtle trap can be identified by wave field attenuation attribute and absorption analysis. ④ It’s the first time to identify subtle trap by geophysical technique and provide exploration drilling well location. ⑤ The technique system of subtle reservoir geophysical identification is formed to provide available workflow and research ideas for other region of interest.

东濮凹陷低阻油层形成机理与评价方法研究

In order to effectively identify and accurately evaluate low resistivity reservoir in Dongpu depression, using various logging data synthetically, geological and logging characteristics are summarized in term of different blocks on the basis of core analysis, cutting logging, oil testing and commissioning data. The formation mechanism of low resistivity reservoir is studied, and the main factors that cause low resistivity reservoir are discovered. The first factor is fine lithology, high shale content and hydrophilic rock. The second factor is high salinity formation water. The third factor is light oil, high gas quantity dissolved and large difference density of oil-water. The last factor is low amplitude structure of reservoir and low differential degree of oil-water. According to the characteristics of low resistivity reservoir, the method of compound lithology, the method of movable fluid, the method of phase permeability and the method of nuclear magnetic resonance logging are put forward. The compound lithology criterion of distinguishing hydrocarbon is founded in term of different blocks on the basis of electrical efficiency. The evaluation models of reservoir parameters are founded; whose core is oil saturation and phase permeability. In order to calculate oil saturation, the compound lithology model on the basis of electrical efficiency theory is chosen on condition that there is only the combination logging data of acoustic and induction; the W-S model is chosen on condition that there is all-around logging data. The calculational precision of oil saturation in low resistivity reservoir of work area is enhanced when the selection method is utilized. There are 1212 layers of reservoir newly added by the old well reexamination in the ten oil areas. The coincidence rate of logging interpretation reaches 83.2 percent according to the 74 well-times of oil testing or commissioning, which indicates that the distinguishing method and evaluation models of low resistivity reservoir above are feasible.By the reexamination, a ten million tons of proved reserves related to the low resistivity reservoir are newly added, consequently, the groundwork is established to increase reserve and production of old oilfields in the east of China and new livingness is added for the petroleum exploration and development in Dongpu depression.

海上时移地震综合解释技术研究与应用

The practical application and development of the time-lapse seismic reservoir monitor technology has indicated which has already become one of most important development technologies in seeking the surplus oil distribution and improving the reservoir recovering. The paper, first obtained the rock physics experiment analysis data according to the Bohai Sea loose sandstone in-situ measure technical, and determined the feasibility research of the S oil-field on the time-lapse seismic reservoir monitoring combining with the time-lapse numeric simulation technology, which was used to analyze the time-lapse seismic respond raw of the reservoir parameters change and pointed out the attentive problems during the real time-lapse seismic processing and interpretation. Next, simply introduced the technical link and the effect of the time-lapse mutual constrained fidelity and match processing aiming at the local complex gathering condition, geological condition, development engineering condition. Third, introduced the time-lapse integrated interpretation and the technical system with the innovative key technology that includes the time-lapse difference explanation technology, the time-lapse seismic multi-attributes integrated interpretation technology, and the time-lapse constrained reservoir parameters inversion technology, and so on. Using the time-lapse difference direct explanation technology, directly obtained the surplus oil macroscopic distribution through the difference seismic data; Using the presenting 8 big principles of the sublayer isochronisms comparison, carried on the time-lapse integrated interpretation analysis on the fine sublayer comparison and the thin oil-layer(group) contrast and the oil layer (group); The paper putted up the research, contrast, applications of the multi-sides sensitive attribute analysis and the RBF nerve network on the nearest study algorithm, and predicted the reservoir parameters and the surplus oil distribution with them; Combining with innovative researches and the time-lapse seismic constrained reservoir parameters inversion technology realized the good combination of the seismic and the reservoir engineering. Fourth, under fully analyzing the geology condition, the reservoir condition, the exploit dynamic data, and the seismic data of the S oil-field, and analyzing the time-lapse difference factors with reservoir dynamic exploit data, calibrated the oil-gas saturation change, the pressure change, the water saturation change, and determined the rationality of the time-lapse seismic difference, and finally obtained the surplus oil distribution, the water flood characteristic understanding, reservoir degasification, and pressure drop raw, and so on, which had been used in the well pattern tightening plan proof of the S oil-field development adjustment plan. Finally, the paper summarized the knowledge and understanding of the marine time-lapse seismic integrated interpretation, also had pointed out the further need researched question.