试用500hPa高度资料做中长期雾日预测

利用鲁西南地区雾日与同期、前期全球500hPa高度资料，统计得出欧亚大陆槽脊位置，亚洲南北两支锋区的位置、强度、走向等与鲁西南地区雾日密切相关，并选取优势因子建立鲁西南地区月、旬、候雾日预测方程，试报结果表明，用前期全球500hPa高度资料预测雾日具有一定的效果。     

岱海的"中世纪暖期"

内蒙古岱海沉积物近2200a来Rb/Sr比值、CaCO3和有机碳含量的变化展现了包括中世纪暖期（MWP）及小冰期（LIA）等典型气候事件在内的环境演化过程,总体表现为暖期的沉积物Rb/Sr比值低,冷期的则高：CaCO3和有机碳含量则相反。这里,以单一流域化学风化记录表明我国北方存在明显的中世纪暖期,发生时间约900－1200aB.P..主要环境特征表现为流域化学风化的显著增强（低Rb/Sr比值）、生物生产力逐步提高（高有机碳）、湖泊水位大幅度抬升的湖泊沉积记录,其间经历的化学风化是近两千年内最强的,并且其发生时间与全球其他地区基本一致。     

Comparative assessment of nitrogen fixation rate by 15N2 tracer assays in the South China Sea

Nitrogen fixation is one of the most important sources of new nitrogen in the ocean and thus profoundly affects the nitrogen and carbon biogeochemical processes. The distribution, controlling factors, and flux of N₂ fixation in the global ocean remain uncertain, partly because of the lack of methodological uniformity. The 15N₂ tracer assay (the original bubble method → the 15N₂-enriched seawater method → the modified bubble method) is the mainstream method for field measurements of N₂ fixation rates (NFRs), among which the original bubble method is the most frequently used. However, accumulating evidence has suggested an underestimation of NFRs when using this method. To improve the availability of previous data, we compared NFRs measured by three 15N₂ tracer assays in the South China Sea. Our results indicate that the relationship between NFRs measured by the original bubble method and the 15N₂-enriched seawater method varies obviously with area and season, which may be influenced by incubation time, diazotrophic composition, and environmental factors. In comparison, the relationship between NFRs measured by the original bubble method and the modified bubble method is more stable, indicating that the N₂ fixation rates based on the original bubble methods may be underestimated by approximately 50%. Based on this result, we revised the flux of N₂ fixation in the South China Sea to 40 mmol/(m2·a). Our results improve the availability and comparability of literature NFR data in the South China Sea. The comparison of the 15N₂ tracer assay for NFRs measurements on a larger scale is urgently necessary over the global ocean for a more robust understanding of the role of N₂ fixation in the marine nitrogen cycle.     

Controlling factors on the charging process of oil and gas in the eastern main sub-sag of the Baiyun Sag,Zhujiang River (Pearl River) Mouth Basin

The eastern main sub-sag (E-MSS) of the Baiyun Sag was the main zone for gas exploration in the deep-water area of the Zhujiang River (Pearl River) Mouth Basin at its early exploration stage, but the main goal of searching gas in this area was broken through by the successful exploration of the W3-2 and H34B volatile oil reservoirs, which provides a new insight for exploration of the Paleogene oil reservoirs in the E-MSS. Nevertheless, it is not clear on the distribution of “gas accumulated in the upper layer, oil accumulated in the lower layer” (Gas_upper-Oil_lower) under the high heat flow, different source-rock beds, multi-stages of oil and gas charge, and multi-fluid phases, and not yet a definite understanding of the genetic relationship and formation mechanism among volatile oil, light oil and condensate gas reservoirs, and the migration and sequential charge model of oil and gas. These puzzles directly lead to the lack of a clear direction for oil exploration and drilling zone in this area. In this work, the PVT fluid phase, the origin of crude oil and condensate, the secondary alteration of oil and gas reservoirs, the evolution sequence of oil and gas formation, the phase state of oil and gas migration, and the configuration of fault activity were analyzed, which established the migration and accumulation model of Gas_upper-Oil_lower co-controlled by source and heat, and fractionation controlled by facies in the E-MSS. Meanwhile, the fractionation evolution model among common black reservoirs, volatile reservoirs, condensate reservoirs and gas reservoirs is discussed, which proposed that the distribution pattern of Gas_upper-Oil_lower in the E-MSS is controlled by the generation attribute of oil and gas from source rocks, the difference of thermal evolution, and the fractionation controlled by phases after mixing the oil and gas. Overall, we suggest that residual oil reservoirs should be found in the lower strata of the discovered gas reservoirs in the oil-source fault and diapir-developed areas, while volatile oil reservoirs should be found in the deeper strata near the sag with no oil-source fault area.     

南海西北部水域斑节对虾资源的调查研究

1989－1991年对南海西北部水域进行斑节对虾Penaeusmonodon资源专项调查。结果表明,斑节对虾的密集分布区在海南岛东部和南部海区,其现存资源量为82．6万尾,周年有体长30mm以下的幼虾出现。主要产卵期在9－12月。产卵场在海南岛东部和南部水深30-60m的海区。     

Mapping QTLs of caudal fin length in common carp (Cyprinus carpio L.)

Common carp (Cyprinus carpio L.) exhibits significant morphological variability in the shape and size of the caudal fin. In this study, we used 190 progeny from two F₁ parents to identify and map quantitative trait loci (QTLs) that influence caudal fin length (CFL) and the ratio (RCS) between caudal fin length and standard length (SL) based on a microsatellite genetic map of common carp. A total of 15 QTLs were detected in seven different linkage groups. One significant and eight suggestive QTLs affecting CFL were identified on LG8, LG14, LG29, LG32 and LG44, which explained 8.0%–22.1% of the phenotypic variation; six suggestive QTLs affecting RCS were detected on LG8, LG32, LG46 and LG48, which explained 7.0%–15.4% of the phenotypic variation. The QTLs for caudal fin length detected in this study may serve as a starting point for identification of genes involved in caudal fin development in common carp.     

An experimental study on microscopic characteristics of gas-bearing sediments under different gas reservoir pressures

Gas-bearing sediments are widely distributed in five continents all over the world. Most of the gases exist in the soil skeleton in the form of discrete large bubbles. The existence of gas-phase may increase or decrease the strength of the soil skeleton. So far, bubbles’ structural morphology and evolution characteristics in soil skeleton lack research, and the influence of different gas reservoir pressures on bubbles are still unclear. The micro characteristics of bubbles in the same sediment sample were studied using an industrial CT scanning test system to solve these problems. Using the image processing software, the micro variation characteristics of gas-bearing sediments in gas reservoir pressure change are obtained. The results show that the number and volume of bubbles in different equivalent radius ranges will change regularly under different gas reservoir pressure. With the increase of gas reservoir pressure, the number and volume of tiny bubbles decrease. In contrast, the number and volume of large bubbles increase, and the gas content in different positions increases and occupies a dominant position, driving the reduction of pore water and soil skeleton movement.     

基于稳定同位素方法的吕泗渔场近岸海域主要生物潜在碳源及营养级分析

基于稳定同位素方法,对2018年吕泗渔场近岸海域夏季主要生物种类的潜在碳源及其营养级进行分析,利用IsoSource模型计算该海域消费者的3大碳源（浮游植物、悬浮颗粒有机物、底质有机物）贡献值,并比较叠加潜在碳源影响前后主要生物种类的营养级变化。结果表明,浮游植物和底质有机物对37种主要生物种类的贡献比例分别为58.7%和28.2%,而悬浮颗粒有机物的贡献较小。因此判定吕泗渔场近岸海域夏季主要生物种类的潜在碳源主要是浮游植物和底质有机物。通过分别叠加3大潜在碳源和单一物种作为基准值构建两个营养级谱,右营养级谱的生物种类营养级范围为1.74～3.92,比左营养级谱平均下降0.19个营养级,尽管两个营养级谱的整体趋势走向不变,但部分鱼类和多数虾类的营养位置发生改变。右营养级谱的基准值随着潜在碳源叠加比例的不同而变化,能有效反映生物营养级,更适用于低营养级的虾蟹类。但对于处于中高级消费者位置的鱼类来说,这种叠加的效果影响不大。     

Characteristics and origins of middle Miocene mounds and channels in the northern South China Sea

Numerous elongated mounds and channels were found at the top of the middle Miocene strata using 2D/3D seismic data in the Liwan Sag of Zhujiang River Mouth Basin(ZRMB) and the Beijiao Sag of Qiongdongnan Basin(QDNB). They occur at intervals and are rarely revealed by drilling wells in the deepwater areas. Origins of the mounds and channels are controversial and poorly understood. Based on an integrated analysis of the seismic attribute, palaeotectonics and palaeogeography, and drilling well enco...     

Coherent control of non-resonant two-photon transition in molecular system

In this paper, we study theoretically and experimentally the coherent control of non-resonant two-photon transition in a molecular system (Perylene dissolved in chloroform solution) by shaping the femtosecond pulses with simple phase patterns (cosinusoidal and π phase step-function shape). The control efficiency of the two-photon transition probability is correlated with both the laser field and the molecular absorption bandwidth. Our results demonstrate that, the two-photon transition probability in a molecular system can be reduced but not completely eliminated by manipulating the laser field, and the control efficiency is minimal when the molecular absorption bandwidth is larger than twice the laser spectral bandwidth.