Chinikomycins A and B: Isolation, structure elucidation, and biological activity of novel antibiotics from a marine Streptomyces sp isolate M045

In our screening of marine Streptomycetes for bioactive principles, two novel antitumor antibiotics designated as chinikomycins A (2a) and B (2b) were isolated together with manumycin A (1), and their structures were elucidated by a detailed interpretation of their spectra. Chinikomycins A (2a) and B (2b) are chlorine-containing aromatized manumycin derivatives of the type 64-pABA-2 with an unusual para orientation of the side chains. They exhibited antitumor activity against different human cancer cell lines, but were inactive in antiviral, antimicrobial, and phytotoxicity tests.

Construction of AFLP-based genetic linkage map for Zhikong scallop, Chlamys farreri Jones et Preston and mapping of sex-linked markers

Zhikong scallop (Chlamys farreri) is an economically important aquaculture species in China; however, frequent mass mortality seriously affects the development of its industry. Genetic linkage map is useful for genetic improvement and selective breeding of C. farreri. Linkage maps were constructed using an intraspecific F-1 cross and amplified fragment length polymorphism (AFLP) markers. Thirty-two selected AFLP primer combinations produced 545 AFLP markers that were polymorphic in either of the parents and segregated in the progeny. Of these segregating markers, 166 were mapped to 19 linkage groups of the female framework map, covering a total of 1503.9 cM, with an average marker spacing of 10.2 cM; and 197 markers were assigned to 20 linkage groups of the male map, covering a total of 1630.7 cM, with 9.2 cM per marker. A sex-linked marker was mapped on the female map with zero recombination and a LOD of 27.3. The genetic length of C farreri genome was estimated as 1889.0 cM for the female and 1995.9 cM for the male. The coverage of the framework map was calculated as 79.6% for the female and 81.7% for the male. When the triplets and doublets were considered, the observed length of the map was calculated as 1610.2 cM with coverage of 85.2% for the female, and 1880.5 cM with coverage of 94.2% for the male. The genetic maps presented here will serve as a basis for the construction of a high-resolution genetic map and mapping of economically important genes. (C) 2004 Published by Elsevier B.V.

渤海南部海域沉积物-海水界面附近磷、硅赋存形态及其生物地球化学过程研究

本文系统研究了渤海南部海域沉积物-海水界面附近（包括上覆水、悬浮颗粒物和沉积物）P、Si的赋存形态及其生物地球化学过程。其特色在于提出了“自然粒度下形态研究”的概念，探讨了能真正参与循环的P、Si及其控制关键环节，为渤海资源特别是生物资源的可持续利用战略的制定提供理论基础。得到的主要结论包括：研究了渤海南部海域覆水、悬浮颗粒物中P、Si的变异特征。上覆水体PO_4-P、SiO_3-Si的平均含量均低于大洋底层水PO_4-P、SiO_3-Si的平均含量。悬浮颗粒物中TIP、BP的来源和循环控制机制不同，TISi、BSi有一定的相似性。稀释作用和表层沉积物中可交换态P、Si的循环控制上覆水体中P、Si的地球化学行为。颗粒物中TIP、TISi的行为受离子交换和化学吸附过程影响，其中化学吸附可能与Fe（III）的氧化物有关；生物过程对颗粒物中生源P、Si的地球化学行为有重要影响。渤海南部海域沉积物P、Si的分布特征及其成岩过程研究表明。表层沉积物可交换态磷中，OSF-P是磷的优势赋存形态，占总磷的10.7%；CF-Si是硅的优势赋存形态，占总硅的0.05%。 不同形态P的成岩过程有一定的相似性。TSi与其它相中的Si呈负相关或不呈显著相关，且可交换态Si的量仅占总Si的0.12%以下，说明以往采用测定总Si含量来研究Si的生物地球化学过程不可能得出有价值的信息。IMOF-P、OSF-P、IMOF-Si、CF-Si在P、Si的生物地球化学循环中有重要作用。CaCO_3、Fe（III）和Corg等对P、Si界面循环有重要影响，有机质的钙化导OSF-P的矿化作用而释放P；Fe（III）的还原引起IMOF-P， CF-P和CF-Si对P、Si的释放。Corg的成岩过程对CF-Si有影响。约79%的BP和75%的BSi沉积后转化为相对稳定状态，在较短时间内不再参与循环。柱状沉积物中，OSF-P和CF-P之间存在沉积转化。CF-Si呈双指数分布。P、Si在表层沉积物中垂向分布的差异，表明底栖生物扰动对加强界面P、Si交换的作用。室内模拟沉积物-海水界面附近P、Si交换过程表明，P、Si在沉积物、上覆海水间的交换通量分别为0.8μ mol/ (m~2 · h)。P、Si的埋藏与释放主要受OSF-P、IMOF-Si 和平共处BSi的影响。对渤海P、Si年循环的估算显示，P在渤海湾、莱州湾的年循环量达30.9 * 10~5kg 和13.8 * 10~5kg， Si则分别为22.8 * 10~7 kg和15.5 * 10~7 kg，这其中沉积物向上覆海水扩散的P占87.7%和87.0%， Si占22.4%和14.2%。就整个渤海而言，沉积物向海水释放的磷、硅在其总循环中分别占88.7%和34.0%，所以沉积物-海水界面过程对磷、硅在渤海的生物地球化学循环有重要影响，是渤海P、Si循环的关键控制过程之一。

Seasonal and spatial distribution of matrix-bound phosphine and its relationship with the environment in the Changjiang River Estuary, China

Sediment is commonly considered as a source of phosphine, which is a highly toxic and reactive atmospheric trace gas. This study aims to investigate the seasonal and spatial distribution of matrix-bound phosphine (MBP) and its relationship with the environment in the Changjiang River Estuary. A total of 43 surface sediments were collected in four seasons of 2006, and concentrations of MBP and relative environmental factors were analyzed. MBP ranged from 1.93 to 94.86 ng kg(-1) dry weight (dw) with an average concentration of 17.14 ng kg(-1) dw. The concentrations of MBP in the tipper estuary were, higher than those in the lower estuary, which could be attributed to greater pollutant inputs in the upper estuary. The concentrations of MBP also varied with season, with November > August > May > February. Significant correlations existed between MBP and total phosphorus (TP), organic phosphorus (OP), inorganic phosphorus (W), organic carbon (OC), total nitrogen (TN), the grain size, and redox potential (Eh), suggesting that these sedimentary environmental characteristics played an important role in controlling the MBP levels in the sediments. Notably, there were positive linear relationships between the concentrations of soluble reactive phosphorus (SRP), TP, and chlorophyll a (Chl a) in bottom water and MBP in sediments. These relationships might be very complicated and need further exploration. This work is the first comprehensive study of the seasonal and spatial distribution of MBP in sediments and its relationships with environmental factors in a typical estuary, and will lead to deeper understanding of the phosphorus (P) biogeochemical cycle. (C) 2008 Elsevier Ltd. All rights reserved.

叠前时间偏移：各向异性、多次波衰减及应用

At present, in order to image complex structures more accurately, the seismic migration methods has been developed from isotropic media to the anisotropic media. This dissertation develops a prestack time migration algorithm and application aspects for complex structures systematically. In transversely isotropic media with a vertical symmetry axis (VTI media), the dissertation starts from the theory that the prestack time migration is an approximation of the prestack depth migration, based on the one way wave equation and VTI time migration dispersion relation, by combining the stationary-phase theory gives a wave equation based VTI prestack time migration algorithm. Based on this algorithm, we can analytically obtain the travel time and amplitude expression in VTI media, as while conclude how the anisotropic parameter influence the time migration, and by analyzing the normal moveout of the far offset seismic data and lateral inhomogeneity of velocity, we can update the velocity model and estimate the anisotropic parameter model through the time migration. When anisotropic parameter is zero, this algorithm degenerates to the isotropic time migration algorithm naturally, so we can propose an isotopic processing procedure for imaging. This procedure may keep the main character of time migration such as high computational efficiency and velocity estimation through the migration, and, additionally, partially compensate the geometric divergence by adopting the deconvolution imaging condition of wave equation migration. Application of this algorithm to the complicated synthetic dataset and field data demonstrates the effectiveness of the approach. In the dissertation we also present an approach for estimating the velocity model and anisotropic parameter model. After analyzing the velocity and anisotropic parameter impaction on the time migration, and based on the normal moveout of the far offset seismic data and lateral inhomogeneity of velocity, through migration we can update the velocity model and estimate the anisotropic parameter model by combining the advantages of velocity analysis in isotropic media and anisotropic parameter estimation in VTI media. Testing on the synthetic and field data, demonstrates the method is effective and very steady. Massive synthetic dataset、2D sea dataset and 3D field datasets are used for VTI prestack time migration and compared to the stacked section after NMO and prestack isotropic time migration stacked section to demonstrate that VTI prestack time migration method in this paper can obtain better focusing and less positioning errors of complicated dip reflectors. When subsurface is more complex, primaries and multiples could not be separated in the Radon domain because they can no longer be described with simple functions (parabolic). We propose an attenuating multiple method in the image domain to resolve this problem. For a given velocity model，since time migration takes the complex structures wavefield propagation in to account, primaries and multiples have different offset-domain moveout discrepancies, then can be separated using techniques similar to the prior migration with Radon transform. Since every individual offset-domain common-reflection point gather incorporates complex 3D propagation effects, our method has the advantage of working with 3D data and complicated geology. Testing on synthetic and real data, we demonstrate the power of the method in discriminating between primaries and multiples after prestack time migration, and multiples can be attenuated in the image space considerably.

波动方程基准面校正方法研究

Datuming which has not been well solved in complex areas is a long-existing problem in seismic processing and imaging. Theoretically, Wave-equation datuming(WED) works well in the areas with substantial surface topography and areas of complex velocity structure. However, many difficulties still exist in practice. There are three main reasons: (1) It’s difficult to obtain the velocity model. (2) The computational cost is high and the efficiency is low. (3) Reflection waveform distortions are introduced by low S/N ratio in seismic data. The second and third problems are involved in the paper. To improve computational efficiency, DP1 proposed by Fu Li-Yun is applied in WED. Some quantitative and semi-quantitative conclusions of assessing the computational accuracy and efficiency have been obtained by comparing the adaptation of three operators( PS, SSF, DP1) to the surface topography and the lateral velocity variation. Moreover, the impacts of near surface scattering associated with complex surface topography on WED is analyzed theoretically. According to the analysis results, the following conclusions have been obtained. WED is stable and effective when the field data has high S/N ratio and velocity model is accurate. However ,it doesn’t work well when S/N ratio of field data is low. So denoising techniques in process of WED is important for low S/N data. The paper presents the theoretical analysis for the issues facing WED, which is expected to provide a useful reference to the further development of this technology.

贵州省遵义市大气降水中有机和无机地球化学特征研究

正确认识降水中的化学组分是评价酸雨和大气环境质量的重要途径，降水中低分子有机酸的研究是认识C、H、O等元素生物地球化学循环和酸雨成因的重要内容。贵州省遵义市作为我国酸雨高发地区，是降水化学组成尤其是低分子有机酸地球化学循环研究的典型区域。我们在遵义市进行了为期一年(2006年5月~2007年4月)的降水采集(共76个样品)，对pH值、电导率和主要的阴离子(包括有机和无机)、阳离子进行了测定，并进行了分析和讨论。 (1) pH和电导率的雨量加权平均值分别为4.11(范围：2.30~ 6.04)和62.10 μs•cm-1 (范围：6.60 ~ 1630.00 μs•cm-1)，酸雨频率高达93.2%，pH存在着显著的季节变化，其中冬季pH值最低，表明遵义市酸雨污染较为严重，冬季为最。 (2) 遵义市监测期间离子浓度的大小顺序为SO42-> Ca2+> H+> NH4+> NO3-> Cl-> F->HCOO-> Mg2+> K+> CH3COO-> Na+> (COO)22-> PO43-> NO2-，其中SO42-、Ca2+、H+、NH4+、NO3-是最主要离子，浓度分别为148.15 μmol•L-1、81.89 μmol•L-1、77.74 μmol•L-1、43.80 μmol•L-1和31.50μmol•L-1，它们分别占离子总量的31.97%、17.67%、16.78%、9.45%和6.54%；遵义市大气降水中主要的致酸物质是SO42-和NO3-，主要的缓冲物质是Ca2+和NH4+，大气污染类型属硫酸钙型。相对酸度和中和因子结果表明降水中仅有77%的降水酸度被碱性物质(以Ca2+和NH4+为主)中和；因子分析中H+、NO3-、nss-SO42-(非海源性硫酸根)、NH4+归为一组，再次表明SO42-和NO3-对降水酸度的重要贡献。富集系数和源的贡献分析表明，SO42-和NO3-主要来自人为活动的贡献，SO42-来源主要包括工业、民用的燃煤燃烧释放的SO2，NO3-主要是遵义市电厂和其它工厂向大气中排放的NOx的化学转化而成。Ca2+主要来自于遵义市的土壤及水泥厂等的排放；Mg2+主要来自陆源输入，部分来自海水的贡献。氮肥生产、大面积农田化肥的使用以及生物排放源很可能是该地区降水中NH4+的主要污染源。值得注意的是，作为海盐性离子的Cl-，在遵义市降水中重要的部分还是人为活动，主要是遵义工厂(如碱厂和钛厂)向大气中排放的HCl和Cl2转化而成。无机离子浓度的季节变化表明，对于遵义市，需要逐步改变能源结构尤其是冬季工业、居民燃煤的使用，才能有效地改善遵义市当前的环境污染。 (3) 遵义市降水中含量较高的常见有机酸是[HCOO-]T、[CH3COO-]T和[(COO)22-]T，它们的雨量加权平均值各为9.29 μmol•L -1、6.47 μmol•L-1和5.06 μmol•L-1；遵义市区降水中有机酸总浓度为22.28 μmol•L-1，占阴离子总量的9.39 %；遵义市降水中四季的有机酸浓度由高到低分别为：春季>冬季>秋季>夏季。以上结果表明，遵义市的有机酸是降水中的重要组成部分，其浓度存在明显的季节性变化。在一次降雨事件中，有机酸的浓度一般随降雨时间的延长而降低，但在降雨中后期有时会出现上升的现象，表明有机酸主要来自云下淋滤作用，少数情况下来自大气远距离的传输。 (4) 相关性分析发现甲酸和乙酸具有强烈的正相关(r= 0.86)，表明甲酸和乙酸具有共同的来源。有机酸与降水中的主要无机离子NO3-、nss-SO42-、K+、Na+、Ca2+等存在着中度相关，表明有机酸的来源与人为活动有着重要的关系。应用气液平衡的原理，提出了降水中甲酸、乙酸比值(F/A)aq的有机酸来源判定方法。发现遵义降水中的有机酸春季和冬季主要来自人类活动的释放，其中春季主要来自遵义市南郊的工业污染，由南方水汽(占春季总量的54%)将其污染物传输至遵义市中心城区，冬季主要是大量燃煤的燃烧释放；夏季和秋季则主要来自植物的释放，其中秋季中的部分有机酸也受到华中和华东地区(其气团占秋季总量的45%)的远距离影响。而遵义市区的山间盆地地形、高湿度、高静风率和低风速、以尘埃为主的大气污染物和有机酸的短生命周期(几小时~几天)为有机酸来源于当地创造了有利条件。 (5) 根据热力学平衡计算新方法，发现遵义市pH≤5的降水中甲酸和乙酸对自由酸度的贡献分别为14.79% (范围：0.42~91.14%)、3.66% (范围：0.02~31.55%)。对比显示，遵义市的有机酸贡献量低于边远地区，主要由于遵义市降水的低pH值和高无机酸度所致。在春、夏、秋、冬季节，降水中的有机酸对自由酸度的平均贡献值分别为31.95%、26.16%、8.02%、11.17%，表明有机酸酸度有着明显的季节性差异，春季有机酸的高贡献量主要受降水中的有机酸高含量、低水温和高pH值的共同作用，夏季受高pH值的影响，而秋季和冬季的低贡献量主要受降水的低pH值所控制。 (6) 在遵义市的沉降通量中，无机离子的湿沉降通量占所有离子湿沉降总量的94%，并存在明显的季节性变化。SO42-、Ca2+、H+、NH4+、NO3-为最主要的贡献者，分别为90.1、49.8、47.3、26.0和19.2 mmol•m-2•yr-1。对比显示，SO42-、Ca2+、H+的沉降量均属于我国的高值区，而NO3-的沉降量属于我国中值区，NH4+的沉降量属我国低值水平。营养元素总无机氮TIN(TIN= NH4+ -N+ NO3- -N+ NO2- -N)的湿沉降总量为45.7 mmol•m-2•yr-1，其中NH4+和NO3-分别占TIN的57.0%和41.9%，遵义地区高TIN值当地氮肥的施用量和工业NOx的释放量密不可分；营养元素P的沉降量为1.97 mmol•m-2•yr-1，由于P的来源较少，促使P的湿沉降通量较低。有机酸占湿沉降总量的6%，其四季的湿沉降量顺序由高到低依次为：春>秋>冬>夏，这是有机离子的浓度和四季的降雨量共同作用的结果。根据气液平衡理论可知，挥发性有机酸(HCOO-、CH3COO-和CH3CH2COO-)的干沉降量占总沉降量的47.2%，表明遵义市有机酸沉降方式包括干湿沉降两种。因此在研究遵义市的污染物尤其是有机酸类对生态系统和城市建设的影响时，有必要同时收集气样和水样。