Seasonal and interannual variability of primary and export production in the South China Sea: a three-dimensional physical-biogeochemical model study

To investigate the seasonal and interannual variations in biological productivity in the South China Sea (SCS), a Pacific basin-wide physical - biogeochemical model has been developed and used to estimate the biological productivity and export flux in the SCS. The Pacific circulation model, based on the Regional Ocean Model Systems (ROMS), is forced with daily air-sea fluxes derived from the NCEP (National Centers for Environmental Prediction) reanalysis between 1990 and 2004. The biogeochemical processes are simulated with a carbon, Si(OH)(4), and nitrogen ecosystem (CoSiNE) model consisting of silicate, nitrate, ammonium, two phytoplankton groups (small phytoplankton and large phytoplankton), two zooplankton grazers (small micrograzers and large mesozooplankton), and two detritus pools. The ROMS-CoSiNE model favourably reproduces many of the observed features, such as ChI a, nutrients, and primary production (PP) in the SCS. The modelled depth-integrated PP over the euphotic zone (0-125 m) varies seasonally, with the highest value of 386 mg C m (-2) d (-1) during winter and the lowest value of 156 mg C m (-2) d (-1) during early summer. The annual mean value is 196 mg C m (-2) d (-1). The model-integrated annual mean new production (uptake of nitrate), in carbon units, is 64.4 mg C m (-2) d (-1) which yields an f-ratio of 0.33 for the entire SCS. The modelled export ratio (e-ratio: the ratio of export to PP) is 0.24 for the basin-wide SCS. The year-to-year variation of biological productivity in the SCS is weaker than the seasonal variation. The large phytoplankton group tends to dominate over the smaller phytoplankton group, and likely plays an important role in determining the interannual variability of primary and new production.

Strain H-2-419-4 of Haematococcus pluvialis induced by ethyl methanesulphonate and ultraviolet radiation

Two strains H-2-410 and H-2-419 were obtained from the chemically mutated survivors of wild Haematococcus pluvialis 2 by using ethyl methanesulphonate (EMS). Strains H2-410 and H2-419 showed a fast cell growth with 13% and 20% increase in biomass compared to wild type, respectively. Then H-2-419-4, a fast cell growth and high astaxanthin accumulation strain, was obtained by exposing the strain H2-419 to ultraviolet radiation (UV) further. The total biomass, the astaxanthin content per cell, astaxanthin production of H-2-4194 showed 68%, 28%, and 120% increase compared to wild H. pluvialis 2, respectively. HPLC (High Performance Liquid Chromatography) data showed also an obvious proportional variation of different carotenoid compositions in the extracts of H2-4194 and the wild type, although no peak of carotenoids appeared or disappeared. Therefore, the main compositions in strain H-2-419-4, like its wild one, were free of astaxanthin, monoester, and diester of astaxanthin. The asexual reproduction in survivors after exposed to UV was not synchronous, and different from the normal synchronous asexual reproduction as the mother cells were motile instead of non-motile. Interestingly, some survivors from UV irradiation produced many mini-spores (or gamete?), the spores moved away from the mother cell gradually 4 or 5 days later. This is quite similar to sexual reproduction described by Elliot in 1934. However, whether this was sexual reproduction remains questionable, as no mating process has been observed.

Growth and survival of reciprocal crosses between two bay scallops, Argopecten irradians concentricus Say and A-irradians irradians Lamarck

A complete diallel cross between two bay scallop populations, Argopecten irradians concentricus Say (M) and A. irradians irradians Lamarck (C), was carried out. Growth and survival were compared among hybrids and pure populations. No significant difference in the shell length was found among the four groups on the first day of D-larvae. On day 10, shell lengths of the two reciprocal crosses (CM, MC)(female x male ) were significantly greater than those of the CC (141.97 mu m) and MM (146.20 mu m) groups, with the growth rate of the MC (156.14 mu m) cross greater than that of the CM (155.35 mu m) cross. Also, heterosis for survival was significantly larger than that for growth. Both maternal origin and mating strategy had significant effects on growth and survival throughout the whole larval stage. Heterosis was also observed in later spat and adult stages. On day 170, the mean shell length, shell height and total weight of the CM cross were significantly larger than those of the other crosses (P<0.05). The results from this study indicate that hybridization between A. irradians concentricus and A. irradians irradians may be a promising way for genetic improvement of existing bay scallop brood stocks in China. (c) 2007 Elsevier B.V. All rights reserved.

青海家牦牛HIF-1α基因组织特异性表达

[目的]探究青海家牦牛HIF-1α基因组织的特异性表达。[方法]应用半定量反转录PCR和实时定量反转录PCR（SYBRGreen）技术对青海家牦牛HIF-1α基因的组织特异性表达进行检测。通过提取不同组织总RNA，经DNase I消化后，用随机引物进行反转录合成cDNA，采用特异性引物分别对HIF-1α和β-actin基因进行RT-PCR和Real Time RT-PCR扩增。[结果]结果表明，HIF-1α基因在心、肝、脾、肺、肾、脑、肌肉、睾丸组织中均有表达，其中以睾丸和脾中HIF-1α基因表达量最高，肌肉的表达量最低。[结论]该研究为进一步揭示HIF-1α在高原土著动物低氧适应过程中的分子机制有着重要的意义。

Potential refugium on the Qinghai-Tibet Plateau revealed by the chloroplast DNA phylogeography of the alpine species Metagentiana striata (Gentianaceae)

Metagentiana striata is an alpine annual herbaceous plant endemic to the east of the Qinghai-Tibet (Q-T) Plateau and adjacent areas. The phylogeography of M. striata was studied by sequencing the chloroplast DNA (cpDNA) trnS-trnG intergenic spacer. Ten haplotypes were identified from an investigation of 232 individuals of M. striata from 14 populations covering the entire geographical range of this species. The level of differentiation amongst populations was very high (G(ST) = 0.746; N-ST = 0.774) and a significant phylogeographical structure was observed (P < 0.05). An analysis of molecular variance found a high variation amongst populations (76%), with F-ST = 0.762 (highly significant, P < 0.001), indicating that little gene flow occurred amongst the different regions; this was explained by the isolation of populations by high mountains along the Q-T Plateau and adjacent areas (N-m = 0.156). Only one ancestral haplotype (A) was common and widespread throughout the distributional range of M. striata. The populations of the Hengduan Mountains region of the south-eastern Q-T Plateau showed high diversity and uniqueness of haplotypes. It is suggested that this region was the potential refugium of M. striata during the Quaternary glaciation, and that interglacial and postglacial range expansion occurred from this refugium. This scenario was in good agreement with the results of nested clade analysis, which inferred that the current spatial distribution of cpDNA haplotypes and populations resulted from range expansion, together with past allopatric fragmentation events. (c) 2008 The Linnean Society of London.

Molecular evidence for double maternal origins of the diploid hybrid Hippophae goniocarpa (Elaeagnaceae)

Homoploid hybrid plant species are rare, and the mechanisms of their speciation are largely unknown, especially for homoploid hybrid tree species. Two contrasting hypotheses have been proposed to explain the origin of Hippophae goniocarpa: (1) it is a diploid hybrid originating from H. rhamnoides ssp. sinensis x H. neurocarpa ssp. neurocarpa, and (2) it originated via marginal differentiation from H. rhamnoides ssp. sinensis. Regardless of which of these hypotheses is true (if either), previous studies have suggested that H. rhamnoides ssp. sinensis is the only maternal donor for this hybrid species. In this study, we aim to elucidate the maternal composition of H. goniocarpa and to test the two hypotheses. For this purpose, we sequenced the maternal chloroplast DNA trnL-F region of 75 individuals representing H. goniocarpa, H. rhamnoides ssp. sinensis, and H. neurocarpa ssp. neurocarpa in two co-occurring sites of the taxa. Seven haplotypes were identified from three taxonomic units, and their phylogenetic relationships were further constructed by means of maximum parsimony, maximum likelihood, and network analyses. These seven haplotypes clustered into two distinct, highly divergent lineages. Two haplotypes from one lineage were found in H. rhamnoides ssp. sinensis, and five (representing the other lineage) in H. neurocarpa ssp. neurocarpa. Hippophae goniocarpa shared four common haplotypes from both lineages, but the haplotypes detected from the two populations differed to some extent, and in each case were identical to local haplotypes of the putative parental species. Thus, both H. rhamnoides ssp. sinensis and H. neurocarpa ssp. neurocarpa appear to have together contributed to the maternal establishment of H. goniocarpa. These results clearly demonstrate that the marginal origin hypothesis should be rejected, and support the hybrid origin hypothesis. Hippophae goniocarpa exhibits a sympatric distribution with its two parent species, without occupying new niches or displaying complete ecological isolation. However, this species has effectively developed reproductive isolation from its sympatric parent species. Our preliminary results suggest that H. goniocarpa may provide a useful model system for studying diploid hybrid speciation in trees. (c) 2008 The Linnean Society of London.

Patterns of genetic variation in Swertia przewalskii, an endangered endemic species of the Qinghai-Tibet Plateau

Swertia przewalskii Pissjauk. (Gentianaceae) is a critically endangered and endemic plant of the Qinghai-Tibet Plateau in China. RAPD and ISSR analyses were carried out on a total of 63 individuals to assess the extent of genetic variation in the remaining three populations. Percentage of polymorphic bands was 94% (156 bands) for RAPD and 96% (222 bands) for ISSR. A pairwise distance measure calculated from the RAPD and ISSR data was used as input for analysis of molecular variance (AMOVA). AMOVA indicated that a high proportion of the total genetic variation (52% for RAPD and 56% for ISSR) was found among populations; pairwise Phi(ST) comparisons showed that the three populations examined were significantly different (p < 0.001). Significant genetic differentiation was found based on different measures (AMOVA and Hickory theta(B)) in S. przewalskii (0.52 on RAPD and 0.56 on ISSR; 0.46 on RAPD and 0.45 on ISSR). The differentiation of the populations corresponded to low average gene flow (0.28 based on RAPD and 0.31 based on ISSR), whereas genetic distance-based clustering and coalescent-based assignment analyses revealed significant genetic isolation among populations. Our results indicate that genetic diversity is independent of population size. We conclude that although sexual reproduction and gene flow between populations of S. przewalskii are very limited, they have preserved high levels of genetic diversity. The main factors responsible for the high level of difference among populations are the isolation and recent fragmentation under human disturbance.

动态环境下移动机器人自主规划方法研究

动态环境下的自主规划方法是移动机器人研究的重要方向之一。如何将机器人自身的本体（动力学）能力、以及周边动态环境作为优化行为产生的约束，并提高优化过程的实时性，是目前有待深入研究的主要问题。针对这两方面问题，本文提出了三种新的自主规划方法，旨在逐步实现在具有本体动力学和动态环境约束情况下的优化算法实时性与最优性的统一。 首先，针对基于进化计算（EA）方法解决动态路径规划问题中的实时性问题以及人工势场（AP）法的优化和局部极小问题，提出了用AP引导EA的搜索方法（APEA）。该方法把人工势场与EA搜索相结合，在传统EA中加入势场作为引导，使搜索沿着势场方向进行，从而得到一条相对于搜索区域的次优轨迹。APEA方法借鉴了AP的快速性和EA的优化性，改善了单纯EA法盲目搜索的缺陷，提高了收敛率和实时性。通过仿真对APEA和单纯EA两种搜索方法的性能进行了比较，结果表明APEA方法在处理动态多障碍物问题时相对单纯EA方法具有实时、高效、收敛的特点，同时在很大程度上解决了单纯AP方法在解决多障碍物问题时的局部极小问题。 其次，为弥补APEA方法的次最优性以及进一步提高算法的实时性，本文提出了相对速度坐标系下基于混合整数线性规划（MILP）的最优轨迹产生方法。在相对速度坐标系下，把动态环境下机器人路径规划这一非线性问题，描述成满足一组线性约束同时使目标函数极小的线性规划问题，嵌入基于MILP的规划器，从而得到一条满足性能要求的最优路径。仿真结果验证了算法的实用性及有效性，与势场引导进化计算方法相比较表明，该方法的优化程度更高、实时性更好。 第三，基于认知仿生的研究成果，将人基于知识经验的优化决策机制引入到机器人的轨迹规划中来，提出了基于离线训练知识库、在线智能发育以及利用知识引导优化的移动机器人自主智能发育方法。给出了复杂环境下移动机器人路径规划问题的自主智能发育模型。介绍了基于递增分层判别回归（IHDR）知识表达、存储、积累、更新机制，以及用于轨迹规划问题时的离线训练、在线知识更新以及知识检索过程，同时提出了性能评价指标，从而形成一套完整的面向轨迹规划的自主智能发育机制。对于一个新的机器人本体，通过对其路径规划技能的离线训练，使这种知识存储于IHDR内，从而产生一定的自主路径规划能力。当机器人需要完成某种规划任务时，根据外部环境以及自身状态的不同，在其内部知识库中检索到最匹配的状态，与之对应的行为作为被选行为，通过一定的评价指标进行评价：若达到一定的满意度，机器人即采用该行为；若不能达到评价指标的要求，则需要通过重新学习，对知识库进行更新补充，以达到对新情况的很好应对。 最后，利用上述自主智能发育模型从直接规划和间接规划两方面对动态环境中移动机器人的路径规划问题进行研究，并对于不同的规划目的提出了不同的自主规划模型和评价机制。所谓直接规划是指利用知识库检索直接得出机器人的具体行为，作为规划结果指导机器人前进；间接规划则是将检索结果作为一种优化指导，从而减小最优规划算法（如进化算法、线性规划等方法）的搜索空间，降低计算量，从而达到在线计算的目的。仿真结果验证了两种方法的有效性，并说明了这种自主智能发育模型具有很强的自适应、自学习能力。

大别山碰撞造山带逆冲推覆构造运动学和动力学研究

Since the discovery of coesite-bearing eclogites in Dabie and Sulu region over ten years ago, the Dabie collisional orogen has been the "hot-spot" across the world. While many great progresses have been made for the last decade in the researches on the Dabie and Sulu UHP metamorphic rocks in the following fields, such as, petrology, mineralogy, isotope chronology, and geochemistry, the study of the structural geology on the Dabie orogen is still in great need. Thrust and nappe tectonics commonly developed in any collisional orogenic belt during the syncollisional process of the orogen. It is the same as the Dabic collisional orogen is concerned. The paper put much stress on the thrust and nappe tectonics in the Dabic orogenic belt, which have been seldom systematically studied before. The geometric features including the division and the spatial distribution of various thrust and nappe tectonics in the Dabie orogen have been first studied, which is followed by the detailed studies on their kinematic characteristics in different scales varying from regional tectonics to microtectonics. In the thesis, new deformation ages have been obtained by the isotopic methods of ~(40)Ar-~(39)Ar, Sm-Nd and Rb-Sr minerals-whole rock isochrons on the mylonites formed in three ductile shear zones which bounded three different major nappes in the Dabie collisional orogenic belt. And the petrological, geochemical characteristics of some metamorphic rocks as well as the geotectonics of their protoliths, which have also deformed in the ductile shear zone, are analyzed and discussed. In the paper, twelve nappes in the Dabie orogen are first divided, which are bounded by various important NWW or NW-strike faults and three NNE-strike faults. They are Shangcheng Nappe, Huoshan Nappe, Yuexi Nappe, Yingshanjian-Hengzhong Nappe, Huangzhen Nappe, Xishui-Huangmei Nappe, Zhoudang Nappe, Suhe-Huwan Nappe, Xinxian Nappe, Hong'an Nappe, Mulan Nappe and Hhuangpi-Susong Nappe. In the Dabie orogen, three types of thrust and nappe tectonics belonging to two stages have been confirmed. They are: (1) early stage ductile thrust -nappe tectonics which movement direction was top-to-the-south; (2) late stage brittle to ductile-brittle thrust-nappe tectonics which are characterized by double-vergence movement, including top-to-the-north and top-to-the-south; (3) the third type also belongs to the late stage which also characterized by double-vergence movement, including top-to-the-east and top-to-the-west, and related to the strike-slip movement. The deformation ages of both Wuhe-Shuihou ductile shear zone and Taihu-Mamiao ductile shear zone have been dated by ~(40)Ar-~(39)Ar method. ~(40)Ar/~(39)Ar plateau ages of biotite and mica from the mylonites in these two shear zones are 219.57Ma and 229.12Ma. The plateau ages record the time of ductile deformation of the ductile shear zones, which made the concerned minerals of the mylonites exhume from amphibolite facies to the middle-upper crustal conditions by the early stage ductile thrust-nappe tectonics. The mineral isochons of Sm-Nd and Rb-Sr dating on the same mylonite sample of the metamafic rocks are 156.5Ma and 124.56Ma respectively. The two isochron ages suggest that the mylonitic rock strongly deformed in the amphilbolite facies at 156Ma and then exhumed to the upper crustal green schist condition at 124Ma with the activities of the Quiliping-Changlinggang ductile shear zone which bounded to the southen edge of Xinxian Nappe. Studies of the petrological and geochemical characteristics of some meta-mafic rocks and discussion on the geotectonics of their protoliths indicate that their protoliths were developped in an island arc or back-arc basin or active continental margin in which calc-alkline basalts formed. This means that arc-accretion orogeny had evolved in the margins of North china plate and/or Yangtze plate before these two plates directly collided with each other during the evolution process of Dabie orogen. Three-stage evolution of the thrust-nappe tectonics in Dabie collisional orogen has been induced based on the above-mentioned studies and previous work of others. And a possible 3-stage exhumation model (Thrust-Positive Flower Structure Model) has also been proposed.

晚震旦世至早寒武世扬子地台北缘碳同位素研究

震旦-寒武交变期是地史上一个重大转折期，亦是一个具有特殊意义的过渡时期。运用碳同位素地球化学方法，探讨扬子地台北缘四川南江地区晚震旦世-早寒武世交变期，碳同位素地球化学异常与环境变化和生物演化的相互联系。南江剖面沉积岩有机碳同位素组成在-35．8‰～-30．1‰间变化；碳酸盐碳同位素组成从-3．5‰～+0．5‰。在灯影组顶部、牛蹄塘组下部和上部，变化的碳、硫同位素组成和不同的黄铁矿与有机碳含量反映了有机碳埋藏量和环境的变化。下寒武统富有机碳和黄铁矿的黑色页岩沉积，暗示了早寒武世早期缺氧环境的存在。

贵阳市大气中气态汞形态分布特征的初步研究

2002年3月份我们对贵阳市大气的气态汞形态进行了采样分析。大气气态总汞用Tekran537A大气自动测汞仪采集测定。活性气态汞用镀KCl扩散管采集，热还原法分解并以冷原子荧光法(CVAFS)分析。结果显示，采样期间贵阳市气态总汞平均浓度为7．09ng/m^3，活性气态汞平均含量38．3pg/m^3。气态总汞浓度远高于全球背景浓度值；活性气态汞浓度稍高于欧洲和美国的边远地区。活性气态汞浓度与大气相对湿度呈负相关关系，相关系数为—0．39(α＜0．01)。由于大气相对湿度较高，活性气态汞只占气态总汞的0．5％。原子态汞和活性气态汞的基本来源是燃煤释放。

华南白垩一第三纪地壳拉张与铀成矿的关系

华南是中国最重要的铀矿产区之一。按赋矿围岩的不同，该区主要产出花岗岩型、火山岩型和碳硅泥岩型3类铀矿床。铀矿区都分布有比铀成矿超前形成的富铀岩石；铀矿床成矿热液中的水主要为大气成因地下水，成矿温度约为120~250 C，成矿热液的δ13C值主要为～4‰～ 一8‰ ，表明幔源Co2参与了成矿作用；矿床的N(。He)／N( He)为0．10～2．02 R ，显示成矿热液中大量幔源He的存在。这些铀矿床的成矿时代与赋矿围岩的岩性和时代无关，都集中在该区地壳受到强烈拉张因而断陷盆地广泛发育并伴有幔源基性岩浆活动(基性脉岩、玄武岩)的白垩一第三纪。研究表明，白垩一第三纪导致了地幔与地壳表层沟通的地壳拉张，把该区3大类型的铀矿床串联成了一个有机的整体：(1)地壳拉张通过控制向大气成因的贫C 热液提供铀成矿必不可少的幔源Co2，而与铀成矿发生联系；(2)同一机制形成的富Co2热液浸取同一或不同铀源岩石中的铀并在不同围岩中成矿，形成了按赋矿围岩划分的各种矿床类型(花岗岩型、火山岩型和碳硅泥岩型)。

硒资源及其开发利用概况

硒是一种稀少而又分散的元素，在各种地球化学样品中含量甚微，在自然界它不易形成独立矿物而分散于其他矿物和介质中，早年人们只知道硒及其化合物的毒性，20世纪到50年代才发现硒还是动物和人体所必需 的一种元素，它对生物生长和人体健康的显著作用，已经引起医学、地学、农业和生物等方面学者的关注，目前已被广泛应用于玻璃工业、冶金工业、电子工业、国防工业、化工、医学和农业等。