Black sea: recent sedimentary history

Three distinct sedimentary units, which can be correlated throughout the basin, occur in cores collected from the Black Sea. Carbon-14 ages help to define the recent sedimentary history of the Black Sea.     

Mediation of sulfur speciation by a black sea facultative anaerobe

Shewanella putrefaciens, a respiratory facultative anaerobe isolated from the Black Sea, can reduce thiosulfate, sulfite, and elemental sulfur to sulfide readily and quantitatively. This widespread and anaerobically versatile microorganism, which is incapable of reducing sulfate, uses oxidized sulfur intermediates as electron acceptors during the respiratory oxidation of organic matter. Because of its widespread distribution and abundance, it may play a significant role in sulfur and trace metal cycling in the Black Sea and in other marine and freshwater anaerobic environments.     

GIS在管道工业中的应用

介绍了GIS数据库及从地图、航空照相、卫星遥感获得GIS数据的三种方法及管道工业成功应用GIS的两个事例。美国的西北天然气公司利用GIS使其许多工作自动化,如计算机辅助泄漏检查、管网模型分析、紧急事故响应和系统规划等,GIS已使该公司的工作环境远远超过CAD时代。Bechtel公司在铺设从里海到黑海的原油输送管道时,利用GIS和卫星遥感建立一个最小费用线路的计算机模型。结果表明,利用GIS软件的地面覆盖自动辨别能力和遥感卫星生成的地面覆盖地图建立的线路模型选线,将比在里海与黑海之间采用直线线路的费用少14%。     

7000 years of Emiliania huxleyi viruses in the Black Sea

A 7000-year record of Coccolithovirus and its host, the calcifying haptophyte Emiliania huxleyi, was reconstructed on the basis of genetic signatures preserved in sediments underlying the Black Sea. The data show that the same virus and host populations can persist for centuries. Major changes in virus and host populations occurred during early sapropel deposition, ~5600 years ago, and throughout the formation of the coccolith-bearing sediments of Unit I during the past 2500 years, when the Black Sea experienced dramatic changes in hydrologic and nutrient regimes. Unit I saw a reoccurrence of the same host genotype thousands of years later in the presence of a different subset of viruses. Historical plankton virus populations can thus be included in paleoecological and paleoenvironmental studies.     

乐清湾海域鱼类中多溴联苯醚的分布特征

使用气相色谱-质谱-化学离子源（GC—MS-NCI）检测法对持久性有机污染物多溴联苯醚（PBDEs）的10种同系物（∑10PBDEs）在海洋鱼类（红鲈、黑鲷、鲈鱼）中的含量进行了检测。结果表明,红鲈、黑鲷、鲈鱼肌肉中∑10PBDEs的含量分别为252．6～662．2、454．6～1413．4、147．4-760．5ng／kg湿重（ww）。鱼肌肉样品中BDE47的相对含量最高。鱼肝对多溴联苯醚的富集能力强于鱼肉。     

Copper porphyrins in deep-sea sediments: a possible indicator of oxidized terrestrial organic matter

Copper porphyrins have been isolated from deep-sea sediments collected during six legs of the Deep Sea Drilling Project-International Program of Ocean Drilling. These pigments are present in depositional areas receiving high inputs of terrestrially derived oxidized organic matter. Such areas include the Black Sea, the Bay of Biscay, the Blake-Bahama Basin, and slumped Miocene deposits off Cape Bojador on the west coast of Africa.     

路易斯安娜鸢尾品种引进及种苗生产研究

[目的]对引进的8个路易斯安娜鸢尾品种的物候期、生长特性、结实性、分生能力等进行观察测定。[方法]8个品种分别为‘B1ackGamecock’、‘RegalRicochet’、‘Teven’、‘SeaWisp’、‘WaihiWedding’、‘HotAndSpicy’、‘SeriouslyBlue’和‘Gunner’。[结果]8个引进品种在苏州均能正常开花,叶片冬季绿色,品种间在花期、花色、花茎高度等方面的差异为园林应用提供了丰富的植物材料;5个品种人工授粉后,大田开放授粉植株的结实率高于设施内隔离授粉的植株,‘SeaWisp’结实率最高达70．4％,可用于实生苗生产;‘BlackGamecock’品种在大田自然生长环境中分生系数最高达9,可用于分生苗生产;‘HotAndSpicy’不结实,分生系数低,需要依靠组培方式生产种苗。[结论]根据品种的不同特性选择不同种苗生产途径,可为苏州地区种苗生产提供参考。     

Carbon-13 in black sea waters and implications for the origin of hydrogen sulfide

A combination of measurements of carbon-13 and the hydrogen sulfide content in Black Sea waters with available data on the total carbon dioxide in these waters indicates that the contribution of organic sulfur to the hydrogen sulfide lies between 3 and 5 percent and increases with depth. Likely causes for the increase are increasing productivity or upward movement of the anoxic zone during the facts last 2000 year.     

The Beginnings of Metallurgy: A New Look: Arguments over diffusion and independent invention ignore the complex metallurgic crafts leading to iron

In the 9 years since my first survey of early metallurgy appeared in this journal (65) metallurgy has become a major battleground between those who argue independent invention and those who argue diffusion in the evolution of urban civilization. In this new article I contend that: 1) The upland belt and debouching river valleys of southwestern Asia have a clear priority in the beginnings of copper metallurgy and extractive metallurgy generally, suggesting that the forces of urbanization contributing to the rise of metallurgy there were more massive, widespread, and better integrated than elsewhere. 2) The trend to polymetallism, against the background of pyrotechnology generally and the other important technologies of urbanism, established a necessary sequence to early metallurgy. This sequence was a prerequisite to the coming of the Iron Age, which was uniquely contained at first within the environment of Anatolia and the eastern Mediterranean and spread outward from there. 3) The course of metallurgy and possibly of the other urbanizing technologies can best be understood through a process of diffusion and multiple innovation interrelating metallurgical evolution over much of Eurasia, but with the area defined by the Black Sea, the Caspian Sea, the Red Sea, and the eastern Mediterranean as its center. Only in this fashion can we place metallurgy in its proper role as an important subsystem in the rise of civilization.     

Microbial reefs in the Black Sea fueled by anaerobic oxidation of methane

Massive microbial mats covering up to 4-meter-high carbonate buildups prosper at methane seeps in anoxic waters of the northwestern Black Sea shelf. Strong 13C depletions indicate an incorporation of methane carbon into carbonates, bulk biomass, and specific lipids. The mats mainly consist of densely aggregated archaea (phylogenetic ANME-1 cluster) and sulfate-reducing bacteria (Desulfosarcina/Desulfococcus group). If incubated in vitro, these mats perform anaerobic oxidation of methane coupled to sulfate reduction. Obviously, anaerobic microbial consortia can generate both carbonate precipitation and substantial biomass accumulation, which has implications for our understanding of carbon cycling during earlier periods of Earth's history.     

Evolutionary trends in the geochemistry of steppe soils under long-term agricultural use

The aim of this research was to identify long-term changes in the material composition of arable and fallow lands in the agricultural district of an ancient center in the Northern Black Sea region. Geochemical features of changes in the upper mineral soil horizon of different-aged arable and fallow lands near the ancient city of Kerkinitis were studied. The multitemporal boundary between arable lands of different ages was identified, and indicators to diagnose residual signs of former agricultural loads were revealed in the material composition of agrozems using geostatistical methods. The use of such unique objects of study as soils of ancient agricultural areas is related to the potential evaluation of risks of fertility loss because of slow but practically irreversible processes of pedogenesis and the opportunity to prevent or reduce their negative manifestations in arable land.     

Assessment of resistance of soddy-calcareous typical soils of the Black Sea Coast of the Caucasus to chemical contamination

Based on laboratory modeling, a conclusion has been made that contamination of soddy-calcareous typical soil of the Black Sea Coast of the Caucasus by Cr, Cu, Ni, Pb, and oil results in its poorer biological properties. The total number of bacteria drops, the activity of catalase and dehydrogenase and celluloselytic activity become smaller, the amount of bacteria of the Azotobacter genus decreases, and the parameters of germination and initial growth of radish become poorer. With respect to the adverse effect on the biological properties of the investigates soil, heavy metals may be arranged into the following series: Cr > Cu ≥ Ni = Pb. Qualitative benchmarks of the regional maximum permissible contents of Cr, Cu, Ni, Pb, and oil in soddycalcareous typical soils of this region were determined on the basis of changes in ecological soil functions.     

Fantasy and reality: The black farmer's place in American agriculture

The shared hopes of farm ownership in America motivated many Black farmers and educators during the nineteenth and early twentieth centuries. Although an independent Black yeomanry was not to be, and a host of factors have combined to remove Black Americans from farming, the quest has not been a vain one. Black land-grant institutions continue to redefine their mission in a changing world and in the process maintain their relevancy.     

Soluble Mn(III) in suboxic zones

Soluble manganese(III) [Mn(III)] has been thought to disproportionate to soluble Mn(II) and particulate Mn(IV)O2 in natural waters, although it persists as complexes in laboratory solutions. We report that, in the Black Sea, soluble Mn(III) concentrations were as high as 5 micromolar and constituted up to 100% of the total dissolved Mn pool. Depth profiles indicated that soluble Mn(III) was produced at the top of the suboxic zone by Mn(II) oxidation and at the bottom of the suboxic zone by Mn(IV)O2 reduction, then stabilized in each case by unknown natural ligands. We also found micromolar concentrations of dissolved Mn(III) in the Chesapeake Bay. Dissolved Mn(III) can maintain the existence of suboxic zones because it can act as either an electron acceptor or donor. Our data indicate that Mn(III) should be ubiquitous at all water column and sediment oxic/anoxic interfaces in the environment.     

海南黑牛体型外貌测定与杂交效果初探

海南黑牛是利用良种日本黑毛和牛的冷冻精液与海南黄牛(雷琼黄牛)母牛进行人工授精所产的杂交后代.通过对海南黑牛进行外貌观察和体尺测量,研究其体型外貌与双亲的差异.结果表明,海南黑牛的多项体尺指标与母、父本相比都发生了变化.其外貌主要特征表现为头小颈短、面部清秀,体躯紧凑,背腰平直,无肩峰,毛呈黑色;而体尺测量除管围和管围指数外,体重、体高、胸围、体长等指标均比海南黄牛要小.即在外貌特征上,海南黑牛总体表现双亲的特性,毛色呈现日本和牛黑毛,体型接近海南黄牛小而清秀,但前期生长发育缓慢,表现出当地小型黄牛的特性.     

The African American experience in agriculture

Shrinking enrollments in the agricultural programs of the 1890 schools can be partly explained by negative attitudes of Blacks toward agriculture. This attitude has roots in the historical experiences of African Americans and has negative implications for the agricultural programs of the 1890 schools. A collection of data from a sample of Black Louisiana Farmers lends credence to the claim that Black Farmers are not encouraging their children to go into farming. To counter the impact on the 1890 schools, an active recruiting program should be undertaken, partly to show Black students that career openings in various agricultural fields offer excellent opportunities for Black students. These fields extend beyond the traditional farmgate.     

瘦肉型杂交猪肥育、屠宰效果的研究

本研究是《推广瘦肉型杂交猪》重点科技承包项目的重点配套研究课题。1987—1989年分别对杜×甘白、杜×甘黑、汉×甘白、汉×甘黑、长×甘白、长×甘黑、大约×甘白(杜:杜洛克猪;汉:汉普夏猪;长:长白猪;大约:大约克夏猪;甘黑:甘肃黑猪;甘白:甘肃白猪。)的七个杂交组合和甘白×甘白、甘黑×甘黑、甘白×甘黑三个母本专试组进行了测定。育肥试猪共178头,屠宰试猪共114头。结果表明,杂交组合的肥育和屠宰各项指标均高于母本纯繁对照,日增重高55.18克相似文献   

Speciation of Black-necked Crane

1　Introduction　　 The latest crane species to be discribed was the Black- necked Crane (Grus nigricollis) ofthe Qinghai- Tibetan Plateau.It was first located in1 876 at Qinghai Lake,China,since thenChinese scientists have conducted extensive research on this species,especially on its popula-tion status and distribution(Yao and L iao1 984) ,population structure(L i and Zhou1 987) ,wintering ecology(L u1 983,Wu1 985) ,and breeding ecology(Lu and Yao1 980 ,Yao and Liao1 984) .However,li…     

山羊GHRL 基因多态性及其与 体重、体尺性状的关系研究

采用PCR-SSCP 技术对贵州黑山羊和贵州白山羊GHRL 基因进行单核苷酸多态性检测,并分析其多态与体重、体尺性状间的关联性。结果发现,在GHRL 基因外显子4 处存在1 个同义突变位点（C345T）,表现为2 种基因型,分别命名为CC 和CT。基因型与体重、体尺性状关联分析结果显示,在贵州黑山羊（麦坪）群体中,CT 基因型个体的体重、体高和胸围均显著高于CC 基因型个体,而在贵州黑山羊（纳雍）和贵州白山羊群体中差异不显著。研究结果揭示,GHRL 基因突变位点（C345T）影响贵州黑山羊生长性状可能性较大,该位点有望作为山羊生长性状的一个标记辅助选择位点。     

和田黑鸡与三黄鸡血浆蛋白及血象指标的比较研究

应用常规的血液学指标测定方法,测定了和田黑鸡与三黄鸡血液学指标。结果表明:和田黑鸡雌雄个体之间血浆总蛋白、血浆白蛋白和血浆球蛋白无显著差异（P>0.05）,其中白蛋白与球蛋白之比小于1。和田黑鸡的血浆总蛋白、血浆白蛋白和血浆球蛋白极显著（P<0.01）高于三黄鸡。和田黑鸡WBC雄性高于雌性,但差异不显著（P>0.05）;而RBC、HGB表现为雌性高于雄性,其中HGB差异不显著（P>0.05）,RBC雌性为(4.52±0.041×10¹²/L,雄性为（3.78±0.12）×10¹²/L,雌性显著高于雄性（0.01相似文献