Current and thermohaline characteristics of the Arabian Sea during January 1998

Based on a ship survey during January 1998, the characteristics of the flow, the thermohaline properties and the volume transport of the Arabian Sea are discussed. A strong westward flow exists between 10.5?N and 11?N, part of which turns to the south as the Somali current near the coast at about 10?N and the rest turns north. At the passage between the African continent and the So- cotra Island, the northern branch separates into two flows: the left one enters the passage and the right one flows eastward along the southern slope of the island. Off the island the flow separates once more, most of it meandering northeast and a small fraction flow- ing southeast. Volume transport calculation suggests that the tidal transport is one or two orders of magnitude smaller than the total transport in this region and it becomes more important near the coast. The average velocity of the flow in the upper layer (0-150 m) is about 20 cm s-1, with a maximum of 53 cm s-1 appearing east of the Socotra Island, and the subsurface layer (200-800 m) has an aver- age velocity of 8.6 cm s-1; the velocity becomes smaller at greater depths. The depth of the seasonal thermocline is about 100 m, above which there is a layer with well mixed temperature and dissolved oxygen. High-salinity and oxygen-rich water appears near the surface of the northern Arabian Sea; a salinity maximum and oxygen minimum at 100 m depth along 8?N testifies the subduction of surface water from the northern Arabian Sea. Waters from the Red Sea and the Persian Gulf also influence the salinity of the area.     

Preliminary Study on Applicability of Microsatellite DNA Primers from Parasite Protozoa Trypanosoma cruzi in Free-living Protozoa

1　Introduction　Generallyknownasacodominantgeneticmarker ,microsatellitehasbeenwidelyusedinstudiesonpopu lationgenetics,high resolutiongenotyping ,genemap ping ,evolution ,linkageanalysis ,conservationbiology ,behaviouralecology ,relationsbetweenparasite…     

VARIATIONAL ITERATION SOLVING METHOD FOR SEA-AIR OSCILLATOR MODEL OF INTERDECADAL CLIMATE FLUCTUATIONS

1IN T R O D U C T IO NInteractionsbetween the ocean and atmosphere con-tributeto climatefluctuationosver a broad spectrum oftime scales.Studiesof those interactionhsave farfo-cused on El Ni o-SouthernOscillation(ENSO)phe-nomenon thathas a period of3to4yea…     

A search for periodicities from a ULX in the LINER galaxy NGC 4736

We report our findings on a new quasi-periodic oscillation (QPO) and a long period from the ultraluminous X-ray source (ULX) X-2 in nearby galaxy NGC 4736 based on the Chandra and XMM-Newton archival data. To examine the timing properties, power density spectra of the source have been obtained using Fast Fourier Transform. Also the spectral parameters of the source have been calculated by obtaining and fitting the energy spectra. Power density spectrum of this source reveals a QPO peak at \(0.73_{-0.14}^{+0.16}~\mathrm{mHz}\) with an fractional rms variability of 16 % using the Chandra data (in the year 2000-lower state of the source). The XMM-Newton data analysis indicates a peak at \(0.53_{-0.35}^{+0.09}~\mathrm{mHz}\) with a fractional rms variation of 5 % (in the year 2006-higher state of the source). These recovered QPOs overlap within errors and may be the same oscillation. In addition, we detect a long periodicity or a QPO in the Chandra data of about (5.2±2.0)×10^?5 Hz (～5.4 h) over 3 σ confidence level. If this is a QPO, it is the lowest QPO detected from a ULX. The mass of the compact object in ULX X-2 is estimated using the Eddington luminosity and a disk blackbody model in the range (10–80) M _⊙.     

A proposal for the theoretical analysis of the interactive coupled effects between urbanization and the eco-environment in mega-urban agglomerations

Mega-urban agglomerations are strategic core areas for national economic development and the main regions of new urbanization. They also have important roles in shifting the global economic center of gravity to China. However, the development of mega-urban agglomerations has triggered the interactive coercion between resources and the eco-environment. The interactive coupled effects between urbanization and the eco-environment in mega-urban agglomerations represent frontier and high-priority research topics in the field of Earth system science over the next decade. In this paper, we carried out systematic theoretical analysis of the interactive coupling mechanisms and coercing effects between urbanization and the eco-environment in mega-urban agglomerations. In detail, we analyzed the nonlinear-coupled relationships and the coupling characteristics between natural and human elements in mega-urban agglomerations. We also investigated the interactive coercion intensities between internal and external elements, and the mechanisms and patterns of local couplings and telecouplings in mega-urban agglomeration systems, which are affected by key internal and external control elements. In addition, we proposed the interactive coupling theory on urbanization and the eco-environment in mega-urban agglomerations. Furthermore, we established a spatiotemporal dynamic coupling model with multi-element, multi-scale, multi-scenario, multi-module and multi-agent integrations, which can be used to develop an intelligent decision support system for sustainable development of mega-urban agglomerations. In general, our research may provide theoretical guidance and method support to solve problems related to mega-urban agglomerations and maintain their sustainable development.     

新滩滑坡后两岸边坡的位移监测及形变趋势

本文介绍新滩滑坡后两岸边坡监测的工作,对边坡变形提出了趋势意见。认为新滩斜坡目前正处于整体稳定下的局部调整阶段,变形缓慢平稳,但要注视广家崖的危岩动态;链子崖仍有趋势性的倾江形变。5—6号缝围成的7万方危岩及江段的5万方危岩体尚有一触即崩之势,须加强监视。     

矿物热电系数及其在地质找矿中的应用

作者的研究表明,在非本征激发区,矿物热电系数随着活化温度的增高而增大;在本征激发区,随活化温度的增高而减小。矿物晶体中所含杂质的种类和含量多少决定矿物的导电类型。矿物热电系数可广泛应用于地质找矿和矿床评价中,以黄铁矿为例,在同一水平面上的含金矿脉,矿脉中黄铁矿热电系数正值高时,其矿石含金量也高。应用黄铁矿热电系数的正高值、混合型和负值可确定矿体和矿体的剥蚀深度。     

Comparative analysis on microbial community associated with different gastrointestinal regions of wild northern snakehead Channa argus Cantor, 1842

Microbial communities in different gastrointestinal regions(stomach, foregut, midgut, and hindgut) of the northern snakehead C hanna argus(Cantor, 1842) were compared by polymerase chain reaction and partial 16 S r DNA sequencing. A total of 194, 140, 212, and 122 OTUs were detected in the stomach, foregut, midgut, and hindgut, respectively. Significant dif ferences were found in the Sobs, ACE, Shannon, and Simpson indices among samples(P 0.05). The gastrointestinal microbial community of C. argus consisted predominantly of Proteobacteria with either H alomonas, Shewanella, Plesiomonas, or Sphingomonas. Fusobacteria, Firmicutes, and Bacteroidetes also existed in the gastrointestinal tracts. However, significant diff erences were found in the compositions of microbial community among the four regions( P 0.05). Cyanobacteria and Spirochetes were significantly higher in the midgut and hindgut( P 0.05). Fusobacteria and Firmicutes were dominant in the hindgut and foregut, respectively(P 0.05). Proteobacteria was the lowest in the hindgut( P 0.05). At genus level, C etobacterium and Plesiomonas were significantly higher in the hindgut than in the other three samples( P 0.05). Clostridium and Prevotella were the highest in the midgut(P 0.05). Halomonas, Shewanella, and S phingomonas were the highest in the foregut( P 0.05). Paracoccus and Vibrio were the highest in the stomach. Several genera were only detected in certain regions, as follows: stomach, P aracoccus and Vibrio; foregut, Halomonas, Shewanella, and Sphingomonas; midgut, Clostridium and Prevotella; and hindgut, C etobacterium and Plesiomonas( P 0.05). At the species level, A cinetobacter rhizosphaerae was only detected in the stomach. P revotella copri and Clostridium perfring were not detected in the foregut and midgut, respectively, whereas Prevotella copri and Faecalibacterium pra were not detected in the hindgut. These findings provide valuable information on the microbial community in each gastrointestinal region of C. argus. Moreover, this study indicated that microbial community was not only related to rearing environment but also to the physico-chemical characteristics of each gastrointestinal region.     

农村居民点动态演变及驱动机制研究——以江苏省宜兴市为例

选取宜兴市为研究区,在GIS和RS技术的支撑下,对农村居民点用地的规模变化和空间分布进行分析,对引起农村居民点用地变化的驱动因素进行研究。结果表明:1农村居民点用地整体呈下降趋势,变化速度逐年减慢,主要新增来源是农用地,主要转移去向是城镇建设用地;2在地形平坦、距离水源和农用地较近的地区,农村居民点分布密集;3经济发展、人口减少、交通改善和城市化水平提高是影响农村居民点变化的主要驱动因素。