Two New Species of Free-Living Marine Nematodes of the Desmodoridae from Mangrove Wetlands of Xiamen Bay,China     

ZHOU Xiping  ZENG Jiali  CAI Lizhe  FU Sujing  TAN Wenjuan 《中国海洋大学学报(英文版)》2020,19(1):143-150

Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove wetlands.Fujian Province is the most northern point of China’s natural mangrove distribution,and it is also one of the provinces with the earliest constructed mangrove forest.In this paper,two new free-living marine nematode species of Desmodoridae from the Xiamen mangrove wetlands in China are described.Metachromadora xiamenensis sp.nov.is characterized by a cylindrical body,and smooth head capsule set off from the rest of the body.The cuticle is finely annulated and thickened at the midbody.Lateral ridges run from the posterior end of the pharynx to the middle of the tail.The amphid foveae is loop shaped and opens at the top with a double contour amphidial,pharynx with bipartite cuticularized internal cavity.There are 18 tubular precloacal supplements and tail with three small protuberances.Molgolaimus euryformis sp.nov.is characterized by a relatively short and plump body with finely annulated cuticle,which is particularly obvious in the tail.The head is small and wide with intensive striates.The inner and outer labial sensilla are indistinct with short spicules and ventral apophysis,a gubernaculum with a block-shaped hook,a swollen conical-cylindrical tail and an absence of precloacal supplements.  相似文献   

Spatial distribution of atmospheric carbon monoxide over Bay of Bengal and Arabian Sea: Measurements during pre-monsoon period of 2006     

V. R. Aneesh  G. Mohankumar  S. Sampath 《Journal of Earth System Science》2008,117(4):449-455

Indian Space Research Organization (ISRO) conducted the ‘Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB)’ for a two-month pre-monsoon period in 2006 with the ocean segment covering Bay of Bengal and Arabian Sea. During this campaign, carbon monoxide (CO) was continuously monitored using a non-dispersive IR analyser. Quantifying CO in ambient air is vital in determining the air quality of a region. Being toxic, CO is a criteria pollutant, but it is a weak green house gas. Globally, very few measurements exist over marine atmospheres to study its temporal pattern; particularly in situ CO measurements are few over the Bay of Bengal and Arabian Sea for comparison. Present measurements indicate: (i) predominant single peak in the diurnal pattern of CO over the marine atmosphere in contrast to the double peak over the continent, (ii) the mean diurnal CO over the marine atmosphere showing an increasing trend towards evening hours, (iii) the amplitude of the AN peaks over the marine atmosphere was ∼ 100 ppbv, while at a remote island site in the Indian Ocean it was ∼ 5 ppbv and (iv) high CO values were observed close to continent and the long range transport by wind also caused CO highs.  相似文献   

Compositional and geochemical characteristics of light hydrocarbons for typical marine oils and typical coal-generated oils in China     

Xiang Wang  Min Zhang 《中国地球化学学报》2008,27(4):407-411

Different types of crude oils have different light hydrocarbon compositional and geochemical characteristics. Based on the light hydrocarbon data from two kinds of oils, i.e., coal-generated oils and marine oils in China, light hydrocarbons in marine oils in the Tazhong area are generally relatively enriched in n-heptane, and coal-generated oils from the Turpan Basin are enriched in methylcyclohexane. The K1 values, reported by Mango （1987）, range from 0.97 to 1.19 in marine oils, basically consistent with what was reported by Mango on light hydrocarbons in terms of the majority of the crude oil data. But the K1 values of coal-generated oils are particularly high （1.35-1.66） and far greater than those of marine oils; heptane values in marine oils, ranging from 32.3% to 45.4%, and isoheptane values, ranging from 1.9 to 3.7, are respectively higher than those of coal-generated oils, indicating that the oils are in the high-maturity stage. In addition, expulsion temperatures of coal-generated oils from the Turpan Basin are obviously lower than those of marine oils from the Tazhong area.  相似文献   

基于海洋功能区划的海域开发利用承载力评价——以津冀海域为例   总被引：2，自引：1，他引：1  

曹可  张志峰  马红伟  杨正先  索安宁 《地理科学进展》2017,36(3):320-326

海洋功能区划是海域法确定的海域开发利用的重要依据。本文针对海域开发利用管理的技术需求,采用专家咨询法,确定海域使用分类8个一级类型所包含的30个二级类型的资源耗用系数,构建了海域开发利用强度指数及海域开发利用评价标准,以此为基础形成了基于海洋功能区划的海域开发利用承载力指数,并以津冀海域为例开展了实证评价研究。结果表明：①以海洋功能区划为依据的海域开发利用承载力评价方法可客观地揭示海域开发利用承载力程度。②津冀海域的曹妃甸海域、天津滨海新区海域和黄骅海域开发利用承载力指数分别达到10.30、13.87和10.30,处于承载力较高状态;昌黎海域开发利用承载力指数为7.61,处于承载力适中状态;其余的秦皇岛市区、抚宁县、乐亭县、滦南县和丰南区海域开发利用承载力指数都小于5.0,处于承载力较低状态。  相似文献   

环渤海地区海洋产业生态系统适应性时空演变及影响因素   总被引：2，自引：0，他引：2  

李博  张志强  苏飞  韩增林 《地理科学》2017,37(5):701-708

将产业生态系统引入到海洋研究中,开展海洋产业生态系统适应性研究,界定海洋产业生态系统适应性的内涵及特征;采用均方差赋权法进行权重赋值,构建海洋产业生态系统适应性评价指标体系与评估模型,分析环渤海地区海洋产业生态系统的适应性时空演变及影响因素。结果表明： 从整体来看,环渤海地区海洋产业生态系统适应性差异较大,主要问题是环渤海地区各省市海洋产业发展参差不齐,产业基础和发展速度差异较大,海洋生态环境建设水平不一; 从空间来看,海洋产业生态系统适应性呈现山东>辽宁>天津>河北的空间分布特征;在海洋产业子系统各要素中,呈现敏感性越大,弹性越大的特征,海洋环境子系统适应性特征不明显; 从时间来看,环渤海地区海洋产业生态系统适应性在波动中不断增强,各省市适应性综合指数差距呈现逐渐扩大的趋势,这种扩大的趋势是由于海洋产业子系统年均增长的差异所致; 区域内部海洋产业生态系统适应性差异明显：天津市海洋产业子系统适应性指数最高,海洋环境子系统发展水平滞后;河北省海洋产业、环境子系统适应性指数较低,海洋产业生态系统发展水平低;辽宁省海洋产业、环境子系统适应性指数较小,海洋产业、环境子系统发育较平衡;山东省海洋产业、环境子系统适应性指数较高,海洋产业生态系统发展水平高,海洋产业子系统发展迅速。  相似文献   

基于Bootstrap-DEA模型环渤海地区海洋经济效率空间演化与影响因素分析   总被引：6，自引：4，他引：2  

邹玮  孙才志  覃雄合 《地理科学》2017,37(6):859-867

借助Bootstrap-DEA模型综合测算了环渤海地区17个城市海洋经济效率,并结合标准差椭圆和重心坐标方法,定量刻画了2000~2012年环渤海地区海洋经济效率空间格局演化特征,考察了影响空间格局演化的重要因素及其影响机制。结果表明：① 基于Bootstrap-DEA模型纠偏后的海洋经济效率更低,但准确性更高;计算得到的环渤海地区海洋经济效率总体上且呈现先上升后下降的趋势,低海洋经济效率的城市主要分布于渤海西南沿岸。② 从标准差椭圆分布来看,海洋经济效率总体呈现南（偏西）-北（偏东）的空间格局;从重心的移动轨迹来看,效率重心先向渤海西南部海洋经济区移动,再转向辽东半岛海洋经济区与渤海西部海洋经济区移动,最后转向山东半岛蓝色经济区移动。③ 针对海洋经济效率空间格局演化驱动机制的分析表明,区位优势对海洋经济效率产生正向影响,海洋产业结构和外商直接投资对海洋经济效率产生负向影响,资源消耗型海洋产业比重过大是导致海洋经济效率下降的主要原因。  相似文献   

An Assessment of HOx Chemistry in the Tropical Pacific Boundary Layer: Comparison of Model Simulations with Observations Recorded during PEM Tropics A     

G. Chen  D. Davis  J. Crawford  B. Heikes  D. O'Sullivan  M. Lee  F. Eisele  L. Mauldin  D. Tanner  J. Collins  J. Barrick  B. Anderson  D. Blake  J. Bradshaw  S. Sandholm  M. Carroll  G. Albercook  A. Clarke 《Journal of Atmospheric Chemistry》2001,38(3):317-344

Reported are the results from a comparison of OH,H₂O₂CH₃OOH, and O₃ observationswithmodel predictions based on current HO_x–CH₄reaction mechanisms. The field observations are thoserecorded during the NASA GTE field program, PEM-Tropics A. The major focus ofthis paper is on thosedata generated on the NASA P-3B aircraft during a mission flown in the marineboundary layer (MBL) nearChristmas Island, a site located in the central equatorial Pacific (i.e.,2° N, 157° W). Taking advantage of thestability of the southeastern trade-winds, an air parcel was sampled in aLagrangian mode over a significantfraction of a solar day. Analyses of these data revealed excellent agreementbetween model simulated andobserved OH. In addition, the model simulations reproduced the major featuresin the observed diurnalprofiles of H₂O₂ and CH₃OOH. In the case ofO₃, the model captured the key observational feature whichinvolved an early morning maximum. An examination of the MBL HO_xbudget indicated that the O(¹D) + H₂Oreaction is the major source of HO_x while the major sinks involveboth physical and chemical processes involving the peroxide species,H₂O₂ and CH₃OOH. Overall, the generally goodagreement between modeland observations suggests that our current understanding ofHO_x–CH₄ chemistry in the tropical MBL isquite good; however, there remains a need to critically examine this chemistrywhen both CH₂O and HO₂are added to the species measured.  相似文献   

Latitude versus Depth Simulations of Ecodynamics and Dissolved Gas Chemistry Relationships in the Central Pacific     

Shaoping Chu  Scott Elliott 《Journal of Atmospheric Chemistry》2001,40(3):305-333

Nutrient ecology and trace gas processing are intimately coupled in the surface ocean and participate in key linkages through the Earth biogeochemical system. We have added water column photochemistry for volatile sulfur and organic compounds to large scale nutrient cycle modules, in order to create a one dimensional, open ocean ecochemistry simulator. Phyto- and zooplankton, recyclers and biological waste products are represented through N and Fe densities. Dimethyl sulfide, carbonyl sulfide and the methyl halides are tracked individually along with certain precursors and nonmethane hydrocarbons. The model is applied along the 180 degree meridian in the Northern Hemisphere. Ecodynamics are validated against satellite ocean color maps. Biological/photochemical production terms are then iterated upon to match measured distributions for the trace gases. Data are most complete for dimethyl sulfide. Major patterns in its climatology are captured within individual ecological provinces. However, at the basin scale reduced sulfur release must be varied over almost an order of magnitude because the mechanism developed contains only one plant taxon. Based on sparser data, first order rate constants are estimated for phytoplanktonic exudation of the methyl halides. Parameters are also established for photolytic injection of carbonyl sulfide and propylene from the dissolved organics. Ocean general circulation models and interactive ocean-atmosphere transport simulations are discussed as frameworks for future application.  相似文献   

结构性对琼州海峡软土压缩特性的影响   总被引：10，自引：0，他引：10  

吕海波  汪稔  孔令伟  单华刚 《岩土力学》2001,22(4):467-469,473

天然软土大多具有结构性，且结构性因地而异。通过室内试验研究了结构性对琼州海峡两种海洋软土压缩特性的影响，并结合琼州海峡铁路轮渡工程，讨论了土结构性的存在对该工程防波堤地基处理工程效应的影响。  相似文献   

海底资源与环境立体探测技术发展方向与对策     

杨胜雄  陈邦彦  刘保华  王权  吴宣志  赵洪伟 《中国地质》2001,28(10):10-15

21世纪是人类全面开发利用海洋的新世纪。目前国际海底资源与环境探测，正在由海面、水中发展到空中、海底，形成立体的综合勘测。在21世纪前期，作为海洋大国，中国在维护海洋权益方面所面临的形势严峻复杂。如何发展、开发利用高新技术，以适应日新月异的世界海底资源与环境探测竞争需要，是广大海洋工作者都关心的课题。本文对立体探测技术发展方向和对策进行了简单探讨。  相似文献