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1.
We compared environmental effects on the macrobenthic community of the Han River Estuary in summer, when freshwater input from the Han River increased, and in spring, when freshwater input decreased. Field samples were taken from the upper region of the Shingok reservoir to the southern area of Ganghwado at 18 sampling sites after rainy (August 2006) and dry (March 2007) seasons. Macrobenthic fauna were collected using a Van Veen Grab (0.025 m2 and 0.1 m2) and environmental factors were measured simultaneously. Dominant species of macrobenthic fauna and the macrobenthic community were divided into two areas, the area of the Han River with no salinity (< 0.1 psu) and the southern part of Ganghwado with salinity (> 20 psu). The dominant species Byblis japonicus appeared at Junruri in the dry season. The distributions of two polychaetes, Hediste japonica and Nephtys caeca, were divided into the lower and upper areas of the Singok submerged weir. BIO-ENV (the matching of biotic to environmental patterns) analysis revealed that salinity was the most important factor affecting macrobenthic communities in the Han River Estuary, with other factors such as sediment grain size, bottom dissolved oxygen, and total organic carbon of sediment being secondary.  相似文献   

2.
A field experiment was carried out in Hong Kong to study the patterns of recolonization and succession of subtidal macrobenthos in defaunated sediment contaminated with petroleum hydrocarbons and to determine the time required for benthic recovery from petroleum contamination. A total of 31 species was found and 83 animals/tray and 14 species/tray on an average were recorded after one month. Initial colonization was dominated by polychaetes in both abundance and species number (accounting for 69.1% and 64.5%, respectively). Abundance of macrobenthos came to a small crest (308 animals/tray) after three months, reached a sharp peak (1257 animals/tray) after six months, and then declined to a steady level. Abundance, species number and diversity in the petroleum-contaminated sediment were significantly lower than those in the control sediment in the early successional stages, indicating deleterious effects of petroleum hydrocarbons on recolonization and succession of macrobenthos. Petroleum hydrocarbons in sediment significantly altered species composition of macrobenthos in recolonization and succession. No significant differences in community parameters and species composition between the petroleum-contaminated and the control communities were found after 11 months, indicating that macrobenthic community had recovered from petroleum contamination.  相似文献   

3.
渤海大型底栖动物种类组成与群落结构研究   总被引:1,自引:1,他引:0  
本文利用2008年8月在渤海23个站位采集的样品对大型底栖动物的丰度、生物量、群落结构及其与环境因子的关系进行了研究。共鉴定出大型底栖动物300种,主要类群包括环节动物多毛类、节肢动物甲壳类、软体动物、棘皮动物等。研究海域大型底栖动物的平均丰度为1 094.7ind/m2,平均生物量为11.78g/m2,其中丰度最高区位于辽东湾,最低区位于渤海湾;生物量最高区位于渤海中部,最低区出现在渤海海峡湾口处。依据丰度和生物量进行了CLUSTER聚类和MDS标序图分析,结果可将研究站位划分为6个站组,均与沉积物底质类型密切相关。所研究海域底质类型包括黏土质粉砂、砂、砂质粉砂、粉砂质砂、砂-粉砂-黏土5种。通过BIOENV分析,发现影响大型底栖动物群落结构和分布的主要环境因子有水深、黏土粉砂含量、脱镁叶绿酸含量、叶绿素含量等。与20世纪90年代历史数据的对比发现,本次研究大型底栖动物的物种数目明显减少,平均丰度也减少,特别是优势物种表现出了小型化趋势,传统的大型种类,如心形海胆、双壳类等,被小个体的多毛类和甲壳类所取代。本研究表明渤海近年来受人类活动影响,出现了不同程度的污染,导致大型底栖动物群落结构发生了变化。  相似文献   

4.
5.
From the Indian coast only limited data are available on the benthic fauna of the seagrass communities. In this study, seasonal variation in the distribution of macrobenthos and influence of environmental parameters was explored at four seagrass beds and two mangrove stations along the Minicoy Island, Lakshadweep, India, from September 1999 to August 2001. A total of 160 macrobenthic species from eight major groups represented the macrofauna of the Minicoy Island. Of the identified taxa, molluscs 70(gastropods 41.46%, bivalves 7.5%), polychaetes 27(16.88%), crustaceans 30(18.75%), echinoderms 11(6.88%) and remaining others. Average seasonal abundance of benthic macrofauna ranged from 219 to 711 ind./m2, species diversity varied from 1.45 to 3.64 bits per individual, species richness index ranged from 4.01 to 26.17, evenness 0.69 to 1.66. In general, the higher abundance and species diversity was noticed in southern seagrass stations and northern seagrass stations, but in the mangrove stations comparatively low species diversity was observed. Three-way analysis of variance indicated that all communities resulted as being significantly different between seagrass and mangrove station, mainly when the seasonal interaction was considered. Multivariate analyses were employed to help define benthic characteristic and the relationship between environmental parameters at the six monitoring stations. Results of cluster analyses and multidimensional scale plot suggest that for mangrove region, different physiographic provinces, lower salinity, dissolved oxygen and sediment biotic structure have a higher influence on the species composition and diversity than other oceanographic conditions.  相似文献   

6.
In order to realize the spatiotemporal variations of benthic macrofaunal communities at the "Amphioxus Sand"habitat, six surveys including four seasons and three consecutive summers(i.e., 2014, 2015 and 2016) were conducted in two core sites, i.e., Huangcuo(HC) and Nanxian-Shibaxian(NX), in the Xiamen Amphioxus Nature Reserve in China. A total of 155 species of macrofauna were recorded, therein, polychaetes were dominant in terms of species number and density. Significant spatiotemporal variations of macrofaunal communities were observed. The density of polychaetes and the biomass of molluscs in the HC site were higher than those in the NX site. Macrofauna were more diverse and abundant in the cold seasons(winter and spring) than that in the warm seasons(summer and autumn). The annual variations of macrofaunal communities may be attributed to the changes in sediment texture among the three years of the survey. The variations in macrofaunal communities were mainly related to the proportion of polychaetes within the community. In addition, the density of amphioxus(include Branchiostoma japonicum and B. belcheri) was negatively correlated to that of polychaetes, bivalves, and crustaceans. Amphioxus was less likely to be found in the sediments with higher silt and clay content. Five biotic indices including Margaref's richness index(d), Peilou's evenness index(J′), Shannon-Wiener diversity index(H′),AMBI and M-AMBI were calculated in the present study. AMBI seems suitable in assessing benthic health at the"Amphioxus Sand" habitat, and a potential risk of ecological health in Xiamen Amphioxus Nature Reserve should be aware.  相似文献   

7.
Mapping surveys of coastal benthic habitat in Qeshm Island Geopark, Persian Gulf, were conducted using a combination of biological, sedimentological and echo‐sounding data. The survey area covered approximately 233 km2 in a depth range of 5–25 m, and the data were acquired from a single beam echo sounder, grab, video and still photography. Sediment and macrofauna samples were collected by grab at 76 stations and subjected to classification and ordination analyses. Two acoustic classes were identified differentiating along the near/offshore axis. Sediment texture was dominated by fine grain sizes, with five distinct sub‐sediment types. In total, 214 macrobenthic taxa were identified, of which polychaetes accounted for 60%. Other dominant groups included young sponges, nematodes, malacostracan crustacean, bivalves, ostracods and ophiuroids. Underwater videos and still photos integrated the macrofaunal and sedimentary data and revealed a range of biogenic sedimentary features such as burrows and tubes. The biological data identified six main biological assemblages showing an inshore/offshore pattern. The macrobenthic abundance did not demonstrate a significant difference with depth, although polychaetes were positively correlated with depth. The highest abundance and species richness were observed at median depths. Species distribution and diversity did not show any correlation with sediment type. A preliminary habitat mapping of the south coast of the Qeshm Island Geopark has been carried out, integrating acoustic, sediment and biological data.  相似文献   

8.
The biogeography of macrobenthic communities with large-scale differences in species distribution and abundance was studied along the eastern and western coastal regions of the Gulf of Suez to indicate biodiversity of benthos in relation to the prevailing environmental conditions. In general, benthos have a wide variety of species of mainly polychaet worms, crustaceans, bivalves, and other bottom invertebrates living in burrows in/or on the sediment surface. Coastal development clearly affects the ecosystem after the construction of coastal projects. The highest values of benthic diversity, evenness, richness and dominance are found at the Gulf of Suez (WG 1, WG 3), Ras Gharib (WG 7, WG 8) and Ras Shukier (WG 9a) by contrast to others. The abundance of macrobenthic organsims along the coasts of Gulf of Suez can be arranged in the following sequence: other groups (34%) greater than crustaceans (25%) greater than polychaetes (22%) greater than molluscs (17%) greater than echinoderms (2%). The biomass of benthic assemblages at different sampling sites can also be ranked as follows: echinoderms (52%) greater than molluscs (27%) greater than crustaceans (16%) greater than polychaetes (2%) greater than other groups (3%). Some benthic groups or species indicated a distinctive correlation to pollution sources in the marine ecosystem which obviously increased in the coastal areas due to the extension of the coastal development. These activities needed regular information to establish database for the biology and distribution of marine benthic communities. The density and diversity of benthos are significantly affected by eutrophication at Ain Sukhna, whereas the benthos in the open Gulf of Suez do not seem to be adversely affected by pollution.  相似文献   

9.
Sediment organic and metal chemistry, benthic infauna and tissue contaminants surveys have been conducted over 19 years before and following tailings deposition from a metal (Mo, Pb, Zn) mine in Alice Arm, a British Columbia fjord. We found changes in benthic fauna and habitat after tailings disposal to be predictable in terms of sediment chemistry and faunal recolonization. What was not predictable was the timing and extent of slope failure or resuspension following abandonment. These events can have essentially the same or greater effect than the initial tailings disposal and produce long-term unpredictability particular to cases of submarine disposal on slopes. The present study focused on the submarine deposition of 4 x 10(6) tonnes of tailings during an 18-months period ending October 1982. When the mine closed, gross defaunation had occurred at three stations in the tailings path, and two others showed recent defaunation and recolonization. A year later, a large tailings slump near the outfall transported tailings to the deep basin; fauna were impoverished both in the slump region and through most of the deep basin. Declining metal concentrations in surface sediments was accompanied by considerable recovery of fauna 3 years after the mine closed. Nevertheless, fauna at the three stations defaunated at the time of mine closure could still be statistically distinguished from all other stations due to high abundances of small opportunistic polychaetes and bivalves. A resuspension in tailings between 1988 and 1990 coincided with a moderate decline in abundance of all macrofauna taxa. From 1989 to 1995 recovery toward natural sediment conditions was evident as increasing organic content together with the highest faunal biomass values found during the study. Small polychaetes were the first recolonizers in defaunated areas, whereas small bivalves were more tolerant of moderate tailings deposition. By 1989 and 1995 small colonizers had declined and amphipods and larger echinoderms had increased. Dominant species patterns and exceptionally high biomass values in 1995 show that the largest fauna did not recover until much later than smaller taxa. One genus of bivalve (Yoldia spp.) accumulated metals in a pattern similar to the sediment chemistry, indicating that the metals from the most recent mine had entered the benthic food chain. It is not possible to tell from this study whether biota were affected by toxicity from metals. However, many of the observed biotic effects could be caused by physical disruption from tailings.  相似文献   

10.
利用综合生物标志物响应(IBR)指数对北部湾潮间带沉积环境中多氯联苯(PCBs)、石油烃(TPH)、壬基酚(NP) 和苯并芘(B[a]P)的综合污染水平进行评价。在9个站位采集波纹巴非蛤(Paphia undulata)和沉积物样品,测定沉积物和生物软组织中有机污染物含量,同时对鳃、内脏中与细胞防御系统有关的各7种标志物(包括还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)、谷胱甘肽过氧化物酶(GPx)、过氧化氢酶(CAT)等)进行分析。利用相关性分析法筛选出对1~2种有机污染物响应敏感的生物标志物共8种,分别为内脏中的GPx、GSH、GSSG、CAT和鳃中的GPx、GSH、GSSG、CAT。以筛选的8种生物标志物为基础, 9个站位IBR指数范围为0.27~1.48,其中站位S2(湛江市乐民镇码头)、站位S9(湛江市江洪码头)的IBR较小,显示污染程度最轻;站位S4(防城港西湾)、站位S3(钦州湾老人沙浅滩) IBR较高,显示生物体因有机污染产生氧化逆境。不同站位的IBR值与污染源分布、化学污染物分析结果基本一致,表明该方法可用于北部湾潮间带沉积物有机污染程度的综合评价。  相似文献   

11.
为探究华南沿海海草床大型底栖动物群落特征、地区差异及其与海草群落间的关系,2020年在华南沿海12个海草床区域开展了大型底栖动物调查。共布设33个调查断面99个站位,在主要群落参数的基础上,运用相关性分析和聚类分析、nMDS排序、相似性百分比分析等群落生态学统计方法分析了底栖动物群落特征及其与海草群落的关系。共鉴定出大型底栖动物9大门类199种,其中,软体动物种类最多,占总种类数的39.7%。各区域底栖动物的平均栖息密度为155.7 ind/m2,青葛—龙湾(琼海)的平均栖息密度最低,珍珠湾(防城港)的平均栖息密度最高;平均生物量为118.36 g/m2,最低值出现在义丰溪(汕头),最高值出现在珍珠湾。各区域底栖动物的优势种以潮间带泥沙滩常见腹足类、双壳类和多毛类为主;底栖动物的种类多样性指数(H′)平均值为1.12,最低值出现在唐家湾(珠海),最高值出现在铁山港(北海);各调查区域底栖动物主要群落参数大致呈现“北部湾>海南沿岸>珠江口及粤东”的规律。华南沿海海草床分布区大型底栖动物群落的区域性特征较为明显,地理位置相近的海草床底...  相似文献   

12.
Vertical distribution (0–15 cm) of the macrobenthic community and its relationships to natural sediment characteristics and trace metal contents and bioavailability were studied at five locations in the lower Douro estuary, Portugal. An analysis of vertical metal distribution, for the interpretation of anthropogenic impact on the estuarine sediments, was also investigated. Sediment characterisation included organic matter, grain size, metals (Al, Fe, Cu, Pb, Cr, Ni, Cd, Zn and Mn), acid volatile sulphide (AVS) and simultaneously extracted metals (SEM). The macrobenthic community had low diversity (14 species), was dominated by small size opportunists and seemed to be controlled mainly by natural factors such as grain size distribution, Al and Fe contents and sediment depth. The vertically heterogeneous distribution of macrobenthic community appears to affect redox status of the sediments and consequently metal bioavailability. Despite anthropogenic contamination in terms of Zn, Cu, Pb, Cr and Ni having already been detected in the north bank, the analysis of vertical distribution was essential for the identification of current anthropogenic contamination in terms of Zn, Pb and Cd in the south bank.  相似文献   

13.
为了明确黄河调水调沙对河口海域大型底栖动物群落结构的影响,本研究于2012至2016年调水调沙后进行了大型底栖动物样品的采集工作。整个研究时期共鉴定出大型底栖动物7门138种,生物量和丰度2012年显著高于2016年,生物量年间无显著差异;研究时期内优势种以小型多毛类为主,鲜见软体动物、节肢动物和棘皮动物,其中2016年优势种全部为小个体多毛类;MDS显示,随时间的推移距河口不同距离梯度的大型底栖动物逐渐演变为相同的群落结构,且Shannon-Wiener多样性指数和Margalef丰富度指数呈下降趋势;CCA显示研究海域主要底栖动物种类的生态需求为高中值粒径、低溶解氧、pH、黏土和硫化物含量。本研究推测调水调沙工程一定程度上影响了底层生物群落结构,特别是研究海域的A断面。  相似文献   

14.
海底石油管线泄漏可能导致海床内部形成高浓度石油污染。在波浪作用下,海床沉积物易发生再悬浮甚至液化失稳现象,进而导致海床内部石油类污染物通过多种途径向水体再次释放并在土体内部发生迁移,造成更大范围的石油扩散。本研究以总石油烃(Total Petroleum Hydrocarbon,TPH)设为代表性污染物,将污染泥浆以椭球状埋设在沉积物内部,采用波浪水槽试验研究不同强度波浪作用下TPH向上覆水体的释放规律及在沉积物内部的迁移规律。结果表明,在沉积物静置固结阶段前期,TPH随孔隙水由沉积物向上覆水体迁移释放,固结阶段前期TPH向上覆水体的释放量高于后期。在波浪作用未引起沉积物液化阶段,波浪促进石油类污染物向水体释放的作用较弱,由于悬浮泥沙对石油类污染物的吸附作用,水体中石油类污染物的浓度略低于静置固结阶段。在波浪作用引起沉积物液化阶段,随着悬浮泥沙浓度升高,TPH向上覆水体释放量加大;TPH在沉积物内部垂向迁移及平面扩散迁移距离加大,平面迁移距离大于垂向迁移距离,垂向扩散深度与液化深度基本一致,污染土体体积占比约为土体未液化时的3倍。  相似文献   

15.
The assemblage structure and spatial distribution patterns of macrobenthic communities according to environmental conditions were analysed through five samplings carried out at 14 intertidal soft sediment stations in the Oualidia lagoon (NW Morocco). A total of 89 macrobenthic taxa were collected, amounting to 55.188 specimens. Molluscs, polychaetes and arthropods were the most species‐rich groups. The snail Peringia ulvae was the most dominant species, especially abundant in the mid‐ and upper lagoon sections (nearly 64% of the total specimens gathered), followed by the mollusc Scrobicularia plana (10%). Diversity values were generally low (<3 bit) pointing out the high dominance by few species. Multivariate analyses clearly distinguished three distinct macrobenthic assemblages, successively distributed from lagoon inlets towards inner parts. Nevertheless, each assemblage was found in particular habitat types and had a specific species composition in response to different environmental characteristics. (a) The Scolelepis fuliginosa community occupied sandy substrates at the lower section of the lagoon with stronger marine influence and, (b) the P. ulvae community lived in sandy‐muddy substrates, including two sub‐communities dominated, respectively, by Cerastoderma edule, S. plana and Tritia pfeffeiri inhabiting the middle section and S. plana the upper section. The combination of salinity, temperature, pH and silt content was identified as the major environmental variable subset with the highest correlation with the observed macrofaunal patterns and silt fraction as the single best correlated variable. The results demonstrated significant spatial differences in macrobenthic assemblage structure and composition along environmental gradients in spite of the absence of direct freshwater river inflow.  相似文献   

16.
The present work aimed to identify the main environmental drivers shaping temporal and spatial dynamics of macrobenthic communities within a eutrophic coastal lagoon. Sediments in the óbidos lagoon showed a gradient of increasing metal contamination from the inlet area to inner branches. The mid-lower lagoon area exhibited an intermediate contaminated condition between the inlet and upstream areas, suggesting that the effects of the organic loadings into the lagoon may be reflected until this area. This transitional feature was corroborated by biological data, with macrobenthic assemblages displaying characteristics of down- and upstream areas. Macrobenthic abundance peaked in winter, which was associated with a higher nutrient availability (mainly ammonium) and the proliferation of green macroalgae in mid-lower and inner lagoon areas. However, massive macroalgae growth resulted in a sharp decrease of macrobenthic diversity and abundance in spring, particularly where the higher amounts of decaying algae were detected. Higher dissimilarities between assemblages were detected during winter (and spring, for trophic composition), while in summer, differences were highly attenuated. The least contaminated area (close to the sea inlet) experienced smaller temporal variations for environmental variables, as well as the lowest temporal biological variability. This area was dominated by carnivores, which were related with increased salinity. Deposit-feeders were numerically dominant in the lagoon, being generally spread within organically enriched sandy and muddy areas. The high concentration of chlorophyll a and suspended particulate matter in water was reflected in the abundance of deposit-feeders/suspension-feeders, taking benefit of the high primary productivity. On the other hand, deposit-feeders/herbivores responded to the decay of macroalgae mats in the sediment. Biological associations varied with the biological data used (taxonomic versus trophic group composition; abundance versus biomass), highlighting the relevance of the combination of different data analysis' approaches. In general, BIOENV analysis indicated total phosphorus, biomass of Ulva, metals and organic carbon and nitrogen as being significantly influencing benthic patterns. On the other hand, discrepancies in ecological behaviours of some taxa were also detected in the present study stressing the need for additional studies on the relationships between macrobenthic communities and environmental variables. Implications of the present results for monitoring studies are discussed.  相似文献   

17.
渤海大型底栖动物丰度和生物量的研究   总被引:4,自引:2,他引:4  
于 1997年 6月、1998年 9月和 1999年 4月 3个航次对渤海的大型底栖动物进行了定量研究。在研究海区共采到大型底栖动物 30 6种 ,其中甲壳动物 97种 ,环节动物 95种 ,软体动物 88种 ,棘皮动物 11种 ,其它动物共 15种。其总平均丰度和生物量分别为 2 5 76 ind./m2和4 4 .4 7g/m2。渤海大部海区的总平均生物量在过去十年中可能未发生大的变化。渤海含砂量相对高的生境有较高的动物丰度 ,而在水位较深的水域 ,由于有较高的初级生产量到达底部 ,从而支持着较高的大型底栖动物的生物量。渤海海峡口可能是渤海大型底栖动物生物量的高值区  相似文献   

18.
大连新港"7.16"输油管道爆炸溢油事故发生后,为探究石油污染与细菌群落结构变化之间的关系及在石油生物降解过程中起重要作用的细菌菌群,本研究对大连湾表层沉积物中石油烃含量和细菌宏基因组16SrDNA V3区进行分析。结果表明:溢油初期2010年8月DLW01站位表层沉积物石油烃含量高达1 492mg/kg,符合第三类沉积物质量标准,随着时间推移,2011年4月、2011年7月、2011年12月航次各站位沉积物中石油烃含量基本呈下降趋势,且均符合第一类沉积物质量标准;16S rDNA PCR-DGGE方法分析表明,石油烃含量高的区域优势细菌种类少,反之则较丰富;海洋环境中同一地点的细菌群落能保持一定稳定性;大连湾石油污染沉积物中变形菌门γ-变形菌纲和拟杆菌门一直保持较高的优势度,是在石油生物降解过程中起重要作用的细菌菌群,而厚壁菌门只在石油烃含量低的区域出现;此外,出现的对污染物敏感的嗜冷杆菌可作为石油污染指示生物进行深入研究。  相似文献   

19.
南海西北部浅海沉积物重金属污染的综合评价   总被引:6,自引:0,他引:6  
利用在南海西北部北部湾和海南岛周边海域采集的492个站位的底质沉积物样品,以同一海区内同时采集的柱状样品的底层样品和"清洁区"样品中各重金属元素含量值作为背景值,运用潜在生态危害指数法、沉积物富集系数法和ArcGIS软件,对其Cd、Zn、Pb、Cu和Crs种重金属元素分布特征及其上述2种污染指数的分布图进行了分析和比较...  相似文献   

20.
This work describes short-term responses of sandy-bottom infaunal macrobenthic communities to environmental disturbances, such as episodic storms and the intertidal sewage discharge of the Mar del Plata City (38° S, 57° W, Argentina). Sewage discharge increases by up to 60% every summer due to tourism pressure. Episodic storms affect the area during autumn-winter and arguably have a cleaning effect on the water and sediment quality. Quantitative data on benthic communities (based on Van Veen grab samples), water and sediment variables were obtained in November 1999 and March 2000. During March the sampling was carried out before and after a storm. Parametric and non- parametric tests showed highly significant differences in both environmental (pH, dissolved oxygen, salinity, temperature, grain size and total organic carbon of sediments) and biological data (species distribution and abundances, density, species number, diversity and evenness), reflecting changes that might be related to increasing sewage discharge between November and March, and to storm effects of March. High values of pH and dissolved oxygen, including a slight stratification in the water column, as well as high values of mean grain size and total organic carbon were observed in March with the increasing sewage volume. Nevertheless, diversity and evenness showed low values, but higher density. The ratio crustacean/polychaetes + molluscs also showed low values compared to November data. Maldanid polychaetes (indicator of low content of organic matter in sediments) dominated in November, but they were replaced by the polychaete Prionospio spp. (indicator of organic enrichment in subtidal areas) and the tanaidacean Kalliapseudes schubarti in March. Before the storm event, values of both environmental and biological data returned to relatively normal conditions, but without reaching the November values, reflecting the disturbance produced by a moderate northern storm. In spite of an inappropriate replication in time, the present results strongly suggest that these changes were related to both sewage disturbance and storm effects. These data are in agreement with and explain the pattern observed in shallow-shelf benthic communities of the SW Atlantic. Implications for environmental management and decision making are discussed, because a pulse disturbance (storms) becomes a press disturbance, keeping the environment healthy in spite of strong pressure and pulse sewage-disturbances.  相似文献   

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