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1.
Rapid population increase and economic growth in eastern China has lead to the degradation of many water bodies in the region, such as Lake Taihu, the third largest freshwater lake in China. Using data from recent investigations, the correlations between algae (measured as chlorophyll-a) and water quality indices in Lake Taihu were described by multivariate statistical analyses, and the key driving factors for the lake eutrophication were identified by principal component analysis. Results revealed strong spatiotemporal variation in the correlations between algae and water quality indices, suggesting that the limiting factor for the dominant algae growth depends on seasonality and location and it is necessary to reduce both nitrogen and phosphorus inputs for a long-term eutrophication control in this hyper-eutrophic system. Water temperature was another important controlling factor for algal growth in the lake. Using principal component analysis, nutrient contaminations from anthropogenic and natural inputs were identified as the key driving factor for the water quality problems of the lake. Moreover, five principal components were extracted and characterized with high spatial and seasonal variations in Lake Taihu. The key driving factors were believed to influence spatial variations including heavily polluted areas located in the northern and northwestern parts of the lake, where many manufacturing factories were built and wastewater from domestic and industrial plants was discharged. Based on this analysis, attention should be paid to effective land management, industrial wastewater treatment, and macrophytic vegetation restoration to reduce the pollutant loads and improve water quality. Principal component analysis was found to be a useful and effective method to reduce the number of analytical parameters without notably impairing the quality of information in this study.  相似文献   

2.
太湖生态环境演化及其原因分析   总被引:2,自引:1,他引:2       下载免费PDF全文
太湖地处长江下游三角洲,水域面积为2338km2,平均水深1.9m,最大水深不足2.6m,为一典型的大型浅水湖泊。太湖流域地势平坦,河网密布,河湖水力关系复杂。其主要补给径流来自西南部的天目山区及西部的宜溧河流域。每年夏天,大部分入湖洪水通过位于东太湖的太浦河及东北部的望虞河分别排入黄浦江与长江,由于出入湖河道的特殊位置,使得太湖南部的换水周期较短而北部较长。近几十年来,太湖由于污染而逐步呈现富营养化特征,污染物主要来自北部的无锡市和常州市,通过河道排入太湖北部的五里湖与梅梁湾,因此上述两地的水质较南部差。在东太湖,水产养殖对水环境的影响很大,亦呈现出富营养化特征,并殃及该地区的供水,加之该地区为太湖主要的泄洪通道,因此泥沙淤积严重,而且水生植物生长旺盛,呈现出明显的沼泽化趋势;在太湖四周地区,由于湖泊围垦和水利工程建设,其污染净化能力将降低,从而加速水环境恶化的趋势。太湖所面临这些问题,有待于强化湖泊科学管理来解决。  相似文献   

3.
太湖生态环境演化及其原因分析   总被引:42,自引:10,他引:32  
太湖地处长江下游三角洲,水域面积为2338km2,平均水深1.9m,最大水深不足2.6m,为一典型的大型浅水湖泊。太湖流域地势平坦,河网密布,河湖水力关系复杂。其主要补给径流来自西南部的天目山区及西部的宜溧河流域。每年夏天,大部分入湖洪水通过位于东太湖的太浦河及东北部的望虞河分别排入黄浦江与长江,由于出入湖河道的特殊位置,使得太湖南部的换水周期较短而北部较长。近几十年来,太湖由于污染而逐步呈现富营养化特征,污染物主要来自北部的无锡市和常州市,通过河道排入太湖北部的五里湖与梅梁湾,因此上述两地的水质较南部差。在东太湖,水产养殖对水环境的影响很大,亦呈现出富营养化特征,并殃及该地区的供水,加之该地区为太湖主要的泄洪通道,因此泥沙淤积严重,而且水生植物生长旺盛,呈现出明显的沼泽化趋势;在太湖四周地区,由于湖泊围垦和水利工程建设,其污染净化能力将降低,从而加速水环境恶化的趋势。太湖所面临这些问题,有待于强化湖泊科学管理来解决。  相似文献   

4.
Pollution in Taihu Lake China: causal chain and policy options analyses   总被引:1,自引:0,他引:1  
Taihu Lake is located at the densely populated region of the eastern coast of China. Taihu Basin is one of the most developed regions of China. Over the past decades, especially since the reforming and opening-up of China in 1980s, the lake has received more and more pressure from a variety of interlinked human activities, including industrial pollution, fertilizer and pesticide application, eutrophication, overfishing, etc. Water quality has been deteriorating sharply in the lake. In this paper, we made a comprehensive assessment of the environmental and socio-economic issues to affect Taihu Lake ecosystem health. Pollution was identified as the most serious environmental concern. The root causes of these environmental problems are recognized to be diverse, including dense population, high urbanization, heavy industrialization, fast economic development, insufficient sewage treatment, weak public awareness of environment conservation, and lack of institutional capacity and insufficient enforcement through regulations and legislation. On the policy part, past and current policies and measures are reviewed, especially the “Zero” discharge action and phosphate ban in detergents in Taihu Basin. In order to mitigate environmental problems, some further policy options have been proposed, including: improving the fishery management; strengthening cross- provincial collaboration; making efforts to reduce flood disaster and increasing investment to new environmental protection technologies. It is important to assess the economic, social and environmental values of natural resources (soil, water and organisms) in order to allocate them efficiently and fairly between the present and future generations.  相似文献   

5.
太湖14000年以来古环境演变的湖泊记录   总被引:5,自引:0,他引:5  
本文根据东西太湖短柱岩芯的沉积物的物理、化学、生物指标的综合分析,讨论了该区距今14ka来的古气候变化过程,结果表明14.3-13.3kaBP,太湖水位低,环境指标甚至表现为暴露特征,反映了气候干旱:13.3-12.4kaBP,为偏暖湿的过渡阶段;该孔柱270-280cm (11.5kaBP左右)各类指标均明显反映冷干特征,可能是YoungerDrays事件的记录,与我国东部其它地区有可比性;约10.9-10kaBP,这一时期是整个研究时段内一个较显著的温暖期。表现为还原沉积环境和水位相对较深;约10-7.2kaBP为冷暖交替的过渡带;7.2-5.737kaBP为暖湿气候;5.05kaBP多项分析指标发生突变,反映物源发生显著变化,可能存在沉积间断;表层沉积物则呈现现代环境的特征,西太湖藻类生长茂盛,偏氧化的沉积环境。目前湖泊生产力较高,富营养化程度高,表现为藻型湖泊特征;东太湖有机质来源以东太湖中生长较为茂盛的维管水生植物为主,目前湖泊生产力较低,富营养化程度低,表现为典型的草型湖泊特征。   相似文献   

6.
太湖富营养化与蓝藻水华引起的饮用水危机——原因与对策   总被引:58,自引:0,他引:58  
[ZW(*][HT6H]〓收稿日期:. 〓作者简介:[HT6SS](1963 ),男,江苏苏州人,研究员,主要从事水环境研究.[WT6HZ]E mail:[WT6BZ]qinbq@niglas.ac.cn[ZW)] [HT4F][HT5K]()[JZ)] [HT5H][GK2] 摘〓要:[HT5K]2007年5月份发生在无锡太湖蓝藻水华引起的自来水危机事件进一步凸现我国湖泊富营养化的严峻局面和蓝藻水华频发的现状。从分析太湖富营养化发生、发展,蓝藻水华爆发的原因和机制入手,提出湖泊富营养化治理和蓝藻水华控制的途径和措施。研究表明,太湖富营养化之所以如此严重而且治理起来异常艰难,主要是由于太湖发育于长江中下游洪泛平原,营养本底高;由于水浅和沉水植被的退化使得频繁的风浪扰动造成内源营养盐负荷维持在一个非常高的水平;而流域内社会经济的高速发展,进一步加剧了太湖富营养化进程。蓝藻水华爆发一方面与蓝藻本身的生理特征有关,如固碳、伪空泡、光吸收及营养盐利用的能力;另一方面则与系统内物理、化学、生物环境有关,如独特的浅水湖泊水下光场结构和低的捕食压力。太湖的富营养化治理需遵循控源截污、湖泊生态修复和流域管理的原则,具体措施包括前置库和人工湿地的面源污染物控制技术;物理机械和生物去除内源营养盐削减技术;沉水植被恢复的湖泊生态修复技术。而蓝藻水华的控制技术则包括围隔拦截和导流的物理工程方法、絮凝沉降和抑藻物添加的化学工程方法以及生态浮床和生物操纵的生态工程方法。具体使用时,需要先诊断、后治理。    相似文献   

7.
太湖流域营养盐产量演变和趋势的数值模拟研究   总被引:4,自引:4,他引:0       下载免费PDF全文
于革  沈华东 《第四纪研究》2008,28(4):667-673
认识流域湖泊水体富营养化的演变和趋势是湖泊污染控制和治理中的重要研究课题。本文将在分析和论证太湖流域营养盐自然本底、人类活动作用急剧增加的近50年来太湖流域营养盐的变化情况、以及全球气候变化和流域经济发展未来30年太湖流域营养盐变化趋势等三方面的基础上,对太湖流域营养盐产量变化做出评估和预测。研究表明,在未来气候变化概率分析和区域经济发展规划基础上,太湖流域未来30年营养盐流域产量将比现代(2000s)增加25%~33%,这将增大太湖水体污染的压力。  相似文献   

8.
To understand the geochemical cycle of Hg in hypereutrophic freshwater lake, two sampling campaigns were conducted in Lake Taihu in China during May and September of 2009. The concentrations of unfiltered total Hg (unfTHg) were in the range of 6.8–83 ng L−1 (28 ± 18 ng L−1) in the lake water and total Hg in the sediment was 12–470 ng g−1, both of which are higher than in other background lakes. The concentration of unfTHg in ∼11% of the lake water samples exceeded the second class of the Chinese environmental standards for surface water of 50 ng L−1 (GB 3838-2002), indicating that a high ecological risk is posed by the Hg in Lake Taihu. However, the concentrations of unfiltered total MeHg (unfMeHg) were relatively low in the lake water (0.14 ± 0.05 ng L−1, excluding two samples with 0.81 and 1.0 ng L−1). Lake sediment MeHg varied from 0.2–0.96 ng g−1, with generally low ratios of MeHg/THg of <1%. The low concentrations of TMeHg in the lake water may have resulted from a strong uptake by the high primary productivity and the demethylation of MeHg in oxic conditions. In addition, contrary to the results of previous research conducted in deep-water lakes and reservoirs, the low concentrations of MeHg and low ratio of MeHg/THg in the lake sediment indicates that the net methylation of Hg was not accelerated by the elevated organic matter load created by the eutrophication of Lake Taihu. The results also showed that sediments were a source of THg and MeHg in the water. Higher diffusion fluxes of THg and MeHg may be partly responsible for the higher concentrations of THg in the lake water in May, 2009.  相似文献   

9.
傍江备用应急地下水源地建设及意义   总被引:1,自引:0,他引:1       下载免费PDF全文
缪晓图 《江苏地质》2008,32(3):239-243
根据太湖水源水质富营养化现状和长江地表水源所处的地理位置,论述长江两侧地带系第四纪以来古长江河道沉积区,孔隙含水层厚度大、储存资源丰富、水质好,有江水天然补给条件,具备建设若干个江南、江北区域备用应急地下水源地的条件。建议开展沿江两侧地带备用应急水源地勘察评价,为长江三角洲地区应对地表水供水水源遭遇突发污染事件,提供备用应急地下水源,保障城乡居民饮用供水安全。  相似文献   

10.
云南程海富营养化过程的碳氧稳定同位素示踪   总被引:9,自引:2,他引:9  
近500年来程海生物成因碳酸盐δ18O和δ13C及其有机质δ13C同位素记录了程海湖泊环境由贫营养到中富营养的演化过程.碳酸盐δ18O记录显示,大约1690年程海成为封闭湖泊后,当时湖泊贫营养环境并没有发生变化,但造成了湖泊水体交换周期加长,碳酸盐δ13C、有机质δ13C及其色素含量、碳酸盐含量变化指示湖泊生产力开始增高.1911~1942年碳酸盐δ18O和δ13C及有机质δ13C突然显著偏负,表明湖泊生物种群结构发生转变,湖泊初级生产力迅速增加,湖泊由贫营养向中营养转化.湖泊沉积物色素含量及碳酸盐含量变化也记录了这一湖泊环境的转换过程.约1986年以来,随着藻类养殖业及其农业耕作方式的转变,程海水环境渐渐转变成目前的中富营养化状态.  相似文献   

11.
Taihu Basin is one of the most developed and industrialized regions in China. In the last two decades, rapid development of economy as well as an increase in population has resulted in an increase of pollutants produced and discharged into rivers and lakes. Much more attention has been paid on the serious water pollution problems due to high frequency of algal blooming. The dataset, obtained during the period 2001–2002 from the Water Resources Protection Bureau of the Taihu Basin, consisted of eight physicochemical variables surveyed monthly at 22 sampling sites in the Taihu Basin, China. Principal component analysis (PCA) and cluster analysis (CA) were used to identify the characteristics of the surface water quality in the studied area. The temporal and spatial variations of water quality were also evaluated by using the fuzzy synthetic evaluation (FSE) method. PCA extracted the first two principal components (PCs), explaining 86.18% of the total variance of the raw data. Especially, PC1 (73.72%) had strong positive correlation with DO, and was negatively associated with CODMn, COD, BOD, NH4 +–N, TP and TN. PC2 (12.46%) was characterized by pH. CA showed that most sites were highly polluted by industrial and domestic wastewater which contributed significantly to PC1. The sites located in the west of Lake Taihu were influenced by farmland runoff which may contribute to nitrogen pollution of Lake Taihu, whereas the monitoring sites in the eastern of Lake Taihu demonstrated that urban residential subsistence and domestic wastewater are the major contaminants. FSE indicates that there is no obvious variance between 2001 and 2002 among most sites. Only several sites free from point-source pollution appear to exhibit good water quality through the studied period.  相似文献   

12.
Climatic changes and anthropogenic activities could affect nutrients?? status significantly in the different lake ecosystems. Nutrients in Lake Hulun and Lake Taihu, two largest shallow cyanobacteria-blooming lakes in northern and southern China, respectively, were at eutrophicated levels in 2009. The concentrations of total nitrogen and total phosphorus were 3.346 and 2.250?mg/L as well as 0.435 and 0.062?mg/L, respectively, in these two lakes with different causes of eutrophication. For Lake Hulun, it was the decreased amount of water as a result of the warming and drying climate that accounted for the abrupt increase of total nitrogen and total phosphorus levels through inspissation. In addition, the icebound effects, no outflows, low nutrients sequestration by the sediment and the reduction of aquatic productivity made the situation even worse. On the contrary, high population densities, the rapid development of agriculture and industry as well as urbanization have increased the nitrogen and phosphorus loads on Lake Taihu. Therefore, higher criteria of total nitrogen and total phosphorus should be applied in Lake Hulun given the difficulties in controlling climatic changes while much more rigorous standards should be established for Lake Taihu since the anthropogenic impacts on nutrient status are relatively easy to control.  相似文献   

13.
Hulun Lake and Taihu Lake are both large shallow lakes in China. In summer and winter of 2009, water, sediments and fish samples were collected from the two lakes and the concentrations of metal(loids) were analyzed. The results demonstrated that aqueous concentrations of arsenic (As), chromium (Cr), cadmium (Cd), nickel (Ni) and copper (Cu) in Hulun Lake were significantly higher than those in Taihu Lake. Especially, the As concentrations (about 130 μg/L) in Hulun Lake dramatically exceeded the permissible level of drinking water. Compared with Taihu Lake, metal(loid) concentrations in the sediments of Hulun Lake were significantly lower, which might have less impacts on the metal exchanges between water and sediments. In contrast, concentrations of the measured metal(loids) (including As) in fish from Hulun Lake and Taihu Lake were comparable, suggesting that the dramatic difference in aqueous and sediment metal(loid) concentrations had less influence on the metal(loid) bioavailability. The higher concentrations of dissolved organic carbon (DOC) and cations (e.g., Na+, K+ and Mg2+) in lake water might contribute to the reduced metal(loid) bioavailability to fish in Hulun Lake.  相似文献   

14.
To assess the contamination trends and potential bio-availability of sediment-bound heavy metals, concentrations of heavy metals in acid-leaching fraction and in bulk sediments from the two typical bays (the Meiliang Bay and Xuhu Bay) of the Taihu Lake, East China, were studied. Pb and Zn showed elevated concentrations in the sediments from both areas, although sedimentation history and degree of pollution are different between the two bays. In the Meiliang Bay, both Pb and Zn pollutions started in the late 1970’s, the same time as the beginning of eutrophication of the lake, while the in the Xuhu Bay the metal contamination started since recent 10 years. The concentrations of acid-leachable Pb in the sediments from the Meiliang Bay are correlated with the historical eutrophication process. Before the eutrophication and heavy metal pollution, the chemical properties of the lake sediments were the same as the source compositions of the Xiashu loess. Both Pb and Zn in the sediments mainly occur in leachable forms by nitric or hydrochloric acid, whilst most of Cu is in residual fraction. The results indicate that both Pb and Zn may have higher mobility and bioavailability in water and biology than Cu.  相似文献   

15.
Total organic carbon (TOC), Total nitrogen (TN) and the phosphorus species concentrations of sediment cores taken from Zhushan Bay, Meiliang Bay, and East Taihu Lake regions in Taihu Lake, a large shallow lake in China, were determined. Experimental results showed a conspicuous eutrophication trend in the northern area of Taihu Lake. Inorganic P was found to be the main phosphorus form. Fe-bound P accounted for the largest proportion of Inorganic P in Meiliang Bay, an alga-type lake region. In East Taihu Lake, a macrophytic lake region, Ca-bound P was found in higher proportions than in other lake regions, with Organic P present in similarly large proportions. With respect to Taihu Lake sediment cores, the date at approximately 20 cm layer depth was roughly identified as 1950s, while upper 5 cm layers corresponded to the turn of the century. The drastic increase in phosphorus species concentration except for Ca-bound P was indicative of the large quantities of effluent discharge into Zhushan Bay owing to the increased industrial and agricultural production from the 1950s onwards. TN, Inorganic P, Organic P, and total phosphorus (TP) concentrations increased by over 2, 2.5, 2 and 2.5-fold, respectively, over the past five decades. A large proportion of Organic P accounted for TP, and high C/N ratios indicated that East Taihu Lake can be properly classified as an oligotrophic lake.  相似文献   

16.
太湖流域土壤重金属元素污染历史的重建:以Pb、Cd为例   总被引:5,自引:1,他引:4  
太湖是位于长江下游的一个大型浅水湖泊,通过对4个代表太湖不同沉积环境的湖底沉积剖面的137Cs和210Pb沉积定年,重建太湖湖底沉积物和太湖来水流域土壤Cd、Pb的污染历史。结果显示:1980年以前,太湖底积物中Cd、Pb含量与流域内的自然背景含量相当,1980年以后,湖底沉积物中的Cd、Pb含量显著增高,这与我国大规模工业化进程的起始时间基本一致,推测工业化进程是湖底沉积物中Cd、Pb含量增加的主要原因。1900年以来太湖湖底沉积物中累积含有Cd和Pb分别为146t和25980t,其中苕溪来水提供的Cd和Pb分别为40t、6777t,宜溧河来水提供的Cd、Pb分别为36t、6023t,其他来水(洮、滆、运河)提供的Cd、Pb分别为71t、13179t,其他来水是太湖Cd、Pd累积的主要输入途径。Cd、Pb累积的高峰期为20世纪80—90年代,1980年以来,运河来水Cd、Pb的输出通量为28.26t、3419t;苕溪流域Cd、Pb的输出总量分别为13.70t、1585t,其中人为源的Cd、Pb为8.90t、610t,人为源输出的Cd、Pb通量占总输出量的64.96%和38.47%;宜溧河流域Cd、Pb的输出总量分别为10.09t、1063t,人为源的Cd、Pb分别6.96t和500t,人为源输出的Cd、Pb通量占总输出量的68.68%和47.08%,表明太湖流域人类活动所导致的Cd已超过自然剥蚀过程,因此削减工业化进程中的Cd、Pb排放总量,控制太湖运河来水的输出通量是改善太湖底积物Cd、Pb环境质量的关键措施。  相似文献   

17.
Lake Kastoria is a shallow lake with many anthropogenic activities concentrated in its catchment area. Surficial runoff rich in agricultural waste and underground seepage from urban and rural areas enrich the lake with nutrients intensifying the eutrophication problem of the water.Restoration techniques, with different approach, each one are proposed to restore the lake water. Treatment with alum is very effective but needs special care during the application. Reeds harvesting is an inexpensive and effective way and in combination with the city sewage redirection will improve the water quality and the trophic status of the lake sufficiently.  相似文献   

18.
长江流域水资源、灾害及水环境状况初步分析   总被引:1,自引:0,他引:1  
长江是我国第一、世界第三大河流,发源于青藏高原,全长6300多公里,流域面积180×104km2,占中国陆地面积的1/5。长江及其流域不仅以其不可替代的自然资源优势和其他江河无法比拟的区位优势,在我国国民经济和社会发展中扮演着举足轻重的角色,特别是约占全国的36%、拥有9616×108m3的年径流量(为黄河的20倍),是我国最重要的水源地。这不仅对长江流域资源优势的发挥和缓解我国北方地区日趋严重的水资源短缺问题至关重要,而且对全国的可持续发展也将产生深远影响。然而,在长江流域大规模开发及经济快速发展的同时,人类活动与自然规律的负面效应相互叠加,导致了流域环境的生态调节和自我恢复功能大幅降低,引起了日趋严重的水环境退化、洪涝灾害威胁加剧等问题。文章首先对长江流域水资源的重要性及其作用做了分析,肯定了其丰富的资源和重要的战略地位,该流域在占全国不足18%的土地上,集中了40%以上的人口及国民生产总值,而且其经济地位有进一步上升的趋势,在水量及水能的蕴藏上,全流域湖泊面积达10323km2,占我国淡水湖泊总面积的37.2%,水能蕴藏总计达2.7×108kW。另外,对长江流域日趋严重灾害及水环境问题做了探讨,尤其中游的洪水、淤积以及随着经济发  相似文献   

19.
长江流域水资源、灾害及水环境状况初步分析   总被引:11,自引:0,他引:11       下载免费PDF全文
长江是我国第一、世界第三大河流,发源于青藏高原,全长6300多公里,流域面积180×104km2,占中国陆地面积的1/5。长江及其流域不仅以其不可替代的自然资源优势和其他江河无法比拟的区位优势,在我国国民经济和社会发展中扮演着举足轻重的角色,特别是约占全国的36%、拥有9616×108m3的年径流量(为黄河的20倍),是我国最重要的水源地。这不仅对长江流域资源优势的发挥和缓解我国北方地区日趋严重的水资源短缺问题至关重要,而且对全国的可持续发展也将产生深远影响。然而,在长江流域大规模开发及经济快速发展的同时,人类活动与自然规律的负面效应相互叠加,导致了流域环境的生态调节和自我恢复功能大幅降低,引起了日趋严重的水环境退化、洪涝灾害威胁加剧等问题。文章首先对长江流域水资源的重要性及其作用做了分析,肯定了其丰富的资源和重要的战略地位,该流域在占全国不足18%的土地上,集中了40%以上的人口及国民生产总值,而且其经济地位有进一步上升的趋势,在水量及水能的蕴藏上,全流域湖泊面积达10323km2,占我国淡水湖泊总面积的37.2%,水能蕴藏总计达2.7×108kW。另外,对长江流域日趋严重灾害及水环境问题做了探讨,尤其中游的洪水、淤积以及随着经济发  相似文献   

20.
太湖湖体总氮平衡及水质可控目标   总被引:3,自引:0,他引:3       下载免费PDF全文
胡开明  逄勇  王华 《水科学进展》2012,23(4):555-562
通过对2007~2010年环太湖水文巡测及降水调查,进行了湖体总氮平衡分析,在充分调查现有与规划的各类型污染源总量控制工程措施的基础上,量化出具有空间分布的流域总氮污染削减率,利用构建的太湖流域及湖体水环境数学模型模拟污染削减后的太湖湖体总氮浓度场,并提出水质可控目标。结果表明:太湖出入水量共127.8亿 m3,其中通过降水进入太湖的水量为24.9亿 m3,占入湖总水量的19.5%;全年总氮收支量达到4.47万t,其中通过干湿沉降进入太湖的总氮量为0.70万t,占入湖总通量的15.5%,可见干湿沉降进入太湖的污染物不容忽视,其变化趋势与太湖地区降水特征相关性较好。同时通过模型推算,定出2015年太湖湖体不同功能区总氮的可控目标,整个湖体平均值约为2.3 mg/L,为太湖总量控制提供科学依据。  相似文献   

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