共查询到19条相似文献，搜索用时 31 毫秒
1.
着重研究了红海湾养殖区底质水中 NO-3 -N、NO-2 -N、NH 4-N、PO3 -4 -P、有机质及 c( NO-3 -N) /c P 和 ∑c N/c P( ∑c N=c( NO-2 ) c( NO-3 ) c( NH 4) )比值的分布特征 ,并对该湾低质水中氮、磷及有机质的季节变化及其它们之间的相互关系作了讨论 ,结果表明 :在春、夏、冬三个季节中 ,NH 4-N的浓度比NO-2 -N及 NO-3 -N高 ,春季 NH 4-N的平均浓度为 92 .60 μm ol/L,占总无机氮 80 .57% ;夏季浓度为4 7.0 4μmol/L ,占总无机氮 61 .64 % ;冬季 NH 4-N的浓度最低 ,为 9.60μmol/L ,占总无机氮 4 5.76% ;而夏季 PO3 -4 -P浓度及有机质的含量比春、冬季高 ,分别为 53 .68μm ol/L和 1 .3 62 %。分析指出该湾底质水中无机氮是以 NH 4-N为主要存在形态。 相似文献
2.
不同温度下罗非鱼人工感染海豚链球菌后血液生化指标及组织病理 总被引：1，自引：0，他引：1
在28℃、33℃两种温度下,用海豚链球菌人工感染尼罗罗非鱼后,测定尼罗罗非鱼血液生化指标。结果显示:两个温度水平病鱼的血清总蛋白(TP)随时间延长都呈现升高趋势;谷丙转氨酶(ALT)、谷草转氨酶(AST)活性随时间延长先升高后降低再升高,33℃实验组ALT、AST活性比28℃实验组达峰值时间短,并显著高于对照组(p<0.05);尿素、钾(K+)含量随时间延长逐渐升高后降低,钠(Na+)含量先升高后降低再升高,肌酐含量呈上升趋势;血清碱性磷酸酶(AKP)活性28℃实验组呈先升高后降低趋势,33℃实验组呈升高趋势;超氧化歧化酶(SOD)活性随时间延长先升高后降低再升高,33℃实验组各个时间点基本高于28℃实验组;球蛋白(GLO)随感染后时间延长呈现升高趋势,至120 h,显著高于对照组(p<0.05),但温度组间各时间点没有显著差异(p>0.05)。组织病理学观察发现,33℃实验组肝细胞、肾小管上皮细胞水肿变性;28℃实验组肝细胞出现嗜酸性小体;肾小管上皮细胞出现嗜酸性的红色小体,颗粒变性。表明感染海豚链球菌的尼罗罗非鱼肝脏、肾脏均有损伤,造成功能障碍,高温时损伤更严重。 相似文献
3.
《广东海洋大学学报》2018,(1)
目的】研究了珠江口区域近年来大气湿沉降中无机氮的变化特征及其对近海海水生态系统的影响。【方法】对2003-2014年珠海市香洲地区湿沉降中NO_3~--N和NH_4~+-N浓度及湿沉降通量的变化特征进行了分析。【结果】香洲地区湿沉降中NO_3~--N和NH_4~+-N的浓度均有明显的季节变化,表现为旱季高而雨季低,与降雨量呈相反的变化趋势;氮素的浓度在年际变化有波动,但无明显变化趋势;氮素湿沉降通量与浓度变化相反,雨季明显高于旱季;降水量、当地污染状况、大气中污染物(气溶胶粒子)浓度、降雨类型以及气象条件等因素是造成季节差异的主要原因;此外,香洲地区大气无机氮湿沉降具有很强的事件特征。【结论】香洲地区氮素湿沉降浓度春秋季高于海水,且DIN成分比例与海水有差异,可能改变表层水体营养盐结构,影响浮游植物的生长。 相似文献
4.
模拟湛江港涉海工程施工产生的悬浮物,探讨底泥悬浮物对工程附近海区近江牡蛎养殖的影响,研究不同浓度悬浮物对大、小规格近江牡蛎(Crassostrea rivularis)的毒害效应。结果表明,悬浮物对大规格近江牡蛎(8.12±1.76 cm)的毒害影响不明显;对小规格近江牡蛎(2.33±0.78 cm),悬浮物浓度≤270 mg/L时死亡率低于30%,悬浮物浓度≥810 mg/L时死亡明显增加,死亡率达60%。通过概率单位法计算,小规格近江牡蛎的96 h半致死浓度为627.17 mg/L。 相似文献
5.
《广东海洋大学学报》2021,(3)
【目的】研究珠江口2000—2016年湿沉降的酸度、无机氮、SO_4~(2-)及其他离子的浓度变化和发展趋势,阐明珠江口大气氮(N)、硫(S)等溶解性无机离子的污染状况。【方法】利用东亚酸沉降监测网2000—2016年珠江口湿沉降浓度数据,分析其化学特征和长期变化趋势。【结果】2001—2006年,珠江口雨水中的铵根(NH_4~+)、硝酸根(NO_3~-)和硫酸根(SO_4~(2-))浓度波动下降;2007—2016年,NO_3~-和NH_4~+浓度总体缓慢波动上升,SO_4~(2-)浓度无明显变化。pH值在2000—2005年波动变化较大,2006—2016年总体呈上升趋势,但仍低于酸雨值(pH 5.6);降雨酸度变化不仅受当地污染物排放的影响,同时也受到广东省内大气污染物排放的影响。SO_4~(2-)、NH_4~+、NO_3~-、钙离子(Ca~(2+))和氯离子(Cl~-)的沉降通量在2000—2006年间呈下降趋势,2007—2016年总体波动上升,人为来源是N、S和Cl沉降通量升高的主要因素。与其他区域相比,N和S沉降通量高于南海其他近岸区域,但低于中国南方其他城市区域。【结论】N、S和Cl沉降通量的不断升高,会使珠江口雨水酸化加重,进一步危害其生态系统,需要加强对N、S和Cl排放的管控。 相似文献
6.
Soil organic carbon and nutrients along an alpine grassland transect across Northern Tibet 总被引：4，自引：1，他引：3
Soil carbon and nutrient contents and their importance in advancing our understanding of biogeochemical cycling in terrestrial ecosystem, has motivated ecologists to find their spatial patterns in various geographical area. Few studies have focused on changes in the physical and chemical properties of soils at high altitudes. Our aim was to identify the spatial distribution of soil physical and chemical properties in cold and arid climatic region. We also tried to explore relationship between soil organic carbon (SOC) and total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), soil particle size distribution (PSD). Samples were collected at 44 sites along a 300 km transect across the alpine grassland of northern Tibet. The study results showed that grassland type was the main factor influencing SOC, TN and TP distribution along the Gangdise Mountain-Shenzha-Shuanghu Transect. SOC, TN and TP contents were significantly higher in alpine meadow than alpine steppe ecosystems. SOC, TN, TP and AN contents in two soil layers (0-15 cm and 15-30 cm) showed no significant differences, while AP content in top soil (0-15 cm) was significantly higher than that in sub-top soil (15-30 cm). SOC content was correlated positively with TN and TP content (r = 0.901 and 0.510, respectively). No correlations were detected for clay content and fractal dimension of particle size distribution (D). Our study results indicated the effects of vegetation on soil C, N and P seem to be more important than that of rocks itself along latitude gradient on the northern Tibetan Plateau. However, we did not found similar impacts of vegetation on soil properties in depth. Inaddition, this study also provided an interesting contribution to the global data pool on soil carbon stocks. 相似文献
7.
《广东海洋大学学报》2020,(4)
【目的】探讨石油污染水体油浓度及后向散射系数垂向分布特性,为研究石油类污染水体水下光场变化奠定基础。【方法】于2018年8月25-27日在大连港采用站点固定、时间随潮汐变化的观测方式,测量不同深度的油物质和悬浮物浓度,以及含油水体的后向散射系数(backscattering coefficient, bb)。【结果】油浓度随深度的变化比较复杂,未呈现明显的逐渐下降或者逐渐升高的趋势;不同波段的bb随着深度的变化趋势是一致的;在量级上,bb值最小对应的波段是700 nm,其次是590 nm波段,最大是510、470、442和420 nm,且这4个波段的bb值差别不大;水体后向散射系数bb随深度的变化可以分为陡增型、平缓增加型和单峰型等三种类型。【结论】在含油水体中油浓度和后向散射系数的垂向变化受到潮汐的影响,处于不同涨落潮时不同来向的海水其组分含量不同;石油物质通过吸附在悬浮颗粒物表面形成一个双层结构,共同影响着水体的后向散射系数。 相似文献
8.
为探究环境中抗生素输入方式对反硝化过程的影响,选择盐酸洛美沙星(LOM)为代表抗生素,以纳米乳化油为碳源,开展了LOM浓度(200 ng·L-1和2 mg·L-1)与输入方式(一次输入和两次输入)不同组合条件下的反硝化模拟实验.结果表明:相同输入方式下,高浓度体系对NO-3-N还原的抑制率比低浓度体系高;相同浓度不同输... 相似文献
9.
【目的】探究海参酶解液对高糖高脂所致的斑马鱼抑郁样行为的改善作用。【方法】将斑马鱼随机分为对照组、模型组各1组,和海参酶解液高剂量(1.0m L/L)治疗组、低剂量(0.5m L/L)治疗组各1组。每天利用高浓度葡萄糖(质量分数2%)系统浸泡及高胆固醇(质量分数10%)饲料饲喂诱导斑马鱼高糖高脂模型,高低浓度海参酶解液浸泡治疗。14 d后进行新鱼缸潜水行为实验,取鱼体匀浆进行组织各生化指标的检测,包括葡萄糖(Glucose, Glu)、总胆固醇(Total cholesterol, TC)、皮质醇(Cortisol, Cor)浓度。【结果】新鱼缸行为实验中,与对照组相比较,模型组斑马鱼的行为学实验都有明显差异,其中焦虑型行为潜伏期、冻结次数和冻结时间等抑郁型行为增加,探究型行为顶部转移和顶部时间减少,而1.0 mL/L高剂量海参酶解液可以逆转这些变化。模型组葡萄糖、总胆固醇、皮质醇浓度相比对照组显著升高,而给予海参酶解液治疗后,高剂量治疗组对模型组的葡萄糖、总胆固醇及皮质醇浓度均有显著降低的作用。【结论】海参酶解液可以通过改善高糖高脂诱导的糖尿病模型中糖脂水平来改善抑郁样行为和应激激素。 相似文献
10.
【目的】探讨白骨壤人工湿地处理模拟对虾养殖废水的效果。【方法】通过室内构建白骨壤垂直流人工湿地和无植被人工湿地系统,研究处理时间和水力负荷对人工湿地处理模拟对虾养殖废水的影响,并分析人工湿地内部生物膜的细菌群落结构。【结果】人工湿地启动60d后的稳定运行阶段,白骨壤人工湿地总氮和氨氮的去除率分别在77.19%～84.66%,91.62%～98.48%,无植被人工湿地总氮和氨氮去除率分别在41.40%～61.69%,47.08%～79.79%,白骨壤人工湿地对总氮和氨氮去除率显著高于无植被人工湿地(P <0.05);在总磷、有机物和总有机碳去除率方面,两者无显著差异。白骨壤人工湿地处理养殖废水3d后总氮、氨氮、总磷、有机物和总有机碳去除率分别为84.7%、94.1%、92.0%、64.1%和66.2%,出水浓度均低于海水养殖废水排放标准(GB3097-1997)。白骨壤人工湿地生物膜中变形杆菌门(Proteobacteria)、硝化螺旋菌门(Nitrospinae)丰度显著高于无植被人工湿地(P <0.05);无植被人工湿地蓝细菌占细菌总量的5.36%。水力负荷对总氮、氨氮和总磷的去除率影响显著(P<0.05);当水力负荷0.06m^3/(m^2·d-1)时,总氮、氨氮和总磷的去除率均达到最大值,分别为66.6%、75.0%和41.8%;日去污量均值为51.6、73.5和10.4 mg/d。有机物和总有机碳在不同水力负荷下去除率变化不显著(P> 0.05)。【结论】白骨壤构建海水人工湿地是循环海水养殖废水生物处理的一种有效途径。 相似文献
11.
总氮质量浓度是衡量水环境的主要指标之一。以粤西海域为研究对象,将实测的总氮质量浓度和水体高光谱遥感反射率数据进行回归分析处理,结果表明:无论是单波段,还是波段因子,总氮质量浓度与水体高光谱遥感反射率的相关性仅达到0.593;研究区域的总氮和悬浮物具有较好的相关性,相关系数最高可以达到0.76。通过悬浮物间接的遥感监测粤西海域的总氮是一个有效的途径。 相似文献
12.
LU Yan LIU Lyuyi QIN Fen WANG Jiayao LIU Jianzhong LI Yingjie WAN Luwen 《中国地理科学(英文版)》2023,(3):512-530
As total nitrogen(TN) and total phosphorus(TP) pollution is the main source of water pollution in the Huaihe River watershed in China, it is important to understand how TN and TP pollution affect the relationship between water supply and demand. Quantifying their impacts and describing the spatiotemporal distribution of these relationships are necessary for furtherly deepening the theory of TN and TP pollution on water bodies, and this information is also particularly essential for managing wate... 相似文献
13.
Guohong Lin Xianli Song Dongliang Lu Keqiang Li Shengkang Liang Xiulin Wang 《中国海洋大学学报(英文版)》2020,19(3):622-632
Total pollutant load control management for total dissolved nitrogen (TDN) is an urgent task required to gain a good water quality status in Jiaozhou Bay ( 相似文献
14.
Eutrophication has emerged as a key environmental problem in Chinese coastal waters, especially in the Changjiang (Yangtze) River estuary. In this area, large nutrient inputs result in frequent harmful algal blooms and serious hypoxia in bottom waters. Four cruises were made in the estuary in 2006 to assess the concentration and distribution of dissolved inorganic nitrogen (DIN) and phosphorus (DIP). The concentration of DIN decreased gradually in a linear relationship with salinity from the river mouth to ... 相似文献
15.
利用2010年湛江湾区域的自然条件、人口、农业、工业、环保等基本统计数据和相关参数对该区域氮的收支进行估算,分析其产生原因和环境影响。结果表明,2010年湛江湾区域氮的输入总量为53 718.55 t,各氮源按输入量大小排序为化肥氮、人畜排泄物氮、大气沉降氮、农田自身固氮、作物残体氮、农田共生固氮和工业废水氮;区域氮输出量为44 536.75 t,其中34.12%由水体输送到湛江湾,33.53%通过反硝化和17.13%经挥发进入大气,作物收获氮带走了剩余的15.22%;盈余氮量9 181.80 t储存于区域内。湛江湾区域氮负荷为249.99kg·hm-2·a-1,陆地氮通量为200.11 kg·hm-2·a-1,远高于北江流域、珠江三角洲地区,仅稍低于经济发达的长江三角洲地区。 相似文献
16.
This paper describes a time series experiment examining the nitrogen and phosphorus intake of natural phytoplankton communities by a microcosms approach.Seawater samples containing natural phytoplankton communities were collected from waters around Baozhu Islet in inner Xiamen Bay and around Qingyu Islet in the outer bay.The goal was to elucidate the relationship between phytoplankton population enhancement,the biological removal of nitrogen and phosphorus from the seawater,and the phytoplankton nitrogen an... 相似文献
17.
基于现有重力梯度仪结构特点和研究基础,提出一种将三轴加速度计与旋转相结合的全张量重力梯度测量系统,并从数学上证明其可行性和结构优越性,为国产重力梯度仪的自主研发提供参考。 相似文献
18.
《中国海洋大学学报(英文版)》2021,20(3)
Effects of different nitrogen(N) compounds and concentrations on the growth of the three different phytoplankton taxa, Skeletonema costatum(Bacillariophyceae), Prorocentrum micans(Dinophyceae), and Chattonella marina(Raphidophyceae), were investigated. The Monod equation was applied to examine effects of N concentrations on the growth of algal cells. Results showed that nitrate(NO_3~-N) and urea served as good N sources for the three phytoplankton taxa. S. costatum grew well on all of the seven N sources. C. marina can effectively use the two amino acids, glycine(Gly) and serine(Ser), however cannot utilize alanine(Ala), threonine(Thr), and asparaginic acid(Asp). P. micans cannot grow in five amino acid substrates. All of the three phytoplankton taxa grew well under different proportions of urea-N, and C. marina grew significantly better in medium with both NO_3~-and urea-N. The values of maximum growth rate(μmax) and half-saturation nutrient concentration(KS) for NO_3~-N were 0.71 divisions d~(-1) and 53.55 μmol L~(-1) for S. costatum, 0.67 divisions d~(-1) and 23.31 μmol L~(-1) for P. micans, and 0.23 divisions d~(-1) and 17.57 μmol L~(-1) for C. marina, respectively. The results suggested that S. costatum had a high N demand for growth, and was capable of using wide ranges of N compounds. The strategy of N utilization for S. costatum may make this species an advantage in N-enriched sea areas especially the dissolved organic nitrogen(DON) rich coastal waters, which might be the reason why S. costatum widely distributes in the cosmopolitan coastal and estuarine sea areas. 相似文献
19.
We established a budget model of nitrogen (N) inputs and outputs between watersheds and waterbodies to determine the sources of riverine N in the Changjiang (Yangtze) River drainage area. Nitrogen inputs in the budget included N from synthetic fertilizer, biological fixation by leguminous and other crops, wet/dry atmospheric deposition, excreta from humans and animals, and crop residues. The total N input was estimated to be 17.6 Tg, of which 20% or 3.5 Tg N was transported into waterbodies. Of the total N transported into waterbodies, the largest proportion was N from animal waste (26%), followed by N from atmospheric wet/dry deposition (25%), synthetic fertilizer N (17%), N in sewage wastes (17%), N in human waste from rural areas (6%) and industrial wastewater N (9%). We studied the spatial patterns of N inputs and outputs by dividing the Changjiang River drainage area into four sub-basins, from upstream to downstream: the Tongtian River drainage area (TTD, the headwater drainage area, 138 000 km 2 , less disturbed by human activities); the Jinsha River drainage area (JSD, 347 000 km 2 , less disturbed by human activities, approx. 3 500 km upstream of the Changjiang estuary); the Pingshan-Yichang drainage area (PYD, 520 500 km 2 , large-scale human disturbance, about 2 000 km upstream of the Changjiang estuary); and the Yichang-Datong drainage area (YDD, 699 900 km 2 , large-scale human disturbance, approx. 620 km upstream of the Changjiang estuary). The average N input into waterbodies was 2.3, 7.3, 24.1, and 28.2 kg N/ha in the TTD, JSD, PYD, and YDD sub-basins, respectively, suggesting an increase of N-components of more than 10 times from upstream to downstream areas. 相似文献