Simulating the influence of various nutrient sources on hypoxia off the Changjiang River Estuary     

Jingjing Zheng  Shan Gao  Guimei Liu  Yun Li  Zhijie Li  Xueming Zhu 《海洋学报(英文版)》2022,41(11):58-72

Hypoxia is increasingly reported off the Changjiang River Estuary with the confluence of multiple high volume nutrient sources. The Regional Ocean Modeling System coupled with a biological model was used to analyze the effect of different nutrient sources on the development of hypoxia off the Changjiang River Estuary. By comparing to observed data, our model suitably captured the regional dynamics of chlorophyll a, dissolved oxygen, and nutrient concentration. A series of sensitivity experiments were conducted to investigate the hypoxia response to the various nutrient sources, such as loading from the Changjiang River, Kuroshio and Taiwan Warm Current. Our model results indicated that nutrients from different sources significantly influenced the hypoxia off the Changjiang River Estuary, and it was mostly affected by nutrients sourced from the Kuroshio. The nutrients input from the Changjiang River had larger impacts on the hypoxia in the north of 30°N than that in the south of 30°N. The nutrients sourced from the Taiwan Strait had a least influence on the hypoxia off the Changjiang River Estuary.  相似文献   

Genetic variation of the small yellow croaker (Larimichthys polyactis) inferred from mitochondrial DNA provides novel insight into the fluctuation of resources     

Jian Zheng  Tianxiang Gao  Yunrong Yan  Na Song 《海洋学报(英文版)》2022,41(11):88-95

The small yellow croaker (Larimichthys polyactis) belongs to the family Sciaenidae, which is an offshore warm fish species and widely distributed in the western Pacific. In this study, the variation of genetic diversity and genetic differentiation among L. polyactis populations was analyzed by mitochondrial DNA control region. A total of 110 polymorphic sites were checked, which defined 134 haplotypes. High level of haplotype diversity (h=0.993±0.002) was detected in the examined range. Population genetic structure analyse (analysis of molecular variance, F_st) showed there were high gene flow among L. polyactis populations. The result showed that there were relatively high genetic diversity and low genetic differentiation among the Yellow Sea and the East China Sea populations, which can be attributed to diverse habitats, wide distribution range and high mutation rate of control region. Using phylogenetic methods, coalescent analyses (neutrality tests, mismatch distribution analysis, Bayesian skyline analyses) and molecular dating interpreted in conjunction with paleoclimatic and physiographic evidence, we inferred that the genetic make-up of extant populations of L. polyactis was shaped by Pleistocene environmental impacts on the historical demography of this species. Besides, relatively constant genetic diversity and larger effective population size were detected in recent L. polyactis population. The result showed that the fishing policy certainly, such as the summer closed fishing, played a role in protecting resources of L. polyactis. This study can offer a wealth of biological novelties which indicates genetic structure of L. polyactis population and provides the foundation for resources protection and policy setting.  相似文献   

Dynamic Response Analysis and Vibration Control for A Fixed-Bottom Offshore Wind Turbine Subjected to Multiple External Excitations     

XIE Shuang-yi  ZHANG Cheng-lin  HE Jiao  JIANG Jing  GAO Jian 《中国海洋工程》2022,36(1):50-64

For the offshore wind turbines installed in earthquake areas, their operation is affected by seismic loads in addition to wind and wave loads. Therefore, it is necessary to study the dynamic responses and vibration control of the wind turbines. In previous studies, the structural responses of offshore wind turbines are usually investigated in the parked case, while the blade rotation effect is usually not considered. The evaluation on the structural responses may be inaccurate under this conditi...  相似文献   

祛脂护肝饮治疗非酒精性脂肪性肝炎湿浊内停证40例临床观察          下载免费PDF全文

邰玲  曾岳祥  范瑞园 《应用海洋学学报》2022,38(3):9

目的：观察祛脂护肝饮治疗非酒精性脂肪性肝炎（NASH）湿浊内停证的临床疗效。方法：将80例NASH湿浊内停证患者随机分为治疗组和对照组,每组各40例。2组均予饮食调节和适宜运动等基础治疗,在此之上治疗组予以祛脂护肝饮治疗,对照组予以水飞蓟宾葡甲胺片治疗,2组疗程均为12周。观察2组治疗前后体质量指数（BMI）、肝功能［丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、谷氨酰转肽酶（GGT）］、血脂［总胆固醇（TC）、三酰甘油（TG）］、肝脂肪受控衰减参数（CAP）、肝脏硬度值（LSM）,并进行中医证候疗效评价。结果:中医证候疗效总有效率治疗组为92.5%（37/40）,对照组为77.5%（31/40）,组间比较,差异有统计学意义（P＜0.05）。2组BMI、ALT、AST、GGT、TC、TG值治疗后均较治疗前下降,治疗组CAP、LSM值治疗后亦较治疗前下降,差异均有统计学意义（P＜0.01或P＜0.05）;且治疗组BMI、ALT、GGT、TC、TG、CAP值下降幅度均大于对照组,差异均有统计学意义（P＜0.05）。结论:祛脂护肝饮治疗NASH湿浊内停证有较好疗效,具有保肝降脂的效果。  相似文献   

阳和汤联合唑来膦酸治疗阳虚寒凝型乳腺癌骨转移30例          下载免费PDF全文

冯磊  李玲  李阳 《应用海洋学学报》2022,38(10):12

目的：观察阳和汤联合唑来膦酸治疗阳虚寒凝型乳腺癌骨转移的临床疗效及安全性。方法：将60 例阳虚寒凝型乳腺癌骨转移患者随机分为治疗组和对照组,每组各30 例。对照组给予唑来膦酸注射液治疗,治疗组在对照组基础上加用阳和汤治疗。观察2组的癌痛疗效、生活质量、数字分级法（NRS）评分、中医证候积分、骨代谢指标［血钙、血清骨代谢标志物碱性磷酸酶（ALP）、I型胶原N末端肽（NTX）水平］以及不良反应。结果：骨转移癌痛总有效率治疗组为73.4%（22/30）,对照组为60.0%（18/30）;生活质量总有效率治疗组为86.7%（26/30）,对照组为73.3%（22/30）,2组比较,差异均有统计学意义（P<0.05）。治疗组NRS评分、中医证候积分治疗前后组内比较及治疗后与对照组比较,2组ALP、NTX水平治疗前后组内比较及治疗后组间比较,差异均有统计学意义（P<0.05或P<0.01）。2组血钙水平、不良反应发生率比较,差异均无统计学意义（P>0.05）。结论：阳和汤可以作为阳虚寒凝型乳腺癌骨转移患者的辅助治疗手段,值得临床推广应用。  相似文献   

Effects of oxytetracycline dihydrate and sulfamethoxazole on Microcystis aeruginosa and Chlamydomonas microsphaera     

Zhou  Xudong  Jiang  Xincheng  Gao  Shan  Wan  Zhenjia  Gao  Pengcheng 《中国海洋湖沼学报》2021,39(1):160-172

The increasing use of pharmaceuticals has become a major environmental issue in China.The presence of antibiotics in water may have deleterious effects on non-target aquatic organisms such as microalgae.In this study,a cyanobacterium and an alga species in surface waters,Microcystis aeruginosa and Chlamydomonas microsphaera,were exposed to 0,0.1,0.5,1.0,2.0,5.0,10.0,and 20.0 mg/L of oxytetracycline dihydrate(OXY) and sulfamethoxazole(SMZ) for 96 h to determine the effects of these antibiotics on the growth and surface morphology.Moreover,the photosynthetic activity and the contents of superoxide dismutase(SOD),malondialdehyde(MDA),and protein were measured to examine the biochemical characteristics of M.aeruginosa and C.microsphaera under OXY and SMZ stress.The effects of both antibiotics on the growth of both species were concentration-dependent and characterized by low-dose stimulation and high-dose inhibition.C.microsphaera was more sensitive to both antibiotics than M.aeruginosa was.The algal cell membranes of both species disintegrated after exposure to a high concentration of OXY.All of the physiological parameters measured in this study were relatively stable at low concentrations of OXY and SMZ.After exposure to high concentrations of OXY and SMZ,photosynthetic activity decreased significantly,whereas lipid peroxidation and the abundance of SOD,MDA,and protein increased significantly.Thus,low-dose antibiotics may increase algal blooms in eutrophic waters.  相似文献   

The influence of turbulent mixing on the subsurface chlorophyll maximum layer in the northern South China Sea     

Shang  Chenjing  Liang  Changrong  Chen  Guiying  Gao  Yongli 《中国海洋湖沼学报》2021,39(6):2167-2180

Journal of Oceanology and Limnology - We present observations from deployments of turbulent microstructure instrument and CTD package in the northern South China Sea from April to May 2010. From...  相似文献   

Transcriptome profile of Dunaliella salina in Yuncheng Salt Lake reveals salt-stress-related genes under different salinity stresses     

Gao  Fan  Nan  Fangru  Feng  Jia  Lü  Junping  Liu  Qi  Liu  Xudong  Xie  Shulian 《中国海洋湖沼学报》2021,39(6):2336-2362

Journal of Oceanology and Limnology - Salt stress is an abiotic stress to plants in especially saline lakes. Dunaliella, a halophilic microalga distributed throughout salt lakes and seas, can...  相似文献   

协同多时相波谱特征的不透水面信息级联提取     

帅艳民  马现伟  曲歌  邵聪颖  刘涛  刘守民  黄华兵  谷玲霄  拉提帕•吐尔汗江  梁继  李玲 《地球信息科学学报》2021,23(1):171-186

不透水面作为反应城市表征变化和区域城镇化的重要技术指标,其位置、图斑大小、空间分布等信息在地表水热循环和能量平衡等领域被广泛需求。传统方法大都基于单一时相信息提取不透水面,而忽略多时相所蕴含的丰富信息。因此,本文提出多时相信息融合的不透水面级联提取方法,利用Landsat-8 OLI遥感影像分析归一化植被指数（Normalized Difference Vegetation Index, NDVI）、改进的归一化水体指数（Modified Normalized Difference Water Index, MNDWI）和归一化建筑指数（Normalized Difference Building Index, NDBI）年内时序变化特点和典型地物间多时相波谱曲线的协同特征,并归纳不透水面多时相变化规律;再根据先验知识所获取的有效地表信息,进行多时相分级提取不透水面信息。此外,基于实地考察数据和同期2 m GF-1遥感影像屏幕数字化生成30 m不透水面图斑,进行精度验证、分析和对比单时相、四季相及多时相3种时序情况下的提取精度。结果表明：单时相提取不透水面总精度最低,四季相提取精度优于单时相,而多时相提取精度最高（精度可达93.66%,Kappa系数为0.81）。本方法在偏远城镇不透水面的有效识别中显露潜在优势,可为不透水面提取方法融合时序波谱特征提供新思路。  相似文献   

基于深度学习的滑坡灾害易发性分析     

王毅  方志策  牛瑞卿  彭令 《地球信息科学学报》2021,23(12):2244-2260

滑坡灾害成因机理复杂、影响因素众多,深度学习作为当前人工智能领域的热点,能够更好地模拟滑坡灾害的形成并准确预测潜在的斜坡。为了挖掘深度学习在滑坡易发性的应用潜能,本文构建了一维、二维和三维的滑坡数据表达形式,并提出3种基于卷积神经网络模型（Convolutional Neural Networks, CNN）的滑坡易发性分析处理框架：基于CNN分类器、基于CNN与逻辑回归的融合和基于CNN集成,最后以江西省铅山县为研究对象进行验证,结果表明：所有基于CNN的易发性模型都能够获得准确且可靠的滑坡易发性分析结果。其中,基于二维数据的CNN模型在所有单分类器中预测精度最高,为78.95%。此外,二维CNN特征提取能够显著提升逻辑回归的预测精度,其准确率提升7.9%。最后,异质集成策略能够大幅度提升基于CNN分类器的滑坡预测精度,其准确率提升4.35%~8.78%。  相似文献