贝类净化技术研究现状与展望     

邱天龙  陈文超  祁剑飞  刘金虎  董逸  孙建明 《海洋科学》2021,45(3):134-142

随着养殖水域环境问题日益凸显,贝类食品安全问题越来越受到重视,贝类在进入流通环节前进行净化将成为不可缺少的处理环节.本文从贝类净化工艺类型、净化用水处理技术,以及贝类净化对风味的影响等方面对当前国内外研究进展进行了总结梳理,并提出下一步贝类净化应重点解决的问题,为深入开展贝类净化相关研究提供参考.  相似文献   

Agricultural Non-point Source Pollution in China: Evaluation,Convergence Characteristics and Spatial Effects     

QIU Wenwen  ZHONG Zhangbao  LI Zhaoliang 《中国地理科学(英文版)》2021,(3):571-584

In this study, an inventory analysis approach was used to investigate the intensity of agricultural non-point source pollution(ANSP) and its spatial convergence at national and provincial levels in China from 1999 to 2017. On this basis, spatial factors affecting ANSP were explored by constructing a spatial econometric model. The results indicate that: 1) The intensity of China's ANSP emission showed an overall upward trend and an obvious spatial difference, with the values being high in the eastern and central regions and relatively low in the western region. 2) Significant spatial agglomeration was shown in China's ANSP intensity, and the agglomeration effect was increasing gradually. 3) In the convergence analysis, a spatial lag model was found applicable for interpretation of the ANSP intensity, with the convergence rate being accelerated after considering the spatial factors but slower than that of regional economic growth.4) The spatial factors affecting the ANSP intensity are shown to be reduced by improving agricultural infrastructure investment, laborforce quality, and crop production ratio, while the expansion of agricultural economy scale and precipitation and runoff have positive impact on ANSP in the study region. However, agricultural research and development(RD) investment showed no direct significant effect on the ANSP intensity. Meanwhile, improving the quality of the labor force would significantly reduce the ANSP intensity in the surrounding areas, while the precipitation and runoff would significantly increase the pollution of neighboring regions. This research has laid a theoretical basis for formulation and optimization of ANSP prevention strategies in China and related regions.  相似文献   

近岸波浪破碎区不规则波浪的数值模拟   总被引：2，自引：0，他引：2  

唐军  沈永明  崔雷  邱大洪 《海洋学报》2008,30(2):147-152

基于近岸不规则波浪传播的抛物型缓坡方程和两类波浪破碎能量损耗因子,对近岸波浪破碎区不规则波浪的波高分布进行了数值模拟,并结合实验结果对数值模拟结果进行了验证分析,结果表明采用两类波浪破碎能量损耗因子所模拟的破碎区波高与实测值均吻合良好,波浪破碎能量损耗因子及波浪破碎指标对破碎区波浪波高分布影响较明显。  相似文献   

Size-fractionated uranium isotopes in surface waters in the Jiulong Estuary in China   总被引：1，自引：1，他引：0  

L&#; E  ZHANG Lei  CHEN Min  QIU Yusheng  XING N  YANG Weifeng  LI Yanping  HUANG Yipu 《海洋学报(英文版)》2008,27(1):29-41

Surface water was collected from the Jiulong Estuary for determination of activity concentrations of uranium isotopes in different size fractions, namely, greater than 53, 10 -53, 2 - 10, 0.4 -2 μm, 10 000 u -0.4 μm and less than 10 000 u fractions by microfihration and cross-flow uhrafiltration technologies. Results indicated that most of the dissolved uranium （ 〈 0.4 μm） exis- ted in the low molecular mass fraction （ 〈 10 000 u）, and the colloidal uranium-238 （10 000 u -0.4 μm） only contributed less than 1% of the dissolved uranium-238. The fractions of colloidal uranium in the dissolved phases decreased with the increasing sa- linity. A positive linear relationship between uranium-238 activities and salinities was observed for the dissolved, colloidal and low molecular mass fractions, indicating a conservative behavior of uranium in the Jiulong Estuary. In the particulate phases （ 〉 0.4 μm）, the partitioning of uranium isotopes among different size fractions was controlled by the partitioning of particle concentrations. In the regions with salinities below 20, the partitioning of uranium-238 among different size fractions was as follows： 10 - 53 μm 〉 2 - 10 μm 〉 0.4 - 2 μm greater than above 53 μm. However, the order at the offshore station with salinities above 30 changed as follows ： 0.4 - 2 μm 〉 10 - 53 μm 〉 2 - 10 μm greater than above 53 μm. The fraction of the 0.4 - 2 μm particles increased at the offshore station, suggesting the increased contribution of the authigenic uranium. The activity ratio of uranium-234 to uranium-238 in the dissolved phases, including the low molecular mass fraction and the colloidal fraction, was larger than unity, showing the occurrence of excess uranium-234. In contrast, the activity ratio of uranium-234 to uranium-238 in all size fractions of the particulate phase was close to the equilibrium value （1.0）. The observed different values of the activity ratio of uranium-234 to uranium-238 in the dissolved phase and the partic  相似文献   

珠江口盆地白云凹陷陆坡区10.5 Ma以来的沉积体系   总被引：2，自引：0，他引：2  

武强  解习农  邱燕  刘明玲 《海洋地质与第四纪地质》2008,28(2):1-6

通过对珠江口盆地白云凹陷陆坡区10.5Ma以来的地震相分析,共识别出席状平行亚平行地震相、透镜状前积地震相、深切河谷地震相、帚状地震相和杂乱地震相,不同的地震相分别代表不同的沉积体系类型。综合所识别的地震相类型,分析了陆架边缘下切谷、浊积扇和陆架边缘三角洲3种主要的沉积体系及其配置关系。物源供给是影响陆坡区沉积体系发育的最重要因素,是沉积体系发育的物质基础,海平面变化和构造运动为沉积体系发育提供了可容纳空间,3种影响因素共同影响了陆坡区沉积体系的发育。  相似文献   

栖霞市马家窑金矿床成矿流体地球化学特征   总被引：1，自引：0，他引：1  

胡伟华  邱介玲  程鑫  林永芸 《山东国土资源》2008,24(1):26-29

马家窑金矿床是胶东地区比较典型的石英脉型金矿床代表,属中低温热液矿床,成矿流体盐度较低,气相成分以H2O,CO2为主,其次是Na^＋,Ca^＋和Cl^-,K^＋和F^-较贫,流体的成分与大气降水热液相类似。成矿流体的H,O同位素值则反映大气降水在不同温度和不同水／岩值条件下与栖霞超单元回龙夼单元交换后的分布特征,认为马家窑金矿床的成矿热液属大气降水成因。  相似文献   

SPOT影像光束法平差复共线性消除          下载免费PDF全文

岳庆兴  马福诚  邱振戈  张春玲 《海洋测绘》2008,28(2):17-20

CCD卫星影像空间后方交会时,存在系数矩阵列向量间的强相关的问题,用光束法平差同样存在这个问题,将光束法平差与线角元素分求法、广义岭估计、附有限制条件的平差结合,证实三种方法都可以克服平差时外元素和变率改正数震荡大的缺点,并且取得了合理的空间后方交会精度和地面点定位精度。  相似文献   

GPS网平差中的稳健估计     

冯玉钊  邱蕾 《地理空间信息》2009,7(2):45-48

GPS网平差利用三维基线向量为观测值,与常规的粗差探测不同,根据RECO法基本原理,以GPS网为例,说明RECO法在GPS网平差中粗差探测中的优越性,得出一些有益的结论。  相似文献   

基于WoS和Citespace的应急避难场所知识图谱和进展分析     

唐波  邱锦安 《世界地理研究》2019,28(4):85-95

以近30 年Web of Science 核心数据库收录的2472 篇应急避难场所相关文献为基础,首先统计发文数量时间分布和期刊分布,然后利用Citespace可视化软件,从发文作者、机构、国家、关键词和学科方向5个方面分别进行知识图谱分析。结果表明：近30年来应急避难场所研究发文呈现由缓慢探索、稳步发展向高速发展的阶段;发文期刊主要为自然灾害类、紧急医学类、工程技术类;研究作者群较多,学术交流较为紧密;美国和中国为发文量最多的国家;路易斯安那州立大学和中国科学技术大学是主要的发文机构;从关键词发现应急避难场所目标人群主要围绕灾害救援和社会弱势群体,研究视角从单一问题和事件开始向综合系统演变,研究方法从定性的方法模型转向动力机制和信息系统开发,研究内容则注重多学科交叉和微观尺度、重视案例实证和信息共享和强调应急避难场所管理;学科方向主要为工程学和公共环境与健康两个学科。在建设韧性城市的背景下,可借鉴国际经验来构建中国应急避难场所研究体系和管理。  相似文献   

库岸边坡倾角及水位变化对红土型库岸稳定性影响研究     

张祖莲  梁谏杰  黄英  邱观贵  袁强 《山地学报》2019,(1):62-69

水库库岸失稳对水库安全运行有重大影响。采用土工试验和干湿循环试验,结合数值计算及理论分析,研究红土型库岸边坡倾角和库水位升降与库岸稳定性的关系。结果表明:(1)在一定初始干密度条件下,红土抗剪强度随水位升降循环次数增加而非线性减小,且在水位升降循环约10次时趋于稳定。(2)在一定水位升降速率、升降幅度和升降循环次数条件下,红土型库岸稳定安全系数随库岸边坡倾角的增加总体上呈减小的趋势,且在边坡倾角为50°左右存在稳定安全系数极小值。(3)在一定水位升降循环次数条件下,水位上升到坡高的60%左右为上升阶段的相对危险区域,且水位上升速率对库岸稳定安全系数影响很小;水位下降至坡高的70%左右为库水位下降阶段的相对危险区域,且水位下降速率越大,库岸稳定安全系数越小。(4)针对一定初始干密度,库岸稳定安全系数先随水位升降循环次数的增加而减小,但在水位升降循环次数约10次后逐渐趋于稳定。库岸岩土体性质及库岸边坡倾角、水位变化都会对库岸稳定产生影响。  相似文献