Marine bacterium strain screening and pyrethroid insecticide-degrading efficiency analysis     

孙爱丽  刘菁华  史西志  李德祥  陈炯  唐道军 《中国海洋湖沼学报》2014,32(5):1029-1035

A pyrethroid insecticide-degrading bacterium, strain HS-24, was isolated from an offshore seawater environment. The strain, which can degrade cypermethrin(CYP) and deltamethrin(DEL), was identified as Methylophaga sp. The optimal culture and degradation conditions for CYP and DEL by strain HS-24 is pH 7 at 28°C. Under optimum culture conditions, strain HS-24 exhibited a broad degradation concentration range of 100, 200, 400, 600, and 800 mg/L for CYP and DEL. The metabolic intermediates were analyzed by NMR, which provided strong evidence that CYP and DEL removal occurred mainly because of a biological process. The toxicity of the degradation products of strain HS-24 was studied simultaneously by measuring the light output of the luminescence bacterium. This demonstrated that the biodegradation ability of strain HS-24 significantly decreased the toxicity of CYP- and DEL-contaminated aquaculture seawater. Finally, the findings of this paper indicate that strain HS-24 is thus revealed as a biological agent for the remediation of marine aquatic environments.  相似文献   

Deriving Changjiang coastal zone wind from C-band SAR and its application to salinity simulation     

王利花  周云轩  朱建荣  沈芳  田波 《中国海洋湖沼学报》2014,32(4):946-957

Wind plays an important role in hydrodynamic processes such as the expansion of Changjiang （Yangtze） River Diluted Water （CDW）, and shelf circulation in the Changjiang estuary. Thus, it is essential to include wind in the numerical simulation of these phenomena. Synthetic aperture radar （SAR） with high resolution and wide spatial coverage is valuable for measuring spatially inhomogeneous ocean surface wind fields. We have collected 87 ERS-2 SAR images with wind-induced streaks that cover the Cbangjiang coastal area, to verify and improve the validity of wind direction retrieval using the 2D fast Fourier transform method. We then used these wind directions as inputs to derive SAR wind speeds using the C-band model. To demonstrate the applicability of the algorithms, we validated the SAR-retrieved wind fields using QuikSCAT measurements and the atmospheric Weather Research Forecasting model. In general, we found good agreement between the datasets, indicating the reliability and applicability of SAR- retrieved algorithms under different atmospheric conditions. We investigated the main error sources of this process, and conducted sensitivity analyses to estimate the wind speed errors caused by the effect of speckle, uncertainties in wind direction, and inaccuracies in the normalized radar cross section. Finally, we used the SAR-retrieved wind fields to simulate the salinity distribution off the Changjiang estuary. The findings of this study will be valuable for wind resource assessment and the development of future numerical ocean models based on SAR images.  相似文献   

双偏振雷达差分传播相移的五种滤波方法对比分析     

魏庆  ;胡志群  ;刘黎平 《成都信息工程学院学报》2014,(6):596-602

为了对双线偏振雷达的差分传播相移ΦDP进行滤波降噪处理,提高双线偏振雷达识别粒子、估测降水的能力。通过对C波段双线偏振雷达差分传播相移分别采用滑动平均、中值滤波、FIR滤波、卡尔曼滤波和小波分析5种不同方法地介绍,利用中国气象科学研究院灾害天气国家重点实验室移动式C波段双线偏振雷达(POLC)2013年外场试验观测资料,对比分析了经5种方法处理后的差分传播相移ΦDP径向数据,及其分别在降水估测中应用的效果。结果表明:采用FIR滤波方法、卡尔曼滤波方法和小波分析方法对ΦDP径向数据进行处理的效果比传统的滑动平均和中值滤波方法好;其中小波分析处理的ΦDP径向数据波动最小,再经过变距离法拟合的KDP数据的负值能够得到最有效地抑制,最后应用到R(KDP)降水估测中的精度最高。  相似文献   

宁波大榭实华45万吨原油码头最佳靠泊时间分析     

舒志光  陆伟先  沈光  吕翠兰  朱龙 《海洋预报》2014,(3)

船舶在停靠码头时,需要根据潮汐、潮流条件选择合适的靠泊时间,特别是对于大型重载船舶,合适的靠泊时间是靠泊安全的基础。文中通过对宁波大榭实华45万吨原油码头一个月的潮汐、潮流资料进行统计和分析,确定码头的最佳靠泊时间,为码头的安全靠泊和引航员的实际操作提供科学建议。  相似文献   

三体散射长钉（TBSS）在C波段雷达中的应用研究     

王晓君  夏文梅  段鹤  王秀英 《气象》2014,40(11):1380-1388

利用普洱CIND3830-CC天气雷达资料、地面观测资料进行统计分析,研究2004-2013年普洱C波段天气雷达中27次三体散射长钉(TBSS)的统计特征、地面降雹与TBSS的对应关系,并对TBSS在冰雹预警方面的应用进行探讨,结果表明:(1)C波段雷达中,产生TBSS的回波的反射率因子范围为55.0~68.4 dBz,70%的TBSS出现在反射率因子≥60 dBz时。(2)TBSS的维持时间为10~79 min,63%的TBSS维持时间超过20 min。(3)TBSS一般出现在4.0~9.5 km,最低出现在2.6 km,最高出现在11.4 km。(4)TBSS长5.6~22.4 km,宽1.5~14.6 km,TBSS宽度与强回波区径向外侧的60 dBz以上回波的面积成正比,但TBSS的长度与反射率因子核心的强度和宽度无明显对应关系。(5)出现TBSS时,59%的回波出现了降雹,11%的回波出现了强冰雹。(6)出现TBSS且出现降雹的过程中,TBSS预报冰雹的时间提前量为5~100 min,平均为34.5 min。(7)在出现TBSS且出现降雹的过程中,TBSS的宽度与冰雹的大小或降雹密度成正比。此外,分析了出现TBSS但未降雹的原因,找出了TBSS配合垂直液态水含量密度(D_(VIL))和45 dBz伸展高度、TBSS配合回波宽度和45 dBz伸展高度的预报冰雹的方法,在出现TBSS特征的回波中,上述方法的预报准确率分别达89%和94%(临界成功指数为0.89和0.94)。  相似文献   

A Velocity Dealiasing Scheme for C-band Weather Radar Systems简     

LI Gang  HE Guangxin  Xiaolei ZOU  Peter Sawin RAY 《大气科学进展》2014,31(1):17-26

A dealiasing algorithm for radar radial velocity observed by C-band Doppler radars is presented as an extension of an existing S-band dealiasing algorithm. This has operational significance in that many portable and many commercial broadcast radars, as well as approximately one half of the Chinese weather radar network （CINRAD）, are C-band radars. With a wavelength of about 5 cm, the Nyquist interval of C-band radars is just about one half that of S-band radars （wavelength of about 10 cm） and thus has more velocity folding. The proposed algorithm includes seven modules to remove noisy data, find the starting radials, dealias velocities, and apply least squares error checking in both the radial and azimuth directions. The proposed velocity dealiasing method was applied to one widespread rain case and three strong convective cases from radars operating in China. It was found that, on average, 92.95% of the aliased radial velocity data could be correctly de-aliased by the algorithm, resulting in 96.65% of the data being valid.  相似文献   

基于均值变点法提取地形起伏度的影响因素分析——以黄河流域(山西段)为例     

宁婷  崔伟  马晓勇 《测绘通报》2022,(2):159-163

地形起伏度因子在宏观尺度生态评估中具有重要作用。均值变点法是确定地形起伏度最佳分析窗口的常用方法,但其影响因素尚缺乏研究。本文以黄河流域（山西段）为例,基于DEM数据和均值变点法提取了研究区地形起伏度,并探讨了分析窗口样本数量、DEM分辨率和地貌类型3种因素的影响。结果表明：①分析窗口样本数量对最佳分析窗口取值有明显影响。随着样本数量的增加,变点所在的最佳分析窗口面积也不断增加。②DEM分辨率对最佳分析窗口取值有一定影响。分析窗口面积取值范围一致时,基于30 m ASTER GDEM计算得到的最佳分析窗口面积小于基于90 m SRTM DEM的最佳分析窗口面积。③地貌类型对最佳分析窗口取值的影响不大。当分析窗口样本数量一致时,不同地貌类型区及整个研究区最佳分析窗口相同或接近。总体而言,分析窗口样本数量是最关键的影响因素。  相似文献   

基于无人机可见光影像的城市植被信息提取     

张晓同  徐佳  陈仁喜 《地理空间信息》2022,20(5):63-68

  相似文献   

L波段雷达探测资料质量控制方法探讨          下载免费PDF全文

张颖梅  张聪娥 《陕西气象》2014,(5):46-48

<正>目前各探空站L波段雷达—电子探空仪系统的投入使用实现了角度自动跟踪、自动测距、自动数据处理功能,在减少人为失误的同时大幅度提高了工作效率。但是常因复杂天气、探空仪器性能不够稳定等因素造成探测记录出现异常,为此结合基层探空站值班和报表预审中常见问题,总结高空资料质量控制的思路和流程,确保探空资料的完整性、准确性和代表性,为天气预报、气候分析、科学研究和国际交换,提供及时、准确的高空气象探测资料。  相似文献   

基于经验模型的Hyperion数据植被叶绿素含量反演   总被引：1，自引：0，他引：1  

丰明博  牛铮 《国土资源遥感》2014,(1)

对于反演植被叶绿素含量而言,基于Hyperion等高光谱传感器数据、利用经验方法建模是一种快速准确的方法。利用多种植被的实测数据以及Hyperion模拟数据,分析植被反射率及其变化形式与叶绿素含量的相关性,并进一步针对红边参数、植被指数等分析植被反射率与叶绿素含量的关系,选取最准确的经验建模方法。经过对比,改进的简单比值指数(modified simple ratio,MSR)与叶绿素含量相关性最高,其回归模型能比较准确地反演出叶绿素含量。通过Hyperion图像、利用MSR指数与实测叶绿素含量得到回归模型,建立区域叶绿素含量分布图;并对张掖地区植被叶绿素含量进行了反演,反演结果具有较高精度,相对误差低于5%。  相似文献