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71.
An engineering application tool for prediction of the static equilibrium bay(Beach Mod)is established to describe two bay shape formulas by use of the programming software "MATLAB" with a graphic user interface(GUI).The tool is user-friendly for engineering students for the design of beach shapes.This tool was tested through application on three types of beaches in Taiwan and Australia.By implementing the concept of Headland Control,the Beach Mod program allows users to draw a structure and create an artificial headland.The results indicate that Beach Mod can efficiently forecast beach changes as well as MEPBAY,a competing software package,while boasting a better user interface.  相似文献   
72.
养殖对虾与海捕对虾鉴别方法初探   总被引:1,自引:1,他引:1  
通过对养殖中国对虾(Penaeus orientalis)和海捕中国对虾肌肉煮熟后的失水率,提取物中的甜菜碱和氧化三甲胺含量,以及虾肉脂质中所含脂肪酸组成和含量进行了分析比较,得到下列结果:(1)两类对虾鲜样煮熟后失水率相差6%以上;(2)海捕对虾肌肉中的甜菜碱和氧化三甲胺含量比养殖对虾的高,两者有显著差别;(3)养殖对虾肌肉所含C18:2ω6为17.3±1.5%,海捕对虾为2.0±0.8%。从以上结果本文推荐以脂肪酸C18:2ω6含量来鉴别养殖对虾与海捕对虾。  相似文献   
73.
从相空间重构的角度,提出利用伪近邻方法判别ARMA 系统的总阶数。该方法可在数据量较小和阈值固定的情况下判别ARMA 系统总阶数。数值计算表明,使用该方法判别线性ARMA系统总阶数,取得了比较满意的结果。  相似文献   
74.
通过自然条件下沙表层和水面溢油的模拟风化实验,采用GC-MS作为检测器,研究原油中的正构烷烃在厦门地区的风化规律.结果表明,在一个月的风化模拟实验中,两种不同介质溢油风化均明显体现轻组分的正构烷烃丢失现象,且正构烷烃组分在水面溢油的风化速率低于沙表层溢油速率1~2个碳数.沙上模拟实验后期APr/APh比值明显受到风化影响,诊断比值不适用于油源鉴别.诊断比值An-C17/APr、An-C18/APh在短期风化过程中受风化影响小.水面溢油模拟实验结束后发现水体中n-C13-n-C29的正构烷烃组分含量升高2.9%~327.4%.  相似文献   
75.
A data-driven model has been developed to analyse the long-term evolution of a sandbank system and to make ensemble predictions in a period of 8 years. The method uses a combination of empirical orthogonal function (EOF) analysis, (to define spatial and temporal patterns of variability), jack-knife resampling, (to generate an ensemble of EOFs), a causal auto-regression technique, (to extrapolate the temporal eigenfunctions), and straightforward statistical analysis of the resulting ensemble of predictions to determine a ‘forecast’ and associated uncertainty. The methodology has been applied to a very demanding site which includes a curved shoreline and a group of mobile nearshore sandbanks. The site is on the eastern coast of the UK and includes the Great Yarmouth sandbanks and neighbouring shoreline. A sequence of 33 high quality historical survey charts reaching back to 1848 have been used to analyse the patterns and to predict morphological evolution of the sandbank system. The forecasts demonstrate an improved skill relative to an assumption of persistence, but suffer in locations where there are propagating features in the morphology that are not well-described by EOFs.  相似文献   
76.
冬季刺参养殖环境与肠道内细菌菌群的研究   总被引:2,自引:0,他引:2  
运用传统细菌分离培养与分子生物学技术相结合的方法,对2008年11月至2009年1月冬季刺参(Apostichopus japonicus Liao)养殖池塘环境(养殖水、底泥、附着基)及刺参肠道内的细菌菌群进行了分析。应用平板稀释涂布培养计数法测得刺参养殖池塘水体、底泥、附着基和肠道细菌数量分别为0.75×102~1.4×104cfu/mL、8.7×104~8.1×105cfu/g、3.8×105~2.8×106cfu/g、7.1×105~1.5×107cfu/g;根据形态学差异从培养所得的细菌中筛选得到22株菌,用限制性内切酶Rsa I和Msp I对所分离菌株进行ARDRA(Amplified rDNA Restriction Analysis)分析,这22株菌被分为8种不同的分类单元(Operational Taxonomic Unit,OTU),其中OTU2与OTU3所包含的菌株分别占分离菌株种数的30%和20%;此外,作者对不同环境培养所得的优势度最高的细菌进行分子鉴定分析。结果表明:水环境中优势菌为施氏假单胞菌(Pseudomonas stutzeri)、门多萨假单胞菌(Pseudomonas mendocina)及巨大芽孢杆菌(Bacillus megaterium),沉积物中优势菌为巨大芽孢杆菌(B.megaterium)、施氏假单胞菌(P.stutzeri)、苏云金芽孢杆菌(Bacillus thuringiensis),附着基中优势菌为巨大芽孢杆菌(B.megaterium)、苏云金芽孢杆菌(B.thuringiensis),灿烂弧菌(Vibrio splendidus),肠道中优势菌为巨大芽孢杆菌(B.megaterium)、苏云金芽孢杆菌(B.thuringiensis),灿烂弧菌(V.splendidus)、施氏假单胞菌(P.stutzeri)。通过对冬季刺参池塘细菌菌群多样性分析和优势菌鉴定,为筛选低温益生菌和防治刺参疾病提供了有益参考。  相似文献   
77.
It is widely recognised that palaeobathymetry is a key control on the distribution of turbidite deposits. Thus, the utilisation of palaeobathymetric surfaces as an input for numerical turbidity current modelling offers a potentially powerful method to predict the distribution of deep marine sands in ancient (subsurface or outcrop) successions. Such an approach has been tested on an Aptian turbidite deposit from the Buchan Graben, UK Central North Sea, where modelled sand distributions could be quality controlled against available well data.  相似文献   
78.
Harmonic analysis, the traditional tidal forecasting method, cannot take into account the impact of noncyclical factors, and is also based on the BP neural network tidal prediction model which is easily limited by the amount of data. According to the movement of celestial bodies, and considering the insufficient tidal characteristics of historical data which are impacted by the nonperiodic weather, a tidal prediction method is designed based on support vector machine (SVM) to carry out the simulation experiment by using tidal data from Xiamen Tide Gauge, Luchaogang Tide Gauge and Weifang Tide Gauge individually. And the results show that the model satisfactorily carries out the tide prediction which is influenced by noncyclical factors. At the same time, it also proves that the proposed prediction method, which when compared with harmonic analysis method and the BP neural network method, has faster modeling speed, higher prediction precision and stronger generalization ability.  相似文献   
79.
2016年6月,江苏某异育银鲫(Carassius auratus gibelio)养殖场暴发一种传染性急性出血病,造成养殖银鲫大量死亡。为分析此次疾病病因及流行规律,本研究从发病养殖场采集患出血病的异育银鲫,从细菌、病毒及寄生虫三个方面对病原进行了分析。采用病原菌分离、组织病理学观察、超薄切片电镜观察、病毒核酸分析、回感实验等对病原进行鉴定。结果显示从发病鲫鱼体内分离到病毒一株,未发现寄生虫及细菌感染。经测序及序列分析,该病毒为鲤疱疹病毒Ⅱ型(Cyprinid herpesvirus2,CyHV-2)病毒,组织病理学观察结果显示患病鱼的鳃和肾脏有明显病变,电镜下可观察到病鱼脾脏组织有带囊膜的球形病毒,囊膜直径约为170—200nm,病毒衣壳直径约为110—120nm,核心直径约为60nm,用组织匀浆感染鲫鱼囊胚细胞系(CGB)可稳定地观察到典型的细胞病变,用患病鱼组织匀浆液人工感染异育银鲫的死亡率高达100%,荧光定量PCR检测到该病毒可感染多器官,其中以脾脏中病毒含量最高,其次是脑,肝脏中最少。本研究可为CyHV-2的诊断防控及疫苗研制提供资料。  相似文献   
80.
In the identifying process of an oil spill accident, manual integral and artificial visual comparison are commonly used at present to determine the oil spill sources, these methods are time-consuming and easily affected by human factors. Therefore, it is difficult to achieve the purpose of rapid identification of an oil spill accident. In this paper, an intelligent method of automatic recognition, integration and calculation of diagnostic ratio of Gas Chromatography-Mass Spectrometer (GC/MS) spectrum are established. Firstly, four hundreds of samples collected around the world were analyzed using a standard method and Retention time locking technology (RTL) was applied to reduce the change of retention time of GC/MS spectrum. Secondly, the automatic identification, integration of n-alkanes, biomarker compounds, polycyclic aromatic hydrocarbons and calculation of the diagnostic ratios were realized by MATLAB software. Finally, a database of oil fingerprints were established and applied successfully in a spill oil accident. Based on the new method and database, we could acquire the diagnostic ratios of an oil sample and find out the suspected oil within a few minutes. This method and database can improve the efficiency in spilled oil identification.  相似文献   
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