Fast local binary fitting optimization approach for image segmentation

针对灰度不均匀图像难以正确分割和分割结果依赖于初始轮廓的问题,提出一种快速稳定的分割算法,首先通过自适应距离保持水平集演化(AdPlS)算法进行初始分割以获取较好的初始轮廓,然后采用局部二值拟合(lbf)模型进行快速分割。实验表明,改进后的模型有良好的分割效果,较好地解决了分割速度、精度及稳定性之间的矛盾。It is difficult to get the correct segmentation results for the intensity inhomogeneity images,and the segmentation results are very sensitive to the initial contours.Thus,a fast and stable approach was proposed to overcome these disadvantages.First,an Adaptive Distance Preserving Level Set(ADPLS) method was utilized to get a better initial contour.Second,the Local Binary Fitting(LBF) model was used for a further segmentation.The experimental results show that the improved model can achieve good performance and is better to solve the contradiction among the segmentation speed,accuracy and stability.南京军区重点项目(11Z023); 福建省自然科学基金资助项目(2008J0312

Improved Method for Fuzzy C-Means Clustering Algorithm

由于传统的模糊C均值(fuzzy C-MEAnS,fCM)算法没有考虑像素点的空间邻域信息,仅涉及像素的单点灰度,在处理含有噪声的图像时有很大的局限性,因此分割效果较差。针对fCM的缺陷,提出一种新的改进算法,该算法引入gIbbS随机场,将gIbbS随机场先验概率与像素点隶属度的乘积作为新的像素隶属度。实验表明,改进后的算法有良好的分割效果,既可以较为完整地保留图像边界细节,又能较好地去除图像的噪声。The traditional fuzzy C-means (FCM) algorithm has great limitations in dealing with the noisy images owing to not considering the spatial information of the pixels and only involving the pixel gray of a single point,so it's poor in segmenting an image.For the defects of the FCM algorithm,a new improved algorithm is proposed in this article,in which a product of Gibbs priori probability and the membership is regarded as the new pixel membership.Experimental results show that the improved algorithm has a good segmentation result;it can retain more complete edge details of image and can remove the image noise more effectively.南京军区重点项目(项目编号:11Z023); 福建省自然科学基金项目(项目编号:2008J0312

非离子态氨对转“全鱼”生长激素基因鲤鱼的急性毒性和慢性毒性

在自然水体和人工水体中氨氮对鱼类是有毒的.利用静水更新式生物测试研究了非离子态氨对转基因鲤鱼和对照鱼的96h急性毒性实验和21d慢性毒性实验.通过96h非离子态氨急性毒性实验发现,转基因鲤鱼的非离子态氨氮24,48,72和96h半数致死浓度(LC50)(2.64,2.44,2.28和2.16mg/L)分别比对照鲤鱼相应的24,48,72和96h半数致死浓度(LC50)(2.70,2.64,2.52和2.33mg/L)略低,没有显著性差异;但在不同非离子态氨氮(3.86,3.29和2.09mg/L)胁迫下

Improvement of Segmentation Correction Model Based on Local Features

基于局部特性的分割校正模型能够在图像分割的同时实现对非均匀场的校正,从而对灰度不均匀图像有较好的分割效果,然而,该模型具有局部特性,且采用多相分割,使得活动轮廓曲线对初始位置较为敏感,且分割速度较慢。针对该不足,通过引入自适应距离保持水平集算法,采用分割校正模型与自适应距离保持水平集相结合的方法,提出一种新的快速分割算法。实验结果表明,该算法可摆脱初始轮廓的限制,避免在分割灰度不均匀图像时边缘泄漏和分割不足现象,并且具有分割快速的特点。Segmentation correction model based on local features can implement the correction of intensity inhomogeneity images,for which has better segmentation effect,but with the local features of the proposed model,and using multiphase segmentation,so that it is sensitive to the initial position of the active contour curve and the segmentation is slow.Aiming at the shortage,a new fast segmentation algorithm is proposed by introducing Adaptive Distance Preserving Level Set(ADPLS) algorithm,combining the segmentation correction model and adaptive distance preserving level set method.Experimental results show that the improved algorithm not only gets rid of the influence of the initial contour,but also avoids the edge leakage and segmentation shortage phenomenon,maintains the fast segmentation.福建省自然科学基金资助项目(2008J0312

五配位磷化合物与生物化学

综述了五配位磷化合物与生物化学的关系,发现当α-氨基酸的氨基接上磷酰基团以后,化学性质发生了许多奇特的现象,在室温下可发生自身活化现象而成肽、成酯、磷上酯交换及N→O磷酰基转位;丝氨酸和苏氨酸与核苷缀合以后,在弱碱性条件下能够对不同的碱基进行识别;磷酰化组氨酸和丝组二肽可以在中性条件下切割核酸、蛋白、酯.发现上述现象的发生都经历了一个五配位磷中间体,认为五配位磷中间体是决定它们活性的结构因素

Species composition and ecological distribution of planktonic diatoms in the Changjiang River estuary during Spring

20 0 2年春季 ,在长江口附近海域典型赤潮高发区 2 8个大面站位采集了 5 3个样品 ,从中共鉴定出隶属于 31个硅藻属的 80个种和变种 ;其中种类多样性较高的属为圆筛藻属 (Coscinodiscus) ,有 17个种 ,斜纹藻属 (Pleurosigma) ,有 8个种和变种 ;数量上较优势的种为柔弱拟菱形藻 (Pseudo nitzschiadeli catissma) ,为 3.4 8× 10 3 cells·L-1,占 2 8.5 4 % ;具槽直链藻 (Melosirasulcata) ,为 1.4 3× 10 3 cells·L-1,占16 .98% ;尖刺拟菱形藻 (Pseudo nitzschiapungens) ,为 0 .71× 10 3 cells·L-1,占 9.85 % .它们在大部分站位中都有出现 ;柔弱拟菱形藻和尖刺拟菱形藻的高细胞密度区主要出现在 12 30E断面的站位 ,而具槽直链藻则主要出现在长江口的 31～ 32°N断面的站位 .浮游硅藻总细胞丰度变化于 0 .4 3× 10 3 ～ 2 3.3× 10 3 cells·L-1,平均 4 .6 1× 10 3 c... 【英文摘要】 water samples were collected from 28 stations in typical regions where redtide frequently occurred in the Changjiang River estuary during Spring, 2002. In total, 80 diatom species and varieties belonging to 31 genera were identified, among which, genera with high species biodiversity included Coscinodiscus which contained 17 species and Pleurosigma which contained 8 species and varieties. Quantitative analysis of diatom cell density showed that Pseudo-nitzschia delicatissma (3.48×10 3cells·L -1, 28.54%...国家重点基础研究发展规划资助项目 ( 2 0 0 1CB40 970 1)

中国物理海洋学研究70年：发展历程、学术成就概览

本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军

Reconstruction model for heat release rate based on artificial neural network

Optimizing the distribution of heat release rate (HRR) is the key to improve the performance of various combustors. However, limited by current diagnostic techniques, the spatial measurement of HRR in many realistic combustion devices is often difficult or even impossible. HRR prediction is theoretically possible through establishing correlations between HRR and other quantities (e.g., chemiluminescence intensity) that can be experimentally determined; however, up to now, few universal correlations have been established. A novel artificial neural network (ANN) approach was adopted to build the mapping relationship between the combustion heat release rate and the measurable chemiluminescent species. Proper orthogonal -12omposition (POD) technology is used to extract the combustion physics and reduce the data of the spatial-temporally high-resolution combustion field. The correlation between the reduced-order HRR and chemiluminescent species is built using an ANN model. A unique segmentation approach was proposed to improve the training efficiency and accuracy. Validation in a supersonic hydrogen-oxygen nonpremixed flame proves the accuracy and efficiency of the proposed HRR reconstruction model based on the reduced-order POD method and data-driven ANN model. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

大岗山水电站边坡抗剪岩-洞相互作用研究

大岗山水电站右岸边坡地质条件复杂,地应力较高,发育有辉绿岩脉、中倾坡外的断层、卸荷裂隙密集带等不利组合体,边坡稳定性问题极为突出。将实际微震监测技术与有限差分数值软件FLAC（3D）结合,对抗剪洞加固前、后的边坡稳定性以及岩-洞两体的相互作用进行分析。指出边坡开挖过程中岩体空间损伤劣化的微震活动规律和可能发生坡体失稳的潜在滑动面位置。研究发现抗剪洞起到了很好的加固作用,加固后潜在滑体产生的位移几乎不到加固前的一半、坡体的安全系数提高了36.2%及微震监测得到的微震事件降低了约66.4%