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An integrated decision method for prediction of tropical cyclone movement by using genetic algorithm

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Science China Earth sciences 2005年第3期48卷 429-440页

作者： YANG Yuanqin1 & WANG Jizhi2.1. National Meteorological Center, Beijing 100081,China 2. Chinese academy of Meteorological sciences, Beijing 100081, China National Meteorological Center Beijing China Chinese academy of Meteorological sciences Beijing China

In this study an integrated decision method for the multi-prediction results of tropical cyclone movements by using genetic algorithm (GA) has been adopted. A genetic learning artifi- cial neural network (GLANN) as a learning mechanism for track prediction was developed through training with the huge samples of typhoon tracks from 1884 to 2.02. The prediction of typhoon motion is to consider how to suit the dynamic change of environment, where typhoon passed through. The neural network structure is described by GA. A fitness function for choice of GA is given to approach the maximum of fitness (the minimum of the errors). Parallel comparing analyses for prediction abilities of unusual typhoon tracks in recent years by GLANN with multi-forecast methods were conducted. More types of cases were employed in the comparing analyses, which consist of the typhoon, Winnie, No.11, in 1997, characterized by a long life over the ocean and in the mainland with severe effect on China, the 10 unusual typhoon tracks in the 1990s, the tracks with landfall and affected action in 1998 and the typhoons born in the Northwestern Pacific and the South China Sea in 2.00, including the 2.—48 h forecast, etc. The results indicated that for prediction ability of typhoon tracks, specially for unusual typhoons, GA decision-making developed in this study is superior to the others.

关键词： genetic algorithm, integrated decision, prediction of tropical cyclone.

Numerical simulations of the bi-level and branched structure of intracloud lightning flashes

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Science China Earth sciences 2006年第6期49卷 661-672页

作者： TAN Yongbo1, TAO Shanchang1, ZHU Baoyou1, MA Ming2.& LU Weitao2.1. School of Earth and Space sciences, University of Science and Technology of China, Hefei 2.002., China 2. Chinese academy of Meteorological sciences, Beijing 100081, China School of Earth and Space sciences University of Science and Technology of China Hefei China Chinese academy of Meteorological sciences Beijing China

Intracloud (IC) lightning flashes have been simulated in fine resolution (12.5 m) by using a bidirectional stochastic lightning parameterization scheme within 2.dimensional domain. The simu-lated results show that the IC flashes have a bilevel channel structure and the altitudes of the hori-zontal channels are at the same heights of potential wells, which are supported by the previous VHF source observations and balloon soundings of electric field profile in the thundercloud. Further con-clusions are: (1) After an IC flash is initiated near the boundary between positve and nagetive charge zone, the negative (or positive) leader tends to propagate into the positive (or negative) charge zone. Both types of positive and negative IC flashes have been reproduced and their polarity depends on the up and down disposition of the positive and negative charge regions. (2. The extension range of leaders is correlative with the cloud charge distribution. The leader is possible to extend through the inverted charge region all over where it is extending, but keeps away from the isolated charge area of the same polarity. (3) The channel structures also depend on the electric potential distributions in the thundercloud. Before propagating into the central area of potential wells, the leader tends to extend along the direction with the maximum of potential gradient. Once extending away from the center of potential wells, the leader tends to extend along the direction with the slowest potential change. (4) The IC flash channels have the fractal feature with fractal dimension 1.45 before leaders pass through the central area of charge regions. The exponent decreases rapidly once leaders extend into the low-density charge regions. (5) The induced charges of opposite polarity are deposited in the leader channels within preexisting positive and negative charge regions during IC flash discharges. This causes a new and complicated charge distribution in the thundercloud, and the potential

关键词： IC, lightning parameterization, branched bilevel structure, fractal feature, propagation tendency.

Hydrochemical characteristics of salt marsh wetlands in western Songnen Plain

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Journal of Geographical sciences 2001年第2期11卷 217-223页

作者： DENG Wei~1, HE Yan~2. SONG Xin-shan~1, YAN Bai-xing~1 (1. Changchun Institute of Geography, CAS, Changchun 13002., China 2. Chinese academy of sciences, Beijing 100864, China) Changchun Institute of Geography CAS Chinese academy of sciences

In western Songnen Plain of China, the saline-alkaline degree of water bodies is high in salt marsh wetlands. Generally, pH is above 8.0, and the hydrochemical types belong to HCO3 2.-Na+. Through analysis on the basic saline variables such as CO3 2., HCO3 2., Cl?, Ca2., Mg2., SO4 2., Na+, and the derivative variables such as SAR, SDR, RSC, SSP, the relationships between different variables are found, and the discriminant equations are established to identify different saline-alkaline water bodies by using principal component analysis.

关键词： salt marsh wetland hydrochemical types correlation analysis principal component analysis discriminant analysis Songnen Plain

Protein-only" or "virino" in prion diseases?

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Chinese Science Bulletin 2000年第3期45卷 285-288页

作者： YANG Chiming (Chi Ming Yang) & CHEN Yi1. Institute for Life Science and Health at UCSD, P.O.Box 12.35, La Jolla, CA 92.39, USA 2. Institute of Chemistry, academy of sciences, Beijing 100080, China Correspondence should be addressed to Yang Chiming Institute for Life Science and Health at UCSD La Jolla USA Institute of Chemistry Academy of Sciences Beijing China

60-year prion and scrapie research has led to a dilemma in understanding the unknown aetiology of the infectious neurodegenerative disorders with intriguing features. Current progress and dilemma in prion research are briefly but critically reviewed. Instead of providing a comprehensive coverage of the research history, attentions in this view are drawn toward both the major breakthrough in the advancement of protein-only hypothesis, and the puzzle why this hypothesis has not been fully accepted. In order to resolve the prion enigma in neuroscience, it is suggested that both technical and concept barriers remain to be crossed. Since prion research is a multi-interdisciplinary subject, this view is intended to both facilitate a bette r understanding of prion phenomenon by more scientists in natural science, and invite scientists outside the fields of molecular genetics and protein science for collaboration.

关键词： prions mad cow disease neurodegenerative disorder subviral pathogen prion radical.

热带西太平洋大气气候基本态与厄尔尼诺期间赤道附近西风异常

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海洋学报 2002年第2期24卷 39-50页

作者：严邦良张人禾中国科学院大气物理研究所北京100080 中国气象科学研究院北京100081

利用合成分析的方法分析了自1961年以来观测到的8次厄尔尼诺事件中赤道西太平洋地区西风异常与大气气候基本态的关系,结果发现厄尔尼诺年赤道西太平洋地区西风异常具有和大气气候基本态相一致的季节变化特征.利用一个简单热带海-气耦合... 详细信息

利用合成分析的方法分析了自1961年以来观测到的8次厄尔尼诺事件中赤道西太平洋地区西风异常与大气气候基本态的关系,结果发现厄尔尼诺年赤道西太平洋地区西风异常具有和大气气候基本态相一致的季节变化特征.利用一个简单热带海-气耦合模式较好地模拟出了观测到的厄尔尼诺年赤道西太平洋地区西风异常的变化特征.对模式结果的分析表明,大气气候基本态对厄尔尼诺年赤道西太平洋地区西风异常的形成起重要作用,它是通过影响大气模式中的加热场来影响赤道西太平洋地区西风异常.大气模式中赤道太平洋地区的加热场的形成具有阶段性和地区性,在厄尔尼诺事件的初始阶段,大气气候基本态是大气模式中的加热场形成的主要因子,而在厄尔尼诺事件的发展和成熟阶段,赤道中东太平洋地区的海表温度异常（SSTA）是加热场形成的主要因子.模式模拟结果对大气气候基本态依赖的敏感性试验说明,在大气模式加热场中含有大气气候基本态的模拟中,沿中西太平洋赤道附近的纬向风异常表现出和观测类似的传播特征.

关键词：厄尔尼诺事件海气耦合模式大气气候基本态太平洋西风异常

基于网格控制容差的屏幕数字化在土地利用分类上应用的研究

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土壤通报 2003年第6期34卷 498-500页

作者：吴连喜王茂新东华理工学院江西抚州344000 中国气象科学研究院北京100081

本文对基于网格控制容差的屏幕数字化的有关理论和方法进行了探讨。试验表明采用屏幕数字化,即采取人机交互的方式,将RS和GIS,专家知识和目视解译结合起来进行地物识别,是一种分类精度较为准确的方法。

关键词：网格控制容差屏幕数字化土地利用分类地物识别分类精度

洮儿河中下游流域景观格局的形成及水环境效应分析

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水土保持学报 2003年第6期17卷 32-35页

作者：郭跃东何岩邓伟中国科学院东北地理与农业生态研究所吉林长春130012 中国科学院北京100864

景观格局是地貌格局、土壤格局、植被分布格局、水资源格局及生产力格局等的综合。从景观发育的动力因素角度,分析了洮儿河中下游流域景观格局特征,总结了推动景观格局形成的地质地貌、气象水文及社会生产力因素,重点阐述了水环境系统... 详细信息

景观格局是地貌格局、土壤格局、植被分布格局、水资源格局及生产力格局等的综合。从景观发育的动力因素角度,分析了洮儿河中下游流域景观格局特征,总结了推动景观格局形成的地质地貌、气象水文及社会生产力因素,重点阐述了水环境系统演化与景观格局发育的耦合过程和特征,探讨不同景观要素对水环境特征分异的关系,分析景观格局对水环境系统中水量、水质及空间分布的整体影响。

关键词：景观格局水环境系统水空间

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SOTER支持下海南土壤侵蚀量估算

水土保持学报 2003年第6期17卷 51-54页

作者：余炜敏漆智平西南农业大学资源与环境学院重庆400716 中国热带农业科学院海南儋州571737

在已建立的SOTER数据库基础上,利用SWEAP模型运算可知:海南土壤侵蚀主要发生在丘陵和陡坡地;海南土壤侵蚀量的空间分布与地形构造一致,中部山区(保亭)土壤侵蚀量较大,北部(琼山)沿海平原区侵蚀量较小;坡度为8％～30％的丘陵地区,采用梯... 详细信息

在已建立的SOTER数据库基础上,利用SWEAP模型运算可知:海南土壤侵蚀主要发生在丘陵和陡坡地;海南土壤侵蚀量的空间分布与地形构造一致,中部山区(保亭)土壤侵蚀量较大,北部(琼山)沿海平原区侵蚀量较小;坡度为8％～30％的丘陵地区,采用梯化或等高种植的耕作措施可以大幅度降低土壤侵蚀量。研究表明,在SOTER数据库的支持下,SWEAP用于海南土壤侵蚀量的估算结果可靠程度较高。

关键词： SOTER 海南土壤侵蚀量估算

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星云湖流域畜禽粪便污染负荷及其环境影响

上海环境科学 2011年第1期30卷 12-17,22页

作者：王晋虎张德华陈异晖昆明理工大学环境学院昆明650093 云南省环境科学研究院昆明650034

从星云湖流域畜禽养殖业现状分析入手,通过排泄系数法原理,估算流域各乡镇的畜禽污染物产生量,进一步核算农田畜禽粪便负荷量,在此基础上,对各乡镇农田畜禽粪便负荷承受程度进行警报与分级。同时,对畜禽养殖对水环境的影响进行了分析,... 详细信息

从星云湖流域畜禽养殖业现状分析入手,通过排泄系数法原理,估算流域各乡镇的畜禽污染物产生量,进一步核算农田畜禽粪便负荷量,在此基础上,对各乡镇农田畜禽粪便负荷承受程度进行警报与分级。同时,对畜禽养殖对水环境的影响进行了分析,根据各乡镇畜禽粪便污染物的产生量,测算了各地污染物流失进入水体的排放量,为了分析出各类污染物对水体污染的贡献值的大小,引入污染物等标排放量评价方法。结果表明,流域各地畜禽污染物产生量与农田畜禽粪便负荷警报值并不成对应关系,污染物产生量较小的路居镇对环境已达到威胁级别;畜禽污染物流失进入水体的排放量较大,各类污染物中,猪尿排放对水体的影响较大,在各类污染因子里,TP对星云湖的贡献值最大,其次是TN、COD。

关键词：星云潮流域畜禽粪便负荷环境风险评价污染物水体流失量