含季节性虚拟变量的GM(1,1)模型及其应用

针对GM（1，1）模型难以准确预测季节性时间序列的问题，本文将季节性虚拟变量作为灰作用量引入传统GM（1，1）模型中，提出了含季节性虚拟变量的GM（1，1）模型（简记为GMSD（1，1））.在GMSD（1，1）模型定义型和白化型的基础上，推导了GMSD（1，1，x⁽¹⁾）模型、GMSD（1，1，x⁽⁰⁾）模型、GMSD（1，1，b）模型、GMSD（1，1，exp）模型、GMSD（1，1，C）模型等五种派生型GMSD（1，1）模型，构建了季节性虚拟变量GM（1，1）模型群.同时利用粒子群算法对GMSD（1，1）模型和GMSD（1，1，exp）模型中的解析式进行最优化求解.最后以中国水力发电量的季度数据为例，验证了含季节性虚拟变量的GM（1，1）模型及其派生模型的有效性和优越性.结果表明：相较于传统GM（1，1）模型，引入季节性虚拟变量的GMSD（1，1）模型及其派生模型更能准确地描述系统特征序列的季节性波动和周期性变化特征.     

用多目标遗传算法优化设计水库分期汛限水位

水库分期汛限水位利用洪水的季节性规律,可在不降低水库防洪标准的前提下,显著提高水库兴利效益.论述了优化设计分期汛限水位的必要性、基于模拟调度优化设计分期汛限水位的可行性.以防洪、发电、航运等多目标来评价分期汛限水位方案,以不降低水库防洪能力为约束条件,建立了优化设计模型.对简单遗传算法进行了多目标评价、引入共享函数、线性变换适应度函数、优解保持策略、重新洗牌等改进,建立了一种改进的多目标遗传算法,用以优化设计分期汛限水位方案.以三峡水库为研究背景,采用混合编码方法描述分期汛限水位方案,利用1882~2003年宜昌站汛期的实测日流量资料进行模拟优化,得出了较优的分期汛限水位方案.计算结果表明,分期汛限水位优化设计能权衡防洪与兴利之间的关系,在满足防洪要求的前提下,显著提高水库兴利效益.     

Efficient Statistical Leakage Power Analysis Method for Function Blocks Considering All Process Variations

With technology scaling into nanometer regime, rampant process variations impact visible influences on leakage power estimation of very large scale integrations (VLSIs). In order to deal with the case of large inter- and intra-die variations, we induce a novel theory prototype of the statistical leakage power analysis (SLPA) for function blocks. Because inter-die variations can be pinned down into a small range but the number of gates in function blocks is large(>1000), we continue to simplify the prototype. At last, we induce the efficient methodology of SLPA. The method can save much running time for SLPA in the low power design since it is of the local-updating advantage. A large number of experimental data show that the method only takes feasible running time (0.32 s) to obtain accurate results (3 σ-error <0.5% on maximum) as function block circuits simultaneous suffer from 7.5%(3 σ/mean) inter-die and 7.5% intra-die length variations, which demonstrates that our method is suitable for statistical leakage power analysis of VLSIs under rampant process variations.     

深圳福田红树林区浮游藻类时空分布的研究

在2005年11月（秋）、2006年1月（冬）、2006年4月（春）,分别对深圳福田红树林保护区5个水质监测站的浮游藻类进行采样研究.共鉴定到浮游藻类5门27属52种（含1变种和9未知种）,密度在1.2×10^6～8.8×10^6个/L之间,平均密度为4.9×10^6个/L.硅藻门种类最多,有17属35种（含未知7种）,占总种类数的67.3%,而且密度最大,高达8.7×10^6个/L;最少为隐藻门的种类,尚未发现甲藻门的种类.耐污染特征的种类如极微小环藻（Cyclotella caspia）、颤藻（Oscillatoriaspp.）和小球藻（Chlorella vulgaris）是藻类群落的主要成分.各站分布的藻类群落组成季节差异明显,而种类数和密度并没有明显的季节变化.各站的优势种和优势类群存在时空差异.评价各站水质,反映出该红树林区水体处在中营养至富营养化状态.     

Recent temperature increase recorded in an ice core in the source region of Yangtze River

Interests on climate change in the source region of Yangtze River have been raised since it is a region with the greatest warming over the Tibetan Plateau (TP). A 70-year history of precipitation δ~(18)O has been recovered using an ice core record retrieved in a plat portion of the firn area in the Guoqu Glacier (33°34′37.8″N, 91°10′35.3″E, 5720 m a.s.l.), Mt. Geladaindong (the source region of Yangtze River), in November, 2005. By using a significant positive relationship between ice core δ~(18)O record and summer air temperature (July to September) from the nearby meteorological stations, a history of summer air temperature has been reconstructed for the last 70 years. Summer temperature was relatively low in 1940s and high in 1950s to the middle of 1960s. The lowest temperature occurred in the middle of 1970s. Temperature was low in 1980s and dramatically increased since 1990s, keeping the trend to the begin-ning of the 21st century. The warming rate recorded in the ice core with 0.5℃/10 a since 1970s is much higher that that in the central TP and the Northern Hemisphere (NH), and it becomes 1.1℃/10 a since 1990s which is also higher than these from the central TP and the NH, reflecting an accelerated warm-ing and a more sensitive response to global warming in the high elevation region.     

西藏岁时节日民俗概述

岁时节日民俗,主要指与天时、物候的周期转换相适应,在人们的生活中形成不同的民俗事象传承。西藏的岁时节日民俗丰富多彩、形式多种多样,不仅反映出我们的祖先对自然及其变化规律的认识和把握,同时也从包罗万象的节俗活动显示出雪域高原各个历史时期的文明发展水平。文章通过对西藏岁时节日民俗的由来、节日的分类、节俗产生的内动力、节日的发展演变规律的释析,探讨西藏节日习俗的文化现象。     

内蒙古荒漠草原土壤微生物的分布特征及季节动态变化研究

研究了内蒙古荒漠草原土壤中主要微生物类群的数量随季节变化的规律，以及土壤中微生物的垂直分布特征．结果表明，土壤中3大类群微生物的数量关系为细菌〉放线菌〉真菌，各类群微生物的垂直分布均为0～10cm层多于10-20cm层．细菌、真菌、自生固氮菌以及微生物总数量的峰值出现在春季，而放线菌数量的峰值出现在秋季．     

Seasonal variation of global stratosphere-troposphere mass exchange

By Wei formula in pressure coordinate, the stratosphere-troposphere mass exchange (STME) is diagnosed globally for 44 years from 1958 to 2001 using the European Center for Medium-Range Weather Forecasts (ECMWF) reanalysis datasets. Regions of mass flux into the stratosphere are found over Indonesia, bay of Bangladesh and the mid-west coast of South Africa. Compensating mass outflow from the stratosphere appears mainly over mid-latitudes near large-scale troughs. Upward and downward transport of mass at the middle and high latitudes accompany with each other. Mass flux into troposphere is stronger in autumn and winter than in spring and summer. Strong downward mass flux into the troposphere occurs in eastern Asia the whole year with nearly stable sites. Although the area of eastern Asia accounts for only 5.6% of that of the northern hemisphere (NH), its net mass exchange reaches 15.83% of that of the NH, which means that research on STME of eastern Asia is greatly important to that of the NH and even the global areas. Air across the tropopause enters more from stratosphere to troposphere than that from troposphere to stratosphere, which is possibly related with systematic bias of the assimilated datasets and with persistent rise of the tropopause height. Contributions of the mass exchange and the mass flux exchange in the NH and southern hemisphere (SH) on their latitudes increase from equator to pole, with larger contributions in the NH. Mass exchange and mass flux exchange per areas at high latitudes are larger than that at low latitudes, which means greater mass exchange efficiency at high latitudes.     

加热率对比及大气加热性质的研究

首先对比分析了气候平均的ERA与NCEP再分析的全球加热率资料，以及两套资料在青藏高原地区的差异。发现在全球范围内，主要差异在于ERA的总加热率比NCEP的总加热率普遍要大，NCEP资料优于ERA资料。再利用NCEP资料分析高原的加热性质及加热的季节变化规律，发现对于青藏高原主体（80-100°E、27．5-37．5°N）而言，平均的辐射冷却全年少变；高原在夏季表现为强大的热源主要由潜热加热引起，感热加热次之，冬季的冷源则以辐射冷却为主，过渡季节的急剧变化主要因感热的变化引起。     

鲫鱼尾部神经分泌系统Dahlgren细胞季节性变化的细胞计量学研究

本文用光镜和彩色图像分析系统,研究了雌性鲫鱼尾部神经分泌系统Dahlgren细胞的定量细胞学的季节性变化特点.结果发现:尾部最后7～12节脊髓中Dahlgren细胞的大小,在相邻季节间的变化为;从春至冬,逐渐减小（仅夏秋间无明显变化）,冬季后又逐渐增大,差异均极显著;而最后1～3节的变化为:只在春夏之间减小,夏季后则不断增大,差异也极显著.上述Dahlgren细胞计量学的变化,不同程度地呈现出与卵巢同步发育的关系.这为尾部神经分泌系统的变化与鱼类性成熟的相关性提供了新的依据.