基于最大类间方差法的天空图像云空识别模型

准确的云空辨识对提高光伏发电功率超短期预测精度具有重要意义。首先针对由全天空成像仪采集的一系列天空图像进行预处理,然后提取样本图像的灰度矩阵,最后根据所提取的灰度矩阵建立基于最大类间方差法的天空图像云空识别模型。为验证本文提出的云空辨识模型的有效性,利用云南地区光伏电站中全天空成像仪(Total Sky Imager,TSI)采集的图像进行测试验证,与固定阈值法处理效果对比的结果表明,在复杂天气情况下面对不同分布特性的云团,本文提出的基于最大类间方差法的云空辨识模型更为准确、高效。

服务于区域光伏预测的天空图像K-means云空辨识模型

地基天空图像的云空辨识及云团预测是研究区域电网光伏发电功率分布与变化的前提,对支撑调度提高光伏发电消纳比例具有重要意义。首先分别采用较高的红蓝分量比值和较低的红蓝分量比值作为固定阈值分割地基天空图像,依次提取辨识结果中的天空像素点和云像素点的位置信息并获取原图像中对应位置的天空像素点和云像素点的RGB值;其次对获得的天空像素和云像素求均值并将各自均值中的红蓝分量相除获取初始聚类中心;然后使用K-means算法,利用加权欧式距离计算每一个聚类样本与聚类中心之间的距离,通过数次迭代得到聚类结果,进而将聚类结果还原成矩阵得到地基天空图像的云空辨识结果图;最后利用云南某光伏电站全天空成像仪TSI-VIS-J1006采集的天空图像进行仿真,结果表明该方法较固定阈值法的收敛速度更快、聚类精度更高,能够有效实现地基天空图像的云空辨识。

紫芝词“云空”意象考论——以《竹坡词》为例

南宋前期词坛名家周紫芝所存词以清雅旷远的风格而名著当时,所撰《竹坡词》,其中之意境,率皆擅摹风物,清丽温愁,涵工深致,为南宋前期词坛的工雅于体式者。

基于探空云识别方法的云垂直结构分布特征

云的垂直结构特征作为云重要的宏观特征之一,直接决定了云的类型,进而通过发射和吸收辐射的方式影响着地气系统的能量收支平衡,因此对云垂直结构特征的研究一直都是云物理研究的一个重要方向。作为观测云垂直结构特征的一种方式,探空气球通过获取沿路径方向高分辨率的廓线信息,采用一定反演方法从而能够较为准确的识别云的垂直结构。本文即利用我国业务布网探空站的观测资料,采用相对湿度阈值法识别云垂直结构,并同激光云高仪、"风云四号"静止卫星和毫米波云雷达对识别的云结构特征量进行了一致性检验。在此基础上,统计分析了2015~2017年单层、两层和三层云的垂直结构分布特征、日变化和季节变化特征以及全国区域分布特征,结果表明:(1)整体分布上,单层云在垂直方向上出现的高度范围介于多层云的高度范围内,并且随着云层数的增加,云在垂直方向上更为伸展,即高层云越高,低层云越低;(2)在日变化中,中午单层和多层云中最低层云的云底高度均高于早晨,而夜间单层和多层云中最高层云的云顶高度则高于早晨和中午,同时中间层云厚的变化要小于最上层和最下层云厚的变化;(3)在季节变化中,夏季云量较其他季节更多,云体发展也更为深厚,表明温暖的大气条件更有利于云的形成和发展;(4)我国云垂直结构分布特征具有明显的纬向变化趋势,从以青藏高原为中心的西南地区的云底较高云体较薄的云,逐步过渡到以东南沿海地区为中心的云底较低云体较为深厚的云,表明不同地形和气候带的差异与不同云类型的分布直接相关。

A Study on Vertical Spatial Transfer of Cultivated Land in Yunnan Province from 1986 to 2008

Based upon ArCGIS,the vertical spatial transfer law of cultivated land in Yunnan was studied through referring to three periods of remote sensing data of Land-Use and Land-Cover Change（LUCC） in Yunnan in 1986,1995 and 2000,Digital Elevation Model（DEM） of Yunnan Province and LUCC data in Yunnan from 2000 to 2008.The main factors that promote vertical spatial transfer law of cultivated land were analyzed by using SPSS,and the influence of policies and government acts upon the change of cultivated land was clarified.The findings indicated that for Yunnan cultivated land there is a trend that in the vertical direction steep slope areas and gentle slope areas divert into mid-slope areas.The primary factor influencing the vertical spatial transfer of cultivated land was policies and government acts.Also,the gradient of ground,total population and number of agriculture employed persons were also main factors in influencing the change of cultivated land,whose influence was obviously below policies and government acts.

Design and achievement of cloud geodatabase for a sponge city

Building a cloud geodatabase for a sponge city is crucial to integrate the geospatial information dispersed in various departments for multi-user high concurrent access and retrieval,high scalability and availability,efficient storage and management.In this study,Hadoop distributed computing framework,including Hadoop distributed file system and MapReduce(mapper and reducer),is firstly designed with a parallel computing framework to process massive spatial data.Then,access control with a series of standard application programming interfaces for different functions is designed,including spatial data storage layer,cloud geodatabase access layer,spatial data access layer and spatial data analysis layer.Subsequently,a retrieval model is designed,including direct addressing via file name,three-level concurrent retrieval and block data retrieval strategies.Main functions are realised,including real-time concurrent access,high-performance computing,communication,massive data storage,efficient retrieval and scheduling decisions on the multi-scale,multi-source and massive spatial data.Finally,the performance of Hadoop cloud geodatabases is validated and compared with that of the Oracle database.The cloud geodatabase for the sponge city can avoid redundant configuration of personnel,hardware and software,support the data transfer,model debugging and application development,and provide accurate,real-time,virtual,intelligent,reliable,elastically scalable,dynamic and on-demand cloud services of the basic and thematic geographic information for the construction and management of the sponge city.

Experimental Study on Unconfined Vapor Cloud Explosion

An experimental system was setup to study the pressure field of unconfined vapor cloud explosions. The semi-spherical vapor clouds were formed by slotted 0.02mm polyethylene film. In the center of the cloud was an ignition electrode that met ISO6164 'Explosion Protection System' and NFPA68 'Guide for Venting of Deflagrations'. A data-acquisition system, with dynamic responding time less than 0.001s with 0.5% accuracy, recorded the pressure-time diagram of acetylene-air mixture explosion with stoichiometrical ratio. The initial cloud diameters varied from 60 cm to 300 cm. Based on the analysis of experimental data, the quantitative relationship is obtained for the cloud explosion pressure, the cloud radius and the distance from ignition point. Present results provide a useful way to evaluate the building damage caused by unconfined vapor cloud explosions and to determine the indispensable explosion grade in the application of multi-energy model.

Macrophysical properties of specific cloud types from radiosonde and surface active remote sensing measurements over the ARM Southern Great Plains site

Accurate observation of clouds is challenging because of the high variability and complexity of cloud types and occurrences.By using the long-term cloud data collected during the ARM program at the Southern Great Plains central facility during 2001-2010,the consistencies and differences in the macrophysical properties of clouds between radiosonde and ground-based active remote sensing are quantitatively evaluated according to six cloud types：low;mid-low（ML）;high-midlow;mid;high-mid（HM）;and high.A similar variability trend is exhibited by the radiosonde and surface observations for the cloud fractions of the six cloud types.However,the magnitudes of the differences between the two methods are different among the six cloud types,with the largest difference seen in the high clouds.The distribution of the cloud-base height of the ML,mid,and HM clouds agrees in both methods,whereas large differences are seen in the cloud-top height for the ML and high clouds.The cloud thickness variations generally agree between the two datasets for the six cloud types.

Spatial Distribution of Integrated Impact Index of Mega-event——A Case Study of Expo '99 Kunming

Taking the affinity between events and media as a conceptualization base, a total of 1032 related news re-ports of Expo '99 Kunming, gathered from the internet data bank of China INFOBANK from 1992 to 2003, are used as data sources. After classifying them with a communication research method-the content analysis, a data bank for SPSS is set up, and a mathematic model called the Integrated Impact Index of Expo '99 Kunming is constituted. With the model, the spatial distribution of the total integrated impacts of Expo '99 Kunming on the regions or cities with different regional scales is analysed quantitatively. The conclusions are: 1) the Expo '99 Kunming made obvious integrated impacts on the regions or cities of every scale, especially in the venue city and the region-Kunming City and Yunnan Province; 2) it had corresponding impacts on other provinces; 3) the spatial distribution of Integrated Impact Index had a disaggregation with both plane extension and spotted decentralization; and 4) there was a distance decay law in all three scales of regions (Kunming City, Yunnan Province and the whole China), which incarnated the spatial extension law of the integrated impact of a special mega-event.

Temporal changes in wetland plant communities with decades of cumulative water pollution in two plateau lakes in China's Yunnan Province

Abstract： Wetland plant communities in the plateau lakes of Yunnan Province, China, have decreased significantly over the past decades. To better understand this degradation, we analyzed the processes and characteristics of changes in wetland plant communities in two of the largest lakes in Yunnan Province, Dianchi and Erhai lakes. We collected records of native and alien plant communities in the two lakes from literature published from the 195os to current period. We calculated plant community types and their area in some historical periods when related data were reported, and analyzed the relationship between chances in nlant communities and water nollution. InDianehi Lake, 12 community types of native plant communities, covering over 80% of the surface in the 195os and 196os, were reduced to four types covering 2.4% by the late 2ooos. Alien plant communities started to appear in the lake in the late 197os, and have since come to cover 4.9% of the lake surface, thereby becoming dominant. In Erhai Lake, 16 community types of native plant communities, covering 47.1% of the lake surface in the late 197os, declined to lo community types, covering 9.3% of the surface, by the late 2ooos. Alien plant communities appeared in the middle 198os, and at present cover 0.7% of the surface area. It was indicated that changes in plant communities were significant related to water eutrophication. The area occupied by native and alien plant communities was, respectively, negatively andpositively related to the content of nutrients in water. This showed lacustrine pollution played an important role in native plant loss and alien plant invasion in the two plateau lakes.

Speciation and spatial distribution of Cr in chromite ore processing residue site,Yunnan,China

Remediation of COPR sites requires the key information including chromium oxidation, speciation and spatial distribution. Samples were gathered from a COPR site in Luliang County in Qujing, Yunnan Province of China. The total Cr, Cr(VI) and chromium species were investigated. Results indicated the concentration of total Cr was between 110.5 and 21,774 mg/kg, and the concentration of Cr(VI) was between 0.1 and 1075 mg/kg. The map of total-Cr and ratio of Cr(VI)/total-Cr(%) showed that the maximum of total-Cr and Cr(VI) appeared in the layers near the surface. In the horizontal direction, the pollution was more serious in the middle and southeast part than that in the west. Additionally, acid extractable chromium increased in the layers at depth from-0.3 to-2.0 m, and it decreased in the deeper layers. There was a trend that the movable Cr(VI) migrated to the deeper layers, and then it turned into Cr(III). Water played an important role for the Cr distribution. Cr(VI) in COPR released to the soil solution after rainfall, and then gravity led the solution down to the deeper layers. After repeated rainfall and leaching,Cr(VI) moved to the deeper soil layers. Due to capillarity and evaporation, Cr(VI) migrated and was enriched at thesurface layer. Therefore, measures on controlling water movement should be taken in the remediation of the COPR site.

Distribution Patterns and Associations of Dominant Tree Species in a Mixed Coniferous-Broadleaf Forest in the Changbai Mountains

In 2012 a plot was established with 1-ha area in a mixed coniferous-broadleaf forest in the Changbai Mountains, northeastern China for examining local forest processes, structure and succession. A method of O-ring statistics （pair- correlation function） was applied to analyze the spatial patterns and associations of the dominant species within different vertical layers. After the evaluation by their importance values, six tree species （or group） （i.e. Abies nephrolepis, Picea jezoensis, Pinus koraiensis, Tilia amurensis, and species group of Betula ssp. and species group of Acer ssp.） were determined as dominant trees species. It was found that some of these species exhibited closely clustered distributions at fine distances. As spatial distance increased, a random or even regular distribution gradually appeared with the exception of the upper layers of A. nephrolepis and P. koraiensis, and the lower layers of P. jezoensis, P. koraiensis and Betula ssp., which were substantially randomly distributed. Intra- and inter-species spatial associations varied in accordance with species, tree height and reciprocal distances. Positive associations were observed between the lower and upper height classes of trees of the same species （except for that of P. jezoensis） at fine distances. This may be owing to limited seed dispersal and geological heterogeneity. The aggregation intensity declines with increasing distances and this consistent with the predictions of self-thinning. Some coniferous trees （e.g. Pinus koraiensis） in the lower height class were positively associated with T. amurensis and group of Betula ssp. of the upper height class at some distances, suggesting that saplings of coniferous trees occupy a broader niche and can grow well under the canopy of the adult of broad-leaved trees. Negative associations were observed between upper coniferous trees and lower broad-leaved trees and between upper P. jezoensis and lower P. koraiensis, suggesting that a canopy of these trees might not provide suitable environment for the survival, establishment, and growth of o lower individuals, corresponding well to Janzen-Connell hypothesis.

Spatiotemporal Patterns of Road Network and Road Development Pri-ority in Three Parallel Rivers Region in Yunnan,China:An Evaluation Based on Modified Kernel Distance Estimate

Road network is a critical component of public infrastructure,and the supporting system of social and economic development.Based on a modified kernel density estimate(KDE)algorithm,this study evaluated the road service capacity provided by a road network composed of multi-level roads(i.e.national,provincial,county and rural roads),by taking account of the differences of effect extent and intensity for roads of different levels.Summarized at town scale,the population burden and the annual rural economic income of unit road service capacity were used as the surrogates of social and economic demands for road service.This method was applied to the road network of the Three Parallel River Region,the northwestern Yunnan Province,China to evaluate the development of road network in this region.In results,the total road length of this region in 2005 was 3.70×104km,and the length ratio between national,provincial,county and rural roads was 1∶2∶8∶47.From 1989 to 2005,the regional road service capacity increased by 13.1%,of which the contributions from the national,provincial,county and rural roads were 11.1%,19.4%,22.6%,and 67.8%,respectively,revealing the effect of′All Village Accessible′policy of road development in the mountainous regions in the last decade.The spatial patterns of population burden and economic requirement of unit road service suggested that the areas farther away from the national and provincial roads have higher road development priority(RDP).Based on the modified KDE model and the framework of RDP evaluation,this study provided a useful approach for developing an optimal plan of road development at regional scale.

The Spatial-temporal Distribution and Their Statistical Characteristics of Foreshocks in the Yunnan Region

We analyzed 223 earthquakes with M 1〉 5.0 that occurred in the Yunnan region during 1965 - 2014, among which 74 （ about 33. 2 % ） had foreshocks. There are great differences in foreshock populations in different tectonic blocks： the most abundant foreshocks occurred in the Lancang-Gengma and Tengchong-Baoshan blocks, which have the most abundant foreshocks in the Yunnan region. The predominant magnitude difference, time interval and spatial distance are 0. 5 -2. 9, within 10 days and within 20km, respectively. These characteristics can be used to forecast the mainshock after the identification of a foreshock.

Secondary Electron Yield Studies on Vacuum Materials

A secondary electron yield test device for vacuum material study is set up,and its detailed design described in this paper.The test results for a few common vacuum materials with and without TiN film coating are presented,and the influential factors on secondary electron yield are analyzed.All the work will be helpful to the surface pretreatment of vacuum materials.

Determining wind field and electric field by a barium release experiment in the ionosphere

Barium release experiment is an effective way to study the near-earth environment, in which artificial plasma cloud is created via ionization of neutral gases released from a rocket or a satellite. The first barium release experiment in China was success- fully carried out by a sounding rocket at a height of about 190 km on April 5, 2013. The observed barium cloud images show that the neutral cloud follows a damping motion, whose velocity decreases exponentially and finally tends towards the wind velocity of the background. But for the ion cloud, the motion is controlled mainly by the Lorentz force and a ExB drift happens This work is devoted to calculating the wind and electric field of the background by analyzing the observed images from dif- ferent stations. It turns out that the wind has a magnitude of 51.28 m/s, which is mainly in the northeast direction but also has an appreciable vertical component; the ion cloud has a drift velocity of 71.38 m/s, with a large vertical velocity component be- sides the horizontal components, then the electric field is obtained from the drift velocity as 2.49 mV/m. It is interesting that the wind field shows a better agreement with GITM model than the other empirical or theoretical models, and the GITM model can also give a good prediction for the ion velocity observed by us, which is consistent with the ISR observation at Jicamarca as well.

Spatial Distribution and Tourism Activation of Traditional Villages in Yunnan Province

Using ArcGIS to analyze the spatial distribution of traditional villages in Yunnan Province in combination with the actual local conditions of traditional villages,the purpose of this study is to determine the development model suitable for their characteristics.The results show several important features of traditional village distribution.(1)The traditional villages in Yunnan Province have spatial structural characteristics of unbalanced cohesive distribution,and they are mainly distributed in the higher-level cities and prefectures such as northwest Yunnan,west Yunnan and south Yunnan.Among them,the traditional villages of Baoshan City have the highest distribution density of 66.33 per 10000 km^(2).This is followed by Dali Prefecture and Honghe Prefecture,where the densities of traditional villages are 44.13 per 10000 km^(2) and 37.66 per 10000 km^(2),respectively.(2)The factors affecting the spatial distribution structure of traditional villages in Yunnan Province are natural geographical factors,humanistic historical factors and transportation factors.Among them,the natural geographical conditions with a large vertical gap in Yunnan Province gave birth to the human settlement environment of traditional villages.The history of a farming civilization that has been passed down from generation to generation has laid a brilliant and splendid humanistic foundation for traditional villages,and the high-altitude areas are relatively primitive.The transportation conditions have delayed the destruction of traditional villages by urbanization and industrialization.In summary,these factors have affected the spatial distribution pattern of traditional villages in Yunnan Province to some extent.(3)According to the law of the spatial distribution of traditional villages in Yunnan Province,it is necessary to explore the activation path of traditional village tourism with regional characteristics and ethnic characteristics,and also to carry out differentiated development according to the different endowment characteristics of local resources,that is to develop a series of activation modes including agricultural tourism,cultural tourism and ecological tourism.

以石补拙两例

树石盆景更加贴近自然,表现形式多样,内蕴丰富,创作上不拘一格,因材施艺,巧妙组合;其中树石互补,以石补拙是最常用的艺术手法之一。下面列举近作2例,与同好交流。《横空凌云》

Temporal allocation of metabolic tolerance to transgenic Bt cotton in beet armyworm,Spodoptera exigua(Hübner)

Digestive and detoxification enzyme activity and nutrient composition were examined in the body of fourth instar beet armyworms,Spodoptera exigua(Hübner),fed on transgenic Bacillus thuringiensis(Bt) and non-Bt cotton for different time periods.Nutrient composition and specific enzyme activities differed significantly between the S.exigua fed Bt vs.non-Bt cotton.At 1,6 and 24 h,free fatty acid and glucose levels were significantly lower in S.exigua fed on Bt cotton than those fed on non-Bt cotton.S.exigua fed on Bt cotton had significantly higher trypsin and total superoxide dismutase(T-SOD) activities and significantly lower lipase,carboxylesterase and acetylcholinesterase activities than non-Bt fed worms for all feeding time periods.Differences were also observed among feeding times within each cotton variety group.Significantly lower free fatty acid and total amino acid were observed in S.exigua fed on Bt cotton for 24 h than in those fed for 1 h.Significantly lower activities of lipase and trypsin were detected in S.exigua fed on Bt cotton for 24 h than those for 1 and 4 h.However,carboxylesterase and acetylcholinesterase activities in S.exigua fed on Bt cotton for 24 h were significantly higher than those for 1,4 and 6 h.The interaction between cotton variety and feeding time significantly affected the activities of lipase,trypsin,acetylcholinesterase and T-SOD enzymes in S.exigua.Measuring the temporal allocation of protection and detoxification enzyme activities in the body of S.exigua in response to B.thuringiensis can provide a meaningful evaluation on the metabolic tolerance of herbivorous insects under the continuous selection pressure of a toxic protein.