识“气象”者必有“气象”--评赵松元等人的《选堂气象:饶宗颐研究论集》

《选堂气象:饶宗颐研究论集》一书集中展示了学者们在饶宗颐诗学、艺术学、文章学及相关方面研究的最新成果,尤其是其中提出了一崭新的概念和命题即“选堂气象”,该论断得到学界的一致称许与赞誉。作为研究对象的饶公选堂之学因其无所不包之大而本自成“气象”,选堂之学的“大”,不仅表现为其广度或规模之“大”,而且还表现为其创造或创新与影响之“大”。由于学者们因良好地缘和学缘的关系与饶公有着千丝万缕的联系甚至私交有加使得该书成员能长期近“气象”,学者们从最有创获的诗论、文论和艺术史论入手,对饶宗颐先生学术精神、文学与艺术成就、家学谱系及其学术贡献的深入研究,从而揭示出饶宗颐在文学史、艺术史以及学术史上的重要价值与意义,因该书成员有着深厚的学养和研究功力亦是各具“气象”,故使得该书能识饶学之“气象”并开创饶学研究的新“气象”。

Recognition of Similar Weather Scenarios in Terminal Area Based on Contrastive Learning

In order to improve the recognition accuracy of similar weather scenarios(SWSs)in terminal area,a recognition model for SWS based on contrastive learning(SWS-CL)is proposed.Firstly,a data augmentation method is designed to improve the number and quality of weather scenarios samples according to the characteristics of convective weather images.Secondly,in the pre-trained recognition model of SWS-CL,a loss function is formulated to minimize the distance between the anchor and positive samples,and maximize the distance between the anchor and the negative samples in the latent space.Finally,the pre-trained SWS-CL model is fine-tuned with labeled samples to improve the recognition accuracy of SWS.The comparative experiments on the weather images of Guangzhou terminal area show that the proposed data augmentation method can effectively improve the quality of weather image dataset,and the proposed SWS-CL model can achieve satisfactory recognition accuracy.It is also verified that the fine-tuned SWS-CL model has obvious advantages in datasets with sparse labels.

Coupling Relationship Between Summer Microclimate and Spatial Layout of Street Canyons in the White Stupa Temple Area of Beijing

With the rapid urbanization, many high-rise buildings and new districts have been built continuously. However, the old town of cities has gradually been forgotten by people and its environment is becoming increasingly harsh. The old town usually has diversified space and function. As an important part of the old town, the street canyon that is closely related to human settlements is a public space where people communicate and do activities. Therefore, research on microclimate-based improvement of the street canyon in the old town is of great significance. Six typical street canyons in the White Stupa Temple area of Beijing were selected for research to explore spatial characteristics of the street canyon. Microclimate factors such as temperature, humidity, wind speed, and solar radiation were measured on the spot in summer. These factors were combined with two microclimate assessment indexes of physiological equivalent temperature(PET) and wet bulb globe temperature(WBGT) to evaluate the microclimate of the street canyon. In the analysis of the measured data, the mean value comparison method was used to analyze the average values of the microclimate factors in different time periods. Spatial layout of microclimate included the orientation of the canyon, the ratio of the canyon height to canyon width, and green coverage of the canyon, and an in-depth study was made on the coupling relationship between the spatial layout and the microclimate of the canyon. Research results can provide an optimization strategy for the transformation design of the street canyon in White Stupa Temple area, and provide a scientific reference for the research on spatial layout and microclimate improvement in the old town, so as to improve the living quality of residents in the old town.

An Assessment and Identification of Avalanche Hazard Sites in Uri Sector and its Surroundings on Himalayan Mountain

Avalanches are one of the most natural hazard in the mountain areas and therefore, identification of avalanche hazard is necessary for planning future development activities. The study area falls under the international boundary region which generally covered by the snow(38%) on high altitude regions of the western part of Himalayas. Avalanches are triggered in study area during snowfall resulting in loss of human life, property and moreover the transportation and communication affected by the debris which ultimately delays the relief measures. Therefore in this study three major causative parameters i.e terrain, ground cover and meteorological have been incorporated for the identification of avalanche hazard zones(AHZ) by integrating Analytical Hierarchical Process(AHP) method in Geographical Information System(GIS). In the first part of study, avalanche sites have been identified by the criteria related to terrain(slope, aspect and curvature) and ground cover. Weights and ratings to these causative factors and their cumulative effects have been assigned on the basis of experience and knowledge of field. In the second part of the study, single point interpolation and Inverse Distance Weighted(IDW) method has been employed as only one weather station falls in study area. Accordingly, it has been performed to generate the meteorological parameter maps(viz. air temperature and relative humidity) from the field observatories and Automatic Weather Stations(AWS) located at Baaj OP in Uri sector. Finally, the meteorological parameter maps were superimposed on the terrain-based avalanche hazard thematic layers to identify the dynamic avalanche hazard sites. Conventional weighted approach and Analytical Hierarchical Process(AHP) method have been implemented for the identification of AHZ that shows approximately 55% area under maximum hazard zone. Further, the results were validated by overlapping the existing registered avalanche sites. The sites were identified through field survey and avalanche data card followed by its delineation from the toposheet(1:50,000 scale). Interestingly study found that 28% area under moderate and maximum AHZ correlated well with registered avalanche sites when they were overlapped. The accuracy for such works can be increased by field survey under favorable weather condition and by adding data from more number of AWS for predicting avalanche hazards in mountainous regions.

RESEARCH ON AUTOMATIC FOG IDENTIFICATION TECHNOLOGY BY METEOROLOGICAL SATELLITE REMOTE SENSING

There is an urgent need for the development of a method that can undertake rapid, effective, and accurate monitoring and identification of fog by satellite remote sensing, since heavy fog can cause enormous disasters to China’s national economy and people's lives and property in the urban and coastal areas. In this paper, the correlative relationship between the reflectivity of land surface and clouds in different time phases is found, based on the analysis of the radiative and satellite-based spectral characteristics of fog. Through calculation and analyses of the relative variability of the reflectivity in the images, the threshold to identify quasi-fog areas is generated automatically. Furthermore, using the technique of quick image run-length encoding, and in combination with such practical methods as analyzing texture and shape fractures, smoothness, and template characteristics, the automatic identification of fog and fog-cloud separation using meteorological satellite remote sensing images are studied, with good results in application.

《子虚赋》、《上林赋》:艺术转型与新范式的确立

《子虚赋》、《上林赋》在写作时间上跨越十年。十年间,汉代中央王朝与诸侯关系巨变,司马相如本人的经历与认识都发生重大变化,导致作品中所表现的使臣意识、汉家意识和审美取向有明显的转换。《子虚赋》、《上林赋》为汉代文坛确立了新的艺术范式。