基于局部密度聚类的雷达目标散射中心区域分割

散射中心是描述雷达目标高频散射机理的重要特征,准确提取雷达目标散射中心参数对解析雷达目标有着极其重要的研究意义。为了提高散射中心参数计算速度,通常将整幅SAR图分解为多个包含散射中心的小区域,对每个小区域分别进行特征提取和参数计算。根据雷达目标散射中心的特点,本文提出了一种基于局部密度聚类的雷达目标散射中心区域分割技术。首先,首先对雷达图像进行Frost滤波、LSM图像分割和面积滤波的一系列图像预处理获得目标ROI区域,然后对预处理后的图像利用局部密度聚类算法检测散射中心并进行区域分割。实验中,采用模拟数据和真实数据对本文方法和传统图像分割算法展开数值实验,实验结果验证了本文方法在雷达目标散射中心区域分割的有效性和优越性。     

夏商时期考古学遗存发现和研究的回顾与反思——以鄂西峡江地区为研究对象

本文系统回顾了鄂西峡江地区夏商时期考古学遗存的发现与研究历程,并对目前这一领域研究中存在的问题提出了几点思考。     

额济纳旗大狐狸山地区干泉组烃源岩评价

通过对大狐狸山地区干泉组实测剖面烃源岩展布特征及烃源岩的有机质丰度、有机质类型和成熟度的研究,认为干泉组下段暗色泥岩发育,厚度达到了240.1 m,主要沉积于浅海陆棚环境。有机碳含量分布在0.35%~2.87%,平均值为1.01%。根据Ph/n—C18和Pr/n—C17相关关系及图版,并结合C27甾烷(ααα20R)、C28甾烷(ααα20R)、C29甾烷(ααα20R)的相对关系图版来研究大狐狸山地区干泉组烃源岩有机质类型,结果均显示其有机质为Ⅱ1型。镜质组反射率及黏土矿物的研究均表明有机质成熟度极高,可能与区内动力变质作用有关。综合评价认为,干泉组具备较好的生气潜力。     

Morphological and molecular separation between Macrocamptoptera grangeri Soyka and M. metotarsa (Girault) (Hymenoptera: Mymaridae)

ABSTRACT

Based on morphological and molecular evidence, the European fairyfly Herulia sundholmi Hedqvist syn. n. (Hymenoptera: Mymaridae) is removed from previous synonymy with the Nearctic Macrocamptoptera metotarsa (Girault), and synonymised with the Palaearctic M. grangeri Soyka, which is newly recorded from Georgia, Slovakia and Spain. Macrocamptoptera bulagarica (Donev) syn. n., known from Bulgaria and Italy, is also synonymised with M. grangeri. An updated key to females of the three currently recognised species of the rarely collected genus Macrocamptoptera Girault is given.     

中国区域技术创新能力的评价与比较

区域技术创新能力评价重在对不同地区的创新投入、创新产出、创新主体、创新环境等因素进行分析比较。通过构建包含21项指标的区域技术创新能力评价体系,运用因子分析方法对中国大陆30个省级地区的技术创新能力进行研究,提取了企业创新、创新绩效和创新支持3个因子。东部地区技术创新能力最强,中部和东北地区次之,西部地区最弱,省级地区之间技术创新能力差异显著。提升区域技术创新能力是缩小地区经济差距,实现区域经济均衡发展的必然选择。     

基于GIS的土地利用动态变化分析——以毕节市七星关区为例

基于GIS数据分析平台下,运用单一土地利用动态度模型和地类转移矩阵对1990年、2000年和2010年七星关区3期土地利用分布数据进行分析。结果表明:七星关区在北部、西部和南部3个方向上土地利用变化幅度较大,中部地区土地利用变化幅度较小。经研究发现:人口增长、经济发展和宏观政策是造成该区域土地利用变化的主要驱动力。     

能源开发对新疆维吾尔自治区水土流失的影响

能源是人类赖以生存和发展的重要资源,是经济社会发展和人民生活改善的重要物质基础.国家制定的＂立足国内,多元发展＂的能源战略成就了新疆维吾尔自治区作为＂立足国内＂的重要能源基地的地位.然而多年来东西部地区的经济发展差距持续拉大,新疆维吾尔自治区的能源开发质量与＂基地＂地位严重不符,这种状况不仅影响了国家的能源安全、经济安全,也影响了和谐社会的建设.针对能源开发对新疆维吾尔自治区水土流失的影响,以我国的能源形势作为切入点,分析了新疆维吾尔自治区水土流失特征,介绍了新疆维吾尔自治区能源开发造成水土流失的共同特点,探讨了新疆维吾尔自治区能源开发建设项目水土流失危害,提出了治理对策.（1）调查研究,搞好水土流失的治理规划和监测;（2）强化水保方案编报审批和实施;（3）开展科学研究和成果的推广;（4）提高认识,依法行使职权,加大监督执法力度.     

“重”与“轻”的两维视域——论新世纪以降迟子健东北地域小说的审美风格

迟子健的东北地域小说创作,存在着＂重＂与＂轻＂的两维视域。这里的＂重＂蕴含着苦难遭际、命运多舛、令人窒息的沉沦,同时也昭示着人类存在都要面对的＂原初痛苦＂和生存困境。＂重＂之维度集中描摹大地的悲歌与死亡的沉重,而＂轻＂是集人性思考与构建精神生活完整性的艺术试验,蕴含着对神秘的彼岸世界的无限怀想,在富有地方风情的描述中建构了＂神＂与＂人＂的超验维度。＂重＂与＂轻＂二者相辅相成,一体互动,建构了迟子健地域小说独特的艺术魅力。     

Tasmanian Phoridae (Diptera) and some additional Australasian species

The list of Phoridae recorded from Tasmania is increased from five species in three genera to at least 52 species in eight genera. One species on the original list is transferred to the status of being incertae sedis. One new genus and 37 new species are described, two being reported from mainland Australia also. One species was previously only known from New Zealand, five from mainland Australia, four from Europe but one of which is now an almost cosmopolitan tramp species and one being from the Holarctic Region. However, one of the 'European' species may have orginally been introduced to Europe from Tasmania. Keys to genera, to all known species of Aphiura, to the Tasmanian species of Megaselia and to the Australasian species of Metopina are provided. A newly named and a new mainland Australian species of Aphiura, three mainland Australasian species of Metopina and three from Papua New Guinea are described and seven undescribed males (given code letters only) of this genus are included in the key (four from Papua New Guinea, two from Western Australia and one from Tonga). Aphiura and Paraphiura are transferred to the tribe Metopinini and the tribe Beckerinini is set aside, as it cannot be satisfactorily characterized as it is currently conceived. Megaselia dissita is synonymized with M. comparabilis.     

Cladistics and taxonomy of the Afrotropical Empis (Coptophlebia) chrysocera-group (Diptera,Empididae)

The Afrotropical Empis (Coptophlebia) chrysocera-group (Diptera: Empididae) is defined on the basis of two synapomorphies, namely epandrial lamellae connected anteriorly and male cerci made up of an anterior almost bare lobe and a posterior bristled lobe. This group includes 10 species: E. (C.) brazzavillensis sp. n., E. (C.) barbitos Smith, E. (C.) juxtaripa sp. n., E. (C.) lyra Smith, E. (C.) plumata sp. n., E. (C.) chrysocera Collin, E. (C.) cuthbertsoni Smith, E. (C.) machipandensis Smith, E. (C.) samaruensis sp. n. and E. (C.) singulare sp. n. All species are described and keyed. The relationships between these species are established and two complexes of species distinguished. The Empis (Coptophlebia) chrysocera-group apparently occurs everywhere in the Afrotropical region except South Africa.