GIS中文查询系统中SQL语句的形成

由于GIS中文查询语句与SQL语句相差很大,直接转化非常困难,所以需要有某种中间逻辑形式语言。本文首先分析了查询语句的句型和基于此句型的栈式中间语言结构,然后重点研究了这种中间语言到SQL语句的转换。在此对SQL语句的结构中的查询条件段、查询目标段、分组段的判断策略进行了研究,难点在于嵌套结构的判断,在此借助中间关系进行转换,系统设计了相应的转换算法,并对算法进行了测试,测试表明系统所提出的转换策略和算法对大多数查询语句能转换为相应的SQL语句,为该课题的进一步研究奠定了基础。     

Galileo与GPS卫星导航系统的性能比较研究

讨论了伽利略全球导航定位系统最新状况,比较了体系结构和信号结构、频率调制、定位精度等的差异及优越性。指出伽利略优于GPS的干扰性、兼容性和互用性,对促进和完善全球卫星导航系统具有重要的意义。     

诱导子对海洋真菌Penicillium crustosum 2A4-Z15菌株生物碱代谢的调节作用

分别采用4种生物源诱导子和5种非生物源诱导子,对具有较强抑菌活性的海洋真菌壳青霉Penicillium crustosum2A4-Z15菌株进行诱导,考察诱导子对于菌株产生物碱的代谢调节作用。结果表明,不同来源的诱导子对菌株的生物碱产量和生物量影响不同,生物源诱导子的正向调节作用较明显,且其中以细菌源诱导子最为明显。当海洋细菌源诱导子在2A4-Z15菌株发酵对数生长期末,以10μg/cm3的浓度加入时,发酵物生物碱产量最高,较对照提高44.1%。     

兖州市颜店矿区洪福寺铁矿床地质特征

洪福寺铁矿床处于济宁磁异常的北端,为隐伏矿床,埋深1000 m左右,赋存于新太古代济宁岩群浅变质岩中。该矿床发育11个铁矿体,矿体呈层状、似层状产出,产状与地层产状基本一致,探明的铁矿石资源量6.22亿t,平均品位TFe28.42%,mFe20.96%。矿床规模大、埋藏深,矿体形态和结构较简单,厚度较稳定,品位变化不大,矿石属于需选贫铁矿石。该矿床的勘探表明了分布于鲁西地区的新太古代济宁岩群存在较大规模的变质沉积铁矿,为该地区铁矿勘查开阔了空间。     

国际数学地球科学协会2009年会综述

<正>"国际数学地球科学协会(International Associa-tion for Mathematical Geosciences,简称IAMG)2009年会"于2009年8月23-28日在美国旧金山召开。这是协会更名后(International Association for Math-     

2000~2016年青藏高原地表反照率时空分布及动态变化

应用MODIS地表反照率产品MCD43C3,结合青藏高原自然带数据、积雪覆盖率和植被指数数据,采用一元线性回归方法分析了2000~2016年青藏高原地表反照率的分布及变化特征,结果表明:1）高原地表反照率空间分布差异大,整体上东南部低、西北部高,受地形和地表覆盖影响较大。2）高原地表反照率四季的空间分布变化明显,高海拔山脉和高寒灌丛草甸是高原地表反照率年内和年际变化的敏感地区。3）高原地表反照率年变化介于0.19~0.26,一定程度上表现为“双峰单谷”型,与地表覆盖类型的季节变化密切相关。4）高原地表反照率年际变化整体呈缓慢波动减小的趋势,平均变率约为－0.4×10-3 a-1,减小的区域约占高原总面积的66%,川西 —藏东针叶林带的西南部地区减小得最快,减小速率超过1.0×10-2 a-1。5）高原地表反照率减小与冰川消融和积雪减少密切相关,高原植被覆盖改善也是一个重要因素。     

footprint方法在湍流扩散分析中的应用

引入通量footprint分析方法,结合广西白龙核电厂拟建厂址的湍流实测资料,分析了观测站点不同方向上的通量footprint,并由此确定了水平扩散尺度及水平扩散时间,最终估算了水平扩散参数。与环境评价导则中推荐的扩散时间计算所得的水平扩散参数进行了对比分析。结果表明,离岸流的扩散参数比向岸流大,有利于湍流扩散,从而证明扩散参数具有偏保守性和局地扩散的特性。分析表明,footprint方法在湍流扩散参数分析中具有实际的应用价值。     

A New Genus of Fossil Cycads Yixianophyllum gen. nov. from the Late Jurassic Yixian Formation, Western Liaoning, China

A new genus of fossil Cycads, Yixianophyllum gen. nov., is reported here. The specimens were collected from the southern hill of Jinjiagou village, Toudaohezi Town, Yixian County, western Liaoning Province, China. The fossil plant-beating bed belongs to the lower part, the Zhuanchengzi bed, of the Upper Jurassic Yixian Formation （Yixianian）. The new genus in leaf shape, venation and epidermal structure shows a transitional form between Mesozoic Cycads （Ctenis, Nilssonia） and modem Cycads （Stangeria and Encephalartos）. Since the features of these specimens differ from any known genera of Cycads, a new generic name Yixianophyllum is proposed for these leaves. Typical species, Yixianophyllum jinjiagouense gen. et sp. nov. is described here. A supposed evolutionary tendency of Cycadean leaf-forms with Taeniopteris-type is discussed.     

A Preliminary Study on the Red Beds in the Northern Heyuan Basin, Guangdong Province, China

The red beds of the northern Heyuan Basin （Guangdong Province, China） are more than 4,000 m thick. Based on the lithological characters, in ascending order these beds are divided into the Dafeng Formation, Zhutian Formation, and Zhenshui Formation of the Nanxiong Group, Shanghu Formation and Danxia Formation. The Nanxiong Group with relatively mature coarse clastic rocks attains about 2940 m in thickness. The Dafeng Formation is 837 m thick, consisting of conglomerates and sandy conglomerates; the Zhutian Formation, which is 1.200 m thick, consists of purplish red sandstone with gravels, poorly sorted sandstone, feldspathic quartzose sandstone banded granular conglomerate, siltstone, and sandy mudstone. The Zhutian Formation is rich in calcareous concretions. Heyuannia （Oviraptoridae） and turtle fossils were found in this formation. The Zhenshui Formation deposited to a thickness of 900 m consists of coarse sediments, including granular conglomerate, and gravelly sandstone with well developed cross-beddings; the Shanghu Formation, which is 820 m thick, consists of purplish red granular conglomerate coarse sandstone intercalated with fine si~tstone; the Danxia Formation characterized by the Danxia ~andform is composed of coarse c~astic gravels and sandy gravels. The lower part of the Nanxiong Group whence dinosaur eggs and derived oviraptorosaurs come, belongs to the Late Cretaceous. No fossils are found in the Shanghu Formation or the Danxia Formation, but their stratigraphic order of superposition on the Nanxiong Group clearly shows their younger age.     

旅游与社区一体化发展研究

旅游与社区一体化发展的实现过程包括实现旅游与社区一体化发展的内外部环境构建、社区与旅游一体化发展的旅游规划、社区与旅游一体化发展的旅游影响评价等3个过程。文章对这3个过程进行了分析,并对如何实现旅游与社区一体化发展及如何构建旅游与社区一体化发展程度的评价指标体系进行了初步探讨。