甘肃省不同地区不同时段人员在室率研究

本文依据甘肃省区域特点,针对城市和不同农村区域,根据人员活动,采用在室率对人员在室内的情况进行评估研究。采用泊松公式表示家庭人数概率分布,建立城市和不同农村区域不同时段人员在室内的分区概率公式。研究结果表明,对于城市区域,工作日与节假日人员在室率具有明显差别;对于农村区域或牧区,因区域、季节不同,不同时段人员在室率有所不同;总体上甘南牧区每年10月至次年3月人员在室率较高,省内其他农村区域每年11月至次年2月人员在室率较高。     

简述基于高考评价体系的高考地理主观题阅卷评分细则制定

本文基于评分细则的制定,对《中国高考评价体系》进行解读。高考评价体系坚持立德树人为价值引领、注重学科素养考查、突出创新思维和创新能力评价、以学习探索情境作为考查的载体等。在解读的基础上,提出了评分细则制定的做法并示例,认为要旗帜鲜明地突出“价值引领”原则、突出地理学科素养、重视创新思维和创新能力、关注学习探索情境等。     

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.     

An Undercover Angiosperm from the Jurassic of China

<正>Searching for early angiosperms is a riveting activity in botany because it helps to resolve the phylogenetic relationships among seed plants and among angiosperms themselves.One of the challenges for this job is what the target fossils look like.Most possibly early angiosperms may elude our scrutiny with gymnospermous appearances.This possibility becomes a reality in a Jurassic plant,Solaranthus gen.nov,which bears a peltaspermalean appearance and enclosed ovules.According to knowledge available hitherto,the latter feature makes it an angiosperm.However,such a feature is more likely to be eclipsed by its gymnospermous appearance.The early age and unexpected character assemblage of Solaranthus urge for a fresh look on the assumed-simple relationship between angiosperms and gymnosperms.Its resemblance to the order Peltaspermales favors the Mostly Male Theory.     

Depth measurement of remote sources using multipath propagation

A submerged acoustic source radiates narrowband Gaussian noise. Its signal propagates to a remote, large aperture vertical array over a multipath channel whose characteristics may or may not be fully known. The primary concern of this study is the accuracy of source depth estimates obtainable from the array output. Cramer-Rao bounds for the depth estimate are calculated. When the velocity profile is known exactly, the value of the bound is quite insensitive to the precise form of the velocity profile. A bound calculated from a constant velocity profile yields an excellent approximation for many situations likely to be encountered in practice. Introduction of an unknown parameter into the velocity profile has little effect on the Cramer-Rao bound for depth. However, a maximum likelihood estimator of depth working with an inaccurate value of the unknown parameter performs poorly. To obtain satisfactory performance, one must estimate the unknown parameters along with the source depth. Simulations demonstrate the success of this approach     

影响我国北方热带气旋的若干统计特征

利用中国气象局出版的１９４９—１９９４年台风年鉴资料，在大量普查的基础上，定义进入３０°Ｎ以北、１２５°Ｅ以西热带气旋为影响我国北方的热带气旋。根据其后期移动路径的不同划分为：沿海北上、沿海转向、登陆北上、登陆填塞、登陆转向及西折６类。最后，对各类不同路径的热带气旋的气候特征及产生的暴雨区和暴雨强度做了详细的分析     

城子河组的新材料及其地层意义

黑龙江省密山县金沙农场北部鹿山地区被钻孔揭示的城子河组剖面产有海相一半成水相双壳类、沟鞭藻，孢子花粉及植物化石，这些新材料进一步证明城子河组的时代应属早白垩世早中期，从而为侏罗～白垩系界线划分及鸡西群与龙爪沟群对比提供了新的生物地层依据。     

多源遥感影像水体指数的交互对比

在对地观测系统中,Landsat和EO-1数据比较适合于监测城市水体变化。但是这两种传感器数据的水体指数之间的关系不清楚,针对这一问题。该文利用两对同日过空的Landsat-7ETM+与EO-1ALI影像来查明二者水体指数之间的定量关系,通过回归统计分析来求出两种传感器水体指数之间的转换方程。结果表明,Landsat-7ETM+与EO-1ALI影像分别基于DN数据、IACM反射率数据计算的MNDWI水体指数间,均存在较好的线性相关关系,决定系数均在0.75以上;基于EO-1ALI的MNDWI指数影像信息更为丰富,因为其动态范围大于Landsat-7ETM+。     

广东潮阳沙荒地的改造与开发

广东省潮阳市田心镇农林场自１９５９年起用工程措施和生物措施相结合的方法进行沙荒了的改造及综合利用,在近海边营造木麻黄防护林带,近陆面营造防护林网,网格内种植作物和水果。经多年的实践,筛选出了适生的防护林树种和果树品种。在沙滩地上开展林,果综合利用可提高植物多样性,改变土壤结构和增加肥力,改善小气候,增强防风固沙能力,并伴有较大的经济效益。     

多次透射公式在衰减波场中的实现

在多次透射公式的基础上，引进一衰减系数，用来模拟外行的衰减波，将透射公式推广到考虑衰减波入射时的情形；并对衰减波入射时两种极限情形下(理想稳态和理想暂态情形)的反射系数进行了分析. 结果表明, 多次透射公式对弱衰减波仍可适用，对于强衰减波则需应用加衰减系数的多次透射公式进行透射．最后，通过两相介质两个数值实验, 验证了该边界条件在模拟衰减波时的精度．