级数解边界积分法及其在地震波散射问题中的应用

级数解边界积分法是利用相应的齐次微分方程的解完备系作权函数来建立边界积分方程。本文采用级数解边界积分法并选取傅氏级数作试函数求解SH波散射问题,并将计算结果同解析解或其它数值方法的解做了比较。结果表明,本文方法计算简单、精度较高而且节省机时。文中还提出了用傅氏级数拟合复杂边界的方法。     

地震危险性分析中对烈度衰减的不确定性校正

针对近来就地震危险性分析中对地震烈度衰减的不确定性校正方法逻辑上缺陷的批评,在严格限定烈度是一有序分类变量、等震线是烈度分区的外包线的基础上,本文提出了一个简单实用的校正方法,并通过实例比较了不同方法得出的结果在数值上的差异。     

台湾的软玉

台湾软玉形成于五万年前,系超镁铁岩变成的蛇纹岩经交代而成。软玉主要为普通软玉、猫眼玉和蜡光玉三种。比其它的软玉稍硬些,且硬度与闪光性都有方向性,并含数种矿物包裹体。其地球化学特征是含铬极高,并影响到软玉的颜色。     

奇异值分解(SVD)在位场数据去噪中的应用

根据奇异值分解原理,分析其在位场去噪中的可行性,提出了一种判断有效阶次k的方法。对多边形厚板模型的重力异常进行奇异值分解去噪和小波去噪效果的对比,证明了奇异值分解去噪的有效性和优势。将其应用于实测重力数据的处理中,取得较好的效果。理论模型和实测资料的处理结果表明:基于奇异值分解的去噪方法可以有效地去除随机噪声,提高数据处理和解释的精度。     

Combined impact of climate change,cultivar shift,and sowing date on spring wheat phenology in Northern China

Distinct climate changes since the end of the 1980s have led to clear responses in crop phenology in many parts of the world. This study investigated the trends in the dates of spring wheat phenology in relation to mean temperature for different growth stages. It also analyzed the impacts of climate change, cultivar shift, and sowing date adjustments on phenological events/phases of spring wheat in northern China (NC). The results showed that significant changes have occurred in spring wheat phenology in NC due to climate warming in the past 30 years. Specifically, the dates of anthesis and maturity of spring wheat advanced on average by 1.8 and 1.7 day (10 yr)^?1. Moreover, while the vegetative growth period (VGP) shortened at most stations, the reproductive growth period (RGP) prolonged slightly at half of the investigated stations. As a result, the whole growth period (WGP) of spring wheat shortened at most stations. The findings from the Agricultural Production Systems Simulator (APSIM)-Wheat model simulated results for six representative stations further suggested that temperature rise generally shortened the spring wheat growth period in NC. Although the warming trend shortened the lengths of VGP, RGP, and WGP, the shift of new cultivars with high accumulated temperature requirements, to some extent, mitigated and adapted to the ongoing climate change. Furthermore, shifts in sowing date exerted significant impacts on the phenology of spring wheat. Generally, an advanced sowing date was able to lower the rise in mean temperature during the different growth stages (i.e., VGP, RGP, and WGP) of spring wheat. As a result, the lengths of the growth stages should be prolonged. Both measures (cultivar shift and sowing date adjustments) could be vital adaptation strategies of spring wheat to a warming climate, with potentially beneficial effects in terms of productivity.     

基于注册测绘师的高职工程测量专业教学改革研究

注册测绘师制度的推行,对我国测绘行业人员提出了更高要求,为了适应新形势下国家对测绘人才培养的需求,高职工程测量专业进行教学改革迫在眉睫。从注册测绘师所要求的知识结构和专业能力入手分析,探讨了工程测量专业课程体系、实践教学、师资队伍、教学方法与手段、学生考核评价方式以及校企合作方式的教学改革,为高职工程测量人才培养提供了保障。     

我国东北甲区钼矿化有关热液蝕变黑云母的物理-化学性貭及其成因

黑云母是我国东北甲区合有銅矿化的奥长花崗斑岩中分布广的矿物之一。原生的黑云母經受到含矿热液作用后变化多,蝕变強,与銅矿化的关系也較紧密,因之对各种蝕变黑云母的物理性貭,化学組分,成因以及其相互关系的研究,不只是有助于闡述成矿作用和矿床成因,并且有利于对銅矿的探寻。以前在进行普查勘探工作时,曾提到过合銅矿化奥长花崗斑岩中富含有黑云母与钼矿化有关。但沒有进一步对黑云母进行研究。     

秋季南海台风的预报

本文分析了1960-1983年10-11月南海台风的路径,得出秋季南海台风的路径和强度变化与北侧大陆上的气压、温度、风场有关,认为在秋季低层气流对台风的引导是显著的,而低层引导气流的强弱又与副热带高压脊西伸的程度有着密切的关系。