提高暗筒式日照纸感光质量的技巧   总被引：1，自引：0，他引：1  

甘灿明 《气象研究与应用》2008,29(4):68-69

暗筒式日照计日照纸所用药品品质好坏、配药比例和涂药方法是否得当,是造成日照纸感光质量好坏的主要原因。本文针对部分测报员在日照纸配药、涂药和浸漂操作处理过程中存在的问题提出相关改进措施和建议。  相似文献   

Magnetic connection and current distribution in black hole accretion discs     

Cheng-Xuan Zhao  Ding-Xiong Wang  Zhao-Ming Gan 《Monthly notices of the Royal Astronomical Society》2009,398(4):1886-1890

We discuss one of the possible origins of large-scale magnetic fields based on a continuous distribution of toroidal electric current flowing in the inner region of the disc around a Kerr black hole (BH) in the framework of general relativity. It turns out that four types of configuration of the magnetic connection (MC) are generated, i.e. MC of the BH with the remote astrophysical load (MCHL), MC of the BH with the disc (MCHD), MC of the plunging region with the disc (MCPD) and MC of the inner and outer disc regions (MCDD). It turns out that the Blandford–Znajek process can be regarded as one type of MC, i.e. MCHL. In addition, we propose a scenario for fitting the quasi-periodic oscillations in BH binaries based on MCDD associated with the magnetic reconnection.  相似文献   

东北地区农业结构转型时期土地利用变化的成因与效应     

刘彦随  甘红  Jay GAO  DENG Xusheng 《地理学报(英文版)》2004,14(4):488-494

During the last decade of the 20th century, extensive conversion in agricultural land use took place in Northeast China. The goal of this study is to ascertain its spatial distribution and regional differentiation, determine its causes, and analyze its environmental impact, Especially we attempt to elucidate how institutional constraints have facilitated the change at a time of agrarian restructuring when newly emerging free market was hybridized with the former planned economy. Information on six categories of land use was mapped from interpretation of Landsat TM images recorded in 1990,1995 and 2000. Most of land use changes took place during the first half of the decade, coinciding with abrupt and chaotic changes in government directives. Farmland was changed mainly to woodland,water body and built-up areas while woodland and grassland were converted chiefly to farmland.Spatially, the change from farmland to woodland was restricted to the west of the study area. The change from grassland to farmland took place in the grazing and farming interlocked west. These chaotic and occasionally conflicting changes were largely caused by lack of stability and consistency in agricultural land use policies promulgated. They have exerted adverse impacts on the local environment, including land degradation, increased flooding, and modified climate regime.  相似文献   

基于问题探究式学习开展初中跨学科教学的研究——以九年级"小龙虾的'逆袭'"为例     

甘灵  杨莉 《地理教学》2021,(4):36-37,11

在新一轮课改的指引下,如何将不同学科知识体系融合在真实情境中,引导学生解决具体问题,以培养学生跨学科的学习意识和分析能力,成为教学实践者普遍关心的问题。本文对基于问题探究式的初中跨学科教学的背景、意义与教学模式展开研究,并以九年级“小龙虾的‘逆袭’”为例,进行了基于问题探究式学习的课堂教学设计。  相似文献   

Identification of paralytic shellfish toxin-producing microalgae using machine learning and deep learning methods     

Xu  Wei  Niu  Jie  Gan  Wenyu  Gou  Siyu  Zhang  Shuai  Qiu  Han  Jiang  Tianjiu 《中国海洋湖沼学报》2022,40(6):2202-2217

Journal of Oceanology and Limnology - Paralytic shellfish poisoning (PSP) microalgae, as one of the harmful algal blooms, causes great damage to the offshore fishery, marine culture, and marine...  相似文献   

太阳高能观测技术     

常进  蔡明生 《紫金山天文台台刊》1999,18(4):394-404

通常将太阳高能观测划分为三个能段,软Ｘ 射线能段（０ ．１ｋｅＶ～１０ｋｅＶ） ,Ｘ 射线及软γ射线能段（０ ．１ ＭｅＶ～１０ ＭｅＶ） ,γ射线能段（１ ＭｅＶ 以上） 。本文就各个能段的探测技术,包括成像系统和探测器,作了全面的调研,重点在新技术的应用。  相似文献   

1994年冬季洛阳机场天气之特点     

李新芳  王军伟  甘小燕 《高原山地气象研究》1999,9(3)

主要用洛阳15年冬季能见度资料对比,提出1994年11月-12月出现多日大雾天气在历史上是少见的.通过分析1994年几例典型大雾形成的具体特点和影响因素及天气形势.指出稳定层的存在,适宜的地面气压场是导致大雾的直接原因.  相似文献   

Gan—Chen模式在岩土工程中的应用研究   总被引：6，自引：0，他引：6  

甘德福  陈孝培 《上海国土资源》1999,(4):33-49,54

岩土体应力应变之间存在黄金分割比例－０．６１８和０．３８２这对数字关系,据此规律建立比较正确和简便的定量计算－Ｃａｎ－Ｃｈｅｎ模式。此模式可用于确定桩的中和点和中性点,估算单桩实际承载力,估算地基土的竖向变形和侧向变形,估算建（构）筑物沉降量,深基坑围护设计和计算,确定深基坑支撑位置,预估超深沉井的卡位等,通过介质其在岩土工程中的应用研究成果,以求岩土工程界试用、验证。  相似文献   

龙卷风的风强分析与极值推断   总被引：7，自引：0，他引：7  

干莲君  田心如  张东凌  项瑛  罗莹 《气象科学》1999,(1)

本文采用1955－1997年影响盐城市的龙卷风资料,按富士达F等级定义龙卷风风强分类级别,对盐城市受袭击点的破坏程度进行风强分级,并分析各个时段龙卷风风强等级的频数。应用耿贝尔极值分布理论,对影响盐城市的龙卷风风速极值进行统计推断,获得1％风险度龙卷风风速极值,以及各种特定重视期间的极值。  相似文献   

激光探针等离子体质谱同时测定锆石微区铀—铅年龄及微量元素   总被引：19，自引：2，他引：17  

梁细荣  李献华 《岩矿测试》1999,18(4):253-258

建立了一种利用激光探针等离子体质谱技术同时原位测定锆石Ｐｂ－Ｐｂ及Ｐｂ－Ｕ年龄和２５个微量元素的快速分析方法。Ｐ的检出限为１４μｇ／ｇ,Ｓｃ的检出限为３μｇ／ｇ,Ｒｂ、Ｎｂ、Ｂａ稀土元素Ｎｄ、Ｇｄ、Ｄｙ、Ｅｒ及Ｙｂ的检出限为０．１￣０．３μｇ／ｇ,Ｐｂ的检出限０．５μｇ／ｇ,其它稀土元素及Ｓｒ、ｙ、Ｈｆ、Ｔａ、Ｔｈ和Ｕ的检出限为１０￣９０ｎｇ／ｇ。方法对绝大多数微量元素的相对标准偏差为５￣１５％;  相似文献