3，5-二溴水杨醛缩甘氨酸的合成及荧光法测定粮食中微量锌     

邓春梅  康信煌 《广东海洋大学学报》2001,21(1):47-50

合成了新型席夫碱试剂3，5-二溴水杨醛缩甘氨酸（DBSAGLY），建立该试剂荧光度法测定微量Zn（Ⅱ）的新体系，在pH＝7.0～8.0时Zn(Ⅱ)与DBSAGLY形成1∶1的络合物，络合物最大激发和发射波长分别为λ  相似文献   

STUDY ON THE SPATIAL PATTERNS OF LAND-USE CHANGE AND ANALYSES OF DRIVING FORCES IN NORTHEASTERN CHINA DURING 1990-2000   总被引：4，自引：1，他引：3  

Ji-yuan Liu  Xiang-zheng Deng  Ming-liang Liu  Shu-wen Zhang 《中国地理科学(英文版)》2002,12(4):299-308

Land-use change is an important aspect of global environment change. It is, in a sense, the direct result of human activities influencing our physical environment. Supported by the dynamic serving system of national resources, including both the environment database and GIS technology, this paper analyzed the land-use change in northeastern China in the past ten years (1990–2000). It divides northeastern China into five land-use zones based on the dynamic degree (DD) of land-use: woodland/grassland — arable land conversion zone, dry land — paddy field conversion zone, urban expansion zone, interlocked zone of farming and pasturing, and reclamation and abandoned zone. In the past ten years, land-use change of northeastern China can be generalized as follows: increase of cropland area was obvious, paddy field and dry land increased by 74.9 and 276.0 thousand ha respectively; urban area expanded rapidly, area of town and rural residence increased by 76.8 thousand ha; area of forest and grassland decreased sharply with the amount of 1399.0 and 1521.3 thousand ha respectively; area of water body and unused land increased by 148.4 and 513.9 thousand ha respectively. Besides a comprehensive analysis of the spatial patterns of land use, this paper also discusses the driving forces in each land-use dynamic zones. The study shows that some key biophysical factors affect conspicuously the conversion of different land-use types. In this paper, the relationships between land-use conversion and DEM, accumulated temperature (⩾10°C) and precipitation were analysed and represented. We conclude that the land-use changes in northeast China resulted from the change of macro social and economic factors and local physical elements. Rapid population growth and management changes, in some sense, can explain the shaping of woodland/grassland — cropland conversion zone. The conversion from dry land to paddy field in the dry land — paddy field conversion zone, apart from the physical elements change promoting the expansion of paddy field, results from two reasons: one is that the implementation of market-economy in China has given farmers the right to decide what they plant and how they plant their crops, the other factor is originated partially from the change of dietary habit with the social and economic development. The conversion from paddy field to dry land is caused prmarily by the shortfall of irrigation water, which in turn is caused by poor water allocation management by local governments. The shaping of the reclamation and abandoned zone is partially due to the lack of environment protection consciousness among pioneer settlers. The reason for the conversion from grassland to cropland is the relatively higher profits of farming than that of pasturing in the interlocked zone of farming and pasturing. In northeastern China, the rapid expansion of built-up areas results from two factors: the first is its small number of towns; the second comes from the huge potential for expansion of existing towns and cities. It is noticeable that urban expansion in the northeastern China is characterized by gentle topographic relief and low population density. Physiognomy, transportation and economy exert great influences on the urban expansion. Foundation item: Under the auspices of Knowledge Innovation program Key Project of the Chinese Academy of Sciences (KZCX-2-308). Biography: LIU Ji-yuan (1947 - ), male, a native of Shanghai Municipality, professor, Director General of Institute of Geographical Sciences and Natural Resources Research, the Chinese Academy of Sciences. His research interests include environment and resources, remote sensing and geography.  相似文献   

青海省大柴旦镇红柳沟金矿床地质特征及其成因     

吴正寿  邓元良  苏生顺 《青海国土经略》2001,(1)

通过对红柳沟金矿床地质特征及围岩蚀变的研究,总结了金矿控矿因素及其富集规律,认为该矿床的成因为动力变质热液型。  相似文献   

The effects of emission line identification on the redshift distribution of QSO's     

You-Yuan Zhou  Zu-Gan Deng  Zheng-Long Zhou 《Astrophysics and Space Science》1983,97(1):63-71

We use the QSO's in the catalog compiled by Hewitt and Burbidge (1980) as the sample to analyse for the selection effects in the redshift identification. The results show that the redshift distribution caused mainly by the selection effects has almost same global feature as those given by the observations. The analysis leads us to conclude that the observational redshift distribution of QSO's should be heavily affected by these selection effects, and that attention should be paid to them in the investigations of the redshift distribution, the origion of redshift, and the evolutionary properties of QSO's.  相似文献   

Revisiting the characteristics of the spectral lags in short gamma-ray bursts     

Zhibin Zhang  G. Z. Xie  J. G. Deng  W. Jin 《Monthly notices of the Royal Astronomical Society》2006,373(2):729-732

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Cycloartane triterpenes from marine green alga Cladophora fascicularis     

黄新苹朱校斌  邓莉萍邓志威 林文翰 《中国海洋湖沼学报》2006,24(4):443-448

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张家界武陵源区降雨诱发地质灾害风险区划     

李学敏  邓玲 《气象研究与应用》2021,42(4):68-72

为了评估武陵源区降雨诱发的地质灾害风险,提高山岳型景区防灾减灾能力,基于2010-2019年张家界武陵源区16个区域自动站逐日降水量资料和中国区域地面气象要素数据集(CMFD),结合张家界武陵源区数字高程(DEM)和地质灾害详细调查数据,从致灾因子、孕灾环境等方面构建了地质灾害风险指数模型,并基于GIS分析完成了降雨诱发地质灾害的风险区划.结果 表明,武陵源降雨引发地质灾害高风险区占总面积5.5％,主要位于景区东侧和西南部,其中东部的黄龙洞、紫霞山和西南部的黄石寨、杨家界等景点需要做好重点防范;中等风险区占比39.5％,核心景区的大部分面积属于该区;景区西侧、东北侧乡镇风险较低.  相似文献   

First-Order Derivatives of Principal and Main Invariants of Magnetic Gradient Tensor of a Uniformly Magnetized Tesseroid and Spherical Shell     

Deng  Xiao-Le  Shen  Wen-Bin  Yang  Meng  Kuhn  Michael  Ran  Jiangjun 《Surveys in Geophysics》2022,43(4):1233-1262

Surveys in Geophysics - Similar to the gravitational curvatures in the gravity field, the magnetic curvatures (i.e., third-order derivatives of the magnetic potential) have been recently proposed...  相似文献   

2022年6月1日四川芦山6.1级地震应急产品及震源参数初步分析     

梁皓  戴丹青  杨志高  席楠  邓文泽  孙丽 《中国地震》2022,38(2):360-369

北京时间2022年6月1日17时0分四川雅安市芦山县(30.37°N,102.94°E)发生6.1级地震,中国地震台网中心于震后3min发布自动速报结果、震后9min发布正式速报结果,同时联合多家单位启动地震应急产品产出工作,共产出震源参数、历史地震、地震构造、震源机制、余震精定位、推测烈度和震源破裂过程等9类应急产品。结果显示,本次地震发生在龙门山断裂带,位于青藏高原巴颜喀拉地块、岷山构造带、川滇构造带的交汇处;震源机制解表明该地震为一次逆冲型事件;余震精定位结果显示余震展布呈近NE向,与震中区域断裂走向基本一致;烈度速报推测极震区烈度达Ⅸ度,区域面积约2km²,Ⅷ度及以上区域总面积约197km²,涉及四镇一乡。  相似文献   

2022年9月5日四川泸定6.8级地震初步研究结果     

徐泰然  戴丹青  杨志高  席楠  邓文泽  张建勇  房立华  孙丽 《中国地震》2022,38(3):412-424

北京时间2022年9月5日12时52分四川甘孜州泸定县(29.59°N,102.08°E)发生6.8级地震,中国地震预警网于震后6.1s产出首报预警结果;中国地震台网中心于震后3min发布自动速报结果,震后11min发布正式速报结果,同时联合中国地震局地球物理研究所、地质研究所、地震预测研究所和应急管理部国家自然灾害防治研究院启动地震应急产品产出工作,共产出震源基本参数、历史地震、地震构造、地震矩张量、余震精定位、地震烈度和震源破裂过程等9类应急产品。结合上述应急产品,对本次地震进行了研究,初步刻画了地震的构造环境、震源特征、断层形态和受灾区域,并分析了地震成因。结果表明,本次地震是发生在鲜水河断裂带南东段雪门坎—磨西断裂上的一次倾角近直立的走滑型事件,自起始破裂点向南东破裂,破裂长度约20km,最大滑移点深度约6km。余震精定位结果显示余震呈NW—SE向展布,长度约50km,深度主要集中在3～14km,展布方向与震中区域断裂走向基本一致,主震震中处断层倾角近乎垂直,与震源机制揭示的特征一致。烈度速报推测与地震烈度图显示极震区烈度达Ⅸ度,区域面积约280km²,Ⅷ度及以上区域总面积约505km²,涉及17个乡镇。认为本次地震是青藏高原隆升和高原上地壳物质向南东挤出,导致鲜水河断裂南东段雪门坎—磨西断裂上积累的应力的一次快速释放过程。  相似文献