日照市土地档案利用浅析     

毕为正  程祥英 《山东国土资源》2007,23(6):2007/4/25-2007/6/14

土地档案是国土资源管理机关在土地资源管理、开发、使用过程中形成的，具有保存、利用价值的文件、图表、声像等资料，它记载着土地利用的全部过程，是一种重要的具有长期查考、利用价值的信息资源。如何科学合理地利用土地档案资源，充分发挥其在国土资源管理和地方经济建设中的作用，是土地档案管理部门应该认真研究的问题。  相似文献   

Distribution and transport of suspended sediments off the Yellow River (Huanghe) mouth and the nearby Bohai Sea     

Shuqing Qiao  Xuefa Shi  Aimei Zhu  Yanguang Liu  Naishuang Bi  Xisheng Fang  Gang Yang 《Estuarine, Coastal and Shelf Science》2010,86(3):337-344

Hydrological and sedimentological investigations were carried out off the Yellow River (Huanghe) mouth and the nearby Bohai Sea during August–September 2007 to examine the distribution and transport of suspended sediments. Our data witnessed that suspended sediments from the Yellow River mouth primarily extend southerly and southeasterly during the flood season. High suspended sediment concentration (SSC) occurs as turbid plume on both sides of the river mouth, where it can reach >20 mg l^?1 in the surface water and >40 mg l^?1 in the bottom water. Accordingly, salinity varies from 25 to 29 psu, mean grain size (Dmz) is >200 μm, and volume concentration (VC) is >100 μl l^?1. High SSC was concentrated in the river mouth area as two muddy patches, i.e. the North Mud and South Mud, consisting mostly of fine-grained silt and clayey silt sediments. Our results have verified the larger extent of the South Mud than that of the North one, implicating south- and southeastward sediment dispersal paths that prevail near the river mouth area. The existing anti-clockwise and clockwise flows in the river mouth area were synthesized as the major hydrodynamics responsible for forming the two muddy patches. Tidal and residual currents are considered as the key hydrodynamic factors controlling the sediment distribution and transport in the region.  相似文献   

Purification and characterization of lipoxygenase from Entermorpha clathrata     

YANG Wenge  XUE Changhu  XU Dalun  FU Xueyan  HE Xiong 《海洋学报(英文版)》2008,27(1):92-101

The purification and characterization of lipoxygenase （LOX, EC 1.13.11.12） from the green algae Enteromorpha clathrata were studied. Two components marked LOX - 1 and LOX - 2 were purified and their molecular masses were estimated to be 102 and 79 ku by SDS - PAGE. Both LOX - 1 and LOX - 2 were stable over the pH wide range 6.0 - 10.0 and had the optimum pH of 10.0 and 8.6, at optimum temperature of 30 and 25℃, respectively. Substrate specificities of LOX - 1 and LOX - 2 were the greatest towards linoleic acid, followed by arachidonic acid and linolenic acid. The Michaelis constant values of LOX - 1 and LOX - 2 were 0.23 and O. 20 mmol/dm^3 with the substrate of linoleic acid. The LOX activities were stimulated greatly by Ca^2＋ but inhibited by Hg2 ~ and the antioxidants such as BHA, BHT and TBHQ. The hydroperoxide products of LOX were analysed by HPLC with the substrate of methyl linoleate, and the results showed that LOX - 1 formed mainly 9-hydroperoxides while LOX - 2 formed both 9- and 13-hydroperoxides at a ratio of 24： 76.  相似文献   

Observation and Research on the Twisting Characteristics of Flare Loop System     

Li Rufeng  Bi Shaolan  Dun Jinping 《天文研究与技术》1999,(Z1)

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｍａｇｎｅｔｉｃｆｉｅｌｄａｎｄｍａｔｅｒｉａｌｍｏｔｉｏｎｈａｖｅａｌｗａｙｓｂｅｅｎｔｈｅｐｏｉｎｔｓｔｏｗｈｉｃｈｃｌｏｓｅａｔｔｅｎｅｉｏｎｉｓｐａｉｄｉｎｔｈｅｓｔｕｄｙｏｆｓｏｌａｒｆｌａｒｅｐｒｏｃｅｓｓ.Ｅｓｐｅｃｉａｌｌｙｔｈｅｔｗｉｓｔｉｎｇｅｎｅｒｇｙｓｔｏｒｇｅｐｒｏｃｅｓｓｉｓａｐｒｏｂ ｌｅｍｔｈａｔａｕｔｈｏｒｓｏｆｍａｎｙｆｌａｒｅｔｈｅｏｒｉｅｓａｎｄｍｏｄｅｌｓｈｏｐｅｔｏｒｅｓｏｌｖｅ .Ｇｏｌｄ＆Ｈｏｌｙｅ ( 1 96 0 ) ｐｒｅｓ…  相似文献   

社会资本对农户收入的影响——以甘肃省张掖市、甘南藏族自治州与临夏回族自治州为例   总被引：2，自引：0，他引：2  

路慧玲  赵雪雁  周海  侯彩霞  张方圆  张亮 《中国沙漠》2014,34(2):610-616

社会资本作为影响区域经济发展和农户收入的重要因素而备受关注。本文以甘肃省张掖市、甘南藏族自治州及临夏回族自治州为研究区,基于农户调查资料,以信任、网络及规范作为社会资本的测算指标,测算了农户的社会资本指数,并对影响农户收入的因素进行分析。研究发现：（1）汉族地区社会资本指数高于少数民族地区;（2）社会资本对农户收入具有显著影响,其中,普遍信任、社会参与、嵌入网络中的资源及互惠规范对农户收入有显著正向影响。基于此,提出增加农户社会资本、提高农户收入的措施,以期为地区经济发展提供理论借鉴。  相似文献   

基于EEMD的明代北京地区干旱灾害特征分析     

李艳萍  陈昌春  张余庆  毕硕本 《中国沙漠》2014,34(3):835-840

集合经验模态分解（EEMD）是一种适用于非线性、非平稳序列的信号分析方法,将EEMD应用于气候要素时间序列,可提取真实可靠的气候变化信号。根据北京地区历史时期干旱灾害资料,采用EEMD分解方法对明代（1368—1644年）北京地区干旱灾害等级序列进行多时间尺度的分析,获得简洁且平稳性较好的固有模态函数分量,并与所统计的明代北京地区干旱灾害频次多项式拟合曲线进行对比。结果表明：将EEMD应用于干旱灾害等级序列,可以提取干旱灾害中各个尺度的变化,对明代北京地区干旱灾害进行多尺度分析。明代北京地区干旱灾害存在着2.8年、6.3年的年际周期,11.5年、26.6年、53.6年的年代际周期和118.7年、299.5年的世纪周期。北京地区干旱灾害在明代整个时间跨度上呈现着先增加后微减的变化趋势,总体而言明代中期以后旱灾明显增多。  相似文献   

Asteroseismic Analysis of a Cen B: Preliminary Tests of Effects of Rotation and Interior Magnetic Field in the Solar-like Star     

Yan-Ke Tang  Shao-Lan Bi  Ning Gai  Hua-Yin Xu 《中国天文和天体物理学报》2008,8(4)

Taking into consideration the effects of rotation and interior magnetic field during the lifetime of the star, we reconstruct the model of a Cen B to satisfy the latest nonasteroseismic and asteroseismic observational constraints. We find that the effects can induce a change of about 0.3 μHz in the large frequency spacings and can speed up the star's evolution. The model of a Cen B has thereby been improved.  相似文献   

珠江广州河段重污染沉积物中多环芳烃赋存状态初步研究   总被引：8，自引：2，他引：6  

吴启航  麦碧娴  杨清书  彭平安  傅家谟 《地球化学》2004,33(1):37-45

对珠江广州河段重污染沉积物进行粒度分级 (>500 μm、500～ 220 μm、220～ 63 μm、63～ 22 μm和 < 22 μm),每个粒级的样品进行重液分离,收集轻组分 (有机质 )和重组分 (主要为无机矿物及无定型有机质 ).在显微镜下对沉积物中不同粒径轻重组分的吸附剂进行鉴定,对其中的多环芳烃进行定量分析,结果表明,白鹅潭样品中有机质占总质量的 9.10%,富集了 81.55%的多环芳烃,无机矿物和无定型有机质占 90.92%,富集了 18.45%的多环芳烃;黄埔样品中有机质占总质量的 8.95%,富集了 56.50%的多环芳烃,无机矿物和无定型有机质占 91.15%,富集了 43.50%的多环芳烃.轻组分中的有机吸附剂对多环芳烃的富集能力比重组分无机矿物和无定型有机质高 1～ 2个数量级,轻组分有机吸附剂中焦碳和碳黑富集能力较高,植物碎屑较低.总有机碳和碳黑的含量与多环芳烃的富集能力没有明显的相关性.  相似文献   

Identifying sources and hazardous risks of heavy metals in topsoils of rapidly urbanizing East China   总被引：3，自引：0，他引：3  

Yang Liu  Zongwei Ma  Jianshu Lv  Jun Bi 《地理学报(英文版)》2016,26(6):735-749

With rapid economic and social development, soil contamination arising from heavy metals has become a serious problem in many parts of China. We collected a total of 445 samples (0–20 cm) at the nodes of a 2 km×2 km grid in surface soils of Rizhao city, and analyzed sources and risk pattern of 10 heavy metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb and Zn). The combination of Multivariate statistics analysis and Geostatistical methods was applied to identify the sources and hazardous risk of heavy metals in soils. The result indicated that Cr, Ni, Co, Mn, Cu, and As were mainly controlled by parent materials and came from natural sources. Cd and Hg originated from anthropogenic sources. Pb and Zn, belonging to different groups in multivariate analysis, were associated with joint effect of parent materials and human inputs. Ordinary Kriging and Indicator Kriging suggested that single element and elements association from the same principal components had similar spatial distribution. Through comprehensive assessment on all elements, we also found the high risk areas were located in the populated urban areas and western study area, which could be attributed to the higher geological background in the western part and strong human interference in the eastern part.  相似文献   

气候变化对石羊河流域农户生计资本的影响   总被引：1，自引：1，他引：0  

张钦  赵雪雁  王亚茹  雒丽 《中国沙漠》2016,36(3):814-822

气候变化是全球变化的核心问题,其影响已经深入到人类生活的各个领域,引起了国际社会的广泛关注。明确气候变化对农户生计的影响以及农户适应气候变化的策略及其需求,是区域可持续发展中急需解决的关键问题。本文基于石羊河流域1963-2012年气候变化和493个农户的入户调查数据,分析了气候变化对石羊河流域不同福利水平农户生计资本的影响及农户适应气候变化的策略和需求。结果表明:(1)流域上游气候呈显著的暖湿化趋势,中游和下游气候暖湿化趋势不显著。(2)气候变化对中游和下游农户生计资本的影响均大于上游农户,其中,对中等福利群体的生计资本影响最显著,对高福利群体的影响次之,对低福利群体的影响最小。农户自然资本受气候变化的影响最强,物质资本和社会资本受气候变化的影响最弱。(3)流域内农户均倾向选择减少消费和外出务工来适应气候变化,其中,选择减少消费的农户比重最高,选择外出务工和向亲属或政府求助的比重次之。高福利群体中选择减少消费和外出务工策略的比重较高,中等福利群体中选择求助亲属或政府策略的比重较高。(4)流域内农户对信息和资金的需求均较显著,其中,对信息的需求最强烈,对资金、技术和劳动力素质的需求次之。高福利群体和低福利群体在就业信息方面的需求最强烈,中等福利群体在农牧业市场信息方面的需求最强烈。  相似文献