关于提升青岛旅游业发展水平的几点思考

提升旅游业发展水平涉及旅游业“吃、住、行、游、购、娱”六大要求的协调发展,本文侧重于对青岛旅游资源优势进行分析,对青岛市旅游市场定位、旅游产品定位进行探讨,提出实现青岛旅游业更高水平发展要解决的问题和思考 。     

黄河流域农业生产现状及其结构调整

2003年黄河流域耕地面积占全国的12.4%，粮食总产占全国的7.7%，棉花总产占全国的3.4%，苹果总产占全国的40.6%。尽管粮棉产量占全国的比重不大，然而，黄河流域的农业仍是我国重要的生态屏障，是国家生态安全和区域食品安全的保证。本流域农业生产中存在的问题主要为生产水平低、农业结构单一、社会需求与资源环境之间的矛盾突出等。根据农业生产的现状与存在问题、结构调整的原则和比较优势分析，该流域农业结构调整的关键是强化特色农业的发展，即大力发展特色种植业、草食畜牧业、优质果业和特色生物医药产业。据预测，由于特色农业的发展，2000～2020年本流域农林牧渔业总产值年增长率将为3.9%，农业产值所占比重将下降11.0个百分点，牧业产值所占比重将上升12.1个百分点。     

非常规资料在沿海灾害暴雨过程中的应用分析

非常规资料在天津沿海一次灾害暴雨过程中的应用     

近距中等光度IRAS星系的射电观测

使用澳大利亚ＡＴ对６个近距中等红外光度的ＩＲＡＳ星系在双频上同时进行了观测．其中ＩＲＡＳ２０２７２－４７３８、ＩＲＡＳ２３１５６－４２３８探测到射电发射．获得了它们的射电流量、峰值位置、源的大小、频谱指数等射电参数,用红外、射电、光学资料对射电源进行了证认．并结合以前的观测资料讨论了这类星系射电发射的特点．     

淮河流域高温热浪时空演变规律及成因分析

基于淮河流域1960—2014年39个气象站点数据、太平洋气候因子和NECP/NCAR再分析数据基础,利用空间Ward-like层次聚类分析划分4个子区域,通过体感温度的高温热浪指数分析淮河流域不同分区的夏季高温热浪时空演变特征,并通过EOF分析、相关性分析和大气环流遥相关等进一步揭示淮河流域高温热浪演变机理。研究表明：① 1960—2014年淮河流域夏季高温、高温热浪开始时间和持续时间均呈先增后减的趋势,20世纪80年代由暖相位进入冷相位,2010年后由冷相位进入暖相位;② 淮河流域各分区高温热浪开始时间呈现区域差异,分区1的高温热浪事件开始时间最早（平均为5月28日）,分区3次之（平均为6月1日）,分区2和分区4高温热浪开始时间最晚;③ 淮河流域轻度热浪发生频次最多平均为1.24次/a,中度热浪发生频次次之,平均为0.37次/a,重度热浪发生频次最少,平均为0.04次/a;淮河流域高温热浪事件与太平洋东部变暖（厄尔尼诺）或变冷（拉尼娜）变化相同。④ 青藏高原和内蒙古低压减弱导致了热浪高温事件的增加。分区4和分区1发生热浪的时间主要发生6、9月,分区2和分区3热浪发生时间集中在7、8月。分区1（西部）和分区4（东部）与Niño3、Niño1+2、MEI和PDO的相关性较高,分区2和分区3与Niño3.4、PNA相关性较高。     

Zircon and Cassiterite U-Pb Ages and Lu-Hf Isotopic Compositions of Tashan Tin-bearing Porphyry in Guangdong Province,SE China and its Geological SignificanceEI北大核心CSCD

The Tashan porphyry tin polymetallic deposit is located at the southwest part of the Lianhuashan Fault in the eastern Guangdong province. It is one of the three typical porphyry tin deposits in China. In this paper, we reported cassiterite and zircon U-Pb ages, geochemistry and Lu-Hf isotopes of the ore-bearing granite porphyry in the orefield. Zircon LA-ICP-MS U-Pb dating yielded a concordant ages of 136.8±1.1 Ma, whereas analyses of cassiterite yielded a 206Pb/238U-207Pb/238U concordia lower intercept age of 133.6±8.6 Ma and a Tera-Wasserburg lower intercept age of 136.5±8.1 Ma, which suggest a genetic link between the granite porphyry and the ore mineralization. The εHf(t) values of -4.87 to -2.07 and tDM2 ages 1322 Ma to 1507 Ma for zircon from the granite porphyry show that the Tashan granite porphyry was likely derived from partial melting of the Mesoproterozoic crustal rocks with minor input of mantle material. © 2018, Science Press. All right reserved.     

安阳夏玉米生长期气候要素与产量的灰色关联分析

采用灰色关联度分析了安阳夏玉米生育期间主要气象要素与夏玉米产量的关系，明确了当地夏玉米产量在年度间的差异主要以积温为主导因素，不同生育期中的气候因素以拔节-乳熟期的光照和降水量对产量影响最大，而乳熟-成熟的降水量对产量的影响程度最弱。     

地磁感应电流研究综述

因太阳活动而引起的地磁扰动,会在地球表面感生出地电场,从而在地表附近的导体系统中产生地磁感应电流(GICs).太阳表面的异常活动而引起的磁暴会导致强烈的GICs,严重威胁电信设备、电网、油气管道和铁路运输网络等基础设施系统的安全运行,已经成为最严重的空间天气灾害之一.因此,对GICs进行深入研究以建立对其做出迅速预测的能力,在科学和应用方面都有重要意义.本文综述了GICs的研究进展,从引入空间天气的概念开始,将GICs作为从太阳活动到太阳风再到地球扰动的空间天气链的最终环节;重点阐述了GICs的计算中所涉及的三个步骤:地球表面地磁场重建、感应地电场的计算,以及地面导体系统中GICs计算;对每一步骤中主要方法的相关原理和应用做了简要介绍与评估;最后总结了当前GICs的研究现状,并对未来GICs的研究方向与挑战进行了展望.     

Dynamics of saline-alkali land and its ecological regionalization in western Songnen Plain,China

As the important reserve land resources for food production,saline-alkali land should play a significant role to ensure the national food security in the context of global food crisis. The western Songnen Plain is one of main distribution regions of saline-alkali land in China,with great potential in agricultural development. In this study,the extent,transformation,spatial distribution and temporal change of saline-alkali land in the western Songnen Plain during 1954–2005 were investigated by using remote sensing and GIS spatial analysis methods. Saline-alkali land change was detected from a temporal series of topographic maps in 1954,satellite images of Landsat MSS in 1976,Landsat TM/ETM in 1988,2000 and 2005 through artificial visual interpretation. The results indicated a significant expansion in saline-alkali land area and aggravation in salinization. The area of saline-alkali land had increased from 401.48×103 ha in 1954 to 1 097.45×103 ha in 2005. While the ratio of light,moderate and serious salinized land areas changed from 6.72︰2.92︰1.00 to 1.25︰1.06︰1.00 in the study period. Grassland,cropland,swampland and water body were the major land use and land cover types from which saline-alkali land transformed. And the secondary salinization occured mainly in Da′an City,Tongyu County,Changling County,Daqing City,Dorbod Mongolian Autonomous County and Zhaoyuan County. Finally,seven large ecoregions and 14 corresponding sub-ecoregions were delineated out based on spatio-temopral dynamic characteristics of saline-alkali land and geo-relational environmental attributes. According to the results,measures of amelioration and ways of development of saline-alkali land in the western Songnen Plain were put forward.     

Simulating impact of larch caterpillar (<Emphasis Type="Italic">Dendrolimus superans</Emphasis>) on fire regime and forest landscape in Da Hinggan Mountains,Northeast China

Larch caterpillar (Dendrolimus superans) is very common in the Da Hinggan Mountains, Northeast China, affecting fire regime and forest ecosystem change at large spatio-temporal scales. In this study, we used a spatially explicit landscape model, LANDIS, to simulate the changes of fire regime and forest landscape under four larch caterpillar disturbance intensity levels scenarios in Huzhong forest area, northern of Da Hinggan Mountains. The results indicate that larch caterpillar disturbances would decrease ...