中国地级以上城市工业创新效率空间格局研究   总被引：12，自引：4，他引：8  

杜志威  吕拉昌  黄茹 《地理科学》2016,36(3):321-327

以中国288个地级以上城市为研究对象,运用2008年第二次全国经济普查工业创新活动数据,综合考察城市工业创新效率的空间格局及其影响因素。首先,从投入和产出两方面构建了中国城市工业创新效率评价体系,运用DEA包络分析方法,从规模效率和纯技术效率两个维度对城市工业创新技术效率进行分析。然后,以聚类分析划分了3类工业创新效率城市,总结工业创新效率模式的空间特征,并分析了影响空间格局的原因。研究发现：中国城市工业创新效率呈现东强西弱,阶梯状减弱的总体空间格局,工业创新规模效率和纯技术效率的空间特征并不重合;全国尺度上,工业创新效率城市的空间分布与人口密度“黑河-腾冲”线的分布基本一致,区域尺度上,城市间呈现“核心-边缘”空间结构;城市工业创新效率空间格局受到工业发展基础与工业创新能力影响,提高城市工业创新效率关键在于提升工业创新中人力资本要素和优化工业创新投入规模。  相似文献   

夏季风等环流因子对黄河中游径流量周期变化的影响     

颜明  李夫星  贺莉  吕美朝  陈东 《地理科学》2016,36(6):917-925

基于黄河中游4个水文站1919~2010年还原的天然径流量、1873~2011年的夏季风强度指数、北大西洋涛动指数（NAO）和西太平洋副高指数等资料,利用Morlet小波方法分析了黄河中游河口镇-龙门区间（简称河龙区间）,龙门-三门峡区间（简称龙三区间）和三门峡-花园口区间（简称三花区间）径流量的周期变化,并探索了夏季风、中纬度西风与西太平洋副高等环流因子对黄河中游3个区间径流量周期性变化的影响。研究发现,黄河中游3个区间径流量的变化对夏季风、中纬度西风和西太平洋副高存在差异性响应,季风对于黄河中游的径流量不仅在时间上具有趋势性的影响,更为重要的是存在周期性的控制作用,在80 a长周期上对于整个黄河中游都有控制作用,但影响黄河中游降水-径流过程的不仅仅是夏季风,相关统计结果表明还受到西风带和西太平洋副高周期的影响。3个区间都存在一个中等尺度(25 a)的周期,这个周期在夏季风上没有得到体现,河龙区间和龙三区间的25 a周期是受西风带影响所致,而三花区间的中尺度25 a周期是西太平洋副高指数的强度和西界的作用所致。  相似文献   

An improvement of soil temperature simulations on the Tibetan Plateau     

SiQiong Luo  BoLi Chen  ShiHua Lyu  XueWei Fang  JingYuan Wang  XianHong Meng  LunYu Shang  ShaoYing Wang  Di Ma 《寒旱区科学》2018,10(1):80-94

The simulation of soil temperature on the Tibetan Plateau (TP) plays a dominant role in the performance of both global climate and numerical weather forecast models. To improve the simulation of soil temperature on the TP, the Johansen soil thermal conductivity parameterization scheme was introduced into Community Land Model 3.5 (CLM3.5) and Regional Climatic Model 4 (RegCM4). The improved CLM3.5 and RegCM4-CLM were utilized to conduct offline and regional simulation experiments on the TP. Comparison of the new and old schemes revealed that CLM3.5 provides high thermal conductivity parameters of mineral soil solid on the TP. The Johansen scheme is more practical for the TP than the soil thermal conductivity parameterization in CLM3.5. The simulation of soil temperature and liquid water content was improved in offline experiment. The improved parameterization scheme can also reduce the simulation error of soil temperature in winter throughout the entire TP.  相似文献   

三维有云大气辐射变温率数值模拟研究——邻云辐射效应   总被引：1，自引：0，他引：1  

章超  王震  杨军  孙继明  郜海阳  崔生成 《气象学报》2016,74(4):598-612

大气数值模式普遍采用一维辐射传输模型,无法表征有云大气中的三维辐射传输过程,从而影响数值模拟乃至数值天气预报的准确性。为评估这种不确定性,研究了水平云体间的三维辐射相互作用及其改变云体热力结构的规律,力求为改进数值模式辐射计算方案提供理论依据。选取I3RC PhaseⅡ的典型积云场和层积云场作为试验对象,将云场中心区域云体视为目标云体,周围云体为邻近云体,采用宽带三维辐射传输模式SHDOM模拟长波和短波辐射变温率的空间分布,定量阐明邻近云体对目标云体热力结构的影响。结果表明,邻云在长波区域对目标云体主要起辐射保温的作用,目标云体增温区域集中于邻云一侧的云体表面层,增温强度与云覆盖率和云间距离倒数成正比,最高可达3.08K/h,云体增温的厚度与目标云体液态水含量成反比;在短波区域,邻云同时起散射增温和遮蔽降温的作用,太阳垂直入射时,散射增温效应较弱,变温率空间差异小;当太阳天顶角增大后,遮蔽降温效应逐步起主导作用,造成目标云体被邻云遮挡一侧的表面层明显降温,峰值可达-1.72K/h,数值上甚至超过邻云长波增温效应。总之,邻近云体可以明显改变目标云体的变温率空间分布,引入三维邻云辐射效应对改进大气数值模式辐射计算方案具有重要意义。  相似文献   

一种综合机载LiDAR与高分辨率航空影像的铁路轨道提取方法   总被引：1，自引：0，他引：1  

于海洋  牛峰明  罗玲  马慧慧 《测绘工程》2016,25(5):42-46

高分辨率航空遥感数据中铁路轨道线性特征明显,可以直接用于铁路轨道的精细提取。首先根据铁路路基光谱、局域地形等特征,基于机载LiDAR数据建立一种面向对象的铁路区域提取算法;进一步通过数学形态学处理消除干扰因素的影响,选取适当的影像波段进行掩模提取图像中的铁路区域,采用基于高斯平滑和微分几何的线性地物提取算法初步提取铁路轨道线。在噪声消除、线段连接的基础上建立轨道平行线算法模型,从而实现轨道信息的准确提取。实验结果证明上述方法的有效性,轨道提取精度达到94.6%以上。  相似文献   

Effects of aluminum toxicity induced by acid deposition on pine forest ecosystem in Longli of Guizhou Province,Southwestern China     

ZHANG Jing  LYU Zhipeng  SHAO Siya  LI Fangfang  YANG Shengtian  SONG Wenlong  LI Wei  LI Shun-jiang 《中国地理科学(英文版)》2016,26(4):495-507

The effects of acid deposition on pine forest ecosystems in Longli of Guizhou Province, southwestern China are studied using indoor experiments and model simulations. Indoor experiments are designed to explore the aluminum toxicity on pine seedlings, and the long-term soil acidification model（LTSAM） and a terrestrial biogeochemistry model（CENTURY） are used to simulate the influences of acid deposition on pine forest ecosystems. The indoor experiment results of aluminum toxicity show that aluminum ions in solution limit plant growth and acid deposition enhances this effect by facilitating the release of aluminum ions from the soil. Pine seedling biomass and root elongation decrease as the aluminum concentration increases. The results of model simulations show that the soil chemistry varies significantly with different changes in acid deposition. When the acid deposition increases, the pH value in the soil solution decreases and the soil Al³⁺ concentration increases. The increased acid deposition also has negative impacts on the forest ecosystem, i.e., decreases plant biomass, net primary productivity（NPP） and net CO₂ uptake. As a result, the soil organic carbon（SOC） decreases because of the limited supply of decomposition material. Thus acid deposition need be reduced to help protect the forest ecosystems.  相似文献   

Apodized Lyot coronagraph for SPHERE/VLT: II. Laboratory tests and performance     

G��raldine Guerri  Jean-Baptiste Daban  Sylvie Robbe-Dubois  Richard Douet  Lyu Abe  Jacques Baudrand  Marcel Carbillet  Anthony Boccaletti  Philippe Bendjoya  Carole Gouvret  Farrokh Vakili 《Experimental Astronomy》2011,30(1):59-81

SPHERE (which stands for Spectro-Polarimetric High-contrast Exoplanet REsearch) is a second-generation Very Large Telescope (VLT) instrument dedicated to high-contrast direct imaging of exoplanets whose first-light is scheduled for 2011. Within this complex instrument one of the central components is the apodized Lyot coronagraph (ALC). The principal aim of this paper is to report the first laboratory experiment of the ALC designed for the SPHERE instrument. The performance and sensitivity of the optical configuration was first numerically studied with an end-to-end approach (see the results in paper I subtitled ??Detailed numerical study??). Made confident by the results, we then tested a prototype on an infrared coronagraphic bench. We measured the transmission profiles of the apodizer prototype and the coronagraphic performance of the apodized Lyot coronagraph in Y, J, and H bands. The coronagraph sensitivity to lateral and longitudinal misalignments of its three main components (apodizer, coronagraphic mask and Lyot stop) was finally studied in H band. We can conclude that the prototype meets the SPHERE technical requirements for coronagraphy.  相似文献   

LA-ICP-MS褐帘石的U-Th-Pb定年——以广东新丰稀土花岗岩为例     

郭海浩  肖益林  谷湘平  黄建  侯振辉  刘海洋 《地质学报》2014,88(6):1025-1037

褐帘石是一种常见的副矿物,是控制岩石中LREE、Th、U和Sr等微量元素的重要载体。由于Th、U可以在褐帘石中以类质同象形式进入并富集于其晶格,因而褐帘石是一种良好的年代学工具。但是,由于褐帘石中含有不同含量的普通铅,分析结果中的普通铅扣除成为难题,这就使得近年来褐帘石U-Th-Pb定年的应用受到很大的限制。本文利用通过激光熔样-电感耦合等离子质谱（LA-ICP-MS）原位分析技术,对广东新丰稀土花岗岩中褐帘石单颗粒矿物原位分析,运用232Th/206Pbc—208Pb/206Pbc等时线方法,再根据等时线年龄利用铅同位素演化两阶段模型扣除普通铅的方式,对建立单颗粒褐帘石的U-Th-Pb激光定年方法进行了探讨。运用该方法对广东新丰稀土花岗岩中褐帘石单颗粒矿物进行分析得出的年龄约为160Ma,与早期通过岩浆锆石U-Pb定年法得出的年龄之前研究159Ma~165Ma十分相似。褐帘石中微量元素、δEu、Th/U比值和普通铅含量显示其特征的岩浆成因褐帘石。褐帘石定年这一在国内首次使用尚未开展的定年方法具有简单、方便、准确的特点,对于确定含此矿物的岩体年龄,尤其是成成矿花岗岩的岩体形成时年代限制将发挥重大作用,具有非常良好和广泛的应用前景。  相似文献   

Historical variation and recent ecological risk of heavy metals in wetland sediments along Wusuli River,Northeast China   总被引：1，自引：0，他引：1  

Chuanyu Gao  Qianxin Lin  Kunshan Bao  Haiyang Zhao  Zhenqing Zhang  Wei Xing  Xianguo Lu  Guoping Wang 《Environmental Earth Sciences》2014,72(11):4345-4355

The 150-year historical changes in concentrations of pollution elements (Pb, Cu and Zn) in sediment profiles from two riparian freshwater wetlands along the Wusuli River (boundary river between China and Russia) were studied, and the ecological risk of heavy metals and their effects on four riparian wetlands during the urban development from Khanka Lake to Black Bear Island along the Wusuli River were assessed. Results showed that there are sharp increases of the enrichment factor and the ratio of anthropogenic/total of heavy metals in the sediment profiles during the 2000s, which showed that intensive human activities during city development had greatly affected heavy metals distribution since the 1960s. According to the principal component analysis, sediment textures, redox regimes, and organic matter contents accounted for 45.7, 23.6 and 16.5 % of the total variance of element concentrations, respectively. This study also showed that ecological risk of heavy metals was increased along the Wusuli River and closely related to the water quality of the rivers as their hydrological regimes likely affect wetlands.  相似文献   

The research of groundwater flow model in Ejina Basin,Northwestern China   总被引：1，自引：1，他引：0  

Haiyang Xi  Qi Feng  Wei Liu  JianHua Si  Zongqiang Chang  Yonghong Su 《Environmental Earth Sciences》2010,60(5):953-963

Water resources is a primary controlling factor for economical development and ecological environmental protection in the inland river basins of arid western China. Groundwater, as the important component of total water resources, plays a dominant role in the development of western China. In recent years, with the utilization ratio of surface water raised, the groundwater recharge rate has been reduced by surface water, and groundwater was exploited on a large-scale. This has led to the decline of groundwater levels and the degradation of eco-environments in the lower reaches of Heihe watershed, especially. Therefore, the study on the groundwater-level change in recent years, as well as simulating and predicting groundwater levels changes in the future is very significant to improve the ecological environment of the Heihe River Basin, coordinate the water contradiction, and allocate the water resources. The purpose of this study is to analyze the groundwater-level variations of the Ejina region basin on a large-scale, to develop and evaluate a conceptual groundwater model in Ejina Basin; according to the experimental observation data, to establish the groundwater flow model combining MODFLOW and GIS Software; simulated the regional hydrologic regime in recent 10 years and compared with various delivery scenarios from midstream; determined which one would be the best plan for maintaining and recovering the groundwater levels and increasing the area of Ejina Oasis. Finally, this paper discusses the possible vegetation changes of Ejina Basin in the future.  相似文献