我国车载移动测量装备市场发展初探     

索一凡  刘利 《地理信息世界》2016,(6):42-45

车载移动测量技术和应用在国内迅速发展,本文介绍了国内外市场的主要车载移动测量产品,针对车载移动测量系统的核心部件及其主要性能,对我国车载移动测量装备市场发展现状和存在的突出问题进行初步研究,在此基础上提出了促进我国车载移动测量装备市场发展的几点建议。  相似文献   

Activity patterns,socioeconomic status and urban spatial structure: what can social media data tell us?     

Qunying Huang  David W. S. Wong 《International journal of geographical information science》2016,30(9):1873-1898

ABSTRACT

Individual activity patterns are influenced by a wide variety of factors. The more important ones include socioeconomic status (SES) and urban spatial structure. While most previous studies relied heavily on the expensive travel-diary type data, the feasibility of using social media data to support activity pattern analysis has not been evaluated. Despite the various appealing aspects of social media data, including low acquisition cost and relatively wide geographical and international coverage, these data also have many limitations, including the lack of background information of users, such as home locations and SES. A major objective of this study is to explore the extent that Twitter data can be used to support activity pattern analysis. We introduce an approach to determine users’ home and work locations in order to examine the activity patterns of individuals. To infer the SES of individuals, we incorporate the American Community Survey (ACS) data. Using Twitter data for Washington, DC, we analyzed the activity patterns of Twitter users with different SESs. The study clearly demonstrates that while SES is highly important, the urban spatial structure, particularly where jobs are mainly found and the geographical layout of the region, plays a critical role in affecting the variation in activity patterns between users from different communities.  相似文献   

棉兰老流和棉兰老潜流在季节尺度上的关系研究     

王琰  兰健  李理 《海洋学报(英文版)》2016,35(5):1-8

The ocean general circulation model for the earth simulator(OFES) products is applied to estimate the transports of the Mindanao Current(MC) and the Mindanao undercurrent(MUC) and explore the relation between them on seasonal scale. In general, the MUC is composed of the lower part of the Southern Pacific Tropical Water(SPTW)and Antarctic Intermediate Water(AAIW). While the deep northward core below 1 500 m is regarded as a portion of MUC. Both salinity and potential density restrictions become more reasonable to estimate the transports of MC/MUC as the properties of water mass having been taken into consideration. The climatological annual mean transport of MC is(37.4±5.81)×10~6 m~3/s while that of MUC is(23.92±6.47)×10~6 m~3/s integrated between 26.5 σ_θ and 27.7 σ_θ, and(17.53±5.45)×10~6 m~3/s integrated between 26.5 σ_θ and 27.5 σ_θ in the OFES. The variations of MC and MUC have good positive correlation with each other on the seasonal scale: The MC is stronger in spring and weaker in fall, which corresponds well with the MUC, and the correlation coefficient of them is 0.67 in the OFES.The same variations are also appeared in hybrid coordinate ocean model(HYCOM) results. Two sensitive experiments based on HYCOM are conducted to explore the relation between MC and MUC. The MUC(26.5σ_θ27.7) is strengthening as the MC increases with the enhancement of zonal wind field. It is shown,however, that the main part of the increasement is the deeper northward high potential density water(HPDW),while the AAIW almost remains stable, SPTW decreases, and vice versa.  相似文献   

海水观赏鱼产业现状及其存在的问题   总被引：1，自引：0，他引：1  

马本贺  马爱军  孙志宾  何伟国  于宏  徐志进  李伟业  黄智慧  叶星 《海洋科学》2016,40(10):151-159

海水观赏鱼艳丽多彩、风姿绰约,具有一种不可名状的美感,在观赏鱼市场中备受欢迎。作者结合相关资料概述了海水观赏鱼的产业现状及研究进展,讨论了海水观赏鱼产业存在的问题并对海水观赏鱼的发展前景做了展望。  相似文献   

Heat-related mortality: Effect modification and adaptation in Japan from 1972 to 2010     

《Global Environmental Change》2016

Excessive heat is a health risk, yet previous studies have observed a general decline in sensitivity to heat despite increasing temperatures. Conclusive evidence is lacking on whether long-term changes of this sensitivity can be attributed to specific adaptation measures, such as air conditioning, or should be linked to societal adaptation, such as improved healthcare systems or socioeconomic well-being. The aim of this study was to assess the variation of the association between heat and daily mortality during summer in Japan since the 1970s and to examine the influence of air conditioning (AC) prevalence, healthcare resources, and socioeconomic developments at the prefecture level on this variation.We analyzed daily total, cardiovascular and respiratory disease mortality and temperature data from 1972 to 2010 for 47 prefectures. We used Poisson generalized linear model to estimate the effect of heat on mortality, random effects model to obtain the mean national effect estimates, and meta-regression to explore the impact of prefecture-level characteristics.Average summer temperature has increased across Japan during the 39-year period. Excess mortality attributable to summer heat has decreased, with a national reduction of 20 (95%CI: 17, 22), 21 (95%CI: 18, 25), and 46 (95%CI: 36, 55) cases of total, cardiovascular, and respiratory deaths (per 1000 deaths). The increase of AC prevalence was not associated with a reduction of excess mortality over time. Prefectures and populations with improved economic status documented a larger decline of excess mortality. Healthcare resources were associated with fewer heat-related deaths in the 1970s, but the associations did not persist in the more recent period (i.e., 2006–2010).Excess mortality due to heat has reduced in Japan, suggesting population adaptation. Yet, heat remains a significant health risk. Socioeconomic developments may play a role in heat adaptation. These findings may have implications for ensuring effective prevention of heat-related health impacts.  相似文献   

海洋山—老厂铅锌矿床含银矿物赋存状态和特征     

方代干 《南方国土资源》1998,(3)

海洋山—老厂铅锌矿床中伴生银含量较高,但含银矿物颗粒细小。文章通过野外采样、测试分析和镜下观察,对在铅锌矿床中新发现的深红银矿、银锑黝铜矿等主要含银矿物的赋存状态及其特征进行了描述,对该区铅矿石中银的综合回收利用提供科学依据。  相似文献   

中国二叠纪生物礁的研究现状及新进展     

王永标 《地质科技情报》1998,17(1):36-40

对我国二叠纪生物礁的类型、演化规律及研究方法进行了系统的总结。按造礁生物种类的不同可将二叠纪生物礁分为珊瑚礁和海绵礁;按古地理位置的不同可分为岸礁、台地边缘礁及点礁。生物礁研究的方法包括传统方法、结合成岩作用的方法、定量地层学方法、地球化学方法及地球物理方法等。最后对东昆仑地区最新发现的生物礁作了简单的介绍。  相似文献   

对盐津县地质灾害防治的思考     

干晓锐 《中国煤炭地质》2008,20(3):56-58

盐津县境内的地质灾害类型主要为滑坡、崩塌、泥石流、危岩、地面裂缝、潜在不稳定斜坡等多种地质灾害并存,其形成原因主要与大气降水强度、河水淹没和侵蚀作用、地形地貌、岩土类型、地质结构、地震及人类不合理工程活动等相关。针对该县目前地质灾害形势,提出了“以防为主、防治结合、全面规划、综合治理”的防治对策。  相似文献   

黔西南高砷煤开发现状与污染调查   总被引：2，自引：0，他引：2  

龚朝兵 《中国煤炭地质》2008,20(4):63-66

贵州省黔西南州的兴仁县是典型的高砷煤矿区,经化验,该区煤中砷含量普遍偏高,最大可达21 000mg/kg,为Ⅱ型的高砷矿区;水体和土壤砷含量亦高,土壤中砷的最高含量为234.141mg/kg,最低含量5.279mg/kg,平均值37.735mg/kg;水中砷的含量相对较低,最高含量为0.004 3mg/L,平均值为0.000 5mg/L;河流沉积物中砷的最高含量为219.140mg/kg,最低值为20.676mg/kg,平均值为60.700mg/kg。分析认为土壤中砷与受矿业活动影响的灌溉水体有关,矿业开采已造成了当地水环境、土壤环境、大气环境的严重污染。  相似文献   

临涣矿区界沟煤矿环境地质评价     

黄芳友  张宪方  李云峰 《中国煤炭地质》2008,(5):53-56

界沟煤矿位于淮北煤田南部,设计生产能力为0．6Mt／a,新构造活动不强,构造稳定性较好。通过对界沟煤矿环境地质现状监测和调查,认为目前环境现状质量良好;对煤层开采后引起的地面沉降与塌陷、矿井污、废水排放,固体废弃物,空气污染、噪声等对环境地质的影响进行了预测评价,预测地面沉降为12．0m,塌陷积水面积为9．25m^2,受影响的耕地为1316m^2,综合评价环境地质条件为不良即Ⅲ类;提出了采用煤矸石发电,对塌陷区回填复垦．对矿井排水进行处理和综合利用等环境地质保护的方法与措施。  相似文献