物联网常识     

《地理信息世界》2014,(2)

正物联网(TheInternetofthings)的概念是在1999年提出的,它的定义很简单:把所有物品通过射频识别(RFID)、红外感应器、全球定位系统、激光扫描器等信息传感设备与互联网连接起来,进行信息交换和通讯,实现智能化识别、定位、跟踪、监控和管理。物联网把新一代IT技术充分运用在各行各业之中,具体地说,就是把感应器嵌入和装备到电网、铁路、桥梁、隧道、公路、建筑、大坝、油气管道等各种物体中,然后将"物联网"与现有的互联网整合起来,实现人类社会与物理系统的整合,在这个整合的网络当中,存在能力超级强大的中心计算  相似文献   

Soil and vegetation seasonal changes in the grazing Andean Mountain grasslands     

MU?OZ María ángeles  FAZ ángel 《山地科学学报》2014,11(5):1123-1137

Andean grasslands ecosystems are fragile environments with rigorous climatologic conditions and low and variable food for the grazing. The Apolobamba area is located in the Bolivian Andean Mountains. Its high grasslands provide a natural habitat for wild and domestic camelids such as vicuna（Vicugna vicugna） and alpaca（Lama pacos）. The botanical diversity plays an essential role in maintaining vital ecosystem functions. The objectives of this research were to determine the seasonal changes in soil properties, to study the vegetation changes during the wet and dry seasons and the influence of soil properties and camelid densities on the vegetation in the Apolobamba grasslands. Four zones with different vicuna populations were selected to be studied. The following soil parameters were determined： total organic carbon, total nitrogen, available phosphorous, cation exchange capacity, exchangeable cations, pH and texture. The vegetation season changes were studied through botanical identification, above-ground biomass, plant cover and species richness. Results showed that some soil properties such as C/N ratio, CEC, silt and clay percentages kept stable against the seasonal changes. Generally, soil nutrients were relatively higher during the dry season in the surface and subsurface. The results did not point out the predominant vegetation growth during the wet season. The seasonal vegetation growth depended on each species. Thegood soil fertility corresponded to the highest plant cover. Soil fertility presented no influence on the above-ground biomass of the collected species. The negative influence of camelid grazing on soil properties could not be assessed. However, overgrazing could affect some plant species. Therefore, protection is needed in order to preserve the biodiversity in the Andean mountain grasslands.  相似文献   

汶泗河冲洪积扇松散层现场热响应试验数据分析及应用——以兖州市南郊试验场为例          下载免费PDF全文

史启朋 《山东国土资源》2014,30(2):54-57

现场热响应试验是获取岩土体热物性参数的主要方法之一,可为试验场区地源热泵工程地埋管换热器类型及长度的选择,浅层地热能评价和开发利用提供基础数据。该文系统介绍了现场热响应试验的目地任务、试验装置、原理、内容和步骤,数据处理方法,并以位于汶泗河冲洪积扇中上流地区的兖州市南郊试验场松散层现场热响应试验为例,介绍了试验场区水文地质条件,试验过程、试验数据分析及应用。  相似文献   

基于潮沟定点观测的潮间带水、沙、盐交换研究     

李鹏  杨世伦 《海洋与湖沼》2014,45(1):126-133

为研究潮间带和潮下带的水、沙、盐交换,于2006年6月25~28日（夏季大潮）和2006年12月29日~2007年1月4日（冬季中-大潮和小潮）在长江口九段沙一典型潮沟的固定点利用OBS-3A和ADP-XR进行了水深、浊度、盐度、流速流向剖面和回声强度观测。结果和结论为：（1）夏季大潮、冬季中-大潮、冬季小潮的潮周期垂向平均流速分别为26.5、15.9和8.4 cm/s,夏、冬季观测到的最大流速分别为84 cm/s和35 cm/s。（2）夏季盐度变化范围为0.65~4.91,平均盐度2.14;冬季盐度变化范围为3.5~10.3,中-大潮和小潮平均盐度分别为6.26和7.98。（3）高悬沙浓度出现在涨潮初期和部分落潮末期的低水位阶段;涨潮阶段的平均悬沙浓度是落潮阶段的1.11~7.0倍。（4）涨、落潮阶段的水体和盐输运量大体上趋于平衡;（5）无论是冬夏季或大小潮,潮沟在潮周期内的净输沙方向均指向陆,即落潮输沙量小于涨潮输沙量（平均小40%）;平均每个潮周期的净输沙量为6102 kg,结合潮盆面积推算的潮周期沉积速率为0.0112 mm/tide,或8.2 mm/a。  相似文献   

鄱阳湖丰水期水体中叶绿素a含量空间分布及其与环境因子的关系   总被引：2，自引：0，他引：2  

吴召仕  张路  刘宝贵  陈宇炜 《湿地科学》2014,(3)

在2011年8月和2012年7月丰水期,在鄱阳湖湖区布设77个采样点,大规模采集水样,研究浮游植物生物量(以水体中叶绿素a含量表示)在湖区的空间分布,并探讨叶绿素a与相关环境因子之间的关系。结果表明,鄱阳湖丰水期水体中叶绿素a质量浓度较低,平均值为10.58μg/L;叶绿素a含量的空间分布特征为:东南湖区最高,中部湖区居中,北部通江区较低。Spearman秩相关分析结果表明,水体中叶绿素a含量与水体透明度显著正相关,与总悬浮颗粒物含量、总氮含量、亚硝态氮含量、硝态氮含量和溶解性总氮含量显著负相关,与其他营养盐含量不相关。水下光照条件是限制鄱阳湖浮游植物丰水期生长的主要因素;鄱阳湖水体交换时间较短,也在一定程度上抑制了浮游植物的生长;丰水期,高水位稀释了水体中的营养盐浓度,从而掩盖了其对浮游植物的作用,导致营养盐的作用不明显。  相似文献   

铁铝复合氧化物对土壤Mn、Pb和Cd有效性的影响   总被引：1，自引：0，他引：1  

任丽英  马家恒  徐振  胡长伟  王法社  高晓慧  庞雪 《矿物学报》2014,(3)

利用氧化物对土壤重金属的吸附特性,研究了添加铁铝复合氧化物对土壤Mn、Pb和Cd有效性的影响。结果表明,在土壤中添加氧化物后,土壤中3种重金属的交换态含量明显降低。14天时间,添加铁铝氧化物后,土壤中交换态Mn、Pb和Cd的含量分别降低了64.8%、52.9%和89.51%,可见铁铝氧化物明显降低了土壤中Mn、Pb和Cd的有效性。通过方程拟合,建立了氧化物对土壤中交换态Mn、Pb和Cd的吸附模型,其中以Elovich方程和权函数方程拟合度较好,其次是抛物线扩散方程。  相似文献   

厦门浔江湾水体交换的^224Ra和^2H示踪研究   总被引：3，自引：0，他引：3  

《台湾海峡》2000,19(2):157-162

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A photometric study of an EW-type binary system： GV Leo     

Wichean Kriwattanawong  Panompom Poojon 《天文和天体物理学研究(英文版)》2013,(11):1330-1338

A photometric study of a contact binary system, GV Leo is presented. New observations were done using the B VR filter bands. We find that a revised orbital period is 0.26673171 d and the orbital period of this system is decreasing at a rate of dP/ dt = -4.95 × 10-7 d yr-1. The photometric solutions are fairly well fitted at a mass ratio of q = 0.1879, with a fillout factor of f = 17.74%. The results indicate that there exists mass transfer from the more massive component to the less massive one at a rate of relative mass exchange, 6zl/m = -1.09× 10-7 yr-1. It is possible that this weak- contact system, that shows a decreasing orbital period, may undergo contraction of the inner and outer critical Roche lobes and evolve into a deep-contact binary.  相似文献   

pCO_2 and carbon fluxes across sea-air interface in the Changjiang Estuary and Hangzhou Bay   总被引：1，自引：0，他引：1  

高学鲁  宋金明  李学刚  李宁  袁华茂 《中国海洋湖沼学报》2008,26(3)

Partial pressure of CO2(pCO2) was investigated in the Changjiang(Yangtze River) Estuary,Hangzhou Bay and their adjacent areas during a cruise in August 2004,China.The data show that pCO2 in surface waters of the studied area was higher than that in the atmosphere with only exception of a patch east of Zhoushan Archipelago.The pCO2 varied from 168 to 2 264 μatm,which fell in the low range compared with those of other estuaries in the world.The calculated sea-air CO2 fluxes decreased offshore and varied from -10.0 to 88.1 mmol m-2 d-1 in average of 24.4 ± 16.5 mmol m-2 d-1.Although the area studied was estimated only 2 × 104 km2,it emitted(5.9 ± 4.0) × 103 tons of carbon to the atmosphere every day.The estuaries and their plumes must be further studied for better understanding the role of coastal seas playing in the global oceanic carbon cycle.  相似文献   

空间热量测量：地震活动区遥测研究的一种新方法     

С.  АГ 雷文高 《地震地质译丛》1991,13(4):45-48

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