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1.
《The Journal of geography》2012,111(4):168-173
Abstract

This article presents a case study that highlights the benefits and limitations of Web-based video in lab sections of The Geographer’s Craft, an upper-level undergraduate course in which students apply digital geographic methods. Over three years (2010–2013), the authors experimented with different teaching strategies utilizing Web-based video for lab lectures and software demonstrations. This article presents three different approaches for its application, from inside and outside the classroom, to a ”flipped classroom” setting. The authors argue that Web-based video is a valuable tool for teaching digital geographic research methods and techniques while allowing for greater focus on theory and application.  相似文献   

2.
For Svartisen har jeg sokt å foreta en liknende beregning av bremassens minking, som den jeg har foretatt for Jostedalsbreen (Norsk Geografisk Tidsskrift, Bd.VIII, H. 8, 1941, side 273 ff.). Jeg har herunder brukt vannforingsmålinger i Fykanåen i Glomfjord, som har tillop f ra et ganske betydelig omráde, 90 km2, av Svartisen og til sammenlikning målinger i Rosåen, som ligger sonnafor og i Sundsfjordelven nordafor.  相似文献   

3.
No.!Thirty Years In Geomornholosv In the Peonl,’s Renubllc ot China……………………… She。y。ckans(13)Formation and Development of the Settlements of Shaoxing Area In Historical Periods………………··’………·’…’··’··’··’…··’……”··‘…··’·’·’……’…·’··’…………………………………………Che。Qiaoyi(23)Formatloll and Dlstrlbutlon ofChemlcal Precipitates Insolls andQuaternary Sediments In NorthetnChina…·,……………………………………………………  相似文献   

4.
泥石流直墙V型排导槽横断面优化设计   总被引:3,自引:0,他引:3  
游勇  柳金峰 《山地学报》2008,26(2):218-222
排导槽横断面的形状及尺寸是泥石流排导槽设计的重要参数,如何合理选择过流断面的形状和尺寸,使泥石流排导槽具有最佳的排泄能力,目前国内外的研究还比较少涉及.直墙V型断面排导槽是目前泥石流防治工程中广泛采用的横断面形状之一,以其为研究对象,对它的水力条件进行了分析,并对横断面的优化设计进行了探讨.泥石流排导槽的断面形态系数(M)定义为湿周(P)与水力半径(R)之比,直墙v型排导槽水力最佳时相应的断面形态参数M=[8(1 m2v)1/2-4]/mv直墙"V"型排导槽水力条件最佳时的断面形态参数M仅与槽底横坡系数有关.假定在已知泥石流直墙V型排导槽排泄流量Q、槽底纵比降I以及泥石流体颗粒级配特征的条件下,推导出了联合求解最优水力条件下直墙V型槽断面形态尺寸的组合公式,并以大渡河上游左岸的一级支沟把丫沟为例,对该沟的泥石流排导槽横断面进行了优化设计.  相似文献   

5.
Ingrid Semmingsens verk »Veien mot vest« er en moderne og vel underbygget avhandling om utvandringen fra Norge. Annen del som kom i 1950, behandler tida 1865—1915.1 Enhver norsk historiker som behandler dette tidsrommet, vil komme bort i problemer som står i forbindelse med utvandringen.

Ingrid Semmingsen søker å, belyse utvandringsproblemet fra alle sider. Bl. a. gir hun en klar framstilling av hvordan utvandrerstrommen varierte med konjunkturene i Norge og Amerika. Også det sosiale miljø på begge sider blir belyst. En kan lajre meget av kulturgeografisk interesse ved a studere hennes verk.

Likevel er avhandlingen i forste rekke et historisk verk. De kulturgeografiske forhold tas med som et nodvendig ledd for a forklare den historiske utvikling.

Det fins uhyre mengder av spredte opplysninger som lokalhistorikere og bygdegeografer kan utnytte når de skildrer utvandringen og dens betydning for et begrenset område i Norge. For landet som helhet er det nodvendig å, søke til »Veien mot vest« og til offisiell statistikk og utredninger.  相似文献   

6.
ICESat/GLA14是具有较高精度的海拔高程点,以吕梁山为研究区,对该区域内ICESat/GLA14 v33和ICESat/GLA14 v34数据进行了高程差统计,并对其随地形因子、NDVI和土地利用类型的不同分类所发生的变化进行了统计分析。结果表明:高程值2 000 m时,高程差绝对误差均值相对稳定,当高程值在2 000~3 500 m时,绝对误差均值在逐渐增大,随着坡度的不断增加,高程差均值由0.004 m逐渐上升到0.009 m,在平坦区域高程差均值为0.002 m,在其他区域为0.007 m,高程差在植被覆盖区均值和标准差相对较高,即高程差随着高程增加、坡度的上升逐渐增大,且该数据在平坦区域精度明显较高,同时受植被覆盖影响较大。  相似文献   

7.
In the 1920's the Swedish geologist Lennart von Post found evidence of irregular early Holocene isostatic uplift in the region northwest of Lake Vänern in western Sweden. von Post based his conclusions on levellings of ancient shore lines. These were indirectly dated by pollen stratigraphical investigations in basins situated at approximately the same altitudes as the shore lines. To test von Post's hypothesis, we have adopted a different methodological approach. The sediments in twelve small lake basins, within five minor areas in this region, have been investigated with respect to when they became isolated from ancient Lake Vänern. Initially all the lake thresholds were levelled. Altitudes range between 165 and 96 m above sea level. By combining the results of mineral magnetic and diatom stratigraphical analyses it has been possible to determine the level in the sediment when the basin became isolated. The 14C age of this isolation level has been inferred from AMS dates based on the NaOH-soluble fraction of bulk sediment, partly with very low organic content. Altogether, 36 radiocarbon datings have been carried out, ranging from 10080 to 8800 14C years BP. Pollen analyses, and subsequent correspondence analysis (CA) of all pollen spectra, were carried out around the isolation level in each basin as a complement to the AMS datings.If the region had been subject to irregular isostatic uplift, lakes at the same altitude in the five areas should have been isolated at different times. The AMS determined isolation ages, corrected according to CA of the pollen stratigraphy and compensated for the relatively higher rebound of the northerly situated sites support von Post's conclusion, from the beginning of this century, that the region northwest of Lake Vänern has been subjected to irregular isostatic uplift.  相似文献   

8.
达里湖是达里诺尔湿地的重要组成部分.根据2019年达里湖鱼类多样性调查的结果,研究了达里湖鱼类物种资源、种类组成和区系生态类群多样性以及物种分布特征,分析了达里湖鱼类多样性的形成机制及其与水体盐碱化的关系,探讨了达里湖鱼类多样性的动态及其持续健康发展途径.研究结果表明,2019年,达里湖中有鱼类2目3科12属12种,由...  相似文献   

9.
大气运行最根本的原动力是太阳辐射能。进入大气的太阳辐射,部分被反射回太空,部分被大气圈、水圈和陆圈吸收。在大气圈、水圈和陆圈的吸收中,海洋占据了大部分。海洋吸收的太阳辐射,一方面使其本身增暖,同时又通过海洋和大气(以下简称海-气)的  相似文献   

10.
大气运行最根本的原动力是太阳辐射能。进入大气的太阳辐射,部分被反射回太空,部分被大气圈、水圈和陆圈吸收。在大气圈、水圈和陆圈的吸收中,海洋占据了大部分。海洋吸收的太阳辐射,一方面使其本身增暖,同时又通过海洋和大气(以下简称海-气)的  相似文献   

11.
In 2013, we celebrate the 50th anniversary of the publication of V. B. Sochava’s first paper in which he offered the definition of the term “geosystem”. His paper entitled “The definition of some notions and terms in physical geography” remains one of the most frequently cited articles in the national geographical literature. The concept of the geosystem was included in encyclopedias. The geosystem ideology is used in training of specialists in the field of geography.  相似文献   

12.
采用溶胶-凝胶-自蔓延燃烧法和固相法制备了LiNi0.5Mn1.5O4,XRD图谱表明由溶胶-凝胶-自蔓延燃烧法得到纯相的LiNi0.5Mn1.5O4,而用固相法制成的LiNi0.5Mn1.5O4中含杂相物质。采用恒流充放电和倍率放电等分析方法对LiNi0.5Mn1.5O4/Li电池进行测试。结果表明溶胶-凝胶-自蔓延燃烧法制备的样品所组装电池放电容量较高,工作电压较高,循环稳定性较好,且倍率性能优良。  相似文献   

13.
李鹏  刘颖  施冬  肖池伟 《地理研究》2022,41(5):1481-1495
MODIS C6、VIIRS V1和VIIRS J1是NASA火灾信息资源管理系统(FIRMS)2020年首次同步发布的三套全球活跃火遥感产品。鉴于卫星过赤道时间、空间分辨率、火情监测算法有别,分析MODIS和VIIRS不同活跃火产品监测结果一致性和差异性,对明确不同火产品的适用性至关重要。利用中南半岛同年活跃火矢量产品,通过GIS渔网(1 km)定量分析不同时间尺度(全年、旱/雨季和昼/夜)活跃火发生的频次与强度特征,横向对比了三套活跃火产品的一致性与差异。结果表明:① 中南半岛三套产品逐月发生频次一致性最高,逐日次之,逐时最低。全年“有火区”格网占比37.23%,其中VIIRS相应比重三倍于MODIS,且J1略高于V1。三套产品两两比较时,VIIRS V1/VIIRS J1组合总体一致性最高,VIIRS J1/MODIS C6组合一致性最低。② 三套产品旱季“有火区”占比、活跃火发生频次与强度均显著高于雨季,且VIIRS V1与J1活跃火发生强度空间分布一致性更高。旱季V1活跃火累积发生频次最高、发生强度更强;雨季J1相应频次最高,发生强度较强。③ 三套产品白天“有火区”占比、活跃火累积发生频次均高于夜间,发生强度空间分布一致性亦高于夜间,其中VIIRS V1与J1夜间一致性最高。且昼/夜V1活跃火累积发生频次和“有火区”占比均最高,但J1发生强度最强。④ VIIRS V1与J1监测精度更高,空间覆盖范围更广,且VIIRS V1更适用于旱季、白天和夜间活跃火相关研究,而VIIRS J1对雨季活跃火的探测水平更高,但MODIS C6的优势在于历史数据丰富。  相似文献   

14.
15.
As they increase in popularity, social media are regarded as important sources of information on geographical phenomena. Studies have also shown that people rely on social media to communicate during disasters and emergency situation, and that the exchanged messages can be used to get an insight into the situation. Spatial data mining techniques are one way to extract relevant information from social media. In this article, our aim is to contribute to this field by investigating how graph clustering can be applied to support the detection of geo-located communities in Twitter in disaster situations. For this purpose, we have enhanced the fast-greedy optimization of modularity (FGM) clustering algorithm with semantic similarity so that it can deal with the complex social graphs extracted from Twitter. Then, we have coupled the enhanced FGM with the varied density-based spatial clustering of applications with noise spatial clustering algorithm to obtain spatial clusters at different temporal snapshots. The method was experimented with a case study on typhoon Haiyan in the Philippines, and Twitter’s different interaction modes were compared to create the graph of users and to detect communities. The experiments show that communities that are relevant to identify areas where disaster-related incidents were reported can be extracted, and that the enhanced algorithm outperforms the generic one in this task.  相似文献   

16.
17.
前4次文章我们获得并讨论了用于六元体系溶解度计算合理的单独电解质Pitzer参数,及四元交互体系Na+,K+//Cl-,NO3--H2O、K+,Mg2+//NO3-,SO42--H2O、K+,Mg2+//NO3-,Cl--H2O混合参数和它们的应用.此次报道在K+//Cl-,NO3-,SO42-H2O、Mg2+//Cl-,NO3-,SO42--H2O同离子四元体系溶解度预测中的应用.前一个是简单共饱型四元体系,热力学预测表明在后一体系中应有MgSO4·6H2O(Hexahydrite)存在.  相似文献   

18.
前4次文章我们获得并讨论了用于六元体系溶解度计算合理的单独电解质Pitzer参数,及四元交互体系Na^+,K^+∥Cl^-,NO3^--H2O、K^+,Mg^2+∥NO3^-,SO4^2--H2O、K^+,Mg^2+∥NO3^-,Cl^--H2O混合参数和它们的应用。此次报道在K^+∥Cl^-,NO3^-,SO4^2--H2O、Mg^2+∥Cl^-,NO3^-,SO4^2--H2O同离子四元体系溶解度预测中的应用。前一个是简单共饱型四元体系,热力学预测表明在后一体系中应有MgSO4·6H2O(Hexahydrite)存在。  相似文献   

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