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21.
Five commercially available in Estonia brands of bottled water have been analysed for 59 chemical elements by ICP-QMS and ICP-AES techniques to assess the quality of domestic mineral waters in scope of the European Groundwater Geochemistry Project initiated by the Geochemistry Expert Group of EuroGeoSurveys. Contents of 9 cations and anions, pH and electrical conductivity (EC) were measured in the bottled mineral waters by IC, titration and photometric methods. The data showed a significant difference between natural undiluted mineral water (Värska Originaal) characterised by the highest values of pH, EC and majority of trace elements studied, and other domestic waters sold in Estonia.  相似文献   
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Clean Development Mechanism (CDM) project developers have long complained about the complexities of project-specific baseline setting and the vagaries of additionality determination. In response to this, the CDM Executive Board took bold steps towards the standardization of CDM methodologies, culminating in the approval of guidelines for the establishment of performance standards in November 2011. The guidelines specify a performance standard stringency level for both baseline and additionality of 80% for several priority sectors and 90% for all other sectors. However, an analysis of 14 large-scale CDM methodologies that use performance standard approaches challenges this top-down approach to the performance standard design. An appropriate performance standard stringency level strongly depends on sector and technology characteristics. A single stringency level for baseline and additionality determination is appropriate only for greenfield projects, but not for retrofit ones. Overly simple, highly aggregated performance standards are unlikely to ensure high environmental integrity, and difficult questions regarding stringency and updating frequency will eventually have to be addressed on a rather disaggregated level. A careful balance between data requirements and the practicability of performance standards is essential because the heavy data requirements of the existing performance standard methodologies have been the key barrier to their actual implementation.

Policy relevance

CDM regulators have been pushed by many stakeholders to standardize baseline setting and eliminate project-specific additionality determination. At first glance, performance standards seem to provide the perfect solution for both tasks. However, a one-size-fits-all political decision – e.g. the average of the top 20% performers as enshrined in the Marrakech Accords – is inappropriate. Substantial disaggregation of performance standards is required both technologically and geographically in order to limit over- and under-crediting and close loopholes for non-additional projects. As a lack of reliable and complete data has been and will be a key bottleneck for the development of performance standards, international support for data collection will be indispensable, but costly, and time-consuming. Empirically driven, techno-economic assessments of performance standard stringency levels must be the central task of the future work on standardized methodologies, and should not be sidelined by perceived needs of policy makers to take bold decisions under time pressures.  相似文献   
24.
星载原子频率标准在许多空间系统中担当着重要的角色,其性能和可靠性对这些系统的功能有重要的影响。介绍了广泛使用的星载铷原子频率标准的基本工作原理,分析了影响其可靠性的各种因素,并探讨了提高其可靠性的基本途径。  相似文献   
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Abstract

Richard Edes Harrison. The Ginn World Atlas. Ginn &; Co., Statler Office Bldg., Boston 17, Mass., 1963. 62 pages (single page 7 1/2 × 10 in.) with table of contents, colored maps and index. $1.00.

National Geographic Society. Atlas of the World. National Geographic Society, Washington 6, D.C., 1963. 304 pages, including 115 pages of 11-color maps, with 127,071 place names. With introduction, table of contents, etc. The price for the standard edition in a flexible, leather-grained plastic cover is $18.75. The deluxe edition with hard-backed cover in a matching slipcase and gold-stamped lettering with the owner's name is $24.50.

Mary Louise Clifford. The Land and People of Afghanistan. J. B. Lippincott Company, E. Washington Sq., Philadelphia, Pa., 1962. 160 pages, illustrated with photographs, map and index. $3.25.

Pradyumna P. Karan and William M. Jenkins, Jr. The Himalayan Kngdoms: Bhutan, Sikkim, and Nepal. D. Van Nostrand Co., Inc., 120 Alexander St., Princeton, N.J., 1963. 144 pages with preface, table of contents, appendix, bibliography and index. Included are maps and sketches. $1.45.

Donald B. Cole. Atlas of American History. Ginn and Co., Statler Office Bldg., Boston 17, Mass., 1963. 151 pages with table of contents, maps and index. $1.60. (paperback)

D. M. LeBourdais. Stefansson: Ambassador of the North. Harvest House Limited, 220 Elm Ave., Montreal 6, P. Q., Can., 1962. 204 pages with table of contents, map and index. $2.50 (paperback)

Elvajean Hall. The Land and People of Norway (Portraits of the Nations Series). J. B, Lippincott Co., E. Washington Sq., Philadelphia 5, Pa., 1963. 158 pages with table of contents, one place name map, photographs and index. $3.25.

Sir Alan Burns. Fiji. British Information Services, 845 Third Ave., New York 22, N.Y., 1963. xv and 255 pages with table of contents, illustrations, photographs, drawings, maps, appendices and index. $6.00.

George B. Cressey. Asia's Lands and Peoples. McGraw-Hill Book Company, Inc., 330 West 42nd St., New York 36, N.Y., 1963. 652 pages plus table of contents and index. $9.95.

S. Carl Hirsch. The Globe for the Space Age. The Viking Press, 625 Madison Ave., New York, N.Y., 1963. 88 pages including table of contents, index, drawings, suggestions for further reading and list of globe manufacturers. $8.75.

Cuchlaine A. M. King. An Introduction to Oceanography. McGraw Hill Book Company, Inc., 330 West 42nd Street, New York 36, N.Y., 1963. xii and 337 pages with table of contents, index and illustrations. $7.95.

William Bixby. Waves, Pathways of Energy. David McKay &; Co., Inc., 119 W. 40th St., New York 18, N.Y., 1963. 160 pages, illustrations, suggested further readings index. $3.50.

Hans H. Lansberg, Leonard L. Fischman and Joseph L. Fisher. Resources in America's Future: Patterns of Requirements and Availabilities 1960–2000. Johns Hopkins Press, Baltimore 18, Md., 1963. 1067 pages with black and white and colored ilustrations, table of contents, appendices and index. $15.00.

C. Daryll Forde. Habitat, Economy &; Society. E. P. Dutton &; Co., Inc., 201 Park Avenue South, New York 3, N.Y., 1963. xv and 500 pages with preface, table of contents, illustrations, maps, drawings, chapter references, bibliography and index $2.35.

Patricia Horkheimer Suttles. Educators Guide to Free Science Materials, 4th ed. Educators Progress Service, Randolph, Wis., 1963. XV and 313 pages with publisher's foreword, table of contents, general directions, title index, subject index, source and availability index and eleven units. $7.75.

Irwin Isenberg (associate editor). The Soviet Satellites of Eastern Europe. Scholastic Book Services, Scholastic Magazines, Inc., New York, N.Y., 1963. 159 pages with photographs and index. Sixty-five cents, (paperback)  相似文献   
27.
《The Journal of geography》2012,111(5):169-180
ABSTRACT

Research in the cognition and learning sciences has demonstrated that the human brain contains basic structures whose functions are to perform a variety of specific spatial reasoning tasks and that children are capable of learning basic spatial concepts at an early age. There has been a call from within geography to recognize research on spatial cognition in a meaningful way in primary school curriculum. This article utilizes the spatial thinking taxonomy proposed by Gersmehl and Gersmehl (2006) to examine to the extent to which spatial thinking concepts are being practiced in U.S. schools. The National Geography Standards and forty-nine state social studies or geography standards are examined. Using standards as a measure of geography content, it is concluded that while some of spatial thinking concepts appear often in curriculum, others are largely absent. Designing geography standards that address the findings of spatial cognition research may serve as a means of improving geography instruction.  相似文献   
28.
刘艳  武广臣 《东北测绘》2012,(2):223-225
获取与处理类测量规范是测绘标准体系的核心部分,然而,这些测量规范存在着内容重复、引用复杂、系统性差等缺点,因此,建议将现行的获取与处理类测量规范进行重组。通过分析,将该类测量规范规划为两部分:基础测量规范与专业测量规范,重组后的测量规范系统性强、引用简单、索引明确,对指导测绘生产具有重要意义。  相似文献   
29.
GIS是地理信息服务的有效工具和手段。本文基于开源GIS软件Geoserver和Leaflet,首先,介绍了它们的特点和优势,阐述了地理信息服务的规范;然后,提出了构建与调用地理信息服务的体系框架,研究了服务构建和调用等关键技术;最后,基于烟台市地图数据进行实验,取得了满意的效果。  相似文献   
30.
以艾比湖流域主要入湖河流为研究对象,在5月(丰水期)和8月(枯水期)分别沿博尔塔拉河(博河)和精河进行采样,采用平行因子模型(PARAFAC)和三维荧光区域积分法对水体三维荧光特性进行研究并对其与水质的关系在枯、丰水期下的变化进行探讨.结果表明①河流DOM在枯水期与丰水期都含有C1(240、425 nm) UVC类腐殖质,C2(225、290 nm)紫外区内络氨酸类有机物,C3(230/280、330 nm)蛋白类有机物,C4(265、260 nm)腐殖质类共4种组分.通过对水体三维荧光进行区域积分可以看出DOM荧光成分的占比在不同时期的变化.博河在枯水期时EEM光谱中的区域Ⅲ富里酸含量低于丰水期,枯水期时区域Ⅱ芳香类蛋白质、区域Ⅳ可溶性微生物代谢物以及区域Ⅴ类腐殖质酸高于丰水期;对于精河来说,区域Ⅱ芳香类蛋白质和区域Ⅳ可溶性微生物代谢物在枯水期的含量高于丰水期,区域Ⅲ富里酸和区域Ⅴ类腐殖质酸的含量枯水期低于丰水期,这表明水体腐质化程度较高.②本研究选取了一些常规的荧光指数来描述枯、丰水期水体的荧光指数特性.经研究发现,精河的荧光指数、自生源指数和腐殖化指数在不同时期的变化幅度较小,而博河的变化幅度较大.③将荧光指数与水质参数进行相关性分析并建模,结果表明枯水期自生源指数(BIX)与化学需氧量呈显著正相关,相关系数R=0.688;丰水期时BIX与铵态氮浓度呈显著负相关,相关系数R=-0.493.通过对比分析艾比湖主要入湖河流的三维荧光光谱特性与水质在枯、丰水期时的关系进一步表明水体中DOM的特性以及在枯、丰水期下的差异,为艾比湖流域的治理改善提供一定的理论支持和参考依据.  相似文献   
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