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131.
Determining the optimum weight of the armor blocks is of vital importance in the design of conventional breakwaters. The widely used formulae in the literature include the transition region from plunging to surging waves. In this paper, it is aimed to investigate a new design formula without any transition region as an alternative to widely used Van der Meer formulae. The dimensionless parameters of Van der Meer formulae as well as newly generated variables are used as inputs. Nonlinear surface fit best subset regression model is used to find the optimum input combination that keeps the nonlinear relationships. All the input parameters, their second powers, and their two-way interactions are included in the regression analyses to obtain a nonlinear surface fit. Various goodness of fit statistics are applied to check the different perspectives of the model accuracy. It is demonstrated that the proposed model gives a realistic prediction of the stability number for critical data range. Especially for high values of stability number the proposed formula outperforms the benchmark formulae of Van der Meer and Etemad-Shahidi and Bonakdar. The other advantage is that it does not contain any transition region that depends on wave conditions. Besides, there is no need to include “number of waves” and “permeability” parameters into the equation. 相似文献
132.
中软地层绳钻钻头长寿高效的实现与认识 总被引:1,自引:0,他引:1
煤炭系统绳钻效率一直较低。陕西煤田地质局在中软地层钻进中采取:严防金刚石碳化、坚持磨修孔、实行启动规程等措施以延长钻头寿命,提高纯钻进率;同时对人造金刚石孕镶、天表、复合片三种代表性钻头分别按高、中、低速型优选规程指导钻进,并据钻头磨损率在不影响足够寿命的前提下,使用弱磨大参数等适当形式的"大规程"来尽力增大时效。因此,"七·五"期间,陕煤地质局在实现绳钻钻头长寿高效、确保较好地开展绳钻钻进方面取得了显著的成绩。 相似文献
133.
重点介绍了福建省121地质大队在"十一五"期间,紧跟国内科技前沿,积极开展绳索取心煤田深孔钻探技术研究,通过钻探技术创新,新工艺、新技术推广应用和深化钻探管理模式改革,取得了钻探深孔施工能力和钻探效益的显著提高。 相似文献
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136.
福建煤田地质121队在福建、云南、贵州、四川等省份的复杂煤田勘探区推广应用绳索取心金刚石钻进技术,取得了较好的应用效果。通过分析云、贵、州、闽地区的地层特点,介绍了该类地区钻孔结构、冲洗液技术及护壁堵漏技术。在钻具配套、硬岩钻进等方面也进行了有效的探索,并以实例和大量数据说明121队在绳钻技术方面的应用水平。 相似文献
137.
日本最新滑坡调查及防治对策技术——赴日本考察地质灾害监测防治技术报告 总被引:1,自引:0,他引:1
张燕 《中国地质灾害与防治学报》2007,(Z1)
日本的国土面积为38万km2,其中73%是山地与丘陵,可居住面积很小。日本近海的板块运动,使其成为世界上寥寥可数的地震及火山活动多发地带的自然灾区,同时还形成了地壳极为脆弱的日本列岛。这种自然环境及为有效利用狭窄的国土而进行的人类活动,导致了非常多的各种灾害。在滑坡调查方面,最近开发出以提高精度为目标的新的调查方法:①激光高程测量法。通过激光测量可以制作出反映微地形的平面图;②泡沫钻孔采取高质量岩心,实现对滑坡土块的地质构造的正确解释;③滑坡自动观测预警系统。在滑坡防治对策方面,最近开发出以作业的安全化、高效化为目的的施工方法:无人化施工及大口径钢管桩治理滑坡。 相似文献
138.
根据我国地质钻探任务不断增加和向地层深部找矿的需求,研制了XD-3型全液压动力头式岩心钻机。介绍了该钻机的结构设计、工作原理、主要特点以及使用情况。 相似文献
139.
在中国大陆科学钻探工程“科钻一井”的钻井施工中,形成了独具中国特色的新型科学钻探技术体系。详细论述了该新型科学钻探技术体系的具体内容及其在“科钻一井”施工中取得的主要技术指标;简要介绍了目前国内正在或即将实施的科学钻探工程项目情况;结合即将出台的《国务院关于加强地质工作的决定》和2005年已启动的危机矿山接替资源的找矿勘查工作计划,展示了探矿工程广阔的前景。 相似文献
140.
Since 1991 volunteers from the Canadian Gas Potential Committee (CGPC) have conducted assessments of undiscovered gas potential
in Canada. Reports were published in 1997 and 2001. The 2001 CGPC report assessed all established and some conceptual exploration
plays in Canada and incorporated data from about 29,000 discovered gas pools and gas fields. Mainly year-end 1998 data were
used in the analysis of 107 established exploration plays. The CGPC assessed gas in place without using economic cut offs.
Estimates of nominal marketable gas were made, based on the ratio between gas in place and marketable gas in discovered pools.
Only part of the estimated nominal marketable gas actually will be available, primarily because of restrictions on access
to exploration and the small size of many accumulations.
Most plays were assessed using the Petrimes program where it could be applied. Arps-Roberts assessments were made on plays
where too many discovered pools were present to use the Petrimes program. Arps-Roberts assessments were corrected for economic
truncation of the discovered pool sample. Several methods for making such corrections were tried and examples of the results
are shown and compared with results from Petrimes.
In addition to assessments of established plays, 12 conceptual plays, where no discoveries have been made, were assessed using
Petrimes subjective methodology. An additional 65 conceptual plays were recognized, discussed, and ranked without making a
quantitative assessment. No nominal marketable gas was attributed to conceptual plays because of the high risk of failure
in such plays.
Nonconventional gas in the form of coalbed methane, gas hydrates, tight gas, and shale gas are discussed, but no nominal marketable
gas is attributed to those sources pending successful completion of pilot study projects designed to demonstrate commercially
viable production.
Conventional gas resources in Canada include 340 Tcf of gas in place in discovered pools and fields and 252 Tcf of undiscovered
gas in place. Remaining nominal marketable gas includes 96 Tcf in discovered pools and fields and 138 Tcf of undiscovered
nominal marketable gas. The Western Canada Sedimentary Basin holds 61% of the remaining nominal marketable gas. Future discoveries
from that area will be mainly in pools smaller than 2.5 Bcf of marketable gas and increasing levels of exploratory drilling
will be required to harvest this undiscovered resource.
A pragmatic, geologically focussed approach to the assessment of undiscovered gas potential by the CGPC provides a sound basis
for future exploration and development planning. Peer reviewed assessment on a play-by-play basis for entire basins provides
both detailed play information and the ability to evaluate new exploration results and their impact on overall potential. 相似文献