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371.
用RINEX HO软件计算GPS载波相位观测值中的高阶(二阶和三阶)电离层延迟,在此基础上组成GPS双差观测值中的高阶电离层延迟(ΔIH)p,qi,g。讨论了(ΔIH)p,qi,g与地磁纬度、基线长度、基线方向及太阳活动水平间的关系。在其他条件均相同的情况下,用Bernese 5.0软件分别对进行了高阶电离层延迟改正的观测值和未进行高阶电离层延迟改正的观测值进行基线解算,求得高阶电离层延迟对基线向量解的影响ΔbH。结果表明,ΔbH的数值很小,在一般情况下可忽略不计。ΔbH与基线长度及太阳活动水平等因素间并无必然联系,但随着时段的减小,ΔbH会随之增大。  相似文献   
372.
Based on the observational data as well as data of satellite, NCEP reanalysis and moist potential vortex, the heavy rainfall event that occurred away from the outer cycle of tropical depression Kaemi (No.0605) on July 27, 2006 in Shandong Peninsula has been analyzed. The results show that there are three severe convective cloud clusters during the heavy rainfall. The uprightness of coupling pattern between upper-layer jet and low jet and a divergence area, which appeared in the right of upper-layer jet, provided favorable environmental conditions for convective cloud clusters. The strong convective weather happens over the prefrontal warm sector and the storm rainfall mainly distributes in the front of a high-energy area.Positive vorticity distribution and transportation of warm advection in low levels provide dynamic and thermal conditions for the rainstorm. The spatial-temporal evolvements of physical variable fields and MPV2 as the horizontal component of moist potential vorticity show that the rain intensity change is determined by upper and low level jets and the area of MPV2>0 occurs at the front of the low jet cores.  相似文献   
373.
藏西南纳木那尼峰地区第四纪以来经历了多阶段的冰川演化,遗留了各个阶段不同类型的冰川堆积地貌和冰川侵蚀地貌。文章通过对各阶段冰积地貌的分布范围、特征的描述,并根据保存程度确定其相对地貌年龄,初步认为本地区第四纪以来倒数第3次冰期发育了规模最大的冰原冰川,倒数第2次冰期时冰原缩小并逐渐解体,末次冰期以来完全解体为山谷冰川。根据本地区槽谷的形态特征及冰川堆积物的分布,认为本地区末次间冰期前后有一次活跃的构造运动。  相似文献   
374.
侯增谦 《地球化学》1996,25(3):228-241
选择西南太平洋冲绳海槽现代海底烟囱硫化物矿床、日本小坂矿山上向黑矿(第三纪)和中国西南呷村黑矿型矿床(三叠纪)进行了矿石地球化学比较研究。黑矿型矿床矿石吨位-品位模式与其他火山成因块状硫化物(VMS)矿床类似,矿田(20-50km^2)矿石吨位与单个喷气-沉积型(Sedex)矿床相当,金属总量4-6Mt,为矿田范围内热液流体搬运的最大金属量。与洋脊环境VMS矿床相比,岛弧裂谷环境产出的黑矿型矿床相  相似文献   
375.
钓鱼岛石是在我国台湾省钓鱼岛附近海域海底表层沉积物中发现的一种新矿物。钓鱼岛石为无色淡绿色到,薄板状,一轴晶负光性,晶体很小,一般在0.4×0.2×0.03mm~3以下,D=3.30,H_(v15)=1392.8kg/mm~2。电子探针定量分析(以相应氧化物为标样)结果(%):Na_2O4.54、Al_2O_3 93.00、Cr_2O_31.95、MgO0.10、CaO 0.10、SiO_2 0.23、K_2O 0.12,总量100.04。以氧为17计算的化学式为(Na_(0.87) K_(0.02) Mg_(0.02) Ca_(0.01);)_(0.92)(Al_(10.84)Cr_(0.15)Si_(0.02))_(11.01)O_(17)。经四圆单晶衍射证明,该矿物为六方晶系,空间群为P6_3/mmc,a=b=5.602(1)Ac=22.626(5)A,α=β=90°,γ=120°。  相似文献   
376.
In this paper, we mainly summarize and review the progresses in recent climatological studies (by CMSR, IAP/CAS and some associated domestic and international institutions) on the interannual and interdecadal variabilities of monsoon troughs and their impacts on tropical cyclones and typhoons (TCs) geneses over the western North Pacific Ocean. The climatological characteristics of monsoon troughs and four types of circulation patterns favorable to TCs genesis over the western North Pacific Ocean in summer and autumn are given in this paper. It is also shown in this paper that the monsoon trough over the western North Pacific Ocean has obvious interannual and interdecadal variabilities. Especially, it is revealed in this paper that the interannual and interdecadal variabilities of the monsoon trough over the western North Pacific Ocean influence the TCs genesis not only through the impact on distributions of the vorticity in the lower troposphere and the divergence in the upper troposphere, the water vapor in the mid- and lower troposphere and the vertical shear of wind fields between the upper and lower troposphere over the western North Pacific Ocean, but also through the dynamical effects of the transition between convectively coupled tropical waves and providing disturbance energy. Besides, some climatological problems associated with TCs activity over the western North Pacific Ocean that need to be studied further are also pointed out in this paper.  相似文献   
377.
A heavy rainfall event that occurred in Shandong Province in 26 28 August 2004 was caused mainly by Typhoon Acre and cold air activities related to a westerly trough. The event was triggered by an inverted typhoon trough, which was closely associated with the intensification of the low-level southeasterly flow and the northward transport of heat and momentum in the periphery of the typhoon low. A numerical simulation of this event is performed using the nonhydrostatic mesoscale model MM5 with two-way interactive and triply-nested grids, and the structure of the inverted typhoon trough is studied. Furthermore, the formation and development mechanism of the inverted typhoon trough and a mesoscale vortex are discussed through a vorticity budget analysis. The results show that the heavy rainfall was induced by the strong convergence between the strong and weak winds within the inverted typhoon trough. Dynamic effects of the low-level jet and the diabatic heating of precipitation played an important role in the development of the inverted typhoon trough and the formation of the mesoscale vortex. The vorticity budget analysis suggests that the divergence term in the low troposphere, the horizontal advection term, and the convection term in the middle troposphere were main contributors to positive vorticity. Nonetheless, at the same pressure level, the effect of the divergence term and that of the adveetion term were opposite to each other. In the middle troposphere, the vertical transport term made a positive contribution while the tilting term made a negative contribution, and the total vorticity tendency was the net result of their counteractions. It is found that the change tendency of the relative vorticity was not uniform horizontally. A strong positive vorticity tendency occurred in the southeast of the mesoscale vortex, which is why the heavy rainfall was concentrated there. The increase of positive vorticity in the low (upper) troposphere was caused by horizontal convergence (upward transport of vorticity from the lower troposphere). Therefore, the development of the inverted typhoon trough and the formation of the mesoscale vortex were mainly attributed to the vorticity generated in the low troposphere, and also the vertical transport of vorticity from the low and middle troposphere.  相似文献   
378.
地电场多极距观测的异常识别和分析   总被引:1,自引:0,他引:1  
李伟  马钦忠  王冠玥 《中国地震》2014,30(1):91-101
以上海地区的3个地电场观测台站的资料为例,结合地电场多极距观测原理对地电场信号异常进行识别分析。结果表明,利用地电场多极距观测装置系统和分析方法可以有效识别并区分地电场观测中的电极极化干扰、雷击干扰、高压直流输电干扰、电离层扰动干扰和自然电场异常等信号。  相似文献   
379.
针对强电离层延迟影响周跳探测与修复精度的问题,本文基于北斗三频数据特性构建了无几何消电离层组合,并对其组合系数进行了筛选。然后,联合MW(Melbourne-Wbbena)组合和电离层残差法构建周跳检验量实现对北斗三频实测数据的周跳探测与修复。在试验过程中通过设置不同类型的周跳组合对本文算法进行全面有效地检验。试验结果表明:本文算法能够探测出所有大小的周跳,包括不敏感周跳,并能将其完整地修复。  相似文献   
380.
早前寒武纪古地热状态的构造环境意义   总被引:2,自引:0,他引:2  
白瑾 《地学前缘》1999,6(4):323-330
区域变质作用是在造山运动中地热流和动力联合作用的体现。在早前寒武纪的造山带中,随着地壳的缩短,古地热流向构造边界聚敛,形成由高温到低温的区域变质相带序列,它既指示古地热流运移的方向,又是构造边界的指向。古地热流值的高低同构造环境的性质有关,如陆内裂陷带的区域变质仅达绿片岩相,而陆缘活动带的则可高达角闪岩相。古地热流从活动带的边界向中心运移,具有向心性,随着构造层的深埋,构成地热槽,它的片段则表现为地热斜。识别这些古地热状态,可为构造环境属性的鉴定提供有力的依据  相似文献   
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