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351.
宿迁市文体馆基础隔震非线性时程分析研究 总被引:1,自引:0,他引:1
宿迁市文体馆4500座位,约13000m^2,位于8度抗震设防区,主体结构为钢筋混凝土结构空间框架,钢网壳屋盖。该工程采用基础隔震技术设计,在桩基顶面与上部结构之间设置架空层,用作安置设备管道及隔震层。隔震层由叠层橡胶隔震支座和粘滞阻尼器组成。对主体结构基础隔震采用空间模型非线性时程分析方法进行了详细分析,结果表明:采用基础隔震措施可显著降低结构地震作用,上部结构水平地震作用减震系数可按0.25采用;设置附加粘滞阻尼器能较好地解决降低地震作用和限制隔震层位移之间的矛盾,对提高隔震体系的性能具有重要作用。技术经济比较表明,本工程采用基础隔震措施,具有明显的社会、经济效益。 相似文献
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354.
Humin Zong Xindong MaGuangshui Na Chuanlin HuoXiutang Yuan Zhifeng Zhang 《Marine pollution bulletin》2014
Polycyclic aromatic hydrocarbons (PAHs) were detected in water and sediment samples collected from three mariculture zones in China’s northern Yellow Sea. In these samples, total PAH concentrations ranged from 110.8 ng/L to 997.2 ng/L and 142.2 ng/g dry weight (dw) to 750.2 ng/g dw, respectively. The log KOC values of the various PAH compounds examined in this study increased with the log KOW values, which is consistent with the prediction regarding PAH behavior in the environment. However, these KOC values were lower than the predicted values as a result of the effects of organic matters, which were abundant in the mariculture water. The isomeric ratios of the PAHs in sediment indicated that the source of the PAHs in the mariculture zones were mainly pyrolytic. The TEQcarc values of PAHs ranged from 7 ng TEQ/g dw to 92 ng TEQ/g dw, and only a few samples met the safe criterion with respect to individual PAH concentrations. 相似文献
355.
QiuGang Zong YiXin Hao Hong Zou SuiYan Fu XuZhi Zhou Jie Ren LingHua Wang ChongJing Yuan ZhiYang Liu XiangHong Jia Lin Quan Ying Liu YongFu Wang 《中国科学:地球科学(英文版)》2016,59(7):1508-1516
In cases where substorm injections can be observed simultaneously by multiple spacecraft,they can help elucidate the potential mechanisms of particle transport and energization,of great importance to understanding and modeling the magnetosphere.In this paper,using data returned from the BeiDa-IES(BD-IES) instrument onboard a satellite in an inclined(55°) geosynchronous orbit(IGSO),in combination with two geo-transfer orbiting(GTO) satellite Van Allen Probes(A and B),we analyze a substorm injection event that occurred on the 16 th of October 2015.During this substorm injection,the IGSO onboard BD-IES was outbound,while both Van Allen Probe satellites(A and B) were inbound,a configuration of multiple trajectories that provides a unique opportunity to simultaneously investigate both the inward and outward radial propagation of substorm injection.Indicated by AE/AL indices,this substorm was closely related to an IMF/solar wind discontinuity that showed a sharp change in IMF Bz direction to the north.The innermost signature of this substorm injection was detected by Van Allen Probes A and B at L-3.7,while the outermost signature was observed by the onboard BD-IES instrument at L~\0.These data indicate that the substorm had a global,rather than just local,effect.Finally,we suggest that electric fields carried by fast-mode compressional waves around the substorm injection are the most likely candidate mechanism for the electron injection signatures observed in the inner- and outermost inner magnetosphere. 相似文献
356.
Effects of Soil Rhizosphere Aeration on the Root Growth and Water Absorption of Tomato 总被引:3,自引:0,他引:3
Soil rhizosphere aeration status is an important aspect of soil quality and soil ecology. The objective of the current study was to determine the appropriate moisture environment that facilitates rhizosphere soil aeration and ensures normal root respiration in tomato. In the potted experiment, five treatments of soil aeration were used (0.4, 0.8, 1.2, 1.6 ventilation volume of 50% porosity of soil, and no ventilation) under conditions of the different soil moisture upper limits. The effects of different rhizosphere soil aerations on the physiological indicators and water absorption of tomato were studied. Under the same soil moisture condition, plant growth and root vitality initially increased, and then decreased when the soil ventilation volume increased. The combination of soil moisture with 80% of field capacity and 0.8 ventilation volume with 50% soil porosity raised the chlorophyll content by 29.98% and the root vitality by 61.55%, as compared with the non‐ventilated treatment. Therefore, the appropriate volume of rhizosphere ventilation can effectively improve the capacity of water absorption in tomato. The result provides a new view about soil quality and soil ecology in terms of soil–root system. 相似文献
357.
Hou Kangming Zong Kaihong Guo Jiangning Xiong Zhen Li Limei Zhou Caixia Jiang Bo 《中国地震研究》2009,23(1):78-86
The Changjiang fault zone, also known as the Mufushan-Jiaoshan fault, is a famous fault located at the southern bank of the Changjiang River, near the Nanjing downtown area. Based on multidisciplinary data from shallow artificial seismic explorations in the target detecting area (Nanjing city and the nearby areas), trenching and drilling explorations, classification of Quaternary strata and chronology dating data, this paper provides the most up-to-date results regarding activities of the Changjiang fault zone, including the most recent active time, activity nature, related active parameters, and their relation to seismic activity. 相似文献
358.
对非径向脉动δScuti(盾牌座δ)型变星4CVn的最新光电测光观测,证实了其振幅和周期的长期缓慢变化.两种多重频率分析方法都一致确认出已知7个频率中的5个(f1,f2,f3,f5,f7).观测还发现三个可疑频率.目前主频的振幅和十几年前的一样,基本保持不变,可能正处于向最大振幅变化的增加阶段或者处于刚过极大的下降段.其它四个频率的振幅都不同程度地变大.f2,f3和f5的振幅增幅分别为63%,25%和120%,尤其是f7,从上次的0变为0.009mag.频率分析显示除主频f1几乎未变外,其它频率缓慢变化:f2和f7约减小0.08%;f3减小0.14%;f5增加0.03%.用Blazhko效应和不同非径向脉动模式之间的共振解释振幅和周期变化的合理性,尚需进一步从观测上检验. 相似文献
359.
Q. G. Zong T. A. Fritz A. Korth P. W. Daly M. Dunlop A. Balogh J. F. Fennell J. D. Sullivan R. W. H. Friedel H. Reme 《Surveys in Geophysics》2005,26(1-3):215-240
Energetic electrons (e.g., 50 keV) travel along field lines with a high speed of around 20 REs−1. These swift electrons trace out field lines in the magnetosphere in a rather short time, and therefore can provide nearly instantaneous information about the changes in the field configuration in regions of geospace. The energetic electrons in the high latitude boundary regions (including the cusp) have been examined in detail by using Cluster/RAPID data for four consecutive high latitude/cusp crossings between 16 March and 19 March 2001. Energetic electrons with high and stable fluxes were observed in the time interval when the IMF had a predominately positive Bz component. These electrons appeared to be associated with a lower plasma density exhibiting no obvious tailward plasma flow (<20 keV). On the other hand, no electrons or only spike-like electron events have been observed in the cusp region during southward IMF. At that time, the plasma density was as high as that in the magnetosheath and was associated with a clear tailward flow. The fact that no stable energetic electron fluxes were observed during southward IMF indicates that the cusp has an open field line geometry. The observations indicate that both the South and North high latitude magnetospheric boundary regions (including both North and South cusp) can be energetic particle trapping regions. The energetic electron observations provide new ways to investigate the dynamic cusp processes. Finally, trajectory tracing of test particles has been performed using the Tsyganenko 96 model; this demonstrates that energetic particles (both ions and electrons) may be indeed trapped in the high latitude magnetosphere. 相似文献
360.
陕西大茅坪铜矿床赋存于中元古代碧口群火山岩中,是陕西勉略宁三角区西部较典型的铜矿之一,对该矿床的研究有助于有效地指导在本区寻找同类型矿床。文中对原生晕分析数据,物探测量数据进行了不同方法的处理,在此基础上提出了综合找矿模型。其中对原生晕,通过不同方法建立了地球化学背景与异常的概率筛分模型,因子分析及元素组合模型、标准化丰度法及轴向分带模型;对物探数据进行线性加权组合建立了综合物探异常并运用该模型进行了初步预测。 相似文献