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421.
《Marine Policy》2015
Feedbacks occur when advocates engage to clarify the implementation of a policy innovation such as the requirement that federal activities be consistent with objectives of state coastal management plans. Discrete policy feedbacks include advocacy, litigation, appeals of decisions as well as other activities inserted into policy implementation by interests or government agencies acting in their behalf. Feedback analysis is applied to the time after the passage of the 1972 U.S. Coastal Zone Management Act. Conflicts after passage of the law resulted in a negative feedback in the form of a Supreme Court decision in 1984 and a subsequent positive feedback through the 1990 revision of the law effectively reversing the Court decision. New insights documented here suggest that feedback switching, wherein old disputes are moved to new arenas, provides the greatest opportunity for overcoming negative feedbacks that could diminish or eliminate the policy innovation. Furthermore observing feedbacks through time and across multiple policy spaces as demonstrated here provides a robust interpretation of policy evolution from a new perspective. This analysis demonstrates how feedbacks convert a voluntary state program into one with authority over certain federal actions. These findings will be important for other areas of coastal policy and, more broadly, policy evolution in general. 相似文献
422.
Mid-Holocene ocean feedback on global monsoon area, global monsoon precipitation(GMP), and GMP intensity(GMPI) was investigated by a set of numerical experiments performed with the Community Climate System Model version 4. Results showed that ocean feedback induced an increase in land monsoon area for northern Africa but a decrease for Asia and North and South America, and led to an increase in ocean monsoon area for the western Indian Ocean and southeastern Pacific but a decrease for the eastern Indian Ocean, tropical western Pacific, and tropical West Atlantic between the mid-Holocene and pre-industrial period. Dynamic oceaninduced changes in GMP and GMPI were 10.9×109 m3 d-1and-0.11 mm d-1 between the two periods, respectively.Ocean feedback induced consistent change between the Northern and Southern Hemisphere land or ocean but opposite change between land and ocean in the Northern or Southern Hemisphere monsoon areas for monsoon precipitation. The mid-Holocene summer changes in meridional temperature gradient and land-sea thermal contrast were the underlying mechanisms. 相似文献
423.
Based on surfaced-related multiple elimination (SRME),this research has derived the methods on multiples elimination in the inverse data space.Inverse data processing means moving seismic data from forward data space (FDS) to inverse data space (IDS).The surface-related multiples and primaries can then be separated in the IDS,since surface-related multiples will form a focus region in the IDS.Muting the multiples energy can achieve the purpose of multiples elimination and avoid the damage to primaries energy during the process of adaptive subtraction.Randomized singular value decomposition (RSVD) is used to enhance calculation speed and improve the accuracy in the conversion of FDS to IDS.The synthetic shot record of the salt dome model shows that the relationship between primaries and multiples is simple and clear,and RSVD can easily eliminate multiples and save primaries energy.Compared with conventional multiples elimination methods and ordinary methods of multiples elimination in the inverse data space,this technique has an advantage of high calculation speed and reliable outcomes. 相似文献
424.
川滇块体东缘地壳动力学问题的讨论 总被引:2,自引:2,他引:0
从川滇块体东缘的地质构造应力场、地震形变带所反映的构造应力场 ,震源机制解所确定的应力场、地壳应力解除及地壳应力测量所反映的应力场等方面的资料 ,对块体东缘地壳动力学问题进行了讨论 ,结果认为印度板块与欧亚板块的碰撞是川滇块体东缘地壳动力的主要力源。 相似文献
425.
CISK,EVAPORATION-WIND FEEDBACK MECHANISM AND 30—60 DAY OSCILLATIONS IN THE TROPICAL ATMOSPHERE
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A baroclinic semi-geostrophic model with evaporation-wind feedback mechanism(EWFM)and CISK is established,two non-dimensional parameters a and η are introduced to representEWFM and CISK,respectively.Analytic solutions of the model system are obtained,dynamicsanalyses and the model atmosphere calculations further confirm that EWFM and CISK are veryimportant physical processes in leading to the low-frequency oscillations in the tropics. 相似文献
426.
邱伟光 《广东海洋大学学报》2002,22(6):54-57
根据控制系统的特征方程和开环传递函数的关系 ,推导出闭环极点与开环零极点之间的关系式 ,并举例说明其应用 ,该公式简单且具有通用性和实用性。 相似文献
427.
428.
现阶段导航接收机设计的基本架构是FPGA+DSP或者FPGA+ ARM 的工作方式。接收机存在研发时间长,研发难度较大的特点,且DSP/ARM 处理环路跟踪的同时需处理协议上的许多操作,在实现上较为复杂,实时性不高。基于SOC技术,利用Xilinx公司提供的协处理器软核代替DSP部分功能,用于在单片FPGA内实现导航接收机的跟踪环路,并根据实际情况,设计了硬件加速器和相关值预处理模块,利用时分复用的方式节约了硬件资源,在单片FPGA上实现了跟踪环路的设计,降低了硬件成本,为高性能导航接收机芯片设计提供了一种思路。 相似文献
429.
In this paper, we investigate the performance of adaptive modulation (AM) orthogonal frequency division multiplexing (OFDM) system in underwater acoustic (UWA) communications. The aim is to solve the problem of large feedback overhead for channel state information (CSI) in every subcarrier. A novel CSI feedback scheme is proposed based on the theory of compressed sensing (CS). We propose a feedback from the receiver that only feedback the sparse channel parameters. Additionally, prediction of the channel state is proposed every several symbols to realize the AM in practice. We describe a linear channel prediction algorithm which is used in adaptive transmission. This system has been tested in the real underwater acoustic channel. The linear channel prediction makes the AM transmission techniques more feasible for acoustic channel communications. The simulation and experiment show that significant improvements can be obtained both in bit error rate (BER) and throughput in the AM scheme compared with the fixed Quadrature Phase Shift Keying (QPSK) modulation scheme. Moreover, the performance with standard CS outperforms the Discrete Cosine Transform (DCT) method. 相似文献
430.
Influenza disease diffuses from one individual to another through their close contacts, while preventive behavior propagates through inter-personal influences. These two diffusion processes take place simultaneously and interact with one another in opposite directions. Many current influenza studies consider the diffusion of influenza, but few of them have incorporated the diffusion of human preventive behavior. This article proposes an original dual-diffusion model to couple these two diffusion processes. The conceptual framework of the model incorporates these two opposite processes into a human contact network. An agent-based approach, network theory, disease model, and behavioral model are integrated to formulate the conceptual framework. Model implementation simulates an influenza epidemic in an urbanized area of one million individuals. The simulation results suggest that the proposed model offers a close representation of the observed data. The research findings will provide a more rational basis for influenza control. 相似文献