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991.
992.
Improving the authentic learning experience by integrating robots into the mixed-reality environment
The main aim of the modern popular teaching method of authentic learning has been to provide students with everyday-life challenges that develop knowledge and skills through problem solving in different situations. Many emerging information technologies have been used to present authentic environment in pedagogical purpose. However, there are few studies that have been discussed the sense of authenticity and characters in scene and how students interact with the characters involved in the task. We designed a system, RoboStage, with authentic scenes by using mixed-reality technology and robot to investigate the difference in learning with either physical or virtual characters and learning behaviors and performance through the system. Robots were designed to play real interactive characters in the task. The experiment of the study conducted with 36 junior high students. The results indicated that RoboStage significantly improved the sense of authenticity of the task and also positively affected learning motivation. Learning performance was conditionally affected by RoboStage. 相似文献
993.
Tomoko Watanabe Traphagan Yueh-hui Vanessa Chiang Hyeseung Maria Chang Benjaporn Wattanawaha Haekyung Lee Michael Charles Mayrath Jeongwon Woo Hyo-Jin Yoon Min Jung Jee Paul E. Resta 《Computers & Education》2010
Using a framework of cognitive, social, and teaching presence, the nature of learning experiences in a three-dimensional virtual world environment (Second Life) and a text-chat learning environment without visuals (TeachNet) were investigated. A mixed method of code frequencies, coherence graphs, interviews, and a survey was used. The results revealed that the TeachNet debates included more cognitive presence codes that indicate higher levels of cognitive processing than in SL debates. The teams were significantly different from each other in the collaboration style for developing arguments and in the ways to use utterances associated with cognitive, social, and teaching presences, and the groups’ collaboration style became more established with more experience with the tasks. The three critical factors–tool, tasks and group cohesion–that affect cognitive, teaching, and social presence are discussed. 相似文献
994.
Shin-Chih Tu Guey-Yun Chang Jang-Ping Sheu Wei Li Kun-Ying Hsieh 《Journal of Parallel and Distributed Computing》2010
With the advancement of MEMS technologies, sensor networks have opened up broad application prospects. An important issue in wireless sensor networks is object detection and tracking, which typically involves two basic components, collaborative data processing and object location reporting. The former aims to have sensors collaborating in determining a concise digest of object location information, while the latter aims to transport a concise digest to sink in a timely manner. This issue has been intensively studied in individual objects, such as intruders. However, the characteristic of continuous objects has posed new challenges to this issue. Continuous objects can diffuse, increase in size, or split into multiple continuous objects, such as a noxious gas. In this paper, a scalable, topology-control-based approach for continuous object detection and tracking is proposed. Extensive simulations are conducted, which show a significant improvement over existing solutions. 相似文献
995.
Enabling adaptive live streaming in P2P multipath networks 总被引:1,自引:1,他引:0
Live Internet streaming can be regarded as a major current multimedia delivery mode. Efficient delivery under changing network
conditions is a severe challenge in the design of live streaming systems. This study analyzes the key considerations and factors
influencing live stream quality during system operations, and attempts to improve present P2P (peer-to-peer) live streaming
systems by allowing users to enjoy high quality of service under the limitations of network resources. The proposed R-D (Rate-Distortion)
optimized-dynamic-nodes-join algorithm is based on multipath streaming concept and receiver-driven approach. This distributed
algorithm enables the system to evaluate the current network status in order to optimize the end-to-end distortion of P2P
networks and stay in the optimal status. Experiment results of this study demonstrate the effectiveness of the proposed approach. 相似文献
996.
This paper deals with direction-of-arrival (DOA) estimation based on iterative searching technique for code-division multiple
access signals. It has been shown that the iterative searching technique is more likely to converge to a local maximum, causing
errors in DOA estimation. In conjunction with a genetic algorithm for selecting initial search angle, we present an efficient
approach to achieve the advantages of iterative DOA estimation with fast convergence and more accuracy estimate over existing
conventional spectral searching methods. Finally, several computer simulation examples are provided for illustration and comparison. 相似文献
997.
In this paper, we have demonstrated a successful electroplating process of nickel (Ni) in a sulfamate electrolyte bath at ultra low electrolytic temperatures of 273–278 K. The potentiostatic mode is essential for the electroplating process rather than galvanostatic mode. The reason is that diffusion-limited current can be easily obtained by applying a specific potential which is higher than reduction potential. On the contrary, galvanostatic mode can not identify the diffusion-limited current and the reduction will suspend while the setting current is higher than diffusion-limited current ranged in hundreds of μA. The microstructure, morphology and hardness of the Ni electrodeposits were characterized using grazing incidence x-ray diffractometer, atomic force microscopy and nano-indentation test were performed. The hardness of Ni film was much enhanced to around 6.37 GPa at 273 K to 6.18 GPa at 278 K compared with that around 4.11 GPa at 288 K to 4.01 GPa at 293 K. The normal hardness of pure nickel is about 4 GPa. The enhanced hardness of Ni at ultra low temperature is attributed to both mechanisms of reduced grain size strengthening and residual compressive stress hardening. 相似文献
998.
Tao Sheng Xinglei Zhu Guogang Hua Hongxing Guo Jingli Zhou Chang Wen Chen 《Multimedia Systems》2010,16(2):127-137
In most existing Wyner–Ziv video coding schemes, a feedback channel (FC) is expected at the decoder in order to allocate a
proper bit rate for each Wyner–Ziv frame. However, FC not only results in additional latency but also increases decoding complexity
due to the several feedback-decoding iterations. Moreover, FC may be unavailable in many practical video applications. In
this paper, we propose a novel feedback-free rate-allocation scheme for transform domain Wyner–Ziv video coding (TD-WZVC),
which predicts the rate for each Wyner–Ziv frame at the encoder without significantly increasing the complexity of the encoder.
First, a correlation estimation model is presented to characterize the relationship between the source frame and the reference
frame estimated at the encoder in TD-WZVC. Then, an efficient FC-free rate-allocation algorithm is proposed and a linear model
is built to avoid both overestimation and underestimation of the real rate and obtain an optimal rate-distortion performance.
Experimental results show that the proposed scheme is able to achieve a good encoder rate allocation while still maintaining
consistent coding efficiency. 相似文献
999.
The metal multi-user MEMS processes (MetalMUMPs) provide one nickel film, two silicon nitride films and one polysilicon film
for constructing various nickel MEMS devices. The two silicon nitride films are either bonded together as a bi-layered structure
or they sandwich the polysilicon film to form a tri-layered structure to support nickel structures. The residual stress difference
of the two silicon nitride films causes undesired deformations of suspended MetalMUMPs devices. In this paper, the residual
stress difference of the two MetalMUMPs silicon nitride thin films is calibrated and the result is 169 MPa. The Young’s modulus
of the MetalMUMPs nitride films is also measured, which is 209 GPa. 相似文献
1000.
Most anodic aluminum oxide (AAO) or porous anodic aluminum (PAA) films were fabricated using the potentiostatic method from high-purity (99.999%) aluminum films at low temperatures of 0–10°C to avoid dissolution effects at room temperature (RT). In this article, the fabrication of AAO or PAA film from commercial purity (99%) aluminum at RT has been investigated using hybrid pulse anodization under different oxalic acid concentration and process duration. The effect of acid concentration and anodization duration on the formation of AAO size and morphology has been studied. Both pore diameter and oxide layer thickness of AAO films were examined via SEM images and found that both increased with increasing oxalic concentration and anodization duration. In addition, the pore distribution was more concentrated at high electrolytic concentration and anodization duration. 相似文献