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1.
The use of field robots can greatly decrease the amount of time, effort, and associated risk compared to if human workers were to carryout certain tasks such as disaster response. However, transportability and reliability remain two main issues for most current robot systems. To address the issue of transportability, we have developed a lightweight modularizable platform named AeroArm. To address the issue of reliability, we utilize a multimodal sensing approach, combining the use of multiple sensors and sensor types, and the use of different detection algorithms, as well as active continuous closed‐loop feedback to accurately estimate the state of the robot with respect to the environment. We used Challenge 2 of the 2017 Mohammed Bin Zayed International Robotics Competition as an example outdoor manipulation task, demonstrating the capabilities of our robot system and approach in achieving reliable performance in the fields, and ranked fifth place internationally in the competition.  相似文献   
2.
An application of Query-By-Example (QBE) is presented where shots that are visually similar to provided example shots are retrieved. To implement QBE, counter-example shots are required to accurately distinguish shots that are relevant to the query from those that are not (Li and Snoek (2009), Yu et al. (2004)). However, there are usually a huge number of shots, not relevant to a particular query, which can serve as counter-example shots. It is difficult for a user to provide counter-example shots that would aid retrieval. Thus, we developed a QBE method based on partially supervised learning where a retrieval model is constructed by selecting counter-example shots from shots without user supervision. To ensure the speed and accuracy of the QBE method, we select a small number of counter-example shots that are visually similar to given example shots but irrelevant to the query. Such shots are useful for characterizing the boundary between relevant and irrelevant shots. For our method, we first filter shots that are visually dissimilar to example shots based on SVMs on a visual feature. Then we filter shots relevant to the query based on concept detection results from pre-constructed classifiers. Shots that pass the above two tests are considered as counter-example shots. Experimental results obtained using TRECVID 2009 video data validate the effectiveness of our method.  相似文献   
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In this work, a resolved CFD–DEM coupling model for the simulation of gas-liquid-solid flows is developed: the interface capturing method based on the colour function is employed for fluids (i.e. a gas and liquid) whilst Discrete Element Method (DEM) is used for particles. The Volume Penalisation (VP) method is adopted to consider the hydrodynamic interactions between fluids and particles along with the Immersed Free Surface (IFS) method, which artificially extends the gas-liquid interface into the interior of the particle to account for the wettability. The unique point of the proposed model is that the thickness of the gas-liquid interface can be controlled by using both interface compression and diffuse interface techniques simultaneously. From the simulation results, it is presented that the accurate evaluation of the surface tension force as well as the capillary force can be achieved by appropriately controlling the interface thickness. Moreover, the major two methods in the literature to calculate the capillary force are compared in this work. The validity of the proposed model is presented for both static and dynamic cases. The behaviour of two colliding particles with a dynamic liquid bridge is then simulated to demonstrate the applicability of the proposed model to a complex three-phase system.  相似文献   
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Grain-growth inhibition in an Fe-10 mass pct Ni alloy, which was continuously cooled from a melt, was studied at 1673 K in the presence of primary deoxidation products of ZrO2 or MgO particles. The mean grain size and grain-size distribution in a cross section were measured as a function of holding time for up to 240 minutes. The grain growth was strongly inhibited by the inclusion particles and was influenced by the dissolved Zr. In the Zr deoxidation, the number of particles per unit area (N A) ranged from 80 to 650 mm−2, the ZrO2 particle size ( ) varied from 1.1 to 1.6 μm, and the dissolved Zr level was below 1800 mass ppm. In the Mg deoxidation, the particle-number density was 90 to 270 mm−2, the MgO particle size was 1.1 to 1.7 μm, and the dissolved Mg level was below 20 mass ppm. In a logarithmic plot of the ratio of limiting mean grain diameter ( ) to the mean particle diameter ( ) against the volume fraction of particles (f V), both the value for a given f V value, which ranged from 0.014 to 0.074 pct, and the slope were significantly lower than that predicted from the two-dimensional relation =(4/π) · f V /−1 , i.e., Zener’s limit. This discrepancy is discussed in light of the fraction of particles at the grain boundaries measured experimentally. Normal grain growth was confirmed from the grain-size distribution observed as a function of holding time, which was best described by the log-normal distribution.  相似文献   
7.
In order to develop a short-term algal toxicity test, the growth of and the phosphate uptake by the green alga Selenastrum capricornutum during batch culture were observed. In the control medium, S. capricornutum took up phosphate earlier than it grew. It was also observed that the phosphate uptake was inhibited by the presence of a toxicant. From these results, phosphate uptake was considered as one of the useful effect parameters for a short-term algal toxicity test. As the removal rate of phosphate from the medium is a function of the amount of algal cell initially inoculated, the test period is variable. The relationship between the amount of inoculation and phosphate uptake was examined and the test conditions suitable for a 3-h toxicity test were established as one example. According to this test procedure, the inhibitory effect of some toxicants on the phosphate uptake was determined. For comparison, a conventional algal assay based on algal growth was also performed. The EC50s for both tests were close. This indicated that the algal toxicity test method proposed in this paper would be useful for the uses where rapidity is required.  相似文献   
8.
Growth conditions for MnGeP2 thin films have been investigated by using molecular beam epitaxy (MBE) method. Mn and Ge were evaporated by K-cells, and P2 was supplied by decomposing tertialybutylphosphine (TBP). GaAs (001) and InP (001) single crystals were used as substrates. An X-ray diffraction peak, which can be assigned to (008) peak of MnGeP2, was observed at nearly the same position as the (004) peak of GaAs. The lattice constant of the MnGeP2 thin film was determined to be 1.13 nm assuming its crystal structure is a c-axis oriented chalcopyrite type structure. Secondary phases such as GeP, MnGex and MnP were observed for beam fluxes of Mn and Ge as high as 1×10–8 Torr.  相似文献   
9.
This paper describes the first time experimental studies on 60-GHz band transmissions of terrestrial digital broadcasting signals (ISDB-T) with 64-QAM modulations on coded orthogonal frequency division multiplexing (COFDM) format. It has been a very difficult experiment to accomplish because it requires very stable and low phase-noise oscillators in the millimeter-wave band. The use of our proposed millimeter-wave self-heterodyne system, overcame this problem without using a stable oscillator, and provided a bit error rate (BER) of less than 10-6 without any forward error correction. We also discuss the relationship between the carrier-to-noise power ratio and the BER obtained, and demonstrate that the penalty of the required CNR for our experimental system is less than 1 dB compared to the results of a back-to-back BER test  相似文献   
10.
Growth conditions for MnGeP2 thin films have been investigated by using molecular beam epitaxy (MBE) method. Mn and Ge were evaporated by K-cells, and P2 was supplied by decomposing tertialybutylphosphine (TBP). GaAs (001) and InP (001) single crystals were used as substrates. An X-ray diffraction peak, which can be assigned to (008) peak of MnGeP2, was observed at nearly the same position as the (004) peak of GaAs. The lattice constant of the MnGeP2 thin film was determined to be 1.13 nm assuming its crystal structure is a c-axis oriented chalcopyrite type structure. Secondary phases such as GeP, MnGe x and MnP were observed for beam fluxes of Mn and Ge as high as 1×10?8 Torr.  相似文献   
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