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21.
Though widely acknowledged, climate change and global warming considerations are poorly integrated in landscape planning practices. Exploring this matter, the paper analyses the design of a contemporary urban park in Jaffa, Israel, investigating why climate considerations are so poorly addressed. The analysis focuses on the various competing parameters such as social use, design, political considerations and community desires that influence the planning process as well as the park experience. Results confirm a paradox. Though climate conditions are highly acknowledged, and aggravation in heat stress and discomfort conditions are well known in this region, planners and users alike prefer to suspend them in favour of image and aesthetics. Responding to these results, the paper discusses possible venues for further integrating climate considerations into landscape planning.  相似文献   
22.
ON CAPACITY MODELING FOR PRODUCTION PLANNING WITH ALTERNATIVE MACHINE TYPES   总被引:5,自引:0,他引:5  
Analyzing the capacity of production facilities in which manufacturing operations may be performed by alternative machine types presents a seemingly complicated task. In typical enterprise-level production planning models, capacity limitations of alternative machine types are approximated in terms of some single artificial capacitated resource. In this paper we propose procedures for generating compact models that accurately characterize capacity limitations of alternative machine types. Assuming that processing times among alternative machine types are identical or proportional across operations they can perform, capacity limitations of the alternative machine types can be precisely expressed using a formulation that is typically not much larger than the basic linear programming formulation that does not admit alternative resource types. These results have important implications for industrial practice, suggesting that in the case that processing times are nearly proportional among alternatives, the prevalent approximation that involves using a single, capacitated, artificial resource may be dropped in favor of our formulation incorporating the approximation that processing times among the alternatives are proportional. Another advantage is that the set of capacity constraints we formulate can be used to check the feasibility of suggested production schedules or demands simply by plugging mem into the constraints, without need to develop values for allocation variables.  相似文献   
23.
24.
Synthesis of uniform silver nanoparticles with a controllable size   总被引:1,自引:0,他引:1  
Tali Dadosh   《Materials Letters》2009,63(26):2236-2238
A new method for the synthesis of uniform silver nanoparticles using a single silver reduction step is presented. Fine control over the nanoparticle's size is achieved by varying the concentration of tannic acid, one of the reducing agents, resulting in uniform nanoparticles in the range of 18 nm to 30 nm in diameter with a standard deviation of less than 15%. Changes in the optical properties of the nanoparticles are correlated with their diameter. As the diameter increases the absorption peak is red-shifted. Specifically, for six different sizes of nanoparticles, ranging from 18 nm to 30 nm in diameter, a red-shift from 401 nm to 410 nm in the absorption peaks is measured. In addition, the extinction coefficient increases as the third power of the nanoparticle radius. Rhodamine 123 adsorbed to 30 nm silver nanoparticles exhibits characteristic Raman spectrum suggesting that these nanoparticles are efficient substrate for surface-enhanced Raman spectroscopy.  相似文献   
25.
We present a novel method for recovering the 3D structure and scene flow from calibrated multi-view sequences. We propose a 3D point cloud parametrization of the 3D structure and scene flow that allows us to directly estimate the desired unknowns. A unified global energy functional is proposed to incorporate the information from the available sequences and simultaneously recover both depth and scene flow. The functional enforces multi-view geometric consistency and imposes brightness constancy and piecewise smoothness assumptions directly on the 3D unknowns. It inherently handles the challenges of discontinuities, occlusions, and large displacements. The main contribution of this work is the fusion of a 3D representation and an advanced variational framework that directly uses the available multi-view information. This formulation allows us to advantageously bind the 3D unknowns in time and space. Different from optical flow and disparity, the proposed method results in a nonlinear mapping between the images’ coordinates, thus giving rise to additional challenges in the optimization process. Our experiments on real and synthetic data demonstrate that the proposed method successfully recovers the 3D structure and scene flow despite the complicated nonconvex optimization problem.  相似文献   
26.
27.
We report a unique case in which a needle was accidentally swallowed and migrated into the vertebral body. Plain films and CT of the spine revealed fragmented, linear, metallic-density material in the L3 vertebral body. The possible mechanisms of the migration are discussed.  相似文献   
28.
Polyaniline (PANi) was electrodeposited in gold-coated nanoporous alumina membranes (NAMs) by anodic polymerization of aniline. PANi deposition was followed by cathodic deposition of Ag or Cu, to form a layer of PANi–metal segmented nanowires in the NAM. The compact PANi nanowires fill the entire pore volume, providing a sharp transition from the polymer to the metal segment. The deposited metal layer enables SEM visualization of the PANi nanowire length in the membrane. Deposition of Cu on PANi nanowires occurs at potentials where the PANi is in its reduced leucoemeraldine state, with no evidence for penetration of the metal into the polymer matrix. The mechanism of metal ion reduction on the nonconducting polymer wires is not yet clear. Free-standing segmented PANi–Ag and PANi–Cu nanowires obtained by membrane dissolution show a sharp heterojunction between the polymer and metal phases and are mechanically stable. Aniline electropolymerization in the insulating NAM under a lateral potential gradient generated a thickness gradient of the PANi deposit, revealed by subsequent Cu deposition. The potential-dependent length of the PANi nanowires follows the PANi conductivity pattern, reaching a maximum in the region of stability of the conducting emeraldine phase. The results demonstrate the possibility of obtaining nonlinear graded materials using electrochemical systems showing a complex current–voltage behavior.  相似文献   
29.
Stony corals construct their aragonite skeleton by calcium carbonate precipitation, in a process recently suggested to be biologically controlled. Amorphous calcium carbonate and small amounts of calcite are also reported recently, however, their functional role is unknown. Coral acid‐rich proteins (CARPs) are extracted from the coral skeleton and are shown to be active in calcium carbonate precipitation in vitro. However, individual function of these proteins in coral mineralization is not known. Here, the regulatory activity of the aspartate‐rich CARP3 protein is examined. The whole protein and two peptides representing its acidic domain and its variable domain are used in CaCO3 precipitation reactions from Mg‐rich solutions. The biomolecules alter crystallization pathways, promoting Mg‐calcite in place of aragonite, with the acidic peptide capable of eradicating aragonite formation. The activity of CARP3 and its representative peptides is exerted from disordered CaCO3 mineral phases, coating the crystals formed, as shown by 2D 1H–13C heteronuclear correlation nuclear magnetic resonance (NMR) measurements, localizing organic protons in atomic proximity to disordered carbonate carbons. The structures of the protein and individual domains as derived from NMR measurements and folding calculations and their amino acid compositions are discussed in the context of their observed activity and its implication to mineralization in hard corals.  相似文献   
30.
Robotic advances and developments in sensors and acquisition systems facilitate the collection of survey data in remote and challenging scenarios. Semantic segmentation, which attempts to provide per‐pixel semantic labels, is an essential task when processing such data. Recent advances in deep learning approaches have boosted this task's performance. Unfortunately, these methods need large amounts of labeled data, which is usually a challenge in many domains. In many environmental monitoring instances, such as the coral reef example studied here, data labeling demands expert knowledge and is costly. Therefore, many data sets often present scarce and sparse image annotations or remain untouched in image libraries. This study proposes and validates an effective approach for learning semantic segmentation models from sparsely labeled data. Based on augmenting sparse annotations with the proposed adaptive superpixel segmentation propagation, we obtain similar results as if training with dense annotations, significantly reducing the labeling effort. We perform an in‐depth analysis of our labeling augmentation method as well as of different neural network architectures and loss functions for semantic segmentation. We demonstrate the effectiveness of our approach on publicly available data sets of different real domains, with the emphasis on underwater scenarios—specifically, coral reef semantic segmentation. We release new labeled data as well as an encoder trained on half a million coral reef images, which is shown to facilitate the generalization to new coral scenarios.  相似文献   
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