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1.
With the goal to produce a hard and tough coating intended for tribological applications, CrAlN/TiSiN nanolayer coating was prepared by alternative deposition of CrAlN and TiSiN layers. In the first part of the article, a detailed study of phase composition, microstructure, and layer structure of CrAlN/TiSiN coating is presented. In the second part, its mechanical properties, fracture and tribological behavior are compared to the nanocomposite TiSiN coating. An industrial magnetron sputtering unit was used for coating deposition. X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used for compositional and microstructural analysis. Mechanical properties and fracture behavior were studied by instrumented indentation and focused ion beam techniques. Tribological properties were evaluated by ball-on-disk test in a linear reciprocal mode. A complex layer structure was found in the nanolayer coating. The TiSiN layers were epitaxially stabilized inside the coating which led to formation of dislocations at interfaces, to introduction of disturbances in the coating growth, and as a result, to development of fine-grained columnar microstructure. Indentation load required for the onset of fracture was twice lower for the nanolayer CrAlN/TiSiN, compared to the nanocomposite TiSiN coating. This agrees very well with their mechanical properties, with H3/E2 being twice higher for the TiSiN coating. However, the nanolayer coating experienced less severe damage, which had a strong impact on tribological behavior. A magnitude of order lower wear rate and four times lower steady state friction coefficient were found for the nanolayer coating.  相似文献   
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本文报导用于异丁烯(叔丁醇)选择氧化制MAL(甲基丙烯醛)的多元复合氧化物催化剂的研究结果。同共沉淀法制备的催化剂的活性主要决定于其化学组成,同时受到制备条件的影响。最佳催化剂的主要物相组成为PbO3,Bi2MoO3.3、NiMoO4、Sb2O3及a-Fe2O3小颗粒。在355℃,1000~2500h-1空速范围,叔丁醇:水:空气=1:3.3:7(摩尔比)的条件下可获得异丁烯转化率达96%,MAL选择性达89%的结果。  相似文献   
4.
Three series of hyperbranched urethane-acrylates (HB-UA), based on aliphatic hyperbranched polyesters and polyethyleneglycol acrylate, were prepared and evaluated for use in UV-curable coatings. UV-curing kinetics were monitored by FT-IR spectroscopy. The thermal and mechanical properties of UV-cured HB-UA were investigated by means of differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) and correlated to the mechanical properties of coatings (hardness and flexibility). These new HB-UA's are very reactive and did not show oxygen inhibition. Obtained coatings have good mechanical properties and solvent resistance.  相似文献   
5.
车载悬架性能检测与可调阻尼减震器   总被引:2,自引:0,他引:2  
刘文强  王磊  谢伟东 《机床与液压》2003,(3):278-279,296
本文采用模糊控制理论,论述了基于被动悬架性能测试基础上的阻尼调节技术,建立了1/4车被动悬架的检测判别理论模型,进行了模拟计算分析,仿真表明,能够提高车辆的安全性,同时,为设计制造性能可靠高效的可调阻尼悬架系统打下良好基础。  相似文献   
6.
This paper presents a new approach to make current and future television universally accessible. The proposed approach provides a means of universal accessibility both for remotely operating the TV set and for interacting with online services delivered through the TV. This proposal is based on the ISO/IEC 24752 “Universal Remote Console” (URC) standard. This standard defines an abstract user interface layer called the “user interface socket” and allows the development of pluggable (plug-in) user interfaces for any type of user and any control device. The proposed approach lays the foundation for the development of advanced user interfaces that can be interacted within various modalities. Different prototypes have been developed based on this approach and tested with end users. The user tests have shown this approach to be a viable option for the proposed scenarios. Based on the experience gathered with the prototypes, recommendations and implementation options are suggested for commercial adoption.  相似文献   
7.
Materials with controllable multifunctional abilities for optical imaging (OI) and magnetic resonant imaging (MRI) that also can be used in photodynamic therapy are very interesting for future applications. Mesoporous TiO2 sub‐micrometer particles are doped with gadolinium to improve photoluminescence functionality and spin relaxation for MRI, with the added benefit of enhanced generation of reactive oxygen species (ROS). The Gd‐doped TiO2 exhibits red emission at 637 nm that is beneficial for OI and significantly improves MRI relaxation times, with a beneficial decrease in spin–lattice and spin–spin relaxation times. Density functional theory calculations show that Gd3+ ions introduce impurity energy levels inside the bandgap of anatase TiO2, and also create dipoles that are beneficial for charge separation and decreased electron–hole recombination in the doped lattice. The Gd‐doped TiO2 nanobeads (NBs) show enhanced ability for ROS monitored via ?OH radical photogeneration, in comparison with undoped TiO2 nanobeads and TiO2 P25, for Gd‐doping up to 10%. Cellular internalization and biocompatibility of TiO2@x Gd NBs are tested in vitro on MG‐63 human osteosarcoma cells, showing full biocompatibility. After photoactivation of the particles, anticancer trace by means of ROS photogeneration is observed just after 3 min irradiation.  相似文献   
8.
The problem addressed in this paper is information theoretic sensor control for recursive Bayesian multi-object state-space estimation using random finite sets. The proposed algorithm is formulated in the framework of partially observed Markov decision processes where the reward function associated with different sensor actions is computed via the Rényi or alpha divergence between the multi-object prior and the multi-object posterior densities. The proposed algorithm in implemented via the sequential Monte Carlo method. The paper then presents a case study where the problem is to localise an unknown number of sources using a controllable moving sensor which provides range-only detections. Four sensor control reward functions are compared in the study and the proposed scheme is found to perform the best.  相似文献   
9.
This paper presents a novel video augmentation approach: a video recording of a real entity augmented by structured data. This augmented video is a self-contained entity integrating values of perceptible and non-perceptible attributes of the same real entity. It simplifies data search, storage and management. Streaming, sharing, collaboration and synchronization are also simplified by the fact that the structured data (so-called augmented data) are integrated in the video file and therefore only one file needs to be manipulated. Our approach was applied to address the issues which road engineers experience while using the ROad Measurement and Data Acquisition System (ROMDAS). The ROMDAS system collects and analyses the road-condition state through video recordings and the data corresponding acquired by specific measuring devices. Currently, however, road engineers have to search the videos manually in order to find details of interest provided by the analysis of the data measured due to the separation of the video from the data. The ROMDAS system manages a large collection of road-condition data. It does not offer history management of video recordings of the same road captured at different time. We present this hybrid video augmentation system: the Augmented Video stream Framework (AVF). It allows creation, search, history management and playback of such augmented video files for effective road surveying based on the discrete data recorded in parallel to the video recordings. The AVF provides road engineers with effective and more comfortable perceptible and non-perceptible data search, storage and history management to be used for (collaborative) road inspection and maintenance.  相似文献   
10.
In this paper, we describe the first practical application of two methods, which bridge the gap between the non-expert user and machine learning models. The first is a method for explaining classifiers’ predictions, which provides the user with additional information about the decision-making process of a classifier. The second is a reliability estimation methodology for regression predictions, which helps the users to decide to what extent to trust a particular prediction. Both methods are successfully applied to a novel breast cancer recurrence prediction data set and the results are evaluated by expert oncologists.  相似文献   
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