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151.
In absorption with fast chemical reaction, the reaction occurs only in the liquid-side film at the interface whereas the gas concentration in the bulk of the liquid is about zero. The absorption might be more strongly enhanced if the catalyst concentration in the film was locally increased. For the oxidation of glucose to gluconic acid on suspended Pd/Al2O3 particles, particle adhesion at the gas–liquid interface was promoted by moderate hydrophobization with trichloromethylsilane (TCMS). The silanization had no significant effect on the catalyst activity studied under kinetic control. In the mass transfer controlled regime, enhancement of the absorption rate by the hydrophobized Pd/Al2O3 catalyst particles occurred at very low catalyst loadings. This can be attributed to locally higher catalyst concentration in the liquid film. 相似文献
152.
Jens Popper Marius BLugel Hagen Burchardt Steffen Horn Joachim Merx Dr.Detlev Richter Werner Varro Michael Pfeifer Pascal Staub-Lang 《仪器仪表标准化与计量》2019,(4)
SmartFactory~(KL)工作组1 智能基础设施专门处理模块化工业4.0生产设施的安全问题。其旨在提供一种工厂结构,通过模块化等手段确保其灵活性和可变性。本安型模块具有常规的功能安全性。但是,模块间依然存在依赖关系。在支持未知模块的模块化系统中,还需要一个新的安全体系结构。去年,该概念被整合到了工业4.0生产设施中,以实例证明该概念可在当今技术的基础上得以实施。在安全和机器通信的实施中,仅采用了一条单线共存。机器和机器模块可以在运行期间插入生产线或从生产线移除,而不会影响工厂的其它部分。必要的安全相关参数将根据此处导入的安全配置文件自动进行协商、配置和发布。要求如下文所述。 相似文献
153.
Philip Engelhardt Marius Maximini Frank Beckmann Martin Brenner 《International Journal of Hydrogen Energy》2012
This paper presents experimental results of a diesel steam reforming fuel processor operated in conjunction with a gas cleanup module and coupled operation with a PEM fuel cell. The fuel processor was operated with two different precious-metal based reformer catalysts, using diesel surrogate with a sulfur content of less than 2 ppmw as fuel. The first reformer catalyst entails an increasing residual hydrocarbon concentration for increasing reformer fuel feed. The second reformer catalyst exhibits a significantly lower residual hydrocarbon concentration in the reformate gas. 相似文献
154.
155.
The time course of perceptual choice is discussed in a model of gradual, leaky, stochastic, and competitive information accumulation in nonlinear decision units. Special cases of the model match a classical diffusion process, but leakage and competition work together to address several challenges to existing diffusion, random walk, and accumulator models. The model accounts for data from choice tasks using both time-controlled (e.g., response signal) and standard reaction time paradigms and its adequacy compares favorably with other approaches. A new paradigm that controls the time of arrival of information supporting different choice alternatives provides further support. The model captures choice behavior regardless of the number of alternatives, accounting for the log-linear relation between reaction time and number of alternatives (Hick's law) and explains a complex pattern of visual and contextual priming in visual word identification. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
156.
Laura Cocheci Lavinia Lupa Marius Gheju Alin Golban Radu Lazău Rodica Pode 《Clean Technologies and Environmental Policy》2018,20(5):1105-1112
Hot-dip galvanizing process is used worldwide to protect the steel or iron pieces from corrosion. This process is a large generator of waste, considered one of the so-called dirty industries. One of the important wastes, in terms of quantity, is zinc ash that contains a mixture of metallic zinc and zinc oxide with a total content of zinc between 70 and 90%. The aim of this study is the preparation and characterization of a series of Zn R –Al–CO3 (R?=?2–4) layered double hydroxides (LDH) by using as zinc precursor the zinc chloride obtained after hydrochloric acid leaching of fine-grained zinc ash. Results presented herein clearly demonstrated that characteristics of the synthesized samples are close to those of similar materials synthesized starting from analytical grade reagents. At the same time, it was observed that impurities existent in the zinc chloride solution prepared by zinc ash leaching (Pb, Fe, Ca), are found at traces in the synthesized LDH materials; therefore, they have no significant influence on the obtained LDH structure and properties. By this approach, several important benefits may be simultaneously achieved: (1) preventing the pollution associated with hot-dip galvanizing process wastes, (2) obtaining of valuable products with minimized costs, keeping in mind that LDH have multiple utilizations at industrial scale, (3) saving energy and material costs, and (4) increase of product competitiveness with respect to the circular economy. 相似文献
157.
Two objects are independent if they do not affect each other. Independence is well-understood in classical information theory, but less in algorithmic information theory. Working in the framework of algorithmic information theory, the paper proposes two types of independence for arbitrary infinite binary sequences and studies their properties. Our two proposed notions of independence have some of the intuitive properties that one naturally expects. For example, for every sequence x, the set of sequences that are independent with x has measure one. For both notions of independence we investigate to what extent pairs of independent sequences, can be effectively constructed via Turing reductions (from one or more input sequences). In this respect, we prove several impossibility results. For example, it is shown that there is no effective way of producing from an arbitrary sequence with positive constructive Hausdorff dimension two sequences that are independent (even in the weaker type of independence) and have super-logarithmic complexity. Finally, a few conjectures and open questions are discussed. 相似文献
158.
This study examines whether or not a controllable task-lighting system that allows people to select high lighting levels will enhance productivity under real working conditions. For a period of 16 months a study was carried out in a luminaire factory in Finland in which such a task-lighting system was installed above 10 individual workstations. The illuminances selected by the users were recorded and productivity was monitored. Enhancing productivity can be relevant in industrial processes. The increase of productivity for the test group was +4.5% compared to a reference group, and statistically significant. The mechanism for this increase can be improved visual performance, biological effects of light, or psychological effects. Different dimming speeds were used to see whether the subjects' choices were based on illuminance or on the response of the control system. Decreasing the dimming speed of the system decreased the illuminance chosen by 13%. However, at slower dimming speeds the subjects took 55% longer to reach a given level, which suggests that they were aiming to set the lighting to their preferred level and not just pushing the button for a certain time. 相似文献
159.
Hae-Won Choi Marius Paraschivoiu 《Computer Methods in Applied Mechanics and Engineering》2007,196(8):1484-1497
Large-scale numerical simulations of the flow and associated transport phenomena governed by the Navier-Stokes and Energy equations are routinely calculated in engineering practice. Nevertheless, the uncertainty due to spatial discretization limits the confidence of practitioners in numerical solutions. An approach to provide information about the accuracy of the quantity of interest is proposed here-in. The novel a posteriori error estimation technique - the bound method - is based on relaxing Lagrange multipliers that enforces continuity between sub-domains. The method provides fast, efficient, asymptotic but reliable lower and upper bounds to the output of underlying partial differential equations (PDEs). Herein, we highlight the method when applied to outputs of the steady incompressible Navier-Stokes and Energy equations. The bound method in this paper follows the directly equilibrated hybrid-flux approach for the flux calculation between sub-domains and uses the Crouzeix-Raviart () approximation spaces. To improve the effectiveness of the bound method, an adaptive sub-domain refinement strategy leading to sharper bounds is adopted. A convective heat transfer problem in a series of electronic chip devices is investigated. The novelty of this paper is to present bounds using adaptive domain decomposition for outputs associated to a complex three-dimensional field solution of the Navier-Stokes and Energy equations. 相似文献
160.
Bulacu M Schomaker L 《IEEE transactions on pattern analysis and machine intelligence》2007,29(4):701-717
The identification of a person on the basis of scanned images of handwriting is a useful biometric modality with application in forensic and historic document analysis and constitutes an exemplary study area within the research field of behavioral biometrics. We developed new and very effective techniques for automatic writer identification and verification that use probability distribution functions (PDFs) extracted from the handwriting images to characterize writer individuality. A defining property of our methods is that they are designed to be independent of the textual content of the handwritten samples. Our methods operate at two levels of analysis: the texture level and the character-shape (allograph) level. At the texture level, we use contour-based joint directional PDFs that encode orientation and curvature information to give an intimate characterization of individual handwriting style. In our analysis at the allograph level, the writer is considered to be characterized by a stochastic pattern generator of ink-trace fragments, or graphemes. The PDF of these simple shapes in a given handwriting sample is characteristic for the writer and is computed using a common shape codebook obtained by grapheme clustering. Combining multiple features (directional, grapheme, and run-length PDFs) yields increased writer identification and verification performance. The proposed methods are applicable to free-style handwriting (both cursive and isolated) and have practical feasibility, under the assumption that a few text lines of handwritten material are available in order to obtain reliable probability estimates 相似文献