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51.
Carlos Ferreira Lucas Guardalben Tomé Gomes Susana Sargento Paulo Salvador Daniel Robalo Fernando J. Velez 《Journal of Network and Systems Management》2017,25(2):416-456
Nowadays, the prevailing use of networks based on traditional centralized management systems reflects on a fast increase of the management costs. The growth in the number of network equipments and services reinforces the need to distribute the management responsibilities throughout the network devices. In this approach, each device executes common network management functionalities, being part of the overall network management platform. In this paper, we present a Unified Distributed Network Management (UDNM) framework that provides a unified (wired and wireless) management network solution, where further different network services can take part of this infrastructure, e.g., flow monitoring, accurate routing decisions, distributed policies dissemination, etc. This framework is divided in two main components: (A) Situation awareness, which sets up initial information through bootstrapping, discovery, fault-management process and exchange of management information; (B) Autonomic Decision System (ADS) that performs distributed decisions in the network with incomplete information. We deploy the UDNM framework in a testbed which involves two cities (\(\approx\)250 km between), different standards (IEEE 802.3, IEEE 802.11 and IEEE 802.16e) and network technologies, such as, wired virtual grid, wireless ad-hoc gateways, ad-hoc mobile access devices. The UDNM framework integrates management functionalities into the managed devices, proving to be a lightweight and easy-respond framework. The performance analysis shows that the UDNM framework is feasible to unify devices management functionalities and to take accurate decisions on top of a real network. 相似文献
52.
Distributed planning and control systems for the virtual enterprise: organizational requirements and development life-cycle 总被引:9,自引:2,他引:7
Anto´nio Lucas Soares Ame´rico Lopes Azevedo Jorge Pinho de Sousa 《Journal of Intelligent Manufacturing》2000,11(3):253-270
This paper describes the requirements analysis and system specification of an Order Promise module to be used as part of a broader Decision Support System for production and operations planning of a Virtual Enterprise. This work is part of a broader project with a particular focus on the microelectronics industry which is a good example of Virtual Enterprise, and where a quick response to the customers needs and to unpredictable changes in production conditions is considered a major factor for success. First, the analysis and specification are presented within a development framework that involves the study of organizational issues of semiconductor enterprises. The use of ontological engineering for supporting the communication and shared understanding of the system concepts is explained and a virtual enterprise ontology is outlined. Following the clarification of the concept of virtual enterprise, the generic techno-organizational requirements for the information system are derived. Finally, a specification of the global planning module and a more detailed one regarding the order promise module is presented. 相似文献
53.
T. Babaie R. Karimizandi C. Lucas 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2008,12(9):857-873
The multi criteria and purposeful prediction approach has been introduced and is implemented by the fast and efficient behavioral
based brain emotional learning method. On the other side, the emotional learning from brain model has shown good performance
and is characterized by high generalization property. New approach is developed to deal with low computational and memory
resources and can be used with the largest available data sets. The scope of paper is to reveal the advantages of emotional
learning interpretations of brain as a purposeful forecasting system designed to warning; and to make a fair comparison between
the successful neural (MLP) and neurofuzzy (ANFIS) approaches in their best structures and according to prediction accuracy,
generalization, and computational complexity. The auroral electrojet (AE) index are used as practical examples of chaotic
time series and introduced method used to make predictions and warning of geomagnetic disturbances and geomagnetic storms
based on AE index. 相似文献
54.
Hypervolemia with hypertension often occurs 36-72 hours following massive blood and fluid replacement for hypovolemic shock. This syndrome of "fluid overload" has been attributed to the rapid intravascular flux of previously sequestered fluid in patients with impaired diuresis. This hypothesis was tested in 35 injured patients who received a mean of 9.3 L of blood and 17.4 L of salt during resucitation. The renal parameters measured soon after resuscitation included: 1) renal clearance of inulin (GFR), para-amino hippurate (ERPF), milliosmoles, sodium, and free water; 2) inulin space, renal vascular resistance (RVR), O2 consumption, renin, renal blood flow (RBF), and response to furosemide. Eighteen patients developed hypertension, hypervolemia, and respiratory insufficiency. When compared to the 17 normovolemic, non-hypertensive patients, the 18 hypervolemic patients had significantly increased RVR, with a significant decrease in RBF despite an increase in plasma volume and cardiac output. Furosemide produced less diuresis and natriuresis in the hypertensive patients. The balance between hypovolemia and "fluid overload" seemed percarious in the hypertensive patients. Peripheral renin and catecholamine levels were normal in both groups. Patients with post-traumatic "fluid overload" appear to have a combination of hypervolemia, respiratory insufficiency, hypertension, increased cardiac output, decreased extracellular fluid space, and decreased renal perfusion. These findings suggest that decreased interstitial fluid space compliance rather than "fluid overload" is the underlying factor leading to respiratory insufficiency. The therapeutic aspects of these findings are discussed. 相似文献
55.
Markets liquidity is an issue of very high concern in financial risk management. In a perfect liquid market the option pricing model becomes the well-known linear Black–Scholes problem. Nonlinear models appear when transaction costs or illiquid market effects are taken into account. This paper deals with the numerical analysis of nonlinear Black–Scholes equations modeling illiquid markets when price impact in the underlying asset market affects the replication of a European contingent claim. Numerical analysis of a nonlinear model is necessary because disregarded computations may waste a good mathematical model. In this paper we propose a finite-difference numerical scheme that guarantees positivity of the solution as well as stability and consistency. 相似文献
56.
Analytical decision making strategies rely on weighing pros and cons of multiple options in an unbounded rationality manner. Contrary to these strategies, recognition primed decision (RPD) model which is a primary naturalistic decision making (NDM) approach assumes that experienced and professional decision makers when encounter problems in real operating conditions are able to use their previous experiences and trainings in order to diagnose the problem, recall the appropriate solution, evaluate it mentally, and implement it to handle the problem in a satisficing manner. In this paper, a computational form of RPD, now called C-RPD, is presented. Unified Modeling Language was used as a modeling language to represent the proposed C-RPD model in order to make the implementation easy and obvious. To execute the model, RoboCup Rescue agent simulation environment, which is one of the best and the most famous complex and multi-agent large-scale environments, was selected. The environment simulates the incidence of fire and earthquakes in urban areas where it is the duty of the police forces, firefighters and ambulance teams to control the crisis. Firefighters of SOS team are first modeled and implemented by utilizing C-RPD and then the system is trained using an expert’s experience. There are two evaluations. To find out the convergence of different versions developed during experience adding, some of the developed versions are chosen and evaluated on seven maps. Results show performance improvements. The SOS team ranked first in an official world championship and three official open tournaments. 相似文献
57.
In this paper, we present a method to monitor count data so as to be able to detect improvement when the counts are low enough to cause the lower limit to be zero. The method, which is proposed as an add-on to the conventional Shewhart control chart, consists in counting the number of samples in which zero defectives or zero defects per unit occur and signaling an increase in quality if k-in-a-row or 2-in-t samples have zero counts of defectives or zero defects per unit. This method enjoys some similarities to the very popular Shewhart control chart in that it is easy to design, understand and use. It is flexible, robust, and, like the Shewhart chart, yields detection frequencies that are optimal for very large shifts and good for other shifts. Some comparisons with traditional CUSUM charts are provided. Figures enabling Shewhart control chart users to easily design low-side add-on control charts are given for c and np charts. 相似文献
58.
Lucas D Introna 《欧洲信息系统杂志》2003,12(3):235-240
This paper provides a critical discussion of the ongoing concern of Information Systems (IS) academics on the status of IS as an academic discipline. The focal claim of the argument is that the status of IS as an ‘academic discipline’ is not an ontological or an epistemological question but rather a political one. In defending this claim the paper will draw on the work of Foucault, in particular his discussion on the relation between power and knowledge. The paper will conclude that the advice given by Paul (2002) and others may be appropriate but for very different reasons. It will claim that it is equally important, if not more so, to know the reasons why claims to legitimacy may succeed or not, for such claims to be effective as a political programme. 相似文献
59.
Mehrdad Boroushaki Mohammad B. Ghofrani Caro Lucas Mohammad J. Yazdanpanah Nasser Sadati 《Nuclear Engineering and Design》2004,227(3):285-300
Improved load following capability is one of the main technical performances of advanced PWR (APWR). Controlling the nuclear reactor core during load following operation encounters some difficulties. These difficulties mainly arise from nuclear reactor core limitations in local power peaking, while the core is subject to large and sharp variation of local power density during transients. Axial offset (AO) is the parameter usually used to represent of core power peaking, in form of a practical parameter. This paper, proposes a new intelligent approach to AO control of PWR nuclear reactors core during load following operation. This method uses a neural network model of the core to predict the dynamic behavior of the core and a fuzzy critic based on the operator knowledge and experience for the purpose of decision-making during load following operations. Simulation results show that this method can use optimum control rod groups maneuver with variable overlapping and may improve the reactor load following capability. 相似文献
60.
In this paper, we attempt to show how phenomenology, in a traditional methodological form, can provide an interesting and novel basis for thinking about screens in a world where screens now pervade a great many aspects of human experience. In our analysis, we aim to give a phenomenological account of screen(ing), that is, of its fundamental and foundational meaning. In doing the phenomenological analysis, we ground our argument on the ontology of Heidegger's Being and Time. In doing this, we claim that the screen will only show itself, as that which it is, as a screen in-the-world, where screens already are or have their being ‘as screens’ for this and that purpose, activity or work. We claim, and aim to show, that our analysis provides many insights about the meaning of screens that would be difficult to gain through any other method of investigation. We also argue and show that, although our method is not empirical, its results have important implications for the empirical world. 相似文献