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971.
A complete solution classification of the perspective-three-point (P3P) problem is given by using the Gröbner basis method. The structure of the solution space of the polynomial system deduced by the P3P problem can be obtained by computing a comprehensive Gröbner system. Combining with properties of the generalized discriminant sequences, the authors give the explicit conditions to determine the number of distinct real positive solutions of the P3P problem. Several examples are provided to illustrate the effectiveness of the proposed conditions.  相似文献   
972.
Farr-Gao algorithm is a state-of-the-art algorithm for reduced Gröbner bases of vanishing ideals of finite points, which has been implemented in Maple as a build-in command. This paper presents a two-dimensional improvement for it that employs a preprocessing strategy for computing reduced Gröbner bases associated with tower subsets of given point sets. Experimental results show that the preprocessed Farr-Gao algorithm is more efficient than the classical one.  相似文献   
973.
In recent years,bank credit business is booming with the increasing borrowing intention of China’s listed companies,and debt financing has become the major approach among listed companies’financing strategies.As a series of institutional arrangements about rights,responsibilities and benefits between different shareholders,corporate governance mechanism has a significant influence on the cost of debt financing.This paper employs variable coefficient panel data model to investigate the relationship of the listed company’s debt financing costs and corporate governance mechanism in terms of structural characteristics and time series characteristics.The results show that optimizing the structure of both Board of Directors and Board of Supervisors,establishing a reasonable management incentive system and reducing the concentration of ownership properly can directly contribute to a lower company’s debt financing costs.Meanwhile,property rights have an interactive influence on corporate governance from four aspects,which indirectly effect in company’s debt financing costs.  相似文献   
974.
This paper proposes a knowledge-scientific approach to evaluation of community service systems from the viewpoints of knowledge creation, consciousness reform, and value co-creation. A concrete example of the community service system treated here is an education program for old men to find their reason for living after the retirement. After introducing this program and the traditional evaluation methods for such a program, the paper emphasizes the necessity of developing new evaluation methods for such a community service system based on knowledge science. The paper proposes a new evaluation framework and reports an actual evaluation result using the interview data from participants in that program.  相似文献   
975.
This study develops a conceptual system optimization model of adoption of a new infrastructure technology with multiple resource sites and multiple demand sites. With the model, this paper analyzes how the distance, spillover effect, demand, initial investment cost, and learning rate influence the adoption of the new infrastructure technology and presents optimization results of the model in different scenarios. The main findings of the study are: from the perspective of system optimization, (1) different distances among different resource-demand pairs will result in different adoption time of a new infrastructure; (2) technological spillover among different resource-demand pairs will accelerate the adoption of a new infrastructure; (3) it is hard to say that higher demand will pull faster adoption of a new infrastructure, and the optimal time of adopting of a new infrastructure is very sensitive to its technological learning rate.  相似文献   
976.
Tracking mobile nodes in dynamic and noisy conditions of industrial environments has provided a paradigm for many issues inherent in the area of distributed control systems in general and wireless sensor networks in particular. Due to the dynamic nature of the industrial environments, a practical tracking system is required that is adaptable to the changes in the environment. More specifically, given the limited resources of wireless nodes and the challenges created by harsh industrial environments there is a need for a technique that can modify the configuration of the system on the fly as new wireless nodes are added to the network and obsolete ones are removed. To address these issues, two cluster-based tracking systems, one static and the other dynamic, are proposed to organize the overall network field into a set of tracking zones, each composed of a sink node and a set of corresponding anchor nodes. To manage the wireless nodes activities and inter and intra cluster communications, an agent-based technique is employed. To compare the architectures, we report on a set of experiments performed in JADE (Java Agent Development Environment). In these experiments, we compare two agent-based approaches (dynamic and static) for managing clusters of wireless sensor nodes in a distributed tracking system. The experimental results corroborate the efficiency of the static clusters versus the robustness and effectiveness of the dynamic clusters.  相似文献   
977.
An effective prognostic program is crucial to the predictive maintenance of complex equipment since it can improve productivity, prolong equipment life, and enhance system safety. This paper proposes a novel technique for accurate failure prognosis based on back propagation neural network and quantum multi-agent algorithm. Inspired by the extensive research of quantum computing theory and multi-agent systems, the technique employs a quantum multi-agent strategy, with the main characteristics of quantum agent representation and several operations including fitness evaluation, cooperation, crossover and mutation, for parameters optimization of neural network to avoid the deficiencies such as slow convergence and liability of getting stuck to local minima. To validate the feasibility of the proposed approach, several numerical approximation experiments were firstly designed, after which real vibrational data of bearings from the Laboratory of Cincinnati University were analyzed and used to assess the health condition for a given future point. The results were rather encouraging and indicated that the presented forecasting method has the potential to be utilized as an estimation tool for failure prediction in industrial machinery.  相似文献   
978.
This paper introduces a generalized multivariate Gumbel (GMG) distribution using a survival copula. Various dependence properties of the GMG distribution and some analytical properties of the generators of the GMG distribution are studied. Furthermore, the authors also investigate the dependence behavior of the residual lifetime vector of the GMG distribution. As an illustration, the GMG distribution is applied to fit a real data set.  相似文献   
979.
Compared with standard logit-based stochastic user equilibrium assignment model, the C-logit model describes route choice behavior in a more realistic way by considering the overlapping effect between routes. This paper investigates the inefficiency upper bounds of this model against the deterministic system optimum and the C-logit stochastic system optimum in terms of the total network travel time. It is found that the commonality factor of overlapping routes significantly affects the inefficiency bound, besides link congestion degree, total demand and the number of feasible routes. If the commonality factor is not considered, the efficiency loss resulting from selfishly stochastic travel behavior will be to large extent underestimated.  相似文献   
980.
The semi-global stabilization problem for a class of nonlinear systems with state time-delay is addressed in this paper. By using Lyapunov-Krasovskii functional method and homogeneous domination approach, a homogeneous observer and an output feedback controller with a scaling gain are designed. Then the scaling gain is adjusted such that the closed-loop system is semi-global asymptotically stable. A numerical example is presented to illustrate the effectiveness of the obtained results in this paper.  相似文献   
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