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81.
An efficient multiobjective differential evolution algorithm for array synthesis is proposed in this article. By introducing novel strategies in the generalized differential evolution (GDE3), the proposed algorithm can generate a better converged and distributed Pareto front than the standard GDE3. Five typical benchmark functions are optimized by the proposed improved GDE3 (IGDE) to verify its effectiveness. Furthermore, the proposed algorithm is applied in two‐pattern synthesis problems, including an unequal spaced linear array and a conformal array. The superior performance of the proposed IGDE demonstrates that it is an efficient and competitive algorithm in the function optimization, pattern synthesis, and other electromagnetic problems. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:161–169, 2014. 相似文献
82.
Adjusting parameters iteratively is a traditional way of training neural networks, and the Rough RBF Neural Networks (R-RBF-NN) follows the same idea. However, this idea has many disadvantages, for instance, the training accuracy and generalization accuracy etc. So how to change this condition is a hot topic in Academics. On the basis of Extreme Learning Machine (ELM), this paper proposes a Weighted Regularized Extreme Learning Machine (WRELM), taking into account both minimizing structured risk and weighted least-squares principle, to train R-RBF-NN. The traditional iterative training method is replaced by the minimal norm least-squares solution of general linear system. The method proposed in this paper, increasing controllability of the entire learning process and considering the structured risk and empirical risk, can improve the performance of learning and generalization. Experiments show that it can reach a very superior performance in both time and accuracy when WRELM trains the Rough RBF Neural Networks in pattern classification and function regression, especially in pattern classification, which can improve the generalization accuracy more than 3.36 % compared with ELM. Obviously, the performance of the method proposed in this paper is better than the traditional methods. 相似文献
83.
Guodong Jing Yunhui Shi Dehui Kong Wenpeng Ding Baocai Yin 《Multimedia Tools and Applications》2014,70(2):741-755
Sparse representation provides a new method of generating a super-resolution image from a single low resolution input image. An over-complete base for sparse representation is an essential part of such methods. However, discovering the over-complete base with efficient representation from a large amount of image patches is a difficult problem. In this paper, we propose a super-resolution construction based on multi-space sparse representation to efficiently solve the problem. In the representation, image patches are decomposed into a structure component and a texture component represented by the over-complete bases of their own spaces so that their high-level features can be captured by the bases. In the implementation, a prior knowledge about low resolution images generation is combined to the typical base construction for high construction quality. Experiment results demonstrate that the proposed method significantly improves the PSNR, SSIM and visual quality of reconstructed high-resolution image. 相似文献
84.
Yunhui Shi Bo Wen Wenpeng Ding Na Qi Baocai Yin 《Multimedia Tools and Applications》2014,70(3):2125-2137
The benefit of using the geometry image to represent an arbitrary 3D mesh is that the 3D mesh can be re-sampled as a completely regular structure and coded efficiently by common image compression methods. For geometry image-based 3D mesh compression, we need to code the normal-map images while coding geometry images to improve the subjective quality and realistic effects of the reconstructed model. In traditional methods, a geometry image and a normal-map image are coded independently. However a strong correlation exists between these two kinds of images, because both of them are generated from the same 3D mesh and share the same parameterization. In this paper we propose a predictive coding framework, in which the normal-map image is predicted based on the geometric correlation between them. Additionally we utilize the strong geometric correlation among three components of normal-map image to improve the predicting accuracy. The experimental results show the proposed coding framework improves the coding efficiency of normal-map image, meanwhile the realistic effect of a 3D mesh is significantly enhanced. 相似文献
85.
ECN树脂中的可水解氯含量是决定树脂质量的—个重要指标。本文研究了反应温度、ECH/OCN配比、反应时间和碱用量等因素的影响,取得了规律性的认识,并获得最佳配方,制备出高纯度的ECN树脂系列产品。 相似文献
86.
The service mashup programming paradigm is a blooming faction of service oriented Architecture for developing web applications. A mashup application constructs its functionality by combining data, presentation and functionalities obtained from online services published by service providers such as Google and Amazon. This paradigm significantly facilitates the implementation of application and reduces the workload. But it also makes the application rely on the availability and qualities of the online services which beyond its control in which case the robustness of the system requires more concern. This paper proposes a formal model to specify and analyze the behavior and robustness of service mashups under a certain environment where some services may become unavailable. The specification contains both system specification and environment situation. Refinement theory are employed to specify the correctness of dynamic service selection. The framework realizes the service selection by allowing virtual service requests to be handled by any online service having consistent interface and refined functionality. The framework provides a clear definition of the robustness of mashup systems and proposes several rules as well as approaches to preserve the robustness during the development and maintenance of the system. 相似文献
87.
十二烷基苯磺酸钠水溶液聚集性质的研究 总被引:8,自引:0,他引:8
用滴体积法测出十二烷基苯磺酸钠(SDBS)稀水溶液的表面张力;然后求出其临界胶束浓度(CMC)。同时通过溶液的电导率、吸收光谱以及荧光光谱测定求出其CMC。这样测出的CMC值为1.2~1.6×10-3mol/L,与文献值相符。也研究了部分水解的聚丙烯酰胺(PHPAM)对SDBS聚集性质的影响;发现SDBS的CMC值随PHPAM的加人而减少并且PHPAM水溶液的粘度随SDBS的存在而急剧降低(类似盐效应)。这些方法与性质对强化采油(EOR)是重要的。 相似文献
88.
针对BOC(n,n)型信号自相关函数存在三个峰值导致伪码捕获模糊性的问题,提出了一种新的基于相关函数的精确无模糊的捕获算法。该算法将信号进行频域的多普勒补偿,通过本地增设QBOC(n,n)支路,利用BOC(n,n)信号自相关以及BOC(n,n)和QBOC(n,n)互相关,经移位±TC/4、取模、求和、平方运算而实现。理论与仿真分析表明,该算法在不改变自相关主峰宽度的情况下完全消除相关副峰的同时,显著提高了主峰峰值;比传统捕获算法的性能好4.5 dB左右,并且捕获精度良好、易于实现。 相似文献
89.
本文首先叙述了智能家居的基本概念以及分析了智能家居中的通信技术,分析了WiFi技术在智能家居中的应用优势。接着讨论了串口WiFi的功能,以WiFi插座为例,描述了串口WiFi在智能家居中的具体应用。最后叙述了基于WiFi技术的智能家居系统。 相似文献
90.
嵌入式系统的运行需要可靠性和实时性的保证,因此良好的可靠性和实时性是嵌入式系统软件设计的重要标准。同时为了使软件系统的鲁棒性更强,嵌入式系统的设计需要一个非常好的软件架构。这里介绍了一种基于MCU平台的嵌入式系统软件架构方法。在这个方法中,事件驱动机制的引入满足了对软件架构的要求,主程序中不仅采用了优先调度机制,同时也加入了软件抗干扰措施,这些都使系统的实时性和可靠性得到了明显的提高。设计实验比较由该方法得到的软件架构与原始软件架构的实时性,得出由该方法优化后的软件架构确实具有更好的性能。 相似文献