全文获取类型
收费全文 | 13418篇 |
免费 | 1141篇 |
国内免费 | 602篇 |
专业分类
电工技术 | 799篇 |
技术理论 | 1篇 |
综合类 | 813篇 |
化学工业 | 2095篇 |
金属工艺 | 877篇 |
机械仪表 | 759篇 |
建筑科学 | 925篇 |
矿业工程 | 358篇 |
能源动力 | 409篇 |
轻工业 | 849篇 |
水利工程 | 238篇 |
石油天然气 | 834篇 |
武器工业 | 93篇 |
无线电 | 1683篇 |
一般工业技术 | 1645篇 |
冶金工业 | 818篇 |
原子能技术 | 165篇 |
自动化技术 | 1800篇 |
出版年
2024年 | 78篇 |
2023年 | 206篇 |
2022年 | 343篇 |
2021年 | 519篇 |
2020年 | 387篇 |
2019年 | 340篇 |
2018年 | 412篇 |
2017年 | 438篇 |
2016年 | 392篇 |
2015年 | 495篇 |
2014年 | 643篇 |
2013年 | 702篇 |
2012年 | 801篇 |
2011年 | 830篇 |
2010年 | 722篇 |
2009年 | 717篇 |
2008年 | 717篇 |
2007年 | 735篇 |
2006年 | 715篇 |
2005年 | 606篇 |
2004年 | 400篇 |
2003年 | 461篇 |
2002年 | 450篇 |
2001年 | 391篇 |
2000年 | 373篇 |
1999年 | 370篇 |
1998年 | 347篇 |
1997年 | 319篇 |
1996年 | 310篇 |
1995年 | 212篇 |
1994年 | 174篇 |
1993年 | 128篇 |
1992年 | 94篇 |
1991年 | 84篇 |
1990年 | 67篇 |
1989年 | 45篇 |
1988年 | 33篇 |
1987年 | 26篇 |
1986年 | 20篇 |
1985年 | 12篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
Chengjun Yao Yixun Liu Jianhua Yao Dongxiao Zhuang Jinsong Wu Zhiyong Qin Ying Mao Liangfu Zhou 《Computer methods and programs in biomedicine》2014
Background
Preoperatively acquired diffusion tensor image (DTI) and blood oxygen level dependent (BOLD) have been proved to be effective in providing more anatomical and functional information; however, the brain deformation induced by brain shift and tumor resection severely impairs the correspondence between the image space and the patient space in image-guided neurosurgery.Method
To address the brain deformation, we developed a hybrid non-rigid registration method to register high-field preoperative MRI with low-field intra-operative MRI in order to recover the deformation induced by brain shift and tumor resection. The registered DTI and BOLD are fused with low-field intra-operative MRI for image-guided neurosurgery.Results
The proposed hybrid registration method was evaluated by comparing the landmarks predicted by the hybrid registration method with the landmarks identified in the low-field intra-operative MRI for 10 patients. The prediction error of the hybrid method is 1.92 ± 0.54 mm, and the compensation accuracy is 74.3 ± 5.0%. Compared to the landmarks far from the resection region, those near the resection region demonstrated a higher compensation accuracy (P-value = .003) although these landmarks had larger initial displacements.Conclusions
The proposed hybrid registration method is able to bring preoperatively acquired BOLD and DTI into the operating room and compensate for the deformation to augment low-field intra-operative MRI with rich anatomical and functional information. 相似文献53.
54.
Qin Zou Yu Cao Qingquan Li Qingzhou Mao Song Wang 《Machine Vision and Applications》2014,25(7):1841-1858
Recent inpainting techniques usually require human interactions which are labor intensive and dependent on the user experiences. In this paper, we introduce an automatic inpainting technique to remove undesired fence-like structures from images. Specifically, the proposed technique works on the RGBD images which have recently become cheaper and easier to obtain using the Microsoft Kinect. The basic idea is to segment and remove the undesired fence-like structures by using both depth and color information, and then adapt an existing inpainting algorithm to fill the holes resulting from the structure removal. We found that it is difficult to achieve a satisfactory segmentation of such structures by only using the depth channel. In this paper, we use the depth information to help identify a set of foreground and background strokes, with which we apply a graph-cut algorithm on the color channels to obtain a more accurate segmentation for inpainting. We demonstrate the effectiveness of the proposed technique by experiments on a set of Kinect images. 相似文献
55.
As an effective approach for multi-input multi-output regression estimation problems, a multi-dimensional support vector regression (SVR), named M-SVR, is generally capable of obtaining better predictions than applying a conventional support vector machine (SVM) independently for each output dimension. However, although there are many generalization error bounds for conventional SVMs, all of them cannot be directly applied to M-SVR. In this paper, a new leave-one-out (LOO) error estimate for M-SVR is derived firstly through a virtual LOO cross-validation procedure. This LOO error estimate can be straightway calculated once a training process ended with less computational complexity than traditional LOO method. Based on this LOO estimate, a new model selection methods for M-SVR based on multi-objective optimization strategy is further proposed in this paper. Experiments on toy noisy function regression and practical engineering data set, that is, dynamic load identification on cylinder vibration system, are both conducted, demonstrating comparable results of the proposed method in terms of generalization performance and computational cost. 相似文献
56.
壁面处湍流速度梯度脉动的测量对于深入了解壁面附近湍流的结构和传热、传质是很重要的.本文叙述了电化学法测量的原理,介绍了用一半圆电极对同时测量壁面上二维湍流速度梯度脉动的方法和测量结果.在直径0.194m的充分发展圆管湍流中,用碘和碘化钾溶液作为流动介质,半圆电极对直径为5×10~-4m,测得壁面处轴向和周向速度梯度的湍流脉动强度分别为0.3—0.33和0.11—0.12. 相似文献
57.
58.
In this article, motion/force control problem of a class of constrained mobile manipulators with unknown dynamics is considered. The system is subject to both holonomic and nonholonomic constraints. An adaptive recurrent neural network controller is proposed to deal with the unmodelled system dynamics. The proposed control strategy guarantees that the system motion asymptotically converges to the desired manifold while the constraint force remains bounded. In addition, an adaptive method is proposed to identify the contact surface. Simulation studies are carried out to verify the validation of the proposed approach. 相似文献
59.
60.
移动计算环境中带宽具有非对称性,并且移动设备资源有限,传统的缓存管理策略需要占用大量的设备计算资源和网络带宽,有效的缓存管理技术能够极大提高移动计算的性能。对此提出一系列的针对移动计算的缓存管理策略。首先根据用户访问频率建立对应的具有生命周期的数据项缓存,然后使用自适应一致性维护策略维护缓存的一致性。通过实验分析,提出的管理策略能够很好地降低带宽占用,并且有效地减少对移动客户端的资源需求。 相似文献