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91.
准确有效地提取肝脏CT序列的轮廓线是腹部软组织三维模型重建与可视化的关键问题之一。针对肝脏轮廓线提取准确性不高的问题, 提出了一种基于先验知识的肝脏轮廓线提取算法。首先利用拉普拉斯算法进行CT图像增强, 再利用基于边缘先验知识的套索模型对感兴趣区域进行半自动的初始化, 最后通过改进的Snake算法准确地提取肝脏CT图像的边缘。针对序列CT肝脏的边缘提取, 提出根据CT图像序列之间的相关性, 将上一幅图像的轮廓线提取结果作为下一幅CT图像边缘提取的初始化点, 接着批处理地提取CT序列的肝脏边缘。实验结果表明:该算法大大减少了手动初始化结果对目标边缘轮廓准确提取的依赖性, 并有效地解决了肝脏轮廓线的提取问题。  相似文献   
92.
With the increasing diversity of application needs and computing units, the server with heterogeneous pro- cessors is more and more widespread. However, conventional SMP/ccNUMA server architecture introduces communication bottleneck between heterogeneous processors and only uses heterogeneous processors as coprocessors, which limits the efficiency and flexibility of using heterogeneous processors. To solve this problem, this paper proposes an intra-server inter- connect fabric that supports both intra-server peer-to-peer interconnection and I/O resource sharing among heterogeneous processors. By connecting processors and I/O devices with the proposed fabric, heterogeneous processors can perform direct communication with each other and run in stand-alone mode with shared intra-server resources. We design the proposed fabric by extending the de-facto system I/O bus protocol PCIe (Peripheral Computer Interconnect Express) and implement it with a single chip cZodiac. By making full use of PCIe's original advantages, the interconnection and the I/O sharing mechanism are light weight and efficient. Evaluations that have been carried out on both the FPGA (Field Programmable Gate Array) prototype and the cycle-accurate simulator demonstrate that our design is feasible and scalable. In addition, our design is suitable for not only the heterogeneous server but also the high density server.  相似文献   
93.
The adsorption of dyes from aqueous solution using diatomite   总被引:2,自引:0,他引:2  
Raw diatomite was calcined at 450 °C for dyes removal from aqueous solution. SEM and FTIR analysis show that the raw diatomite contains organic impurities, which are removed after the calcination. The impurities removal decreases the specific surface area and increases the average pore diameter of raw diatomite, while improves its adsorption capability of dyes. The adsorption isotherm and kinetics experiments of methylene blue onto calcined diatomite were then carried out to investigate the adsorption property. It shows that the adsorption capacity of methylene blue is about 50 mg/g. The adsorption isotherm was fitted by the Langmuir, Freundlich and Redlich-Peterson models, which reveals that the Redlich-Peterson isotherm is the best one. Two kinetic models, pseudo-first order and pseudo-second order, were rearranged for expediently investigating the adsortpion mechanisms. Fitting results show that the pseudo-first-order model is better in describing the adsorption process.  相似文献   
94.
邻氟苯甲腈的合成研究   总被引:6,自引:0,他引:6  
以邻甲苯胺为原料 ,采用四步反应法合成邻氟苯甲腈。 (1)邻甲苯胺经西曼反应合成邻氟甲苯 ,收率 6 5 % ;(2 )邻氟甲苯经氯化、水解得到邻氟苯甲醛 ,以过氧化苯甲酰为氯化引发剂 ,氧化锌为水解催化剂 ,收率 80 % ;(3)邻氟苯甲醛经肟化反应得到邻氟苯甲醛肟 ,收率 87% ;(4)肟用乙酸酐脱水合成出邻氟苯甲腈 ,收率 76 % ,产品质量分数大于 99%。  相似文献   
95.
GOR-C降烯烃催化剂的工业应用   总被引:6,自引:1,他引:6  
大庆炼化公司林源生产指挥部催化裂化装置原料油为典型石蜡基原油的常压渣油,生产的催化汽油中的烯烃含量较高,为此试用长岭炼化公司催化剂厂生产的降烯烃催化剂GOR-C。结果表明,降烯烃效果明显,产品分布无明显变化,能满足现有生产要求,经济效益显著。  相似文献   
96.
本研究采用三种丙烯酸酯单体(M01、M02、M03)和一种紫外光引发剂(I01)配制了紫外光固化胶粘剂,探讨了不同原料配比对产品拉伸剪切强度的影响。实验结果表明:当原料配比为M01:2.07mmol、M02:7.02mmol、M03:13.7mmol、I01:0.585mmol时产品的拉伸剪切强度较好。  相似文献   
97.
不同的加工工艺赋予聚酯纤维特殊的微观结构,为正确认识其微观结构以利于工艺的选择及性能的优化,综述了聚酯纤维微观结构的研究,并作了较详细的分析。  相似文献   
98.
This paper addresses a multi-supplier, multi-affected area, multi-relief, and multi-vehicle relief allocation problem in disaster relief logistics. A multi-objective optimisation model based on disaster scenario information updates is proposed in an attempt to coordinate efficiency and equity through timely and appropriate decisions regarding issues such as vehicle routing and relief allocation. An optimal stopping rule is also proposed to determine the optimum period of delay before responding to disaster, because decision making requires accurate disaster information. The main contribution of this paper is solving relief allocation problem in a novel way by correlating operational research with statistical decision making and Bayesian sequential analysis. Finally, a case is presented based on the post-disaster rescue in Eastern China after supertyphoon Saomai to test the applicability and show the potential advantages of the proposed model.  相似文献   
99.
李嘉  张战 《硅酸盐学报》1992,20(4):387-392
本文主要介绍了用微波等离子体化学气相沉积法(以下简称MP CVD法)以甲醇-氢气混合气和丙酮-氢气混合气为源气体,分别以单晶硅的(111)面和人造金刚石的(100)面为衬底材料,制备出了面积为20mm×20mm厚为10μm的多晶金刚石膜和面积为1.0mm×1.0mm厚为5μm的单晶金刚石膜。通过试验发现,源气体配比和衬底温度对薄膜质量起决定性作用。另外,衬底在反应腔中的位置对薄膜的生成也有很大影响。单晶金刚石膜制备过程中衬底金刚石的晶体取向与金刚石薄膜的生长及质量有密切的关系。在金刚石的(100),(110)和(111)面上分别获得了单晶金刚石膜和金刚石多晶粒子。选用扫描电镜、显微激光拉曼、反射电子衍射对多晶金刚石膜及单晶金刚石膜的性能进行了测试。  相似文献   
100.
Automatically identifying and extracting the target information of a webpage, especially main text, is a critical task in many web content analysis applications, such as information retrieval and automated screen reading. However, compared with typical plain texts, the structures of information on the web are extremely complex and have no single fixed template or layout. On the other hand, the amount of presentation elements on web pages, such as dynamic navigational menus, flashing logos, and a multitude of ad blocks, has increased rapidly in the past decade. In this paper, we have proposed a statistics-based approach that integrates the concept of fuzzy association rules (FAR) with that of sliding window (SW) to efficiently extract the main text content from web pages. Our approach involves two separate stages. In Stage 1, the original HTML source is pre-processed and features are extracted for every line of text; then, a supervised learning is performed to detect fuzzy association rules in training web pages. In Stage 2, necessary HTML source preprocessing and text line feature extraction are conducted the same way as that of Stage 1, after which each text line is tested whether it belongs to the main text by extracted fuzzy association rules. Next, a sliding window is applied to segment the web page into several potential topical blocks. Finally, a simple selection algorithm is utilized to select those important blocks that are then united as the detected topical region (main texts). Experimental results on real world data show that the efficiency and accuracy of our approach are better than existing Document Object Model (DOM)-based and Vision-based approaches.  相似文献   
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