全文获取类型
收费全文 | 5611篇 |
免费 | 2113篇 |
国内免费 | 273篇 |
专业分类
电工技术 | 65篇 |
综合类 | 142篇 |
化学工业 | 1996篇 |
金属工艺 | 243篇 |
机械仪表 | 69篇 |
建筑科学 | 41篇 |
矿业工程 | 149篇 |
能源动力 | 420篇 |
轻工业 | 408篇 |
水利工程 | 4篇 |
石油天然气 | 72篇 |
武器工业 | 23篇 |
无线电 | 1126篇 |
一般工业技术 | 2959篇 |
冶金工业 | 188篇 |
原子能技术 | 25篇 |
自动化技术 | 67篇 |
出版年
2024年 | 77篇 |
2023年 | 297篇 |
2022年 | 332篇 |
2021年 | 587篇 |
2020年 | 648篇 |
2019年 | 700篇 |
2018年 | 688篇 |
2017年 | 794篇 |
2016年 | 688篇 |
2015年 | 642篇 |
2014年 | 675篇 |
2013年 | 553篇 |
2012年 | 433篇 |
2011年 | 282篇 |
2010年 | 141篇 |
2009年 | 80篇 |
2008年 | 46篇 |
2007年 | 62篇 |
2006年 | 44篇 |
2005年 | 35篇 |
2004年 | 34篇 |
2003年 | 24篇 |
2002年 | 11篇 |
2001年 | 19篇 |
2000年 | 12篇 |
1999年 | 19篇 |
1998年 | 18篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1951年 | 9篇 |
排序方式: 共有7997条查询结果,搜索用时 10 毫秒
131.
Xiaoxi Zhou Bin Luo Ke Kang Yujia Zhang Peipei Jiang Fang Lan Qiangying Yi Yao Wu 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(17)
Downstream studies of circulating tumor cells (CTCs), which may provide indicative evaluation information for therapeutic efficacy, cancer metastases, and cancer prognosis, are seriously hindered by the poor purity of enriched CTCs as large amounts of interfering leukocytes still nonspecifically bind to the isolation platform. In this work, biomimetic immunomagnetic nanoparticles (BIMNs) with the following features are designed: i) the leukocyte membrane camouflage, which could greatly reduce homologous leukocyte interaction and actualize high‐purity CTCs isolation, is easily extracted by graphene nanosheets; ii) facile antibody conjugation can be achieved through the “insertion” of biotinylated lipid molecules into leukocyte‐membrane‐coated nanoparticles and streptavidin conjunction; iii) layer‐by‐layer assembly techniques could integrate high‐magnetization Fe3O4 nanoparticles and graphene nanosheets efficiently. Consequently, the resulting BIMNs achieve a capture efficiency above 85.0% and CTCs purity higher than 94.4% from 1 mL blood with 20–200 CTCs after 2 min incubation. Besides, 98.0% of the isolated CTCs remain viable and can be directly cultured in vitro. Moreover, application of the BIMNs to cancer patients' peripheral blood shows good reproducibility (mean relative standard deviation 8.7 ± 5.6%). All results above suggest that the novel biomimetic nanoplatform may serve as a promising tool for CTCs enrichment and detection from clinical samples. 相似文献
132.
石墨烯是一种具有独特结构和优异性能的二维材料,自从2004年其被成功制备以来,迅速成为材料、化学、物理和工程领域的研究热点。目前,制备石墨烯的方法有很多,包括化学氧化还原法、化学气相沉积法以及液相剥离法等,其中液相剥离法是一种非常重要的制备方法,有望实现高质量石墨烯的工业化生产。主要总结了以超声波作为动力的液相剥离法的相关报道,并对其进行了分类讨论。解释了超声波的作用,着重介绍了以纯溶剂和二元溶剂为剥离溶剂的液相剥离方法,以及助剂辅助剥离的液相剥离方法的研究进展,并综述了各种方法的剥离机理。同时提出了提高石墨剥离效率的方法,指出了选择新溶剂或助剂的原则,旨在为研究更高效生产高质量石墨烯的方法提供参考。 相似文献
133.
Xiaozhi Xu Ding Yi Zhichang Wang Jiachen Yu Zhihong Zhang Ruixi Qiao Zhanghao Sun Zonghai Hu Peng Gao Hailin Peng Zhongfan Liu Dapeng Yu Enge Wang Ying Jiang Feng Ding Kaihui Liu 《Advanced materials (Deerfield Beach, Fla.)》2018,30(6)
Metal corrosion is a long‐lasting problem in history and ultrahigh anticorrosion is one ultimate pursuit in the metal‐related industry. Graphene, in principle, can be a revolutionary material for anticorrosion due to its excellent impermeability to any molecule or ion (except for protons). However, in real applications, it is found that the metallic graphene forms an electrochemical circuit with the protected metals to accelerate the corrosion once the corrosive fluids leaks into the interface. Therefore, whether graphene can be used as an excellent anticorrosion material is under intense debate now. Here, graphene‐coated Cu is employed to investigate the facet‐dependent anticorrosion of metals. It is demonstrated that as‐grown graphene can protect Cu(111) surface from oxidation in humid air lasting for more than 2.5 years, in sharp contrast with the accelerated oxidation of graphene‐coated Cu(100) surface. Further atomic‐scale characterization and ab initio calculations reveal that the strong interfacial coupling of the commensurate graphene/Cu(111) prevents H2O diffusion into the graphene/Cu(111) interface, but the one‐dimensional wrinkles formed in the incommensurate graphene on Cu(100) can facilitate the H2O diffusion at the interface. This study resolves the contradiction on the anticorrosion capacity of graphene and opens a new opportunity for ultrahigh metal anticorrosion through commensurate graphene coating. 相似文献
134.
Alternating Stacked Graphene‐Conducting Polymer Compact Films with Ultrahigh Areal and Volumetric Capacitances for High‐Energy Micro‐Supercapacitors 下载免费PDF全文
135.
136.
pH Sensing Properties of Flexible,Bias‐Free Graphene Microelectrodes in Complex Fluids: From Phosphate Buffer Solution to Human Serum 下载免费PDF全文
Jinglei Ping Jacquelyn E. Blum Ramya Vishnubhotla Amey Vrudhula Carl H. Naylor Zhaoli Gao Jeffery G. Saven Alan T. Charlie Johnson 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(30)
Advances in techniques for monitoring pH in complex fluids can have a significant impact on analytical and biomedical applications. This study develops flexible graphene microelectrodes (GEs) for rapid (<5 s), very‐low‐power (femtowatt) detection of the pH of complex biofluids by measuring real‐time Faradaic charge transfer between the GE and a solution at zero electrical bias. For an idealized sample of phosphate buffer solution (PBS), the Faradaic current is varied monotonically and systematically with the pH, with a resolution of ≈0.2 pH unit. The current–pH dependence is well described by a hybrid analytical–computational model, where the electric double layer derives from an intrinsic, pH‐independent (positive) charge associated with the graphene–water interface and ionizable (negative) charged groups. For ferritin solution, the relative Faradaic current, defined as the difference between the measured current response and a baseline response due to PBS, shows a strong signal associated with ferritin disassembly and the release of ferric ions at pH ≈2.0. For samples of human serum, the Faradaic current shows a reproducible rapid (<20 s) response to pH. By combining the Faradaic current and real‐time current variation, the methodology is potentially suitable for use to detect tumor‐induced changes in extracellular pH. 相似文献
137.
138.
Kuan‐I Ho Jia‐Hong Liao Chi‐Hsien Huang Chang‐Lung Hsu Wenjing Zhang Ang‐Yu Lu Lain‐Jong Li Chao‐Sung Lai Ching‐Yuan Su 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(5):989-997
In this study, the scalable and one‐step fabrication of single atomic‐layer transistors is demonstrated by the selective fluorination of graphene using a low‐damage CF4 plasma treatment, where the generated F‐radicals preferentially fluorinated the graphene at low temperature (<200 °C) while defect formation was suppressed by screening out the effect of ion damage. The chemical structure of the C–F bonds is well correlated with their optical and electrical properties in fluorinated graphene, as determined by X‐ray photoelectron spectroscopy, Raman spectroscopy, and optical and electrical characterizations. The electrical conductivity of the resultant fluorinated graphene (F‐graphene) was demonstrated to be in the range between 1.6 kΩ/sq and 1 MΩ/sq by adjusting the stoichiometric ratio of C/F in the range between 27.4 and 5.6, respectively. Moreover, a unique heterojunction structure of semi‐metal/semiconductor/insulator can be directly formed in a single layer of graphene using a one‐step fluorination process by introducing a Au thin‐film as a buffer layer. With this heterojunction structure, it would be possible to fabricate transistors in a single graphene film via a one‐step fluorination process, in which pristine graphene, partial F‐graphene, and highly F‐graphene serve as the source/drain contacts, the channel, and the channel isolation in a transistor, respectively. The demonstrated graphene transistor exhibits an on‐off ratio above 10, which is 3‐fold higher than that of devices made from pristine graphene. This efficient transistor fabrication method produces electrical heterojunctions of graphene over a large area and with selective patterning, providing the potential for the integration of electronics down to the single atomic‐layer scale. 相似文献
139.
140.
构建一种基于氧化石墨烯/聚吡咯-铟锡氧化物GO/PPy-ITO(Graphene Oxide/Polypyrrole-Indium Tin Oxide)微电极的细胞阻抗生物传感器并用于细胞粘附增殖行为学检测。ITO微电极采用光刻技术对感光干膜绝缘层蚀刻而成,通过一步法电聚合技术在ITO微电极表面沉积GO/PPy纳米复合膜制备GO/PPy-ITO微电极;形状测量激光显微镜和扫描电子显微镜分别对GO/PPy表面粗糙度和拓扑形貌进行表征;电化学循环伏安法及阻抗谱表征GO/PPy-ITO微电极的电化学性质;人肺癌细胞株A549粘附、铺展和增殖实验考察GO/PPy界面的生物相容性;以GO/PPy-ITO微电极作为传感电极,利用电化学阻抗谱技术对A549细胞的粘附增殖行为进行检测。结果显示,ITO微电极表面上电沉积的GO/PPy纳米复合物表面平整,分布大量的微孔结构;电化————————————学实验结果显示GO/PPy-ITO微电极比裸ITO微电极具有更低的阻抗特征和更高的电化学活性;GO/PPy比纯PPy膜更能促进A549细胞粘附、铺展和增殖;GO/PPy-ITO微电极表面A549细胞的粘附增殖行为改变电极系统的阻抗谱特征,通过对阻抗谱数据进行等效电路拟合分析获得细胞粘附增殖行为学信息。本文发展的GO/PPy-ITO微电极兼具优良的电化学性质和细胞生物相容性,基于该电极系统构建的细胞阻抗生物传感器可用于细胞病理生理学行为、药物筛选等研究领域。 相似文献