全文获取类型
收费全文 | 8438篇 |
免费 | 832篇 |
国内免费 | 350篇 |
专业分类
电工技术 | 558篇 |
综合类 | 497篇 |
化学工业 | 1478篇 |
金属工艺 | 411篇 |
机械仪表 | 460篇 |
建筑科学 | 539篇 |
矿业工程 | 186篇 |
能源动力 | 335篇 |
轻工业 | 793篇 |
水利工程 | 142篇 |
石油天然气 | 363篇 |
武器工业 | 64篇 |
无线电 | 1076篇 |
一般工业技术 | 1233篇 |
冶金工业 | 322篇 |
原子能技术 | 112篇 |
自动化技术 | 1051篇 |
出版年
2024年 | 21篇 |
2023年 | 108篇 |
2022年 | 229篇 |
2021年 | 324篇 |
2020年 | 257篇 |
2019年 | 255篇 |
2018年 | 245篇 |
2017年 | 273篇 |
2016年 | 300篇 |
2015年 | 311篇 |
2014年 | 495篇 |
2013年 | 547篇 |
2012年 | 572篇 |
2011年 | 664篇 |
2010年 | 596篇 |
2009年 | 508篇 |
2008年 | 504篇 |
2007年 | 465篇 |
2006年 | 391篇 |
2005年 | 407篇 |
2004年 | 270篇 |
2003年 | 271篇 |
2002年 | 287篇 |
2001年 | 273篇 |
2000年 | 189篇 |
1999年 | 164篇 |
1998年 | 128篇 |
1997年 | 105篇 |
1996年 | 67篇 |
1995年 | 80篇 |
1994年 | 63篇 |
1993年 | 51篇 |
1992年 | 42篇 |
1991年 | 24篇 |
1990年 | 23篇 |
1989年 | 21篇 |
1988年 | 12篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1981年 | 12篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1975年 | 3篇 |
1973年 | 3篇 |
1970年 | 2篇 |
排序方式: 共有9620条查询结果,搜索用时 15 毫秒
61.
Designing Metallic and Insulating Nanocrystal Heterostructures to Fabricate Highly Sensitive and Solution Processed Strain Gauges for Wearable Sensors 下载免费PDF全文
Woo Seok Lee Seung‐Wook Lee Hyungmok Joh Mingi Seong Haneun Kim Min Su Kang Ki‐Hyun Cho Yun‐Mo Sung Soong Ju Oh 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(47)
All‐solution processed, high‐performance wearable strain sensors are demonstrated using heterostructure nanocrystal (NC) solids. By incorporating insulating artificial atoms of CdSe quantum dot NCs into metallic artificial atoms of Au NC thin film matrix, metal–insulator heterostructures are designed. This hybrid structure results in a shift close to the percolation threshold, modifying the charge transport mechanism and enhancing sensitivity in accordance with the site percolation theory. The number of electrical pathways is also manipulated by creating nanocracks to further increase its sensitivity, inspired from the bond percolation theory. The combination of the two strategies achieves gauge factor up to 5045, the highest sensitivity recorded among NC‐based strain gauges. These strain sensors show high reliability, durability, frequency stability, and negligible hysteresis. The fundamental charge transport behavior of these NC solids is investigated and the combined site and bond percolation theory is developed to illuminate the origin of their enhanced sensitivity. Finally, all NC‐based and solution‐processed strain gauge sensor arrays are fabricated, which effectively measure the motion of each finger joint, the pulse of heart rate, and the movement of vocal cords of human. This work provides a pathway for designing low‐cost and high‐performance electronic skin or wearable devices. 相似文献
62.
Multicolor Photo‐Crosslinkable AIEgens toward Compact Nanodots for Subcellular Imaging and STED Nanoscopy 下载免费PDF全文
Xiaofeng Fang Xuanze Chen Rongqin Li Zhihe Liu Haobin Chen Zezhou Sun Bo Ju Yifei Liu Sean Xiao‐An Zhang Dan Ding Yujie Sun Changfeng Wu 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(41)
Aggregation induced emission (AIE) has attracted considerable interest for the development of fluorescence probes. However, controlling the bioconjugation and cellular labeling of AIE dots is a challenging problem. Here, this study reports a general approach for preparing small and bioconjugated AIE dots for specific labeling of cellular targets. The strategy is based on the synthesis of oxetane‐substituted AIEgens to generate compact and ultrastable AIE dots via photo‐crosslinking. A small amount of polymer enriched with oxetane groups is cocondensed with most of the AIEgens to functionalize the nanodot surface for subsequent streptavidin bioconjugation. Due to their small sizes, good stability, and surface functionalization, the cell‐surface markers and subcellular structures are specifically labeled by the AIE dot bioconjugates. Remarkably, stimulated emission depletion imaging with AIE dots is achieved for the first time, and the spatial resolution is significantly enhanced to ≈95 nm. This study provides a general approach for small functional molecules for preparing small sized and ultrastable nanodots. 相似文献
63.
64.
Tumor Bioimaging: Morphology‐Tailoring of a Red AIEgen from Microsized Rods to Nanospheres for Tumor‐Targeted Bioimaging (Adv. Mater. 16/2016) 下载免费PDF全文
65.
Nanoconfined Nickel@Carbon Core–Shell Cocatalyst Promoting Highly Efficient Visible‐Light Photocatalytic H2 Production 下载免费PDF全文
Ke Zhang Jingrun Ran Bicheng Zhu Huanxin Ju Jiaguo Yu Li Song Shi‐Zhang Qiao 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(38)
The realization of large‐scale solar hydrogen (H2) production relies on the development of high‐performance and low‐cost photocatalysts driven by sunlight. Recently, cocatalysts have demonstrated immense potential in enhancing the activity and stability of photocatalysts. Hence, the rational design of highly active and inexpensive cocatalysts is of great significance. Here, a facile method is reported to synthesize Ni@C core–shell nanoparticles as a highly active cocatalyst. After merging Ni@C cocatalyst with CdS nanorod (NR), a tremendously enhanced visible‐light photocatalytic H2‐production performance of 76.1 mmol g?1 h?1 is achieved, accompanied with an outstanding quantum efficiency of 31.2% at 420 nm. The state‐of‐art characterizations (e.g., synchrotron‐based X‐ray absorption near edge structure) and theoretical calculations strongly support the presence of pronounced nanoconfinement effect in Ni@C core–shell nanoparticles, which leads to controlled Ni core size, intimate interfacial contact and rapid charge transfer, optimized electronic structure, and protection against chemical corrosion. Hence, the combination of nanoconfined Ni@C with CdS nanorod leads to significantly improved photocatalytic activity and stability. This work not only for the first time demonstrates the great potential of using highly active and inexpensive Ni@C core–shell structure to replace expensive Pt in photocatalysis but also opens new avenues for synthesizing cocatalyst/photocatalyst hybridized systems with excellent performance by introducing nanoconfinement effect. 相似文献
66.
Yongfeng Ju Yang Liao Long Zhang Yinglong Sheng Qiang Zhang Danping Chen Ya Cheng Zhizhan Xu Koji Sugioka Katsumi Midorikawa 《Microfluidics and nanofluidics》2011,11(1):111-117
We report on fabrication of large-volume, square-shaped microfluidic chamber embedded in glass by scanning a tightly focused
femtosecond laser beam inside a porous glass immersed in water. After the hollow structure is created in the porous glass
substrate, the fabricated glass sample is post-annealed at 1,050°C during which it can be sintered into a compact glass. By
the use of this technique, a 1 mm × 1 mm × 100 μm microchamber connected to four microfluidic channels is created inside the
transparent glass substrate, showing that our technique allows for fabrication of not only thin channel structures with arbitrary
lengths and configurations, but also hollow structures with infinitely large sizes. 相似文献
67.
Yong‐Kyu Jang Seong Jun Lee Jae Young Lee Yi Li Jae Hoon Hwang Sang Woo Kim Chang Woo Shim Ju Yeon Seo Nam Jin Kim Yi Joon Ahn Nam Hee Kim Seon Hong Ahn Seong Ryong Lee Dae Hee Park Chi Woo Kim 《Journal of the Society for Information Display》2011,19(3):253-257
Abstract— A novel pixel design for vertical‐alignment LCDs with superior transmittance has been developed. The new liquid‐crystal mode, refered to as the hole‐induced vertical‐alignment mode (Hi‐VA), uses a via hole of an organic layer on a TFT substrate to achieve multi‐domain alignment. Compared to the conventional design, the Hi‐VA mode has a transmittance of up to 135% with a contrast ratio of 2000:1. Moreover, the new structure is free from ITO patterning or protrusion on the color‐filter side, which makes the fabrication process simple and low cost. 相似文献
68.
69.
标准可加模糊行为系统在避障控制中的应用 总被引:2,自引:1,他引:1
为了提高月球车控制系统的可靠性和稳定性,保证其运动规划过程的安全性,并针对月球车运行于非结构化环境中,难以用精确的数学模型描述等特点,将行为控制与模糊控制相结合,提出了月球车运动规划的标准可加模糊行为系统,基于凸和的基本性质,对该系统的有界性、连续性、可导性进行了证明;然后设计了权重系数调整控制器,将趋向目标行为以及避障行为以凸组合的方式进行行为融合,并进行了仿真,仿真结果证明了凸组合方法的有效性以及分析结果的正确性。 相似文献
70.