全文获取类型
收费全文 | 303篇 |
免费 | 30篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 62篇 |
金属工艺 | 27篇 |
机械仪表 | 14篇 |
建筑科学 | 3篇 |
能源动力 | 10篇 |
轻工业 | 35篇 |
无线电 | 64篇 |
一般工业技术 | 81篇 |
冶金工业 | 8篇 |
原子能技术 | 7篇 |
自动化技术 | 20篇 |
出版年
2023年 | 4篇 |
2022年 | 1篇 |
2021年 | 11篇 |
2020年 | 4篇 |
2019年 | 14篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 26篇 |
2011年 | 35篇 |
2010年 | 35篇 |
2009年 | 30篇 |
2008年 | 22篇 |
2007年 | 13篇 |
2006年 | 10篇 |
2005年 | 13篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有334条查询结果,搜索用时 31 毫秒
121.
An optimal path provides efficient operation of unmanned ground vehicles (UGVs) for many kinds of tasks such as transportation, exploration, surveillance, and search and rescue in unstructured areas that include various unexpected obstacles. Various onboard sensors such as LiDAR, radar, sonar, and cameras are used to detect obstacles around the UGVs. However, their range of view is often limited by movable obstacles or barriers, resulting in inefficient path generation. Here, we present the aerial online mapping system to generate an efficient path for a UGV on a two-dimensional map. The map is updated by projecting obstacles detected in the aerial images taken by an unmanned aerial vehicle through an object detector based on a conventional convolutional neural network. The proposed system is implemented in real-time by a skid steering ground vehicle and a quadcopter with relatively small, low-cost embedded systems. The frameworks and each module of the systems are given in detail to evaluate the performance. The system is also demonstrated in unstructured outdoor environments such as in a football field and a park with unreliable communication links. The results show that the aerial online mapping is effective in path generation for autonomous UGVs in real environments. 相似文献
122.
Sang‐Hyuk Lee In‐Sun Park Hee Hwan Choe Mun‐Pyo Hong Jong Hyun Seo Pal‐gon Kim 《Journal of the Society for Information Display》2011,19(5):380-386
Abstract— To overcome the “pseudo‐puddling effect” in a low‐angle‐tilt transfer system with an oversized glass substrate over 2 m, a vertical transfer is suggested. The aim of the present work is to study the wet‐etching behavior of an aluminum/molybdenum double layer deposited on the glass substrate in a vertical transfer wet etching system and compare it with a typical 5°‐tilt‐transfer system. Compared with the tilt‐transfer wet station, the vertical etching system has three advantages, namely, 50% space savings, higher throughput due to the high etch rate, and good etch uniformity over the entire glass for thin‐film‐transistor application. The computational fluid‐dynamics analysis is used to predict the change of the etch uniformity as a function of the tilt angle of the glass substrate. 相似文献
123.
Multiscale Modulation of Nanocrystalline Cellulose Hydrogel via Nanocarbon Hybridization for 3D Neuronal Bilayer Formation
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dongyoon Kim Subeom Park Insu Jo Seong‐Min Kim Dong Hee Kang Sung‐Pyo Cho Jong Bo Park Byung Hee Hong Myung‐Han Yoon 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(26)
Bacterial biopolymers have drawn much attention owing to their unconventional three‐dimensional structures and interesting functions, which are closely integrated with bacterial physiology. The nongenetic modulation of bacterial (Acetobacter xylinum) cellulose synthesis via nanocarbon hybridization, and its application to the emulation of layered neuronal tissue, is reported. The controlled dispersion of graphene oxide (GO) nanoflakes into bacterial cellulose (BC) culture media not only induces structural changes within a crystalline cellulose nanofibril, but also modulates their 3D collective association, leading to substantial reduction in Young's modulus (≈50%) and clear definition of water–hydrogel interfaces. Furthermore, real‐time investigation of 3D neuronal networks constructed in this GO‐incorporated BC hydrogel with broken chiral nematic ordering revealed the vertical locomotion of growth cones, the accelerated neurite outgrowth (≈100 µm per day) with reduced backward travel length, and the efficient formation of synaptic connectivity with distinct axonal bifurcation abundancy at the ≈750 µm outgrowth from a cell body. In comparison with the pristine BC, GO‐BC supports the formation of well‐defined neuronal bilayer networks with flattened interfacial profiles and vertical axonal outgrowth, apparently emulating the neuronal development in vivo. We envisioned that our findings may contribute to various applications of engineered BC hydrogel to fundamental neurobiology studies and neural engineering. 相似文献
124.
3D Neuronal Networks: Multiscale Modulation of Nanocrystalline Cellulose Hydrogel via Nanocarbon Hybridization for 3D Neuronal Bilayer Formation (Small 26/2017)
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
125.
126.
127.
A study on the distribution of chlorination by-products (CBPs) in treated water in Korea 总被引:9,自引:0,他引:9
Fifteen chlorination by-products were analyzed in 416 water samples collected from 35 water treatment plants in Korea from 1996 to 1998. These samples were divided into five groups according to water sources (Han-river, Nakdong-river, Youngsan-river, Kum-river and Cheju) and detected CBPs were classified into six classes (trihalomethanes; THMs, haloacetic acids; HAAs, haloacetonitriles: HANs haloketones; HKs, chloralhydrate; CH, chloropicrin; CP) and then, it was observed the detection tendency and frequency of CBPs in each water source. The total concentration of CBPs in treated water from Nakdong-river or Han-river was higher than those from the other rivers. And the distribution pattern of each class of CBPs was similar in all water sources. THMs were the highest portion in the range of 40-50%, and HAAs and HANs were 28-35 and 9-15%, respectively. And there was a strong correlation between HANs and HKs (r=0.813). Each and total concentrations of CBPs showed to be more affected by the water source in two-way analysis of variance (two-way ANOVA) among the concentration of CBPs, the source of water and season. 相似文献
128.
Young Tack Lee Pyo Jin Jeon Jae Hyun Han Jongtae Ahn Hyo Sun Lee June Yeong Lim Won Kook Choi Jin Dong Song Min‐Chul Park Seongil Im Do Kyung Hwang 《Advanced functional materials》2017,27(47)
2D layered van der Waals (vdW) atomic crystals are an emerging class of new materials that are receiving increasing attention owing to their unique properties. In particular, the dangling‐bond‐free surface of 2D materials enables integration of differently dimensioned materials into mixed‐dimensional vdW heterostructures. Such mixed‐dimensional heterostructures herald new opportunities for conducting fundamental nanoscience studies and developing nanoscale electronic/optoelectronic applications. This study presents a 1D ZnO nanowire (n‐type)–2D WSe2 nanosheet (p‐type) vdW heterojunction diode for photodetection and imaging process. After amorphous fluoropolymer passivation, the ZnO–WSe2 diode shows superior performance with a much‐enhanced rectification (ON/OFF) ratio of over 106 and an ideality factor of 3.4–3.6 due to the carbon–fluorine (C? F) dipole effect. This heterojunction device exhibits spectral photoresponses from ultraviolet (400 nm) to near infrared (950 nm). Furthermore, a prototype visible imager is demonstrated using the ZnO–WSe2 heterojunction diode as an imaging pixel. To the best of our knowledge, this is the first demonstration of an optoelectronic device based on a 1D–2D hybrid vdW heterojunction. This approach using a 1D ZnO–2D WSe2 heterojunction paves the way for the further development of electronic/optoelectronic applications using mixed‐dimensional vdW heterostructures. 相似文献
129.
Hierarchically Nanostructured 1D Conductive Bundle Yarn‐Based Triboelectric Nanogenerators
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Won Bae Ko Da Song Choi Choong Hyun Lee Jung Yup Yang Gap Soo Yoon Jin Pyo Hong 《Advanced materials (Deerfield Beach, Fla.)》2017,29(47)
Wearable 2D textile platforms are the subject of intense focus to promote the creation of outstanding added value for textile‐based applications in consumer electronics, energy harvesting, and storage. In particular, 2D textile‐based energy harvesters from the living environment of human motions exhibit insufficient geometry deformation and low current density, thereby providing low power generation. Therefore, a unique starting point in this work is the use of 1D conductive bundle yarn (1D CBY) as a generic step for the development of 1D CBY‐based energy harvesters through a weaving technology. The performance of 1D CBY‐based triboelectric nanogenerators (1D CBY‐TENGs) is addressed through contact electrification between the arrays of nanostructured 1D CBYs and 2D conductive fabric serving as tribomaterials. The manipulation of hierarchically nanostructured surfaces on the 1D CBYs by the hydrothermal process represents one of the crucial approaches of enhancing power generation through a large contact surface area. The 1D CBY‐TENGs with a variation in the number of 1D CBY and stack configurations are also tested as a simple integration scheme, confirming the expected 1D CBY number and stack dependency in the output performance. 相似文献
130.
Analysis of the Bipolar Resistive Switching Behavior of a Biocompatible Glucose Film for Resistive Random Access Memory
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sung Pyo Park Young Jun Tak Hee Jun Kim Jin Hyeok Lee Hyukjoon Yoo Hyun Jae Kim 《Advanced materials (Deerfield Beach, Fla.)》2018,30(26)
Resistive random access memory (RRAM) devices are fabricated through a simple solution process using glucose, which is a natural biomaterial for the switching layer of RRAM. The fabricated glucose‐based RRAM device shows nonvolatile bipolar resistive switching behavior, with a switching window of 103. In addition, the endurance and data retention capability of glucose‐based RRAM exhibit stable characteristics up to 100 consecutive cycles and 104 s under constant voltage stress at 0.3 V. The interface between the top electrode and the glucose film is carefully investigated to demonstrate the bipolar switching mechanism of the glucose‐based RRAM device. The glucose based‐RRAM is also evaluated on a polyimide film to verify the possibility of a flexible platform. Additionally, a cross‐bar array structure with a magnesium electrode is prepared on various substrates to assess the degradability and biocompatibility for the implantable bioelectronic devices, which are harmless and nontoxic to the human body. It is expected that this research can provide meaningful insights for developing the future bioelectronic devices. 相似文献