全文获取类型
收费全文 | 1019篇 |
免费 | 59篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 59篇 |
综合类 | 3篇 |
化学工业 | 256篇 |
金属工艺 | 28篇 |
机械仪表 | 24篇 |
建筑科学 | 37篇 |
能源动力 | 50篇 |
轻工业 | 128篇 |
水利工程 | 7篇 |
石油天然气 | 3篇 |
无线电 | 86篇 |
一般工业技术 | 244篇 |
冶金工业 | 9篇 |
原子能技术 | 33篇 |
自动化技术 | 117篇 |
出版年
2023年 | 6篇 |
2022年 | 17篇 |
2021年 | 47篇 |
2020年 | 21篇 |
2019年 | 38篇 |
2018年 | 27篇 |
2017年 | 24篇 |
2016年 | 41篇 |
2015年 | 39篇 |
2014年 | 57篇 |
2013年 | 72篇 |
2012年 | 80篇 |
2011年 | 117篇 |
2010年 | 75篇 |
2009年 | 70篇 |
2008年 | 81篇 |
2007年 | 61篇 |
2006年 | 34篇 |
2005年 | 38篇 |
2004年 | 35篇 |
2003年 | 29篇 |
2002年 | 17篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 9篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1983年 | 2篇 |
排序方式: 共有1084条查询结果,搜索用时 234 毫秒
111.
Synthesis of non-equilibrium phases in immiscible metals mechanically mixed by high pressure torsion
Tatsuya Miyazaki Daisuke Terada Yoji Miyajima Challapalli Suryanarayana Reiko Murao Yoshihiko Yokoyama Kazumasa Sugiyama Minoru Umemoto Yoshikazu Todaka Nobuhiro Tsuji 《Journal of Materials Science》2011,46(12):4296-4301
The structural changes in mechanically mixed metals of immiscible combinations of elements caused by bulk mechanical alloying
(MA) through the use of high pressure torsion (HPT) were investigated in Ag–Ni and Nb–Zr systems. There was no alloying between
Ag and Ni on atomic scale even after 100 rotations of HPT. On the other hand, the β-Zr phase started to appear after HPT 2
rotations in the Nb–Zr system, even though β-Zr is a high temperature phase. Further, Nb and Zr were completely mixed to form
a bcc structured single phase after HPT 100 rotations. The sequence of alloying in the Nb–Zr system during HPT was discussed.
These results clearly suggest that non-equilibrium phases can form in the Nb–Zr system by bulk MA by the use of HPT. 相似文献
112.
Dhinesh Babu Velusamy Richard Hahnkee Kim Kazuto Takaishi Tsuyoshi Muto Daisuke Hashizume Soyoon Lee Masanobu Uchiyama Tetsuya Aoyama Jean-Charles Ribierre Cheolmin Park 《Organic Electronics》2014,15(11):2719-2727
Polymer ferroelectric-gate field effect transistors (Fe-FETs) employing ferroelectric polymer thin films as gate insulators are highly attractive as a next-generation non-volatile memory. For minimizing gate leakage current of a device which arises from electrically defective ferroelectric polymer layer in particular at low operation voltage, the materials design of interlayers between the ferroelectric insulator and gate electrode is essential. Here, we introduce a new solution-processed interlayer of conductive reduced graphene oxides (rGOs) modified with a conjugated block copolymer, poly(styrene-block-paraphenylene) (PS-b-PPP). A FeFET with a solution-processed p-type oligomeric semiconducting channel and ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) insulator exhibited characteristic source–drain current hysteresis arising from ferroelectric polarization switching of a PVDF-TrFE insulator. Our PS-b-PPP modified rGOs (PMrGOs) with conductive moieties embedded in insulating polymer matrix not only significantly reduced the gate leakage current but also efficiently lowered operation voltage of the device. In consequence, the device showed large memory gate voltage window and high ON/OFF source–drain current ratio with excellent data retention and read/write cycle endurance. Furthermore, our PMrGOs interlayers were successfully employed to FeFETs fabricated on mechanically flexible substrates with promising non-volatile memory performance under repetitive bending deformation. 相似文献
113.
Nano Molecular‐Platform: A Protocol to Write Energy Transmission Program Inside a Molecule for Bio‐Inspired Supramolecular Engineering
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Subrata Ghosh Mrinal Dutta Satyajit Sahu Daisuke Fujita Anirban Bandyopadhyay 《Advanced functional materials》2014,24(10):1364-1371
In a coded self‐assembly, a simple code is written in the molecule, which self‐assembles the molecules into a fractal like structure, which acts as a seed for the next step. As the molecule turns into a complex seed, the code transforms into another form and several seeds self‐assemble into another structure, which acts as a seed for the next step. Until now, this technology was considered as a prerogative of nature. Here, a dendritic network is used to write a basic code by synthetically attaching 32 molecular rotors and doping two controller molecules in its cavity. The code live, which is an energy transmission path in the molecule, is imaged. When the energy transmission path or code is triggered, a series of products generate one after another spontaneously. Two examples are: i) dendritic seed (5–6 nm)→paired nanowire (≈12 nm)→nanowire (≈200 nm)→microwire (500 nm)→wire like rod (1–2 μm)→jelly→rectangular sheet (5 μm). ii) dendritic seed→nano‐sphere (20 nm)→micro‐sphere (500 nm)→large balls(1 μm)→oval shape rod (5–10 μm)→Y, L or T shaped rod assembly. The energy level interactions are tracked using spectroscopy how exactly a directed energy transfer code generates multi‐step synthesis from nano to the visible scale. 相似文献
114.
Katsuyuki Shibata Kunio Onizawa Daisuke Kato Yinsheng Li Genki Yagawa 《Nuclear Engineering and Design》2002,214(1-2)
At the Japan Atomic Energy Research Institute (JAERI), research activities related to probabilistic fracture mechanics (PFM) have been conducted as a part of the research program on aging and structural integrity of LWR components. This paper describes the outline of two activities related to PFM, i.e. the development of a PFM code and a contract research on ‘Application of PFM Methodology to Reliability Assessment of Nuclear Components’ implemented by the Japan Welding Engineering Society (JWES). In the former research, a new PFM code PASCAL (PFM Analysis of Structural Components in Aging LWR) was developed. This code has some new functions in models of semi-elliptical crack extension, elastic–plastic fracture analysis based on R6 method and options for the evaluation of overlay cladding and warm pre-stress (WPS) effect. Besides, the code has the function to evaluate the effect of irradiation embrittlement recovery by thermal annealing of a reactor pressure vessel and re-irradiation embrittlement. Based on the analyses on benchmark problem conducted by USNRC/EPRI, performance and functions introduced in the code were examined. Some case studies were also carried out to investigate the influence of various parameters. On the other hand, JAERI has been sponsoring the PFM related activities in relation to the structural integrity of LWR components. These activities have been conducted at JSME and JWES. The objective of this activity has been to provide for the future need of PFM methodology. 相似文献
115.
Haruhiko Kaiya Daisuke Shinbara Jinichi Kawano Motoshi Saeki 《Requirements Engineering》2005,10(4):289-303
This paper introduces a technique to identify requirements discordances among stakeholders. This technique is validated in
experiments. An extended version of the goal-oriented requirements elicitation method, named attributed goal-oriented analysis
(AGORA), and its supporting tool are used. Two types of requirements discordances among stakeholders are defined: the first
arises from the different interpretations by the stakeholders and the second is the result of different evaluations of preferences.
Discordances are detected by the preference matrices in AGORA. Each preference matrix represents both preferences of each
stakeholder and the estimated preferences of other stakeholders. A supporting tool for the AGORA method was developed. This
tool is a groupware that seamlessly combines face-to-face meetings for goal elicitation and distributed individual sessions
for scoring preference values. The experimental results showed that the proposed classification of discordances was sound
and that the occurrences of the requirements discordances could be detected by preference matrices. 相似文献
116.
Daisuke Hiramatsu Kaoru Koyanagi Kaiichirou Hirayama Yoichi Uemura Mikio Kakiuchi Toshiyuki Satoh Akahiro Ara 《Electrical Engineering in Japan》2005,153(3):31-40
This paper describes the effect of mutual leakage reactance in the rotor circuit on the analysis of generator transient characteristics. The authors derive a detailed equivalent circuit model for a 48P‐15,750‐kVA generator, analyze sudden short circuits and asynchronization phenomena of the generator by simulations with an electromagnetic transients program (ATP‐EMTP), and compare the results with experimental data. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(3): 31–40, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20147 相似文献
117.
Takayuki Tomaru Shinji Miyoki Masatake Ohashi Kazuaki Kuroda Takashi Uchiyama Toshikazu Suzuki Akira Yamamoto Takakazu Shintomi Akitoshi Ueda Daisuke Tatsumi Shuichi Sato Koji Arai Masaki Ando Koji Watanabe Kenji Nakamura Masahiko Watanabe Kazuhiko Ito Izumi Kataoka Hiroaki Yamamoto Brett Bochner Yaron Hefetz 《Applied optics》2003,42(7):1306-1307
118.
The tensile fatigue behavior of a cross-ply carbon-carbon (C/C) laminate was examined at room temperature. Tension-tension cyclic fatigue tests were conducted under load control at a sinusoidal frequency of 10 Hz to obtain stress-fracture cycles (S-N) relationship. The fatigue limit of the C/C was found to be 213 MPa (93% of the tensile strength), and no fracture was observed at over 104 cycles. The residual tensile strength of specimens that survived fatigue loading was enhanced with increase in fatigue cycles and applied stress. Observations of the fatigue-loaded specimens revealed that the formation of micro-cracks at the fiber-matrix interfaces was facilitated during fatigue loading. These interfacial cracks were concluded to protect the fibers from being damaged by matrix cracks and this behavior was considered to be the governing mechanism of strength enhancement by fatigue loading. 相似文献
119.
Direct imaging of single-walled carbon nanotubes (SWNTs) suspended on pillar-patterned Si or SiO2 substrates is investigated using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The suspended nanotubes are successfully observed by direct TEM imaging and it is seen that they have either individual or bundles of SWNTs. Low energy (< or =2 keV) SEM produces high contrast images of suspended SWNTs. On the contrary, when SWNTs contact a SiO2 substrate, they are imaged using electron-beam induced current. The image brightness depends on the length of SWNTs. 相似文献
120.