全文获取类型
收费全文 | 1897篇 |
免费 | 108篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 26篇 |
综合类 | 2篇 |
化学工业 | 396篇 |
金属工艺 | 74篇 |
机械仪表 | 138篇 |
建筑科学 | 32篇 |
矿业工程 | 4篇 |
能源动力 | 84篇 |
轻工业 | 132篇 |
水利工程 | 13篇 |
石油天然气 | 4篇 |
武器工业 | 1篇 |
无线电 | 304篇 |
一般工业技术 | 394篇 |
冶金工业 | 116篇 |
原子能技术 | 21篇 |
自动化技术 | 271篇 |
出版年
2024年 | 1篇 |
2023年 | 34篇 |
2022年 | 29篇 |
2021年 | 79篇 |
2020年 | 55篇 |
2019年 | 77篇 |
2018年 | 60篇 |
2017年 | 62篇 |
2016年 | 79篇 |
2015年 | 54篇 |
2014年 | 117篇 |
2013年 | 147篇 |
2012年 | 142篇 |
2011年 | 153篇 |
2010年 | 100篇 |
2009年 | 101篇 |
2008年 | 97篇 |
2007年 | 98篇 |
2006年 | 78篇 |
2005年 | 50篇 |
2004年 | 53篇 |
2003年 | 45篇 |
2002年 | 21篇 |
2001年 | 39篇 |
2000年 | 23篇 |
1999年 | 25篇 |
1998年 | 43篇 |
1997年 | 24篇 |
1996年 | 19篇 |
1995年 | 12篇 |
1994年 | 9篇 |
1993年 | 16篇 |
1992年 | 12篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1977年 | 7篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1964年 | 1篇 |
1941年 | 1篇 |
排序方式: 共有2012条查询结果,搜索用时 703 毫秒
61.
Minh Son Phan Étienne Baudrier Loïc Mazo Mohamed Tajine 《Journal of Mathematical Imaging and Vision》2017,57(2):164-182
This paper introduces a new method for estimating the angular difference between two tomographic projections belonging to a set of projections taken at unknown directions in 2D and 3D. Our method relies on the projection neighbor selection in projection moment space, the calculation of the angular differences between these neighboring projections using moment properties and a projection moment neighborhood graph. The accuracy and the robustness of our method are shown on a test database including fifty 2D and 3D gray-level images at different resolutions and with different levels of noise. 相似文献
62.
Yoen-Ju Son 《Drug development and industrial pharmacy》2013,39(9):948-959
The dry powder inhaler (DPI) has become widely known as a very attractive platform for drug delivery. Many patients have traditionally used DPIs to treat asthma and chronic obstructive pulmonary disease. Recently, the development of new DPIs for delivering therapeutic proteins such as insulin has been accelerated by patient demands, and innovative research. The current market for DPIs has over 20 devices presently in use, and many devices under development for delivering a variety of therapeutic agents. DPIs are recognized as suitable alternatives to pressurized metered dose inhalers for some patients, but the performance of DPI devices may vary according to a given patient's physiological condition. This variation can be associated with the necessary powder dispersion mechanism of each device. As such, much interest has focused on the development of efficient powder dispersion mechanisms, as this effectively minimizes the influence of interpatient variability. This article reviews DPI devices currently available, advantages of newly developed devices, outlines some requirements for future device design. 相似文献
63.
Kiho Bae Kyung Sik Son Jun Woo Kim Suk Won Park Jihwan An Fritz B. Prinz Joon Hyung Shim 《International Journal of Hydrogen Energy》2014
This work elucidated the proton-incorporation mechanism in ALD YSZ1. Isotope 2H2O was used as an oxidant to trace proton incorporation. The ratio of ZrO2 to Y2O3 ALD cycles was varied from 1:1 to 5:1. TEM confirmed that the ALD YSZ films grew as fully crystallized columnar grains in the cubic ZrO2 phase. SIMS indicated that the Y3+ and 2H+ concentrations were linearly correlated, indicating yttria-deposition-induced proton incorporation. XPS confirmed an appreciable amount of Y(OH)3 proportional to the 2H+ content in the ALD YSZ, as was also detected by SIMS. Oxide ion vacancies created by the replacement of ZrO2 with relatively small amounts of Y2O3 provided additional vacancies for proton incorporation, resulting in steeper [2H+]/[Y3+] slopes. 相似文献
64.
So Gun-Baek Yi Hyun-Sik Son Yung-Deug Jin Gang-Gyoo 《International Journal of Control, Automation and Systems》2018,16(6):3047-3054
International Journal of Control, Automation and Systems - This paper presents two nonlinear PID (NPID) controllers which control the glycol temperature of a regasification system for LNG-fuelled... 相似文献
65.
Dae Chul Ha Ha Young Lee Yeo Won Son Soon Hong Yuk Youn Woong Choi Byung Kook Kwak Byung Cheol Shin Cheong-Weon Cho Sun Hang Cho 《Nanoscale research letters》2014,9(1):38
The purpose of this study was to synthesize biocompatible poly(2-hydroxyethyl aspartamide)–C16-iron oxide (PHEA-C16-iron oxide) nanoparticles and to evaluate their efficacy as a contrast agent for magnetic resonance imaging of lymph nodes. The PHEA-C16-iron oxide nanoparticles were synthesized by coprecipitation method. The core size of the PHEA-C16-iron oxide nanoparticles was about 5 to 7 nm, and the overall size of the nanoparticles was around 20, 60, and 150 nm in aqueous solution. The size of the nanoparticles was controlled by the amount of C16. The 3.0-T MRI signal intensity of a rabbit lymph node was effectively reduced after intravenous administration of PHEA-C16-iron oxide with the size of 20 nm. The in vitro and in vivo toxicity tests revealed the high biocompatibility of PHEA-C16-iron oxide nanoparticles. Therefore, PHEA-C16-iron oxide nanoparticles with 20-nm size can be potentially useful as T2-weighted MR imaging contrast agents for the detection of lymph nodes. 相似文献
66.
Thin films of NiO were deposited on Pt/Ta/glass sub-strates using a radio frequency (RF) sputtering method. The NiO thin films showed polycrystalline nature, indicating preferentially (111)-oriented structure. The resistive random access memory (RRAM) capacitor of a Pt/NiO/Pt structure exhibited unipolar switching characteristics and bistable resistivities for 200 repeated switching cycles. Furthermore, RRAM nanobits array was formed on the NiO thin films by applying a bias. The RRAM nanobits had a diameter of approximately 8 nm and were observed via a conducting atomic force microscope (CAFM). The density of the RRAM nanobits array was estimated to be approximately 0.64 Tbit/cm2. 相似文献
67.
So Young Kim Cheol Park Min Yeong Kim Seon Yeong Ji Hyun Hwangbo Hyesook Lee Su Hyun Hong Min Ho Han Jin-Woo Jeong Gi-Young Kim Chang-Gue Son JaeHun Cheong Yung Hyun Choi 《International journal of molecular sciences》2021,22(9)
Coptidis Rhizoma is the dried rhizome from the Coptis chinensis Franch. that has been shown to have a number of beneficial pharmacological properties including antioxidant, anti-inflammatory, and anti-cancer effects. However, the anti-cancer effects of Coptidis Rhizoma on hepatocellular carcinoma (HCC) remain unclear. In this study, we investigated the anti-cancer properties of Coptidis Rhizoma ethanol extract (CR) in HCC Hep3B cells and in a xenograft mouse model. Our results showed that the CR significantly inhibited cell growth and induced apoptosis in Hep3B cells through increased expression of Bcl-2 associated x-protein (Bax) and cleavage of poly-ADP ribose polymerase (PARP), reduced expression of Bcl-2, and activated caspases. CR also increased the generation of intracellular reactive oxygen species (ROS), which caused a loss of mitochondrial membrane potential (MMP, ΔΨm) and activation of the mitochondria-mediated intrinsic apoptosis pathway. Moreover, N-acetylcysteine (NAC), a ROS inhibitor, markedly blocked the effects of CR on apoptotic pathways. CR also induced the expression of light chain 3 (LC3)-I/II, a key autophagy regulator, whereas CR-mediated autophagy was significantly suppressed by NAC. In addition, pre-treatment with NAC perfectly attenuated the inhibition of cell invasion and migration of CR-stimulated Hep3B cells. Furthermore, oral administration of CR suppressed Hep3B tumor growth in xenograft mice without toxicity, alterations to body weight, or changes in hematological and biochemical profiles. Taken together, our findings suggest that CR has anti-tumor effects that result from ROS generation, and may be a potential pharmacological intervention for HCC. 相似文献
68.
In this study, we demonstrate an atomic force microscopy process for manipulating multiferroic BiFeO3 nanodots smaller than 15 nm to desired positions on a Nb‐doped SrTiO3 substrate. For formation of the BiFeO3 nanodot array, nanocrystal movement was achieved using a +1.2 V biased conducting atomic force microscopy (CAFM) followed by nanocrystal attachment to the tip. Using this method, high‐density BiFeO3 nanodot arrays with a density greater than 0.5 Tb/in.2 can be achieved. Perfectly flipped ferroelectric polarization with an external electric field was observed for each BiFeO3 nanodot, whose ferroelectric properties were confirmed using piezoelectric force microscopy. 相似文献
69.
<正>即使在北欧人力费用极高的情况下,卡尔·汉森·桑仍以近乎苛刻的标准进行手工制作,并将这份永恒的经典和淡然的精致传递给全世界的使用者。丹麦设计界流传着这样一则故事:1807年,英国轰炸丹麦首都哥本哈根。时任丹麦国王下令从斯德哥尔摩南部到汉堡北部,用一切办法遍植橡树以躲避战争的创伤,并规定:"每棵树都不可被砍掉,除非新种一棵。"结果,战争的炮火并未殃及丹麦,这些橡树幸运存活了下来,年复一年,长成茂密森林。闻着木香,我们来到哥本哈根繁华都市的心脏处——自1780年起就开始引领丹麦设计与工艺时尚的Bredgade大街,百年品牌卡尔·汉森·桑(Carl Hansen&Son)全球旗舰店就坐落于此。 相似文献
70.
Minh Truong Xuan Nguyen Minh-Kha Nguyen Phuong Thi Thuy Pham Ha Ky Phuong Huynh Son Truong Nguyen 《International Journal of Hydrogen Energy》2021,46(5):3909-3921
One-dimensional (1D) metal-coated Pd structures are efficient catalysts for the ethanol electro-oxidation and promising strategy for minimizing the Pd-loading toward commercialization of direct ethanol fuel cells (DEFCs). Herein, the decorated and core-shell architectures of a novel Pd coating on Ag nanowires (PdAg-NWs) are controllable by a two-step polyol method based on the galvanic replacement reaction. The integration of uniform shell with a low Pd concentration and partial hollow structure onto 1D PdAg-NWs exhibits the highest efficiency for ethanol oxidation reaction (EOR) in alkaline solution. In comparison with Pd nanoparticles (PdNPs/C), the PdAgNWs/C performes 11 times superior EOR activity, and the onset potential shifts 80 mV negatively. The presence of Ag in PdAg-NWs enhances the absorption capacity of ethanol molecules and hydroxyl ions on the active sites, and improves the catalyst tolerance to CO-like intermediates, making them a potential anodic catalyst for DEFCs. 相似文献