全文获取类型
收费全文 | 2225篇 |
免费 | 59篇 |
国内免费 | 7篇 |
学科分类
工业技术 | 2291篇 |
出版年
2023年 | 8篇 |
2022年 | 30篇 |
2021年 | 38篇 |
2020年 | 23篇 |
2019年 | 27篇 |
2018年 | 34篇 |
2017年 | 28篇 |
2016年 | 48篇 |
2015年 | 35篇 |
2014年 | 73篇 |
2013年 | 194篇 |
2012年 | 127篇 |
2011年 | 136篇 |
2010年 | 104篇 |
2009年 | 108篇 |
2008年 | 141篇 |
2007年 | 89篇 |
2006年 | 85篇 |
2005年 | 81篇 |
2004年 | 77篇 |
2003年 | 72篇 |
2002年 | 59篇 |
2001年 | 59篇 |
2000年 | 51篇 |
1999年 | 63篇 |
1998年 | 84篇 |
1997年 | 61篇 |
1996年 | 69篇 |
1995年 | 34篇 |
1994年 | 38篇 |
1993年 | 29篇 |
1992年 | 21篇 |
1991年 | 23篇 |
1990年 | 17篇 |
1989年 | 14篇 |
1988年 | 12篇 |
1987年 | 7篇 |
1986年 | 10篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1974年 | 3篇 |
1973年 | 3篇 |
排序方式: 共有2291条查询结果,搜索用时 10 毫秒
81.
β-Ga2O3 nanobelts were synthesized using a vapor transport process in a controlled ambient. Structural characterization revealed that the as-synthesized samples consisted of monoclinic β-Ga2O3 nanobelts, and the presence of gallium-associated defects was verified using cathodoluminescence (CL). The formation of gallium-associated defects was explained by the insufficiency of the supply of cations, generating gallium vacancies on the (010) facet during growth. Furthermore, field-emission measurements indicated that β-Ga2O3 nanobelts exhibited defect-related electron emission. The turn-on fields of β-Ga2O3 nanobelts increased significantly with the degree of structural defects. For a sample prepared under 15% ambient oxygen, Fowler–Nordheim (F–N) analysis revealed two distinct field-enhancement factors of 1194 and 276, respectively. A correlation between field emission and structural defects was proposed. The experimental results demonstrate the presence of gallium-associated defects, which behave as electron traps, degrading the electron field-emission properties of β-Ga2O3 nanobelts. 相似文献
82.
Chung‐Yung Lee Jacob Yeuk‐Lung Ho Man‐Chun Tseng Hoi‐Sing Kwok 《Journal of the Society for Information Display》2013,21(9):407-410
A new type of nanostructured alignment surface is proposed and demonstrated. As in previous nanostructured alignment surfaces, a large pretilt angle of near 45° can be produced reliably. Moreover, this new structure is fabricated with a mask, and there is no randomness involved. The uniformity and anchoring properties of this new surface have been measured to be of excellent quality. 相似文献
83.
Lu-Yen Chen Chung-Hwei Su Kuen-Yuan Chuang Chun-Ping Lin Shuh-Woei Yu Jo-Ming Tseng 《Korean Journal of Chemical Engineering》2012,29(10):1292-1297
Tert-butyl(2-ethylhexyl)monoperoxy carbonate (TBEHC) 95 mass% is intrinsically a very unstable substance that can induce self-decomposition even under normal atmospheric condition. During storage, TBEHC 95mass% can release an enormous amount of heat if the temperature is higher than the recommended storage temperature, due to the self-accelerating reaction having been ignited. In this study, TBEHC 95mass% was tested by differential scanning calorimetry (DSC) under five heating rates (1, 2, 4, 6, and 8 °C/min) and four isothermal conditions (120, 125, 130, and 135 °C) to evaluate the basic kinetic and safety parameters of time to maximum rate (TMR), self-accelerating decomposition temperature (SADT), and temperature of no return (TNR). Under runaway reaction TBEHC 95 mass% releases a great quantity of heat. This study establishes an important guiding principle for related manufacturing processes worldwide. 相似文献
84.
James Won-Ki Hong Yuan-Kuang Tu Choong Seon Hong Shian-Shyong Tseng Yoshiaki Kiriha Han-Chieh Chao Marat Zhanikeev Wang-Cheol Song 《Journal of Network and Systems Management》2012,20(1):134-142
This article presents a report on APNOMS 2011, which was held September 21–23, 2011 in Taipei, Taiwan. The theme of APNOMS
2011 was “Managing Clouds, Smart Networks and Services.” 相似文献
85.
Abstract In this paper, we present a multi‐purpose medical diagnostic system named AEA — the Acute Exanthem Advisor, and the methodologies of its implementation. AEA provides an accurate diagnosis of acute exanthemas and a complete environment including a user‐friendly interface, reviewing function, record keeping function and explanation function. Therefore, it may serve as an assistant, a record keeper or an educational tool. A prediction program is also provided which is capable of predicting the number of potential patients who are going to have acute exanthemas in the near future. To illustrate the processes of the consultation and the prediction of the AEA, an example is given. Finally, for the 25 different test cases given to the diagnosticians and the AEA, the answers are almost the same, so we can conclude that the performance of the AEA is satisfactory. Now, we are trying to extend the AEA system to be a medical diagnostic net for acute exanthemas, which will be able to be remote accessed through network communications. 相似文献
86.
Shr-Nan Bai Tseung-Yuen Tseng 《Journal of Materials Science: Materials in Electronics》2009,20(7):604-608
ZnO nanowire arrays have been grown on the ZnO film-coated silicon (100) substrates by hydrothermal method, and the deposited
nanowires are found to have a uniform size distribution with sharp hexagonal-shaped tips. The structural and optical properties
of the nanowires were investigated using atomic force microscopy (AFM), X-ray diffraction (XRD), scanning electron microscopy
(SEM), transmission electron microscopy (TEM), and cathodoluminescence (CL) techniques. The XRD and SEM results demonstrate
that the well-aligned ZnO nanowires are single crystalline structure formed along the c-axis orientation. TEM analysis further
confirms that the ZnO nanowires are highly preferred grown along the (002) crystal plane. The spacing between adjacent (002)
lattice planes is estimated as 0.52 nm. The optical properties of the nanowires were measured using CL after annealing in
oxygen and nitrogen atmospheres at 550 °C for various times. The CL spectra in the visible spectrum exhibit two weak deep-level
emission bands that may be attributed to the intrinsic or extrinsic defects. It can be observed that the ZnO nanowires show
different optical behaviors after various annealing times. The dependence of the optical properties on the annealing conditions
is also discussed. 相似文献
87.
Self‐Crack‐Filled Graphene Films by Metallic Nanoparticles for High‐Performance Graphene Heterojunction Solar Cells 下载免费PDF全文
88.
Greta Jarockyte Egle Daugelaite Marius Stasys Urte Statkute Vilius Poderys Ting-Chen Tseng Shan-Hui Hsu Vitalijus Karabanovas Ricardas Rotomskis 《International journal of molecular sciences》2016,17(8)
The uptake and distribution of negatively charged superparamagnetic iron oxide (Fe3O4) nanoparticles (SPIONs) in mouse embryonic fibroblasts NIH3T3, and magnetic resonance imaging (MRI) signal influenced by SPIONs injected into experimental animals, were visualized and investigated. Cellular uptake and distribution of the SPIONs in NIH3T3 after staining with Prussian Blue were investigated by a bright-field microscope equipped with digital color camera. SPIONs were localized in vesicles, mostly placed near the nucleus. Toxicity of SPION nanoparticles tested with cell viability assay (XTT) was estimated. The viability of NIH3T3 cells remains approximately 95% within 3–24 h of incubation, and only a slight decrease of viability was observed after 48 h of incubation. MRI studies on Wistar rats using a clinical 1.5 T MRI scanner were showing that SPIONs give a negative contrast in the MRI. The dynamic MRI measurements of the SPION clearance from the injection site shows that SPIONs slowly disappear from injection sites and only a low concentration of nanoparticles was completely eliminated within three weeks. No functionalized SPIONs accumulate in cells by endocytic mechanism, none accumulate in the nucleus, and none are toxic at a desirable concentration. Therefore, they could be used as a dual imaging agent: as contrast agents for MRI and for traditional optical biopsy by using Prussian Blue staining. 相似文献
89.
One major problem that arises in the design of plastic parts, especially those that are fiber reinforced, is the change of shape and dimension as a result of shrinkage and warpage. These material inhomogeneities are caused by flowinduced fiber orientation, curing, poor thermal mold lay-out, and other processing conditions. This paper presents a simulation that predicts shirnkage and warpage of 3-D compression molded fiber reinforced composite parts. The simulation represents the structure with the 3-noded shell elements used in mold filling simulations. The calculated results indicate that fiber orientation strongly affect the final properties, which vary with different chage locations, have a significant effect on warpage. Unsymmetric curing, caused by uneven mold temperatures, could lead to a thermal moment that could possibly help reduce warpage. 相似文献
90.
Pauline Hibon Heinz von Seggern Hsin-Rong Tseng Christoph Leonhard Manuel Hamburger Gaëlle Béalle 《应用聚合物科学杂志》2020,137(29):48895
Interface control remains a top challenge of solution-processed organic light emitting diodes (OLED) stacks since the device performance heavily relies on it. Film stability of an inkjet deposited and crosslinked layer against subsequent exposure to a suitable inkjet printed solvent has been investigated. Impact of processing solvent (solvent used to prepare the polymer layer) on solution-cast thin film properties has already been shown for polymer films. To our knowledge, this study is the first one analyzing thin films stability against solvent exposure using technology relevant materials processed via inkjet printing (IJP). The outcome of this research showed that the stability of the crosslinked films is affected by the solvent used for ink formulation. These findings are of great interest for multilayered semiconductors devices, such as OLEDs, field-effect transistors and dye-sensitized solar cells. Differential scanning calorimetry (DSC) was used to quantify the efficiency of the polymer crosslinking reaction in pure powder and in thin films, as processed from different solvents. Crosslinking efficiency measured by DSC correlated well with the deformation induced by the solvent and observed on layer surfaces. The interaction in solution between polymer and solvent has also been evaluated to explain its impact on thin film stability against successive solvent printing. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48895. 相似文献