全文获取类型
收费全文 | 230篇 |
免费 | 25篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 62篇 |
金属工艺 | 7篇 |
机械仪表 | 16篇 |
建筑科学 | 7篇 |
能源动力 | 16篇 |
轻工业 | 31篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 22篇 |
一般工业技术 | 37篇 |
冶金工业 | 5篇 |
自动化技术 | 44篇 |
出版年
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 25篇 |
2020年 | 16篇 |
2019年 | 18篇 |
2018年 | 33篇 |
2017年 | 17篇 |
2016年 | 19篇 |
2015年 | 16篇 |
2014年 | 20篇 |
2013年 | 31篇 |
2012年 | 7篇 |
2011年 | 14篇 |
2010年 | 14篇 |
2009年 | 6篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 1篇 |
排序方式: 共有256条查询结果,搜索用时 109 毫秒
101.
Hadi Beitollahi Zahra Dourandish Somayeh Tajik Mohammad Reza Ganjali Parviz Norouzi Farnoush Faridbod 《中国稀土学报(英文版)》2018,36(7):750-757
The current work focuses on the development of a sensitive and selective electrochemical device based on a graphite screen printed electrode modified with Dy_2(WO_4)_3 nanoparticles(DWO/SPE) for the analysis of epinephrine in samples also containing acetylcholine. The study proves that the sensor has excellent electron-mediating behavior in the oxidation of epinephrine in a 0.1 mol/L phosphate buffer solution(PBS)(pH 7.0). The application of the DWO/SPE in differential pulse voltammetry(DPV) is found to lead to distinct response for the oxidation of epinephrine and acetylcholine, with the potentials of the epinephrine and acetylcholine peaks(△E_p) to be 550 mV apart. The detection limits of the method for epinephrine and acetylcholine are 0.5 and 0.7 μmol/L(S/N = 3) and the responses are found to be linear in the concentration ranges of 1.0-900.0 μmol/L and 1.0-1200.0 μmol/L in a PBS buffer(pH = 7.0)respectively. The modified electrode was used for the detection of epinephrine and acetylcholine in real samples and found to produce satisfactory results. These results can be a proof that Dy_2(WO_4)_3 nanoparticles can find promising applications in electrochemical sensors to be used for the analysis of(bio)chemical species. 相似文献
102.
The electrolytic hydrogen evolution reaction (HER) on platinum coated nanoporous gold film (PtNPGF) electrode is demonstrated. The deposition of platinum occurred as a spontaneous redox process in which a copper layer, obtained by underpotential deposition, was oxidized by platinum ions, which were reduced and simultaneously deposited. The present method could provide a very low Pt-loading electrode and the results demonstrated that ultra thin Pt coating effected efficiently and behaved as the nanostructured Pt for electrocatalytic hydrogen evolution reaction. The loading of Pt was calculated as 4.2 × 10−3 μg cm−2 for PtNPGF electrode. The current density at −0.4 V and −0.8 V vs. Ag/AgCl was as high as 0.66 A μg−1 Pt and 3 A μg−1 Pt, respectively and the j0 was evaluated as 0.03 mA cm−2 or 8 mA μg−1 Pt. The results indicated that increasing electrode area had no catalytic effect, but the nanostructure nature of as-fabricated electrode and submonolayer deposition of copper resulted in electrocatalytic activity for PtNPGF electrode. 相似文献
103.
104.
105.
106.
107.
108.
Ultrasonic bath cleaning technique was successfully applied for the pre-treatment of the gas diffusion electrode (GDE) before membrane-electrode assembly (MEA). The results show that ultrasonic bath pre-treatment significantly improves MEA performance in all current density regions, especially at the high current density region. This technique also reduces the time of the MEA conditioning, at least 30%. Electrochemical impedance spectroscopy (EIS) results demonstrate that pre-treatment of GDEs by ultrasonic bath technique leads to a decrease in the cell impedance especially in the ohmic resistance, which is very well due to the GDE cleaning process. 相似文献
109.
110.
Saeed Ayat Hojjat A. Farahani Mehdi Aghamohamadi Mahmood Alian Somayeh Aghamohamadi Zeynab Kazemi 《Neural computing & applications》2013,23(5):1381-1386
New approaches adopted by behavioral science researchers to use modern modeling and predicting tools such as artificial neural networks have necessitated the study and comparison of the efficiency of different learning algorithms of these networks for various applications. By using well-known and different learning algorithms, this study examines and compares the Perceptron artificial neural network as predicting tendency for suicide based on risk factors within 33 input parameters framework used in neural network. To find the “best” learning algorithm, the algorithms were compared in terms of train and capability. The experimental data were collected through questionnaires distributed among 800 university students. All questionnaires used in this research were standardized with appropriate validity and reliability. The study findings indicated that LM and BFG algorithms had close evaluation in terms of performance index and true acceptance rate (TAR), and they showed higher predictive accuracy than the other algorithms. Furthermore, CFG algorithm had the minimum training time. 相似文献