全文获取类型
收费全文 | 146篇 |
免费 | 5篇 |
专业分类
电工技术 | 8篇 |
综合类 | 2篇 |
化学工业 | 28篇 |
金属工艺 | 11篇 |
机械仪表 | 1篇 |
建筑科学 | 2篇 |
能源动力 | 5篇 |
轻工业 | 7篇 |
无线电 | 12篇 |
一般工业技术 | 57篇 |
冶金工业 | 2篇 |
自动化技术 | 16篇 |
出版年
2023年 | 1篇 |
2022年 | 8篇 |
2021年 | 14篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 1篇 |
2014年 | 15篇 |
2013年 | 14篇 |
2012年 | 15篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2001年 | 1篇 |
1993年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有151条查询结果,搜索用时 31 毫秒
1.
Noor-Ul-Ain Babar Yasir Faheem Joya Hassan Khalil Fayyaz Hussain Khurram Saleem Joya 《International Journal of Hydrogen Energy》2021,46(11):7885-7902
Developing only Fe derived bifunctional overall water splitting electrocatalyst both for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) while performing at low onset overpotential and with high catalytic stability is a rare instance. We present here the first demonstration of unique iron-oxide nanobeads (FeOx-NBs) based electrocatalyst executing both OER and HER with high activity. Thin-film electrocatalytic FeOx-NBs assembly is surface grown via simple spray coating (SC). The unique SC/FeOx-NBs propels OER initiating water oxidation just at 1.49 VRHE (η = 260 mV) that is the lowest observable onset potential for OER on simple Fe-oxide based catalytic films reported so far. Catalyst also reveals decently high HER activity and competent overall water splitting performance in the FeOx-NBs two-electrode system as well. Catalyst also presents stable kinetics, with promising high electrochemically active surface area (ECSA) of 1765 cm2, notable Tafel slopes of just 54 mV dec1? (OER) and 85 mV dec1? (HER), high exchange current density of 1.10 mA cm2? (OER), 0.58 mA cm2? (HER) and TOF of 74.29s1?@1.58VRHE, 262s1?@1.62VRHE (OER) and 82.5s1?@-0.45VRHE, 681s1?@-0.56VRHE (HER). 相似文献
2.
Yasir Ali Elsheikh Zakaria Man Faheem Hassan Akhtar 《Korean Journal of Chemical Engineering》2014,31(3):431-435
A study was undertaken to prepare biodiesel via two-step process using ionic liquid as first step catalyst due to the unsuitability of using the straight alkaline-catalyzed transesterification of high FFA presented in crude palm oil (CPO). In the first step, esterification of the FFA presented in the CPO was carried out using butylimidazolium hydrogen sulfate (BIMHSO4), in which the acid value was reduced from 6.93 to 1.02mg KOH/g and then, KOH-catalyzed transesterification was applied. The conversion rate of FFA attained 85.3% when 4.8 wt% of BIMHSO4 was applied to the reaction system containing methanol to CPO ratio of 12: 1 reacted at 170 °C for 150min. The final yield in 97.3% revealed that the process proposed in this study could lead to an excellent biodiesel meeting the ASTM requirements. Furthermore, this new two-step catalysis process could solve the old conventional catalysis process drawbacks. 相似文献
3.
Muhammad Atta Jatoi Abdul Sattar Mazari Shaukat Ali Abro Rashid Mubarak Nabisab Mujawar Ahmed Shoaib Shah Asif Memon Abdul Qayoom Akhter Faheem Wahocho Shafique Ahmed 《Journal of Porous Materials》2021,28(6):1945-1960
Journal of Porous Materials - Compared with traditional battery and super capacitor materials, nanomaterials can significantly improve ion transport and electron conductivity. There are many... 相似文献
4.
Faheem Ullah Fatima Javed Muhammad Bisyrul Hafi Othman Zulkifli Ahmad 《国际聚合物材料杂志》2017,66(16):824-834
There is an urgent need to treat diabetes, and therefore, this work reports on a chitosan-built hydrogel functionalized by a glucose sensing moiety, which simulates pancreatic activity. The effect of external stimuli on various internal properties was investigated to establish the action of the hydrogel. The model drugs, fluorescein (D1) and rhodamine (D2), with a diol architecture, were investigated spectroscopically with 75.94% loading and 65.63% release. Consequently, a ligand to glucose ratio of 2:1 in comparison with a ligand to model drug ratio of 1:1 was addressed. The system was expected to lead to findings on applications for the self-controlled release of insulin in response to blood glucose levels. 相似文献
5.
M. Mumtaz Nawazish A. Khan Faheem Ashraf 《Journal of Superconductivity and Novel Magnetism》2011,24(6):1985-1989
The relatively higher electronegative elements (M = Pd, Nb, Bi, Hg) have been partially doped at Tl sites in Cu0.5Tl0.5−x
M
x
Ba2O4−δ
(x=0,0.25) charge reservoir layer of Cu0.5Tl0.5−x
M
x
Ba2Ca2Cu3O10−δ
superconductor. These elements may retain more oxygen in the charge reservoir layer due to their higher electronegativity
as compared to Tl, and the higher population of oxygen in the charge reservoir layer can optimize the charge carriers’ density
in the conducting CuO2 planes. The optimum density of mobile charge carriers in the conducting CuO2 increases Fermi wave-vector K
F and Fermi velocity v
F of the carriers, which results in the improvement of superconducting properties of the material. 相似文献
6.
We introduce a design of an associative memory array processor (AMAP) to be used in character recognition. The design example is based upon the bit-parallel organization. The AMAP consists of identical processing elements that can store information about a specific position into the pattern and also contain some logic gates to carry out logical operations. No effort has been made to perform either processing or feature extraction of any kind 相似文献
7.
M. Mumtaz Nawazish A. Khan S. M. Hasnain Faheem Ashraf 《Journal of Superconductivity and Novel Magnetism》2012,25(7):2291-2295
Superconductivity has been improved by partial substitution of slightly higher electronegative (M=Bi, Hg) elements at Tl sites in (Cu0.5Tl0.5?x M x )Ba2O4??? (x=0,0.25) charge reservoir layer of (Cu0.5Tl0.5?x M x )Ba2Ca2Cu3O10??? superconductor. These samples were characterized by X-ray diffractometry, dc-resistivity, ac-susceptibility, FTIR absorption spectroscopy, and fluctuation-induced conductivity (FIC) analysis. The FIC analysis has been carried out in the light of Aslamasov?CLarkin (AL) theory on the resistivity versus temperature curves of (Cu0.5Tl0.5?x M x )Ba2Ca2Cu3O10??? superconductor. The microscopic parameters such as cross-over temperature (T o ), zero-temperature coherence length ?? c (0), inter-layer coupling (J), and critical exponents (?? 2D and ?? 3D) have been determined from FIC analysis of these samples and tried to correlate them to the superconductivity order parameters. A?direct correlation between the cross-over temperatures (T o ) and zero resistivity critical temperature {T c (R=0)} and carrier concentration in these samples has been observed. The improvement in T c (R=0) and the shift of 3D AL region to higher temperature values with the doping of Bi and Hg have also been observed. 相似文献
8.
Forecasting the foreign exchange rate is an uphill task. Numerous methods have been used over the years to develop an efficient and reliable network for forecasting the foreign exchange rate. This study utilizes recurrent neural networks (RNNs) for forecasting the foreign currency exchange rates. Cartesian genetic programming (CGP) is used for evolving the artificial neural network (ANN) to produce the prediction model. RNNs that are evolved through CGP have shown great promise in time series forecasting. The proposed approach utilizes the trends present in the historical data for its training purpose. Thirteen different currencies along with the trade-weighted index (TWI) and special drawing rights (SDR) is used for the performance analysis of recurrent Cartesian genetic programming-based artificial neural networks (RCGPANN) in comparison with various other prediction models proposed to date. The experimental results show that RCGPANN is not only capable of obtaining an accurate but also a computationally efficient prediction model for the foreign currency exchange rates. The results demonstrated a prediction accuracy of 98.872 percent (using 6 neurons only) for a single-day prediction in advance and, on average, 92% for predicting a 1000 days’ exchange rate in advance based on ten days of data history. The results prove RCGPANN to be the ultimate choice for any time series data prediction, and its capabilities can be explored in a range of other fields. 相似文献
9.
Roqia Ashraf Tariq Maqbool Mushtaq A. Beigh Arvind H. Jadhav Hasham S. Sofi Faheem A. Sheikh 《应用聚合物科学杂志》2021,138(25):50594
There is an extensive possibility of improving characteristics of fibers used in hard tissue engineering, being hydrophobic and less osteoconductive, resulting in the dynamic growth of new tissues. The current work focuses on the fabrication of nanofibers incorporated with titanium dioxide (TiO2) ''as osteoconductive'' and silver (Ag) ''as self-healing'' nanoparticles (NPs). The incorporation of AgNO3 by in situ method not only helped to impart the antibacterial activity but also changed the contact angle from 81 ± 03° in the case of pristine nanofibers to 74 ± 03°, 61 ± 03°, 50 ± 08°, and 39 ± 1.1°, in the composite scaffolds containing 0.01, 0.03, 0.05, and 0.07 M of Ag salts. The incubation in simulated body fluid at 37°C to induce mineralization on nanofiber scaffolds indicated Ca and P crystals' formation. The antibacterial activity showed significantly more toxicity toward E. coli (8.3 ± 0.9 mm) than S. aureus (1.2 ± 0.1 mm). Biocompatibility studies using MTT assay on the pre-osteoblasts showed that both TiO2 and Ag NPs present in the nanofibers are non-toxic to the bone-like cells. However, results show that a higher concentration of Ag NPs (i.e., 0.07 M) is toxic to cells growing. Finally, all the results suggest that the nanofiber scaffolds have considerable scope for future bone tissue engineering materials. 相似文献
10.
Nasser A.M. Barakat K.A. Khalil Faheem A. Sheikh A.M. Omran Babita Gaihre Soeb M. Khil Hak Yong Kim 《Materials science & engineering. C, Materials for biological applications》2008,28(8):1381-1387
In the present study, subcritical water and alkaline hydrolysis methods are proposed methodologies for extraction of natural hydroxyapatite bioceramic from bovine bone. In these processes, the bovine bones powder were treated by high pressure water at 250 °C for 1 h and 25% (wt) sodium hydroxide at 250 °C for 5 h, respectively. Also the conventional calcination methodology has been utilized as well (T = 850 °C for 1 h). The obtained apatites from the three treatment processes have been characterized by powder X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT IR), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), electron scanning microscopy (SEM), energy dispersive X-ray analysis (EDX) and field emission scanning electron microscopy (FE SEM). FT IR and XRD results affirmed that both the proposed methods and the traditional one can eliminate the collagen and other organic materials present in the bovine bones. The physiochemical characterizations for the obtained apatites have proved that the subcritical water and the alkaline hydrolysis relatively preserve the carbonate content present in the biological apatite, so they yield carbonated hydroxyapatite which is medically preferable. While, the thermal process produces almost hydroxyapatite carbonate-free. 相似文献