全文获取类型
收费全文 | 143篇 |
免费 | 10篇 |
学科分类
工业技术 | 153篇 |
出版年
2023年 | 6篇 |
2022年 | 4篇 |
2021年 | 14篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 11篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 10篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 6篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有153条查询结果,搜索用时 15 毫秒
1.
Sammar Minallah Erum Pervaiz M. Usman Yousaf M. Bilal Khan Niazi Liu Honghong 《分离科学与技术》2020,55(15):2623-2641
ABSTRACT Current health situations have instigated increased frequency of taking antibiotics for cure of infections but this amplified use is posing threats to environment. This research is focused to remove Tetracycline (TC), an antibiotic from water, using an advanced nanohybrid that compact the properties of adsorbent and photocatalyst. Compared to conventional methods for remediation of TC, large surface area (452 m2g?1) adsorbent photocatalyst hybrid (APH) g-C3N4/α-MoO3/ZIF-67 (CMZ) have found much effective as 97% degradation of TC is observed in 110 min with 0.1 g of APH. Increasing g-C3N4 in the hybrids has improved percent degradation of TC molecules. CMZ-3 is found as a potential candidate for water treatment. 相似文献
2.
Kim Moon-Won Noh Seung-Yoon Zahir Muhammad Zeeshan Yook Se-Jin 《Journal of Mechanical Science and Technology》2021,35(5):2229-2236
Journal of Mechanical Science and Technology - In this study, the performance of a zigzag type mist eliminator with drainage channels was improved using slit plates. The collection efficiency of... 相似文献
3.
Chang Abeer Memon Tayab Din Hussain Zahir M. Kalwar Imtiaz Hussain Chowdhry Bhawani Shankar 《Wireless Personal Communications》2019,106(4):1915-1929
Wireless Personal Communications - Matched filtering has found its way in many diverse applications such as communication, signal processing and more. The emphasis of this paper is on the design... 相似文献
4.
Spinel powders MAl2O4 (M = Ga and Zn) have been prepared by the co-precipitation of aqueous solutions containing corresponding metal, aluminum nitrate and ammonium carbonate. The NO reduction activities of composite spinel type powders in the Ga2O3–Al2O3–ZnO (GAZ) system were studied, in regard to their high-temperature application as an automotive lean-burn exhaust catalyst. A correlation between the NH3-TPD results and the activity of GAZ reveals that a high population of surface acid sites is important to achieve high activity. The cordierite honeycombs with cell sizes 100, 200, 400 and 900 cpsi (cells per square inch) were washcoated with the GAZ slurries and their NO reduction activity was evaluated. The durability of GAZ/cordierites was studied in the presence of H2O vapor, SO2 and O2. 相似文献
5.
Construction professionals are subjected to a plethora of occupational demands that can have a negative effect on their psychological wellbeing. Such demands can have an adverse influence on individual and organizational performance. To investigate the nature of self and social supports and mental health among construction professionals, an exploratory study was undertaken using the Stress and Mental Health Survey. The survey was distributed to construction professionals throughout Australia and 449 responses were received. Analysis revealed that those working for a contracting organization on-site reported higher levels of poor mental health and greater work stress than consultants. Those working on-site also experienced greater levels of self-stress, whereas consultants reported higher levels of self and work support. Work support was a significant predictor of poor mental health for consultants. Good health, however, was predicted by self, situational, and work support, whereas those working for a contractor only self-support predicated good mental health. It is concluded that while supports are essential in the fostering of good mental health, the absence of these supports can have a significant impact on poor mental health. 相似文献
6.
Effective MgO‐doped TiO2 nanoaerogel coating for crystalline silicon solar cells improvement 下载免费PDF全文
This study looks at investigating the influence of high surface area TiO2 and MgO‐doped TiO2 aerogel nanomaterials to improve the photovoltaic performance of monocrystalline silicon (mono‐Si) solar cells. TiO2 and MgO‐doped TiO2 anatase nanoaerogels were synthesized via a single‐step colloidal homogeneous precipitation sol‐gel method in a compact high‐pressure hydrogen reactor. TiO2‐based nanoparticles were encapsulated in ethylene vinyl acetate resins, and the obtained composite solutions were screen printed on the textured surface of the cells. The specific surface area, microstructural, composition, and optical properties of the nanoaerogels were characterized by Brunaur‐Emmett‐Teller, X‐ray powder diffractometer, energy‐dispersive X‐ray spectroscopy, field emission transmission electron microscope, field emission scanning electron microscope, and ultraviolet‐visible spectrophotometry. We observed that the MgO‐doped TiO2 (2% mol) nanoaerogel exhibited a much superior specific surface area (231 m2/g) compared with the undoped TiO2 (154 m2/g). Experimental results showed that the calculated relative power conversion efficiency increased by 4.6% for the MgO‐doped TiO2 coating and 3.4% for the undoped TiO2 under a simulated one‐sun illumination. 相似文献
7.
Three experiments provide evidence that 2 mechanisms, 1 automatic and 1 controlled, produce variations in the efficiency with which local and global forms are processed. Targets are identified faster if they appear at the same level (global or local) as the target on the previous trial. M. R. Lamb, B. London, H. M. Pond, and K. A. Whitt (see record 1997-39043-003) provided evidence that the beneficial effect of level repetition is due to an automatic process that is outside voluntary control. In the present experiments, pretrial cues informed participants as to the level of the upcoming target. Valid cues benefited performance, whereas invalid cues harmed performance relative to noninformative neutral cues. This was so even when the relation between the cue and the level it signaled was arbitrary, indicating that the cues initiated voluntary shifts of attention. The benefit associated with level repetition, however, was unaffected by the cues. These data suggest that the benefit of level repetition results from a process that is not subject to voluntary control. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
8.
M Waqas Iqbal M Zahir Iqbal M Farooq Khan Xiaozhan Jin Chanyong Hwang 《Science and Technology of Advanced Materials》2014,15(5)
The properties of graphene are strongly affected by metal adsorbates and clusters on graphene. Here, we study the effect of a thin layer of platinum (Pt) metal on exfoliated single, bi- and trilayer graphene and on chemical vapor deposition-grown single-layer graphene by using Raman spectroscopy and transport measurements. The Raman spectra and transport measurements show that Pt affects the structure as well as the electronic properties of graphene. The shift of peak frequencies, intensities and widths of the Raman bands were analyzed after the deposition of Pt with different thicknesses (1, 3, 5 nm) on the graphene. The shifts in the G and 2D peak positions of the Raman spectra indicate the n-type doping effect by the Pt metal. The doping effect was also confirmed by gate-voltage dependent resistivity measurements. The doping effect by the Pt metal is stable under ambient conditions, and the doping intensity increases with the increasing Pt deposition without inducing a severe degradation of the charge carrier mobility. 相似文献
9.
Adil Fahad Zahir Tari Ibrahim Khalil Ibrahim Habib Hussein Alnuweiri 《Computer Networks》2013,57(9):2040-2057
There is significant interest in the network management and industrial security community about the need to identify the “best” and most relevant features for network traffic in order to properly characterize user behaviour and predict future traffic. The ability to eliminate redundant features is an important Machine Learning (ML) task because it helps to identify the best features in order to improve the classification accuracy as well as to reduce the computational complexity related to the construction of the classifier. In practice, feature selection (FS) techniques can be used as a preprocessing step to eliminate irrelevant features and as a knowledge discovery tool to reveal the “best” features in many soft computing applications. In this paper, we investigate the advantages and disadvantages of such FS techniques with new proposed metrics (namely goodness, stability and similarity). We continue our efforts toward developing an integrated FS technique that is built on the key strengths of existing FS techniques. A novel way is proposed to identify efficiently and accurately the “best” features by first combining the results of some well-known FS techniques to find consistent features, and then use the proposed concept of support to select a smallest set of features and cover data optimality. The empirical study over ten high-dimensional network traffic data sets demonstrates significant gain in accuracy and improved run-time performance of a classifier compared to individual results produced by some well-known FS techniques. 相似文献
10.
Mohammad Mizanur Rahman Md. Hasan Zahir Md. Eyasin Arafat Mohammad Abu Jafar Mazumder Rami Suleiman A. Madhan Kumar 《应用聚合物科学杂志》2021,138(9):49904
A waste material called oil fly ash (OFA) was acid-functionalized, yielding f-OFA-COOH, which was then reacted with cerium oxide (CeO2) to make CeO2-functionalized OFA, or f-OFA-CeO2. Pristine OFA and f-OFA-CeO2 were used to make waterborne polyurethane (WBPU) dispersions, referred to as WBPU/OFA and WBPU/f-OFA-CeO2, respectively, with defined OFA and f-OFA-CeO2 content. All the dispersions were applied to mild steel as organic coatings to evaluate their protective properties, such as their hydrophobicity, adhesive strength and UV-shielding resistance. These protective properties varied based on the OFA and f-OFA-CeO2 content. The highest water contact angle, minimum water swelling and maximum adhesive strength were found using WBPU/f-OFA-CeO2-20 coating (using 2.00 wt% f-OFA-CeO2), which also showed the maximum ultraviolet (UV) absorption via UV–vis spectroscopy analysis. This UV shielding result also matched field test results, as that coating was found to exhibit the lowest UV degradation near a marine atmosphere, as shown by X-ray photoelectron spectroscopy (XPS) analysis. The least affected hydrophobicity was also recorded for the sample with the WBPU/f-OFA-CeO2-20 coating. 相似文献