全文获取类型
收费全文 | 413篇 |
免费 | 15篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 14篇 |
化学工业 | 112篇 |
金属工艺 | 8篇 |
机械仪表 | 11篇 |
建筑科学 | 11篇 |
能源动力 | 40篇 |
轻工业 | 38篇 |
水利工程 | 3篇 |
石油天然气 | 4篇 |
无线电 | 36篇 |
一般工业技术 | 86篇 |
冶金工业 | 16篇 |
原子能技术 | 3篇 |
自动化技术 | 49篇 |
出版年
2023年 | 5篇 |
2022年 | 23篇 |
2021年 | 29篇 |
2020年 | 32篇 |
2019年 | 21篇 |
2018年 | 17篇 |
2017年 | 32篇 |
2016年 | 20篇 |
2015年 | 14篇 |
2014年 | 24篇 |
2013年 | 29篇 |
2012年 | 31篇 |
2011年 | 30篇 |
2010年 | 15篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 11篇 |
2006年 | 10篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有431条查询结果,搜索用时 15 毫秒
131.
Aziz Tariq Zheng Jieyuan Jamil Muhammad Imran Fan Hong Ullah Roh Iqbal Mudassir Ali Amjad Khan Farman Ullah Ullah Asmat 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(8):3290-3300
Journal of Inorganic and Organometallic Polymers and Materials - Bio-based epoxy resins are being used due to their green chemistry. They have better properties than petroleum-based epoxy resins.... 相似文献
132.
The CA hybrid membrane with enhanced anti-fouling property and higher permeability was prepared by nonsolvent induced phase separation method combined with chemical reaction. The impacts of different solvents (N-methyl-2-pyrrolidone, N, N- Dimethylacetamide, Dimethyl sulfoxide and N, N-Dimethylformamide), organic acids (citric acid/fumaric acid) and titanium dioxide (TiO2) nanoparticles (NPs) on the separation performance and thermal stability of CA hybrid membranes were investigated. Results showed that the introduction of organic acids to membrane matrix caused asymmetry in the membrane structure with more uniform pore size distribution and higher porosity (82.5%). This is attributed to the production of CO2 bubbles by a reaction between organic acid in the casting solution and salt in the coagulation bath. Meanwhile, a tremendous rise in anti-fouling property (from 89.7% to 94%), pure water flux (from 329.7 to 821.5 L/m2 h) and permeation flux (from 265.8 to 546.3 L/m2 h) indicates a significant improvement in the hydrophilicity and the permeability of prepared membranes. In addition, a significant improvement in thermal stability (by 90°C) was achieved owing to the formation of dative bonds between TiO2 NPs and CA polymer. Therefore, this approach can significantly improve the anti-fouling property and the separation performance of the CA membrane. 相似文献
133.
Yue-Xian Bao Ming Yuan Qiqige Du Yu-Bo Li Jing-Yu Gao Abdul Jamil Khan Feng Zhang 《核技术(英文版)》2019,30(8)
Nanostructures/patterns formed by biomolecules can produce different physicochemical properties in terms of hydrophobicity, zeta-potential, color, etc., which play paramount roles in life. Peptides, as the main bio-building blocks, can form nanostructures with different functions,either in solutions or on interfaces. Previously, we synthesized a short peptide with the inspiration of an Alzheimer's disease-related peptide: amyloid β peptide(A-p),namely GAV-9, which can epitaxially self-assemble into regular nanofilaments on liquid-solid interfaces, and it was found that both the hydrophobicity and charge state of the interfaces can significantly influence its assembling behavior. It was also reported that another A-β-containing dipeptide, FF,can self-assemble into nanostructures in solutions. Owing to the close relationship between these two short peptides, it is interesting to conjugate them into a de novo peptide with two separated structural domains and study its self-assembling behavior. To this end, herein we have synthesized the GAV-FF peptide with a sequence of NH2-VGGAVVAGVFF-CONH2 and verified its selfassembling property using the in situ liquid-phase atomic force microscopy. The results show that the GAV-FF peptide can self-assemble into nanofilaments both in solutions and on aqueous-solid interfaces, but with different morphologies. The FF domain accelerates the template-assisted self-assembling(TASA) process of the GAV domain, which in return enhances the solubility of FF in aqueous solutions and further participates in the fibrillization of FF. The current results could help deepen the understanding of the aggregation mechanism of diseaserelated peptides and could also shed light on the strategies to create artificial bio-functional nanostructures/patterns,which hold a significant potential for biomedical applications. 相似文献
134.
Z. Imran S.S. Batool H. Jamil M. Usman M. Israr-Qadir S.H. Shah S. Jamil-Rana M.A. Rafiq M.M. Hasan M. Willander 《Ceramics International》2013,39(1):457-462
We report humidity sensing characteristics of CdTiO3 nanofibers prepared by electrospinning. The nanofibers were porous having an average diameter and length of ~50–200 nm and ~100 μm, respectively. The nanofiber humidity sensor was fabricated by defining aluminum electrodes using photolithography on top of the nanofibers deposited on glass substrate. The performance of the CdTiO3 nanofiber humidity sensor was evaluated by AC electrical characterization from 40% to 90% relative humidity at 25 °C. The frequency of the AC signal was varied from 10?1 to 106 Hz. Fast response time and recovery time of 4 s and 6 s were observed, respectively. The sensor was highly sensitive and exhibited a reversible response with small hysteresis of less than 7%. Long term stability of the sensor was confirmed during 30 day test. The excellent sensing characteristics prove that the CdTiO3 nanofibers are potential candidate for use in high performance humidity sensors. 相似文献
135.
Muhammad Zafar Muddassir Ali Shahzad Maqsood Khan Tahir Jamil Muhammad Taqi Zahid Butt 《Desalination》2012
In this work, various cellulose acetate (CA) membranes for pervaporation were prepared by the incorporation of different additives, i.e. polyethylene glycol-600 (PEG-600), propylene glycol (PG), and ethylene glycol (EG) to enhance the separation of isopropanol (IPA)/water mixtures. These membranes were characterized by FTIR, DSC, TGA, SEM and UTM. Each additive was responsible for its characteristic effect on the membrane morphology, mechanical strength, permeation flux and separation factor. The SEM micrograph showed that the additives were evenly dispersed in the membrane matrix with the formation of dense membranes. The UTM tests for the membrane reveled that both the Young's Modulus and tensile strength increased with the increase in additive contents. TGA studies for the CA/PEG blend membrane exhibited the highest thermal stability as compared to the CA/PG and CA/EG blends. For each of these synthesized membranes, the separation factor decreased while the permeation flux increased with the increase in additive contents, while the CA/PG membrane with 20 wt.% additive content showed highest permeation flux of 452.27 g/m2h. 相似文献
136.
The behavioral responses of cowpea weevil,Callosobruchus chinensis to the leaf extracts of the aquatic weed, water hyacinth,Eichhornia crassipes (Mart) Solms. was evaluated by three different methods. The petroleum ether-soluble fraction ofE. crassipes induced high weevil attraction in all methods employed. The olfactometer assay provided a reading on weevil chemosensory responses, whereas the free-choice tests measured response and preference of weevils to the untreated or extract-treated food grain of their choice over a longer period. The extracts were also presented under no choice test conditions to assay them for the presence of oviposition stimulants. In all these methods the extracts of water hyacinth evoked a quick directional response. Another interesting feature is that the extract, besides producing attraction, also caused mortality of the insects. 相似文献
137.
Omer Abdalla Ahmed Hamdi Shevin Rizal Feroz Jamil A. Shilpi El Hassane Anouar Abdul Kadir Mukarram Saharuddin B. Mohamad Saad Tayyab Khalijah Awang 《International journal of molecular sciences》2015,16(3):5180-5193
Curcumenol and curcumenone are two major constituents of the plants of medicinally important genus of Curcuma, and often govern the pharmacological effect of these plant extracts. These two compounds, isolated from C. zedoaria rhizomes were studied for their binding to human serum albumin (HSA) using the fluorescence quench titration method. Molecular docking was also performed to get a more detailed insight into their interaction with HSA at the binding site. Additions of these sesquiterpenes to HSA produced significant fluorescence quenching and blue shifts in the emission spectra of HSA. Analysis of the fluorescence data pointed toward moderate binding affinity between the ligands and HSA, with curcumenone showing a relatively higher binding constant (2.46 × 105 M−1) in comparison to curcumenol (1.97 × 104 M−1). Cluster analyses revealed that site I is the preferred binding site for both molecules with a minimum binding energy of −6.77 kcal·mol−1. However, binding of these two molecules to site II cannot be ruled out as the binding energies were found to be −5.72 and −5.74 kcal·mol−1 for curcumenol and curcumenone, respectively. The interactions of both ligands with HSA involved hydrophobic interactions as well as hydrogen bonding. 相似文献
138.
Zhenjing Duan Changhe Li Wenfeng Ding Yanbin Zhang Min Yang Teng Gao Huajun Cao Xuefeng Xu Dazhong Wang Cong Mao Hao Nan Li Gupta Munish Kumar Zafar Said Sujan Debnath Muhammad Jamil Hafiz Muhammad Ali 《机械工程学报(英文版)》2021,34(1):54-88
Aluminum alloy is the main structural material of aircraft,launch vehicle,spaceship,and space station and is pro-cessed by milling.However,tool wear and vibration are the bottlenecks in the milling process of aviation aluminum alloy.The machining accuracy and surface quality of aluminum alloy milling depend on the cutting parameters,material mechanical properties,machine tools,and other parameters.In particular,milling force is the crucial factor to determine material removal and workpiece surface integrity.However,establishing the prediction model of milling force is important and difficult because milling force is the result of multiparameter coupling of process system.The research progress of cutting force model is reviewed from three modeling methods:empirical model,finite element simulation,and instantaneous milling force model.The problems of cutting force modeling are also determined.In view of these problems,the future work direction is proposed in the following four aspects:(1)high-speed milling is adopted for the thin-walled structure of large aviation with large cutting depth,which easily produces high residual stress.The residual stress should be analyzed under this particular condition.(2)Multiple factors(e.g.,eccentric swing milling parameters,lubrication conditions,tools,tool and workpiece deformation,and size effect)should be consid-ered comprehensively when modeling instantaneous milling forces,especially for micro milling and complex surface machining.(3)The database of milling force model,including the corresponding workpiece materials,working condi-tion,cutting tools(geometric figures and coatings),and other parameters,should be established.(4)The effect of chatter on the prediction accuracy of milling force cannot be ignored in thin-walled workpiece milling.(5)The cutting force of aviation aluminum alloy milling under the condition of minimum quantity lubrication(mql)and nanofluid mql should be predicted. 相似文献
139.
140.
Imran Shafi Jamil Ahmad Syed Ismail Shah Faisal M. Kashif 《Circuits, Systems, and Signal Processing》2008,27(3):277-294
This paper presents an effective correlation vectored taxonomy algorithm to compute highly concentrated time-frequency distributions
(TFDs) using localized neural networks (LNNs). Spectrograms and pre-processed Wigner–Ville distributions of known signals
are vectorized and clustered as per the elbow criterion to constitute the training data for multiple artificial neural networks.
The best trained networks become part of the LNNs. Test TFDs of unknown signals are then processed through the algorithm and
presented to the LNNs. Experimental results demonstrate that appropriately vectored and clustered data once processed through
the LNNs produce high resolution TFDs. Examples are presented to show the effectiveness of the proposed algorithm via analysis
based on entropy and visual interpretation.
This work was supported by the Higher Education Commission (HEC) of Pakistan under the 200 Merit Scholarship Scheme. 相似文献