全文获取类型
收费全文 | 145篇 |
免费 | 12篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 159篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 13篇 |
2021年 | 16篇 |
2020年 | 11篇 |
2019年 | 12篇 |
2018年 | 11篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 3篇 |
2014年 | 8篇 |
2013年 | 16篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1980年 | 1篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
排序方式: 共有159条查询结果,搜索用时 765 毫秒
81.
Multirate IIR filter design and implementation in STLC7545 analoguefront-end for voice communication
The authors present a design method for the synthesis of infinite impulse response (HR) filters embedded in the enhanced V.34 analogue front-end chip STLC7545 for voice communication. The chip provides a powerful solution for the implementation of several high speed modems. Each IIR filter is designed as a cascade of second-order quadratic sections. A procedure for scaling the amplitude and representing the coefficients of these filters in fixed point format is then presented. Extensive numerical simulations have been carried out, and the viability of the design method is justified by successful implementation of these filters on the hardware 相似文献
82.
83.
Salma Ikram Jolly Jacob M.I. Arshad K. Mahmood A. Ali N. Sabir N. Amin S. Hussain 《Ceramics International》2019,45(3):3563-3569
In this paper, we have tailored the structural, magnetic and dielectric properties of Ni0.5Zn0.3Cd0.2Fe2-yLayO4 (y?=?0.0–0.21) nano-structured spinel ferrites by the substitution of La3+ ions. The investigated samples were synthesized by Sol-gel auto-combustion method and were characterized using XRD, SEM, VSM, FTIR and dielectric measurements. Single phase nanostructure formation of synthesized material was confirmed by XRD analysis. The effect of La3+ ions on crystallite size, grain size, lattice constant and bulk densities was calculated and it was found that lattice constant first increased upto concentration y?=?0.105 then decreased with further substitution of dopant ions. FTIR results for all synthesized samples demonstrated two absorption bands at υ1 =?540.8?cm?1 and υ2 =?490.8?cm?1 corresponds to tetrahedral and octahedral sites of spinel structure respectively. With the increase in La3+ ions concentration, saturation magnetization and remanence both found to be decreased down to lowest Ms value of 34.1?emu/g which is not yet reported in the literature according to best of our knowledge. Dielectric results showed that by decreasing frequency, both dielectric loss and dielectric constant decreases. AC conductivity has two regions, at low frequency region ac conductivity increases while at high frequency region, it decreases with increasing frequency. The measured results for all synthesized nano-ferrites suggested that synthesized nanoferrites are recommended for high frequency and microwave absorbing applications. 相似文献
84.
Naqi Syed Muhammad Sharif Muhammad Lali Ikram Ullah 《Multimedia Tools and Applications》2019,78(18):26287-26311
Multimedia Tools and Applications - Lungs cancer is a fatal disease. However, its early detection increases the chances of survival among patients. An automated nodule detection system provides the... 相似文献
85.
M.Asif AmnaIkram 《等离子体科学和技术》2004,6(2):2199-2203
In the experiment to determine the plasma electron temperature, a modified multichannel PIN diodes assembly is used as detectors to record the X-ray pulses from a low-energy Mather-type plasma focus device energized by a 32μF, 15 kV (3.6 k J) single capacitor, with deuterium as a filling gas. The ratio of the integrated bremsstrahlung emission transmitting through foils to the total incident flux as a function of foil thickness at various temperatures is obtained for foil absorbers of material. Using 3μm, 6μm, 9μm,12μm,15μm and 18μm thick aluminium absorbers, the transmitted X-ray flux is detected. By comparing the experimental and theoretical curves through a computer program, the plasma electron temperature is determined. Results show that the deuterium focus plasma electron temperature is about 800 eV. 相似文献
86.
Sana Ikram LianYan Huang Huijuan Zhang Jing Wang Meng Yin 《Journal of food science》2017,82(10):2232-2242
Brewer's spent grain (BSG), a major brewing industry byproduct, is generated in large quantities annually. This review summarizes research into the composition and preservation of BSG, different extraction techniques for BSG proteins and phenolic acids, and the bioactivities of these phenolic components. Moreover, this article also highlights BSG integration into foodstuff for human consumption and animal feed supplements. BSG is considered a rich source of fiber, protein, and phenolic compounds. The phenolic acids present in BSG are hydroxycinnamic acids (ferulic, p‐coumaric, and caffeic acids), which have many biofunctions, such as antioxidant, anticarcinogenic, antiatherogenic, and antiinflammatory activities. Previously, attempts have been made to integrate BSG into human food, such as ready‐to‐eat snacks, cookies and bread, to increase fiber and protein contents. The addition of BSG to animal feed leads to increased milk yields, higher fat contents in milk, and is a good source of essential amino acids. Therefore, many studies have concluded that integrating the biofunctional compounds in BSG into human food and animal feed has various health benefits. 相似文献
87.
Microsystem Technologies - Current work focuses on stagnation point flow of MHD Carreau fluid with heterogeneous–homogeneous reactions. Non-linear stretched sheet of variable thickness is the... 相似文献
88.
Shahid Ullah Khan Waheed Ullah Khan Wasim Ullah Khan Dilfaraz Khan Sumbul Saeed Syed Badshah Muhammad Ikram Tawfik A. Saleh 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(25)
The luminous efficiency of inorganic white light‐emitting diodes, to be used by the next generation as light initiators, is continuously progressing and is an emerging interest for researchers. However, low color‐rendering index (Ra), high correlated color temperature (CCT), and poor stability limit its wider application. Herein, it is reported that Sm3+‐ and Eu3+‐doped calcium scandate (CaSc2O4 (CSO)) are an emerging deep‐red‐emitting material with promising light absorption, enhanced emission properties, and excellent thermal stability that make it a promising candidate with potential applications in emission display, solid‐state white lighting, and the device performance of perovskite solar cells (PSCs). The average crystal structures of Sm3+‐doped CSO are studied by synchrotron X‐ray data that correspond to an extremely rigid host structure. Samarium ion is incorporated as a sensitizer that enhances the emission intensity up to 30%, with a high color purity of 88.9% with a 6% increment. The impacts of hosting the sensitizer are studied by quantifying the lifetime curves. The CaSc2O4:0.15Eu3+,0.03Sm3+ phosphor offers significant resistance to thermal quenching. The incorporation of lanthanide ion‐doped phosphors CSOE into PSCs is investigated along with their potential applications. The CSOE‐coated PSCs devices exhibit a high current density and a high power conversion efficiency (15.96%) when compared to the uncoated control devices. 相似文献
89.
Ikram Ullah Munam Ali Shah Abdul Wahid Amjad Mehmood Houbing Song 《Telecommunication Systems》2018,67(4):553-575
The Internet of Things (IoT) means connecting everything with every other thing through the Internet. In IoT, millions of devices communicate to exchange data and information with each other. During communication, security and privacy issues arise which need to be addressed. To protect information about users’ location, an efficient technique should be devised. Several techniques have already been proposed for preserving location privacy in IoT. However, the existing research lags in preserving location privacy in IoT and has highlighted several issues such as being specific or being restricted to a certain location. In this paper, we propose a new location privacy technique called the enhanced semantic obfuscation technique (ESOT) to preserve the location information of a user. Experimental results show that ESOT achieves improved location privacy and service utility when compared with a well-known existing approach, the semantic obfuscation technique. 相似文献
90.
Maria Ehsan Naveed Iqbal Raja ZiaurRehman Mashwani Muhammad Ikram Efat Zohra Syeda Sadaf Zehra Fozia Abasi Mubashir Hussain Muhammad Iqbal Nilofar Mustafa Asad Ali 《IET nanobiotechnology / IET》2021,15(7):602
Wheat (Triticum aestivum L.) is the most important staple food crop globally. According to economic survey 2018‐19, agriculture sector of Pakistan grew by 0.85%, with wheat accounting for 8.9% of agriculture and 1.6% of GDP, and its production fell short of the target by 4.9%. Wheat requires beneficial ties to improve its efficiency with the help of modern technology. Nanotechnology modifies conventional agricultural practices as these are stimulating agents for plant growth. Green bimetallic Ag/ZnO alloy nanoparticles (NPs) synthesised from salts reduced by Moringa oleifera and characterised by UV‐visible spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy are studied herein. Different concentrations of urea and Ag/ZnO alloy NPs were applied exogenously to wheat plants (Pakistan‐13 and Galaxy13). A significant effect of 100 mg/L urea and 75 ppm Ag/ZnO alloy NPs was observed on the morphology of wheat, with a maximum increase of 58% plant length, 85% leaf area, 89% plant fresh weight and 76% plant dried weight. In physiological parameters, relative water content and membrane stability index have shown maximum increases of 39% and 77%, while chlorophyll a, b, and total chlorophyll content (TCC) showed maximum increases of 92%, 71%, and 84% respectively. Evidence of the morpho‐physiological responses of urea and green synthesised alloy NPs on wheat varieties are reported on. 相似文献