首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11篇
  免费   0篇
建筑科学   1篇
轻工业   2篇
无线电   2篇
冶金工业   1篇
自动化技术   5篇
  2020年   1篇
  2019年   1篇
  2018年   3篇
  2017年   2篇
  2013年   1篇
  1996年   1篇
  1995年   1篇
  1989年   1篇
排序方式: 共有11条查询结果,搜索用时 15 毫秒
1.
It is necessary to study the suitable effect of plasma parameters, such as exposure time and applied voltage on the wicking properties of silk fabrics. Wicking property of silk fabric has been improved by using air dielectric barrier discharge plasma treatment. The plasma treatment has been utilized to modify the surface properties of silk fabrics. Untreated and plasma-treated fabrics have been characterized by contact angle Goniometer, wicking test, Wet-out time, scanning electron microscope, Attenuated Total Reflection Fourier Transforms Infrared spectrometer (ATR-FTIR) and dye uptake test. The ATR-FTIR characterization shows that the hydroxyl functional group has been increased after plasma treatment of silk fabric. The experimental results of wicking rate and Wet-out time of the plasma-treated silk fabrics have shown significant improvement in hydrophilic properties that could be confirmed by contact angle measurement which is close to 0°. The tensile strength of untreated and plasma-treated fabrics has been measured to confirm the enhanced surface property.  相似文献   
2.
Gray cotton fabric shows hydrophobic characteristics due to presence of non-cellulosic impurities in outermost layers of cotton fiber. In the present study, atmospheric pressure plasma treatment for the removal of the non-cellulosic impurities from gray cotton fabric is investigated. Gray cotton fabric is treated with air dielectric barrier discharge at different time interval, and characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). Different species formed in plasma are identified using optical emission spectroscopy. The results clearly show that the plasma treatment improves wettability of gray cotton which is due to the removal of non-cellulosic impurities and due to the formation of polar carboxylate group. Removal of wax after plasma treatment is clearly reflected in ATR-FTIR spectra as disappearance of symmetric and asymmetric stretching of alkyl group at 2852.24 and 2917.81?cm?1. Further, ATR-FTIR spectroscopy provides a fast and satisfactory assessment of removal of impurities from cotton surface when untreated and plasma-treated cotton fabric is exposed to HCl vapor and subsequently spectra are collected. We observed a strong carboxyl peak is induced at 1749?cm?1 in case of untreated cotton. While for plasma-treated cotton fabrics substantial variation in the intensity of 1641 and 1749?cm?1 peak is observed with increase in plasma treatment time. The morphological changes observed by SEM are in accordance with ATR-FTIR results. The results are compared with conventionally (alkaline scouring) treated cotton fabric. The study reveals that atmospheric pressure plasma has potential to become dry and environment friendly process to improve wettability of gray cotton fabric.  相似文献   
3.
We propose a comprehensive design methodology for control and data planes of wavelength-routed optical networks (WRONs) employing mixed-line-rate (MLR) transmission for cost-effective resource provisioning. The proposed approach attempts to minimize the maximum lightpath capacity demand in Gbps (representing the measure of lightpath congestion) in network for a given traffic matrix by using a mix of a heuristic scheme and linear programming (LP). In the first step of the proposed three-step design, some lightpaths are set up on a set of judiciously selected fiber links (with point-to-point lightpaths between neighboring nodes), on a specific wavelength throughout the network, and an appropriate fraction of the same set of lightpaths is utilized for carrying control information, forming therefore the control plane (CP) of the WRON. The remaining bandwidth of these lightpaths is utilized to carry the data traffic along with all other designed lightpaths of the WRON using appropriate algorithm, forming the overall data plane (DP) of the WRON. In the second step, traffic routing is carried out through LP to minimize lightpath congestion in the network. In the third step, we utilize the results of LP to assign rates to lightpaths, such that the cost (considering only the transceiver cost) of the network is minimized. This design leads to congestion-aware MLR network with due consideration to cost-effectiveness without compromising the network restoration response against link failures. We carry out simulation studies employing possible CPs using both symmetric (CP topology being same as the physical topology) as well as asymmetric (using fewer fiber links than the symmetric case) topology. The results of our simulations indicate that the proposed design of CP with symmetric/asymmetric topology and in-band transmission with sub-lightpath capacity can bring down network congestion and cost with respect to symmetric out-of-band transmission (using fully reserved lightpaths for CP), without any perceptible sacrifice in respect of the network restoration time. Failure can occur either in CP or DP, or in both the planes. We investigate the effect of design of CP with symmetric/asymmetric topology on network restoration time for single- and double-link failures. We further present DP design methodology with hybrid restoration scheme, i.e., combination of dedicated (1:1) path protection and path restoration. We analyze the effect of symmetric CP topology and degree of protection on the congestion of the network. Some lightpaths, that support more traffic, are protected against failures, while the others are left for path restoration in the event of failures. As more lightpaths are protected, the congestion and power consumption of network increase. We provide an analysis of the factors that come into play while altering the degree of protection and observe how the choice for the degree of protection in DP can be arrived at using an appropriate design methodology.  相似文献   
4.
Microsystem Technologies - Piezoelectric Energy Harvester (PEH) is a promising technology for harvesting energy from low frequency ambient vibrations. To generate the power from these low-frequency...  相似文献   
5.
This paper identifies areas of concern within the detailed design of flexible riser systems and presents solutions to a series of problems encountered by the authors involving structural and hydrodynamic nonlinearities. Five critical situations are selected: (1) detailed dynamic analysis of a flexible jumper connected between a floater and a jacket structure with emphasis on the design of bend stiffeners at both ends of the system; (2) dynamic analysis of a multiple flexible riser system with emphasis on the response of a common intermediate subsurface buoyant arch; (3) combined effects of torsional and current loading on a short flexible hose supported at one end on a layover arch; (4) dynamic analysis of a ‘pliant wave’ flexible riser configuration; (5) dynamic analysis of a flexible jumper disconnection procedure and assessment of clashing with the floater at pontoon level.

These solutions are produced using computer programs which use optimized finite difference methods particularly suited to these types of problems. The numerical modelling techniques and results are presented for each condition and the influence of these results on the design of various piping systems is discussed.  相似文献   

6.

The operational bandwidth of Vibration Energy Harvesters (VEH) is area of concern due to stochastic, time-varying, random and multi-frequency nature of available environmental vibrating sources. Most of the VEH have narrow bandwidth providing usable power at specific frequencies. Efforts have been made to increase the frequency range by introducing non-linear structures and techniques. In this paper, multi-band output of the non-linear Piezoelectric Energy Harvester (PEH) is transformed into single wider band output using additional non-linear phenomenon. Dual region operation of PEH results into two separate band output. First region is the outcome of beam resonance and Centre of Gravity (CoG) shift whereas second region is due to the non-linear behaviour of cylinders. In this work, these separate bands are merged to form a single wider band. For merging these two bands and enhancing the bandwidth of PEH, additional phenomenon is introduced using two permanent magnets. A varying magnetic field by changing the distance between magnets changes stiffness of the cantilever beam and that leads to a change in the resonant frequency of band-I. Thus, the overall process shifts band-I towards band-II. In this work, the two separate bands are merged to have one wider band providing 53.22% more frequency coverage than our previous work with a bandwidth of 47.5 Hz. This band includes vibrational frequency range of 25.65–73.15 Hz at 1.4 g acceleration. Cylinder material and its effect with magnetic interaction is also studied. The magnetic force between two permanent magnets is measured experimentally. Effect of magnetic force on centre resonant frequency of beam is compared with experimental and simulated results. Effect of magnetic force on bandwidth of the device is studied.

  相似文献   
7.
This paper focuses on telemedicine implementation, which can be used to extend modern medical knowledge to remote areas in developing countries. By examining doctor- patient interactions in the context of a telemedicine program in India, we posit how the behaviour of the actors interacting over virtual media is determined by interplay between two dominant institutional logics, namely logic of care and logic of choice. The paper draws on the tenets of institutional logics to extend the theoretical understanding about processes of engagement of actors with a new technology and explicates how the engagement evolves with the use of technology. The research emphasizes the essential role of considering the dynamics of logic of care and logic of choice in the design and implementation process.  相似文献   
8.
Microsystem Technologies - Energy harvesters are preferred for enhancing the life of IoT nodes. In this paper, a vibration energy harvester with wideband auto-tunable resonant frequency for...  相似文献   
9.
Knowledge representation using fuzzy deduction graphs   总被引:2,自引:0,他引:2  
A new knowledge representation model, known as fuzzy deduction graph (FDG), is introduced in this paper. An FDG can represent a knowledge base containing the fuzzy propositions and fuzzy rules. In an FDG, a systematic method of finding the fuzzy reasoning path (FRP) is given which is based on Dijkstra's shortest path framework. The FRP gives a relationship between the antecedent (source) proposition and consequent (goal) proposition, such that the consequent proposition is reached with the greatest fuzzy value. The process of finding the FRP is illustrated with examples.  相似文献   
10.
BACKGROUND/AIM: Hepatic tumors with elements of both hepatocellular and cholangiocellular carcinoma are occasionally encountered; however, the independent and simultaneous occurrence of different epithelial malignant tumors in different lobes is rare. This is a case report of resected double cancer in different lobes of the liver. MATERIALS AND METHODS: A 73 year old Japanese man, with hepatic mass and a history of peritonitis and hepatitis, underwent laparotomy and hepatic resection of the posterior inferior and the left lateral segment, and cholecystectomy for cholecystlithiasis with left-sided gallbladder at our hospital in 1991. RESULTS: The tumor, located in the posterior inferior segment, a yellow-white, round, highly circumscribed mass with a thick capsule, was about 9.0 by 8.0 cm in size. The other tumor located in the left lateral segment, grayish-white on the cut section, was approximately 5.0 by 4.0 cm. CONCLUSION: In our case, it is unlikely the tumor in the right lobe metastasized to the left lobe and transformed into a different type. The two tumors showed clearly different microscopic features. Improved imaging will increase the frequency and number of double cancer diagnosis. This additional data may shed light on the pathogenesis and etiology of double cancer.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号