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排序方式: 共有155条查询结果,搜索用时 46 毫秒
81.
TiO2–metal vanadate nanocomposites (TiO2–MV) were synthesized by the precipitation method and successfully characterized using UV–visible diffuse reflectance spectroscopy (UV–vis-DRS), powder X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) techniques. The photocatalytic activity of TiO2–MV was investigated for the degradation of fast green (FG) dye under visible light irradiation. The photocatalytic activity of TiO2–silver vanadate [TiO2–Ag3VO4] was found to be much higher than that of TiO2–cadmium vanadate [TiO2–CdV2O6], TiO2–strontium vanadate [TiO2–Sr3(VO4)2] and TiO2. The effect of operational parameters such as pH, photocatalyst concentration and initial dye concentration on the photodegradation of FG was examined in detail. The mineralization of FG was confirmed by chemical oxygen demand (COD) and total organic carbon (TOC) measurements. Moreover, TiO2–Ag3VO4 was found to be a reusable photocatalyst.  相似文献   
82.
In the present study, wetting characteristics and evolution of microstructure of Sn?C3.5Ag solder on Ag/Ni and Ni electroplated 304 stainless steel (304SS) substrates have been investigated. Solder alloy spread on Ag/Ni plated 304SS substrates exhibited better wetting as compared to Ni/304SS substrate. The formations of irregular shaped and coarser IMCs were found at the interface of solder/Ni/304SS substrate region whereas, solder/Ag/Ni/substrate interface showed continuous scallop and needle shaped IMCs. The precipitation of Ag3Sn, Ni?CSn, FeSn2 and lesser percentage of Fe?CCr?CSn IMCs were found at the interface of solder/Ag/Ni/substrate region whereas, solder/Ni/304 SS substrate exhibited predominantly FeSn2 and Fe?CCr?CSn IMCs. Presence of higher amount of Fe?CCr?CSn IMCs at the solder/Ni/304SS substrate interface inhibited the further wetting of solder alloy.  相似文献   
83.
As the decreasing availability of the fossil fuel is rising day by day, the search of alternate fuel that can be used as a substitute to the conventional fuels is rising rapidly. A new type of biofuel, chicha oil biodiesel, is introduced in this work for the purpose of fuelling diesel engine. Chicha oil was transesterified with methanol using potassium hydroxide as catalyst to obtain chicha oil methyl ester (COME). The calorific value of this biodiesel is lower, when compared to that of diesel. The COME and their blends of 20%, 40%, 60% and 80% with diesel were tested in a single cylinder, four stroke, direct injection diesel engine and the performance, combustion and emission results were compared with diesel. The test result indicates that there is a slight increase in brake thermal efficiency and decrease in brake-specific fuel consumption for all blended fuels when compared to that of diesel fuel. The use of biodiesel resulted in lower emissions of CO and HC and increased emissions of CO2 and NOx. The experimental results proved that the use of biodiesel (produced from chicha oil) in compression ignition engine is a viable alternative to diesel.  相似文献   
84.
A novel device structure for thermally activated delayed fluorescence(TADF)top emission organic light-emitting diodes(TEOLEDs)that improves the viewing angle ch...  相似文献   
85.
By organizing a company's business elements into a conceptual model, strategic data planning can help the company gain a competitive edge. This article describes how an insurance company used an Information Cycle strategy and a subject data model to distribute information processing costs over its entire product line.  相似文献   
86.
A modification of phase-shifting interferometry is proposed for microsurface profiling of flat surfaces under vibrating conditions. With this technique the required phase shift, achieved by quarter-wave plates and polarizers, is free of errors associated with motion. A nearly common optical-path configuration is achieved, and the effect of environment is reduced. The effect of environment on the optical system is also studied. Moreover, the measurement of phase is instantaneous, which increases the versatility of this technique to measure vibrating objects. Experiments were carried out on a smooth mirror surface excited with high-frequency vibrations, and the technique was found to be immune to vibrations of both high and low frequency.  相似文献   
87.
Cicione  Antonio  Walls  Richard  Stevens  Sam  Sander  Zara  Flores  Natalia  Narayanan  Vignesh  Rush  David 《Fire Technology》2022,58(1):217-250
Fire Technology - The one billion people that currently reside in informal settlements are exposed to a high and daily risk of large conflagrations. With the number of informal settlement dwellers...  相似文献   
88.

Mobile Ad-Hoc Network (MANET) consist a numerous nodes and these nodes are structured with remote transceivers. These nodes forward the message with one another by getting to the typical channel. In MANET, security is the principle challenge to be analyzed. Due to the behaviour of malevolent nodes, the network security is weakened. Along these lines, the significant goal of this research is to enhance the network security by detecting the malevolent nodes. So, for the detection of malevolent node, an effective trust management method is presented in this paper. Improving the trust score the optimized fuzzy framework is proposed. For enhancing the execution of the fuzzy framework, the triangular membership function of the input parameters is improved with the Cat Swarm Optimization. After estimating the trust score for every node in the network, threshold depend decision module is processed for detecting the activity of malevolent nodes. Implementation results illustrate that the execution of the proposed model achieves maximum network lifetime and minimum energy consumption.

  相似文献   
89.
The potential usage of Copper (Cu) is very limited, where combined mechanical and thermal properties are desirable, which can be overcome by using carbon nanotube (CNT) as a reinforcement. An attempt was made to synthesize Cu/CNT composites by varying CNT diameter and its concentration through a molecular level mixing technique followed by uniaxial compaction and conventional sintering. The sintering behaviour of Cu and Cu/CNT composites was studied to understand the influence of different parameters. The sintering duration of Copper was decreased with an increase of CNT diameter. The maximum enhancement of properties was achieved at 0.25 wt.% CNT irrespective of its diameter, where the thermal conductivity and hardness were obtained as 328 W/mK at 20–40 nm diameter CNT composites and 81.2 ± 2.9 VHN at 40–60 nm diameter CNT composites, respectively. The conventional method of synthesize can generate the desired characteristics of composites at par with high end techniques, such as SPS.  相似文献   
90.
Enhancing web browser security against malware extensions   总被引:1,自引:0,他引:1  
In this paper we examine security issues of functionality extension mechanisms supported by web browsers. Extensions (or “plug-ins”) in modern web browsers enjoy unrestrained access at all times and thus are attractive vectors for malware. To solidify the claim, we take on the role of malware writers looking to assume control of a user’s browser space. We have taken advantage of the lack of security mechanisms for browser extensions and implemented a malware application for the popular Firefox web browser, which we call browserSpy, that requires no special privileges to be installed. browserSpy takes complete control of the user’s browser space, can observe all activity performed through the browser and is undetectable. We then adopt the role of defenders to discuss defense strategies against such malware. Our primary contribution is a mechanism that uses code integrity checking techniques to control the extension installation and loading process. We describe two implementations of this mechanism: a drop-in solution that employs JavaScript and a faster, in-browser solution that makes uses of the browser’s native cryptography implementation. We also discuss techniques for runtime monitoring of extension behavior to provide a foundation for defending threats posed by installed extensions.  相似文献   
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