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   114篇
  免费   3篇
化学工业   22篇
金属工艺   1篇
机械仪表   3篇
建筑科学   5篇
能源动力   5篇
轻工业   9篇
无线电   17篇
一般工业技术   43篇
冶金工业   1篇
原子能技术   1篇
自动化技术   10篇
  2024年   2篇
  2023年   2篇
  2022年   10篇
  2021年   12篇
  2020年   9篇
  2019年   11篇
  2018年   10篇
  2017年   5篇
  2016年   1篇
  2015年   4篇
  2014年   11篇
  2013年   9篇
  2012年   9篇
  2011年   7篇
  2010年   4篇
  2009年   3篇
  2008年   1篇
  2007年   1篇
  2006年   2篇
  2004年   1篇
  2002年   1篇
  1996年   1篇
  1995年   1篇
排序方式: 共有117条查询结果,搜索用时 15 毫秒
1.
Polyacrylonitrile (PAN) based polymer electrolyte membranes complexed with Ammonium hexafluorophosphate (NH4PF6) with different molar concentration are prepared by solution casting method. Increase in the amorphous nature by the addition of Ammonium salt and the formation of polymer-salt complex are confirmed by X ray diffraction studies and infrared spectroscopy respectively. The glass transition temperature is measured for all membranes and it showed a lowest value for the PAN complexed with 20 mol% of NH4PF6. Electrical properties are studied by AC impedance spectroscopy. An ionic conductivity of the order of 10?3 Scm?1 is obtained for the 80 PAN / 20 NH4PF6 polymer electrolyte. Conductivity, dielectric and modulus spectra from the impedance data are analysed to understand the ionic transport mechanism. Transference number measurement is done to study the ionic contribution to the charge transport. A proton battery with the configuration, Zn+ ZnSO4. 7H2O /80 PAN / 20 NH4PF6 / PbO2 +V2O5 has been constructed and its discharge characteristics are studied.  相似文献   
2.
In this present study, the compression ignition engine was designed to run on CIME (Calophyllum inophyllum methyl ester) biodiesel with nanoparticles. The TiO2 nanoparticle is added to the biodiesel in the form of nanofluid at concentration levels of 100?ppm whereas ethanox is added at levels of 100, 200 and 500?ppm. The nanoparticle and the ethanox are dispersed by the ultrasonication process. The addition of nanofluid reduces the particulate emission like nitrogen oxide (NOx) at 100% load. The efficiency is better and emission is reduced owing to the influence of explosion of water molecules present in the biodiesel. We found ethanox to be a superlative nanofluid to reduce the emission of toxic gas at appreciable levels. We have witnessed a 20% reduction in emission of NOx and 10% reduction of other particulate emission. In addition, the exit geometry of exhaust is modified from a circular shape to an elliptical one and the consequence of the geometry is calculated.  相似文献   
3.
A dendritic-benzimidazole (D-BI) has been prepared using polyphosphoric acid (PPA) as a condensing medium with diaminobenzidine (DAB), 1,3,5-benzene tricarboxylic acid, and isophthalic acid as monomers. The structure of D-BI was ascertained by elemental analysis, FTIR, 1H NMR, and solid-state 13C-NMR. The D-BI was incorporated into polysulphone (PSf) by blending with polyvinylpyrrolidone (PVP K-30) as a macromolecular additive. The membranes were cast by phase inversion technique. The physical properties such as surface morphology and the chemical properties such as contact angle and the performance attributes, such as NOM rejection, salt rejection, and pure water flux were studied. It is imperative that the infusibility of rigid polymeric backbone is overcome by the introduction of polar moieties with no compromise on thermal stability. The membranes displayed substantial increase in thermal stability with D-BI content. The marginal increase in flux has been attributed to the branching and steric effect of D-BI. This is because the introduction of polar group efficiently affords to stabilize the adjacent aromatic rings. The salt rejection shows the order of MgSO4 ≈ Na2SO4 > MgCl2 > NaCl, which follows that the divalent ions are rejected more than monovalent ions. The antifouling behaviour was also significant as the irreversible fouling (RIr 9%), which was found to be minimal for D-BI-incorporated membrane. The blended membranes exhibited good hydrophilicity, antifouling, and fairly good rejection of salts.  相似文献   
4.
The present research is focused on the development of ecofriendly biopolymer blend based nanocomposites to enhance the effect of cytotoxic activity. Novel eco-friendly synthesis of pure Chitosan–Agar blend and Chitosan–Agar/ZnO nanocomposites was successfully synthesized by in-situ chemical synthesis method. The influence of Chitosan–Agar (1:1 wt/wt%) concentrations (0.1, 0.5, 1 and 3 g) was studied. The presence of ZnO nanoparticles in Chitosan–Agar polymer matrix was confirmed by UV, FTIR, XRD, FESEM, EDAX and TEM. The crystallite size of the nanocomposites in the range of 12–17 nm is observed from XRD analysis. PL and UV reveal that Nanocomposites shows an blue shift by increase in the blend concentrations. TEM analysis shows that 0.1 and 3 g of Chitosan–Agar/ZnO Nanocomposites are in spindle and spherical shape with polycrystalline nature. The prepared Nanocomposites shows the respectable Antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Pseudomonas aureginosa and Klebsilla pneumonia) bacteria. The potential toxicity of Chitosan–Agar/ZnO nanocomposites was studied for normal (L929) and breast cancer cell line (MB231). The result of this investigation shows that the Chitosan–Agar/ZnO nanocomposites deliver a dose dependent toxicity in normal and cancer cell line.  相似文献   
5.
An analytical method has been developed to differentiate the electrical and thermal resistance of the PEM fuel cell assembly in the fuel cell operating conditions. The usefulness of this method lies in the determination of the electrical resistance based on the polarization curve and the thermal resistance from the mass balance. This method also paves way for the evaluation of cogeneration from a PEMFC power plant. Based on this approach, the increase in current and resistance due to unit change in temperature at a particular current density has been evaluated. It was observed that the internal resistance of the cell is dependent on the electrode fabrication process, which also play a major role in the thermal management of the fuel cell stack.  相似文献   
6.
In this present study, a hybrid Chi‐Fe3 O4 was prepared, characterised and evaluated for its antibacterial and antibiofilm potential against Staphylococcus aureus and Staphylococcus marcescens bacterial pathogens. Intense peak around 260 nm in the ultraviolet–visible spectrum specify the formation of magnetite nanoparticles. Spherical‐shaped particles with less agglomeration and particle size distribution of 3.78–46.40 nm were observed using transmission electron microscopy analysis and strong interaction of chitosan with the surface of magnetite nanoparticles was studied using field emission scanning microscopy (FESEM). X‐ray diffraction analysis exhibited the polycrystalline and spinel structure configuration of the nanocomposite. Presence of Fe and O, C and Cl elements were confirmed using energy dispersive X‐ray microanalysis. Fourier transform infrared spectroscopic analysis showed the reduction and formation of Chi‐Fe3 O4 nanocomposite. The antibacterial activity by deformation of the bacterial cell walls on treatment with Chi‐Fe3 O4 nanocomposite and its interaction was visualised using FESEM and the antibiofilm activity was determined using antibiofilm assay. In conclusion, this present study shows the green synthesis of Chi‐Fe3 O4 nanocomposite and evaluation of its antibacterial and antibiofilm potential, proving its significance in medical and biological applicationsInspec keywords: visible spectra, particle size, magnetic particles, nanocomposites, nanoparticles, X‐ray diffraction, nanofabrication, transmission electron microscopy, X‐ray chemical analysis, nanomagnetics, microorganisms, antibacterial activity, iron compounds, ultraviolet spectra, biomedical materials, field emission scanning electron microscopy, Fourier transform infrared spectra, filled polymers, crystal growth from solution, polymer structureOther keywords: potential antibacterial material, antibiofilm potential, magnetite nanoparticles, solvothermal‐assisted green synthesis, hybrid Chi‐Fe3 O4 nanocomposites, staphylococcus aureus, staphylococcus marcescens, bacterial pathogens, ultraviolet–visible spectrum, spherical‐shaped particles, particle size, transmission electron microscopy, FESEM, field emission scanning electron microscopy, X‐ray diffraction, spinel structure, polycrystalline structure, energy dispersive X‐ray microanalysis, Fourier transform infrared spectroscopic analysis, deformation, bacterial cell walls, Fe3 O4   相似文献   
7.
8.
Nanocrystalline ceria has been synthesized by a non-hydrolytic method using organic solvent and precipitant. The effect of the source compound on final nanocrystalline powder was investigated. The cerium nitrate hexahydrate subjected to different vacuum/thermal treatments to get cerium source compound having different extent of water of crystallization. The nanoceria, synthesized from these compounds was characterized by TGA-MS, XRD, HR-TEM and AFM.  相似文献   
9.
The cure kinetics of medium reactivity unsaturated polyester resin formulated for Liquid Composite Molding process simulation was studied by Differential Scanning Calorimetry (DSC) under isothermal conditions over a specific range of temperature. For isothermal curing reactions performed at 100, 110, and 120°C, several influencing factors were evaluated using the heat evolution behavior of curing process. We propose two‐ and three‐parameter kinetic models to describe the cure kinetics of thermoset resins. Comparisons of the model solutions with our experimental data showed that the three‐parameter model was the lowest parameter model capable of capturing both the degree of cure and the curing rate qualitatively and quantitatively. The model parameters were evaluated by a non‐linear multiple regression method and the temperature dependence of the kinetic rate constants thus obtained has been determined by fitting to the Arrhenius equation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   
10.
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