411   The effects on morphologies of cuprous oxide prepared by solvothermal method using different alcohols The effects on morphologies of cuprous oxide prepared by solvothermal method using different alcohols    2010 Cuprous oxide microparticles with different morphologies were prepared by solvothermal method using copper acetate, triethanolamine, and alcohol as raw materials. The morphology and crystalline phase of the products were examined by SEM and XRD separately; the results show that, at an appropriate reaction temperature, choosing different alcohols will lead to forming micron spherical cuprous oxide. Furthermore, with increasing hydroxyl in alcohol, the reaction temperature for forming spherical cu... 查看全文

412   Study of preparation of water-soluble cefadroxil microparticles based on supercritical fluid technique Study of preparation of water-soluble cefadroxil microparticles based on supercritical fluid technique    2011 Cefadroxil (CD) microparticles were successfully prepared from CD-water+ethanol-CO2 mix-solution by the supercritical fluid expansion depressurization (SFED) process. The influences of the operation parameters, including the pressure and temperature in the mixing vessel, the feed solution rate and the solution concentration on the particle morphology, size and size distribution, were investigated. The experimental results show that CD microparticles with the diameter range of 1-3 μm which is ... 查看全文

413   A High-Resolution 43Ca Solid-State NMR Study of the Calcium Sites of Hydroxyapatite A High-Resolution 43Ca Solid-State NMR Study of the Calcium Sites of Hydroxyapatite Danielle Laurencin,† Alan Wong,† John V. Hanna,‡ Ray Dupree,† and Mark E. Smith†*    2008 High resolution 43Ca solid-state NMR studies of hydroxyapatite (Ca10(PO4)6(OH)2) were performed at 14.1 T. The two crystallographically distinct calcium sites were unequivocally resolved by a triple-quantum magic angle spinning experiment, and the unambiguous assignment of the signals was possible using 1H-43Ca rotational echo double resonance and 1H-43Ca cross polarization magic angle spinning experiments. 查看全文

414   On the heating of nano- and microparticles in process plasmas On the heating of nano- and microparticles in process plasmas    2011 Determination and understanding of energy fluxes to nano- or microparticles, which are confined in process plasmas, is highly desirable because the energy balance results in an equilibrium particle temperature which may even initiate the crystallization of nanoparticles. A simple balance model has been used to estimate the energy fluxes between plasma and immersed particles on the basis of measured plasma parameters. Addition of molecular hydrogen to the argon plasma results in additional heatin... 查看全文

415   Regio- and stereoselective preparation of ascomycin-d1 and FK 506-d1 Regio- and stereoselective preparation of ascomycin-d1 and FK 506-d1 David J. Harvey    2002 The immunosuppressive macrolides ascomycin 1 and FK 506 2 were stereoselectively deuteriated at C(32) using Curran's radical translocating method. Both AIBN and Et3B/O2 were tested as radical initiator for the radical translocation/reduction step with Bu3SnD as reducing agent. Despite only minor structural differences, ascomycin and FK 506 showed remarkably different behaviour under the radical translocation/reduction conditions. Higher stereoselectivities were observed with Et3B/O2 as initiator... 查看全文

416   Versuchsanlage zur Untersuchung der Deckschichtablösung von keramischen MembranenPilot-Scale Device for Filter Cake Resuspension of Ceramic Membranes Versuchsanlage zur Untersuchung der Deckschichtablösung von keramischen MembranenPilot-Scale Device for Filter Cake Resuspension of Ceramic Membranes Thomas Bligaard    2011 Die Entfernung von Deckschichten auf überströmten Membranen ist einer der wichtigsten Faktoren für das ökonomisch sinnvolle Betreiben von Mikro- und Ultrafiltrationsmembranen. Bei der Wiederablösung der Partikeln von der Membranoberflche muss der Haftkraft besondere Bedeutung beigemessen werden. In dem vorliegenden Beitrag wird eine Apparatur zur experimentellen Beschreibung der Haftung von mineralischen Einzelpartikeln und zusammenhngenden Partikelsystemen an keramische... 查看全文

417   Control of Metal Dispersion and Structure by Changes in the Solid-State Chemistry of Supported Cobalt Fischer–Tropsch Catalysts Control of Metal Dispersion and Structure by Changes in the Solid-State Chemistry of Supported Cobalt Fischer–Tropsch Catalysts Stuart L. Soled, Enrique Iglesia, Rocco A. Fiato, Joseph E. Baumgartner, Hilda Vroman;Sabato Miseo    2003 Controlling preparation variables in supported cobalt Fischer–Tropsch catalysts has a dramatic effect on the dispersion and distribution of cobalt, and determines how active and selective the resulting catalyst will be. We detail specific examples of catalyst synthesis strategies for modifying interactions between the support and the cobalt precursor, promoting reduction, stabilizing catalysts to high-temperature treatments, minimizing deleterious support metal interactions, and controlli... 查看全文

418   Formation of nano- and microparticles CdS from thiourea solutions Formation of nano- and microparticles CdS from thiourea solutions    2011 Effect of synthesis conditions (precipitation temperature, thiourea concentration) on CdS particles morphology has been studied under precipitation from 0.01, 0.1 and 1 M cadmium nitrate solutions using thiourea. Decrease of temperature to 20-25°C or increase of thiourea concentration above the stoichiometrical value leads to formation of the spherical particles. Use of microwave promotes formation of the spherical particles with the form. of "flowers" consisting of small plates with wall th... 查看全文

419   Development and Characterization of A Snack Food Product using Broken Rice Flour Development and Characterization of A Snack Food Product using Broken Rice Flour Ingmar Olsson, Richard Wheeler, Catherine Johansson, Bjouml;rn Ekstrouml;m, Nils Stafstrouml;m, Rama    2006 A snack food utilizing broken rice flour as its main ingredient was developed and characterized. One hundred percent rice flour displayed the best charactistics over mixtures with other carbohydrate sources to develop a snack food. Optimum gelatinization time (15 min), moisture content (12–15%) and frying temperature (196°C) were investigated. Physical and sensory analyses during a 4-week storage period showed the following: no significant (P > 0.05) change in color, flavor, accepta... 查看全文

420   Hypericin, Hypocrellin, and Model Compounds:  Primary Photoprocesses of Light-Induced Antiviral Agents Hypericin, Hypocrellin, and Model Compounds:  Primary Photoprocesses of Light-Induced Antiviral Agents D. S. English, K. Das, J. M. Zenner, W. Zhang, G. A. Kraus, R. C. Larock, and J. W. Petrich*    1997 The excited-state photophysics of the light-induced antiviral agents hypericin and hypocrellin are compared with those of the hexa- and tetramethoxy analogues of hypericin. The results are consistent with the interpretation of the primary photoprocess in hypericin and hypocrellin as that of excited-state intramolecular proton or atom transfer. 查看全文

421   Contribution of low tension ion-milling to heterostructural semiconductors preparation Contribution of low tension ion-milling to heterostructural semiconductors preparation M. Korytov, O. Tottereau, J. M. Chauveau;P. Vennéguès    2008 Specimens of superior quality are required for quantitative Transmission Electron Microscopy. The classical preparation of heterostructural semiconductors includes stages of mechanical polishing followed by ion-milling up to the transparency of the sample. The last stage is critical, as incorrectly carried out ion-milling brings to the appearance of the different types of preparation defects. Ionic radiation can create crystalline defects which will superpose over the int... 查看全文

422   DESIGN AND PERFORMANCE ASSESSMENT OF A FLAT-PLATE SOLAR MILK PASTEURIZER FOR ARID PASTORAL AREAS OF KENYA DESIGN AND PERFORMANCE ASSESSMENT OF A FLAT-PLATE SOLAR MILK PASTEURIZER FOR ARID PASTORAL AREAS OF KENYA Brian S. Sorg and Ashley J. Welch    2012 A solar milk pasteurizer consisting of flat-plate water-heating collector and a 1.5-mm thick stainless steel cylindrical milk vat was designed and tested in an arid pastoral area of northern Kenya. The milk vat had a capacity of 80 L and a 50-mm wide hot water jacket insulated with 38-mm thick fiberglass. Hot water produced by the collector was used for pasteurizing milk. The optimum quantity of milk that could be pasteurized by this device under the study conditions was 40 L, and the ... 查看全文

423   The 2-Vinylphosphirane−3-Phospholene Rearrangement:  Biradicaloid and Concerted Features The 2-Vinylphosphirane−3-Phospholene Rearrangement:  Biradicaloid and Concerted Features Maurice J. van Eis, Tom Nijbacker, Franciscus J. J. de Kanter, Willem H. de Wolf, Koop Lammertsma,*    2000 Activation parameters have been determined for the 2-vinylphosphirane?3-phospholene rearrangement in the cycloheptane annellated series 7 → 8. For the thermal reaction, the mean activation parameters (ΔH = 125 ± 5 kJ mol-1 and ΔS = ?1 ± 14 J K-1 mol-1) are as expected for a biradicaloid character of the transition structure. In the presence of Cu(I) as a catalyst, the activation parameters for this conversion (ΔH = 80.2 ± 3 kJ mol-1 and ΔS = ?100 ± 7 J K-1 mol-1) are strikingly different and mor 查看全文

424   Low‐cost multicrystalline silicon for high‐efficiency solar cells Low‐cost multicrystalline silicon for high‐efficiency solar cells C. P. Khattak;F. Schmid    0 An HEM furnace with complete automation has been used for production of 44 cm square cross‐section, 80 kg multicrystalline silicon ingots. The labor requirement was reduced to loading and unloading of the furnace. The furnace is scaled up to produce 55 cm square cross‐section silicon ingots, weighing up to 155 kg with a cycle time of 48–56 hours. The combination of high performance HEM silicon and complete automation is expected to reduce the production costs of silicon substrates. ? 1996 Americ 查看全文

425   The effects of synthesis parameters on the formation of PbI2 particles under DTAB-assisted hydrothermal process The effects of synthesis parameters on the formation of PbI2 particles under DTAB-assisted hydrothermal process    2011 Submicron- and micron-sized lead iodide (PbI2) particles with well-controlled morphologies were successfully fabricated via a low-temperature hydrothermal process assisted by dodecyltrimethylammonium bromide (DTAB) as cationic surfactant. The as-synthesized powders were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-vis spectroscopy. The effects of synthesis parameters (temperature, time, pH, and surfactant amount) were systematically i... 查看全文

426   Controlling apatite microparticles formation by calcining electrospun sol-gel derived ultrafine silica fibers Controlling apatite microparticles formation by calcining electrospun sol-gel derived ultrafine silica fibers    2012 Electrospun ultrafine silica fibers were calcined at 150-800°C. The relation of calcination temperature to the ability to form. biomimetic apatite in a simulated body fluid solution (SBF) was evaluated. The largest apatite particles, formed on non-calcined fibers after 1 week of soaking in SBF, were 10 μm in diameter, had a narrow size distribution (coefficient of variation 9%), and were similar to pearls on string. The particles size decreased with increasing calcination temperature belo... 查看全文

427   Manufacturing of agarose-based chromatographic adsorbents with controlled pore and particle sizes Manufacturing of agarose-based chromatographic adsorbents with controlled pore and particle sizes    2011 The effect of ionic strength and quenching temperature on the mechanical properties and structure of agarose-based chromatographic adsorbents in micro-beads for bioseparation was investigated. The pore size/size distribution of the beads was measured by analysis of their AFM images. Their mechanical properties were determined by a micromanipulation technique based on compression of single micro-particles. It was found that the mean pore size and stiffness of agarose beads increase with ionic str... 查看全文

428   Magnetic properties of γ‐Fe2O3 nanoparticles obtained by vaporization condensation in a solar furnace Magnetic properties of γ‐Fe2O3 nanoparticles obtained by vaporization condensation in a solar furnace B. Martínez;A. Roig;X. Obradors;E. Molins;A. Rouanet;C. Monty    0 The magnetic properties of γ‐Fe2O3 nanoparticles synthesized by vaporization condensation in a solar image furnace have been studied using both magnetic measurements and M?ssbauer spectroscopy. The mean size of the particles turns out to be easily controlled by changing the pressure conditions in the growth chamber. The particles exhibit superparamagnetic behavior. at room temperature. Magnetic measurements show the appearance of magnetic hysteresis in the low‐temperature range and from the evol 查看全文

429   Micro laser sintering (microLS) for rapid prototyping of metal-ceramics Micro laser sintering (microLS) for rapid prototyping of metal-ceramics    2006 The world market for micro system technology is constantly raising the technical demands for the production of metallic tools and functional parts. With a view to product development rapid prototyping production (RP) methods are one of the most essential instruments of component manufacturing. In particular the macroscopic 3D laser beam processing technologies have proved their high potential with regard to flexible manufacturing of metallic components. The development of new beam sources is giv... 查看全文

430   Study of the liquid phase volume expansion for CO2/organic solvent systems Study of the liquid phase volume expansion for CO2/organic solvent systems    2005 The supercritical antisolvent (SAS) process has been developed in recent years for the formation of nano-and micro-particles. It is necessary to study the liquid phase volume expansion (LPVE) and find the relationships between the operating conditions and the LPVE in order to develop a practical method for determining the operation conditions and selecting an organic solvent for SAS process. The PR equation of state with vdW-1 mixing rule is used to calculate the LPVE for CO2/toluene, CO2/aceton... 查看全文

431   Web Site: Spielerei verdeckt Nützliches Web Site: Spielerei verdeckt Nützliches    2003 查看全文

432   Magnetic damping array implemented into a space‐compatible multizone furnace for semiconductor crystal growth Magnetic damping array implemented into a space‐compatible multizone furnace for semiconductor crystal growth Ch. Stenzel;P. Dold;K. W. Benz    0 For damping residual, unsteady flows in semiconductor melts a space‐compatible multizone furnace including a magnetic damping array consisting of two radially magnetized permanent magnet rings has been developed. The performance of the whole system has been verified by measuring the temperature fluctuations caused by the time‐dependent thermal convection in a Ga melt at 850?°C. By applying a static magnetic induction of 186 mT the fluctuations could be reduced from about 1.5?°C to less than 0.02 查看全文

433   Phase separation of aqueous poly(vinyl methyl ether) solutions induced by the photon pressure of a focused near-infrared laser beam Phase separation of aqueous poly(vinyl methyl ether) solutions induced by the photon pressure of a focused near-infrared laser beam    2007 We demonstrate that phase separation of an aqueous poly(vinyl methyl ether) (PVME) solution can be triggered not only by a temperature change but also by photon pressure. A near-infrared continuous wave laser beam (λ = 1064nm) was focused through an objective lens into a heavy water (D2O) solution of PVME. A single PVME micro-particle was produced and trapped at the focal point of the laser beam within several hundreds of seconds after switching on the laser. The origin of the micropartic... 查看全文

434   Rheological study on O-carboxymethylated chitosan/ cellulose polyblends from LiCl/N,N-dimethylacetamide solution Rheological study on O-carboxymethylated chitosan/ cellulose polyblends from LiCl/N,N-dimethylacetamide solution    2003 An O-carboxymethylated chitosan (O-CMCh) water solution (I) and N,N-dimethylacetamide (DMAc) emulsion (II) were blended with a cellulose LiCl/DMAc solution, and corresponding polyblends (Polyblends I and II) were obtained. The rheology of the three fluids, that is, the cellulose solution and Polyblends I and II, was investigated. The cellulose solution was characterized by a power-law fluid. When an O-CMCh water solution or DMAc emulsion was added to the cellulose solution, the power-law curve w... 查看全文

435   Performance of the single-chamber solid oxide fuel cell with a La 0.75 Sr0.25 Cr0.5 Mn0.5 O 3-δ -based perovskite anode Performance of the single-chamber solid oxide fuel cell with a La 0.75 Sr0.25 Cr0.5 Mn0.5 O 3-δ -based perovskite anode    2010 In this paper, perovskite oxide La0.75 Sr0.25 Cr 0.5 Mn0.5 O3-δ (LSCM) mixed with a small fraction Ni has been used as the anode of single-chamber solid oxide fuel cell(s) operating in a methane-oxygen mixture. The anode is prepared by an ion impregnation method, whereby a proper mixed solution with metal nitrates and urea is incorporated into the porous presintered yttria-stabilized zirconia (YSZ) anode matrix. After sintering at 1100°C, the impregnated materials change to unique micr... 查看全文

436   Green synthesis of hematite (α-Fe2O3) submicron particles Green synthesis of hematite (α-Fe2O3) submicron particles    2010 Iron oxide microparticles have been synthesized through a green technique using hydrogen peroxide under sunlight irradiation. The X-ray powder diffraction measurement shows that these particles are hematite (α-Fe 2O3). The microstructure and particle size were investigated using scanning electron microscopy. The magnetic characterization shows the presence of Morin transition at about 258 K, which is very close to the normal value (263 K) of bulk hematite. These hematite particles show typ... 查看全文

437   Synthesis and optical properties of dendrite-like GaP nanostructures Synthesis and optical properties of dendrite-like GaP nanostructures    2010 Dendrite-like GaP nanostructures have been prepared at low temperature via a solvothermal route using mesoporous silica SBA-15 microparticles (SMP) with surface channels as the structure-directing agent. The samples were characterized with X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), diffuse reflection ultraviolet-visible (UV-vis) spectroscopy, and room-temperature photoluminescence. The formation mechanism and optica... 查看全文

438   Understanding degradation of phenolic compounds during olive oil processing by inhibitor addition Understanding degradation of phenolic compounds during olive oil processing by inhibitor addition EDWARD A. NEBESKY, WILLIAM B. ESSELEN JR., A. M. KAPLAN and CARL R. FELLERS    2012 The aim of this work was to study, under different conditions, degradation of secoiridoids during extraction of extra virgin olive oil by following the effect of ascorbic and citric acid addition. Their effect was evaluated on oil obtained from both damaged olives and undamaged fresh olives. Addition of enzyme inhibitors to damaged olives during olive milling allowed us to obtain oil with a higher phenolic compound content. Conversely, addition of the same inhibitors to undamaged fresh olives, d... 查看全文

439   Co-precipitation of amoxicillin and ethyl cellulose microparticles by supercritical antisolvent process Co-precipitation of amoxicillin and ethyl cellulose microparticles by supercritical antisolvent process    2011 Microparticles of ethyl cellulose (EC) and amoxicillin (AMC) have been precipitated by a supercritical antisolvent process (SAS) using CO2 as the antisolvent and a mixture of dichloromethane (DCM) and dimethyl sulfoxide (DMSO) as solvents. Combinations of three temperatures (308, 323 and 333 K) and four pressures (100, 150, 200 and 250 bar) were assessed in the vessel and the rest of the variables were held constant (i.e. CO2 flow rate, sample flow rate, washing time, nozzle diameter and the amo... 查看全文

440   In Situ Measurement of Bovine Serum Albumin Interaction with Gold Nanospheres In Situ Measurement of Bovine Serum Albumin Interaction with Gold Nanospheres Sergio Dominguez-Medina†, Steven McDonough†, Pattanawit Swanglap†, Christy F. Landes†, and Stephan L    2012 We present in situ observations of adsorption of bovine serum albumin (BSA) on citrate-stabilized gold nanospheres. We implemented scattering correlation spectroscopy as a tool to quantify changes in the nanoparticle Brownian motion resulting from BSA adsorption onto the nanoparticle surface. Protein binding was observed as an increase in the nanoparticle hydrodynamic radius. Our results indicate the formation of a protein monolayer at similar albumin concentrations as those found in human blood 查看全文

[1]  [2]  [3]  [4]  [5]  [6]  [7]  [8]  [9]  [10]  [11]  [12]  [13]  [14]  [15]  [16]  [17]  [18]  [19]  [20]  [21]  [22]  [23]  [24]  [25]  [26]  [27]  [28]  [29]  [30]  [31]  [32]  [33]  [34]  [35]  [36]  [37]  [38]  [39]  [40]  [41]  42  [43]  [44]  [45]  [46]  [47]  [48]  [49]  [50]  [51]  [52]  [53]  [54]  [55]  [56]  [57]  [58]  [59]  [60]  [61]  [62]  [63]  [64]  [65]  [66]  [67]  [68]  [69]  [70]  [71]  [72]  [73]  [74]  [75]  [76]  [77]  [78]  [79]  [80]  [81]  [82]  [83]  [84]  [85]  [86]  [87]  [88]  [89]  [90]  [91]  [92]  [93]  [94]  [95]  [96]  [97]  [98]  [99]  [100]  [101]  [102]  [103]  [104]  [105]  [106]  [107]  [108]  [109]  [110]  [111]  [112]  [113]  [114]  [115]  [116]  [117]  [118]  [119]  [120]  [121]  [122]  [123]  [124]  [125]  [126]  [127]  [128]  [129]  [130]  [131]  [132]  [133]  [134]  [135]  [136]  [137]  [138]  [139]  [140]  [141]  [142]  [143]  [144]  [145]  [146]  [147]  [148]  [149]  [150]  [151]  [152]  [153]  [154]  [155]  [156]  [157]  [158]  [159]  [160]  [161]  [162]  [163]  [164]  [165]  [166]  [167]  [168]  [169]  [170]  [171]  [172]  [173]  [174]  [175]  [176]  [177]  [178]  [179]  [180]  [181]  [182]  [183]  [184]  [185]  [186]  [187]  [188]  [189]  [190]  [191]  [192]  [193]  [194]  [195]  [196]  [197]  [198]  [199]  [200]  [201]  [202]  [203]  [204]  [205]  [206]  [207]  [208]  [209]  [210]  [211]  [212]  [213]  [214]  [215]  [216]  [217]  [218]  [219]  [220]  [221]  [222]  [223]  [224]  [225]  [226]  [227]  [228]  [229]  [230]  [231]  [232]  [233]  [234]  [235]  [236]  [237]  [238]  [239]  [240]  [241]  [242]  [243]  [244]  [245]  [246]  [247]  [248]  [249]  [250]  [251]  [252]  [253]  [254]  [255]  [256]  [257]  [258]  [259]  [260]  [261]  [262]  [263]  [264]  [265]  [266]  [267]  [268]  [269]  [270]  [271]  [272]  [273]  [274]  [275]  [276]  [277]  [278]  [279]  [280]  [281]  [282]  [283]  [284]  [285]  [286]  [287]  [288]  [289]  [290]  [291]  [292]  [293]  [294]  [295]  [296]  [297]  [298]  [299]  [300]  [301]  [302]  [303]  [304]  [305]  [306]  [307]  [308]  [309]  [310]  [311]  [312]  [313]  [314]  [315]  [316]  [317]  [318]  [319]  [320]  [321]  [322]  [323]  [324]  [325]  [326]  [327]  [328]  [329]  [330]  [331]  [332]  [333]  [334]  [335]  [336]  [337]  [338]  [339]  [340]  [341]  [342]  [343]  [344]  [345]  [346]  [347]  [348]  [349]  [350]  [351]  [352]  [353]  [354]  [355]  [356]  [357]  [358]  [359]  [360]  [361]  [362]  [363]  [364]  [365]  [366]  [367]  [368]  [369]  [370]  [371]  [372]  [373]  [374]  [375]  [376]  [377]  [378]  [379]  [380]  [381]  [382]  [383]  [384]  [385]  [386]  [387]  [388]  [389]  [390]  [391]  [392]  [393]  [394]  [395]  [396]  [397]  [398]  [399]  [400]  [401]  [402]  [403]  [404]  [405]  [406]  [407]  [408]  [409]  [410]  [411]  [412]  [413]  [414]  [415]  [416]  [417]  [418]  [419]  [420]  [421]  [422]  [423]  [424]  [425]  [426]  [427]  [428]  [429]  [430]  [431]  [432]  [433]  [434]  [435]  [436]  [437]  [438]  [439]  [440]  [441]  [442]  [443]  [444]  [445]  [446]  [447]  [448]  [449]  [450]  [451]  [452]  [453]  [454]  [455]  [456]  [457]  [458]  [459]  [460]  [461]  [462]  [463]  [464]  [465]  [466]  [467]  [468]  [469]  [470]  [471]  [472]  [473]  [474]  [475]  [476]  [477]  [478]  [479]  [480]  [481]  [482]  [483]  [484]  [485]  [486]  [487]  [488]  [489]  [490]  [491]  [492]  [493]  [494]  [495]  [496]  [497]  [498]  [499]  [500]   下一页