1,120 research outputs found
Dian nao fu zhu fan yi de duo yuan jin lu yan jiu: yi Xianggang yi yuan xun lian wei li.
No full text袁晓蕾.Thesis (Ph.D.)--Chinese University of Hong Kong, 2013.Includes bibliographical references (leaves 129-144)Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Abstracts in Chinese and English.Yuan Xiaolei
Test and analysis methods for resolving fan/motor vibration problems in air-conditioning units
No full textThis thesis deals with part of ASHRAE Research Project No. 685-RP: Test and Analysis Methods for Resolving Fan/Motor Vibration Problems in Air-Conditioning Units. The objective is to develop the basic analytical models and experimental procedures that can be used to find the vibration modes associated with fan impeller, motor and motor mount in air-conditioning units that are excited by fan impeller unbalance, taking into account the gyroscopic effect of the rotating fan impeller; Two air-conditioning units were investigated in the project. They were designated as test units #1 and #2. For the test unit #1 and test unit #2, the vibration problems associated with fan impeller, motor and motor mount system that are excited by fan impeller unbalance taking into account the gyroscopic effect of the rotating fan impeller were investigated; Both non-rotating and rotating tests were conducted in this work. The non-rotating tests were used to measure the vibration modes associated with fan impeller, motor and motor mount system and to identify the parameters used in the analytical models. The rotating tests were used to measure the vibration mode shifting due to the gyroscopic effect of the rotating fan impeller and to locate the resonance speeds corresponding to both the forward and backward rocking modes. (Abstract shortened by UMI.)
AmyloWiki: an integrated database for Bacillus velezensis FZB42, the model strain for plant growth-promoting Bacilli
No full textSince its isolation 20 years ago, many studies have been devoted to Bacillus velezensis FZB42 (former name Bacillus amyloliquefaciens subsp. plantarum FZB42), which has been gradually accepted as a model organism for Gram-positive rhizobacteria. FZB42 is different from another widely studied bacterial strain, Bacillus subtilis 168, in its many features that are closely associated with plants. FZB42 represents a large group of Bacillus isolates that are beneficial to plants and of great importance in agriculture. In this work a database for FZB42 named 'AmyloWiki' is built to integrate all information of FZB42 available to date. The information includes the genomic, transcriptomic, proteomic, post-translational data as well as FZB42 unique genes, protein regulators, mutant availability, publications and etc. The website is built up with PHP and MySQL with a function of keyword searching, browsing, data-downloading and other functions
Controllable Synthesis, Diffusion Study and Catalysis of Hierarchical Zeolites
No full textHierarchical zeolites refer to zeolitic materials having bi-/multi-modal interconnective pores arranged in order of certain ranks, which improve the molecular diffusion within their frameworks, and hence the performance in their applications such as adsorption and heterogeneous catalysis. Hierarchical zeolites are commonly produced via the top-down post-synthetic treatments(such as dealumination and/or desilication) of pre-synthesized zeolites(i.e. the parent zeolites) and the bottom-up synthesis-by-design methods(such as soft/hard templating). This review presents the recent advances(mainly post 2000) in the strategies of making hierarchical zeolites, with the emphasis on the top-down approaches due to their relatively high practicality. Since hierarchical zeolites are proposed to improve intracrystalline diffusion, experimental studies of guest molecules diffusion in hierarchical zeolites are also reviewed. Additionally, catalytic applications of hierarchical zeolites, in comparison with the conventional microporous pristine zeolites, are also commented to highlight the advantages of hierarchical zeolites to improve catalysis
Generation of Current-wave-supported Sediment Gravity Flow Promoted by Wave-induced Liquefaction on an Abandoned Estuary Delta
No full textThis dataset includes sediment concentrations,velocities, and residual pore pressure data measured at two sites in the abandoned Yellow River Delta of the North Yellow Sea, China.Corresponding author: X. Liu ([email protected]); Y.P. Wang ([email protected]
Hierarchical zeolite catalysed fructose dehydration to 5-hydroxymethylfurfural within a biphasic solvent system under microwave irradiation
No full textRealising sustainability within the chemical industry necessitates a shift from the traditional linear approach, based on crude oil, to a circular economy using alternative feedstock such as biomass, from which 5-hydroxymethylfurfural (HMF) is a potentially highly interesting platform chemical. While its production is relatively straightforward via the dehydration of fructose, derived from either saccharides or lignocellulosic biomass, its production is hindered by undesirable side reactions, which decrease the selectivity of the intended reaction to HMF, hence diminishing the overallyield. Here we report a green, highly selective approach to producing 5-hydroxymethylfurfural (HMF) from fructose based on the co-deployment of a biphasic reaction medium, microwave radiation, and a commercial solid acid catalyst (FAU Y zeolites). Following an initial evaluation of catalyst-solvent interactions and diffusion, a hierarchical mesoporous Y zeolite was chosen and deployed within a range of reaction media and process conditions for process optimisation, identifying a biphasic system consisting of ((6:4 Water:DMSO) / (7:3 MIBK:2-BuOH)) as the optimal reaction medium. This solvent combination facilitated an HMF yield of ~73.9 mol% with an excellent selectivity of ~86.1 % at 160 °C after only 45 minutes under microwave irradiation. These, in turn, result in optimal energy efficiency and excellent green credentials relative to conventional heating. Sustainability spotlightBiomass-derived 5-hydroxymethylfurfural is regarded as a versatile and key intermediate for the production of a range of sustainable bio-based chemicals, and thus it has drawn widespread academic and industrial attention. To further cement HMF as a sustainable platform chemical, synthetic routes with greater efficiency and reduced waste production are critical. The research presented here demonstrates a highly selective and energy-efficient HMF production route from fructose, based on the cooperation of a biphasic reaction media, microwave irradiation, and commercially available FAU Y zeolites, and aligns with the UN sustainable development goals: affordable and clean energy (SDG 7), responsible consumption and production (SDG 12), and climate action (SDG 13)
Supporting Data for the paper titled"Diurnal Variation of Liquid Water Path Derived from Two Polar-Orbiting FengYun-3 Microwave Radiation Imagers"
No full text<p>The dataset contains:</p>
<p>a) 4 files with name indicating collocated satellite, sensor, latitude,longitude and brightness temperature; format</p>
<p>b) annual mean liquid water path derived from FY-3B/C Level 1 data; satellite,sensor, region; format</p>
<p>c) annual mean amplitude and phase</p>
<p>d) four seasons (winter,spring,summer, and autumn) mean amplitude</p>
<p>d) 24 files with name indicating sensor, lwp, region, local solar time hour, format</p>
<p>All files can be read by using matlab language.</p>
<p> </p>
<p>The first author was supported by National Natural Science Foundation of China Grant 91337218, and the second author was supported by NOAA grant NA14NES4320003 (Cooperative Institute for Climate and Satellites-CICS) at the University of Maryland/ESSIC.</p>
<p>Corresponding author: Xiaolei Zou,[email protected]</p>
Using regional geochemical survey data to trace anomalous samples through geochemical genes: The Tieshanlong tungsten deposit area (Southeastern China) case study
No full textIn order to determine and trace geochemical anomalies in soils, a tungsten (W) metallogene was constructed according to the idea of the gold (Au) metallogene previously developed. Based on the outcomes obtained for the Tieshanlong tungsten deposit area in southeast China from both three weathered profiles and a subset of data extracted from a regional geochemical survey database, a value of 40% of similarity between a W metallogene and an ideal ore was set as a criterion to individuate samples with potential W mineralization. Based on their W or Au metallogenes, a value of 70% of similarity was also chosen as the threshold criterion to locate samples with similar genes relative to a parent rocks or its weathered products. Based on the regional geochemical survey data available for the Tieshanlong tungsten deposit area, single elemental anomalies were determined and classified by means of the “seven levels' classification” method. Integrated anomalies were also determined and classified by using similarities (relative to their ideal ore) on W and Au metallogenes. Results indicate that the determined anomaly regions are well spatially consistent with the known deposits and that the metallogenes can be used to trace mineralized soil samples. Furthermore, the location of mineralized samples sourced by (altered) magmatic rock could be well pinpointed on geochemical genes, as well.
It was also observed that a value of 80% similarity for a lithogene (a geochemical gene based on a sequence of eleven immobile elements) which, similarly to metallogene, allow to compares samples to a specific parent rock and its weathered products, may be too stringent in the case of sedimentary rocks (even if metamorphosed) due to their relevant geochemical heterogeneity
Interfacial and transport phenomena of bioinspired vesicles
No full textIn the design of drug delivery vehicles, self-assembled nanostructured materials such as liposomes, polymerosomes and hybrid biomaterials bears increasing attentions. The key challenges in the optimal modification of these soft materials is the prediction of resultant morphologies in favor of circulation time, as well as the optimization of surface properties to adjust the interactions between bio-inspired materials with nanoparticles and bio-macromolecules such as peptides, proteins and nucleic acids. One of the ways to overcome these challenges is through the development of flexible modeling tools to address physical phenomena under a mesoscopic scale, allowing us to deeply investigate interfacial problems of nanostructured materials in a dynamic approach. In this work, we utilize the Dissipative Particle Dynamics simulation technique to examine the interaction between peptide mimetic nanoparticles (nanopin) and multicomponent vesicles. We study the role of nanopin architecture and cholesterol concentration on the capture of the nanopins by the bilayer, their insertion and post-insertion self-organization. Furthermore, we investigate the transportation of hybrid vesicle with various concentrations of end-functionalized lipids. We draw correlation among the morphology, composition and mechanical properties of the vesicle and flow conditions. Our results can potentially help in the design of drug delivery system with respect to their transport in blood capillaries, and tissue engineering for the design of microfluidic devices with better in-vivo transportation efficiency. Our study can also provide guidelines for designing peptide-mimetic nanoparticles or macromolecules which can interface with living cells to serve as sensors for applications in medicine, sustainability and energy.M.S.Includes bibliographical referencesby Xiaolei Ch
Investigation of pressure drop in 3D replicated open-cell foams: Coupling CFD with experimental data on additively manufactured foams
Full text linkOpen-cell foams as structured catalyst supports are promising candidates for the design of high throughput catalytic processes. In this contribution, we employ a coupled numerical and experimental approach to assess the pressure losses in foams. Large discrepancies between experimental results and predictions by empirical/analytical correlations are present in the literature, mainly due to the structural differences between adopted models and real foams. To exclude such structural differences, we explore virtually-generated foam models and their 3D printed replicas for a combined CFD and experimental study of fluid dynamics in foams. In particular, we focus our analysis on the low Reynolds number regime (Re < 50), where deviations between the existing correlation and experimental data are more pronounced. We find a very good agreement between CFD simulations and experimental measurements in evaluating the pressure drop of gas flows across foams. The effect of porosity, cell sizes and strut shape are studied, leading to the derivation of an engineering correlation for the pressure drop in open-cell foams. Subsequently, the derived correlation is used to evaluate the trade-off between the external transport rate and the pressure drop, which is a pivotal aspect in most environmental catalytic processes: results show that open-cell foams can outperform honeycomb monoliths in the range of low Reynolds numbers
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